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 static struct ftrace_ops ftrace_list_end __read_mostly = {
69 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
72 /* ftrace_enabled is a method to turn ftrace on or off */
73 int ftrace_enabled __read_mostly;
74 static int last_ftrace_enabled;
76 /* Quick disabling of function tracer. */
77 int function_trace_stop __read_mostly;
79 /* Current function tracing op */
80 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
82 /* List for set_ftrace_pid's pids. */
83 LIST_HEAD(ftrace_pids);
85 struct list_head list;
90 * ftrace_disabled is set when an anomaly is discovered.
91 * ftrace_disabled is much stronger than ftrace_enabled.
93 static int ftrace_disabled __read_mostly;
95 static DEFINE_MUTEX(ftrace_lock);
97 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
98 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
99 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
100 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
101 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
102 static struct ftrace_ops global_ops;
103 static struct ftrace_ops control_ops;
105 #if ARCH_SUPPORTS_FTRACE_OPS
106 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
107 struct ftrace_ops *op, struct pt_regs *regs);
109 /* See comment below, where ftrace_ops_list_func is defined */
110 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
111 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
115 * Traverse the ftrace_global_list, invoking all entries. The reason that we
116 * can use rcu_dereference_raw() is that elements removed from this list
117 * are simply leaked, so there is no need to interact with a grace-period
118 * mechanism. The rcu_dereference_raw() calls are needed to handle
119 * concurrent insertions into the ftrace_global_list.
121 * Silly Alpha and silly pointer-speculation compiler optimizations!
123 #define do_for_each_ftrace_op(op, list) \
124 op = rcu_dereference_raw(list); \
128 * Optimized for just a single item in the list (as that is the normal case).
130 #define while_for_each_ftrace_op(op) \
131 while (likely(op = rcu_dereference_raw((op)->next)) && \
132 unlikely((op) != &ftrace_list_end))
135 * ftrace_nr_registered_ops - return number of ops registered
137 * Returns the number of ftrace_ops registered and tracing functions
139 int ftrace_nr_registered_ops(void)
141 struct ftrace_ops *ops;
144 mutex_lock(&ftrace_lock);
146 for (ops = ftrace_ops_list;
147 ops != &ftrace_list_end; ops = ops->next)
150 mutex_unlock(&ftrace_lock);
156 ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
157 struct ftrace_ops *op, struct pt_regs *regs)
161 bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX);
165 do_for_each_ftrace_op(op, ftrace_global_list) {
166 op->func(ip, parent_ip, op, regs);
167 } while_for_each_ftrace_op(op);
169 trace_clear_recursion(bit);
172 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
173 struct ftrace_ops *op, struct pt_regs *regs)
175 if (!test_tsk_trace_trace(current))
178 ftrace_pid_function(ip, parent_ip, op, regs);
181 static void set_ftrace_pid_function(ftrace_func_t func)
183 /* do not set ftrace_pid_function to itself! */
184 if (func != ftrace_pid_func)
185 ftrace_pid_function = func;
189 * clear_ftrace_function - reset the ftrace function
191 * This NULLs the ftrace function and in essence stops
192 * tracing. There may be lag
194 void clear_ftrace_function(void)
196 ftrace_trace_function = ftrace_stub;
197 ftrace_pid_function = ftrace_stub;
200 static void control_ops_disable_all(struct ftrace_ops *ops)
204 for_each_possible_cpu(cpu)
205 *per_cpu_ptr(ops->disabled, cpu) = 1;
208 static int control_ops_alloc(struct ftrace_ops *ops)
210 int __percpu *disabled;
212 disabled = alloc_percpu(int);
216 ops->disabled = disabled;
217 control_ops_disable_all(ops);
221 static void control_ops_free(struct ftrace_ops *ops)
223 free_percpu(ops->disabled);
226 static void update_global_ops(void)
231 * If there's only one function registered, then call that
232 * function directly. Otherwise, we need to iterate over the
233 * registered callers.
235 if (ftrace_global_list == &ftrace_list_end ||
236 ftrace_global_list->next == &ftrace_list_end) {
237 func = ftrace_global_list->func;
239 * As we are calling the function directly.
240 * If it does not have recursion protection,
241 * the function_trace_op needs to be updated
244 if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
245 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
247 global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
249 func = ftrace_global_list_func;
250 /* The list has its own recursion protection. */
251 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
255 /* If we filter on pids, update to use the pid function */
256 if (!list_empty(&ftrace_pids)) {
257 set_ftrace_pid_function(func);
258 func = ftrace_pid_func;
261 global_ops.func = func;
264 static void update_ftrace_function(void)
271 * If we are at the end of the list and this ops is
272 * recursion safe and not dynamic and the arch supports passing ops,
273 * then have the mcount trampoline call the function directly.
275 if (ftrace_ops_list == &ftrace_list_end ||
276 (ftrace_ops_list->next == &ftrace_list_end &&
277 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
278 (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
279 !FTRACE_FORCE_LIST_FUNC)) {
280 /* Set the ftrace_ops that the arch callback uses */
281 if (ftrace_ops_list == &global_ops)
282 function_trace_op = ftrace_global_list;
284 function_trace_op = ftrace_ops_list;
285 func = ftrace_ops_list->func;
287 /* Just use the default ftrace_ops */
288 function_trace_op = &ftrace_list_end;
289 func = ftrace_ops_list_func;
292 ftrace_trace_function = func;
295 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
299 * We are entering ops into the list but another
300 * CPU might be walking that list. We need to make sure
301 * the ops->next pointer is valid before another CPU sees
302 * the ops pointer included into the list.
304 rcu_assign_pointer(*list, ops);
307 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
309 struct ftrace_ops **p;
312 * If we are removing the last function, then simply point
313 * to the ftrace_stub.
315 if (*list == ops && ops->next == &ftrace_list_end) {
316 *list = &ftrace_list_end;
320 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
331 static void add_ftrace_list_ops(struct ftrace_ops **list,
332 struct ftrace_ops *main_ops,
333 struct ftrace_ops *ops)
335 int first = *list == &ftrace_list_end;
336 add_ftrace_ops(list, ops);
338 add_ftrace_ops(&ftrace_ops_list, main_ops);
341 static int remove_ftrace_list_ops(struct ftrace_ops **list,
342 struct ftrace_ops *main_ops,
343 struct ftrace_ops *ops)
345 int ret = remove_ftrace_ops(list, ops);
346 if (!ret && *list == &ftrace_list_end)
347 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
351 static int __register_ftrace_function(struct ftrace_ops *ops)
353 if (unlikely(ftrace_disabled))
356 if (FTRACE_WARN_ON(ops == &global_ops))
359 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
362 /* We don't support both control and global flags set. */
363 if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
366 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
368 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
369 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
370 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
372 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
373 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
376 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
377 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
380 if (!core_kernel_data((unsigned long)ops))
381 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
383 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
384 add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
385 ops->flags |= FTRACE_OPS_FL_ENABLED;
386 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
387 if (control_ops_alloc(ops))
389 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
391 add_ftrace_ops(&ftrace_ops_list, ops);
394 update_ftrace_function();
399 static int __unregister_ftrace_function(struct ftrace_ops *ops)
406 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
409 if (FTRACE_WARN_ON(ops == &global_ops))
412 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
413 ret = remove_ftrace_list_ops(&ftrace_global_list,
416 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
417 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
418 ret = remove_ftrace_list_ops(&ftrace_control_list,
422 * The ftrace_ops is now removed from the list,
423 * so there'll be no new users. We must ensure
424 * all current users are done before we free
428 control_ops_free(ops);
431 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
437 update_ftrace_function();
440 * Dynamic ops may be freed, we must make sure that all
441 * callers are done before leaving this function.
443 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
449 static void ftrace_update_pid_func(void)
451 /* Only do something if we are tracing something */
452 if (ftrace_trace_function == ftrace_stub)
455 update_ftrace_function();
458 #ifdef CONFIG_FUNCTION_PROFILER
459 struct ftrace_profile {
460 struct hlist_node node;
462 unsigned long counter;
463 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
464 unsigned long long time;
465 unsigned long long time_squared;
469 struct ftrace_profile_page {
470 struct ftrace_profile_page *next;
472 struct ftrace_profile records[];
475 struct ftrace_profile_stat {
477 struct hlist_head *hash;
478 struct ftrace_profile_page *pages;
479 struct ftrace_profile_page *start;
480 struct tracer_stat stat;
483 #define PROFILE_RECORDS_SIZE \
484 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
486 #define PROFILES_PER_PAGE \
487 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
489 static int ftrace_profile_bits __read_mostly;
490 static int ftrace_profile_enabled __read_mostly;
492 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
493 static DEFINE_MUTEX(ftrace_profile_lock);
495 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
497 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
500 function_stat_next(void *v, int idx)
502 struct ftrace_profile *rec = v;
503 struct ftrace_profile_page *pg;
505 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
511 if ((void *)rec >= (void *)&pg->records[pg->index]) {
515 rec = &pg->records[0];
523 static void *function_stat_start(struct tracer_stat *trace)
525 struct ftrace_profile_stat *stat =
526 container_of(trace, struct ftrace_profile_stat, stat);
528 if (!stat || !stat->start)
531 return function_stat_next(&stat->start->records[0], 0);
534 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
535 /* function graph compares on total time */
536 static int function_stat_cmp(void *p1, void *p2)
538 struct ftrace_profile *a = p1;
539 struct ftrace_profile *b = p2;
541 if (a->time < b->time)
543 if (a->time > b->time)
549 /* not function graph compares against hits */
550 static int function_stat_cmp(void *p1, void *p2)
552 struct ftrace_profile *a = p1;
553 struct ftrace_profile *b = p2;
555 if (a->counter < b->counter)
557 if (a->counter > b->counter)
564 static int function_stat_headers(struct seq_file *m)
566 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
567 seq_printf(m, " Function "
570 "--- ---- --- ---\n");
572 seq_printf(m, " Function Hit\n"
578 static int function_stat_show(struct seq_file *m, void *v)
580 struct ftrace_profile *rec = v;
581 char str[KSYM_SYMBOL_LEN];
583 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
584 static struct trace_seq s;
585 unsigned long long avg;
586 unsigned long long stddev;
588 mutex_lock(&ftrace_profile_lock);
590 /* we raced with function_profile_reset() */
591 if (unlikely(rec->counter == 0)) {
596 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
597 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
599 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
602 do_div(avg, rec->counter);
604 /* Sample standard deviation (s^2) */
605 if (rec->counter <= 1)
608 stddev = rec->time_squared - rec->counter * avg * avg;
610 * Divide only 1000 for ns^2 -> us^2 conversion.
611 * trace_print_graph_duration will divide 1000 again.
613 do_div(stddev, (rec->counter - 1) * 1000);
617 trace_print_graph_duration(rec->time, &s);
618 trace_seq_puts(&s, " ");
619 trace_print_graph_duration(avg, &s);
620 trace_seq_puts(&s, " ");
621 trace_print_graph_duration(stddev, &s);
622 trace_print_seq(m, &s);
626 mutex_unlock(&ftrace_profile_lock);
631 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
633 struct ftrace_profile_page *pg;
635 pg = stat->pages = stat->start;
638 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
643 memset(stat->hash, 0,
644 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
647 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
649 struct ftrace_profile_page *pg;
654 /* If we already allocated, do nothing */
658 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
662 #ifdef CONFIG_DYNAMIC_FTRACE
663 functions = ftrace_update_tot_cnt;
666 * We do not know the number of functions that exist because
667 * dynamic tracing is what counts them. With past experience
668 * we have around 20K functions. That should be more than enough.
