diff options
Diffstat (limited to 'kernel')
53 files changed, 5743 insertions, 6693 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 3d9c7e2..187c89b 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -87,7 +87,6 @@ obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o -obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_FUNCTION_TRACER) += trace/ @@ -96,7 +95,7 @@ obj-$(CONFIG_X86_DS) += trace/ obj-$(CONFIG_RING_BUFFER) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o obj-$(CONFIG_SLOW_WORK) += slow-work.o -obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o +obj-$(CONFIG_PERF_EVENTS) += perf_event.o ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c7ece8f..cd83d99 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -596,7 +596,7 @@ void cgroup_unlock(void) static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode); static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry); static int cgroup_populate_dir(struct cgroup *cgrp); -static struct inode_operations cgroup_dir_inode_operations; +static const struct inode_operations cgroup_dir_inode_operations; static struct file_operations proc_cgroupstats_operations; static struct backing_dev_info cgroup_backing_dev_info = { @@ -961,7 +961,7 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) return ret; } -static struct super_operations cgroup_ops = { +static const struct super_operations cgroup_ops = { .statfs = simple_statfs, .drop_inode = generic_delete_inode, .show_options = cgroup_show_options, @@ -1711,7 +1711,7 @@ static struct file_operations cgroup_file_operations = { .release = cgroup_file_release, }; -static struct inode_operations cgroup_dir_inode_operations = { +static const struct inode_operations cgroup_dir_inode_operations = { .lookup = simple_lookup, .mkdir = cgroup_mkdir, .rmdir = cgroup_rmdir, @@ -2314,7 +2314,7 @@ static int cgroup_tasks_show(struct seq_file *s, void *v) return seq_printf(s, "%d\n", *(int *)v); } -static struct seq_operations cgroup_tasks_seq_operations = { +static const struct seq_operations cgroup_tasks_seq_operations = { .start = cgroup_tasks_start, .stop = cgroup_tasks_stop, .next = cgroup_tasks_next, diff --git a/kernel/exit.c b/kernel/exit.c index ae5d866..60d6fdc 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -47,7 +47,7 @@ #include <linux/tracehook.h> #include <linux/fs_struct.h> #include <linux/init_task.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <trace/events/sched.h> #include <asm/uaccess.h> @@ -154,8 +154,8 @@ static void delayed_put_task_struct(struct rcu_head *rhp) { struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); -#ifdef CONFIG_PERF_COUNTERS - WARN_ON_ONCE(tsk->perf_counter_ctxp); +#ifdef CONFIG_PERF_EVENTS + WARN_ON_ONCE(tsk->perf_event_ctxp); #endif trace_sched_process_free(tsk); put_task_struct(tsk); @@ -359,8 +359,10 @@ void __set_special_pids(struct pid *pid) { struct task_struct *curr = current->group_leader; - if (task_session(curr) != pid) + if (task_session(curr) != pid) { change_pid(curr, PIDTYPE_SID, pid); + proc_sid_connector(curr); + } if (task_pgrp(curr) != pid) change_pid(curr, PIDTYPE_PGID, pid); @@ -945,6 +947,8 @@ NORET_TYPE void do_exit(long code) if (group_dead) { hrtimer_cancel(&tsk->signal->real_timer); exit_itimers(tsk->signal); + if (tsk->mm) + setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm); } acct_collect(code, group_dead); if (group_dead) @@ -981,7 +985,7 @@ NORET_TYPE void do_exit(long code) * Flush inherited counters to the parent - before the parent * gets woken up by child-exit notifications. */ - perf_counter_exit_task(tsk); + perf_event_exit_task(tsk); exit_notify(tsk, group_dead); #ifdef CONFIG_NUMA @@ -1208,6 +1212,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) if (likely(!traced) && likely(!task_detached(p))) { struct signal_struct *psig; struct signal_struct *sig; + unsigned long maxrss; /* * The resource counters for the group leader are in its @@ -1256,6 +1261,9 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) psig->coublock += task_io_get_oublock(p) + sig->oublock + sig->coublock; + maxrss = max(sig->maxrss, sig->cmaxrss); + if (psig->cmaxrss < maxrss) + psig->cmaxrss = maxrss; task_io_accounting_add(&psig->ioac, &p->ioac); task_io_accounting_add(&psig->ioac, &sig->ioac); spin_unlock_irq(&p->real_parent->sighand->siglock); diff --git a/kernel/fork.c b/kernel/fork.c index bfee931..8f45b0e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -49,6 +49,7 @@ #include <linux/ftrace.h> #include <linux/profile.h> #include <linux/rmap.h> +#include <linux/ksm.h> #include <linux/acct.h> #include <linux/tsacct_kern.h> #include <linux/cn_proc.h> @@ -61,7 +62,7 @@ #include <linux/blkdev.h> #include <linux/fs_struct.h> #include <linux/magic.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> @@ -136,9 +137,17 @@ struct kmem_cache *vm_area_cachep; /* SLAB cache for mm_struct structures (tsk->mm) */ static struct kmem_cache *mm_cachep; +static void account_kernel_stack(struct thread_info *ti, int account) +{ + struct zone *zone = page_zone(virt_to_page(ti)); + + mod_zone_page_state(zone, NR_KERNEL_STACK, account); +} + void free_task(struct task_struct *tsk) { prop_local_destroy_single(&tsk->dirties); + account_kernel_stack(tsk->stack, -1); free_thread_info(tsk->stack); rt_mutex_debug_task_free(tsk); ftrace_graph_exit_task(tsk); @@ -253,6 +262,9 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) tsk->btrace_seq = 0; #endif tsk->splice_pipe = NULL; + + account_kernel_stack(ti, 1); + return tsk; out: @@ -288,6 +300,9 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) rb_link = &mm->mm_rb.rb_node; rb_parent = NULL; pprev = &mm->mmap; + retval = ksm_fork(mm, oldmm); + if (retval) + goto out; for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) { struct file *file; @@ -424,7 +439,8 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) atomic_set(&mm->mm_count, 1); init_rwsem(&mm->mmap_sem); INIT_LIST_HEAD(&mm->mmlist); - mm->flags = (current->mm) ? current->mm->flags : default_dump_filter; + mm->flags = (current->mm) ? + (current->mm->flags & MMF_INIT_MASK) : default_dump_filter; mm->core_state = NULL; mm->nr_ptes = 0; set_mm_counter(mm, file_rss, 0); @@ -485,6 +501,7 @@ void mmput(struct mm_struct *mm) if (atomic_dec_and_test(&mm->mm_users)) { exit_aio(mm); + ksm_exit(mm); exit_mmap(mm); set_mm_exe_file(mm, NULL); if (!list_empty(&mm->mmlist)) { @@ -849,6 +866,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; + sig->maxrss = sig->cmaxrss = 0; task_io_accounting_init(&sig->ioac); sig->sum_sched_runtime = 0; taskstats_tgid_init(sig); @@ -863,6 +881,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) tty_audit_fork(sig); + sig->oom_adj = current->signal->oom_adj; + return 0; } @@ -1075,10 +1095,12 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->bts = NULL; + p->stack_start = stack_start; + /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p, clone_flags); - retval = perf_counter_init_task(p); + retval = perf_event_init_task(p); if (retval) goto bad_fork_cleanup_policy; @@ -1253,7 +1275,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, write_unlock_irq(&tasklist_lock); proc_fork_connector(p); cgroup_post_fork(p); - perf_counter_fork(p); + perf_event_fork(p); return p; bad_fork_free_pid: @@ -1280,7 +1302,7 @@ bad_fork_cleanup_semundo: bad_fork_cleanup_audit: audit_free(p); bad_fork_cleanup_policy: - perf_counter_free_task(p); + perf_event_free_task(p); #ifdef CONFIG_NUMA mpol_put(p->mempolicy); bad_fork_cleanup_cgroup: diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 3a29dbe..8b6b8b6 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -59,7 +59,8 @@ static inline int is_kernel_inittext(unsigned long addr) static inline int is_kernel_text(unsigned long addr) { - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) + if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || + arch_is_kernel_text(addr)) return 1; return in_gate_area_no_task(addr); } diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 26539e3..3765ff3 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -117,7 +117,7 @@ EXPORT_SYMBOL(kfifo_free); * writer, you don't need extra locking to use these functions. */ unsigned int __kfifo_put(struct kfifo *fifo, - unsigned char *buffer, unsigned int len) + const unsigned char *buffer, unsigned int len) { unsigned int l; diff --git a/kernel/kmod.c b/kernel/kmod.c index 9fcb53a..689d20f 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -143,6 +143,7 @@ struct subprocess_info { static int ____call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; + enum umh_wait wait = sub_info->wait; int retval; BUG_ON(atomic_read(&sub_info->cred->usage) != 1); @@ -184,10 +185,14 @@ static int ____call_usermodehelper(void *data) */ set_user_nice(current, 0); + if (wait == UMH_WAIT_EXEC) + complete(sub_info->complete); + retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp); /* Exec failed? */ - sub_info->retval = retval; + if (wait != UMH_WAIT_EXEC) + sub_info->retval = retval; do_exit(0); } @@ -266,16 +271,14 @@ static void __call_usermodehelper(struct work_struct *work) switch (wait) { case UMH_NO_WAIT: + case UMH_WAIT_EXEC: break; case UMH_WAIT_PROC: if (pid > 0) break; sub_info->retval = pid; - /* FALLTHROUGH */ - - case UMH_WAIT_EXEC: - complete(sub_info->complete); + break; } } diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ef177d6..cfadc12 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1321,7 +1321,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) return 0; } -static struct seq_operations kprobes_seq_ops = { +static const struct seq_operations kprobes_seq_ops = { .start = kprobe_seq_start, .next = kprobe_seq_next, .stop = kprobe_seq_stop, diff --git a/kernel/lockdep.c b/kernel/lockdep.c index f74d2d7..3815ac1d 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -578,6 +578,9 @@ static int static_obj(void *obj) if ((addr >= start) && (addr < end)) return 1; + if (arch_is_kernel_data(addr)) + return 1; + #ifdef CONFIG_SMP /* * percpu var? diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index d4b3dbc..d4aba4f 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -594,7 +594,7 @@ static int ls_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations lockstat_ops = { +static const struct seq_operations lockstat_ops = { .start = ls_start, .next = ls_next, .stop = ls_stop, diff --git a/kernel/marker.c b/kernel/marker.c deleted file mode 100644 index ea54f26..0000000 --- a/kernel/marker.c +++ /dev/null @@ -1,930 +0,0 @@ -/* - * Copyright (C) 2007 Mathieu Desnoyers - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - */ -#include <linux/module.h> -#include <linux/mutex.h> -#include <linux/types.h> -#include <linux/jhash.h> -#include <linux/list.h> -#include <linux/rcupdate.h> -#include <linux/marker.h> -#include <linux/err.h> -#include <linux/slab.h> - -extern struct marker __start___markers[]; -extern struct marker __stop___markers[]; - -/* Set to 1 to enable marker debug output */ -static const int marker_debug; - -/* - * markers_mutex nests inside module_mutex. Markers mutex protects the builtin - * and module markers and the hash table. - */ -static DEFINE_MUTEX(markers_mutex); - -/* - * Marker hash table, containing the active markers. - * Protected by module_mutex. - */ -#define MARKER_HASH_BITS 6 -#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) -static struct hlist_head marker_table[MARKER_TABLE_SIZE]; - -/* - * Note about RCU : - * It is used to make sure every handler has finished using its private data - * between two consecutive operation (add or remove) on a given marker. It is - * also used to delay the free of multiple probes array until a quiescent state - * is reached. - * marker entries modifications are protected by the markers_mutex. - */ -struct marker_entry { - struct hlist_node hlist; - char *format; - /* Probe wrapper */ - void (*call)(const struct marker *mdata, void *call_private, ...); - struct marker_probe_closure single; - struct marker_probe_closure *multi; - int refcount; /* Number of times armed. 0 if disarmed. */ - struct rcu_head rcu; - void *oldptr; - int rcu_pending; - unsigned char ptype:1; - unsigned char format_allocated:1; - char name[0]; /* Contains name'\0'format'\0' */ -}; - -/** - * __mark_empty_function - Empty probe callback - * @probe_private: probe private data - * @call_private: call site private data - * @fmt: format string - * @...: variable argument list - * - * Empty callback provided as a probe to the markers. By providing this to a - * disabled marker, we make sure the execution flow is always valid even - * though the function pointer change and the marker enabling are two distinct - * operations that modifies the execution flow of preemptible code. - */ -notrace void __mark_empty_function(void *probe_private, void *call_private, - const char *fmt, va_list *args) -{ -} -EXPORT_SYMBOL_GPL(__mark_empty_function); - -/* - * marker_probe_cb Callback that prepares the variable argument list for probes. - * @mdata: pointer of type struct marker - * @call_private: caller site private data - * @...: Variable argument list. - * - * Since we do not use "typical" pointer based RCU in the 1 argument case, we - * need to put a full smp_rmb() in this branch. This is why we do not use - * rcu_dereference() for the pointer read. - */ -notrace void marker_probe_cb(const struct marker *mdata, - void *call_private, ...) -{ - va_list args; - char ptype; - - /* - * rcu_read_lock_sched does two things : disabling preemption to make - * sure the teardown of the callbacks can be done correctly when they - * are in modules and they insure RCU read coherency. - */ - rcu_read_lock_sched_notrace(); - ptype = mdata->ptype; - if (likely(!ptype)) { - marker_probe_func *func; - /* Must read the ptype before ptr. They are not data dependant, - * so we put an explicit smp_rmb() here. */ - smp_rmb(); - func = mdata->single.func; - /* Must read the ptr before private data. They are not data - * dependant, so we put an explicit smp_rmb() here. */ - smp_rmb(); - va_start(args, call_private); - func(mdata->single.probe_private, call_private, mdata->format, - &args); - va_end(args); - } else { - struct marker_probe_closure *multi; - int i; - /* - * Read mdata->ptype before mdata->multi. - */ - smp_rmb(); - multi = mdata->multi; - /* - * multi points to an array, therefore accessing the array - * depends on reading multi. However, even in this case, - * we must insure that the pointer is read _before_ the array - * data. Same as rcu_dereference, but we need a full smp_rmb() - * in the fast path, so put the explicit barrier here. - */ - smp_read_barrier_depends(); - for (i = 0; multi[i].func; i++) { - va_start(args, call_private); - multi[i].func(multi[i].probe_private, call_private, - mdata->format, &args); - va_end(args); - } - } - rcu_read_unlock_sched_notrace(); -} -EXPORT_SYMBOL_GPL(marker_probe_cb); - -/* - * marker_probe_cb Callback that does not prepare the variable argument list. - * @mdata: pointer of type struct marker - * @call_private: caller site private data - * @...: Variable argument list. - * - * Should be connected to markers "MARK_NOARGS". - */ -static notrace void marker_probe_cb_noarg(const struct marker *mdata, - void *call_private, ...) -{ - va_list args; /* not initialized */ - char ptype; - - rcu_read_lock_sched_notrace(); - ptype = mdata->ptype; - if (likely(!ptype)) { - marker_probe_func *func; - /* Must read the ptype before ptr. They are not data dependant, - * so we put an explicit smp_rmb() here. */ - smp_rmb(); - func = mdata->single.func; - /* Must read the ptr before private data. They are not data - * dependant, so we put an explicit smp_rmb() here. */ - smp_rmb(); - func(mdata->single.probe_private, call_private, mdata->format, - &args); - } else { - struct marker_probe_closure *multi; - int i; - /* - * Read mdata->ptype before mdata->multi. - */ - smp_rmb(); - multi = mdata->multi; - /* - * multi points to an array, therefore accessing the array - * depends on reading multi. However, even in this case, - * we must insure that the pointer is read _before_ the array - * data. Same as rcu_dereference, but we need a full smp_rmb() - * in the fast path, so put the explicit barrier here. - */ - smp_read_barrier_depends(); - for (i = 0; multi[i].func; i++) - multi[i].func(multi[i].probe_private, call_private, - mdata->format, &args); - } - rcu_read_unlock_sched_notrace(); -} - -static void free_old_closure(struct rcu_head *head) -{ - struct marker_entry *entry = container_of(head, - struct marker_entry, rcu); - kfree(entry->oldptr); - /* Make sure we free the data before setting the pending flag to 0 */ - smp_wmb(); - entry->rcu_pending = 0; -} - -static void debug_print_probes(struct marker_entry *entry) -{ - int i; - - if (!marker_debug) - return; - - if (!entry->ptype) { - printk(KERN_DEBUG "Single probe : %p %p\n", - entry->single.func, - entry->single.probe_private); - } else { - for (i = 0; entry->multi[i].func; i++) - printk(KERN_DEBUG "Multi probe %d : %p %p\n", i, - entry->multi[i].func, - entry->multi[i].probe_private); - } -} - -static struct marker_probe_closure * -marker_entry_add_probe(struct marker_entry *entry, - marker_probe_func *probe, void *probe_private) -{ - int nr_probes = 0; - struct marker_probe_closure *old, *new; - - WARN_ON(!probe); - - debug_print_probes(entry); - old = entry->multi; - if (!entry->ptype) { - if (entry->single.func == probe && - entry->single.probe_private == probe_private) - return ERR_PTR(-EBUSY); - if (entry->single.func == __mark_empty_function) { - /* 0 -> 1 probes */ - entry->single.func = probe; - entry->single.probe_private = probe_private; - entry->refcount = 1; - entry->ptype = 0; - debug_print_probes(entry); - return NULL; - } else { - /* 1 -> 2 probes */ - nr_probes = 1; - old = NULL; - } - } else { - /* (N -> N+1), (N != 0, 1) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) - if (old[nr_probes].func == probe - && old[nr_probes].probe_private - == probe_private) - return ERR_PTR(-EBUSY); - } - /* + 2 : one for new probe, one for NULL func */ - new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure), - GFP_KERNEL); - if (new == NULL) - return ERR_PTR(-ENOMEM); - if (!old) - new[0] = entry->single; - else - memcpy(new, old, - nr_probes * sizeof(struct marker_probe_closure)); - new[nr_probes].func = probe; - new[nr_probes].probe_private = probe_private; - entry->refcount = nr_probes + 1; - entry->multi = new; - entry->ptype = 1; - debug_print_probes(entry); - return old; -} - -static struct marker_probe_closure * -marker_entry_remove_probe(struct marker_entry *entry, - marker_probe_func *probe, void *probe_private) -{ - int nr_probes = 0, nr_del = 0, i; - struct marker_probe_closure *old, *new; - - old = entry->multi; - - debug_print_probes(entry); - if (!entry->ptype) { - /* 0 -> N is an error */ - WARN_ON(entry->single.func == __mark_empty_function); - /* 1 -> 0 probes */ - WARN_ON(probe && entry->single.func != probe); - WARN_ON(entry->single.probe_private != probe_private); - entry->single.func = __mark_empty_function; - entry->refcount = 0; - entry->ptype = 0; - debug_print_probes(entry); - return NULL; - } else { - /* (N -> M), (N > 1, M >= 0) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) { - if ((!probe || old[nr_probes].func == probe) - && old[nr_probes].probe_private - == probe_private) - nr_del++; - } - } - - if (nr_probes - nr_del == 0) { - /* N -> 0, (N > 1) */ - entry->single.func = __mark_empty_function; - entry->refcount = 0; - entry->ptype = 0; - } else if (nr_probes - nr_del == 1) { - /* N -> 1, (N > 1) */ - for (i = 0; old[i].func; i++) - if ((probe && old[i].func != probe) || - old[i].probe_private != probe_private) - entry->single = old[i]; - entry->refcount = 1; - entry->ptype = 0; - } else { - int j = 0; - /* N -> M, (N > 1, M > 1) */ - /* + 1 for NULL */ - new = kzalloc((nr_probes - nr_del + 1) - * sizeof(struct marker_probe_closure), GFP_KERNEL); - if (new == NULL) - return ERR_PTR(-ENOMEM); - for (i = 0; old[i].func; i++) - if ((probe && old[i].func != probe) || - old[i].probe_private != probe_private) - new[j++] = old[i]; - entry->refcount = nr_probes - nr_del; - entry->ptype = 1; - entry->multi = new; - } - debug_print_probes(entry); - return old; -} - -/* - * Get marker if the marker is present in the marker hash table. - * Must be called with markers_mutex held. - * Returns NULL if not present. - */ -static struct marker_entry *get_marker(const char *name) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - u32 hash = jhash(name, strlen(name), 0); - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) - return e; - } - return NULL; -} - -/* - * Add the marker to the marker hash table. Must be called with markers_mutex - * held. - */ -static struct marker_entry *add_marker(const char *name, const char *format) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - size_t name_len = strlen(name) + 1; - size_t format_len = 0; - u32 hash = jhash(name, name_len-1, 0); - - if (format) - format_len = strlen(format) + 1; - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - printk(KERN_NOTICE - "Marker %s busy\n", name); - return ERR_PTR(-EBUSY); /* Already there */ - } - } - /* - * Using kmalloc here to allocate a variable length element. Could - * cause some memory fragmentation if overused. - */ - e = kmalloc(sizeof(struct marker_entry) + name_len + format_len, - GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - memcpy(&e->name[0], name, name_len); - if (format) { - e->format = &e->name[name_len]; - memcpy(e->format, format, format_len); - if (strcmp(e->format, MARK_NOARGS) == 0) - e->call = marker_probe_cb_noarg; - else - e->call = marker_probe_cb; - trace_mark(core_marker_format, "name %s format %s", - e->name, e->format); - } else { - e->format = NULL; - e->call = marker_probe_cb; - } - e->single.func = __mark_empty_function; - e->single.probe_private = NULL; - e->multi = NULL; - e->ptype = 0; - e->format_allocated = 0; - e->refcount = 0; - e->rcu_pending = 0; - hlist_add_head(&e->hlist, head); - return e; -} - -/* - * Remove the marker from the marker hash table. Must be called with mutex_lock - * held. - */ -static int remove_marker(const char *name) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - int found = 0; - size_t len = strlen(name) + 1; - u32 hash = jhash(name, len-1, 0); - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - found = 1; - break; - } - } - if (!found) - return -ENOENT; - if (e->single.func != __mark_empty_function) - return -EBUSY; - hlist_del(&e->hlist); - if (e->format_allocated) - kfree(e->format); - /* Make sure the call_rcu has been executed */ - if (e->rcu_pending) - rcu_barrier_sched(); - kfree(e); - return 0; -} - -/* - * Set the mark_entry format to the format found in the element. - */ -static int marker_set_format(struct marker_entry *entry, const char *format) -{ - entry->format = kstrdup(format, GFP_KERNEL); - if (!entry->format) - return -ENOMEM; - entry->format_allocated = 1; - - trace_mark(core_marker_format, "name %s format %s", - entry->name, entry->format); - return 0; -} - -/* - * Sets the probe callback corresponding to one marker. - */ -static int set_marker(struct marker_entry *entry, struct marker *elem, - int active) -{ - int ret = 0; - WARN_ON(strcmp(entry->name, elem->name) != 0); - - if (entry->format) { - if (strcmp(entry->format, elem->format) != 0) { - printk(KERN_NOTICE - "Format mismatch for probe %s " - "(%s), marker (%s)\n", - entry->name, - entry->format, - elem->format); - return -EPERM; - } - } else { - ret = marker_set_format(entry, elem->format); - if (ret) - return ret; - } - - /* - * probe_cb setup (statically known) is done here. It is - * asynchronous with the rest of execution, therefore we only - * pass from a "safe" callback (with argument) to an "unsafe" - * callback (does not set arguments). - */ - elem->call = entry->call; - /* - * Sanity check : - * We only update the single probe private data when the ptr is - * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) - */ - WARN_ON(elem->single.func != __mark_empty_function - && elem->single.probe_private != entry->single.probe_private - && !elem->ptype); - elem->single.probe_private = entry->single.probe_private; - /* - * Make sure the private data is valid when we update the - * single probe ptr. - */ - smp_wmb(); - elem->single.func = entry->single.func; - /* - * We also make sure that the new probe callbacks array is consistent - * before setting a pointer to it. - */ - rcu_assign_pointer(elem->multi, entry->multi); - /* - * Update the function or multi probe array pointer before setting the - * ptype. - */ - smp_wmb(); - elem->ptype = entry->ptype; - - if (elem->tp_name && (active ^ elem->state)) { - WARN_ON(!elem->tp_cb); - /* - * It is ok to directly call the probe registration because type - * checking has been done in the __trace_mark_tp() macro. - */ - - if (active) { - /* - * try_module_get should always succeed because we hold - * lock_module() to get the tp_cb address. - */ - ret = try_module_get(__module_text_address( - (unsigned long)elem->tp_cb)); - BUG_ON(!ret); - ret = tracepoint_probe_register_noupdate( - elem->tp_name, - elem->tp_cb); - } else { - ret = tracepoint_probe_unregister_noupdate( - elem->tp_name, - elem->tp_cb); - /* - * tracepoint_probe_update_all() must be called - * before the module containing tp_cb is unloaded. - */ - module_put(__module_text_address( - (unsigned long)elem->tp_cb)); - } - } - elem->state = active; - - return ret; -} - -/* - * Disable a marker and its probe callback. - * Note: only waiting an RCU period after setting elem->call to the empty - * function insures that the original callback is not used anymore. This insured - * by rcu_read_lock_sched around the call site. - */ -static void disable_marker(struct marker *elem) -{ - int ret; - - /* leave "call" as is. It is known statically. */ - if (elem->tp_name && elem->state) { - WARN_ON(!elem->tp_cb); - /* - * It is ok to directly call the probe registration because type - * checking has been done in the __trace_mark_tp() macro. - */ - ret = tracepoint_probe_unregister_noupdate(elem->tp_name, - elem->tp_cb); - WARN_ON(ret); - /* - * tracepoint_probe_update_all() must be called - * before the module containing tp_cb is unloaded. - */ - module_put(__module_text_address((unsigned long)elem->tp_cb)); - } - elem->state = 0; - elem->single.func = __mark_empty_function; - /* Update the function before setting the ptype */ - smp_wmb(); - elem->ptype = 0; /* single probe */ - /* - * Leave the private data and id there, because removal is racy and - * should be done only after an RCU period. These are never used until - * the next initialization anyway. - */ -} - -/** - * marker_update_probe_range - Update a probe range - * @begin: beginning of the range - * @end: end of the range - * - * Updates the probe callback corresponding to a range of markers. - */ -void marker_update_probe_range(struct marker *begin, - struct marker *end) -{ - struct marker *iter; - struct marker_entry *mark_entry; - - mutex_lock(&markers_mutex); - for (iter = begin; iter < end; iter++) { - mark_entry = get_marker(iter->name); - if (mark_entry) { - set_marker(mark_entry, iter, !!mark_entry->refcount); - /* - * ignore error, continue - */ - } else { - disable_marker(iter); - } - } - mutex_unlock(&markers_mutex); -} - -/* - * Update probes, removing the faulty probes. - * - * Internal callback only changed before the first probe is connected to it. - * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 - * transitions. All other transitions will leave the old private data valid. - * This makes the non-atomicity of the callback/private data updates valid. - * - * "special case" updates : - * 0 -> 1 callback - * 1 -> 0 callback - * 1 -> 2 callbacks - * 2 -> 1 callbacks - * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. - * Site effect : marker_set_format may delete the marker entry (creating a - * replacement). - */ -static void marker_update_probes(void) -{ - /* Core kernel markers */ - marker_update_probe_range(__start___markers, __stop___markers); - /* Markers in modules. */ - module_update_markers(); - tracepoint_probe_update_all(); -} - -/** - * marker_probe_register - Connect a probe to a marker - * @name: marker name - * @format: format string - * @probe: probe handler - * @probe_private: probe private data - * - * private data must be a valid allocated memory address, or NULL. - * Returns 0 if ok, error value on error. - * The probe address must at least be aligned on the architecture pointer size. - */ -int marker_probe_register(const char *name, const char *format, - marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - int ret = 0; - struct marker_probe_closure *old; - - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) { - entry = add_marker(name, format); - if (IS_ERR(entry)) - ret = PTR_ERR(entry); - } else if (format) { - if (!entry->format) - ret = marker_set_format(entry, format); - else if (strcmp(entry->format, format)) - ret = -EPERM; - } - if (ret) - goto end; - - /* - * If we detect that a call_rcu is pending for this marker, - * make sure it's executed now. - */ - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_add_probe(entry, probe, probe_private); - if (IS_ERR(old)) { - ret = PTR_ERR(old); - goto end; - } - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_register); - -/** - * marker_probe_unregister - Disconnect a probe from a marker - * @name: marker name - * @probe: probe function pointer - * @probe_private: probe private data - * - * Returns the private data given to marker_probe_register, or an ERR_PTR(). - * We do not need to call a synchronize_sched to make sure the probes have - * finished running before doing a module unload, because the module unload - * itself uses stop_machine(), which insures that every preempt disabled section - * have finished. - */ -int marker_probe_unregister(const char *name, - marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - struct marker_probe_closure *old; - int ret = -ENOENT; - - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_remove_probe(entry, probe, probe_private); - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); - remove_marker(name); /* Ignore busy error message */ - ret = 0; -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_unregister); - -static struct marker_entry * -get_marker_from_private_data(marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - unsigned int i; - struct hlist_head *head; - struct hlist_node *node; - - for (i = 0; i < MARKER_TABLE_SIZE; i++) { - head = &marker_table[i]; - hlist_for_each_entry(entry, node, head, hlist) { - if (!entry->ptype) { - if (entry->single.func == probe - && entry->single.probe_private - == probe_private) - return entry; - } else { - struct marker_probe_closure *closure; - closure = entry->multi; - for (i = 0; closure[i].func; i++) { - if (closure[i].func == probe && - closure[i].probe_private - == probe_private) - return entry; - } - } - } - } - return NULL; -} - -/** - * marker_probe_unregister_private_data - Disconnect a probe from a marker - * @probe: probe function - * @probe_private: probe private data - * - * Unregister a probe by providing the registered private data. - * Only removes the first marker found in hash table. - * Return 0 on success or error value. - * We do not need to call a synchronize_sched to make sure the probes have - * finished running before doing a module unload, because the module unload - * itself uses stop_machine(), which insures that every preempt disabled section - * have finished. - */ -int marker_probe_unregister_private_data(marker_probe_func *probe, - void *probe_private) -{ - struct marker_entry *entry; - int ret = 0; - struct marker_probe_closure *old; - - mutex_lock(&markers_mutex); - entry = get_marker_from_private_data(probe, probe_private); - if (!entry) { - ret = -ENOENT; - goto end; - } - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_remove_probe(entry, NULL, probe_private); - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker_from_private_data(probe, probe_private); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); - remove_marker(entry->name); /* Ignore busy error message */ -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); - -/** - * marker_get_private_data - Get a marker's probe private data - * @name: marker name - * @probe: probe to match - * @num: get the nth matching probe's private data - * - * Returns the nth private data pointer (starting from 0) matching, or an - * ERR_PTR. - * Returns the private data pointer, or an ERR_PTR. - * The private data pointer should _only_ be dereferenced if the caller is the - * owner of the data, or its content could vanish. This is mostly used to - * confirm that a caller is the owner of a registered probe. - */ -void *marker_get_private_data(const char *name, marker_probe_func *probe, - int num) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - size_t name_len = strlen(name) + 1; - u32 hash = jhash(name, name_len-1, 0); - int i; - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - if (!e->ptype) { - if (num == 0 && e->single.func == probe) - return e->single.probe_private; - } else { - struct marker_probe_closure *closure; - int match = 0; - closure = e->multi; - for (i = 0; closure[i].func; i++) { - if (closure[i].func != probe) - continue; - if (match++ == num) - return closure[i].probe_private; - } - } - break; - } - } - return ERR_PTR(-ENOENT); -} -EXPORT_SYMBOL_GPL(marker_get_private_data); - -#ifdef CONFIG_MODULES - -int marker_module_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - struct module *mod = data; - - switch (val) { - case MODULE_STATE_COMING: - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - break; - case MODULE_STATE_GOING: - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - break; - } - return 0; -} - -struct notifier_block marker_module_nb = { - .notifier_call = marker_module_notify, - .priority = 0, -}; - -static int init_markers(void) -{ - return register_module_notifier(&marker_module_nb); -} -__initcall(init_markers); - -#endif /* CONFIG_MODULES */ diff --git a/kernel/module.c b/kernel/module.c index 05ce49c..e6bc4b2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -47,6 +47,7 @@ #include <linux/rculist.h> #include <asm/uaccess.h> #include <asm/cacheflush.h> +#include <asm/mmu_context.h> #include <linux/license.h> #include <asm/sections.h> #include <linux/tracepoint.h> @@ -1535,6 +1536,10 @@ static void free_module(struct module *mod) /* Finally, free the core (containing the module structure) */ module_free(mod, mod->module_core); + +#ifdef CONFIG_MPU + update_protections(current->mm); +#endif } void *__symbol_get(const char *symbol) @@ -2237,10 +2242,6 @@ static noinline struct module *load_module(void __user *umod, sizeof(*mod->ctors), &mod->num_ctors); #endif -#ifdef CONFIG_MARKERS - mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", - sizeof(*mod->markers), &mod->num_markers); -#endif #ifdef CONFIG_TRACEPOINTS mod->tracepoints = section_objs(hdr, sechdrs, secstrings, "__tracepoints", @@ -2958,20 +2959,6 @@ void module_layout(struct module *mod, EXPORT_SYMBOL(module_layout); #endif -#ifdef CONFIG_MARKERS -void module_update_markers(void) -{ - struct module *mod; - - mutex_lock(&module_mutex); - list_for_each_entry(mod, &modules, list) - if (!mod->taints) - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - mutex_unlock(&module_mutex); -} -#endif - #ifdef CONFIG_TRACEPOINTS void module_update_tracepoints(void) { diff --git a/kernel/panic.c b/kernel/panic.c index 512ab73..bcdef26 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -177,7 +177,7 @@ static const struct tnt tnts[] = { * 'W' - Taint on warning. * 'C' - modules from drivers/staging are loaded. * - * The string is overwritten by the next call to print_taint(). + * The string is overwritten by the next call to print_tainted(). */ const char *print_tainted(void) { diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c deleted file mode 100644 index 8cb94a5..0000000 --- a/kernel/perf_counter.c +++ /dev/null @@ -1,4963 +0,0 @@ -/* - * Performance counter core code - * - * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> - * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar - * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> - * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> - * - * For licensing details see kernel-base/COPYING - */ - -#include <linux/fs.h> -#include <linux/mm.h> -#include <linux/cpu.h> -#include <linux/smp.h> -#include <linux/file.h> -#include <linux/poll.h> -#include <linux/sysfs.h> -#include <linux/dcache.h> -#include <linux/percpu.h> -#include <linux/ptrace.h> -#include <linux/vmstat.h> -#include <linux/hardirq.h> -#include <linux/rculist.h> -#include <linux/uaccess.h> -#include <linux/syscalls.h> -#include <linux/anon_inodes.h> -#include <linux/kernel_stat.h> -#include <linux/perf_counter.h> - -#include <asm/irq_regs.h> - -/* - * Each CPU has a list of per CPU counters: - */ -DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); - -int perf_max_counters __read_mostly = 1; -static int perf_reserved_percpu __read_mostly; -static int perf_overcommit __read_mostly = 1; - -static atomic_t nr_counters __read_mostly; -static atomic_t nr_mmap_counters __read_mostly; -static atomic_t nr_comm_counters __read_mostly; -static atomic_t nr_task_counters __read_mostly; - -/* - * perf counter paranoia level: - * -1 - not paranoid at all - * 0 - disallow raw tracepoint access for unpriv - * 1 - disallow cpu counters for unpriv - * 2 - disallow kernel profiling for unpriv - */ -int sysctl_perf_counter_paranoid __read_mostly = 1; - -static inline bool perf_paranoid_tracepoint_raw(void) -{ - return sysctl_perf_counter_paranoid > -1; -} - -static inline bool perf_paranoid_cpu(void) -{ - return sysctl_perf_counter_paranoid > 0; -} - -static inline bool perf_paranoid_kernel(void) -{ - return sysctl_perf_counter_paranoid > 1; -} - -int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */ - -/* - * max perf counter sample rate - */ -int sysctl_perf_counter_sample_rate __read_mostly = 100000; - -static atomic64_t perf_counter_id; - -/* - * Lock for (sysadmin-configurable) counter reservations: - */ -static DEFINE_SPINLOCK(perf_resource_lock); - -/* - * Architecture provided APIs - weak aliases: - */ -extern __weak const struct pmu *hw_perf_counter_init(struct perf_counter *counter) -{ - return NULL; -} - -void __weak hw_perf_disable(void) { barrier(); } -void __weak hw_perf_enable(void) { barrier(); } - -void __weak hw_perf_counter_setup(int cpu) { barrier(); } -void __weak hw_perf_counter_setup_online(int cpu) { barrier(); } - -int __weak -hw_perf_group_sched_in(struct perf_counter *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx, int cpu) -{ - return 0; -} - -void __weak perf_counter_print_debug(void) { } - -static DEFINE_PER_CPU(int, perf_disable_count); - -void __perf_disable(void) -{ - __get_cpu_var(perf_disable_count)++; -} - -bool __perf_enable(void) -{ - return !