diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/Kconfig | 1 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 313 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 358 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 48 | ||||
| -rw-r--r-- | kernel/trace/trace_entries.h | 4 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 219 | ||||
| -rw-r--r-- | kernel/trace/trace_functions.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 19 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_mmiotrace.c | 10 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.c | 33 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.h | 10 |
12 files changed, 565 insertions, 453 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index fafeaf8..f4b86e8 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -542,6 +542,7 @@ config HIST_TRIGGERS bool "Histogram triggers" depends on ARCH_HAVE_NMI_SAFE_CMPXCHG select TRACING_MAP + select TRACING default n help Hist triggers allow one or more arbitrary trace event fields diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 900dbb1..84752c8 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -89,16 +89,16 @@ struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; /* What to set function_trace_op to */ static struct ftrace_ops *set_function_trace_op; -/* List for set_ftrace_pid's pids. */ -LIST_HEAD(ftrace_pids); -struct ftrace_pid { - struct list_head list; - struct pid *pid; -}; - -static bool ftrace_pids_enabled(void) +static bool ftrace_pids_enabled(struct ftrace_ops *ops) { - return !list_empty(&ftrace_pids); + struct trace_array *tr; + + if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) + return false; + + tr = ops->private; + + return tr->function_pids != NULL; } static void ftrace_update_trampoline(struct ftrace_ops *ops); @@ -179,7 +179,9 @@ int ftrace_nr_registered_ops(void) static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs) { - if (!test_tsk_trace_trace(current)) + struct trace_array *tr = op->private; + + if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid)) return; op->saved_func(ip, parent_ip, op, regs); @@ -417,7 +419,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) /* Always save the function, and reset at unregistering */ ops->saved_func = ops->func; - if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled()) + if (ftrace_pids_enabled(ops)) ops->func = ftrace_pid_func; ftrace_update_trampoline(ops); @@ -450,7 +452,6 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) static void ftrace_update_pid_func(void) { - bool enabled = ftrace_pids_enabled(); struct ftrace_ops *op; /* Only do something if we are tracing something */ @@ -459,8 +460,8 @@ static void ftrace_update_pid_func(void) do_for_each_ftrace_op(op, ftrace_ops_list) { if (op->flags & FTRACE_OPS_FL_PID) { - op->func = enabled ? ftrace_pid_func : - op->saved_func; + op->func = ftrace_pids_enabled(op) ? + ftrace_pid_func : op->saved_func; ftrace_update_trampoline(op); } } while_for_each_ftrace_op(op); @@ -5324,179 +5325,99 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) return ops->func; } -static void clear_ftrace_swapper(void) +static void +ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, + struct task_struct *prev, struct task_struct *next) { - struct task_struct *p; - int cpu; + struct trace_array *tr = data; + struct trace_pid_list *pid_list; - get_online_cpus(); - for_each_online_cpu(cpu) { - p = idle_task(cpu); - clear_tsk_trace_trace(p); - } - put_online_cpus(); -} - -static void set_ftrace_swapper(void) -{ - struct task_struct *p; - int cpu; + pid_list = rcu_dereference_sched(tr->function_pids); - get_online_cpus(); - for_each_online_cpu(cpu) { - p = idle_task(cpu); - set_tsk_trace_trace(p); - } - put_online_cpus(); + this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, + trace_ignore_this_task(pid_list, next)); } -static void clear_ftrace_pid(struct pid *pid) +static void clear_ftrace_pids(struct trace_array *tr) { - struct task_struct *p; + struct trace_pid_list *pid_list; + int cpu; - rcu_read_lock(); - do_each_pid_task(pid, PIDTYPE_PID, p) { - clear_tsk_trace_trace(p); - } while_each_pid_task(pid, PIDTYPE_PID, p); - rcu_read_unlock(); + pid_list = rcu_dereference_protected(tr->function_pids, + lockdep_is_held(&ftrace_lock)); + if (!pid_list) + return; - put_pid(pid); -} + unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); -static void set_ftrace_pid(struct pid *pid) -{ - struct task_struct *p; + for_each_possible_cpu(cpu) + per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false; - rcu_read_lock(); - do_each_pid_task(pid, PIDTYPE_PID, p) { - set_tsk_trace_trace(p); - } while_each_pid_task(pid, PIDTYPE_PID, p); - rcu_read_unlock(); -} + rcu_assign_pointer(tr->function_pids, NULL); -static void clear_ftrace_pid_task(struct pid *pid) -{ - if (pid == ftrace_swapper_pid) - clear_ftrace_swapper(); - else - clear_ftrace_pid(pid); -} + /* Wait till all users are no longer using pid filtering */ + synchronize_sched(); -static void set_ftrace_pid_task(struct pid *pid) -{ - if (pid == ftrace_swapper_pid) - set_ftrace_swapper(); - else - set_ftrace_pid(pid); + trace_free_pid_list(pid_list); } -static int ftrace_pid_add(int p) +static void ftrace_pid_reset(struct trace_array *tr) { - struct pid *pid; - struct ftrace_pid *fpid; - int ret = -EINVAL; - mutex_lock(&ftrace_lock); - - if (!p) - pid = ftrace_swapper_pid; - else - pid = find_get_pid(p); - - if (!pid) - goto out; - - ret = 0; - - list_for_each_entry(fpid, &ftrace_pids, list) - if (fpid->pid == pid) - goto out_put; - - ret = -ENOMEM; - - fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); - if (!fpid) - goto out_put; - - list_add(&fpid->list, &ftrace_pids); - fpid->pid = pid; - - set_ftrace_pid_task(pid); + clear_ftrace_pids(tr); ftrace_update_pid_func(); - ftrace_startup_all(0); mutex_unlock(&ftrace_lock); - return 0; - -out_put: - if (pid != ftrace_swapper_pid) - put_pid(pid); - -out: - mutex_unlock(&ftrace_lock); - return ret; } -static void ftrace_pid_reset(void) -{ - struct ftrace_pid *fpid, *safe; - - mutex_lock(&ftrace_lock); - list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { - struct pid *pid = fpid->pid; - - clear_ftrace_pid_task(pid); - - list_del(&fpid->list); - kfree(fpid); - } - - ftrace_update_pid_func(); - ftrace_startup_all(0); - - mutex_unlock(&ftrace_lock); -} +/* Greater than any max PID */ +#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) static void *fpid_start(struct seq_file *m, loff_t *pos) + __acquires(RCU) { + struct trace_pid_list *pid_list; + struct trace_array *tr = m->private; + mutex_lock(&ftrace_lock); + rcu_read_lock_sched(); - if (!ftrace_pids_enabled() && (!*pos)) - return (void *) 1; + pid_list = rcu_dereference_sched(tr->function_pids); - return seq_list_start(&ftrace_pids, *pos); + if (!pid_list) + return !(*pos) ? FTRACE_NO_PIDS : NULL; + + return trace_pid_start(pid_list, pos); } static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) { - if (v == (void *)1) + struct trace_array *tr = m->private; + struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); + + if (v == FTRACE_NO_PIDS) return NULL; - return seq_list_next(v, &ftrace_pids, pos); + return trace_pid_next(pid_list, v, pos); } static void fpid_stop(struct seq_file *m, void *p) + __releases(RCU) { + rcu_read_unlock_sched(); mutex_unlock(&ftrace_lock); } static int fpid_show(struct seq_file *m, void *v) { - const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); - - if (v == (void *)1) { + if (v == FTRACE_NO_PIDS) { seq_puts(m, "no pid\n"); return 0; } - if (fpid->pid == ftrace_swapper_pid) - seq_puts(m, "swapper tasks\n"); - else - seq_printf(m, "%u\n", pid_vnr(fpid->pid)); - - return 0; + return trace_pid_show(m, v); } static const struct seq_operations ftrace_pid_sops = { @@ -5509,58 +5430,103 @@ static const struct seq_operations ftrace_pid_sops = { static int ftrace_pid_open(struct inode *inode, struct file *file) { + struct trace_array *tr = inode->i_private; + struct seq_file *m; int ret = 0; + if (trace_array_get(tr) < 0) + return -ENODEV; + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) - ftrace_pid_reset(); + ftrace_pid_reset(tr); - if (file->f_mode & FMODE_READ) - ret = seq_open(file, &ftrace_pid_sops); + ret = seq_open(file, &ftrace_pid_sops); + if (ret < 0) { + trace_array_put(tr); + } else { + m = file->private_data; + /* copy tr over to seq ops */ + m->private = tr; + } return ret; } +static void ignore_task_cpu(void *data) +{ + struct trace_array *tr = data; + struct trace_pid_list *pid_list; + + /* + * This function is called by on_each_cpu() while the + * event_mutex is held. + */ + pid_list = rcu_dereference_protected(tr->function_pids, + mutex_is_locked(&ftrace_lock)); + + this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, + trace_ignore_this_task(pid_list, current)); +} + static ssize_t ftrace_pid_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - char buf[64], *tmp; - long val; - int ret; + struct seq_file *m = filp->private_data; + struct trace_array *tr = m->private; + struct trace_pid_list *filtered_pids = NULL; + struct trace_pid_list *pid_list; + ssize_t ret; - if (cnt >= sizeof(buf)) - return -EINVAL; + if (!cnt) + return 0; + + mutex_lock(&ftrace_lock); + + filtered_pids = rcu_dereference_protected(tr->function_pids, + lockdep_is_held(&ftrace_lock)); + + ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); + if (ret < 0) + goto out; - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; + rcu_assign_pointer(tr->function_pids, pid_list); - buf[cnt] = 0; + if (filtered_pids) { + synchronize_sched(); + trace_free_pid_list(filtered_pids); + } else if (pid_list) { + /* Register a probe to set whether to ignore the tracing of a task */ + register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); + } /* - * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" - * to clean the filter quietly. + * Ignoring of pids is done at task switch. But we have to + * check for those tasks that are currently running. + * Always do this in case a pid was appended or removed. */ - tmp = strstrip(buf); - if (strlen(tmp) == 0) - return 1; + on_each_cpu(ignore_task_cpu, tr, 1); - ret = kstrtol(tmp, 10, &val); - if (ret < 0) - return ret; + ftrace_update_pid_func(); + ftrace_startup_all(0); + out: + mutex_unlock(&ftrace_lock); - ret = ftrace_pid_add(val); + if (ret > 0) + *ppos += ret; - return ret ? ret : cnt; + return ret; } static int ftrace_pid_release(struct inode *inode, struct file *file) { - if (file->f_mode & FMODE_READ) - seq_release(inode, file); + struct trace_array *tr = inode->i_private; - return 0; + trace_array_put(tr); + + return seq_release(inode, file); } static const struct file_operations ftrace_pid_fops = { @@ -5571,24 +5537,21 @@ static const struct file_operations