669 * It is highly unlikely we will execute every function in
675 pg = stat->start = stat->pages;
677 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
679 for (i = 0; i < pages; i++) {
680 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
691 unsigned long tmp = (unsigned long)pg;
697 free_page((unsigned long)stat->pages);
704 static int ftrace_profile_init_cpu(int cpu)
706 struct ftrace_profile_stat *stat;
709 stat = &per_cpu(ftrace_profile_stats, cpu);
712 /* If the profile is already created, simply reset it */
713 ftrace_profile_reset(stat);
718 * We are profiling all functions, but usually only a few thousand
719 * functions are hit. We'll make a hash of 1024 items.
721 size = FTRACE_PROFILE_HASH_SIZE;
723 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
728 if (!ftrace_profile_bits) {
731 for (; size; size >>= 1)
732 ftrace_profile_bits++;
735 /* Preallocate the function profiling pages */
736 if (ftrace_profile_pages_init(stat) < 0) {
745 static int ftrace_profile_init(void)
750 for_each_online_cpu(cpu) {
751 ret = ftrace_profile_init_cpu(cpu);
759 /* interrupts must be disabled */
760 static struct ftrace_profile *
761 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
763 struct ftrace_profile *rec;
764 struct hlist_head *hhd;
765 struct hlist_node *n;
768 key = hash_long(ip, ftrace_profile_bits);
769 hhd = &stat->hash[key];
771 if (hlist_empty(hhd))
774 hlist_for_each_entry_rcu(rec, n, hhd, node) {
782 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
783 struct ftrace_profile *rec)
787 key = hash_long(rec->ip, ftrace_profile_bits);
788 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
792 * The memory is already allocated, this simply finds a new record to use.
794 static struct ftrace_profile *
795 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
797 struct ftrace_profile *rec = NULL;
799 /* prevent recursion (from NMIs) */
800 if (atomic_inc_return(&stat->disabled) != 1)
804 * Try to find the function again since an NMI
805 * could have added it
807 rec = ftrace_find_profiled_func(stat, ip);
811 if (stat->pages->index == PROFILES_PER_PAGE) {
812 if (!stat->pages->next)
814 stat->pages = stat->pages->next;
817 rec = &stat->pages->records[stat->pages->index++];
819 ftrace_add_profile(stat, rec);
822 atomic_dec(&stat->disabled);
828 function_profile_call(unsigned long ip, unsigned long parent_ip,
829 struct ftrace_ops *ops, struct pt_regs *regs)
831 struct ftrace_profile_stat *stat;
832 struct ftrace_profile *rec;
835 if (!ftrace_profile_enabled)
838 local_irq_save(flags);
840 stat = &__get_cpu_var(ftrace_profile_stats);
841 if (!stat->hash || !ftrace_profile_enabled)
844 rec = ftrace_find_profiled_func(stat, ip);
846 rec = ftrace_profile_alloc(stat, ip);
853 local_irq_restore(flags);
856 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
857 static int profile_graph_entry(struct ftrace_graph_ent *trace)
859 function_profile_call(trace->func, 0, NULL, NULL);
863 static void profile_graph_return(struct ftrace_graph_ret *trace)
865 struct ftrace_profile_stat *stat;
866 unsigned long long calltime;
867 struct ftrace_profile *rec;
870 local_irq_save(flags);
871 stat = &__get_cpu_var(ftrace_profile_stats);
872 if (!stat->hash || !ftrace_profile_enabled)
875 /* If the calltime was zero'd ignore it */
876 if (!trace->calltime)
879 calltime = trace->rettime - trace->calltime;
881 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
884 index = trace->depth;
886 /* Append this call time to the parent time to subtract */
888 current->ret_stack[index - 1].subtime += calltime;
890 if (current->ret_stack[index].subtime < calltime)
891 calltime -= current->ret_stack[index].subtime;
896 rec = ftrace_find_profiled_func(stat, trace->func);
898 rec->time += calltime;
899 rec->time_squared += calltime * calltime;
903 local_irq_restore(flags);
906 static int register_ftrace_profiler(void)
908 return register_ftrace_graph(&profile_graph_return,
909 &profile_graph_entry);
912 static void unregister_ftrace_profiler(void)
914 unregister_ftrace_graph();
917 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
918 .func = function_profile_call,
919 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
922 static int register_ftrace_profiler(void)
924 return register_ftrace_function(&ftrace_profile_ops);
927 static void unregister_ftrace_profiler(void)
929 unregister_ftrace_function(&ftrace_profile_ops);
931 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
934 ftrace_profile_write(struct file *filp, const char __user *ubuf,
935 size_t cnt, loff_t *ppos)
940 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
946 mutex_lock(&ftrace_profile_lock);
947 if (ftrace_profile_enabled ^ val) {
949 ret = ftrace_profile_init();
955 ret = register_ftrace_profiler();
960 ftrace_profile_enabled = 1;
962 ftrace_profile_enabled = 0;
964 * unregister_ftrace_profiler calls stop_machine
965 * so this acts like an synchronize_sched.
967 unregister_ftrace_profiler();
971 mutex_unlock(&ftrace_profile_lock);
979 ftrace_profile_read(struct file *filp, char __user *ubuf,
980 size_t cnt, loff_t *ppos)
982 char buf[64]; /* big enough to hold a number */
985 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
986 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
989 static const struct file_operations ftrace_profile_fops = {
990 .open = tracing_open_generic,
991 .read = ftrace_profile_read,
992 .write = ftrace_profile_write,
993 .llseek = default_llseek,
996 /* used to initialize the real stat files */
997 static struct tracer_stat function_stats __initdata = {
999 .stat_start = function_stat_start,
1000 .stat_next = function_stat_next,
1001 .stat_cmp = function_stat_cmp,
1002 .stat_headers = function_stat_headers,
1003 .stat_show = function_stat_show
1006 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1008 struct ftrace_profile_stat *stat;
1009 struct dentry *entry;
1014 for_each_possible_cpu(cpu) {
1015 stat = &per_cpu(ftrace_profile_stats, cpu);
1017 /* allocate enough for function name + cpu number */
1018 name = kmalloc(32, GFP_KERNEL);
1021 * The files created are permanent, if something happens
1022 * we still do not free memory.
1025 "Could not allocate stat file for cpu %d\n",
1029 stat->stat = function_stats;
1030 snprintf(name, 32, "function%d", cpu);
1031 stat->stat.name = name;
1032 ret = register_stat_tracer(&stat->stat);
1035 "Could not register function stat for cpu %d\n",
1042 entry = debugfs_create_file("function_profile_enabled", 0644,
1043 d_tracer, NULL, &ftrace_profile_fops);
1045 pr_warning("Could not create debugfs "
1046 "'function_profile_enabled' entry\n");
1049 #else /* CONFIG_FUNCTION_PROFILER */
1050 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1053 #endif /* CONFIG_FUNCTION_PROFILER */
1055 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1057 #ifdef CONFIG_DYNAMIC_FTRACE
1059 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1060 # error Dynamic ftrace depends on MCOUNT_RECORD
1063 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1065 struct ftrace_func_probe {
1066 struct hlist_node node;
1067 struct ftrace_probe_ops *ops;
1068 unsigned long flags;
1071 struct rcu_head rcu;
1074 struct ftrace_func_entry {
1075 struct hlist_node hlist;
1079 struct ftrace_hash {
1080 unsigned long size_bits;
1081 struct hlist_head *buckets;
1082 unsigned long count;
1083 struct rcu_head rcu;
1087 * We make these constant because no one should touch them,
1088 * but they are used as the default "empty hash", to avoid allocating
1089 * it all the time. These are in a read only section such that if
1090 * anyone does try to modify it, it will cause an exception.
1092 static const struct hlist_head empty_buckets[1];
1093 static const struct ftrace_hash empty_hash = {
1094 .buckets = (struct hlist_head *)empty_buckets,
1096 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1098 static struct ftrace_ops global_ops = {
1099 .func = ftrace_stub,
1100 .notrace_hash = EMPTY_HASH,
1101 .filter_hash = EMPTY_HASH,
1102 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
1105 static DEFINE_MUTEX(ftrace_regex_lock);
1107 struct ftrace_page {
1108 struct ftrace_page *next;
1109 struct dyn_ftrace *records;
1114 static struct ftrace_page *ftrace_new_pgs;
1116 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1117 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1119 /* estimate from running different kernels */
1120 #define NR_TO_INIT 10000
1122 static struct ftrace_page *ftrace_pages_start;
1123 static struct ftrace_page *ftrace_pages;
1125 static bool ftrace_hash_empty(struct ftrace_hash *hash)
1127 return !hash || !hash->count;
1130 static struct ftrace_func_entry *
1131 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1134 struct ftrace_func_entry *entry;
1135 struct hlist_head *hhd;
1136 struct hlist_node *n;
1138 if (ftrace_hash_empty(hash))
1141 if (hash->size_bits > 0)
1142 key = hash_long(ip, hash->size_bits);
1146 hhd = &hash->buckets[key];
1148 hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1149 if (entry->ip == ip)
1155 static void __add_hash_entry(struct ftrace_hash *hash,
1156 struct ftrace_func_entry *entry)
1158 struct hlist_head *hhd;
1161 if (hash->size_bits)
1162 key = hash_long(entry->ip, hash->size_bits);
1166 hhd = &hash->buckets[key];
1167 hlist_add_head(&entry->hlist, hhd);
1171 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1173 struct ftrace_func_entry *entry;
1175 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1180 __add_hash_entry(hash, entry);
1186 free_hash_entry(struct ftrace_hash *hash,
1187 struct ftrace_func_entry *entry)
1189 hlist_del(&entry->hlist);
1195 remove_hash_entry(struct ftrace_hash *hash,
1196 struct ftrace_func_entry *entry)
1198 hlist_del(&entry->hlist);
1202 static void ftrace_hash_clear(struct ftrace_hash *hash)
1204 struct hlist_head *hhd;
1205 struct hlist_node *tp, *tn;
1206 struct ftrace_func_entry *entry;
1207 int size = 1 << hash->size_bits;
1213 for (i = 0; i < size; i++) {
1214 hhd = &hash->buckets[i];
1215 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
1216 free_hash_entry(hash, entry);
1218 FTRACE_WARN_ON(hash->count);
1221 static void free_ftrace_hash(struct ftrace_hash *hash)
1223 if (!hash || hash == EMPTY_HASH)
1225 ftrace_hash_clear(hash);
1226 kfree(hash->buckets);
1230 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1232 struct ftrace_hash *hash;
1234 hash = container_of(rcu, struct ftrace_hash, rcu);
1235 free_ftrace_hash(hash);
1238 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1240 if (!hash || hash == EMPTY_HASH)
1242 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1245 void ftrace_free_filter(struct ftrace_ops *ops)
1247 free_ftrace_hash(ops->filter_hash);
1248 free_ftrace_hash(ops->notrace_hash);
1251 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1253 struct ftrace_hash *hash;
1256 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1260 size = 1 << size_bits;
1261 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1263 if (!hash->buckets) {
1268 hash->size_bits = size_bits;
1273 static struct ftrace_hash *
1274 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1276 struct ftrace_func_entry *entry;
1277 struct ftrace_hash *new_hash;
1278 struct hlist_node *tp;
1283 new_hash = alloc_ftrace_hash(size_bits);
1288 if (ftrace_hash_empty(hash))
1291 size = 1 << hash->size_bits;
1292 for (i = 0; i < size; i++) {
1293 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1294 ret = add_hash_entry(new_hash, entry->ip);
1300 FTRACE_WARN_ON(new_hash->count != hash->count);
1305 free_ftrace_hash(new_hash);
1310 ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1312 ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1315 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1316 struct ftrace_hash **dst, struct ftrace_hash *src)
1318 struct ftrace_func_entry *entry;
1319 struct hlist_node *tp, *tn;
1320 struct hlist_head *hhd;
1321 struct ftrace_hash *old_hash;
1322 struct ftrace_hash *new_hash;
1324 int size = src->count;
1330 * Remove the current set, update the hash and add
1333 ftrace_hash_rec_disable(ops, enable);
1336 * If the new source is empty, just free dst and assign it
1340 free_ftrace_hash_rcu(*dst);
1341 rcu_assign_pointer(*dst, EMPTY_HASH);
1342 /* still need to update the function records */
1348 * Make the hash size about 1/2 the # found
1350 for (size /= 2; size; size >>= 1)
1353 /* Don't allocate too much */
1354 if (bits > FTRACE_HASH_MAX_BITS)
1355 bits = FTRACE_HASH_MAX_BITS;
1358 new_hash = alloc_ftrace_hash(bits);
1362 size = 1 << src->size_bits;
1363 for (i = 0; i < size; i++) {
1364 hhd = &src->buckets[i];
1365 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1367 key = hash_long(entry->ip, bits);
1370 remove_hash_entry(src, entry);
1371 __add_hash_entry(new_hash, entry);
1376 rcu_assign_pointer(*dst, new_hash);
1377 free_ftrace_hash_rcu(old_hash);
1382 * Enable regardless of ret:
1383 * On success, we enable the new hash.
