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 Nadia Yvette Chambers
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/bsearch.h>
26 #include <linux/module.h>
27 #include <linux/ftrace.h>
28 #include <linux/sysctl.h>
29 #include <linux/slab.h>
30 #include <linux/ctype.h>
31 #include <linux/sort.h>
32 #include <linux/list.h>
33 #include <linux/hash.h>
34 #include <linux/rcupdate.h>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
60 #define FTRACE_HASH_BITS 7
61 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62 #define FTRACE_HASH_DEFAULT_BITS 10
63 #define FTRACE_HASH_MAX_BITS 12
65 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
67 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_REGEX_LOCK(opsname) \
69 .regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock),
71 #define INIT_REGEX_LOCK(opsname)
74 static struct ftrace_ops ftrace_list_end __read_mostly = {
76 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
79 /* ftrace_enabled is a method to turn ftrace on or off */
80 int ftrace_enabled __read_mostly;
81 static int last_ftrace_enabled;
83 /* Quick disabling of function tracer. */
84 int function_trace_stop __read_mostly;
86 /* Current function tracing op */
87 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
89 /* List for set_ftrace_pid's pids. */
90 LIST_HEAD(ftrace_pids);
92 struct list_head list;
97 * ftrace_disabled is set when an anomaly is discovered.
98 * ftrace_disabled is much stronger than ftrace_enabled.
100 static int ftrace_disabled __read_mostly;
102 static DEFINE_MUTEX(ftrace_lock);
104 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
105 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
106 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
107 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
108 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
109 static struct ftrace_ops global_ops;
110 static struct ftrace_ops control_ops;
112 #if ARCH_SUPPORTS_FTRACE_OPS
113 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
114 struct ftrace_ops *op, struct pt_regs *regs);
116 /* See comment below, where ftrace_ops_list_func is defined */
117 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
118 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
122 * Traverse the ftrace_global_list, invoking all entries. The reason that we
123 * can use rcu_dereference_raw() is that elements removed from this list
124 * are simply leaked, so there is no need to interact with a grace-period
125 * mechanism. The rcu_dereference_raw() calls are needed to handle
126 * concurrent insertions into the ftrace_global_list.
128 * Silly Alpha and silly pointer-speculation compiler optimizations!
130 #define do_for_each_ftrace_op(op, list) \
131 op = rcu_dereference_raw(list); \
135 * Optimized for just a single item in the list (as that is the normal case).
137 #define while_for_each_ftrace_op(op) \
138 while (likely(op = rcu_dereference_raw((op)->next)) && \
139 unlikely((op) != &ftrace_list_end))
141 static inline void ftrace_ops_init(struct ftrace_ops *ops)
143 #ifdef CONFIG_DYNAMIC_FTRACE
144 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
145 mutex_init(&ops->regex_lock);
146 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
152 * ftrace_nr_registered_ops - return number of ops registered
154 * Returns the number of ftrace_ops registered and tracing functions
156 int ftrace_nr_registered_ops(void)
158 struct ftrace_ops *ops;
161 mutex_lock(&ftrace_lock);
163 for (ops = ftrace_ops_list;
164 ops != &ftrace_list_end; ops = ops->next)
167 mutex_unlock(&ftrace_lock);
173 ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
174 struct ftrace_ops *op, struct pt_regs *regs)
178 bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX);
182 do_for_each_ftrace_op(op, ftrace_global_list) {
183 op->func(ip, parent_ip, op, regs);
184 } while_for_each_ftrace_op(op);
186 trace_clear_recursion(bit);
189 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
190 struct ftrace_ops *op, struct pt_regs *regs)
192 if (!test_tsk_trace_trace(current))
195 ftrace_pid_function(ip, parent_ip, op, regs);
198 static void set_ftrace_pid_function(ftrace_func_t func)
200 /* do not set ftrace_pid_function to itself! */
201 if (func != ftrace_pid_func)
202 ftrace_pid_function = func;
206 * clear_ftrace_function - reset the ftrace function
208 * This NULLs the ftrace function and in essence stops
209 * tracing. There may be lag
211 void clear_ftrace_function(void)
213 ftrace_trace_function = ftrace_stub;
214 ftrace_pid_function = ftrace_stub;
217 static void control_ops_disable_all(struct ftrace_ops *ops)
221 for_each_possible_cpu(cpu)
222 *per_cpu_ptr(ops->disabled, cpu) = 1;
225 static int control_ops_alloc(struct ftrace_ops *ops)
227 int __percpu *disabled;
229 disabled = alloc_percpu(int);
233 ops->disabled = disabled;
234 control_ops_disable_all(ops);
238 static void control_ops_free(struct ftrace_ops *ops)
240 free_percpu(ops->disabled);
243 static void update_global_ops(void)
248 * If there's only one function registered, then call that
249 * function directly. Otherwise, we need to iterate over the
250 * registered callers.
252 if (ftrace_global_list == &ftrace_list_end ||
253 ftrace_global_list->next == &ftrace_list_end) {
254 func = ftrace_global_list->func;
256 * As we are calling the function directly.
257 * If it does not have recursion protection,
258 * the function_trace_op needs to be updated
261 if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
262 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
264 global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
266 func = ftrace_global_list_func;
267 /* The list has its own recursion protection. */
268 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
272 /* If we filter on pids, update to use the pid function */
273 if (!list_empty(&ftrace_pids)) {
274 set_ftrace_pid_function(func);
275 func = ftrace_pid_func;
278 global_ops.func = func;
281 static void update_ftrace_function(void)
288 * If we are at the end of the list and this ops is
289 * recursion safe and not dynamic and the arch supports passing ops,
290 * then have the mcount trampoline call the function directly.
292 if (ftrace_ops_list == &ftrace_list_end ||
293 (ftrace_ops_list->next == &ftrace_list_end &&
294 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
295 (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
296 !FTRACE_FORCE_LIST_FUNC)) {
297 /* Set the ftrace_ops that the arch callback uses */
298 if (ftrace_ops_list == &global_ops)
299 function_trace_op = ftrace_global_list;
301 function_trace_op = ftrace_ops_list;
302 func = ftrace_ops_list->func;
304 /* Just use the default ftrace_ops */
305 function_trace_op = &ftrace_list_end;
306 func = ftrace_ops_list_func;
309 ftrace_trace_function = func;
312 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
316 * We are entering ops into the list but another
317 * CPU might be walking that list. We need to make sure
318 * the ops->next pointer is valid before another CPU sees
319 * the ops pointer included into the list.
321 rcu_assign_pointer(*list, ops);
324 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
326 struct ftrace_ops **p;
329 * If we are removing the last function, then simply point
330 * to the ftrace_stub.
332 if (*list == ops && ops->next == &ftrace_list_end) {
333 *list = &ftrace_list_end;
337 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
348 static void add_ftrace_list_ops(struct ftrace_ops **list,
349 struct ftrace_ops *main_ops,
350 struct ftrace_ops *ops)
352 int first = *list == &ftrace_list_end;
353 add_ftrace_ops(list, ops);
355 add_ftrace_ops(&ftrace_ops_list, main_ops);
358 static int remove_ftrace_list_ops(struct ftrace_ops **list,
359 struct ftrace_ops *main_ops,
360 struct ftrace_ops *ops)
362 int ret = remove_ftrace_ops(list, ops);
363 if (!ret && *list == &ftrace_list_end)
364 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
368 static int __register_ftrace_function(struct ftrace_ops *ops)
370 if (unlikely(ftrace_disabled))
373 if (FTRACE_WARN_ON(ops == &global_ops))
376 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
379 /* We don't support both control and global flags set. */
380 if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
383 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
385 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
386 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
387 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
389 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
390 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
393 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
394 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
397 if (!core_kernel_data((unsigned long)ops))
398 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
400 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
401 add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
402 ops->flags |= FTRACE_OPS_FL_ENABLED;
403 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
404 if (control_ops_alloc(ops))
406 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
408 add_ftrace_ops(&ftrace_ops_list, ops);
411 update_ftrace_function();
416 static int __unregister_ftrace_function(struct ftrace_ops *ops)
423 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
426 if (FTRACE_WARN_ON(ops == &global_ops))
429 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
430 ret = remove_ftrace_list_ops(&ftrace_global_list,
433 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
434 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
435 ret = remove_ftrace_list_ops(&ftrace_control_list,
439 * The ftrace_ops is now removed from the list,
440 * so there'll be no new users. We must ensure
441 * all current users are done before we free
445 control_ops_free(ops);
448 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
454 update_ftrace_function();
457 * Dynamic ops may be freed, we must make sure that all
458 * callers are done before leaving this function.
460 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
466 static void ftrace_update_pid_func(void)
468 /* Only do something if we are tracing something */
469 if (ftrace_trace_function == ftrace_stub)
472 update_ftrace_function();
475 #ifdef CONFIG_FUNCTION_PROFILER
476 struct ftrace_profile {
477 struct hlist_node node;
479 unsigned long counter;
480 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
481 unsigned long long time;
482 unsigned long long time_squared;
486 struct ftrace_profile_page {
487 struct ftrace_profile_page *next;
489 struct ftrace_profile records[];
492 struct ftrace_profile_stat {
494 struct hlist_head *hash;
495 struct ftrace_profile_page *pages;
496 struct ftrace_profile_page *start;
497 struct tracer_stat stat;
500 #define PROFILE_RECORDS_SIZE \
501 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
503 #define PROFILES_PER_PAGE \
504 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
506 static int ftrace_profile_enabled __read_mostly;
508 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
509 static DEFINE_MUTEX(ftrace_profile_lock);
511 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
513 #define FTRACE_PROFILE_HASH_BITS 10
514 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
517 function_stat_next(void *v, int idx)
519 struct ftrace_profile *rec = v;
520 struct ftrace_profile_page *pg;
522 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
528 if ((void *)rec >= (void *)&pg->records[pg->index]) {
532 rec = &pg->records[0];
540 static void *function_stat_start(struct tracer_stat *trace)
542 struct ftrace_profile_stat *stat =
543 container_of(trace, struct ftrace_profile_stat, stat);
545 if (!stat || !stat->start)
548 return function_stat_next(&stat->start->records[0], 0);
551 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
552 /* function graph compares on total time */
553 static int function_stat_cmp(void *p1, void *p2)
555 struct ftrace_profile *a = p1;
556 struct ftrace_profile *b = p2;
558 if (a->time < b->time)
560 if (a->time > b->time)
566 /* not function graph compares against hits */
567 static int function_stat_cmp(void *p1, void *p2)
569 struct ftrace_profile *a = p1;
570 struct ftrace_profile *b = p2;
572 if (a->counter < b->counter)
574 if (a->counter > b->counter)
581 static int function_stat_headers(struct seq_file *m)
583 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
584 seq_printf(m, " Function "
587 "--- ---- --- ---\n");
589 seq_printf(m, " Function Hit\n"
595 static int function_stat_show(struct seq_file *m, void *v)
597 struct ftrace_profile *rec = v;
598 char str[KSYM_SYMBOL_LEN];
600 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
601 static struct trace_seq s;
602 unsigned long long avg;
603 unsigned long long stddev;
605 mutex_lock(&ftrace_profile_lock);
607 /* we raced with function_profile_reset() */
608 if (unlikely(rec->counter == 0)) {
613 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
614 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
616 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
619 do_div(avg, rec->counter);
621 /* Sample standard deviation (s^2) */
622 if (rec->counter <= 1)
625 stddev = rec->time_squared - rec->counter * avg * avg;
627 * Divide only 1000 for ns^2 -> us^2 conversion.
628 * trace_print_graph_duration will divide 1000 again.
630 do_div(stddev, (rec->counter - 1) * 1000);
634 trace_print_graph_duration(rec->time, &s);
635 trace_seq_puts(&s, " ");
636 trace_print_graph_duration(avg, &s);
637 trace_seq_puts(&s, " ");
638 trace_print_graph_duration(stddev, &s);
639 trace_print_seq(m, &s);
643 mutex_unlock(&ftrace_profile_lock);
648 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
650 struct ftrace_profile_page *pg;
652 pg = stat->pages = stat->start;
655 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
660 memset(stat->hash, 0,
661 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
664 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
666 struct ftrace_profile_page *pg;
671 /* If we already allocated, do nothing */
675 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
679 #ifdef CONFIG_DYNAMIC_FTRACE
680 functions = ftrace_update_tot_cnt;
683 * We do not know the number of functions that exist because
684 * dynamic tracing is what counts them. With past experience
685 * we have around 20K functions. That should be more than enough.