--__get_cpu_var(perf_disable_count); -} - -void perf_disable(void) -{ - __perf_disable(); - hw_perf_disable(); -} - -void perf_enable(void) -{ - if (__perf_enable()) - hw_perf_enable(); -} - -static void get_ctx(struct perf_counter_context *ctx) -{ - WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); -} - -static void free_ctx(struct rcu_head *head) -{ - struct perf_counter_context *ctx; - - ctx = container_of(head, struct perf_counter_context, rcu_head); - kfree(ctx); -} - -static void put_ctx(struct perf_counter_context *ctx) -{ - if (atomic_dec_and_test(&ctx->refcount)) { - if (ctx->parent_ctx) - put_ctx(ctx->parent_ctx); - if (ctx->task) - put_task_struct(ctx->task); - call_rcu(&ctx->rcu_head, free_ctx); - } -} - -static void unclone_ctx(struct perf_counter_context *ctx) -{ - if (ctx->parent_ctx) { - put_ctx(ctx->parent_ctx); - ctx->parent_ctx = NULL; - } -} - -/* - * If we inherit counters we want to return the parent counter id - * to userspace. - */ -static u64 primary_counter_id(struct perf_counter *counter) -{ - u64 id = counter->id; - - if (counter->parent) - id = counter->parent->id; - - return id; -} - -/* - * Get the perf_counter_context for a task and lock it. - * This has to cope with with the fact that until it is locked, - * the context could get moved to another task. - */ -static struct perf_counter_context * -perf_lock_task_context(struct task_struct *task, unsigned long *flags) -{ - struct perf_counter_context *ctx; - - rcu_read_lock(); - retry: - ctx = rcu_dereference(task->perf_counter_ctxp); - if (ctx) { - /* - * If this context is a clone of another, it might - * get swapped for another underneath us by - * perf_counter_task_sched_out, though the - * rcu_read_lock() protects us from any context - * getting freed. Lock the context and check if it - * got swapped before we could get the lock, and retry - * if so. If we locked the right context, then it - * can't get swapped on us any more. - */ - spin_lock_irqsave(&ctx->lock, *flags); - if (ctx != rcu_dereference(task->perf_counter_ctxp)) { - spin_unlock_irqrestore(&ctx->lock, *flags); - goto retry; - } - - if (!atomic_inc_not_zero(&ctx->refcount)) { - spin_unlock_irqrestore(&ctx->lock, *flags); - ctx = NULL; - } - } - rcu_read_unlock(); - return ctx; -} - -/* - * Get the context for a task and increment its pin_count so it - * can't get swapped to another task. This also increments its - * reference count so that the context can't get freed. - */ -static struct perf_counter_context *perf_pin_task_context(struct task_struct *task) -{ - struct perf_counter_context *ctx; - unsigned long flags; - - ctx = perf_lock_task_context(task, &flags); - if (ctx) { - ++ctx->pin_count; - spin_unlock_irqrestore(&ctx->lock, flags); - } - return ctx; -} - -static void perf_unpin_context(struct perf_counter_context *ctx) -{ - unsigned long flags; - - spin_lock_irqsave(&ctx->lock, flags); - --ctx->pin_count; - spin_unlock_irqrestore(&ctx->lock, flags); - put_ctx(ctx); -} - -/* - * Add a counter from the lists for its context. - * Must be called with ctx->mutex and ctx->lock held. - */ -static void -list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx) -{ - struct perf_counter *group_leader = counter->group_leader; - - /* - * Depending on whether it is a standalone or sibling counter, - * add it straight to the context's counter list, or to the group - * leader's sibling list: - */ - if (group_leader == counter) - list_add_tail(&counter->list_entry, &ctx->counter_list); - else { - list_add_tail(&counter->list_entry, &group_leader->sibling_list); - group_leader->nr_siblings++; - } - - list_add_rcu(&counter->event_entry, &ctx->event_list); - ctx->nr_counters++; - if (counter->attr.inherit_stat) - ctx->nr_stat++; -} - -/* - * Remove a counter from the lists for its context. - * Must be called with ctx->mutex and ctx->lock held. - */ -static void -list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) -{ - struct perf_counter *sibling, *tmp; - - if (list_empty(&counter->list_entry)) - return; - ctx->nr_counters--; - if (counter->attr.inherit_stat) - ctx->nr_stat--; - - list_del_init(&counter->list_entry); - list_del_rcu(&counter->event_entry); - - if (counter->group_leader != counter) - counter->group_leader->nr_siblings--; - - /* - * If this was a group counter with sibling counters then - * upgrade the siblings to singleton counters by adding them - * to the context list directly: - */ - list_for_each_entry_safe(sibling, tmp, - &counter->sibling_list, list_entry) { - - list_move_tail(&sibling->list_entry, &ctx->counter_list); - sibling->group_leader = sibling; - } -} - -static void -counter_sched_out(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx) -{ - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - return; - - counter->state = PERF_COUNTER_STATE_INACTIVE; - if (counter->pending_disable) { - counter->pending_disable = 0; - counter->state = PERF_COUNTER_STATE_OFF; - } - counter->tstamp_stopped = ctx->time; - counter->pmu->disable(counter); - counter->oncpu = -1; - - if (!is_software_counter(counter)) - cpuctx->active_oncpu--; - ctx->nr_active--; - if (counter->attr.exclusive || !cpuctx->active_oncpu) - cpuctx->exclusive = 0; -} - -static void -group_sched_out(struct perf_counter *group_counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx) -{ - struct perf_counter *counter; - - if (group_counter->state != PERF_COUNTER_STATE_ACTIVE) - return; - - counter_sched_out(group_counter, cpuctx, ctx); - - /* - * Schedule out siblings (if any): - */ - list_for_each_entry(counter, &group_counter->sibling_list, list_entry) - counter_sched_out(counter, cpuctx, ctx); - - if (group_counter->attr.exclusive) - cpuctx->exclusive = 0; -} - -/* - * Cross CPU call to remove a performance counter - * - * We disable the counter on the hardware level first. After that we - * remove it from the context list. - */ -static void __perf_counter_remove_from_context(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter *counter = info; - struct perf_counter_context *ctx = counter->ctx; - - /* - * If this is a task context, we need to check whether it is - * the current task context of this cpu. If not it has been - * scheduled out before the smp call arrived. - */ - if (ctx->task && cpuctx->task_ctx != ctx) - return; - - spin_lock(&ctx->lock); - /* - * Protect the list operation against NMI by disabling the - * counters on a global level. - */ - perf_disable(); - - counter_sched_out(counter, cpuctx, ctx); - - list_del_counter(counter, ctx); - - if (!ctx->task) { - /* - * Allow more per task counters with respect to the - * reservation: - */ - cpuctx->max_pertask = - min(perf_max_counters - ctx->nr_counters, - perf_max_counters - perf_reserved_percpu); - } - - perf_enable(); - spin_unlock(&ctx->lock); -} - - -/* - * Remove the counter from a task's (or a CPU's) list of counters. - * - * Must be called with ctx->mutex held. - * - * CPU counters are removed with a smp call. For task counters we only - * call when the task is on a CPU. - * - * If counter->ctx is a cloned context, callers must make sure that - * every task struct that counter->ctx->task could possibly point to - * remains valid. This is OK when called from perf_release since - * that only calls us on the top-level context, which can't be a clone. - * When called from perf_counter_exit_task, it's OK because the - * context has been detached from its task. - */ -static void perf_counter_remove_from_context(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Per cpu counters are removed via an smp call and - * the removal is always sucessful. - */ - smp_call_function_single(counter->cpu, - __perf_counter_remove_from_context, - counter, 1); - return; - } - -retry: - task_oncpu_function_call(task, __perf_counter_remove_from_context, - counter); - - spin_lock_irq(&ctx->lock); - /* - * If the context is active we need to retry the smp call. - */ - if (ctx->nr_active && !list_empty(&counter->list_entry)) { - spin_unlock_irq(&ctx->lock); - goto retry; - } - - /* - * The lock prevents that this context is scheduled in so we - * can remove the counter safely, if the call above did not - * succeed. - */ - if (!list_empty(&counter->list_entry)) { - list_del_counter(counter, ctx); - } - spin_unlock_irq(&ctx->lock); -} - -static inline u64 perf_clock(void) -{ - return cpu_clock(smp_processor_id()); -} - -/* - * Update the record of the current time in a context. - */ -static void update_context_time(struct perf_counter_context *ctx) -{ - u64 now = perf_clock(); - - ctx->time += now - ctx->timestamp; - ctx->timestamp = now; -} - -/* - * Update the total_time_enabled and total_time_running fields for a counter. - */ -static void update_counter_times(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - u64 run_end; - - if (counter->state < PERF_COUNTER_STATE_INACTIVE || - counter->group_leader->state < PERF_COUNTER_STATE_INACTIVE) - return; - - counter->total_time_enabled = ctx->time - counter->tstamp_enabled; - - if (counter->state == PERF_COUNTER_STATE_INACTIVE) - run_end = counter->tstamp_stopped; - else - run_end = ctx->time; - - counter->total_time_running = run_end - counter->tstamp_running; -} - -/* - * Update total_time_enabled and total_time_running for all counters in a group. - */ -static void update_group_times(struct perf_counter *leader) -{ - struct perf_counter *counter; - - update_counter_times(leader); - list_for_each_entry(counter, &leader->sibling_list, list_entry) - update_counter_times(counter); -} - -/* - * Cross CPU call to disable a performance counter - */ -static void __perf_counter_disable(void *info) -{ - struct perf_counter *counter = info; - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter_context *ctx = counter->ctx; - - /* - * If this is a per-task counter, need to check whether this - * counter's task is the current task on this cpu. - */ - if (ctx->task && cpuctx->task_ctx != ctx) - return; - - spin_lock(&ctx->lock); - - /* - * If the counter is on, turn it off. - * If it is in error state, leave it in error state. - */ - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) { - update_context_time(ctx); - update_group_times(counter); - if (counter == counter->group_leader) - group_sched_out(counter, cpuctx, ctx); - else - counter_sched_out(counter, cpuctx, ctx); - counter->state = PERF_COUNTER_STATE_OFF; - } - - spin_unlock(&ctx->lock); -} - -/* - * Disable a counter. - * - * If counter->ctx is a cloned context, callers must make sure that - * every task struct that counter->ctx->task could possibly point to - * remains valid. This condition is satisifed when called through - * perf_counter_for_each_child or perf_counter_for_each because they - * hold the top-level counter's child_mutex, so any descendant that - * goes to exit will block in sync_child_counter. - * When called from perf_pending_counter it's OK because counter->ctx - * is the current context on this CPU and preemption is disabled, - * hence we can't get into perf_counter_task_sched_out for this context. - */ -static void perf_counter_disable(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Disable the counter on the cpu that it's on - */ - smp_call_function_single(counter->cpu, __perf_counter_disable, - counter, 1); - return; - } - - retry: - task_oncpu_function_call(task, __perf_counter_disable, counter); - - spin_lock_irq(&ctx->lock); - /* - * If the counter is still active, we need to retry the cross-call. - */ - if (counter->state == PERF_COUNTER_STATE_ACTIVE) { - spin_unlock_irq(&ctx->lock); - goto retry; - } - - /* - * Since we have the lock this context can't be scheduled - * in, so we can change the state safely. - */ - if (counter->state == PERF_COUNTER_STATE_INACTIVE) { - update_group_times(counter); - counter->state = PERF_COUNTER_STATE_OFF; - } - - spin_unlock_irq(&ctx->lock); -} - -static int -counter_sched_in(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx, - int cpu) -{ - if (counter->state <= PERF_COUNTER_STATE_OFF) - return 0; - - counter->state = PERF_COUNTER_STATE_ACTIVE; - counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ - /* - * The new state must be visible before we turn it on in the hardware: - */ - smp_wmb(); - - if (counter->pmu->enable(counter)) { - counter->state = PERF_COUNTER_STATE_INACTIVE; - counter->oncpu = -1; - return -EAGAIN; - } - - counter->tstamp_running += ctx->time - counter->tstamp_stopped; - - if (!is_software_counter(counter)) - cpuctx->active_oncpu++; - ctx->nr_active++; - - if (counter->attr.exclusive) - cpuctx->exclusive = 1; - - return 0; -} - -static int -group_sched_in(struct perf_counter *group_counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx, - int cpu) -{ - struct perf_counter *counter, *partial_group; - int ret; - - if (group_counter->state == PERF_COUNTER_STATE_OFF) - return 0; - - ret = hw_perf_group_sched_in(group_counter, cpuctx, ctx, cpu); - if (ret) - return ret < 0 ? ret : 0; - - if (counter_sched_in(group_counter, cpuctx, ctx, cpu)) - return -EAGAIN; - - /* - * Schedule in siblings as one group (if any): - */ - list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { - if (counter_sched_in(counter, cpuctx, ctx, cpu)) { - partial_group = counter; - goto group_error; - } - } - - return 0; - -group_error: - /* - * Groups can be scheduled in as one unit only, so undo any - * partial group before returning: - */ - list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { - if (counter == partial_group) - break; - counter_sched_out(counter, cpuctx, ctx); - } - counter_sched_out(group_counter, cpuctx, ctx); - - return -EAGAIN; -} - -/* - * Return 1 for a group consisting entirely of software counters, - * 0 if the group contains any hardware counters. - */ -static int is_software_only_group(struct perf_counter *leader) -{ - struct perf_counter *counter; - - if (!is_software_counter(leader)) - return 0; - - list_for_each_entry(counter, &leader->sibling_list, list_entry) - if (!is_software_counter(counter)) - return 0; - - return 1; -} - -/* - * Work out whether we can put this counter group on the CPU now. - */ -static int group_can_go_on(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - int can_add_hw) -{ - /* - * Groups consisting entirely of software counters can always go on. - */ - if (is_software_only_group(counter)) - return 1; - /* - * If an exclusive group is already on, no other hardware - * counters can go on. - */ - if (cpuctx->exclusive) - return 0; - /* - * If this group is exclusive and there are already - * counters on the CPU, it can't go on. - */ - if (counter->attr.exclusive && cpuctx->active_oncpu) - return 0; - /* - * Otherwise, try to add it if all previous groups were able - * to go on. - */ - return can_add_hw; -} - -static void add_counter_to_ctx(struct perf_counter *counter, - struct perf_counter_context *ctx) -{ - list_add_counter(counter, ctx); - counter->tstamp_enabled = ctx->time; - counter->tstamp_running = ctx->time; - counter->tstamp_stopped = ctx->time; -} - -/* - * Cross CPU call to install and enable a performance counter - * - * Must be called with ctx->mutex held - */ -static void __perf_install_in_context(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter *counter = info; - struct perf_counter_context *ctx = counter->ctx; - struct perf_counter *leader = counter->group_leader; - int cpu = smp_processor_id(); - int err; - - /* - * If this is a task context, we need to check whether it is - * the current task context of this cpu. If not it has been - * scheduled out before the smp call arrived. - * Or possibly this is the right context but it isn't - * on this cpu because it had no counters. - */ - if (ctx->task && cpuctx->task_ctx != ctx) { - if (cpuctx->task_ctx || ctx->task != current) - return; - cpuctx->task_ctx = ctx; - } - - spin_lock(&ctx->lock); - ctx->is_active = 1; - update_context_time(ctx); - - /* - * Protect the list operation against NMI by disabling the - * counters on a global level. NOP for non NMI based counters. - */ - perf_disable(); - - add_counter_to_ctx(counter, ctx); - - /* - * Don't put the counter on if it is disabled or if - * it is in a group and the group isn't on. - */ - if (counter->state != PERF_COUNTER_STATE_INACTIVE || - (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE)) - goto unlock; - - /* - * An exclusive counter can't go on if there are already active - * hardware counters, and no hardware counter can go on if there - * is already an exclusive counter on. - */ - if (!group_can_go_on(counter, cpuctx, 1)) - err = -EEXIST; - else - err = counter_sched_in(counter, cpuctx, ctx, cpu); - - if (err) { - /* - * This counter couldn't go on. If it is in a group - * then we have to pull the whole group off. - * If the counter group is pinned then put it in error state. - */ - if (leader != counter) - group_sched_out(leader, cpuctx, ctx); - if (leader->attr.pinned) { - update_group_times(leader); - leader->state = PERF_COUNTER_STATE_ERROR; - } - } - - if (!err && !ctx->task && cpuctx->max_pertask) - cpuctx->max_pertask--; - - unlock: - perf_enable(); - - spin_unlock(&ctx->lock); -} - -/* - * Attach a performance counter to a context - * - * First we add the counter to the list with the hardware enable bit - * in counter->hw_config cleared. - * - * If the counter is attached to a task which is on a CPU we use a smp - * call to enable it in the task context. The task might have been - * scheduled away, but we check this in the smp call again. - * - * Must be called with ctx->mutex held. - */ -static void -perf_install_in_context(struct perf_counter_context *ctx, - struct perf_counter *counter, - int cpu) -{ - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Per cpu counters are installed via an smp call and - * the install is always sucessful. - */ - smp_call_function_single(cpu, __perf_install_in_context, - counter, 1); - return; - } - -retry: - task_oncpu_function_call(task, __perf_install_in_context, - counter); - - spin_lock_irq(&ctx->lock); - /* - * we need to retry the smp call. - */ - if (ctx->is_active && list_empty(&counter->list_entry)) { - spin_unlock_irq(&ctx->lock); - goto retry; - } - - /* - * The lock prevents that this context is scheduled in so we - * can add the counter safely, if it the call above did not - * succeed. - */ - if (list_empty(&counter->list_entry)) - add_counter_to_ctx(counter, ctx); - spin_unlock_irq(&ctx->lock); -} - -/* - * Put a counter into inactive state and update time fields. - * Enabling the leader of a group effectively enables all - * the group members that aren't explicitly disabled, so we - * have to update their ->tstamp_enabled also. - * Note: this works for group members as well as group leaders - * since the non-leader members' sibling_lists will be empty. - */ -static void __perf_counter_mark_enabled(struct perf_counter *counter, - struct perf_counter_context *ctx) -{ - struct perf_counter *sub; - - counter->state = PERF_COUNTER_STATE_INACTIVE; - counter->tstamp_enabled = ctx->time - counter->total_time_enabled; - list_for_each_entry(sub, &counter->sibling_list, list_entry) - if (sub->state >= PERF_COUNTER_STATE_INACTIVE) - sub->tstamp_enabled = - ctx->time - sub->total_time_enabled; -} - -/* - * Cross CPU call to enable a performance counter - */ -static void __perf_counter_enable(void *info) -{ - struct perf_counter *counter = info; - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter_context *ctx = counter->ctx; - struct perf_counter *leader = counter->group_leader; - int err; - - /* - * If this is a per-task counter, need to check whether this - * counter's task is the current task on this cpu. - */ - if (ctx->task && cpuctx->task_ctx != ctx) { - if (cpuctx->task_ctx || ctx->task != current) - return; - cpuctx->task_ctx = ctx; - } - - spin_lock(&ctx->lock); - ctx->is_active = 1; - update_context_time(ctx); - - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) - goto unlock; - __perf_counter_mark_enabled(counter, ctx); - - /* - * If the counter is in a group and isn't the group leader, - * then don't put it on unless the group is on. - */ - if (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE) - goto unlock; - - if (!group_can_go_on(counter, cpuctx, 1)) { - err = -EEXIST; - } else { - perf_disable(); - if (counter == leader) - err = group_sched_in(counter, cpuctx, ctx, - smp_processor_id()); - else - err = counter_sched_in(counter, cpuctx, ctx, - smp_processor_id()); - perf_enable(); - } - - if (err) { - /* - * If this counter can't go on and it's part of a - * group, then the whole group has to come off. - */ - if (leader != counter) - group_sched_out(leader, cpuctx, ctx); - if (leader->attr.pinned) { - update_group_times(leader); - leader->state = PERF_COUNTER_STATE_ERROR; - } - } - - unlock: - spin_unlock(&ctx->lock); -} - -/* - * Enable a counter. - * - * If counter->ctx is a cloned context, callers must make sure that - * every task struct that counter->ctx->task could possibly point to - * remains valid. This condition is satisfied when called through - * perf_counter_for_each_child or perf_counter_for_each as described - * for perf_counter_disable. - */ -static void perf_counter_enable(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Enable the counter on the cpu that it's on - */ - smp_call_function_single(counter->cpu, __perf_counter_enable, - counter, 1); - return; - } - - spin_lock_irq(&ctx->lock); - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) - goto out; - - /* - * If the counter is in error state, clear that first. - * That way, if we see the counter in error state below, we - * know that it has gone back into error state, as distinct - * from the task having been scheduled away before the - * cross-call arrived. - */ - if (counter->state == PERF_COUNTER_STATE_ERROR) - counter->state = PERF_COUNTER_STATE_OFF; - - retry: - spin_unlock_irq(&ctx->lock); - task_oncpu_function_call(task, __perf_counter_enable, counter); - - spin_lock_irq(&ctx->lock); - - /* - * If the context is active and the counter is still off, - * we need to retry the cross-call. - */ - if (ctx->is_active && counter->state == PERF_COUNTER_STATE_OFF) - goto retry; - - /* - * Since we have the lock this context can't be scheduled - * in, so we can change the state safely. - */ - if (counter->state == PERF_COUNTER_STATE_OFF) - __perf_counter_mark_enabled(counter, ctx); - - out: - spin_unlock_irq(&ctx->lock); -} - -static int perf_counter_refresh(struct perf_counter *counter, int refresh) -{ - /* - * not supported on inherited counters - */ - if (counter->attr.inherit) - return -EINVAL; - - atomic_add(refresh, &counter->event_limit); - perf_counter_enable(counter); - - return 0; -} - -void __perf_counter_sched_out(struct perf_counter_context *ctx, - struct perf_cpu_context *cpuctx) -{ - struct perf_counter *counter; - - spin_lock(&ctx->lock); - ctx->is_active = 0; - if (likely(!ctx->nr_counters)) - goto out; - update_context_time(ctx); - - perf_disable(); - if (ctx->nr_active) { - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (counter != counter->group_leader) - counter_sched_out(counter, cpuctx, ctx); - else - group_sched_out(counter, cpuctx, ctx); - } - } - perf_enable(); - out: - spin_unlock(&ctx->lock); -} - -/* - * Test whether two contexts are equivalent, i.e. whether they - * have both been cloned from the same version of the same context - * and they both have the same number of enabled counters. - * If the number of enabled counters is the same, then the set - * of enabled counters should be the same, because these are both - * inherited contexts, therefore we can't access individual counters - * in them directly with an fd; we can only enable/disable all - * counters via prctl, or enable/disable all counters in a family - * via ioctl, which will have the same effect on both contexts. - */ -static int context_equiv(struct perf_counter_context *ctx1, - struct perf_counter_context *ctx2) -{ - return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx - && ctx1->parent_gen == ctx2->parent_gen - && !ctx1->pin_count && !ctx2->pin_count; -} - -static void __perf_counter_read(void *counter); - -static void __perf_counter_sync_stat(struct perf_counter *counter, - struct perf_counter *next_counter) -{ - u64 value; - - if (!counter->attr.inherit_stat) - return; - - /* - * Update the counter value, we cannot use perf_counter_read() - * because we're in the middle of a context switch and have IRQs - * disabled, which upsets smp_call_function_single(), however - * we know the counter must be on the current CPU, therefore we - * don't need to use it. - */ - switch (counter->state) { - case PERF_COUNTER_STATE_ACTIVE: - __perf_counter_read(counter); - break; - - case PERF_COUNTER_STATE_INACTIVE: - update_counter_times(counter); - break; - - default: - break; - } - - /* - * In order to keep per-task stats reliable we need to flip the counter - * values when we flip the contexts. - */ - value = atomic64_read(&next_counter->count); - value = atomic64_xchg(&counter->count, value); - atomic64_set(&next_counter->count, value); - - swap(counter->total_time_enabled, next_counter->total_time_enabled); - swap(counter->total_time_running, next_counter->total_time_running); - - /* - * Since we swizzled the values, update the user visible data too. - */ - perf_counter_update_userpage(counter); - perf_counter_update_userpage(next_counter); -} - -#define list_next_entry(pos, member) \ - list_entry(pos->member.next, typeof(*pos), member) - -static void perf_counter_sync_stat(struct perf_counter_context *ctx, - struct perf_counter_context *next_ctx) -{ - struct perf_counter *counter, *next_counter; - - if (!ctx->nr_stat) - return; - - counter = list_first_entry(&ctx->event_list, - struct perf_counter, event_entry); - - next_counter = list_first_entry(&next_ctx->event_list, - struct perf_counter, event_entry); - - while (&counter->event_entry != &ctx->event_list && - &next_counter->event_entry != &next_ctx->event_list) { - - __perf_counter_sync_stat(counter, next_counter); - - counter = list_next_entry(counter, event_entry); - next_counter = list_next_entry(next_counter, event_entry); - } -} - -/* - * Called from scheduler to remove the counters of the current task, - * with interrupts disabled. - * - * We stop each counter and update the counter value in counter->count. - * - * This does not protect us against NMI, but disable() - * sets the disabled bit in the control field of counter _before_ - * accessing the counter control register. If a NMI hits, then it will - * not restart the counter. - */ -void perf_counter_task_sched_out(struct task_struct *task, - struct task_struct *next, int cpu) -{ - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); - struct perf_counter_context *ctx = task->perf_counter_ctxp; - struct perf_counter_context *next_ctx; - struct perf_counter_context *parent; - struct pt_regs *regs; - int do_switch = 1; - - regs = task_pt_regs(task); - perf_swcounter_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0); - - if (likely(!ctx || !cpuctx->task_ctx)) - return; - - update_context_time(ctx); - - rcu_read_lock(); - parent = rcu_dereference(ctx->parent_ctx); - next_ctx = next->perf_counter_ctxp; - if (parent && next_ctx && - rcu_dereference(next_ctx->parent_ctx) == parent) { - /* - * Looks like the two contexts are clones, so we might be - * able to optimize the context switch. We lock both - * contexts and check that they are clones under the - * lock (including re-checking that neither has been - * uncloned in the meantime). It doesn't matter which - * order we take the locks because no other cpu could - * be trying to lock both of these tasks. - */ - spin_lock(&ctx->lock); - spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); - if (context_equiv(ctx, next_ctx)) { - /* - * XXX do we need a memory barrier of sorts - * wrt to rcu_dereference() of perf_counter_ctxp - */ - task->perf_counter_ctxp = next_ctx; - next->perf_counter_ctxp = ctx; - ctx->task = next; - next_ctx->task = task; - do_switch = 0; - - perf_counter_sync_stat(ctx, next_ctx); - } - spin_unlock(&next_ctx->lock); - spin_unlock(&ctx->lock); - } - rcu_read_unlock(); - - if (do_switch) { - __perf_counter_sched_out(ctx, cpuctx); - cpuctx->task_ctx = NULL; - } -} - -/* - * Called with IRQs disabled - */ -static void __perf_counter_task_sched_out(struct perf_counter_context *ctx) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - - if (!cpuctx->task_ctx) - return; - - if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) - return; - - __perf_counter_sched_out(ctx, cpuctx); - cpuctx->task_ctx = NULL; -} - -/* - * Called with IRQs disabled - */ -static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx) -{ - __perf_counter_sched_out(&cpuctx->ctx, cpuctx); -} - -static void -__perf_counter_sched_in(struct perf_counter_context *ctx, - struct perf_cpu_context *cpuctx, int cpu) -{ - struct perf_counter *counter; - int can_add_hw = 1; - - spin_lock(&ctx->lock); - ctx->is_active = 1; - if (likely(!ctx->nr_counters)) - goto out; - - ctx->timestamp = perf_clock(); - - perf_disable(); - - /* - * First go through the list and put on any pinned groups - * in order to give them the best chance of going on. - */ - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (counter->state <= PERF_COUNTER_STATE_OFF || - !counter->attr.pinned) - continue; - if (counter->cpu != -1 && counter->cpu != cpu) - continue; - - if (counter != counter->group_leader) - counter_sched_in(counter, cpuctx, ctx, cpu); - else { - if (group_can_go_on(counter, cpuctx, 1)) - group_sched_in(counter, cpuctx, ctx, cpu); - } - - /* - * If this pinned group hasn't been scheduled, - * put it in error state. - */ - if (counter->state == PERF_COUNTER_STATE_INACTIVE) { - update_group_times(counter); - counter->state = PERF_COUNTER_STATE_ERROR; - } - } - - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - /* - * Ignore counters in OFF or ERROR state, and - * ignore pinned counters since we did them already. - */ - if (counter->state <= PERF_COUNTER_STATE_OFF || - counter->attr.pinned) - continue; - - /* - * Listen to the 'cpu' scheduling filter constraint - * of counters: - */ - if (counter->cpu != -1 && counter->cpu != cpu) - continue; - - if (counter != counter->group_leader) { - if (counter_sched_in(counter, cpuctx, ctx, cpu)) - can_add_hw = 0; - } else { - if (group_can_go_on(counter, cpuctx, can_add_hw)) { - if (group_sched_in(counter, cpuctx, ctx, cpu)) - can_add_hw = 0; - } - } - } - perf_enable(); - out: - spin_unlock(&ctx->lock); -} - -/* - * Called from scheduler to add the counters of the current task - * with interrupts disabled. - * - * We restore the counter value and then enable it. - * - * This does not protect us against NMI, but enable() - * sets the enabled bit in the control field of counter _before_ - * accessing the counter control register. If a NMI hits, then it will - * keep the counter running. - */ -void perf_counter_task_sched_in(struct task_struct *task, int cpu) -{ - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); - struct perf_counter_context *ctx = task->perf_counter_ctxp; - - if (likely(!ctx)) - return; - if (cpuctx->task_ctx == ctx) - return; - __perf_counter_sched_in(ctx, cpuctx, cpu); - cpuctx->task_ctx = ctx; -} - -static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) -{ - struct perf_counter_context *ctx = &cpuctx->ctx; - - __perf_counter_sched_in(ctx, cpuctx, cpu); -} - -#define MAX_INTERRUPTS (~0ULL) - -static void perf_log_throttle(struct perf_counter *counter, int enable); - -static void perf_adjust_period(struct perf_counter *counter, u64 events) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 period, sample_period; - s64 delta; - - events *= hwc->sample_period; - period = div64_u64(events, counter->attr.sample_freq); - - delta = (s64)(period - hwc->sample_period); - delta = (delta + 7) / 8; /* low pass filter */ - - sample_period = hwc->sample_period + delta; - - if (!sample_period) - sample_period = 1; - - hwc->sample_period = sample_period; -} - -static void perf_ctx_adjust_freq(struct perf_counter_context *ctx) -{ - struct perf_counter *counter; - struct hw_perf_counter *hwc; - u64 interrupts, freq; - - spin_lock(&ctx->lock); - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - continue; - - hwc = &counter->hw; - - interrupts = hwc->interrupts; - hwc->interrupts = 0; - - /* - * unthrottle counters on the tick - */ - if (interrupts == MAX_INTERRUPTS) { - perf_log_throttle(counter, 1); - counter->pmu->unthrottle(counter); - interrupts = 2*sysctl_perf_counter_sample_rate/HZ; - } - - if (!counter->attr.freq || !counter->attr.sample_freq) - continue; - - /* - * if the specified freq < HZ then we need to skip ticks - */ - if (counter->attr.sample_freq < HZ) { - freq = counter->attr.sample_freq; - - hwc->freq_count += freq; - hwc->freq_interrupts += interrupts; - - if (hwc->freq_count < HZ) - continue; - - interrupts = hwc->freq_interrupts; - hwc->freq_interrupts = 0; - hwc->freq_count -= HZ; - } else - freq = HZ; - - perf_adjust_period(counter, freq * interrupts); - - /* - * In order to avoid being stalled by an (accidental) huge - * sample period, force reset the sample period if we didn't - * get any events in this freq period. - */ - if (!interrupts) { - perf_disable(); - counter->pmu->disable(counter); - atomic64_set(&hwc->period_left, 0); - counter->pmu->enable(counter); - perf_enable(); - } - } - spin_unlock(&ctx->lock); -} - -/* - * Round-robin a context's counters: - */ -static void rotate_ctx(struct perf_counter_context *ctx) -{ - struct perf_counter *counter; - - if (!ctx->nr_counters) - return; - - spin_lock(&ctx->lock); - /* - * Rotate the first entry last (works just fine for group counters too): - */ - perf_disable(); - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - list_move_tail(&counter->list_entry, &ctx->counter_list); - break; - } - perf_enable(); - - spin_unlock(&ctx->lock); -} - -void perf_counter_task_tick(struct task_struct *curr, int cpu) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx; - - if (!atomic_read(&nr_counters)) - return; - - cpuctx = &per_cpu(perf_cpu_context, cpu); - ctx = curr->perf_counter_ctxp; - - perf_ctx_adjust_freq(&cpuctx->ctx); - if (ctx) - perf_ctx_adjust_freq(ctx); - - perf_counter_cpu_sched_out(cpuctx); - if (ctx) - __perf_counter_task_sched_out(ctx); - - rotate_ctx(&cpuctx->ctx); - if (ctx) - rotate_ctx(ctx); - - perf_counter_cpu_sched_in(cpuctx, cpu); - if (ctx) - perf_counter_task_sched_in(curr, cpu); -} - -/* - * Enable all of a task's counters that have been marked enable-on-exec. - * This expects task == current. - */ -static void perf_counter_enable_on_exec(struct task_struct *task) -{ - struct perf_counter_context *ctx; - struct perf_counter *counter; - unsigned long flags; - int enabled = 0; - - local_irq_save(flags); - ctx = task->perf_counter_ctxp; - if (!ctx || !ctx->nr_counters) - goto out; - - __perf_counter_task_sched_out(ctx); - - spin_lock(&ctx->lock); - - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (!counter->attr.enable_on_exec) - continue; - counter->attr.enable_on_exec = 0; - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) - continue; - __perf_counter_mark_enabled(counter, ctx); - enabled = 1; - } - - /* - * Unclone this context if we enabled any counter. - */ - if (enabled) - unclone_ctx(ctx); - - spin_unlock(&ctx->lock); - - perf_counter_task_sched_in(task, smp_processor_id()); - out: - local_irq_restore(flags); -} - -/* - * Cross CPU call to read the hardware counter - */ -static void __perf_counter_read(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter *counter = info; - struct perf_counter_context *ctx = counter->ctx; - unsigned long flags; - - /* - * If this is a task context, we need to check whether it is - * the current task context of this cpu. If not it has been - * scheduled out before the smp call arrived. In that case - * counter->count would have been updated to a recent sample - * when the counter was scheduled out. - */ - if (ctx->task && cpuctx->task_ctx != ctx) - return; - - local_irq_save(flags); - if (ctx->is_active) - update_context_time(ctx); - counter->pmu->read(counter); - update_counter_times(counter); - local_irq_restore(flags); -} - -static u64 perf_counter_read(struct perf_counter *counter) -{ - /* - * If counter is enabled and currently active on a CPU, update the - * value in the counter structure: - */ - if (counter->state == PERF_COUNTER_STATE_ACTIVE) { - smp_call_function_single(counter->oncpu, - __perf_counter_read, counter, 1); - } else if (counter->state == PERF_COUNTER_STATE_INACTIVE) { - update_counter_times(counter); - } - - return atomic64_read(&counter->count); -} - -/* - * Initialize the perf_counter context in a task_struct: - */ -static void -__perf_counter_init_context(struct perf_counter_context *ctx, - struct task_struct *task) -{ - memset(ctx, 0, sizeof(*ctx)); - spin_lock_init(&ctx->lock); - mutex_init(&ctx->mutex); - INIT_LIST_HEAD(&ctx->counter_list); - INIT_LIST_HEAD(&ctx->event_list); - atomic_set(&ctx->refcount, 1); - ctx->task = task; -} - -static struct perf_counter_context *find_get_context(pid_t pid, int cpu) -{ - struct perf_counter_context *ctx; - struct perf_cpu_context *cpuctx; - struct task_struct *task; - unsigned long flags; - int err; - - /* - * If cpu is not a wildcard then this is a percpu counter: - */ - if (cpu != -1) { - /* Must be root to operate on a CPU counter: */ - if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) - return ERR_PTR(-EACCES); - - if (cpu < 0 || cpu > num_possible_cpus()) - return ERR_PTR(-EINVAL); - - /* - * We could be clever and allow to attach a counter to an - * offline CPU and activate it when the CPU comes up, but - * that's for later. - */ - if (!cpu_isset(cpu, cpu_online_map)) - return ERR_PTR(-ENODEV); - - cpuctx = &per_cpu(perf_cpu_context, cpu); - ctx = &cpuctx->ctx; - get_ctx(ctx); - - return ctx; - } - - rcu_read_lock(); - if (!pid) - task = current; - else - task = find_task_by_vpid(pid); - if (task) - get_task_struct(task); - rcu_read_unlock(); - - if (!task) - return ERR_PTR(-ESRCH); - - /* - * Can't attach counters to a dying task. - */ - err = -ESRCH; - if (task->flags & PF_EXITING) - goto errout; - - /* Reuse ptrace permission checks for now. */ - err = -EACCES; - if (!ptrace_may_access(task, PTRACE_MODE_READ)) - goto errout; - - retry: - ctx = perf_lock_task_context(task, &flags); - if (ctx) { - unclone_ctx(ctx); - spin_unlock_irqrestore(&ctx->lock, flags); - } - - if (!ctx) { - ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL); - err = -ENOMEM; - if (!ctx) - goto errout; - __perf_counter_init_context(ctx, task); - get_ctx(ctx); - if (cmpxchg(&task->perf_counter_ctxp, NULL, ctx)) { - /* - * We raced with some other task; use - * the context they set. - */ - kfree(ctx); - goto retry; - } - get_task_struct(task); - } - - put_task_struct(task); - return ctx; - - errout: - put_task_struct(task); - return ERR_PTR(err); -} - -static void free_counter_rcu(struct rcu_head *head) -{ - struct perf_counter *counter; - - counter = container_of(head, struct perf_counter, rcu_head); - if (counter->ns) - put_pid_ns(counter->ns); - kfree(counter); -} - -static void perf_pending_sync(struct perf_counter *counter); - -static void free_counter(struct perf_counter *counter) -{ - perf_pending_sync(counter); - - if (!counter->parent) { - atomic_dec(&nr_counters); - if (counter->attr.mmap) - atomic_dec(&nr_mmap_counters); - if (counter->attr.comm) - atomic_dec(&nr_comm_counters); - if (counter->attr.task) - atomic_dec(&nr_task_counters); - } - - if (counter->output) { - fput(counter->output->filp); - counter->output = NULL; - } - - if (counter->destroy) - counter->destroy(counter); - - put_ctx(counter->ctx); - call_rcu(&counter->rcu_head, free_counter_rcu); -} - -/* - * Called when the last reference to the file is gone. - */ -static int perf_release(struct inode *inode, struct file *file) -{ - struct perf_counter *counter = file->private_data; - struct perf_counter_context *ctx = counter->ctx; - - file->private_data = NULL; - - WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - perf_counter_remove_from_context(counter); - mutex_unlock(&ctx->mutex); - - mutex_lock(&counter->owner->perf_counter_mutex); - list_del_init(&counter->owner_entry); - mutex_unlock(&counter->owner->perf_counter_mutex); - put_task_struct(counter->owner); - - free_counter(counter); - - return 0; -} - -static int perf_counter_read_size(struct perf_counter *counter) -{ - int entry = sizeof(u64); /* value */ - int size = 0; - int nr = 1; - - if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) - size += sizeof(u64); - - if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) - size += sizeof(u64); - - if (counter->attr.read_format & PERF_FORMAT_ID) - entry += sizeof(u64); - - if (counter->attr.read_format & PERF_FORMAT_GROUP) { - nr += counter->group_leader->nr_siblings; - size += sizeof(u64); - } - - size += entry * nr; - - return size; -} - -static u64 perf_counter_read_value(struct perf_counter *counter) -{ - struct perf_counter *child; - u64 total = 0; - - total += perf_counter_read(counter); - list_for_each_entry(child, &counter->child_list, child_list) - total += perf_counter_read(child); - - return total; -} - -static int perf_counter_read_entry(struct perf_counter *counter, - u64 read_format, char __user *buf) -{ - int n = 0, count = 0; - u64 values[2]; - - values[n++] = perf_counter_read_value(counter); - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(counter); - - count = n * sizeof(u64); - - if (copy_to_user(buf, values, count)) - return -EFAULT; - - return count; -} - -static int perf_counter_read_group(struct perf_counter *counter, - u64 read_format, char __user *buf) -{ - struct perf_counter *leader = counter->group_leader, *sub; - int n = 0, size = 0, err = -EFAULT; - u64 values[3]; - - values[n++] = 1 + leader->nr_siblings; - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { - values[n++] = leader->total_time_enabled + - atomic64_read(&leader->child_total_time_enabled); - } - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { - values[n++] = leader->total_time_running + - atomic64_read(&leader->child_total_time_running); - } - - size = n * sizeof(u64); - - if (copy_to_user(buf, values, size)) - return -EFAULT; - - err = perf_counter_read_entry(leader, read_format, buf + size); - if (err < 0) - return err; - - size += err; - - list_for_each_entry(sub, &leader->sibling_list, list_entry) { - err = perf_counter_read_entry(sub, read_format, - buf + size); - if (err < 0) - return err; - - size += err; - } - - return size; -} - -static int perf_counter_read_one(struct perf_counter *counter, - u64 read_format, char __user *buf) -{ - u64 values[4]; - int n = 0; - - values[n++] = perf_counter_read_value(counter); - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { - values[n++] = counter->total_time_enabled + - atomic64_read(&counter->child_total_time_enabled); - } - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { - values[n++] = counter->total_time_running + - atomic64_read(&counter->child_total_time_running); - } - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(counter); - - if (copy_to_user(buf, values, n * sizeof(u64))) - return -EFAULT; - - return n * sizeof(u64); -} - -/* - * Read the performance counter - simple non blocking version for now - */ -static ssize_t -perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) -{ - u64 read_format = counter->attr.read_format; - int ret; - - /* - * Return end-of-file for a read on a counter that is in - * error state (i.e. because it was pinned but it couldn't be - * scheduled on to the CPU at some point). - */ - if (counter->state == PERF_COUNTER_STATE_ERROR) - return 0; - - if (count < perf_counter_read_size(counter)) - return -ENOSPC; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - mutex_lock(&counter->child_mutex); - if (read_format & PERF_FORMAT_GROUP) - ret = perf_counter_read_group(counter, read_format, buf); - else - ret = perf_counter_read_one(counter, read_format, buf); - mutex_unlock(&counter->child_mutex); - - return ret; -} - -static ssize_t -perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) -{ - struct perf_counter *counter = file->private_data; - - return perf_read_hw(counter, buf, count); -} - -static unsigned int perf_poll(struct file *file, poll_table *wait) -{ - struct perf_counter *counter = file->private_data; - struct perf_mmap_data *data; - unsigned int events = POLL_HUP; - - rcu_read_lock(); - data = rcu_dereference(counter->data); - if (data) - events = atomic_xchg(&data->poll, 0); - rcu_read_unlock(); - - poll_wait(file, &counter->waitq, wait); - - return events; -} - -static void perf_counter_reset(struct perf_counter *counter) -{ - (void)perf_counter_read(counter); - atomic64_set(&counter->count, 0); - perf_counter_update_userpage(counter); -} - -/* - * Holding the top-level counter's child_mutex means that any - * descendant process that has inherited this counter will block - * in sync_child_counter if it goes to exit, thus satisfying the - * task existence requirements of perf_counter_enable/disable. - */ -static void perf_counter_for_each_child(struct perf_counter *counter, - void (*func)(struct perf_counter *)) -{ - struct perf_counter *child; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - mutex_lock(&counter->child_mutex); - func(counter); - list_for_each_entry(child, &counter->child_list, child_list) - func(child); - mutex_unlock(&counter->child_mutex); -} - -static void perf_counter_for_each(struct perf_counter *counter, - void (*func)(struct perf_counter *)) -{ - struct perf_counter_context *ctx = counter->ctx; - struct perf_counter *sibling; - - WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - counter = counter->group_leader; - - perf_counter_for_each_child(counter, func); - func(counter); - list_for_each_entry(sibling, &counter->sibling_list, list_entry) - perf_counter_for_each_child(counter, func); - mutex_unlock(&ctx->mutex); -} - -static int perf_counter_period(struct perf_counter *counter, u64 __user *arg) -{ - struct perf_counter_context *ctx = counter->ctx; - unsigned long size; - int ret = 0; - u64 value; - - if (!counter->attr.sample_period) - return -EINVAL; - - size = copy_from_user(&value, arg, sizeof(value)); - if (size != sizeof(value)) - return -EFAULT; - - if (!value) - return -EINVAL; - - spin_lock_irq(&ctx->lock); - if (counter->attr.freq) { - if (value > sysctl_perf_counter_sample_rate) { - ret = -EINVAL; - goto unlock; - } - - counter->attr.sample_freq = value; - } else { - counter->attr.sample_period = value; - counter->hw.sample_period = value; - } -unlock: - spin_unlock_irq(&ctx->lock); - - return ret; -} - -int perf_counter_set_output(struct perf_counter *counter, int output_fd); - -static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) -{ - struct perf_counter *counter = file->private_data; - void (*func)(struct perf_counter *); - u32 flags = arg; - - switch (cmd) { - case PERF_COUNTER_IOC_ENABLE: - func = perf_counter_enable; - break; - case PERF_COUNTER_IOC_DISABLE: - func = perf_counter_disable; - break; - case PERF_COUNTER_IOC_RESET: - func = perf_counter_reset; - break; - - case PERF_COUNTER_IOC_REFRESH: - return perf_counter_refresh(counter, arg); - - case PERF_COUNTER_IOC_PERIOD: - return perf_counter_period(counter, (u64 __user *)arg); - - case PERF_COUNTER_IOC_SET_OUTPUT: - return perf_counter_set_output(counter, arg); - - default: - return -ENOTTY; - } - - if (flags & PERF_IOC_FLAG_GROUP) - perf_counter_for_each(counter, func); - else - perf_counter_for_each_child(counter, func); - - return 0; -} - -int perf_counter_task_enable(void) -{ - struct perf_counter *counter; - - mutex_lock(¤t->perf_counter_mutex); - list_for_each_entry(counter, ¤t->perf_counter_list, owner_entry) - perf_counter_for_each_child(counter, perf_counter_enable); - mutex_unlock(¤t->perf_counter_mutex); - - return 0; -} - -int perf_counter_task_disable(void) -{ - struct perf_counter *counter; - - mutex_lock(¤t->perf_counter_mutex); - list_for_each_entry(counter, ¤t->perf_counter_list, owner_entry) - perf_counter_for_each_child(counter, perf_counter_disable); - mutex_unlock(¤t->perf_counter_mutex); - - return 0; -} - -#ifndef PERF_COUNTER_INDEX_OFFSET -# define PERF_COUNTER_INDEX_OFFSET 0 -#endif - -static int perf_counter_index(struct perf_counter *counter) -{ - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - return 0; - - return counter->hw.idx + 1 - PERF_COUNTER_INDEX_OFFSET; -} - -/* - * Callers need to ensure there can be no nesting of this function, otherwise - * the seqlock logic goes bad. We can not serialize this because the arch - * code calls this from NMI context. - */ -void perf_counter_update_userpage(struct perf_counter *counter) -{ - struct perf_counter_mmap_page *userpg; - struct perf_mmap_data *data; - - rcu_read_lock(); - data = rcu_dereference(counter->data); - if (!data) - goto unlock; - - userpg = data->user_page; - - /* - * Disable preemption so as to not let the corresponding user-space - * spin too long if we get preempted. - */ - preempt_disable(); - ++userpg->lock; - barrier(); - userpg->index = perf_counter_index(counter); - userpg->offset = atomic64_read(&counter->count); - if (counter->state == PERF_COUNTER_STATE_ACTIVE) - userpg->offset -= atomic64_read(&counter->hw.prev_count); - - userpg->time_enabled = counter->total_time_enabled + - atomic64_read(&counter->child_total_time_enabled); - - userpg->time_running = counter->total_time_running + - atomic64_read(&counter->child_total_time_running); - - barrier(); - ++userpg->lock; - preempt_enable(); -unlock: - rcu_read_unlock(); -} - -static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - struct perf_counter *counter = vma->vm_file->private_data; - struct perf_mmap_data *data; - int ret = VM_FAULT_SIGBUS; - - if (vmf->flags & FAULT_FLAG_MKWRITE) { - if (vmf->pgoff == 0) - ret = 0; - return ret; - } - - rcu_read_lock(); - data = rcu_dereference(counter->data); - if (!data) - goto unlock; - - if (vmf->pgoff == 0) { - vmf->page = virt_to_page(data->user_page); - } else { - int nr = vmf->pgoff - 1; - - if ((unsigned)nr > data->nr_pages) - goto unlock; - - if (vmf->flags & FAULT_FLAG_WRITE) - goto unlock; - - vmf->page = virt_to_page(data->data_pages[nr]); - } - - get_page(vmf->page); - vmf->page->mapping = vma->vm_file->f_mapping; - vmf->page->index = vmf->pgoff; - - ret = 0; -unlock: - rcu_read_unlock(); - - return ret; -} - -static int perf_mmap_data_alloc(struct perf_counter *counter, int nr_pages) -{ - struct perf_mmap_data *data; - unsigned long size; - int i; - - WARN_ON(atomic_read(&counter->mmap_count)); - - size = sizeof(struct perf_mmap_data); - size += nr_pages * sizeof(void *); - - data = kzalloc(size, GFP_KERNEL); - if (!data) - goto fail; - - data->user_page = (void *)get_zeroed_page(GFP_KERNEL); - if (!data->user_page) - goto fail_user_page; - - for (i = 0; i < nr_pages; i++) { - data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL); - if (!data->data_pages[i]) - goto fail_data_pages; - } - - data->nr_pages = nr_pages; - atomic_set(&data->lock, -1); - - rcu_assign_pointer(counter->data, data); - - return 0; - -fail_data_pages: - for (i--; i >= 0; i--) - free_page((unsigned long)data->data_pages[i]); - - free_page((unsigned long)data->user_page); - -fail_user_page: - kfree(data); - -fail: - return -ENOMEM; -} - -static void perf_mmap_free_page(unsigned long addr) -{ - struct page *page = virt_to_page((void *)addr); - - page->mapping = NULL; - __free_page(page); -} - -static void __perf_mmap_data_free(struct rcu_head *rcu_head) -{ - struct perf_mmap_data *data; - int i; - - data = container_of(rcu_head, struct perf_mmap_data, rcu_head); - - perf_mmap_free_page((unsigned long)data->user_page); - for (i = 0; i < data->nr_pages; i++) - perf_mmap_free_page((unsigned long)data->data_pages[i]); - - kfree(data); -} - -static void perf_mmap_data_free(struct perf_counter *counter) -{ - struct perf_mmap_data *data = counter->data; - - WARN_ON(atomic_read(&counter->mmap_count)); - - rcu_assign_pointer(counter->data, NULL); - call_rcu(&data->rcu_head, __perf_mmap_data_free); -} - -static void perf_mmap_open(struct vm_area_struct *vma) -{ - struct perf_counter *counter = vma->vm_file->private_data; - - atomic_inc(&counter->mmap_count); -} - -static void perf_mmap_close(struct vm_area_struct *vma) -{ - struct perf_counter *counter = vma->vm_file->private_data; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - if (atomic_dec_and_mutex_lock(&counter->mmap_count, &counter->mmap_mutex)) { - struct user_struct *user = current_user(); - - atomic_long_sub(counter->data->nr_pages + 1, &user->locked_vm); - vma->vm_mm->locked_vm -= counter->data->nr_locked; - perf_mmap_data_free(counter); - mutex_unlock(&counter->mmap_mutex); - } -} - -static struct vm_operations_struct perf_mmap_vmops = { - .open = perf_mmap_open, - .close = perf_mmap_close, - .fault = perf_mmap_fault, - .page_mkwrite = perf_mmap_fault, -}; - -static int perf_mmap(struct file *file, struct vm_area_struct *vma) -{ - struct perf_counter *counter = file->private_data; - unsigned long user_locked, user_lock_limit; - struct user_struct *user = current_user(); - unsigned long locked, lock_limit; - unsigned long vma_size; - unsigned long nr_pages; - long user_extra, extra; - int ret = 0; - - if (!