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>
35 #include <asm/setup.h>
37 #include "trace_output.h"
38 #include "trace_stat.h"
40 #define FTRACE_WARN_ON(cond) \
46 #define FTRACE_WARN_ON_ONCE(cond) \
48 if (WARN_ON_ONCE(cond)) \
52 /* hash bits for specific function selection */
53 #define FTRACE_HASH_BITS 7
54 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
56 /* ftrace_enabled is a method to turn ftrace on or off */
57 int ftrace_enabled __read_mostly;
58 static int last_ftrace_enabled;
60 /* Quick disabling of function tracer. */
61 int function_trace_stop;
64 * ftrace_disabled is set when an anomaly is discovered.
65 * ftrace_disabled is much stronger than ftrace_enabled.
67 static int ftrace_disabled __read_mostly;
69 static DEFINE_MUTEX(ftrace_lock);
71 static struct ftrace_ops ftrace_list_end __read_mostly =
76 static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
77 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
78 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
79 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
81 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
83 struct ftrace_ops *op = ftrace_list;
85 /* in case someone actually ports this to alpha! */
86 read_barrier_depends();
88 while (op != &ftrace_list_end) {
90 read_barrier_depends();
91 op->func(ip, parent_ip);
96 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
98 if (!test_tsk_trace_trace(current))
101 ftrace_pid_function(ip, parent_ip);
104 static void set_ftrace_pid_function(ftrace_func_t func)
106 /* do not set ftrace_pid_function to itself! */
107 if (func != ftrace_pid_func)
108 ftrace_pid_function = func;
112 * clear_ftrace_function - reset the ftrace function
114 * This NULLs the ftrace function and in essence stops
115 * tracing. There may be lag
117 void clear_ftrace_function(void)
119 ftrace_trace_function = ftrace_stub;
120 __ftrace_trace_function = ftrace_stub;
121 ftrace_pid_function = ftrace_stub;
124 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
126 * For those archs that do not test ftrace_trace_stop in their
127 * mcount call site, we need to do it from C.
129 static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
131 if (function_trace_stop)
134 __ftrace_trace_function(ip, parent_ip);
138 static int __register_ftrace_function(struct ftrace_ops *ops)
140 ops->next = ftrace_list;
142 * We are entering ops into the ftrace_list but another
143 * CPU might be walking that list. We need to make sure
144 * the ops->next pointer is valid before another CPU sees
145 * the ops pointer included into the ftrace_list.
150 if (ftrace_enabled) {
153 if (ops->next == &ftrace_list_end)
156 func = ftrace_list_func;
158 if (ftrace_pid_trace) {
159 set_ftrace_pid_function(func);
160 func = ftrace_pid_func;
164 * For one func, simply call it directly.
165 * For more than one func, call the chain.
167 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
168 ftrace_trace_function = func;
170 __ftrace_trace_function = func;
171 ftrace_trace_function = ftrace_test_stop_func;
178 static int __unregister_ftrace_function(struct ftrace_ops *ops)
180 struct ftrace_ops **p;
183 * If we are removing the last function, then simply point
184 * to the ftrace_stub.
186 if (ftrace_list == ops && ops->next == &ftrace_list_end) {
187 ftrace_trace_function = ftrace_stub;
188 ftrace_list = &ftrace_list_end;
192 for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
201 if (ftrace_enabled) {
202 /* If we only have one func left, then call that directly */
203 if (ftrace_list->next == &ftrace_list_end) {
204 ftrace_func_t func = ftrace_list->func;
206 if (ftrace_pid_trace) {
207 set_ftrace_pid_function(func);
208 func = ftrace_pid_func;
210 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
211 ftrace_trace_function = func;
213 __ftrace_trace_function = func;
221 static void ftrace_update_pid_func(void)
225 if (ftrace_trace_function == ftrace_stub)
228 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
229 func = ftrace_trace_function;
231 func = __ftrace_trace_function;
234 if (ftrace_pid_trace) {
235 set_ftrace_pid_function(func);
236 func = ftrace_pid_func;
238 if (func == ftrace_pid_func)
239 func = ftrace_pid_function;
242 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
243 ftrace_trace_function = func;
245 __ftrace_trace_function = func;
249 #ifdef CONFIG_FUNCTION_PROFILER
250 struct ftrace_profile {
251 struct hlist_node node;
253 unsigned long counter;
254 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
255 unsigned long long time;
259 struct ftrace_profile_page {
260 struct ftrace_profile_page *next;
262 struct ftrace_profile records[];
265 struct ftrace_profile_stat {
267 struct hlist_head *hash;
268 struct ftrace_profile_page *pages;
269 struct ftrace_profile_page *start;
270 struct tracer_stat stat;
273 #define PROFILE_RECORDS_SIZE \
274 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
276 #define PROFILES_PER_PAGE \
277 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
279 static int ftrace_profile_bits __read_mostly;
280 static int ftrace_profile_enabled __read_mostly;
282 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
283 static DEFINE_MUTEX(ftrace_profile_lock);
285 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
287 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
290 function_stat_next(void *v, int idx)
292 struct ftrace_profile *rec = v;
293 struct ftrace_profile_page *pg;
295 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
301 if ((void *)rec >= (void *)&pg->records[pg->index]) {
305 rec = &pg->records[0];
313 static void *function_stat_start(struct tracer_stat *trace)
315 struct ftrace_profile_stat *stat =
316 container_of(trace, struct ftrace_profile_stat, stat);
318 if (!stat || !stat->start)
321 return function_stat_next(&stat->start->records[0], 0);
324 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
325 /* function graph compares on total time */
326 static int function_stat_cmp(void *p1, void *p2)
328 struct ftrace_profile *a = p1;
329 struct ftrace_profile *b = p2;
331 if (a->time < b->time)
333 if (a->time > b->time)
339 /* not function graph compares against hits */
340 static int function_stat_cmp(void *p1, void *p2)
342 struct ftrace_profile *a = p1;
343 struct ftrace_profile *b = p2;
345 if (a->counter < b->counter)
347 if (a->counter > b->counter)
354 static int function_stat_headers(struct seq_file *m)
356 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
357 seq_printf(m, " Function "
362 seq_printf(m, " Function Hit\n"
368 static int function_stat_show(struct seq_file *m, void *v)
370 struct ftrace_profile *rec = v;
371 char str[KSYM_SYMBOL_LEN];
373 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
374 static struct trace_seq s;
375 unsigned long long avg;
377 mutex_lock(&ftrace_profile_lock);
379 /* we raced with function_profile_reset() */
380 if (unlikely(rec->counter == 0)) {
385 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
386 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
388 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
391 do_div(avg, rec->counter);
394 trace_print_graph_duration(rec->time, &s);
395 trace_seq_puts(&s, " ");
396 trace_print_graph_duration(avg, &s);
397 trace_print_seq(m, &s);
401 mutex_unlock(&ftrace_profile_lock);
406 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
408 struct ftrace_profile_page *pg;
410 pg = stat->pages = stat->start;
413 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
418 memset(stat->hash, 0,
419 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
422 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
424 struct ftrace_profile_page *pg;
429 /* If we already allocated, do nothing */
433 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
437 #ifdef CONFIG_DYNAMIC_FTRACE
438 functions = ftrace_update_tot_cnt;
441 * We do not know the number of functions that exist because
442 * dynamic tracing is what counts them. With past experience
443 * we have around 20K functions. That should be more than enough.
444 * It is highly unlikely we will execute every function in
450 pg = stat->start = stat->pages;
452 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
454 for (i = 0; i < pages; i++) {
455 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
466 unsigned long tmp = (unsigned long)pg;
472 free_page((unsigned long)stat->pages);
479 static int ftrace_profile_init_cpu(int cpu)
481 struct ftrace_profile_stat *stat;
484 stat = &per_cpu(ftrace_profile_stats, cpu);
487 /* If the profile is already created, simply reset it */
488 ftrace_profile_reset(stat);
493 * We are profiling all functions, but usually only a few thousand
494 * functions are hit. We'll make a hash of 1024 items.
