2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 William Lee Irwin III
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/debugfs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/kprobes.h>
26 #include <linux/ftrace.h>
27 #include <linux/sysctl.h>
28 #include <linux/ctype.h>
29 #include <linux/list.h>
30 #include <linux/hash.h>
32 #include <trace/events/sched.h>
34 #include <asm/ftrace.h>
36 #include "trace_output.h"
37 #include "trace_stat.h"
39 #define FTRACE_WARN_ON(cond) \
45 #define FTRACE_WARN_ON_ONCE(cond) \
47 if (WARN_ON_ONCE(cond)) \
51 /* hash bits for specific function selection */
52 #define FTRACE_HASH_BITS 7
53 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
55 /* ftrace_enabled is a method to turn ftrace on or off */
56 int ftrace_enabled __read_mostly;
57 static int last_ftrace_enabled;
59 /* Quick disabling of function tracer. */
60 int function_trace_stop;
63 * ftrace_disabled is set when an anomaly is discovered.
64 * ftrace_disabled is much stronger than ftrace_enabled.
66 static int ftrace_disabled __read_mostly;
68 static DEFINE_MUTEX(ftrace_lock);
70 static struct ftrace_ops ftrace_list_end __read_mostly =
75 static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
76 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
77 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
78 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
80 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
82 struct ftrace_ops *op = ftrace_list;
84 /* in case someone actually ports this to alpha! */
85 read_barrier_depends();
87 while (op != &ftrace_list_end) {
89 read_barrier_depends();
90 op->func(ip, parent_ip);
95 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
97 if (!test_tsk_trace_trace(current))
100 ftrace_pid_function(ip, parent_ip);
103 static void set_ftrace_pid_function(ftrace_func_t func)
105 /* do not set ftrace_pid_function to itself! */
106 if (func != ftrace_pid_func)
107 ftrace_pid_function = func;
111 * clear_ftrace_function - reset the ftrace function
113 * This NULLs the ftrace function and in essence stops
114 * tracing. There may be lag
116 void clear_ftrace_function(void)
118 ftrace_trace_function = ftrace_stub;
119 __ftrace_trace_function = ftrace_stub;
120 ftrace_pid_function = ftrace_stub;
123 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
125 * For those archs that do not test ftrace_trace_stop in their
126 * mcount call site, we need to do it from C.
128 static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
130 if (function_trace_stop)
133 __ftrace_trace_function(ip, parent_ip);
137 static int __register_ftrace_function(struct ftrace_ops *ops)
139 ops->next = ftrace_list;
141 * We are entering ops into the ftrace_list but another
142 * CPU might be walking that list. We need to make sure
143 * the ops->next pointer is valid before another CPU sees
144 * the ops pointer included into the ftrace_list.
149 if (ftrace_enabled) {
152 if (ops->next == &ftrace_list_end)
155 func = ftrace_list_func;
157 if (ftrace_pid_trace) {
158 set_ftrace_pid_function(func);
159 func = ftrace_pid_func;
163 * For one func, simply call it directly.
164 * For more than one func, call the chain.
166 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
167 ftrace_trace_function = func;
169 __ftrace_trace_function = func;
170 ftrace_trace_function = ftrace_test_stop_func;
177 static int __unregister_ftrace_function(struct ftrace_ops *ops)
179 struct ftrace_ops **p;
182 * If we are removing the last function, then simply point
183 * to the ftrace_stub.
185 if (ftrace_list == ops && ops->next == &ftrace_list_end) {
186 ftrace_trace_function = ftrace_stub;
187 ftrace_list = &ftrace_list_end;
191 for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
200 if (ftrace_enabled) {
201 /* If we only have one func left, then call that directly */
202 if (ftrace_list->next == &ftrace_list_end) {
203 ftrace_func_t func = ftrace_list->func;
205 if (ftrace_pid_trace) {
206 set_ftrace_pid_function(func);
207 func = ftrace_pid_func;
209 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
210 ftrace_trace_function = func;
212 __ftrace_trace_function = func;
220 static void ftrace_update_pid_func(void)
224 if (ftrace_trace_function == ftrace_stub)
227 func = ftrace_trace_function;
229 if (ftrace_pid_trace) {
230 set_ftrace_pid_function(func);
231 func = ftrace_pid_func;
233 if (func == ftrace_pid_func)
234 func = ftrace_pid_function;
237 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
238 ftrace_trace_function = func;
240 __ftrace_trace_function = func;
244 #ifdef CONFIG_FUNCTION_PROFILER
245 struct ftrace_profile {
246 struct hlist_node node;
248 unsigned long counter;
249 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
250 unsigned long long time;
254 struct ftrace_profile_page {
255 struct ftrace_profile_page *next;
257 struct ftrace_profile records[];
260 struct ftrace_profile_stat {
262 struct hlist_head *hash;
263 struct ftrace_profile_page *pages;
264 struct ftrace_profile_page *start;
265 struct tracer_stat stat;
268 #define PROFILE_RECORDS_SIZE \
269 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
271 #define PROFILES_PER_PAGE \
272 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
274 static int ftrace_profile_bits __read_mostly;
275 static int ftrace_profile_enabled __read_mostly;
277 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
278 static DEFINE_MUTEX(ftrace_profile_lock);
280 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
282 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
285 function_stat_next(void *v, int idx)
287 struct ftrace_profile *rec = v;
288 struct ftrace_profile_page *pg;
290 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
294 if ((void *)rec >= (void *)&pg->records[pg->index]) {
298 rec = &pg->records[0];
306 static void *function_stat_start(struct tracer_stat *trace)
308 struct ftrace_profile_stat *stat =
309 container_of(trace, struct ftrace_profile_stat, stat);
311 if (!stat || !stat->start)
314 return function_stat_next(&stat->start->records[0], 0);
317 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
318 /* function graph compares on total time */
319 static int function_stat_cmp(void *p1, void *p2)
321 struct ftrace_profile *a = p1;
322 struct ftrace_profile *b = p2;
324 if (a->time < b->time)
326 if (a->time > b->time)
332 /* not function graph compares against hits */
333 static int function_stat_cmp(void *p1, void *p2)
335 struct ftrace_profile *a = p1;
336 struct ftrace_profile *b = p2;
338 if (a->counter < b->counter)
340 if (a->counter > b->counter)
347 static int function_stat_headers(struct seq_file *m)
349 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
350 seq_printf(m, " Function "
355 seq_printf(m, " Function Hit\n"
361 static int function_stat_show(struct seq_file *m, void *v)
363 struct ftrace_profile *rec = v;
364 char str[KSYM_SYMBOL_LEN];
365 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
366 static DEFINE_MUTEX(mutex);
367 static struct trace_seq s;
368 unsigned long long avg;
371 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
372 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
374 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
377 do_div(avg, rec->counter);
381 trace_print_graph_duration(rec->time, &s);
382 trace_seq_puts(&s, " ");
383 trace_print_graph_duration(avg, &s);
384 trace_print_seq(m, &s);
385 mutex_unlock(&mutex);
392 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
394 struct ftrace_profile_page *pg;
396 pg = stat->pages = stat->start;
399 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
404 memset(stat->hash, 0,
405 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
408 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
410 struct ftrace_profile_page *pg;
415 /* If we already allocated, do nothing */
419 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
423 #ifdef CONFIG_DYNAMIC_FTRACE
424 functions = ftrace_update_tot_cnt;
427 * We do not know the number of functions that exist because
428 * dynamic tracing is what counts them. With past experience
429 * we have around 20K functions. That should be more than enough.
430 * It is highly unlikely we will execute every function in
436 pg = stat->start = stat->pages;
438 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
440 for (i = 0; i < pages; i++) {
441 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
452 unsigned long tmp = (unsigned long)pg;
458 free_page((unsigned long)stat->pages);
465 static int ftrace_profile_init_cpu(int cpu)
467 struct ftrace_profile_stat *stat;
470 stat = &per_cpu(ftrace_profile_stats, cpu);
473 /* If the profile is already created, simply reset it */
474 ftrace_profile_reset(stat);
479 * We are profiling all functions, but usually only a few thousand
480 * functions are hit. We'll make a hash of 1024 items.