1384 * On failure, we re-enable the original hash.
1386 ftrace_hash_rec_enable(ops, enable);
1392 * Test the hashes for this ops to see if we want to call
1393 * the ops->func or not.
1395 * It's a match if the ip is in the ops->filter_hash or
1396 * the filter_hash does not exist or is empty,
1398 * the ip is not in the ops->notrace_hash.
1400 * This needs to be called with preemption disabled as
1401 * the hashes are freed with call_rcu_sched().
1404 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1406 struct ftrace_hash *filter_hash;
1407 struct ftrace_hash *notrace_hash;
1410 filter_hash = rcu_dereference_raw(ops->filter_hash);
1411 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1413 if ((ftrace_hash_empty(filter_hash) ||
1414 ftrace_lookup_ip(filter_hash, ip)) &&
1415 (ftrace_hash_empty(notrace_hash) ||
1416 !ftrace_lookup_ip(notrace_hash, ip)))
1425 * This is a double for. Do not use 'break' to break out of the loop,
1426 * you must use a goto.
1428 #define do_for_each_ftrace_rec(pg, rec) \
1429 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1431 for (_____i = 0; _____i < pg->index; _____i++) { \
1432 rec = &pg->records[_____i];
1434 #define while_for_each_ftrace_rec() \
1439 static int ftrace_cmp_recs(const void *a, const void *b)
1441 const struct dyn_ftrace *key = a;
1442 const struct dyn_ftrace *rec = b;
1444 if (key->flags < rec->ip)
1446 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1451 static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1453 struct ftrace_page *pg;
1454 struct dyn_ftrace *rec;
1455 struct dyn_ftrace key;
1458 key.flags = end; /* overload flags, as it is unsigned long */
1460 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1461 if (end < pg->records[0].ip ||
1462 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1464 rec = bsearch(&key, pg->records, pg->index,
1465 sizeof(struct dyn_ftrace),
1475 * ftrace_location - return true if the ip giving is a traced location
1476 * @ip: the instruction pointer to check
1478 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1479 * That is, the instruction that is either a NOP or call to
1480 * the function tracer. It checks the ftrace internal tables to
1481 * determine if the address belongs or not.
1483 unsigned long ftrace_location(unsigned long ip)
1485 return ftrace_location_range(ip, ip);
1489 * ftrace_text_reserved - return true if range contains an ftrace location
1490 * @start: start of range to search
1491 * @end: end of range to search (inclusive). @end points to the last byte to check.
1493 * Returns 1 if @start and @end contains 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 int ftrace_text_reserved(void *start, void *end)
1502 ret = ftrace_location_range((unsigned long)start,
1503 (unsigned long)end);
1508 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1512 struct ftrace_hash *hash;
1513 struct ftrace_hash *other_hash;
1514 struct ftrace_page *pg;
1515 struct dyn_ftrace *rec;
1519 /* Only update if the ops has been registered */
1520 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1524 * In the filter_hash case:
1525 * If the count is zero, we update all records.
1526 * Otherwise we just update the items in the hash.
1528 * In the notrace_hash case:
1529 * We enable the update in the hash.
1530 * As disabling notrace means enabling the tracing,
1531 * and enabling notrace means disabling, the inc variable
1535 hash = ops->filter_hash;
1536 other_hash = ops->notrace_hash;
1537 if (ftrace_hash_empty(hash))
1541 hash = ops->notrace_hash;
1542 other_hash = ops->filter_hash;
1544 * If the notrace hash has no items,
1545 * then there's nothing to do.
1547 if (ftrace_hash_empty(hash))
1551 do_for_each_ftrace_rec(pg, rec) {
1552 int in_other_hash = 0;
1558 * Only the filter_hash affects all records.
1559 * Update if the record is not in the notrace hash.
1561 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1564 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1565 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1570 if (filter_hash && in_hash && !in_other_hash)
1572 else if (!filter_hash && in_hash &&
1573 (in_other_hash || ftrace_hash_empty(other_hash)))
1581 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1584 * If any ops wants regs saved for this function
1585 * then all ops will get saved regs.
1587 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1588 rec->flags |= FTRACE_FL_REGS;
1590 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1595 /* Shortcut, if we handled all records, we are done. */
1596 if (!all && count == hash->count)
1598 } while_for_each_ftrace_rec();
1601 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1604 __ftrace_hash_rec_update(ops, filter_hash, 0);
1607 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1610 __ftrace_hash_rec_update(ops, filter_hash, 1);
1613 static void print_ip_ins(const char *fmt, unsigned char *p)
1617 printk(KERN_CONT "%s", fmt);
1619 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1620 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1624 * ftrace_bug - report and shutdown function tracer
1625 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1626 * @ip: The address that failed
1628 * The arch code that enables or disables the function tracing
1629 * can call ftrace_bug() when it has detected a problem in
1630 * modifying the code. @failed should be one of either:
1631 * EFAULT - if the problem happens on reading the @ip address
1632 * EINVAL - if what is read at @ip is not what was expected
1633 * EPERM - if the problem happens on writting to the @ip address
1635 void ftrace_bug(int failed, unsigned long ip)
1639 FTRACE_WARN_ON_ONCE(1);
1640 pr_info("ftrace faulted on modifying ");
1644 FTRACE_WARN_ON_ONCE(1);
1645 pr_info("ftrace failed to modify ");
1647 print_ip_ins(" actual: ", (unsigned char *)ip);
1648 printk(KERN_CONT "\n");
1651 FTRACE_WARN_ON_ONCE(1);
1652 pr_info("ftrace faulted on writing ");
1656 FTRACE_WARN_ON_ONCE(1);
1657 pr_info("ftrace faulted on unknown error ");
1662 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
1664 unsigned long flag = 0UL;
1667 * If we are updating calls:
1669 * If the record has a ref count, then we need to enable it
1670 * because someone is using it.
1672 * Otherwise we make sure its disabled.
1674 * If we are disabling calls, then disable all records that
1677 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1678 flag = FTRACE_FL_ENABLED;
1681 * If enabling and the REGS flag does not match the REGS_EN, then
1682 * do not ignore this record. Set flags to fail the compare against
1686 (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
1687 flag |= FTRACE_FL_REGS;
1689 /* If the state of this record hasn't changed, then do nothing */
1690 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1691 return FTRACE_UPDATE_IGNORE;
1694 /* Save off if rec is being enabled (for return value) */
1695 flag ^= rec->flags & FTRACE_FL_ENABLED;
1698 rec->flags |= FTRACE_FL_ENABLED;
1699 if (flag & FTRACE_FL_REGS) {
1700 if (rec->flags & FTRACE_FL_REGS)
1701 rec->flags |= FTRACE_FL_REGS_EN;
1703 rec->flags &= ~FTRACE_FL_REGS_EN;
1708 * If this record is being updated from a nop, then
1709 * return UPDATE_MAKE_CALL.
1710 * Otherwise, if the EN flag is set, then return
1711 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1712 * from the non-save regs, to a save regs function.
1714 * return UPDATE_MODIFY_CALL to tell the caller to convert
1715 * from the save regs, to a non-save regs function.
1717 if (flag & FTRACE_FL_ENABLED)
1718 return FTRACE_UPDATE_MAKE_CALL;
1719 else if (rec->flags & FTRACE_FL_REGS_EN)
1720 return FTRACE_UPDATE_MODIFY_CALL_REGS;
1722 return FTRACE_UPDATE_MODIFY_CALL;
1726 /* If there's no more users, clear all flags */
1727 if (!(rec->flags & ~FTRACE_FL_MASK))
1730 /* Just disable the record (keep REGS state) */
1731 rec->flags &= ~FTRACE_FL_ENABLED;
1734 return FTRACE_UPDATE_MAKE_NOP;
1738 * ftrace_update_record, set a record that now is tracing or not
1739 * @rec: the record to update
1740 * @enable: set to 1 if the record is tracing, zero to force disable
1742 * The records that represent all functions that can be traced need
1743 * to be updated when tracing has been enabled.
1745 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1747 return ftrace_check_record(rec, enable, 1);
1751 * ftrace_test_record, check if the record has been enabled or not
1752 * @rec: the record to test
1753 * @enable: set to 1 to check if enabled, 0 if it is disabled
1755 * The arch code may need to test if a record is already set to
1756 * tracing to determine how to modify the function code that it
1759 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1761 return ftrace_check_record(rec, enable, 0);
1765 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1767 unsigned long ftrace_old_addr;
1768 unsigned long ftrace_addr;
1771 ret = ftrace_update_record(rec, enable);
1773 if (rec->flags & FTRACE_FL_REGS)
1774 ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
1776 ftrace_addr = (unsigned long)FTRACE_ADDR;
1779 case FTRACE_UPDATE_IGNORE:
1782 case FTRACE_UPDATE_MAKE_CALL:
1783 return ftrace_make_call(rec, ftrace_addr);
1785 case FTRACE_UPDATE_MAKE_NOP:
1786 return ftrace_make_nop(NULL, rec, ftrace_addr);
1788 case FTRACE_UPDATE_MODIFY_CALL_REGS:
1789 case FTRACE_UPDATE_MODIFY_CALL:
1790 if (rec->flags & FTRACE_FL_REGS)
1791 ftrace_old_addr = (unsigned long)FTRACE_ADDR;
1793 ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
1795 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
1798 return -1; /* unknow ftrace bug */
1801 void __weak ftrace_replace_code(int enable)
1803 struct dyn_ftrace *rec;
1804 struct ftrace_page *pg;
1807 if (unlikely(ftrace_disabled))
1810 do_for_each_ftrace_rec(pg, rec) {
1811 failed = __ftrace_replace_code(rec, enable);
1813 ftrace_bug(failed, rec->ip);
1814 /* Stop processing */
1817 } while_for_each_ftrace_rec();
1820 struct ftrace_rec_iter {
1821 struct ftrace_page *pg;
1826 * ftrace_rec_iter_start, start up iterating over traced functions
1828 * Returns an iterator handle that is used to iterate over all
1829 * the records that represent address locations where functions
1832 * May return NULL if no records are available.
1834 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
1837 * We only use a single iterator.
1838 * Protected by the ftrace_lock mutex.
1840 static struct ftrace_rec_iter ftrace_rec_iter;
1841 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
1843 iter->pg = ftrace_pages_start;
1846 /* Could have empty pages */
1847 while (iter->pg && !iter->pg->index)
1848 iter->pg = iter->pg->next;
1857 * ftrace_rec_iter_next, get the next record to process.
1858 * @iter: The handle to the iterator.
1860 * Returns the next iterator after the given iterator @iter.