496 size = FTRACE_PROFILE_HASH_SIZE;
498 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
503 if (!ftrace_profile_bits) {
506 for (; size; size >>= 1)
507 ftrace_profile_bits++;
510 /* Preallocate the function profiling pages */
511 if (ftrace_profile_pages_init(stat) < 0) {
520 static int ftrace_profile_init(void)
525 for_each_online_cpu(cpu) {
526 ret = ftrace_profile_init_cpu(cpu);
534 /* interrupts must be disabled */
535 static struct ftrace_profile *
536 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
538 struct ftrace_profile *rec;
539 struct hlist_head *hhd;
540 struct hlist_node *n;
543 key = hash_long(ip, ftrace_profile_bits);
544 hhd = &stat->hash[key];
546 if (hlist_empty(hhd))
549 hlist_for_each_entry_rcu(rec, n, hhd, node) {
557 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
558 struct ftrace_profile *rec)
562 key = hash_long(rec->ip, ftrace_profile_bits);
563 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
567 * The memory is already allocated, this simply finds a new record to use.
569 static struct ftrace_profile *
570 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
572 struct ftrace_profile *rec = NULL;
574 /* prevent recursion (from NMIs) */
575 if (atomic_inc_return(&stat->disabled) != 1)
579 * Try to find the function again since an NMI
580 * could have added it
582 rec = ftrace_find_profiled_func(stat, ip);
586 if (stat->pages->index == PROFILES_PER_PAGE) {
587 if (!stat->pages->next)
589 stat->pages = stat->pages->next;
592 rec = &stat->pages->records[stat->pages->index++];
594 ftrace_add_profile(stat, rec);
597 atomic_dec(&stat->disabled);
603 function_profile_call(unsigned long ip, unsigned long parent_ip)
605 struct ftrace_profile_stat *stat;
606 struct ftrace_profile *rec;
609 if (!ftrace_profile_enabled)
612 local_irq_save(flags);
614 stat = &__get_cpu_var(ftrace_profile_stats);
615 if (!stat->hash || !ftrace_profile_enabled)
618 rec = ftrace_find_profiled_func(stat, ip);
620 rec = ftrace_profile_alloc(stat, ip);
627 local_irq_restore(flags);
630 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
631 static int profile_graph_entry(struct ftrace_graph_ent *trace)
633 function_profile_call(trace->func, 0);
637 static void profile_graph_return(struct ftrace_graph_ret *trace)
639 struct ftrace_profile_stat *stat;
640 unsigned long long calltime;
641 struct ftrace_profile *rec;
644 local_irq_save(flags);
645 stat = &__get_cpu_var(ftrace_profile_stats);
646 if (!stat->hash || !ftrace_profile_enabled)
649 calltime = trace->rettime - trace->calltime;
651 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
654 index = trace->depth;
656 /* Append this call time to the parent time to subtract */
658 current->ret_stack[index - 1].subtime += calltime;
660 if (current->ret_stack[index].subtime < calltime)
661 calltime -= current->ret_stack[index].subtime;
666 rec = ftrace_find_profiled_func(stat, trace->func);
668 rec->time += calltime;
671 local_irq_restore(flags);
674 static int register_ftrace_profiler(void)
676 return register_ftrace_graph(&profile_graph_return,
677 &profile_graph_entry);
680 static void unregister_ftrace_profiler(void)
682 unregister_ftrace_graph();
685 static struct ftrace_ops ftrace_profile_ops __read_mostly =
687 .func = function_profile_call,
690 static int register_ftrace_profiler(void)
692 return register_ftrace_function(&ftrace_profile_ops);
695 static void unregister_ftrace_profiler(void)
697 unregister_ftrace_function(&ftrace_profile_ops);
699 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
702 ftrace_profile_write(struct file *filp, const char __user *ubuf,
703 size_t cnt, loff_t *ppos)
706 char buf[64]; /* big enough to hold a number */
709 if (cnt >= sizeof(buf))
712 if (copy_from_user(&buf, ubuf, cnt))
717 ret = strict_strtoul(buf, 10, &val);
723 mutex_lock(&ftrace_profile_lock);
724 if (ftrace_profile_enabled ^ val) {
726 ret = ftrace_profile_init();
732 ret = register_ftrace_profiler();
737 ftrace_profile_enabled = 1;
739 ftrace_profile_enabled = 0;
741 * unregister_ftrace_profiler calls stop_machine
742 * so this acts like an synchronize_sched.
744 unregister_ftrace_profiler();
748 mutex_unlock(&ftrace_profile_lock);
756 ftrace_profile_read(struct file *filp, char __user *ubuf,
757 size_t cnt, loff_t *ppos)
759 char buf[64]; /* big enough to hold a number */
762 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
763 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
766 static const struct file_operations ftrace_profile_fops = {
767 .open = tracing_open_generic,
768 .read = ftrace_profile_read,
769 .write = ftrace_profile_write,
772 /* used to initialize the real stat files */
773 static struct tracer_stat function_stats __initdata = {
775 .stat_start = function_stat_start,
776 .stat_next = function_stat_next,
777 .stat_cmp = function_stat_cmp,
778 .stat_headers = function_stat_headers,
779 .stat_show = function_stat_show
782 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
784 struct ftrace_profile_stat *stat;
785 struct dentry *entry;
790 for_each_possible_cpu(cpu) {
791 stat = &per_cpu(ftrace_profile_stats, cpu);
793 /* allocate enough for function name + cpu number */
794 name = kmalloc(32, GFP_KERNEL);
797 * The files created are permanent, if something happens
798 * we still do not free memory.
801 "Could not allocate stat file for cpu %d\n",
805 stat->stat = function_stats;
806 snprintf(name, 32, "function%d", cpu);
807 stat->stat.name = name;
808 ret = register_stat_tracer(&stat->stat);
811 "Could not register function stat for cpu %d\n",
818 entry = debugfs_create_file("function_profile_enabled", 0644,
819 d_tracer, NULL, &ftrace_profile_fops);
821 pr_warning("Could not create debugfs "
822 "'function_profile_enabled' entry\n");
825 #else /* CONFIG_FUNCTION_PROFILER */
826 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
829 #endif /* CONFIG_FUNCTION_PROFILER */
831 /* set when tracing only a pid */
832 struct pid *ftrace_pid_trace;
833 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
835 #ifdef CONFIG_DYNAMIC_FTRACE
837 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
838 # error Dynamic ftrace depends on MCOUNT_RECORD
841 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
843 struct ftrace_func_probe {
844 struct hlist_node node;
845 struct ftrace_probe_ops *ops;
853 FTRACE_ENABLE_CALLS = (1 << 0),
854 FTRACE_DISABLE_CALLS = (1 << 1),
855 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
856 FTRACE_ENABLE_MCOUNT = (1 << 3),
857 FTRACE_DISABLE_MCOUNT = (1 << 4),
858 FTRACE_START_FUNC_RET = (1 << 5),
859 FTRACE_STOP_FUNC_RET = (1 << 6),
862 static int ftrace_filtered;
864 static struct dyn_ftrace *ftrace_new_addrs;
866 static DEFINE_MUTEX(ftrace_regex_lock);
869 struct ftrace_page *next;
871 struct dyn_ftrace records[];
874 #define ENTRIES_PER_PAGE \
875 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
877 /* estimate from running different kernels */
878 #define NR_TO_INIT 10000
880 static struct ftrace_page *ftrace_pages_start;
881 static struct ftrace_page *ftrace_pages;
883 static struct dyn_ftrace *ftrace_free_records;
886 * This is a double for. Do not use 'break' to break out of the loop,
887 * you must use a goto.
