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/ftrace.h>
26 #include <linux/sysctl.h>
27 #include <linux/slab.h>
28 #include <linux/ctype.h>
29 #include <linux/list.h>
30 #include <linux/hash.h>
31 #include <linux/rcupdate.h>
33 #include <trace/events/sched.h>
35 #include <asm/setup.h>
37 #include "trace_output.h"
38 #include "trace_stat.h"
40 #define FTRACE_WARN_ON(cond) \
48 #define FTRACE_WARN_ON_ONCE(cond) \
51 if (WARN_ON_ONCE(___r)) \
56 /* hash bits for specific function selection */
57 #define FTRACE_HASH_BITS 7
58 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
59 #define FTRACE_HASH_DEFAULT_BITS 10
60 #define FTRACE_HASH_MAX_BITS 12
62 /* ftrace_enabled is a method to turn ftrace on or off */
63 int ftrace_enabled __read_mostly;
64 static int last_ftrace_enabled;
66 /* Quick disabling of function tracer. */
67 int function_trace_stop;
69 /* List for set_ftrace_pid's pids. */
70 LIST_HEAD(ftrace_pids);
72 struct list_head list;
77 * ftrace_disabled is set when an anomaly is discovered.
78 * ftrace_disabled is much stronger than ftrace_enabled.
80 static int ftrace_disabled __read_mostly;
82 static DEFINE_MUTEX(ftrace_lock);
84 static struct ftrace_ops ftrace_list_end __read_mostly = {
88 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
89 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
90 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
91 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
92 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
93 static struct ftrace_ops global_ops;
96 ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
99 * Traverse the ftrace_global_list, invoking all entries. The reason that we
100 * can use rcu_dereference_raw() is that elements removed from this list
101 * are simply leaked, so there is no need to interact with a grace-period
102 * mechanism. The rcu_dereference_raw() calls are needed to handle
103 * concurrent insertions into the ftrace_global_list.
105 * Silly Alpha and silly pointer-speculation compiler optimizations!
107 static void ftrace_global_list_func(unsigned long ip,
108 unsigned long parent_ip)
110 struct ftrace_ops *op;
112 if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
115 trace_recursion_set(TRACE_GLOBAL_BIT);
116 op = rcu_dereference_raw(ftrace_global_list); /*see above*/
117 while (op != &ftrace_list_end) {
118 op->func(ip, parent_ip);
119 op = rcu_dereference_raw(op->next); /*see above*/
121 trace_recursion_clear(TRACE_GLOBAL_BIT);
124 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
126 if (!test_tsk_trace_trace(current))
129 ftrace_pid_function(ip, parent_ip);
132 static void set_ftrace_pid_function(ftrace_func_t func)
134 /* do not set ftrace_pid_function to itself! */
135 if (func != ftrace_pid_func)
136 ftrace_pid_function = func;
140 * clear_ftrace_function - reset the ftrace function
142 * This NULLs the ftrace function and in essence stops
143 * tracing. There may be lag
145 void clear_ftrace_function(void)
147 ftrace_trace_function = ftrace_stub;
148 __ftrace_trace_function = ftrace_stub;
149 ftrace_pid_function = ftrace_stub;
152 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
154 * For those archs that do not test ftrace_trace_stop in their
155 * mcount call site, we need to do it from C.
157 static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
159 if (function_trace_stop)
162 __ftrace_trace_function(ip, parent_ip);
166 static void update_global_ops(void)
171 * If there's only one function registered, then call that
172 * function directly. Otherwise, we need to iterate over the
173 * registered callers.
175 if (ftrace_global_list == &ftrace_list_end ||
176 ftrace_global_list->next == &ftrace_list_end)
177 func = ftrace_global_list->func;
179 func = ftrace_global_list_func;
181 /* If we filter on pids, update to use the pid function */
182 if (!list_empty(&ftrace_pids)) {
183 set_ftrace_pid_function(func);
184 func = ftrace_pid_func;
187 global_ops.func = func;
190 static void update_ftrace_function(void)
197 * If we are at the end of the list and this ops is
198 * not dynamic, then have the mcount trampoline call
199 * the function directly
201 if (ftrace_ops_list == &ftrace_list_end ||
202 (ftrace_ops_list->next == &ftrace_list_end &&
203 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
204 func = ftrace_ops_list->func;
206 func = ftrace_ops_list_func;
208 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
209 ftrace_trace_function = func;
211 __ftrace_trace_function = func;
212 ftrace_trace_function = ftrace_test_stop_func;
216 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
220 * We are entering ops into the list but another
221 * CPU might be walking that list. We need to make sure
222 * the ops->next pointer is valid before another CPU sees
223 * the ops pointer included into the list.
225 rcu_assign_pointer(*list, ops);
228 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
230 struct ftrace_ops **p;
233 * If we are removing the last function, then simply point
234 * to the ftrace_stub.
236 if (*list == ops && ops->next == &ftrace_list_end) {
237 *list = &ftrace_list_end;
241 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
252 static int __register_ftrace_function(struct ftrace_ops *ops)
257 if (FTRACE_WARN_ON(ops == &global_ops))
260 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
263 if (!core_kernel_data((unsigned long)ops))
264 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
266 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
267 int first = ftrace_global_list == &ftrace_list_end;
268 add_ftrace_ops(&ftrace_global_list, ops);
269 ops->flags |= FTRACE_OPS_FL_ENABLED;
271 add_ftrace_ops(&ftrace_ops_list, &global_ops);
273 add_ftrace_ops(&ftrace_ops_list, ops);
276 update_ftrace_function();
281 static int __unregister_ftrace_function(struct ftrace_ops *ops)
288 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
291 if (FTRACE_WARN_ON(ops == &global_ops))
294 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
295 ret = remove_ftrace_ops(&ftrace_global_list, ops);
296 if (!ret && ftrace_global_list == &ftrace_list_end)
297 ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops);
299 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
301 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
307 update_ftrace_function();
310 * Dynamic ops may be freed, we must make sure that all
311 * callers are done before leaving this function.
313 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
319 static void ftrace_update_pid_func(void)
321 /* Only do something if we are tracing something */
322 if (ftrace_trace_function == ftrace_stub)
325 update_ftrace_function();
328 #ifdef CONFIG_FUNCTION_PROFILER
329 struct ftrace_profile {
330 struct hlist_node node;
332 unsigned long counter;
333 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
334 unsigned long long time;
335 unsigned long long time_squared;
339 struct ftrace_profile_page {
340 struct ftrace_profile_page *next;
342 struct ftrace_profile records[];
345 struct ftrace_profile_stat {
347 struct hlist_head *hash;
348 struct ftrace_profile_page *pages;
349 struct ftrace_profile_page *start;
350 struct tracer_stat stat;
353 #define PROFILE_RECORDS_SIZE \
354 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
356 #define PROFILES_PER_PAGE \
357 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
359 static int ftrace_profile_bits __read_mostly;
360 static int ftrace_profile_enabled __read_mostly;
362 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
363 static DEFINE_MUTEX(ftrace_profile_lock);
365 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
367 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
370 function_stat_next(void *v, int idx)
372 struct ftrace_profile *rec = v;
373 struct ftrace_profile_page *pg;
375 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
381 if ((void *)rec >= (void *)&pg->records[pg->index]) {
385 rec = &pg->records[0];
393 static void *function_stat_start(struct tracer_stat *trace)
395 struct ftrace_profile_stat *stat =
396 container_of(trace, struct ftrace_profile_stat, stat);
398 if (!stat || !stat->start)
401 return function_stat_next(&stat->start->records[0], 0);
404 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
405 /* function graph compares on total time */
406 static int function_stat_cmp(void *p1, void *p2)
408 struct ftrace_profile *a = p1;
409 struct ftrace_profile *b = p2;
411 if (a->time < b->time)
413 if (a->time > b->time)
419 /* not function graph compares against hits */
420 static int function_stat_cmp(void *p1, void *p2)
422 struct ftrace_profile *a = p1;
423 struct ftrace_profile *b = p2;
425 if (a->counter < b->counter)
427 if (a->counter > b->counter)
434 static int function_stat_headers(struct seq_file *m)
436 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
437 seq_printf(m, " Function "
440 "--- ---- --- ---\n");
442 seq_printf(m, " Function Hit\n"
448 static int function_stat_show(struct seq_file *m, void *v)
450 struct ftrace_profile *rec = v;
451 char str[KSYM_SYMBOL_LEN];
453 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
454 static struct trace_seq s;
455 unsigned long long avg;
456 unsigned long long stddev;
458 mutex_lock(&ftrace_profile_lock);
460 /* we raced with function_profile_reset() */
461 if (unlikely(rec->counter == 0)) {
466 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
467 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
469 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
472 do_div(avg, rec->counter);
474 /* Sample standard deviation (s^2) */
475 if (rec->counter <= 1)
478 stddev = rec->time_squared - rec->counter * avg * avg;
480 * Divide only 1000 for ns^2 -> us^2 conversion.
481 * trace_print_graph_duration will divide 1000 again.
483 do_div(stddev, (rec->counter - 1) * 1000);
487 trace_print_graph_duration(rec->time, &s);
488 trace_seq_puts(&s, " ");
489 trace_print_graph_duration(avg, &s);
490 trace_seq_puts(&s, " ");
491 trace_print_graph_duration(stddev, &s);
492 trace_print_seq(m, &s);
496 mutex_unlock(&ftrace_profile_lock);
501 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
503 struct ftrace_profile_page *pg;
505 pg = stat->pages = stat->start;
508 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
513 memset(stat->hash, 0,
514 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
517 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
519 struct ftrace_profile_page *pg;
524 /* If we already allocated, do nothing */
528 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
532 #ifdef CONFIG_DYNAMIC_FTRACE
533 functions = ftrace_update_tot_cnt;
536 * We do not know the number of functions that exist because
537 * dynamic tracing is what counts them. With past experience
538 * we have around 20K functions. That should be more than enough.