1862 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
1866 if (iter->index >= iter->pg->index) {
1867 iter->pg = iter->pg->next;
1870 /* Could have empty pages */
1871 while (iter->pg && !iter->pg->index)
1872 iter->pg = iter->pg->next;
1882 * ftrace_rec_iter_record, get the record at the iterator location
1883 * @iter: The current iterator location
1885 * Returns the record that the current @iter is at.
1887 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
1889 return &iter->pg->records[iter->index];
1893 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1900 if (unlikely(ftrace_disabled))
1903 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1905 ftrace_bug(ret, ip);
1912 * archs can override this function if they must do something
1913 * before the modifying code is performed.
1915 int __weak ftrace_arch_code_modify_prepare(void)
1921 * archs can override this function if they must do something
1922 * after the modifying code is performed.
1924 int __weak ftrace_arch_code_modify_post_process(void)
1929 void ftrace_modify_all_code(int command)
1931 if (command & FTRACE_UPDATE_CALLS)
1932 ftrace_replace_code(1);
1933 else if (command & FTRACE_DISABLE_CALLS)
1934 ftrace_replace_code(0);
1936 if (command & FTRACE_UPDATE_TRACE_FUNC)
1937 ftrace_update_ftrace_func(ftrace_trace_function);
1939 if (command & FTRACE_START_FUNC_RET)
1940 ftrace_enable_ftrace_graph_caller();
1941 else if (command & FTRACE_STOP_FUNC_RET)
1942 ftrace_disable_ftrace_graph_caller();
1945 static int __ftrace_modify_code(void *data)
1947 int *command = data;
1949 ftrace_modify_all_code(*command);
1955 * ftrace_run_stop_machine, go back to the stop machine method
1956 * @command: The command to tell ftrace what to do
1958 * If an arch needs to fall back to the stop machine method, the
1959 * it can call this function.
1961 void ftrace_run_stop_machine(int command)
1963 stop_machine(__ftrace_modify_code, &command, NULL);
1967 * arch_ftrace_update_code, modify the code to trace or not trace
1968 * @command: The command that needs to be done
1970 * Archs can override this function if it does not need to
1971 * run stop_machine() to modify code.
1973 void __weak arch_ftrace_update_code(int command)
1975 ftrace_run_stop_machine(command);
1978 static void ftrace_run_update_code(int command)
1982 ret = ftrace_arch_code_modify_prepare();
1983 FTRACE_WARN_ON(ret);
1987 * Do not call function tracer while we update the code.
1988 * We are in stop machine.
1990 function_trace_stop++;
1993 * By default we use stop_machine() to modify the code.
1994 * But archs can do what ever they want as long as it
1995 * is safe. The stop_machine() is the safest, but also
1996 * produces the most overhead.
1998 arch_ftrace_update_code(command);
2000 function_trace_stop--;
2002 ret = ftrace_arch_code_modify_post_process();
2003 FTRACE_WARN_ON(ret);
2006 static ftrace_func_t saved_ftrace_func;
2007 static int ftrace_start_up;
2008 static int global_start_up;
2010 static void ftrace_startup_enable(int command)
2012 if (saved_ftrace_func != ftrace_trace_function) {
2013 saved_ftrace_func = ftrace_trace_function;
2014 command |= FTRACE_UPDATE_TRACE_FUNC;
2017 if (!command || !ftrace_enabled)
2020 ftrace_run_update_code(command);
2023 static int ftrace_startup(struct ftrace_ops *ops, int command)
2025 bool hash_enable = true;
2027 if (unlikely(ftrace_disabled))
2031 command |= FTRACE_UPDATE_CALLS;
2033 /* ops marked global share the filter hashes */
2034 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2036 /* Don't update hash if global is already set */
2037 if (global_start_up)
2038 hash_enable = false;
2042 ops->flags |= FTRACE_OPS_FL_ENABLED;
2044 ftrace_hash_rec_enable(ops, 1);
2046 ftrace_startup_enable(command);
2051 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
2053 bool hash_disable = true;
2055 if (unlikely(ftrace_disabled))
2060 * Just warn in case of unbalance, no need to kill ftrace, it's not
2061 * critical but the ftrace_call callers may be never nopped again after
2062 * further ftrace uses.
2064 WARN_ON_ONCE(ftrace_start_up < 0);
2066 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2069 WARN_ON_ONCE(global_start_up < 0);
2070 /* Don't update hash if global still has users */
2071 if (global_start_up) {
2072 WARN_ON_ONCE(!ftrace_start_up);
2073 hash_disable = false;
2078 ftrace_hash_rec_disable(ops, 1);
2080 if (ops != &global_ops || !global_start_up)
2081 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2083 command |= FTRACE_UPDATE_CALLS;
2085 if (saved_ftrace_func != ftrace_trace_function) {
2086 saved_ftrace_func = ftrace_trace_function;
2087 command |= FTRACE_UPDATE_TRACE_FUNC;
2090 if (!command || !ftrace_enabled)
2093 ftrace_run_update_code(command);
2096 static void ftrace_startup_sysctl(void)
2098 if (unlikely(ftrace_disabled))
2101 /* Force update next time */
2102 saved_ftrace_func = NULL;
2103 /* ftrace_start_up is true if we want ftrace running */
2104 if (ftrace_start_up)
2105 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
2108 static void ftrace_shutdown_sysctl(void)
2110 if (unlikely(ftrace_disabled))
2113 /* ftrace_start_up is true if ftrace is running */
2114 if (ftrace_start_up)
2115 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
2118 static cycle_t ftrace_update_time;
2119 static unsigned long ftrace_update_cnt;
2120 unsigned long ftrace_update_tot_cnt;
2122 static int ops_traces_mod(struct ftrace_ops *ops)
2124 struct ftrace_hash *hash;
2126 hash = ops->filter_hash;
2127 return ftrace_hash_empty(hash);
2130 static int ftrace_update_code(struct module *mod)
2132 struct ftrace_page *pg;
2133 struct dyn_ftrace *p;
2134 cycle_t start, stop;
2135 unsigned long ref = 0;
2139 * When adding a module, we need to check if tracers are
2140 * currently enabled and if they are set to trace all functions.
2141 * If they are, we need to enable the module functions as well
2142 * as update the reference counts for those function records.
2145 struct ftrace_ops *ops;
2147 for (ops = ftrace_ops_list;
2148 ops != &ftrace_list_end; ops = ops->next) {
2149 if (ops->flags & FTRACE_OPS_FL_ENABLED &&
2150 ops_traces_mod(ops))
2155 start = ftrace_now(raw_smp_processor_id());
2156 ftrace_update_cnt = 0;
2158 for (pg = ftrace_new_pgs; pg; pg = pg->next) {
2160 for (i = 0; i < pg->index; i++) {
2161 /* If something went wrong, bail without enabling anything */
2162 if (unlikely(ftrace_disabled))
2165 p = &pg->records[i];
2169 * Do the initial record conversion from mcount jump
2170 * to the NOP instructions.
2172 if (!ftrace_code_disable(mod, p))
2175 ftrace_update_cnt++;
2178 * If the tracing is enabled, go ahead and enable the record.
2180 * The reason not to enable the record immediatelly is the
2181 * inherent check of ftrace_make_nop/ftrace_make_call for
2182 * correct previous instructions. Making first the NOP
2183 * conversion puts the module to the correct state, thus
2184 * passing the ftrace_make_call check.
2186 if (ftrace_start_up && ref) {
2187 int failed = __ftrace_replace_code(p, 1);
2189 ftrace_bug(failed, p->ip);
2194 ftrace_new_pgs = NULL;
2196 stop = ftrace_now(raw_smp_processor_id());
2197 ftrace_update_time = stop - start;
2198 ftrace_update_tot_cnt += ftrace_update_cnt;
2203 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2208 if (WARN_ON(!count))
2211 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2214 * We want to fill as much as possible. No more than a page
2217 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2221 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2224 /* if we can't allocate this size, try something smaller */
2231 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2240 static struct ftrace_page *
2241 ftrace_allocate_pages(unsigned long num_to_init)
2243 struct ftrace_page *start_pg;
2244 struct ftrace_page *pg;
2251 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2256 * Try to allocate as much as possible in one continues
2257 * location that fills in all of the space. We want to
2258 * waste as little space as possible.
2261 cnt = ftrace_allocate_records(pg, num_to_init);
2269 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2280 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2281 free_pages((unsigned long)pg->records, order);
2282 start_pg = pg->next;
2286 pr_info("ftrace: FAILED to allocate memory for functions\n");
2290 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
2295 pr_info("ftrace: No functions to be traced?\n");
2299 cnt = num_to_init / ENTRIES_PER_PAGE;
2300 pr_info("ftrace: allocating %ld entries in %d pages\n",
2301 num_to_init, cnt + 1);
2306 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2308 struct ftrace_iterator {
2311 struct ftrace_page *pg;
2312 struct dyn_ftrace *func;
2313 struct ftrace_func_probe *probe;
2314 struct trace_parser parser;
2315 struct ftrace_hash *hash;
2316 struct ftrace_ops *ops;
2323 t_hash_next(struct seq_file *m, loff_t *pos)
2325 struct ftrace_iterator *iter = m->private;
2326 struct hlist_node *hnd = NULL;
2327 struct hlist_head *hhd;
2333 hnd = &iter->probe->node;
2335 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2338 hhd = &ftrace_func_hash[iter->hidx];
2340 if (hlist_empty(hhd)) {
2356 if (WARN_ON_ONCE(!hnd))
2359 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2364 static void *t_hash_start(struct seq_file *m, loff_t *pos)
2366 struct ftrace_iterator *iter = m->private;
2370 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2373 if (iter->func_pos > *pos)
2377 for (l = 0; l <= (*pos - iter->func_pos); ) {
2378 p = t_hash_next(m, &l);
2385 /* Only set this if we have an item */
2386 iter->flags |= FTRACE_ITER_HASH;
2392 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2394 struct ftrace_func_probe *rec;
2397 if (WARN_ON_ONCE(!rec))
2400 if (rec->ops->print)
2401 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2403 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2406 seq_printf(m, ":%p", rec->data);
2413 t_next(struct seq_file *m, void *v, loff_t *pos)
2415 struct ftrace_iterator *iter = m->private;
2416 struct ftrace_ops *ops = iter->ops;
2417 struct dyn_ftrace *rec = NULL;
2419 if (unlikely(ftrace_disabled))
2422 if (iter->flags & FTRACE_ITER_HASH)
2423 return t_hash_next(m, pos);
2426 iter->pos = iter->func_pos = *pos;
2428 if (iter->flags & FTRACE_ITER_PRINTALL)
2429 return t_hash_start(m, pos);
2432 if (iter->idx >= iter->pg->index) {
2433 if (iter->pg->next) {
2434 iter->pg = iter->pg->next;
2439 rec = &iter->pg->records[iter->idx++];
2440 if (((iter->flags & FTRACE_ITER_FILTER) &&
2441 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
2443 ((iter->flags & FTRACE_ITER_NOTRACE) &&
2444 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2446 ((iter->flags & FTRACE_ITER_ENABLED) &&
2447 !(rec->flags & ~FTRACE_FL_MASK))) {
2455 return t_hash_start(m, pos);
2462 static void reset_iter_read(struct ftrace_iterator *iter)
2466 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
2469 static void *t_start(struct seq_file *m, loff_t *pos)
2471 struct ftrace_iterator *iter = m->private;
2472 struct ftrace_ops *ops = iter->ops;
2476 mutex_lock(&ftrace_lock);
2478 if (unlikely(ftrace_disabled))
2482 * If an lseek was done, then reset and start from beginning.
2484 if (*pos < iter->pos)
2485 reset_iter_read(iter);
2488 * For set_ftrace_filter reading, if we have the filter
2489 * off, we can short cut and just print out that all
2490 * functions are enabled.