482 size = FTRACE_PROFILE_HASH_SIZE;
484 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
489 if (!ftrace_profile_bits) {
492 for (; size; size >>= 1)
493 ftrace_profile_bits++;
496 /* Preallocate the function profiling pages */
497 if (ftrace_profile_pages_init(stat) < 0) {
506 static int ftrace_profile_init(void)
511 for_each_online_cpu(cpu) {
512 ret = ftrace_profile_init_cpu(cpu);
520 /* interrupts must be disabled */
521 static struct ftrace_profile *
522 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
524 struct ftrace_profile *rec;
525 struct hlist_head *hhd;
526 struct hlist_node *n;
529 key = hash_long(ip, ftrace_profile_bits);
530 hhd = &stat->hash[key];
532 if (hlist_empty(hhd))
535 hlist_for_each_entry_rcu(rec, n, hhd, node) {
543 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
544 struct ftrace_profile *rec)
548 key = hash_long(rec->ip, ftrace_profile_bits);
549 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
553 * The memory is already allocated, this simply finds a new record to use.
555 static struct ftrace_profile *
556 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
558 struct ftrace_profile *rec = NULL;
560 /* prevent recursion (from NMIs) */
561 if (atomic_inc_return(&stat->disabled) != 1)
565 * Try to find the function again since an NMI
566 * could have added it
568 rec = ftrace_find_profiled_func(stat, ip);
572 if (stat->pages->index == PROFILES_PER_PAGE) {
573 if (!stat->pages->next)
575 stat->pages = stat->pages->next;
578 rec = &stat->pages->records[stat->pages->index++];
580 ftrace_add_profile(stat, rec);
583 atomic_dec(&stat->disabled);
589 function_profile_call(unsigned long ip, unsigned long parent_ip)
591 struct ftrace_profile_stat *stat;
592 struct ftrace_profile *rec;
595 if (!ftrace_profile_enabled)
598 local_irq_save(flags);
600 stat = &__get_cpu_var(ftrace_profile_stats);
604 rec = ftrace_find_profiled_func(stat, ip);
606 rec = ftrace_profile_alloc(stat, ip);
613 local_irq_restore(flags);
616 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
617 static int profile_graph_entry(struct ftrace_graph_ent *trace)
619 function_profile_call(trace->func, 0);
623 static void profile_graph_return(struct ftrace_graph_ret *trace)
625 struct ftrace_profile_stat *stat;
626 unsigned long long calltime;
627 struct ftrace_profile *rec;
630 local_irq_save(flags);
631 stat = &__get_cpu_var(ftrace_profile_stats);
635 calltime = trace->rettime - trace->calltime;
637 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
640 index = trace->depth;
642 /* Append this call time to the parent time to subtract */
644 current->ret_stack[index - 1].subtime += calltime;
646 if (current->ret_stack[index].subtime < calltime)
647 calltime -= current->ret_stack[index].subtime;
652 rec = ftrace_find_profiled_func(stat, trace->func);
654 rec->time += calltime;
657 local_irq_restore(flags);
660 static int register_ftrace_profiler(void)
662 return register_ftrace_graph(&profile_graph_return,
663 &profile_graph_entry);
666 static void unregister_ftrace_profiler(void)
668 unregister_ftrace_graph();
671 static struct ftrace_ops ftrace_profile_ops __read_mostly =
673 .func = function_profile_call,
676 static int register_ftrace_profiler(void)
678 return register_ftrace_function(&ftrace_profile_ops);
681 static void unregister_ftrace_profiler(void)
683 unregister_ftrace_function(&ftrace_profile_ops);
685 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
688 ftrace_profile_write(struct file *filp, const char __user *ubuf,
689 size_t cnt, loff_t *ppos)
692 char buf[64]; /* big enough to hold a number */
695 if (cnt >= sizeof(buf))
698 if (copy_from_user(&buf, ubuf, cnt))
703 ret = strict_strtoul(buf, 10, &val);
709 mutex_lock(&ftrace_profile_lock);
710 if (ftrace_profile_enabled ^ val) {
712 ret = ftrace_profile_init();
718 ret = register_ftrace_profiler();
723 ftrace_profile_enabled = 1;
725 ftrace_profile_enabled = 0;
726 unregister_ftrace_profiler();
730 mutex_unlock(&ftrace_profile_lock);
738 ftrace_profile_read(struct file *filp, char __user *ubuf,
739 size_t cnt, loff_t *ppos)
741 char buf[64]; /* big enough to hold a number */
744 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
745 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
748 static const struct file_operations ftrace_profile_fops = {
749 .open = tracing_open_generic,
750 .read = ftrace_profile_read,
751 .write = ftrace_profile_write,
754 /* used to initialize the real stat files */
755 static struct tracer_stat function_stats __initdata = {
757 .stat_start = function_stat_start,
758 .stat_next = function_stat_next,
759 .stat_cmp = function_stat_cmp,
760 .stat_headers = function_stat_headers,
761 .stat_show = function_stat_show
764 static void ftrace_profile_debugfs(struct dentry *d_tracer)
766 struct ftrace_profile_stat *stat;
767 struct dentry *entry;
772 for_each_possible_cpu(cpu) {
773 stat = &per_cpu(ftrace_profile_stats, cpu);
775 /* allocate enough for function name + cpu number */
776 name = kmalloc(32, GFP_KERNEL);
779 * The files created are permanent, if something happens
780 * we still do not free memory.
784 "Could not allocate stat file for cpu %d\n",
788 stat->stat = function_stats;
789 snprintf(name, 32, "function%d", cpu);
790 stat->stat.name = name;
791 ret = register_stat_tracer(&stat->stat);
794 "Could not register function stat for cpu %d\n",
801 entry = debugfs_create_file("function_profile_enabled", 0644,
802 d_tracer, NULL, &ftrace_profile_fops);
804 pr_warning("Could not create debugfs "
805 "'function_profile_enabled' entry\n");
808 #else /* CONFIG_FUNCTION_PROFILER */
809 static void ftrace_profile_debugfs(struct dentry *d_tracer)
812 #endif /* CONFIG_FUNCTION_PROFILER */
814 /* set when tracing only a pid */
815 struct pid *ftrace_pid_trace;
816 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
818 #ifdef CONFIG_DYNAMIC_FTRACE
820 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
821 # error Dynamic ftrace depends on MCOUNT_RECORD
824 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
826 struct ftrace_func_probe {
827 struct hlist_node node;
828 struct ftrace_probe_ops *ops;
836 FTRACE_ENABLE_CALLS = (1 << 0),
837 FTRACE_DISABLE_CALLS = (1 << 1),
838 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
839 FTRACE_ENABLE_MCOUNT = (1 << 3),
840 FTRACE_DISABLE_MCOUNT = (1 << 4),
841 FTRACE_START_FUNC_RET = (1 << 5),
842 FTRACE_STOP_FUNC_RET = (1 << 6),
845 static int ftrace_filtered;
847 static struct dyn_ftrace *ftrace_new_addrs;
849 static DEFINE_MUTEX(ftrace_regex_lock);
852 struct ftrace_page *next;
854 struct dyn_ftrace records[];
857 #define ENTRIES_PER_PAGE \
858 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
860 /* estimate from running different kernels */
861 #define NR_TO_INIT 10000
863 static struct ftrace_page *ftrace_pages_start;
864 static struct ftrace_page *ftrace_pages;
866 static struct dyn_ftrace *ftrace_free_records;
869 * This is a double for. Do not use 'break' to break out of the loop,
870 * you must use a goto.