686 * It is highly unlikely we will execute every function in
692 pg = stat->start = stat->pages;
694 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
696 for (i = 1; i < pages; i++) {
697 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
708 unsigned long tmp = (unsigned long)pg;
720 static int ftrace_profile_init_cpu(int cpu)
722 struct ftrace_profile_stat *stat;
725 stat = &per_cpu(ftrace_profile_stats, cpu);
728 /* If the profile is already created, simply reset it */
729 ftrace_profile_reset(stat);
734 * We are profiling all functions, but usually only a few thousand
735 * functions are hit. We'll make a hash of 1024 items.
737 size = FTRACE_PROFILE_HASH_SIZE;
739 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
744 /* Preallocate the function profiling pages */
745 if (ftrace_profile_pages_init(stat) < 0) {
754 static int ftrace_profile_init(void)
759 for_each_online_cpu(cpu) {
760 ret = ftrace_profile_init_cpu(cpu);
768 /* interrupts must be disabled */
769 static struct ftrace_profile *
770 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
772 struct ftrace_profile *rec;
773 struct hlist_head *hhd;
776 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
777 hhd = &stat->hash[key];
779 if (hlist_empty(hhd))
782 hlist_for_each_entry_rcu(rec, hhd, node) {
790 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
791 struct ftrace_profile *rec)
795 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
796 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
800 * The memory is already allocated, this simply finds a new record to use.
802 static struct ftrace_profile *
803 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
805 struct ftrace_profile *rec = NULL;
807 /* prevent recursion (from NMIs) */
808 if (atomic_inc_return(&stat->disabled) != 1)
812 * Try to find the function again since an NMI
813 * could have added it
815 rec = ftrace_find_profiled_func(stat, ip);
819 if (stat->pages->index == PROFILES_PER_PAGE) {
820 if (!stat->pages->next)
822 stat->pages = stat->pages->next;
825 rec = &stat->pages->records[stat->pages->index++];
827 ftrace_add_profile(stat, rec);
830 atomic_dec(&stat->disabled);
836 function_profile_call(unsigned long ip, unsigned long parent_ip,
837 struct ftrace_ops *ops, struct pt_regs *regs)
839 struct ftrace_profile_stat *stat;
840 struct ftrace_profile *rec;
843 if (!ftrace_profile_enabled)
846 local_irq_save(flags);
848 stat = &__get_cpu_var(ftrace_profile_stats);
849 if (!stat->hash || !ftrace_profile_enabled)
852 rec = ftrace_find_profiled_func(stat, ip);
854 rec = ftrace_profile_alloc(stat, ip);
861 local_irq_restore(flags);
864 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
865 static int profile_graph_entry(struct ftrace_graph_ent *trace)
867 function_profile_call(trace->func, 0, NULL, NULL);
871 static void profile_graph_return(struct ftrace_graph_ret *trace)
873 struct ftrace_profile_stat *stat;
874 unsigned long long calltime;
875 struct ftrace_profile *rec;
878 local_irq_save(flags);
879 stat = &__get_cpu_var(ftrace_profile_stats);
880 if (!stat->hash || !ftrace_profile_enabled)
883 /* If the calltime was zero'd ignore it */
884 if (!trace->calltime)
887 calltime = trace->rettime - trace->calltime;
889 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
892 index = trace->depth;
894 /* Append this call time to the parent time to subtract */
896 current->ret_stack[index - 1].subtime += calltime;
898 if (current->ret_stack[index].subtime < calltime)
899 calltime -= current->ret_stack[index].subtime;
904 rec = ftrace_find_profiled_func(stat, trace->func);
906 rec->time += calltime;
907 rec->time_squared += calltime * calltime;
911 local_irq_restore(flags);
914 static int register_ftrace_profiler(void)
916 return register_ftrace_graph(&profile_graph_return,
917 &profile_graph_entry);
920 static void unregister_ftrace_profiler(void)
922 unregister_ftrace_graph();
925 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
926 .func = function_profile_call,
927 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
928 INIT_REGEX_LOCK(ftrace_profile_ops)
931 static int register_ftrace_profiler(void)
933 return register_ftrace_function(&ftrace_profile_ops);
936 static void unregister_ftrace_profiler(void)
938 unregister_ftrace_function(&ftrace_profile_ops);
940 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
943 ftrace_profile_write(struct file *filp, const char __user *ubuf,
944 size_t cnt, loff_t *ppos)
949 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
955 mutex_lock(&ftrace_profile_lock);
956 if (ftrace_profile_enabled ^ val) {
958 ret = ftrace_profile_init();
964 ret = register_ftrace_profiler();
969 ftrace_profile_enabled = 1;
971 ftrace_profile_enabled = 0;
973 * unregister_ftrace_profiler calls stop_machine
974 * so this acts like an synchronize_sched.
976 unregister_ftrace_profiler();
980 mutex_unlock(&ftrace_profile_lock);
988 ftrace_profile_read(struct file *filp, char __user *ubuf,
989 size_t cnt, loff_t *ppos)
991 char buf[64]; /* big enough to hold a number */
994 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
995 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
998 static const struct file_operations ftrace_profile_fops = {
999 .open = tracing_open_generic,
1000 .read = ftrace_profile_read,
1001 .write = ftrace_profile_write,
1002 .llseek = default_llseek,
1005 /* used to initialize the real stat files */
1006 static struct tracer_stat function_stats __initdata = {
1007 .name = "functions",
1008 .stat_start = function_stat_start,
1009 .stat_next = function_stat_next,
1010 .stat_cmp = function_stat_cmp,
1011 .stat_headers = function_stat_headers,
1012 .stat_show = function_stat_show
1015 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1017 struct ftrace_profile_stat *stat;
1018 struct dentry *entry;
1023 for_each_possible_cpu(cpu) {
1024 stat = &per_cpu(ftrace_profile_stats, cpu);
1026 /* allocate enough for function name + cpu number */
1027 name = kmalloc(32, GFP_KERNEL);
1030 * The files created are permanent, if something happens
1031 * we still do not free memory.
1034 "Could not allocate stat file for cpu %d\n",
1038 stat->stat = function_stats;
1039 snprintf(name, 32, "function%d", cpu);
1040 stat->stat.name = name;
1041 ret = register_stat_tracer(&stat->stat);
1044 "Could not register function stat for cpu %d\n",
1051 entry = debugfs_create_file("function_profile_enabled", 0644,
1052 d_tracer, NULL, &ftrace_profile_fops);
1054 pr_warning("Could not create debugfs "
1055 "'function_profile_enabled' entry\n");
1058 #else /* CONFIG_FUNCTION_PROFILER */
1059 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1062 #endif /* CONFIG_FUNCTION_PROFILER */
1064 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1067 ftrace_filter_lseek(struct file *file, loff_t offset, int whence)
1071 if (file->f_mode & FMODE_READ)
1072 ret = seq_lseek(file, offset, whence);
1074 file->f_pos = ret = 1;
1079 #ifdef CONFIG_DYNAMIC_FTRACE
1081 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1082 # error Dynamic ftrace depends on MCOUNT_RECORD
1085 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1087 struct ftrace_func_probe {
1088 struct hlist_node node;
1089 struct ftrace_probe_ops *ops;
1090 unsigned long flags;
1093 struct list_head free_list;
1096 struct ftrace_func_entry {
1097 struct hlist_node hlist;
1101 struct ftrace_hash {
1102 unsigned long size_bits;
1103 struct hlist_head *buckets;
1104 unsigned long count;
1105 struct rcu_head rcu;
1109 * We make these constant because no one should touch them,
1110 * but they are used as the default "empty hash", to avoid allocating
1111 * it all the time. These are in a read only section such that if
1112 * anyone does try to modify it, it will cause an exception.
1114 static const struct hlist_head empty_buckets[1];
1115 static const struct ftrace_hash empty_hash = {
1116 .buckets = (struct hlist_head *)empty_buckets,
1118 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1120 static struct ftrace_ops global_ops = {
1121 .func = ftrace_stub,
1122 .notrace_hash = EMPTY_HASH,
1123 .filter_hash = EMPTY_HASH,
1124 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
1125 INIT_REGEX_LOCK(global_ops)
1128 struct ftrace_page {
1129 struct ftrace_page *next;
1130 struct dyn_ftrace *records;
1135 static struct ftrace_page *ftrace_new_pgs;
1137 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1138 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1140 /* estimate from running different kernels */
1141 #define NR_TO_INIT 10000
1143 static struct ftrace_page *ftrace_pages_start;
1144 static struct ftrace_page *ftrace_pages;
1146 static bool ftrace_hash_empty(struct ftrace_hash *hash)
1148 return !hash || !hash->count;
1151 static struct ftrace_func_entry *
1152 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1155 struct ftrace_func_entry *entry;
1156 struct hlist_head *hhd;
1158 if (ftrace_hash_empty(hash))
1161 if (hash->size_bits > 0)
1162 key = hash_long(ip, hash->size_bits);
1166 hhd = &hash->buckets[key];
1168 hlist_for_each_entry_rcu(entry, hhd, hlist) {
1169 if (entry->ip == ip)
1175 static void __add_hash_entry(struct ftrace_hash *hash,
1176 struct ftrace_func_entry *entry)
1178 struct hlist_head *hhd;
1181 if (hash->size_bits)
1182 key = hash_long(entry->ip, hash->size_bits);
1186 hhd = &hash->buckets[key];
1187 hlist_add_head(&entry->hlist, hhd);
1191 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1193 struct ftrace_func_entry *entry;
1195 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1200 __add_hash_entry(hash, entry);
1206 free_hash_entry(struct ftrace_hash *hash,
1207 struct ftrace_func_entry *entry)
1209 hlist_del(&entry->hlist);
1215 remove_hash_entry(struct ftrace_hash *hash,
1216 struct ftrace_func_entry *entry)
1218 hlist_del(&entry->hlist);
1222 static void ftrace_hash_clear(struct ftrace_hash *hash)
1224 struct hlist_head *hhd;
1225 struct hlist_node *tn;
1226 struct ftrace_func_entry *entry;
1227 int size = 1 << hash->size_bits;
1233 for (i = 0; i < size; i++) {
1234 hhd = &hash->buckets[i];
1235 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1236 free_hash_entry(hash, entry);
1238 FTRACE_WARN_ON(hash->count);
1241 static void free_ftrace_hash(struct ftrace_hash *hash)
1243 if (!hash || hash == EMPTY_HASH)
1245 ftrace_hash_clear(hash);
1246 kfree(hash->buckets);
1250 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1252 struct ftrace_hash *hash;
1254 hash = container_of(rcu, struct ftrace_hash, rcu);
1255 free_ftrace_hash(hash);
1258 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1260 if (!hash || hash == EMPTY_HASH)
1262 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1265 void ftrace_free_filter(struct ftrace_ops *ops)
1267 ftrace_ops_init(ops);
1268 free_ftrace_hash(ops->filter_hash);
1269 free_ftrace_hash(ops->notrace_hash);
1272 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1274 struct ftrace_hash *hash;
1277 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1281 size = 1 << size_bits;
1282 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1284 if (!hash->buckets) {
1289 hash->size_bits = size_bits;
1294 static struct ftrace_hash *
1295 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1297 struct ftrace_func_entry *entry;
1298 struct ftrace_hash *new_hash;
1303 new_hash = alloc_ftrace_hash(size_bits);
1308 if (ftrace_hash_empty(hash))
1311 size = 1 << hash->size_bits;
1312 for (i = 0; i < size; i++) {
1313 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1314 ret = add_hash_entry(new_hash, entry->ip);
1320 FTRACE_WARN_ON(new_hash->count != hash->count);
1325 free_ftrace_hash(new_hash);
1330 ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1332 ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1335 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1336 struct ftrace_hash **dst, struct ftrace_hash *src)
1338 struct ftrace_func_entry *entry;
1339 struct hlist_node *tn;
1340 struct hlist_head *hhd;
1341 struct ftrace_hash *old_hash;
1342 struct ftrace_hash *new_hash;
1343 int size = src->count;
1349 * Remove the current set, update the hash and add
1352 ftrace_hash_rec_disable(ops, enable);
1355 * If the new source is empty, just free dst and assign it
1359 free_ftrace_hash_rcu(*dst);
1360 rcu_assign_pointer(*dst, EMPTY_HASH);
1361 /* still need to update the function records */
1367 * Make the hash size about 1/2 the # found
1369 for (size /= 2; size; size >>= 1)
1372 /* Don't allocate too much */
1373 if (bits > FTRACE_HASH_MAX_BITS)
1374 bits = FTRACE_HASH_MAX_BITS;
1377 new_hash = alloc_ftrace_hash(bits);
1381 size = 1 << src->size_bits;
1382 for (i = 0; i < size; i++) {
1383 hhd = &src->buckets[i];
1384 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1385 remove_hash_entry(src, entry);
1386 __add_hash_entry(new_hash, entry);
1391 rcu_assign_pointer(*dst, new_hash);
1392 free_ftrace_hash_rcu(old_hash);
1397 * Enable regardless of ret:
1398 * On success, we enable the new hash.