(vma->vm_flags & VM_SHARED)) - return -EINVAL; - - vma_size = vma->vm_end - vma->vm_start; - nr_pages = (vma_size / PAGE_SIZE) - 1; - - /* - * If we have data pages ensure they're a power-of-two number, so we - * can do bitmasks instead of modulo. - */ - if (nr_pages != 0 && !is_power_of_2(nr_pages)) - return -EINVAL; - - if (vma_size != PAGE_SIZE * (1 + nr_pages)) - return -EINVAL; - - if (vma->vm_pgoff != 0) - return -EINVAL; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - mutex_lock(&counter->mmap_mutex); - if (counter->output) { - ret = -EINVAL; - goto unlock; - } - - if (atomic_inc_not_zero(&counter->mmap_count)) { - if (nr_pages != counter->data->nr_pages) - ret = -EINVAL; - goto unlock; - } - - user_extra = nr_pages + 1; - user_lock_limit = sysctl_perf_counter_mlock >> (PAGE_SHIFT - 10); - - /* - * Increase the limit linearly with more CPUs: - */ - user_lock_limit *= num_online_cpus(); - - user_locked = atomic_long_read(&user->locked_vm) + user_extra; - - extra = 0; - if (user_locked > user_lock_limit) - extra = user_locked - user_lock_limit; - - lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; - lock_limit >>= PAGE_SHIFT; - locked = vma->vm_mm->locked_vm + extra; - - if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { - ret = -EPERM; - goto unlock; - } - - WARN_ON(counter->data); - ret = perf_mmap_data_alloc(counter, nr_pages); - if (ret) - goto unlock; - - atomic_set(&counter->mmap_count, 1); - atomic_long_add(user_extra, &user->locked_vm); - vma->vm_mm->locked_vm += extra; - counter->data->nr_locked = extra; - if (vma->vm_flags & VM_WRITE) - counter->data->writable = 1; - -unlock: - mutex_unlock(&counter->mmap_mutex); - - vma->vm_flags |= VM_RESERVED; - vma->vm_ops = &perf_mmap_vmops; - - return ret; -} - -static int perf_fasync(int fd, struct file *filp, int on) -{ - struct inode *inode = filp->f_path.dentry->d_inode; - struct perf_counter *counter = filp->private_data; - int retval; - - mutex_lock(&inode->i_mutex); - retval = fasync_helper(fd, filp, on, &counter->fasync); - mutex_unlock(&inode->i_mutex); - - if (retval < 0) - return retval; - - return 0; -} - -static const struct file_operations perf_fops = { - .release = perf_release, - .read = perf_read, - .poll = perf_poll, - .unlocked_ioctl = perf_ioctl, - .compat_ioctl = perf_ioctl, - .mmap = perf_mmap, - .fasync = perf_fasync, -}; - -/* - * Perf counter wakeup - * - * If there's data, ensure we set the poll() state and publish everything - * to user-space before waking everybody up. - */ - -void perf_counter_wakeup(struct perf_counter *counter) -{ - wake_up_all(&counter->waitq); - - if (counter->pending_kill) { - kill_fasync(&counter->fasync, SIGIO, counter->pending_kill); - counter->pending_kill = 0; - } -} - -/* - * Pending wakeups - * - * Handle the case where we need to wakeup up from NMI (or rq->lock) context. - * - * The NMI bit means we cannot possibly take locks. Therefore, maintain a - * single linked list and use cmpxchg() to add entries lockless. - */ - -static void perf_pending_counter(struct perf_pending_entry *entry) -{ - struct perf_counter *counter = container_of(entry, - struct perf_counter, pending); - - if (counter->pending_disable) { - counter->pending_disable = 0; - __perf_counter_disable(counter); - } - - if (counter->pending_wakeup) { - counter->pending_wakeup = 0; - perf_counter_wakeup(counter); - } -} - -#define PENDING_TAIL ((struct perf_pending_entry *)-1UL) - -static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = { - PENDING_TAIL, -}; - -static void perf_pending_queue(struct perf_pending_entry *entry, - void (*func)(struct perf_pending_entry *)) -{ - struct perf_pending_entry **head; - - if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL) - return; - - entry->func = func; - - head = &get_cpu_var(perf_pending_head); - - do { - entry->next = *head; - } while (cmpxchg(head, entry->next, entry) != entry->next); - - set_perf_counter_pending(); - - put_cpu_var(perf_pending_head); -} - -static int __perf_pending_run(void) -{ - struct perf_pending_entry *list; - int nr = 0; - - list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL); - while (list != PENDING_TAIL) { - void (*func)(struct perf_pending_entry *); - struct perf_pending_entry *entry = list; - - list = list->next; - - func = entry->func; - entry->next = NULL; - /* - * Ensure we observe the unqueue before we issue the wakeup, - * so that we won't be waiting forever. - * -- see perf_not_pending(). - */ - smp_wmb(); - - func(entry); - nr++; - } - - return nr; -} - -static inline int perf_not_pending(struct perf_counter *counter) -{ - /* - * If we flush on whatever cpu we run, there is a chance we don't - * need to wait. - */ - get_cpu(); - __perf_pending_run(); - put_cpu(); - - /* - * Ensure we see the proper queue state before going to sleep - * so that we do not miss the wakeup. -- see perf_pending_handle() - */ - smp_rmb(); - return counter->pending.next == NULL; -} - -static void perf_pending_sync(struct perf_counter *counter) -{ - wait_event(counter->waitq, perf_not_pending(counter)); -} - -void perf_counter_do_pending(void) -{ - __perf_pending_run(); -} - -/* - * Callchain support -- arch specific - */ - -__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) -{ - return NULL; -} - -/* - * Output - */ - -struct perf_output_handle { - struct perf_counter *counter; - struct perf_mmap_data *data; - unsigned long head; - unsigned long offset; - int nmi; - int sample; - int locked; - unsigned long flags; -}; - -static bool perf_output_space(struct perf_mmap_data *data, - unsigned int offset, unsigned int head) -{ - unsigned long tail; - unsigned long mask; - - if (!data->writable) - return true; - - mask = (data->nr_pages << PAGE_SHIFT) - 1; - /* - * Userspace could choose to issue a mb() before updating the tail - * pointer. So that all reads will be completed before the write is - * issued. - */ - tail = ACCESS_ONCE(data->user_page->data_tail); - smp_rmb(); - - offset = (offset - tail) & mask; - head = (head - tail) & mask; - - if ((int)(head - offset) < 0) - return false; - - return true; -} - -static void perf_output_wakeup(struct perf_output_handle *handle) -{ - atomic_set(&handle->data->poll, POLL_IN); - - if (handle->nmi) { - handle->counter->pending_wakeup = 1; - perf_pending_queue(&handle->counter->pending, - perf_pending_counter); - } else - perf_counter_wakeup(handle->counter); -} - -/* - * Curious locking construct. - * - * We need to ensure a later event doesn't publish a head when a former - * event isn't done writing. However since we need to deal with NMIs we - * cannot fully serialize things. - * - * What we do is serialize between CPUs so we only have to deal with NMI - * nesting on a single CPU. - * - * We only publish the head (and generate a wakeup) when the outer-most - * event completes. - */ -static void perf_output_lock(struct perf_output_handle *handle) -{ - struct perf_mmap_data *data = handle->data; - int cpu; - - handle->locked = 0; - - local_irq_save(handle->flags); - cpu = smp_processor_id(); - - if (in_nmi() && atomic_read(&data->lock) == cpu) - return; - - while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) - cpu_relax(); - - handle->locked = 1; -} - -static void perf_output_unlock(struct perf_output_handle *handle) -{ - struct perf_mmap_data *data = handle->data; - unsigned long head; - int cpu; - - data->done_head = data->head; - - if (!handle->locked) - goto out; - -again: - /* - * The xchg implies a full barrier that ensures all writes are done - * before we publish the new head, matched by a rmb() in userspace when - * reading this position. - */ - while ((head = atomic_long_xchg(&data->done_head, 0))) - data->user_page->data_head = head; - - /* - * NMI can happen here, which means we can miss a done_head update. - */ - - cpu = atomic_xchg(&data->lock, -1); - WARN_ON_ONCE(cpu != smp_processor_id()); - - /* - * Therefore we have to validate we did not indeed do so. - */ - if (unlikely(atomic_long_read(&data->done_head))) { - /* - * Since we had it locked, we can lock it again. - */ - while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) - cpu_relax(); - - goto again; - } - - if (atomic_xchg(&data->wakeup, 0)) - perf_output_wakeup(handle); -out: - local_irq_restore(handle->flags); -} - -static void perf_output_copy(struct perf_output_handle *handle, - const void *buf, unsigned int len) -{ - unsigned int pages_mask; - unsigned int offset; - unsigned int size; - void **pages; - - offset = handle->offset; - pages_mask = handle->data->nr_pages - 1; - pages = handle->data->data_pages; - - do { - unsigned int page_offset; - int nr; - - nr = (offset >> PAGE_SHIFT) & pages_mask; - page_offset = offset & (PAGE_SIZE - 1); - size = min_t(unsigned int, PAGE_SIZE - page_offset, len); - - memcpy(pages[nr] + page_offset, buf, size); - - len -= size; - buf += size; - offset += size; - } while (len); - - handle->offset = offset; - - /* - * Check we didn't copy past our reservation window, taking the - * possible unsigned int wrap into account. - */ - WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); -} - -#define perf_output_put(handle, x) \ - perf_output_copy((handle), &(x), sizeof(x)) - -static int perf_output_begin(struct perf_output_handle *handle, - struct perf_counter *counter, unsigned int size, - int nmi, int sample) -{ - struct perf_counter *output_counter; - struct perf_mmap_data *data; - unsigned int offset, head; - int have_lost; - struct { - struct perf_event_header header; - u64 id; - u64 lost; - } lost_event; - - rcu_read_lock(); - /* - * For inherited counters we send all the output towards the parent. - */ - if (counter->parent) - counter = counter->parent; - - output_counter = rcu_dereference(counter->output); - if (output_counter) - counter = output_counter; - - data = rcu_dereference(counter->data); - if (!data) - goto out; - - handle->data = data; - handle->counter = counter; - handle->nmi = nmi; - handle->sample = sample; - - if (!data->nr_pages) - goto fail; - - have_lost = atomic_read(&data->lost); - if (have_lost) - size += sizeof(lost_event); - - perf_output_lock(handle); - - do { - offset = head = atomic_long_read(&data->head); - head += size; - if (unlikely(!perf_output_space(data, offset, head))) - goto fail; - } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); - - handle->offset = offset; - handle->head = head; - - if ((offset >> PAGE_SHIFT) != (head >> PAGE_SHIFT)) - atomic_set(&data->wakeup, 1); - - if (have_lost) { - lost_event.header.type = PERF_EVENT_LOST; - lost_event.header.misc = 0; - lost_event.header.size = sizeof(lost_event); - lost_event.id = counter->id; - lost_event.lost = atomic_xchg(&data->lost, 0); - - perf_output_put(handle, lost_event); - } - - return 0; - -fail: - atomic_inc(&data->lost); - perf_output_unlock(handle); -out: - rcu_read_unlock(); - - return -ENOSPC; -} - -static void perf_output_end(struct perf_output_handle *handle) -{ - struct perf_counter *counter = handle->counter; - struct perf_mmap_data *data = handle->data; - - int wakeup_events = counter->attr.wakeup_events; - - if (handle->sample && wakeup_events) { - int events = atomic_inc_return(&data->events); - if (events >= wakeup_events) { - atomic_sub(wakeup_events, &data->events); - atomic_set(&data->wakeup, 1); - } - } - - perf_output_unlock(handle); - rcu_read_unlock(); -} - -static u32 perf_counter_pid(struct perf_counter *counter, struct task_struct *p) -{ - /* - * only top level counters have the pid namespace they were created in - */ - if (counter->parent) - counter = counter->parent; - - return task_tgid_nr_ns(p, counter->ns); -} - -static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p) -{ - /* - * only top level counters have the pid namespace they were created in - */ - if (counter->parent) - counter = counter->parent; - - return task_pid_nr_ns(p, counter->ns); -} - -static void perf_output_read_one(struct perf_output_handle *handle, - struct perf_counter *counter) -{ - u64 read_format = counter->attr.read_format; - u64 values[4]; - int n = 0; - - values[n++] = atomic64_read(&counter->count); - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { - values[n++] = counter->total_time_enabled + - atomic64_read(&counter->child_total_time_enabled); - } - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { - values[n++] = counter->total_time_running + - atomic64_read(&counter->child_total_time_running); - } - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(counter); - - perf_output_copy(handle, values, n * sizeof(u64)); -} - -/* - * XXX PERF_FORMAT_GROUP vs inherited counters seems difficult. - */ -static void perf_output_read_group(struct perf_output_handle *handle, - struct perf_counter *counter) -{ - struct perf_counter *leader = counter->group_leader, *sub; - u64 read_format = counter->attr.read_format; - u64 values[5]; - int n = 0; - - values[n++] = 1 + leader->nr_siblings; - - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) - values[n++] = leader->total_time_enabled; - - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) - values[n++] = leader->total_time_running; - - if (leader != counter) - leader->pmu->read(leader); - - values[n++] = atomic64_read(&leader->count); - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(leader); - - perf_output_copy(handle, values, n * sizeof(u64)); - - list_for_each_entry(sub, &leader->sibling_list, list_entry) { - n = 0; - - if (sub != counter) - sub->pmu->read(sub); - - values[n++] = atomic64_read(&sub->count); - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(sub); - - perf_output_copy(handle, values, n * sizeof(u64)); - } -} - -static void perf_output_read(struct perf_output_handle *handle, - struct perf_counter *counter) -{ - if (counter->attr.read_format & PERF_FORMAT_GROUP) - perf_output_read_group(handle, counter); - else - perf_output_read_one(handle, counter); -} - -void perf_counter_output(struct perf_counter *counter, int nmi, - struct perf_sample_data *data) -{ - int ret; - u64 sample_type = counter->attr.sample_type; - struct perf_output_handle handle; - struct perf_event_header header; - u64 ip; - struct { - u32 pid, tid; - } tid_entry; - struct perf_callchain_entry *callchain = NULL; - int callchain_size = 0; - u64 time; - struct { - u32 cpu, reserved; - } cpu_entry; - - header.type = PERF_EVENT_SAMPLE; - header.size = sizeof(header); - - header.misc = 0; - header.misc |= perf_misc_flags(data->regs); - - if (sample_type & PERF_SAMPLE_IP) { - ip = perf_instruction_pointer(data->regs); - header.size += sizeof(ip); - } - - if (sample_type & PERF_SAMPLE_TID) { - /* namespace issues */ - tid_entry.pid = perf_counter_pid(counter, current); - tid_entry.tid = perf_counter_tid(counter, current); - - header.size += sizeof(tid_entry); - } - - if (sample_type & PERF_SAMPLE_TIME) { - /* - * Maybe do better on x86 and provide cpu_clock_nmi() - */ - time = sched_clock(); - - header.size += sizeof(u64); - } - - if (sample_type & PERF_SAMPLE_ADDR) - header.size += sizeof(u64); - - if (sample_type & PERF_SAMPLE_ID) - header.size += sizeof(u64); - - if (sample_type & PERF_SAMPLE_STREAM_ID) - header.size += sizeof(u64); - - if (sample_type & PERF_SAMPLE_CPU) { - header.size += sizeof(cpu_entry); - - cpu_entry.cpu = raw_smp_processor_id(); - cpu_entry.reserved = 0; - } - - if (sample_type & PERF_SAMPLE_PERIOD) - header.size += sizeof(u64); - - if (sample_type & PERF_SAMPLE_READ) - header.size += perf_counter_read_size(counter); - - if (sample_type & PERF_SAMPLE_CALLCHAIN) { - callchain = perf_callchain(data->regs); - - if (callchain) { - callchain_size = (1 + callchain->nr) * sizeof(u64); - header.size += callchain_size; - } else - header.size += sizeof(u64); - } - - if (sample_type & PERF_SAMPLE_RAW) { - int size = sizeof(u32); - - if (data->raw) - size += data->raw->size; - else - size += sizeof(u32); - - WARN_ON_ONCE(size & (sizeof(u64)-1)); - header.size += size; - } - - ret = perf_output_begin(&handle, counter, header.size, nmi, 1); - if (ret) - return; - - perf_output_put(&handle, header); - - if (sample_type & PERF_SAMPLE_IP) - perf_output_put(&handle, ip); - - if (sample_type & PERF_SAMPLE_TID) - perf_output_put(&handle, tid_entry); - - if (sample_type & PERF_SAMPLE_TIME) - perf_output_put(&handle, time); - - if (sample_type & PERF_SAMPLE_ADDR) - perf_output_put(&handle, data->addr); - - if (sample_type & PERF_SAMPLE_ID) { - u64 id = primary_counter_id(counter); - - perf_output_put(&handle, id); - } - - if (sample_type & PERF_SAMPLE_STREAM_ID) - perf_output_put(&handle, counter->id); - - if (sample_type & PERF_SAMPLE_CPU) - perf_output_put(&handle, cpu_entry); - - if (sample_type & PERF_SAMPLE_PERIOD) - perf_output_put(&handle, data->period); - - if (sample_type & PERF_SAMPLE_READ) - perf_output_read(&handle, counter); - - if (sample_type & PERF_SAMPLE_CALLCHAIN) { - if (callchain) - perf_output_copy(&handle, callchain, callchain_size); - else { - u64 nr = 0; - perf_output_put(&handle, nr); - } - } - - if (sample_type & PERF_SAMPLE_RAW) { - if (data->raw) { - perf_output_put(&handle, data->raw->size); - perf_output_copy(&handle, data->raw->data, data->raw->size); - } else { - struct { - u32 size; - u32 data; - } raw = { - .size = sizeof(u32), - .data = 0, - }; - perf_output_put(&handle, raw); - } - } - - perf_output_end(&handle); -} - -/* - * read event - */ - -struct perf_read_event { - struct perf_event_header header; - - u32 pid; - u32 tid; -}; - -static void -perf_counter_read_event(struct perf_counter *counter, - struct task_struct *task) -{ - struct perf_output_handle handle; - struct perf_read_event event = { - .header = { - .type = PERF_EVENT_READ, - .misc = 0, - .size = sizeof(event) + perf_counter_read_size(counter), - }, - .pid = perf_counter_pid(counter, task), - .tid = perf_counter_tid(counter, task), - }; - int ret; - - ret = perf_output_begin(&handle, counter, event.header.size, 0, 0); - if (ret) - return; - - perf_output_put(&handle, event); - perf_output_read(&handle, counter); - - perf_output_end(&handle); -} - -/* - * task tracking -- fork/exit - * - * enabled by: attr.comm | attr.mmap | attr.task - */ - -struct perf_task_event { - struct task_struct *task; - struct perf_counter_context *task_ctx; - - struct { - struct perf_event_header header; - - u32 pid; - u32 ppid; - u32 tid; - u32 ptid; - } event; -}; - -static void perf_counter_task_output(struct perf_counter *counter, - struct perf_task_event *task_event) -{ - struct perf_output_handle handle; - int size = task_event->event.header.size; - struct task_struct *task = task_event->task; - int ret = perf_output_begin(&handle, counter, size, 0, 0); - - if (ret) - return; - - task_event->event.pid = perf_counter_pid(counter, task); - task_event->event.ppid = perf_counter_pid(counter, current); - - task_event->event.tid = perf_counter_tid(counter, task); - task_event->event.ptid = perf_counter_tid(counter, current); - - perf_output_put(&handle, task_event->event); - perf_output_end(&handle); -} - -static int perf_counter_task_match(struct perf_counter *counter) -{ - if (counter->attr.comm || counter->attr.mmap || counter->attr.task) - return 1; - - return 0; -} - -static void perf_counter_task_ctx(struct perf_counter_context *ctx, - struct perf_task_event *task_event) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_counter_task_match(counter)) - perf_counter_task_output(counter, task_event); - } - rcu_read_unlock(); -} - -static void perf_counter_task_event(struct perf_task_event *task_event) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx = task_event->task_ctx; - - cpuctx = &get_cpu_var(perf_cpu_context); - perf_counter_task_ctx(&cpuctx->ctx, task_event); - put_cpu_var(perf_cpu_context); - - rcu_read_lock(); - if (!ctx) - ctx = rcu_dereference(task_event->task->perf_counter_ctxp); - if (ctx) - perf_counter_task_ctx(ctx, task_event); - rcu_read_unlock(); -} - -static void perf_counter_task(struct task_struct *task, - struct perf_counter_context *task_ctx, - int new) -{ - struct perf_task_event task_event; - - if (!atomic_read(&nr_comm_counters) && - !atomic_read(&nr_mmap_counters) && - !atomic_read(&nr_task_counters)) - return; - - task_event = (struct perf_task_event){ - .task = task, - .task_ctx = task_ctx, - .event = { - .header = { - .type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT, - .misc = 0, - .size = sizeof(task_event.event), - }, - /* .pid */ - /* .ppid */ - /* .tid */ - /* .ptid */ - }, - }; - - perf_counter_task_event(&task_event); -} - -void perf_counter_fork(struct task_struct *task) -{ - perf_counter_task(task, NULL, 1); -} - -/* - * comm tracking - */ - -struct perf_comm_event { - struct task_struct *task; - char *comm; - int comm_size; - - struct { - struct perf_event_header header; - - u32 pid; - u32 tid; - } event; -}; - -static void perf_counter_comm_output(struct perf_counter *counter, - struct perf_comm_event *comm_event) -{ - struct perf_output_handle handle; - int size = comm_event->event.header.size; - int ret = perf_output_begin(&handle, counter, size, 0, 0); - - if (ret) - return; - - comm_event->event.pid = perf_counter_pid(counter, comm_event->task); - comm_event->event.tid = perf_counter_tid(counter, comm_event->task); - - perf_output_put(&handle, comm_event->event); - perf_output_copy(&handle, comm_event->comm, - comm_event->comm_size); - perf_output_end(&handle); -} - -static int perf_counter_comm_match(struct perf_counter *counter) -{ - if (counter->attr.comm) - return 1; - - return 0; -} - -static void perf_counter_comm_ctx(struct perf_counter_context *ctx, - struct perf_comm_event *comm_event) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_counter_comm_match(counter)) - perf_counter_comm_output(counter, comm_event); - } - rcu_read_unlock(); -} - -static void perf_counter_comm_event(struct perf_comm_event *comm_event) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx; - unsigned int size; - char comm[TASK_COMM_LEN]; - - memset(comm, 0, sizeof(comm)); - strncpy(comm, comm_event->task->comm, sizeof(comm)); - size = ALIGN(strlen(comm)+1, sizeof(u64)); - - comm_event->comm = comm; - comm_event->comm_size = size; - - comm_event->event.header.size = sizeof(comm_event->event) + size; - - cpuctx = &get_cpu_var(perf_cpu_context); - perf_counter_comm_ctx(&cpuctx->ctx, comm_event); - put_cpu_var(perf_cpu_context); - - rcu_read_lock(); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_counter_ctxp); - if (ctx) - perf_counter_comm_ctx(ctx, comm_event); - rcu_read_unlock(); -} - -void perf_counter_comm(struct task_struct *task) -{ - struct perf_comm_event comm_event; - - if (task->perf_counter_ctxp) - perf_counter_enable_on_exec(task); - - if (!atomic_read(&nr_comm_counters)) - return; - - comm_event = (struct perf_comm_event){ - .task = task, - /* .comm */ - /* .comm_size */ - .event = { - .header = { - .type = PERF_EVENT_COMM, - .misc = 0, - /* .size */ - }, - /* .pid */ - /* .tid */ - }, - }; - - perf_counter_comm_event(&comm_event); -} - -/* - * mmap tracking - */ - -struct perf_mmap_event { - struct vm_area_struct *vma; - - const char *file_name; - int file_size; - - struct { - struct perf_event_header header; - - u32 pid; - u32 tid; - u64 start; - u64 len; - u64 pgoff; - } event; -}; - -static void perf_counter_mmap_output(struct perf_counter *counter, - struct perf_mmap_event *mmap_event) -{ - struct perf_output_handle handle; - int size = mmap_event->event.header.size; - int ret = perf_output_begin(&handle, counter, size, 0, 0); - - if (ret) - return; - - mmap_event->event.pid = perf_counter_pid(counter, current); - mmap_event->event.tid = perf_counter_tid(counter, current); - - perf_output_put(&handle, mmap_event->event); - perf_output_copy(&handle, mmap_event->file_name, - mmap_event->file_size); - perf_output_end(&handle); -} - -static int perf_counter_mmap_match(struct perf_counter *counter, - struct perf_mmap_event *mmap_event) -{ - if (counter->attr.mmap) - return 1; - - return 0; -} - -static void perf_counter_mmap_ctx(struct perf_counter_context *ctx, - struct perf_mmap_event *mmap_event) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_counter_mmap_match(counter, mmap_event)) - perf_counter_mmap_output(counter, mmap_event); - } - rcu_read_unlock(); -} - -static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx; - struct vm_area_struct *vma = mmap_event->vma; - struct file *file = vma->vm_file; - unsigned int size; - char tmp[16]; - char *buf = NULL; - const char *name; - - memset(tmp, 0, sizeof(tmp)); - - if (file) { - /* - * d_path works from the end of the buffer backwards, so we - * need to add enough zero bytes after the string to handle - * the 64bit alignment we do later. - */ - buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL); - if (!buf) { - name = strncpy(tmp, "//enomem", sizeof(tmp)); - goto got_name; - } - name = d_path(&file->f_path, buf, PATH_MAX); - if (IS_ERR(name)) { - name = strncpy(tmp, "//toolong", sizeof(tmp)); - goto got_name; - } - } else { - if (arch_vma_name(mmap_event->vma)) { - name = strncpy(tmp, arch_vma_name(mmap_event->vma), - sizeof(tmp)); - goto got_name; - } - - if (!vma->vm_mm) { - name = strncpy(tmp, "[vdso]", sizeof(tmp)); - goto got_name; - } - - name = strncpy(tmp, "//anon", sizeof(tmp)); - goto got_name; - } - -got_name: - size = ALIGN(strlen(name)+1, sizeof(u64)); - - mmap_event->file_name = name; - mmap_event->file_size = size; - - mmap_event->event.header.size = sizeof(mmap_event->event) + size; - - cpuctx = &get_cpu_var(perf_cpu_context); - perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event); - put_cpu_var(perf_cpu_context); - - rcu_read_lock(); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_counter_ctxp); - if (ctx) - perf_counter_mmap_ctx(ctx, mmap_event); - rcu_read_unlock(); - - kfree(buf); -} - -void __perf_counter_mmap(struct vm_area_struct *vma) -{ - struct perf_mmap_event mmap_event; - - if (!atomic_read(&nr_mmap_counters)) - return; - - mmap_event = (struct perf_mmap_event){ - .vma = vma, - /* .file_name */ - /* .file_size */ - .event = { - .header = { - .type = PERF_EVENT_MMAP, - .misc = 0, - /* .size */ - }, - /* .pid */ - /* .tid */ - .start = vma->vm_start, - .len = vma->vm_end - vma->vm_start, - .pgoff = vma->vm_pgoff, - }, - }; - - perf_counter_mmap_event(&mmap_event); -} - -/* - * IRQ throttle logging - */ - -static void perf_log_throttle(struct perf_counter *counter, int enable) -{ - struct perf_output_handle handle; - int ret; - - struct { - struct perf_event_header header; - u64 time; - u64 id; - u64 stream_id; - } throttle_event = { - .header = { - .type = PERF_EVENT_THROTTLE, - .misc = 0, - .size = sizeof(throttle_event), - }, - .time = sched_clock(), - .id = primary_counter_id(counter), - .stream_id = counter->id, - }; - - if (enable) - throttle_event.header.type = PERF_EVENT_UNTHROTTLE; - - ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0); - if (ret) - return; - - perf_output_put(&handle, throttle_event); - perf_output_end(&handle); -} - -/* - * Generic counter overflow handling, sampling. - */ - -int perf_counter_overflow(struct perf_counter *counter, int nmi, - struct perf_sample_data *data) -{ - int events = atomic_read(&counter->event_limit); - int throttle = counter->pmu->unthrottle != NULL; - struct hw_perf_counter *hwc = &counter->hw; - int ret = 0; - - if (!throttle) { - hwc->interrupts++; - } else { - if (hwc->interrupts != MAX_INTERRUPTS) { - hwc->interrupts++; - if (HZ * hwc->interrupts > - (u64)sysctl_perf_counter_sample_rate) { - hwc->interrupts = MAX_INTERRUPTS; - perf_log_throttle(counter, 0); - ret = 1; - } - } else { - /* - * Keep re-disabling counters even though on the previous - * pass we disabled it - just in case we raced with a - * sched-in and the counter got enabled again: - */ - ret = 1; - } - } - - if (counter->attr.freq) { - u64 now = sched_clock(); - s64 delta = now - hwc->freq_stamp; - - hwc->freq_stamp = now; - - if (delta > 0 && delta < TICK_NSEC) - perf_adjust_period(counter, NSEC_PER_SEC / (int)delta); - } - - /* - * XXX event_limit might not quite work as expected on inherited - * counters - */ - - counter->pending_kill = POLL_IN; - if (events && atomic_dec_and_test(&counter->event_limit)) { - ret = 1; - counter->pending_kill = POLL_HUP; - if (nmi) { - counter->pending_disable = 1; - perf_pending_queue(&counter->pending, - perf_pending_counter); - } else - perf_counter_disable(counter); - } - - perf_counter_output(counter, nmi, data); - return ret; -} - -/* - * Generic software counter infrastructure - */ - -/* - * We directly increment counter->count and keep a second value in - * counter->hw.period_left to count intervals. This period counter - * is kept in the range [-sample_period, 0] so that we can use the - * sign as trigger. - */ - -static u64 perf_swcounter_set_period(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 period = hwc->last_period; - u64 nr, offset; - s64 old, val; - - hwc->last_period = hwc->sample_period; - -again: - old = val = atomic64_read(&hwc->period_left); - if (val < 0) - return 0; - - nr = div64_u64(period + val, period); - offset = nr * period; - val -= offset; - if (atomic64_cmpxchg(&hwc->period_left, old, val) != old) - goto again; - - return nr; -} - -static void perf_swcounter_overflow(struct perf_counter *counter, - int nmi, struct perf_sample_data *data) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 overflow; - - data->period = counter->hw.last_period; - overflow = perf_swcounter_set_period(counter); - - if (hwc->interrupts == MAX_INTERRUPTS) - return; - - for (; overflow; overflow--) { - if (perf_counter_overflow(counter, nmi, data)) { - /* - * We inhibit the overflow from happening when - * hwc->interrupts == MAX_INTERRUPTS. - */ - break; - } - } -} - -static void perf_swcounter_unthrottle(struct perf_counter *counter) -{ - /* - * Nothing to do, we already reset hwc->interrupts. - */ -} - -static void perf_swcounter_add(struct perf_counter *counter, u64 nr, - int nmi, struct perf_sample_data *data) -{ - struct hw_perf_counter *hwc = &counter->hw; - - atomic64_add(nr, &counter->count); - - if (!hwc->sample_period) - return; - - if (!data->regs) - return; - - if (!atomic64_add_negative(nr, &hwc->period_left)) - perf_swcounter_overflow(counter, nmi, data); -} - -static int perf_swcounter_is_counting(struct perf_counter *counter) -{ - /* - * The counter is active, we're good! - */ - if (counter->state == PERF_COUNTER_STATE_ACTIVE) - return 1; - - /* - * The counter is off/error, not counting. - */ - if (counter->state != PERF_COUNTER_STATE_INACTIVE) - return 0; - - /* - * The counter is inactive, if the context is active - * we're part of a group that didn't make it on the 'pmu', - * not counting. - */ - if (counter->ctx->is_active) - return 0; - - /* - * We're inactive and the context is too, this means the - * task is scheduled out, we're counting events that happen - * to us, like migration events. - */ - return 1; -} - -static int perf_swcounter_match(struct perf_counter *counter, - enum perf_type_id type, - u32 event, struct pt_regs *regs) -{ - if (!perf_swcounter_is_counting(counter)) - return 0; - - if (counter->attr.type != type) - return 0; - if (counter->attr.config != event) - return 0; - - if (regs) { - if (counter->attr.exclude_user && user_mode(regs)) - return 0; - - if (counter->attr.exclude_kernel && !user_mode(regs)) - return 0; - } - - return 1; -} - -static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, - enum perf_type_id type, - u32 event, u64 nr, int nmi, - struct perf_sample_data *data) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_swcounter_match(counter, type, event, data->regs)) - perf_swcounter_add(counter, nr, nmi, data); - } - rcu_read_unlock(); -} - -static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx) -{ - if (in_nmi()) - return &cpuctx->recursion[3]; - - if (in_irq()) - return &cpuctx->recursion[2]; - - if (in_softirq()) - return &cpuctx->recursion[1]; - - return &cpuctx->recursion[0]; -} - -static void do_perf_swcounter_event(enum perf_type_id type, u32 event, - u64 nr, int nmi, - struct perf_sample_data *data) -{ - struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); - int *recursion = perf_swcounter_recursion_context(cpuctx); - struct perf_counter_context *ctx; - - if (*recursion) - goto out; - - (*recursion)++; - barrier(); - - perf_swcounter_ctx_event(&cpuctx->ctx, type, event, - nr, nmi, data); - rcu_read_lock(); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_counter_ctxp); - if (ctx) - perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data); - rcu_read_unlock(); - - barrier(); - (*recursion)--; - -out: - put_cpu_var(perf_cpu_context); -} - -void __perf_swcounter_event(u32 event, u64 nr, int nmi, - struct pt_regs *regs, u64 addr) -{ - struct perf_sample_data data = { - .regs = regs, - .addr = addr, - }; - - do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, &data); -} - -static void perf_swcounter_read(struct perf_counter *counter) -{ -} - -static int perf_swcounter_enable(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - - if (hwc->sample_period) { - hwc->last_period = hwc->sample_period; - perf_swcounter_set_period(counter); - } - return 0; -} - -static void perf_swcounter_disable(struct perf_counter *counter) -{ -} - -static const struct pmu perf_ops_generic = { - .enable = perf_swcounter_enable, - .disable = perf_swcounter_disable, - .read = perf_swcounter_read, - .unthrottle = perf_swcounter_unthrottle, -}; - -/* - * hrtimer based swcounter callback - */ - -static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) -{ - enum hrtimer_restart ret = HRTIMER_RESTART; - struct perf_sample_data data; - struct perf_counter *counter; - u64 period; - - counter = container_of(hrtimer, struct perf_counter, hw.hrtimer); - counter->pmu->read(counter); - - data.addr = 0; - data.regs = get_irq_regs(); - /* - * In case we exclude kernel IPs or are somehow not in interrupt - * context, provide the next best thing, the user IP. - */ - if ((counter->attr.exclude_kernel || !data.regs) && - !counter->attr.exclude_user) - data.regs = task_pt_regs(current); - - if (data.regs) { - if (perf_counter_overflow(counter, 0, &data)) - ret = HRTIMER_NORESTART; - } - - period = max_t(u64, 10000, counter->hw.sample_period); - hrtimer_forward_now(hrtimer, ns_to_ktime(period)); - - return ret; -} - -/* - * Software counter: cpu wall time clock - */ - -static void cpu_clock_perf_counter_update(struct perf_counter *counter) -{ - int cpu = raw_smp_processor_id(); - s64 prev; - u64 now; - - now = cpu_clock(cpu); - prev = atomic64_read(&counter->hw.prev_count); - atomic64_set(&counter->hw.prev_count, now); - atomic64_add(now - prev, &counter->count); -} - -static int cpu_clock_perf_counter_enable(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - int cpu = raw_smp_processor_id(); - - atomic64_set(&hwc->prev_count, cpu_clock(cpu)); - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hwc->hrtimer.function = perf_swcounter_hrtimer; - if (hwc->sample_period) { - u64 period = max_t(u64, 10000, hwc->sample_period); - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL, 0); - } - - return 0; -} - -static void cpu_clock_perf_counter_disable(struct perf_counter *counter) -{ - if (counter->hw.sample_period) - hrtimer_cancel(&counter->hw.hrtimer); - cpu_clock_perf_counter_update(counter); -} - -static void cpu_clock_perf_counter_read(struct perf_counter *counter) -{ - cpu_clock_perf_counter_update(counter); -} - -static const struct pmu perf_ops_cpu_clock = { - .enable = cpu_clock_perf_counter_enable, - .disable = cpu_clock_perf_counter_disable, - .read = cpu_clock_perf_counter_read, -}; - -/* - * Software counter: task time clock - */ - -static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now) -{ - u64 prev; - s64 delta; - - prev = atomic64_xchg(&counter->hw.prev_count, now); - delta = now - prev; - atomic64_add(delta, &counter->count); -} - -static int task_clock_perf_counter_enable(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 now; - - now = counter->ctx->time; - - atomic64_set(&hwc->prev_count, now); - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hwc->hrtimer.function = perf_swcounter_hrtimer; - if (hwc->sample_period) { - u64 period = max_t(u64, 10000, hwc->sample_period); - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL, 0); - } - - return 0; -} - -static void task_clock_perf_counter_disable(struct perf_counter *counter) -{ - if (counter->hw.sample_period) - hrtimer_cancel(&counter->hw.hrtimer); - task_clock_perf_counter_update(counter, counter->ctx->time); - -} - -static void task_clock_perf_counter_read(struct perf_counter *counter) -{ - u64 time; - - if (!in_nmi()) { - update_context_time(counter->ctx); - time = counter->ctx->time; - } else { - u64 now = perf_clock(); - u64 delta = now - counter->ctx->timestamp; - time = counter->ctx->time + delta; - } - - task_clock_perf_counter_update(counter, time); -} - -static const struct pmu perf_ops_task_clock = { - .enable = task_clock_perf_counter_enable, - .disable = task_clock_perf_counter_disable, - .read = task_clock_perf_counter_read, -}; - -#ifdef CONFIG_EVENT_PROFILE -void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record, - int entry_size) -{ - struct perf_raw_record raw = { - .size = entry_size, - .data = record, - }; - - struct perf_sample_data data = { - .regs = get_irq_regs(), - .addr = addr, - .raw = &raw, - }; - - if (!data.regs) - data.regs = task_pt_regs(current); - - do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, &data); -} -EXPORT_SYMBOL_GPL(perf_tpcounter_event); - -extern int ftrace_profile_enable(int); -extern void ftrace_profile_disable(int); - -static void tp_perf_counter_destroy(struct perf_counter *counter) -{ - ftrace_profile_disable(counter->attr.config); -} - -static const struct pmu *tp_perf_counter_init(struct perf_counter *counter) -{ - /* - * Raw tracepoint data is a severe data leak, only allow root to - * have these. - */ - if ((counter->attr.sample_type & PERF_SAMPLE_RAW) && - perf_paranoid_tracepoint_raw() && - !capable(CAP_SYS_ADMIN)) - return ERR_PTR(-EPERM); - - if (ftrace_profile_enable(counter->attr.config)) - return NULL; - - counter->destroy = tp_perf_counter_destroy; - - return &perf_ops_generic; -} -#else -static const struct pmu *tp_perf_counter_init(struct perf_counter *counter) -{ - return NULL; -} -#endif - -atomic_t perf_swcounter_enabled[PERF_COUNT_SW_MAX]; - -static void sw_perf_counter_destroy(struct perf_counter *counter) -{ - u64 event = counter->attr.config; - - WARN_ON(counter->parent); - - atomic_dec(&perf_swcounter_enabled[event]); -} - -static const