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/ftrace.h>
36 #include <asm/setup.h>
38 #include "trace_output.h"
39 #include "trace_stat.h"
41 #define FTRACE_WARN_ON(cond) \
49 #define FTRACE_WARN_ON_ONCE(cond) \
52 if (WARN_ON_ONCE(___r)) \
57 /* hash bits for specific function selection */
58 #define FTRACE_HASH_BITS 7
59 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
60 #define FTRACE_HASH_DEFAULT_BITS 10
61 #define FTRACE_HASH_MAX_BITS 12
63 /* ftrace_enabled is a method to turn ftrace on or off */
64 int ftrace_enabled __read_mostly;
65 static int last_ftrace_enabled;
67 /* Quick disabling of function tracer. */
68 int function_trace_stop;
70 /* List for set_ftrace_pid's pids. */
71 LIST_HEAD(ftrace_pids);
73 struct list_head list;
78 * ftrace_disabled is set when an anomaly is discovered.
79 * ftrace_disabled is much stronger than ftrace_enabled.
81 static int ftrace_disabled __read_mostly;
83 static DEFINE_MUTEX(ftrace_lock);
85 static struct ftrace_ops ftrace_list_end __read_mostly =
90 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
91 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
92 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
93 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
94 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
95 static struct ftrace_ops global_ops;
98 ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
101 * Traverse the ftrace_global_list, invoking all entries. The reason that we
102 * can use rcu_dereference_raw() is that elements removed from this list
103 * are simply leaked, so there is no need to interact with a grace-period
104 * mechanism. The rcu_dereference_raw() calls are needed to handle
105 * concurrent insertions into the ftrace_global_list.
107 * Silly Alpha and silly pointer-speculation compiler optimizations!
109 static void ftrace_global_list_func(unsigned long ip,
110 unsigned long parent_ip)
112 struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/
114 while (op != &ftrace_list_end) {
115 op->func(ip, parent_ip);
116 op = rcu_dereference_raw(op->next); /*see above*/
120 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
122 if (!test_tsk_trace_trace(current))
125 ftrace_pid_function(ip, parent_ip);
128 static void set_ftrace_pid_function(ftrace_func_t func)
130 /* do not set ftrace_pid_function to itself! */
131 if (func != ftrace_pid_func)
132 ftrace_pid_function = func;
136 * clear_ftrace_function - reset the ftrace function
138 * This NULLs the ftrace function and in essence stops
139 * tracing. There may be lag
141 void clear_ftrace_function(void)
143 ftrace_trace_function = ftrace_stub;
144 __ftrace_trace_function = ftrace_stub;
145 ftrace_pid_function = ftrace_stub;
148 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
150 * For those archs that do not test ftrace_trace_stop in their
151 * mcount call site, we need to do it from C.
153 static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
155 if (function_trace_stop)
158 __ftrace_trace_function(ip, parent_ip);
162 static void update_global_ops(void)
167 * If there's only one function registered, then call that
168 * function directly. Otherwise, we need to iterate over the
169 * registered callers.
171 if (ftrace_global_list == &ftrace_list_end ||
172 ftrace_global_list->next == &ftrace_list_end)
173 func = ftrace_global_list->func;
175 func = ftrace_global_list_func;
177 /* If we filter on pids, update to use the pid function */
178 if (!list_empty(&ftrace_pids)) {
179 set_ftrace_pid_function(func);
180 func = ftrace_pid_func;
183 global_ops.func = func;
186 static void update_ftrace_function(void)
193 * If we are at the end of the list and this ops is
194 * not dynamic, then have the mcount trampoline call
195 * the function directly
197 if (ftrace_ops_list == &ftrace_list_end ||
198 (ftrace_ops_list->next == &ftrace_list_end &&
199 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
200 func = ftrace_ops_list->func;
202 func = ftrace_ops_list_func;
204 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
205 ftrace_trace_function = func;
207 __ftrace_trace_function = func;
208 ftrace_trace_function = ftrace_test_stop_func;
212 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
216 * We are entering ops into the list but another
217 * CPU might be walking that list. We need to make sure
218 * the ops->next pointer is valid before another CPU sees
219 * the ops pointer included into the list.
221 rcu_assign_pointer(*list, ops);
224 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
226 struct ftrace_ops **p;
229 * If we are removing the last function, then simply point
230 * to the ftrace_stub.
232 if (*list == ops && ops->next == &ftrace_list_end) {
233 *list = &ftrace_list_end;
237 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
248 static int __register_ftrace_function(struct ftrace_ops *ops)
253 if (FTRACE_WARN_ON(ops == &global_ops))
256 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
259 if (!core_kernel_data((unsigned long)ops))
260 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
262 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
263 int first = ftrace_global_list == &ftrace_list_end;
264 add_ftrace_ops(&ftrace_global_list, ops);
265 ops->flags |= FTRACE_OPS_FL_ENABLED;
267 add_ftrace_ops(&ftrace_ops_list, &global_ops);
269 add_ftrace_ops(&ftrace_ops_list, ops);
272 update_ftrace_function();
277 static int __unregister_ftrace_function(struct ftrace_ops *ops)
284 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
287 if (FTRACE_WARN_ON(ops == &global_ops))
290 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
291 ret = remove_ftrace_ops(&ftrace_global_list, ops);
292 if (!ret && ftrace_global_list == &ftrace_list_end)
293 ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops);
295 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
297 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
303 update_ftrace_function();
306 * Dynamic ops may be freed, we must make sure that all
307 * callers are done before leaving this function.
309 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
315 static void ftrace_update_pid_func(void)
317 /* Only do something if we are tracing something */
318 if (ftrace_trace_function == ftrace_stub)
321 update_ftrace_function();
324 #ifdef CONFIG_FUNCTION_PROFILER
325 struct ftrace_profile {
326 struct hlist_node node;
328 unsigned long counter;
329 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
330 unsigned long long time;
331 unsigned long long time_squared;
335 struct ftrace_profile_page {
336 struct ftrace_profile_page *next;
338 struct ftrace_profile records[];
341 struct ftrace_profile_stat {
343 struct hlist_head *hash;
344 struct ftrace_profile_page *pages;
345 struct ftrace_profile_page *start;
346 struct tracer_stat stat;
349 #define PROFILE_RECORDS_SIZE \
350 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
352 #define PROFILES_PER_PAGE \
353 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
355 static int ftrace_profile_bits __read_mostly;
356 static int ftrace_profile_enabled __read_mostly;
358 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
359 static DEFINE_MUTEX(ftrace_profile_lock);
361 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
363 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
366 function_stat_next(void *v, int idx)
368 struct ftrace_profile *rec = v;
369 struct ftrace_profile_page *pg;
371 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
377 if ((void *)rec >= (void *)&pg->records[pg->index]) {
381 rec = &pg->records[0];
389 static void *function_stat_start(struct tracer_stat *trace)
391 struct ftrace_profile_stat *stat =
392 container_of(trace, struct ftrace_profile_stat, stat);
394 if (!stat || !stat->start)
397 return function_stat_next(&stat->start->records[0], 0);
400 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
401 /* function graph compares on total time */
402 static int function_stat_cmp(void *p1, void *p2)
404 struct ftrace_profile *a = p1;
405 struct ftrace_profile *b = p2;
407 if (a->time < b->time)
409 if (a->time > b->time)
415 /* not function graph compares against hits */
416 static int function_stat_cmp(void *p1, void *p2)
418 struct ftrace_profile *a = p1;
419 struct ftrace_profile *b = p2;
421 if (a->counter < b->counter)
423 if (a->counter > b->counter)
430 static int function_stat_headers(struct seq_file *m)
432 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
433 seq_printf(m, " Function "
436 "--- ---- --- ---\n");
438 seq_printf(m, " Function Hit\n"
444 static int function_stat_show(struct seq_file *m, void *v)
446 struct ftrace_profile *rec = v;
447 char str[KSYM_SYMBOL_LEN];
449 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
450 static struct trace_seq s;
451 unsigned long long avg;
452 unsigned long long stddev;
454 mutex_lock(&ftrace_profile_lock);
456 /* we raced with function_profile_reset() */
457 if (unlikely(rec->counter == 0)) {
462 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
463 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
465 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
468 do_div(avg, rec->counter);
470 /* Sample standard deviation (s^2) */
471 if (rec->counter <= 1)
474 stddev = rec->time_squared - rec->counter * avg * avg;
476 * Divide only 1000 for ns^2 -> us^2 conversion.
477 * trace_print_graph_duration will divide 1000 again.
479 do_div(stddev, (rec->counter - 1) * 1000);
483 trace_print_graph_duration(rec->time, &s);
484 trace_seq_puts(&s, " ");
485 trace_print_graph_duration(avg, &s);
486 trace_seq_puts(&s, " ");
487 trace_print_graph_duration(stddev, &s);
488 trace_print_seq(m, &s);
492 mutex_unlock(&ftrace_profile_lock);
497 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
499 struct ftrace_profile_page *pg;
501 pg = stat->pages = stat->start;
504 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
509 memset(stat->hash, 0,
510 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
513 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
515 struct ftrace_profile_page *pg;
520 /* If we already allocated, do nothing */
524 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
528 #ifdef CONFIG_DYNAMIC_FTRACE
529 functions = ftrace_update_tot_cnt;
532 * We do not know the number of functions that exist because
533 * dynamic tracing is what counts them. With past experience
534 * we have around 20K functions. That should be more than enough.
535 * It is highly unlikely we will execute every function in
541 pg = stat->start = stat->pages;
543 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
545 for (i = 0; i < pages; i++) {
546 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
557 unsigned long tmp = (unsigned long)pg;
563 free_page((unsigned long)stat->pages);
570 static int ftrace_profile_init_cpu(int cpu)
572 struct ftrace_profile_stat *stat;
575 stat = &per_cpu(ftrace_profile_stats, cpu);
578 /* If the profile is already created, simply reset it */
579 ftrace_profile_reset(stat);
584 * We are profiling all functions, but usually only a few thousand
585 * functions are hit. We'll make a hash of 1024 items.