889 #define do_for_each_ftrace_rec(pg, rec) \
890 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
892 for (_____i = 0; _____i < pg->index; _____i++) { \
893 rec = &pg->records[_____i];
895 #define while_for_each_ftrace_rec() \
899 #ifdef CONFIG_KPROBES
901 static int frozen_record_count;
903 static inline void freeze_record(struct dyn_ftrace *rec)
905 if (!(rec->flags & FTRACE_FL_FROZEN)) {
906 rec->flags |= FTRACE_FL_FROZEN;
907 frozen_record_count++;
911 static inline void unfreeze_record(struct dyn_ftrace *rec)
913 if (rec->flags & FTRACE_FL_FROZEN) {
914 rec->flags &= ~FTRACE_FL_FROZEN;
915 frozen_record_count--;
919 static inline int record_frozen(struct dyn_ftrace *rec)
921 return rec->flags & FTRACE_FL_FROZEN;
924 # define freeze_record(rec) ({ 0; })
925 # define unfreeze_record(rec) ({ 0; })
926 # define record_frozen(rec) ({ 0; })
927 #endif /* CONFIG_KPROBES */
929 static void ftrace_free_rec(struct dyn_ftrace *rec)
931 rec->freelist = ftrace_free_records;
932 ftrace_free_records = rec;
933 rec->flags |= FTRACE_FL_FREE;
936 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
938 struct dyn_ftrace *rec;
940 /* First check for freed records */
941 if (ftrace_free_records) {
942 rec = ftrace_free_records;
944 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
945 FTRACE_WARN_ON_ONCE(1);
946 ftrace_free_records = NULL;
950 ftrace_free_records = rec->freelist;
951 memset(rec, 0, sizeof(*rec));
955 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
956 if (!ftrace_pages->next) {
957 /* allocate another page */
959 (void *)get_zeroed_page(GFP_KERNEL);
960 if (!ftrace_pages->next)
963 ftrace_pages = ftrace_pages->next;
966 return &ftrace_pages->records[ftrace_pages->index++];
969 static struct dyn_ftrace *
970 ftrace_record_ip(unsigned long ip)
972 struct dyn_ftrace *rec;
977 rec = ftrace_alloc_dyn_node(ip);
982 rec->newlist = ftrace_new_addrs;
983 ftrace_new_addrs = rec;
988 static void print_ip_ins(const char *fmt, unsigned char *p)
992 printk(KERN_CONT "%s", fmt);
994 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
995 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
998 static void ftrace_bug(int failed, unsigned long ip)
1002 FTRACE_WARN_ON_ONCE(1);
1003 pr_info("ftrace faulted on modifying ");
1007 FTRACE_WARN_ON_ONCE(1);
1008 pr_info("ftrace failed to modify ");
1010 print_ip_ins(" actual: ", (unsigned char *)ip);
1011 printk(KERN_CONT "\n");
1014 FTRACE_WARN_ON_ONCE(1);
1015 pr_info("ftrace faulted on writing ");
1019 FTRACE_WARN_ON_ONCE(1);
1020 pr_info("ftrace faulted on unknown error ");
1027 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1029 unsigned long ftrace_addr;
1030 unsigned long flag = 0UL;
1032 ftrace_addr = (unsigned long)FTRACE_ADDR;
1035 * If this record is not to be traced or we want to disable it,
1038 * If we want to enable it and filtering is off, then enable it.
1040 * If we want to enable it and filtering is on, enable it only if
1043 if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) {
1044 if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER))
1045 flag = FTRACE_FL_ENABLED;
1048 /* If the state of this record hasn't changed, then do nothing */
1049 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1053 rec->flags |= FTRACE_FL_ENABLED;
1054 return ftrace_make_call(rec, ftrace_addr);
1057 rec->flags &= ~FTRACE_FL_ENABLED;
1058 return ftrace_make_nop(NULL, rec, ftrace_addr);
1061 static void ftrace_replace_code(int enable)
1063 struct dyn_ftrace *rec;
1064 struct ftrace_page *pg;
1067 do_for_each_ftrace_rec(pg, rec) {
1069 * Skip over free records, records that have
1070 * failed and not converted.
1072 if (rec->flags & FTRACE_FL_FREE ||
1073 rec->flags & FTRACE_FL_FAILED ||
1074 !(rec->flags & FTRACE_FL_CONVERTED))
1077 /* ignore updates to this record's mcount site */
1078 if (get_kprobe((void *)rec->ip)) {
1082 unfreeze_record(rec);
1085 failed = __ftrace_replace_code(rec, enable);
1087 rec->flags |= FTRACE_FL_FAILED;
1088 ftrace_bug(failed, rec->ip);
1089 /* Stop processing */
1092 } while_for_each_ftrace_rec();
1096 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1103 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1105 ftrace_bug(ret, ip);
1106 rec->flags |= FTRACE_FL_FAILED;
1113 * archs can override this function if they must do something
1114 * before the modifying code is performed.
1116 int __weak ftrace_arch_code_modify_prepare(void)
1122 * archs can override this function if they must do something
1123 * after the modifying code is performed.
1125 int __weak ftrace_arch_code_modify_post_process(void)
1130 static int __ftrace_modify_code(void *data)
1132 int *command = data;
1134 if (*command & FTRACE_ENABLE_CALLS)
1135 ftrace_replace_code(1);
1136 else if (*command & FTRACE_DISABLE_CALLS)
1137 ftrace_replace_code(0);
1139 if (*command & FTRACE_UPDATE_TRACE_FUNC)
1140 ftrace_update_ftrace_func(ftrace_trace_function);
1142 if (*command & FTRACE_START_FUNC_RET)
1143 ftrace_enable_ftrace_graph_caller();
1144 else if (*command & FTRACE_STOP_FUNC_RET)
1145 ftrace_disable_ftrace_graph_caller();
1150 static void ftrace_run_update_code(int command)
1154 ret = ftrace_arch_code_modify_prepare();
1155 FTRACE_WARN_ON(ret);
1159 stop_machine(__ftrace_modify_code, &command, NULL);
1161 ret = ftrace_arch_code_modify_post_process();
1162 FTRACE_WARN_ON(ret);
1165 static ftrace_func_t saved_ftrace_func;
1166 static int ftrace_start_up;
1168 static void ftrace_startup_enable(int command)
1170 if (saved_ftrace_func != ftrace_trace_function) {
1171 saved_ftrace_func = ftrace_trace_function;
1172 command |= FTRACE_UPDATE_TRACE_FUNC;
1175 if (!command || !ftrace_enabled)
1178 ftrace_run_update_code(command);
1181 static void ftrace_startup(int command)
1183 if (unlikely(ftrace_disabled))
1187 command |= FTRACE_ENABLE_CALLS;
1189 ftrace_startup_enable(command);
1192 static void ftrace_shutdown(int command)
1194 if (unlikely(ftrace_disabled))
1199 * Just warn in case of unbalance, no need to kill ftrace, it's not
1200 * critical but the ftrace_call callers may be never nopped again after
1201 * further ftrace uses.
1203 WARN_ON_ONCE(ftrace_start_up < 0);
1205 if (!ftrace_start_up)
1206 command |= FTRACE_DISABLE_CALLS;
1208 if (saved_ftrace_func != ftrace_trace_function) {
1209 saved_ftrace_func = ftrace_trace_function;
1210 command |= FTRACE_UPDATE_TRACE_FUNC;
1213 if (!command || !ftrace_enabled)
1216 ftrace_run_update_code(command);
1219 static void ftrace_startup_sysctl(void)
1221 int command = FTRACE_ENABLE_MCOUNT;
1223 if (unlikely(ftrace_disabled))
1226 /* Force update next time */
1227 saved_ftrace_func = NULL;
1228 /* ftrace_start_up is true if we want ftrace running */
1229 if (ftrace_start_up)
1230 command |= FTRACE_ENABLE_CALLS;
1232 ftrace_run_update_code(command);
1235 static void ftrace_shutdown_sysctl(void)
1237 int command = FTRACE_DISABLE_MCOUNT;
1239 if (unlikely(ftrace_disabled))
1242 /* ftrace_start_up is true if ftrace is running */
1243 if (ftrace_start_up)
1244 command |= FTRACE_DISABLE_CALLS;
1246 ftrace_run_update_code(command);
1249 static cycle_t ftrace_update_time;
1250 static unsigned long ftrace_update_cnt;
1251 unsigned long ftrace_update_tot_cnt;
1253 static int ftrace_update_code(struct module *mod)
1255 struct dyn_ftrace *p;
1256 cycle_t start, stop;
1258 start = ftrace_now(raw_smp_processor_id());
1259 ftrace_update_cnt = 0;
1261 while (ftrace_new_addrs) {
1263 /* If something went wrong, bail without enabling anything */
1264 if (unlikely(ftrace_disabled))
1267 p = ftrace_new_addrs;
1268 ftrace_new_addrs = p->newlist;
1271 /* convert record (i.e, patch mcount-call with NOP) */
1272 if (ftrace_code_disable(mod, p)) {
1273 p->flags |= FTRACE_FL_CONVERTED;
1274 ftrace_update_cnt++;
1279 stop = ftrace_now(raw_smp_processor_id());
1280 ftrace_update_time = stop - start;
1281 ftrace_update_tot_cnt += ftrace_update_cnt;
1286 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
1288 struct ftrace_page *pg;
1292 /* allocate a few pages */
1293 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
1294 if (!ftrace_pages_start)
1298 * Allocate a few more pages.
