diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/Kconfig | 22 | ||||
| -rw-r--r-- | kernel/trace/Makefile | 1 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 6 | ||||
| -rw-r--r-- | kernel/trace/trace_entries.h | 15 | ||||
| -rw-r--r-- | kernel/trace/trace_ksym.c | 508 | ||||
| -rw-r--r-- | kernel/trace/trace_selftest.c | 54 |
6 files changed, 0 insertions, 606 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index f669092..f5306cb 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -308,28 +308,6 @@ config BRANCH_TRACER Say N if unsure. -config KSYM_TRACER - bool "Trace read and write access on kernel memory locations" - depends on HAVE_HW_BREAKPOINT - select TRACING - help - This tracer helps find read and write operations on any given kernel - symbol i.e. /proc/kallsyms. - -config PROFILE_KSYM_TRACER - bool "Profile all kernel memory accesses on 'watched' variables" - depends on KSYM_TRACER - help - This tracer profiles kernel accesses on variables watched through the - ksym tracer ftrace plugin. Depending upon the hardware, all read - and write operations on kernel variables can be monitored for - accesses. - - The results will be displayed in: - /debugfs/tracing/profile_ksym - - Say N if unsure. - config STACK_TRACER bool "Trace max stack" depends on HAVE_FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 469a1c7..84b2c99 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -53,7 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_event_perf.o endif obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o -obj-$(CONFIG_KSYM_TRACER) += trace_ksym.o obj-$(CONFIG_EVENT_TRACING) += power-traces.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index cc90ccd..84d3f12 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -30,7 +30,6 @@ enum trace_type { TRACE_GRAPH_ENT, TRACE_USER_STACK, TRACE_BLK, - TRACE_KSYM, __TRACE_LAST_TYPE, }; @@ -200,7 +199,6 @@ extern void __ftrace_bad_type(void); TRACE_GRAPH_ENT); \ IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ TRACE_GRAPH_RET); \ - IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\ __ftrace_bad_type(); \ } while (0) @@ -361,8 +359,6 @@ int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); int is_tracing_stopped(void); -extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr); - extern unsigned long nsecs_to_usecs(unsigned long nsecs); extern unsigned long tracing_thresh; @@ -436,8 +432,6 @@ extern int trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr); -extern int trace_selftest_startup_ksym(struct tracer *trace, - struct trace_array *tr); #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index 13abc15..8412837 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -291,18 +291,3 @@ FTRACE_ENTRY(branch, trace_branch, __entry->func, __entry->file, __entry->correct) ); -FTRACE_ENTRY(ksym_trace, ksym_trace_entry, - - TRACE_KSYM, - - F_STRUCT( - __field( unsigned long, ip ) - __field( unsigned char, type ) - __array( char , cmd, TASK_COMM_LEN ) - __field( unsigned long, addr ) - ), - - F_printk("ip: %pF type: %d ksym_name: %pS cmd: %s", - (void *)__entry->ip, (unsigned int)__entry->type, - (void *)__entry->addr, __entry->cmd) -); diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c deleted file mode 100644 index 8eaf007..0000000 --- a/kernel/trace/trace_ksym.c +++ /dev/null @@ -1,508 +0,0 @@ -/* - * trace_ksym.c - Kernel Symbol Tracer - * - * 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. - * - * Copyright (C) IBM Corporation, 2009 - */ - -#include <linux/kallsyms.h> -#include <linux/uaccess.h> -#include <linux/debugfs.h> -#include <linux/ftrace.