587 size = FTRACE_PROFILE_HASH_SIZE;
589 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
594 if (!ftrace_profile_bits) {
597 for (; size; size >>= 1)
598 ftrace_profile_bits++;
601 /* Preallocate the function profiling pages */
602 if (ftrace_profile_pages_init(stat) < 0) {
611 static int ftrace_profile_init(void)
616 for_each_online_cpu(cpu) {
617 ret = ftrace_profile_init_cpu(cpu);
625 /* interrupts must be disabled */
626 static struct ftrace_profile *
627 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
629 struct ftrace_profile *rec;
630 struct hlist_head *hhd;
631 struct hlist_node *n;
634 key = hash_long(ip, ftrace_profile_bits);
635 hhd = &stat->hash[key];
637 if (hlist_empty(hhd))
640 hlist_for_each_entry_rcu(rec, n, hhd, node) {
648 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
649 struct ftrace_profile *rec)
653 key = hash_long(rec->ip, ftrace_profile_bits);
654 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
658 * The memory is already allocated, this simply finds a new record to use.
660 static struct ftrace_profile *
661 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
663 struct ftrace_profile *rec = NULL;
665 /* prevent recursion (from NMIs) */
666 if (atomic_inc_return(&stat->disabled) != 1)
670 * Try to find the function again since an NMI
671 * could have added it
673 rec = ftrace_find_profiled_func(stat, ip);
677 if (stat->pages->index == PROFILES_PER_PAGE) {
678 if (!stat->pages->next)
680 stat->pages = stat->pages->next;
683 rec = &stat->pages->records[stat->pages->index++];
685 ftrace_add_profile(stat, rec);
688 atomic_dec(&stat->disabled);
694 function_profile_call(unsigned long ip, unsigned long parent_ip)
696 struct ftrace_profile_stat *stat;
697 struct ftrace_profile *rec;
700 if (!ftrace_profile_enabled)
703 local_irq_save(flags);
705 stat = &__get_cpu_var(ftrace_profile_stats);
706 if (!stat->hash || !ftrace_profile_enabled)
709 rec = ftrace_find_profiled_func(stat, ip);
711 rec = ftrace_profile_alloc(stat, ip);
718 local_irq_restore(flags);
721 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
722 static int profile_graph_entry(struct ftrace_graph_ent *trace)
724 function_profile_call(trace->func, 0);
728 static void profile_graph_return(struct ftrace_graph_ret *trace)
730 struct ftrace_profile_stat *stat;
731 unsigned long long calltime;
732 struct ftrace_profile *rec;
735 local_irq_save(flags);
736 stat = &__get_cpu_var(ftrace_profile_stats);
737 if (!stat->hash || !ftrace_profile_enabled)
740 /* If the calltime was zero'd ignore it */
741 if (!trace->calltime)
744 calltime = trace->rettime - trace->calltime;
746 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
749 index = trace->depth;
751 /* Append this call time to the parent time to subtract */
753 current->ret_stack[index - 1].subtime += calltime;
755 if (current->ret_stack[index].subtime < calltime)
756 calltime -= current->ret_stack[index].subtime;
761 rec = ftrace_find_profiled_func(stat, trace->func);
763 rec->time += calltime;
764 rec->time_squared += calltime * calltime;
768 local_irq_restore(flags);
771 static int register_ftrace_profiler(void)
773 return register_ftrace_graph(&profile_graph_return,
774 &profile_graph_entry);
777 static void unregister_ftrace_profiler(void)
779 unregister_ftrace_graph();
782 static struct ftrace_ops ftrace_profile_ops __read_mostly =
784 .func = function_profile_call,
787 static int register_ftrace_profiler(void)
789 return register_ftrace_function(&ftrace_profile_ops);
792 static void unregister_ftrace_profiler(void)
794 unregister_ftrace_function(&ftrace_profile_ops);
796 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
799 ftrace_profile_write(struct file *filp, const char __user *ubuf,
800 size_t cnt, loff_t *ppos)
803 char buf[64]; /* big enough to hold a number */
806 if (cnt >= sizeof(buf))
809 if (copy_from_user(&buf, ubuf, cnt))
814 ret = strict_strtoul(buf, 10, &val);
820 mutex_lock(&ftrace_profile_lock);
821 if (ftrace_profile_enabled ^ val) {
823 ret = ftrace_profile_init();
829 ret = register_ftrace_profiler();
834 ftrace_profile_enabled = 1;
836 ftrace_profile_enabled = 0;
838 * unregister_ftrace_profiler calls stop_machine
839 * so this acts like an synchronize_sched.
841 unregister_ftrace_profiler();
845 mutex_unlock(&ftrace_profile_lock);
853 ftrace_profile_read(struct file *filp, char __user *ubuf,
854 size_t cnt, loff_t *ppos)
856 char buf[64]; /* big enough to hold a number */
859 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
860 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
863 static const struct file_operations ftrace_profile_fops = {
864 .open = tracing_open_generic,
865 .read = ftrace_profile_read,
866 .write = ftrace_profile_write,
867 .llseek = default_llseek,
870 /* used to initialize the real stat files */
871 static struct tracer_stat function_stats __initdata = {
873 .stat_start = function_stat_start,
874 .stat_next = function_stat_next,
875 .stat_cmp = function_stat_cmp,
876 .stat_headers = function_stat_headers,
877 .stat_show = function_stat_show
880 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
882 struct ftrace_profile_stat *stat;
883 struct dentry *entry;
888 for_each_possible_cpu(cpu) {
889 stat = &per_cpu(ftrace_profile_stats, cpu);
891 /* allocate enough for function name + cpu number */
892 name = kmalloc(32, GFP_KERNEL);
895 * The files created are permanent, if something happens
896 * we still do not free memory.
899 "Could not allocate stat file for cpu %d\n",
903 stat->stat = function_stats;
904 snprintf(name, 32, "function%d", cpu);
905 stat->stat.name = name;
906 ret = register_stat_tracer(&stat->stat);
909 "Could not register function stat for cpu %d\n",
916 entry = debugfs_create_file("function_profile_enabled", 0644,
917 d_tracer, NULL, &ftrace_profile_fops);
919 pr_warning("Could not create debugfs "
920 "'function_profile_enabled' entry\n");
923 #else /* CONFIG_FUNCTION_PROFILER */
924 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
927 #endif /* CONFIG_FUNCTION_PROFILER */
929 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
931 #ifdef CONFIG_DYNAMIC_FTRACE
933 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
934 # error Dynamic ftrace depends on MCOUNT_RECORD
937 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
939 struct ftrace_func_probe {
940 struct hlist_node node;
941 struct ftrace_probe_ops *ops;
949 FTRACE_ENABLE_CALLS = (1 << 0),
950 FTRACE_DISABLE_CALLS = (1 << 1),
951 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
952 FTRACE_START_FUNC_RET = (1 << 3),
953 FTRACE_STOP_FUNC_RET = (1 << 4),
955 struct ftrace_func_entry {
956 struct hlist_node hlist;
961 unsigned long size_bits;
962 struct hlist_head *buckets;
968 * We make these constant because no one should touch them,
969 * but they are used as the default "empty hash", to avoid allocating
970 * it all the time. These are in a read only section such that if
971 * anyone does try to modify it, it will cause an exception.
973 static const struct hlist_head empty_buckets[1];
974 static const struct ftrace_hash empty_hash = {
975 .buckets = (struct hlist_head *)empty_buckets,
977 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
979 static struct ftrace_ops global_ops = {
981 .notrace_hash = EMPTY_HASH,
982 .filter_hash = EMPTY_HASH,
985 static struct dyn_ftrace *ftrace_new_addrs;
987 static DEFINE_MUTEX(ftrace_regex_lock);
990 struct ftrace_page *next;
992 struct dyn_ftrace records[];
995 #define ENTRIES_PER_PAGE \
996 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
998 /* estimate from running different kernels */
999 #define NR_TO_INIT 10000
1001 static struct ftrace_page *ftrace_pages_start;
1002 static struct ftrace_page *ftrace_pages;
1004 static struct dyn_ftrace *ftrace_free_records;
1006 static struct ftrace_func_entry *
1007 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1010 struct ftrace_func_entry *entry;
1011 struct hlist_head *hhd;
1012 struct hlist_node *n;
1017 if (hash->size_bits > 0)
1018 key = hash_long(ip, hash->size_bits);
1022 hhd = &hash->buckets[key];
1024 hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1025 if (entry->ip == ip)
1031 static void __add_hash_entry(struct ftrace_hash *hash,
1032 struct ftrace_func_entry *entry)
1034 struct hlist_head *hhd;
1037 if (hash->size_bits)
1038 key = hash_long(entry->ip, hash->size_bits);
1042 hhd = &hash->buckets[key];
1043 hlist_add_head(&entry->hlist, hhd);
1047 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1049 struct ftrace_func_entry *entry;
1051 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1056 __add_hash_entry(hash, entry);
1062 free_hash_entry(struct ftrace_hash *hash,
1063 struct ftrace_func_entry *entry)
1065 hlist_del(&entry->hlist);
1071 remove_hash_entry(struct ftrace_hash *hash,
1072 struct ftrace_func_entry *entry)
1074 hlist_del(&entry->hlist);
1078 static void ftrace_hash_clear(struct ftrace_hash *hash)
1080 struct hlist_head *hhd;
1081 struct hlist_node *tp, *tn;
1082 struct ftrace_func_entry *entry;
1083 int size = 1 << hash->size_bits;
1089 for (i = 0; i < size; i++) {
1090 hhd = &hash->buckets[i];
1091 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
1092 free_hash_entry(hash, entry);
1094 FTRACE_WARN_ON(hash->count);
1097 static void free_ftrace_hash(struct ftrace_hash *hash)
1099 if (!hash || hash == EMPTY_HASH)
1101 ftrace_hash_clear(hash);
1102 kfree(hash->buckets);
1106 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1108 struct ftrace_hash *hash;
1110 hash = container_of(rcu, struct ftrace_hash, rcu);
1111 free_ftrace_hash(hash);
1114 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1116 if (!hash || hash == EMPTY_HASH)
1118 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1121 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1123 struct ftrace_hash *hash;
1126 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1130 size = 1 << size_bits;
1131 hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL);
1133 if (!hash->buckets) {
1138 hash->size_bits = size_bits;
1143 static struct ftrace_hash *
1144 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1146 struct ftrace_func_entry *entry;
1147 struct ftrace_hash *new_hash;
1148 struct hlist_node *tp;
1153 new_hash = alloc_ftrace_hash(size_bits);
1158 if (!hash || !hash->count)
1161 size = 1 << hash->size_bits;
1162 for (i = 0; i < size; i++) {
1163 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1164 ret = add_hash_entry(new_hash, entry->ip);
1170 FTRACE_WARN_ON(new_hash->count != hash->count);
1175 free_ftrace_hash(new_hash);
1180 ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
1182 struct ftrace_func_entry *entry;
1183 struct hlist_node *tp, *tn;
1184 struct hlist_head *hhd;
1185 struct ftrace_hash *old_hash;
1186 struct ftrace_hash *new_hash;
1188 int size = src->count;
1193 * If the new source is empty, just free dst and assign it
1197 free_ftrace_hash_rcu(*dst);
1198 rcu_assign_pointer(*dst, EMPTY_HASH);
1203 * Make the hash size about 1/2 the # found
1205 for (size /= 2; size; size >>= 1)
1208 /* Don't allocate too much */
1209 if (bits > FTRACE_HASH_MAX_BITS)
1210 bits = FTRACE_HASH_MAX_BITS;
1212 new_hash = alloc_ftrace_hash(bits);
1216 size = 1 << src->size_bits;
1217 for (i = 0; i < size; i++) {
1218 hhd = &src->buckets[i];
1219 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1221 key = hash_long(entry->ip, bits);
1224 remove_hash_entry(src, entry);
1225 __add_hash_entry(new_hash, entry);
1230 rcu_assign_pointer(*dst, new_hash);
1231 free_ftrace_hash_rcu(old_hash);
1237 * Test the hashes for this ops to see if we want to call
1238 * the ops->func or not.