struct pmu *sw_perf_counter_init(struct perf_counter *counter) -{ - const struct pmu *pmu = NULL; - u64 event = counter->attr.config; - - /* - * Software counters (currently) can't in general distinguish - * between user, kernel and hypervisor events. - * However, context switches and cpu migrations are considered - * to be kernel events, and page faults are never hypervisor - * events. - */ - switch (event) { - case PERF_COUNT_SW_CPU_CLOCK: - pmu = &perf_ops_cpu_clock; - - break; - case PERF_COUNT_SW_TASK_CLOCK: - /* - * If the user instantiates this as a per-cpu counter, - * use the cpu_clock counter instead. - */ - if (counter->ctx->task) - pmu = &perf_ops_task_clock; - else - pmu = &perf_ops_cpu_clock; - - break; - case PERF_COUNT_SW_PAGE_FAULTS: - case PERF_COUNT_SW_PAGE_FAULTS_MIN: - case PERF_COUNT_SW_PAGE_FAULTS_MAJ: - case PERF_COUNT_SW_CONTEXT_SWITCHES: - case PERF_COUNT_SW_CPU_MIGRATIONS: - if (!counter->parent) { - atomic_inc(&perf_swcounter_enabled[event]); - counter->destroy = sw_perf_counter_destroy; - } - pmu = &perf_ops_generic; - break; - } - - return pmu; -} - -/* - * Allocate and initialize a counter structure - */ -static struct perf_counter * -perf_counter_alloc(struct perf_counter_attr *attr, - int cpu, - struct perf_counter_context *ctx, - struct perf_counter *group_leader, - struct perf_counter *parent_counter, - gfp_t gfpflags) -{ - const struct pmu *pmu; - struct perf_counter *counter; - struct hw_perf_counter *hwc; - long err; - - counter = kzalloc(sizeof(*counter), gfpflags); - if (!counter) - return ERR_PTR(-ENOMEM); - - /* - * Single counters are their own group leaders, with an - * empty sibling list: - */ - if (!group_leader) - group_leader = counter; - - mutex_init(&counter->child_mutex); - INIT_LIST_HEAD(&counter->child_list); - - INIT_LIST_HEAD(&counter->list_entry); - INIT_LIST_HEAD(&counter->event_entry); - INIT_LIST_HEAD(&counter->sibling_list); - init_waitqueue_head(&counter->waitq); - - mutex_init(&counter->mmap_mutex); - - counter->cpu = cpu; - counter->attr = *attr; - counter->group_leader = group_leader; - counter->pmu = NULL; - counter->ctx = ctx; - counter->oncpu = -1; - - counter->parent = parent_counter; - - counter->ns = get_pid_ns(current->nsproxy->pid_ns); - counter->id = atomic64_inc_return(&perf_counter_id); - - counter->state = PERF_COUNTER_STATE_INACTIVE; - - if (attr->disabled) - counter->state = PERF_COUNTER_STATE_OFF; - - pmu = NULL; - - hwc = &counter->hw; - hwc->sample_period = attr->sample_period; - if (attr->freq && attr->sample_freq) - hwc->sample_period = 1; - hwc->last_period = hwc->sample_period; - - atomic64_set(&hwc->period_left, hwc->sample_period); - - /* - * we currently do not support PERF_FORMAT_GROUP on inherited counters - */ - if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) - goto done; - - switch (attr->type) { - case PERF_TYPE_RAW: - case PERF_TYPE_HARDWARE: - case PERF_TYPE_HW_CACHE: - pmu = hw_perf_counter_init(counter); - break; - - case PERF_TYPE_SOFTWARE: - pmu = sw_perf_counter_init(counter); - break; - - case PERF_TYPE_TRACEPOINT: - pmu = tp_perf_counter_init(counter); - break; - - default: - break; - } -done: - err = 0; - if (!pmu) - err = -EINVAL; - else if (IS_ERR(pmu)) - err = PTR_ERR(pmu); - - if (err) { - if (counter->ns) - put_pid_ns(counter->ns); - kfree(counter); - return ERR_PTR(err); - } - - counter->pmu = pmu; - - if (!counter->parent) { - atomic_inc(&nr_counters); - if (counter->attr.mmap) - atomic_inc(&nr_mmap_counters); - if (counter->attr.comm) - atomic_inc(&nr_comm_counters); - if (counter->attr.task) - atomic_inc(&nr_task_counters); - } - - return counter; -} - -static int perf_copy_attr(struct perf_counter_attr __user *uattr, - struct perf_counter_attr *attr) -{ - int ret; - u32 size; - - if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) - return -EFAULT; - - /* - * zero the full structure, so that a short copy will be nice. - */ - memset(attr, 0, sizeof(*attr)); - - ret = get_user(size, &uattr->size); - if (ret) - return ret; - - if (size > PAGE_SIZE) /* silly large */ - goto err_size; - - if (!size) /* abi compat */ - size = PERF_ATTR_SIZE_VER0; - - if (size < PERF_ATTR_SIZE_VER0) - goto err_size; - - /* - * If we're handed a bigger struct than we know of, - * ensure all the unknown bits are 0. - */ - if (size > sizeof(*attr)) { - unsigned long val; - unsigned long __user *addr; - unsigned long __user *end; - - addr = PTR_ALIGN((void __user *)uattr + sizeof(*attr), - sizeof(unsigned long)); - end = PTR_ALIGN((void __user *)uattr + size, - sizeof(unsigned long)); - - for (; addr < end; addr += sizeof(unsigned long)) { - ret = get_user(val, addr); - if (ret) - return ret; - if (val) - goto err_size; - } - size = sizeof(*attr); - } - - ret = copy_from_user(attr, uattr, size); - if (ret) - return -EFAULT; - - /* - * If the type exists, the corresponding creation will verify - * the attr->config. - */ - if (attr->type >= PERF_TYPE_MAX) - return -EINVAL; - - if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3) - return -EINVAL; - - if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) - return -EINVAL; - - if (attr->read_format & ~(PERF_FORMAT_MAX-1)) - return -EINVAL; - -out: - return ret; - -err_size: - put_user(sizeof(*attr), &uattr->size); - ret = -E2BIG; - goto out; -} - -int perf_counter_set_output(struct perf_counter *counter, int output_fd) -{ - struct perf_counter *output_counter = NULL; - struct file *output_file = NULL; - struct perf_counter *old_output; - int fput_needed = 0; - int ret = -EINVAL; - - if (!output_fd) - goto set; - - output_file = fget_light(output_fd, &fput_needed); - if (!output_file) - return -EBADF; - - if (output_file->f_op != &perf_fops) - goto out; - - output_counter = output_file->private_data; - - /* Don't chain output fds */ - if (output_counter->output) - goto out; - - /* Don't set an output fd when we already have an output channel */ - if (counter->data) - goto out; - - atomic_long_inc(&output_file->f_count); - -set: - mutex_lock(&counter->mmap_mutex); - old_output = counter->output; - rcu_assign_pointer(counter->output, output_counter); - mutex_unlock(&counter->mmap_mutex); - - if (old_output) { - /* - * we need to make sure no existing perf_output_*() - * is still referencing this counter. - */ - synchronize_rcu(); - fput(old_output->filp); - } - - ret = 0; -out: - fput_light(output_file, fput_needed); - return ret; -} - -/** - * sys_perf_counter_open - open a performance counter, associate it to a task/cpu - * - * @attr_uptr: event type attributes for monitoring/sampling - * @pid: target pid - * @cpu: target cpu - * @group_fd: group leader counter fd - */ -SYSCALL_DEFINE5(perf_counter_open, - struct perf_counter_attr __user *, attr_uptr, - pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) -{ - struct perf_counter *counter, *group_leader; - struct perf_counter_attr attr; - struct perf_counter_context *ctx; - struct file *counter_file = NULL; - struct file *group_file = NULL; - int fput_needed = 0; - int fput_needed2 = 0; - int err; - - /* for future expandability... */ - if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT)) - return -EINVAL; - - err = perf_copy_attr(attr_uptr, &attr); - if (err) - return err; - - if (!attr.exclude_kernel) { - if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) - return -EACCES; - } - - if (attr.freq) { - if (attr.sample_freq > sysctl_perf_counter_sample_rate) - return -EINVAL; - } - - /* - * Get the target context (task or percpu): - */ - ctx = find_get_context(pid, cpu); - if (IS_ERR(ctx)) - return PTR_ERR(ctx); - - /* - * Look up the group leader (we will attach this counter to it): - */ - group_leader = NULL; - if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) { - err = -EINVAL; - group_file = fget_light(group_fd, &fput_needed); - if (!group_file) - goto err_put_context; - if (group_file->f_op != &perf_fops) - goto err_put_context; - - group_leader = group_file->private_data; - /* - * Do not allow a recursive hierarchy (this new sibling - * becoming part of another group-sibling): - */ - if (group_leader->group_leader != group_leader) - goto err_put_context; - /* - * Do not allow to attach to a group in a different - * task or CPU context: - */ - if (group_leader->ctx != ctx) - goto err_put_context; - /* - * Only a group leader can be exclusive or pinned - */ - if (attr.exclusive || attr.pinned) - goto err_put_context; - } - - counter = perf_counter_alloc(&attr, cpu, ctx, group_leader, - NULL, GFP_KERNEL); - err = PTR_ERR(counter); - if (IS_ERR(counter)) - goto err_put_context; - - err = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0); - if (err < 0) - goto err_free_put_context; - - counter_file = fget_light(err, &fput_needed2); - if (!counter_file) - goto err_free_put_context; - - if (flags & PERF_FLAG_FD_OUTPUT) { - err = perf_counter_set_output(counter, group_fd); - if (err) - goto err_fput_free_put_context; - } - - counter->filp = counter_file; - WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - perf_install_in_context(ctx, counter, cpu); - ++ctx->generation; - mutex_unlock(&ctx->mutex); - - counter->owner = current; - get_task_struct(current); - mutex_lock(¤t->perf_counter_mutex); - list_add_tail(&counter->owner_entry, ¤t->perf_counter_list); - mutex_unlock(¤t->perf_counter_mutex); - -err_fput_free_put_context: - fput_light(counter_file, fput_needed2); - -err_free_put_context: - if (err < 0) - kfree(counter); - -err_put_context: - if (err < 0) - put_ctx(ctx); - - fput_light(group_file, fput_needed); - - return err; -} - -/* - * inherit a counter from parent task to child task: - */ -static struct perf_counter * -inherit_counter(struct perf_counter *parent_counter, - struct task_struct *parent, - struct perf_counter_context *parent_ctx, - struct task_struct *child, - struct perf_counter *group_leader, - struct perf_counter_context *child_ctx) -{ - struct perf_counter *child_counter; - - /* - * Instead of creating recursive hierarchies of counters, - * we link inherited counters back to the original parent, - * which has a filp for sure, which we use as the reference - * count: - */ - if (parent_counter->parent) - parent_counter = parent_counter->parent; - - child_counter = perf_counter_alloc(&parent_counter->attr, - parent_counter->cpu, child_ctx, - group_leader, parent_counter, - GFP_KERNEL); - if (IS_ERR(child_counter)) - return child_counter; - get_ctx(child_ctx); - - /* - * Make the child state follow the state of the parent counter, - * not its attr.disabled bit. We hold the parent's mutex, - * so we won't race with perf_counter_{en, dis}able_family. - */ - if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE) - child_counter->state = PERF_COUNTER_STATE_INACTIVE; - else - child_counter->state = PERF_COUNTER_STATE_OFF; - - if (parent_counter->attr.freq) - child_counter->hw.sample_period = parent_counter->hw.sample_period; - - /* - * Link it up in the child's context: - */ - add_counter_to_ctx(child_counter, child_ctx); - - /* - * Get a reference to the parent filp - we will fput it - * when the child counter exits. This is safe to do because - * we are in the parent and we know that the filp still - * exists and has a nonzero count: - */ - atomic_long_inc(&parent_counter->filp->f_count); - - /* - * Link this into the parent counter's child list - */ - WARN_ON_ONCE(parent_counter->ctx->parent_ctx); - mutex_lock(&parent_counter->child_mutex); - list_add_tail(&child_counter->child_list, &parent_counter->child_list); - mutex_unlock(&parent_counter->child_mutex); - - return child_counter; -} - -static int inherit_group(struct perf_counter *parent_counter, - struct task_struct *parent, - struct perf_counter_context *parent_ctx, - struct task_struct *child, - struct perf_counter_context *child_ctx) -{ - struct perf_counter *leader; - struct perf_counter *sub; - struct perf_counter *child_ctr; - - leader = inherit_counter(parent_counter, parent, parent_ctx, - child, NULL, child_ctx); - if (IS_ERR(leader)) - return PTR_ERR(leader); - list_for_each_entry(sub, &parent_counter->sibling_list, list_entry) { - child_ctr = inherit_counter(sub, parent, parent_ctx, - child, leader, child_ctx); - if (IS_ERR(child_ctr)) - return PTR_ERR(child_ctr); - } - return 0; -} - -static void sync_child_counter(struct perf_counter *child_counter, - struct task_struct *child) -{ - struct perf_counter *parent_counter = child_counter->parent; - u64 child_val; - - if (child_counter->attr.inherit_stat) - perf_counter_read_event(child_counter, child); - - child_val = atomic64_read(&child_counter->count); - - /* - * Add back the child's count to the parent's count: - */ - atomic64_add(child_val, &parent_counter->count); - atomic64_add(child_counter->total_time_enabled, - &parent_counter->child_total_time_enabled); - atomic64_add(child_counter->total_time_running, - &parent_counter->child_total_time_running); - - /* - * Remove this counter from the parent's list - */ - WARN_ON_ONCE(parent_counter->ctx->parent_ctx); - mutex_lock(&parent_counter->child_mutex); - list_del_init(&child_counter->child_list); - mutex_unlock(&parent_counter->child_mutex); - - /* - * Release the parent counter, if this was the last - * reference to it. - */ - fput(parent_counter->filp); -} - -static void -__perf_counter_exit_task(struct perf_counter *child_counter, - struct perf_counter_context *child_ctx, - struct task_struct *child) -{ - struct perf_counter *parent_counter; - - update_counter_times(child_counter); - perf_counter_remove_from_context(child_counter); - - parent_counter = child_counter->parent; - /* - * It can happen that parent exits first, and has counters - * that are still around due to the child reference. These - * counters need to be zapped - but otherwise linger. - */ - if (parent_counter) { - sync_child_counter(child_counter, child); - free_counter(child_counter); - } -} - -/* - * When a child task exits, feed back counter values to parent counters. - */ -void perf_counter_exit_task(struct task_struct *child) -{ - struct perf_counter *child_counter, *tmp; - struct perf_counter_context *child_ctx; - unsigned long flags; - - if (likely(!child->perf_counter_ctxp)) { - perf_counter_task(child, NULL, 0); - return; - } - - local_irq_save(flags); - /* - * We can't reschedule here because interrupts are disabled, - * and either child is current or it is a task that can't be - * scheduled, so we are now safe from rescheduling changing - * our context. - */ - child_ctx = child->perf_counter_ctxp; - __perf_counter_task_sched_out(child_ctx); - - /* - * Take the context lock here so that if find_get_context is - * reading child->perf_counter_ctxp, we wait until it has - * incremented the context's refcount before we do put_ctx below. - */ - spin_lock(&child_ctx->lock); - child->perf_counter_ctxp = NULL; - /* - * If this context is a clone; unclone it so it can't get - * swapped to another process while we're removing all - * the counters from it. - */ - unclone_ctx(child_ctx); - spin_unlock_irqrestore(&child_ctx->lock, flags); - - /* - * Report the task dead after unscheduling the counters so that we - * won't get any samples after PERF_EVENT_EXIT. We can however still - * get a few PERF_EVENT_READ events. - */ - perf_counter_task(child, child_ctx, 0); - - /* - * We can recurse on the same lock type through: - * - * __perf_counter_exit_task() - * sync_child_counter() - * fput(parent_counter->filp) - * perf_release() - * mutex_lock(&ctx->mutex) - * - * But since its the parent context it won't be the same instance. - */ - mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); - -again: - list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list, - list_entry) - __perf_counter_exit_task(child_counter, child_ctx, child); - - /* - * If the last counter was a group counter, it will have appended all - * its siblings to the list, but we obtained 'tmp' before that which - * will still point to the list head terminating the iteration. - */ - if (!list_empty(&child_ctx->counter_list)) - goto again; - - mutex_unlock(&child_ctx->mutex); - - put_ctx(child_ctx); -} - -/* - * free an unexposed, unused context as created by inheritance by - * init_task below, used by fork() in case of fail. - */ -void perf_counter_free_task(struct task_struct *task) -{ - struct perf_counter_context *ctx = task->perf_counter_ctxp; - struct perf_counter *counter, *tmp; - - if (!ctx) - return; - - mutex_lock(&ctx->mutex); -again: - list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) { - struct perf_counter *parent = counter->parent; - - if (WARN_ON_ONCE(!parent)) - continue; - - mutex_lock(&parent->child_mutex); - list_del_init(&counter->child_list); - mutex_unlock(&parent->child_mutex); - - fput(parent->filp); - - list_del_counter(counter, ctx); - free_counter(counter); - } - - if (!list_empty(&ctx->counter_list)) - goto again; - - mutex_unlock(&ctx->mutex); - - put_ctx(ctx); -} - -/* - * Initialize the perf_counter context in task_struct - */ -int perf_counter_init_task(struct task_struct *child) -{ - struct perf_counter_context *child_ctx, *parent_ctx; - struct perf_counter_context *cloned_ctx; - struct perf_counter *counter; - struct task_struct *parent = current; - int inherited_all = 1; - int ret = 0; - - child->perf_counter_ctxp = NULL; - - mutex_init(&child->perf_counter_mutex); - INIT_LIST_HEAD(&child->perf_counter_list); - - if (likely(!parent->perf_counter_ctxp)) - return 0; - - /* - * This is executed from the parent task context, so inherit - * counters that have been marked for cloning. - * First allocate and initialize a context for the child. - */ - - child_ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL); - if (!child_ctx) - return -ENOMEM; - - __perf_counter_init_context(child_ctx, child); - child->perf_counter_ctxp = child_ctx; - get_task_struct(child); - - /* - * If the parent's context is a clone, pin it so it won't get - * swapped under us. - */ - parent_ctx = perf_pin_task_context(parent); - - /* - * No need to check if parent_ctx != NULL here; since we saw - * it non-NULL earlier, the only reason for it to become NULL - * is if we exit, and since we're currently in the middle of - * a fork we can't be exiting at the same time. - */ - - /* - * Lock the parent list. No need to lock the child - not PID - * hashed yet and not running, so nobody can access it. - */ - mutex_lock(&parent_ctx->mutex); - - /* - * We dont have to disable NMIs - we are only looking at - * the list, not manipulating it: - */ - list_for_each_entry_rcu(counter, &parent_ctx->event_list, event_entry) { - if (counter != counter->group_leader) - continue; - - if (!counter->attr.inherit) { - inherited_all = 0; - continue; - } - - ret = inherit_group(counter, parent, parent_ctx, - child, child_ctx); - if (ret) { - inherited_all = 0; - break; - } - } - - if (inherited_all) { - /* - * Mark the child context as a clone of the parent - * context, or of whatever the parent is a clone of. - * Note that if the parent is a clone, it could get - * uncloned at any point, but that doesn't matter - * because the list of counters and the generation - * count can't have changed since we took the mutex. - */ - cloned_ctx = rcu_dereference(parent_ctx->parent_ctx); - if (cloned_ctx) { - child_ctx->parent_ctx = cloned_ctx; - child_ctx->parent_gen = parent_ctx->parent_gen; - } else { - child_ctx->parent_ctx = parent_ctx; - child_ctx->parent_gen = parent_ctx->generation; - } - get_ctx(child_ctx->parent_ctx); - } - - mutex_unlock(&parent_ctx->mutex); - - perf_unpin_context(parent_ctx); - - return ret; -} - -static void __cpuinit perf_counter_init_cpu(int cpu) -{ - struct perf_cpu_context *cpuctx; - - cpuctx = &per_cpu(perf_cpu_context, cpu); - __perf_counter_init_context(&cpuctx->ctx, NULL); - - spin_lock(&perf_resource_lock); - cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu; - spin_unlock(&perf_resource_lock); - - hw_perf_counter_setup(cpu); -} - -#ifdef CONFIG_HOTPLUG_CPU -static void __perf_counter_exit_cpu(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter_context *ctx = &cpuctx->ctx; - struct perf_counter *counter, *tmp; - - list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) - __perf_counter_remove_from_context(counter); -} -static void perf_counter_exit_cpu(int cpu) -{ - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); - struct perf_counter_context *ctx = &cpuctx->ctx; - - mutex_lock(&ctx->mutex); - smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1); - mutex_unlock(&ctx->mutex); -} -#else -static inline void perf_counter_exit_cpu(int cpu) { } -#endif - -static int __cpuinit -perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) -{ - unsigned int cpu = (long)hcpu; - - switch (action) { - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - perf_counter_init_cpu(cpu); - break; - - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - hw_perf_counter_setup_online(cpu); - break; - - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - perf_counter_exit_cpu(cpu); - break; - - default: - break; - } - - return NOTIFY_OK; -} - -/* - * This has to have a higher priority than migration_notifier in sched.c. - */ -static struct notifier_block __cpuinitdata perf_cpu_nb = { - .notifier_call = perf_cpu_notify, - .priority = 20, -}; - -void __init perf_counter_init(void) -{ - perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, - (void *)(long)smp_processor_id()); - perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE, - (void *)(long)smp_processor_id()); - register_cpu_notifier(&perf_cpu_nb); -} - -static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) -{ - return sprintf(buf, "%d\n", perf_reserved_percpu); -} - -static ssize_t -perf_set_reserve_percpu(struct sysdev_class *class, - const char *buf, - size_t count) -{ - struct perf_cpu_context *cpuctx; - unsigned long val; - int err, cpu, mpt; - - err = strict_strtoul(buf, 10, &val); - if (err) - return err; - if (val > perf_max_counters) - return -EINVAL; - - spin_lock(&perf_resource_lock); - perf_reserved_percpu = val; - for_each_online_cpu(cpu) { - cpuctx = &per_cpu(perf_cpu_context, cpu); - spin_lock_irq(&cpuctx->ctx.lock); - mpt = min(perf_max_counters - cpuctx->ctx.nr_counters, - perf_max_counters - perf_reserved_percpu); - cpuctx->max_pertask = mpt; - spin_unlock_irq(&cpuctx->ctx.lock); - } - spin_unlock(&perf_resource_lock); - - return count; -} - -static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) -{ - return sprintf(buf, "%d\n", perf_overcommit); -} - -static ssize_t -perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) -{ - unsigned long val; - int err; - - err = strict_strtoul(buf, 10, &val); - if (err) - return err; - if (val > 1) - return -EINVAL; - - spin_lock(&perf_resource_lock); - perf_overcommit = val; - spin_unlock(&perf_resource_lock); - - return count; -} - -static SYSDEV_CLASS_ATTR( - reserve_percpu, - 0644, - perf_show_reserve_percpu, - perf_set_reserve_percpu - ); - -static SYSDEV_CLASS_ATTR( - overcommit, - 0644, - perf_show_overcommit, - perf_set_overcommit - ); - -static struct attribute *perfclass_attrs[] = { - &attr_reserve_percpu.attr, - &attr_overcommit.attr, - NULL -}; - -static struct attribute_group perfclass_attr_group = { - .attrs = perfclass_attrs, - .name = "perf_counters", -}; - -static int __init perf_counter_sysfs_init(void) -{ - return sysfs_create_group(&cpu_sysdev_class.kset.kobj, - &perfclass_attr_group); -} -device_initcall(perf_counter_sysfs_init); diff --git a/kernel/perf_event.c b/kernel/perf_event.c new file mode 100644 index 0000000..76ac4db --- /dev/null +++ b/kernel/perf_event.c @@ -0,0 +1,5000 @@ +/* + * Performance events core code: + * + * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> + * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar + * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> + * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> + * + * For licensing details see kernel-base/COPYING + */ + +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/cpu.h> +#include <linux/smp.h> +#include <linux/file.h> +#include <linux/poll.h> +#include <linux/sysfs.h> +#include <linux/dcache.h> +#include <linux/percpu.h> +#include <linux/ptrace.h> +#include <linux/vmstat.h> +#include <linux/hardirq.h> +#include <linux/rculist.h> +#include <linux/uaccess.h> +#include <linux/syscalls.h> +#include <linux/anon_inodes.h> +#include <linux/kernel_stat.h> +#include <linux/perf_event.h> + +#include <asm/irq_regs.h> + +/* + * Each CPU has a list of per CPU events: + */ +DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); + +int perf_max_events __read_mostly = 1; +static int perf_reserved_percpu __read_mostly; +static int perf_overcommit __read_mostly = 1; + +static atomic_t nr_events __read_mostly; +static atomic_t nr_mmap_events __read_mostly; +static atomic_t nr_comm_events __read_mostly; +static atomic_t nr_task_events __read_mostly; + +/* + * perf event paranoia level: + * -1 - not paranoid at all + * 0 - disallow raw tracepoint access for unpriv + * 1 - disallow cpu events for unpriv + * 2 - disallow kernel profiling for unpriv + */ +int sysctl_perf_event_paranoid __read_mostly = 1; + +static inline bool perf_paranoid_tracepoint_raw(void) +{ + return sysctl_perf_event_paranoid > -1; +} + +static inline bool perf_paranoid_cpu(void) +{ + return sysctl_perf_event_paranoid > 0; +} + +static inline bool perf_paranoid_kernel(void) +{ + return sysctl_perf_event_paranoid > 1; +} + +int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */ + +/* + * max perf event sample rate + */ +int sysctl_perf_event_sample_rate __read_mostly = 100000; + +static atomic64_t perf_event_id; + +/* + * Lock for (sysadmin-configurable) event reservations: + */ +static DEFINE_SPINLOCK(perf_resource_lock); + +/* + * Architecture provided APIs - weak aliases: + */ +extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event) +{ + return NULL; +} + +void __weak hw_perf_disable(void) { barrier(); } +void __weak hw_perf_enable(void) { barrier(); } + +void __weak hw_perf_event_setup(int cpu) { barrier(); } +void __weak hw_perf_event_setup_online(int cpu) { barrier(); } + +int __weak +hw_perf_group_sched_in(struct perf_event *group_leader, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx, int cpu) +{ + return 0; +} + +void __weak perf_event_print_debug(void) { } + +static DEFINE_PER_CPU(int, perf_disable_count); + +void __perf_disable(void) +{ + __get_cpu_var(perf_disable_count)++; +} + +bool __perf_enable(void) +{ + return !--__get_cpu_var(perf_disable_count); +} + +void perf_disable(void) +{ + __perf_disable(); + hw_perf_disable(); +} + +void perf_enable(void) +{ + if (__perf_enable()) + hw_perf_enable(); +} + +static void get_ctx(struct perf_event_context *ctx) +{ + WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); +} + +static void free_ctx(struct rcu_head *head) +{ + struct perf_event_context *ctx; + + ctx = container_of(head, struct perf_event_context, rcu_head); + kfree(ctx); +} + +static void put_ctx(struct perf_event_context *ctx) +{ + if (atomic_dec_and_test(&ctx->refcount)) { + if (ctx->parent_ctx) + put_ctx(ctx->parent_ctx); + if (ctx->task) + put_task_struct(ctx->task); + call_rcu(&ctx->rcu_head, free_ctx); + } +} + +static void unclone_ctx(struct perf_event_context *ctx) +{ + if (ctx->parent_ctx) { + put_ctx(ctx->parent_ctx); + ctx->parent_ctx = NULL; + } +} + +/* + * If we inherit events we want to return the parent event id + * to userspace. + */ +static u64 primary_event_id(struct perf_event *event) +{ + u64 id = event->id; + + if (event->parent) + id = event->parent->id; + + return id; +} + +/* + * Get the perf_event_context for a task and lock it. + * This has to cope with with the fact that until it is locked, + * the context could get moved to another task. + */ +static struct perf_event_context * +perf_lock_task_context(struct task_struct *task, unsigned long *flags) +{ + struct perf_event_context *ctx; + + rcu_read_lock(); + retry: + ctx = rcu_dereference(task->perf_event_ctxp); + if (ctx) { + /* + * If this context is a clone of another, it might + * get swapped for another underneath us by + * perf_event_task_sched_out, though the + * rcu_read_lock() protects us from any context + * getting freed. Lock the context and check if it + * got swapped before we could get the lock, and retry + * if so. If we locked the right context, then it + * can't get swapped on us any more. + */ + spin_lock_irqsave(&ctx->lock, *flags); + if (ctx != rcu_dereference(task->perf_event_ctxp)) { + spin_unlock_irqrestore(&ctx->lock, *flags); + goto retry; + } + + if (!atomic_inc_not_zero(&ctx->refcount)) { + spin_unlock_irqrestore(&ctx->lock, *flags); + ctx = NULL; + } + } + rcu_read_unlock(); + return ctx; +} + +/* + * Get the context for a task and increment its pin_count so it + * can't get swapped to another task. This also increments its + * reference count so that the context can't get freed. + */ +static struct perf_event_context *perf_pin_task_context(struct task_struct *task) +{ + struct perf_event_context *ctx; + unsigned long flags; + + ctx = perf_lock_task_context(task, &flags); + if (ctx) { + ++ctx->pin_count; + spin_unlock_irqrestore(&ctx->lock, flags); + } + return ctx; +} + +static void perf_unpin_context(struct perf_event_context *ctx) +{ + unsigned long flags; + + spin_lock_irqsave(&ctx->lock, flags); + --ctx->pin_count; + spin_unlock_irqrestore(&ctx->lock, flags); + put_ctx(ctx); +} + +/* + * Add a event from the lists for its context. + * Must be called with ctx->mutex and ctx->lock held. + */ +static void +list_add_event(struct perf_event *event, struct perf_event_context *ctx) +{ + struct perf_event *group_leader = event->group_leader; + + /* + * Depending on whether it is a standalone or sibling event, + * add it straight to the context's event list, or to the group + * leader's sibling list: + */ + if (group_leader == event) + list_add_tail(&event->group_entry, &ctx->group_list); + else { + list_add_tail(&event->group_entry, &group_leader->sibling_list); + group_leader->nr_siblings++; + } + + list_add_rcu(&event->event_entry, &ctx->event_list); + ctx->nr_events++; + if (event->attr.inherit_stat) + ctx->nr_stat++; +} + +/* + * Remove a event from the lists for its context. + * Must be called with ctx->mutex and ctx->lock held. + */ +static void +list_del_event(struct perf_event *event, struct perf_event_context *ctx) +{ + struct perf_event *sibling, *tmp; + + if (list_empty(&event->group_entry)) + return; + ctx->nr_events--; + if (event->attr.inherit_stat) + ctx->nr_stat--; + + list_del_init(&event->group_entry); + list_del_rcu(&event->event_entry); + + if (event->group_leader != event) + event->group_leader->nr_siblings--; + + /* + * If this was a group event with sibling events then + * upgrade the siblings to singleton events by adding them + * to the context list directly: + */ + list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { + + list_move_tail(&sibling->group_entry, &ctx->group_list); + sibling->group_leader = sibling; + } +} + +static void +event_sched_out(struct perf_event *event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + if (event->state != PERF_EVENT_STATE_ACTIVE) + return; + + event->state = PERF_EVENT_STATE_INACTIVE; + if (event->pending_disable) { + event->pending_disable = 0; + event->state = PERF_EVENT_STATE_OFF; + } + event->tstamp_stopped = ctx->time; + event->pmu->disable(event); + event->oncpu = -1; + + if (!is_software_event(event)) + cpuctx->active_oncpu--; + ctx->nr_active--; + if (event->attr.exclusive || !cpuctx->active_oncpu) + cpuctx->exclusive = 0; +} + +static void +group_sched_out(struct perf_event *group_event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + struct perf_event *event; + + if (group_event->state != PERF_EVENT_STATE_ACTIVE) + return; + + event_sched_out(group_event, cpuctx, ctx); + + /* + * Schedule out siblings (if any): + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) + event_sched_out(event, cpuctx, ctx); + + if (group_event->attr.exclusive) + cpuctx->exclusive = 0; +} + +/* + * Cross CPU call to remove a performance event + * + * We disable the event on the hardware level first. After that we + * remove it from the context list. + */ +static void __perf_event_remove_from_context(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event *event = info; + struct perf_event_context *ctx = event->ctx; + + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + + spin_lock(&ctx->lock); + /* + * Protect the list operation against NMI by disabling the + * events on a global level. + */ + perf_disable(); + + event_sched_out(event, cpuctx, ctx); + + list_del_event(event, ctx); + + if (!ctx->task) { + /* + * Allow more per task events with respect to the + * reservation: + */ + cpuctx->max_pertask = + min(perf_max_events - ctx->nr_events, + perf_max_events - perf_reserved_percpu); + } + + perf_enable(); + spin_unlock(&ctx->lock); +} + + +/* + * Remove the event from a task's (or a CPU's) list of events. + * + * Must be called with ctx->mutex held. + * + * CPU events are removed with a smp call. For task events we only + * call when the task is on a CPU. + * + * If event->ctx is a cloned context, callers must make sure that + * every task struct that event->ctx->task could possibly point to + * remains valid. This is OK when called from perf_release since + * that only calls us on the top-level context, which can't be a clone. + * When called from perf_event_exit_task, it's OK because the + * context has been detached from its task. + */ +static void perf_event_remove_from_context(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Per cpu events are removed via an smp call and + * the removal is always sucessful. + */ + smp_call_function_single(event->cpu, + __perf_event_remove_from_context, + event, 1); + return; + } + +retry: + task_oncpu_function_call(task, __perf_event_remove_from_context, + event); + + spin_lock_irq(&ctx->lock); + /* + * If the context is active we need to retry the smp call. + */ + if (ctx->nr_active && !list_empty(&event->group_entry)) { + spin_unlock_irq(&ctx->lock); + goto retry; + } + + /* + * The lock prevents that this context is scheduled in so we + * can remove the event safely, if the call above did not + * succeed. + */ + if (!list_empty(&event->group_entry)) { + list_del_event(event, ctx); + } + spin_unlock_irq(&ctx->lock); +} + +static inline u64 perf_clock(void) +{ + return cpu_clock(smp_processor_id()); +} + +/* + * Update the record of the current time in a context. + */ +static void update_context_time(struct perf_event_context *ctx) +{ + u64 now = perf_clock(); + + ctx->time += now - ctx->timestamp; + ctx->timestamp = now; +} + +/* + * Update the total_time_enabled and total_time_running fields for a event. + */ +static void update_event_times(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + u64 run_end; + + if (event->state < PERF_EVENT_STATE_INACTIVE || + event->group_leader->state < PERF_EVENT_STATE_INACTIVE) + return; + + event->total_time_enabled = ctx->time - event->tstamp_enabled; + + if (event->state == PERF_EVENT_STATE_INACTIVE) + run_end = event->tstamp_stopped; + else + run_end = ctx->time; + + event->total_time_running = run_end - event->tstamp_running; +} + +/* + * Update total_time_enabled and total_time_running for all events in a group. + */ +static void update_group_times(struct perf_event *leader) +{ + struct perf_event *event; + + update_event_times(leader); + list_for_each_entry(event, &leader->sibling_list, group_entry) + update_event_times(event); +} + +/* + * Cross CPU call to disable a performance event + */ +static void __perf_event_disable(void *info) +{ + struct perf_event *event = info; + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = event->ctx; + + /* + * If this is a per-task event, need to check whether this + * event's task is the current task on this cpu. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + + spin_lock(&ctx->lock); + + /* + * If the event is on, turn it off. + * If it is in error state, leave it in error state. + */ + if (event->state >= PERF_EVENT_STATE_INACTIVE) { + update_context_time(ctx); + update_group_times(event); + if (event == event->group_leader) + group_sched_out(event, cpuctx, ctx); + else + event_sched_out(event, cpuctx, ctx); + event->state = PERF_EVENT_STATE_OFF; + } + + spin_unlock(&ctx->lock); +} + +/* + * Disable a event. + * + * If event->ctx is a cloned context, callers must make sure that + * every task struct that event->ctx->task could possibly point to + * remains valid. This condition is satisifed when called through + * perf_event_for_each_child or perf_event_for_each because they + * hold the top-level event's child_mutex, so any descendant that + * goes to exit will block in sync_child_event. + * When called from perf_pending_event it's OK because event->ctx + * is the current context on this CPU and preemption is disabled, + * hence we can't get into perf_event_task_sched_out for this context. + */ +static void perf_event_disable(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Disable the event on the cpu that it's on + */ + smp_call_function_single(event->cpu, __perf_event_disable, + event, 1); + return; + } + + retry: + task_oncpu_function_call(task, __perf_event_disable, event); + + spin_lock_irq(&ctx->lock); + /* + * If the event is still active, we need to retry the cross-call. + */ + if (event->state == PERF_EVENT_STATE_ACTIVE) { + spin_unlock_irq(&ctx->lock); + goto retry; + } + + /* + * Since we have the lock this context can't be scheduled + * in, so we can change the state safely. + */ + if (event->state == PERF_EVENT_STATE_INACTIVE) { + update_group_times(event); + event->state = PERF_EVENT_STATE_OFF; + } + + spin_unlock_irq(&ctx->lock); +} + +static int +event_sched_in(struct perf_event *event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx, + int cpu) +{ + if (event->state <= PERF_EVENT_STATE_OFF) + return 0; + + event->state = PERF_EVENT_STATE_ACTIVE; + event->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ + /* + * The new state must be visible before we turn it on in the hardware: + */ + smp_wmb(); + + if (event->pmu->enable(event)) { + event->state = PERF_EVENT_STATE_INACTIVE; + event->oncpu = -1; + return -EAGAIN; + } + + event->tstamp_running += ctx->time - event->tstamp_stopped; + + if (!is_software_event(event)) + cpuctx->active_oncpu++; + ctx->nr_active++; + + if (event->attr.exclusive) + cpuctx->exclusive = 1; + + return 0; +} + +static int +group_sched_in(struct perf_event *group_event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx, + int cpu) +{ + struct perf_event *event, *partial_group; + int ret; + + if (group_event->state == PERF_EVENT_STATE_OFF) + return 0; + + ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu); + if (ret) + return ret < 0 ? ret : 0; + + if (event_sched_in(group_event, cpuctx, ctx, cpu)) + return -EAGAIN; + + /* + * Schedule in siblings as one group (if any): + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) { + if (event_sched_in(event, cpuctx, ctx, cpu)) { + partial_group = event; + goto group_error; + } + } + + return 0; + +group_error: + /* + * Groups can be scheduled in as one unit only, so undo any + * partial group before returning: + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) { + if (event == partial_group) + break; + event_sched_out(event, cpuctx, ctx); + } + event_sched_out(group_event, cpuctx, ctx); + + return -EAGAIN; +} + +/* + * Return 1 for a group consisting entirely of software events, + * 0 if the group contains any hardware events. + */ +static int is_software_only_group(struct perf_event *leader) +{ + struct perf_event *event; + + if (!is_software_event(leader)) + return 0; + + list_for_each_entry(event, &leader->sibling_list, group_entry) + if (!is_software_event(event)) + return 0; + + return 1; +} + +/* + * Work out whether we can put this event group on the CPU now. + */ +static int group_can_go_on(struct perf_event *event, + struct perf_cpu_context *cpuctx, + int can_add_hw) +{ + /* + * Groups consisting entirely of software events can always go on. + */ + if (is_software_only_group(event)) + return 1; + /* + * If an exclusive group is already on, no other hardware + * events can go on. + */ + if (cpuctx->exclusive) + return 0; + /* + * If this group is exclusive and there are already + * events on the CPU, it can't go on. + */ + if (event->attr.exclusive && cpuctx->active_oncpu) + return 0; + /* + * Otherwise, try to add it if all previous groups were able + * to go on. + */ + return can_add_hw; +} + +static void add_event_to_ctx(struct perf_event *event, + struct perf_event_context *ctx) +{ + list_add_event(event, ctx); + event->tstamp_enabled = ctx->time; + event->tstamp_running = ctx->time; + event->tstamp_stopped = ctx->time; +} + +/* + * Cross CPU call to install and enable a performance event + * + * Must be called with ctx->mutex held + */ +static void __perf_install_in_context(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event *event = info; + struct perf_event_context *ctx = event->ctx; + struct perf_event *leader = event->group_leader; + int cpu = smp_processor_id(); + int err; + + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. + * Or possibly this is the right context but it isn't + * on this cpu because it had no events. + */ + if (ctx->task && cpuctx->task_ctx != ctx) { + if (cpuctx->task_ctx || ctx->task != current) + return; + cpuctx->task_ctx = ctx; + } + + spin_lock(&ctx->lock); + ctx->is_active = 1; + update_context_time(ctx); + + /* + * Protect the list operation against NMI by disabling the + * events on a global level. NOP for non NMI based events. + */ + perf_disable(); + + add_event_to_ctx(event, ctx); + + /* + * Don't put the event on if it is disabled or if + * it is in a group and the group isn't on. + */ + if (event->state != PERF_EVENT_STATE_INACTIVE || + (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)) + goto unlock; + + /* + * An exclusive event can't go on if there are already active + * hardware events, and no hardware event can go on if there + * is already an exclusive event on. + */ + if (!group_can_go_on(event, cpuctx, 1)) + err = -EEXIST; + else + err = event_sched_in(event, cpuctx, ctx, cpu); + + if (err) { + /* + * This event couldn't go on. If it is in a group + * then we have to pull the whole group off. + * If the event group is pinned then put it in error state. + */ + if (leader != event) + group_sched_out(leader, cpuctx, ctx); + if (leader->attr.pinned) { + update_group_times(leader); + leader->state = PERF_EVENT_STATE_ERROR; + } + } + + if (!err && !ctx->task && cpuctx->max_pertask) + cpuctx->max_pertask--; + + unlock: + perf_enable(); + + spin_unlock(&ctx->lock); +} + +/* + * Attach a performance event to a context + * + * First we add the event to the list with the hardware enable bit + * in event->hw_config cleared. + * + * If the event is attached to a task which is on a CPU we use a smp + * call to enable it in the task context. The task might have been + * scheduled away, but we check this in the smp call again. + * + * Must be called with ctx->mutex held. + */ +static void +perf_install_in_context(struct perf_event_context *ctx, + struct perf_event *event, + int cpu) +{ + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Per cpu events are installed via an smp call and + * the install is always sucessful. + */ + smp_call_function_single(cpu, __perf_install_in_context, + event, 1); + return; + } + +retry: + task_oncpu_function_call(task, __perf_install_in_context, + event); + + spin_lock_irq(&ctx->lock); + /* + * we need to retry the smp call. + */ + if (ctx->is_active && list_empty(&event->group_entry)) { + spin_unlock_irq(&ctx->lock); + goto retry; + } + + /* + * The lock prevents that this context is scheduled in so we + * can add the event safely, if it the call above did not + * succeed. + */ + if (list_empty(&event->group_entry)) + add_event_to_ctx(event, ctx); + spin_unlock_irq(&ctx->lock); +} + +/* + * Put a event into inactive state and update time fields. + * Enabling the leader of a group effectively enables all + * the group members that aren't explicitly disabled, so we + * have to update their ->tstamp_enabled also. + * Note: this works for group members as well as group leaders + * since the non-leader members' sibling_lists will be empty. + */ +static void __perf_event_mark_enabled(struct perf_event *event, + struct perf_event_context *ctx) +{ + struct perf_event *sub; + + event->state = PERF_EVENT_STATE_INACTIVE; + event->tstamp_enabled = ctx->time - event->total_time_enabled; + list_for_each_entry(sub, &event->sibling_list, group_entry) + if (sub->state >= PERF_EVENT_STATE_INACTIVE) + sub->tstamp_enabled = + ctx->time - sub->total_time_enabled; +} + +/* + * Cross CPU call to enable a performance event + */ +static void __perf_event_enable(void *info) +{ + struct perf_event *event = info; + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = event->ctx; + struct perf_event *leader = event->group_leader; + int err; + + /* + * If this is a per-task event, need to check whether this + * event's task is the current task on this cpu. + */ + if (ctx->task && cpuctx->task_ctx != ctx) { + if (cpuctx->task_ctx || ctx->task != current) + return; + cpuctx->task_ctx = ctx; + } + + spin_lock(&ctx->lock); + ctx->is_active = 1; + update_context_time(ctx); + + if (event->state >= PERF_EVENT_STATE_INACTIVE) + goto unlock; + __perf_event_mark_enabled(event, ctx); + + /* + * If the event is in a group and isn't the group leader, + * then don't put it on unless the group is on. + */ + if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) + goto unlock; + + if (!group_can_go_on(event, cpuctx, 1)) { + err = -EEXIST; + } else { + perf_disable(); + if (event == leader) + err = group_sched_in(event, cpuctx, ctx, + smp_processor_id()); + else + err = event_sched_in(event, cpuctx, ctx, + smp_processor_id()); + perf_enable(); + } + + if (err) { + /* + * If this event can't go on and it's part of a + * group, then the whole group has to come off. + */ + if (leader != event) + group_sched_out(leader, cpuctx, ctx); + if (leader->attr.pinned) { + update_group_times(leader); + leader->state = PERF_EVENT_STATE_ERROR; + } + } + + unlock: + spin_unlock(&ctx->lock); +} + +/* + * Enable a event. + * + * If event->ctx is a cloned context, callers must make sure that + * every task struct that event->ctx->task could possibly point to + * remains valid. This condition is satisfied when called through + * perf_event_for_each_child or perf_event_for_each as described + * for perf_event_disable. + */ +static void perf_event_enable(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Enable the event on the cpu that it's on + */ + smp_call_function_single(event->cpu, __perf_event_enable, + event, 1); + return; + } + + spin_lock_irq(&ctx->lock); + if (event->state >= PERF_EVENT_STATE_INACTIVE) + goto out; + + /* + * If the event is in error state, clear that first. + * That way, if we see the event in error state below, we + * know that it has gone back into error state, as distinct + * from the task having been scheduled away before the + * cross-call arrived. + */ + if (event->state == PERF_EVENT_STATE_ERROR) + event->state = PERF_EVENT_STATE_OFF; + + retry: + spin_unlock_irq(&ctx->lock); + task_oncpu_function_call(task, __perf_event_enable, event); + + spin_lock_irq(&ctx->lock); + + /* + * If the context is active and the event is still off, + * we need to retry the cross-call. + */ + if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) + goto retry; + + /* + * Since we have the lock this context can't be scheduled + * in, so we can change the state safely. + */ + if (event->state == PERF_EVENT_STATE_OFF) + __perf_event_mark_enabled(event, ctx); + + out: + spin_unlock_irq(&ctx->lock); +} + +static int perf_event_refresh(struct perf_event *event, int refresh) +{ + /* + * not supported on inherited events + */ + if (event->attr.inherit) + return -EINVAL; + + atomic_add(refresh, &event->event_limit); + perf_event_enable(event); + + return 0; +} + +void __perf_event_sched_out(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx) +{ + struct perf_event *event; + + spin_lock(&ctx->lock); + ctx->is_active = 0; + if (likely(!ctx->nr_events)) + goto out; + update_context_time(ctx); + + perf_disable(); + if (ctx->nr_active) { + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (event != event->group_leader) + event_sched_out(event, cpuctx, ctx); + else + group_sched_out(event, cpuctx, ctx); + } + } + perf_enable(); + out: + spin_unlock(&ctx->lock); +} + +/* + * Test whether two contexts are equivalent, i.e. whether they + * have both been cloned from the same version of the same context + * and they both have the same number of enabled events. + * If the number of enabled events is the same, then the set + * of enabled events should be the same, because these are both + * inherited contexts, therefore we can't access individual events + * in them directly with an fd; we can only enable/disable all + * events via prctl, or enable/disable all events in a family + * via ioctl, which will have the same effect on both contexts. + */ +static int context_equiv(struct perf_event_context *ctx1, + struct perf_event_context *ctx2) +{ + return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx + && ctx1->parent_gen == ctx2->parent_gen + && !ctx1->pin_count && !ctx2->pin_count; +} + +static void __perf_event_read(void *event); + +static void __perf_event_sync_stat(struct perf_event *event, + struct perf_event *next_event) +{ + u64 value; + + if (!event->attr.inherit_stat) + return; + + /* + * Update the event value, we cannot use perf_event_read() + * because we're in the middle of a context switch and have IRQs + * disabled, which upsets smp_call_function_single(), however + * we know the event must be on the current CPU, therefore we + * don't need to use it. + */ + switch (event->state) { + case PERF_EVENT_STATE_ACTIVE: + __perf_event_read(event); + break; + + case PERF_EVENT_STATE_INACTIVE: + update_event_times(event); + break; + + default: + break; + } + + /* + * In order to keep per-task stats reliable we need to flip the event + * values when we flip the contexts. + */ + value = atomic64_read(&next_event->count); + value = atomic64_xchg(&event->count, value); + atomic64_set(&next_event->count, value); + + swap(event->total_time_enabled, next_event->total_time_enabled); + swap(event->total_time_running, next_event->total_time_running); + + /* + * Since we swizzled the values, update the user visible data too. + */ + perf_event_update_userpage(event); + perf_event_update_userpage(next_event); +} + +#define list_next_entry(pos, member) \ + list_entry(pos->member.next, typeof(*pos), member) + +static void perf_event_sync_stat(struct perf_event_context *ctx, + struct perf_event_context *next_ctx) +{ + struct perf_event *event, *next_event; + + if (!ctx->nr_stat) + return; + + event = list_first_entry(&ctx->event_list, + struct perf_event, event_entry); + + next_event = list_first_entry(&next_ctx->event_list, + struct perf_event, event_entry); + + while (&event->event_entry != &ctx->event_list && + &next_event->event_entry != &next_ctx->event_list) { + + __perf_event_sync_stat(event, next_event); + + event = list_next_entry(event, event_entry); + next_event = list_next_entry(next_event, event_entry); + } +} + +/* + * Called from scheduler to remove the events of the current task, + * with interrupts disabled. + * + * We stop each event and update the event value in event->count. + * + * This does not protect us against NMI, but disable() + * sets the disabled bit in the control field of event _before_ + * accessing the event control register. If a NMI hits, then it will + * not restart the event. + */ +void perf_event_task_sched_out(struct task_struct *task, + struct task_struct *next, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_event_context *ctx = task->perf_event_ctxp; + struct perf_event_context *next_ctx; + struct perf_event_context *parent; + struct pt_regs *regs; + int do_switch = 1; + + regs = task_pt_regs(task); + perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0); + + if (likely(!ctx || !cpuctx->task_ctx)) + return; + + update_context_time(ctx); + + rcu_read_lock(); + parent = rcu_dereference(ctx->parent_ctx); + next_ctx = next->perf_event_ctxp; + if (parent && next_ctx && + rcu_dereference(next_ctx->parent_ctx) == parent) { + /* + * Looks like the two contexts are clones, so we might be + * able to optimize the context switch. We lock both + * contexts and check that they are clones under the + * lock (including re-checking that neither has been + * uncloned in the meantime). It doesn't matter which + * order we take the locks because no other cpu could + * be trying to lock both of these tasks. + */ + spin_lock(&ctx->lock); + spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); + if (context_equiv(ctx, next_ctx)) { + /* + * XXX do we need a memory barrier of sorts + * wrt to rcu_dereference() of perf_event_ctxp + */ + task->perf_event_ctxp = next_ctx; + next->perf_event_ctxp = ctx; + ctx->task = next; + next_ctx->task = task; + do_switch = 0; + + perf_event_sync_stat(ctx, next_ctx); + } + spin_unlock(&next_ctx->lock); + spin_unlock(&ctx->lock); + } + rcu_read_unlock(); + + if (do_switch) { + __perf_event_sched_out(ctx, cpuctx); + cpuctx->task_ctx = NULL; + } +} + +/* + * Called with IRQs disabled + */ +static void __perf_event_task_sched_out(struct perf_event_context *ctx) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + + if (!cpuctx->task_ctx) + return; + + if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) + return; + + __perf_event_sched_out(ctx, cpuctx); + cpuctx->task_ctx = NULL; +} + +/* + * Called with IRQs disabled + */ +static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx) +{ + __perf_event_sched_out(&cpuctx->ctx, cpuctx); +} + +static void +__perf_event_sched_in(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx, int cpu) +{ + struct perf_event *event; + int can_add_hw = 1; + + spin_lock(&ctx->lock); + ctx->is_active = 1; + if (likely(!ctx->nr_events)) + goto out; + + ctx->timestamp = perf_clock(); + + perf_disable(); + + /* + * First go through the list and put on any pinned groups + * in order to give them the best chance of going on. + */ + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (event->state <= PERF_EVENT_STATE_OFF || + !event->attr.pinned) + continue; + if (event->cpu != -1 && event->cpu != cpu) + continue; + + if (event != event->group_leader) + event_sched_in(event, cpuctx, ctx, cpu); + else { + if (group_can_go_on(event, cpuctx, 1)) + group_sched_in(event, cpuctx, ctx, cpu); + } + + /* + * If this pinned group hasn't been scheduled, + * put it in error state. + */ + if (event->state == PERF_EVENT_STATE_INACTIVE) { + update_group_times(event); + event->state = PERF_EVENT_STATE_ERROR; + } + } + + list_for_each_entry(event, &ctx->group_list, group_entry) { + /* + * Ignore events in OFF or ERROR state, and + * ignore pinned events since we did them already. + */ + if (event->state <= PERF_EVENT_STATE_OFF || + event->attr.pinned) + continue; + + /* + * Listen to the 'cpu' scheduling filter constraint + * of events: + */ + if (event->cpu != -1 && event->cpu != cpu) + continue; + + if (event != event->group_leader) { + if (event_sched_in(event, cpuctx, ctx, cpu)) + can_add_hw = 0; + } else { + if (group_can_go_on(event, cpuctx, can_add_hw)) { + if (group_sched_in(event, cpuctx, ctx, cpu)) + can_add_hw = 0; + } + } + } + perf_enable(); + out: + spin_unlock(&ctx->lock); +} + +/* + * Called from scheduler to add the events of the current task + * with interrupts disabled. + * + * We restore the event value and then enable it. + * + * This does not protect us against NMI, but enable() + * sets the enabled bit in the control field of event _before_ + * accessing the event control register. If a NMI hits, then it will + * keep the event running. + */ +void perf_event_task_sched_in(struct task_struct *task, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_event_context *ctx = task->perf_event_ctxp; + + if (likely(!ctx)) + return; + if (cpuctx->task_ctx == ctx) + return; + __perf_event_sched_in(ctx, cpuctx, cpu); + cpuctx->task_ctx = ctx; +} + +static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) +{ + struct perf_event_context *ctx = &cpuctx->ctx; + + __perf_event_sched_in(ctx, cpuctx, cpu); +} + +#define MAX_INTERRUPTS (~0ULL) + +static void perf_log_throttle(struct perf_event *event, int enable); + +static void perf_adjust_period(struct perf_event *event, u64 events) +{ + struct hw_perf_event *hwc = &event->hw; + u64 period, sample_period; + s64 delta; + + events *= hwc->sample_period; + period = div64_u64(events, event->attr.sample_freq); + + delta = (s64)(period - hwc->sample_period); + delta = (delta + 7) / 8; /* low pass filter */ + + sample_period = hwc->sample_period + delta; + + if (!sample_period) + sample_period = 1; + + hwc->sample_period = sample_period; +} + +static void perf_ctx_adjust_freq(struct perf_event_context *ctx) +{ + struct perf_event *event; + struct hw_perf_event *hwc; + u64 interrupts, freq; + + spin_lock(&ctx->lock); + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (event->state != PERF_EVENT_STATE_ACTIVE) + continue; + + hwc = &event->hw; + + interrupts = hwc->interrupts; + hwc->interrupts = 0; + + /* + * unthrottle events on the tick + */ + if (interrupts == MAX_INTERRUPTS) { + perf_log_throttle(event, 1); + event->pmu->unthrottle(event); + interrupts = 2*sysctl_perf_event_sample_rate/HZ; + } + + if (!event->attr.freq || !event->attr.sample_freq) + continue; + + /* + * if the specified freq < HZ then we need to skip ticks + */ + if (event->attr.sample_freq < HZ) { + freq = event->attr.sample_freq; + + hwc->freq_count += freq; + hwc->freq_interrupts += interrupts; + + if (hwc->freq_count < HZ) + continue; + + interrupts = hwc->freq_interrupts; + hwc->freq_interrupts = 0; + hwc->freq_count -= HZ; + } else + freq = HZ; + + perf_adjust_period(event, freq * interrupts); + + /* + * In order to avoid being stalled by an (accidental) huge + * sample period, force reset the sample period if we didn't + * get any events in this freq period. + */ + if (!interrupts) { + perf_disable(); + event->pmu->disable(event); + atomic64_set(&hwc->period_left, 0); + event->pmu->enable(event); + perf_enable(); + } + } + spin_unlock(&ctx->lock); +} + +/* + * Round-robin a context's events: + */ +static void rotate_ctx(struct perf_event_context *ctx) +{ + struct perf_event *event; + + if (!ctx->nr_events) + return; + + spin_lock(&ctx->lock); + /* + * Rotate the first entry last (works just fine for group events too): + */ + perf_disable(); + list_for_each_entry(event, &ctx->group_list, group_entry) { + list_move_tail(&event->group_entry, &ctx->group_list); + break; + } + perf_enable(); + + spin_unlock(&ctx->lock); +} + +void perf_event_task_tick(struct task_struct *curr, int cpu) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; + + if (!atomic_read(&nr_events)) + return; + + cpuctx = &per_cpu(perf_cpu_context, cpu); + ctx = curr->perf_event_ctxp; + + perf_ctx_adjust_freq(&cpuctx->ctx); + if (ctx) + perf_ctx_adjust_freq(ctx); + + perf_event_cpu_sched_out(cpuctx); + if (ctx) + __perf_event_task_sched_out(ctx); + + rotate_ctx(&cpuctx->ctx); + if (ctx) + rotate_ctx(ctx); + + perf_event_cpu_sched_in(cpuctx, cpu); + if (ctx) + perf_event_task_sched_in(curr, cpu); +} + +/* + * Enable all of a task's events that have been marked enable-on-exec. + * This expects task == current. + */ +static void perf_event_enable_on_exec(struct task_struct *task) +{ + struct perf_event_context *ctx; + struct perf_event *event; + unsigned long flags; + int enabled = 0; + + local_irq_save(flags); + ctx = task->perf_event_ctxp; + if (!ctx || !ctx->nr_events) + goto out; + + __perf_event_task_sched_out(ctx); + + spin_lock(&ctx->lock); + + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (!event->attr.enable_on_exec) + continue; + event->attr.enable_on_exec = 0; + if (event->state >= PERF_EVENT_STATE_INACTIVE) + continue; + __perf_event_mark_enabled(event, ctx); + enabled = 1; + } + + /* + * Unclone this context if we enabled any event. + */ + if (enabled) + unclone_ctx(ctx); + + spin_unlock(&ctx->lock); + + perf_event_task_sched_in(task, smp_processor_id()); + out: + local_irq_restore(flags); +} + +/* + * Cross CPU call to read the hardware event + */ +static void __perf_event_read(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event *event = info; + struct perf_event_context *ctx = event->ctx; + unsigned long flags; + + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. In that case + * event->count would have been updated to a recent sample + * when the event was scheduled out. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + + local_irq_save(flags); + if (ctx->is_active) + update_context_time(ctx); + event->pmu->read(event); + update_event_times(event); + local_irq_restore(flags); +} + +static u64 perf_event_read(struct perf_event *event) +{ + /* + * If event is enabled and currently active on a CPU, update the + * value in the event structure: + */ + if (event->state == PERF_EVENT_STATE_ACTIVE) { + smp_call_function_single(event->oncpu, + __perf_event_read, event, 1); + } else if (event->state == PERF_EVENT_STATE_INACTIVE) { + update_event_times(event); + } + + return atomic64_read(&event->count); +} + +/* + * Initialize the perf_event context in a task_struct: + */ +static void +__perf_event_init_context(struct perf_event_context *ctx, + struct task_struct *task) +{ + memset(ctx, 0, sizeof(*ctx)); + spin_lock_init(&ctx->lock); + mutex_init(&ctx->mutex); + INIT_LIST_HEAD(&ctx->group_list); + INIT_LIST_HEAD(&ctx->event_list); + atomic_set(&ctx->refcount, 1); + ctx->task = task; +} + +static struct perf_event_context *find_get_context(pid_t pid, int cpu) +{ + struct perf_event_context *ctx; + struct perf_cpu_context *cpuctx; + struct task_struct *task; + unsigned long flags; + int err; + + /* + * If cpu is not a wildcard then this is a percpu event: + */ + if (cpu != -1) { + /* Must be root to operate on a CPU event: */ + if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EACCES); + + if (cpu < 0 || cpu > num_possible_cpus()) + return ERR_PTR(-EINVAL); + + /* + * We could be clever and allow to attach a event to an + * offline CPU and activate it when the CPU comes up, but + * that's for later. + */ + if (!cpu_isset(cpu, cpu_online_map)) + return ERR_PTR(-ENODEV); + + cpuctx = &per_cpu(perf_cpu_context, cpu); + ctx = &cpuctx->ctx; + get_ctx(ctx); + + return ctx; + } + + rcu_read_lock(); + if (!pid) + task = current; + else + task = find_task_by_vpid(pid); + if (task) + get_task_struct(task); + rcu_read_unlock(); + + if (!task) + return ERR_PTR(-ESRCH); + + /* + * Can't attach events to a dying task. + */ + err = -ESRCH; + if (task->flags & PF_EXITING) + goto errout; + + /* Reuse ptrace permission checks for now. */ + err = -EACCES; + if (!ptrace_may_access(task, PTRACE_MODE_READ)) + goto errout; + + retry: + ctx = perf_lock_task_context(task, &flags); + if (ctx) { + unclone_ctx(ctx); + spin_unlock_irqrestore(&ctx->lock, flags); + } + + if (!ctx) { + ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL); + err = -ENOMEM; + if (!ctx) + goto errout; + __perf_event_init_context(ctx, task); + get_ctx(ctx); + if (cmpxchg(&task->perf_event_ctxp, NULL, ctx)) { + /* + * We raced with some other task; use + * the context they set. + */ + kfree(ctx); + goto retry; + } + get_task_struct(task); + } + + put_task_struct(task); + return ctx; + + errout: + put_task_struct(task); + return ERR_PTR(err); +} + +static void free_event_rcu(struct rcu_head *head) +{ + struct perf_event *event; + + event = container_of(head, struct perf_event, rcu_head); + if (event->ns) + put_pid_ns(event->ns); + kfree(event); +} + +static void perf_pending_sync(struct perf_event *event); + +static void free_event(struct perf_event *event) +{ + perf_pending_sync(event); + + if (!event->parent) { + atomic_dec(&nr_events); + if (event->attr.mmap) + atomic_dec(&nr_mmap_events); + if (event->attr.comm) + atomic_dec(&nr_comm_events); + if (event->attr.task) + atomic_dec(&nr_task_events); + } + + if (event->output) { + fput(event->output->filp); + event->output = NULL; + } + + if (event->destroy) + event->destroy(event); + + put_ctx(event->ctx); + call_rcu(&event->rcu_head, free_event_rcu); +} + +/* + * Called when the last reference to the file is gone. + */ +static int perf_release(struct inode *inode, struct file *file) +{ + struct perf_event *event = file->private_data; + struct perf_event_context *ctx = event->ctx; + + file->private_data = NULL; + + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + perf_event_remove_from_context(event); + mutex_unlock(&ctx->mutex); + + mutex_lock(&event->owner->perf_event_mutex); + list_del_init(&event->owner_entry); + mutex_unlock(&event->owner->perf_event_mutex); + put_task_struct(event->owner); + + free_event(event); + + return 0; +} + +static int perf_event_read_size(struct perf_event *event) +{ + int entry = sizeof(u64); /* value */ + int size = 0; + int nr = 1; + + if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) + size += sizeof(u64); + + if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) + size += sizeof(u64); + + if (event->attr.read_format & PERF_FORMAT_ID) + entry += sizeof(u64); + + if (event->attr.read_format & PERF_FORMAT_GROUP) { + nr += event->group_leader->nr_siblings; + size += sizeof(u64); + } + + size += entry * nr; + + return size; +} + +static u64 perf_event_read_value(struct perf_event *event) +{ + struct perf_event *child; + u64 total = 0; + + total += perf_event_read(event); + list_for_each_entry(child, &event->child_list, child_list) + total += perf_event_read(child); + + return total; +} + +static int perf_event_read_entry(struct perf_event *event, + u64 read_format, char __user *buf) +{ + int n = 0, count = 0; + u64 values[2]; + + values[n++] = perf_event_read_value(event); + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(event); + + count = n * sizeof(u64); + + if (copy_to_user(buf, values, count)) + return -EFAULT; + + return count; +} + +static int perf_event_read_group(struct perf_event *event, + u64 read_format, char __user *buf) +{ + struct perf_event *leader = event->group_leader, *sub; + int n = 0, size = 0, err = -EFAULT; + u64 values[3]; + + values[n++] = 1 + leader->nr_siblings; + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { + values[n++] = leader->total_time_enabled + + atomic64_read(&leader->child_total_time_enabled); + } + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { + values[n++] = leader->total_time_running + + atomic64_read(&leader->child_total_time_running); + } + + size = n * sizeof(u64); + + if (copy_to_user(buf, values, size)) + return -EFAULT; + + err = perf_event_read_entry(leader, read_format, buf + size); + if (err < 0) + return err; + + size += err; + + list_for_each_entry(sub, &leader->sibling_list, group_entry) { + err = perf_event_read_entry(sub, read_format, + buf + size); + if (err < 0) + return err; + + size += err; + } + + return size; +} + +static int perf_event_read_one(struct perf_event *event, + u64 read_format, char __user *buf) +{ + u64 values[4]; + int n = 0; + + values[n++] = perf_event_read_value(event); + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { + values[n++] = event->total_time_enabled + + atomic64_read(&event->child_total_time_enabled); + } + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { + values[n++] = event->total_time_running + + atomic64_read(&event->child_total_time_running); + } + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(event); + + if (copy_to_user(buf, values, n * sizeof(u64))) + return -EFAULT; + + return n * sizeof(u64); +} + +/* + * Read the performance event - simple non blocking version for now + */ +static ssize_t +perf_read_hw(struct perf_event *event, char __user *buf, size_t count) +{ + u64 read_format = event->attr.read_format; + int ret; + + /* + * Return end-of-file for a read on a event that is in + * error state (i.e. because it was pinned but it couldn't be + * scheduled on to the CPU at some point). + */ + if (event->state == PERF_EVENT_STATE_ERROR) + return 0; + + if (count < perf_event_read_size(event)) + return -ENOSPC; + + WARN_ON_ONCE(event->ctx->parent_ctx); + mutex_lock(&event->child_mutex); + if (read_format & PERF_FORMAT_GROUP) + ret = perf_event_read_group(event, read_format, buf); + else + ret = perf_event_read_one(event, read_format, buf); + mutex_unlock(&event->child_mutex); + + return ret; +} + +static ssize_t +perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) +{ + struct perf_event *event = file->private_data; + + return perf_read_hw(event, buf, count); +} + +static unsigned int perf_poll(struct file *file, poll_table *wait) +{ + struct perf_event *event = file->private_data; + struct perf_mmap_data *data; + unsigned int events = POLL_HUP; + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (data) + events = atomic_xchg(&data->poll, 0); + rcu_read_unlock(); + + poll_wait(file, &event->waitq, wait); + + return events; +} + +static void perf_event_reset(struct perf_event *event) +{ + (void)perf_event_read(event); + atomic64_set(&event->count, 0); + perf_event_update_userpage(event); +} + +/* + * Holding the top-level event's child_mutex means that any + * descendant process that has inherited this event will block + * in sync_child_event if it goes to exit, thus satisfying the + * task existence requirements of perf_event_enable/disable. + */ +static void perf_event_for_each_child(struct perf_event *event, + void (*func)(struct perf_event *)) +{ + struct perf_event *child; + + WARN_ON_ONCE(event->ctx->parent_ctx); + mutex_lock(&event->child_mutex); + func(event); + list_for_each_entry(child, &event->child_list, child_list) + func(child); + mutex_unlock(&event->child_mutex); +} + +static void perf_event_for_each(struct perf_event *event, + void (*func)(struct perf_event *)) +{ + struct perf_event_context *ctx = event->ctx; + struct perf_event *sibling; + + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + event = event->group_leader; + + perf_event_for_each_child(event, func); + func(event); + list_for_each_entry(sibling, &event->sibling_list, group_entry) + perf_event_for_each_child(event, func); + mutex_unlock(&ctx->mutex); +} + +static int perf_event_period(struct perf_event *event, u64 __user *arg) +{ + struct perf_event_context *ctx = event->ctx; + unsigned long size; + int ret = 0; + u64 value; + + if (!event->attr.sample_period) + return -EINVAL; + + size = copy_from_user(&value, arg, sizeof(value)); + if (size != sizeof(value)) + return -EFAULT; + + if (!value) + return -EINVAL; + + spin_lock_irq(&ctx->lock); + if (event->attr.freq) { + if (value > sysctl_perf_event_sample_rate) { + ret = -EINVAL; + goto unlock; + } + + event->attr.sample_freq = value; + } else { + event->attr.sample_period = value; + event->hw.sample_period = value; + } +unlock: + spin_unlock_irq(&ctx->lock); + + return ret; +} + +int perf_event_set_output(struct perf_event *event, int output_fd); + +static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct perf_event *event = file->private_data; + void (*func)(struct perf_event *); + u32 flags = arg; + + switch (cmd) { + case PERF_EVENT_IOC_ENABLE: + func = perf_event_enable; + break; + case PERF_EVENT_IOC_DISABLE: + func = perf_event_disable; + break; + case PERF_EVENT_IOC_RESET: + func = perf_event_reset; + break; + + case PERF_EVENT_IOC_REFRESH: + return perf_event_refresh(event, arg); + + case PERF_EVENT_IOC_PERIOD: + return perf_event_period(event, (u64 __user *)arg); + + case PERF_EVENT_IOC_SET_OUTPUT: + return perf_event_set_output(event, arg); + + default: + return -ENOTTY; + } + + if (flags & PERF_IOC_FLAG_GROUP) + perf_event_for_each(event, func); + else + perf_event_for_each_child(event, func); + + return 0; +} + +int perf_event_task_enable(void) +{ + struct perf_event *event; + + mutex_lock(¤t->perf_event_mutex); + list_for_each_entry(event, ¤t->perf_event_list, owner_entry) + perf_event_for_each_child(event, perf_event_enable); + mutex_unlock(¤t->perf_event_mutex); + + return 0; +} + +int perf_event_task_disable(void) +{ + struct perf_event *event; + + mutex_lock(¤t->perf_event_mutex); + list_for_each_entry(event, ¤t->perf_event_list, owner_entry) + perf_event_for_each_child(event, perf_event_disable); + mutex_unlock(¤t->perf_event_mutex); + + return 0; +} + +#ifndef PERF_EVENT_INDEX_OFFSET +# define PERF_EVENT_INDEX_OFFSET 0 +#endif + +static int perf_event_index(struct perf_event *event) +{ + if (event->state != PERF_EVENT_STATE_ACTIVE) + return 0; + + return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET; +} + +/* + * Callers need to ensure there can be no nesting of this function, otherwise + * the seqlock logic goes bad. We can not serialize this because the arch + * code calls this from NMI context. + */ +void perf_event_update_userpage(struct perf_event *event) +{ + struct perf_event_mmap_page *userpg; + struct perf_mmap_data *data; + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (!data) + goto unlock; + + userpg = data->user_page; + + /* + * Disable preemption so as to not let the corresponding user-space + * spin too long if we get preempted. + */ + preempt_disable(); + ++userpg->lock; + barrier(); + userpg->index = perf_event_index(event); + userpg->offset = atomic64_read(&event->count); + if (event->state == PERF_EVENT_STATE_ACTIVE) + userpg->offset -= atomic64_read(&event->hw.prev_count); + + userpg->time_enabled = event->total_time_enabled + + atomic64_read(&event->child_total_time_enabled); + + userpg->time_running = event->total_time_running + + atomic64_read(&event->child_total_time_running); + + barrier(); + ++userpg->lock; + preempt_enable(); +unlock: + rcu_read_unlock(); +} + +static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct perf_event *event = vma->vm_file->private_data; + struct perf_mmap_data *data; + int ret = VM_FAULT_SIGBUS; + + if (vmf->flags & FAULT_FLAG_MKWRITE) { + if (vmf->pgoff == 0) + ret = 0; + return ret; + } + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (!data) + goto unlock; + + if (vmf->pgoff == 0) { + vmf->page = virt_to_page(data->user_page); + } else { + int nr = vmf->pgoff - 1; + + if ((unsigned)nr > data->nr_pages) + goto unlock; + + if (vmf->flags & FAULT_FLAG_WRITE) + goto unlock; + + vmf->page = virt_to_page(data->data_pages[nr]); + } + + get_page(vmf->page); + vmf->page->mapping = vma->vm_file->f_mapping; + vmf->page->index = vmf->pgoff; + + ret = 0; +unlock: + rcu_read_unlock(); + + return ret; +} + +static int perf_mmap_data_alloc(struct perf_event *event, int nr_pages) +{ + struct perf_mmap_data *data; + unsigned long size; + int i; + + WARN_ON(atomic_read(&event->mmap_count)); + + size = sizeof(struct perf_mmap_data); + size += nr_pages * sizeof(void *); + + data = kzalloc(size, GFP_KERNEL); + if (!data) + goto fail; + + data->user_page = (void *)get_zeroed_page(GFP_KERNEL); + if (!data->user_page) + goto fail_user_page; + + for (i = 0; i < nr_pages; i++) { + data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL); + if (!data->data_pages[i]) + goto fail_data_pages; + } + + data->nr_pages = nr_pages; + atomic_set(&data->lock, -1); + + if (event->attr.watermark) { + data->watermark = min_t(long, PAGE_SIZE * nr_pages, + event->attr.wakeup_watermark); + } + if (!data->watermark) + data->watermark = max(PAGE_SIZE, PAGE_SIZE * nr_pages / 4); + + rcu_assign_pointer(event->data, data); + + return 0; + +fail_data_pages: + for (i--; i >= 0; i--) + free_page((unsigned long)data->data_pages[i]); + + free_page((unsigned long)data->user_page); + +fail_user_page: + kfree(data); + +fail: + return -ENOMEM; +} + +static void perf_mmap_free_page(unsigned long addr) +{ + struct page *page = virt_to_page((void *)addr); + + page->mapping = NULL; + __free_page(page); +} + +static void __perf_mmap_data_free(struct rcu_head *rcu_head) +{ + struct perf_mmap_data *data; + int i; + + data = container_of(rcu_head, struct perf_mmap_data, rcu_head); + + perf_mmap_free_page((unsigned long)data->user_page); + for (i = 0; i < data->nr_pages; i++) + perf_mmap_free_page((unsigned long)data->data_pages[i]); + + kfree(data); +} + +static void perf_mmap_data_free(struct perf_event *event) +{ + struct perf_mmap_data *data = event->data; + + WARN_ON(atomic_read(&event->mmap_count)); + + rcu_assign_pointer(event->data, NULL); + call_rcu(&data->rcu_head, __perf_mmap_data_free); +} + +static void perf_mmap_open(struct vm_area_struct *vma) +{ + struct perf_event *event = vma->vm_file->private_data; + + atomic_inc(&event->mmap_count); +} + +static void perf_mmap_close(struct vm_area_struct *vma) +{ + struct perf_event *event = vma->vm_file->private_data; + + WARN_ON_ONCE(event->ctx->parent_ctx); + if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) { + struct user_struct *user = current_user(); + + atomic_long_sub(event->data->nr_pages + 1, &user->locked_vm); + vma->vm_mm->locked_vm -= event->data->nr_locked; + perf_mmap_data_free(event); + mutex_unlock(&event->mmap_mutex); + } +} + +static struct vm_operations_struct perf_mmap_vmops = { + .open = perf_mmap_open, + .close = perf_mmap_close, + .fault = perf_mmap_fault, + .page_mkwrite = perf_mmap_fault, +}; + +static int perf_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct perf_event *event = file->private_data; + unsigned long user_locked, user_lock_limit; + struct user_struct *user = current_user(); + unsigned long locked, lock_limit; + unsigned long vma_size; + unsigned long nr_pages; + long user_extra, extra; + int ret = 0; + + if (!(vma->vm_flags & VM_SHARED)) + return -EINVAL; + + vma_size = vma->vm_end - vma->vm_start; + nr_pages = (vma_size / PAGE_SIZE) - 1; + + /* + * If we have data pages ensure they're a power-of-two number, so we + * can do bitmasks instead of modulo. + */ + if (nr_pages != 0 && !is_power_of_2(nr_pages)) + return -EINVAL; + + if (vma_size != PAGE_SIZE * (1 + nr_pages)) + return -EINVAL; + + if (vma->vm_pgoff != 0) + return -EINVAL; + + WARN_ON_ONCE(event->ctx->parent_ctx); + mutex_lock(&event->mmap_mutex); + if (event->output) { + ret = -EINVAL; + goto unlock; + } + + if (atomic_inc_not_zero(&event->mmap_count)) { + if (nr_pages != event->data->nr_pages) + ret = -EINVAL; + goto unlock; + } + + user_extra = nr_pages + 1; + user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); + + /* + * Increase the limit linearly with more CPUs: + */ + user_lock_limit *= num_online_cpus(); + + user_locked = atomic_long_read(&user->locked_vm) + user_extra; + + extra = 0; + if (user_locked > user_lock_limit) + extra = user_locked - user_lock_limit; + + lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; + lock_limit >>= PAGE_SHIFT; + locked = vma->vm_mm->locked_vm + extra; + + if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && + !capable(CAP_IPC_LOCK)) { + ret = -EPERM; + goto unlock; + } + + WARN_ON(event->data); + ret = perf_mmap_data_alloc(event, nr_pages); + if (ret) + goto unlock; + + atomic_set(&event->mmap_count, 1); + atomic_long_add(user_extra, &user->locked_vm); + vma->vm_mm->locked_vm += extra; + event->data->nr_locked = extra; + if (vma->vm_flags & VM_WRITE) + event->data->writable = 1; + +unlock: + mutex_unlock(&event->mmap_mutex); + + vma->vm_flags |= VM_RESERVED; + vma->vm_ops = &perf_mmap_vmops; + + return ret; +} + +static int perf_fasync(int fd, struct file *filp, int on) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + struct perf_event *event = filp->private_data; + int retval; + + mutex_lock(&inode->i_mutex); + retval = fasync_helper(fd, filp, on, &event->fasync); + mutex_unlock(&inode->i_mutex); + + if (retval < 0) + return retval; + + return 0; +} + +static const struct file_operations perf_fops = { + .release = perf_release, + .read = perf_read, + .poll = perf_poll, + .unlocked_ioctl = perf_ioctl, + .compat_ioctl = perf_ioctl, + .mmap = perf_mmap, + .fasync = perf_fasync, +}; + +/* + * Perf event wakeup + * + * If there's data, ensure we set the poll() state and publish everything + * to user-space before waking everybody up. + */ + +void perf_event_wakeup(struct perf_event *event) +{ + wake_up_all(&event->waitq); + + if (event->pending_kill) { + kill_fasync(&event->fasync, SIGIO, event->pending_kill); + event->pending_kill = 0; + } +} + +/* + * Pending wakeups + * + * Handle the case where we need to wakeup up from NMI (or rq->lock) context. + * + * The NMI bit means we cannot possibly take locks. Therefore, maintain a + * single linked list and use cmpxchg() to add entries lockless. + */ + +static void perf_pending_event(struct perf_pending_entry *entry) +{ + struct perf_event *event = container_of(entry, + struct perf_event, pending); + + if (event->pending_disable) { + event->pending_disable = 0; + __perf_event_disable(event); + } + + if (event->pending_wakeup) { + event->pending_wakeup = 0; + perf_event_wakeup(event); + } +} + +#define PENDING_TAIL ((struct perf_pending_entry *)-1UL) + +static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = { + PENDING_TAIL, +}; + +static void perf_pending_queue(struct perf_pending_entry *entry, + void (*func)(struct perf_pending_entry *)) +{ + struct perf_pending_entry **head; + + if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL) + return; + + entry->func = func; + + head = &get_cpu_var(perf_pending_head); + + do { + entry->next = *head; + } while (cmpxchg(head, entry->next, entry) != entry->next); + + set_perf_event_pending(); + + put_cpu_var(perf_pending_head); +} + +static int __perf_pending_run(void) +{ + struct perf_pending_entry *list; + int nr = 0; + + list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL); + while (list != PENDING_TAIL) { + void (*func)(struct perf_pending_entry *); + struct perf_pending_entry *entry = list; + + list = list->next; + + func = entry->func; + entry->next = NULL; + /* + * Ensure we observe the unqueue before we issue the wakeup, + * so that we won't be waiting forever. + * -- see perf_not_pending(). + */ + smp_wmb(); + + func(entry); + nr++; + } + + return nr; +} + +static inline int perf_not_pending(struct perf_event *event) +{ + /* + * If we flush on whatever cpu we run, there is a chance we don't + * need to wait. + */ + get_cpu(); + __perf_pending_run(); + put_cpu(); + + /* + * Ensure we see the proper queue state before going to sleep + * so that we do not miss the wakeup. -- see perf_pending_handle() + */ + smp_rmb(); + return event->pending.next == NULL; +} + +static void perf_pending_sync(struct perf_event *event) +{ + wait_event(event->waitq, perf_not_pending(event)); +} + +void perf_event_do_pending(void) +{ + __perf_pending_run(); +} + +/* + * Callchain support -- arch specific + */ + +__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) +{ + return NULL; +} + +/* + * Output + */ +static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail, + unsigned long offset, unsigned long head) +{ + unsigned long mask; + + if (!data->writable) + return true; + + mask = (data->nr_pages << PAGE_SHIFT) - 1; + + offset = (offset - tail) & mask; + head = (head - tail) & mask; + + if ((int)(head - offset) < 0) + return false; + + return true; +} + +static void perf_output_wakeup(struct perf_output_handle *handle) +{ + atomic_set(&handle->data->poll, POLL_IN); + + if (handle->nmi) { + handle->event->pending_wakeup = 1; + perf_pending_queue(&handle->event->pending, + perf_pending_event); + } else + perf_event_wakeup(handle->event); +} + +/* + * Curious locking construct. + * + * We need to ensure a later event_id doesn't publish a head when a former + * event_id isn't done writing. However since we need to deal with NMIs we + * cannot fully serialize things. + * + * What we do is serialize between CPUs so we only have to deal with NMI + * nesting on a single CPU. + * + * We only publish the head (and generate a wakeup) when the outer-most + * event_id completes. + */ +static void perf_output_lock(struct perf_output_handle *handle) +{ + struct perf_mmap_data *data = handle->data; + int cpu; + + handle->locked = 0; + + local_irq_save(handle->flags); + cpu = smp_processor_id(); + + if (in_nmi() && atomic_read(&data->lock) == cpu) + return; + + while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) + cpu_relax(); + + handle->locked = 1; +} + +static void perf_output_unlock(struct perf_output_handle *handle) +{ + struct perf_mmap_data *data = handle->data; + unsigned long head; + int cpu; + + data->done_head = data->head; + + if (!handle->locked) + goto out; + +again: + /* + * The xchg implies a full barrier that ensures all writes are done + * before we publish the new head, matched by a rmb() in userspace when + * reading this position. + */ + while ((head = atomic_long_xchg(&data->done_head, 0))) + data->user_page->data_head = head; + + /* + * NMI can happen here, which means we can miss a done_head update. + */ + + cpu = atomic_xchg(&data->lock, -1); + WARN_ON_ONCE(cpu != smp_processor_id()); + + /* + * Therefore we have to validate we did not indeed do so. + */ + if (unlikely(atomic_long_read(&data->done_head))) { + /* + * Since we had it locked, we can lock it again. + */ + while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) + cpu_relax(); + + goto again; + } + + if (atomic_xchg(&data->wakeup, 0)) + perf_output_wakeup(handle); +out: + local_irq_restore(handle->flags); +} + +void perf_output_copy(struct perf_output_handle *handle, + const void *buf, unsigned int len) +{ + unsigned int pages_mask; + unsigned int offset; + unsigned int size; + void **pages; + + offset = handle->offset; + pages_mask = handle->data->nr_pages - 1; + pages = handle->data->data_pages; + + do { + unsigned int page_offset; + int nr; + + nr = (offset >> PAGE_SHIFT) & pages_mask; + page_offset = offset & (PAGE_SIZE - 1); + size = min_t(unsigned int, PAGE_SIZE - page_offset, len); + + memcpy(pages[nr] + page_offset, buf, size); + + len -= size; + buf += size; + offset += size; + } while (len); + + handle->offset = offset; + + /* + * Check we didn't copy past our reservation window, taking the + * possible unsigned int wrap into account. + */ + WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); +} + +int perf_output_begin(struct perf_output_handle *handle, + struct perf_event *event, unsigned int size, + int nmi, int sample) +{ + struct perf_event *output_event; + struct perf_mmap_data *data; + unsigned long tail, offset, head; + int have_lost; + struct { + struct perf_event_header header; + u64 id; + u64 lost; + } lost_event; + + rcu_read_lock(); + /* + * For inherited events we send all the output towards the parent. + */ + if (event->parent) + event = event->parent; + + output_event = rcu_dereference(event->output); + if (output_event) + event = output_event; + + data = rcu_dereference(event->data); + if (!data) + goto out; + + handle->data = data; + handle->event = event; + handle->nmi = nmi; + handle->sample = sample; + + if (!data->nr_pages) + goto fail; + + have_lost = atomic_read(&data->lost); + if (have_lost) + size += sizeof(lost_event); + + perf_output_lock(handle); + + do { + /* + * Userspace could choose to issue a mb() before updating the + * tail pointer. So