1399 * On failure, we re-enable the original hash.
1401 ftrace_hash_rec_enable(ops, enable);
1407 * Test the hashes for this ops to see if we want to call
1408 * the ops->func or not.
1410 * It's a match if the ip is in the ops->filter_hash or
1411 * the filter_hash does not exist or is empty,
1413 * the ip is not in the ops->notrace_hash.
1415 * This needs to be called with preemption disabled as
1416 * the hashes are freed with call_rcu_sched().
1419 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1421 struct ftrace_hash *filter_hash;
1422 struct ftrace_hash *notrace_hash;
1425 filter_hash = rcu_dereference_raw(ops->filter_hash);
1426 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1428 if ((ftrace_hash_empty(filter_hash) ||
1429 ftrace_lookup_ip(filter_hash, ip)) &&
1430 (ftrace_hash_empty(notrace_hash) ||
1431 !ftrace_lookup_ip(notrace_hash, ip)))
1440 * This is a double for. Do not use 'break' to break out of the loop,
1441 * you must use a goto.
1443 #define do_for_each_ftrace_rec(pg, rec) \
1444 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1446 for (_____i = 0; _____i < pg->index; _____i++) { \
1447 rec = &pg->records[_____i];
1449 #define while_for_each_ftrace_rec() \
1454 static int ftrace_cmp_recs(const void *a, const void *b)
1456 const struct dyn_ftrace *key = a;
1457 const struct dyn_ftrace *rec = b;
1459 if (key->flags < rec->ip)
1461 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1466 static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1468 struct ftrace_page *pg;
1469 struct dyn_ftrace *rec;
1470 struct dyn_ftrace key;
1473 key.flags = end; /* overload flags, as it is unsigned long */
1475 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1476 if (end < pg->records[0].ip ||
1477 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1479 rec = bsearch(&key, pg->records, pg->index,
1480 sizeof(struct dyn_ftrace),
1490 * ftrace_location - return true if the ip giving is a traced location
1491 * @ip: the instruction pointer to check
1493 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1494 * That is, the instruction that is either a NOP or call to
1495 * the function tracer. It checks the ftrace internal tables to
1496 * determine if the address belongs or not.
1498 unsigned long ftrace_location(unsigned long ip)
1500 return ftrace_location_range(ip, ip);
1504 * ftrace_text_reserved - return true if range contains an ftrace location
1505 * @start: start of range to search
1506 * @end: end of range to search (inclusive). @end points to the last byte to check.
1508 * Returns 1 if @start and @end contains a ftrace location.
1509 * That is, the instruction that is either a NOP or call to
1510 * the function tracer. It checks the ftrace internal tables to
1511 * determine if the address belongs or not.
1513 int ftrace_text_reserved(void *start, void *end)
1517 ret = ftrace_location_range((unsigned long)start,
1518 (unsigned long)end);
1523 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1527 struct ftrace_hash *hash;
1528 struct ftrace_hash *other_hash;
1529 struct ftrace_page *pg;
1530 struct dyn_ftrace *rec;
1534 /* Only update if the ops has been registered */
1535 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1539 * In the filter_hash case:
1540 * If the count is zero, we update all records.
1541 * Otherwise we just update the items in the hash.
1543 * In the notrace_hash case:
1544 * We enable the update in the hash.
1545 * As disabling notrace means enabling the tracing,
1546 * and enabling notrace means disabling, the inc variable
1550 hash = ops->filter_hash;
1551 other_hash = ops->notrace_hash;
1552 if (ftrace_hash_empty(hash))
1556 hash = ops->notrace_hash;
1557 other_hash = ops->filter_hash;
1559 * If the notrace hash has no items,
1560 * then there's nothing to do.
1562 if (ftrace_hash_empty(hash))
1566 do_for_each_ftrace_rec(pg, rec) {
1567 int in_other_hash = 0;
1573 * Only the filter_hash affects all records.
1574 * Update if the record is not in the notrace hash.
1576 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1579 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1580 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1585 if (filter_hash && in_hash && !in_other_hash)
1587 else if (!filter_hash && in_hash &&
1588 (in_other_hash || ftrace_hash_empty(other_hash)))
1596 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1599 * If any ops wants regs saved for this function
1600 * then all ops will get saved regs.
1602 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1603 rec->flags |= FTRACE_FL_REGS;
1605 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1610 /* Shortcut, if we handled all records, we are done. */
1611 if (!all && count == hash->count)
1613 } while_for_each_ftrace_rec();
1616 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1619 __ftrace_hash_rec_update(ops, filter_hash, 0);
1622 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1625 __ftrace_hash_rec_update(ops, filter_hash, 1);
1628 static void print_ip_ins(const char *fmt, unsigned char *p)
1632 printk(KERN_CONT "%s", fmt);
1634 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1635 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1639 * ftrace_bug - report and shutdown function tracer
1640 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1641 * @ip: The address that failed
1643 * The arch code that enables or disables the function tracing
1644 * can call ftrace_bug() when it has detected a problem in
1645 * modifying the code. @failed should be one of either:
1646 * EFAULT - if the problem happens on reading the @ip address
1647 * EINVAL - if what is read at @ip is not what was expected
1648 * EPERM - if the problem happens on writting to the @ip address
1650 void ftrace_bug(int failed, unsigned long ip)
1654 FTRACE_WARN_ON_ONCE(1);
1655 pr_info("ftrace faulted on modifying ");
1659 FTRACE_WARN_ON_ONCE(1);
1660 pr_info("ftrace failed to modify ");
1662 print_ip_ins(" actual: ", (unsigned char *)ip);
1663 printk(KERN_CONT "\n");
1666 FTRACE_WARN_ON_ONCE(1);
1667 pr_info("ftrace faulted on writing ");
1671 FTRACE_WARN_ON_ONCE(1);
1672 pr_info("ftrace faulted on unknown error ");
1677 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
1679 unsigned long flag = 0UL;
1682 * If we are updating calls:
1684 * If the record has a ref count, then we need to enable it
1685 * because someone is using it.
1687 * Otherwise we make sure its disabled.
1689 * If we are disabling calls, then disable all records that
1692 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1693 flag = FTRACE_FL_ENABLED;
1696 * If enabling and the REGS flag does not match the REGS_EN, then
1697 * do not ignore this record. Set flags to fail the compare against
1701 (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
1702 flag |= FTRACE_FL_REGS;
1704 /* If the state of this record hasn't changed, then do nothing */
1705 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1706 return FTRACE_UPDATE_IGNORE;
1709 /* Save off if rec is being enabled (for return value) */
1710 flag ^= rec->flags & FTRACE_FL_ENABLED;
1713 rec->flags |= FTRACE_FL_ENABLED;
1714 if (flag & FTRACE_FL_REGS) {
1715 if (rec->flags & FTRACE_FL_REGS)
1716 rec->flags |= FTRACE_FL_REGS_EN;
1718 rec->flags &= ~FTRACE_FL_REGS_EN;
1723 * If this record is being updated from a nop, then
1724 * return UPDATE_MAKE_CALL.
1725 * Otherwise, if the EN flag is set, then return
1726 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1727 * from the non-save regs, to a save regs function.
1729 * return UPDATE_MODIFY_CALL to tell the caller to convert
1730 * from the save regs, to a non-save regs function.
1732 if (flag & FTRACE_FL_ENABLED)
1733 return FTRACE_UPDATE_MAKE_CALL;
1734 else if (rec->flags & FTRACE_FL_REGS_EN)
1735 return FTRACE_UPDATE_MODIFY_CALL_REGS;
1737 return FTRACE_UPDATE_MODIFY_CALL;
1741 /* If there's no more users, clear all flags */
1742 if (!(rec->flags & ~FTRACE_FL_MASK))
1745 /* Just disable the record (keep REGS state) */
1746 rec->flags &= ~FTRACE_FL_ENABLED;
1749 return FTRACE_UPDATE_MAKE_NOP;
1753 * ftrace_update_record, set a record that now is tracing or not
1754 * @rec: the record to update
1755 * @enable: set to 1 if the record is tracing, zero to force disable
1757 * The records that represent all functions that can be traced need
1758 * to be updated when tracing has been enabled.
1760 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1762 return ftrace_check_record(rec, enable, 1);
1766 * ftrace_test_record, check if the record has been enabled or not
1767 * @rec: the record to test
1768 * @enable: set to 1 to check if enabled, 0 if it is disabled
1770 * The arch code may need to test if a record is already set to
1771 * tracing to determine how to modify the function code that it
1774 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1776 return ftrace_check_record(rec, enable, 0);
1780 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1782 unsigned long ftrace_old_addr;
1783 unsigned long ftrace_addr;
1786 ret = ftrace_update_record(rec, enable);
1788 if (rec->flags & FTRACE_FL_REGS)
1789 ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
1791 ftrace_addr = (unsigned long)FTRACE_ADDR;
1794 case FTRACE_UPDATE_IGNORE:
1797 case FTRACE_UPDATE_MAKE_CALL:
1798 return ftrace_make_call(rec, ftrace_addr);
1800 case FTRACE_UPDATE_MAKE_NOP:
1801 return ftrace_make_nop(NULL, rec, ftrace_addr);
1803 case FTRACE_UPDATE_MODIFY_CALL_REGS:
1804 case FTRACE_UPDATE_MODIFY_CALL:
1805 if (rec->flags & FTRACE_FL_REGS)
1806 ftrace_old_addr = (unsigned long)FTRACE_ADDR;
1808 ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
1810 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
1813 return -1; /* unknow ftrace bug */
1816 void __weak ftrace_replace_code(int enable)
1818 struct dyn_ftrace *rec;
1819 struct ftrace_page *pg;
1822 if (unlikely(ftrace_disabled))
1825 do_for_each_ftrace_rec(pg, rec) {
1826 failed = __ftrace_replace_code(rec, enable);
1828 ftrace_bug(failed, rec->ip);
1829 /* Stop processing */
1832 } while_for_each_ftrace_rec();
1835 struct ftrace_rec_iter {
1836 struct ftrace_page *pg;
1841 * ftrace_rec_iter_start, start up iterating over traced functions
1843 * Returns an iterator handle that is used to iterate over all
1844 * the records that represent address locations where functions
1847 * May return NULL if no records are available.
1849 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
1852 * We only use a single iterator.
1853 * Protected by the ftrace_lock mutex.
1855 static struct ftrace_rec_iter ftrace_rec_iter;
1856 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
1858 iter->pg = ftrace_pages_start;
1861 /* Could have empty pages */
1862 while (iter->pg && !iter->pg->index)
1863 iter->pg = iter->pg->next;
1872 * ftrace_rec_iter_next, get the next record to process.
1873 * @iter: The handle to the iterator.