539 * It is highly unlikely we will execute every function in
545 pg = stat->start = stat->pages;
547 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
549 for (i = 0; i < pages; i++) {
550 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
561 unsigned long tmp = (unsigned long)pg;
567 free_page((unsigned long)stat->pages);
574 static int ftrace_profile_init_cpu(int cpu)
576 struct ftrace_profile_stat *stat;
579 stat = &per_cpu(ftrace_profile_stats, cpu);
582 /* If the profile is already created, simply reset it */
583 ftrace_profile_reset(stat);
588 * We are profiling all functions, but usually only a few thousand
589 * functions are hit. We'll make a hash of 1024 items.
591 size = FTRACE_PROFILE_HASH_SIZE;
593 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
598 if (!ftrace_profile_bits) {
601 for (; size; size >>= 1)
602 ftrace_profile_bits++;
605 /* Preallocate the function profiling pages */
606 if (ftrace_profile_pages_init(stat) < 0) {
615 static int ftrace_profile_init(void)
620 for_each_online_cpu(cpu) {
621 ret = ftrace_profile_init_cpu(cpu);
629 /* interrupts must be disabled */
630 static struct ftrace_profile *
631 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
633 struct ftrace_profile *rec;
634 struct hlist_head *hhd;
635 struct hlist_node *n;
638 key = hash_long(ip, ftrace_profile_bits);
639 hhd = &stat->hash[key];
641 if (hlist_empty(hhd))
644 hlist_for_each_entry_rcu(rec, n, hhd, node) {
652 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
653 struct ftrace_profile *rec)
657 key = hash_long(rec->ip, ftrace_profile_bits);
658 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
662 * The memory is already allocated, this simply finds a new record to use.
664 static struct ftrace_profile *
665 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
667 struct ftrace_profile *rec = NULL;
669 /* prevent recursion (from NMIs) */
670 if (atomic_inc_return(&stat->disabled) != 1)
674 * Try to find the function again since an NMI
675 * could have added it
677 rec = ftrace_find_profiled_func(stat, ip);
681 if (stat->pages->index == PROFILES_PER_PAGE) {
682 if (!stat->pages->next)
684 stat->pages = stat->pages->next;
687 rec = &stat->pages->records[stat->pages->index++];
689 ftrace_add_profile(stat, rec);
692 atomic_dec(&stat->disabled);
698 function_profile_call(unsigned long ip, unsigned long parent_ip)
700 struct ftrace_profile_stat *stat;
701 struct ftrace_profile *rec;
704 if (!ftrace_profile_enabled)
707 local_irq_save(flags);
709 stat = &__get_cpu_var(ftrace_profile_stats);
710 if (!stat->hash || !ftrace_profile_enabled)
713 rec = ftrace_find_profiled_func(stat, ip);
715 rec = ftrace_profile_alloc(stat, ip);
722 local_irq_restore(flags);
725 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
726 static int profile_graph_entry(struct ftrace_graph_ent *trace)
728 function_profile_call(trace->func, 0);
732 static void profile_graph_return(struct ftrace_graph_ret *trace)
734 struct ftrace_profile_stat *stat;
735 unsigned long long calltime;
736 struct ftrace_profile *rec;
739 local_irq_save(flags);
740 stat = &__get_cpu_var(ftrace_profile_stats);
741 if (!stat->hash || !ftrace_profile_enabled)
744 /* If the calltime was zero'd ignore it */
745 if (!trace->calltime)
748 calltime = trace->rettime - trace->calltime;
750 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
753 index = trace->depth;
755 /* Append this call time to the parent time to subtract */
757 current->ret_stack[index - 1].subtime += calltime;
759 if (current->ret_stack[index].subtime < calltime)
760 calltime -= current->ret_stack[index].subtime;
765 rec = ftrace_find_profiled_func(stat, trace->func);
767 rec->time += calltime;
768 rec->time_squared += calltime * calltime;
772 local_irq_restore(flags);
775 static int register_ftrace_profiler(void)
777 return register_ftrace_graph(&profile_graph_return,
778 &profile_graph_entry);
781 static void unregister_ftrace_profiler(void)
783 unregister_ftrace_graph();
786 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
787 .func = function_profile_call,
790 static int register_ftrace_profiler(void)
792 return register_ftrace_function(&ftrace_profile_ops);
795 static void unregister_ftrace_profiler(void)
797 unregister_ftrace_function(&ftrace_profile_ops);
799 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
802 ftrace_profile_write(struct file *filp, const char __user *ubuf,
803 size_t cnt, loff_t *ppos)
808 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
814 mutex_lock(&ftrace_profile_lock);
815 if (ftrace_profile_enabled ^ val) {
817 ret = ftrace_profile_init();
823 ret = register_ftrace_profiler();
828 ftrace_profile_enabled = 1;
830 ftrace_profile_enabled = 0;
832 * unregister_ftrace_profiler calls stop_machine
833 * so this acts like an synchronize_sched.
835 unregister_ftrace_profiler();
839 mutex_unlock(&ftrace_profile_lock);
847 ftrace_profile_read(struct file *filp, char __user *ubuf,
848 size_t cnt, loff_t *ppos)
850 char buf[64]; /* big enough to hold a number */
853 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
854 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
857 static const struct file_operations ftrace_profile_fops = {
858 .open = tracing_open_generic,
859 .read = ftrace_profile_read,
860 .write = ftrace_profile_write,
861 .llseek = default_llseek,
864 /* used to initialize the real stat files */
865 static struct tracer_stat function_stats __initdata = {
867 .stat_start = function_stat_start,
868 .stat_next = function_stat_next,
869 .stat_cmp = function_stat_cmp,
870 .stat_headers = function_stat_headers,
871 .stat_show = function_stat_show
874 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
876 struct ftrace_profile_stat *stat;
877 struct dentry *entry;
882 for_each_possible_cpu(cpu) {
883 stat = &per_cpu(ftrace_profile_stats, cpu);
885 /* allocate enough for function name + cpu number */
886 name = kmalloc(32, GFP_KERNEL);
889 * The files created are permanent, if something happens
890 * we still do not free memory.
893 "Could not allocate stat file for cpu %d\n",
897 stat->stat = function_stats;
898 snprintf(name, 32, "function%d", cpu);
899 stat->stat.name = name;
900 ret = register_stat_tracer(&stat->stat);
903 "Could not register function stat for cpu %d\n",
910 entry = debugfs_create_file("function_profile_enabled", 0644,
911 d_tracer, NULL, &ftrace_profile_fops);
913 pr_warning("Could not create debugfs "
914 "'function_profile_enabled' entry\n");
917 #else /* CONFIG_FUNCTION_PROFILER */
918 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
921 #endif /* CONFIG_FUNCTION_PROFILER */
923 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
925 #ifdef CONFIG_DYNAMIC_FTRACE
927 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
928 # error Dynamic ftrace depends on MCOUNT_RECORD
931 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
933 struct ftrace_func_probe {
934 struct hlist_node node;
935 struct ftrace_probe_ops *ops;
943 FTRACE_ENABLE_CALLS = (1 << 0),
944 FTRACE_DISABLE_CALLS = (1 << 1),
945 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
946 FTRACE_START_FUNC_RET = (1 << 3),
947 FTRACE_STOP_FUNC_RET = (1 << 4),
949 struct ftrace_func_entry {
950 struct hlist_node hlist;
955 unsigned long size_bits;
956 struct hlist_head *buckets;
962 * We make these constant because no one should touch them,
963 * but they are used as the default "empty hash", to avoid allocating
964 * it all the time. These are in a read only section such that if
965 * anyone does try to modify it, it will cause an exception.
967 static const struct hlist_head empty_buckets[1];
968 static const struct ftrace_hash empty_hash = {
969 .buckets = (struct hlist_head *)empty_buckets,
971 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
973 static struct ftrace_ops global_ops = {
975 .notrace_hash = EMPTY_HASH,
976 .filter_hash = EMPTY_HASH,
979 static struct dyn_ftrace *ftrace_new_addrs;
981 static DEFINE_MUTEX(ftrace_regex_lock);
984 struct ftrace_page *next;
986 struct dyn_ftrace records[];
989 #define ENTRIES_PER_PAGE \
990 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
992 /* estimate from running different kernels */
993 #define NR_TO_INIT 10000
995 static struct ftrace_page *ftrace_pages_start;
996 static struct ftrace_page *ftrace_pages;
998 static struct dyn_ftrace *ftrace_free_records;
1000 static struct ftrace_func_entry *
1001 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1004 struct ftrace_func_entry *entry;
1005 struct hlist_head *hhd;
1006 struct hlist_node *n;
1011 if (hash->size_bits > 0)
1012 key = hash_long(ip, hash->size_bits);
1016 hhd = &hash->buckets[key];
1018 hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1019 if (entry->ip == ip)
1025 static void __add_hash_entry(struct ftrace_hash *hash,
1026 struct ftrace_func_entry *entry)
1028 struct hlist_head *hhd;
1031 if (hash->size_bits)
1032 key = hash_long(entry->ip, hash->size_bits);
1036 hhd = &hash->buckets[key];
1037 hlist_add_head(&entry->hlist, hhd);
1041 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1043 struct ftrace_func_entry *entry;
1045 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1050 __add_hash_entry(hash, entry);
1056 free_hash_entry(struct ftrace_hash *hash,
1057 struct ftrace_func_entry *entry)
1059 hlist_del(&entry->hlist);
1065 remove_hash_entry(struct ftrace_hash *hash,
1066 struct ftrace_func_entry *entry)
1068 hlist_del(&entry->hlist);
1072 static void ftrace_hash_clear(struct ftrace_hash *hash)
1074 struct hlist_head *hhd;
1075 struct hlist_node *tp, *tn;
1076 struct ftrace_func_entry *entry;
1077 int size = 1 << hash->size_bits;
1083 for (i = 0; i < size; i++) {
1084 hhd = &hash->buckets[i];
1085 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
1086 free_hash_entry(hash, entry);
1088 FTRACE_WARN_ON(hash->count);
1091 static void free_ftrace_hash(struct ftrace_hash *hash)
1093 if (!hash || hash == EMPTY_HASH)
1095 ftrace_hash_clear(hash);
1096 kfree(hash->buckets);
1100 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1102 struct ftrace_hash *hash;
1104 hash = container_of(rcu, struct ftrace_hash, rcu);
1105 free_ftrace_hash(hash);
1108 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1110 if (!hash || hash == EMPTY_HASH)
1112 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1115 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1117 struct ftrace_hash *hash;
1120 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1124 size = 1 << size_bits;
1125 hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL);
1127 if (!hash->buckets) {
1132 hash->size_bits = size_bits;
1137 static struct ftrace_hash *
1138 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1140 struct ftrace_func_entry *entry;
1141 struct ftrace_hash *new_hash;
1142 struct hlist_node *tp;
1147 new_hash = alloc_ftrace_hash(size_bits);
1152 if (!hash || !hash->count)
1155 size = 1 << hash->size_bits;
1156 for (i = 0; i < size; i++) {
1157 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1158 ret = add_hash_entry(new_hash, entry->ip);
1164 FTRACE_WARN_ON(new_hash->count != hash->count);
1169 free_ftrace_hash(new_hash);
1174 ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
1176 struct ftrace_func_entry *entry;
1177 struct hlist_node *tp, *tn;
1178 struct hlist_head *hhd;
1179 struct ftrace_hash *old_hash;
1180 struct ftrace_hash *new_hash;
1182 int size = src->count;
1187 * If the new source is empty, just free dst and assign it
1191 free_ftrace_hash_rcu(*dst);
1192 rcu_assign_pointer(*dst, EMPTY_HASH);
1197 * Make the hash size about 1/2 the # found
1199 for (size /= 2; size; size >>= 1)
1202 /* Don't allocate too much */
1203 if (bits > FTRACE_HASH_MAX_BITS)
1204 bits = FTRACE_HASH_MAX_BITS;
1206 new_hash = alloc_ftrace_hash(bits);
1210 size = 1 << src->size_bits;
1211 for (i = 0; i < size; i++) {
1212 hhd = &src->buckets[i];
1213 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1215 key = hash_long(entry->ip, bits);
1218 remove_hash_entry(src, entry);
1219 __add_hash_entry(new_hash, entry);
1224 rcu_assign_pointer(*dst, new_hash);
1225 free_ftrace_hash_rcu(old_hash);
1231 * Test the hashes for this ops to see if we want to call
1232 * the ops->func or not.