2492 if (iter->flags & FTRACE_ITER_FILTER &&
2493 ftrace_hash_empty(ops->filter_hash)) {
2495 return t_hash_start(m, pos);
2496 iter->flags |= FTRACE_ITER_PRINTALL;
2497 /* reset in case of seek/pread */
2498 iter->flags &= ~FTRACE_ITER_HASH;
2502 if (iter->flags & FTRACE_ITER_HASH)
2503 return t_hash_start(m, pos);
2506 * Unfortunately, we need to restart at ftrace_pages_start
2507 * every time we let go of the ftrace_mutex. This is because
2508 * those pointers can change without the lock.
2510 iter->pg = ftrace_pages_start;
2512 for (l = 0; l <= *pos; ) {
2513 p = t_next(m, p, &l);
2519 return t_hash_start(m, pos);
2524 static void t_stop(struct seq_file *m, void *p)
2526 mutex_unlock(&ftrace_lock);
2529 static int t_show(struct seq_file *m, void *v)
2531 struct ftrace_iterator *iter = m->private;
2532 struct dyn_ftrace *rec;
2534 if (iter->flags & FTRACE_ITER_HASH)
2535 return t_hash_show(m, iter);
2537 if (iter->flags & FTRACE_ITER_PRINTALL) {
2538 seq_printf(m, "#### all functions enabled ####\n");
2547 seq_printf(m, "%ps", (void *)rec->ip);
2548 if (iter->flags & FTRACE_ITER_ENABLED)
2549 seq_printf(m, " (%ld)%s",
2550 rec->flags & ~FTRACE_FL_MASK,
2551 rec->flags & FTRACE_FL_REGS ? " R" : "");
2552 seq_printf(m, "\n");
2557 static const struct seq_operations show_ftrace_seq_ops = {
2565 ftrace_avail_open(struct inode *inode, struct file *file)
2567 struct ftrace_iterator *iter;
2569 if (unlikely(ftrace_disabled))
2572 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2574 iter->pg = ftrace_pages_start;
2575 iter->ops = &global_ops;
2578 return iter ? 0 : -ENOMEM;
2582 ftrace_enabled_open(struct inode *inode, struct file *file)
2584 struct ftrace_iterator *iter;
2586 if (unlikely(ftrace_disabled))
2589 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2591 iter->pg = ftrace_pages_start;
2592 iter->flags = FTRACE_ITER_ENABLED;
2593 iter->ops = &global_ops;
2596 return iter ? 0 : -ENOMEM;
2599 static void ftrace_filter_reset(struct ftrace_hash *hash)
2601 mutex_lock(&ftrace_lock);
2602 ftrace_hash_clear(hash);
2603 mutex_unlock(&ftrace_lock);
2607 * ftrace_regex_open - initialize function tracer filter files
2608 * @ops: The ftrace_ops that hold the hash filters
2609 * @flag: The type of filter to process
2610 * @inode: The inode, usually passed in to your open routine
2611 * @file: The file, usually passed in to your open routine
2613 * ftrace_regex_open() initializes the filter files for the
2614 * @ops. Depending on @flag it may process the filter hash or
2615 * the notrace hash of @ops. With this called from the open
2616 * routine, you can use ftrace_filter_write() for the write
2617 * routine if @flag has FTRACE_ITER_FILTER set, or
2618 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2619 * ftrace_regex_lseek() should be used as the lseek routine, and
2620 * release must call ftrace_regex_release().
2623 ftrace_regex_open(struct ftrace_ops *ops, int flag,
2624 struct inode *inode, struct file *file)
2626 struct ftrace_iterator *iter;
2627 struct ftrace_hash *hash;
2630 if (unlikely(ftrace_disabled))
2633 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2637 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2642 if (flag & FTRACE_ITER_NOTRACE)
2643 hash = ops->notrace_hash;
2645 hash = ops->filter_hash;
2650 if (file->f_mode & FMODE_WRITE) {
2651 mutex_lock(&ftrace_lock);
2652 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2653 mutex_unlock(&ftrace_lock);
2656 trace_parser_put(&iter->parser);
2662 mutex_lock(&ftrace_regex_lock);
2664 if ((file->f_mode & FMODE_WRITE) &&
2665 (file->f_flags & O_TRUNC))
2666 ftrace_filter_reset(iter->hash);
2668 if (file->f_mode & FMODE_READ) {
2669 iter->pg = ftrace_pages_start;
2671 ret = seq_open(file, &show_ftrace_seq_ops);
2673 struct seq_file *m = file->private_data;
2677 free_ftrace_hash(iter->hash);
2678 trace_parser_put(&iter->parser);
2682 file->private_data = iter;
2683 mutex_unlock(&ftrace_regex_lock);
2689 ftrace_filter_open(struct inode *inode, struct file *file)
2691 return ftrace_regex_open(&global_ops,
2692 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
2697 ftrace_notrace_open(struct inode *inode, struct file *file)
2699 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2704 ftrace_regex_lseek(struct file *file, loff_t offset, int whence)
2708 if (file->f_mode & FMODE_READ)
2709 ret = seq_lseek(file, offset, whence);
2711 file->f_pos = ret = 1;
2716 static int ftrace_match(char *str, char *regex, int len, int type)
2723 if (strcmp(str, regex) == 0)
2726 case MATCH_FRONT_ONLY:
2727 if (strncmp(str, regex, len) == 0)
2730 case MATCH_MIDDLE_ONLY:
2731 if (strstr(str, regex))
2734 case MATCH_END_ONLY:
2736 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2745 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2747 struct ftrace_func_entry *entry;
2750 entry = ftrace_lookup_ip(hash, rec->ip);
2752 /* Do nothing if it doesn't exist */
2756 free_hash_entry(hash, entry);
2758 /* Do nothing if it exists */
2762 ret = add_hash_entry(hash, rec->ip);
2768 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2769 char *regex, int len, int type)
2771 char str[KSYM_SYMBOL_LEN];
2774 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2777 /* module lookup requires matching the module */
2778 if (!modname || strcmp(modname, mod))
2781 /* blank search means to match all funcs in the mod */
2786 return ftrace_match(str, regex, len, type);
2790 match_records(struct ftrace_hash *hash, char *buff,
2791 int len, char *mod, int not)
2793 unsigned search_len = 0;
2794 struct ftrace_page *pg;
2795 struct dyn_ftrace *rec;
2796 int type = MATCH_FULL;
2797 char *search = buff;
2802 type = filter_parse_regex(buff, len, &search, ¬);
2803 search_len = strlen(search);
2806 mutex_lock(&ftrace_lock);
2808 if (unlikely(ftrace_disabled))
2811 do_for_each_ftrace_rec(pg, rec) {
2812 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2813 ret = enter_record(hash, rec, not);
2820 } while_for_each_ftrace_rec();
2822 mutex_unlock(&ftrace_lock);
2828 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2830 return match_records(hash, buff, len, NULL, 0);
2834 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2838 /* blank or '*' mean the same */
2839 if (strcmp(buff, "*") == 0)
2842 /* handle the case of 'dont filter this module' */
2843 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2848 return match_records(hash, buff, strlen(buff), mod, not);
2852 * We register the module command as a template to show others how
2853 * to register the a command as well.
2857 ftrace_mod_callback(struct ftrace_hash *hash,
2858 char *func, char *cmd, char *param, int enable)
2864 * cmd == 'mod' because we only registered this func
2865 * for the 'mod' ftrace_func_command.
2866 * But if you register one func with multiple commands,
2867 * you can tell which command was used by the cmd
2871 /* we must have a module name */
2875 mod = strsep(¶m, ":");
2879 ret = ftrace_match_module_records(hash, func, mod);
2888 static struct ftrace_func_command ftrace_mod_cmd = {
2890 .func = ftrace_mod_callback,
2893 static int __init ftrace_mod_cmd_init(void)
2895 return register_ftrace_command(&ftrace_mod_cmd);
2897 core_initcall(ftrace_mod_cmd_init);
2899 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
2900 struct ftrace_ops *op, struct pt_regs *pt_regs)
2902 struct ftrace_func_probe *entry;
2903 struct hlist_head *hhd;
2904 struct hlist_node *n;
2907 key = hash_long(ip, FTRACE_HASH_BITS);
2909 hhd = &ftrace_func_hash[key];
2911 if (hlist_empty(hhd))
2915 * Disable preemption for these calls to prevent a RCU grace
2916 * period. This syncs the hash iteration and freeing of items
2917 * on the hash. rcu_read_lock is too dangerous here.
2919 preempt_disable_notrace();
2920 hlist_for_each_entry_rcu(entry, n, hhd, node) {
2921 if (entry->ip == ip)
2922 entry->ops->func(ip, parent_ip, &entry->data);
2924 preempt_enable_notrace();
2927 static struct ftrace_ops trace_probe_ops __read_mostly =
2929 .func = function_trace_probe_call,
2932 static int ftrace_probe_registered;
2934 static void __enable_ftrace_function_probe(void)
2939 if (ftrace_probe_registered)
2942 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2943 struct hlist_head *hhd = &ftrace_func_hash[i];
2947 /* Nothing registered? */
2948 if (i == FTRACE_FUNC_HASHSIZE)
2951 ret = __register_ftrace_function(&trace_probe_ops);
2953 ret = ftrace_startup(&trace_probe_ops, 0);
2955 ftrace_probe_registered = 1;
2958 static void __disable_ftrace_function_probe(void)
2963 if (!ftrace_probe_registered)
2966 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2967 struct hlist_head *hhd = &ftrace_func_hash[i];
2972 /* no more funcs left */
2973 ret = __unregister_ftrace_function(&trace_probe_ops);
2975 ftrace_shutdown(&trace_probe_ops, 0);
2977 ftrace_probe_registered = 0;
2981 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2983 struct ftrace_func_probe *entry =
2984 container_of(rhp, struct ftrace_func_probe, rcu);
2986 if (entry->ops->free)
2987 entry->ops->free(&entry->data);
2993 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2996 struct ftrace_func_probe *entry;
2997 struct ftrace_page *pg;
2998 struct dyn_ftrace *rec;
3004 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3005 len = strlen(search);
3007 /* we do not support '!' for function probes */
3011 mutex_lock(&ftrace_lock);
3013 if (unlikely(ftrace_disabled))
3016 do_for_each_ftrace_rec(pg, rec) {
3018 if (!ftrace_match_record(rec, NULL, search, len, type))
3021 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3023 /* If we did not process any, then return error */
3034 * The caller might want to do something special
3035 * for each function we find. We call the callback
3036 * to give the caller an opportunity to do so.