872 #define do_for_each_ftrace_rec(pg, rec) \
873 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
875 for (_____i = 0; _____i < pg->index; _____i++) { \
876 rec = &pg->records[_____i];
878 #define while_for_each_ftrace_rec() \
882 #ifdef CONFIG_KPROBES
884 static int frozen_record_count;
886 static inline void freeze_record(struct dyn_ftrace *rec)
888 if (!(rec->flags & FTRACE_FL_FROZEN)) {
889 rec->flags |= FTRACE_FL_FROZEN;
890 frozen_record_count++;
894 static inline void unfreeze_record(struct dyn_ftrace *rec)
896 if (rec->flags & FTRACE_FL_FROZEN) {
897 rec->flags &= ~FTRACE_FL_FROZEN;
898 frozen_record_count--;
902 static inline int record_frozen(struct dyn_ftrace *rec)
904 return rec->flags & FTRACE_FL_FROZEN;
907 # define freeze_record(rec) ({ 0; })
908 # define unfreeze_record(rec) ({ 0; })
909 # define record_frozen(rec) ({ 0; })
910 #endif /* CONFIG_KPROBES */
912 static void ftrace_free_rec(struct dyn_ftrace *rec)
914 rec->freelist = ftrace_free_records;
915 ftrace_free_records = rec;
916 rec->flags |= FTRACE_FL_FREE;
919 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
921 struct dyn_ftrace *rec;
923 /* First check for freed records */
924 if (ftrace_free_records) {
925 rec = ftrace_free_records;
927 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
928 FTRACE_WARN_ON_ONCE(1);
929 ftrace_free_records = NULL;
933 ftrace_free_records = rec->freelist;
934 memset(rec, 0, sizeof(*rec));
938 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
939 if (!ftrace_pages->next) {
940 /* allocate another page */
942 (void *)get_zeroed_page(GFP_KERNEL);
943 if (!ftrace_pages->next)
946 ftrace_pages = ftrace_pages->next;
949 return &ftrace_pages->records[ftrace_pages->index++];
952 static struct dyn_ftrace *
953 ftrace_record_ip(unsigned long ip)
955 struct dyn_ftrace *rec;
960 rec = ftrace_alloc_dyn_node(ip);
965 rec->newlist = ftrace_new_addrs;
966 ftrace_new_addrs = rec;
971 static void print_ip_ins(const char *fmt, unsigned char *p)
975 printk(KERN_CONT "%s", fmt);
977 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
978 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
981 static void ftrace_bug(int failed, unsigned long ip)
985 FTRACE_WARN_ON_ONCE(1);
986 pr_info("ftrace faulted on modifying ");
990 FTRACE_WARN_ON_ONCE(1);
991 pr_info("ftrace failed to modify ");
993 print_ip_ins(" actual: ", (unsigned char *)ip);
994 printk(KERN_CONT "\n");
997 FTRACE_WARN_ON_ONCE(1);
998 pr_info("ftrace faulted on writing ");
1002 FTRACE_WARN_ON_ONCE(1);
1003 pr_info("ftrace faulted on unknown error ");
1010 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1012 unsigned long ftrace_addr;
1013 unsigned long ip, fl;
1015 ftrace_addr = (unsigned long)FTRACE_ADDR;
1020 * If this record is not to be traced and
1021 * it is not enabled then do nothing.
1023 * If this record is not to be traced and
1024 * it is enabled then disable it.
1027 if (rec->flags & FTRACE_FL_NOTRACE) {
1028 if (rec->flags & FTRACE_FL_ENABLED)
1029 rec->flags &= ~FTRACE_FL_ENABLED;
1033 } else if (ftrace_filtered && enable) {
1038 fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
1040 /* Record is filtered and enabled, do nothing */
1041 if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
1044 /* Record is not filtered or enabled, do nothing */
1048 /* Record is not filtered but enabled, disable it */
1049 if (fl == FTRACE_FL_ENABLED)
1050 rec->flags &= ~FTRACE_FL_ENABLED;
1052 /* Otherwise record is filtered but not enabled, enable it */
1053 rec->flags |= FTRACE_FL_ENABLED;
1055 /* Disable or not filtered */
1058 /* if record is enabled, do nothing */
1059 if (rec->flags & FTRACE_FL_ENABLED)
1062 rec->flags |= FTRACE_FL_ENABLED;
1066 /* if record is not enabled, do nothing */
1067 if (!(rec->flags & FTRACE_FL_ENABLED))
1070 rec->flags &= ~FTRACE_FL_ENABLED;
1074 if (rec->flags & FTRACE_FL_ENABLED)
1075 return ftrace_make_call(rec, ftrace_addr);
1077 return ftrace_make_nop(NULL, rec, ftrace_addr);
1080 static void ftrace_replace_code(int enable)
1082 struct dyn_ftrace *rec;
1083 struct ftrace_page *pg;
1086 do_for_each_ftrace_rec(pg, rec) {
1088 * Skip over free records, records that have
1089 * failed and not converted.
1091 if (rec->flags & FTRACE_FL_FREE ||
1092 rec->flags & FTRACE_FL_FAILED ||
1093 !(rec->flags & FTRACE_FL_CONVERTED))
1096 /* ignore updates to this record's mcount site */
1097 if (get_kprobe((void *)rec->ip)) {
1101 unfreeze_record(rec);
1104 failed = __ftrace_replace_code(rec, enable);
1106 rec->flags |= FTRACE_FL_FAILED;
1107 if ((system_state == SYSTEM_BOOTING) ||
1108 !core_kernel_text(rec->ip)) {
1109 ftrace_free_rec(rec);
1111 ftrace_bug(failed, rec->ip);
1112 /* Stop processing */
1116 } while_for_each_ftrace_rec();
1120 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1127 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1129 ftrace_bug(ret, ip);
1130 rec->flags |= FTRACE_FL_FAILED;
1137 * archs can override this function if they must do something
1138 * before the modifying code is performed.
1140 int __weak ftrace_arch_code_modify_prepare(void)
1146 * archs can override this function if they must do something
1147 * after the modifying code is performed.
1149 int __weak ftrace_arch_code_modify_post_process(void)
1154 static int __ftrace_modify_code(void *data)
1156 int *command = data;
1158 if (*command & FTRACE_ENABLE_CALLS)
1159 ftrace_replace_code(1);
1160 else if (*command & FTRACE_DISABLE_CALLS)
1161 ftrace_replace_code(0);
1163 if (*command & FTRACE_UPDATE_TRACE_FUNC)
1164 ftrace_update_ftrace_func(ftrace_trace_function);
1166 if (*command & FTRACE_START_FUNC_RET)
1167 ftrace_enable_ftrace_graph_caller();
1168 else if (*command & FTRACE_STOP_FUNC_RET)
1169 ftrace_disable_ftrace_graph_caller();
1174 static void ftrace_run_update_code(int command)
1178 ret = ftrace_arch_code_modify_prepare();
1179 FTRACE_WARN_ON(ret);
1183 stop_machine(__ftrace_modify_code, &command, NULL);
1185 ret = ftrace_arch_code_modify_post_process();
1186 FTRACE_WARN_ON(ret);
1189 static ftrace_func_t saved_ftrace_func;
1190 static int ftrace_start_up;
1192 static void ftrace_startup_enable(int command)
1194 if (saved_ftrace_func != ftrace_trace_function) {
1195 saved_ftrace_func = ftrace_trace_function;
1196 command |= FTRACE_UPDATE_TRACE_FUNC;
1199 if (!command || !ftrace_enabled)
1202 ftrace_run_update_code(command);
1205 static void ftrace_startup(int command)
1207 if (unlikely(ftrace_disabled))
1211 command |= FTRACE_ENABLE_CALLS;
1213 ftrace_startup_enable(command);
1216 static void ftrace_shutdown(int command)
1218 if (unlikely(ftrace_disabled))
1222 if (!ftrace_start_up)
1223 command |= FTRACE_DISABLE_CALLS;
1225 if (saved_ftrace_func != ftrace_trace_function) {
1226 saved_ftrace_func = ftrace_trace_function;
1227 command |= FTRACE_UPDATE_TRACE_FUNC;
1230 if (!command || !ftrace_enabled)
1233 ftrace_run_update_code(command);
1236 static void ftrace_startup_sysctl(void)
1238 int command = FTRACE_ENABLE_MCOUNT;
1240 if (unlikely(ftrace_disabled))
1243 /* Force update next time */
1244 saved_ftrace_func = NULL;
1245 /* ftrace_start_up is true if we want ftrace running */
1246 if (ftrace_start_up)
1247 command |= FTRACE_ENABLE_CALLS;
1249 ftrace_run_update_code(command);
1252 static void ftrace_shutdown_sysctl(void)
1254 int command = FTRACE_DISABLE_MCOUNT;
1256 if (unlikely(ftrace_disabled))
1259 /* ftrace_start_up is true if ftrace is running */
1260 if (ftrace_start_up)
1261 command |= FTRACE_DISABLE_CALLS;
1263 ftrace_run_update_code(command);
1266 static cycle_t ftrace_update_time;
1267 static unsigned long ftrace_update_cnt;
1268 unsigned long ftrace_update_tot_cnt;
1270 static int ftrace_update_code(struct module *mod)
1272 struct dyn_ftrace *p;
1273 cycle_t start, stop;
1275 start = ftrace_now(raw_smp_processor_id());
1276 ftrace_update_cnt = 0;
1278 while (ftrace_new_addrs) {
1280 /* If something went wrong, bail without enabling anything */
1281 if (unlikely(ftrace_disabled))
1284 p = ftrace_new_addrs;
1285 ftrace_new_addrs = p->newlist;
1288 /* convert record (i.e, patch mcount-call with NOP) */
1289 if (ftrace_code_disable(mod, p)) {
1290 p->flags |= FTRACE_FL_CONVERTED;
1291 ftrace_update_cnt++;
1296 stop = ftrace_now(raw_smp_processor_id());
1297 ftrace_update_time = stop - start;
1298 ftrace_update_tot_cnt += ftrace_update_cnt;
1303 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
1305 struct ftrace_page *pg;
1309 /* allocate a few pages */
1310 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
1311 if (!ftrace_pages_start)
1315 * Allocate a few more pages.