1234 * It's a match if the ip is in the ops->filter_hash or
1235 * the filter_hash does not exist or is empty,
1237 * the ip is not in the ops->notrace_hash.
1239 * This needs to be called with preemption disabled as
1240 * the hashes are freed with call_rcu_sched().
1243 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1245 struct ftrace_hash *filter_hash;
1246 struct ftrace_hash *notrace_hash;
1249 filter_hash = rcu_dereference_raw(ops->filter_hash);
1250 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1252 if ((!filter_hash || !filter_hash->count ||
1253 ftrace_lookup_ip(filter_hash, ip)) &&
1254 (!notrace_hash || !notrace_hash->count ||
1255 !ftrace_lookup_ip(notrace_hash, ip)))
1264 * This is a double for. Do not use 'break' to break out of the loop,
1265 * you must use a goto.
1267 #define do_for_each_ftrace_rec(pg, rec) \
1268 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1270 for (_____i = 0; _____i < pg->index; _____i++) { \
1271 rec = &pg->records[_____i];
1273 #define while_for_each_ftrace_rec() \
1277 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1281 struct ftrace_hash *hash;
1282 struct ftrace_hash *other_hash;
1283 struct ftrace_page *pg;
1284 struct dyn_ftrace *rec;
1288 /* Only update if the ops has been registered */
1289 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1293 * In the filter_hash case:
1294 * If the count is zero, we update all records.
1295 * Otherwise we just update the items in the hash.
1297 * In the notrace_hash case:
1298 * We enable the update in the hash.
1299 * As disabling notrace means enabling the tracing,
1300 * and enabling notrace means disabling, the inc variable
1304 hash = ops->filter_hash;
1305 other_hash = ops->notrace_hash;
1306 if (!hash || !hash->count)
1310 hash = ops->notrace_hash;
1311 other_hash = ops->filter_hash;
1313 * If the notrace hash has no items,
1314 * then there's nothing to do.
1316 if (hash && !hash->count)
1320 do_for_each_ftrace_rec(pg, rec) {
1321 int in_other_hash = 0;
1327 * Only the filter_hash affects all records.
1328 * Update if the record is not in the notrace hash.
1330 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1333 in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip);
1334 in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip);
1339 if (filter_hash && in_hash && !in_other_hash)
1341 else if (!filter_hash && in_hash &&
1342 (in_other_hash || !other_hash->count))
1350 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1353 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1358 /* Shortcut, if we handled all records, we are done. */
1359 if (!all && count == hash->count)
1361 } while_for_each_ftrace_rec();
1364 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1367 __ftrace_hash_rec_update(ops, filter_hash, 0);
1370 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1373 __ftrace_hash_rec_update(ops, filter_hash, 1);
1376 static void ftrace_free_rec(struct dyn_ftrace *rec)
1378 rec->freelist = ftrace_free_records;
1379 ftrace_free_records = rec;
1380 rec->flags |= FTRACE_FL_FREE;
1383 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
1385 struct dyn_ftrace *rec;
1387 /* First check for freed records */
1388 if (ftrace_free_records) {
1389 rec = ftrace_free_records;
1391 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
1392 FTRACE_WARN_ON_ONCE(1);
1393 ftrace_free_records = NULL;
1397 ftrace_free_records = rec->freelist;
1398 memset(rec, 0, sizeof(*rec));
1402 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
1403 if (!ftrace_pages->next) {
1404 /* allocate another page */
1405 ftrace_pages->next =
1406 (void *)get_zeroed_page(GFP_KERNEL);
1407 if (!ftrace_pages->next)
1410 ftrace_pages = ftrace_pages->next;
1413 return &ftrace_pages->records[ftrace_pages->index++];
1416 static struct dyn_ftrace *
1417 ftrace_record_ip(unsigned long ip)
1419 struct dyn_ftrace *rec;
1421 if (ftrace_disabled)
1424 rec = ftrace_alloc_dyn_node(ip);
1429 rec->newlist = ftrace_new_addrs;
1430 ftrace_new_addrs = rec;
1435 static void print_ip_ins(const char *fmt, unsigned char *p)
1439 printk(KERN_CONT "%s", fmt);
1441 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1442 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1445 static void ftrace_bug(int failed, unsigned long ip)
1449 FTRACE_WARN_ON_ONCE(1);
1450 pr_info("ftrace faulted on modifying ");
1454 FTRACE_WARN_ON_ONCE(1);
1455 pr_info("ftrace failed to modify ");
1457 print_ip_ins(" actual: ", (unsigned char *)ip);
1458 printk(KERN_CONT "\n");
1461 FTRACE_WARN_ON_ONCE(1);
1462 pr_info("ftrace faulted on writing ");
1466 FTRACE_WARN_ON_ONCE(1);
1467 pr_info("ftrace faulted on unknown error ");
1473 /* Return 1 if the address range is reserved for ftrace */
1474 int ftrace_text_reserved(void *start, void *end)
1476 struct dyn_ftrace *rec;
1477 struct ftrace_page *pg;
1479 do_for_each_ftrace_rec(pg, rec) {
1480 if (rec->ip <= (unsigned long)end &&
1481 rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
1483 } while_for_each_ftrace_rec();
1489 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1491 unsigned long ftrace_addr;
1492 unsigned long flag = 0UL;
1494 ftrace_addr = (unsigned long)FTRACE_ADDR;
1497 * If we are enabling tracing:
1499 * If the record has a ref count, then we need to enable it
1500 * because someone is using it.
1502 * Otherwise we make sure its disabled.
1504 * If we are disabling tracing, then disable all records that
1507 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1508 flag = FTRACE_FL_ENABLED;
1510 /* If the state of this record hasn't changed, then do nothing */
1511 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1515 rec->flags |= FTRACE_FL_ENABLED;
1516 return ftrace_make_call(rec, ftrace_addr);
1519 rec->flags &= ~FTRACE_FL_ENABLED;
1520 return ftrace_make_nop(NULL, rec, ftrace_addr);
1523 static void ftrace_replace_code(int enable)
1525 struct dyn_ftrace *rec;
1526 struct ftrace_page *pg;
1529 if (unlikely(ftrace_disabled))
1532 do_for_each_ftrace_rec(pg, rec) {
1533 /* Skip over free records */
1534 if (rec->flags & FTRACE_FL_FREE)
1537 failed = __ftrace_replace_code(rec, enable);
1539 ftrace_bug(failed, rec->ip);
1540 /* Stop processing */
1543 } while_for_each_ftrace_rec();
1547 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1554 if (unlikely(ftrace_disabled))
1557 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1559 ftrace_bug(ret, ip);
1566 * archs can override this function if they must do something
1567 * before the modifying code is performed.
1569 int __weak ftrace_arch_code_modify_prepare(void)
1575 * archs can override this function if they must do something
1576 * after the modifying code is performed.
