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 * ftrace_nr_registered_ops - return number of ops registered
117 * Returns the number of ftrace_ops registered and tracing functions
119 int ftrace_nr_registered_ops(void)
121 struct ftrace_ops *ops;
124 mutex_lock(&ftrace_lock);
126 for (ops = ftrace_ops_list;
127 ops != &ftrace_list_end; ops = ops->next)
130 mutex_unlock(&ftrace_lock);
136 * Traverse the ftrace_global_list, invoking all entries. The reason that we
137 * can use rcu_dereference_raw() is that elements removed from this list
138 * are simply leaked, so there is no need to interact with a grace-period
139 * mechanism. The rcu_dereference_raw() calls are needed to handle
140 * concurrent insertions into the ftrace_global_list.
142 * Silly Alpha and silly pointer-speculation compiler optimizations!
145 ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
146 struct ftrace_ops *op, struct pt_regs *regs)
148 if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
151 trace_recursion_set(TRACE_GLOBAL_BIT);
152 op = rcu_dereference_raw(ftrace_global_list); /*see above*/
153 while (op != &ftrace_list_end) {
154 op->func(ip, parent_ip, op, regs);
155 op = rcu_dereference_raw(op->next); /*see above*/
157 trace_recursion_clear(TRACE_GLOBAL_BIT);
160 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
161 struct ftrace_ops *op, struct pt_regs *regs)
163 if (!test_tsk_trace_trace(current))
166 ftrace_pid_function(ip, parent_ip, op, regs);
169 static void set_ftrace_pid_function(ftrace_func_t func)
171 /* do not set ftrace_pid_function to itself! */
172 if (func != ftrace_pid_func)
173 ftrace_pid_function = func;
177 * clear_ftrace_function - reset the ftrace function
179 * This NULLs the ftrace function and in essence stops
180 * tracing. There may be lag
182 void clear_ftrace_function(void)
184 ftrace_trace_function = ftrace_stub;
185 ftrace_pid_function = ftrace_stub;
188 static void control_ops_disable_all(struct ftrace_ops *ops)
192 for_each_possible_cpu(cpu)
193 *per_cpu_ptr(ops->disabled, cpu) = 1;
196 static int control_ops_alloc(struct ftrace_ops *ops)
198 int __percpu *disabled;
200 disabled = alloc_percpu(int);
204 ops->disabled = disabled;
205 control_ops_disable_all(ops);
209 static void control_ops_free(struct ftrace_ops *ops)
211 free_percpu(ops->disabled);
214 static void update_global_ops(void)
219 * If there's only one function registered, then call that
220 * function directly. Otherwise, we need to iterate over the
221 * registered callers.
223 if (ftrace_global_list == &ftrace_list_end ||
224 ftrace_global_list->next == &ftrace_list_end) {
225 func = ftrace_global_list->func;
227 * As we are calling the function directly.
228 * If it does not have recursion protection,
229 * the function_trace_op needs to be updated
232 if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
233 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
235 global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
237 func = ftrace_global_list_func;
238 /* The list has its own recursion protection. */
239 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
243 /* If we filter on pids, update to use the pid function */
244 if (!list_empty(&ftrace_pids)) {
245 set_ftrace_pid_function(func);
246 func = ftrace_pid_func;
249 global_ops.func = func;
252 static void update_ftrace_function(void)
259 * If we are at the end of the list and this ops is
260 * recursion safe and not dynamic and the arch supports passing ops,
261 * then have the mcount trampoline call the function directly.
263 if (ftrace_ops_list == &ftrace_list_end ||
264 (ftrace_ops_list->next == &ftrace_list_end &&
265 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
266 (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
267 !FTRACE_FORCE_LIST_FUNC)) {
268 /* Set the ftrace_ops that the arch callback uses */
269 if (ftrace_ops_list == &global_ops)
270 function_trace_op = ftrace_global_list;
272 function_trace_op = ftrace_ops_list;
273 func = ftrace_ops_list->func;
275 /* Just use the default ftrace_ops */
276 function_trace_op = &ftrace_list_end;
277 func = ftrace_ops_list_func;
280 ftrace_trace_function = func;
283 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
287 * We are entering ops into the list but another
288 * CPU might be walking that list. We need to make sure
289 * the ops->next pointer is valid before another CPU sees
290 * the ops pointer included into the list.
292 rcu_assign_pointer(*list, ops);
295 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
297 struct ftrace_ops **p;
300 * If we are removing the last function, then simply point
301 * to the ftrace_stub.
303 if (*list == ops && ops->next == &ftrace_list_end) {
304 *list = &ftrace_list_end;
308 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
319 static void add_ftrace_list_ops(struct ftrace_ops **list,
320 struct ftrace_ops *main_ops,
321 struct ftrace_ops *ops)
323 int first = *list == &ftrace_list_end;
324 add_ftrace_ops(list, ops);
326 add_ftrace_ops(&ftrace_ops_list, main_ops);
329 static int remove_ftrace_list_ops(struct ftrace_ops **list,
330 struct ftrace_ops *main_ops,
331 struct ftrace_ops *ops)
333 int ret = remove_ftrace_ops(list, ops);
334 if (!ret && *list == &ftrace_list_end)
335 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
339 static int __register_ftrace_function(struct ftrace_ops *ops)
341 if (unlikely(ftrace_disabled))
344 if (FTRACE_WARN_ON(ops == &global_ops))
347 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
350 /* We don't support both control and global flags set. */
351 if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
354 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
356 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
357 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
358 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
360 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
361 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
364 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
365 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
368 if (!core_kernel_data((unsigned long)ops))
369 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
371 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
372 add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
373 ops->flags |= FTRACE_OPS_FL_ENABLED;
374 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
375 if (control_ops_alloc(ops))
377 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
379 add_ftrace_ops(&ftrace_ops_list, ops);
382 update_ftrace_function();
387 static int __unregister_ftrace_function(struct ftrace_ops *ops)
394 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
397 if (FTRACE_WARN_ON(ops == &global_ops))
400 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
401 ret = remove_ftrace_list_ops(&ftrace_global_list,
404 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
405 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
406 ret = remove_ftrace_list_ops(&ftrace_control_list,
410 * The ftrace_ops is now removed from the list,
411 * so there'll be no new users. We must ensure
412 * all current users are done before we free
416 control_ops_free(ops);
419 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
425 update_ftrace_function();
428 * Dynamic ops may be freed, we must make sure that all
429 * callers are done before leaving this function.
431 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
437 static void ftrace_update_pid_func(void)
439 /* Only do something if we are tracing something */
440 if (ftrace_trace_function == ftrace_stub)
443 update_ftrace_function();
446 #ifdef CONFIG_FUNCTION_PROFILER
447 struct ftrace_profile {
448 struct hlist_node node;
450 unsigned long counter;
451 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
452 unsigned long long time;
453 unsigned long long time_squared;
457 struct ftrace_profile_page {
458 struct ftrace_profile_page *next;
460 struct ftrace_profile records[];
463 struct ftrace_profile_stat {
465 struct hlist_head *hash;
466 struct ftrace_profile_page *pages;
467 struct ftrace_profile_page *start;
468 struct tracer_stat stat;
471 #define PROFILE_RECORDS_SIZE \
472 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
474 #define PROFILES_PER_PAGE \
475 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
477 static int ftrace_profile_bits __read_mostly;
478 static int ftrace_profile_enabled __read_mostly;
480 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
481 static DEFINE_MUTEX(ftrace_profile_lock);
483 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
485 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
488 function_stat_next(void *v, int idx)
490 struct ftrace_profile *rec = v;
491 struct ftrace_profile_page *pg;
493 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
499 if ((void *)rec >= (void *)&pg->records[pg->index]) {
503 rec = &pg->records[0];
511 static void *function_stat_start(struct tracer_stat *trace)
513 struct ftrace_profile_stat *stat =
514 container_of(trace, struct ftrace_profile_stat, stat);
516 if (!stat || !stat->start)
519 return function_stat_next(&stat->start->records[0], 0);
522 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
523 /* function graph compares on total time */
524 static int function_stat_cmp(void *p1, void *p2)
526 struct ftrace_profile *a = p1;
527 struct ftrace_profile *b = p2;
529 if (a->time < b->time)
531 if (a->time > b->time)
537 /* not function graph compares against hits */
538 static int function_stat_cmp(void *p1, void *p2)
540 struct ftrace_profile *a = p1;
541 struct ftrace_profile *b = p2;
543 if (a->counter < b->counter)
545 if (a->counter > b->counter)
552 static int function_stat_headers(struct seq_file *m)
554 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
555 seq_printf(m, " Function "
558 "--- ---- --- ---\n");
560 seq_printf(m, " Function Hit\n"
566 static int function_stat_show(struct seq_file *m, void *v)
568 struct ftrace_profile *rec = v;
569 char str[KSYM_SYMBOL_LEN];
571 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
572 static struct trace_seq s;
573 unsigned long long avg;
574 unsigned long long stddev;
576 mutex_lock(&ftrace_profile_lock);
578 /* we raced with function_profile_reset() */
579 if (unlikely(rec->counter == 0)) {
584 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
585 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
587 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
590 do_div(avg, rec->counter);
592 /* Sample standard deviation (s^2) */
593 if (rec->counter <= 1)
596 stddev = rec->time_squared - rec->counter * avg * avg;
598 * Divide only 1000 for ns^2 -> us^2 conversion.