1317 * TODO: have some parser search vmlinux before
1318 * final linking to find all calls to ftrace.
1320 * a) know how many pages to allocate.
1322 * b) set up the table then.
1324 * The dynamic code is still necessary for
1328 pg = ftrace_pages = ftrace_pages_start;
1330 cnt = num_to_init / ENTRIES_PER_PAGE;
1331 pr_info("ftrace: allocating %ld entries in %d pages\n",
1332 num_to_init, cnt + 1);
1334 for (i = 0; i < cnt; i++) {
1335 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
1337 /* If we fail, we'll try later anyway */
1348 FTRACE_ITER_FILTER = (1 << 0),
1349 FTRACE_ITER_CONT = (1 << 1),
1350 FTRACE_ITER_NOTRACE = (1 << 2),
1351 FTRACE_ITER_FAILURES = (1 << 3),
1352 FTRACE_ITER_PRINTALL = (1 << 4),
1353 FTRACE_ITER_HASH = (1 << 5),
1356 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1358 struct ftrace_iterator {
1359 struct ftrace_page *pg;
1363 unsigned char buffer[FTRACE_BUFF_MAX+1];
1364 unsigned buffer_idx;
1369 t_hash_next(struct seq_file *m, void *v, loff_t *pos)
1371 struct ftrace_iterator *iter = m->private;
1372 struct hlist_node *hnd = v;
1373 struct hlist_head *hhd;
1375 WARN_ON(!(iter->flags & FTRACE_ITER_HASH));
1380 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
1383 hhd = &ftrace_func_hash[iter->hidx];
1385 if (hlist_empty(hhd)) {
1404 static void *t_hash_start(struct seq_file *m, loff_t *pos)
1406 struct ftrace_iterator *iter = m->private;
1409 iter->flags |= FTRACE_ITER_HASH;
1411 return t_hash_next(m, p, pos);
1414 static int t_hash_show(struct seq_file *m, void *v)
1416 struct ftrace_func_probe *rec;
1417 struct hlist_node *hnd = v;
1418 char str[KSYM_SYMBOL_LEN];
1420 rec = hlist_entry(hnd, struct ftrace_func_probe, node);
1422 if (rec->ops->print)
1423 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
1425 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1426 seq_printf(m, "%s:", str);
1428 kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
1429 seq_printf(m, "%s", str);
1432 seq_printf(m, ":%p", rec->data);
1439 t_next(struct seq_file *m, void *v, loff_t *pos)
1441 struct ftrace_iterator *iter = m->private;
1442 struct dyn_ftrace *rec = NULL;
1444 if (iter->flags & FTRACE_ITER_HASH)
1445 return t_hash_next(m, v, pos);
1449 if (iter->flags & FTRACE_ITER_PRINTALL)
1453 if (iter->idx >= iter->pg->index) {
1454 if (iter->pg->next) {
1455 iter->pg = iter->pg->next;
1462 rec = &iter->pg->records[iter->idx++];
1463 if ((rec->flags & FTRACE_FL_FREE) ||
1465 (!(iter->flags & FTRACE_ITER_FAILURES) &&
1466 (rec->flags & FTRACE_FL_FAILED)) ||
1468 ((iter->flags & FTRACE_ITER_FAILURES) &&
1469 !(rec->flags & FTRACE_FL_FAILED)) ||
1471 ((iter->flags & FTRACE_ITER_FILTER) &&
1472 !(rec->flags & FTRACE_FL_FILTER)) ||
1474 ((iter->flags & FTRACE_ITER_NOTRACE) &&
1475 !(rec->flags & FTRACE_FL_NOTRACE))) {
1484 static void *t_start(struct seq_file *m, loff_t *pos)
1486 struct ftrace_iterator *iter = m->private;
1489 mutex_lock(&ftrace_lock);
1491 * For set_ftrace_filter reading, if we have the filter
1492 * off, we can short cut and just print out that all
1493 * functions are enabled.
1495 if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) {
1497 return t_hash_start(m, pos);
1498 iter->flags |= FTRACE_ITER_PRINTALL;
1503 if (iter->flags & FTRACE_ITER_HASH)
1504 return t_hash_start(m, pos);
1513 p = t_next(m, p, pos);
1516 return t_hash_start(m, pos);
1521 static void t_stop(struct seq_file *m, void *p)
1523 mutex_unlock(&ftrace_lock);
1526 static int t_show(struct seq_file *m, void *v)
1528 struct ftrace_iterator *iter = m->private;
1529 struct dyn_ftrace *rec = v;
1530 char str[KSYM_SYMBOL_LEN];
1532 if (iter->flags & FTRACE_ITER_HASH)
1533 return t_hash_show(m, v);
1535 if (iter->flags & FTRACE_ITER_PRINTALL) {
1536 seq_printf(m, "#### all functions enabled ####\n");
1543 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1545 seq_printf(m, "%s\n", str);
1550 static struct seq_operations show_ftrace_seq_ops = {
1558 ftrace_avail_open(struct inode *inode, struct file *file)
1560 struct ftrace_iterator *iter;
1563 if (unlikely(ftrace_disabled))
1566 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
1570 iter->pg = ftrace_pages_start;
1572 ret = seq_open(file, &show_ftrace_seq_ops);
1574 struct seq_file *m = file->private_data;
1584 int ftrace_avail_release(struct inode *inode, struct file *file)
1586 struct seq_file *m = (struct seq_file *)file->private_data;
1587 struct ftrace_iterator *iter = m->private;
1589 seq_release(inode, file);
1596 ftrace_failures_open(struct inode *inode, struct file *file)
1600 struct ftrace_iterator *iter;
1602 ret = ftrace_avail_open(inode, file);
1604 m = (struct seq_file *)file->private_data;
1605 iter = (struct ftrace_iterator *)m->private;
1606 iter->flags = FTRACE_ITER_FAILURES;
1613 static void ftrace_filter_reset(int enable)
1615 struct ftrace_page *pg;
1616 struct dyn_ftrace *rec;
1617 unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1619 mutex_lock(&ftrace_lock);
1621 ftrace_filtered = 0;
1622 do_for_each_ftrace_rec(pg, rec) {
1623 if (rec->flags & FTRACE_FL_FAILED)
1625 rec->flags &= ~type;
1626 } while_for_each_ftrace_rec();
1627 mutex_unlock(&ftrace_lock);
1631 ftrace_regex_open(struct inode *inode, struct file *file, int enable)
1633 struct ftrace_iterator *iter;
1636 if (unlikely(ftrace_disabled))
1639 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
1643 mutex_lock(&ftrace_regex_lock);
1644 if ((file->f_mode & FMODE_WRITE) &&
1645 !(file->f_flags & O_APPEND))
1646 ftrace_filter_reset(enable);
1648 if (file->f_mode & FMODE_READ) {
1649 iter->pg = ftrace_pages_start;
1650 iter->flags = enable ? FTRACE_ITER_FILTER :
1651 FTRACE_ITER_NOTRACE;
1653 ret = seq_open(file, &show_ftrace_seq_ops);
1655 struct seq_file *m = file->private_data;
1660 file->private_data = iter;
1661 mutex_unlock(&ftrace_regex_lock);
1667 ftrace_filter_open(struct inode *inode, struct file *file)
1669 return ftrace_regex_open(inode, file, 1);
1673 ftrace_notrace_open(struct inode *inode, struct file *file)
1675 return ftrace_regex_open(inode, file, 0);
1679 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
1683 if (file->f_mode & FMODE_READ)
1684 ret = seq_lseek(file, offset, origin);
1686 file->f_pos = ret = 1;
1699 * (static function - no need for kernel doc)
1701 * Pass in a buffer containing a glob and this function will
1702 * set search to point to the search part of the buffer and
1703 * return the type of search it is (see enum above).