1240 * It's a match if the ip is in the ops->filter_hash or
1241 * the filter_hash does not exist or is empty,
1243 * the ip is not in the ops->notrace_hash.
1245 * This needs to be called with preemption disabled as
1246 * the hashes are freed with call_rcu_sched().
1249 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1251 struct ftrace_hash *filter_hash;
1252 struct ftrace_hash *notrace_hash;
1255 filter_hash = rcu_dereference_raw(ops->filter_hash);
1256 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1258 if ((!filter_hash || !filter_hash->count ||
1259 ftrace_lookup_ip(filter_hash, ip)) &&
1260 (!notrace_hash || !notrace_hash->count ||
1261 !ftrace_lookup_ip(notrace_hash, ip)))
1270 * This is a double for. Do not use 'break' to break out of the loop,
1271 * you must use a goto.
1273 #define do_for_each_ftrace_rec(pg, rec) \
1274 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1276 for (_____i = 0; _____i < pg->index; _____i++) { \
1277 rec = &pg->records[_____i];
1279 #define while_for_each_ftrace_rec() \
1283 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1287 struct ftrace_hash *hash;
1288 struct ftrace_hash *other_hash;
1289 struct ftrace_page *pg;
1290 struct dyn_ftrace *rec;
1294 /* Only update if the ops has been registered */
1295 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1299 * In the filter_hash case:
1300 * If the count is zero, we update all records.
1301 * Otherwise we just update the items in the hash.
1303 * In the notrace_hash case:
1304 * We enable the update in the hash.
1305 * As disabling notrace means enabling the tracing,
1306 * and enabling notrace means disabling, the inc variable
1310 hash = ops->filter_hash;
1311 other_hash = ops->notrace_hash;
1312 if (!hash || !hash->count)
1316 hash = ops->notrace_hash;
1317 other_hash = ops->filter_hash;
1319 * If the notrace hash has no items,
1320 * then there's nothing to do.
1322 if (hash && !hash->count)
1326 do_for_each_ftrace_rec(pg, rec) {
1327 int in_other_hash = 0;
1333 * Only the filter_hash affects all records.
1334 * Update if the record is not in the notrace hash.
1336 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1339 in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip);
1340 in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip);
1345 if (filter_hash && in_hash && !in_other_hash)
1347 else if (!filter_hash && in_hash &&
1348 (in_other_hash || !other_hash->count))
1356 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1359 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1364 /* Shortcut, if we handled all records, we are done. */
1365 if (!all && count == hash->count)
1367 } while_for_each_ftrace_rec();
1370 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1373 __ftrace_hash_rec_update(ops, filter_hash, 0);
1376 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1379 __ftrace_hash_rec_update(ops, filter_hash, 1);
1382 static void ftrace_free_rec(struct dyn_ftrace *rec)
1384 rec->freelist = ftrace_free_records;
1385 ftrace_free_records = rec;
1386 rec->flags |= FTRACE_FL_FREE;
1389 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
1391 struct dyn_ftrace *rec;
1393 /* First check for freed records */
1394 if (ftrace_free_records) {
1395 rec = ftrace_free_records;
1397 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
1398 FTRACE_WARN_ON_ONCE(1);
1399 ftrace_free_records = NULL;
1403 ftrace_free_records = rec->freelist;
1404 memset(rec, 0, sizeof(*rec));
1408 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
1409 if (!ftrace_pages->next) {
1410 /* allocate another page */
1411 ftrace_pages->next =
1412 (void *)get_zeroed_page(GFP_KERNEL);
1413 if (!ftrace_pages->next)
1416 ftrace_pages = ftrace_pages->next;
1419 return &ftrace_pages->records[ftrace_pages->index++];
1422 static struct dyn_ftrace *
1423 ftrace_record_ip(unsigned long ip)
1425 struct dyn_ftrace *rec;
1427 if (ftrace_disabled)
1430 rec = ftrace_alloc_dyn_node(ip);
1435 rec->newlist = ftrace_new_addrs;
1436 ftrace_new_addrs = rec;
1441 static void print_ip_ins(const char *fmt, unsigned char *p)
1445 printk(KERN_CONT "%s", fmt);
1447 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1448 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1451 static void ftrace_bug(int failed, unsigned long ip)
1455 FTRACE_WARN_ON_ONCE(1);
1456 pr_info("ftrace faulted on modifying ");
1460 FTRACE_WARN_ON_ONCE(1);
1461 pr_info("ftrace failed to modify ");
1463 print_ip_ins(" actual: ", (unsigned char *)ip);
1464 printk(KERN_CONT "\n");
1467 FTRACE_WARN_ON_ONCE(1);
1468 pr_info("ftrace faulted on writing ");
1472 FTRACE_WARN_ON_ONCE(1);
1473 pr_info("ftrace faulted on unknown error ");
1479 /* Return 1 if the address range is reserved for ftrace */
1480 int ftrace_text_reserved(void *start, void *end)
1482 struct dyn_ftrace *rec;
1483 struct ftrace_page *pg;
1485 do_for_each_ftrace_rec(pg, rec) {
1486 if (rec->ip <= (unsigned long)end &&
1487 rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
1489 } while_for_each_ftrace_rec();
1495 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1497 unsigned long ftrace_addr;
1498 unsigned long flag = 0UL;
1500 ftrace_addr = (unsigned long)FTRACE_ADDR;
1503 * If we are enabling tracing:
1505 * If the record has a ref count, then we need to enable it
1506 * because someone is using it.
1508 * Otherwise we make sure its disabled.
1510 * If we are disabling tracing, then disable all records that
1513 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1514 flag = FTRACE_FL_ENABLED;
1516 /* If the state of this record hasn't changed, then do nothing */
1517 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1521 rec->flags |= FTRACE_FL_ENABLED;
1522 return ftrace_make_call(rec, ftrace_addr);
1525 rec->flags &= ~FTRACE_FL_ENABLED;
1526 return ftrace_make_nop(NULL, rec, ftrace_addr);
1529 static void ftrace_replace_code(int enable)
1531 struct dyn_ftrace *rec;
1532 struct ftrace_page *pg;
1535 if (unlikely(ftrace_disabled))
1538 do_for_each_ftrace_rec(pg, rec) {
1539 /* Skip over free records */
1540 if (rec->flags & FTRACE_FL_FREE)
1543 failed = __ftrace_replace_code(rec, enable);
1545 ftrace_bug(failed, rec->ip);
1546 /* Stop processing */
1549 } while_for_each_ftrace_rec();
1553 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1560 if (unlikely(ftrace_disabled))
1563 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1565 ftrace_bug(ret, ip);
1572 * archs can override this function if they must do something
1573 * before the modifying code is performed.
1575 int __weak ftrace_arch_code_modify_prepare(void)
1581 * archs can override this function if they must do something
1582 * after the modifying code is performed.