1300 * TODO: have some parser search vmlinux before
1301 * final linking to find all calls to ftrace.
1303 * a) know how many pages to allocate.
1305 * b) set up the table then.
1307 * The dynamic code is still necessary for
1311 pg = ftrace_pages = ftrace_pages_start;
1313 cnt = num_to_init / ENTRIES_PER_PAGE;
1314 pr_info("ftrace: allocating %ld entries in %d pages\n",
1315 num_to_init, cnt + 1);
1317 for (i = 0; i < cnt; i++) {
1318 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
1320 /* If we fail, we'll try later anyway */
1331 FTRACE_ITER_FILTER = (1 << 0),
1332 FTRACE_ITER_NOTRACE = (1 << 1),
1333 FTRACE_ITER_FAILURES = (1 << 2),
1334 FTRACE_ITER_PRINTALL = (1 << 3),
1335 FTRACE_ITER_HASH = (1 << 4),
1338 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1340 struct ftrace_iterator {
1341 struct ftrace_page *pg;
1345 struct trace_parser parser;
1349 t_hash_next(struct seq_file *m, void *v, loff_t *pos)
1351 struct ftrace_iterator *iter = m->private;
1352 struct hlist_node *hnd = v;
1353 struct hlist_head *hhd;
1355 WARN_ON(!(iter->flags & FTRACE_ITER_HASH));
1360 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
1363 hhd = &ftrace_func_hash[iter->hidx];
1365 if (hlist_empty(hhd)) {
1384 static void *t_hash_start(struct seq_file *m, loff_t *pos)
1386 struct ftrace_iterator *iter = m->private;
1390 if (!(iter->flags & FTRACE_ITER_HASH))
1393 iter->flags |= FTRACE_ITER_HASH;
1396 for (l = 0; l <= *pos; ) {
1397 p = t_hash_next(m, p, &l);
1404 static int t_hash_show(struct seq_file *m, void *v)
1406 struct ftrace_func_probe *rec;
1407 struct hlist_node *hnd = v;
1409 rec = hlist_entry(hnd, struct ftrace_func_probe, node);
1411 if (rec->ops->print)
1412 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
1414 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
1417 seq_printf(m, ":%p", rec->data);
1424 t_next(struct seq_file *m, void *v, loff_t *pos)
1426 struct ftrace_iterator *iter = m->private;
1427 struct dyn_ftrace *rec = NULL;
1429 if (iter->flags & FTRACE_ITER_HASH)
1430 return t_hash_next(m, v, pos);
1434 if (iter->flags & FTRACE_ITER_PRINTALL)
1438 if (iter->idx >= iter->pg->index) {
1439 if (iter->pg->next) {
1440 iter->pg = iter->pg->next;
1445 rec = &iter->pg->records[iter->idx++];
1446 if ((rec->flags & FTRACE_FL_FREE) ||
1448 (!(iter->flags & FTRACE_ITER_FAILURES) &&
1449 (rec->flags & FTRACE_FL_FAILED)) ||
1451 ((iter->flags & FTRACE_ITER_FAILURES) &&
1452 !(rec->flags & FTRACE_FL_FAILED)) ||
1454 ((iter->flags & FTRACE_ITER_FILTER) &&
1455 !(rec->flags & FTRACE_FL_FILTER)) ||
1457 ((iter->flags & FTRACE_ITER_NOTRACE) &&
1458 !(rec->flags & FTRACE_FL_NOTRACE))) {
1467 static void *t_start(struct seq_file *m, loff_t *pos)
1469 struct ftrace_iterator *iter = m->private;
1473 mutex_lock(&ftrace_lock);
1475 * For set_ftrace_filter reading, if we have the filter
1476 * off, we can short cut and just print out that all
1477 * functions are enabled.
1479 if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) {
1481 return t_hash_start(m, pos);
1482 iter->flags |= FTRACE_ITER_PRINTALL;
1483 /* reset in case of seek/pread */
1484 iter->flags &= ~FTRACE_ITER_HASH;
1488 if (iter->flags & FTRACE_ITER_HASH)
1489 return t_hash_start(m, pos);
1491 iter->pg = ftrace_pages_start;
1493 for (l = 0; l <= *pos; ) {
1494 p = t_next(m, p, &l);
1499 if (!p && iter->flags & FTRACE_ITER_FILTER)
1500 return t_hash_start(m, pos);
1505 static void t_stop(struct seq_file *m, void *p)
1507 mutex_unlock(&ftrace_lock);
1510 static int t_show(struct seq_file *m, void *v)
1512 struct ftrace_iterator *iter = m->private;
1513 struct dyn_ftrace *rec = v;
1515 if (iter->flags & FTRACE_ITER_HASH)
1516 return t_hash_show(m, v);
1518 if (iter->flags & FTRACE_ITER_PRINTALL) {
1519 seq_printf(m, "#### all functions enabled ####\n");
1526 seq_printf(m, "%ps\n", (void *)rec->ip);
1531 static const struct seq_operations show_ftrace_seq_ops = {
1539 ftrace_avail_open(struct inode *inode, struct file *file)
1541 struct ftrace_iterator *iter;
1544 if (unlikely(ftrace_disabled))
1547 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
1551 iter->pg = ftrace_pages_start;
1553 ret = seq_open(file, &show_ftrace_seq_ops);
1555 struct seq_file *m = file->private_data;
1566 ftrace_failures_open(struct inode *inode, struct file *file)
1570 struct ftrace_iterator *iter;
1572 ret = ftrace_avail_open(inode, file);
1574 m = (struct seq_file *)file->private_data;
1575 iter = (struct ftrace_iterator *)m->private;
1576 iter->flags = FTRACE_ITER_FAILURES;
1583 static void ftrace_filter_reset(int enable)
1585 struct ftrace_page *pg;
1586 struct dyn_ftrace *rec;
1587 unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1589 mutex_lock(&ftrace_lock);
1591 ftrace_filtered = 0;
1592 do_for_each_ftrace_rec(pg, rec) {
1593 if (rec->flags & FTRACE_FL_FAILED)
1595 rec->flags &= ~type;
1596 } while_for_each_ftrace_rec();
1597 mutex_unlock(&ftrace_lock);
1601 ftrace_regex_open(struct inode *inode, struct file *file, int enable)
1603 struct ftrace_iterator *iter;
1606 if (unlikely(ftrace_disabled))
1609 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
1613 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
1618 mutex_lock(&ftrace_regex_lock);
1619 if ((file->f_mode & FMODE_WRITE) &&
1620 (file->f_flags & O_TRUNC))
1621 ftrace_filter_reset(enable);
1623 if (file->f_mode & FMODE_READ) {
1624 iter->pg = ftrace_pages_start;
1625 iter->flags = enable ? FTRACE_ITER_FILTER :
1626 FTRACE_ITER_NOTRACE;
1628 ret = seq_open(file, &show_ftrace_seq_ops);
1630 struct seq_file *m = file->private_data;
1633 trace_parser_put(&iter->parser);
1637 file->private_data = iter;
1638 mutex_unlock(&ftrace_regex_lock);
1644 ftrace_filter_open(struct inode *inode, struct file *file)
1646 return ftrace_regex_open(inode, file, 1);
1650 ftrace_notrace_open(struct inode *inode, struct file *file)
1652 return ftrace_regex_open(inode, file, 0);
1656 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
1660 if (file->f_mode & FMODE_READ)
1661 ret = seq_lseek(file, offset, origin);
1663 file->f_pos = ret = 1;
1676 * (static function - no need for kernel doc)
1678 * Pass in a buffer containing a glob and this function will
1679 * set search to point to the search part of the buffer and
1680 * return the type of search it is (see enum above).
1681 * This does modify buff.
1683 * Returns enum type.
1684 * search returns the pointer to use for comparison.
1685 * not returns 1 if buff started with a '!'