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/fs.h> - -#include "trace_output.h" -#include "trace.h" - -#include <linux/hw_breakpoint.h> -#include <asm/hw_breakpoint.h> - -#include <asm/atomic.h> - -#define KSYM_TRACER_OP_LEN 3 /* rw- */ - -struct trace_ksym { - struct perf_event **ksym_hbp; - struct perf_event_attr attr; -#ifdef CONFIG_PROFILE_KSYM_TRACER - atomic64_t counter; -#endif - struct hlist_node ksym_hlist; -}; - -static struct trace_array *ksym_trace_array; - -static unsigned int ksym_tracing_enabled; - -static HLIST_HEAD(ksym_filter_head); - -static DEFINE_MUTEX(ksym_tracer_mutex); - -#ifdef CONFIG_PROFILE_KSYM_TRACER - -#define MAX_UL_INT 0xffffffff - -void ksym_collect_stats(unsigned long hbp_hit_addr) -{ - struct hlist_node *node; - struct trace_ksym *entry; - - rcu_read_lock(); - hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) { - if (entry->attr.bp_addr == hbp_hit_addr) { - atomic64_inc(&entry->counter); - break; - } - } - rcu_read_unlock(); -} -#endif /* CONFIG_PROFILE_KSYM_TRACER */ - -void ksym_hbp_handler(struct perf_event *hbp, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct ring_buffer_event *event; - struct ksym_trace_entry *entry; - struct ring_buffer *buffer; - int pc; - - if (!ksym_tracing_enabled) - return; - - buffer = ksym_trace_array->buffer; - - pc = preempt_count(); - - event = trace_buffer_lock_reserve(buffer, TRACE_KSYM, - sizeof(*entry), 0, pc); - if (!event) - return; - - entry = ring_buffer_event_data(event); - entry->ip = instruction_pointer(regs); - entry->type = hw_breakpoint_type(hbp); - entry->addr = hw_breakpoint_addr(hbp); - strlcpy(entry->cmd, current->comm, TASK_COMM_LEN); - -#ifdef CONFIG_PROFILE_KSYM_TRACER - ksym_collect_stats(hw_breakpoint_addr(hbp)); -#endif /* CONFIG_PROFILE_KSYM_TRACER */ - - trace_buffer_unlock_commit(buffer, event, 0, pc); -} - -/* Valid access types are represented as - * - * rw- : Set Read/Write Access Breakpoint - * -w- : Set Write Access Breakpoint - * --- : Clear Breakpoints - * --x : Set Execution Break points (Not available yet) - * - */ -static int ksym_trace_get_access_type(char *str) -{ - int access = 0; - - if (str[0] == 'r') - access |= HW_BREAKPOINT_R; - - if (str[1] == 'w') - access |= HW_BREAKPOINT_W; - - if (str[2] == 'x') - access |= HW_BREAKPOINT_X; - - switch (access) { - case HW_BREAKPOINT_R: - case HW_BREAKPOINT_W: - case HW_BREAKPOINT_W | HW_BREAKPOINT_R: - return access; - default: - return -EINVAL; - } -} - -/* - * There can be several possible malformed requests and we attempt to capture - * all of them. We enumerate some of the rules - * 1. We will not allow kernel symbols with ':' since it is used as a delimiter. - * i.e. multiple ':' symbols disallowed. Possible uses are of the form - * <module>:<ksym_name>:<op>. - * 2. No delimiter symbol ':' in the input string - * 3. Spurious operator symbols or symbols not in their respective positions - * 4. <ksym_name>:--- i.e. clear breakpoint request when ksym_name not in file - * 5. Kernel symbol not a part of /proc/kallsyms - * 6. Duplicate requests - */ -static int parse_ksym_trace_str(char *input_string, char **ksymname, - unsigned long *addr) -{ - int ret; - - *ksymname = strsep(&input_string, ":"); - *addr = kallsyms_lookup_name(*ksymname); - - /* Check for malformed request: (2), (1) and (5) */ - if ((!input_string) || - (strlen(input_string) != KSYM_TRACER_OP_LEN) || - (*addr == 0)) - return -EINVAL;; - - ret = ksym_trace_get_access_type(input_string); - - return ret; -} - -int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) -{ - struct trace_ksym *entry; - int ret = -ENOMEM; - - entry = kzalloc(sizeof(struct trace_ksym), GFP_KERNEL); - if (!entry) - return -ENOMEM; - - hw_breakpoint_init(&entry->attr); - - entry->attr.bp_type = op; - entry->attr.bp_addr = addr; - entry->attr.bp_len = HW_BREAKPOINT_LEN_4; - - entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr, - ksym_hbp_handler); - - if (IS_ERR(entry->ksym_hbp)) { - ret = PTR_ERR(entry->ksym_hbp); - if (ret == -ENOSPC) { - printk(KERN_ERR "ksym_tracer: Maximum limit reached." - " No new requests for tracing can be accepted now.\n"); - } else { - printk(KERN_INFO "ksym_tracer request failed. Try again" - " later!!