1704 * This does modify buff.
1706 * Returns enum type.
1707 * search returns the pointer to use for comparison.
1708 * not returns 1 if buff started with a '!'
1712 ftrace_setup_glob(char *buff, int len, char **search, int *not)
1714 int type = MATCH_FULL;
1717 if (buff[0] == '!') {
1726 for (i = 0; i < len; i++) {
1727 if (buff[i] == '*') {
1730 type = MATCH_END_ONLY;
1732 if (type == MATCH_END_ONLY)
1733 type = MATCH_MIDDLE_ONLY;
1735 type = MATCH_FRONT_ONLY;
1745 static int ftrace_match(char *str, char *regex, int len, int type)
1752 if (strcmp(str, regex) == 0)
1755 case MATCH_FRONT_ONLY:
1756 if (strncmp(str, regex, len) == 0)
1759 case MATCH_MIDDLE_ONLY:
1760 if (strstr(str, regex))
1763 case MATCH_END_ONLY:
1764 ptr = strstr(str, regex);
1765 if (ptr && (ptr[len] == 0))
1774 ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
1776 char str[KSYM_SYMBOL_LEN];
1778 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1779 return ftrace_match(str, regex, len, type);
1782 static void ftrace_match_records(char *buff, int len, int enable)
1784 unsigned int search_len;
1785 struct ftrace_page *pg;
1786 struct dyn_ftrace *rec;
1792 flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1793 type = ftrace_setup_glob(buff, len, &search, ¬);
1795 search_len = strlen(search);
1797 mutex_lock(&ftrace_lock);
1798 do_for_each_ftrace_rec(pg, rec) {
1800 if (rec->flags & FTRACE_FL_FAILED)
1803 if (ftrace_match_record(rec, search, search_len, type)) {
1805 rec->flags &= ~flag;
1810 * Only enable filtering if we have a function that
1813 if (enable && (rec->flags & FTRACE_FL_FILTER))
1814 ftrace_filtered = 1;
1815 } while_for_each_ftrace_rec();
1816 mutex_unlock(&ftrace_lock);
1820 ftrace_match_module_record(struct dyn_ftrace *rec, char *mod,
1821 char *regex, int len, int type)
1823 char str[KSYM_SYMBOL_LEN];
1826 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
1828 if (!modname || strcmp(modname, mod))
1831 /* blank search means to match all funcs in the mod */
1833 return ftrace_match(str, regex, len, type);
1838 static void ftrace_match_module_records(char *buff, char *mod, int enable)
1840 unsigned search_len = 0;
1841 struct ftrace_page *pg;
1842 struct dyn_ftrace *rec;
1843 int type = MATCH_FULL;
1844 char *search = buff;
1848 flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1850 /* blank or '*' mean the same */
1851 if (strcmp(buff, "*") == 0)
1854 /* handle the case of 'dont filter this module' */
1855 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
1861 type = ftrace_setup_glob(buff, strlen(buff), &search, ¬);
1862 search_len = strlen(search);
1865 mutex_lock(&ftrace_lock);
1866 do_for_each_ftrace_rec(pg, rec) {
1868 if (rec->flags & FTRACE_FL_FAILED)
1871 if (ftrace_match_module_record(rec, mod,
1872 search, search_len, type)) {
1874 rec->flags &= ~flag;
1878 if (enable && (rec->flags & FTRACE_FL_FILTER))
1879 ftrace_filtered = 1;
1881 } while_for_each_ftrace_rec();
1882 mutex_unlock(&ftrace_lock);
1886 * We register the module command as a template to show others how
1887 * to register the a command as well.
1891 ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
1896 * cmd == 'mod' because we only registered this func
1897 * for the 'mod' ftrace_func_command.
1898 * But if you register one func with multiple commands,
1899 * you can tell which command was used by the cmd
1903 /* we must have a module name */
1907 mod = strsep(¶m, ":");
1911 ftrace_match_module_records(func, mod, enable);
1915 static struct ftrace_func_command ftrace_mod_cmd = {
1917 .func = ftrace_mod_callback,
1920 static int __init ftrace_mod_cmd_init(void)
1922 return register_ftrace_command(&ftrace_mod_cmd);
1924 device_initcall(ftrace_mod_cmd_init);
1927 function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
1929 struct ftrace_func_probe *entry;
1930 struct hlist_head *hhd;
1931 struct hlist_node *n;
1935 key = hash_long(ip, FTRACE_HASH_BITS);
1937 hhd = &ftrace_func_hash[key];
1939 if (hlist_empty(hhd))
1943 * Disable preemption for these calls to prevent a RCU grace
1944 * period. This syncs the hash iteration and freeing of items
1945 * on the hash. rcu_read_lock is too dangerous here.
1947 resched = ftrace_preempt_disable();
1948 hlist_for_each_entry_rcu(entry, n, hhd, node) {
1949 if (entry->ip == ip)
1950 entry->ops->func(ip, parent_ip, &entry->data);
1952 ftrace_preempt_enable(resched);
1955 static struct ftrace_ops trace_probe_ops __read_mostly =
1957 .func = function_trace_probe_call,
1960 static int ftrace_probe_registered;
1962 static void __enable_ftrace_function_probe(void)
1966 if (ftrace_probe_registered)
1969 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1970 struct hlist_head *hhd = &ftrace_func_hash[i];
1974 /* Nothing registered? */
1975 if (i == FTRACE_FUNC_HASHSIZE)
1978 __register_ftrace_function(&trace_probe_ops);
1980 ftrace_probe_registered = 1;
1983 static void __disable_ftrace_function_probe(void)
1987 if (!ftrace_probe_registered)
1990 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1991 struct hlist_head *hhd = &ftrace_func_hash[i];
1996 /* no more funcs left */
1997 __unregister_ftrace_function(&trace_probe_ops);
1999 ftrace_probe_registered = 0;
2003 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2005 struct ftrace_func_probe *entry =
2006 container_of(rhp, struct ftrace_func_probe, rcu);
2008 if (entry->ops->free)
2009 entry->ops->free(&entry->data);
2015 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2018 struct ftrace_func_probe *entry;
2019 struct ftrace_page *pg;
2020 struct dyn_ftrace *rec;
2026 type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
2027 len = strlen(search);
2029 /* we do not support '!' for function probes */
2033 mutex_lock(&ftrace_lock);
2034 do_for_each_ftrace_rec(pg, rec) {
2036 if (rec->flags & FTRACE_FL_FAILED)
2039 if (!ftrace_match_record(rec, search, len, type))
2042 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2044 /* If we did not process any, then return error */
2055 * The caller might want to do something special
2056 * for each function we find. We call the callback
2057 * to give the caller an opportunity to do so.