that all reads will be completed before the + * write is issued. + */ + tail = ACCESS_ONCE(data->user_page->data_tail); + smp_rmb(); + offset = head = atomic_long_read(&data->head); + head += size; + if (unlikely(!perf_output_space(data, tail, offset, head))) + goto fail; + } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); + + handle->offset = offset; + handle->head = head; + + if (head - tail > data->watermark) + atomic_set(&data->wakeup, 1); + + if (have_lost) { + lost_event.header.type = PERF_RECORD_LOST; + lost_event.header.misc = 0; + lost_event.header.size = sizeof(lost_event); + lost_event.id = event->id; + lost_event.lost = atomic_xchg(&data->lost, 0); + + perf_output_put(handle, lost_event); + } + + return 0; + +fail: + atomic_inc(&data->lost); + perf_output_unlock(handle); +out: + rcu_read_unlock(); + + return -ENOSPC; +} + +void perf_output_end(struct perf_output_handle *handle) +{ + struct perf_event *event = handle->event; + struct perf_mmap_data *data = handle->data; + + int wakeup_events = event->attr.wakeup_events; + + if (handle->sample && wakeup_events) { + int events = atomic_inc_return(&data->events); + if (events >= wakeup_events) { + atomic_sub(wakeup_events, &data->events); + atomic_set(&data->wakeup, 1); + } + } + + perf_output_unlock(handle); + rcu_read_unlock(); +} + +static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) +{ + /* + * only top level events have the pid namespace they were created in + */ + if (event->parent) + event = event->parent; + + return task_tgid_nr_ns(p, event->ns); +} + +static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) +{ + /* + * only top level events have the pid namespace they were created in + */ + if (event->parent) + event = event->parent; + + return task_pid_nr_ns(p, event->ns); +} + +static void perf_output_read_one(struct perf_output_handle *handle, + struct perf_event *event) +{ + u64 read_format = event->attr.read_format; + u64 values[4]; + int n = 0; + + values[n++] = atomic64_read(&event->count); + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { + values[n++] = event->total_time_enabled + + atomic64_read(&event->child_total_time_enabled); + } + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { + values[n++] = event->total_time_running + + atomic64_read(&event->child_total_time_running); + } + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(event); + + perf_output_copy(handle, values, n * sizeof(u64)); +} + +/* + * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. + */ +static void perf_output_read_group(struct perf_output_handle *handle, + struct perf_event *event) +{ + struct perf_event *leader = event->group_leader, *sub; + u64 read_format = event->attr.read_format; + u64 values[5]; + int n = 0; + + values[n++] = 1 + leader->nr_siblings; + + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) + values[n++] = leader->total_time_enabled; + + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) + values[n++] = leader->total_time_running; + + if (leader != event) + leader->pmu->read(leader); + + values[n++] = atomic64_read(&leader->count); + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(leader); + + perf_output_copy(handle, values, n * sizeof(u64)); + + list_for_each_entry(sub, &leader->sibling_list, group_entry) { + n = 0; + + if (sub != event) + sub->pmu->read(sub); + + values[n++] = atomic64_read(&sub->count); + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(sub); + + perf_output_copy(handle, values, n * sizeof(u64)); + } +} + +static void perf_output_read(struct perf_output_handle *handle, + struct perf_event *event) +{ + if (event->attr.read_format & PERF_FORMAT_GROUP) + perf_output_read_group(handle, event); + else + perf_output_read_one(handle, event); +} + +void perf_output_sample(struct perf_output_handle *handle, + struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_event *event) +{ + u64 sample_type = data->type; + + perf_output_put(handle, *header); + + if (sample_type & PERF_SAMPLE_IP) + perf_output_put(handle, data->ip); + + if (sample_type & PERF_SAMPLE_TID) + perf_output_put(handle, data->tid_entry); + + if (sample_type & PERF_SAMPLE_TIME) + perf_output_put(handle, data->time); + + if (sample_type & PERF_SAMPLE_ADDR) + perf_output_put(handle, data->addr); + + if (sample_type & PERF_SAMPLE_ID) + perf_output_put(handle, data->id); + + if (sample_type & PERF_SAMPLE_STREAM_ID) + perf_output_put(handle, data->stream_id); + + if (sample_type & PERF_SAMPLE_CPU) + perf_output_put(handle, data->cpu_entry); + + if (sample_type & PERF_SAMPLE_PERIOD) + perf_output_put(handle, data->period); + + if (sample_type & PERF_SAMPLE_READ) + perf_output_read(handle, event); + + if (sample_type & PERF_SAMPLE_CALLCHAIN) { + if (data->callchain) { + int size = 1; + + if (data->callchain) + size += data->callchain->nr; + + size *= sizeof(u64); + + perf_output_copy(handle, data->callchain, size); + } else { + u64 nr = 0; + perf_output_put(handle, nr); + } + } + + if (sample_type & PERF_SAMPLE_RAW) { + if (data->raw) { + perf_output_put(handle, data->raw->size); + perf_output_copy(handle, data->raw->data, + data->raw->size); + } else { + struct { + u32 size; + u32 data; + } raw = { + .size = sizeof(u32), + .data = 0, + }; + perf_output_put(handle, raw); + } + } +} + +void perf_prepare_sample(struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_event *event, + struct pt_regs *regs) +{ + u64 sample_type = event->attr.sample_type; + + data->type = sample_type; + + header->type = PERF_RECORD_SAMPLE; + header->size = sizeof(*header); + + header->misc = 0; + header->misc |= perf_misc_flags(regs); + + if (sample_type & PERF_SAMPLE_IP) { + data->ip = perf_instruction_pointer(regs); + + header->size += sizeof(data->ip); + } + + if (sample_type & PERF_SAMPLE_TID) { + /* namespace issues */ + data->tid_entry.pid = perf_event_pid(event, current); + data->tid_entry.tid = perf_event_tid(event, current); + + header->size += sizeof(data->tid_entry); + } + + if (sample_type & PERF_SAMPLE_TIME) { + data->time = perf_clock(); + + header->size += sizeof(data->time); + } + + if (sample_type & PERF_SAMPLE_ADDR) + header->size += sizeof(data->addr); + + if (sample_type & PERF_SAMPLE_ID) { + data->id = primary_event_id(event); + + header->size += sizeof(data->id); + } + + if (sample_type & PERF_SAMPLE_STREAM_ID) { + data->stream_id = event->id; + + header->size += sizeof(data->stream_id); + } + + if (sample_type & PERF_SAMPLE_CPU) { + data->cpu_entry.cpu = raw_smp_processor_id(); + data->cpu_entry.reserved = 0; + + header->size += sizeof(data->cpu_entry); + } + + if (sample_type & PERF_SAMPLE_PERIOD) + header->size += sizeof(data->period); + + if (sample_type & PERF_SAMPLE_READ) + header->size += perf_event_read_size(event); + + if (sample_type & PERF_SAMPLE_CALLCHAIN) { + int size = 1; + + data->callchain = perf_callchain(regs); + + if (data->callchain) + size += data->callchain->nr; + + header->size += size * sizeof(u64); + } + + if (sample_type & PERF_SAMPLE_RAW) { + int size = sizeof(u32); + + if (data->raw) + size += data->raw->size; + else + size += sizeof(u32); + + WARN_ON_ONCE(size & (sizeof(u64)-1)); + header->size += size; + } +} + +static void perf_event_output(struct perf_event *event, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_output_handle handle; + struct perf_event_header header; + + perf_prepare_sample(&header, data, event, regs); + + if (perf_output_begin(&handle, event, header.size, nmi, 1)) + return; + + perf_output_sample(&handle, &header, data, event); + + perf_output_end(&handle); +} + +/* + * read event_id + */ + +struct perf_read_event { + struct perf_event_header header; + + u32 pid; + u32 tid; +}; + +static void +perf_event_read_event(struct perf_event *event, + struct task_struct *task) +{ + struct perf_output_handle handle; + struct perf_read_event read_event = { + .header = { + .type = PERF_RECORD_READ, + .misc = 0, + .size = sizeof(read_event) + perf_event_read_size(event), + }, + .pid = perf_event_pid(event, task), + .tid = perf_event_tid(event, task), + }; + int ret; + + ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0); + if (ret) + return; + + perf_output_put(&handle, read_event); + perf_output_read(&handle, event); + + perf_output_end(&handle); +} + +/* + * task tracking -- fork/exit + * + * enabled by: attr.comm | attr.mmap | attr.task + */ + +struct perf_task_event { + struct task_struct *task; + struct perf_event_context *task_ctx; + + struct { + struct perf_event_header header; + + u32 pid; + u32 ppid; + u32 tid; + u32 ptid; + u64 time; + } event_id; +}; + +static void perf_event_task_output(struct perf_event *event, + struct perf_task_event *task_event) +{ + struct perf_output_handle handle; + int size; + struct task_struct *task = task_event->task; + int ret; + + size = task_event->event_id.header.size; + ret = perf_output_begin(&handle, event, size, 0, 0); + + if (ret) + return; + + task_event->event_id.pid = perf_event_pid(event, task); + task_event->event_id.ppid = perf_event_pid(event, current); + + task_event->event_id.tid = perf_event_tid(event, task); + task_event->event_id.ptid = perf_event_tid(event, current); + + task_event->event_id.time = perf_clock(); + + perf_output_put(&handle, task_event->event_id); + + perf_output_end(&handle); +} + +static int perf_event_task_match(struct perf_event *event) +{ + if (event->attr.comm || event->attr.mmap || event->attr.task) + return 1; + + return 0; +} + +static void perf_event_task_ctx(struct perf_event_context *ctx, + struct perf_task_event *task_event) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_event_task_match(event)) + perf_event_task_output(event, task_event); + } + rcu_read_unlock(); +} + +static void perf_event_task_event(struct perf_task_event *task_event) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx = task_event->task_ctx; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_event_task_ctx(&cpuctx->ctx, task_event); + put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + if (!ctx) + ctx = rcu_dereference(task_event->task->perf_event_ctxp); + if (ctx) + perf_event_task_ctx(ctx, task_event); + rcu_read_unlock(); +} + +static void perf_event_task(struct task_struct *task, + struct perf_event_context *task_ctx, + int new) +{ + struct perf_task_event task_event; + + if (!atomic_read(&nr_comm_events) && + !atomic_read(&nr_mmap_events) && + !atomic_read(&nr_task_events)) + return; + + task_event = (struct perf_task_event){ + .task = task, + .task_ctx = task_ctx, + .event_id = { + .header = { + .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, + .misc = 0, + .size = sizeof(task_event.event_id), + }, + /* .pid */ + /* .ppid */ + /* .tid */ + /* .ptid */ + }, + }; + + perf_event_task_event(&task_event); +} + +void perf_event_fork(struct task_struct *task) +{ + perf_event_task(task, NULL, 1); +} + +/* + * comm tracking + */ + +struct perf_comm_event { + struct task_struct *task; + char *comm; + int comm_size; + + struct { + struct perf_event_header header; + + u32 pid; + u32 tid; + } event_id; +}; + +static void perf_event_comm_output(struct perf_event *event, + struct perf_comm_event *comm_event) +{ + struct perf_output_handle handle; + int size = comm_event->event_id.header.size; + int ret = perf_output_begin(&handle, event, size, 0, 0); + + if (ret) + return; + + comm_event->event_id.pid = perf_event_pid(event, comm_event->task); + comm_event->event_id.tid = perf_event_tid(event, comm_event->task); + + perf_output_put(&handle, comm_event->event_id); + perf_output_copy(&handle, comm_event->comm, + comm_event->comm_size); + perf_output_end(&handle); +} + +static int perf_event_comm_match(struct perf_event *event) +{ + if (event->attr.comm) + return 1; + + return 0; +} + +static void perf_event_comm_ctx(struct perf_event_context *ctx, + struct perf_comm_event *comm_event) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_event_comm_match(event)) + perf_event_comm_output(event, comm_event); + } + rcu_read_unlock(); +} + +static void perf_event_comm_event(struct perf_comm_event *comm_event) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; + unsigned int size; + char comm[TASK_COMM_LEN]; + + memset(comm, 0, sizeof(comm)); + strncpy(comm, comm_event->task->comm, sizeof(comm)); + size = ALIGN(strlen(comm)+1, sizeof(u64)); + + comm_event->comm = comm; + comm_event->comm_size = size; + + comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_event_comm_ctx(&cpuctx->ctx, comm_event); + put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_event_ctxp); + if (ctx) + perf_event_comm_ctx(ctx, comm_event); + rcu_read_unlock(); +} + +void perf_event_comm(struct task_struct *task) +{ + struct perf_comm_event comm_event; + + if (task->perf_event_ctxp) + perf_event_enable_on_exec(task); + + if (!atomic_read(&nr_comm_events)) + return; + + comm_event = (struct perf_comm_event){ + .task = task, + /* .comm */ + /* .comm_size */ + .event_id = { + .header = { + .type = PERF_RECORD_COMM, + .misc = 0, + /* .size */ + }, + /* .pid */ + /* .tid */ + }, + }; + + perf_event_comm_event(&comm_event); +} + +/* + * mmap tracking + */ + +struct perf_mmap_event { + struct vm_area_struct *vma; + + const char *file_name; + int file_size; + + struct { + struct perf_event_header header; + + u32 pid; + u32 tid; + u64 start; + u64 len; + u64 pgoff; + } event_id; +}; + +static void perf_event_mmap_output(struct perf_event *event, + struct perf_mmap_event *mmap_event) +{ + struct perf_output_handle handle; + int size = mmap_event->event_id.header.size; + int ret = perf_output_begin(&handle, event, size, 0, 0); + + if (ret) + return; + + mmap_event->event_id.pid = perf_event_pid(event, current); + mmap_event->event_id.tid = perf_event_tid(event, current); + + perf_output_put(&handle, mmap_event->event_id); + perf_output_copy(&handle, mmap_event->file_name, + mmap_event->file_size); + perf_output_end(&handle); +} + +static int perf_event_mmap_match(struct perf_event *event, + struct perf_mmap_event *mmap_event) +{ + if (event->attr.mmap) + return 1; + + return 0; +} + +static void perf_event_mmap_ctx(struct perf_event_context *ctx, + struct perf_mmap_event *mmap_event) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_event_mmap_match(event, mmap_event)) + perf_event_mmap_output(event, mmap_event); + } + rcu_read_unlock(); +} + +static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; + struct vm_area_struct *vma = mmap_event->vma; + struct file *file = vma->vm_file; + unsigned int size; + char tmp[16]; + char *buf = NULL; + const char *name; + + memset(tmp, 0, sizeof(tmp)); + + if (file) { + /* + * d_path works from the end of the buffer backwards, so we + * need to add enough zero bytes after the string to handle + * the 64bit alignment we do later. + */ + buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL); + if (!buf) { + name = strncpy(tmp, "//enomem", sizeof(tmp)); + goto got_name; + } + name = d_path(&file->f_path, buf, PATH_MAX); + if (IS_ERR(name)) { + name = strncpy(tmp, "//toolong", sizeof(tmp)); + goto got_name; + } + } else { + if (arch_vma_name(mmap_event->vma)) { + name = strncpy(tmp, arch_vma_name(mmap_event->vma), + sizeof(tmp)); + goto got_name; + } + + if (!vma->vm_mm) { + name = strncpy(tmp, "[vdso]", sizeof(tmp)); + goto got_name; + } + + name = strncpy(tmp, "//anon", sizeof(tmp)); + goto got_name; + } + +got_name: + size = ALIGN(strlen(name)+1, sizeof(u64)); + + mmap_event->file_name = name; + mmap_event->file_size = size; + + mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_event_mmap_ctx(&cpuctx->ctx, mmap_event); + put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_event_ctxp); + if (ctx) + perf_event_mmap_ctx(ctx, mmap_event); + rcu_read_unlock(); + + kfree(buf); +} + +void __perf_event_mmap(struct vm_area_struct *vma) +{ + struct perf_mmap_event mmap_event; + + if (!atomic_read(&nr_mmap_events)) + return; + + mmap_event = (struct perf_mmap_event){ + .vma = vma, + /* .file_name */ + /* .file_size */ + .event_id = { + .header = { + .type = PERF_RECORD_MMAP, + .misc = 0, + /* .size */ + }, + /* .pid */ + /* .tid */ + .start = vma->vm_start, + .len = vma->vm_end - vma->vm_start, + .pgoff = vma->vm_pgoff, + }, + }; + + perf_event_mmap_event(&mmap_event); +} + +/* + * IRQ throttle logging + */ + +static void perf_log_throttle(struct perf_event *event, int enable) +{ + struct perf_output_handle handle; + int ret; + + struct { + struct perf_event_header header; + u64 time; + u64 id; + u64 stream_id; + } throttle_event = { + .header = { + .type = PERF_RECORD_THROTTLE, + .misc = 0, + .size = sizeof(throttle_event), + }, + .time = perf_clock(), + .id = primary_event_id(event), + .stream_id = event->id, + }; + + if (enable) + throttle_event.header.type = PERF_RECORD_UNTHROTTLE; + + ret = perf_output_begin(&handle, event, sizeof(throttle_event), 1, 0); + if (ret) + return; + + perf_output_put(&handle, throttle_event); + perf_output_end(&handle); +} + +/* + * Generic event overflow handling, sampling. + */ + +static int __perf_event_overflow(struct perf_event *event, int nmi, + int throttle, struct perf_sample_data *data, + struct pt_regs *regs) +{ + int events = atomic_read(&event->event_limit); + struct hw_perf_event *hwc = &event->hw; + int ret = 0; + + throttle = (throttle && event->pmu->unthrottle != NULL); + + if (!throttle) { + hwc->interrupts++; + } else { + if (hwc->interrupts != MAX_INTERRUPTS) { + hwc->interrupts++; + if (HZ * hwc->interrupts > + (u64)sysctl_perf_event_sample_rate) { + hwc->interrupts = MAX_INTERRUPTS; + perf_log_throttle(event, 0); + ret = 1; + } + } else { + /* + * Keep re-disabling events even though on the previous + * pass we disabled it - just in case we raced with a + * sched-in and the event got enabled again: + */ + ret = 1; + } + } + + if (event->attr.freq) { + u64 now = perf_clock(); + s64 delta = now - hwc->freq_stamp; + + hwc->freq_stamp = now; + + if (delta > 0 && delta < TICK_NSEC) + perf_adjust_period(event, NSEC_PER_SEC / (int)delta); + } + + /* + * XXX event_limit might not quite work as expected on inherited + * events + */ + + event->pending_kill = POLL_IN; + if (events && atomic_dec_and_test(&event->event_limit)) { + ret = 1; + event->pending_kill = POLL_HUP; + if (nmi) { + event->pending_disable = 1; + perf_pending_queue(&event->pending, + perf_pending_event); + } else + perf_event_disable(event); + } + + perf_event_output(event, nmi, data, regs); + return ret; +} + +int perf_event_overflow(struct perf_event *event, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + return __perf_event_overflow(event, nmi, 1, data, regs); +} + +/* + * Generic software event infrastructure + */ + +/* + * We directly increment event->count and keep a second value in + * event->hw.period_left to count intervals. This period event + * is kept in the range [-sample_period, 0] so that we can use the + * sign as trigger. + */ + +static u64 perf_swevent_set_period(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 period = hwc->last_period; + u64 nr, offset; + s64 old, val; + + hwc->last_period = hwc->sample_period; + +again: + old = val = atomic64_read(&hwc->period_left); + if (val < 0) + return 0; + + nr = div64_u64(period + val, period); + offset = nr * period; + val -= offset; + if (atomic64_cmpxchg(&hwc->period_left, old, val) != old) + goto again; + + return nr; +} + +static void perf_swevent_overflow(struct perf_event *event, + int nmi, struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct hw_perf_event *hwc = &event->hw; + int throttle = 0; + u64 overflow; + + data->period = event->hw.last_period; + overflow = perf_swevent_set_period(event); + + if (hwc->interrupts == MAX_INTERRUPTS) + return; + + for (; overflow; overflow--) { + if (__perf_event_overflow(event, nmi, throttle, + data, regs)) { + /* + * We inhibit the overflow from happening when + * hwc->interrupts == MAX_INTERRUPTS. + */ + break; + } + throttle = 1; + } +} + +static void perf_swevent_unthrottle(struct perf_event *event) +{ + /* + * Nothing to do, we already reset hwc->interrupts. + */ +} + +static void perf_swevent_add(struct perf_event *event, u64 nr, + int nmi, struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct hw_perf_event *hwc = &event->hw; + + atomic64_add(nr, &event->count); + + if (!hwc->sample_period) + return; + + if (!regs) + return; + + if (!atomic64_add_negative(nr, &hwc->period_left)) + perf_swevent_overflow(event, nmi, data, regs); +} + +static int perf_swevent_is_counting(struct perf_event *event) +{ + /* + * The event is active, we're good! + */ + if (event->state == PERF_EVENT_STATE_ACTIVE) + return 1; + + /* + * The event is off/error, not counting. + */ + if (event->state != PERF_EVENT_STATE_INACTIVE) + return 0; + + /* + * The event is inactive, if the context is active + * we're part of a group that didn't make it on the 'pmu', + * not counting. + */ + if (event->ctx->is_active) + return 0; + + /* + * We're inactive and the context is too, this means the + * task is scheduled out, we're counting events that happen + * to us, like migration events. + */ + return 1; +} + +static int perf_swevent_match(struct perf_event *event, + enum perf_type_id type, + u32 event_id, struct pt_regs *regs) +{ + if (!perf_swevent_is_counting(event)) + return 0; + + if (event->attr.type != type) + return 0; + if (event->attr.config != event_id) + return 0; + + if (regs) { + if (event->attr.exclude_user && user_mode(regs)) + return 0; + + if (event->attr.exclude_kernel && !user_mode(regs)) + return 0; + } + + return 1; +} + +static void perf_swevent_ctx_event(struct perf_event_context *ctx, + enum perf_type_id type, + u32 event_id, u64 nr, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_swevent_match(event, type, event_id, regs)) + perf_swevent_add(event, nr, nmi, data, regs); + } + rcu_read_unlock(); +} + +static int *perf_swevent_recursion_context(struct perf_cpu_context *cpuctx) +{ + if (in_nmi()) + return &cpuctx->recursion[3]; + + if (in_irq()) + return &cpuctx->recursion[2]; + + if (in_softirq()) + return &cpuctx->recursion[1]; + + return &cpuctx->recursion[0]; +} + +static void do_perf_sw_event(enum perf_type_id type, u32 event_id, + u64 nr, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); + int *recursion = perf_swevent_recursion_context(cpuctx); + struct perf_event_context *ctx; + + if (*recursion) + goto out; + + (*recursion)++; + barrier(); + + perf_swevent_ctx_event(&cpuctx->ctx, type, event_id, + nr, nmi, data, regs); + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_event_ctxp); + if (ctx) + perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs); + rcu_read_unlock(); + + barrier(); + (*recursion)--; + +out: + put_cpu_var(perf_cpu_context); +} + +void __perf_sw_event(u32 event_id, u64 nr, int nmi, + struct pt_regs *regs, u64 addr) +{ + struct perf_sample_data data = { + .addr = addr, + }; + + do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, + &data, regs); +} + +static void perf_swevent_read(struct perf_event *event) +{ +} + +static int perf_swevent_enable(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + + if (hwc->sample_period) { + hwc->last_period = hwc->sample_period; + perf_swevent_set_period(event); + } + return 0; +} + +static void perf_swevent_disable(struct perf_event *event) +{ +} + +static const struct pmu perf_ops_generic = { + .enable = perf_swevent_enable, + .disable = perf_swevent_disable, + .read = perf_swevent_read, + .unthrottle = perf_swevent_unthrottle, +}; + +/* + * hrtimer based swevent callback + */ + +static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) +{ + enum hrtimer_restart ret = HRTIMER_RESTART; + struct perf_sample_data data; + struct pt_regs *regs; + struct perf_event *event; + u64 period; + + event = container_of(hrtimer, struct perf_event, hw.hrtimer); + event->pmu->read(event); + + data.addr = 0; + regs = get_irq_regs(); + /* + * In case we exclude kernel IPs or are somehow not in interrupt + * context, provide the next best thing, the user IP. + */ + if ((event->attr.exclude_kernel || !regs) && + !event->attr.exclude_user) + regs = task_pt_regs(current); + + if (regs) { + if (perf_event_overflow(event, 0, &data, regs)) + ret = HRTIMER_NORESTART; + } + + period = max_t(u64, 10000, event->hw.sample_period); + hrtimer_forward_now(hrtimer, ns_to_ktime(period)); + + return ret; +} + +/* + * Software event: cpu wall time clock + */ + +static void cpu_clock_perf_event_update(struct perf_event *event) +{ + int cpu = raw_smp_processor_id(); + s64 prev; + u64 now; + + now = cpu_clock(cpu); + prev = atomic64_read(&event->hw.prev_count); + atomic64_set(&event->hw.prev_count, now); + atomic64_add(now - prev, &event->count); +} + +static int cpu_clock_perf_event_enable(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int cpu = raw_smp_processor_id(); + + atomic64_set(&hwc->prev_count, cpu_clock(cpu)); + hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hwc->hrtimer.function = perf_swevent_hrtimer; + if (hwc->sample_period) { + u64 period = max_t(u64, 10000, hwc->sample_period); + __hrtimer_start_range_ns(&hwc->hrtimer, + ns_to_ktime(period), 0, + HRTIMER_MODE_REL, 0); + } + + return 0; +} + +static void cpu_clock_perf_event_disable(struct perf_event *event) +{ + if (event->hw.sample_period) + hrtimer_cancel(&event->hw.hrtimer); + cpu_clock_perf_event_update(event); +} + +static void cpu_clock_perf_event_read(struct perf_event *event) +{ + cpu_clock_perf_event_update(event); +} + +static const struct pmu perf_ops_cpu_clock = { + .enable = cpu_clock_perf_event_enable, + .disable = cpu_clock_perf_event_disable, + .read = cpu_clock_perf_event_read, +}; + +/* + * Software event: task time clock + */ + +static void task_clock_perf_event_update(struct perf_event *event, u64 now) +{ + u64 prev; + s64 delta; + + prev = atomic64_xchg(&event->hw.prev_count, now); + delta = now - prev; + atomic64_add(delta, &event->count); +} + +static int task_clock_perf_event_enable(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 now; + + now = event->ctx->time; + + atomic64_set(&hwc->prev_count, now); + hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hwc->hrtimer.function = perf_swevent_hrtimer; + if (hwc->sample_period) { + u64 period = max_t(u64, 10000, hwc->sample_period); + __hrtimer_start_range_ns(&hwc->hrtimer, + ns_to_ktime(period), 0, + HRTIMER_MODE_REL, 0); + } + + return 0; +} + +static void task_clock_perf_event_disable(struct perf_event *event) +{ + if (event->hw.sample_period) + hrtimer_cancel(&event->hw.hrtimer); + task_clock_perf_event_update(event, event->ctx->time); + +} + +static void task_clock_perf_event_read(struct perf_event *event) +{ + u64 time; + + if (!in_nmi()) { + update_context_time(event->ctx); + time = event->ctx->time; + } else { + u64 now = perf_clock(); + u64 delta = now - event->ctx->timestamp; + time = event->ctx->time + delta; + } + + task_clock_perf_event_update(event, time); +} + +static const struct pmu perf_ops_task_clock = { + .enable = task_clock_perf_event_enable, + .disable = task_clock_perf_event_disable, + .read = task_clock_perf_event_read, +}; + +#ifdef CONFIG_EVENT_PROFILE +void perf_tp_event(int event_id, u64 addr, u64 count, void *record, + int entry_size) +{ + struct perf_raw_record raw = { + .size = entry_size, + .data = record, + }; + + struct perf_sample_data data = { + .addr = addr, + .raw = &raw, + }; + + struct pt_regs *regs = get_irq_regs(); + + if (!regs) + regs = task_pt_regs(current); + + do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, + &data, regs); +} +EXPORT_SYMBOL_GPL(perf_tp_event); + +extern int ftrace_profile_enable(int); +extern void ftrace_profile_disable(int); + +static void tp_perf_event_destroy(struct perf_event *event) +{ + ftrace_profile_disable(event->attr.config); +} + +static const struct pmu *tp_perf_event_init(struct perf_event *event) +{ + /* + * Raw tracepoint data is a severe data leak, only allow root to + * have these. + */ + if ((event->attr.sample_type & PERF_SAMPLE_RAW) && + perf_paranoid_tracepoint_raw() && + !capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EPERM); + + if (ftrace_profile_enable(event->attr.config)) + return NULL; + + event->destroy = tp_perf_event_destroy; + + return &perf_ops_generic; +} +#else +static const struct pmu *tp_perf_event_init(struct perf_event *event) +{ + return NULL; +} +#endif + +atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; + +static void sw_perf_event_destroy(struct perf_event *event) +{ + u64 event_id = event->attr.config; + + WARN_ON(event->parent); + + atomic_dec(&perf_swevent_enabled[event_id]); +} + +static const struct pmu *sw_perf_event_init(struct perf_event *event) +{ + const struct pmu *pmu = NULL; + u64 event_id = event->attr.config; + + /* + * Software events (currently) can't in general distinguish + * between user, kernel and hypervisor events. + * However, context switches and cpu migrations are considered + * to be kernel events, and page faults are never hypervisor + * events. + */ + switch (event_id) { + case PERF_COUNT_SW_CPU_CLOCK: + pmu = &perf_ops_cpu_clock; + + break; + case PERF_COUNT_SW_TASK_CLOCK: + /* + * If the user instantiates this as a per-cpu event, + * use the cpu_clock event instead. + */ + if (event->ctx->task) + pmu = &perf_ops_task_clock; + else + pmu = &perf_ops_cpu_clock; + + break; + case PERF_COUNT_SW_PAGE_FAULTS: + case PERF_COUNT_SW_PAGE_FAULTS_MIN: + case PERF_COUNT_SW_PAGE_FAULTS_MAJ: + case PERF_COUNT_SW_CONTEXT_SWITCHES: + case PERF_COUNT_SW_CPU_MIGRATIONS: + if (!event->parent) { + atomic_inc(&perf_swevent_enabled[event_id]); + event->destroy = sw_perf_event_destroy; + } + pmu = &perf_ops_generic; + break; + } + + return pmu; +} + +/* + * Allocate and initialize a event structure + */ +static struct perf_event * +perf_event_alloc(struct perf_event_attr *attr, + int cpu, + struct perf_event_context *ctx, + struct perf_event *group_leader, + struct perf_event *parent_event, + gfp_t gfpflags) +{ + const struct pmu *pmu; + struct perf_event *event; + struct hw_perf_event *hwc; + long err; + + event = kzalloc(sizeof(*event), gfpflags); + if (!event) + return ERR_PTR(-ENOMEM); + + /* + * Single events are their own group leaders, with an + * empty sibling list: + */ + if (!group_leader) + group_leader = event; + + mutex_init(&event->child_mutex); + INIT_LIST_HEAD(&event->child_list); + + INIT_LIST_HEAD(&event->group_entry); + INIT_LIST_HEAD(&event->event_entry); + INIT_LIST_HEAD(&event->sibling_list); + init_waitqueue_head(&event->waitq); + + mutex_init(&event->mmap_mutex); + + event->cpu = cpu; + event->attr = *attr; + event->group_leader = group_leader; + event->pmu = NULL; + event->ctx = ctx; + event->oncpu = -1; + + event->parent = parent_event; + + event->ns = get_pid_ns(current->nsproxy->pid_ns); + event->id = atomic64_inc_return(&perf_event_id); + + event->state = PERF_EVENT_STATE_INACTIVE; + + if (attr->disabled) + event->state = PERF_EVENT_STATE_OFF; + + pmu = NULL; + + hwc = &event->hw; + hwc->sample_period = attr->sample_period; + if (attr->freq && attr->sample_freq) + hwc->sample_period = 1; + hwc->last_period = hwc->sample_period; + + atomic64_set(&hwc->period_left, hwc->sample_period); + + /* + * we currently do not support PERF_FORMAT_GROUP on inherited events + */ + if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) + goto done; + + switch (attr->type) { + case PERF_TYPE_RAW: + case PERF_TYPE_HARDWARE: + case PERF_TYPE_HW_CACHE: + pmu = hw_perf_event_init(event); + break; + + case PERF_TYPE_SOFTWARE: + pmu = sw_perf_event_init(event); + break; + + case PERF_TYPE_TRACEPOINT: + pmu = tp_perf_event_init(event); + break; + + default: + break; + } +done: + err = 0; + if (!pmu) + err = -EINVAL; + else if (IS_ERR(pmu)) + err = PTR_ERR(pmu); + + if (err) { + if (event->ns) + put_pid_ns(event->ns); + kfree(event); + return ERR_PTR(err); + } + + event->pmu = pmu; + + if (!event->parent) { + atomic_inc(&nr_events); + if (event->attr.mmap) + atomic_inc(&nr_mmap_events); + if (event->attr.comm) + atomic_inc(&nr_comm_events); + if (event->attr.task) + atomic_inc(&nr_task_events); + } + + return event; +} + +static int perf_copy_attr(struct perf_event_attr __user *uattr, + struct perf_event_attr *attr) +{ + u32 size; + int ret; + + if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) + return -EFAULT; + + /* + * zero the full structure, so that a short copy will be nice. + */ + memset(attr, 0, sizeof(*attr)); + + ret = get_user(size, &uattr->size); + if (ret) + return ret; + + if (size > PAGE_SIZE) /* silly large */ + goto err_size; + + if (!size) /* abi compat */ + size = PERF_ATTR_SIZE_VER0; + + if (size < PERF_ATTR_SIZE_VER0) + goto err_size; + + /* + * If we're handed a bigger struct than we know of, + * ensure all the unknown bits are 0 - i.e. new + * user-space does not rely on any kernel feature + * extensions we dont know about yet. + */ + if (size > sizeof(*attr)) { + unsigned char __user *addr; + unsigned char __user *end; + unsigned char val; + + addr = (void __user *)uattr + sizeof(*attr); + end = (void __user *)uattr + size; + + for (; addr < end; addr++) { + ret = get_user(val, addr); + if (ret) + return ret; + if (val) + goto err_size; + } + size = sizeof(*attr); + } + + ret = copy_from_user(attr, uattr, size); + if (ret) + return -EFAULT; + + /* + * If the type exists, the corresponding creation will verify + * the attr->config. + */ + if (attr->type >= PERF_TYPE_MAX) + return -EINVAL; + + if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3) + return -EINVAL; + + if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) + return -EINVAL; + + if (attr->read_format & ~(PERF_FORMAT_MAX-1)) + return -EINVAL; + +out: + return ret; + +err_size: + put_user(sizeof(*attr), &uattr->size); + ret = -E2BIG; + goto out; +} + +int perf_event_set_output(struct perf_event *event, int output_fd) +{ + struct perf_event *output_event = NULL; + struct file *output_file = NULL; + struct perf_event *old_output; + int fput_needed = 0; + int ret = -EINVAL; + + if (!output_fd) + goto set; + + output_file = fget_light(output_fd, &fput_needed); + if (!output_file) + return -EBADF; + + if (output_file->f_op != &perf_fops) + goto out; + + output_event = output_file->private_data; + + /* Don't chain output fds */ + if (output_event->output) + goto out; + + /* Don't set an output fd when we already have an output channel */ + if (event->data) + goto out; + + atomic_long_inc(&output_file->f_count); + +set: + mutex_lock(&event->mmap_mutex); + old_output = event->output; + rcu_assign_pointer(event->output, output_event); + mutex_unlock(&event->mmap_mutex); + + if (old_output) { + /* + * we need to make sure no existing perf_output_*() + * is still referencing this event. + */ + synchronize_rcu(); + fput(old_output->filp); + } + + ret = 0; +out: + fput_light(output_file, fput_needed); + return ret; +} + +/** + * sys_perf_event_open - open a performance event, associate it to a task/cpu + * + * @attr_uptr: event_id type attributes for monitoring/sampling + * @pid: target pid + * @cpu: target cpu + * @group_fd: group leader event fd + */ +SYSCALL_DEFINE5(perf_event_open, + struct perf_event_attr __user *, attr_uptr, + pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) +{ + struct perf_event *event, *group_leader; + struct perf_event_attr attr; + struct perf_event_context *ctx; + struct file *event_file = NULL; + struct file *group_file = NULL; + int fput_needed = 0; + int fput_needed2 = 0; + int err; + + /* for future expandability... */ + if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT)) + return -EINVAL; + + err = perf_copy_attr(attr_uptr, &attr); + if (err) + return err; + + if (!attr.exclude_kernel) { + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) + return -EACCES; + } + + if (attr.freq) { + if (attr.sample_freq > sysctl_perf_event_sample_rate) + return -EINVAL; + } + + /* + * Get the target context (task or percpu): + */ + ctx = find_get_context(pid, cpu); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + + /* + * Look up the group leader (we will attach this event to it): + */ + group_leader = NULL; + if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) { + err = -EINVAL; + group_file = fget_light(group_fd, &fput_needed); + if (!group_file) + goto err_put_context; + if (group_file->f_op != &perf_fops) + goto err_put_context; + + group_leader = group_file->private_data; + /* + * Do not allow a recursive hierarchy (this new sibling + * becoming part of another group-sibling): + */ + if (group_leader->group_leader != group_leader) + goto err_put_context; + /* + * Do not allow to attach to a group in a different + * task or CPU context: + */ + if (group_leader->ctx != ctx) + goto err_put_context; + /* + * Only a group leader can be exclusive or pinned + */ + if (attr.exclusive || attr.pinned) + goto err_put_context; + } + + event = perf_event_alloc(&attr, cpu, ctx, group_leader, + NULL, GFP_KERNEL); + err = PTR_ERR(event); + if (IS_ERR(event)) + goto err_put_context; + + err = anon_inode_getfd("[perf_event]", &perf_fops, event, 0); + if (err < 0) + goto err_free_put_context; + + event_file = fget_light(err, &fput_needed2); + if (!event_file) + goto err_free_put_context; + + if (flags & PERF_FLAG_FD_OUTPUT) { + err = perf_event_set_output(event, group_fd); + if (err) + goto err_fput_free_put_context; + } + + event->filp = event_file; + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + perf_install_in_context(ctx, event, cpu); + ++ctx->generation; + mutex_unlock(&ctx->mutex); + + event->owner = current; + get_task_struct(current); + mutex_lock(¤t->perf_event_mutex); + list_add_tail(&event->owner_entry, ¤t->perf_event_list); + mutex_unlock(¤t->perf_event_mutex); + +err_fput_free_put_context: + fput_light(event_file, fput_needed2); + +err_free_put_context: + if (err < 0) + kfree(event); + +err_put_context: + if (err < 0) + put_ctx(ctx); + + fput_light(group_file, fput_needed); + + return err; +} + +/* + * inherit a event from parent task to child task: + */ +static struct perf_event * +inherit_event(struct perf_event *parent_event, + struct task_struct *parent, + struct perf_event_context *parent_ctx, + struct task_struct *child, + struct perf_event *group_leader, + struct perf_event_context *child_ctx) +{ + struct perf_event *child_event; + + /* + * Instead of creating recursive hierarchies of events, + * we link inherited events back to the original parent, + * which has a filp for sure, which we use as the reference + * count: + */ + if (parent_event->parent) + parent_event = parent_event->parent; + + child_event = perf_event_alloc(&parent_event->attr, + parent_event->cpu, child_ctx, + group_leader, parent_event, + GFP_KERNEL); + if (IS_ERR(child_event)) + return child_event; + get_ctx(child_ctx); + + /* + * Make the child state follow the state of the parent event, + * not its attr.disabled bit. We hold the parent's mutex, + * so we won't race with perf_event_{en, dis}able_family. + */ + if (parent_event->state >= PERF_EVENT_STATE_INACTIVE) + child_event->state = PERF_EVENT_STATE_INACTIVE; + else + child_event->state = PERF_EVENT_STATE_OFF; + + if (parent_event->attr.freq) + child_event->hw.sample_period = parent_event->hw.sample_period; + + /* + * Link it up in the child's context: + */ + add_event_to_ctx(child_event, child_ctx); + + /* + * Get a reference to the parent filp - we will fput it + * when the child event exits. This is safe to do because + * we are in the parent and we know that the filp still + * exists and has a nonzero count: + */ + atomic_long_inc(&parent_event->filp->f_count); + + /* + * Link this into the parent event's child list + */ + WARN_ON_ONCE(parent_event->ctx->parent_ctx); + mutex_lock(&parent_event->child_mutex); + list_add_tail(&child_event->child_list, &parent_event->child_list); + mutex_unlock(&parent_event->child_mutex); + + return child_event; +} + +static int inherit_group(struct perf_event *parent_event, + struct task_struct *parent, + struct perf_event_context *parent_ctx, + struct task_struct *child, + struct perf_event_context *child_ctx) +{ + struct perf_event *leader; + struct perf_event *sub; + struct perf_event *child_ctr; + + leader = inherit_event(parent_event, parent, parent_ctx, + child, NULL, child_ctx); + if (IS_ERR(leader)) + return PTR_ERR(leader); + list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { + child_ctr = inherit_event(sub, parent, parent_ctx, + child, leader, child_ctx); + if (IS_ERR(child_ctr)) + return PTR_ERR(child_ctr); + } + return 0; +} + +static void sync_child_event(struct perf_event *child_event, + struct task_struct *child) +{ + struct perf_event *parent_event = child_event->parent; + u64 child_val; + + if (child_event->attr.inherit_stat) + perf_event_read_event(child_event, child); + + child_val = atomic64_read(&child_event->count); + + /* + * Add back the child's count to the parent's count: + */ + atomic64_add(child_val, &parent_event->count); + atomic64_add(child_event->total_time_enabled, + &parent_event->child_total_time_enabled); + atomic64_add(child_event->total_time_running, + &parent_event->child_total_time_running); + + /* + * Remove this event from the parent's list + */ + WARN_ON_ONCE(parent_event->ctx->parent_ctx); + mutex_lock(&parent_event->child_mutex); + list_del_init(&child_event->child_list); + mutex_unlock(&parent_event->child_mutex); + + /* + * Release the parent event, if this was the last + * reference to it. + */ + fput(parent_event->filp); +} + +static void +__perf_event_exit_task(struct perf_event *child_event, + struct perf_event_context *child_ctx, + struct task_struct *child) +{ + struct perf_event *parent_event; + + update_event_times(child_event); + perf_event_remove_from_context(child_event); + + parent_event = child_event->parent; + /* + * It can happen that parent exits first, and has events + * that are still around due to the child reference. These + * events need to be zapped - but otherwise linger. + */ + if (parent_event) { + sync_child_event(child_event, child); + free_event(child_event); + } +} + +/* + * When a child task exits, feed back event values to parent events. + */ +void perf_event_exit_task(struct task_struct *child) +{ + struct perf_event *child_event, *tmp; + struct perf_event_context *child_ctx; + unsigned long flags; + + if (likely(!child->perf_event_ctxp)) { + perf_event_task(child, NULL, 0); + return; + } + + local_irq_save(flags); + /* + * We can't reschedule here because interrupts are disabled, + * and either child is current or it is a task that can't be + * scheduled, so we are now safe from rescheduling changing + * our context. + */ + child_ctx = child->perf_event_ctxp; + __perf_event_task_sched_out(child_ctx); + + /* + * Take the context lock here so that if find_get_context is + * reading child->perf_event_ctxp, we wait until it has + * incremented the context's refcount before we do put_ctx below. + */ + spin_lock(&child_ctx->lock); + child->perf_event_ctxp = NULL; + /* + * If this context is a clone; unclone it so it can't get + * swapped to another process while we're removing all + * the events from it. + */ + unclone_ctx(child_ctx); + spin_unlock_irqrestore(&child_ctx->lock, flags); + + /* + * Report the task dead after unscheduling the events so that we + * won't get any samples after PERF_RECORD_EXIT. We can however still + * get a few PERF_RECORD_READ events. + */ + perf_event_task(child, child_ctx, 0); + + /* + * We can recurse on the same lock type through: + * + * __perf_event_exit_task() + * sync_child_event() + * fput(parent_event->filp) + * perf_release() + * mutex_lock(&ctx->mutex) + * + * But since its the parent context it won't be the same instance. + */ + mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); + +again: + list_for_each_entry_safe(child_event, tmp, &child_ctx->group_list, + group_entry) + __perf_event_exit_task(child_event, child_ctx, child); + + /* + * If the last event was a group event, it will have appended all + * its siblings to the list, but we obtained 'tmp' before that which + * will still point to the list head terminating the iteration. + */ + if (!list_empty(&child_ctx->group_list)) + goto again; + + mutex_unlock(&child_ctx->mutex); + + put_ctx(child_ctx); +} + +/* + * free an unexposed, unused context as created by inheritance by + * init_task below, used by fork() in case of fail. + */ +void perf_event_free_task(struct task_struct *task) +{ + struct perf_event_context *ctx = task->perf_event_ctxp; + struct perf_event *event, *tmp; + + if (!ctx) + return; + + mutex_lock(&ctx->mutex); +again: + list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) { + struct perf_event *parent = event->parent; + + if (WARN_ON_ONCE(!parent)) + continue; + + mutex_lock(&parent->child_mutex); + list_del_init(&event->child_list); + mutex_unlock(&parent->child_mutex); + + fput(parent->filp); + + list_del_event(event, ctx); + free_event(event); + } + + if (!list_empty(&ctx->group_list)) + goto again; + + mutex_unlock(&ctx->mutex); + + put_ctx(ctx); +} + +/* + * Initialize the perf_event context in task_struct + */ +int perf_event_init_task(struct task_struct *child) +{ + struct perf_event_context *child_ctx, *parent_ctx; + struct perf_event_context *cloned_ctx; + struct perf_event *event; + struct task_struct *parent = current; + int inherited_all = 1; + int ret = 0; + + child->perf_event_ctxp = NULL; + + mutex_init(&child->perf_event_mutex); + INIT_LIST_HEAD(&child->perf_event_list); + + if (likely(!parent->perf_event_ctxp)) + return 0; + + /* + * This is executed from the parent task context, so inherit + * events that have been marked for cloning. + * First allocate and initialize a context for the child. + */ + + child_ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL); + if (!child_ctx) + return -ENOMEM; + + __perf_event_init_context(child_ctx, child); + child->perf_event_ctxp = child_ctx; + get_task_struct(child); + + /* + * If the parent's context is a clone, pin it so it won't get + * swapped under us. + */ + parent_ctx = perf_pin_task_context(parent); + + /* + * No need to check if parent_ctx != NULL here; since we saw + * it non-NULL earlier, the only reason for it to become NULL + * is if we exit, and since we're currently in the middle of + * a fork we can't be exiting at the same time. + */ + + /* + * Lock the parent list. No need to lock the child - not PID + * hashed yet and not running, so nobody can access it. + */ + mutex_lock(&parent_ctx->mutex); + + /* + * We dont have to disable NMIs - we are only looking at + * the list, not manipulating it: + */ + list_for_each_entry_rcu(event, &parent_ctx->event_list, event_entry) { + if (event != event->group_leader) + continue; + + if (!event->attr.inherit) { + inherited_all = 0; + continue; + } + + ret = inherit_group(event, parent, parent_ctx, + child, child_ctx); + if (ret) { + inherited_all = 0; + break; + } + } + + if (inherited_all) { + /* + * Mark the child context as a clone of the parent + * context, or of whatever the parent is a clone of. + * Note that if the parent is a clone, it could get + * uncloned at any point, but that doesn't matter + * because the list of events and the generation + * count can't have changed since we took the mutex. + */ + cloned_ctx = rcu_dereference(parent_ctx->parent_ctx); + if (cloned_ctx) { + child_ctx->parent_ctx = cloned_ctx; + child_ctx->parent_gen = parent_ctx->parent_gen; + } else { + child_ctx->parent_ctx = parent_ctx; + child_ctx->parent_gen = parent_ctx->generation; + } + get_ctx(child_ctx->parent_ctx); + } + + mutex_unlock(&parent_ctx->mutex); + + perf_unpin_context(parent_ctx); + + return ret; +} + +static void __cpuinit perf_event_init_cpu(int cpu) +{ + struct perf_cpu_context *cpuctx; + + cpuctx = &per_cpu(perf_cpu_context, cpu); + __perf_event_init_context(&cpuctx->ctx, NULL); + + spin_lock(&perf_resource_lock); + cpuctx->max_pertask = perf_max_events - perf_reserved_percpu; + spin_unlock(&perf_resource_lock); + + hw_perf_event_setup(cpu); +} + +#ifdef CONFIG_HOTPLUG_CPU +static void __perf_event_exit_cpu(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = &cpuctx->ctx; + struct perf_event *event, *tmp; + + list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) + __perf_event_remove_from_context(event); +} +static void perf_event_exit_cpu(int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_event_context *ctx = &cpuctx->ctx; + + mutex_lock(&ctx->mutex); + smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1); + mutex_unlock(&ctx->mutex); +} +#else +static inline void perf_event_exit_cpu(int cpu) { } +#endif + +static int __cpuinit +perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) +{ + unsigned int cpu = (long)hcpu; + + switch (action) { + + case CPU_UP_PREPARE: + case CPU_UP_PREPARE_FROZEN: + perf_event_init_cpu(cpu); + break; + + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + hw_perf_event_setup_online(cpu); + break; + + case CPU_DOWN_PREPARE: + case CPU_DOWN_PREPARE_FROZEN: + perf_event_exit_cpu(cpu); + break; + + default: + break; + } + + return NOTIFY_OK; +} + +/* + * This has to have a higher priority than migration_notifier in sched.c. + */ +static struct notifier_block __cpuinitdata perf_cpu_nb = { + .notifier_call = perf_cpu_notify, + .priority = 20, +}; + +void __init perf_event_init(void) +{ + perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, + (void *)(long)smp_processor_id()); + perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE, + (void *)(long)smp_processor_id()); + register_cpu_notifier(&perf_cpu_nb); +} + +static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) +{ + return sprintf(buf, "%d\n", perf_reserved_percpu); +} + +static ssize_t +perf_set_reserve_percpu(struct sysdev_class *class, + const char *buf, + size_t count) +{ + struct perf_cpu_context *cpuctx; + unsigned long val; + int err, cpu, mpt; + + err = strict_strtoul(buf, 10, &val); + if (err) + return err; + if (val > perf_max_events) + return -EINVAL; + + spin_lock(&perf_resource_lock); + perf_reserved_percpu = val; + for_each_online_cpu(cpu) { + cpuctx = &per_cpu(perf_cpu_context, cpu); + spin_lock_irq(&cpuctx->ctx.lock); + mpt = min(perf_max_events - cpuctx->ctx.nr_events, + perf_max_events - perf_reserved_percpu); + cpuctx->max_pertask = mpt; + spin_unlock_irq(&cpuctx->ctx.lock); + } + spin_unlock(&perf_resource_lock); + + return count; +} + +static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) +{ + return sprintf(buf, "%d\n", perf_overcommit); +} + +static ssize_t +perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) +{ + unsigned long val; + int err; + + err = strict_strtoul(buf, 10, &val); + if (err) + return err; + if (val > 1) + return -EINVAL; + + spin_lock(&perf_resource_lock); + perf_overcommit = val; + spin_unlock(&perf_resource_lock); + + return count; +} + +static SYSDEV_CLASS_ATTR( + reserve_percpu, + 0644, + perf_show_reserve_percpu, + perf_set_reserve_percpu + ); + +static SYSDEV_CLASS_ATTR( + overcommit, + 0644, + perf_show_overcommit, + perf_set_overcommit + ); + +static struct attribute *perfclass_attrs[] = { + &attr_reserve_percpu.attr, + &attr_overcommit.attr, + NULL +}; + +static struct attribute_group perfclass_attr_group = { + .attrs = perfclass_attrs, + .name = "perf_events", +}; + +static int __init perf_event_sysfs_init(void) +{ + return sysfs_create_group(&cpu_sysdev_class.kset.kobj, + &perfclass_attr_group); +} +device_initcall(perf_event_sysfs_init); diff --git a/kernel/pid.c b/kernel/pid.c index 31310b5..d3f722d 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -40,7 +40,7 @@ #define pid_hashfn(nr, ns) \ hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift) static struct hlist_head *pid_hash; -static int pidhash_shift; +static unsigned int pidhash_shift = 4; struct pid init_struct_pid = INIT_STRUCT_PID; int pid_max = PID_MAX_DEFAULT; @@ -499,19 +499,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) void __init pidhash_init(void) { int i, pidhash_size; - unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT); - pidhash_shift = max(4, fls(megabytes * 4)); - pidhash_shift = min(12, pidhash_shift); + pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18, + HASH_EARLY | HASH_SMALL, + &pidhash_shift, NULL, 4096); pidhash_size = 1 << pidhash_shift; - printk("PID hash table entries: %d (order: %d, %Zd bytes)\n", - pidhash_size, pidhash_shift, - pidhash_size * sizeof(struct hlist_head)); - - pid_hash = alloc_bootmem(pidhash_size * sizeof(*(pid_hash))); - if (!pid_hash) - panic("Could not alloc pidhash!\n"); for (i = 0; i < pidhash_size; i++) INIT_HLIST_HEAD(&pid_hash[i]); } diff --git a/kernel/power/console.c b/kernel/power/console.c index a3961b20..5187136 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -14,56 +14,13 @@ #define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1) static int orig_fgconsole, orig_kmsg; -static int disable_vt_switch; - -/* - * Normally during a suspend, we allocate a new console and switch to it. - * When we resume, we switch back to the original console. This switch - * can be slow, so on systems where the framebuffer can handle restoration - * of video registers anyways, there's little point in doing the console - * switch. This function allows you to disable it by passing it '0'. - */ -void pm_set_vt_switch(int do_switch) -{ - acquire_console_sem(); - disable_vt_switch = !do_switch; - release_console_sem(); -} -EXPORT_SYMBOL(pm_set_vt_switch); int pm_prepare_console(void) { - acquire_console_sem(); - - if (disable_vt_switch) { - release_console_sem(); - return 0; - } - - orig_fgconsole = fg_console; - - if (vc_allocate(SUSPEND_CONSOLE)) { - /* we can't have a free VC for now. Too bad, - * we don't want to mess the screen for now. */ - release_console_sem(); + orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1); + if (orig_fgconsole < 0) return 1; - } - if (set_console(SUSPEND_CONSOLE)) { - /* - * We're unable to switch to the SUSPEND_CONSOLE. - * Let the calling function know so it can decide - * what to do. - */ - release_console_sem(); - return 1; - } - release_console_sem(); - - if (vt_waitactive(SUSPEND_CONSOLE)) { - pr_debug("Suspend: Can't switch VCs."); - return 1; - } orig_kmsg = kmsg_redirect; kmsg_redirect = SUSPEND_CONSOLE; return 0; @@ -71,19 +28,9 @@ int pm_prepare_console(void) void pm_restore_console(void) { - acquire_console_sem(); - if (disable_vt_switch) { - release_console_sem(); - return; - } - set_console(orig_fgconsole); - release_console_sem(); - - if (vt_waitactive(orig_fgconsole)) { - pr_debug("Resume: Can't switch VCs."); - return; + if (orig_fgconsole >= 0) { + vt_move_to_console(orig_fgconsole, 0); + kmsg_redirect = orig_kmsg; } - - kmsg_redirect = orig_kmsg; } #endif diff --git a/kernel/power/process.c b/kernel/power/process.c index da2072d..cc2e553 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -9,6 +9,7 @@ #undef DEBUG #include <linux/interrupt.h> +#include <linux/oom.h> #include <linux/suspend.h> #include <linux/module.h> #include <linux/syscalls.h> diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 97955b0..36cb168 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -619,7 +619,7 @@ __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn, BUG_ON(!region); } else /* This allocation cannot fail */ - region = alloc_bootmem_low(sizeof(struct nosave_region)); + region = alloc_bootmem(sizeof(struct nosave_region)); region->start_pfn = start_pfn; region->end_pfn = end_pfn; list_add_tail(®ion->list, &nosave_regions); diff --git a/kernel/printk.c b/kernel/printk.c index 602033a..f38b07f 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -206,12 +206,11 @@ __setup("log_buf_len=", log_buf_len_setup); #ifdef CONFIG_BOOT_PRINTK_DELAY static unsigned int boot_delay; /* msecs delay after each printk during bootup */ -static unsigned long long printk_delay_msec; /* per msec, based on boot_delay */ +static unsigned long long loops_per_msec; /* based on boot_delay */ static int __init boot_delay_setup(char *str) { unsigned long lpj; - unsigned long long loops_per_msec; lpj = preset_lpj ? preset_lpj : 1000000; /* some guess */ loops_per_msec = (unsigned long long)lpj / 1000 * HZ; @@ -220,10 +219,9 @@ static int __init boot_delay_setup(char *str) if (boot_delay > 10 * 1000) boot_delay = 0; - printk_delay_msec = loops_per_msec; - printk(KERN_DEBUG "boot_delay: %u, preset_lpj: %ld, lpj: %lu, " - "HZ: %d, printk_delay_msec: %llu\n", - boot_delay, preset_lpj, lpj, HZ, printk_delay_msec); + pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, " + "HZ: %d, loops_per_msec: %llu\n", + boot_delay, preset_lpj, lpj, HZ, loops_per_msec); return 1; } __setup("boot_delay=", boot_delay_setup); @@ -236,7 +234,7 @@ static void boot_delay_msec(void) if (boot_delay == 0 || system_state != SYSTEM_BOOTING) return; - k = (unsigned long long)printk_delay_msec * boot_delay; + k = (unsigned long long)loops_per_msec * boot_delay; timeout = jiffies + msecs_to_jiffies(boot_delay); while (k) { @@ -655,6 +653,20 @@ static int recursion_bug; static int new_text_line = 1; static char printk_buf[1024]; +int printk_delay_msec __read_mostly; + +static inline void printk_delay(void) +{ + if (unlikely(printk_delay_msec)) { + int m = printk_delay_msec; + + while (m--) { + mdelay(1); + touch_nmi_watchdog(); + } + } +} + asmlinkage int vprintk(const char *fmt, va_list args) { int printed_len = 0; @@ -664,6 +676,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) char *p; boot_delay_msec(); + printk_delay(); preempt_disable(); /* This stops the holder of console_sem just where we want him */ diff --git a/kernel/profile.c b/kernel/profile.c index 419250e..a55d3a3 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -442,48 +442,51 @@ void profile_tick(int type) #ifdef CONFIG_PROC_FS #include <linux/proc_fs.h> +#include <linux/seq_file.h> #include <asm/uaccess.h> -static int prof_cpu_mask_read_proc(char *page, char **start, off_t off, - int count, int *eof, void *data) +static int prof_cpu_mask_proc_show(struct seq_file *m, void *v) { - int len = cpumask_scnprintf(page, count, data); - if (count - len < 2) - return -EINVAL; - len += sprintf(page + len, "\n"); - return len; + seq_cpumask(m, prof_cpu_mask); + seq_putc(m, '\n'); + return 0; } -static int prof_cpu_mask_write_proc(struct file *file, - const char __user *buffer, unsigned long count, void *data) +static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, prof_cpu_mask_proc_show, NULL); +} + +static ssize_t prof_cpu_mask_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) { - struct cpumask *mask = data; - unsigned long full_count = count, err; cpumask_var_t new_value; + int err; if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; err = cpumask_parse_user(buffer, count, new_value); if (!err) { - cpumask_copy(mask, new_value); - err = full_count; + cpumask_copy(prof_cpu_mask, new_value); + err = count; } free_cpumask_var(new_value); return err; } +static const struct file_operations prof_cpu_mask_proc_fops = { + .open = prof_cpu_mask_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = prof_cpu_mask_proc_write, +}; + void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) { - struct proc_dir_entry *entry; - /* create /proc/irq/prof_cpu_mask */ - entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir); - if (!entry) - return; - entry->data = prof_cpu_mask; - entry->read_proc = prof_cpu_mask_read_proc; - entry->write_proc = prof_cpu_mask_write_proc; + proc_create("prof_cpu_mask", 0600, root_irq_dir, &prof_cpu_mask_proc_fops); } /* diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index bd5d5c8..37ac454 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -19,7 +19,7 @@ * * Authors: Dipankar Sarma <dipankar@in.ibm.com> * Manfred Spraul <manfred@colorfullife.com> - * + * * Based on the original work by Paul McKenney <paulmck@us.ibm.com> * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: @@ -27,7 +27,7 @@ * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001) * * For detailed explanation of Read-Copy Update mechanism see - - * http://lse.sourceforge.net/locking/rcupdate.html + * http://lse.sourceforge.net/locking/rcupdate.html * */ #include <linux/types.h> @@ -74,6 +74,8 @@ void wakeme_after_rcu(struct rcu_head *head) complete(&rcu->completion); } +#ifdef CONFIG_TREE_PREEMPT_RCU + /** * synchronize_rcu - wait until a grace period has elapsed. * @@ -87,7 +89,7 @@ void synchronize_rcu(void) { struct rcu_synchronize rcu; - if (rcu_blocking_is_gp()) + if (!rcu_scheduler_active) return; init_completion(&rcu.completion); @@ -98,6 +100,46 @@ void synchronize_rcu(void) } EXPORT_SYMBOL_GPL(synchronize_rcu); +#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ + +/** + * synchronize_sched - wait until an rcu-sched grace period has elapsed. + * + * Control will return to the caller some time after a full rcu-sched + * grace period has elapsed, in other words after all currently executing + * rcu-sched read-side critical sections have completed. These read-side + * critical sections are delimited by rcu_read_lock_sched() and + * rcu_read_unlock_sched(), and may be nested. Note that preempt_disable(), + * local_irq_disable(), and so on may be used in place of + * rcu_read_lock_sched(). + * + * This means that all preempt_disable code sequences, including NMI and + * hardware-interrupt handlers, in progress on entry will have completed + * before this primitive returns. However, this does not guarantee that + * softirq handlers will have completed, since in some kernels, these + * handlers can run in process context, and can block. + * + * This primitive provides the guarantees made by the (now removed) + * synchronize_kernel() API. In contrast, synchronize_rcu() only + * guarantees that rcu_read_lock() sections will have completed. + * In "classic RCU", these two guarantees happen to be one and + * the same, but can differ in realtime RCU implementations. + */ +void synchronize_sched(void) +{ + struct rcu_synchronize rcu; + + if (rcu_blocking_is_gp()) + return; + + init_completion(&rcu.completion); + /* Will wake me after RCU finished. */ + call_rcu_sched(&rcu.head, wakeme_after_rcu); + /* Wait for it. */ + wait_for_completion(&rcu.completion); +} +EXPORT_SYMBOL_GPL(synchronize_sched); + /** * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed. * diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index b33db53..233768f 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -18,7 +18,7 @@ * Copyright (C) IBM Corporation, 2005, 2006 * * Authors: Paul E. McKenney <paulmck@us.ibm.com> - * Josh Triplett <josh@freedesktop.org> + * Josh Triplett <josh@freedesktop.org> * * See also: Documentation/RCU/torture.txt */ @@ -50,7 +50,7 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and " - "Josh Triplett <josh@freedesktop.org>"); + "Josh Triplett <josh@freedesktop.org>"); static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */ static int nfakewriters = 4; /* # fake writer threads */ @@ -110,8 +110,8 @@ struct rcu_torture { }; static LIST_HEAD(rcu_torture_freelist); -static struct rcu_torture *rcu_torture_current = NULL; -static long rcu_torture_current_version = 0; +static struct rcu_torture *rcu_torture_current; +static long rcu_torture_current_version; static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; static DEFINE_SPINLOCK(rcu_torture_lock); static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = @@ -124,11 +124,11 @@ static atomic_t n_rcu_torture_alloc_fail; static atomic_t n_rcu_torture_free; static atomic_t n_rcu_torture_mberror; static atomic_t n_rcu_torture_error; -static long n_rcu_torture_timers = 0; +static long n_rcu_torture_timers; static struct list_head rcu_torture_removed; static cpumask_var_t shuffle_tmp_mask; -static int stutter_pause_test = 0; +static int stutter_pause_test; #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) #define RCUTORTURE_RUNNABLE_INIT 1 @@ -267,7 +267,8 @@ struct rcu_torture_ops { int irq_capable; char *name; }; -static struct rcu_torture_ops *cur_ops = NULL; + +static struct rcu_torture_ops *cur_ops; /* * Definitions for rcu torture testing. @@ -281,14 +282,17 @@ static int rcu_torture_read_lock(void) __acquires(RCU) static void rcu_read_delay(struct rcu_random_state *rrsp) { - long delay; - const long longdelay = 200; + const unsigned long shortdelay_us = 200; + const unsigned long longdelay_ms = 50; - /* We want there to be long-running readers, but not all the time. */ + /* We want a short delay sometimes to make a reader delay the grace + * period, and we want a long delay occasionally to trigger + * force_quiescent_state. */ - delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay); - if (!delay) - udelay(longdelay); + if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) + mdelay(longdelay_ms); + if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) + udelay(shortdelay_us); } static void rcu_torture_read_unlock(int idx) __releases(RCU) @@ -339,8 +343,8 @@ static struct rcu_torture_ops rcu_ops = { .sync = synchronize_rcu, .cb_barrier = rcu_barrier, .stats = NULL, - .irq_capable = 1, - .name = "rcu" + .irq_capable = 1, + .name = "rcu" }; static void rcu_sync_torture_deferred_free(struct rcu_torture *p) @@ -638,7 +642,8 @@ rcu_torture_writer(void *arg) do { schedule_timeout_uninterruptible(1); - if ((rp = rcu_torture_alloc()) == NULL) + rp = rcu_torture_alloc(); + if (rp == NULL) continue; rp->rtort_pipe_count = 0; udelay(rcu_random(&rand) & 0x3ff); @@ -1110,7 +1115,7 @@ rcu_torture_init(void) printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", torture_type); mutex_unlock(&fullstop_mutex); - return (-EINVAL); + return -EINVAL; } if (cur_ops->init) cur_ops->init(); /* no "goto unwind" prior to this point!!! */ @@ -1161,7 +1166,7 @@ rcu_torture_init(void) goto unwind; } fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), - GFP_KERNEL); + GFP_KERNEL); if (fakewriter_tasks == NULL) { VERBOSE_PRINTK_ERRSTRING("out of memory"); firsterr = -ENOMEM; @@ -1170,7 +1175,7 @@ rcu_torture_init(void) for (i = 0; i < nfakewriters; i++) { VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, - "rcu_torture_fakewriter"); + "rcu_torture_fakewriter"); if (IS_ERR(fakewriter_tasks[i])) { firsterr = PTR_ERR(fakewriter_tasks[i]); VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 6b11b07..52b06f6 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -25,7 +25,7 @@ * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * * For detailed explanation of Read-Copy Update mechanism see - - * Documentation/RCU + * Documentation/RCU */ #include <linux/types.h> #include <linux/kernel.h> @@ -107,27 +107,23 @@ static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp, */ void rcu_sched_qs(int cpu) { - unsigned long flags; struct rcu_data *rdp; - local_irq_save(flags); rdp = &per_cpu(rcu_sched_data, cpu); - rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; - rcu_preempt_qs(cpu); - local_irq_restore(flags); + barrier(); + rdp->passed_quiesc = 1; + rcu_preempt_note_context_switch(cpu); } void rcu_bh_qs(int cpu) { - unsigned long flags; struct rcu_data *rdp; - local_irq_save(flags); rdp = &per_cpu(rcu_bh_data, cpu); - rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; - local_irq_restore(flags); + barrier(); + rdp->passed_quiesc = 1; } #ifdef CONFIG_NO_HZ @@ -605,8 +601,6 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) { struct rcu_data *rdp = rsp->rda[smp_processor_id()]; struct rcu_node *rnp = rcu_get_root(rsp); - struct rcu_node *rnp_cur; - struct rcu_node *rnp_end; if (!cpu_needs_another_gp(rsp, rdp)) { spin_unlock_irqrestore(&rnp->lock, flags); @@ -615,6 +609,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) /* Advance to a new grace period and initialize state. */ rsp->gpnum++; + WARN_ON_ONCE(rsp->signaled == RCU_GP_INIT); rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */ rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS; record_gp_stall_check_time(rsp); @@ -631,7 +626,9 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) /* Special-case the common single-level case. */ if (NUM_RCU_NODES == 1) { + rcu_preempt_check_blocked_tasks(rnp); rnp->qsmask = rnp->qsmaskinit; + rnp->gpnum = rsp->gpnum; rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */ spin_unlock_irqrestore(&rnp->lock, flags); return; @@ -644,42 +641,28 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) spin_lock(&rsp->onofflock); /* irqs already disabled. */ /* - * Set the quiescent-state-needed bits in all the non-leaf RCU - * nodes for all currently online CPUs. This operation relies - * on the layout of the hierarchy within the rsp->node[] array. - * Note that other CPUs will access only the leaves of the - * hierarchy, which still indicate that no grace period is in - * progress. In addition, we have excluded CPU-hotplug operations. - * - * We therefore do not need to hold any locks. Any required - * memory barriers will be supplied by the locks guarding the - * leaf rcu_nodes in the hierarchy. - */ - - rnp_end = rsp->level[NUM_RCU_LVLS - 1]; - for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) - rnp_cur->qsmask = rnp_cur->qsmaskinit; - - /* - * Now set up the leaf nodes. Here we must be careful. First, - * we need to hold the lock in order to exclude other CPUs, which - * might be contending for the leaf nodes' locks. Second, as - * soon as we initialize a given leaf node, its CPUs might run - * up the rest of the hierarchy. We must therefore acquire locks - * for each node that we touch during this stage. (But we still - * are excluding CPU-hotplug operations.) + * Set the quiescent-state-needed bits in all the rcu_node + * structures for all currently online CPUs in breadth-first + * order, starting from the root rcu_node structure. This + * operation relies on the layout of the hierarchy within the + * rsp->node[] array. Note that other CPUs will access only + * the leaves of the hierarchy, which still indicate that no + * grace period is in progress, at least until the corresponding + * leaf node has been initialized. In addition, we have excluded + * CPU-hotplug operations. * * Note that the grace period cannot complete until we finish * the initialization process, as there will be at least one * qsmask bit set in the root node until that time, namely the - * one corresponding to this CPU. + * one corresponding to this CPU, due to the fact that we have + * irqs disabled. */ - rnp_end = &rsp->node[NUM_RCU_NODES]; - rnp_cur = rsp->level[NUM_RCU_LVLS - 1]; - for (; rnp_cur < rnp_end; rnp_cur++) { - spin_lock(&rnp_cur->lock); /* irqs already disabled. */ - rnp_cur->qsmask = rnp_cur->qsmaskinit; - spin_unlock(&rnp_cur->lock); /* irqs already disabled. */ + for (rnp = &rsp->node[0]; rnp < &rsp->node[NUM_RCU_NODES]; rnp++) { + spin_lock(&rnp->lock); /* irqs already disabled. */ + rcu_preempt_check_blocked_tasks(rnp); + rnp->qsmask = rnp->qsmaskinit; + rnp->gpnum = rsp->gpnum; + spin_unlock(&rnp->lock); /* irqs already disabled. */ } rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */ @@ -722,6 +705,7 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp) static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags) __releases(rnp->lock) { + WARN_ON_ONCE(rsp->completed == rsp->gpnum); rsp->completed = rsp->gpnum; rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]); rcu_start_gp(rsp, flags); /* releases root node's rnp->lock. */ @@ -739,6 +723,8 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp, unsigned long flags) __releases(rnp->lock) { + struct rcu_node *rnp_c; + /* Walk up the rcu_node hierarchy. */ for (;;) { if (!(rnp->qsmask & mask)) { @@ -762,8 +748,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp, break; } spin_unlock_irqrestore(&rnp->lock, flags); + rnp_c = rnp; rnp = rnp->parent; spin_lock_irqsave(&rnp->lock, flags); + WARN_ON_ONCE(rnp_c->qsmask); } /* @@ -776,10 +764,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp, /* * Record a quiescent state for the specified CPU, which must either be - * the current CPU or an offline CPU. The lastcomp argument is used to - * make sure we are still in the grace period of interest. We don't want - * to end the current grace period based on quiescent states detected in - * an earlier grace period! + * the current CPU. The lastcomp argument is used to make sure we are + * still in the grace period of interest. We don't want to end the current + * grace period based on quiescent states detected in an earlier grace + * period! */ static void cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp) @@ -814,7 +802,6 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp) * This GP can't end until cpu checks in, so all of our * callbacks can be processed during the next GP. */ - rdp = rsp->rda[smp_processor_id()]; rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL]; cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */ @@ -872,7 +859,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_lock_irqsave(&rsp->onofflock, flags); /* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */ - rnp = rdp->mynode; + rnp = rdp->mynode; /* this is the outgoing CPU's rnp. */ mask = rdp->grpmask; /* rnp->grplo is constant. */ do { spin_lock(&rnp->lock); /* irqs already disabled. */ @@ -881,7 +868,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_unlock(&rnp->lock); /* irqs remain disabled. */ break; } - rcu_preempt_offline_tasks(rsp, rnp); + rcu_preempt_offline_tasks(rsp, rnp, rdp); mask = rnp->grpmask; spin_unlock(&rnp->lock); /* irqs remain disabled. */ rnp = rnp->parent; @@ -890,9 +877,6 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ - /* Being offline is a quiescent state, so go record it. */ - cpu_quiet(cpu, rsp, rdp, lastcomp); - /* * Move callbacks from the outgoing CPU to the running CPU. * Note that the outgoing CPU is now quiscent, so it is now @@ -1457,20 +1441,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) rnp = rnp->parent; } while (rnp != NULL && !(rnp->qsmaskinit & mask)); - spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ - - /* - * A new grace period might start here. If so, we will be part of - * it, and its gpnum will be greater than ours, so we will - * participate. It is also possible for the gpnum to have been - * incremented before this function was called, and the bitmasks - * to not be filled out until now, in which case we will also - * participate due to our gpnum being behind. - */ - - /* Since it is coming online, the CPU is in a quiescent state. */ - cpu_quiet(cpu, rsp, rdp, lastcomp); - local_irq_restore(flags); + spin_unlock_irqrestore(&rsp->onofflock, flags); } static void __cpuinit rcu_online_cpu(int cpu) diff --git a/kernel/rcutree.h b/kernel/rcutree.h index bf8a6f9..8e8287a 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -142,7 +142,7 @@ struct rcu_data { */ struct rcu_head *nxtlist; struct rcu_head **nxttail[RCU_NEXT_SIZE]; - long qlen; /* # of queued callbacks */ + long qlen; /* # of queued callbacks */ long blimit; /* Upper limit on a processed batch */ #ifdef CONFIG_NO_HZ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 4778936..1cee04f 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -64,22 +64,31 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed); * not in a quiescent state. There might be any number of tasks blocked * while in an RCU read-side critical section. */ -static void rcu_preempt_qs_record(int cpu) +static void rcu_preempt_qs(int cpu) { struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu); - rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; + barrier(); + rdp->passed_quiesc = 1; } /* - * We have entered the scheduler or are between softirqs in ksoftirqd. - * If we are in an RCU read-side critical section, we need to reflect - * that in the state of the rcu_node structure corresponding to this CPU. - * Caller must disable hardirqs. + * We have entered the scheduler, and the current task might soon be + * context-switched away from. If this task is in an RCU read-side + * critical section, we will no longer be able to rely on the CPU to + * record that fact, so we enqueue the task on the appropriate entry + * of the blocked_tasks[] array. The task will dequeue itself when + * it exits the outermost enclosing RCU read-side critical section. + * Therefore, the current grace period cannot be permitted to complete + * until the blocked_tasks[] entry indexed by the low-order bit of + * rnp->gpnum empties. + * + * Caller must disable preemption. */ -static void rcu_preempt_qs(int cpu) +static void rcu_preempt_note_context_switch(int cpu) { struct task_struct *t = current; + unsigned long flags; int phase; struct rcu_data *rdp; struct rcu_node *rnp; @@ -90,7 +99,7 @@ static void rcu_preempt_qs(int cpu) /* Possibly blocking in an RCU read-side critical section. */ rdp = rcu_preempt_state.rda[cpu]; rnp = rdp->mynode; - spin_lock(&rnp->lock); + spin_lock_irqsave(&rnp->lock, flags); t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED; t->rcu_blocked_node = rnp; @@ -103,11 +112,15 @@ static void rcu_preempt_qs(int cpu) * state for the current grace period), then as long * as that task remains queued, the current grace period * cannot end. + * + * But first, note that the current CPU must still be + * on line! */ - phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1); + WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0); + WARN_ON_ONCE(!list_empty(&t->rcu_node_entry)); + phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1; list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]); - smp_mb(); /* Ensure later ctxt swtch seen after above. */ - spin_unlock(&rnp->lock); + spin_unlock_irqrestore(&rnp->lock, flags); } /* @@ -119,9 +132,10 @@ static void rcu_preempt_qs(int cpu) * grace period, then the fact that the task has been enqueued * means that we continue to block the current grace period. */ - rcu_preempt_qs_record(cpu); - t->rcu_read_unlock_special &= ~(RCU_READ_UNLOCK_NEED_QS | - RCU_READ_UNLOCK_GOT_QS); + rcu_preempt_qs(cpu); + local_irq_save(flags); + t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; + local_irq_restore(flags); } /* @@ -157,7 +171,7 @@ static void rcu_read_unlock_special(struct task_struct *t) special = t->rcu_read_unlock_special; if (special & RCU_READ_UNLOCK_NEED_QS) { t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; - t->rcu_read_unlock_special |= RCU_READ_UNLOCK_GOT_QS; + rcu_preempt_qs(smp_processor_id()); } /* Hardware IRQ handlers cannot block. */ @@ -177,10 +191,10 @@ static void rcu_read_unlock_special(struct task_struct *t) */ for (;;) { rnp = t->rcu_blocked_node; - spin_lock(&rnp->lock); + spin_lock(&rnp->lock); /* irqs already disabled. */ if (rnp == t->rcu_blocked_node) break; - spin_unlock(&rnp->lock); + spin_unlock(&rnp->lock); /* irqs remain disabled. */ } empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]); list_del_init(&t->rcu_node_entry); @@ -194,9 +208,8 @@ static void rcu_read_unlock_special(struct task_struct *t) */ if (!empty && rnp->qsmask == 0 && list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) { - t->rcu_read_unlock_special &= - ~(RCU_READ_UNLOCK_NEED_QS | - RCU_READ_UNLOCK_GOT_QS); + struct rcu_node *rnp_p; + if (rnp->parent == NULL) { /* Only one rcu_node in the tree. */ cpu_quiet_msk_finish(&rcu_preempt_state, flags); @@ -205,9 +218,10 @@ static void rcu_read_unlock_special(struct task_struct *t) /* Report up the rest of the hierarchy. */ mask = rnp->grpmask; spin_unlock_irqrestore(&rnp->lock, flags); - rnp = rnp->parent; - spin_lock_irqsave(&rnp->lock, flags); - cpu_quiet_msk(mask, &rcu_preempt_state, rnp, flags); + rnp_p = rnp->parent; + spin_lock_irqsave(&rnp_p->lock, flags); + WARN_ON_ONCE(rnp->qsmask); + cpu_quiet_msk(mask, &rcu_preempt_state, rnp_p, flags); return; } spin_unlock(&rnp->lock); @@ -259,6 +273,19 @@ static void rcu_print_task_stall(struct rcu_node *rnp) #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ /* + * Check that the list of blocked tasks for the newly completed grace + * period is in fact empty. It is a serious bug to complete a grace + * period that still has RCU readers blocked! This function must be + * invoked -before- updating this rnp's ->gpnum, and the rnp's ->lock + * must be held by the caller. + */ +static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) +{ + WARN_ON_ONCE(!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])); + WARN_ON_ONCE(rnp->qsmask); +} + +/* * Check for preempted RCU readers for the specified rcu_node structure. * If the caller needs a reliable answer, it must hold the rcu_node's * >lock. @@ -280,7 +307,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp) * The caller must hold rnp->lock with irqs disabled. */ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, - struct rcu_node *rnp) + struct rcu_node *rnp, + struct rcu_data *rdp) { int i; struct list_head *lp; @@ -292,6 +320,9 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, WARN_ONCE(1, "Last CPU thought to be offlined?"); return; /* Shouldn't happen: at least one CPU online. */ } + WARN_ON_ONCE(rnp != rdp->mynode && + (!list_empty(&rnp->blocked_tasks[0]) || + !list_empty(&rnp->blocked_tasks[1]))); /* * Move tasks up to root rcu_node. Rely on the fact that the @@ -335,20 +366,12 @@ static void rcu_preempt_check_callbacks(int cpu) struct task_struct *t = current; if (t->rcu_read_lock_nesting == 0) { - t->rcu_read_unlock_special &= - ~(RCU_READ_UNLOCK_NEED_QS | RCU_READ_UNLOCK_GOT_QS); - rcu_preempt_qs_record(cpu); + t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; + rcu_preempt_qs(cpu); return; } - if (per_cpu(rcu_preempt_data, cpu).qs_pending) { - if (t->rcu_read_unlock_special & RCU_READ_UNLOCK_GOT_QS) { - rcu_preempt_qs_record(cpu); - t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_GOT_QS; - } else if (!(t->rcu_read_unlock_special & - RCU_READ_UNLOCK_NEED_QS)) { - t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS; - } - } + if (per_cpu(rcu_preempt_data, cpu).qs_pending) + t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS; } /* @@ -434,7 +457,7 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed); * Because preemptable RCU does not exist, we never have to check for * CPUs being in quiescent states. */ -static void rcu_preempt_qs(int cpu) +static void rcu_preempt_note_context_switch(int cpu) { } @@ -451,6 +474,16 @@ static void rcu_print_task_stall(struct rcu_node *rnp) #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ /* + * Because there is no preemptable RCU, there can be no readers blocked, + * so there is no need to check for blocked tasks. So check only for + * bogus qsmask values. + */ +static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) +{ + WARN_ON_ONCE(rnp->qsmask); +} + +/* * Because preemptable RCU does not exist, there are never any preempted * RCU readers. */ @@ -466,7 +499,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp) * tasks that were blocked within RCU read-side critical sections. */ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, - struct rcu_node *rnp) + struct rcu_node *rnp, + struct rcu_data *rdp) { } diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index 0ea1bff..c89f5e9 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -20,7 +20,7 @@ * Papers: http://www.rdrop.com/users/paulmck/RCU * * For detailed explanation of Read-Copy Update mechanism see - - * Documentation/RCU + * Documentation/RCU * */ #include <linux/types.h> diff --git a/kernel/resource.c b/kernel/resource.c index 78b0872..fb11a58 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -223,13 +223,13 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); -#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY) +#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) /* * Finds the lowest memory reosurce exists within [res->start.res->end) - * the caller must specify res->start, res->end, res->flags. + * the caller must specify res->start, res->end, res->flags and "name". * If found, returns 0, res is overwritten, if not found, returns -1. */ -static int find_next_system_ram(struct resource *res) +static int find_next_system_ram(struct resource *res, char *name) { resource_size_t start, end; struct resource *p; @@ -245,6 +245,8 @@ static int find_next_system_ram(struct resource *res) /* system ram is just marked as IORESOURCE_MEM */ if (p->flags != res->flags) continue; + if (name && strcmp(p->name, name)) + continue; if (p->start > end) { p = NULL; break; @@ -262,19 +264,26 @@ static int find_next_system_ram(struct resource *res) res->end = p->end; return 0; } -int -walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, - int (*func)(unsigned long, unsigned long, void *)) + +/* + * This function calls callback against all memory range of "System RAM" + * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. + * Now, this function is only for "System RAM". + */ +int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg, int (*func)(unsigned long, unsigned long, void *)) { struct resource res; unsigned long pfn, len; u64 orig_end; int ret = -1; + res.start = (u64) start_pfn << PAGE_SHIFT; res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; orig_end = res.end; - while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) { + while ((res.start < res.end) && + (find_next_system_ram(&res, "System RAM") >= 0)) { pfn = (unsigned long)(res.start >> PAGE_SHIFT); len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT); ret = (*func)(pfn, len, arg); diff --git a/kernel/sched.c b/kernel/sched.c index faf4d46..0ac9053 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -39,7 +39,7 @@ #include <linux/completion.h> #include <linux/kernel_stat.h> #include <linux/debug_locks.