1578 int __weak ftrace_arch_code_modify_post_process(void)
1583 static int __ftrace_modify_code(void *data)
1585 int *command = data;
1587 if (*command & FTRACE_ENABLE_CALLS)
1588 ftrace_replace_code(1);
1589 else if (*command & FTRACE_DISABLE_CALLS)
1590 ftrace_replace_code(0);
1592 if (*command & FTRACE_UPDATE_TRACE_FUNC)
1593 ftrace_update_ftrace_func(ftrace_trace_function);
1595 if (*command & FTRACE_START_FUNC_RET)
1596 ftrace_enable_ftrace_graph_caller();
1597 else if (*command & FTRACE_STOP_FUNC_RET)
1598 ftrace_disable_ftrace_graph_caller();
1603 static void ftrace_run_update_code(int command)
1607 ret = ftrace_arch_code_modify_prepare();
1608 FTRACE_WARN_ON(ret);
1612 stop_machine(__ftrace_modify_code, &command, NULL);
1614 ret = ftrace_arch_code_modify_post_process();
1615 FTRACE_WARN_ON(ret);
1618 static ftrace_func_t saved_ftrace_func;
1619 static int ftrace_start_up;
1620 static int global_start_up;
1622 static void ftrace_startup_enable(int command)
1624 if (saved_ftrace_func != ftrace_trace_function) {
1625 saved_ftrace_func = ftrace_trace_function;
1626 command |= FTRACE_UPDATE_TRACE_FUNC;
1629 if (!command || !ftrace_enabled)
1632 ftrace_run_update_code(command);
1635 static int ftrace_startup(struct ftrace_ops *ops, int command)
1637 bool hash_enable = true;
1639 if (unlikely(ftrace_disabled))
1643 command |= FTRACE_ENABLE_CALLS;
1645 /* ops marked global share the filter hashes */
1646 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1648 /* Don't update hash if global is already set */
1649 if (global_start_up)
1650 hash_enable = false;
1654 ops->flags |= FTRACE_OPS_FL_ENABLED;
1656 ftrace_hash_rec_enable(ops, 1);
1658 ftrace_startup_enable(command);
1663 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
1665 bool hash_disable = true;
1667 if (unlikely(ftrace_disabled))
1672 * Just warn in case of unbalance, no need to kill ftrace, it's not
1673 * critical but the ftrace_call callers may be never nopped again after
1674 * further ftrace uses.
1676 WARN_ON_ONCE(ftrace_start_up < 0);
1678 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1681 WARN_ON_ONCE(global_start_up < 0);
1682 /* Don't update hash if global still has users */
1683 if (global_start_up) {
1684 WARN_ON_ONCE(!ftrace_start_up);
1685 hash_disable = false;
1690 ftrace_hash_rec_disable(ops, 1);
1692 if (ops != &global_ops || !global_start_up)
1693 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
1695 if (!ftrace_start_up)
1696 command |= FTRACE_DISABLE_CALLS;
1698 if (saved_ftrace_func != ftrace_trace_function) {
1699 saved_ftrace_func = ftrace_trace_function;
1700 command |= FTRACE_UPDATE_TRACE_FUNC;
1703 if (!command || !ftrace_enabled)
1706 ftrace_run_update_code(command);
1709 static void ftrace_startup_sysctl(void)
1711 if (unlikely(ftrace_disabled))
1714 /* Force update next time */
1715 saved_ftrace_func = NULL;
1716 /* ftrace_start_up is true if we want ftrace running */
1717 if (ftrace_start_up)
1718 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
1721 static void ftrace_shutdown_sysctl(void)
1723 if (unlikely(ftrace_disabled))
1726 /* ftrace_start_up is true if ftrace is running */
1727 if (ftrace_start_up)
1728 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
1731 static cycle_t ftrace_update_time;
1732 static unsigned long ftrace_update_cnt;
1733 unsigned long ftrace_update_tot_cnt;
1735 static int ftrace_update_code(struct module *mod)
1737 struct dyn_ftrace *p;
1738 cycle_t start, stop;
1740 start = ftrace_now(raw_smp_processor_id());
1741 ftrace_update_cnt = 0;
1743 while (ftrace_new_addrs) {
1745 /* If something went wrong, bail without enabling anything */
1746 if (unlikely(ftrace_disabled))
1749 p = ftrace_new_addrs;
1750 ftrace_new_addrs = p->newlist;
1754 * Do the initial record conversion from mcount jump
1755 * to the NOP instructions.
1757 if (!ftrace_code_disable(mod, p)) {
1763 ftrace_update_cnt++;
1766 * If the tracing is enabled, go ahead and enable the record.
1768 * The reason not to enable the record immediatelly is the
1769 * inherent check of ftrace_make_nop/ftrace_make_call for
1770 * correct previous instructions. Making first the NOP
1771 * conversion puts the module to the correct state, thus
1772 * passing the ftrace_make_call check.
1774 if (ftrace_start_up) {
1775 int failed = __ftrace_replace_code(p, 1);
1777 ftrace_bug(failed, p->ip);
1783 stop = ftrace_now(raw_smp_processor_id());
1784 ftrace_update_time = stop - start;
1785 ftrace_update_tot_cnt += ftrace_update_cnt;
1790 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
1792 struct ftrace_page *pg;
1796 /* allocate a few pages */
1797 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
1798 if (!ftrace_pages_start)
1802 * Allocate a few more pages.
1804 * TODO: have some parser search vmlinux before
1805 * final linking to find all calls to ftrace.
1807 * a) know how many pages to allocate.
1809 * b) set up the table then.
1811 * The dynamic code is still necessary for
1815 pg = ftrace_pages = ftrace_pages_start;
1817 cnt = num_to_init / ENTRIES_PER_PAGE;
1818 pr_info("ftrace: allocating %ld entries in %d pages\n",
1819 num_to_init, cnt + 1);
1821 for (i = 0; i < cnt; i++) {
1822 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
1824 /* If we fail, we'll try later anyway */
1835 FTRACE_ITER_FILTER = (1 << 0),
1836 FTRACE_ITER_NOTRACE = (1 << 1),
1837 FTRACE_ITER_PRINTALL = (1 << 2),
1838 FTRACE_ITER_HASH = (1 << 3),
1839 FTRACE_ITER_ENABLED = (1 << 4),
1842 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1844 struct ftrace_iterator {
1847 struct ftrace_page *pg;
1848 struct dyn_ftrace *func;
1849 struct ftrace_func_probe *probe;
1850 struct trace_parser parser;
1851 struct ftrace_hash *hash;
1852 struct ftrace_ops *ops;
1859 t_hash_next(struct seq_file *m, loff_t *pos)
1861 struct ftrace_iterator *iter = m->private;
1862 struct hlist_node *hnd = NULL;
1863 struct hlist_head *hhd;
1869 hnd = &iter->probe->node;
1871 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
1874 hhd = &ftrace_func_hash[iter->hidx];
1876 if (hlist_empty(hhd)) {
1892 if (WARN_ON_ONCE(!hnd))
1895 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
1900 static void *t_hash_start(struct seq_file *m, loff_t *pos)
1902 struct ftrace_iterator *iter = m->private;
1906 if (iter->func_pos > *pos)
1910 for (l = 0; l <= (*pos - iter->func_pos); ) {
1911 p = t_hash_next(m, &l);
1918 /* Only set this if we have an item */
1919 iter->flags |= FTRACE_ITER_HASH;
1925 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
1927 struct ftrace_func_probe *rec;
1930 if (WARN_ON_ONCE(!rec))
1933 if (rec->ops->print)
1934 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
1936 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
1939 seq_printf(m, ":%p", rec->data);
1946 t_next(struct seq_file *m, void *v, loff_t *pos)
1948 struct ftrace_iterator *iter = m->private;
1949 struct ftrace_ops *ops = &global_ops;
1950 struct dyn_ftrace *rec = NULL;
1952 if (unlikely(ftrace_disabled))
1955 if (iter->flags & FTRACE_ITER_HASH)
1956 return t_hash_next(m, pos);
1959 iter->pos = iter->func_pos = *pos;
1961 if (iter->flags & FTRACE_ITER_PRINTALL)
1962 return t_hash_start(m, pos);
1965 if (iter->idx >= iter->pg->index) {
1966 if (iter->pg->next) {
1967 iter->pg = iter->pg->next;
1972 rec = &iter->pg->records[iter->idx++];
1973 if ((rec->flags & FTRACE_FL_FREE) ||
1975 ((iter->flags & FTRACE_ITER_FILTER) &&
1976 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
1978 ((iter->flags & FTRACE_ITER_NOTRACE) &&
1979 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
1981 ((iter->flags & FTRACE_ITER_ENABLED) &&
1982 !(rec->flags & ~FTRACE_FL_MASK))) {
1990 return t_hash_start(m, pos);
1997 static void reset_iter_read(struct ftrace_iterator *iter)
2001 iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
2004 static void *t_start(struct seq_file *m, loff_t *pos)
2006 struct ftrace_iterator *iter = m->private;
2007 struct ftrace_ops *ops = &global_ops;
2011 mutex_lock(&ftrace_lock);
2013 if (unlikely(ftrace_disabled))
2017 * If an lseek was done, then reset and start from beginning.
2019 if (*pos < iter->pos)
2020 reset_iter_read(iter);
2023 * For set_ftrace_filter reading, if we have the filter
2024 * off, we can short cut and just print out that all
2025 * functions are enabled.
2027 if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) {
2029 return t_hash_start(m, pos);
2030 iter->flags |= FTRACE_ITER_PRINTALL;
2031 /* reset in case of seek/pread */
2032 iter->flags &= ~FTRACE_ITER_HASH;
2036 if (iter->flags & FTRACE_ITER_HASH)
2037 return t_hash_start(m, pos);
2040 * Unfortunately, we need to restart at ftrace_pages_start
2041 * every time we let go of the ftrace_mutex. This is because
2042 * those pointers can change without the lock.