1689 ftrace_setup_glob(char *buff, int len, char **search, int *not)
1691 int type = MATCH_FULL;
1694 if (buff[0] == '!') {
1703 for (i = 0; i < len; i++) {
1704 if (buff[i] == '*') {
1707 type = MATCH_END_ONLY;
1709 if (type == MATCH_END_ONLY)
1710 type = MATCH_MIDDLE_ONLY;
1712 type = MATCH_FRONT_ONLY;
1722 static int ftrace_match(char *str, char *regex, int len, int type)
1729 if (strcmp(str, regex) == 0)
1732 case MATCH_FRONT_ONLY:
1733 if (strncmp(str, regex, len) == 0)
1736 case MATCH_MIDDLE_ONLY:
1737 if (strstr(str, regex))
1740 case MATCH_END_ONLY:
1741 ptr = strstr(str, regex);
1742 if (ptr && (ptr[len] == 0))
1751 ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
1753 char str[KSYM_SYMBOL_LEN];
1755 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1756 return ftrace_match(str, regex, len, type);
1759 static void ftrace_match_records(char *buff, int len, int enable)
1761 unsigned int search_len;
1762 struct ftrace_page *pg;
1763 struct dyn_ftrace *rec;
1769 flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1770 type = ftrace_setup_glob(buff, len, &search, ¬);
1772 search_len = strlen(search);
1774 mutex_lock(&ftrace_lock);
1775 do_for_each_ftrace_rec(pg, rec) {
1777 if (rec->flags & FTRACE_FL_FAILED)
1780 if (ftrace_match_record(rec, search, search_len, type)) {
1782 rec->flags &= ~flag;
1787 * Only enable filtering if we have a function that
1790 if (enable && (rec->flags & FTRACE_FL_FILTER))
1791 ftrace_filtered = 1;
1792 } while_for_each_ftrace_rec();
1793 mutex_unlock(&ftrace_lock);
1797 ftrace_match_module_record(struct dyn_ftrace *rec, char *mod,
1798 char *regex, int len, int type)
1800 char str[KSYM_SYMBOL_LEN];
1803 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
1805 if (!modname || strcmp(modname, mod))
1808 /* blank search means to match all funcs in the mod */
1810 return ftrace_match(str, regex, len, type);
1815 static void ftrace_match_module_records(char *buff, char *mod, int enable)
1817 unsigned search_len = 0;
1818 struct ftrace_page *pg;
1819 struct dyn_ftrace *rec;
1820 int type = MATCH_FULL;
1821 char *search = buff;
1825 flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1827 /* blank or '*' mean the same */
1828 if (strcmp(buff, "*") == 0)
1831 /* handle the case of 'dont filter this module' */
1832 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
1838 type = ftrace_setup_glob(buff, strlen(buff), &search, ¬);
1839 search_len = strlen(search);
1842 mutex_lock(&ftrace_lock);
1843 do_for_each_ftrace_rec(pg, rec) {
1845 if (rec->flags & FTRACE_FL_FAILED)
1848 if (ftrace_match_module_record(rec, mod,
1849 search, search_len, type)) {
1851 rec->flags &= ~flag;
1855 if (enable && (rec->flags & FTRACE_FL_FILTER))
1856 ftrace_filtered = 1;
1858 } while_for_each_ftrace_rec();
1859 mutex_unlock(&ftrace_lock);
1863 * We register the module command as a template to show others how
1864 * to register the a command as well.
1868 ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
1873 * cmd == 'mod' because we only registered this func
1874 * for the 'mod' ftrace_func_command.
1875 * But if you register one func with multiple commands,
1876 * you can tell which command was used by the cmd
1880 /* we must have a module name */
1884 mod = strsep(¶m, ":");
1888 ftrace_match_module_records(func, mod, enable);
1892 static struct ftrace_func_command ftrace_mod_cmd = {
1894 .func = ftrace_mod_callback,
1897 static int __init ftrace_mod_cmd_init(void)
1899 return register_ftrace_command(&ftrace_mod_cmd);
1901 device_initcall(ftrace_mod_cmd_init);
1904 function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
1906 struct ftrace_func_probe *entry;
1907 struct hlist_head *hhd;
1908 struct hlist_node *n;
1912 key = hash_long(ip, FTRACE_HASH_BITS);
1914 hhd = &ftrace_func_hash[key];
1916 if (hlist_empty(hhd))
1920 * Disable preemption for these calls to prevent a RCU grace
1921 * period. This syncs the hash iteration and freeing of items
1922 * on the hash. rcu_read_lock is too dangerous here.
1924 resched = ftrace_preempt_disable();
1925 hlist_for_each_entry_rcu(entry, n, hhd, node) {
1926 if (entry->ip == ip)
1927 entry->ops->func(ip, parent_ip, &entry->data);
1929 ftrace_preempt_enable(resched);
1932 static struct ftrace_ops trace_probe_ops __read_mostly =
1934 .func = function_trace_probe_call,
1937 static int ftrace_probe_registered;
1939 static void __enable_ftrace_function_probe(void)
1943 if (ftrace_probe_registered)
1946 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1947 struct hlist_head *hhd = &ftrace_func_hash[i];
1951 /* Nothing registered? */
1952 if (i == FTRACE_FUNC_HASHSIZE)
1955 __register_ftrace_function(&trace_probe_ops);
1957 ftrace_probe_registered = 1;
1960 static void __disable_ftrace_function_probe(void)
1964 if (!ftrace_probe_registered)
1967 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1968 struct hlist_head *hhd = &ftrace_func_hash[i];
1973 /* no more funcs left */
1974 __unregister_ftrace_function(&trace_probe_ops);
1976 ftrace_probe_registered = 0;
1980 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
1982 struct ftrace_func_probe *entry =
1983 container_of(rhp, struct ftrace_func_probe, rcu);
1985 if (entry->ops->free)
1986 entry->ops->free(&entry->data);
1992 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
1995 struct ftrace_func_probe *entry;
1996 struct ftrace_page *pg;
1997 struct dyn_ftrace *rec;
2003 type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
2004 len = strlen(search);
2006 /* we do not support '!' for function probes */
2010 mutex_lock(&ftrace_lock);
2011 do_for_each_ftrace_rec(pg, rec) {
2013 if (rec->flags & FTRACE_FL_FAILED)
2016 if (!ftrace_match_record(rec, search, len, type))
2019 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2021 /* If we did not process any, then return error */
2032 * The caller might want to do something special
2033 * for each function we find. We call the callback
2034 * to give the caller an opportunity to do so.