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <linux/security.h> #include <linux/notifier.h> #include <linux/profile.h> @@ -681,15 +681,9 @@ inline void update_rq_clock(struct rq *rq) * This interface allows printk to be called with the runqueue lock * held and know whether or not it is OK to wake up the klogd. */ -int runqueue_is_locked(void) +int runqueue_is_locked(int cpu) { - int cpu = get_cpu(); - struct rq *rq = cpu_rq(cpu); - int ret; - - ret = spin_is_locked(&rq->lock); - put_cpu(); - return ret; + return spin_is_locked(&cpu_rq(cpu)->lock); } /* @@ -2059,7 +2053,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) if (task_hot(p, old_rq->clock, NULL)) schedstat_inc(p, se.nr_forced2_migrations); #endif - perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS, + perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); } p->se.vruntime -= old_cfsrq->min_vruntime - @@ -2724,7 +2718,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) */ prev_state = prev->state; finish_arch_switch(prev); - perf_counter_task_sched_in(current, cpu_of(rq)); + perf_event_task_sched_in(current, cpu_of(rq)); finish_lock_switch(rq, prev); fire_sched_in_preempt_notifiers(current); @@ -2910,6 +2904,19 @@ unsigned long nr_iowait(void) return sum; } +unsigned long nr_iowait_cpu(void) +{ + struct rq *this = this_rq(); + return atomic_read(&this->nr_iowait); +} + +unsigned long this_cpu_load(void) +{ + struct rq *this = this_rq(); + return this->cpu_load[0]; +} + + /* Variables and functions for calc_load */ static atomic_long_t calc_load_tasks; static unsigned long calc_load_update; @@ -5199,7 +5206,7 @@ void scheduler_tick(void) curr->sched_class->task_tick(rq, curr, 0); spin_unlock(&rq->lock); - perf_counter_task_tick(curr, cpu); + perf_event_task_tick(curr, cpu); #ifdef CONFIG_SMP rq->idle_at_tick = idle_cpu(cpu); @@ -5415,7 +5422,7 @@ need_resched_nonpreemptible: if (likely(prev != next)) { sched_info_switch(prev, next); - perf_counter_task_sched_out(prev, next, cpu); + perf_event_task_sched_out(prev, next, cpu); rq->nr_switches++; rq->curr = next; @@ -6825,23 +6832,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, if (retval) goto out_unlock; - /* - * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER - * tasks that are on an otherwise idle runqueue: - */ - time_slice = 0; - if (p->policy == SCHED_RR) { - time_slice = DEF_TIMESLICE; - } else if (p->policy != SCHED_FIFO) { - struct sched_entity *se = &p->se; - unsigned long flags; - struct rq *rq; + time_slice = p->sched_class->get_rr_interval(p); - rq = task_rq_lock(p, &flags); - if (rq->cfs.load.weight) - time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); - task_rq_unlock(rq, &flags); - } read_unlock(&tasklist_lock); jiffies_to_timespec(time_slice, &t); retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; @@ -7692,7 +7684,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) /* * Register at high priority so that task migration (migrate_all_tasks) * happens before everything else. This has to be lower priority than - * the notifier in the perf_counter subsystem, though. + * the notifier in the perf_event subsystem, though. */ static struct notifier_block __cpuinitdata migration_notifier = { .notifier_call = migration_call, @@ -9171,6 +9163,7 @@ void __init sched_init_smp(void) cpumask_var_t non_isolated_cpus; alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); + alloc_cpumask_var(&fallback_doms, GFP_KERNEL); #if defined(CONFIG_NUMA) sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), @@ -9202,7 +9195,6 @@ void __init sched_init_smp(void) sched_init_granularity(); free_cpumask_var(non_isolated_cpus); - alloc_cpumask_var(&fallback_doms, GFP_KERNEL); init_sched_rt_class(); } #else @@ -9549,7 +9541,7 @@ void __init sched_init(void) alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); #endif /* SMP */ - perf_counter_init(); + perf_event_init(); scheduler_running = 1; } diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index e1d16c9..ac2e1dc 100644 --- a/kernel/sched_clock.c +++ b/kernel/sched_clock.c @@ -48,13 +48,6 @@ static __read_mostly int sched_clock_running; __read_mostly int sched_clock_stable; struct sched_clock_data { - /* - * Raw spinlock - this is a special case: this might be called - * from within instrumentation code so we dont want to do any - * instrumentation ourselves. - */ - raw_spinlock_t lock; - u64 tick_raw; u64 tick_gtod; u64 clock; @@ -80,7 +73,6 @@ void sched_clock_init(void) for_each_possible_cpu(cpu) { struct sched_clock_data *scd = cpu_sdc(cpu); - scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; scd->tick_raw = 0; scd->tick_gtod = ktime_now; scd->clock = ktime_now; @@ -109,14 +101,19 @@ static inline u64 wrap_max(u64 x, u64 y) * - filter out backward motion * - use the GTOD tick value to create a window to filter crazy TSC values */ -static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now) +static u64 sched_clock_local(struct sched_clock_data *scd) { - s64 delta = now - scd->tick_raw; - u64 clock, min_clock, max_clock; + u64 now, clock, old_clock, min_clock, max_clock; + s64 delta; +again: + now = sched_clock(); + delta = now - scd->tick_raw; if (unlikely(delta < 0)) delta = 0; + old_clock = scd->clock; + /* * scd->clock = clamp(scd->tick_gtod + delta, * max(scd->tick_gtod, scd->clock), @@ -124,84 +121,73 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now) */ clock = scd->tick_gtod + delta; - min_clock = wrap_max(scd->tick_gtod, scd->clock); - max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC); + min_clock = wrap_max(scd->tick_gtod, old_clock); + max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC); clock = wrap_max(clock, min_clock); clock = wrap_min(clock, max_clock); - scd->clock = clock; + if (cmpxchg(&scd->clock, old_clock, clock) != old_clock) + goto again; - return scd->clock; + return clock; } -static void lock_double_clock(struct sched_clock_data *data1, - struct sched_clock_data *data2) +static u64 sched_clock_remote(struct sched_clock_data *scd) { - if (data1 < data2) { - __raw_spin_lock(&data1->lock); - __raw_spin_lock(&data2->lock); + struct sched_clock_data *my_scd = this_scd(); + u64 this_clock, remote_clock; + u64 *ptr, old_val, val; + + sched_clock_local(my_scd); +again: + this_clock = my_scd->clock; + remote_clock = scd->clock; + + /* + * Use the opportunity that we have both locks + * taken to couple the two clocks: we take the + * larger time as the latest time for both + * runqueues. (this creates monotonic movement) + */ + if (likely((s64)(remote_clock - this_clock) < 0)) { + ptr = &scd->clock; + old_val = remote_clock; + val = this_clock; } else { - __raw_spin_lock(&data2->lock); - __raw_spin_lock(&data1->lock); + /* + * Should be rare, but possible: + */ + ptr = &my_scd->clock; + old_val = this_clock; + val = remote_clock; } + + if (cmpxchg(ptr, old_val, val) != old_val) + goto again; + + return val; } u64 sched_clock_cpu(int cpu) { - u64 now, clock, this_clock, remote_clock; struct sched_clock_data *scd; + u64 clock; + + WARN_ON_ONCE(!irqs_disabled()); if (sched_clock_stable) return sched_clock(); - scd = cpu_sdc(cpu); - - /* - * Normally this is not called in NMI context - but if it is, - * trying to do any locking here is totally lethal. - */ - if (unlikely(in_nmi())) - return scd->clock; - if (unlikely(!sched_clock_running)) return 0ull; - WARN_ON_ONCE(!irqs_disabled()); - now = sched_clock(); - - if (cpu != raw_smp_processor_id()) { - struct sched_clock_data *my_scd = this_scd(); - - lock_double_clock(scd, my_scd); - - this_clock = __update_sched_clock(my_scd, now); - remote_clock = scd->clock; - - /* - * Use the opportunity that we have both locks - * taken to couple the two clocks: we take the - * larger time as the latest time for both - * runqueues. (this creates monotonic movement) - */ - if (likely((s64)(remote_clock - this_clock) < 0)) { - clock = this_clock; - scd->clock = clock; - } else { - /* - * Should be rare, but possible: - */ - clock = remote_clock; - my_scd->clock = remote_clock; - } - - __raw_spin_unlock(&my_scd->lock); - } else { - __raw_spin_lock(&scd->lock); - clock = __update_sched_clock(scd, now); - } + scd = cpu_sdc(cpu); - __raw_spin_unlock(&scd->lock); + if (cpu != smp_processor_id()) + clock = sched_clock_remote(scd); + else + clock = sched_clock_local(scd); return clock; } @@ -223,11 +209,9 @@ void sched_clock_tick(void) now_gtod = ktime_to_ns(ktime_get()); now = sched_clock(); - __raw_spin_lock(&scd->lock); scd->tick_raw = now; scd->tick_gtod = now_gtod; - __update_sched_clock(scd, now); - __raw_spin_unlock(&scd->lock); + sched_clock_local(scd); } /* diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 10d218a..ecc637a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -513,6 +513,7 @@ static void update_curr(struct cfs_rq *cfs_rq) if (entity_is_task(curr)) { struct task_struct *curtask = task_of(curr); + trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime); cpuacct_charge(curtask, delta_exec); account_group_exec_runtime(curtask, delta_exec); } @@ -709,31 +710,28 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) if (initial && sched_feat(START_DEBIT)) vruntime += sched_vslice(cfs_rq, se); - if (!initial) { - /* sleeps upto a single latency don't count. */ - if (sched_feat(FAIR_SLEEPERS)) { - unsigned long thresh = sysctl_sched_latency; + /* sleeps up to a single latency don't count. */ + if (!initial && sched_feat(FAIR_SLEEPERS)) { + unsigned long thresh = sysctl_sched_latency; - /* - * Convert the sleeper threshold into virtual time. - * SCHED_IDLE is a special sub-class. We care about - * fairness only relative to other SCHED_IDLE tasks, - * all of which have the same weight. - */ - if (sched_feat(NORMALIZED_SLEEPER) && - (!entity_is_task(se) || - task_of(se)->policy != SCHED_IDLE)) - thresh = calc_delta_fair(thresh, se); + /* + * Convert the sleeper threshold into virtual time. + * SCHED_IDLE is a special sub-class. We care about + * fairness only relative to other SCHED_IDLE tasks, + * all of which have the same weight. + */ + if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) || + task_of(se)->policy != SCHED_IDLE)) + thresh = calc_delta_fair(thresh, se); - /* - * Halve their sleep time's effect, to allow - * for a gentler effect of sleepers: - */ - if (sched_feat(GENTLE_FAIR_SLEEPERS)) - thresh >>= 1; + /* + * Halve their sleep time's effect, to allow + * for a gentler effect of sleepers: + */ + if (sched_feat(GENTLE_FAIR_SLEEPERS)) + thresh >>= 1; - vruntime -= thresh; - } + vruntime -= thresh; } /* ensure we never gain time by being placed backwards. */ @@ -1342,7 +1340,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { - if (sched_feat(AFFINE_WAKEUPS)) + if (sched_feat(AFFINE_WAKEUPS) && + cpumask_test_cpu(cpu, &p->cpus_allowed)) want_affine = 1; new_cpu = prev_cpu; } @@ -1940,6 +1939,25 @@ static void moved_group_fair(struct task_struct *p) } #endif +unsigned int get_rr_interval_fair(struct task_struct *task) +{ + struct sched_entity *se = &task->se; + unsigned long flags; + struct rq *rq; + unsigned int rr_interval = 0; + + /* + * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise + * idle runqueue: + */ + rq = task_rq_lock(task, &flags); + if (rq->cfs.load.weight) + rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); + task_rq_unlock(rq, &flags); + + return rr_interval; +} + /* * All the scheduling class methods: */ @@ -1968,6 +1986,8 @@ static const struct sched_class fair_sched_class = { .prio_changed = prio_changed_fair, .switched_to = switched_to_fair, + .get_rr_interval = get_rr_interval_fair, + #ifdef CONFIG_FAIR_GROUP_SCHED .moved_group = moved_group_fair, #endif diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index a8b448a..b133a28 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -97,6 +97,11 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p, check_preempt_curr(rq, p, 0); } +unsigned int get_rr_interval_idle(struct task_struct *task) +{ + return 0; +} + /* * Simple, special scheduling class for the per-CPU idle tasks: */ @@ -122,6 +127,8 @@ static const struct sched_class idle_sched_class = { .set_curr_task = set_curr_task_idle, .task_tick = task_tick_idle, + .get_rr_interval = get_rr_interval_idle, + .prio_changed = prio_changed_idle, .switched_to = switched_to_idle, diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 13de712..a4d790c 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1734,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq) dequeue_pushable_task(rq, p); } +unsigned int get_rr_interval_rt(struct task_struct *task) +{ + /* + * Time slice is 0 for SCHED_FIFO tasks + */ + if (task->policy == SCHED_RR) + return DEF_TIMESLICE; + else + return 0; +} + static const struct sched_class rt_sched_class = { .next = &fair_sched_class, .enqueue_task = enqueue_task_rt, @@ -1762,6 +1773,8 @@ static const struct sched_class rt_sched_class = { .set_curr_task = set_curr_task_rt, .task_tick = task_tick_rt, + .get_rr_interval = get_rr_interval_rt, + .prio_changed = prio_changed_rt, .switched_to = switched_to_rt, }; diff --git a/kernel/smp.c b/kernel/smp.c index 8e21850..fd47a25 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -29,8 +29,7 @@ enum { struct call_function_data { struct call_single_data csd; - spinlock_t lock; - unsigned int refs; + atomic_t refs; cpumask_var_t cpumask; }; @@ -39,9 +38,7 @@ struct call_single_queue { spinlock_t lock; }; -static DEFINE_PER_CPU(struct call_function_data, cfd_data) = { - .lock = __SPIN_LOCK_UNLOCKED(cfd_data.lock), -}; +static DEFINE_PER_CPU(struct call_function_data, cfd_data); static int hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) @@ -196,25 +193,18 @@ void generic_smp_call_function_interrupt(void) list_for_each_entry_rcu(data, &call_function.queue, csd.list) { int refs; - spin_lock(&data->lock); - if (!cpumask_test_cpu(cpu, data->cpumask)) { - spin_unlock(&data->lock); + if (!cpumask_test_and_clear_cpu(cpu, data->cpumask)) continue; - } - cpumask_clear_cpu(cpu, data->cpumask); - spin_unlock(&data->lock); data->csd.func(data->csd.info); - spin_lock(&data->lock); - WARN_ON(data->refs == 0); - refs = --data->refs; + refs = atomic_dec_return(&data->refs); + WARN_ON(refs < 0); if (!refs) { spin_lock(&call_function.lock); list_del_rcu(&data->csd.list); spin_unlock(&call_function.lock); } - spin_unlock(&data->lock); if (refs) continue; @@ -419,23 +409,20 @@ void smp_call_function_many(const struct cpumask *mask, data = &__get_cpu_var(cfd_data); csd_lock(&data->csd); - spin_lock_irqsave(&data->lock, flags); data->csd.func = func; data->csd.info = info; cpumask_and(data->cpumask, mask, cpu_online_mask); cpumask_clear_cpu(this_cpu, data->cpumask); - data->refs = cpumask_weight(data->cpumask); + atomic_set(&data->refs, cpumask_weight(data->cpumask)); - spin_lock(&call_function.lock); + spin_lock_irqsave(&call_function.lock, flags); /* * Place entry at the _HEAD_ of the list, so that any cpu still * observing the entry in generic_smp_call_function_interrupt() * will not miss any other list entries: */ list_add_rcu(&data->csd.list, &call_function.queue); - spin_unlock(&call_function.lock); - - spin_unlock_irqrestore(&data->lock, flags); + spin_unlock_irqrestore(&call_function.lock, flags); /* * Make the list addition visible before sending the ipi. diff --git a/kernel/sys.c b/kernel/sys.c index b3f1097..ebcb156 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -14,7 +14,7 @@ #include <linux/prctl.h> #include <linux/highuid.h> #include <linux/fs.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <linux/resource.h> #include <linux/kernel.h> #include <linux/kexec.h> @@ -1338,6 +1338,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long flags; cputime_t utime, stime; struct task_cputime cputime; + unsigned long maxrss = 0; memset((char *) r, 0, sizeof *r); utime = stime = cputime_zero; @@ -1346,6 +1347,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) utime = task_utime(current); stime = task_stime(current); accumulate_thread_rusage(p, r); + maxrss = p->signal->maxrss; goto out; } @@ -1363,6 +1365,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_majflt = p->signal->cmaj_flt; r->ru_inblock = p->signal->cinblock; r->ru_oublock = p->signal->coublock; + maxrss = p->signal->cmaxrss; if (who == RUSAGE_CHILDREN) break; @@ -1377,6 +1380,8 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_majflt += p->signal->maj_flt; r->ru_inblock += p->signal->inblock; r->ru_oublock += p->signal->oublock; + if (maxrss < p->signal->maxrss) + maxrss = p->signal->maxrss; t = p; do { accumulate_thread_rusage(t, r); @@ -1392,6 +1397,15 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) out: cputime_to_timeval(utime, &r->ru_utime); cputime_to_timeval(stime, &r->ru_stime); + + if (who != RUSAGE_CHILDREN) { + struct mm_struct *mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + } + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } int getrusage(struct task_struct *p, int who, struct rusage __user *ru) @@ -1511,11 +1525,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_SET_TSC: error = SET_TSC_CTL(arg2); break; - case PR_TASK_PERF_COUNTERS_DISABLE: - error = perf_counter_task_disable(); + case PR_TASK_PERF_EVENTS_DISABLE: + error = perf_event_task_disable(); break; - case PR_TASK_PERF_COUNTERS_ENABLE: - error = perf_counter_task_enable(); + case PR_TASK_PERF_EVENTS_ENABLE: + error = perf_event_task_enable(); break; case PR_GET_TIMERSLACK: error = current->timer_slack_ns; diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 68320f6..515bc23 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -177,4 +177,4 @@ cond_syscall(sys_eventfd); cond_syscall(sys_eventfd2); /* performance counters: */ -cond_syscall(sys_perf_counter_open); +cond_syscall(sys_perf_event_open); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 1a631ba..0dfaa47 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -50,7 +50,7 @@ #include <linux/reboot.h> #include <linux/ftrace.h> #include <linux/slow-work.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -106,6 +106,9 @@ static int __maybe_unused one = 1; static int __maybe_unused two = 2; static unsigned long one_ul = 1; static int one_hundred = 100; +#ifdef CONFIG_PRINTK +static int ten_thousand = 10000; +#endif /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; @@ -722,6 +725,17 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "printk_delay", + .data = &printk_delay_msec, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &ten_thousand, + }, #endif { .ctl_name = KERN_NGROUPS_MAX, @@ -964,28 +978,28 @@ static struct ctl_table kern_table[] = { .child = slow_work_sysctls, }, #endif -#ifdef CONFIG_PERF_COUNTERS +#ifdef CONFIG_PERF_EVENTS { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_paranoid", - .data = &sysctl_perf_counter_paranoid, - .maxlen = sizeof(sysctl_perf_counter_paranoid), + .procname = "perf_event_paranoid", + .data = &sysctl_perf_event_paranoid, + .maxlen = sizeof(sysctl_perf_event_paranoid), .mode = 0644, .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_mlock_kb", - .data = &sysctl_perf_counter_mlock, - .maxlen = sizeof(sysctl_perf_counter_mlock), + .procname = "perf_event_mlock_kb", + .data = &sysctl_perf_event_mlock, + .maxlen = sizeof(sysctl_perf_event_mlock), .mode = 0644, .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_max_sample_rate", - .data = &sysctl_perf_counter_sample_rate, - .maxlen = sizeof(sysctl_perf_counter_sample_rate), + .procname = "perf_event_max_sample_rate", + .data = &sysctl_perf_event_sample_rate, + .maxlen = sizeof(sysctl_perf_event_sample_rate), .mode = 0644, .proc_handler = &proc_dointvec, }, diff --git a/kernel/timer.c b/kernel/timer.c index bbb5107..811e5c3 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -37,7 +37,7 @@ #include <linux/delay.h> #include <linux/tick.h> #include <linux/kallsyms.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <linux/sched.h> #include <asm/uaccess.h> @@ -1187,7 +1187,7 @@ static void run_timer_softirq(struct softirq_action *h) { struct tvec_base *base = __get_cpu_var(tvec_bases); - perf_counter_do_pending(); + perf_event_do_pending(); hrtimer_run_pending(); diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e716346..b416512 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -83,7 +83,7 @@ config RING_BUFFER_ALLOW_SWAP # This allows those options to appear when no other tracer is selected. But the # options do not appear when something else selects it. We need the two options # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the -# hidding of the automatic options options. +# hidding of the automatic options. config TRACING bool diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 844164d..26f03ac 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -42,7 +42,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o -obj-$(CONFIG_POWER_TRACER) += trace_power.o obj-$(CONFIG_KMEMTRACE) += kmemtrace.o obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o @@ -54,5 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o +obj-$(CONFIG_EVENT_TRACING) += power-traces.o libftrace-y := ftrace.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index cc615f8..23df7771 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1520,7 +1520,7 @@ static int t_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations show_ftrace_seq_ops = { +static const struct seq_operations show_ftrace_seq_ops = { .start = t_start, .next = t_next, .stop = t_stop, @@ -2414,11 +2414,9 @@ unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; static void * __g_next(struct seq_file *m, loff_t *pos) { - unsigned long *array = m->private; - if (*pos >= ftrace_graph_count) return NULL; - return &array[*pos]; + return &ftrace_graph_funcs[*pos]; } static void * @@ -2461,7 +2459,7 @@ static int g_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations ftrace_graph_seq_ops = { +static const struct seq_operations ftrace_graph_seq_ops = { .start = g_start, .next = g_next, .stop = g_stop, @@ -2482,16 +2480,10 @@ ftrace_graph_open(struct inode *inode, struct file *file) ftrace_graph_count = 0; memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); } + mutex_unlock(&graph_lock); - if (file->f_mode & FMODE_READ) { + if (file->f_mode & FMODE_READ) ret = seq_open(file, &ftrace_graph_seq_ops); - if (!ret) { - struct seq_file *m = file->private_data; - m->private = ftrace_graph_funcs; - } - } else - file->private_data = ftrace_graph_funcs; - mutex_unlock(&graph_lock); return ret; } @@ -2560,7 +2552,6 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_parser parser; - unsigned long *array; size_t read = 0; ssize_t ret; @@ -2574,12 +2565,6 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, goto out; } - if (file->f_mode & FMODE_READ) { - struct seq_file *m = file->private_data; - array = m->private; - } else - array = file->private_data; - if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { ret = -ENOMEM; goto out; @@ -2591,7 +2576,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, parser.buffer[parser.idx] = 0; /* we allow only one expression at a time */ - ret = ftrace_set_func(array, &ftrace_graph_count, + ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, parser.buffer); if (ret) goto out; diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c new file mode 100644 index 0000000..e06c6e3 --- /dev/null +++ b/kernel/trace/power-traces.c @@ -0,0 +1,20 @@ +/* + * Power trace points + * + * Copyright (C) 2009 Arjan van de Ven <arjan@linux.intel.com> + */ + +#include <linux/string.h> +#include <linux/types.h> +#include <linux/workqueue.h> +#include <linux/sched.h> +#include <linux/module.h> +#include <linux/slab.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/power.h> + +EXPORT_TRACEPOINT_SYMBOL_GPL(power_start); +EXPORT_TRACEPOINT_SYMBOL_GPL(power_end); +EXPORT_TRACEPOINT_SYMBOL_GPL(power_frequency); + diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 6eef389..d4ff019 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -201,8 +201,6 @@ int tracing_is_on(void) } EXPORT_SYMBOL_GPL(tracing_is_on); -#include "trace.h" - #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array)) #define RB_ALIGNMENT 4U #define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fd52a19..6c0f6a8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -125,13 +125,13 @@ int ftrace_dump_on_oops; static int tracing_set_tracer(const char *buf); -#define BOOTUP_TRACER_SIZE 100 -static char bootup_tracer_buf[BOOTUP_TRACER_SIZE] __initdata; +#define MAX_TRACER_SIZE 100 +static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; static char *default_bootup_tracer; static int __init set_ftrace(char *str) { - strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE); + strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); default_bootup_tracer = bootup_tracer_buf; /* We are using ftrace early, expand it */ ring_buffer_expanded = 1; @@ -242,13 +242,6 @@ static struct tracer *trace_types __read_mostly; static struct tracer *current_trace __read_mostly; /* - * max_tracer_type_len is used to simplify the allocating of - * buffers to read userspace tracer names. We keep track of - * the longest tracer name registered. - */ -static int max_tracer_type_len; - -/* * trace_types_lock is used to protect the trace_types list. * This lock is also used to keep user access serialized. * Accesses from userspace will grab this lock while userspace @@ -275,12 +268,18 @@ static DEFINE_SPINLOCK(tracing_start_lock); */ void trace_wake_up(void) { + int cpu; + + if (trace_flags & TRACE_ITER_BLOCK) + return; /* * The runqueue_is_locked() can fail, but this is the best we * have for now: */ - if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked()) + cpu = get_cpu(); + if (!runqueue_is_locked(cpu)) wake_up(&trace_wait); + put_cpu(); } static int __init set_buf_size(char *str) @@ -619,7 +618,6 @@ __releases(kernel_lock) __acquires(kernel_lock) { struct tracer *t; - int len; int ret = 0; if (!type->name) { @@ -627,6 +625,11 @@ __acquires(kernel_lock) return -1; } + if (strlen(type->name) > MAX_TRACER_SIZE) { + pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); + return -1; + } + /* * When this gets called we hold the BKL which means that * preemption is disabled. Various trace selftests however @@ -641,7 +644,7 @@ __acquires(kernel_lock) for (t = trace_types; t; t = t->next) { if (strcmp(type->name, t->name) == 0) { /* already found */ - pr_info("Trace %s already registered\n", + pr_info("Tracer %s already registered\n", type->name); ret = -1; goto out; @@ -692,9 +695,6 @@ __acquires(kernel_lock) type->next = trace_types; trace_types = type; - len = strlen(type->name); - if (len > max_tracer_type_len) - max_tracer_type_len = len; out: tracing_selftest_running = false; @@ -703,7 +703,7 @@ __acquires(kernel_lock) if (ret || !default_bootup_tracer) goto out_unlock; - if (strncmp(default_bootup_tracer, type->name, BOOTUP_TRACER_SIZE)) + if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) goto out_unlock; printk(KERN_INFO "Starting tracer '%s'\n", type->name); @@ -725,14 +725,13 @@ __acquires(kernel_lock) void unregister_tracer(struct tracer *type) { struct tracer **t; - int len; mutex_lock(&trace_types_lock); for (t = &trace_types; *t; t = &(*t)->next) { if (*t == type) goto found; } - pr_info("Trace %s not registered\n", type->name); + pr_info("Tracer %s not registered\n", type->name); goto out; found: @@ -745,17 +744,7 @@ void unregister_tracer(struct tracer *type) current_trace->stop(&global_trace); current_trace = &nop_trace; } - - if (strlen(type->name) != max_tracer_type_len) - goto out; - - max_tracer_type_len = 0; - for (t = &trace_types; *t; t = &(*t)->next) { - len = strlen((*t)->name); - if (len > max_tracer_type_len) - max_tracer_type_len = len; - } - out: +out: mutex_unlock(&trace_types_lock); } @@ -1960,7 +1949,7 @@ static int s_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations tracer_seq_ops = { +static const struct seq_operations tracer_seq_ops = { .start = s_start, .next = s_next, .stop = s_stop, @@ -2174,7 +2163,7 @@ static int t_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations show_traces_seq_ops = { +static const struct seq_operations show_traces_seq_ops = { .start = t_start, .next = t_next, .stop = t_stop, @@ -2604,7 +2593,7 @@ static ssize_t tracing_set_trace_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - char buf[max_tracer_type_len+2]; + char buf[MAX_TRACER_SIZE+2]; int r; mutex_lock(&trace_types_lock); @@ -2754,15 +2743,15 @@ static ssize_t tracing_set_trace_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - char buf[max_tracer_type_len+1]; + char buf[MAX_TRACER_SIZE+1]; int i; size_t ret; int err; ret = cnt; - if (cnt > max_tracer_type_len) - cnt = max_tracer_type_len; + if (cnt > MAX_TRACER_SIZE) + cnt = MAX_TRACER_SIZE; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 86bcff9..405cb85 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -11,7 +11,6 @@ #include <linux/ftrace.h> #include <trace/boot.h> #include <linux/kmemtrace.h> -#include <trace/power.h> #include <linux/trace_seq.h> #include <linux/ftrace_event.h> @@ -37,7 +36,6 @@ enum trace_type { TRACE_HW_BRANCHES, TRACE_KMEM_ALLOC, TRACE_KMEM_FREE, - TRACE_POWER, TRACE_BLK, __TRACE_LAST_TYPE, @@ -207,7 +205,6 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ TRACE_GRAPH_RET); \ IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ - IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \ TRACE_KMEM_ALLOC); \ IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index a431748..ead3d72 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -330,23 +330,6 @@ FTRACE_ENTRY(hw_branch, hw_branch_entry, F_printk("from: %llx to: %llx", __entry->from, __entry->to) ); -FTRACE_ENTRY(power, trace_power, - - TRACE_POWER, - - F_STRUCT( - __field_struct( struct power_trace, state_data ) - __field_desc( s64, state_data, stamp ) - __field_desc( s64, state_data, end ) - __field_desc( int, state_data, type ) - __field_desc( int, state_data, state ) - ), - - F_printk("%llx->%llx type:%u state:%u", - __entry->stamp, __entry->end, - __entry->type, __entry->state) -); - FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry, TRACE_KMEM_ALLOC, diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index 55a25c9..dd44b87 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -8,6 +8,57 @@ #include <linux/module.h> #include "trace.h" +/* + * We can't use a size but a type in alloc_percpu() + * So let's create a dummy type that matches the desired size + */ +typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t; + +char *trace_profile_buf; +EXPORT_SYMBOL_GPL(trace_profile_buf); + +char *trace_profile_buf_nmi; +EXPORT_SYMBOL_GPL(trace_profile_buf_nmi); + +/* Count the events in use (per event id, not per instance) */ +static int total_profile_count; + +static int ftrace_profile_enable_event(struct ftrace_event_call *event) +{ + char *buf; + int ret = -ENOMEM; + + if (atomic_inc_return(&event->profile_count)) + return 0; + + if (!total_profile_count++) { + buf = (char *)alloc_percpu(profile_buf_t); + if (!buf) + goto fail_buf; + + rcu_assign_pointer(trace_profile_buf, buf); + + buf = (char *)alloc_percpu(profile_buf_t); + if (!buf) + goto fail_buf_nmi; + + rcu_assign_pointer(trace_profile_buf_nmi, buf); + } + + ret = event->profile_enable(); + if (!ret) + return 0; + + kfree(trace_profile_buf_nmi); +fail_buf_nmi: + kfree(trace_profile_buf); +fail_buf: + total_profile_count--; + atomic_dec(&event->profile_count); + + return ret; +} + int ftrace_profile_enable(int event_id) { struct ftrace_event_call *event; @@ -17,7 +68,7 @@ int ftrace_profile_enable(int event_id) list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id && event->profile_enable && try_module_get(event->mod)) { - ret = event->profile_enable(event); + ret = ftrace_profile_enable_event(event); break; } } @@ -26,6 +77,33 @@ int ftrace_profile_enable(int event_id) return ret; } +static void ftrace_profile_disable_event(struct ftrace_event_call *event) +{ + char *buf, *nmi_buf; + + if (!atomic_add_negative(-1, &event->profile_count)) + return; + + event->profile_disable(); + + if (!--total_profile_count) { + buf = trace_profile_buf; + rcu_assign_pointer(trace_profile_buf, NULL); + + nmi_buf = trace_profile_buf_nmi; + rcu_assign_pointer(trace_profile_buf_nmi, NULL); + + /* + * Ensure every events in profiling have finished before + * releasing the buffers + */ + synchronize_sched(); + + free_percpu(buf); + free_percpu(nmi_buf); + } +} + void ftrace_profile_disable(int event_id) { struct ftrace_event_call *event; @@ -33,7 +111,7 @@ void ftrace_profile_disable(int event_id) mutex_lock(&event_mutex); list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id) { - event->profile_disable(event); + ftrace_profile_disable_event(event); module_put(event->mod); break; } diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 56c260b..6f03c8a 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -271,42 +271,32 @@ ftrace_event_write(struct file *file, const char __user *ubuf, static void * t_next(struct seq_file *m, void *v, loff_t *pos) { - struct list_head *list = m->private; - struct ftrace_event_call *call; + struct ftrace_event_call *call = v; (*pos)++; - for (;;) { - if (list == &ftrace_events) - return NULL; - - call = list_entry(list, struct ftrace_event_call, list); - + list_for_each_entry_continue(call, &ftrace_events, list) { /* * The ftrace subsystem is for showing formats only. * They can not be enabled or disabled via the event files. */ if (call->regfunc) - break; - - list = list->next; + return call; } - m->private = list->next; - - return call; + return NULL; } static void *t_start(struct seq_file *m, loff_t *pos) { - struct ftrace_event_call *call = NULL; + struct ftrace_event_call *call; loff_t l; mutex_lock(&event_mutex); - m->private = ftrace_events.next; + call = list_entry(&ftrace_events, struct ftrace_event_call, list); for (l = 0; l <= *pos; ) { - call = t_next(m, NULL, &l); + call = t_next(m, call, &l); if (!call) break; } @@ -316,37 +306,28 @@ static void *t_start(struct seq_file *m, loff_t *pos) static void * s_next(struct seq_file *m, void *v, loff_t *pos) { - struct list_head *list = m->private; - struct ftrace_event_call *call; + struct ftrace_event_call *call = v; (*pos)++; - retry: - if (list == &ftrace_events) - return NULL; - - call = list_entry(list, struct ftrace_event_call, list); - - if (!call->enabled) { - list = list->next; - goto retry; + list_for_each_entry_continue(call, &ftrace_events, list) { + if (call->enabled) + return call; } - m->private = list->next; - - return call; + return NULL; } static void *s_start(struct seq_file *m, loff_t *pos) { - struct ftrace_event_call *call = NULL; + struct ftrace_event_call *call; loff_t l; mutex_lock(&event_mutex); - m->private = ftrace_events.next; + call = list_entry(&ftrace_events, struct ftrace_event_call, list); for (l = 0; l <= *pos; ) { - call = s_next(m, NULL, &l); + call = s_next(m, call, &l); if (!call) break; } diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c index ca7d7c4..23b6385 100644 --- a/kernel/trace/trace_hw_branches.c +++ b/kernel/trace/trace_hw_branches.c @@ -155,7 +155,7 @@ static enum print_line_t bts_trace_print_line(struct trace_iterator *iter) seq_print_ip_sym(seq, it->from, symflags) && trace_seq_printf(seq, "\n")) return TRACE_TYPE_HANDLED; - return TRACE_TYPE_PARTIAL_LINE;; + return TRACE_TYPE_PARTIAL_LINE; } return TRACE_TYPE_UNHANDLED; } diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c deleted file mode 100644 index fe1a00f..0000000 --- a/kernel/trace/trace_power.c +++ /dev/null @@ -1,218 +0,0 @@ -/* - * ring buffer based C-state tracer - * - * Arjan van de Ven <arjan@linux.intel.com> - * Copyright (C) 2008 Intel Corporation - * - * Much is borrowed from trace_boot.c which is - * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com> - * - */ - -#include <linux/init.h> -#include <linux/debugfs.h> -#include <trace/power.h> -#include <linux/kallsyms.h> -#include <linux/module.h> - -#include "trace.h" -#include "trace_output.h" - -static struct trace_array *power_trace; -static int __read_mostly trace_power_enabled; - -static void probe_power_start(struct power_trace *it, unsigned int type, - unsigned int level) -{ - if (!trace_power_enabled) - return; - - memset(it, 0, sizeof(struct power_trace)); - it->state = level; - it->type = type; - it->stamp = ktime_get(); -} - - -static void probe_power_end(struct power_trace *it) -{ - struct ftrace_event_call *call = &event_power; - struct ring_buffer_event *event; - struct ring_buffer *buffer; - struct trace_power *entry; - struct trace_array_cpu *data; - struct trace_array *tr = power_trace; - - if (!trace_power_enabled) - return; - - buffer = tr->buffer; - - preempt_disable(); - it->end = ktime_get(); - data = tr->data[smp_processor_id()]; - - event = trace_buffer_lock_reserve(buffer, TRACE_POWER, - sizeof(*entry), 0, 0); - if (!event) - goto out; - entry = ring_buffer_event_data(event); - entry->state_data = *it; - if (!filter_check_discard(call, entry, buffer, event)) - trace_buffer_unlock_commit(buffer, event, 0, 0); - out: - preempt_enable(); -} - -static void probe_power_mark(struct power_trace *it, unsigned int type, - unsigned int level) -{ - struct ftrace_event_call *call = &event_power; - struct ring_buffer_event *event; - struct ring_buffer *buffer; - struct trace_power *entry; - struct trace_array_cpu *data; - struct trace_array *tr = power_trace; - - if (!trace_power_enabled) - return; - - buffer = tr->buffer; - - memset(it, 0, sizeof(struct power_trace)); - it->state = level; - it->type = type; - it->stamp = ktime_get(); - preempt_disable(); - it->end = it->stamp; - data = tr->data[smp_processor_id()]; - - event = trace_buffer_lock_reserve(buffer, TRACE_POWER, - sizeof(*entry), 0, 0); - if (!event) - goto out; - entry = ring_buffer_event_data(event); - entry->state_data = *it; - if (!filter_check_discard(call, entry, buffer, event)) - trace_buffer_unlock_commit(buffer, event, 0, 0); - out: - preempt_enable(); -} - -static int tracing_power_register(void) -{ - int ret; - - ret = register_trace_power_start(probe_power_start); - if (ret) { - pr_info("power trace: Couldn't activate tracepoint" - " probe to trace_power_start\n"); - return ret; - } - ret = register_trace_power_end(probe_power_end); - if (ret) { - pr_info("power trace: Couldn't activate tracepoint" - " probe to trace_power_end\n"); - goto fail_start; - } - ret = register_trace_power_mark(probe_power_mark); - if (ret) { - pr_info("power trace: Couldn't activate tracepoint" - " probe to trace_power_mark\n"); - goto fail_end; - } - return ret; -fail_end: - unregister_trace_power_end(probe_power_end); -fail_start: - unregister_trace_power_start(probe_power_start); - return ret; -} - -static void start_power_trace(struct trace_array *tr) -{ - trace_power_enabled = 1; -} - -static void stop_power_trace(struct trace_array *tr) -{ - trace_power_enabled = 0; -} - -static void power_trace_reset(struct trace_array *tr) -{ - trace_power_enabled = 0; - unregister_trace_power_start(probe_power_start); - unregister_trace_power_end(probe_power_end); - unregister_trace_power_mark(probe_power_mark); -} - - -static int power_trace_init(struct trace_array *tr) -{ - power_trace = tr; - - trace_power_enabled = 1; - tracing_power_register(); - - tracing_reset_online_cpus(tr); - return 0; -} - -static enum print_line_t power_print_line(struct trace_iterator *iter) -{ - int ret = 0; - struct trace_entry *entry = iter->ent; - struct trace_power *field ; - struct power_trace *it; - struct trace_seq *s = &iter->seq; - struct timespec stamp; - struct timespec duration; - - trace_assign_type(field, entry); - it = &field->state_data; - stamp = ktime_to_timespec(it->stamp); - duration = ktime_to_timespec(ktime_sub(it->end, it->stamp)); - - if (entry->type == TRACE_POWER) { - if (it->type == POWER_CSTATE) - ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n", - stamp.tv_sec, - stamp.tv_nsec, - it->state, iter->cpu, - duration.tv_sec, - duration.tv_nsec); - if (it->type == POWER_PSTATE) - ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n", - stamp.tv_sec, - stamp.tv_nsec, - it->state, iter->cpu); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - return TRACE_TYPE_HANDLED; - } - return TRACE_TYPE_UNHANDLED; -} - -static void power_print_header(struct seq_file *s) -{ - seq_puts(s, "# TIMESTAMP STATE EVENT\n"); - seq_puts(s, "# | | |\n"); -} - -static struct tracer power_tracer __read_mostly = -{ - .name = "power", - .init = power_trace_init, - .start = start_power_trace, - .stop = stop_power_trace, - .reset = power_trace_reset, - .print_line = power_print_line, - .print_header = power_print_header, -}; - -static int init_power_trace(void) -{ - return register_tracer(&power_tracer); -} -device_initcall(init_power_trace); diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 687699d..2547d88 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -11,7 +11,6 @@ #include <linux/ftrace.h> #include <linux/string.h> #include <linux/module.h> -#include <linux/marker.h> #include <linux/mutex.h> #include <linux/ctype.h> #include <linux/list.h> diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 8712ce3..9fbce6c 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -2,7 +2,7 @@ #include <trace/events/syscalls.h> #include <linux/kernel.h> #include <linux/ftrace.h> -#include <linux/perf_counter.h> +#include <linux/perf_event.h> #include <asm/syscall.h> #include "trace_output.h" @@ -384,10 +384,13 @@ static int sys_prof_refcount_exit; static void prof_syscall_enter(struct pt_regs *regs, long id) { - struct syscall_trace_enter *rec; struct syscall_metadata *sys_data; + struct syscall_trace_enter *rec; + unsigned long flags; + char *raw_data; int syscall_nr; int size; + int cpu; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_enter_syscalls)) @@ -402,20 +405,38 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) size = ALIGN(size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - do { - char raw_data[size]; + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "profile buffer not large enough")) + return; + + /* Protect the per cpu buffer, begin the rcu read side */ + local_irq_save(flags); - /* zero the dead bytes from align to not leak stack to user */ - *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + cpu = smp_processor_id(); + + if (in_nmi()) + raw_data = rcu_dereference(trace_profile_buf_nmi); + else + raw_data = rcu_dereference(trace_profile_buf); + + if (!raw_data) + goto end; - rec = (struct syscall_trace_enter *) raw_data; - tracing_generic_entry_update(&rec->ent, 0, 0); - rec->ent.type = sys_data->enter_id; - rec->nr = syscall_nr; - syscall_get_arguments(current, regs, 0, sys_data->nb_args, - (unsigned long *)&rec->args); - perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); - } while(0); + raw_data = per_cpu_ptr(raw_data, cpu); + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_trace_enter *) raw_data; + tracing_generic_entry_update(&rec->ent, 0, 0); + rec->ent.type = sys_data->enter_id; + rec->nr = syscall_nr; + syscall_get_arguments(current, regs, 0, sys_data->nb_args, + (unsigned long *)&rec->args); + perf_tp_event(sys_data->enter_id, 0, 1, rec, size); + +end: + local_irq_restore(flags); } int reg_prof_syscall_enter(char *name) @@ -460,8 +481,12 @@ void unreg_prof_syscall_enter(char *name) static void prof_syscall_exit(struct pt_regs *regs, long ret) { struct syscall_metadata *sys_data; - struct syscall_trace_exit rec; + struct syscall_trace_exit *rec; + unsigned long flags; int syscall_nr; + char *raw_data; + int size; + int cpu; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_exit_syscalls)) @@ -471,12 +496,46 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) if (!sys_data) return; - tracing_generic_entry_update(&rec.ent, 0, 0); - rec.ent.type = sys_data->exit_id; - rec.nr = syscall_nr; - rec.ret = syscall_get_return_value(current, regs); + /* We can probably do that at build time */ + size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); - perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec)); + /* + * Impossible, but be paranoid with the future + * How to put this check outside runtime? + */ + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "exit event has grown above profile buffer size")) + return; + + /* Protect the per cpu buffer, begin the rcu read side */ + local_irq_save(flags); + cpu = smp_processor_id(); + + if (in_nmi()) + raw_data = rcu_dereference(trace_profile_buf_nmi); + else + raw_data = rcu_dereference(trace_profile_buf); + + if (!raw_data) + goto end; + + raw_data = per_cpu_ptr(raw_data, cpu); + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_trace_exit *)raw_data; + + tracing_generic_entry_update(&rec->ent, 0, 0); + rec->ent.type = sys_data->exit_id; + rec->nr = syscall_nr; + rec->ret = syscall_get_return_value(current, regs); + + perf_tp_event(sys_data->exit_id, 0, 1, rec, size); + +end: + local_irq_restore(flags); } int reg_prof_syscall_exit(char *name) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 9489a0a..cc89be5 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -48,7 +48,7 @@ static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE]; /* * Note about RCU : - * It is used to to delay the free of multiple probes array until a quiescent + * It is used to delay the free of multiple probes array until a quiescent * state is reached. * Tracepoint entries modifications are protected by the tracepoints_mutex. */ |