2044 iter->pg = ftrace_pages_start;
2046 for (l = 0; l <= *pos; ) {
2047 p = t_next(m, p, &l);
2053 if (iter->flags & FTRACE_ITER_FILTER)
2054 return t_hash_start(m, pos);
2062 static void t_stop(struct seq_file *m, void *p)
2064 mutex_unlock(&ftrace_lock);
2067 static int t_show(struct seq_file *m, void *v)
2069 struct ftrace_iterator *iter = m->private;
2070 struct dyn_ftrace *rec;
2072 if (iter->flags & FTRACE_ITER_HASH)
2073 return t_hash_show(m, iter);
2075 if (iter->flags & FTRACE_ITER_PRINTALL) {
2076 seq_printf(m, "#### all functions enabled ####\n");
2085 seq_printf(m, "%ps", (void *)rec->ip);
2086 if (iter->flags & FTRACE_ITER_ENABLED)
2087 seq_printf(m, " (%ld)",
2088 rec->flags & ~FTRACE_FL_MASK);
2089 seq_printf(m, "\n");
2094 static const struct seq_operations show_ftrace_seq_ops = {
2102 ftrace_avail_open(struct inode *inode, struct file *file)
2104 struct ftrace_iterator *iter;
2107 if (unlikely(ftrace_disabled))
2110 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2114 iter->pg = ftrace_pages_start;
2116 ret = seq_open(file, &show_ftrace_seq_ops);
2118 struct seq_file *m = file->private_data;
2129 ftrace_enabled_open(struct inode *inode, struct file *file)
2131 struct ftrace_iterator *iter;
2134 if (unlikely(ftrace_disabled))
2137 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2141 iter->pg = ftrace_pages_start;
2142 iter->flags = FTRACE_ITER_ENABLED;
2144 ret = seq_open(file, &show_ftrace_seq_ops);
2146 struct seq_file *m = file->private_data;
2156 static void ftrace_filter_reset(struct ftrace_hash *hash)
2158 mutex_lock(&ftrace_lock);
2159 ftrace_hash_clear(hash);
2160 mutex_unlock(&ftrace_lock);
2164 ftrace_regex_open(struct ftrace_ops *ops, int flag,
2165 struct inode *inode, struct file *file)
2167 struct ftrace_iterator *iter;
2168 struct ftrace_hash *hash;
2171 if (unlikely(ftrace_disabled))
2174 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2178 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2183 if (flag & FTRACE_ITER_NOTRACE)
2184 hash = ops->notrace_hash;
2186 hash = ops->filter_hash;
2191 if (file->f_mode & FMODE_WRITE) {
2192 mutex_lock(&ftrace_lock);
2193 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2194 mutex_unlock(&ftrace_lock);
2197 trace_parser_put(&iter->parser);
2203 mutex_lock(&ftrace_regex_lock);
2205 if ((file->f_mode & FMODE_WRITE) &&
2206 (file->f_flags & O_TRUNC))
2207 ftrace_filter_reset(iter->hash);
2209 if (file->f_mode & FMODE_READ) {
2210 iter->pg = ftrace_pages_start;
2212 ret = seq_open(file, &show_ftrace_seq_ops);
2214 struct seq_file *m = file->private_data;
2218 free_ftrace_hash(iter->hash);
2219 trace_parser_put(&iter->parser);
2223 file->private_data = iter;
2224 mutex_unlock(&ftrace_regex_lock);
2230 ftrace_filter_open(struct inode *inode, struct file *file)
2232 return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER,
2237 ftrace_notrace_open(struct inode *inode, struct file *file)
2239 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2244 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
2248 if (file->f_mode & FMODE_READ)
2249 ret = seq_lseek(file, offset, origin);
2251 file->f_pos = ret = 1;
2256 static int ftrace_match(char *str, char *regex, int len, int type)
2263 if (strcmp(str, regex) == 0)
2266 case MATCH_FRONT_ONLY:
2267 if (strncmp(str, regex, len) == 0)
2270 case MATCH_MIDDLE_ONLY:
2271 if (strstr(str, regex))
2274 case MATCH_END_ONLY:
2276 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2285 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2287 struct ftrace_func_entry *entry;
2290 entry = ftrace_lookup_ip(hash, rec->ip);
2292 /* Do nothing if it doesn't exist */
2296 free_hash_entry(hash, entry);
2298 /* Do nothing if it exists */
2302 ret = add_hash_entry(hash, rec->ip);
2308 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2309 char *regex, int len, int type)
2311 char str[KSYM_SYMBOL_LEN];
2314 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2317 /* module lookup requires matching the module */
2318 if (!modname || strcmp(modname, mod))
2321 /* blank search means to match all funcs in the mod */
2326 return ftrace_match(str, regex, len, type);
2330 match_records(struct ftrace_hash *hash, char *buff,
2331 int len, char *mod, int not)
2333 unsigned search_len = 0;
2334 struct ftrace_page *pg;
2335 struct dyn_ftrace *rec;
2336 int type = MATCH_FULL;
2337 char *search = buff;
2342 type = filter_parse_regex(buff, len, &search, ¬);
2343 search_len = strlen(search);
2346 mutex_lock(&ftrace_lock);
2348 if (unlikely(ftrace_disabled))
2351 do_for_each_ftrace_rec(pg, rec) {
2353 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2354 ret = enter_record(hash, rec, not);
2361 } while_for_each_ftrace_rec();
2363 mutex_unlock(&ftrace_lock);
2369 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2371 return match_records(hash, buff, len, NULL, 0);
2375 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2379 /* blank or '*' mean the same */
2380 if (strcmp(buff, "*") == 0)
2383 /* handle the case of 'dont filter this module' */
2384 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2389 return match_records(hash, buff, strlen(buff), mod, not);
2393 * We register the module command as a template to show others how
2394 * to register the a command as well.
2398 ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
2400 struct ftrace_ops *ops = &global_ops;
2401 struct ftrace_hash *hash;
2406 * cmd == 'mod' because we only registered this func
2407 * for the 'mod' ftrace_func_command.
2408 * But if you register one func with multiple commands,
2409 * you can tell which command was used by the cmd
2413 /* we must have a module name */
2417 mod = strsep(¶m, ":");
2422 hash = ops->filter_hash;
2424 hash = ops->notrace_hash;
2426 ret = ftrace_match_module_records(hash, func, mod);
2435 static struct ftrace_func_command ftrace_mod_cmd = {
2437 .func = ftrace_mod_callback,
2440 static int __init ftrace_mod_cmd_init(void)
2442 return register_ftrace_command(&ftrace_mod_cmd);
2444 device_initcall(ftrace_mod_cmd_init);
2447 function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
2449 struct ftrace_func_probe *entry;
2450 struct hlist_head *hhd;
2451 struct hlist_node *n;
2454 key = hash_long(ip, FTRACE_HASH_BITS);
2456 hhd = &ftrace_func_hash[key];
2458 if (hlist_empty(hhd))
2462 * Disable preemption for these calls to prevent a RCU grace
2463 * period. This syncs the hash iteration and freeing of items
2464 * on the hash. rcu_read_lock is too dangerous here.
2466 preempt_disable_notrace();
2467 hlist_for_each_entry_rcu(entry, n, hhd, node) {
2468 if (entry->ip == ip)
2469 entry->ops->func(ip, parent_ip, &entry->data);
2471 preempt_enable_notrace();
2474 static struct ftrace_ops trace_probe_ops __read_mostly =
2476 .func = function_trace_probe_call,
2479 static int ftrace_probe_registered;
2481 static void __enable_ftrace_function_probe(void)
2486 if (ftrace_probe_registered)
2489 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2490 struct hlist_head *hhd = &ftrace_func_hash[i];
2494 /* Nothing registered? */
2495 if (i == FTRACE_FUNC_HASHSIZE)
2498 ret = __register_ftrace_function(&trace_probe_ops);
2500 ret = ftrace_startup(&trace_probe_ops, 0);
2502 ftrace_probe_registered = 1;
2505 static void __disable_ftrace_function_probe(void)
2510 if (!ftrace_probe_registered)
2513 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2514 struct hlist_head *hhd = &ftrace_func_hash[i];
2519 /* no more funcs left */
2520 ret = __unregister_ftrace_function(&trace_probe_ops);
2522 ftrace_shutdown(&trace_probe_ops, 0);
2524 ftrace_probe_registered = 0;
2528 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2530 struct ftrace_func_probe *entry =
2531 container_of(rhp, struct ftrace_func_probe, rcu);
2533 if (entry->ops->free)
2534 entry->ops->free(&entry->data);
2540 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2543 struct ftrace_func_probe *entry;
2544 struct ftrace_page *pg;
2545 struct dyn_ftrace *rec;
2551 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2552 len = strlen(search);
2554 /* we do not support '!' for function probes */
2558 mutex_lock(&ftrace_lock);
2560 if (unlikely(ftrace_disabled))
2563 do_for_each_ftrace_rec(pg, rec) {
2565 if (!ftrace_match_record(rec, NULL, search, len, type))
2568 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2570 /* If we did not process any, then return error */
2581 * The caller might want to do something special
2582 * for each function we find. We call the callback
2583 * to give the caller an opportunity to do so.