1875 * Returns the next iterator after the given iterator @iter.
1877 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
1881 if (iter->index >= iter->pg->index) {
1882 iter->pg = iter->pg->next;
1885 /* Could have empty pages */
1886 while (iter->pg && !iter->pg->index)
1887 iter->pg = iter->pg->next;
1897 * ftrace_rec_iter_record, get the record at the iterator location
1898 * @iter: The current iterator location
1900 * Returns the record that the current @iter is at.
1902 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
1904 return &iter->pg->records[iter->index];
1908 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1915 if (unlikely(ftrace_disabled))
1918 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1920 ftrace_bug(ret, ip);
1927 * archs can override this function if they must do something
1928 * before the modifying code is performed.
1930 int __weak ftrace_arch_code_modify_prepare(void)
1936 * archs can override this function if they must do something
1937 * after the modifying code is performed.
1939 int __weak ftrace_arch_code_modify_post_process(void)
1944 void ftrace_modify_all_code(int command)
1946 if (command & FTRACE_UPDATE_CALLS)
1947 ftrace_replace_code(1);
1948 else if (command & FTRACE_DISABLE_CALLS)
1949 ftrace_replace_code(0);
1951 if (command & FTRACE_UPDATE_TRACE_FUNC)
1952 ftrace_update_ftrace_func(ftrace_trace_function);
1954 if (command & FTRACE_START_FUNC_RET)
1955 ftrace_enable_ftrace_graph_caller();
1956 else if (command & FTRACE_STOP_FUNC_RET)
1957 ftrace_disable_ftrace_graph_caller();
1960 static int __ftrace_modify_code(void *data)
1962 int *command = data;
1964 ftrace_modify_all_code(*command);
1970 * ftrace_run_stop_machine, go back to the stop machine method
1971 * @command: The command to tell ftrace what to do
1973 * If an arch needs to fall back to the stop machine method, the
1974 * it can call this function.
1976 void ftrace_run_stop_machine(int command)
1978 stop_machine(__ftrace_modify_code, &command, NULL);
1982 * arch_ftrace_update_code, modify the code to trace or not trace
1983 * @command: The command that needs to be done
1985 * Archs can override this function if it does not need to
1986 * run stop_machine() to modify code.
1988 void __weak arch_ftrace_update_code(int command)
1990 ftrace_run_stop_machine(command);
1993 static void ftrace_run_update_code(int command)
1997 ret = ftrace_arch_code_modify_prepare();
1998 FTRACE_WARN_ON(ret);
2002 * Do not call function tracer while we update the code.
2003 * We are in stop machine.
2005 function_trace_stop++;
2008 * By default we use stop_machine() to modify the code.
2009 * But archs can do what ever they want as long as it
2010 * is safe. The stop_machine() is the safest, but also
2011 * produces the most overhead.
2013 arch_ftrace_update_code(command);
2015 function_trace_stop--;
2017 ret = ftrace_arch_code_modify_post_process();
2018 FTRACE_WARN_ON(ret);
2021 static ftrace_func_t saved_ftrace_func;
2022 static int ftrace_start_up;
2023 static int global_start_up;
2025 static void ftrace_startup_enable(int command)
2027 if (saved_ftrace_func != ftrace_trace_function) {
2028 saved_ftrace_func = ftrace_trace_function;
2029 command |= FTRACE_UPDATE_TRACE_FUNC;
2032 if (!command || !ftrace_enabled)
2035 ftrace_run_update_code(command);
2038 static int ftrace_startup(struct ftrace_ops *ops, int command)
2040 bool hash_enable = true;
2042 if (unlikely(ftrace_disabled))
2046 command |= FTRACE_UPDATE_CALLS;
2048 /* ops marked global share the filter hashes */
2049 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2051 /* Don't update hash if global is already set */
2052 if (global_start_up)
2053 hash_enable = false;
2057 ops->flags |= FTRACE_OPS_FL_ENABLED;
2059 ftrace_hash_rec_enable(ops, 1);
2061 ftrace_startup_enable(command);
2066 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
2068 bool hash_disable = true;
2070 if (unlikely(ftrace_disabled))
2075 * Just warn in case of unbalance, no need to kill ftrace, it's not
2076 * critical but the ftrace_call callers may be never nopped again after
2077 * further ftrace uses.
2079 WARN_ON_ONCE(ftrace_start_up < 0);
2081 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2084 WARN_ON_ONCE(global_start_up < 0);
2085 /* Don't update hash if global still has users */
2086 if (global_start_up) {
2087 WARN_ON_ONCE(!ftrace_start_up);
2088 hash_disable = false;
2093 ftrace_hash_rec_disable(ops, 1);
2095 if (ops != &global_ops || !global_start_up)
2096 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2098 command |= FTRACE_UPDATE_CALLS;
2100 if (saved_ftrace_func != ftrace_trace_function) {
2101 saved_ftrace_func = ftrace_trace_function;
2102 command |= FTRACE_UPDATE_TRACE_FUNC;
2105 if (!command || !ftrace_enabled)
2108 ftrace_run_update_code(command);
2111 static void ftrace_startup_sysctl(void)
2113 if (unlikely(ftrace_disabled))
2116 /* Force update next time */
2117 saved_ftrace_func = NULL;
2118 /* ftrace_start_up is true if we want ftrace running */
2119 if (ftrace_start_up)
2120 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
2123 static void ftrace_shutdown_sysctl(void)
2125 if (unlikely(ftrace_disabled))
2128 /* ftrace_start_up is true if ftrace is running */
2129 if (ftrace_start_up)
2130 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
2133 static cycle_t ftrace_update_time;
2134 static unsigned long ftrace_update_cnt;
2135 unsigned long ftrace_update_tot_cnt;
2137 static int ops_traces_mod(struct ftrace_ops *ops)
2139 struct ftrace_hash *hash;
2141 hash = ops->filter_hash;
2142 return ftrace_hash_empty(hash);
2145 static int ftrace_update_code(struct module *mod)
2147 struct ftrace_page *pg;
2148 struct dyn_ftrace *p;
2149 cycle_t start, stop;
2150 unsigned long ref = 0;
2154 * When adding a module, we need to check if tracers are
2155 * currently enabled and if they are set to trace all functions.
2156 * If they are, we need to enable the module functions as well
2157 * as update the reference counts for those function records.
2160 struct ftrace_ops *ops;
2162 for (ops = ftrace_ops_list;
2163 ops != &ftrace_list_end; ops = ops->next) {
2164 if (ops->flags & FTRACE_OPS_FL_ENABLED &&
2165 ops_traces_mod(ops))
2170 start = ftrace_now(raw_smp_processor_id());
2171 ftrace_update_cnt = 0;
2173 for (pg = ftrace_new_pgs; pg; pg = pg->next) {
2175 for (i = 0; i < pg->index; i++) {
2176 /* If something went wrong, bail without enabling anything */
2177 if (unlikely(ftrace_disabled))
2180 p = &pg->records[i];
2184 * Do the initial record conversion from mcount jump
2185 * to the NOP instructions.
2187 if (!ftrace_code_disable(mod, p))
2190 ftrace_update_cnt++;
2193 * If the tracing is enabled, go ahead and enable the record.
2195 * The reason not to enable the record immediatelly is the
2196 * inherent check of ftrace_make_nop/ftrace_make_call for
2197 * correct previous instructions. Making first the NOP
2198 * conversion puts the module to the correct state, thus
2199 * passing the ftrace_make_call check.
2201 if (ftrace_start_up && ref) {
2202 int failed = __ftrace_replace_code(p, 1);
2204 ftrace_bug(failed, p->ip);
2209 ftrace_new_pgs = NULL;
2211 stop = ftrace_now(raw_smp_processor_id());
2212 ftrace_update_time = stop - start;
2213 ftrace_update_tot_cnt += ftrace_update_cnt;
2218 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2223 if (WARN_ON(!count))
2226 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2229 * We want to fill as much as possible. No more than a page
2232 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2236 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2239 /* if we can't allocate this size, try something smaller */
2246 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2255 static struct ftrace_page *
2256 ftrace_allocate_pages(unsigned long num_to_init)
2258 struct ftrace_page *start_pg;
2259 struct ftrace_page *pg;
2266 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2271 * Try to allocate as much as possible in one continues
2272 * location that fills in all of the space. We want to
2273 * waste as little space as possible.
2276 cnt = ftrace_allocate_records(pg, num_to_init);
2284 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2295 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2296 free_pages((unsigned long)pg->records, order);
2297 start_pg = pg->next;
2301 pr_info("ftrace: FAILED to allocate memory for functions\n");
2305 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
2310 pr_info("ftrace: No functions to be traced?\n");
2314 cnt = num_to_init / ENTRIES_PER_PAGE;
2315 pr_info("ftrace: allocating %ld entries in %d pages\n",
2316 num_to_init, cnt + 1);
2321 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2323 struct ftrace_iterator {
2326 struct ftrace_page *pg;
2327 struct dyn_ftrace *func;
2328 struct ftrace_func_probe *probe;
2329 struct trace_parser parser;
2330 struct ftrace_hash *hash;
2331 struct ftrace_ops *ops;
2338 t_hash_next(struct seq_file *m, loff_t *pos)
2340 struct ftrace_iterator *iter = m->private;
2341 struct hlist_node *hnd = NULL;
2342 struct hlist_head *hhd;
2348 hnd = &iter->probe->node;
2350 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2353 hhd = &ftrace_func_hash[iter->hidx];
2355 if (hlist_empty(hhd)) {
2371 if (WARN_ON_ONCE(!hnd))
2374 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2379 static void *t_hash_start(struct seq_file *m, loff_t *pos)
2381 struct ftrace_iterator *iter = m->private;
2385 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2388 if (iter->func_pos > *pos)
2392 for (l = 0; l <= (*pos - iter->func_pos); ) {
2393 p = t_hash_next(m, &l);
2400 /* Only set this if we have an item */
2401 iter->flags |= FTRACE_ITER_HASH;
2407 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2409 struct ftrace_func_probe *rec;
2412 if (WARN_ON_ONCE(!rec))
2415 if (rec->ops->print)
2416 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2418 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2421 seq_printf(m, ":%p", rec->data);
2428 t_next(struct seq_file *m, void *v, loff_t *pos)
2430 struct ftrace_iterator *iter = m->private;
2431 struct ftrace_ops *ops = iter->ops;
2432 struct dyn_ftrace *rec = NULL;
2434 if (unlikely(ftrace_disabled))
2437 if (iter->flags & FTRACE_ITER_HASH)
2438 return t_hash_next(m, pos);
2441 iter->pos = iter->func_pos = *pos;
2443 if (iter->flags & FTRACE_ITER_PRINTALL)
2444 return t_hash_start(m, pos);
2447 if (iter->idx >= iter->pg->index) {
2448 if (iter->pg->next) {
2449 iter->pg = iter->pg->next;
2454 rec = &iter->pg->records[iter->idx++];
2455 if (((iter->flags & FTRACE_ITER_FILTER) &&
2456 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
2458 ((iter->flags & FTRACE_ITER_NOTRACE) &&
2459 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2461 ((iter->flags & FTRACE_ITER_ENABLED) &&
2462 !(rec->flags & ~FTRACE_FL_MASK))) {
2470 return t_hash_start(m, pos);
2477 static void reset_iter_read(struct ftrace_iterator *iter)
2481 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
2484 static void *t_start(struct seq_file *m, loff_t *pos)
2486 struct ftrace_iterator *iter = m->private;
2487 struct ftrace_ops *ops = iter->ops;
2491 mutex_lock(&ftrace_lock);
2493 if (unlikely(ftrace_disabled))
2497 * If an lseek was done, then reset and start from beginning.
2499 if (*pos < iter->pos)
2500 reset_iter_read(iter);
2503 * For set_ftrace_filter reading, if we have the filter
2504 * off, we can short cut and just print out that all
2505 * functions are enabled.