\n"); - } - goto err; - } - - hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); - - return 0; - -err: - kfree(entry); - - return ret; -} - -static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, - size_t count, loff_t *ppos) -{ - struct trace_ksym *entry; - struct hlist_node *node; - struct trace_seq *s; - ssize_t cnt = 0; - int ret; - - s = kmalloc(sizeof(*s), GFP_KERNEL); - if (!s) - return -ENOMEM; - trace_seq_init(s); - - mutex_lock(&ksym_tracer_mutex); - - hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { - ret = trace_seq_printf(s, "%pS:", - (void *)(unsigned long)entry->attr.bp_addr); - if (entry->attr.bp_type == HW_BREAKPOINT_R) - ret = trace_seq_puts(s, "r--\n"); - else if (entry->attr.bp_type == HW_BREAKPOINT_W) - ret = trace_seq_puts(s, "-w-\n"); - else if (entry->attr.bp_type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R)) - ret = trace_seq_puts(s, "rw-\n"); - WARN_ON_ONCE(!ret); - } - - cnt = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); - - mutex_unlock(&ksym_tracer_mutex); - - kfree(s); - - return cnt; -} - -static void __ksym_trace_reset(void) -{ - struct trace_ksym *entry; - struct hlist_node *node, *node1; - - mutex_lock(&ksym_tracer_mutex); - hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head, - ksym_hlist) { - unregister_wide_hw_breakpoint(entry->ksym_hbp); - hlist_del_rcu(&(entry->ksym_hlist)); - synchronize_rcu(); - kfree(entry); - } - mutex_unlock(&ksym_tracer_mutex); -} - -static ssize_t ksym_trace_filter_write(struct file *file, - const char __user *buffer, - size_t count, loff_t *ppos) -{ - struct trace_ksym *entry; - struct hlist_node *node; - char *buf, *input_string, *ksymname = NULL; - unsigned long ksym_addr = 0; - int ret, op, changed = 0; - - buf = kzalloc(count + 1, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - ret = -EFAULT; - if (copy_from_user(buf, buffer, count)) - goto out; - - buf[count] = '\0'; - input_string = strstrip(buf); - - /* - * Clear all breakpoints if: - * 1: echo > ksym_trace_filter - * 2: echo 0 > ksym_trace_filter - * 3: echo "*:---" > ksym_trace_filter - */ - if (!input_string[0] || !strcmp(input_string, "0") || - !strcmp(input_string, "*:---")) { - __ksym_trace_reset(); - ret = 0; - goto out; - } - - ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr); - if (ret < 0) - goto out; - - mutex_lock(&ksym_tracer_mutex); - - ret = -EINVAL; - hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { - if (entry->attr.bp_addr == ksym_addr) { - /* Check for malformed request: (6) */ - if (entry->attr.bp_type != op) - changed = 1; - else - goto out_unlock; - break; - } - } - if (changed) { - unregister_wide_hw_breakpoint(entry->ksym_hbp); - entry->attr.bp_type = op; - ret = 0; - if (op > 0) { - entry->ksym_hbp = - register_wide_hw_breakpoint(&entry->attr, - ksym_hbp_handler); - if (IS_ERR(entry->ksym_hbp)) - ret = PTR_ERR(entry->ksym_hbp); - else - goto out_unlock; - } - /* Error or "symbol:---" case: drop it */ - hlist_del_rcu(&(entry->ksym_hlist)); - synchronize_rcu(); - kfree(entry); - goto out_unlock; - } else { - /* Check for malformed request: (4) */ - if (op) - ret = process_new_ksym_entry(ksymname, op, ksym_addr); - } -out_unlock: - mutex_unlock(&ksym_tracer_mutex); -out: - kfree(buf); - return !ret ? count : ret; -} - -static const struct file_operations ksym_tracing_fops = { - .open = tracing_open_generic, - .read = ksym_trace_filter_read, - .write = ksym_trace_filter_write, -}; - -static void ksym_trace_reset(struct trace_array *tr) -{ - ksym_tracing_enabled = 0; - __ksym_trace_reset(); -} - -static int ksym_trace_init(struct trace_array *tr) -{ - int cpu, ret = 0; - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); - ksym_tracing_enabled = 1; - ksym_trace_array = tr; - - return ret; -} - -static void ksym_trace_print_header(struct seq_file *m) -{ - seq_puts(m, - "# TASK-PID CPU# Symbol " - "Type Function\n"); - seq_puts(m, - "# | | | " - " | |\n"); -} - -static enum print_line_t ksym_trace_output(struct trace_iterator *iter) -{ - struct trace_entry *entry = iter->ent; - struct trace_seq *s = &iter->seq; - struct ksym_trace_entry *field; - char str[KSYM_SYMBOL_LEN]; - int ret; - - if (entry->type != TRACE_KSYM) - return TRACE_TYPE_UNHANDLED; - - trace_assign_type(field, entry); - - ret = trace_seq_printf(s, "%11s-%-5d [%03d] %pS", field->cmd, - entry->pid, iter->cpu, (char *)field->addr); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - switch (field->type) { - case