2585 if (ops->callback) {
2586 if (ops->callback(rec->ip, &entry->data) < 0) {
2587 /* caller does not like this func */
2594 entry->ip = rec->ip;
2596 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2597 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2599 } while_for_each_ftrace_rec();
2600 __enable_ftrace_function_probe();
2603 mutex_unlock(&ftrace_lock);
2609 PROBE_TEST_FUNC = 1,
2614 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2615 void *data, int flags)
2617 struct ftrace_func_probe *entry;
2618 struct hlist_node *n, *tmp;
2619 char str[KSYM_SYMBOL_LEN];
2620 int type = MATCH_FULL;
2624 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
2629 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2630 len = strlen(search);
2632 /* we do not support '!' for function probes */
2637 mutex_lock(&ftrace_lock);
2638 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2639 struct hlist_head *hhd = &ftrace_func_hash[i];
2641 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2643 /* break up if statements for readability */
2644 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
2647 if ((flags & PROBE_TEST_DATA) && entry->data != data)
2650 /* do this last, since it is the most expensive */
2652 kallsyms_lookup(entry->ip, NULL, NULL,
2654 if (!ftrace_match(str, glob, len, type))
2658 hlist_del(&entry->node);
2659 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2662 __disable_ftrace_function_probe();
2663 mutex_unlock(&ftrace_lock);
2667 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2670 __unregister_ftrace_function_probe(glob, ops, data,
2671 PROBE_TEST_FUNC | PROBE_TEST_DATA);
2675 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
2677 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
2680 void unregister_ftrace_function_probe_all(char *glob)
2682 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
2685 static LIST_HEAD(ftrace_commands);
2686 static DEFINE_MUTEX(ftrace_cmd_mutex);
2688 int register_ftrace_command(struct ftrace_func_command *cmd)
2690 struct ftrace_func_command *p;
2693 mutex_lock(&ftrace_cmd_mutex);
2694 list_for_each_entry(p, &ftrace_commands, list) {
2695 if (strcmp(cmd->name, p->name) == 0) {
2700 list_add(&cmd->list, &ftrace_commands);
2702 mutex_unlock(&ftrace_cmd_mutex);
2707 int unregister_ftrace_command(struct ftrace_func_command *cmd)
2709 struct ftrace_func_command *p, *n;
2712 mutex_lock(&ftrace_cmd_mutex);
2713 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
2714 if (strcmp(cmd->name, p->name) == 0) {
2716 list_del_init(&p->list);
2721 mutex_unlock(&ftrace_cmd_mutex);
2726 static int ftrace_process_regex(struct ftrace_hash *hash,
2727 char *buff, int len, int enable)
2729 char *func, *command, *next = buff;
2730 struct ftrace_func_command *p;
2733 func = strsep(&next, ":");
2736 ret = ftrace_match_records(hash, func, len);
2746 command = strsep(&next, ":");
2748 mutex_lock(&ftrace_cmd_mutex);
2749 list_for_each_entry(p, &ftrace_commands, list) {
2750 if (strcmp(p->name, command) == 0) {
2751 ret = p->func(func, command, next, enable);
2756 mutex_unlock(&ftrace_cmd_mutex);
2762 ftrace_regex_write(struct file *file, const char __user *ubuf,
2763 size_t cnt, loff_t *ppos, int enable)
2765 struct ftrace_iterator *iter;
2766 struct trace_parser *parser;
2772 mutex_lock(&ftrace_regex_lock);
2775 if (unlikely(ftrace_disabled))
2778 if (file->f_mode & FMODE_READ) {
2779 struct seq_file *m = file->private_data;
2782 iter = file->private_data;
2784 parser = &iter->parser;
2785 read = trace_get_user(parser, ubuf, cnt, ppos);
2787 if (read >= 0 && trace_parser_loaded(parser) &&
2788 !trace_parser_cont(parser)) {
2789 ret = ftrace_process_regex(iter->hash, parser->buffer,
2790 parser->idx, enable);
2791 trace_parser_clear(parser);
2798 mutex_unlock(&ftrace_regex_lock);
2804 ftrace_filter_write(struct file *file, const char __user *ubuf,
2805 size_t cnt, loff_t *ppos)
2807 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
2811 ftrace_notrace_write(struct file *file, const char __user *ubuf,
2812 size_t cnt, loff_t *ppos)
2814 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
2818 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
2819 int reset, int enable)
2821 struct ftrace_hash **orig_hash;
2822 struct ftrace_hash *hash;
2825 /* All global ops uses the global ops filters */
2826 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
2829 if (unlikely(ftrace_disabled))
2833 orig_hash = &ops->filter_hash;
2835 orig_hash = &ops->notrace_hash;
2837 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
2841 mutex_lock(&ftrace_regex_lock);
2843 ftrace_filter_reset(hash);
2845 ftrace_match_records(hash, buf, len);
2847 mutex_lock(&ftrace_lock);
2848 ret = ftrace_hash_move(orig_hash, hash);
2849 mutex_unlock(&ftrace_lock);
2851 mutex_unlock(&ftrace_regex_lock);
2853 free_ftrace_hash(hash);
2858 * ftrace_set_filter - set a function to filter on in ftrace
2859 * @ops - the ops to set the filter with
2860 * @buf - the string that holds the function filter text.
2861 * @len - the length of the string.
2862 * @reset - non zero to reset all filters before applying this filter.
2864 * Filters denote which functions should be enabled when tracing is enabled.
2865 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2867 void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
2870 ftrace_set_regex(ops, buf, len, reset, 1);
2872 EXPORT_SYMBOL_GPL(ftrace_set_filter);
2875 * ftrace_set_notrace - set a function to not trace in ftrace
2876 * @ops - the ops to set the notrace filter with
2877 * @buf - the string that holds the function notrace text.
2878 * @len - the length of the string.
2879 * @reset - non zero to reset all filters before applying this filter.
2881 * Notrace Filters denote which functions should not be enabled when tracing
2882 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2885 void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
2888 ftrace_set_regex(ops, buf, len, reset, 0);
2890 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
2892 * ftrace_set_filter - set a function to filter on in ftrace
2893 * @ops - the ops to set the filter with
2894 * @buf - the string that holds the function filter text.
2895 * @len - the length of the string.
2896 * @reset - non zero to reset all filters before applying this filter.
2898 * Filters denote which functions should be enabled when tracing is enabled.
2899 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2901 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
2903 ftrace_set_regex(&global_ops, buf, len, reset, 1);
2905 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
2908 * ftrace_set_notrace - set a function to not trace in ftrace
2909 * @ops - the ops to set the notrace filter with
2910 * @buf - the string that holds the function notrace text.
2911 * @len - the length of the string.
2912 * @reset - non zero to reset all filters before applying this filter.
2914 * Notrace Filters denote which functions should not be enabled when tracing
2915 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2918 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
2920 ftrace_set_regex(&global_ops, buf, len, reset, 0);
2922 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
2925 * command line interface to allow users to set filters on boot up.
2927 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
2928 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
2929 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
2931 static int __init set_ftrace_notrace(char *str)
2933 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
2936 __setup("ftrace_notrace=", set_ftrace_notrace);
2938 static int __init set_ftrace_filter(char *str)
2940 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
2943 __setup("ftrace_filter=", set_ftrace_filter);
2945 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2946 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
2947 static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
2949 static int __init set_graph_function(char *str)
2951 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
2954 __setup("ftrace_graph_filter=", set_graph_function);
2956 static void __init set_ftrace_early_graph(char *buf)
2962 func = strsep(&buf, ",");
2963 /* we allow only one expression at a time */
2964 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
2967 printk(KERN_DEBUG "ftrace: function %s not "
2968 "traceable\n", func);
2971 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2974 set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
2979 func = strsep(&buf, ",");
2980 ftrace_set_regex(ops, func, strlen(func), 0, enable);
2984 static void __init set_ftrace_early_filters(void)
2986 if (ftrace_filter_buf[0])
2987 set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1);
2988 if (ftrace_notrace_buf[0])
2989 set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0);
2990 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2991 if (ftrace_graph_buf[0])
2992 set_ftrace_early_graph(ftrace_graph_buf);
2993 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2997 ftrace_regex_release(struct inode *inode, struct file *file)
2999 struct seq_file *m = (struct seq_file *)file->private_data;
3000 struct ftrace_iterator *iter;
3001 struct ftrace_hash **orig_hash;
3002 struct trace_parser *parser;
3006 mutex_lock(&ftrace_regex_lock);
3007 if (file->f_mode & FMODE_READ) {
3010 seq_release(inode, file);
3012 iter = file->private_data;
3014 parser = &iter->parser;
3015 if (trace_parser_loaded(parser)) {
3016 parser->buffer[parser->idx] = 0;
3017 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3020 trace_parser_put(parser);
3022 if (file->f_mode & FMODE_WRITE) {
3023 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3026 orig_hash = &iter->ops->filter_hash;
3028 orig_hash = &iter->ops->notrace_hash;
3030 mutex_lock(&ftrace_lock);
3032 * Remove the current set, update the hash and add
3035 ftrace_hash_rec_disable(iter->ops, filter_hash);
3036 ret = ftrace_hash_move(orig_hash, iter->hash);
3038 ftrace_hash_rec_enable(iter->ops, filter_hash);
3039 if (iter->ops->flags & FTRACE_OPS_FL_ENABLED
3041 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
3043 mutex_unlock(&ftrace_lock);
3045 free_ftrace_hash(iter->hash);
3048 mutex_unlock(&ftrace_regex_lock);
3052 static const struct file_operations ftrace_avail_fops = {
3053 .open = ftrace_avail_open,
3055 .llseek = seq_lseek,
3056 .release = seq_release_private,
3059 static const struct file_operations ftrace_enabled_fops = {
3060 .open = ftrace_enabled_open,
3062 .llseek = seq_lseek,
3063 .release = seq_release_private,
3066 static const struct file_operations ftrace_filter_fops = {
3067 .open = ftrace_filter_open,
3069 .write = ftrace_filter_write,
3070 .llseek = ftrace_regex_lseek,
3071 .release = ftrace_regex_release,
3074 static const struct file_operations ftrace_notrace_fops = {
3075 .open = ftrace_notrace_open,