ftrace_pid_fops = { .release = ftrace_pid_release, }; -static __init int ftrace_init_tracefs(void) +void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) { - struct dentry *d_tracer; + trace_create_file("set_ftrace_pid", 0644, d_tracer, + tr, &ftrace_pid_fops); +} - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) - return 0; +void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, + struct dentry *d_tracer) +{ + /* Only the top level directory has the dyn_tracefs and profile */ + WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); ftrace_init_dyn_tracefs(d_tracer); - - trace_create_file("set_ftrace_pid", 0644, d_tracer, - NULL, &ftrace_pid_fops); - ftrace_profile_tracefs(d_tracer); - - return 0; } -fs_initcall(ftrace_init_tracefs); /** * ftrace_kill - kill ftrace diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8a4bd6b..dade4c9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -25,7 +25,7 @@ #include <linux/hardirq.h> #include <linux/linkage.h> #include <linux/uaccess.h> -#include <linux/kprobes.h> +#include <linux/vmalloc.h> #include <linux/ftrace.h> #include <linux/module.h> #include <linux/percpu.h> @@ -319,6 +319,258 @@ int call_filter_check_discard(struct trace_event_call *call, void *rec, return 0; } +void trace_free_pid_list(struct trace_pid_list *pid_list) +{ + vfree(pid_list->pids); + kfree(pid_list); +} + +/** + * trace_find_filtered_pid - check if a pid exists in a filtered_pid list + * @filtered_pids: The list of pids to check + * @search_pid: The PID to find in @filtered_pids + * + * Returns true if @search_pid is fonud in @filtered_pids, and false otherwis. + */ +bool +trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid) +{ + /* + * If pid_max changed after filtered_pids was created, we + * by default ignore all pids greater than the previous pid_max. + */ + if (search_pid >= filtered_pids->pid_max) + return false; + + return test_bit(search_pid, filtered_pids->pids); +} + +/** + * trace_ignore_this_task - should a task be ignored for tracing + * @filtered_pids: The list of pids to check + * @task: The task that should be ignored if not filtered + * + * Checks if @task should be traced or not from @filtered_pids. + * Returns true if @task should *NOT* be traced. + * Returns false if @task should be traced. + */ +bool +trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) +{ + /* + * Return false, because if filtered_pids does not exist, + * all pids are good to trace. + */ + if (!filtered_pids) + return false; + + return !trace_find_filtered_pid(filtered_pids, task->pid); +} + +/** + * trace_pid_filter_add_remove - Add or remove a task from a pid_list + * @pid_list: The list to modify + * @self: The current task for fork or NULL for exit + * @task: The task to add or remove + * + * If adding a task, if @self is defined, the task is only added if @self + * is also included in @pid_list. This happens on fork and tasks should + * only be added when the parent is listed. If @self is NULL, then the + * @task pid will be removed from the list, which would happen on exit + * of a task. + */ +void trace_filter_add_remove_task(struct trace_pid_list *pid_list, + struct task_struct *self, + struct task_struct *task) +{ + if (!pid_list) + return; + + /* For forks, we only add if the forking task is listed */ + if (self) { + if (!trace_find_filtered_pid(pid_list, self->pid)) + return; + } + + /* Sorry, but we don't support pid_max changing after setting */ + if (task->pid >= pid_list->pid_max) + return; + + /* "self" is set for forks, and NULL for exits */ + if (self) + set_bit(task->pid, pid_list->pids); + else + clear_bit(task->pid, pid_list->pids); +} + +/** + * trace_pid_next - Used for seq_file to get to the next pid of a pid_list + * @pid_list: The pid list to show + * @v: The last pid that was shown (+1 the actual pid to let zero be displayed) + * @pos: The position of the file + * + * This is used by the seq_file "next" operation to iterate the pids + * listed in a trace_pid_list structure. + * + * Returns the pid+1 as we want to display pid of zero, but NULL would + * stop the iteration. + */ +void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos) +{ + unsigned long pid = (unsigned long)v; + + (*pos)++; + + /* pid already is +1 of the actual prevous bit */ + pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid); + + /* Return pid + 1 to allow zero to be represented */ + if (pid < pid_list->pid_max) + return (void *)(pid + 1); + + return NULL; +} + +/** + * trace_pid_start - Used for seq_file to start reading pid lists + * @pid_list: The pid list to show + * @pos: The position of the file + * + * This is used by seq_file "start" operation to start the iteration + * of listing pids. + * + * Returns the pid+1 as we want to display pid of zero, but NULL would + * stop the iteration. + */ +void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos) +{ + unsigned long pid; + loff_t l = 0; + + pid = find_first_bit(pid_list->pids, pid_list->pid_max); + if (pid >= pid_list->pid_max) + return NULL; + + /* Return pid + 1 so that zero can be the exit value */ + for (pid++; pid && l < *pos; + pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l)) + ; + return (void *)pid; +} + +/** + * trace_pid_show - show the current pid in seq_file processing + * @m: The seq_file structure to write into + * @v: A void pointer of the pid (+1) value to display + * + * Can be