2036 if (ops->callback) {
2037 if (ops->callback(rec->ip, &entry->data) < 0) {
2038 /* caller does not like this func */
2045 entry->ip = rec->ip;
2047 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2048 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2050 } while_for_each_ftrace_rec();
2051 __enable_ftrace_function_probe();
2054 mutex_unlock(&ftrace_lock);
2060 PROBE_TEST_FUNC = 1,
2065 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2066 void *data, int flags)
2068 struct ftrace_func_probe *entry;
2069 struct hlist_node *n, *tmp;
2070 char str[KSYM_SYMBOL_LEN];
2071 int type = MATCH_FULL;
2075 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
2080 type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
2081 len = strlen(search);
2083 /* we do not support '!' for function probes */
2088 mutex_lock(&ftrace_lock);
2089 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2090 struct hlist_head *hhd = &ftrace_func_hash[i];
2092 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2094 /* break up if statements for readability */
2095 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
2098 if ((flags & PROBE_TEST_DATA) && entry->data != data)
2101 /* do this last, since it is the most expensive */
2103 kallsyms_lookup(entry->ip, NULL, NULL,
2105 if (!ftrace_match(str, glob, len, type))
2109 hlist_del(&entry->node);
2110 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2113 __disable_ftrace_function_probe();
2114 mutex_unlock(&ftrace_lock);
2118 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2121 __unregister_ftrace_function_probe(glob, ops, data,
2122 PROBE_TEST_FUNC | PROBE_TEST_DATA);
2126 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
2128 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
2131 void unregister_ftrace_function_probe_all(char *glob)
2133 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
2136 static LIST_HEAD(ftrace_commands);
2137 static DEFINE_MUTEX(ftrace_cmd_mutex);
2139 int register_ftrace_command(struct ftrace_func_command *cmd)
2141 struct ftrace_func_command *p;
2144 mutex_lock(&ftrace_cmd_mutex);
2145 list_for_each_entry(p, &ftrace_commands, list) {
2146 if (strcmp(cmd->name, p->name) == 0) {
2151 list_add(&cmd->list, &ftrace_commands);
2153 mutex_unlock(&ftrace_cmd_mutex);
2158 int unregister_ftrace_command(struct ftrace_func_command *cmd)
2160 struct ftrace_func_command *p, *n;
2163 mutex_lock(&ftrace_cmd_mutex);
2164 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
2165 if (strcmp(cmd->name, p->name) == 0) {
2167 list_del_init(&p->list);
2172 mutex_unlock(&ftrace_cmd_mutex);
2177 static int ftrace_process_regex(char *buff, int len, int enable)
2179 char *func, *command, *next = buff;
2180 struct ftrace_func_command *p;
2183 func = strsep(&next, ":");
2186 ftrace_match_records(func, len, enable);
2192 command = strsep(&next, ":");
2194 mutex_lock(&ftrace_cmd_mutex);
2195 list_for_each_entry(p, &ftrace_commands, list) {
2196 if (strcmp(p->name, command) == 0) {
2197 ret = p->func(func, command, next, enable);
2202 mutex_unlock(&ftrace_cmd_mutex);
2208 ftrace_regex_write(struct file *file, const char __user *ubuf,
2209 size_t cnt, loff_t *ppos, int enable)
2211 struct ftrace_iterator *iter;
2212 struct trace_parser *parser;
2218 mutex_lock(&ftrace_regex_lock);
2220 if (file->f_mode & FMODE_READ) {
2221 struct seq_file *m = file->private_data;
2224 iter = file->private_data;
2226 parser = &iter->parser;
2227 read = trace_get_user(parser, ubuf, cnt, ppos);
2229 if (read >= 0 && trace_parser_loaded(parser) &&
2230 !trace_parser_cont(parser)) {
2231 ret = ftrace_process_regex(parser->buffer,
2232 parser->idx, enable);
2236 trace_parser_clear(parser);
2241 mutex_unlock(&ftrace_regex_lock);
2247 ftrace_filter_write(struct file *file, const char __user *ubuf,
2248 size_t cnt, loff_t *ppos)
2250 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
2254 ftrace_notrace_write(struct file *file, const char __user *ubuf,
2255 size_t cnt, loff_t *ppos)
2257 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
2261 ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
2263 if (unlikely(ftrace_disabled))
2266 mutex_lock(&ftrace_regex_lock);
2268 ftrace_filter_reset(enable);
2270 ftrace_match_records(buf, len, enable);
2271 mutex_unlock(&ftrace_regex_lock);
2275 * ftrace_set_filter - set a function to filter on in ftrace
2276 * @buf - the string that holds the function filter text.
2277 * @len - the length of the string.
2278 * @reset - non zero to reset all filters before applying this filter.
2280 * Filters denote which functions should be enabled when tracing is enabled.
2281 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2283 void ftrace_set_filter(unsigned char *buf, int len, int reset)
2285 ftrace_set_regex(buf, len, reset, 1);
2289 * ftrace_set_notrace - set a function to not trace in ftrace
2290 * @buf - the string that holds the function notrace text.
2291 * @len - the length of the string.
2292 * @reset - non zero to reset all filters before applying this filter.
2294 * Notrace Filters denote which functions should not be enabled when tracing
2295 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2298 void ftrace_set_notrace(unsigned char *buf, int len, int reset)
2300 ftrace_set_regex(buf, len, reset, 0);
2304 * command line interface to allow users to set filters on boot up.
2306 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
2307 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
2308 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
2310 static int __init set_ftrace_notrace(char *str)
2312 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
2315 __setup("ftrace_notrace=", set_ftrace_notrace);
2317 static int __init set_ftrace_filter(char *str)
2319 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
2322 __setup("ftrace_filter=", set_ftrace_filter);
2324 static void __init set_ftrace_early_filter(char *buf, int enable)
2329 func = strsep(&buf, ",");
2330 ftrace_set_regex(func, strlen(func), 0, enable);
2334 static void __init set_ftrace_early_filters(void)
2336 if (ftrace_filter_buf[0])
2337 set_ftrace_early_filter(ftrace_filter_buf, 1);
2338 if (ftrace_notrace_buf[0])
2339 set_ftrace_early_filter(ftrace_notrace_buf, 0);
2343 ftrace_regex_release(struct inode *inode, struct file *file, int enable)
2345 struct seq_file *m = (struct seq_file *)file->private_data;
2346 struct ftrace_iterator *iter;
2347 struct trace_parser *parser;
2349 mutex_lock(&ftrace_regex_lock);
2350 if (file->f_mode & FMODE_READ) {
2353 seq_release(inode, file);
2355 iter = file->private_data;
2357 parser = &iter->parser;
2358 if (trace_parser_loaded(parser)) {
2359 parser->buffer[parser->idx] = 0;
2360 ftrace_match_records(parser->buffer, parser->idx, enable);
2363 mutex_lock(&ftrace_lock);
2364 if (ftrace_start_up && ftrace_enabled)
2365 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
2366 mutex_unlock(&ftrace_lock);
2368 trace_parser_put(parser);
2371 mutex_unlock(&ftrace_regex_lock);
2376 ftrace_filter_release(struct inode *inode, struct file *file)
2378 return ftrace_regex_release(inode, file, 1);
2382 ftrace_notrace_release(struct inode *inode, struct file *file)
2384 return ftrace_regex_release(inode, file, 0);
2387 static const struct file_operations ftrace_avail_fops = {
2388 .open = ftrace_avail_open,
2390 .llseek = seq_lseek,
2391 .release = seq_release_private,
2394 static const struct file_operations ftrace_failures_fops = {
2395 .open = ftrace_failures_open,
2397 .llseek = seq_lseek,
2398 .release = seq_release_private,
2401 static const struct file_operations ftrace_filter_fops = {
2402 .open = ftrace_filter_open,
2404 .write = ftrace_filter_write,
2405 .llseek = no_llseek,
2406 .release = ftrace_filter_release,
2409 static const struct file_operations ftrace_notrace_fops = {
2410 .open = ftrace_notrace_open,
2412 .write = ftrace_notrace_write,
2413 .llseek = ftrace_regex_lseek,
2414 .release = ftrace_notrace_release,
2417 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2419 static DEFINE_MUTEX(graph_lock);
2421 int ftrace_graph_count;
2422 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
2425 __g_next(struct seq_file *m, loff_t *pos)
2427 if (*pos >= ftrace_graph_count)
2429 return &ftrace_graph_funcs[*pos];
2433 g_next(struct seq_file *m, void *v, loff_t *pos)
2436 return __g_next(m, pos);
2439 static void *g_start(struct seq_file *m, loff_t *pos)
2441 mutex_lock(&graph_lock);
2443 /* Nothing, tell g_show to print all functions are enabled */
2444 if (!ftrace_graph_count && !*pos)
2447 return __g_next(m, pos);
2450 static void g_stop(struct seq_file *m, void *p)
2452 mutex_unlock(&graph_lock);
2455 static int g_show(struct seq_file *m, void *v)
2457 unsigned long *ptr = v;
2462 if (ptr == (unsigned long *)1) {
2463 seq_printf(m, "#### all functions enabled ####\n");
2467 seq_printf(m, "%ps\n", (void *)*ptr);
2472 static const struct seq_operations ftrace_graph_seq_ops = {
2480 ftrace_graph_open(struct inode *inode, struct file *file)
2484 if (unlikely(ftrace_disabled))
2487 mutex_lock(&graph_lock);
2488 if ((file->f_mode & FMODE_WRITE) &&
2489 (file->f_flags & O_TRUNC)) {
2490 ftrace_graph_count = 0;
2491 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
2493 mutex_unlock(&graph_lock);
2495 if (file->f_mode & FMODE_READ)
2496 ret = seq_open(file, &ftrace_graph_seq_ops);
2502 ftrace_graph_release(struct inode *inode, struct file *file)
2504 if (file->f_mode & FMODE_READ)
2505 seq_release(inode, file);
2510 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
2512 struct dyn_ftrace *rec;
2513 struct ftrace_page *pg;
2521 if (ftrace_disabled)
2525 type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬);
2529 search_len = strlen(search);
2531 mutex_lock(&ftrace_lock);
2532 do_for_each_ftrace_rec(pg, rec) {
2534 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
2537 if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
2540 if (ftrace_match_record(rec, search, search_len, type)) {
2541 /* ensure it is not already in the array */
2543 for (i = 0; i < *idx; i++)
2544 if (array[i] == rec->ip) {
2549 array[(*idx)++] = rec->ip;
2553 } while_for_each_ftrace_rec();
2555 mutex_unlock(&ftrace_lock);
2557 return found ? 0 : -EINVAL;
2561 ftrace_graph_write(struct file *file, const char __user *ubuf,
2562 size_t cnt, loff_t *ppos)
2564 struct trace_parser parser;
2567 if (!cnt || cnt < 0)
2570 mutex_lock(&graph_lock);
2572 if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
2577 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
2582 read = trace_get_user(&parser, ubuf, cnt, ppos);
2584 if (read >= 0 && trace_parser_loaded((&parser))) {
2585 parser.buffer[parser.idx] = 0;
2587 /* we allow only one expression at a time */
2588 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
2597 trace_parser_put(&parser);
2599 mutex_unlock(&graph_lock);
2604 static const struct file_operations ftrace_graph_fops = {
2605 .open = ftrace_graph_open,
2607 .write = ftrace_graph_write,
2608 .release = ftrace_graph_release,
2610 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2612 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
2615 trace_create_file("available_filter_functions", 0444,
2616 d_tracer, NULL, &ftrace_avail_fops);
2618 trace_create_file("failures", 0444,
2619 d_tracer, NULL, &ftrace_failures_fops);
2621 trace_create_file("set_ftrace_filter", 0644, d_tracer,
2622 NULL, &ftrace_filter_fops);
2624 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
2625 NULL, &ftrace_notrace_fops);
2627 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2628 trace_create_file("set_graph_function", 0444, d_tracer,
2630 &ftrace_graph_fops);
2631 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2636 static int ftrace_convert_nops(struct module *mod,
2637 unsigned long *start,
2642 unsigned long flags;
2644 mutex_lock(&ftrace_lock);
2647 addr = ftrace_call_adjust(*p++);
2649 * Some architecture linkers will pad between
2650 * the different mcount_loc sections of different
2651 * object files to satisfy alignments.