599 * trace_print_graph_duration will divide 1000 again.
601 do_div(stddev, (rec->counter - 1) * 1000);
605 trace_print_graph_duration(rec->time, &s);
606 trace_seq_puts(&s, " ");
607 trace_print_graph_duration(avg, &s);
608 trace_seq_puts(&s, " ");
609 trace_print_graph_duration(stddev, &s);
610 trace_print_seq(m, &s);
614 mutex_unlock(&ftrace_profile_lock);
619 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
621 struct ftrace_profile_page *pg;
623 pg = stat->pages = stat->start;
626 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
631 memset(stat->hash, 0,
632 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
635 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
637 struct ftrace_profile_page *pg;
642 /* If we already allocated, do nothing */
646 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
650 #ifdef CONFIG_DYNAMIC_FTRACE
651 functions = ftrace_update_tot_cnt;
654 * We do not know the number of functions that exist because
655 * dynamic tracing is what counts them. With past experience
656 * we have around 20K functions. That should be more than enough.
657 * It is highly unlikely we will execute every function in
663 pg = stat->start = stat->pages;
665 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
667 for (i = 0; i < pages; i++) {
668 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
679 unsigned long tmp = (unsigned long)pg;
685 free_page((unsigned long)stat->pages);
692 static int ftrace_profile_init_cpu(int cpu)
694 struct ftrace_profile_stat *stat;
697 stat = &per_cpu(ftrace_profile_stats, cpu);
700 /* If the profile is already created, simply reset it */
701 ftrace_profile_reset(stat);
706 * We are profiling all functions, but usually only a few thousand
707 * functions are hit. We'll make a hash of 1024 items.
709 size = FTRACE_PROFILE_HASH_SIZE;
711 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
716 if (!ftrace_profile_bits) {
719 for (; size; size >>= 1)
720 ftrace_profile_bits++;
723 /* Preallocate the function profiling pages */
724 if (ftrace_profile_pages_init(stat) < 0) {
733 static int ftrace_profile_init(void)
738 for_each_online_cpu(cpu) {
739 ret = ftrace_profile_init_cpu(cpu);
747 /* interrupts must be disabled */
748 static struct ftrace_profile *
749 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
751 struct ftrace_profile *rec;
752 struct hlist_head *hhd;
753 struct hlist_node *n;
756 key = hash_long(ip, ftrace_profile_bits);
757 hhd = &stat->hash[key];
759 if (hlist_empty(hhd))
762 hlist_for_each_entry_rcu(rec, n, hhd, node) {
770 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
771 struct ftrace_profile *rec)
775 key = hash_long(rec->ip, ftrace_profile_bits);
776 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
780 * The memory is already allocated, this simply finds a new record to use.
782 static struct ftrace_profile *
783 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
785 struct ftrace_profile *rec = NULL;
787 /* prevent recursion (from NMIs) */
788 if (atomic_inc_return(&stat->disabled) != 1)
792 * Try to find the function again since an NMI
793 * could have added it
795 rec = ftrace_find_profiled_func(stat, ip);
799 if (stat->pages->index == PROFILES_PER_PAGE) {
800 if (!stat->pages->next)
802 stat->pages = stat->pages->next;
805 rec = &stat->pages->records[stat->pages->index++];
807 ftrace_add_profile(stat, rec);
810 atomic_dec(&stat->disabled);
816 function_profile_call(unsigned long ip, unsigned long parent_ip,
817 struct ftrace_ops *ops, struct pt_regs *regs)
819 struct ftrace_profile_stat *stat;
820 struct ftrace_profile *rec;
823 if (!ftrace_profile_enabled)
826 local_irq_save(flags);
828 stat = &__get_cpu_var(ftrace_profile_stats);
829 if (!stat->hash || !ftrace_profile_enabled)
832 rec = ftrace_find_profiled_func(stat, ip);
834 rec = ftrace_profile_alloc(stat, ip);
841 local_irq_restore(flags);
844 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
845 static int profile_graph_entry(struct ftrace_graph_ent *trace)
847 function_profile_call(trace->func, 0, NULL, NULL);
851 static void profile_graph_return(struct ftrace_graph_ret *trace)
853 struct ftrace_profile_stat *stat;
854 unsigned long long calltime;
855 struct ftrace_profile *rec;
858 local_irq_save(flags);
859 stat = &__get_cpu_var(ftrace_profile_stats);
860 if (!stat->hash || !ftrace_profile_enabled)
863 /* If the calltime was zero'd ignore it */
864 if (!trace->calltime)
867 calltime = trace->rettime - trace->calltime;
869 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
872 index = trace->depth;
874 /* Append this call time to the parent time to subtract */
876 current->ret_stack[index - 1].subtime += calltime;
878 if (current->ret_stack[index].subtime < calltime)
879 calltime -= current->ret_stack[index].subtime;
884 rec = ftrace_find_profiled_func(stat, trace->func);
886 rec->time += calltime;
887 rec->time_squared += calltime * calltime;
891 local_irq_restore(flags);
894 static int register_ftrace_profiler(void)
896 return register_ftrace_graph(&profile_graph_return,
897 &profile_graph_entry);
900 static void unregister_ftrace_profiler(void)
902 unregister_ftrace_graph();
905 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
906 .func = function_profile_call,
907 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
910 static int register_ftrace_profiler(void)
912 return register_ftrace_function(&ftrace_profile_ops);
915 static void unregister_ftrace_profiler(void)
917 unregister_ftrace_function(&ftrace_profile_ops);
919 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
922 ftrace_profile_write(struct file *filp, const char __user *ubuf,
923 size_t cnt, loff_t *ppos)
928 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
934 mutex_lock(&ftrace_profile_lock);
935 if (ftrace_profile_enabled ^ val) {
937 ret = ftrace_profile_init();
943 ret = register_ftrace_profiler();
948 ftrace_profile_enabled = 1;
950 ftrace_profile_enabled = 0;
952 * unregister_ftrace_profiler calls stop_machine
953 * so this acts like an synchronize_sched.
955 unregister_ftrace_profiler();
959 mutex_unlock(&ftrace_profile_lock);
967 ftrace_profile_read(struct file *filp, char __user *ubuf,
968 size_t cnt, loff_t *ppos)
970 char buf[64]; /* big enough to hold a number */
973 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
974 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
977 static const struct file_operations ftrace_profile_fops = {
978 .open = tracing_open_generic,
979 .read = ftrace_profile_read,
980 .write = ftrace_profile_write,
981 .llseek = default_llseek,
984 /* used to initialize the real stat files */
985 static struct tracer_stat function_stats __initdata = {
987 .stat_start = function_stat_start,
988 .stat_next = function_stat_next,
989 .stat_cmp = function_stat_cmp,
990 .stat_headers = function_stat_headers,
991 .stat_show = function_stat_show
994 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
996 struct ftrace_profile_stat *stat;
997 struct dentry *entry;
1002 for_each_possible_cpu(cpu) {
1003 stat = &per_cpu(ftrace_profile_stats, cpu);
1005 /* allocate enough for function name + cpu number */
1006 name = kmalloc(32, GFP_KERNEL);
1009 * The files created are permanent, if something happens
1010 * we still do not free memory.