directly used by seq_file operations to display the current + * pid value. + */ +int trace_pid_show(struct seq_file *m, void *v) +{ + unsigned long pid = (unsigned long)v - 1; + + seq_printf(m, "%lu\n", pid); + return 0; +} + +/* 128 should be much more than enough */ +#define PID_BUF_SIZE 127 + +int trace_pid_write(struct trace_pid_list *filtered_pids, + struct trace_pid_list **new_pid_list, + const char __user *ubuf, size_t cnt) +{ + struct trace_pid_list *pid_list; + struct trace_parser parser; + unsigned long val; + int nr_pids = 0; + ssize_t read = 0; + ssize_t ret = 0; + loff_t pos; + pid_t pid; + + if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1)) + return -ENOMEM; + + /* + * Always recreate a new array. The write is an all or nothing + * operation. Always create a new array when adding new pids by + * the user. If the operation fails, then the current list is + * not modified. + */ + pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); + if (!pid_list) + return -ENOMEM; + + pid_list->pid_max = READ_ONCE(pid_max); + + /* Only truncating will shrink pid_max */ + if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max) + pid_list->pid_max = filtered_pids->pid_max; + + pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); + if (!pid_list->pids) { + kfree(pid_list); + return -ENOMEM; + } + + if (filtered_pids) { + /* copy the current bits to the new max */ + for_each_set_bit(pid, filtered_pids->pids, + filtered_pids->pid_max) { + set_bit(pid, pid_list->pids); + nr_pids++; + } + } + + while (cnt > 0) { + + pos = 0; + + ret = trace_get_user(&parser, ubuf, cnt, &pos); + if (ret < 0 || !trace_parser_loaded(&parser)) + break; + + read += ret; + ubuf += ret; + cnt -= ret; + + parser.buffer[parser.idx] = 0; + + ret = -EINVAL; + if (kstrtoul(parser.buffer, 0, &val)) + break; + if (val >= pid_list->pid_max) + break; + + pid = (pid_t)val; + + set_bit(pid, pid_list->pids); + nr_pids++; + + trace_parser_clear(&parser); + ret = 0; + } + trace_parser_put(&parser); + + if (ret < 0) { + trace_free_pid_list(pid_list); + return ret; + } + + if (!nr_pids) { + /* Cleared the list of pids */ + trace_free_pid_list(pid_list); + read = ret; + pid_list = NULL; + } + + *new_pid_list = pid_list; + + return read; +} + static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) { u64 ts; @@ -1862,7 +2114,17 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, { __buffer_unlock_commit(buffer, event); - ftrace_trace_stack(tr, buffer, flags, 0, pc, regs); + /* + * If regs is not set, then skip the following callers: + * trace_buffer_unlock_commit_regs + * event_trigger_unlock_commit + * trace_event_buffer_commit + * trace_event_raw_event_sched_switch + * Note, we can still get here via blktrace, wakeup tracer + * and mmiotrace, but that's ok if they lose a function or + * two. They are that meaningful. + */ + ftrace_trace_stack(tr, buffer, flags, regs ? 0 : 4, pc, regs); ftrace_trace_userstack(buffer, flags, pc); } @@ -1913,6 +2175,13 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, trace.skip = skip; /* + * Add two, for this function and the call to save_stack_trace() + * If regs is set, then these functions will not be in the way. + */ + if (!regs) + trace.skip += 2; + + /* * Since events can happen in NMIs there's no safe way to * use the per cpu ftrace_stacks. We reserve it and if an interrupt * or NMI comes in, it will just have to use the default @@ -2083,83 +2352,41 @@ static void __trace_userstack(struct trace_array *tr, unsigned long flags) /* created for use with alloc_percpu */ struct trace_buffer_struct { - char buffer[TRACE_BUF_SIZE]; + int nesting; + char buffer[4][TRACE_BUF_SIZE]; }; static struct trace_buffer_struct *trace_percpu_buffer; -static struct trace_buffer_struct *trace_percpu_sirq_buffer; -static struct trace_buffer_struct *trace_percpu_irq_buffer; -static struct trace_buffer_struct *trace_percpu_nmi_buffer; /* - * The buffer used is dependent on the context. There is a per cpu - * buffer for normal context, softirq contex, hard irq context and - * for NMI context. Thise allows for lockless recording. - * - * Note, if the buffers failed to be allocated, then this returns NULL + * Thise allows for lockless recording. If we're nested too deeply, then + * this returns NULL. */ static char *get_trace_buf(void) { - struct trace_buffer_struct *percpu_buffer; - - /* - * If we have allocated per cpu buffers, then we do not - * need to do any locking. - */ - if (in_nmi()) - percpu_buffer = trace_percpu_nmi_buffer; - else if (in_irq()) - percpu_buffer = trace_percpu_irq_buffer; - else if (in_softirq()) - percpu_buffer = trace_percpu_sirq_buffer; - else - percpu_buffer = trace_percpu_buffer; + struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer); - if (!percpu_buffer) + if (!buffer || buffer->nesting >= 4) return NULL; - return this_cpu_ptr(&percpu_buffer->buffer[0]); + return &buffer->buffer[buffer->nesting++][0]; +} + +static void put_trace_buf(void) +{ + this_cpu_dec(trace_percpu_buffer->nesting); } static int alloc_percpu_trace_buffer(void) { struct trace_buffer_struct *buffers; - struct trace_buffer_struct *sirq_buffers; - struct trace_buffer_struct *irq_buffers; - struct trace_buffer_struct *nmi_buffers; buffers = alloc_percpu(struct trace_buffer_struct); - if (!buffers) - goto err_warn; - - sirq_buffers = alloc_percpu(struct trace_buffer_struct); - if (!sirq_buffers) - goto