2507 if (iter->flags & FTRACE_ITER_FILTER &&
2508 ftrace_hash_empty(ops->filter_hash)) {
2510 return t_hash_start(m, pos);
2511 iter->flags |= FTRACE_ITER_PRINTALL;
2512 /* reset in case of seek/pread */
2513 iter->flags &= ~FTRACE_ITER_HASH;
2517 if (iter->flags & FTRACE_ITER_HASH)
2518 return t_hash_start(m, pos);
2521 * Unfortunately, we need to restart at ftrace_pages_start
2522 * every time we let go of the ftrace_mutex. This is because
2523 * those pointers can change without the lock.
2525 iter->pg = ftrace_pages_start;
2527 for (l = 0; l <= *pos; ) {
2528 p = t_next(m, p, &l);
2534 return t_hash_start(m, pos);
2539 static void t_stop(struct seq_file *m, void *p)
2541 mutex_unlock(&ftrace_lock);
2544 static int t_show(struct seq_file *m, void *v)
2546 struct ftrace_iterator *iter = m->private;
2547 struct dyn_ftrace *rec;
2549 if (iter->flags & FTRACE_ITER_HASH)
2550 return t_hash_show(m, iter);
2552 if (iter->flags & FTRACE_ITER_PRINTALL) {
2553 seq_printf(m, "#### all functions enabled ####\n");
2562 seq_printf(m, "%ps", (void *)rec->ip);
2563 if (iter->flags & FTRACE_ITER_ENABLED)
2564 seq_printf(m, " (%ld)%s",
2565 rec->flags & ~FTRACE_FL_MASK,
2566 rec->flags & FTRACE_FL_REGS ? " R" : "");
2567 seq_printf(m, "\n");
2572 static const struct seq_operations show_ftrace_seq_ops = {
2580 ftrace_avail_open(struct inode *inode, struct file *file)
2582 struct ftrace_iterator *iter;
2584 if (unlikely(ftrace_disabled))
2587 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2589 iter->pg = ftrace_pages_start;
2590 iter->ops = &global_ops;
2593 return iter ? 0 : -ENOMEM;
2597 ftrace_enabled_open(struct inode *inode, struct file *file)
2599 struct ftrace_iterator *iter;
2601 if (unlikely(ftrace_disabled))
2604 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2606 iter->pg = ftrace_pages_start;
2607 iter->flags = FTRACE_ITER_ENABLED;
2608 iter->ops = &global_ops;
2611 return iter ? 0 : -ENOMEM;
2614 static void ftrace_filter_reset(struct ftrace_hash *hash)
2616 mutex_lock(&ftrace_lock);
2617 ftrace_hash_clear(hash);
2618 mutex_unlock(&ftrace_lock);
2622 * ftrace_regex_open - initialize function tracer filter files
2623 * @ops: The ftrace_ops that hold the hash filters
2624 * @flag: The type of filter to process
2625 * @inode: The inode, usually passed in to your open routine
2626 * @file: The file, usually passed in to your open routine
2628 * ftrace_regex_open() initializes the filter files for the
2629 * @ops. Depending on @flag it may process the filter hash or
2630 * the notrace hash of @ops. With this called from the open
2631 * routine, you can use ftrace_filter_write() for the write
2632 * routine if @flag has FTRACE_ITER_FILTER set, or
2633 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2634 * ftrace_filter_lseek() should be used as the lseek routine, and
2635 * release must call ftrace_regex_release().
2638 ftrace_regex_open(struct ftrace_ops *ops, int flag,
2639 struct inode *inode, struct file *file)
2641 struct ftrace_iterator *iter;
2642 struct ftrace_hash *hash;
2645 ftrace_ops_init(ops);
2647 if (unlikely(ftrace_disabled))
2650 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2654 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2662 mutex_lock(&ops->regex_lock);
2664 if (flag & FTRACE_ITER_NOTRACE)
2665 hash = ops->notrace_hash;
2667 hash = ops->filter_hash;
2669 if (file->f_mode & FMODE_WRITE) {
2670 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2672 trace_parser_put(&iter->parser);
2679 if ((file->f_mode & FMODE_WRITE) &&
2680 (file->f_flags & O_TRUNC))
2681 ftrace_filter_reset(iter->hash);
2683 if (file->f_mode & FMODE_READ) {
2684 iter->pg = ftrace_pages_start;
2686 ret = seq_open(file, &show_ftrace_seq_ops);
2688 struct seq_file *m = file->private_data;
2692 free_ftrace_hash(iter->hash);
2693 trace_parser_put(&iter->parser);
2697 file->private_data = iter;
2700 mutex_unlock(&ops->regex_lock);
2706 ftrace_filter_open(struct inode *inode, struct file *file)
2708 return ftrace_regex_open(&global_ops,
2709 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
2714 ftrace_notrace_open(struct inode *inode, struct file *file)
2716 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2720 static int ftrace_match(char *str, char *regex, int len, int type)
2727 if (strcmp(str, regex) == 0)
2730 case MATCH_FRONT_ONLY:
2731 if (strncmp(str, regex, len) == 0)
2734 case MATCH_MIDDLE_ONLY:
2735 if (strstr(str, regex))
2738 case MATCH_END_ONLY:
2740 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2749 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2751 struct ftrace_func_entry *entry;
2754 entry = ftrace_lookup_ip(hash, rec->ip);
2756 /* Do nothing if it doesn't exist */
2760 free_hash_entry(hash, entry);
2762 /* Do nothing if it exists */
2766 ret = add_hash_entry(hash, rec->ip);
2772 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2773 char *regex, int len, int type)
2775 char str[KSYM_SYMBOL_LEN];
2778 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2781 /* module lookup requires matching the module */
2782 if (!modname || strcmp(modname, mod))
2785 /* blank search means to match all funcs in the mod */
2790 return ftrace_match(str, regex, len, type);
2794 match_records(struct ftrace_hash *hash, char *buff,
2795 int len, char *mod, int not)
2797 unsigned search_len = 0;
2798 struct ftrace_page *pg;
2799 struct dyn_ftrace *rec;
2800 int type = MATCH_FULL;
2801 char *search = buff;
2806 type = filter_parse_regex(buff, len, &search, ¬);
2807 search_len = strlen(search);
2810 mutex_lock(&ftrace_lock);
2812 if (unlikely(ftrace_disabled))
2815 do_for_each_ftrace_rec(pg, rec) {
2816 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2817 ret = enter_record(hash, rec, not);
2824 } while_for_each_ftrace_rec();
2826 mutex_unlock(&ftrace_lock);
2832 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2834 return match_records(hash, buff, len, NULL, 0);
2838 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2842 /* blank or '*' mean the same */
2843 if (strcmp(buff, "*") == 0)
2846 /* handle the case of 'dont filter this module' */
2847 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2852 return match_records(hash, buff, strlen(buff), mod, not);
2856 * We register the module command as a template to show others how
2857 * to register the a command as well.
2861 ftrace_mod_callback(struct ftrace_hash *hash,
2862 char *func, char *cmd, char *param, int enable)
2868 * cmd == 'mod' because we only registered this func
2869 * for the 'mod' ftrace_func_command.
2870 * But if you register one func with multiple commands,
2871 * you can tell which command was used by the cmd
2875 /* we must have a module name */
2879 mod = strsep(¶m, ":");
2883 ret = ftrace_match_module_records(hash, func, mod);
2892 static struct ftrace_func_command ftrace_mod_cmd = {
2894 .func = ftrace_mod_callback,
2897 static int __init ftrace_mod_cmd_init(void)
2899 return register_ftrace_command(&ftrace_mod_cmd);
2901 core_initcall(ftrace_mod_cmd_init);
2903 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
2904 struct ftrace_ops *op, struct pt_regs *pt_regs)
2906 struct ftrace_func_probe *entry;
2907 struct hlist_head *hhd;
2910 key = hash_long(ip, FTRACE_HASH_BITS);
2912 hhd = &ftrace_func_hash[key];
2914 if (hlist_empty(hhd))
2918 * Disable preemption for these calls to prevent a RCU grace
2919 * period. This syncs the hash iteration and freeing of items
2920 * on the hash. rcu_read_lock is too dangerous here.
2922 preempt_disable_notrace();
2923 hlist_for_each_entry_rcu(entry, hhd, node) {
2924 if (entry->ip == ip)
2925 entry->ops->func(ip, parent_ip, &entry->data);
2927 preempt_enable_notrace();
2930 static struct ftrace_ops trace_probe_ops __read_mostly =
2932 .func = function_trace_probe_call,
2933 .flags = FTRACE_OPS_FL_INITIALIZED,
2934 INIT_REGEX_LOCK(trace_probe_ops)
2937 static int ftrace_probe_registered;
2939 static void __enable_ftrace_function_probe(void)
2944 if (ftrace_probe_registered)
2947 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2948 struct hlist_head *hhd = &ftrace_func_hash[i];
2952 /* Nothing registered? */
2953 if (i == FTRACE_FUNC_HASHSIZE)
2956 ret = __register_ftrace_function(&trace_probe_ops);
2958 ret = ftrace_startup(&trace_probe_ops, 0);
2960 ftrace_probe_registered = 1;
2963 static void __disable_ftrace_function_probe(void)
2968 if (!ftrace_probe_registered)
2971 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2972 struct hlist_head *hhd = &ftrace_func_hash[i];
2977 /* no more funcs left */
2978 ret = __unregister_ftrace_function(&trace_probe_ops);
2980 ftrace_shutdown(&trace_probe_ops, 0);
2982 ftrace_probe_registered = 0;
2986 static void ftrace_free_entry(struct ftrace_func_probe *entry)
2988 if (entry->ops->free)
2989 entry->ops->free(entry->ops, entry->ip, &entry->data);
2994 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2997 struct ftrace_func_probe *entry;
2998 struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
2999 struct ftrace_hash *hash;
3000 struct ftrace_page *pg;
3001 struct dyn_ftrace *rec;
3008 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3009 len = strlen(search);
3011 /* we do not support '!' for function probes */
3015 mutex_lock(&trace_probe_ops.regex_lock);
3017 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3023 if (unlikely(ftrace_disabled)) {
3028 mutex_lock(&ftrace_lock);
3030 do_for_each_ftrace_rec(pg, rec) {
3032 if (!ftrace_match_record(rec, NULL, search, len, type))
3035 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3037 /* If we did not process any, then return error */
3048 * The caller might want to do something special
3049 * for each function we find. We call the callback
3050 * to give the caller an opportunity to do so.
3053 if (ops->init(ops, rec->ip, &entry->data) < 0) {
3054 /* caller does not like this func */
3060 ret = enter_record(hash, rec, 0);
3068 entry->ip = rec->ip;
3070 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3071 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3073 } while_for_each_ftrace_rec();
3075 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3079 __enable_ftrace_function_probe();
3082 mutex_unlock(&ftrace_lock);
3084 mutex_unlock(&trace_probe_ops.regex_lock);
3085 free_ftrace_hash(hash);
3091 PROBE_TEST_FUNC = 1,
3096 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3097 void *data, int flags)
3099 struct ftrace_func_entry *rec_entry;
3100 struct ftrace_func_probe *entry;
3101 struct ftrace_func_probe *p;
3102 struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
3103 struct list_head free_list;
3104 struct ftrace_hash *hash;
3105 struct hlist_node *tmp;
3106 char str[KSYM_SYMBOL_LEN];
3107 int type = MATCH_FULL;
3111 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
3116 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3117 len = strlen(search);
3119 /* we do not support '!' for function probes */
3124 mutex_lock(&trace_probe_ops.regex_lock);
3126 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3128 /* Hmm, should report this somehow */
3131 INIT_LIST_HEAD(&free_list);
3133 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3134 struct hlist_head *hhd = &ftrace_func_hash[i];
3136 hlist_for_each_entry_safe(entry, tmp, hhd, node) {
3138 /* break up if statements for readability */
3139 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
3142 if ((flags & PROBE_TEST_DATA) && entry->data != data)
3145 /* do this last, since it is the most expensive */
3147 kallsyms_lookup(entry->ip, NULL, NULL,
3149 if (!ftrace_match(str, glob, len, type))
3153 rec_entry = ftrace_lookup_ip(hash, entry->ip);
3154 /* It is possible more than one entry had this ip */
3156 free_hash_entry(hash, rec_entry);
3158 hlist_del_rcu(&entry->node);
3159 list_add(&entry->free_list, &free_list);
3162 mutex_lock(&ftrace_lock);
3163 __disable_ftrace_function_probe();
3165 * Remove after the disable is called. Otherwise, if the last
3166 * probe is removed, a null hash means *all enabled*.