1013 "Could not allocate stat file for cpu %d\n",
1017 stat->stat = function_stats;
1018 snprintf(name, 32, "function%d", cpu);
1019 stat->stat.name = name;
1020 ret = register_stat_tracer(&stat->stat);
1023 "Could not register function stat for cpu %d\n",
1030 entry = debugfs_create_file("function_profile_enabled", 0644,
1031 d_tracer, NULL, &ftrace_profile_fops);
1033 pr_warning("Could not create debugfs "
1034 "'function_profile_enabled' entry\n");
1037 #else /* CONFIG_FUNCTION_PROFILER */
1038 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1041 #endif /* CONFIG_FUNCTION_PROFILER */
1043 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1045 #ifdef CONFIG_DYNAMIC_FTRACE
1047 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1048 # error Dynamic ftrace depends on MCOUNT_RECORD
1051 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1053 struct ftrace_func_probe {
1054 struct hlist_node node;
1055 struct ftrace_probe_ops *ops;
1056 unsigned long flags;
1059 struct rcu_head rcu;
1062 struct ftrace_func_entry {
1063 struct hlist_node hlist;
1067 struct ftrace_hash {
1068 unsigned long size_bits;
1069 struct hlist_head *buckets;
1070 unsigned long count;
1071 struct rcu_head rcu;
1075 * We make these constant because no one should touch them,
1076 * but they are used as the default "empty hash", to avoid allocating
1077 * it all the time. These are in a read only section such that if
1078 * anyone does try to modify it, it will cause an exception.
1080 static const struct hlist_head empty_buckets[1];
1081 static const struct ftrace_hash empty_hash = {
1082 .buckets = (struct hlist_head *)empty_buckets,
1084 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1086 static struct ftrace_ops global_ops = {
1087 .func = ftrace_stub,
1088 .notrace_hash = EMPTY_HASH,
1089 .filter_hash = EMPTY_HASH,
1090 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
1093 static DEFINE_MUTEX(ftrace_regex_lock);
1095 struct ftrace_page {
1096 struct ftrace_page *next;
1097 struct dyn_ftrace *records;
1102 static struct ftrace_page *ftrace_new_pgs;
1104 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1105 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1107 /* estimate from running different kernels */
1108 #define NR_TO_INIT 10000
1110 static struct ftrace_page *ftrace_pages_start;
1111 static struct ftrace_page *ftrace_pages;
1113 static bool ftrace_hash_empty(struct ftrace_hash *hash)
1115 return !hash || !hash->count;
1118 static struct ftrace_func_entry *
1119 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1122 struct ftrace_func_entry *entry;
1123 struct hlist_head *hhd;
1124 struct hlist_node *n;
1126 if (ftrace_hash_empty(hash))
1129 if (hash->size_bits > 0)
1130 key = hash_long(ip, hash->size_bits);
1134 hhd = &hash->buckets[key];
1136 hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1137 if (entry->ip == ip)
1143 static void __add_hash_entry(struct ftrace_hash *hash,
1144 struct ftrace_func_entry *entry)
1146 struct hlist_head *hhd;
1149 if (hash->size_bits)
1150 key = hash_long(entry->ip, hash->size_bits);
1154 hhd = &hash->buckets[key];
1155 hlist_add_head(&entry->hlist, hhd);
1159 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1161 struct ftrace_func_entry *entry;
1163 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1168 __add_hash_entry(hash, entry);
1174 free_hash_entry(struct ftrace_hash *hash,
1175 struct ftrace_func_entry *entry)
1177 hlist_del(&entry->hlist);
1183 remove_hash_entry(struct ftrace_hash *hash,
1184 struct ftrace_func_entry *entry)
1186 hlist_del(&entry->hlist);
1190 static void ftrace_hash_clear(struct ftrace_hash *hash)
1192 struct hlist_head *hhd;
1193 struct hlist_node *tp, *tn;
1194 struct ftrace_func_entry *entry;
1195 int size = 1 << hash->size_bits;
1201 for (i = 0; i < size; i++) {
1202 hhd = &hash->buckets[i];
1203 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
1204 free_hash_entry(hash, entry);
1206 FTRACE_WARN_ON(hash->count);
1209 static void free_ftrace_hash(struct ftrace_hash *hash)
1211 if (!hash || hash == EMPTY_HASH)
1213 ftrace_hash_clear(hash);
1214 kfree(hash->buckets);
1218 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1220 struct ftrace_hash *hash;
1222 hash = container_of(rcu, struct ftrace_hash, rcu);
1223 free_ftrace_hash(hash);
1226 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1228 if (!hash || hash == EMPTY_HASH)
1230 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1233 void ftrace_free_filter(struct ftrace_ops *ops)
1235 free_ftrace_hash(ops->filter_hash);
1236 free_ftrace_hash(ops->notrace_hash);
1239 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1241 struct ftrace_hash *hash;
1244 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1248 size = 1 << size_bits;
1249 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1251 if (!hash->buckets) {
1256 hash->size_bits = size_bits;
1261 static struct ftrace_hash *
1262 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1264 struct ftrace_func_entry *entry;
1265 struct ftrace_hash *new_hash;
1266 struct hlist_node *tp;
1271 new_hash = alloc_ftrace_hash(size_bits);
1276 if (ftrace_hash_empty(hash))
1279 size = 1 << hash->size_bits;
1280 for (i = 0; i < size; i++) {
1281 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1282 ret = add_hash_entry(new_hash, entry->ip);
1288 FTRACE_WARN_ON(new_hash->count != hash->count);
1293 free_ftrace_hash(new_hash);
1298 ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1300 ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1303 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1304 struct ftrace_hash **dst, struct ftrace_hash *src)
1306 struct ftrace_func_entry *entry;
1307 struct hlist_node *tp, *tn;
1308 struct hlist_head *hhd;
1309 struct ftrace_hash *old_hash;
1310 struct ftrace_hash *new_hash;
1312 int size = src->count;
1318 * Remove the current set, update the hash and add
1321 ftrace_hash_rec_disable(ops, enable);
1324 * If the new source is empty, just free dst and assign it
1328 free_ftrace_hash_rcu(*dst);
1329 rcu_assign_pointer(*dst, EMPTY_HASH);
1330 /* still need to update the function records */
1336 * Make the hash size about 1/2 the # found
1338 for (size /= 2; size; size >>= 1)
1341 /* Don't allocate too much */
1342 if (bits > FTRACE_HASH_MAX_BITS)
1343 bits = FTRACE_HASH_MAX_BITS;
1346 new_hash = alloc_ftrace_hash(bits);
1350 size = 1 << src->size_bits;
1351 for (i = 0; i < size; i++) {
1352 hhd = &src->buckets[i];
1353 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1355 key = hash_long(entry->ip, bits);
1358 remove_hash_entry(src, entry);
1359 __add_hash_entry(new_hash, entry);
1364 rcu_assign_pointer(*dst, new_hash);
1365 free_ftrace_hash_rcu(old_hash);
1370 * Enable regardless of ret:
1371 * On success, we enable the new hash.
1372 * On failure, we re-enable the original hash.
1374 ftrace_hash_rec_enable(ops, enable);
1380 * Test the hashes for this ops to see if we want to call
1381 * the ops->func or not.
1383 * It's a match if the ip is in the ops->filter_hash or
1384 * the filter_hash does not exist or is empty,
1386 * the ip is not in the ops->notrace_hash.
1388 * This needs to be called with preemption disabled as
1389 * the hashes are freed with call_rcu_sched().
1392 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1394 struct ftrace_hash *filter_hash;
1395 struct ftrace_hash *notrace_hash;
1398 filter_hash = rcu_dereference_raw(ops->filter_hash);
1399 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1401 if ((ftrace_hash_empty(filter_hash) ||
1402 ftrace_lookup_ip(filter_hash, ip)) &&
1403 (ftrace_hash_empty(notrace_hash) ||
1404 !ftrace_lookup_ip(notrace_hash, ip)))
1413 * This is a double for. Do not use 'break' to break out of the loop,
1414 * you must use a goto.
1416 #define do_for_each_ftrace_rec(pg, rec) \
1417 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1419 for (_____i = 0; _____i < pg->index; _____i++) { \
1420 rec = &pg->records[_____i];
1422 #define while_for_each_ftrace_rec() \
1427 static int ftrace_cmp_recs(const void *a, const void *b)
1429 const struct dyn_ftrace *key = a;
1430 const struct dyn_ftrace *rec = b;
1432 if (key->flags < rec->ip)
1434 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1439 static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1441 struct ftrace_page *pg;
1442 struct dyn_ftrace *rec;
1443 struct dyn_ftrace key;
1446 key.flags = end; /* overload flags, as it is unsigned long */
1448 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1449 if (end < pg->records[0].ip ||
1450 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1452 rec = bsearch(&key, pg->records, pg->index,
1453 sizeof(struct dyn_ftrace),
1463 * ftrace_location - return true if the ip giving is a traced location
1464 * @ip: the instruction pointer to check
1466 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1467 * That is, the instruction that is either a NOP or call to
1468 * the function tracer. It checks the ftrace internal tables to
1469 * determine if the address belongs or not.