err_sirq; - - irq_buffers = alloc_percpu(struct trace_buffer_struct); - if (!irq_buffers) - goto err_irq; - - nmi_buffers = alloc_percpu(struct trace_buffer_struct); - if (!nmi_buffers) - goto err_nmi; + if (WARN(!buffers, "Could not allocate percpu trace_printk buffer")) + return -ENOMEM; trace_percpu_buffer = buffers; - trace_percpu_sirq_buffer = sirq_buffers; - trace_percpu_irq_buffer = irq_buffers; - trace_percpu_nmi_buffer = nmi_buffers; - return 0; - - err_nmi: - free_percpu(irq_buffers); - err_irq: - free_percpu(sirq_buffers); - err_sirq: - free_percpu(buffers); - err_warn: - WARN(1, "Could not allocate percpu trace_printk buffer"); - return -ENOMEM; } static int buffers_allocated; @@ -2250,7 +2477,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) tbuffer = get_trace_buf(); if (!tbuffer) { len = 0; - goto out; + goto out_nobuffer; } len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); @@ -2276,6 +2503,9 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) } out: + put_trace_buf(); + +out_nobuffer: preempt_enable_notrace(); unpause_graph_tracing(); @@ -2307,7 +2537,7 @@ __trace_array_vprintk(struct ring_buffer *buffer, tbuffer = get_trace_buf(); if (!tbuffer) { len = 0; - goto out; + goto out_nobuffer; } len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); @@ -2326,7 +2556,11 @@ __trace_array_vprintk(struct ring_buffer *buffer, __buffer_unlock_commit(buffer, event); ftrace_trace_stack(&global_trace, buffer, flags, 6, pc, NULL); } - out: + +out: + put_trace_buf(); + +out_nobuffer: preempt_enable_notrace(); unpause_graph_tracing(); @@ -6977,6 +7211,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) for_each_tracing_cpu(cpu) tracing_init_tracefs_percpu(tr, cpu); + ftrace_init_tracefs(tr, d_tracer); } static struct vfsmount *trace_automount(void *ingore) @@ -7130,6 +7365,7 @@ static __init int tracer_init_tracefs(void) return 0; init_tracer_tracefs(&global_trace, d_tracer); + ftrace_init_tracefs_toplevel(&global_trace, d_tracer); trace_create_file("tracing_thresh", 0644, d_tracer, &global_trace, &tracing_thresh_fops); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 5167c36..f783df4 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -80,6 +80,12 @@ enum trace_type { FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \ filter) +#undef FTRACE_ENTRY_PACKED +#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print, \ + filter) \ + FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \ + filter) __packed + #include "trace_entries.h" /* @@ -156,6 +162,9 @@ struct trace_array_cpu { char comm[TASK_COMM_LEN]; bool ignore_pid; +#ifdef CONFIG_FUNCTION_TRACER + bool ftrace_ignore_pid; +#endif }; struct tracer; @@ -247,6 +256,7 @@ struct trace_array { int ref; #ifdef CONFIG_FUNCTION_TRACER struct ftrace_ops *ops; + struct trace_pid_list __rcu *function_pids; /* function tracing enabled */ int function_enabled; #endif @@ -628,6 +638,25 @@ extern unsigned long nsecs_to_usecs(unsigned long nsecs); extern unsigned long tracing_thresh; +/* PID filtering */ + +extern int pid_max; + +bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids, + pid_t search_pid); +bool trace_ignore_this_task(struct trace_pid_list *filtered_pids, + struct task_struct *task); +void trace_filter_add_remove_task(struct trace_pid_list *pid_list, + struct task_struct *self, + struct task_struct *task); +void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos); +void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos); +int trace_pid_show(struct seq_file *m, void *v); +void trace_free_pid_list(struct trace_pid_list *pid_list); +int trace_pid_write(struct trace_pid_list *filtered_pids, + struct trace_pid_list **new_pid_list, + const char __user *ubuf, size_t cnt); + #ifdef CONFIG_TRACER_MAX_TRACE void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); void update_max_tr_single(struct trace_array *tr, @@ -821,12 +850,9 @@ extern struct list_head ftrace_pids; #ifdef CONFIG_FUNCTION_TRACER extern bool ftrace_filter_param __initdata; -static inline int ftrace_trace_task(struct task_struct *task) +static inline int ftrace_trace_task(struct trace_array *tr) { - if (list_empty(&ftrace_pids)) - return 1; - - return test_tsk_trace_trace(task); + return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid); } extern int ftrace_is_dead(void); int ftrace_create_function_files(struct trace_array *tr, @@ -836,8 +862,11 @@ void ftrace_init_global_array_ops(struct trace_array *tr); void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func); void ftrace_reset_array_ops(struct trace_array *tr); int using_ftrace_ops_list_func(void); +void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer); +void ftrace_init_tracefs_toplevel(struct trace_array *tr, + struct dentry *d_tracer); #else -static inline int ftrace_trace_task(struct task_struct *task) +static inline int ftrace_trace_task(struct trace_array *tr) { return 1; } @@ -852,6 +881,8 @@ static inline void ftrace_destroy_function_files(struct trace_array *tr) { } static inline __init void ftrace_init_global_array_ops(struct trace_array *tr) { } static inline void ftrace_reset_array_ops(struct trace_array *tr) { } +static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { } +static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { } /* ftace_func_t type is not defined, use macro instead of static inline */ #define ftrace_init_array_ops(tr, func) do { } while (0) #endif /* CONFIG_FUNCTION_TRACER */ @@ -1600,6 +1631,11 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled); #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \ FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \ filter) +#undef FTRACE_ENTRY_PACKED +#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \ + FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \ + filter) + #include "trace_entries.h" #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER) diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index ee7b94a..5c30efc 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -72,7 +72,7 @@ FTRACE_ENTRY_REG(function, ftrace_entry, ); /* Function call entry */ -FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry, +FTRACE_ENTRY_PACKED(funcgraph_entry, ftrace_graph_ent_entry, TRACE_GRAPH_ENT, @@ -88,7 +88,7 @@ FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry, ); /* Function return entry */ -FTRACE_ENTRY(funcgraph_exit, ftrace_graph_ret_entry, +FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry, TRACE_GRAPH_RET, diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 3d41558..03c0a48 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -15,7 +15,6 @@ #include <linux/kthread.h> #include <linux/tracefs.h> #include <linux/uaccess.h> -#include <linux/vmalloc.h> #include <linux/module.h> #include <linux/ctype.h> #include <linux/sort.h> @@ -262,6 +261,14 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, local_save_flags(fbuffer->flags); fbuffer->pc = preempt_count(); + /* + * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables + * preemption (adding one to the preempt_count). Since we are + * interested in the preempt_count at the time the tracepoint was + * hit, we need to subtract one to offset the increment. + */ + if (IS_ENABLED(CONFIG_PREEMPT)) + fbuffer->pc--; fbuffer->trace_file = trace_file; fbuffer->event = @@ -499,60 +506,6 @@ static void ftrace_clear_events(struct trace_array *tr) mutex_unlock(&event_mutex); } -/* Shouldn't this be in a header? */ -extern int pid_max; - -/* Returns true if found in filter */ -static bool -find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid) -{ - /* - * If pid_max changed after filtered_pids was created, we - * by default ignore all pids greater than the previous pid_max. - */ - if (search_pid >= filtered_pids->pid_max) - return false; - - return test_bit(search_pid, filtered_pids->pids); -} - -static bool -ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) -{ - /* - * Return false, because if filtered_pids does not exist, - * all pids are good to trace. - */ - if (!filtered_pids) - return false; - - return !find_filtered_pid(filtered_pids, task->pid); -} - -static void filter_add_remove_task(struct trace_pid_list *pid_list, - struct task_struct *self, - struct task_struct *task) -{ - if (!pid_list) - return; - - /* For forks, we only add if the forking task is listed */ - if (self) { - if (!find_filtered_pid(pid_list, self->pid)) - return; - } - - /* Sorry, but we don't support pid_max changing after setting */ - if (task->pid >= pid_list->pid_max) - return; - - /* "self" is set for forks, and NULL for exits */ - if (self) - set_bit(task->pid, pid_list->pids); - else - clear_bit(task->pid, pid_list->pids); -} - static void event_filter_pid_sched_process_exit(void *data, struct task_struct *task) { @@ -560,7 +513,7 @@ event_filter_pid_sched_process_exit(void *data, struct task_struct *task) struct trace_array *tr = data; pid_list = rcu_dereference_sched(tr->filtered_pids); - filter_add_remove_task(pid_list, NULL, task); + trace_filter_add_remove_task(pid_list, NULL, task); } static void @@ -572,7 +525,7 @@ event_filter_pid_sched_process_fork(void *data, struct trace_array *tr = data; pid_list = rcu_dereference_sched(tr->filtered_pids); - filter_add_remove_task(pid_list, self, task); + trace_filter_add_remove_task(pid_list, self, task); } void trace_event_follow_fork(struct trace_array *tr, bool enable) @@ -600,8 +553,8 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt, pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, prev) && - ignore_this_task(pid_list, next)); + trace_ignore_this_task(pid_list, prev) && + trace_ignore_this_task(pid_list, next)); } static void @@ -614,7 +567,7 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt, pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, next)); + trace_ignore_this_task(pid_list, next)); } static void @@ -630,7 +583,7 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task) pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, task)); + trace_ignore_this_task(pid_list, task)); } static void @@ -647,7 +600,7 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task) /* Set tracing if current is enabled */ this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, current)); + trace_ignore_this_task(pid_list, current)); } static void __ftrace_clear_event_pids(struct trace_array *tr) @@ -685,8 +638,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr) /* Wait till all users are no longer using pid filtering */ synchronize_sched(); - vfree(pid_list->pids); - kfree(pid_list); + trace_free_pid_list(pid_list); } static void ftrace_clear_event_pids(struct trace_array *tr) @@ -1034,18 +986,8 @@ p_next(struct seq_file *m, void *v, loff_t *pos) { struct trace_array *tr = m->private; struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids); - unsigned