1584 int __weak ftrace_arch_code_modify_post_process(void)
1589 static int __ftrace_modify_code(void *data)
1591 int *command = data;
1593 if (*command & FTRACE_ENABLE_CALLS)
1594 ftrace_replace_code(1);
1595 else if (*command & FTRACE_DISABLE_CALLS)
1596 ftrace_replace_code(0);
1598 if (*command & FTRACE_UPDATE_TRACE_FUNC)
1599 ftrace_update_ftrace_func(ftrace_trace_function);
1601 if (*command & FTRACE_START_FUNC_RET)
1602 ftrace_enable_ftrace_graph_caller();
1603 else if (*command & FTRACE_STOP_FUNC_RET)
1604 ftrace_disable_ftrace_graph_caller();
1609 static void ftrace_run_update_code(int command)
1613 ret = ftrace_arch_code_modify_prepare();
1614 FTRACE_WARN_ON(ret);
1618 stop_machine(__ftrace_modify_code, &command, NULL);
1620 ret = ftrace_arch_code_modify_post_process();
1621 FTRACE_WARN_ON(ret);
1624 static ftrace_func_t saved_ftrace_func;
1625 static int ftrace_start_up;
1626 static int global_start_up;
1628 static void ftrace_startup_enable(int command)
1630 if (saved_ftrace_func != ftrace_trace_function) {
1631 saved_ftrace_func = ftrace_trace_function;
1632 command |= FTRACE_UPDATE_TRACE_FUNC;
1635 if (!command || !ftrace_enabled)
1638 ftrace_run_update_code(command);
1641 static void ftrace_startup(struct ftrace_ops *ops, int command)
1643 bool hash_enable = true;
1645 if (unlikely(ftrace_disabled))
1649 command |= FTRACE_ENABLE_CALLS;
1651 /* ops marked global share the filter hashes */
1652 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1654 /* Don't update hash if global is already set */
1655 if (global_start_up)
1656 hash_enable = false;
1660 ops->flags |= FTRACE_OPS_FL_ENABLED;
1662 ftrace_hash_rec_enable(ops, 1);
1664 ftrace_startup_enable(command);
1667 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
1669 bool hash_disable = true;
1671 if (unlikely(ftrace_disabled))
1676 * Just warn in case of unbalance, no need to kill ftrace, it's not
1677 * critical but the ftrace_call callers may be never nopped again after
1678 * further ftrace uses.
1680 WARN_ON_ONCE(ftrace_start_up < 0);
1682 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1685 WARN_ON_ONCE(global_start_up < 0);
1686 /* Don't update hash if global still has users */
1687 if (global_start_up) {
1688 WARN_ON_ONCE(!ftrace_start_up);
1689 hash_disable = false;
1694 ftrace_hash_rec_disable(ops, 1);
1696 if (ops != &global_ops || !global_start_up)
1697 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
1699 if (!ftrace_start_up)
1700 command |= FTRACE_DISABLE_CALLS;
1702 if (saved_ftrace_func != ftrace_trace_function) {
1703 saved_ftrace_func = ftrace_trace_function;
1704 command |= FTRACE_UPDATE_TRACE_FUNC;
1707 if (!command || !ftrace_enabled)
1710 ftrace_run_update_code(command);
1713 static void ftrace_startup_sysctl(void)
1715 if (unlikely(ftrace_disabled))
1718 /* Force update next time */
1719 saved_ftrace_func = NULL;
1720 /* ftrace_start_up is true if we want ftrace running */
1721 if (ftrace_start_up)
1722 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
1725 static void ftrace_shutdown_sysctl(void)
1727 if (unlikely(ftrace_disabled))
1730 /* ftrace_start_up is true if ftrace is running */
1731 if (ftrace_start_up)
1732 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
1735 static cycle_t ftrace_update_time;
1736 static unsigned long ftrace_update_cnt;
1737 unsigned long ftrace_update_tot_cnt;
1739 static int ftrace_update_code(struct module *mod)
1741 struct dyn_ftrace *p;
1742 cycle_t start, stop;
1744 start = ftrace_now(raw_smp_processor_id());
1745 ftrace_update_cnt = 0;
1747 while (ftrace_new_addrs) {
1749 /* If something went wrong, bail without enabling anything */
1750 if (unlikely(ftrace_disabled))
1753 p = ftrace_new_addrs;
1754 ftrace_new_addrs = p->newlist;
1758 * Do the initial record conversion from mcount jump
1759 * to the NOP instructions.
1761 if (!ftrace_code_disable(mod, p)) {
1767 ftrace_update_cnt++;
1770 * If the tracing is enabled, go ahead and enable the record.
1772 * The reason not to enable the record immediatelly is the
1773 * inherent check of ftrace_make_nop/ftrace_make_call for
1774 * correct previous instructions. Making first the NOP
1775 * conversion puts the module to the correct state, thus
1776 * passing the ftrace_make_call check.
1778 if (ftrace_start_up) {
1779 int failed = __ftrace_replace_code(p, 1);
1781 ftrace_bug(failed, p->ip);
1787 stop = ftrace_now(raw_smp_processor_id());
1788 ftrace_update_time = stop - start;
1789 ftrace_update_tot_cnt += ftrace_update_cnt;
1794 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
1796 struct ftrace_page *pg;
1800 /* allocate a few pages */
1801 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
1802 if (!ftrace_pages_start)
1806 * Allocate a few more pages.
1808 * TODO: have some parser search vmlinux before
1809 * final linking to find all calls to ftrace.
1811 * a) know how many pages to allocate.
1813 * b) set up the table then.
1815 * The dynamic code is still necessary for
1819 pg = ftrace_pages = ftrace_pages_start;
1821 cnt = num_to_init / ENTRIES_PER_PAGE;
1822 pr_info("ftrace: allocating %ld entries in %d pages\n",
1823 num_to_init, cnt + 1);
1825 for (i = 0; i < cnt; i++) {
1826 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
1828 /* If we fail, we'll try later anyway */
1839 FTRACE_ITER_FILTER = (1 << 0),
1840 FTRACE_ITER_NOTRACE = (1 << 1),
1841 FTRACE_ITER_PRINTALL = (1 << 2),
1842 FTRACE_ITER_HASH = (1 << 3),
1843 FTRACE_ITER_ENABLED = (1 << 4),
1846 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1848 struct ftrace_iterator {
1851 struct ftrace_page *pg;
1852 struct dyn_ftrace *func;
1853 struct ftrace_func_probe *probe;
1854 struct trace_parser parser;
1855 struct ftrace_hash *hash;
1856 struct ftrace_ops *ops;
1863 t_hash_next(struct seq_file *m, loff_t *pos)
1865 struct ftrace_iterator *iter = m->private;
1866 struct hlist_node *hnd = NULL;
1867 struct hlist_head *hhd;
1873 hnd = &iter->probe->node;
1875 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
1878 hhd = &ftrace_func_hash[iter->hidx];
1880 if (hlist_empty(hhd)) {
1896 if (WARN_ON_ONCE(!hnd))
1899 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
1904 static void *t_hash_start(struct seq_file *m, loff_t *pos)
1906 struct ftrace_iterator *iter = m->private;
1910 if (iter->func_pos > *pos)
1914 for (l = 0; l <= (*pos - iter->func_pos); ) {
1915 p = t_hash_next(m, &l);
1922 /* Only set this if we have an item */
1923 iter->flags |= FTRACE_ITER_HASH;
1929 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
1931 struct ftrace_func_probe *rec;
1934 if (WARN_ON_ONCE(!rec))
1937 if (rec->ops->print)
1938 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
1940 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
1943 seq_printf(m, ":%p", rec->data);
1950 t_next(struct seq_file *m, void *v, loff_t *pos)
1952 struct ftrace_iterator *iter = m->private;
1953 struct ftrace_ops *ops = &global_ops;
1954 struct dyn_ftrace *rec = NULL;
1956 if (unlikely(ftrace_disabled))
1959 if (iter->flags & FTRACE_ITER_HASH)
1960 return t_hash_next(m, pos);
1963 iter->pos = iter->func_pos = *pos;
1965 if (iter->flags & FTRACE_ITER_PRINTALL)
1966 return t_hash_start(m, pos);
1969 if (iter->idx >= iter->pg->index) {
1970 if (iter->pg->next) {
1971 iter->pg = iter->pg->next;
1976 rec = &iter->pg->records[iter->idx++];
1977 if ((rec->flags & FTRACE_FL_FREE) ||
1979 ((iter->flags & FTRACE_ITER_FILTER) &&
1980 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
1982 ((iter->flags & FTRACE_ITER_NOTRACE) &&
1983 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
1985 ((iter->flags & FTRACE_ITER_ENABLED) &&
1986 !(rec->flags & ~FTRACE_FL_MASK))) {
1994 return t_hash_start(m, pos);
2001 static void reset_iter_read(struct ftrace_iterator *iter)
2005 iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
2008 static void *t_start(struct seq_file *m, loff_t *pos)
2010 struct ftrace_iterator *iter = m->private;
2011 struct ftrace_ops *ops = &global_ops;
2015 mutex_lock(&ftrace_lock);
2017 if (unlikely(ftrace_disabled))
2021 * If an lseek was done, then reset and start from beginning.
2023 if (*pos < iter->pos)
2024 reset_iter_read(iter);
2027 * For set_ftrace_filter reading, if we have the filter
2028 * off, we can short cut and just print out that all
2029 * functions are enabled.
2031 if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) {
2033 return t_hash_start(m, pos);
2034 iter->flags |= FTRACE_ITER_PRINTALL;
2035 /* reset in case of seek/pread */
2036 iter->flags &= ~FTRACE_ITER_HASH;
2040 if (iter->flags & FTRACE_ITER_HASH)
2041 return t_hash_start(m, pos);
2044 * Unfortunately, we need to restart at ftrace_pages_start
2045 * every time we let go of the ftrace_mutex. This is because
2046 * those pointers can change without the lock.