2059 if (ops->callback) {
2060 if (ops->callback(rec->ip, &entry->data) < 0) {
2061 /* caller does not like this func */
2068 entry->ip = rec->ip;
2070 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2071 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2073 } while_for_each_ftrace_rec();
2074 __enable_ftrace_function_probe();
2077 mutex_unlock(&ftrace_lock);
2083 PROBE_TEST_FUNC = 1,
2088 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2089 void *data, int flags)
2091 struct ftrace_func_probe *entry;
2092 struct hlist_node *n, *tmp;
2093 char str[KSYM_SYMBOL_LEN];
2094 int type = MATCH_FULL;
2098 if (glob && (strcmp(glob, "*") || !strlen(glob)))
2103 type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
2104 len = strlen(search);
2106 /* we do not support '!' for function probes */
2111 mutex_lock(&ftrace_lock);
2112 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2113 struct hlist_head *hhd = &ftrace_func_hash[i];
2115 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2117 /* break up if statements for readability */
2118 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
2121 if ((flags & PROBE_TEST_DATA) && entry->data != data)
2124 /* do this last, since it is the most expensive */
2126 kallsyms_lookup(entry->ip, NULL, NULL,
2128 if (!ftrace_match(str, glob, len, type))
2132 hlist_del(&entry->node);
2133 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2136 __disable_ftrace_function_probe();
2137 mutex_unlock(&ftrace_lock);
2141 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2144 __unregister_ftrace_function_probe(glob, ops, data,
2145 PROBE_TEST_FUNC | PROBE_TEST_DATA);
2149 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
2151 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
2154 void unregister_ftrace_function_probe_all(char *glob)
2156 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
2159 static LIST_HEAD(ftrace_commands);
2160 static DEFINE_MUTEX(ftrace_cmd_mutex);
2162 int register_ftrace_command(struct ftrace_func_command *cmd)
2164 struct ftrace_func_command *p;
2167 mutex_lock(&ftrace_cmd_mutex);
2168 list_for_each_entry(p, &ftrace_commands, list) {
2169 if (strcmp(cmd->name, p->name) == 0) {
2174 list_add(&cmd->list, &ftrace_commands);
2176 mutex_unlock(&ftrace_cmd_mutex);
2181 int unregister_ftrace_command(struct ftrace_func_command *cmd)
2183 struct ftrace_func_command *p, *n;
2186 mutex_lock(&ftrace_cmd_mutex);
2187 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
2188 if (strcmp(cmd->name, p->name) == 0) {
2190 list_del_init(&p->list);
2195 mutex_unlock(&ftrace_cmd_mutex);
2200 static int ftrace_process_regex(char *buff, int len, int enable)
2202 char *func, *command, *next = buff;
2203 struct ftrace_func_command *p;
2206 func = strsep(&next, ":");
2209 ftrace_match_records(func, len, enable);
2215 command = strsep(&next, ":");
2217 mutex_lock(&ftrace_cmd_mutex);
2218 list_for_each_entry(p, &ftrace_commands, list) {
2219 if (strcmp(p->name, command) == 0) {
2220 ret = p->func(func, command, next, enable);
2225 mutex_unlock(&ftrace_cmd_mutex);
2231 ftrace_regex_write(struct file *file, const char __user *ubuf,
2232 size_t cnt, loff_t *ppos, int enable)
2234 struct ftrace_iterator *iter;
2239 if (!cnt || cnt < 0)
2242 mutex_lock(&ftrace_regex_lock);
2244 if (file->f_mode & FMODE_READ) {
2245 struct seq_file *m = file->private_data;
2248 iter = file->private_data;
2251 iter->flags &= ~FTRACE_ITER_CONT;
2252 iter->buffer_idx = 0;
2255 ret = get_user(ch, ubuf++);
2261 if (!(iter->flags & ~FTRACE_ITER_CONT)) {
2262 /* skip white space */
2263 while (cnt && isspace(ch)) {
2264 ret = get_user(ch, ubuf++);
2272 file->f_pos += read;
2277 iter->buffer_idx = 0;
2280 while (cnt && !isspace(ch)) {
2281 if (iter->buffer_idx < FTRACE_BUFF_MAX)
2282 iter->buffer[iter->buffer_idx++] = ch;
2287 ret = get_user(ch, ubuf++);
2296 iter->buffer[iter->buffer_idx] = 0;
2297 ret = ftrace_process_regex(iter->buffer,
2298 iter->buffer_idx, enable);
2301 iter->buffer_idx = 0;
2303 iter->flags |= FTRACE_ITER_CONT;
2306 file->f_pos += read;
2310 mutex_unlock(&ftrace_regex_lock);
2316 ftrace_filter_write(struct file *file, const char __user *ubuf,
2317 size_t cnt, loff_t *ppos)
2319 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
2323 ftrace_notrace_write(struct file *file, const char __user *ubuf,
2324 size_t cnt, loff_t *ppos)
2326 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
2330 ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
2332 if (unlikely(ftrace_disabled))
2335 mutex_lock(&ftrace_regex_lock);
2337 ftrace_filter_reset(enable);
2339 ftrace_match_records(buf, len, enable);
2340 mutex_unlock(&ftrace_regex_lock);
2344 * ftrace_set_filter - set a function to filter on in ftrace
2345 * @buf - the string that holds the function filter text.
2346 * @len - the length of the string.
2347 * @reset - non zero to reset all filters before applying this filter.
2349 * Filters denote which functions should be enabled when tracing is enabled.
2350 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2352 void ftrace_set_filter(unsigned char *buf, int len, int reset)
2354 ftrace_set_regex(buf, len, reset, 1);
2358 * ftrace_set_notrace - set a function to not trace in ftrace
2359 * @buf - the string that holds the function notrace text.
2360 * @len - the length of the string.
2361 * @reset - non zero to reset all filters before applying this filter.
2363 * Notrace Filters denote which functions should not be enabled when tracing
2364 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2367 void ftrace_set_notrace(unsigned char *buf, int len, int reset)
2369 ftrace_set_regex(buf, len, reset, 0);
2373 ftrace_regex_release(struct inode *inode, struct file *file, int enable)
2375 struct seq_file *m = (struct seq_file *)file->private_data;
2376 struct ftrace_iterator *iter;
2378 mutex_lock(&ftrace_regex_lock);
2379 if (file->f_mode & FMODE_READ) {
2382 seq_release(inode, file);
2384 iter = file->private_data;
2386 if (iter->buffer_idx) {
2388 iter->buffer[iter->buffer_idx] = 0;
2389 ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
2392 mutex_lock(&ftrace_lock);
2393 if (ftrace_start_up && ftrace_enabled)
2394 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
2395 mutex_unlock(&ftrace_lock);
2398 mutex_unlock(&ftrace_regex_lock);
2403 ftrace_filter_release(struct inode *inode, struct file *file)
2405 return ftrace_regex_release(inode, file, 1);
2409 ftrace_notrace_release(struct inode *inode, struct file *file)
2411 return ftrace_regex_release(inode, file, 0);
2414 static const struct file_operations ftrace_avail_fops = {
2415 .open = ftrace_avail_open,
2417 .llseek = seq_lseek,
2418 .release = ftrace_avail_release,
2421 static const struct file_operations ftrace_failures_fops = {
2422 .open = ftrace_failures_open,
2424 .llseek = seq_lseek,
2425 .release = ftrace_avail_release,
2428 static const struct file_operations ftrace_filter_fops = {
2429 .open = ftrace_filter_open,
2431 .write = ftrace_filter_write,
2432 .llseek = ftrace_regex_lseek,
2433 .release = ftrace_filter_release,
2436 static const struct file_operations ftrace_notrace_fops = {
2437 .open = ftrace_notrace_open,
2439 .write = ftrace_notrace_write,
2440 .llseek = ftrace_regex_lseek,
2441 .release = ftrace_notrace_release,
2444 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2446 static DEFINE_MUTEX(graph_lock);
2448 int ftrace_graph_count;
2449 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
2452 g_next(struct seq_file *m, void *v, loff_t *pos)
2454 unsigned long *array = m->private;
2459 if (index >= ftrace_graph_count)
2462 return &array[index];
2465 static void *g_start(struct seq_file *m, loff_t *pos)
2469 mutex_lock(&graph_lock);
2471 /* Nothing, tell g_show to print all functions are enabled */
2472 if (!ftrace_graph_count && !*pos)
2475 p = g_next(m, p, pos);
2480 static void g_stop(struct seq_file *m, void *p)
2482 mutex_unlock(&graph_lock);
2485 static int g_show(struct seq_file *m, void *v)
2487 unsigned long *ptr = v;
2488 char str[KSYM_SYMBOL_LEN];
2493 if (ptr == (unsigned long *)1) {
2494 seq_printf(m, "#### all functions enabled ####\n");
2498 kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
2500 seq_printf(m, "%s\n", str);
2505 static struct seq_operations ftrace_graph_seq_ops = {
2513 ftrace_graph_open(struct inode *inode, struct file *file)
2517 if (unlikely(ftrace_disabled))
2520 mutex_lock(&graph_lock);
2521 if ((file->f_mode & FMODE_WRITE) &&
2522 !(file->f_flags & O_APPEND)) {
2523 ftrace_graph_count = 0;
2524 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
2527 if (file->f_mode & FMODE_READ) {
2528 ret = seq_open(file, &ftrace_graph_seq_ops);