1471 unsigned long ftrace_location(unsigned long ip)
1473 return ftrace_location_range(ip, ip);
1477 * ftrace_text_reserved - return true if range contains an ftrace location
1478 * @start: start of range to search
1479 * @end: end of range to search (inclusive). @end points to the last byte to check.
1481 * Returns 1 if @start and @end contains a ftrace location.
1482 * That is, the instruction that is either a NOP or call to
1483 * the function tracer. It checks the ftrace internal tables to
1484 * determine if the address belongs or not.
1486 int ftrace_text_reserved(void *start, void *end)
1490 ret = ftrace_location_range((unsigned long)start,
1491 (unsigned long)end);
1496 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1500 struct ftrace_hash *hash;
1501 struct ftrace_hash *other_hash;
1502 struct ftrace_page *pg;
1503 struct dyn_ftrace *rec;
1507 /* Only update if the ops has been registered */
1508 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1512 * In the filter_hash case:
1513 * If the count is zero, we update all records.
1514 * Otherwise we just update the items in the hash.
1516 * In the notrace_hash case:
1517 * We enable the update in the hash.
1518 * As disabling notrace means enabling the tracing,
1519 * and enabling notrace means disabling, the inc variable
1523 hash = ops->filter_hash;
1524 other_hash = ops->notrace_hash;
1525 if (ftrace_hash_empty(hash))
1529 hash = ops->notrace_hash;
1530 other_hash = ops->filter_hash;
1532 * If the notrace hash has no items,
1533 * then there's nothing to do.
1535 if (ftrace_hash_empty(hash))
1539 do_for_each_ftrace_rec(pg, rec) {
1540 int in_other_hash = 0;
1546 * Only the filter_hash affects all records.
1547 * Update if the record is not in the notrace hash.
1549 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1552 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1553 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1558 if (filter_hash && in_hash && !in_other_hash)
1560 else if (!filter_hash && in_hash &&
1561 (in_other_hash || ftrace_hash_empty(other_hash)))
1569 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1572 * If any ops wants regs saved for this function
1573 * then all ops will get saved regs.
1575 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1576 rec->flags |= FTRACE_FL_REGS;
1578 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1583 /* Shortcut, if we handled all records, we are done. */
1584 if (!all && count == hash->count)
1586 } while_for_each_ftrace_rec();
1589 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1592 __ftrace_hash_rec_update(ops, filter_hash, 0);
1595 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1598 __ftrace_hash_rec_update(ops, filter_hash, 1);
1601 static void print_ip_ins(const char *fmt, unsigned char *p)
1605 printk(KERN_CONT "%s", fmt);
1607 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1608 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1612 * ftrace_bug - report and shutdown function tracer
1613 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1614 * @ip: The address that failed
1616 * The arch code that enables or disables the function tracing
1617 * can call ftrace_bug() when it has detected a problem in
1618 * modifying the code. @failed should be one of either:
1619 * EFAULT - if the problem happens on reading the @ip address
1620 * EINVAL - if what is read at @ip is not what was expected
1621 * EPERM - if the problem happens on writting to the @ip address
1623 void ftrace_bug(int failed, unsigned long ip)
1627 FTRACE_WARN_ON_ONCE(1);
1628 pr_info("ftrace faulted on modifying ");
1632 FTRACE_WARN_ON_ONCE(1);
1633 pr_info("ftrace failed to modify ");
1635 print_ip_ins(" actual: ", (unsigned char *)ip);
1636 printk(KERN_CONT "\n");
1639 FTRACE_WARN_ON_ONCE(1);
1640 pr_info("ftrace faulted on writing ");
1644 FTRACE_WARN_ON_ONCE(1);
1645 pr_info("ftrace faulted on unknown error ");
1650 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
1652 unsigned long flag = 0UL;
1655 * If we are updating calls:
1657 * If the record has a ref count, then we need to enable it
1658 * because someone is using it.
1660 * Otherwise we make sure its disabled.
1662 * If we are disabling calls, then disable all records that
1665 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1666 flag = FTRACE_FL_ENABLED;
1669 * If enabling and the REGS flag does not match the REGS_EN, then
1670 * do not ignore this record. Set flags to fail the compare against
1674 (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
1675 flag |= FTRACE_FL_REGS;
1677 /* If the state of this record hasn't changed, then do nothing */
1678 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1679 return FTRACE_UPDATE_IGNORE;
1682 /* Save off if rec is being enabled (for return value) */
1683 flag ^= rec->flags & FTRACE_FL_ENABLED;
1686 rec->flags |= FTRACE_FL_ENABLED;
1687 if (flag & FTRACE_FL_REGS) {
1688 if (rec->flags & FTRACE_FL_REGS)
1689 rec->flags |= FTRACE_FL_REGS_EN;
1691 rec->flags &= ~FTRACE_FL_REGS_EN;
1696 * If this record is being updated from a nop, then
1697 * return UPDATE_MAKE_CALL.
1698 * Otherwise, if the EN flag is set, then return
1699 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1700 * from the non-save regs, to a save regs function.
1702 * return UPDATE_MODIFY_CALL to tell the caller to convert
1703 * from the save regs, to a non-save regs function.
1705 if (flag & FTRACE_FL_ENABLED)
1706 return FTRACE_UPDATE_MAKE_CALL;
1707 else if (rec->flags & FTRACE_FL_REGS_EN)
1708 return FTRACE_UPDATE_MODIFY_CALL_REGS;
1710 return FTRACE_UPDATE_MODIFY_CALL;
1714 /* If there's no more users, clear all flags */
1715 if (!(rec->flags & ~FTRACE_FL_MASK))
1718 /* Just disable the record (keep REGS state) */
1719 rec->flags &= ~FTRACE_FL_ENABLED;
1722 return FTRACE_UPDATE_MAKE_NOP;
1726 * ftrace_update_record, set a record that now is tracing or not
1727 * @rec: the record to update
1728 * @enable: set to 1 if the record is tracing, zero to force disable
1730 * The records that represent all functions that can be traced need
1731 * to be updated when tracing has been enabled.
1733 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1735 return ftrace_check_record(rec, enable, 1);
1739 * ftrace_test_record, check if the record has been enabled or not
1740 * @rec: the record to test
1741 * @enable: set to 1 to check if enabled, 0 if it is disabled
1743 * The arch code may need to test if a record is already set to
1744 * tracing to determine how to modify the function code that it
1747 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1749 return ftrace_check_record(rec, enable, 0);
1753 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1755 unsigned long ftrace_old_addr;
1756 unsigned long ftrace_addr;
1759 ret = ftrace_update_record(rec, enable);
1761 if (rec->flags & FTRACE_FL_REGS)
1762 ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
1764 ftrace_addr = (unsigned long)FTRACE_ADDR;
1767 case FTRACE_UPDATE_IGNORE:
1770 case FTRACE_UPDATE_MAKE_CALL:
1771 return ftrace_make_call(rec, ftrace_addr);
1773 case FTRACE_UPDATE_MAKE_NOP:
1774 return ftrace_make_nop(NULL, rec, ftrace_addr);
1776 case FTRACE_UPDATE_MODIFY_CALL_REGS:
1777 case FTRACE_UPDATE_MODIFY_CALL:
1778 if (rec->flags & FTRACE_FL_REGS)
1779 ftrace_old_addr = (unsigned long)FTRACE_ADDR;
1781 ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
1783 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
1786 return -1; /* unknow ftrace bug */
1789 void __weak ftrace_replace_code(int enable)
1791 struct dyn_ftrace *rec;
1792 struct ftrace_page *pg;
1795 if (unlikely(ftrace_disabled))
1798 do_for_each_ftrace_rec(pg, rec) {
1799 failed = __ftrace_replace_code(rec, enable);
1801 ftrace_bug(failed, rec->ip);
1802 /* Stop processing */
1805 } while_for_each_ftrace_rec();
1808 struct ftrace_rec_iter {
1809 struct ftrace_page *pg;
1814 * ftrace_rec_iter_start, start up iterating over traced functions
1816 * Returns an iterator handle that is used to iterate over all
1817 * the records that represent address locations where functions
1820 * May return NULL if no records are available.
1822 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
1825 * We only use a single iterator.
1826 * Protected by the ftrace_lock mutex.
1828 static struct ftrace_rec_iter ftrace_rec_iter;
1829 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
1831 iter->pg = ftrace_pages_start;
1834 /* Could have empty pages */
1835 while (iter->pg && !iter->pg->index)
1836 iter->pg = iter->pg->next;
1845 * ftrace_rec_iter_next, get the next record to process.