2048 iter->pg = ftrace_pages_start;
2050 for (l = 0; l <= *pos; ) {
2051 p = t_next(m, p, &l);
2057 if (iter->flags & FTRACE_ITER_FILTER)
2058 return t_hash_start(m, pos);
2066 static void t_stop(struct seq_file *m, void *p)
2068 mutex_unlock(&ftrace_lock);
2071 static int t_show(struct seq_file *m, void *v)
2073 struct ftrace_iterator *iter = m->private;
2074 struct dyn_ftrace *rec;
2076 if (iter->flags & FTRACE_ITER_HASH)
2077 return t_hash_show(m, iter);
2079 if (iter->flags & FTRACE_ITER_PRINTALL) {
2080 seq_printf(m, "#### all functions enabled ####\n");
2089 seq_printf(m, "%ps", (void *)rec->ip);
2090 if (iter->flags & FTRACE_ITER_ENABLED)
2091 seq_printf(m, " (%ld)",
2092 rec->flags & ~FTRACE_FL_MASK);
2093 seq_printf(m, "\n");
2098 static const struct seq_operations show_ftrace_seq_ops = {
2106 ftrace_avail_open(struct inode *inode, struct file *file)
2108 struct ftrace_iterator *iter;
2111 if (unlikely(ftrace_disabled))
2114 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2118 iter->pg = ftrace_pages_start;
2120 ret = seq_open(file, &show_ftrace_seq_ops);
2122 struct seq_file *m = file->private_data;
2133 ftrace_enabled_open(struct inode *inode, struct file *file)
2135 struct ftrace_iterator *iter;
2138 if (unlikely(ftrace_disabled))
2141 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2145 iter->pg = ftrace_pages_start;
2146 iter->flags = FTRACE_ITER_ENABLED;
2148 ret = seq_open(file, &show_ftrace_seq_ops);
2150 struct seq_file *m = file->private_data;
2160 static void ftrace_filter_reset(struct ftrace_hash *hash)
2162 mutex_lock(&ftrace_lock);
2163 ftrace_hash_clear(hash);
2164 mutex_unlock(&ftrace_lock);
2168 ftrace_regex_open(struct ftrace_ops *ops, int flag,
2169 struct inode *inode, struct file *file)
2171 struct ftrace_iterator *iter;
2172 struct ftrace_hash *hash;
2175 if (unlikely(ftrace_disabled))
2178 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2182 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2187 if (flag & FTRACE_ITER_NOTRACE)
2188 hash = ops->notrace_hash;
2190 hash = ops->filter_hash;
2195 if (file->f_mode & FMODE_WRITE) {
2196 mutex_lock(&ftrace_lock);
2197 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2198 mutex_unlock(&ftrace_lock);
2201 trace_parser_put(&iter->parser);
2207 mutex_lock(&ftrace_regex_lock);
2209 if ((file->f_mode & FMODE_WRITE) &&
2210 (file->f_flags & O_TRUNC))
2211 ftrace_filter_reset(iter->hash);
2213 if (file->f_mode & FMODE_READ) {
2214 iter->pg = ftrace_pages_start;
2216 ret = seq_open(file, &show_ftrace_seq_ops);
2218 struct seq_file *m = file->private_data;
2222 free_ftrace_hash(iter->hash);
2223 trace_parser_put(&iter->parser);
2227 file->private_data = iter;
2228 mutex_unlock(&ftrace_regex_lock);
2234 ftrace_filter_open(struct inode *inode, struct file *file)
2236 return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER,
2241 ftrace_notrace_open(struct inode *inode, struct file *file)
2243 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2248 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
2252 if (file->f_mode & FMODE_READ)
2253 ret = seq_lseek(file, offset, origin);
2255 file->f_pos = ret = 1;
2260 static int ftrace_match(char *str, char *regex, int len, int type)
2267 if (strcmp(str, regex) == 0)
2270 case MATCH_FRONT_ONLY:
2271 if (strncmp(str, regex, len) == 0)
2274 case MATCH_MIDDLE_ONLY:
2275 if (strstr(str, regex))
2278 case MATCH_END_ONLY:
2280 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2289 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2291 struct ftrace_func_entry *entry;
2294 entry = ftrace_lookup_ip(hash, rec->ip);
2296 /* Do nothing if it doesn't exist */
2300 free_hash_entry(hash, entry);
2302 /* Do nothing if it exists */
2306 ret = add_hash_entry(hash, rec->ip);
2312 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2313 char *regex, int len, int type)
2315 char str[KSYM_SYMBOL_LEN];
2318 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2321 /* module lookup requires matching the module */
2322 if (!modname || strcmp(modname, mod))
2325 /* blank search means to match all funcs in the mod */
2330 return ftrace_match(str, regex, len, type);
2334 match_records(struct ftrace_hash *hash, char *buff,
2335 int len, char *mod, int not)
2337 unsigned search_len = 0;
2338 struct ftrace_page *pg;
2339 struct dyn_ftrace *rec;
2340 int type = MATCH_FULL;
2341 char *search = buff;
2346 type = filter_parse_regex(buff, len, &search, ¬);
2347 search_len = strlen(search);
2350 mutex_lock(&ftrace_lock);
2352 if (unlikely(ftrace_disabled))
2355 do_for_each_ftrace_rec(pg, rec) {
2357 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2358 ret = enter_record(hash, rec, not);
2365 } while_for_each_ftrace_rec();
2367 mutex_unlock(&ftrace_lock);
2373 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2375 return match_records(hash, buff, len, NULL, 0);
2379 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2383 /* blank or '*' mean the same */
2384 if (strcmp(buff, "*") == 0)
2387 /* handle the case of 'dont filter this module' */
2388 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2393 return match_records(hash, buff, strlen(buff), mod, not);
2397 * We register the module command as a template to show others how
2398 * to register the a command as well.
2402 ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
2404 struct ftrace_ops *ops = &global_ops;
2405 struct ftrace_hash *hash;
2410 * cmd == 'mod' because we only registered this func
2411 * for the 'mod' ftrace_func_command.
2412 * But if you register one func with multiple commands,
2413 * you can tell which command was used by the cmd
2417 /* we must have a module name */
2421 mod = strsep(¶m, ":");
2426 hash = ops->filter_hash;
2428 hash = ops->notrace_hash;
2430 ret = ftrace_match_module_records(hash, func, mod);
2439 static struct ftrace_func_command ftrace_mod_cmd = {
2441 .func = ftrace_mod_callback,
2444 static int __init ftrace_mod_cmd_init(void)
2446 return register_ftrace_command(&ftrace_mod_cmd);
2448 device_initcall(ftrace_mod_cmd_init);
2451 function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
2453 struct ftrace_func_probe *entry;
2454 struct hlist_head *hhd;
2455 struct hlist_node *n;
2458 key = hash_long(ip, FTRACE_HASH_BITS);
2460 hhd = &ftrace_func_hash[key];
2462 if (hlist_empty(hhd))
2466 * Disable preemption for these calls to prevent a RCU grace
2467 * period. This syncs the hash iteration and freeing of items
2468 * on the hash. rcu_read_lock is too dangerous here.
2470 preempt_disable_notrace();
2471 hlist_for_each_entry_rcu(entry, n, hhd, node) {
2472 if (entry->ip == ip)
2473 entry->ops->func(ip, parent_ip, &entry->data);
2475 preempt_enable_notrace();
2478 static struct ftrace_ops trace_probe_ops __read_mostly =
2480 .func = function_trace_probe_call,
2483 static int ftrace_probe_registered;
2485 static void __enable_ftrace_function_probe(void)
2490 if (ftrace_probe_registered)
2493 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2494 struct hlist_head *hhd = &ftrace_func_hash[i];
2498 /* Nothing registered? */
2499 if (i == FTRACE_FUNC_HASHSIZE)
2502 ret = __register_ftrace_function(&trace_probe_ops);
2504 ftrace_startup(&trace_probe_ops, 0);
2506 ftrace_probe_registered = 1;
2509 static void __disable_ftrace_function_probe(void)
2514 if (!ftrace_probe_registered)
2517 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2518 struct hlist_head *hhd = &ftrace_func_hash[i];
2523 /* no more funcs left */
2524 ret = __unregister_ftrace_function(&trace_probe_ops);
2526 ftrace_shutdown(&trace_probe_ops, 0);
2528 ftrace_probe_registered = 0;
2532 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2534 struct ftrace_func_probe *entry =
2535 container_of(rhp, struct ftrace_func_probe, rcu);
2537 if (entry->ops->free)
2538 entry->ops->free(&entry->data);
2544 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2547 struct ftrace_func_probe *entry;
2548 struct ftrace_page *pg;
2549 struct dyn_ftrace *rec;
2555 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2556 len = strlen(search);
2558 /* we do not support '!' for function probes */
2562 mutex_lock(&ftrace_lock);
2564 if (unlikely(ftrace_disabled))
2567 do_for_each_ftrace_rec(pg, rec) {
2569 if (!ftrace_match_record(rec, NULL, search, len, type))
2572 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2574 /* If we did not process any, then return error */
2585 * The caller might want to do something special
2586 * for each function we find. We call the callback
2587 * to give the caller an opportunity to do so.