3038 if (ops->callback) {
3039 if (ops->callback(rec->ip, &entry->data) < 0) {
3040 /* caller does not like this func */
3047 entry->ip = rec->ip;
3049 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3050 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3052 } while_for_each_ftrace_rec();
3053 __enable_ftrace_function_probe();
3056 mutex_unlock(&ftrace_lock);
3062 PROBE_TEST_FUNC = 1,
3067 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3068 void *data, int flags)
3070 struct ftrace_func_probe *entry;
3071 struct hlist_node *n, *tmp;
3072 char str[KSYM_SYMBOL_LEN];
3073 int type = MATCH_FULL;
3077 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
3082 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3083 len = strlen(search);
3085 /* we do not support '!' for function probes */
3090 mutex_lock(&ftrace_lock);
3091 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3092 struct hlist_head *hhd = &ftrace_func_hash[i];
3094 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
3096 /* break up if statements for readability */
3097 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
3100 if ((flags & PROBE_TEST_DATA) && entry->data != data)
3103 /* do this last, since it is the most expensive */
3105 kallsyms_lookup(entry->ip, NULL, NULL,
3107 if (!ftrace_match(str, glob, len, type))
3111 hlist_del(&entry->node);
3112 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
3115 __disable_ftrace_function_probe();
3116 mutex_unlock(&ftrace_lock);
3120 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3123 __unregister_ftrace_function_probe(glob, ops, data,
3124 PROBE_TEST_FUNC | PROBE_TEST_DATA);
3128 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
3130 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
3133 void unregister_ftrace_function_probe_all(char *glob)
3135 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
3138 static LIST_HEAD(ftrace_commands);
3139 static DEFINE_MUTEX(ftrace_cmd_mutex);
3141 int register_ftrace_command(struct ftrace_func_command *cmd)
3143 struct ftrace_func_command *p;
3146 mutex_lock(&ftrace_cmd_mutex);
3147 list_for_each_entry(p, &ftrace_commands, list) {
3148 if (strcmp(cmd->name, p->name) == 0) {
3153 list_add(&cmd->list, &ftrace_commands);
3155 mutex_unlock(&ftrace_cmd_mutex);
3160 int unregister_ftrace_command(struct ftrace_func_command *cmd)
3162 struct ftrace_func_command *p, *n;
3165 mutex_lock(&ftrace_cmd_mutex);
3166 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3167 if (strcmp(cmd->name, p->name) == 0) {
3169 list_del_init(&p->list);
3174 mutex_unlock(&ftrace_cmd_mutex);
3179 static int ftrace_process_regex(struct ftrace_hash *hash,
3180 char *buff, int len, int enable)
3182 char *func, *command, *next = buff;
3183 struct ftrace_func_command *p;
3186 func = strsep(&next, ":");
3189 ret = ftrace_match_records(hash, func, len);
3199 command = strsep(&next, ":");
3201 mutex_lock(&ftrace_cmd_mutex);
3202 list_for_each_entry(p, &ftrace_commands, list) {
3203 if (strcmp(p->name, command) == 0) {
3204 ret = p->func(hash, func, command, next, enable);
3209 mutex_unlock(&ftrace_cmd_mutex);
3215 ftrace_regex_write(struct file *file, const char __user *ubuf,
3216 size_t cnt, loff_t *ppos, int enable)
3218 struct ftrace_iterator *iter;
3219 struct trace_parser *parser;
3225 mutex_lock(&ftrace_regex_lock);
3228 if (unlikely(ftrace_disabled))
3231 if (file->f_mode & FMODE_READ) {
3232 struct seq_file *m = file->private_data;
3235 iter = file->private_data;
3237 parser = &iter->parser;
3238 read = trace_get_user(parser, ubuf, cnt, ppos);
3240 if (read >= 0 && trace_parser_loaded(parser) &&
3241 !trace_parser_cont(parser)) {
3242 ret = ftrace_process_regex(iter->hash, parser->buffer,
3243 parser->idx, enable);
3244 trace_parser_clear(parser);
3251 mutex_unlock(&ftrace_regex_lock);
3257 ftrace_filter_write(struct file *file, const char __user *ubuf,
3258 size_t cnt, loff_t *ppos)
3260 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3264 ftrace_notrace_write(struct file *file, const char __user *ubuf,
3265 size_t cnt, loff_t *ppos)
3267 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3271 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
3273 struct ftrace_func_entry *entry;
3275 if (!ftrace_location(ip))
3279 entry = ftrace_lookup_ip(hash, ip);
3282 free_hash_entry(hash, entry);
3286 return add_hash_entry(hash, ip);
3290 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
3291 unsigned long ip, int remove, int reset, int enable)
3293 struct ftrace_hash **orig_hash;
3294 struct ftrace_hash *hash;
3297 /* All global ops uses the global ops filters */
3298 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
3301 if (unlikely(ftrace_disabled))
3305 orig_hash = &ops->filter_hash;
3307 orig_hash = &ops->notrace_hash;
3309 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3313 mutex_lock(&ftrace_regex_lock);
3315 ftrace_filter_reset(hash);
3316 if (buf && !ftrace_match_records(hash, buf, len)) {
3318 goto out_regex_unlock;
3321 ret = ftrace_match_addr(hash, ip, remove);
3323 goto out_regex_unlock;
3326 mutex_lock(&ftrace_lock);
3327 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3328 if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
3330 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3332 mutex_unlock(&ftrace_lock);
3335 mutex_unlock(&ftrace_regex_lock);
3337 free_ftrace_hash(hash);
3342 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
3343 int reset, int enable)
3345 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
3349 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3350 * @ops - the ops to set the filter with
3351 * @ip - the address to add to or remove from the filter.
3352 * @remove - non zero to remove the ip from the filter
3353 * @reset - non zero to reset all filters before applying this filter.
3355 * Filters denote which functions should be enabled when tracing is enabled
3356 * If @ip is NULL, it failes to update filter.
3358 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
3359 int remove, int reset)
3361 return ftrace_set_addr(ops, ip, remove, reset, 1);
3363 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
3366 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3367 int reset, int enable)
3369 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
3373 * ftrace_set_filter - set a function to filter on in ftrace
3374 * @ops - the ops to set the filter with
3375 * @buf - the string that holds the function filter text.
3376 * @len - the length of the string.
3377 * @reset - non zero to reset all filters before applying this filter.
3379 * Filters denote which functions should be enabled when tracing is enabled.
3380 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3382 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
3385 return ftrace_set_regex(ops, buf, len, reset, 1);
3387 EXPORT_SYMBOL_GPL(ftrace_set_filter);
3390 * ftrace_set_notrace - set a function to not trace in ftrace
3391 * @ops - the ops to set the notrace filter with
3392 * @buf - the string that holds the function notrace text.
3393 * @len - the length of the string.
3394 * @reset - non zero to reset all filters before applying this filter.
3396 * Notrace Filters denote which functions should not be enabled when tracing
3397 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3400 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
3403 return ftrace_set_regex(ops, buf, len, reset, 0);
3405 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3407 * ftrace_set_filter - set a function to filter on in ftrace
3408 * @ops - the ops to set the filter with
3409 * @buf - the string that holds the function filter text.
3410 * @len - the length of the string.
3411 * @reset - non zero to reset all filters before applying this filter.
3413 * Filters denote which functions should be enabled when tracing is enabled.
3414 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3416 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3418 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3420 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3423 * ftrace_set_notrace - set a function to not trace in ftrace
3424 * @ops - the ops to set the notrace filter with
3425 * @buf - the string that holds the function notrace text.
3426 * @len - the length of the string.
3427 * @reset - non zero to reset all filters before applying this filter.
3429 * Notrace Filters denote which functions should not be enabled when tracing
3430 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3433 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
3435 ftrace_set_regex(&global_ops, buf, len, reset, 0);
3437 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
3440 * command line interface to allow users to set filters on boot up.
3442 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3443 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3444 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3446 static int __init set_ftrace_notrace(char *str)
3448 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3451 __setup("ftrace_notrace=", set_ftrace_notrace);
3453 static int __init set_ftrace_filter(char *str)
3455 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3458 __setup("ftrace_filter=", set_ftrace_filter);
3460 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3461 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3462 static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3464 static int __init set_graph_function(char *str)
3466 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3469 __setup("ftrace_graph_filter=", set_graph_function);
3471 static void __init set_ftrace_early_graph(char *buf)
3477 func = strsep(&buf, ",");
3478 /* we allow only one expression at a time */
3479 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3482 printk(KERN_DEBUG "ftrace: function %s not "
3483 "traceable\n", func);
3486 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3489 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
3494 func = strsep(&buf, ",");
3495 ftrace_set_regex(ops, func, strlen(func), 0, enable);
3499 static void __init set_ftrace_early_filters(void)
3501 if (ftrace_filter_buf[0])
3502 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
3503 if (ftrace_notrace_buf[0])
3504 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
3505 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3506 if (ftrace_graph_buf[0])
3507 set_ftrace_early_graph(ftrace_graph_buf);
3508 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3511 int ftrace_regex_release(struct inode *inode, struct file *file)
3513 struct seq_file *m = (struct seq_file *)file->private_data;
3514 struct ftrace_iterator *iter;
3515 struct ftrace_hash **orig_hash;
3516 struct trace_parser *parser;
3520 mutex_lock(&ftrace_regex_lock);
3521 if (file->f_mode & FMODE_READ) {
3524 seq_release(inode, file);
3526 iter = file->private_data;
3528 parser = &iter->parser;
3529 if (trace_parser_loaded(parser)) {
3530 parser->buffer[parser->idx] = 0;
3531 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3534 trace_parser_put(parser);
3536 if (file->f_mode & FMODE_WRITE) {
3537 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3540 orig_hash = &iter->ops->filter_hash;
3542 orig_hash = &iter->ops->notrace_hash;
3544 mutex_lock(&ftrace_lock);
3545 ret = ftrace_hash_move(iter->ops, filter_hash,
3546 orig_hash, iter->hash);
3547 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
3549 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3551 mutex_unlock(&ftrace_lock);
3553 free_ftrace_hash(iter->hash);
3556 mutex_unlock(&ftrace_regex_lock);
3560 static const struct file_operations ftrace_avail_fops = {
3561 .open = ftrace_avail_open,
3563 .llseek = seq_lseek,
3564 .release = seq_release_private,
3567 static const struct file_operations ftrace_enabled_fops = {
3568 .open = ftrace_enabled_open,
3570 .llseek = seq_lseek,
3571 .release = seq_release_private,
3574 static const struct file_operations ftrace_filter_fops = {
3575 .open = ftrace_filter_open,
3577 .write = ftrace_filter_write,
3578 .llseek = ftrace_regex_lseek,
3579 .release = ftrace_regex_release,
3582 static const struct file_operations ftrace_notrace_fops = {
3583 .open = ftrace_notrace_open,
3585 .write = ftrace_notrace_write,
3586 .llseek = ftrace_regex_lseek,
3587 .release = ftrace_regex_release,
3590 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3592 static DEFINE_MUTEX(graph_lock);
3594 int ftrace_graph_count;
3595 int ftrace_graph_filter_enabled;
3596 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3599 __g_next(struct seq_file *m, loff_t *pos)
3601 if (*pos >= ftrace_graph_count)
3603 return &ftrace_graph_funcs[*pos];
3607 g_next(struct seq_file *m, void *v, loff_t *pos)
3610 return __g_next(m, pos);
3613 static void *g_start(struct seq_file *m, loff_t *pos)
3615 mutex_lock(&graph_lock);
3617 /* Nothing, tell g_show to print all functions are enabled */
3618 if (!ftrace_graph_filter_enabled && !*pos)
3621 return __g_next(m, pos);
3624 static void g_stop(struct seq_file *m, void *p)
3626 mutex_unlock(&graph_lock);
3629 static int g_show(struct seq_file *m, void *v)
3631 unsigned long *ptr = v;
3636 if (ptr == (unsigned long *)1) {
3637 seq_printf(m, "#### all functions enabled ####\n");
3641 seq_printf(m, "%ps\n", (void *)*ptr);
3646 static const struct seq_operations ftrace_graph_seq_ops = {
3654 ftrace_graph_open(struct inode *inode, struct file *file)
3658 if (unlikely(ftrace_disabled))
3661 mutex_lock(&graph_lock);
3662 if ((file->f_mode & FMODE_WRITE) &&
3663 (file->f_flags & O_TRUNC)) {
3664 ftrace_graph_filter_enabled = 0;
3665 ftrace_graph_count = 0;
3666 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3668 mutex_unlock(&graph_lock);
3670 if (file->f_mode & FMODE_READ)
3671 ret = seq_open(file, &ftrace_graph_seq_ops);
3677 ftrace_graph_release(struct inode *inode, struct file *file)
3679 if (file->f_mode & FMODE_READ)
3680 seq_release(inode, file);
3685 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3687 struct dyn_ftrace *rec;
3688 struct ftrace_page *pg;
3697 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3698 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3701 search_len = strlen(search);
3703 mutex_lock(&ftrace_lock);
3705 if (unlikely(ftrace_disabled)) {
3706 mutex_unlock(&ftrace_lock);
3710 do_for_each_ftrace_rec(pg, rec) {
3712 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3713 /* if it is in the array */
3715 for (i = 0; i < *idx; i++) {
3716 if (array[i] == rec->ip) {
3725 array[(*idx)++] = rec->ip;
3726 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3731 array[i] = array[--(*idx)];
3737 } while_for_each_ftrace_rec();
3739 mutex_unlock(&ftrace_lock);
3744 ftrace_graph_filter_enabled = 1;
3749 ftrace_graph_write(struct file *file, const char __user *ubuf,
3750 size_t cnt, loff_t *ppos)
3752 struct trace_parser parser;
3758 mutex_lock(&graph_lock);
3760 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3765 read = trace_get_user(&parser, ubuf, cnt, ppos);
3767 if (read >= 0 && trace_parser_loaded((&parser))) {
3768 parser.buffer[parser.idx] = 0;
3770 /* we allow only one expression at a time */
3771 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3780 trace_parser_put(&parser);
3782 mutex_unlock(&graph_lock);
3787 static const struct file_operations ftrace_graph_fops = {
3788 .open = ftrace_graph_open,
3790 .write = ftrace_graph_write,
3791 .release = ftrace_graph_release,
3792 .llseek = seq_lseek,
3794 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3796 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3799 trace_create_file("available_filter_functions", 0444,
3800 d_tracer, NULL, &ftrace_avail_fops);
3802 trace_create_file("enabled_functions", 0444,
3803 d_tracer, NULL, &ftrace_enabled_fops);
3805 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3806 NULL, &ftrace_filter_fops);
3808 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3809 NULL, &ftrace_notrace_fops);
3811 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3812 trace_create_file("set_graph_function", 0444, d_tracer,
3814 &ftrace_graph_fops);
3815 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3820 static int ftrace_cmp_ips(const void *a, const void *b)
3822 const unsigned long *ipa = a;
3823 const unsigned long *ipb = b;
3832 static void ftrace_swap_ips(void *a, void *b, int size)
3834 unsigned long *ipa = a;
3835 unsigned long *ipb = b;
3843 static int ftrace_process_locs(struct module *mod,
3844 unsigned long *start,
3847 struct ftrace_page *start_pg;
3848 struct ftrace_page *pg;
3849 struct dyn_ftrace *rec;
3850 unsigned long count;
3853 unsigned long flags = 0; /* Shut up gcc */
3856 count = end - start;
3861 sort(start, count, sizeof(*start),
3862 ftrace_cmp_ips, ftrace_swap_ips);
3864 start_pg = ftrace_allocate_pages(count);
3868 mutex_lock(&ftrace_lock);
3871 * Core and each module needs their own pages, as
3872 * modules will free them when they are removed.