1846 * @iter: The handle to the iterator.
1848 * Returns the next iterator after the given iterator @iter.
1850 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
1854 if (iter->index >= iter->pg->index) {
1855 iter->pg = iter->pg->next;
1858 /* Could have empty pages */
1859 while (iter->pg && !iter->pg->index)
1860 iter->pg = iter->pg->next;
1870 * ftrace_rec_iter_record, get the record at the iterator location
1871 * @iter: The current iterator location
1873 * Returns the record that the current @iter is at.
1875 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
1877 return &iter->pg->records[iter->index];
1881 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1888 if (unlikely(ftrace_disabled))
1891 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1893 ftrace_bug(ret, ip);
1900 * archs can override this function if they must do something
1901 * before the modifying code is performed.
1903 int __weak ftrace_arch_code_modify_prepare(void)
1909 * archs can override this function if they must do something
1910 * after the modifying code is performed.
1912 int __weak ftrace_arch_code_modify_post_process(void)
1917 void ftrace_modify_all_code(int command)
1919 if (command & FTRACE_UPDATE_CALLS)
1920 ftrace_replace_code(1);
1921 else if (command & FTRACE_DISABLE_CALLS)
1922 ftrace_replace_code(0);
1924 if (command & FTRACE_UPDATE_TRACE_FUNC)
1925 ftrace_update_ftrace_func(ftrace_trace_function);
1927 if (command & FTRACE_START_FUNC_RET)
1928 ftrace_enable_ftrace_graph_caller();
1929 else if (command & FTRACE_STOP_FUNC_RET)
1930 ftrace_disable_ftrace_graph_caller();
1933 static int __ftrace_modify_code(void *data)
1935 int *command = data;
1937 ftrace_modify_all_code(*command);
1943 * ftrace_run_stop_machine, go back to the stop machine method
1944 * @command: The command to tell ftrace what to do
1946 * If an arch needs to fall back to the stop machine method, the
1947 * it can call this function.
1949 void ftrace_run_stop_machine(int command)
1951 stop_machine(__ftrace_modify_code, &command, NULL);
1955 * arch_ftrace_update_code, modify the code to trace or not trace
1956 * @command: The command that needs to be done
1958 * Archs can override this function if it does not need to
1959 * run stop_machine() to modify code.
1961 void __weak arch_ftrace_update_code(int command)
1963 ftrace_run_stop_machine(command);
1966 static void ftrace_run_update_code(int command)
1970 ret = ftrace_arch_code_modify_prepare();
1971 FTRACE_WARN_ON(ret);
1975 * Do not call function tracer while we update the code.
1976 * We are in stop machine.
1978 function_trace_stop++;
1981 * By default we use stop_machine() to modify the code.
1982 * But archs can do what ever they want as long as it
1983 * is safe. The stop_machine() is the safest, but also
1984 * produces the most overhead.
1986 arch_ftrace_update_code(command);
1988 function_trace_stop--;
1990 ret = ftrace_arch_code_modify_post_process();
1991 FTRACE_WARN_ON(ret);
1994 static ftrace_func_t saved_ftrace_func;
1995 static int ftrace_start_up;
1996 static int global_start_up;
1998 static void ftrace_startup_enable(int command)
2000 if (saved_ftrace_func != ftrace_trace_function) {
2001 saved_ftrace_func = ftrace_trace_function;
2002 command |= FTRACE_UPDATE_TRACE_FUNC;
2005 if (!command || !ftrace_enabled)
2008 ftrace_run_update_code(command);
2011 static int ftrace_startup(struct ftrace_ops *ops, int command)
2013 bool hash_enable = true;
2015 if (unlikely(ftrace_disabled))
2019 command |= FTRACE_UPDATE_CALLS;
2021 /* ops marked global share the filter hashes */
2022 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2024 /* Don't update hash if global is already set */
2025 if (global_start_up)
2026 hash_enable = false;
2030 ops->flags |= FTRACE_OPS_FL_ENABLED;
2032 ftrace_hash_rec_enable(ops, 1);
2034 ftrace_startup_enable(command);
2039 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
2041 bool hash_disable = true;
2043 if (unlikely(ftrace_disabled))
2048 * Just warn in case of unbalance, no need to kill ftrace, it's not
2049 * critical but the ftrace_call callers may be never nopped again after
2050 * further ftrace uses.
2052 WARN_ON_ONCE(ftrace_start_up < 0);
2054 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2057 WARN_ON_ONCE(global_start_up < 0);
2058 /* Don't update hash if global still has users */
2059 if (global_start_up) {
2060 WARN_ON_ONCE(!ftrace_start_up);
2061 hash_disable = false;
2066 ftrace_hash_rec_disable(ops, 1);
2068 if (ops != &global_ops || !global_start_up)
2069 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2071 command |= FTRACE_UPDATE_CALLS;
2073 if (saved_ftrace_func != ftrace_trace_function) {
2074 saved_ftrace_func = ftrace_trace_function;
2075 command |= FTRACE_UPDATE_TRACE_FUNC;
2078 if (!command || !ftrace_enabled)
2081 ftrace_run_update_code(command);
2084 static void ftrace_startup_sysctl(void)
2086 if (unlikely(ftrace_disabled))
2089 /* Force update next time */
2090 saved_ftrace_func = NULL;
2091 /* ftrace_start_up is true if we want ftrace running */
2092 if (ftrace_start_up)
2093 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
2096 static void ftrace_shutdown_sysctl(void)
2098 if (unlikely(ftrace_disabled))
2101 /* ftrace_start_up is true if ftrace is running */
2102 if (ftrace_start_up)
2103 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
2106 static cycle_t ftrace_update_time;
2107 static unsigned long ftrace_update_cnt;
2108 unsigned long ftrace_update_tot_cnt;
2110 static int ops_traces_mod(struct ftrace_ops *ops)
2112 struct ftrace_hash *hash;
2114 hash = ops->filter_hash;
2115 return ftrace_hash_empty(hash);
2118 static int ftrace_update_code(struct module *mod)
2120 struct ftrace_page *pg;
2121 struct dyn_ftrace *p;
2122 cycle_t start, stop;
2123 unsigned long ref = 0;
2127 * When adding a module, we need to check if tracers are
2128 * currently enabled and if they are set to trace all functions.
2129 * If they are, we need to enable the module functions as well
2130 * as update the reference counts for those function records.
2133 struct ftrace_ops *ops;
2135 for (ops = ftrace_ops_list;
2136 ops != &ftrace_list_end; ops = ops->next) {
2137 if (ops->flags & FTRACE_OPS_FL_ENABLED &&
2138 ops_traces_mod(ops))
2143 start = ftrace_now(raw_smp_processor_id());
2144 ftrace_update_cnt = 0;
2146 for (pg = ftrace_new_pgs; pg; pg = pg->next) {
2148 for (i = 0; i < pg->index; i++) {
2149 /* If something went wrong, bail without enabling anything */
2150 if (unlikely(ftrace_disabled))
2153 p = &pg->records[i];
2157 * Do the initial record conversion from mcount jump
2158 * to the NOP instructions.
2160 if (!ftrace_code_disable(mod, p))
2163 ftrace_update_cnt++;
2166 * If the tracing is enabled, go ahead and enable the record.
2168 * The reason not to enable the record immediatelly is the
2169 * inherent check of ftrace_make_nop/ftrace_make_call for
2170 * correct previous instructions. Making first the NOP
2171 * conversion puts the module to the correct state, thus
2172 * passing the ftrace_make_call check.
2174 if (ftrace_start_up && ref) {
2175 int failed = __ftrace_replace_code(p, 1);
2177 ftrace_bug(failed, p->ip);
2182 ftrace_new_pgs = NULL;
2184 stop = ftrace_now(raw_smp_processor_id());
2185 ftrace_update_time = stop - start;
2186 ftrace_update_tot_cnt += ftrace_update_cnt;
2191 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2196 if (WARN_ON(!count))
2199 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2202 * We want to fill as much as possible. No more than a page
2205 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2209 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2212 /* if we can't allocate this size, try something smaller */
2219 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2228 static struct ftrace_page *
2229 ftrace_allocate_pages(unsigned long num_to_init)
2231 struct ftrace_page *start_pg;
2232 struct ftrace_page *pg;
2239 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2244 * Try to allocate as much as possible in one continues
2245 * location that fills in all of the space. We want to
2246 * waste as little space as possible.