2589 if (ops->callback) {
2590 if (ops->callback(rec->ip, &entry->data) < 0) {
2591 /* caller does not like this func */
2598 entry->ip = rec->ip;
2600 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2601 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2603 } while_for_each_ftrace_rec();
2604 __enable_ftrace_function_probe();
2607 mutex_unlock(&ftrace_lock);
2613 PROBE_TEST_FUNC = 1,
2618 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2619 void *data, int flags)
2621 struct ftrace_func_probe *entry;
2622 struct hlist_node *n, *tmp;
2623 char str[KSYM_SYMBOL_LEN];
2624 int type = MATCH_FULL;
2628 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
2633 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2634 len = strlen(search);
2636 /* we do not support '!' for function probes */
2641 mutex_lock(&ftrace_lock);
2642 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2643 struct hlist_head *hhd = &ftrace_func_hash[i];
2645 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2647 /* break up if statements for readability */
2648 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
2651 if ((flags & PROBE_TEST_DATA) && entry->data != data)
2654 /* do this last, since it is the most expensive */
2656 kallsyms_lookup(entry->ip, NULL, NULL,
2658 if (!ftrace_match(str, glob, len, type))
2662 hlist_del(&entry->node);
2663 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2666 __disable_ftrace_function_probe();
2667 mutex_unlock(&ftrace_lock);
2671 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2674 __unregister_ftrace_function_probe(glob, ops, data,
2675 PROBE_TEST_FUNC | PROBE_TEST_DATA);
2679 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
2681 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
2684 void unregister_ftrace_function_probe_all(char *glob)
2686 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
2689 static LIST_HEAD(ftrace_commands);
2690 static DEFINE_MUTEX(ftrace_cmd_mutex);
2692 int register_ftrace_command(struct ftrace_func_command *cmd)
2694 struct ftrace_func_command *p;
2697 mutex_lock(&ftrace_cmd_mutex);
2698 list_for_each_entry(p, &ftrace_commands, list) {
2699 if (strcmp(cmd->name, p->name) == 0) {
2704 list_add(&cmd->list, &ftrace_commands);
2706 mutex_unlock(&ftrace_cmd_mutex);
2711 int unregister_ftrace_command(struct ftrace_func_command *cmd)
2713 struct ftrace_func_command *p, *n;
2716 mutex_lock(&ftrace_cmd_mutex);
2717 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
2718 if (strcmp(cmd->name, p->name) == 0) {
2720 list_del_init(&p->list);
2725 mutex_unlock(&ftrace_cmd_mutex);
2730 static int ftrace_process_regex(struct ftrace_hash *hash,
2731 char *buff, int len, int enable)
2733 char *func, *command, *next = buff;
2734 struct ftrace_func_command *p;
2737 func = strsep(&next, ":");
2740 ret = ftrace_match_records(hash, func, len);
2750 command = strsep(&next, ":");
2752 mutex_lock(&ftrace_cmd_mutex);
2753 list_for_each_entry(p, &ftrace_commands, list) {
2754 if (strcmp(p->name, command) == 0) {
2755 ret = p->func(func, command, next, enable);
2760 mutex_unlock(&ftrace_cmd_mutex);
2766 ftrace_regex_write(struct file *file, const char __user *ubuf,
2767 size_t cnt, loff_t *ppos, int enable)
2769 struct ftrace_iterator *iter;
2770 struct trace_parser *parser;
2776 mutex_lock(&ftrace_regex_lock);
2779 if (unlikely(ftrace_disabled))
2782 if (file->f_mode & FMODE_READ) {
2783 struct seq_file *m = file->private_data;
2786 iter = file->private_data;
2788 parser = &iter->parser;
2789 read = trace_get_user(parser, ubuf, cnt, ppos);
2791 if (read >= 0 && trace_parser_loaded(parser) &&
2792 !trace_parser_cont(parser)) {
2793 ret = ftrace_process_regex(iter->hash, parser->buffer,
2794 parser->idx, enable);
2795 trace_parser_clear(parser);
2802 mutex_unlock(&ftrace_regex_lock);
2808 ftrace_filter_write(struct file *file, const char __user *ubuf,
2809 size_t cnt, loff_t *ppos)
2811 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
2815 ftrace_notrace_write(struct file *file, const char __user *ubuf,
2816 size_t cnt, loff_t *ppos)
2818 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
2822 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
2823 int reset, int enable)
2825 struct ftrace_hash **orig_hash;
2826 struct ftrace_hash *hash;
2829 /* All global ops uses the global ops filters */
2830 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
2833 if (unlikely(ftrace_disabled))
2837 orig_hash = &ops->filter_hash;
2839 orig_hash = &ops->notrace_hash;
2841 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
2845 mutex_lock(&ftrace_regex_lock);
2847 ftrace_filter_reset(hash);
2849 ftrace_match_records(hash, buf, len);
2851 mutex_lock(&ftrace_lock);
2852 ret = ftrace_hash_move(orig_hash, hash);
2853 mutex_unlock(&ftrace_lock);
2855 mutex_unlock(&ftrace_regex_lock);
2857 free_ftrace_hash(hash);
2862 * ftrace_set_filter - set a function to filter on in ftrace
2863 * @ops - the ops to set the filter with
2864 * @buf - the string that holds the function filter text.
2865 * @len - the length of the string.
2866 * @reset - non zero to reset all filters before applying this filter.
2868 * Filters denote which functions should be enabled when tracing is enabled.
2869 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2871 void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
2874 ftrace_set_regex(ops, buf, len, reset, 1);
2876 EXPORT_SYMBOL_GPL(ftrace_set_filter);
2879 * ftrace_set_notrace - set a function to not trace in ftrace
2880 * @ops - the ops to set the notrace filter with
2881 * @buf - the string that holds the function notrace text.
2882 * @len - the length of the string.
2883 * @reset - non zero to reset all filters before applying this filter.
2885 * Notrace Filters denote which functions should not be enabled when tracing
2886 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2889 void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
2892 ftrace_set_regex(ops, buf, len, reset, 0);
2894 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
2896 * ftrace_set_filter - set a function to filter on in ftrace
2897 * @ops - the ops to set the filter with
2898 * @buf - the string that holds the function filter text.
2899 * @len - the length of the string.
2900 * @reset - non zero to reset all filters before applying this filter.
2902 * Filters denote which functions should be enabled when tracing is enabled.
2903 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2905 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
2907 ftrace_set_regex(&global_ops, buf, len, reset, 1);
2909 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
2912 * ftrace_set_notrace - set a function to not trace in ftrace
2913 * @ops - the ops to set the notrace filter with
2914 * @buf - the string that holds the function notrace text.
2915 * @len - the length of the string.
2916 * @reset - non zero to reset all filters before applying this filter.
2918 * Notrace Filters denote which functions should not be enabled when tracing
2919 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2922 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
2924 ftrace_set_regex(&global_ops, buf, len, reset, 0);
2926 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
2929 * command line interface to allow users to set filters on boot up.
2931 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
2932 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
2933 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
2935 static int __init set_ftrace_notrace(char *str)
2937 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
2940 __setup("ftrace_notrace=", set_ftrace_notrace);
2942 static int __init set_ftrace_filter(char *str)
2944 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
2947 __setup("ftrace_filter=", set_ftrace_filter);
2949 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2950 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
2951 static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
2953 static int __init set_graph_function(char *str)
2955 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
2958 __setup("ftrace_graph_filter=", set_graph_function);
2960 static void __init set_ftrace_early_graph(char *buf)
2966 func = strsep(&buf, ",");
2967 /* we allow only one expression at a time */
2968 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
2971 printk(KERN_DEBUG "ftrace: function %s not "
2972 "traceable\n", func);
2975 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2978 set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
2983 func = strsep(&buf, ",");
2984 ftrace_set_regex(ops, func, strlen(func), 0, enable);
2988 static void __init set_ftrace_early_filters(void)
2990 if (ftrace_filter_buf[0])
2991 set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1);
2992 if (ftrace_notrace_buf[0])
2993 set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0);
2994 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2995 if (ftrace_graph_buf[0])
2996 set_ftrace_early_graph(ftrace_graph_buf);
2997 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3001 ftrace_regex_release(struct inode *inode, struct file *file)
3003 struct seq_file *m = (struct seq_file *)file->private_data;
3004 struct ftrace_iterator *iter;
3005 struct ftrace_hash **orig_hash;
3006 struct trace_parser *parser;
3010 mutex_lock(&ftrace_regex_lock);
3011 if (file->f_mode & FMODE_READ) {
3014 seq_release(inode, file);
3016 iter = file->private_data;
3018 parser = &iter->parser;
3019 if (trace_parser_loaded(parser)) {
3020 parser->buffer[parser->idx] = 0;
3021 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3024 trace_parser_put(parser);
3026 if (file->f_mode & FMODE_WRITE) {
3027 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3030 orig_hash = &iter->ops->filter_hash;
3032 orig_hash = &iter->ops->notrace_hash;
3034 mutex_lock(&ftrace_lock);
3036 * Remove the current set, update the hash and add
3039 ftrace_hash_rec_disable(iter->ops, filter_hash);
3040 ret = ftrace_hash_move(orig_hash, iter->hash);
3042 ftrace_hash_rec_enable(iter->ops, filter_hash);
3043 if (iter->ops->flags & FTRACE_OPS_FL_ENABLED
3045 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
3047 mutex_unlock(&ftrace_lock);
3049 free_ftrace_hash(iter->hash);
3052 mutex_unlock(&ftrace_regex_lock);
3056 static const struct file_operations ftrace_avail_fops = {
3057 .open = ftrace_avail_open,
3059 .llseek = seq_lseek,
3060 .release = seq_release_private,
3063 static const struct file_operations ftrace_enabled_fops = {
3064 .open = ftrace_enabled_open,
3066 .llseek = seq_lseek,
3067 .release = seq_release_private,
3070 static const struct file_operations ftrace_filter_fops = {