3168 ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3169 synchronize_sched();
3170 list_for_each_entry_safe(entry, p, &free_list, free_list) {
3171 list_del(&entry->free_list);
3172 ftrace_free_entry(entry);
3174 mutex_unlock(&ftrace_lock);
3177 mutex_unlock(&trace_probe_ops.regex_lock);
3178 free_ftrace_hash(hash);
3182 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3185 __unregister_ftrace_function_probe(glob, ops, data,
3186 PROBE_TEST_FUNC | PROBE_TEST_DATA);
3190 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
3192 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
3195 void unregister_ftrace_function_probe_all(char *glob)
3197 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
3200 static LIST_HEAD(ftrace_commands);
3201 static DEFINE_MUTEX(ftrace_cmd_mutex);
3203 int register_ftrace_command(struct ftrace_func_command *cmd)
3205 struct ftrace_func_command *p;
3208 mutex_lock(&ftrace_cmd_mutex);
3209 list_for_each_entry(p, &ftrace_commands, list) {
3210 if (strcmp(cmd->name, p->name) == 0) {
3215 list_add(&cmd->list, &ftrace_commands);
3217 mutex_unlock(&ftrace_cmd_mutex);
3222 int unregister_ftrace_command(struct ftrace_func_command *cmd)
3224 struct ftrace_func_command *p, *n;
3227 mutex_lock(&ftrace_cmd_mutex);
3228 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3229 if (strcmp(cmd->name, p->name) == 0) {
3231 list_del_init(&p->list);
3236 mutex_unlock(&ftrace_cmd_mutex);
3241 static int ftrace_process_regex(struct ftrace_hash *hash,
3242 char *buff, int len, int enable)
3244 char *func, *command, *next = buff;
3245 struct ftrace_func_command *p;
3248 func = strsep(&next, ":");
3251 ret = ftrace_match_records(hash, func, len);
3261 command = strsep(&next, ":");
3263 mutex_lock(&ftrace_cmd_mutex);
3264 list_for_each_entry(p, &ftrace_commands, list) {
3265 if (strcmp(p->name, command) == 0) {
3266 ret = p->func(hash, func, command, next, enable);
3271 mutex_unlock(&ftrace_cmd_mutex);
3277 ftrace_regex_write(struct file *file, const char __user *ubuf,
3278 size_t cnt, loff_t *ppos, int enable)
3280 struct ftrace_iterator *iter;
3281 struct trace_parser *parser;
3287 if (file->f_mode & FMODE_READ) {
3288 struct seq_file *m = file->private_data;
3291 iter = file->private_data;
3293 if (unlikely(ftrace_disabled))
3296 /* iter->hash is a local copy, so we don't need regex_lock */
3298 parser = &iter->parser;
3299 read = trace_get_user(parser, ubuf, cnt, ppos);
3301 if (read >= 0 && trace_parser_loaded(parser) &&
3302 !trace_parser_cont(parser)) {
3303 ret = ftrace_process_regex(iter->hash, parser->buffer,
3304 parser->idx, enable);
3305 trace_parser_clear(parser);
3316 ftrace_filter_write(struct file *file, const char __user *ubuf,
3317 size_t cnt, loff_t *ppos)
3319 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3323 ftrace_notrace_write(struct file *file, const char __user *ubuf,
3324 size_t cnt, loff_t *ppos)
3326 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3330 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
3332 struct ftrace_func_entry *entry;
3334 if (!ftrace_location(ip))
3338 entry = ftrace_lookup_ip(hash, ip);
3341 free_hash_entry(hash, entry);
3345 return add_hash_entry(hash, ip);
3349 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
3350 unsigned long ip, int remove, int reset, int enable)
3352 struct ftrace_hash **orig_hash;
3353 struct ftrace_hash *hash;
3356 /* All global ops uses the global ops filters */
3357 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
3360 if (unlikely(ftrace_disabled))
3363 mutex_lock(&ops->regex_lock);
3366 orig_hash = &ops->filter_hash;
3368 orig_hash = &ops->notrace_hash;
3370 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3373 goto out_regex_unlock;
3377 ftrace_filter_reset(hash);
3378 if (buf && !ftrace_match_records(hash, buf, len)) {
3380 goto out_regex_unlock;
3383 ret = ftrace_match_addr(hash, ip, remove);
3385 goto out_regex_unlock;
3388 mutex_lock(&ftrace_lock);
3389 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3390 if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
3392 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3394 mutex_unlock(&ftrace_lock);
3397 mutex_unlock(&ops->regex_lock);
3399 free_ftrace_hash(hash);
3404 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
3405 int reset, int enable)
3407 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
3411 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3412 * @ops - the ops to set the filter with
3413 * @ip - the address to add to or remove from the filter.
3414 * @remove - non zero to remove the ip from the filter
3415 * @reset - non zero to reset all filters before applying this filter.
3417 * Filters denote which functions should be enabled when tracing is enabled
3418 * If @ip is NULL, it failes to update filter.
3420 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
3421 int remove, int reset)
3423 ftrace_ops_init(ops);
3424 return ftrace_set_addr(ops, ip, remove, reset, 1);
3426 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
3429 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3430 int reset, int enable)
3432 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
3436 * ftrace_set_filter - set a function to filter on in ftrace
3437 * @ops - the ops to set the filter with
3438 * @buf - the string that holds the function filter text.
3439 * @len - the length of the string.
3440 * @reset - non zero to reset all filters before applying this filter.
3442 * Filters denote which functions should be enabled when tracing is enabled.
3443 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3445 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
3448 ftrace_ops_init(ops);
3449 return ftrace_set_regex(ops, buf, len, reset, 1);
3451 EXPORT_SYMBOL_GPL(ftrace_set_filter);
3454 * ftrace_set_notrace - set a function to not trace in ftrace
3455 * @ops - the ops to set the notrace filter with
3456 * @buf - the string that holds the function notrace text.
3457 * @len - the length of the string.
3458 * @reset - non zero to reset all filters before applying this filter.
3460 * Notrace Filters denote which functions should not be enabled when tracing
3461 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3464 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
3467 ftrace_ops_init(ops);
3468 return ftrace_set_regex(ops, buf, len, reset, 0);
3470 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3472 * ftrace_set_filter - set a function to filter on in ftrace
3473 * @ops - the ops to set the filter with
3474 * @buf - the string that holds the function filter text.
3475 * @len - the length of the string.
3476 * @reset - non zero to reset all filters before applying this filter.
3478 * Filters denote which functions should be enabled when tracing is enabled.
3479 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3481 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3483 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3485 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3488 * ftrace_set_notrace - set a function to not trace in ftrace
3489 * @ops - the ops to set the notrace filter with
3490 * @buf - the string that holds the function notrace text.
3491 * @len - the length of the string.
3492 * @reset - non zero to reset all filters before applying this filter.
3494 * Notrace Filters denote which functions should not be enabled when tracing
3495 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3498 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
3500 ftrace_set_regex(&global_ops, buf, len, reset, 0);
3502 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
3505 * command line interface to allow users to set filters on boot up.
3507 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3508 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3509 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3511 static int __init set_ftrace_notrace(char *str)
3513 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3516 __setup("ftrace_notrace=", set_ftrace_notrace);
3518 static int __init set_ftrace_filter(char *str)
3520 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3523 __setup("ftrace_filter=", set_ftrace_filter);
3525 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3526 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3527 static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3529 static int __init set_graph_function(char *str)
3531 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3534 __setup("ftrace_graph_filter=", set_graph_function);
3536 static void __init set_ftrace_early_graph(char *buf)
3542 func = strsep(&buf, ",");
3543 /* we allow only one expression at a time */
3544 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3547 printk(KERN_DEBUG "ftrace: function %s not "
3548 "traceable\n", func);
3551 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3554 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
3558 ftrace_ops_init(ops);
3561 func = strsep(&buf, ",");
3562 ftrace_set_regex(ops, func, strlen(func), 0, enable);
3566 static void __init set_ftrace_early_filters(void)
3568 if (ftrace_filter_buf[0])
3569 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
3570 if (ftrace_notrace_buf[0])
3571 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
3572 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3573 if (ftrace_graph_buf[0])
3574 set_ftrace_early_graph(ftrace_graph_buf);
3575 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3578 int ftrace_regex_release(struct inode *inode, struct file *file)
3580 struct seq_file *m = (struct seq_file *)file->private_data;
3581 struct ftrace_iterator *iter;
3582 struct ftrace_hash **orig_hash;
3583 struct trace_parser *parser;
3587 if (file->f_mode & FMODE_READ) {
3589 seq_release(inode, file);
3591 iter = file->private_data;
3593 parser = &iter->parser;
3594 if (trace_parser_loaded(parser)) {
3595 parser->buffer[parser->idx] = 0;
3596 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3599 trace_parser_put(parser);
3601 mutex_lock(&iter->ops->regex_lock);
3603 if (file->f_mode & FMODE_WRITE) {
3604 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3607 orig_hash = &iter->ops->filter_hash;
3609 orig_hash = &iter->ops->notrace_hash;
3611 mutex_lock(&ftrace_lock);
3612 ret = ftrace_hash_move(iter->ops, filter_hash,
3613 orig_hash, iter->hash);
3614 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
3616 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3618 mutex_unlock(&ftrace_lock);
3621 mutex_unlock(&iter->ops->regex_lock);
3622 free_ftrace_hash(iter->hash);
3628 static const struct file_operations ftrace_avail_fops = {
3629 .open = ftrace_avail_open,
3631 .llseek = seq_lseek,
3632 .release = seq_release_private,
3635 static const struct file_operations ftrace_enabled_fops = {
3636 .open = ftrace_enabled_open,
3638 .llseek = seq_lseek,
3639 .release = seq_release_private,
3642 static const struct file_operations ftrace_filter_fops = {
3643 .open = ftrace_filter_open,
3645 .write = ftrace_filter_write,
3646 .llseek = ftrace_filter_lseek,
3647 .release = ftrace_regex_release,
3650 static const struct file_operations ftrace_notrace_fops = {
3651 .open = ftrace_notrace_open,
3653 .write = ftrace_notrace_write,
3654 .llseek = ftrace_filter_lseek,
3655 .release = ftrace_regex_release,
3658 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3660 static DEFINE_MUTEX(graph_lock);
3662 int ftrace_graph_count;
3663 int ftrace_graph_filter_enabled;
3664 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3667 __g_next(struct seq_file *m, loff_t *pos)
3669 if (*pos >= ftrace_graph_count)
3671 return &ftrace_graph_funcs[*pos];
3675 g_next(struct seq_file *m, void *v, loff_t *pos)
3678 return __g_next(m, pos);
3681 static void *g_start(struct seq_file *m, loff_t *pos)
3683 mutex_lock(&graph_lock);
3685 /* Nothing, tell g_show to print all functions are enabled */
3686 if (!ftrace_graph_filter_enabled && !*pos)
3689 return __g_next(m, pos);
3692 static void g_stop(struct seq_file *m, void *p)
3694 mutex_unlock(&graph_lock);
3697 static int g_show(struct seq_file *m, void *v)
3699 unsigned long *ptr = v;
3704 if (ptr == (unsigned long *)1) {
3705 seq_printf(m, "#### all functions enabled ####\n");
3709 seq_printf(m, "%ps\n", (void *)*ptr);
3714 static const struct seq_operations ftrace_graph_seq_ops = {
3722 ftrace_graph_open(struct inode *inode, struct file *file)
3726 if (unlikely(ftrace_disabled))
3729 mutex_lock(&graph_lock);
3730 if ((file->f_mode & FMODE_WRITE) &&
3731 (file->f_flags & O_TRUNC)) {
3732 ftrace_graph_filter_enabled = 0;
3733 ftrace_graph_count = 0;
3734 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3736 mutex_unlock(&graph_lock);
3738 if (file->f_mode & FMODE_READ)
3739 ret = seq_open(file, &ftrace_graph_seq_ops);
3745 ftrace_graph_release(struct inode *inode, struct file *file)
3747 if (file->f_mode & FMODE_READ)
3748 seq_release(inode, file);
3753 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3755 struct dyn_ftrace *rec;
3756 struct ftrace_page *pg;
3765 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3766 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3769 search_len = strlen(search);
3771 mutex_lock(&ftrace_lock);
3773 if (unlikely(ftrace_disabled)) {
3774 mutex_unlock(&ftrace_lock);
3778 do_for_each_ftrace_rec(pg, rec) {
3780 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3781 /* if it is in the array */
3783 for (i = 0; i < *idx; i++) {
3784 if (array[i] == rec->ip) {
3793 array[(*idx)++] = rec->ip;
3794 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3799 array[i] = array[--(*idx)];
3805 } while_for_each_ftrace_rec();
3807 mutex_unlock(&ftrace_lock);
3812 ftrace_graph_filter_enabled = !!(*idx);
3818 ftrace_graph_write(struct file *file, const char __user *ubuf,
3819 size_t cnt, loff_t *ppos)
3821 struct trace_parser parser;
3827 mutex_lock(&graph_lock);
3829 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3834 read = trace_get_user(&parser, ubuf, cnt, ppos);
3836 if (read >= 0 && trace_parser_loaded((&parser))) {
3837 parser.buffer[parser.idx] = 0;
3839 /* we allow only one expression at a time */
3840 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3849 trace_parser_put(&parser);
3851 mutex_unlock(&graph_lock);
3856 static const struct file_operations ftrace_graph_fops = {
3857 .open = ftrace_graph_open,
3859 .write = ftrace_graph_write,
3860 .llseek = ftrace_filter_lseek,
3861 .release = ftrace_graph_release,
3863 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3865 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3868 trace_create_file("available_filter_functions", 0444,
3869 d_tracer, NULL, &ftrace_avail_fops);
3871 trace_create_file("enabled_functions", 0444,
3872 d_tracer, NULL, &ftrace_enabled_fops);
3874 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3875 NULL, &ftrace_filter_fops);
3877 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3878 NULL, &ftrace_notrace_fops);
3880 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3881 trace_create_file("set_graph_function", 0444, d_tracer,
3883 &ftrace_graph_fops);
3884 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3889 static int ftrace_cmp_ips(const void *a, const void *b)
3891 const unsigned long *ipa = a;
3892 const unsigned long *ipb = b;
3901 static void ftrace_swap_ips(void *a, void *b, int size)
3903 unsigned long *ipa = a;
3904 unsigned long *ipb = b;
3912 static int ftrace_process_locs(struct module *mod,
3913 unsigned long *start,
3916 struct ftrace_page *start_pg;
3917 struct ftrace_page *pg;
3918 struct dyn_ftrace *rec;
3919 unsigned long count;
3922 unsigned long flags = 0; /* Shut up gcc */
3925 count = end - start;
3930 sort(start, count, sizeof(*start),
3931 ftrace_cmp_ips, ftrace_swap_ips);
3933 start_pg = ftrace_allocate_pages(count);
3937 mutex_lock(&ftrace_lock);
3940 * Core and each module needs their own pages, as
3941 * modules will free them when they are removed.