2652 * Skip any NULL pointers.
2656 ftrace_record_ip(addr);
2659 /* disable interrupts to prevent kstop machine */
2660 local_irq_save(flags);
2661 ftrace_update_code(mod);
2662 local_irq_restore(flags);
2663 mutex_unlock(&ftrace_lock);
2668 #ifdef CONFIG_MODULES
2669 void ftrace_release_mod(struct module *mod)
2671 struct dyn_ftrace *rec;
2672 struct ftrace_page *pg;
2674 if (ftrace_disabled)
2677 mutex_lock(&ftrace_lock);
2678 do_for_each_ftrace_rec(pg, rec) {
2679 if (within_module_core(rec->ip, mod)) {
2681 * rec->ip is changed in ftrace_free_rec()
2682 * It should not between s and e if record was freed.
2684 FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
2685 ftrace_free_rec(rec);
2687 } while_for_each_ftrace_rec();
2688 mutex_unlock(&ftrace_lock);
2691 static void ftrace_init_module(struct module *mod,
2692 unsigned long *start, unsigned long *end)
2694 if (ftrace_disabled || start == end)
2696 ftrace_convert_nops(mod, start, end);
2699 static int ftrace_module_notify(struct notifier_block *self,
2700 unsigned long val, void *data)
2702 struct module *mod = data;
2705 case MODULE_STATE_COMING:
2706 ftrace_init_module(mod, mod->ftrace_callsites,
2707 mod->ftrace_callsites +
2708 mod->num_ftrace_callsites);
2710 case MODULE_STATE_GOING:
2711 ftrace_release_mod(mod);
2718 static int ftrace_module_notify(struct notifier_block *self,
2719 unsigned long val, void *data)
2723 #endif /* CONFIG_MODULES */
2725 struct notifier_block ftrace_module_nb = {
2726 .notifier_call = ftrace_module_notify,
2730 extern unsigned long __start_mcount_loc[];
2731 extern unsigned long __stop_mcount_loc[];
2733 void __init ftrace_init(void)
2735 unsigned long count, addr, flags;
2738 /* Keep the ftrace pointer to the stub */
2739 addr = (unsigned long)ftrace_stub;
2741 local_irq_save(flags);
2742 ftrace_dyn_arch_init(&addr);
2743 local_irq_restore(flags);
2745 /* ftrace_dyn_arch_init places the return code in addr */
2749 count = __stop_mcount_loc - __start_mcount_loc;
2751 ret = ftrace_dyn_table_alloc(count);
2755 last_ftrace_enabled = ftrace_enabled = 1;
2757 ret = ftrace_convert_nops(NULL,
2761 ret = register_module_notifier(&ftrace_module_nb);
2763 pr_warning("Failed to register trace ftrace module notifier\n");
2765 set_ftrace_early_filters();
2769 ftrace_disabled = 1;
2774 static int __init ftrace_nodyn_init(void)
2779 device_initcall(ftrace_nodyn_init);
2781 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
2782 static inline void ftrace_startup_enable(int command) { }
2783 /* Keep as macros so we do not need to define the commands */
2784 # define ftrace_startup(command) do { } while (0)
2785 # define ftrace_shutdown(command) do { } while (0)
2786 # define ftrace_startup_sysctl() do { } while (0)
2787 # define ftrace_shutdown_sysctl() do { } while (0)
2788 #endif /* CONFIG_DYNAMIC_FTRACE */
2791 ftrace_pid_read(struct file *file, char __user *ubuf,
2792 size_t cnt, loff_t *ppos)
2797 if (ftrace_pid_trace == ftrace_swapper_pid)
2798 r = sprintf(buf, "swapper tasks\n");
2799 else if (ftrace_pid_trace)
2800 r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace));
2802 r = sprintf(buf, "no pid\n");
2804 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2807 static void clear_ftrace_swapper(void)
2809 struct task_struct *p;
2813 for_each_online_cpu(cpu) {
2815 clear_tsk_trace_trace(p);
2820 static void set_ftrace_swapper(void)
2822 struct task_struct *p;
2826 for_each_online_cpu(cpu) {
2828 set_tsk_trace_trace(p);
2833 static void clear_ftrace_pid(struct pid *pid)
2835 struct task_struct *p;
2838 do_each_pid_task(pid, PIDTYPE_PID, p) {
2839 clear_tsk_trace_trace(p);
2840 } while_each_pid_task(pid, PIDTYPE_PID, p);
2846 static void set_ftrace_pid(struct pid *pid)
2848 struct task_struct *p;
2851 do_each_pid_task(pid, PIDTYPE_PID, p) {
2852 set_tsk_trace_trace(p);
2853 } while_each_pid_task(pid, PIDTYPE_PID, p);
2857 static void clear_ftrace_pid_task(struct pid **pid)
2859 if (*pid == ftrace_swapper_pid)
2860 clear_ftrace_swapper();
2862 clear_ftrace_pid(*pid);
2867 static void set_ftrace_pid_task(struct pid *pid)
2869 if (pid == ftrace_swapper_pid)
2870 set_ftrace_swapper();
2872 set_ftrace_pid(pid);
2876 ftrace_pid_write(struct file *filp, const char __user *ubuf,
2877 size_t cnt, loff_t *ppos)
2884 if (cnt >= sizeof(buf))
2887 if (copy_from_user(&buf, ubuf, cnt))
2892 ret = strict_strtol(buf, 10, &val);
2896 mutex_lock(&ftrace_lock);
2898 /* disable pid tracing */
2899 if (!ftrace_pid_trace)
2902 clear_ftrace_pid_task(&ftrace_pid_trace);
2905 /* swapper task is special */
2907 pid = ftrace_swapper_pid;
2908 if (pid == ftrace_pid_trace)
2911 pid = find_get_pid(val);
2913 if (pid == ftrace_pid_trace) {
2919 if (ftrace_pid_trace)
2920 clear_ftrace_pid_task(&ftrace_pid_trace);
2925 ftrace_pid_trace = pid;
2927 set_ftrace_pid_task(ftrace_pid_trace);
2930 /* update the function call */
2931 ftrace_update_pid_func();
2932 ftrace_startup_enable(0);
2935 mutex_unlock(&ftrace_lock);
2940 static const struct file_operations ftrace_pid_fops = {
2941 .read = ftrace_pid_read,
2942 .write = ftrace_pid_write,
2945 static __init int ftrace_init_debugfs(void)
2947 struct dentry *d_tracer;
2949 d_tracer = tracing_init_dentry();
2953 ftrace_init_dyn_debugfs(d_tracer);
2955 trace_create_file("set_ftrace_pid", 0644, d_tracer,
2956 NULL, &ftrace_pid_fops);
2958 ftrace_profile_debugfs(d_tracer);
2962 fs_initcall(ftrace_init_debugfs);
2965 * ftrace_kill - kill ftrace
2967 * This function should be used by panic code. It stops ftrace
2968 * but in a not so nice way. If you need to simply kill ftrace
2969 * from a non-atomic section, use ftrace_kill.