2249 cnt = ftrace_allocate_records(pg, num_to_init);
2257 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2268 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2269 free_pages((unsigned long)pg->records, order);
2270 start_pg = pg->next;
2274 pr_info("ftrace: FAILED to allocate memory for functions\n");
2278 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
2283 pr_info("ftrace: No functions to be traced?\n");
2287 cnt = num_to_init / ENTRIES_PER_PAGE;
2288 pr_info("ftrace: allocating %ld entries in %d pages\n",
2289 num_to_init, cnt + 1);
2294 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2296 struct ftrace_iterator {
2299 struct ftrace_page *pg;
2300 struct dyn_ftrace *func;
2301 struct ftrace_func_probe *probe;
2302 struct trace_parser parser;
2303 struct ftrace_hash *hash;
2304 struct ftrace_ops *ops;
2311 t_hash_next(struct seq_file *m, loff_t *pos)
2313 struct ftrace_iterator *iter = m->private;
2314 struct hlist_node *hnd = NULL;
2315 struct hlist_head *hhd;
2321 hnd = &iter->probe->node;
2323 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2326 hhd = &ftrace_func_hash[iter->hidx];
2328 if (hlist_empty(hhd)) {
2344 if (WARN_ON_ONCE(!hnd))
2347 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2352 static void *t_hash_start(struct seq_file *m, loff_t *pos)
2354 struct ftrace_iterator *iter = m->private;
2358 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2361 if (iter->func_pos > *pos)
2365 for (l = 0; l <= (*pos - iter->func_pos); ) {
2366 p = t_hash_next(m, &l);
2373 /* Only set this if we have an item */
2374 iter->flags |= FTRACE_ITER_HASH;
2380 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2382 struct ftrace_func_probe *rec;
2385 if (WARN_ON_ONCE(!rec))
2388 if (rec->ops->print)
2389 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2391 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2394 seq_printf(m, ":%p", rec->data);
2401 t_next(struct seq_file *m, void *v, loff_t *pos)
2403 struct ftrace_iterator *iter = m->private;
2404 struct ftrace_ops *ops = iter->ops;
2405 struct dyn_ftrace *rec = NULL;
2407 if (unlikely(ftrace_disabled))
2410 if (iter->flags & FTRACE_ITER_HASH)
2411 return t_hash_next(m, pos);
2414 iter->pos = iter->func_pos = *pos;
2416 if (iter->flags & FTRACE_ITER_PRINTALL)
2417 return t_hash_start(m, pos);
2420 if (iter->idx >= iter->pg->index) {
2421 if (iter->pg->next) {
2422 iter->pg = iter->pg->next;
2427 rec = &iter->pg->records[iter->idx++];
2428 if (((iter->flags & FTRACE_ITER_FILTER) &&
2429 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
2431 ((iter->flags & FTRACE_ITER_NOTRACE) &&
2432 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2434 ((iter->flags & FTRACE_ITER_ENABLED) &&
2435 !(rec->flags & ~FTRACE_FL_MASK))) {
2443 return t_hash_start(m, pos);
2450 static void reset_iter_read(struct ftrace_iterator *iter)
2454 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
2457 static void *t_start(struct seq_file *m, loff_t *pos)
2459 struct ftrace_iterator *iter = m->private;
2460 struct ftrace_ops *ops = iter->ops;
2464 mutex_lock(&ftrace_lock);
2466 if (unlikely(ftrace_disabled))
2470 * If an lseek was done, then reset and start from beginning.
2472 if (*pos < iter->pos)
2473 reset_iter_read(iter);
2476 * For set_ftrace_filter reading, if we have the filter
2477 * off, we can short cut and just print out that all
2478 * functions are enabled.
2480 if (iter->flags & FTRACE_ITER_FILTER &&
2481 ftrace_hash_empty(ops->filter_hash)) {
2483 return t_hash_start(m, pos);
2484 iter->flags |= FTRACE_ITER_PRINTALL;
2485 /* reset in case of seek/pread */
2486 iter->flags &= ~FTRACE_ITER_HASH;
2490 if (iter->flags & FTRACE_ITER_HASH)
2491 return t_hash_start(m, pos);
2494 * Unfortunately, we need to restart at ftrace_pages_start
2495 * every time we let go of the ftrace_mutex. This is because
2496 * those pointers can change without the lock.
2498 iter->pg = ftrace_pages_start;
2500 for (l = 0; l <= *pos; ) {
2501 p = t_next(m, p, &l);
2507 return t_hash_start(m, pos);
2512 static void t_stop(struct seq_file *m, void *p)
2514 mutex_unlock(&ftrace_lock);
2517 static int t_show(struct seq_file *m, void *v)
2519 struct ftrace_iterator *iter = m->private;
2520 struct dyn_ftrace *rec;
2522 if (iter->flags & FTRACE_ITER_HASH)
2523 return t_hash_show(m, iter);
2525 if (iter->flags & FTRACE_ITER_PRINTALL) {
2526 seq_printf(m, "#### all functions enabled ####\n");
2535 seq_printf(m, "%ps", (void *)rec->ip);
2536 if (iter->flags & FTRACE_ITER_ENABLED)
2537 seq_printf(m, " (%ld)%s",
2538 rec->flags & ~FTRACE_FL_MASK,
2539 rec->flags & FTRACE_FL_REGS ? " R" : "");
2540 seq_printf(m, "\n");
2545 static const struct seq_operations show_ftrace_seq_ops = {
2553 ftrace_avail_open(struct inode *inode, struct file *file)
2555 struct ftrace_iterator *iter;
2557 if (unlikely(ftrace_disabled))
2560 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2562 iter->pg = ftrace_pages_start;
2563 iter->ops = &global_ops;
2566 return iter ? 0 : -ENOMEM;
2570 ftrace_enabled_open(struct inode *inode, struct file *file)
2572 struct ftrace_iterator *iter;
2574 if (unlikely(ftrace_disabled))
2577 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2579 iter->pg = ftrace_pages_start;
2580 iter->flags = FTRACE_ITER_ENABLED;
2581 iter->ops = &global_ops;
2584 return iter ? 0 : -ENOMEM;
2587 static void ftrace_filter_reset(struct ftrace_hash *hash)
2589 mutex_lock(&ftrace_lock);
2590 ftrace_hash_clear(hash);
2591 mutex_unlock(&ftrace_lock);
2595 * ftrace_regex_open - initialize function tracer filter files
2596 * @ops: The ftrace_ops that hold the hash filters
2597 * @flag: The type of filter to process
2598 * @inode: The inode, usually passed in to your open routine
2599 * @file: The file, usually passed in to your open routine
2601 * ftrace_regex_open() initializes the filter files for the
2602 * @ops. Depending on @flag it may process the filter hash or
2603 * the notrace hash of @ops. With this called from the open
2604 * routine, you can use ftrace_filter_write() for the write
2605 * routine if @flag has FTRACE_ITER_FILTER set, or
2606 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2607 * ftrace_regex_lseek() should be used as the lseek routine, and
2608 * release must call ftrace_regex_release().