2530 struct seq_file *m = file->private_data;
2531 m->private = ftrace_graph_funcs;
2534 file->private_data = ftrace_graph_funcs;
2535 mutex_unlock(&graph_lock);
2541 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
2543 struct dyn_ftrace *rec;
2544 struct ftrace_page *pg;
2552 if (ftrace_disabled)
2556 type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬);
2560 search_len = strlen(search);
2562 mutex_lock(&ftrace_lock);
2563 do_for_each_ftrace_rec(pg, rec) {
2565 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
2568 if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
2571 if (ftrace_match_record(rec, search, search_len, type)) {
2572 /* ensure it is not already in the array */
2574 for (i = 0; i < *idx; i++)
2575 if (array[i] == rec->ip) {
2580 array[(*idx)++] = rec->ip;
2584 } while_for_each_ftrace_rec();
2586 mutex_unlock(&ftrace_lock);
2588 return found ? 0 : -EINVAL;
2592 ftrace_graph_write(struct file *file, const char __user *ubuf,
2593 size_t cnt, loff_t *ppos)
2595 unsigned char buffer[FTRACE_BUFF_MAX+1];
2596 unsigned long *array;
2602 if (!cnt || cnt < 0)
2605 mutex_lock(&graph_lock);
2607 if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
2612 if (file->f_mode & FMODE_READ) {
2613 struct seq_file *m = file->private_data;
2616 array = file->private_data;
2618 ret = get_user(ch, ubuf++);
2624 /* skip white space */
2625 while (cnt && isspace(ch)) {
2626 ret = get_user(ch, ubuf++);
2639 while (cnt && !isspace(ch)) {
2640 if (index < FTRACE_BUFF_MAX)
2641 buffer[index++] = ch;
2646 ret = get_user(ch, ubuf++);
2654 /* we allow only one expression at a time */
2655 ret = ftrace_set_func(array, &ftrace_graph_count, buffer);
2659 file->f_pos += read;
2663 mutex_unlock(&graph_lock);
2668 static const struct file_operations ftrace_graph_fops = {
2669 .open = ftrace_graph_open,
2671 .write = ftrace_graph_write,
2673 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2675 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
2678 trace_create_file("available_filter_functions", 0444,
2679 d_tracer, NULL, &ftrace_avail_fops);
2681 trace_create_file("failures", 0444,
2682 d_tracer, NULL, &ftrace_failures_fops);
2684 trace_create_file("set_ftrace_filter", 0644, d_tracer,
2685 NULL, &ftrace_filter_fops);
2687 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
2688 NULL, &ftrace_notrace_fops);
2690 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2691 trace_create_file("set_graph_function", 0444, d_tracer,
2693 &ftrace_graph_fops);
2694 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2699 static int ftrace_convert_nops(struct module *mod,
2700 unsigned long *start,
2705 unsigned long flags;
2707 mutex_lock(&ftrace_lock);
2710 addr = ftrace_call_adjust(*p++);
2712 * Some architecture linkers will pad between
2713 * the different mcount_loc sections of different
2714 * object files to satisfy alignments.
2715 * Skip any NULL pointers.
2719 ftrace_record_ip(addr);
2722 /* disable interrupts to prevent kstop machine */
2723 local_irq_save(flags);
2724 ftrace_update_code(mod);
2725 local_irq_restore(flags);
2726 mutex_unlock(&ftrace_lock);
2731 #ifdef CONFIG_MODULES
2732 void ftrace_release(void *start, void *end)
2734 struct dyn_ftrace *rec;
2735 struct ftrace_page *pg;
2736 unsigned long s = (unsigned long)start;
2737 unsigned long e = (unsigned long)end;
2739 if (ftrace_disabled || !start || start == end)
2742 mutex_lock(&ftrace_lock);
2743 do_for_each_ftrace_rec(pg, rec) {
2744 if ((rec->ip >= s) && (rec->ip < e)) {
2746 * rec->ip is changed in ftrace_free_rec()
2747 * It should not between s and e if record was freed.
2749 FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
2750 ftrace_free_rec(rec);
2752 } while_for_each_ftrace_rec();
2753 mutex_unlock(&ftrace_lock);
2756 static void ftrace_init_module(struct module *mod,
2757 unsigned long *start, unsigned long *end)
2759 if (ftrace_disabled || start == end)
2761 ftrace_convert_nops(mod, start, end);
2764 static int ftrace_module_notify(struct notifier_block *self,
2765 unsigned long val, void *data)
2767 struct module *mod = data;
2770 case MODULE_STATE_COMING:
2771 ftrace_init_module(mod, mod->ftrace_callsites,
2772 mod->ftrace_callsites +
2773 mod->num_ftrace_callsites);
2775 case MODULE_STATE_GOING:
2776 ftrace_release(mod->ftrace_callsites,
2777 mod->ftrace_callsites +
2778 mod->num_ftrace_callsites);
2785 static int ftrace_module_notify(struct notifier_block *self,
2786 unsigned long val, void *data)
2790 #endif /* CONFIG_MODULES */
2792 struct notifier_block ftrace_module_nb = {
2793 .notifier_call = ftrace_module_notify,
2797 extern unsigned long __start_mcount_loc[];
2798 extern unsigned long __stop_mcount_loc[];
2800 void __init ftrace_init(void)
2802 unsigned long count, addr, flags;
2805 /* Keep the ftrace pointer to the stub */
2806 addr = (unsigned long)ftrace_stub;
2808 local_irq_save(flags);
2809 ftrace_dyn_arch_init(&addr);
2810 local_irq_restore(flags);
2812 /* ftrace_dyn_arch_init places the return code in addr */
2816 count = __stop_mcount_loc - __start_mcount_loc;
2818 ret = ftrace_dyn_table_alloc(count);
2822 last_ftrace_enabled = ftrace_enabled = 1;
2824 ret = ftrace_convert_nops(NULL,
2828 ret = register_module_notifier(&ftrace_module_nb);
2830 pr_warning("Failed to register trace ftrace module notifier\n");
2834 ftrace_disabled = 1;
2839 static int __init ftrace_nodyn_init(void)
2844 device_initcall(ftrace_nodyn_init);
2846 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
2847 static inline void ftrace_startup_enable(int command) { }
2848 /* Keep as macros so we do not need to define the commands */
2849 # define ftrace_startup(command) do { } while (0)
2850 # define ftrace_shutdown(command) do { } while (0)
2851 # define ftrace_startup_sysctl() do { } while (0)
2852 # define ftrace_shutdown_sysctl() do { } while (0)
2853 #endif /* CONFIG_DYNAMIC_FTRACE */
2856 ftrace_pid_read(struct file *file, char __user *ubuf,
2857 size_t cnt, loff_t *ppos)
2862 if (ftrace_pid_trace == ftrace_swapper_pid)
2863 r = sprintf(buf, "swapper tasks\n");
2864 else if (ftrace_pid_trace)
2865 r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace));
2867 r = sprintf(buf, "no pid\n");
2869 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2872 static void clear_ftrace_swapper(void)
2874 struct task_struct *p;
2878 for_each_online_cpu(cpu) {
2880 clear_tsk_trace_trace(p);
2885 static void set_ftrace_swapper(void)
2887 struct task_struct *p;
2891 for_each_online_cpu(cpu) {
2893 set_tsk_trace_trace(p);
2898 static void clear_ftrace_pid(struct pid *pid)
2900 struct task_struct *p;
2903 do_each_pid_task(pid, PIDTYPE_PID, p) {
2904 clear_tsk_trace_trace(p);
2905 } while_each_pid_task(pid, PIDTYPE_PID, p);
2911 static void set_ftrace_pid(struct pid *pid)
2913 struct task_struct *p;
2916 do_each_pid_task(pid, PIDTYPE_PID, p) {
2917 set_tsk_trace_trace(p);
2918 } while_each_pid_task(pid, PIDTYPE_PID, p);
2922 static void clear_ftrace_pid_task(struct pid **pid)
2924 if (*pid == ftrace_swapper_pid)
2925 clear_ftrace_swapper();
2927 clear_ftrace_pid(*pid);
2932 static void set_ftrace_pid_task(struct pid *pid)
2934 if (pid == ftrace_swapper_pid)
2935 set_ftrace_swapper();
2937 set_ftrace_pid(pid);
2941 ftrace_pid_write(struct file *filp, const char __user *ubuf,
2942 size_t cnt, loff_t *ppos)
2949 if (cnt >= sizeof(buf))
2952 if (copy_from_user(&buf, ubuf, cnt))
2957 ret = strict_strtol(buf, 10, &val);
2961 mutex_lock(&ftrace_lock);
2963 /* disable pid tracing */
2964 if (!ftrace_pid_trace)
2967 clear_ftrace_pid_task(&ftrace_pid_trace);
2970 /* swapper task is special */
2972 pid = ftrace_swapper_pid;
2973 if (pid == ftrace_pid_trace)
2976 pid = find_get_pid(val);
2978 if (pid == ftrace_pid_trace) {
2984 if (ftrace_pid_trace)
2985 clear_ftrace_pid_task(&ftrace_pid_trace);
2990 ftrace_pid_trace = pid;
2992 set_ftrace_pid_task(ftrace_pid_trace);
2995 /* update the function call */
2996 ftrace_update_pid_func();
2997 ftrace_startup_enable(0);
3000 mutex_unlock(&ftrace_lock);
3005 static const struct file_operations ftrace_pid_fops = {
3006 .read = ftrace_pid_read,
3007 .write = ftrace_pid_write,
3010 static __init int ftrace_init_debugfs(void)
3012 struct dentry *d_tracer;
3014 d_tracer = tracing_init_dentry();
3018 ftrace_init_dyn_debugfs(d_tracer);
3020 trace_create_file("set_ftrace_pid", 0644, d_tracer,
3021 NULL, &ftrace_pid_fops);
3023 ftrace_profile_debugfs(d_tracer);
3027 fs_initcall(ftrace_init_debugfs);
3030 * ftrace_kill - kill ftrace
3032 * This function should be used by panic code. It stops ftrace
3033 * but in a not so nice way. If you need to simply kill ftrace
3034 * from a non-atomic section, use ftrace_kill.