3873 * Force a new page to be allocated for modules.
3876 WARN_ON(ftrace_pages || ftrace_pages_start);
3877 /* First initialization */
3878 ftrace_pages = ftrace_pages_start = start_pg;
3883 if (WARN_ON(ftrace_pages->next)) {
3884 /* Hmm, we have free pages? */
3885 while (ftrace_pages->next)
3886 ftrace_pages = ftrace_pages->next;
3889 ftrace_pages->next = start_pg;
3895 addr = ftrace_call_adjust(*p++);
3897 * Some architecture linkers will pad between
3898 * the different mcount_loc sections of different
3899 * object files to satisfy alignments.
3900 * Skip any NULL pointers.
3905 if (pg->index == pg->size) {
3906 /* We should have allocated enough */
3907 if (WARN_ON(!pg->next))
3912 rec = &pg->records[pg->index++];
3916 /* We should have used all pages */
3919 /* Assign the last page to ftrace_pages */
3922 /* These new locations need to be initialized */
3923 ftrace_new_pgs = start_pg;
3926 * We only need to disable interrupts on start up
3927 * because we are modifying code that an interrupt
3928 * may execute, and the modification is not atomic.
3929 * But for modules, nothing runs the code we modify
3930 * until we are finished with it, and there's no
3931 * reason to cause large interrupt latencies while we do it.
3934 local_irq_save(flags);
3935 ftrace_update_code(mod);
3937 local_irq_restore(flags);
3940 mutex_unlock(&ftrace_lock);
3945 #ifdef CONFIG_MODULES
3947 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
3949 void ftrace_release_mod(struct module *mod)
3951 struct dyn_ftrace *rec;
3952 struct ftrace_page **last_pg;
3953 struct ftrace_page *pg;
3956 mutex_lock(&ftrace_lock);
3958 if (ftrace_disabled)
3962 * Each module has its own ftrace_pages, remove
3963 * them from the list.
3965 last_pg = &ftrace_pages_start;
3966 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
3967 rec = &pg->records[0];
3968 if (within_module_core(rec->ip, mod)) {
3970 * As core pages are first, the first
3971 * page should never be a module page.
3973 if (WARN_ON(pg == ftrace_pages_start))
3976 /* Check if we are deleting the last page */
3977 if (pg == ftrace_pages)
3978 ftrace_pages = next_to_ftrace_page(last_pg);
3980 *last_pg = pg->next;
3981 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3982 free_pages((unsigned long)pg->records, order);
3985 last_pg = &pg->next;
3988 mutex_unlock(&ftrace_lock);
3991 static void ftrace_init_module(struct module *mod,
3992 unsigned long *start, unsigned long *end)
3994 if (ftrace_disabled || start == end)
3996 ftrace_process_locs(mod, start, end);
3999 static int ftrace_module_notify_enter(struct notifier_block *self,
4000 unsigned long val, void *data)
4002 struct module *mod = data;
4004 if (val == MODULE_STATE_COMING)
4005 ftrace_init_module(mod, mod->ftrace_callsites,
4006 mod->ftrace_callsites +
4007 mod->num_ftrace_callsites);
4011 static int ftrace_module_notify_exit(struct notifier_block *self,
4012 unsigned long val, void *data)
4014 struct module *mod = data;
4016 if (val == MODULE_STATE_GOING)
4017 ftrace_release_mod(mod);
4022 static int ftrace_module_notify_enter(struct notifier_block *self,
4023 unsigned long val, void *data)
4027 static int ftrace_module_notify_exit(struct notifier_block *self,
4028 unsigned long val, void *data)
4032 #endif /* CONFIG_MODULES */
4034 struct notifier_block ftrace_module_enter_nb = {
4035 .notifier_call = ftrace_module_notify_enter,
4036 .priority = INT_MAX, /* Run before anything that can use kprobes */
4039 struct notifier_block ftrace_module_exit_nb = {
4040 .notifier_call = ftrace_module_notify_exit,
4041 .priority = INT_MIN, /* Run after anything that can remove kprobes */
4044 extern unsigned long __start_mcount_loc[];
4045 extern unsigned long __stop_mcount_loc[];
4047 void __init ftrace_init(void)
4049 unsigned long count, addr, flags;
4052 /* Keep the ftrace pointer to the stub */
4053 addr = (unsigned long)ftrace_stub;
4055 local_irq_save(flags);
4056 ftrace_dyn_arch_init(&addr);
4057 local_irq_restore(flags);
4059 /* ftrace_dyn_arch_init places the return code in addr */
4063 count = __stop_mcount_loc - __start_mcount_loc;
4065 ret = ftrace_dyn_table_alloc(count);
4069 last_ftrace_enabled = ftrace_enabled = 1;
4071 ret = ftrace_process_locs(NULL,
4075 ret = register_module_notifier(&ftrace_module_enter_nb);
4077 pr_warning("Failed to register trace ftrace module enter notifier\n");
4079 ret = register_module_notifier(&ftrace_module_exit_nb);
4081 pr_warning("Failed to register trace ftrace module exit notifier\n");
4083 set_ftrace_early_filters();
4087 ftrace_disabled = 1;
4092 static struct ftrace_ops global_ops = {
4093 .func = ftrace_stub,
4094 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
4097 static int __init ftrace_nodyn_init(void)
4102 core_initcall(ftrace_nodyn_init);
4104 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
4105 static inline void ftrace_startup_enable(int command) { }
4106 /* Keep as macros so we do not need to define the commands */
4107 # define ftrace_startup(ops, command) \
4109 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4112 # define ftrace_shutdown(ops, command) do { } while (0)
4113 # define ftrace_startup_sysctl() do { } while (0)
4114 # define ftrace_shutdown_sysctl() do { } while (0)
4117 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
4122 #endif /* CONFIG_DYNAMIC_FTRACE */
4125 ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
4126 struct ftrace_ops *op, struct pt_regs *regs)
4128 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
4132 * Some of the ops may be dynamically allocated,
4133 * they must be freed after a synchronize_sched().
4135 preempt_disable_notrace();
4136 trace_recursion_set(TRACE_CONTROL_BIT);
4137 do_for_each_ftrace_op(op, ftrace_control_list) {
4138 if (!ftrace_function_local_disabled(op) &&
4139 ftrace_ops_test(op, ip))
4140 op->func(ip, parent_ip, op, regs);
4141 } while_for_each_ftrace_op(op);
4142 trace_recursion_clear(TRACE_CONTROL_BIT);
4143 preempt_enable_notrace();
4146 static struct ftrace_ops control_ops = {
4147 .func = ftrace_ops_control_func,
4148 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
4152 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4153 struct ftrace_ops *ignored, struct pt_regs *regs)
4155 struct ftrace_ops *op;
4158 if (function_trace_stop)
4161 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4166 * Some of the ops may be dynamically allocated,
4167 * they must be freed after a synchronize_sched().
4169 preempt_disable_notrace();
4170 do_for_each_ftrace_op(op, ftrace_ops_list) {
4171 if (ftrace_ops_test(op, ip))
4172 op->func(ip, parent_ip, op, regs);
4173 } while_for_each_ftrace_op(op);
4174 preempt_enable_notrace();
4175 trace_clear_recursion(bit);
4179 * Some archs only support passing ip and parent_ip. Even though
4180 * the list function ignores the op parameter, we do not want any
4181 * C side effects, where a function is called without the caller
4182 * sending a third parameter.
4183 * Archs are to support both the regs and ftrace_ops at the same time.
4184 * If they support ftrace_ops, it is assumed they support regs.
4185 * If call backs want to use regs, they must either check for regs
4186 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4187 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4188 * An architecture can pass partial regs with ftrace_ops and still
4189 * set the ARCH_SUPPORT_FTARCE_OPS.