2611 ftrace_regex_open(struct ftrace_ops *ops, int flag,
2612 struct inode *inode, struct file *file)
2614 struct ftrace_iterator *iter;
2615 struct ftrace_hash *hash;
2618 if (unlikely(ftrace_disabled))
2621 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2625 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2630 if (flag & FTRACE_ITER_NOTRACE)
2631 hash = ops->notrace_hash;
2633 hash = ops->filter_hash;
2638 if (file->f_mode & FMODE_WRITE) {
2639 mutex_lock(&ftrace_lock);
2640 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2641 mutex_unlock(&ftrace_lock);
2644 trace_parser_put(&iter->parser);
2650 mutex_lock(&ftrace_regex_lock);
2652 if ((file->f_mode & FMODE_WRITE) &&
2653 (file->f_flags & O_TRUNC))
2654 ftrace_filter_reset(iter->hash);
2656 if (file->f_mode & FMODE_READ) {
2657 iter->pg = ftrace_pages_start;
2659 ret = seq_open(file, &show_ftrace_seq_ops);
2661 struct seq_file *m = file->private_data;
2665 free_ftrace_hash(iter->hash);
2666 trace_parser_put(&iter->parser);
2670 file->private_data = iter;
2671 mutex_unlock(&ftrace_regex_lock);
2677 ftrace_filter_open(struct inode *inode, struct file *file)
2679 return ftrace_regex_open(&global_ops,
2680 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
2685 ftrace_notrace_open(struct inode *inode, struct file *file)
2687 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2692 ftrace_regex_lseek(struct file *file, loff_t offset, int whence)
2696 if (file->f_mode & FMODE_READ)
2697 ret = seq_lseek(file, offset, whence);
2699 file->f_pos = ret = 1;
2704 static int ftrace_match(char *str, char *regex, int len, int type)
2711 if (strcmp(str, regex) == 0)
2714 case MATCH_FRONT_ONLY:
2715 if (strncmp(str, regex, len) == 0)
2718 case MATCH_MIDDLE_ONLY:
2719 if (strstr(str, regex))
2722 case MATCH_END_ONLY:
2724 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2733 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2735 struct ftrace_func_entry *entry;
2738 entry = ftrace_lookup_ip(hash, rec->ip);
2740 /* Do nothing if it doesn't exist */
2744 free_hash_entry(hash, entry);
2746 /* Do nothing if it exists */
2750 ret = add_hash_entry(hash, rec->ip);
2756 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2757 char *regex, int len, int type)
2759 char str[KSYM_SYMBOL_LEN];
2762 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2765 /* module lookup requires matching the module */
2766 if (!modname || strcmp(modname, mod))
2769 /* blank search means to match all funcs in the mod */
2774 return ftrace_match(str, regex, len, type);
2778 match_records(struct ftrace_hash *hash, char *buff,
2779 int len, char *mod, int not)
2781 unsigned search_len = 0;
2782 struct ftrace_page *pg;
2783 struct dyn_ftrace *rec;
2784 int type = MATCH_FULL;
2785 char *search = buff;
2790 type = filter_parse_regex(buff, len, &search, ¬);
2791 search_len = strlen(search);
2794 mutex_lock(&ftrace_lock);
2796 if (unlikely(ftrace_disabled))
2799 do_for_each_ftrace_rec(pg, rec) {
2800 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2801 ret = enter_record(hash, rec, not);
2808 } while_for_each_ftrace_rec();
2810 mutex_unlock(&ftrace_lock);
2816 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2818 return match_records(hash, buff, len, NULL, 0);
2822 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2826 /* blank or '*' mean the same */
2827 if (strcmp(buff, "*") == 0)
2830 /* handle the case of 'dont filter this module' */
2831 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2836 return match_records(hash, buff, strlen(buff), mod, not);
2840 * We register the module command as a template to show others how
2841 * to register the a command as well.
2845 ftrace_mod_callback(struct ftrace_hash *hash,
2846 char *func, char *cmd, char *param, int enable)
2852 * cmd == 'mod' because we only registered this func
2853 * for the 'mod' ftrace_func_command.
2854 * But if you register one func with multiple commands,
2855 * you can tell which command was used by the cmd
2859 /* we must have a module name */
2863 mod = strsep(¶m, ":");
2867 ret = ftrace_match_module_records(hash, func, mod);
2876 static struct ftrace_func_command ftrace_mod_cmd = {
2878 .func = ftrace_mod_callback,
2881 static int __init ftrace_mod_cmd_init(void)
2883 return register_ftrace_command(&ftrace_mod_cmd);
2885 core_initcall(ftrace_mod_cmd_init);
2887 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
2888 struct ftrace_ops *op, struct pt_regs *pt_regs)
2890 struct ftrace_func_probe *entry;
2891 struct hlist_head *hhd;
2892 struct hlist_node *n;
2895 key = hash_long(ip, FTRACE_HASH_BITS);
2897 hhd = &ftrace_func_hash[key];
2899 if (hlist_empty(hhd))
2903 * Disable preemption for these calls to prevent a RCU grace
2904 * period. This syncs the hash iteration and freeing of items
2905 * on the hash. rcu_read_lock is too dangerous here.
2907 preempt_disable_notrace();
2908 hlist_for_each_entry_rcu(entry, n, hhd, node) {
2909 if (entry->ip == ip)
2910 entry->ops->func(ip, parent_ip, &entry->data);
2912 preempt_enable_notrace();
2915 static struct ftrace_ops trace_probe_ops __read_mostly =
2917 .func = function_trace_probe_call,
2920 static int ftrace_probe_registered;
2922 static void __enable_ftrace_function_probe(void)
2927 if (ftrace_probe_registered)
2930 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2931 struct hlist_head *hhd = &ftrace_func_hash[i];
2935 /* Nothing registered? */
2936 if (i == FTRACE_FUNC_HASHSIZE)
2939 ret = __register_ftrace_function(&trace_probe_ops);
2941 ret = ftrace_startup(&trace_probe_ops, 0);
2943 ftrace_probe_registered = 1;
2946 static void __disable_ftrace_function_probe(void)
2951 if (!ftrace_probe_registered)
2954 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2955 struct hlist_head *hhd = &ftrace_func_hash[i];
2960 /* no more funcs left */
2961 ret = __unregister_ftrace_function(&trace_probe_ops);
2963 ftrace_shutdown(&trace_probe_ops, 0);
2965 ftrace_probe_registered = 0;
2969 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2971 struct ftrace_func_probe *entry =
2972 container_of(rhp, struct ftrace_func_probe, rcu);
2974 if (entry->ops->free)
2975 entry->ops->free(&entry->data);
2981 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2984 struct ftrace_func_probe *entry;
2985 struct ftrace_page *pg;
2986 struct dyn_ftrace *rec;
2992 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2993 len = strlen(search);
2995 /* we do not support '!' for function probes */
2999 mutex_lock(&ftrace_lock);
3001 if (unlikely(ftrace_disabled))
3004 do_for_each_ftrace_rec(pg, rec) {
3006 if (!ftrace_match_record(rec, NULL, search, len, type))
3009 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3011 /* If we did not process any, then return error */
3022 * The caller might want to do something special
3023 * for each function we find. We call the callback
3024 * to give the caller an opportunity to do so.
3026 if (ops->callback) {
3027 if (ops->callback(rec->ip, &entry->data) < 0) {
3028 /* caller does not like this func */
3035 entry->ip = rec->ip;
3037 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3038 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3040 } while_for_each_ftrace_rec();
3041 __enable_ftrace_function_probe();
3044 mutex_unlock(&ftrace_lock);
3050 PROBE_TEST_FUNC = 1,
3055 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3056 void *data, int flags)
3058 struct ftrace_func_probe *entry;
3059 struct hlist_node *n, *tmp;
3060 char str[KSYM_SYMBOL_LEN];
3061 int type = MATCH_FULL;
3065 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
3070 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3071 len = strlen(search);
3073 /* we do not support '!' for function probes */
3078 mutex_lock(&ftrace_lock);
3079 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3080 struct hlist_head *hhd = &ftrace_func_hash[i];
3082 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
3084 /* break up if statements for readability */
3085 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
3088 if ((flags & PROBE_TEST_DATA) && entry->data != data)
3091 /* do this last, since it is the most expensive */
3093 kallsyms_lookup(entry->ip, NULL, NULL,
3095 if (!ftrace_match(str, glob, len, type))
3099 hlist_del(&entry->node);
3100 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
3103 __disable_ftrace_function_probe();
3104 mutex_unlock(&ftrace_lock);
3108 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3111 __unregister_ftrace_function_probe(glob, ops, data,
3112 PROBE_TEST_FUNC | PROBE_TEST_DATA);
3116 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
3118 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
3121 void unregister_ftrace_function_probe_all(char *glob)
3123 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
3126 static LIST_HEAD(ftrace_commands);
3127 static DEFINE_MUTEX(ftrace_cmd_mutex);
3129 int register_ftrace_command(struct ftrace_func_command *cmd)
3131 struct ftrace_func_command *p;
3134 mutex_lock(&ftrace_cmd_mutex);
3135 list_for_each_entry(p, &ftrace_commands, list) {
3136 if (strcmp(cmd->name, p->name) == 0) {
3141 list_add(&cmd->list, &ftrace_commands);
3143 mutex_unlock(&ftrace_cmd_mutex);
3148 int unregister_ftrace_command(struct ftrace_func_command *cmd)
3150 struct ftrace_func_command *p, *n;
3153 mutex_lock(&ftrace_cmd_mutex);
3154 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3155 if (strcmp(cmd->name, p->name) == 0) {
3157 list_del_init(&p->list);
3162 mutex_unlock(&ftrace_cmd_mutex);
3167 static int ftrace_process_regex(struct ftrace_hash *hash,
3168 char *buff, int len, int enable)
3170 char *func, *command, *next = buff;
3171 struct ftrace_func_command *p;
3174 func = strsep(&next, ":");
3177 ret = ftrace_match_records(hash, func, len);
3187 command = strsep(&next, ":");