long pid = (unsigned long)v; - - (*pos)++; - - /* pid already is +1 of the actual prevous bit */ - pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid); - /* Return pid + 1 to allow zero to be represented */ - if (pid < pid_list->pid_max) - return (void *)(pid + 1); - - return NULL; + return trace_pid_next(pid_list, v, pos); } static void *p_start(struct seq_file *m, loff_t *pos) @@ -1053,8 +995,6 @@ static void *p_start(struct seq_file *m, loff_t *pos) { struct trace_pid_list *pid_list; struct trace_array *tr = m->private; - unsigned long pid; - loff_t l = 0; /* * Grab the mutex, to keep calls to p_next() having the same @@ -1070,15 +1010,7 @@ static void *p_start(struct seq_file *m, loff_t *pos) if (!pid_list) return NULL; - pid = find_first_bit(pid_list->pids, pid_list->pid_max); - if (pid >= pid_list->pid_max) - return NULL; - - /* Return pid + 1 so that zero can be the exit value */ - for (pid++; pid && l < *pos; - pid = (unsigned long)p_next(m, (void *)pid, &l)) - ; - return (void *)pid; + return trace_pid_start(pid_list, pos); } static void p_stop(struct seq_file *m, void *p) @@ -1088,14 +1020,6 @@ static void p_stop(struct seq_file *m, void *p) mutex_unlock(&event_mutex); } -static int p_show(struct seq_file *m, void *v) -{ - unsigned long pid = (unsigned long)v - 1; - - seq_printf(m, "%lu\n", pid); - return 0; -} - static ssize_t event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) @@ -1654,7 +1578,7 @@ static void ignore_task_cpu(void *data) mutex_is_locked(&event_mutex)); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, current)); + trace_ignore_this_task(pid_list, current)); } static ssize_t @@ -1666,13 +1590,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, struct trace_pid_list *filtered_pids = NULL; struct trace_pid_list *pid_list; struct trace_event_file *file; - struct trace_parser parser; - unsigned long val; - loff_t this_pos; - ssize_t read = 0; - ssize_t ret = 0; - pid_t pid; - int nr_pids = 0; + ssize_t ret; if (!cnt) return 0; @@ -1681,93 +1599,15 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, if (ret < 0) return ret; - if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) - return -ENOMEM; - mutex_lock(&event_mutex); + filtered_pids = rcu_dereference_protected(tr->filtered_pids, lockdep_is_held(&event_mutex)); - /* - * Always recreate a new array. The write is an all or nothing - * operation. Always create a new array when adding new pids by - * the user. If the operation fails, then the current list is - * not modified. - */ - pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); - if (!pid_list) { - read = -ENOMEM; - goto out; - } - pid_list->pid_max = READ_ONCE(pid_max); - /* Only truncating will shrink pid_max */ - if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max) - pid_list->pid_max = filtered_pids->pid_max; - pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); - if (!pid_list->pids) { - kfree(pid_list); - read = -ENOMEM; - goto out; - } - if (filtered_pids) { - /* copy the current bits to the new max */ - pid = find_first_bit(filtered_pids->pids, - filtered_pids->pid_max); - while (pid < filtered_pids->pid_max) { - set_bit(pid, pid_list->pids); - pid = find_next_bit(filtered_pids->pids, - filtered_pids->pid_max, - pid + 1); - nr_pids++; - } - } - - while (cnt > 0) { - - this_pos = 0; - - ret = trace_get_user(&parser, ubuf, cnt, &this_pos); - if (ret < 0 || !trace_parser_loaded(&parser)) - break; - - read += ret; - ubuf += ret; - cnt -= ret; - - parser.buffer[parser.idx] = 0; - - ret = -EINVAL; - if (kstrtoul(parser.buffer, 0, &val)) - break; - if (val >= pid_list->pid_max) - break; - - pid = (pid_t)val; - - set_bit(pid, pid_list->pids); - nr_pids++; - - trace_parser_clear(&parser); - ret = 0; - } - trace_parser_put(&parser); - - if (ret < 0) { - vfree(pid_list->pids); - kfree(pid_list); - read = ret; + ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); + if (ret < 0) goto out; - } - if (!nr_pids) { - /* Cleared the list of pids */ - vfree(pid_list->pids); - kfree(pid_list); - read = ret; - if (!filtered_pids) - goto out; - pid_list = NULL; - } rcu_assign_pointer(tr->filtered_pids, pid_list); list_for_each_entry(file, &tr->events, list) { @@ -1776,10 +1616,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, if (filtered_pids) { synchronize_sched(); - - vfree(filtered_pids->pids); - kfree(filtered_pids); - } else { + trace_free_pid_list(filtered_pids); + } else if (pid_list) { /* * Register a probe that is called before all other probes * to set ignore_pid if next or prev do not match. @@ -1817,9 +1655,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&event_mutex); - ret = read; - if (read > 0) - *ppos += read; + if (ret > 0) + *ppos += ret; return ret; } @@ -1846,7 +1683,7 @@ static const struct seq_operations show_set_event_seq_ops = { static const struct seq_operations show_set_pid_seq_ops = { .start = p_start, .next = p_next, - .show = p_show, + .show = trace_pid_show, .stop = p_stop, }; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 5a095c2..0efa00d 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -43,7 +43,7 @@ static int allocate_ftrace_ops(struct trace_array *tr) /* Currently only the non stack verision is supported */ ops->func = function_trace_call; - ops->flags = FTRACE_OPS_FL_RECURSION_SAFE; + ops->flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_PID; tr->ops = ops; ops->private = tr; diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 3a0244f..7363ccf 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -319,7 +319,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) int cpu; int pc; - if (!ftrace_trace_task(current)) + if (!ftrace_trace_task(tr)) return 0; /* trace it when it is-nested-in or is a function enabled. */ @@ -338,6 +338,13 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) if (ftrace_graph_notrace_addr(trace->func)) return 1; + /* + * Stop here if tracing_threshold is set. We only write function return + * events to the ring buffer. + */ + if (tracing_thresh) + return 1; + local_irq_save(flags); cpu = raw_smp_processor_id(); data = per_cpu_ptr(tr->trace_buffer.data, cpu); @@ -355,14 +362,6 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) return ret; } -static int trace_graph_thresh_entry(struct ftrace_graph_ent *trace) -{ - if (tracing_thresh) - return 1; - else - return trace_graph_entry(trace); -} - static void __trace_graph_function(struct trace_array *tr, unsigned long ip, unsigned long flags, int pc) @@ -457,7 +456,7 @@ static int graph_trace_init(struct trace_array *tr) set_graph_array(tr); if (tracing_thresh) ret = register_ftrace_graph(&trace_graph_thresh_return, - &trace_graph_thresh_entry); + &trace_graph_entry); else ret = register_ftrace_graph(&trace_graph_return, &trace_graph_entry); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5546eec..9aedb0b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -587,6 +587,7 @@ static int create_trace_kprobe(int argc, char **argv) * $retval : fetch return value * $stack : fetch stack address * $stackN : fetch Nth of stack (N:0-) + * $comm : fetch current task comm * @ADDR : fetch memory at ADDR (ADDR should be in kernel) * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) * %REG : fetch register REG diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 68f376c..cd7480d 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -68,19 +68,15 @@ static void mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x", dev->bus->number, dev->devfn, dev->vendor, dev->device, dev->irq); - /* - * XXX: is pci_resource_to_user() appropriate, since we are - * supposed to interpret the __ioremap() phys_addr argument based on - * these printed values? - */ for (i = 0; i < 7; i++) { - pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); + start = dev->resource[i].start; trace_seq_printf(s, " %llx", (unsigned long long)(start | (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); } for (i = 0; i < 7; i++) { - pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); + start = dev->resource[i].start; + end = dev->resource[i].end; trace_seq_printf(s, " %llx", dev->resource[i].start < dev->resource[i].end ? (unsigned long long)(end - start) + 1 : 0); diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 1d372fa..74e80a5 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -218,6 +218,28 @@ free_bitfield_fetch_param(struct bitfield_fetch_param *data) kfree(data); } +void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs, + void *data, void *dest) +{ + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + long ret; + + if (!maxlen) + return; + + ret = strlcpy(dst, current->comm, maxlen); + *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); +} +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string)); + +void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs, + void *data, void *dest) +{ + *(u32 *)dest = strlen(current->comm) + 1; +} +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size)); + static const struct fetch_type *find_fetch_type(const char *type, const struct fetch_type *ftbl) { @@ -348,6 +370,11 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, } } else ret = -EINVAL; + } else if (strcmp(arg, "comm") == 0) { + if (strcmp(t->name, "string") != 0 && + strcmp(t->name, "string_size") != 0) + return -EINVAL; + f->fn = t->fetch[FETCH_MTD_comm]; } else ret = -EINVAL; @@ -522,6 +549,12 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, arg[t - parg->comm] = '\0'; t++; } + /* + * The default type of $comm should be "string", and it can't be + * dereferenced. + */ + if (!t && strcmp(arg, "$comm") == 0) + t = "string"; parg->type = find_fetch_type(t, ftbl); if (!parg->type) { pr_info("Unsupported type: %s\n", t); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index f6398db..45400ca 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -102,6 +102,7 @@ enum { FETCH_MTD_reg = 0, FETCH_MTD_stack, FETCH_MTD_retval, + FETCH_MTD_comm, FETCH_MTD_memory, FETCH_MTD_symbol, FETCH_MTD_deref, @@ -183,6 +184,14 @@ DECLARE_BASIC_FETCH_FUNCS(bitfield); #define fetch_bitfield_string NULL #define fetch_bitfield_string_size NULL +/* comm only makes sense as a string */ +#define fetch_comm_u8 NULL +#define fetch_comm_u16 NULL +#define fetch_comm_u32 NULL +#define fetch_comm_u64 NULL +DECLARE_FETCH_FUNC(comm, string); +DECLARE_FETCH_FUNC(comm, string_size); + /* * Define macro for basic types - we don't need to define s* types, because * we have to care only about bitwidth at recording time. @@ -213,6 +222,7 @@ DEFINE_FETCH_##method(u64) ASSIGN_FETCH_FUNC(reg, ftype), \ ASSIGN_FETCH_FUNC(stack, ftype), \ ASSIGN_FETCH_FUNC(retval, ftype), \ +ASSIGN_FETCH_FUNC(comm, ftype), \ ASSIGN_FETCH_FUNC(memory, ftype), \ ASSIGN_FETCH_FUNC(symbol, ftype), \ ASSIGN_FETCH_FUNC(deref, ftype), \ |