4191 #if ARCH_SUPPORTS_FTRACE_OPS
4192 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4193 struct ftrace_ops *op, struct pt_regs *regs)
4195 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
4198 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
4200 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
4204 static void clear_ftrace_swapper(void)
4206 struct task_struct *p;
4210 for_each_online_cpu(cpu) {
4212 clear_tsk_trace_trace(p);
4217 static void set_ftrace_swapper(void)
4219 struct task_struct *p;
4223 for_each_online_cpu(cpu) {
4225 set_tsk_trace_trace(p);
4230 static void clear_ftrace_pid(struct pid *pid)
4232 struct task_struct *p;
4235 do_each_pid_task(pid, PIDTYPE_PID, p) {
4236 clear_tsk_trace_trace(p);
4237 } while_each_pid_task(pid, PIDTYPE_PID, p);
4243 static void set_ftrace_pid(struct pid *pid)
4245 struct task_struct *p;
4248 do_each_pid_task(pid, PIDTYPE_PID, p) {
4249 set_tsk_trace_trace(p);
4250 } while_each_pid_task(pid, PIDTYPE_PID, p);
4254 static void clear_ftrace_pid_task(struct pid *pid)
4256 if (pid == ftrace_swapper_pid)
4257 clear_ftrace_swapper();
4259 clear_ftrace_pid(pid);
4262 static void set_ftrace_pid_task(struct pid *pid)
4264 if (pid == ftrace_swapper_pid)
4265 set_ftrace_swapper();
4267 set_ftrace_pid(pid);
4270 static int ftrace_pid_add(int p)
4273 struct ftrace_pid *fpid;
4276 mutex_lock(&ftrace_lock);
4279 pid = ftrace_swapper_pid;
4281 pid = find_get_pid(p);
4288 list_for_each_entry(fpid, &ftrace_pids, list)
4289 if (fpid->pid == pid)
4294 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4298 list_add(&fpid->list, &ftrace_pids);
4301 set_ftrace_pid_task(pid);
4303 ftrace_update_pid_func();
4304 ftrace_startup_enable(0);
4306 mutex_unlock(&ftrace_lock);
4310 if (pid != ftrace_swapper_pid)
4314 mutex_unlock(&ftrace_lock);
4318 static void ftrace_pid_reset(void)
4320 struct ftrace_pid *fpid, *safe;
4322 mutex_lock(&ftrace_lock);
4323 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
4324 struct pid *pid = fpid->pid;
4326 clear_ftrace_pid_task(pid);
4328 list_del(&fpid->list);
4332 ftrace_update_pid_func();
4333 ftrace_startup_enable(0);
4335 mutex_unlock(&ftrace_lock);
4338 static void *fpid_start(struct seq_file *m, loff_t *pos)
4340 mutex_lock(&ftrace_lock);
4342 if (list_empty(&ftrace_pids) && (!*pos))
4345 return seq_list_start(&ftrace_pids, *pos);
4348 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
4353 return seq_list_next(v, &ftrace_pids, pos);
4356 static void fpid_stop(struct seq_file *m, void *p)
4358 mutex_unlock(&ftrace_lock);
4361 static int fpid_show(struct seq_file *m, void *v)
4363 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
4365 if (v == (void *)1) {
4366 seq_printf(m, "no pid\n");
4370 if (fpid->pid == ftrace_swapper_pid)
4371 seq_printf(m, "swapper tasks\n");
4373 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
4378 static const struct seq_operations ftrace_pid_sops = {
4379 .start = fpid_start,
4386 ftrace_pid_open(struct inode *inode, struct file *file)
4390 if ((file->f_mode & FMODE_WRITE) &&
4391 (file->f_flags & O_TRUNC))
4394 if (file->f_mode & FMODE_READ)
4395 ret = seq_open(file, &ftrace_pid_sops);
4401 ftrace_pid_write(struct file *filp, const char __user *ubuf,
4402 size_t cnt, loff_t *ppos)
4408 if (cnt >= sizeof(buf))
4411 if (copy_from_user(&buf, ubuf, cnt))
4417 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4418 * to clean the filter quietly.
4420 tmp = strstrip(buf);
4421 if (strlen(tmp) == 0)
4424 ret = kstrtol(tmp, 10, &val);
4428 ret = ftrace_pid_add(val);
4430 return ret ? ret : cnt;
4434 ftrace_pid_release(struct inode *inode, struct file *file)
4436 if (file->f_mode & FMODE_READ)
4437 seq_release(inode, file);
4442 static const struct file_operations ftrace_pid_fops = {
4443 .open = ftrace_pid_open,
4444 .write = ftrace_pid_write,
4446 .llseek = seq_lseek,
4447 .release = ftrace_pid_release,
4450 static __init int ftrace_init_debugfs(void)
4452 struct dentry *d_tracer;
4454 d_tracer = tracing_init_dentry();
4458 ftrace_init_dyn_debugfs(d_tracer);
4460 trace_create_file("set_ftrace_pid", 0644, d_tracer,
4461 NULL, &ftrace_pid_fops);
4463 ftrace_profile_debugfs(d_tracer);
4467 fs_initcall(ftrace_init_debugfs);
4470 * ftrace_kill - kill ftrace
4472 * This function should be used by panic code. It stops ftrace
4473 * but in a not so nice way. If you need to simply kill ftrace
4474 * from a non-atomic section, use ftrace_kill.
4476 void ftrace_kill(void)
4478 ftrace_disabled = 1;
4480 clear_ftrace_function();
4484 * Test if ftrace is dead or not.
4486 int ftrace_is_dead(void)
4488 return ftrace_disabled;
4492 * register_ftrace_function - register a function for profiling
4493 * @ops - ops structure that holds the function for profiling.
4495 * Register a function to be called by all functions in the
4498 * Note: @ops->func and all the functions it calls must be labeled
4499 * with "notrace", otherwise it will go into a
4502 int register_ftrace_function(struct ftrace_ops *ops)
4506 mutex_lock(&ftrace_lock);
4508 ret = __register_ftrace_function(ops);
4510 ret = ftrace_startup(ops, 0);
4512 mutex_unlock(&ftrace_lock);
4516 EXPORT_SYMBOL_GPL(register_ftrace_function);
4519 * unregister_ftrace_function - unregister a function for profiling.
4520 * @ops - ops structure that holds the function to unregister
4522 * Unregister a function that was added to be called by ftrace profiling.
4524 int unregister_ftrace_function(struct ftrace_ops *ops)
4528 mutex_lock(&ftrace_lock);
4529 ret = __unregister_ftrace_function(ops);
4531 ftrace_shutdown(ops, 0);
4532 mutex_unlock(&ftrace_lock);
4536 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
4539 ftrace_enable_sysctl(struct ctl_table *table, int write,
4540 void __user *buffer, size_t *lenp,
4545 mutex_lock(&ftrace_lock);
4547 if (unlikely(ftrace_disabled))
4550 ret = proc_dointvec(table, write, buffer, lenp, ppos);
4552 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
4555 last_ftrace_enabled = !!ftrace_enabled;
4557 if (ftrace_enabled) {
4559 ftrace_startup_sysctl();
4561 /* we are starting ftrace again */
4562 if (ftrace_ops_list != &ftrace_list_end) {
4563 if (ftrace_ops_list->next == &ftrace_list_end)
4564 ftrace_trace_function = ftrace_ops_list->func;
4566 ftrace_trace_function = ftrace_ops_list_func;
4570 /* stopping ftrace calls (just send to ftrace_stub) */
4571 ftrace_trace_function = ftrace_stub;
4573 ftrace_shutdown_sysctl();
4577 mutex_unlock(&ftrace_lock);
4581 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4583 static int ftrace_graph_active;
4584 static struct notifier_block ftrace_suspend_notifier;
4586 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
4591 /* The callbacks that hook a function */
4592 trace_func_graph_ret_t ftrace_graph_return =
4593 (trace_func_graph_ret_t)ftrace_stub;
4594 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
4596 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4597 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
4601 unsigned long flags;
4602 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
4603 struct task_struct *g, *t;
4605 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
4606 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
4607 * sizeof(struct ftrace_ret_stack),
4609 if (!ret_stack_list[i]) {
4617 read_lock_irqsave(&tasklist_lock, flags);
4618 do_each_thread(g, t) {
4624 if (t->ret_stack == NULL) {
4625 atomic_set(&t->tracing_graph_pause, 0);
4626 atomic_set(&t->trace_overrun, 0);
4627 t->curr_ret_stack = -1;
4628 /* Make sure the tasks see the -1 first: */
4630 t->ret_stack = ret_stack_list[start++];
4632 } while_each_thread(g, t);
4635 read_unlock_irqrestore(&tasklist_lock, flags);
4637 for (i = start; i < end; i++)
4638 kfree(ret_stack_list[i]);
4643 ftrace_graph_probe_sched_switch(void *ignore,
4644 struct task_struct *prev, struct task_struct *next)
4646 unsigned long long timestamp;
4650 * Does the user want to count the time a function was asleep.
4651 * If so, do not update the time stamps.
4653 if (trace_flags & TRACE_ITER_SLEEP_TIME)
4656 timestamp = trace_clock_local();
4658 prev->ftrace_timestamp = timestamp;
4660 /* only process tasks that we timestamped */
4661 if (!next->ftrace_timestamp)
4665 * Update all the counters in next to make up for the
4666 * time next was sleeping.
4668 timestamp -= next->ftrace_timestamp;
4670 for (index = next->curr_ret_stack; index >= 0; index--)
4671 next->ret_stack[index].calltime += timestamp;
4674 /* Allocate a return stack for each task */
4675 static int start_graph_tracing(void)
4677 struct ftrace_ret_stack **ret_stack_list;
4680 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4681 sizeof(struct ftrace_ret_stack *),
4684 if (!ret_stack_list)
4687 /* The cpu_boot init_task->ret_stack will never be freed */
4688 for_each_online_cpu(cpu) {
4689 if (!idle_task(cpu)->ret_stack)
4690 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
4694 ret = alloc_retstack_tasklist(ret_stack_list);
4695 } while (ret == -EAGAIN);
4698 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4700 pr_info("ftrace_graph: Couldn't activate tracepoint"
4701 " probe to kernel_sched_switch\n");
4704 kfree(ret_stack_list);
4709 * Hibernation protection.
4710 * The state of the current task is too much unstable during
4711 * suspend/restore to disk. We want to protect against that.
4714 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4718 case PM_HIBERNATION_PREPARE:
4719 pause_graph_tracing();
4722 case PM_POST_HIBERNATION:
4723 unpause_graph_tracing();
4729 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4730 trace_func_graph_ent_t entryfunc)
4734 mutex_lock(&ftrace_lock);
4736 /* we currently allow only one tracer registered at a time */
4737 if (ftrace_graph_active) {
4742 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4743 register_pm_notifier(&ftrace_suspend_notifier);
4745 ftrace_graph_active++;
4746 ret = start_graph_tracing();
4748 ftrace_graph_active--;
4752 ftrace_graph_return = retfunc;
4753 ftrace_graph_entry = entryfunc;
4755 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4758 mutex_unlock(&ftrace_lock);
4762 void unregister_ftrace_graph(void)
4764 mutex_lock(&ftrace_lock);
4766 if (unlikely(!ftrace_graph_active))
4769 ftrace_graph_active--;
4770 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4771 ftrace_graph_entry = ftrace_graph_entry_stub;
4772 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4773 unregister_pm_notifier(&ftrace_suspend_notifier);
4774 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4777 mutex_unlock(&ftrace_lock);
4780 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4783 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4785 atomic_set(&t->tracing_graph_pause, 0);
4786 atomic_set(&t->trace_overrun, 0);
4787 t->ftrace_timestamp = 0;
4788 /* make curr_ret_stack visible before we add the ret_stack */
4790 t->ret_stack = ret_stack;
4794 * Allocate a return stack for the idle task. May be the first
4795 * time through, or it may be done by CPU hotplug online.
4797 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4799 t->curr_ret_stack = -1;
4801 * The idle task has no parent, it either has its own
4802 * stack or no stack at all.
4805 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4807 if (ftrace_graph_active) {
4808 struct ftrace_ret_stack *ret_stack;
4810 ret_stack = per_cpu(idle_ret_stack, cpu);
4812 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4813 * sizeof(struct ftrace_ret_stack),
4817 per_cpu(idle_ret_stack, cpu) = ret_stack;
4819 graph_init_task(t, ret_stack);
4823 /* Allocate a return stack for newly created task */
4824 void ftrace_graph_init_task(struct task_struct *t)
4826 /* Make sure we do not use the parent ret_stack */
4827 t->ret_stack = NULL;
4828 t->curr_ret_stack = -1;
4830 if (ftrace_graph_active) {
4831 struct ftrace_ret_stack *ret_stack;
4833 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4834 * sizeof(struct ftrace_ret_stack),
4838 graph_init_task(t, ret_stack);
4842 void ftrace_graph_exit_task(struct task_struct *t)
4844 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4846 t->ret_stack = NULL;
4847 /* NULL must become visible to IRQs before we free it: */
4853 void ftrace_graph_stop(void)