3077 .write = ftrace_notrace_write,
3078 .llseek = ftrace_regex_lseek,
3079 .release = ftrace_regex_release,
3082 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3084 static DEFINE_MUTEX(graph_lock);
3086 int ftrace_graph_count;
3087 int ftrace_graph_filter_enabled;
3088 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3091 __g_next(struct seq_file *m, loff_t *pos)
3093 if (*pos >= ftrace_graph_count)
3095 return &ftrace_graph_funcs[*pos];
3099 g_next(struct seq_file *m, void *v, loff_t *pos)
3102 return __g_next(m, pos);
3105 static void *g_start(struct seq_file *m, loff_t *pos)
3107 mutex_lock(&graph_lock);
3109 /* Nothing, tell g_show to print all functions are enabled */
3110 if (!ftrace_graph_filter_enabled && !*pos)
3113 return __g_next(m, pos);
3116 static void g_stop(struct seq_file *m, void *p)
3118 mutex_unlock(&graph_lock);
3121 static int g_show(struct seq_file *m, void *v)
3123 unsigned long *ptr = v;
3128 if (ptr == (unsigned long *)1) {
3129 seq_printf(m, "#### all functions enabled ####\n");
3133 seq_printf(m, "%ps\n", (void *)*ptr);
3138 static const struct seq_operations ftrace_graph_seq_ops = {
3146 ftrace_graph_open(struct inode *inode, struct file *file)
3150 if (unlikely(ftrace_disabled))
3153 mutex_lock(&graph_lock);
3154 if ((file->f_mode & FMODE_WRITE) &&
3155 (file->f_flags & O_TRUNC)) {
3156 ftrace_graph_filter_enabled = 0;
3157 ftrace_graph_count = 0;
3158 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3160 mutex_unlock(&graph_lock);
3162 if (file->f_mode & FMODE_READ)
3163 ret = seq_open(file, &ftrace_graph_seq_ops);
3169 ftrace_graph_release(struct inode *inode, struct file *file)
3171 if (file->f_mode & FMODE_READ)
3172 seq_release(inode, file);
3177 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3179 struct dyn_ftrace *rec;
3180 struct ftrace_page *pg;
3189 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3190 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3193 search_len = strlen(search);
3195 mutex_lock(&ftrace_lock);
3197 if (unlikely(ftrace_disabled)) {
3198 mutex_unlock(&ftrace_lock);
3202 do_for_each_ftrace_rec(pg, rec) {
3204 if (rec->flags & FTRACE_FL_FREE)
3207 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3208 /* if it is in the array */
3210 for (i = 0; i < *idx; i++) {
3211 if (array[i] == rec->ip) {
3220 array[(*idx)++] = rec->ip;
3221 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3226 array[i] = array[--(*idx)];
3232 } while_for_each_ftrace_rec();
3234 mutex_unlock(&ftrace_lock);
3239 ftrace_graph_filter_enabled = 1;
3244 ftrace_graph_write(struct file *file, const char __user *ubuf,
3245 size_t cnt, loff_t *ppos)
3247 struct trace_parser parser;
3253 mutex_lock(&graph_lock);
3255 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3260 read = trace_get_user(&parser, ubuf, cnt, ppos);
3262 if (read >= 0 && trace_parser_loaded((&parser))) {
3263 parser.buffer[parser.idx] = 0;
3265 /* we allow only one expression at a time */
3266 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3275 trace_parser_put(&parser);
3277 mutex_unlock(&graph_lock);
3282 static const struct file_operations ftrace_graph_fops = {
3283 .open = ftrace_graph_open,
3285 .write = ftrace_graph_write,
3286 .release = ftrace_graph_release,
3287 .llseek = seq_lseek,
3289 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3291 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3294 trace_create_file("available_filter_functions", 0444,
3295 d_tracer, NULL, &ftrace_avail_fops);
3297 trace_create_file("enabled_functions", 0444,
3298 d_tracer, NULL, &ftrace_enabled_fops);
3300 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3301 NULL, &ftrace_filter_fops);
3303 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3304 NULL, &ftrace_notrace_fops);
3306 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3307 trace_create_file("set_graph_function", 0444, d_tracer,
3309 &ftrace_graph_fops);
3310 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3315 static int ftrace_process_locs(struct module *mod,
3316 unsigned long *start,
3322 mutex_lock(&ftrace_lock);
3325 addr = ftrace_call_adjust(*p++);
3327 * Some architecture linkers will pad between
3328 * the different mcount_loc sections of different
3329 * object files to satisfy alignments.
3330 * Skip any NULL pointers.
3334 ftrace_record_ip(addr);
3337 ftrace_update_code(mod);
3338 mutex_unlock(&ftrace_lock);
3343 #ifdef CONFIG_MODULES
3344 void ftrace_release_mod(struct module *mod)
3346 struct dyn_ftrace *rec;
3347 struct ftrace_page *pg;
3349 mutex_lock(&ftrace_lock);
3351 if (ftrace_disabled)
3354 do_for_each_ftrace_rec(pg, rec) {
3355 if (within_module_core(rec->ip, mod)) {
3357 * rec->ip is changed in ftrace_free_rec()
3358 * It should not between s and e if record was freed.
3360 FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
3361 ftrace_free_rec(rec);
3363 } while_for_each_ftrace_rec();
3365 mutex_unlock(&ftrace_lock);
3368 static void ftrace_init_module(struct module *mod,
3369 unsigned long *start, unsigned long *end)
3371 if (ftrace_disabled || start == end)
3373 ftrace_process_locs(mod, start, end);
3376 static int ftrace_module_notify(struct notifier_block *self,
3377 unsigned long val, void *data)
3379 struct module *mod = data;
3382 case MODULE_STATE_COMING:
3383 ftrace_init_module(mod, mod->ftrace_callsites,
3384 mod->ftrace_callsites +
3385 mod->num_ftrace_callsites);
3387 case MODULE_STATE_GOING:
3388 ftrace_release_mod(mod);
3395 static int ftrace_module_notify(struct notifier_block *self,
3396 unsigned long val, void *data)
3400 #endif /* CONFIG_MODULES */
3402 struct notifier_block ftrace_module_nb = {
3403 .notifier_call = ftrace_module_notify,
3407 extern unsigned long __start_mcount_loc[];
3408 extern unsigned long __stop_mcount_loc[];
3410 void __init ftrace_init(void)
3412 unsigned long count, addr, flags;
3415 /* Keep the ftrace pointer to the stub */
3416 addr = (unsigned long)ftrace_stub;
3418 local_irq_save(flags);
3419 ftrace_dyn_arch_init(&addr);
3420 local_irq_restore(flags);
3422 /* ftrace_dyn_arch_init places the return code in addr */
3426 count = __stop_mcount_loc - __start_mcount_loc;
3428 ret = ftrace_dyn_table_alloc(count);
3432 last_ftrace_enabled = ftrace_enabled = 1;
3434 ret = ftrace_process_locs(NULL,
3438 ret = register_module_notifier(&ftrace_module_nb);
3440 pr_warning("Failed to register trace ftrace module notifier\n");
3442 set_ftrace_early_filters();
3446 ftrace_disabled = 1;
3451 static struct ftrace_ops global_ops = {
3452 .func = ftrace_stub,
3455 static int __init ftrace_nodyn_init(void)
3460 device_initcall(ftrace_nodyn_init);
3462 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
3463 static inline void ftrace_startup_enable(int command) { }
3464 /* Keep as macros so we do not need to define the commands */
3465 # define ftrace_startup(ops, command) \
3467 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
3470 # define ftrace_shutdown(ops, command) do { } while (0)
3471 # define ftrace_startup_sysctl() do { } while (0)
3472 # define ftrace_shutdown_sysctl() do { } while (0)
3475 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
3480 #endif /* CONFIG_DYNAMIC_FTRACE */
3483 ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
3485 struct ftrace_ops *op;
3487 if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
3490 trace_recursion_set(TRACE_INTERNAL_BIT);
3492 * Some of the ops may be dynamically allocated,
3493 * they must be freed after a synchronize_sched().
3495 preempt_disable_notrace();
3496 op = rcu_dereference_raw(ftrace_ops_list);
3497 while (op != &ftrace_list_end) {
3498 if (ftrace_ops_test(op, ip))
3499 op->func(ip, parent_ip);
3500 op = rcu_dereference_raw(op->next);
3502 preempt_enable_notrace();
3503 trace_recursion_clear(TRACE_INTERNAL_BIT);
3506 static void clear_ftrace_swapper(void)
3508 struct task_struct *p;
3512 for_each_online_cpu(cpu) {
3514 clear_tsk_trace_trace(p);
3519 static void set_ftrace_swapper(void)
3521 struct task_struct *p;
3525 for_each_online_cpu(cpu) {
3527 set_tsk_trace_trace(p);
3532 static void clear_ftrace_pid(struct pid *pid)
3534 struct task_struct *p;
3537 do_each_pid_task(pid, PIDTYPE_PID, p) {
3538 clear_tsk_trace_trace(p);
3539 } while_each_pid_task(pid, PIDTYPE_PID, p);
3545 static void set_ftrace_pid(struct pid *pid)
3547 struct task_struct *p;
3550 do_each_pid_task(pid, PIDTYPE_PID, p) {
3551 set_tsk_trace_trace(p);
3552 } while_each_pid_task(pid, PIDTYPE_PID, p);
3556 static void clear_ftrace_pid_task(struct pid *pid)
3558 if (pid == ftrace_swapper_pid)
3559 clear_ftrace_swapper();
3561 clear_ftrace_pid(pid);
3564 static void set_ftrace_pid_task(struct pid *pid)
3566 if (pid == ftrace_swapper_pid)
3567 set_ftrace_swapper();
3569 set_ftrace_pid(pid);
3572 static int ftrace_pid_add(int p)
3575 struct ftrace_pid *fpid;
3578 mutex_lock(&ftrace_lock);
3581 pid = ftrace_swapper_pid;
3583 pid = find_get_pid(p);
3590 list_for_each_entry(fpid, &ftrace_pids, list)
3591 if (fpid->pid == pid)
3596 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
3600 list_add(&fpid->list, &ftrace_pids);
3603 set_ftrace_pid_task(pid);
3605 ftrace_update_pid_func();
3606 ftrace_startup_enable(0);
3608 mutex_unlock(&ftrace_lock);
3612 if (pid != ftrace_swapper_pid)
3616 mutex_unlock(&ftrace_lock);
3620 static void ftrace_pid_reset(void)
3622 struct ftrace_pid *fpid, *safe;
3624 mutex_lock(&ftrace_lock);
3625 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
3626 struct pid *pid = fpid->pid;
3628 clear_ftrace_pid_task(pid);
3630 list_del(&fpid->list);
3634 ftrace_update_pid_func();
3635 ftrace_startup_enable(0);
3637 mutex_unlock(&ftrace_lock);
3640 static void *fpid_start(struct seq_file *m, loff_t *pos)
3642 mutex_lock(&ftrace_lock);
3644 if (list_empty(&ftrace_pids) && (!*pos))
3647 return seq_list_start(&ftrace_pids, *pos);
3650 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
3655 return seq_list_next(v, &ftrace_pids, pos);
3658 static void fpid_stop(struct seq_file *m, void *p)
3660 mutex_unlock(&ftrace_lock);
3663 static int fpid_show(struct seq_file *m, void *v)
3665 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
3667 if (v == (void *)1) {
3668 seq_printf(m, "no pid\n");
3672 if (fpid->pid == ftrace_swapper_pid)
3673 seq_printf(m, "swapper tasks\n");
3675 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
3680 static const struct seq_operations ftrace_pid_sops = {
3681 .start = fpid_start,
3688 ftrace_pid_open(struct inode *inode, struct file *file)
3692 if ((file->f_mode & FMODE_WRITE) &&
3693 (file->f_flags & O_TRUNC))
3696 if (file->f_mode & FMODE_READ)
3697 ret = seq_open(file, &ftrace_pid_sops);
3703 ftrace_pid_write(struct file *filp, const char __user *ubuf,
3704 size_t cnt, loff_t *ppos)
3710 if (cnt >= sizeof(buf))
3713 if (copy_from_user(&buf, ubuf, cnt))
3719 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
3720 * to clean the filter quietly.