HW_BREAKPOINT_R: - ret = trace_seq_printf(s, " R "); - break; - case HW_BREAKPOINT_W: - ret = trace_seq_printf(s, " W "); - break; - case HW_BREAKPOINT_R | HW_BREAKPOINT_W: - ret = trace_seq_printf(s, " RW "); - break; - default: - return TRACE_TYPE_PARTIAL_LINE; - } - - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - sprint_symbol(str, field->ip); - ret = trace_seq_printf(s, "%s\n", str); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - return TRACE_TYPE_HANDLED; -} - -struct tracer ksym_tracer __read_mostly = -{ - .name = "ksym_tracer", - .init = ksym_trace_init, - .reset = ksym_trace_reset, -#ifdef CONFIG_FTRACE_SELFTEST - .selftest = trace_selftest_startup_ksym, -#endif - .print_header = ksym_trace_print_header, - .print_line = ksym_trace_output -}; - -#ifdef CONFIG_PROFILE_KSYM_TRACER -static int ksym_profile_show(struct seq_file *m, void *v) -{ - struct hlist_node *node; - struct trace_ksym *entry; - int access_type = 0; - char fn_name[KSYM_NAME_LEN]; - - seq_puts(m, " Access Type "); - seq_puts(m, " Symbol Counter\n"); - seq_puts(m, " ----------- "); - seq_puts(m, " ------ -------\n"); - - rcu_read_lock(); - hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) { - - access_type = entry->attr.bp_type; - - switch (access_type) { - case HW_BREAKPOINT_R: - seq_puts(m, " R "); - break; - case HW_BREAKPOINT_W: - seq_puts(m, " W "); - break; - case HW_BREAKPOINT_R | HW_BREAKPOINT_W: - seq_puts(m, " RW "); - break; - default: - seq_puts(m, " NA "); - } - - if (lookup_symbol_name(entry->attr.bp_addr, fn_name) >= 0) - seq_printf(m, " %-36s", fn_name); - else - seq_printf(m, " %-36s", "<NA>"); - seq_printf(m, " %15llu\n", - (unsigned long long)atomic64_read(&entry->counter)); - } - rcu_read_unlock(); - - return 0; -} - -static int ksym_profile_open(struct inode *node, struct file *file) -{ - return single_open(file, ksym_profile_show, NULL); -} - -static const struct file_operations ksym_profile_fops = { - .open = ksym_profile_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; -#endif /* CONFIG_PROFILE_KSYM_TRACER */ - -__init static int init_ksym_trace(void) -{ - struct dentry *d_tracer; - - d_tracer = tracing_init_dentry(); - - trace_create_file("ksym_trace_filter", 0644, d_tracer, - NULL, &ksym_tracing_fops); - -#ifdef CONFIG_PROFILE_KSYM_TRACER - trace_create_file("ksym_profile", 0444, d_tracer, - NULL, &ksym_profile_fops); -#endif - - return register_tracer(&ksym_tracer); -} -device_initcall(init_ksym_trace); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 250e7f9..39a5ca4 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -17,7 +17,6 @@ static inline int trace_valid_entry(struct trace_entry *entry) case TRACE_BRANCH: case TRACE_GRAPH_ENT: case TRACE_GRAPH_RET: - case TRACE_KSYM: return 1; } return 0; @@ -755,56 +754,3 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) } #endif /* CONFIG_BRANCH_TRACER */ -#ifdef CONFIG_KSYM_TRACER -static int ksym_selftest_dummy; - -int -trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr) -{ - unsigned long count; - int ret; - - /* start the tracing */ - ret = tracer_init(trace, tr); - if (ret) { - warn_failed_init_tracer(trace, ret); - return ret; - } - - ksym_selftest_dummy = 0; - /* Register the read-write tracing request */ - - ret = process_new_ksym_entry("ksym_selftest_dummy", - HW_BREAKPOINT_R | HW_BREAKPOINT_W, - (unsigned long)(&ksym_selftest_dummy)); - - if (ret < 0) { - printk(KERN_CONT "ksym_trace read-write startup test failed\n"); - goto ret_path; - } - /* Perform a read and a write operation over the dummy variable to - * trigger the tracer - */ - if (ksym_selftest_dummy == 0) - ksym_selftest_dummy++; - - /* stop the tracing. */ - tracing_stop(); - /* check the trace buffer */ - ret = trace_test_buffer(tr, &count); - trace->reset(tr); - tracing_start(); - - /* read & write operations - one each is performed on the dummy variable - * triggering two entries in the trace buffer - */ - if (!ret && count != 2) { - printk(KERN_CONT "Ksym tracer startup test failed"); - ret = -1; - } - -ret_path: - return ret; -} -#endif /* CONFIG_KSYM_TRACER */ - |