3942 * Force a new page to be allocated for modules.
3945 WARN_ON(ftrace_pages || ftrace_pages_start);
3946 /* First initialization */
3947 ftrace_pages = ftrace_pages_start = start_pg;
3952 if (WARN_ON(ftrace_pages->next)) {
3953 /* Hmm, we have free pages? */
3954 while (ftrace_pages->next)
3955 ftrace_pages = ftrace_pages->next;
3958 ftrace_pages->next = start_pg;
3964 addr = ftrace_call_adjust(*p++);
3966 * Some architecture linkers will pad between
3967 * the different mcount_loc sections of different
3968 * object files to satisfy alignments.
3969 * Skip any NULL pointers.
3974 if (pg->index == pg->size) {
3975 /* We should have allocated enough */
3976 if (WARN_ON(!pg->next))
3981 rec = &pg->records[pg->index++];
3985 /* We should have used all pages */
3988 /* Assign the last page to ftrace_pages */
3991 /* These new locations need to be initialized */
3992 ftrace_new_pgs = start_pg;
3995 * We only need to disable interrupts on start up
3996 * because we are modifying code that an interrupt
3997 * may execute, and the modification is not atomic.
3998 * But for modules, nothing runs the code we modify
3999 * until we are finished with it, and there's no
4000 * reason to cause large interrupt latencies while we do it.
4003 local_irq_save(flags);
4004 ftrace_update_code(mod);
4006 local_irq_restore(flags);
4009 mutex_unlock(&ftrace_lock);
4014 #ifdef CONFIG_MODULES
4016 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4018 void ftrace_release_mod(struct module *mod)
4020 struct dyn_ftrace *rec;
4021 struct ftrace_page **last_pg;
4022 struct ftrace_page *pg;
4025 mutex_lock(&ftrace_lock);
4027 if (ftrace_disabled)
4031 * Each module has its own ftrace_pages, remove
4032 * them from the list.
4034 last_pg = &ftrace_pages_start;
4035 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
4036 rec = &pg->records[0];
4037 if (within_module_core(rec->ip, mod)) {
4039 * As core pages are first, the first
4040 * page should never be a module page.
4042 if (WARN_ON(pg == ftrace_pages_start))
4045 /* Check if we are deleting the last page */
4046 if (pg == ftrace_pages)
4047 ftrace_pages = next_to_ftrace_page(last_pg);
4049 *last_pg = pg->next;
4050 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
4051 free_pages((unsigned long)pg->records, order);
4054 last_pg = &pg->next;
4057 mutex_unlock(&ftrace_lock);
4060 static void ftrace_init_module(struct module *mod,
4061 unsigned long *start, unsigned long *end)
4063 if (ftrace_disabled || start == end)
4065 ftrace_process_locs(mod, start, end);
4068 static int ftrace_module_notify_enter(struct notifier_block *self,
4069 unsigned long val, void *data)
4071 struct module *mod = data;
4073 if (val == MODULE_STATE_COMING)
4074 ftrace_init_module(mod, mod->ftrace_callsites,
4075 mod->ftrace_callsites +
4076 mod->num_ftrace_callsites);
4080 static int ftrace_module_notify_exit(struct notifier_block *self,
4081 unsigned long val, void *data)
4083 struct module *mod = data;
4085 if (val == MODULE_STATE_GOING)
4086 ftrace_release_mod(mod);
4091 static int ftrace_module_notify_enter(struct notifier_block *self,
4092 unsigned long val, void *data)
4096 static int ftrace_module_notify_exit(struct notifier_block *self,
4097 unsigned long val, void *data)
4101 #endif /* CONFIG_MODULES */
4103 struct notifier_block ftrace_module_enter_nb = {
4104 .notifier_call = ftrace_module_notify_enter,
4105 .priority = INT_MAX, /* Run before anything that can use kprobes */
4108 struct notifier_block ftrace_module_exit_nb = {
4109 .notifier_call = ftrace_module_notify_exit,
4110 .priority = INT_MIN, /* Run after anything that can remove kprobes */
4113 extern unsigned long __start_mcount_loc[];
4114 extern unsigned long __stop_mcount_loc[];
4116 void __init ftrace_init(void)
4118 unsigned long count, addr, flags;
4121 /* Keep the ftrace pointer to the stub */
4122 addr = (unsigned long)ftrace_stub;
4124 local_irq_save(flags);
4125 ftrace_dyn_arch_init(&addr);
4126 local_irq_restore(flags);
4128 /* ftrace_dyn_arch_init places the return code in addr */
4132 count = __stop_mcount_loc - __start_mcount_loc;
4134 ret = ftrace_dyn_table_alloc(count);
4138 last_ftrace_enabled = ftrace_enabled = 1;
4140 ret = ftrace_process_locs(NULL,
4144 ret = register_module_notifier(&ftrace_module_enter_nb);
4146 pr_warning("Failed to register trace ftrace module enter notifier\n");
4148 ret = register_module_notifier(&ftrace_module_exit_nb);
4150 pr_warning("Failed to register trace ftrace module exit notifier\n");
4152 set_ftrace_early_filters();
4156 ftrace_disabled = 1;
4161 static struct ftrace_ops global_ops = {
4162 .func = ftrace_stub,
4163 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
4164 INIT_REGEX_LOCK(global_ops)
4167 static int __init ftrace_nodyn_init(void)
4172 core_initcall(ftrace_nodyn_init);
4174 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
4175 static inline void ftrace_startup_enable(int command) { }
4176 /* Keep as macros so we do not need to define the commands */
4177 # define ftrace_startup(ops, command) \
4179 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4182 # define ftrace_shutdown(ops, command) do { } while (0)
4183 # define ftrace_startup_sysctl() do { } while (0)
4184 # define ftrace_shutdown_sysctl() do { } while (0)
4187 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
4192 #endif /* CONFIG_DYNAMIC_FTRACE */
4195 ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
4196 struct ftrace_ops *op, struct pt_regs *regs)
4198 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
4202 * Some of the ops may be dynamically allocated,
4203 * they must be freed after a synchronize_sched().
4205 preempt_disable_notrace();
4206 trace_recursion_set(TRACE_CONTROL_BIT);
4207 do_for_each_ftrace_op(op, ftrace_control_list) {
4208 if (!(op->flags & FTRACE_OPS_FL_STUB) &&
4209 !ftrace_function_local_disabled(op) &&
4210 ftrace_ops_test(op, ip))
4211 op->func(ip, parent_ip, op, regs);
4212 } while_for_each_ftrace_op(op);
4213 trace_recursion_clear(TRACE_CONTROL_BIT);
4214 preempt_enable_notrace();
4217 static struct ftrace_ops control_ops = {
4218 .func = ftrace_ops_control_func,
4219 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
4220 INIT_REGEX_LOCK(control_ops)
4224 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4225 struct ftrace_ops *ignored, struct pt_regs *regs)
4227 struct ftrace_ops *op;
4230 if (function_trace_stop)
4233 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4238 * Some of the ops may be dynamically allocated,
4239 * they must be freed after a synchronize_sched().
4241 preempt_disable_notrace();
4242 do_for_each_ftrace_op(op, ftrace_ops_list) {
4243 if (ftrace_ops_test(op, ip))
4244 op->func(ip, parent_ip, op, regs);
4245 } while_for_each_ftrace_op(op);
4246 preempt_enable_notrace();
4247 trace_clear_recursion(bit);
4251 * Some archs only support passing ip and parent_ip. Even though
4252 * the list function ignores the op parameter, we do not want any
4253 * C side effects, where a function is called without the caller
4254 * sending a third parameter.
4255 * Archs are to support both the regs and ftrace_ops at the same time.
4256 * If they support ftrace_ops, it is assumed they support regs.
4257 * If call backs want to use regs, they must either check for regs
4258 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4259 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4260 * An architecture can pass partial regs with ftrace_ops and still
4261 * set the ARCH_SUPPORT_FTARCE_OPS.