3071 .open = ftrace_filter_open,
3073 .write = ftrace_filter_write,
3074 .llseek = ftrace_regex_lseek,
3075 .release = ftrace_regex_release,
3078 static const struct file_operations ftrace_notrace_fops = {
3079 .open = ftrace_notrace_open,
3081 .write = ftrace_notrace_write,
3082 .llseek = ftrace_regex_lseek,
3083 .release = ftrace_regex_release,
3086 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3088 static DEFINE_MUTEX(graph_lock);
3090 int ftrace_graph_count;
3091 int ftrace_graph_filter_enabled;
3092 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3095 __g_next(struct seq_file *m, loff_t *pos)
3097 if (*pos >= ftrace_graph_count)
3099 return &ftrace_graph_funcs[*pos];
3103 g_next(struct seq_file *m, void *v, loff_t *pos)
3106 return __g_next(m, pos);
3109 static void *g_start(struct seq_file *m, loff_t *pos)
3111 mutex_lock(&graph_lock);
3113 /* Nothing, tell g_show to print all functions are enabled */
3114 if (!ftrace_graph_filter_enabled && !*pos)
3117 return __g_next(m, pos);
3120 static void g_stop(struct seq_file *m, void *p)
3122 mutex_unlock(&graph_lock);
3125 static int g_show(struct seq_file *m, void *v)
3127 unsigned long *ptr = v;
3132 if (ptr == (unsigned long *)1) {
3133 seq_printf(m, "#### all functions enabled ####\n");
3137 seq_printf(m, "%ps\n", (void *)*ptr);
3142 static const struct seq_operations ftrace_graph_seq_ops = {
3150 ftrace_graph_open(struct inode *inode, struct file *file)
3154 if (unlikely(ftrace_disabled))
3157 mutex_lock(&graph_lock);
3158 if ((file->f_mode & FMODE_WRITE) &&
3159 (file->f_flags & O_TRUNC)) {
3160 ftrace_graph_filter_enabled = 0;
3161 ftrace_graph_count = 0;
3162 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3164 mutex_unlock(&graph_lock);
3166 if (file->f_mode & FMODE_READ)
3167 ret = seq_open(file, &ftrace_graph_seq_ops);
3173 ftrace_graph_release(struct inode *inode, struct file *file)
3175 if (file->f_mode & FMODE_READ)
3176 seq_release(inode, file);
3181 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3183 struct dyn_ftrace *rec;
3184 struct ftrace_page *pg;
3193 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3194 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3197 search_len = strlen(search);
3199 mutex_lock(&ftrace_lock);
3201 if (unlikely(ftrace_disabled)) {
3202 mutex_unlock(&ftrace_lock);
3206 do_for_each_ftrace_rec(pg, rec) {
3208 if (rec->flags & FTRACE_FL_FREE)
3211 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3212 /* if it is in the array */
3214 for (i = 0; i < *idx; i++) {
3215 if (array[i] == rec->ip) {
3224 array[(*idx)++] = rec->ip;
3225 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3230 array[i] = array[--(*idx)];
3236 } while_for_each_ftrace_rec();
3238 mutex_unlock(&ftrace_lock);
3243 ftrace_graph_filter_enabled = 1;
3248 ftrace_graph_write(struct file *file, const char __user *ubuf,
3249 size_t cnt, loff_t *ppos)
3251 struct trace_parser parser;
3257 mutex_lock(&graph_lock);
3259 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3264 read = trace_get_user(&parser, ubuf, cnt, ppos);
3266 if (read >= 0 && trace_parser_loaded((&parser))) {
3267 parser.buffer[parser.idx] = 0;
3269 /* we allow only one expression at a time */
3270 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3279 trace_parser_put(&parser);
3281 mutex_unlock(&graph_lock);
3286 static const struct file_operations ftrace_graph_fops = {
3287 .open = ftrace_graph_open,
3289 .write = ftrace_graph_write,
3290 .release = ftrace_graph_release,
3291 .llseek = seq_lseek,
3293 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3295 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3298 trace_create_file("available_filter_functions", 0444,
3299 d_tracer, NULL, &ftrace_avail_fops);
3301 trace_create_file("enabled_functions", 0444,
3302 d_tracer, NULL, &ftrace_enabled_fops);
3304 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3305 NULL, &ftrace_filter_fops);
3307 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3308 NULL, &ftrace_notrace_fops);
3310 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3311 trace_create_file("set_graph_function", 0444, d_tracer,
3313 &ftrace_graph_fops);
3314 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3319 static int ftrace_process_locs(struct module *mod,
3320 unsigned long *start,
3326 mutex_lock(&ftrace_lock);
3329 addr = ftrace_call_adjust(*p++);
3331 * Some architecture linkers will pad between
3332 * the different mcount_loc sections of different
3333 * object files to satisfy alignments.
3334 * Skip any NULL pointers.
3338 ftrace_record_ip(addr);
3341 ftrace_update_code(mod);
3342 mutex_unlock(&ftrace_lock);
3347 #ifdef CONFIG_MODULES
3348 void ftrace_release_mod(struct module *mod)
3350 struct dyn_ftrace *rec;
3351 struct ftrace_page *pg;
3353 mutex_lock(&ftrace_lock);
3355 if (ftrace_disabled)
3358 do_for_each_ftrace_rec(pg, rec) {
3359 if (within_module_core(rec->ip, mod)) {
3361 * rec->ip is changed in ftrace_free_rec()
3362 * It should not between s and e if record was freed.
3364 FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
3365 ftrace_free_rec(rec);
3367 } while_for_each_ftrace_rec();
3369 mutex_unlock(&ftrace_lock);
3372 static void ftrace_init_module(struct module *mod,
3373 unsigned long *start, unsigned long *end)
3375 if (ftrace_disabled || start == end)
3377 ftrace_process_locs(mod, start, end);
3380 static int ftrace_module_notify(struct notifier_block *self,
3381 unsigned long val, void *data)
3383 struct module *mod = data;
3386 case MODULE_STATE_COMING:
3387 ftrace_init_module(mod, mod->ftrace_callsites,
3388 mod->ftrace_callsites +
3389 mod->num_ftrace_callsites);
3391 case MODULE_STATE_GOING:
3392 ftrace_release_mod(mod);
3399 static int ftrace_module_notify(struct notifier_block *self,
3400 unsigned long val, void *data)
3404 #endif /* CONFIG_MODULES */
3406 struct notifier_block ftrace_module_nb = {
3407 .notifier_call = ftrace_module_notify,
3411 extern unsigned long __start_mcount_loc[];
3412 extern unsigned long __stop_mcount_loc[];
3414 void __init ftrace_init(void)
3416 unsigned long count, addr, flags;
3419 /* Keep the ftrace pointer to the stub */
3420 addr = (unsigned long)ftrace_stub;
3422 local_irq_save(flags);
3423 ftrace_dyn_arch_init(&addr);
3424 local_irq_restore(flags);
3426 /* ftrace_dyn_arch_init places the return code in addr */
3430 count = __stop_mcount_loc - __start_mcount_loc;
3432 ret = ftrace_dyn_table_alloc(count);
3436 last_ftrace_enabled = ftrace_enabled = 1;
3438 ret = ftrace_process_locs(NULL,
3442 ret = register_module_notifier(&ftrace_module_nb);
3444 pr_warning("Failed to register trace ftrace module notifier\n");
3446 set_ftrace_early_filters();
3450 ftrace_disabled = 1;
3455 static struct ftrace_ops global_ops = {
3456 .func = ftrace_stub,
3459 static int __init ftrace_nodyn_init(void)
3464 device_initcall(ftrace_nodyn_init);
3466 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
3467 static inline void ftrace_startup_enable(int command) { }
3468 /* Keep as macros so we do not need to define the commands */
3469 # define ftrace_startup(ops, command) do { } while (0)
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;
3488 * Some of the ops may be dynamically allocated,
3489 * they must be freed after a synchronize_sched().
3491 preempt_disable_notrace();
3492 op = rcu_dereference_raw(ftrace_ops_list);
3493 while (op != &ftrace_list_end) {
3494 if (ftrace_ops_test(op, ip))
3495 op->func(ip, parent_ip);
3496 op = rcu_dereference_raw(op->next);
3498 preempt_enable_notrace();
3501 static void clear_ftrace_swapper(void)
3503 struct task_struct *p;
3507 for_each_online_cpu(cpu) {
3509 clear_tsk_trace_trace(p);
3514 static void set_ftrace_swapper(void)
3516 struct task_struct *p;
3520 for_each_online_cpu(cpu) {
3522 set_tsk_trace_trace(p);
3527 static void clear_ftrace_pid(struct pid *pid)
3529 struct task_struct *p;
3532 do_each_pid_task(pid, PIDTYPE_PID, p) {
3533 clear_tsk_trace_trace(p);
3534 } while_each_pid_task(pid, PIDTYPE_PID, p);
3540 static void set_ftrace_pid(struct pid *pid)
3542 struct task_struct *p;
3545 do_each_pid_task(pid, PIDTYPE_PID, p) {
3546 set_tsk_trace_trace(p);
3547 } while_each_pid_task(pid, PIDTYPE_PID, p);
3551 static void clear_ftrace_pid_task(struct pid *pid)
3553 if (pid == ftrace_swapper_pid)
3554 clear_ftrace_swapper();
3556 clear_ftrace_pid(pid);
3559 static void set_ftrace_pid_task(struct pid *pid)
3561 if (pid == ftrace_swapper_pid)
3562 set_ftrace_swapper();
3564 set_ftrace_pid(pid);
3567 static int ftrace_pid_add(int p)
3570 struct ftrace_pid *fpid;
3573 mutex_lock(&ftrace_lock);
3576 pid = ftrace_swapper_pid;
3578 pid = find_get_pid(p);
3585 list_for_each_entry(fpid, &ftrace_pids, list)
3586 if (fpid->pid == pid)
3591 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
3595 list_add(&fpid->list, &ftrace_pids);
3598 set_ftrace_pid_task(pid);
3600 ftrace_update_pid_func();
3601 ftrace_startup_enable(0);
3603 mutex_unlock(&ftrace_lock);
3607 if (pid != ftrace_swapper_pid)
3611 mutex_unlock(&ftrace_lock);
3615 static void ftrace_pid_reset(void)
3617 struct ftrace_pid *fpid, *safe;
3619 mutex_lock(&ftrace_lock);
3620 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
3621 struct pid *pid = fpid->pid;
3623 clear_ftrace_pid_task(pid);
3625 list_del(&fpid->list);
3629 ftrace_update_pid_func();
3630 ftrace_startup_enable(0);
3632 mutex_unlock(&ftrace_lock);
3635 static void *fpid_start(struct seq_file *m, loff_t *pos)
3637 mutex_lock(&ftrace_lock);
3639 if (list_empty(&ftrace_pids) && (!*pos))
3642 return seq_list_start(&ftrace_pids, *pos);
3645 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
3650 return seq_list_next(v, &ftrace_pids, pos);
3653 static void fpid_stop(struct seq_file *m, void *p)
3655 mutex_unlock(&ftrace_lock);
3658 static int fpid_show(struct seq_file *m, void *v)
3660 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
3662 if (v == (void *)1) {
3663 seq_printf(m, "no pid\n");
3667 if (fpid->pid == ftrace_swapper_pid)
3668 seq_printf(m, "swapper tasks\n");
3670 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
3675 static const struct seq_operations ftrace_pid_sops = {
3676 .start = fpid_start,
3683 ftrace_pid_open(struct inode *inode, struct file *file)
3687 if ((file->f_mode & FMODE_WRITE) &&
3688 (file->f_flags & O_TRUNC))
3691 if (file->f_mode & FMODE_READ)
3692 ret = seq_open(file, &ftrace_pid_sops);
3698 ftrace_pid_write(struct file *filp, const char __user *ubuf,
3699 size_t cnt, loff_t *ppos)
3705 if (cnt >= sizeof(buf))
3708 if (copy_from_user(&buf, ubuf, cnt))
3714 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
3715 * to clean the filter quietly.