2971 void ftrace_kill(void)
2973 ftrace_disabled = 1;
2975 clear_ftrace_function();
2979 * register_ftrace_function - register a function for profiling
2980 * @ops - ops structure that holds the function for profiling.
2982 * Register a function to be called by all functions in the
2985 * Note: @ops->func and all the functions it calls must be labeled
2986 * with "notrace", otherwise it will go into a
2989 int register_ftrace_function(struct ftrace_ops *ops)
2993 if (unlikely(ftrace_disabled))
2996 mutex_lock(&ftrace_lock);
2998 ret = __register_ftrace_function(ops);
3001 mutex_unlock(&ftrace_lock);
3006 * unregister_ftrace_function - unregister a function for profiling.
3007 * @ops - ops structure that holds the function to unregister
3009 * Unregister a function that was added to be called by ftrace profiling.
3011 int unregister_ftrace_function(struct ftrace_ops *ops)
3015 mutex_lock(&ftrace_lock);
3016 ret = __unregister_ftrace_function(ops);
3018 mutex_unlock(&ftrace_lock);
3024 ftrace_enable_sysctl(struct ctl_table *table, int write,
3025 void __user *buffer, size_t *lenp,
3030 if (unlikely(ftrace_disabled))
3033 mutex_lock(&ftrace_lock);
3035 ret = proc_dointvec(table, write, buffer, lenp, ppos);
3037 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
3040 last_ftrace_enabled = !!ftrace_enabled;
3042 if (ftrace_enabled) {
3044 ftrace_startup_sysctl();
3046 /* we are starting ftrace again */
3047 if (ftrace_list != &ftrace_list_end) {
3048 if (ftrace_list->next == &ftrace_list_end)
3049 ftrace_trace_function = ftrace_list->func;
3051 ftrace_trace_function = ftrace_list_func;
3055 /* stopping ftrace calls (just send to ftrace_stub) */
3056 ftrace_trace_function = ftrace_stub;
3058 ftrace_shutdown_sysctl();
3062 mutex_unlock(&ftrace_lock);
3066 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3068 static int ftrace_graph_active;
3069 static struct notifier_block ftrace_suspend_notifier;
3071 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
3076 /* The callbacks that hook a function */
3077 trace_func_graph_ret_t ftrace_graph_return =
3078 (trace_func_graph_ret_t)ftrace_stub;
3079 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
3081 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3082 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
3086 unsigned long flags;
3087 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
3088 struct task_struct *g, *t;
3090 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
3091 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
3092 * sizeof(struct ftrace_ret_stack),
3094 if (!ret_stack_list[i]) {
3102 read_lock_irqsave(&tasklist_lock, flags);
3103 do_each_thread(g, t) {
3109 if (t->ret_stack == NULL) {
3110 atomic_set(&t->tracing_graph_pause, 0);
3111 atomic_set(&t->trace_overrun, 0);
3112 t->curr_ret_stack = -1;
3113 /* Make sure the tasks see the -1 first: */
3115 t->ret_stack = ret_stack_list[start++];
3117 } while_each_thread(g, t);
3120 read_unlock_irqrestore(&tasklist_lock, flags);
3122 for (i = start; i < end; i++)
3123 kfree(ret_stack_list[i]);
3128 ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev,
3129 struct task_struct *next)
3131 unsigned long long timestamp;
3135 * Does the user want to count the time a function was asleep.
3136 * If so, do not update the time stamps.
3138 if (trace_flags & TRACE_ITER_SLEEP_TIME)
3141 timestamp = trace_clock_local();
3143 prev->ftrace_timestamp = timestamp;
3145 /* only process tasks that we timestamped */
3146 if (!next->ftrace_timestamp)
3150 * Update all the counters in next to make up for the
3151 * time next was sleeping.
3153 timestamp -= next->ftrace_timestamp;
3155 for (index = next->curr_ret_stack; index >= 0; index--)
3156 next->ret_stack[index].calltime += timestamp;
3159 /* Allocate a return stack for each task */
3160 static int start_graph_tracing(void)
3162 struct ftrace_ret_stack **ret_stack_list;
3165 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
3166 sizeof(struct ftrace_ret_stack *),
3169 if (!ret_stack_list)
3172 /* The cpu_boot init_task->ret_stack will never be freed */
3173 for_each_online_cpu(cpu) {
3174 if (!idle_task(cpu)->ret_stack)
3175 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
3179 ret = alloc_retstack_tasklist(ret_stack_list);
3180 } while (ret == -EAGAIN);
3183 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch);
3185 pr_info("ftrace_graph: Couldn't activate tracepoint"
3186 " probe to kernel_sched_switch\n");
3189 kfree(ret_stack_list);
3194 * Hibernation protection.
3195 * The state of the current task is too much unstable during
3196 * suspend/restore to disk. We want to protect against that.
3199 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
3203 case PM_HIBERNATION_PREPARE:
3204 pause_graph_tracing();
3207 case PM_POST_HIBERNATION:
3208 unpause_graph_tracing();
3214 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
3215 trace_func_graph_ent_t entryfunc)
3219 mutex_lock(&ftrace_lock);
3221 /* we currently allow only one tracer registered at a time */
3222 if (ftrace_graph_active) {
3227 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
3228 register_pm_notifier(&ftrace_suspend_notifier);
3230 ftrace_graph_active++;
3231 ret = start_graph_tracing();
3233 ftrace_graph_active--;
3237 ftrace_graph_return = retfunc;
3238 ftrace_graph_entry = entryfunc;
3240 ftrace_startup(FTRACE_START_FUNC_RET);
3243 mutex_unlock(&ftrace_lock);
3247 void unregister_ftrace_graph(void)
3249 mutex_lock(&ftrace_lock);
3251 if (unlikely(!ftrace_graph_active))
3254 ftrace_graph_active--;
3255 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
3256 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
3257 ftrace_graph_entry = ftrace_graph_entry_stub;
3258 ftrace_shutdown(FTRACE_STOP_FUNC_RET);
3259 unregister_pm_notifier(&ftrace_suspend_notifier);
3262 mutex_unlock(&ftrace_lock);
3265 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
3268 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
3270 atomic_set(&t->tracing_graph_pause, 0);
3271 atomic_set(&t->trace_overrun, 0);
3272 t->ftrace_timestamp = 0;
3273 /* make curr_ret_stack visable before we add the ret_stack */
3275 t->ret_stack = ret_stack;
3279 * Allocate a return stack for the idle task. May be the first
3280 * time through, or it may be done by CPU hotplug online.
3282 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
3284 t->curr_ret_stack = -1;
3286 * The idle task has no parent, it either has its own
3287 * stack or no stack at all.
3290 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
3292 if (ftrace_graph_active) {
3293 struct ftrace_ret_stack *ret_stack;
3295 ret_stack = per_cpu(idle_ret_stack, cpu);
3297 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
3298 * sizeof(struct ftrace_ret_stack),
3302 per_cpu(idle_ret_stack, cpu) = ret_stack;
3304 graph_init_task(t, ret_stack);
3308 /* Allocate a return stack for newly created task */
3309 void ftrace_graph_init_task(struct task_struct *t)
3311 /* Make sure we do not use the parent ret_stack */
3312 t->ret_stack = NULL;
3313 t->curr_ret_stack = -1;
3315 if (ftrace_graph_active) {
3316 struct ftrace_ret_stack *ret_stack;
3318 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
3319 * sizeof(struct ftrace_ret_stack),
3323 graph_init_task(t, ret_stack);
3327 void ftrace_graph_exit_task(struct task_struct *t)
3329 struct ftrace_ret_stack *ret_stack = t->ret_stack;
3331 t->ret_stack = NULL;
3332 /* NULL must become visible to IRQs before we free it: */
3338 void ftrace_graph_stop(void)