4263 #if ARCH_SUPPORTS_FTRACE_OPS
4264 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4265 struct ftrace_ops *op, struct pt_regs *regs)
4267 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
4270 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
4272 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
4276 static void clear_ftrace_swapper(void)
4278 struct task_struct *p;
4282 for_each_online_cpu(cpu) {
4284 clear_tsk_trace_trace(p);
4289 static void set_ftrace_swapper(void)
4291 struct task_struct *p;
4295 for_each_online_cpu(cpu) {
4297 set_tsk_trace_trace(p);
4302 static void clear_ftrace_pid(struct pid *pid)
4304 struct task_struct *p;
4307 do_each_pid_task(pid, PIDTYPE_PID, p) {
4308 clear_tsk_trace_trace(p);
4309 } while_each_pid_task(pid, PIDTYPE_PID, p);
4315 static void set_ftrace_pid(struct pid *pid)
4317 struct task_struct *p;
4320 do_each_pid_task(pid, PIDTYPE_PID, p) {
4321 set_tsk_trace_trace(p);
4322 } while_each_pid_task(pid, PIDTYPE_PID, p);
4326 static void clear_ftrace_pid_task(struct pid *pid)
4328 if (pid == ftrace_swapper_pid)
4329 clear_ftrace_swapper();
4331 clear_ftrace_pid(pid);
4334 static void set_ftrace_pid_task(struct pid *pid)
4336 if (pid == ftrace_swapper_pid)
4337 set_ftrace_swapper();
4339 set_ftrace_pid(pid);
4342 static int ftrace_pid_add(int p)
4345 struct ftrace_pid *fpid;
4348 mutex_lock(&ftrace_lock);
4351 pid = ftrace_swapper_pid;
4353 pid = find_get_pid(p);
4360 list_for_each_entry(fpid, &ftrace_pids, list)
4361 if (fpid->pid == pid)
4366 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4370 list_add(&fpid->list, &ftrace_pids);
4373 set_ftrace_pid_task(pid);
4375 ftrace_update_pid_func();
4376 ftrace_startup_enable(0);
4378 mutex_unlock(&ftrace_lock);
4382 if (pid != ftrace_swapper_pid)
4386 mutex_unlock(&ftrace_lock);
4390 static void ftrace_pid_reset(void)
4392 struct ftrace_pid *fpid, *safe;
4394 mutex_lock(&ftrace_lock);
4395 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
4396 struct pid *pid = fpid->pid;
4398 clear_ftrace_pid_task(pid);
4400 list_del(&fpid->list);
4404 ftrace_update_pid_func();
4405 ftrace_startup_enable(0);
4407 mutex_unlock(&ftrace_lock);
4410 static void *fpid_start(struct seq_file *m, loff_t *pos)
4412 mutex_lock(&ftrace_lock);
4414 if (list_empty(&ftrace_pids) && (!*pos))
4417 return seq_list_start(&ftrace_pids, *pos);
4420 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
4425 return seq_list_next(v, &ftrace_pids, pos);
4428 static void fpid_stop(struct seq_file *m, void *p)
4430 mutex_unlock(&ftrace_lock);
4433 static int fpid_show(struct seq_file *m, void *v)
4435 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
4437 if (v == (void *)1) {
4438 seq_printf(m, "no pid\n");
4442 if (fpid->pid == ftrace_swapper_pid)
4443 seq_printf(m, "swapper tasks\n");
4445 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
4450 static const struct seq_operations ftrace_pid_sops = {
4451 .start = fpid_start,
4458 ftrace_pid_open(struct inode *inode, struct file *file)
4462 if ((file->f_mode & FMODE_WRITE) &&
4463 (file->f_flags & O_TRUNC))
4466 if (file->f_mode & FMODE_READ)
4467 ret = seq_open(file, &ftrace_pid_sops);
4473 ftrace_pid_write(struct file *filp, const char __user *ubuf,
4474 size_t cnt, loff_t *ppos)
4480 if (cnt >= sizeof(buf))
4483 if (copy_from_user(&buf, ubuf, cnt))
4489 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4490 * to clean the filter quietly.
4492 tmp = strstrip(buf);
4493 if (strlen(tmp) == 0)
4496 ret = kstrtol(tmp, 10, &val);
4500 ret = ftrace_pid_add(val);
4502 return ret ? ret : cnt;
4506 ftrace_pid_release(struct inode *inode, struct file *file)
4508 if (file->f_mode & FMODE_READ)
4509 seq_release(inode, file);
4514 static const struct file_operations ftrace_pid_fops = {
4515 .open = ftrace_pid_open,
4516 .write = ftrace_pid_write,
4518 .llseek = ftrace_filter_lseek,
4519 .release = ftrace_pid_release,
4522 static __init int ftrace_init_debugfs(void)
4524 struct dentry *d_tracer;
4526 d_tracer = tracing_init_dentry();
4530 ftrace_init_dyn_debugfs(d_tracer);
4532 trace_create_file("set_ftrace_pid", 0644, d_tracer,
4533 NULL, &ftrace_pid_fops);
4535 ftrace_profile_debugfs(d_tracer);
4539 fs_initcall(ftrace_init_debugfs);
4542 * ftrace_kill - kill ftrace
4544 * This function should be used by panic code. It stops ftrace
4545 * but in a not so nice way. If you need to simply kill ftrace
4546 * from a non-atomic section, use ftrace_kill.
4548 void ftrace_kill(void)
4550 ftrace_disabled = 1;
4552 clear_ftrace_function();
4556 * Test if ftrace is dead or not.
4558 int ftrace_is_dead(void)
4560 return ftrace_disabled;
4564 * register_ftrace_function - register a function for profiling
4565 * @ops - ops structure that holds the function for profiling.
4567 * Register a function to be called by all functions in the
4570 * Note: @ops->func and all the functions it calls must be labeled
4571 * with "notrace", otherwise it will go into a
4574 int register_ftrace_function(struct ftrace_ops *ops)
4578 ftrace_ops_init(ops);
4580 mutex_lock(&ftrace_lock);
4582 ret = __register_ftrace_function(ops);
4584 ret = ftrace_startup(ops, 0);
4586 mutex_unlock(&ftrace_lock);
4590 EXPORT_SYMBOL_GPL(register_ftrace_function);
4593 * unregister_ftrace_function - unregister a function for profiling.
4594 * @ops - ops structure that holds the function to unregister
4596 * Unregister a function that was added to be called by ftrace profiling.
4598 int unregister_ftrace_function(struct ftrace_ops *ops)
4602 mutex_lock(&ftrace_lock);
4603 ret = __unregister_ftrace_function(ops);
4605 ftrace_shutdown(ops, 0);
4606 mutex_unlock(&ftrace_lock);
4610 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
4613 ftrace_enable_sysctl(struct ctl_table *table, int write,
4614 void __user *buffer, size_t *lenp,
4619 mutex_lock(&ftrace_lock);
4621 if (unlikely(ftrace_disabled))
4624 ret = proc_dointvec(table, write, buffer, lenp, ppos);
4626 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
4629 last_ftrace_enabled = !!ftrace_enabled;
4631 if (ftrace_enabled) {
4633 ftrace_startup_sysctl();
4635 /* we are starting ftrace again */
4636 if (ftrace_ops_list != &ftrace_list_end)
4637 update_ftrace_function();
4640 /* stopping ftrace calls (just send to ftrace_stub) */
4641 ftrace_trace_function = ftrace_stub;
4643 ftrace_shutdown_sysctl();
4647 mutex_unlock(&ftrace_lock);
4651 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4653 static int ftrace_graph_active;
4654 static struct notifier_block ftrace_suspend_notifier;
4656 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
4661 /* The callbacks that hook a function */
4662 trace_func_graph_ret_t ftrace_graph_return =
4663 (trace_func_graph_ret_t)ftrace_stub;
4664 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
4666 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4667 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
4671 unsigned long flags;
4672 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
4673 struct task_struct *g, *t;
4675 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
4676 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
4677 * sizeof(struct ftrace_ret_stack),
4679 if (!ret_stack_list[i]) {
4687 read_lock_irqsave(&tasklist_lock, flags);
4688 do_each_thread(g, t) {
4694 if (t->ret_stack == NULL) {
4695 atomic_set(&t->tracing_graph_pause, 0);
4696 atomic_set(&t->trace_overrun, 0);
4697 t->curr_ret_stack = -1;
4698 /* Make sure the tasks see the -1 first: */
4700 t->ret_stack = ret_stack_list[start++];
4702 } while_each_thread(g, t);
4705 read_unlock_irqrestore(&tasklist_lock, flags);
4707 for (i = start; i < end; i++)
4708 kfree(ret_stack_list[i]);
4713 ftrace_graph_probe_sched_switch(void *ignore,
4714 struct task_struct *prev, struct task_struct *next)
4716 unsigned long long timestamp;
4720 * Does the user want to count the time a function was asleep.
4721 * If so, do not update the time stamps.
4723 if (trace_flags & TRACE_ITER_SLEEP_TIME)
4726 timestamp = trace_clock_local();
4728 prev->ftrace_timestamp = timestamp;
4730 /* only process tasks that we timestamped */
4731 if (!next->ftrace_timestamp)
4735 * Update all the counters in next to make up for the
4736 * time next was sleeping.
4738 timestamp -= next->ftrace_timestamp;
4740 for (index = next->curr_ret_stack; index >= 0; index--)
4741 next->ret_stack[index].calltime += timestamp;
4744 /* Allocate a return stack for each task */
4745 static int start_graph_tracing(void)
4747 struct ftrace_ret_stack **ret_stack_list;
4750 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4751 sizeof(struct ftrace_ret_stack *),
4754 if (!ret_stack_list)
4757 /* The cpu_boot init_task->ret_stack will never be freed */
4758 for_each_online_cpu(cpu) {
4759 if (!idle_task(cpu)->ret_stack)
4760 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
4764 ret = alloc_retstack_tasklist(ret_stack_list);
4765 } while (ret == -EAGAIN);
4768 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4770 pr_info("ftrace_graph: Couldn't activate tracepoint"
4771 " probe to kernel_sched_switch\n");
4774 kfree(ret_stack_list);
4779 * Hibernation protection.
4780 * The state of the current task is too much unstable during
4781 * suspend/restore to disk. We want to protect against that.
4784 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4788 case PM_HIBERNATION_PREPARE:
4789 pause_graph_tracing();
4792 case PM_POST_HIBERNATION:
4793 unpause_graph_tracing();
4799 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4800 trace_func_graph_ent_t entryfunc)
4804 mutex_lock(&ftrace_lock);
4806 /* we currently allow only one tracer registered at a time */
4807 if (ftrace_graph_active) {
4812 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4813 register_pm_notifier(&ftrace_suspend_notifier);
4815 ftrace_graph_active++;
4816 ret = start_graph_tracing();
4818 ftrace_graph_active--;
4822 ftrace_graph_return = retfunc;
4823 ftrace_graph_entry = entryfunc;
4825 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4828 mutex_unlock(&ftrace_lock);
4832 void unregister_ftrace_graph(void)
4834 mutex_lock(&ftrace_lock);
4836 if (unlikely(!ftrace_graph_active))
4839 ftrace_graph_active--;
4840 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4841 ftrace_graph_entry = ftrace_graph_entry_stub;
4842 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4843 unregister_pm_notifier(&ftrace_suspend_notifier);
4844 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4847 mutex_unlock(&ftrace_lock);
4850 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4853 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4855 atomic_set(&t->tracing_graph_pause, 0);
4856 atomic_set(&t->trace_overrun, 0);
4857 t->ftrace_timestamp = 0;
4858 /* make curr_ret_stack visible before we add the ret_stack */
4860 t->ret_stack = ret_stack;
4864 * Allocate a return stack for the idle task. May be the first
4865 * time through, or it may be done by CPU hotplug online.
4867 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4869 t->curr_ret_stack = -1;
4871 * The idle task has no parent, it either has its own
4872 * stack or no stack at all.
4875 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4877 if (ftrace_graph_active) {
4878 struct ftrace_ret_stack *ret_stack;
4880 ret_stack = per_cpu(idle_ret_stack, cpu);
4882 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4883 * sizeof(struct ftrace_ret_stack),
4887 per_cpu(idle_ret_stack, cpu) = ret_stack;
4889 graph_init_task(t, ret_stack);
4893 /* Allocate a return stack for newly created task */
4894 void ftrace_graph_init_task(struct task_struct *t)
4896 /* Make sure we do not use the parent ret_stack */
4897 t->ret_stack = NULL;
4898 t->curr_ret_stack = -1;
4900 if (ftrace_graph_active) {
4901 struct ftrace_ret_stack *ret_stack;
4903 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4904 * sizeof(struct ftrace_ret_stack),
4908 graph_init_task(t, ret_stack);
4912 void ftrace_graph_exit_task(struct task_struct *t)
4914 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4916 t->ret_stack = NULL;
4917 /* NULL must become visible to IRQs before we free it: */
4923 void ftrace_graph_stop(void)