3717 tmp = strstrip(buf);
3718 if (strlen(tmp) == 0)
3721 ret = strict_strtol(tmp, 10, &val);
3725 ret = ftrace_pid_add(val);
3727 return ret ? ret : cnt;
3731 ftrace_pid_release(struct inode *inode, struct file *file)
3733 if (file->f_mode & FMODE_READ)
3734 seq_release(inode, file);
3739 static const struct file_operations ftrace_pid_fops = {
3740 .open = ftrace_pid_open,
3741 .write = ftrace_pid_write,
3743 .llseek = seq_lseek,
3744 .release = ftrace_pid_release,
3747 static __init int ftrace_init_debugfs(void)
3749 struct dentry *d_tracer;
3751 d_tracer = tracing_init_dentry();
3755 ftrace_init_dyn_debugfs(d_tracer);
3757 trace_create_file("set_ftrace_pid", 0644, d_tracer,
3758 NULL, &ftrace_pid_fops);
3760 ftrace_profile_debugfs(d_tracer);
3764 fs_initcall(ftrace_init_debugfs);
3767 * ftrace_kill - kill ftrace
3769 * This function should be used by panic code. It stops ftrace
3770 * but in a not so nice way. If you need to simply kill ftrace
3771 * from a non-atomic section, use ftrace_kill.
3773 void ftrace_kill(void)
3775 ftrace_disabled = 1;
3777 clear_ftrace_function();
3781 * register_ftrace_function - register a function for profiling
3782 * @ops - ops structure that holds the function for profiling.
3784 * Register a function to be called by all functions in the
3787 * Note: @ops->func and all the functions it calls must be labeled
3788 * with "notrace", otherwise it will go into a
3791 int register_ftrace_function(struct ftrace_ops *ops)
3795 mutex_lock(&ftrace_lock);
3797 if (unlikely(ftrace_disabled))
3800 ret = __register_ftrace_function(ops);
3802 ftrace_startup(ops, 0);
3806 mutex_unlock(&ftrace_lock);
3809 EXPORT_SYMBOL_GPL(register_ftrace_function);
3812 * unregister_ftrace_function - unregister a function for profiling.
3813 * @ops - ops structure that holds the function to unregister
3815 * Unregister a function that was added to be called by ftrace profiling.
3817 int unregister_ftrace_function(struct ftrace_ops *ops)
3821 mutex_lock(&ftrace_lock);
3822 ret = __unregister_ftrace_function(ops);
3824 ftrace_shutdown(ops, 0);
3825 mutex_unlock(&ftrace_lock);
3829 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
3832 ftrace_enable_sysctl(struct ctl_table *table, int write,
3833 void __user *buffer, size_t *lenp,
3838 mutex_lock(&ftrace_lock);
3840 if (unlikely(ftrace_disabled))
3843 ret = proc_dointvec(table, write, buffer, lenp, ppos);
3845 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
3848 last_ftrace_enabled = !!ftrace_enabled;
3850 if (ftrace_enabled) {
3852 ftrace_startup_sysctl();
3854 /* we are starting ftrace again */
3855 if (ftrace_ops_list != &ftrace_list_end) {
3856 if (ftrace_ops_list->next == &ftrace_list_end)
3857 ftrace_trace_function = ftrace_ops_list->func;
3859 ftrace_trace_function = ftrace_ops_list_func;
3863 /* stopping ftrace calls (just send to ftrace_stub) */
3864 ftrace_trace_function = ftrace_stub;
3866 ftrace_shutdown_sysctl();
3870 mutex_unlock(&ftrace_lock);
3874 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3876 static int ftrace_graph_active;
3877 static struct notifier_block ftrace_suspend_notifier;
3879 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
3884 /* The callbacks that hook a function */
3885 trace_func_graph_ret_t ftrace_graph_return =
3886 (trace_func_graph_ret_t)ftrace_stub;
3887 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
3889 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3890 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
3894 unsigned long flags;
3895 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
3896 struct task_struct *g, *t;
3898 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
3899 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
3900 * sizeof(struct ftrace_ret_stack),
3902 if (!ret_stack_list[i]) {
3910 read_lock_irqsave(&tasklist_lock, flags);
3911 do_each_thread(g, t) {
3917 if (t->ret_stack == NULL) {
3918 atomic_set(&t->tracing_graph_pause, 0);
3919 atomic_set(&t->trace_overrun, 0);
3920 t->curr_ret_stack = -1;
3921 /* Make sure the tasks see the -1 first: */
3923 t->ret_stack = ret_stack_list[start++];
3925 } while_each_thread(g, t);
3928 read_unlock_irqrestore(&tasklist_lock, flags);
3930 for (i = start; i < end; i++)
3931 kfree(ret_stack_list[i]);
3936 ftrace_graph_probe_sched_switch(void *ignore,
3937 struct task_struct *prev, struct task_struct *next)
3939 unsigned long long timestamp;
3943 * Does the user want to count the time a function was asleep.
3944 * If so, do not update the time stamps.
3946 if (trace_flags & TRACE_ITER_SLEEP_TIME)
3949 timestamp = trace_clock_local();
3951 prev->ftrace_timestamp = timestamp;
3953 /* only process tasks that we timestamped */
3954 if (!next->ftrace_timestamp)
3958 * Update all the counters in next to make up for the
3959 * time next was sleeping.
3961 timestamp -= next->ftrace_timestamp;
3963 for (index = next->curr_ret_stack; index >= 0; index--)
3964 next->ret_stack[index].calltime += timestamp;
3967 /* Allocate a return stack for each task */
3968 static int start_graph_tracing(void)
3970 struct ftrace_ret_stack **ret_stack_list;
3973 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
3974 sizeof(struct ftrace_ret_stack *),
3977 if (!ret_stack_list)
3980 /* The cpu_boot init_task->ret_stack will never be freed */
3981 for_each_online_cpu(cpu) {
3982 if (!idle_task(cpu)->ret_stack)
3983 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
3987 ret = alloc_retstack_tasklist(ret_stack_list);
3988 } while (ret == -EAGAIN);
3991 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
3993 pr_info("ftrace_graph: Couldn't activate tracepoint"
3994 " probe to kernel_sched_switch\n");
3997 kfree(ret_stack_list);
4002 * Hibernation protection.
4003 * The state of the current task is too much unstable during
4004 * suspend/restore to disk. We want to protect against that.
4007 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4011 case PM_HIBERNATION_PREPARE:
4012 pause_graph_tracing();
4015 case PM_POST_HIBERNATION:
4016 unpause_graph_tracing();
4022 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4023 trace_func_graph_ent_t entryfunc)
4027 mutex_lock(&ftrace_lock);
4029 /* we currently allow only one tracer registered at a time */
4030 if (ftrace_graph_active) {
4035 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4036 register_pm_notifier(&ftrace_suspend_notifier);
4038 ftrace_graph_active++;
4039 ret = start_graph_tracing();
4041 ftrace_graph_active--;
4045 ftrace_graph_return = retfunc;
4046 ftrace_graph_entry = entryfunc;
4048 ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4051 mutex_unlock(&ftrace_lock);
4055 void unregister_ftrace_graph(void)
4057 mutex_lock(&ftrace_lock);
4059 if (unlikely(!ftrace_graph_active))
4062 ftrace_graph_active--;
4063 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4064 ftrace_graph_entry = ftrace_graph_entry_stub;
4065 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4066 unregister_pm_notifier(&ftrace_suspend_notifier);
4067 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4070 mutex_unlock(&ftrace_lock);
4073 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4076 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4078 atomic_set(&t->tracing_graph_pause, 0);
4079 atomic_set(&t->trace_overrun, 0);
4080 t->ftrace_timestamp = 0;
4081 /* make curr_ret_stack visible before we add the ret_stack */
4083 t->ret_stack = ret_stack;
4087 * Allocate a return stack for the idle task. May be the first
4088 * time through, or it may be done by CPU hotplug online.
4090 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4092 t->curr_ret_stack = -1;
4094 * The idle task has no parent, it either has its own
4095 * stack or no stack at all.
4098 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4100 if (ftrace_graph_active) {
4101 struct ftrace_ret_stack *ret_stack;
4103 ret_stack = per_cpu(idle_ret_stack, cpu);
4105 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4106 * sizeof(struct ftrace_ret_stack),
4110 per_cpu(idle_ret_stack, cpu) = ret_stack;
4112 graph_init_task(t, ret_stack);
4116 /* Allocate a return stack for newly created task */
4117 void ftrace_graph_init_task(struct task_struct *t)
4119 /* Make sure we do not use the parent ret_stack */
4120 t->ret_stack = NULL;
4121 t->curr_ret_stack = -1;
4123 if (ftrace_graph_active) {
4124 struct ftrace_ret_stack *ret_stack;
4126 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4127 * sizeof(struct ftrace_ret_stack),
4131 graph_init_task(t, ret_stack);
4135 void ftrace_graph_exit_task(struct task_struct *t)
4137 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4139 t->ret_stack = NULL;
4140 /* NULL must become visible to IRQs before we free it: */
4146 void ftrace_graph_stop(void)