3036 void ftrace_kill(void)
3038 ftrace_disabled = 1;
3040 clear_ftrace_function();
3044 * register_ftrace_function - register a function for profiling
3045 * @ops - ops structure that holds the function for profiling.
3047 * Register a function to be called by all functions in the
3050 * Note: @ops->func and all the functions it calls must be labeled
3051 * with "notrace", otherwise it will go into a
3054 int register_ftrace_function(struct ftrace_ops *ops)
3058 if (unlikely(ftrace_disabled))
3061 mutex_lock(&ftrace_lock);
3063 ret = __register_ftrace_function(ops);
3066 mutex_unlock(&ftrace_lock);
3071 * unregister_ftrace_function - unregister a function for profiling.
3072 * @ops - ops structure that holds the function to unregister
3074 * Unregister a function that was added to be called by ftrace profiling.
3076 int unregister_ftrace_function(struct ftrace_ops *ops)
3080 mutex_lock(&ftrace_lock);
3081 ret = __unregister_ftrace_function(ops);
3083 mutex_unlock(&ftrace_lock);
3089 ftrace_enable_sysctl(struct ctl_table *table, int write,
3090 struct file *file, void __user *buffer, size_t *lenp,
3095 if (unlikely(ftrace_disabled))
3098 mutex_lock(&ftrace_lock);
3100 ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
3102 if (ret || !write || (last_ftrace_enabled == ftrace_enabled))
3105 last_ftrace_enabled = ftrace_enabled;
3107 if (ftrace_enabled) {
3109 ftrace_startup_sysctl();
3111 /* we are starting ftrace again */
3112 if (ftrace_list != &ftrace_list_end) {
3113 if (ftrace_list->next == &ftrace_list_end)
3114 ftrace_trace_function = ftrace_list->func;
3116 ftrace_trace_function = ftrace_list_func;
3120 /* stopping ftrace calls (just send to ftrace_stub) */
3121 ftrace_trace_function = ftrace_stub;
3123 ftrace_shutdown_sysctl();
3127 mutex_unlock(&ftrace_lock);
3131 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3133 static int ftrace_graph_active;
3134 static struct notifier_block ftrace_suspend_notifier;
3136 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
3141 /* The callbacks that hook a function */
3142 trace_func_graph_ret_t ftrace_graph_return =
3143 (trace_func_graph_ret_t)ftrace_stub;
3144 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
3146 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3147 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
3151 unsigned long flags;
3152 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
3153 struct task_struct *g, *t;
3155 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
3156 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
3157 * sizeof(struct ftrace_ret_stack),
3159 if (!ret_stack_list[i]) {
3167 read_lock_irqsave(&tasklist_lock, flags);
3168 do_each_thread(g, t) {
3174 if (t->ret_stack == NULL) {
3175 t->curr_ret_stack = -1;
3176 /* Make sure IRQs see the -1 first: */
3178 t->ret_stack = ret_stack_list[start++];
3179 atomic_set(&t->tracing_graph_pause, 0);
3180 atomic_set(&t->trace_overrun, 0);
3182 } while_each_thread(g, t);
3185 read_unlock_irqrestore(&tasklist_lock, flags);
3187 for (i = start; i < end; i++)
3188 kfree(ret_stack_list[i]);
3193 ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev,
3194 struct task_struct *next)
3196 unsigned long long timestamp;
3200 * Does the user want to count the time a function was asleep.
3201 * If so, do not update the time stamps.
3203 if (trace_flags & TRACE_ITER_SLEEP_TIME)
3206 timestamp = trace_clock_local();
3208 prev->ftrace_timestamp = timestamp;
3210 /* only process tasks that we timestamped */
3211 if (!next->ftrace_timestamp)
3215 * Update all the counters in next to make up for the
3216 * time next was sleeping.
3218 timestamp -= next->ftrace_timestamp;
3220 for (index = next->curr_ret_stack; index >= 0; index--)
3221 next->ret_stack[index].calltime += timestamp;
3224 /* Allocate a return stack for each task */
3225 static int start_graph_tracing(void)
3227 struct ftrace_ret_stack **ret_stack_list;
3230 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
3231 sizeof(struct ftrace_ret_stack *),
3234 if (!ret_stack_list)
3237 /* The cpu_boot init_task->ret_stack will never be freed */
3238 for_each_online_cpu(cpu)
3239 ftrace_graph_init_task(idle_task(cpu));
3242 ret = alloc_retstack_tasklist(ret_stack_list);
3243 } while (ret == -EAGAIN);
3246 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch);
3248 pr_info("ftrace_graph: Couldn't activate tracepoint"
3249 " probe to kernel_sched_switch\n");
3252 kfree(ret_stack_list);
3257 * Hibernation protection.
3258 * The state of the current task is too much unstable during
3259 * suspend/restore to disk. We want to protect against that.
3262 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
3266 case PM_HIBERNATION_PREPARE:
3267 pause_graph_tracing();
3270 case PM_POST_HIBERNATION:
3271 unpause_graph_tracing();
3277 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
3278 trace_func_graph_ent_t entryfunc)
3282 mutex_lock(&ftrace_lock);
3284 /* we currently allow only one tracer registered at a time */
3285 if (ftrace_graph_active) {
3290 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
3291 register_pm_notifier(&ftrace_suspend_notifier);
3293 ftrace_graph_active++;
3294 ret = start_graph_tracing();
3296 ftrace_graph_active--;
3300 ftrace_graph_return = retfunc;
3301 ftrace_graph_entry = entryfunc;
3303 ftrace_startup(FTRACE_START_FUNC_RET);
3306 mutex_unlock(&ftrace_lock);
3310 void unregister_ftrace_graph(void)
3312 mutex_lock(&ftrace_lock);
3314 if (unlikely(!ftrace_graph_active))
3317 ftrace_graph_active--;
3318 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
3319 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
3320 ftrace_graph_entry = ftrace_graph_entry_stub;
3321 ftrace_shutdown(FTRACE_STOP_FUNC_RET);
3322 unregister_pm_notifier(&ftrace_suspend_notifier);
3325 mutex_unlock(&ftrace_lock);
3328 /* Allocate a return stack for newly created task */
3329 void ftrace_graph_init_task(struct task_struct *t)
3331 if (ftrace_graph_active) {
3332 t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
3333 * sizeof(struct ftrace_ret_stack),
3337 t->curr_ret_stack = -1;
3338 atomic_set(&t->tracing_graph_pause, 0);
3339 atomic_set(&t->trace_overrun, 0);
3340 t->ftrace_timestamp = 0;
3342 t->ret_stack = NULL;
3345 void ftrace_graph_exit_task(struct task_struct *t)
3347 struct ftrace_ret_stack *ret_stack = t->ret_stack;
3349 t->ret_stack = NULL;
3350 /* NULL must become visible to IRQs before we free it: */
3356 void ftrace_graph_stop(void)