3722 tmp = strstrip(buf);
3723 if (strlen(tmp) == 0)
3726 ret = strict_strtol(tmp, 10, &val);
3730 ret = ftrace_pid_add(val);
3732 return ret ? ret : cnt;
3736 ftrace_pid_release(struct inode *inode, struct file *file)
3738 if (file->f_mode & FMODE_READ)
3739 seq_release(inode, file);
3744 static const struct file_operations ftrace_pid_fops = {
3745 .open = ftrace_pid_open,
3746 .write = ftrace_pid_write,
3748 .llseek = seq_lseek,
3749 .release = ftrace_pid_release,
3752 static __init int ftrace_init_debugfs(void)
3754 struct dentry *d_tracer;
3756 d_tracer = tracing_init_dentry();
3760 ftrace_init_dyn_debugfs(d_tracer);
3762 trace_create_file("set_ftrace_pid", 0644, d_tracer,
3763 NULL, &ftrace_pid_fops);
3765 ftrace_profile_debugfs(d_tracer);
3769 fs_initcall(ftrace_init_debugfs);
3772 * ftrace_kill - kill ftrace
3774 * This function should be used by panic code. It stops ftrace
3775 * but in a not so nice way. If you need to simply kill ftrace
3776 * from a non-atomic section, use ftrace_kill.
3778 void ftrace_kill(void)
3780 ftrace_disabled = 1;
3782 clear_ftrace_function();
3786 * register_ftrace_function - register a function for profiling
3787 * @ops - ops structure that holds the function for profiling.
3789 * Register a function to be called by all functions in the
3792 * Note: @ops->func and all the functions it calls must be labeled
3793 * with "notrace", otherwise it will go into a
3796 int register_ftrace_function(struct ftrace_ops *ops)
3800 mutex_lock(&ftrace_lock);
3802 if (unlikely(ftrace_disabled))
3805 ret = __register_ftrace_function(ops);
3807 ret = ftrace_startup(ops, 0);
3811 mutex_unlock(&ftrace_lock);
3814 EXPORT_SYMBOL_GPL(register_ftrace_function);
3817 * unregister_ftrace_function - unregister a function for profiling.
3818 * @ops - ops structure that holds the function to unregister
3820 * Unregister a function that was added to be called by ftrace profiling.
3822 int unregister_ftrace_function(struct ftrace_ops *ops)
3826 mutex_lock(&ftrace_lock);
3827 ret = __unregister_ftrace_function(ops);
3829 ftrace_shutdown(ops, 0);
3830 mutex_unlock(&ftrace_lock);
3834 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
3837 ftrace_enable_sysctl(struct ctl_table *table, int write,
3838 void __user *buffer, size_t *lenp,
3843 mutex_lock(&ftrace_lock);
3845 if (unlikely(ftrace_disabled))
3848 ret = proc_dointvec(table, write, buffer, lenp, ppos);
3850 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
3853 last_ftrace_enabled = !!ftrace_enabled;
3855 if (ftrace_enabled) {
3857 ftrace_startup_sysctl();
3859 /* we are starting ftrace again */
3860 if (ftrace_ops_list != &ftrace_list_end) {
3861 if (ftrace_ops_list->next == &ftrace_list_end)
3862 ftrace_trace_function = ftrace_ops_list->func;
3864 ftrace_trace_function = ftrace_ops_list_func;
3868 /* stopping ftrace calls (just send to ftrace_stub) */
3869 ftrace_trace_function = ftrace_stub;
3871 ftrace_shutdown_sysctl();
3875 mutex_unlock(&ftrace_lock);
3879 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3881 static int ftrace_graph_active;
3882 static struct notifier_block ftrace_suspend_notifier;
3884 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
3889 /* The callbacks that hook a function */
3890 trace_func_graph_ret_t ftrace_graph_return =
3891 (trace_func_graph_ret_t)ftrace_stub;
3892 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
3894 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3895 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
3899 unsigned long flags;
3900 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
3901 struct task_struct *g, *t;
3903 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
3904 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
3905 * sizeof(struct ftrace_ret_stack),
3907 if (!ret_stack_list[i]) {
3915 read_lock_irqsave(&tasklist_lock, flags);
3916 do_each_thread(g, t) {
3922 if (t->ret_stack == NULL) {
3923 atomic_set(&t->tracing_graph_pause, 0);
3924 atomic_set(&t->trace_overrun, 0);
3925 t->curr_ret_stack = -1;
3926 /* Make sure the tasks see the -1 first: */
3928 t->ret_stack = ret_stack_list[start++];
3930 } while_each_thread(g, t);
3933 read_unlock_irqrestore(&tasklist_lock, flags);
3935 for (i = start; i < end; i++)
3936 kfree(ret_stack_list[i]);
3941 ftrace_graph_probe_sched_switch(void *ignore,
3942 struct task_struct *prev, struct task_struct *next)
3944 unsigned long long timestamp;
3948 * Does the user want to count the time a function was asleep.
3949 * If so, do not update the time stamps.
3951 if (trace_flags & TRACE_ITER_SLEEP_TIME)
3954 timestamp = trace_clock_local();
3956 prev->ftrace_timestamp = timestamp;
3958 /* only process tasks that we timestamped */
3959 if (!next->ftrace_timestamp)
3963 * Update all the counters in next to make up for the
3964 * time next was sleeping.
3966 timestamp -= next->ftrace_timestamp;
3968 for (index = next->curr_ret_stack; index >= 0; index--)
3969 next->ret_stack[index].calltime += timestamp;
3972 /* Allocate a return stack for each task */
3973 static int start_graph_tracing(void)
3975 struct ftrace_ret_stack **ret_stack_list;
3978 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
3979 sizeof(struct ftrace_ret_stack *),
3982 if (!ret_stack_list)
3985 /* The cpu_boot init_task->ret_stack will never be freed */
3986 for_each_online_cpu(cpu) {
3987 if (!idle_task(cpu)->ret_stack)
3988 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
3992 ret = alloc_retstack_tasklist(ret_stack_list);
3993 } while (ret == -EAGAIN);
3996 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
3998 pr_info("ftrace_graph: Couldn't activate tracepoint"
3999 " probe to kernel_sched_switch\n");
4002 kfree(ret_stack_list);
4007 * Hibernation protection.
4008 * The state of the current task is too much unstable during
4009 * suspend/restore to disk. We want to protect against that.
4012 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4016 case PM_HIBERNATION_PREPARE:
4017 pause_graph_tracing();
4020 case PM_POST_HIBERNATION:
4021 unpause_graph_tracing();
4027 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4028 trace_func_graph_ent_t entryfunc)
4032 mutex_lock(&ftrace_lock);
4034 /* we currently allow only one tracer registered at a time */
4035 if (ftrace_graph_active) {
4040 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4041 register_pm_notifier(&ftrace_suspend_notifier);
4043 ftrace_graph_active++;
4044 ret = start_graph_tracing();
4046 ftrace_graph_active--;
4050 ftrace_graph_return = retfunc;
4051 ftrace_graph_entry = entryfunc;
4053 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4056 mutex_unlock(&ftrace_lock);
4060 void unregister_ftrace_graph(void)
4062 mutex_lock(&ftrace_lock);
4064 if (unlikely(!ftrace_graph_active))
4067 ftrace_graph_active--;
4068 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4069 ftrace_graph_entry = ftrace_graph_entry_stub;
4070 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4071 unregister_pm_notifier(&ftrace_suspend_notifier);
4072 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4075 mutex_unlock(&ftrace_lock);
4078 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4081 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4083 atomic_set(&t->tracing_graph_pause, 0);
4084 atomic_set(&t->trace_overrun, 0);
4085 t->ftrace_timestamp = 0;
4086 /* make curr_ret_stack visible before we add the ret_stack */
4088 t->ret_stack = ret_stack;
4092 * Allocate a return stack for the idle task. May be the first
4093 * time through, or it may be done by CPU hotplug online.
4095 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4097 t->curr_ret_stack = -1;
4099 * The idle task has no parent, it either has its own
4100 * stack or no stack at all.
4103 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4105 if (ftrace_graph_active) {
4106 struct ftrace_ret_stack *ret_stack;
4108 ret_stack = per_cpu(idle_ret_stack, cpu);
4110 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4111 * sizeof(struct ftrace_ret_stack),
4115 per_cpu(idle_ret_stack, cpu) = ret_stack;
4117 graph_init_task(t, ret_stack);
4121 /* Allocate a return stack for newly created task */
4122 void ftrace_graph_init_task(struct task_struct *t)
4124 /* Make sure we do not use the parent ret_stack */
4125 t->ret_stack = NULL;
4126 t->curr_ret_stack = -1;
4128 if (ftrace_graph_active) {
4129 struct ftrace_ret_stack *ret_stack;
4131 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4132 * sizeof(struct ftrace_ret_stack),
4136 graph_init_task(t, ret_stack);
4140 void ftrace_graph_exit_task(struct task_struct *t)
4142 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4144 t->ret_stack = NULL;
4145 /* NULL must become visible to IRQs before we free it: */
4151 void ftrace_graph_stop(void)