3189 mutex_lock(&ftrace_cmd_mutex);
3190 list_for_each_entry(p, &ftrace_commands, list) {
3191 if (strcmp(p->name, command) == 0) {
3192 ret = p->func(hash, func, command, next, enable);
3197 mutex_unlock(&ftrace_cmd_mutex);
3203 ftrace_regex_write(struct file *file, const char __user *ubuf,
3204 size_t cnt, loff_t *ppos, int enable)
3206 struct ftrace_iterator *iter;
3207 struct trace_parser *parser;
3213 mutex_lock(&ftrace_regex_lock);
3216 if (unlikely(ftrace_disabled))
3219 if (file->f_mode & FMODE_READ) {
3220 struct seq_file *m = file->private_data;
3223 iter = file->private_data;
3225 parser = &iter->parser;
3226 read = trace_get_user(parser, ubuf, cnt, ppos);
3228 if (read >= 0 && trace_parser_loaded(parser) &&
3229 !trace_parser_cont(parser)) {
3230 ret = ftrace_process_regex(iter->hash, parser->buffer,
3231 parser->idx, enable);
3232 trace_parser_clear(parser);
3239 mutex_unlock(&ftrace_regex_lock);
3245 ftrace_filter_write(struct file *file, const char __user *ubuf,
3246 size_t cnt, loff_t *ppos)
3248 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3252 ftrace_notrace_write(struct file *file, const char __user *ubuf,
3253 size_t cnt, loff_t *ppos)
3255 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3259 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
3261 struct ftrace_func_entry *entry;
3263 if (!ftrace_location(ip))
3267 entry = ftrace_lookup_ip(hash, ip);
3270 free_hash_entry(hash, entry);
3274 return add_hash_entry(hash, ip);
3278 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
3279 unsigned long ip, int remove, int reset, int enable)
3281 struct ftrace_hash **orig_hash;
3282 struct ftrace_hash *hash;
3285 /* All global ops uses the global ops filters */
3286 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
3289 if (unlikely(ftrace_disabled))
3293 orig_hash = &ops->filter_hash;
3295 orig_hash = &ops->notrace_hash;
3297 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3301 mutex_lock(&ftrace_regex_lock);
3303 ftrace_filter_reset(hash);
3304 if (buf && !ftrace_match_records(hash, buf, len)) {
3306 goto out_regex_unlock;
3309 ret = ftrace_match_addr(hash, ip, remove);
3311 goto out_regex_unlock;
3314 mutex_lock(&ftrace_lock);
3315 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3316 if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
3318 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3320 mutex_unlock(&ftrace_lock);
3323 mutex_unlock(&ftrace_regex_lock);
3325 free_ftrace_hash(hash);
3330 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
3331 int reset, int enable)
3333 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
3337 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3338 * @ops - the ops to set the filter with
3339 * @ip - the address to add to or remove from the filter.
3340 * @remove - non zero to remove the ip from the filter
3341 * @reset - non zero to reset all filters before applying this filter.
3343 * Filters denote which functions should be enabled when tracing is enabled
3344 * If @ip is NULL, it failes to update filter.
3346 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
3347 int remove, int reset)
3349 return ftrace_set_addr(ops, ip, remove, reset, 1);
3351 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
3354 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3355 int reset, int enable)
3357 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
3361 * ftrace_set_filter - set a function to filter on in ftrace
3362 * @ops - the ops to set the filter with
3363 * @buf - the string that holds the function filter text.
3364 * @len - the length of the string.
3365 * @reset - non zero to reset all filters before applying this filter.
3367 * Filters denote which functions should be enabled when tracing is enabled.
3368 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3370 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
3373 return ftrace_set_regex(ops, buf, len, reset, 1);
3375 EXPORT_SYMBOL_GPL(ftrace_set_filter);
3378 * ftrace_set_notrace - set a function to not trace in ftrace
3379 * @ops - the ops to set the notrace filter with
3380 * @buf - the string that holds the function notrace text.
3381 * @len - the length of the string.
3382 * @reset - non zero to reset all filters before applying this filter.
3384 * Notrace Filters denote which functions should not be enabled when tracing
3385 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3388 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
3391 return ftrace_set_regex(ops, buf, len, reset, 0);
3393 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3395 * ftrace_set_filter - set a function to filter on in ftrace
3396 * @ops - the ops to set the filter with
3397 * @buf - the string that holds the function filter text.
3398 * @len - the length of the string.
3399 * @reset - non zero to reset all filters before applying this filter.
3401 * Filters denote which functions should be enabled when tracing is enabled.
3402 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3404 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3406 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3408 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3411 * ftrace_set_notrace - set a function to not trace in ftrace
3412 * @ops - the ops to set the notrace filter with
3413 * @buf - the string that holds the function notrace text.
3414 * @len - the length of the string.
3415 * @reset - non zero to reset all filters before applying this filter.
3417 * Notrace Filters denote which functions should not be enabled when tracing
3418 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3421 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
3423 ftrace_set_regex(&global_ops, buf, len, reset, 0);
3425 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
3428 * command line interface to allow users to set filters on boot up.
3430 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3431 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3432 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3434 static int __init set_ftrace_notrace(char *str)
3436 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3439 __setup("ftrace_notrace=", set_ftrace_notrace);
3441 static int __init set_ftrace_filter(char *str)
3443 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3446 __setup("ftrace_filter=", set_ftrace_filter);
3448 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3449 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3450 static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3452 static int __init set_graph_function(char *str)
3454 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3457 __setup("ftrace_graph_filter=", set_graph_function);
3459 static void __init set_ftrace_early_graph(char *buf)
3465 func = strsep(&buf, ",");
3466 /* we allow only one expression at a time */
3467 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3470 printk(KERN_DEBUG "ftrace: function %s not "
3471 "traceable\n", func);
3474 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3477 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
3482 func = strsep(&buf, ",");
3483 ftrace_set_regex(ops, func, strlen(func), 0, enable);
3487 static void __init set_ftrace_early_filters(void)
3489 if (ftrace_filter_buf[0])
3490 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
3491 if (ftrace_notrace_buf[0])
3492 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
3493 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3494 if (ftrace_graph_buf[0])
3495 set_ftrace_early_graph(ftrace_graph_buf);
3496 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3499 int ftrace_regex_release(struct inode *inode, struct file *file)
3501 struct seq_file *m = (struct seq_file *)file->private_data;
3502 struct ftrace_iterator *iter;
3503 struct ftrace_hash **orig_hash;
3504 struct trace_parser *parser;
3508 mutex_lock(&ftrace_regex_lock);
3509 if (file->f_mode & FMODE_READ) {
3512 seq_release(inode, file);
3514 iter = file->private_data;
3516 parser = &iter->parser;
3517 if (trace_parser_loaded(parser)) {
3518 parser->buffer[parser->idx] = 0;
3519 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3522 trace_parser_put(parser);
3524 if (file->f_mode & FMODE_WRITE) {
3525 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3528 orig_hash = &iter->ops->filter_hash;
3530 orig_hash = &iter->ops->notrace_hash;
3532 mutex_lock(&ftrace_lock);
3533 ret = ftrace_hash_move(iter->ops, filter_hash,
3534 orig_hash, iter->hash);
3535 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
3537 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3539 mutex_unlock(&ftrace_lock);
3541 free_ftrace_hash(iter->hash);
3544 mutex_unlock(&ftrace_regex_lock);
3548 static const struct file_operations ftrace_avail_fops = {
3549 .open = ftrace_avail_open,
3551 .llseek = seq_lseek,
3552 .release = seq_release_private,
3555 static const struct file_operations ftrace_enabled_fops = {
3556 .open = ftrace_enabled_open,
3558 .llseek = seq_lseek,
3559 .release = seq_release_private,
3562 static const struct file_operations ftrace_filter_fops = {
3563 .open = ftrace_filter_open,
3565 .write = ftrace_filter_write,
3566 .llseek = ftrace_regex_lseek,
3567 .release = ftrace_regex_release,
3570 static const struct file_operations ftrace_notrace_fops = {
3571 .open = ftrace_notrace_open,
3573 .write = ftrace_notrace_write,
3574 .llseek = ftrace_regex_lseek,
3575 .release = ftrace_regex_release,
3578 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3580 static DEFINE_MUTEX(graph_lock);
3582 int ftrace_graph_count;
3583 int ftrace_graph_filter_enabled;
3584 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3587 __g_next(struct seq_file *m, loff_t *pos)
3589 if (*pos >= ftrace_graph_count)
3591 return &ftrace_graph_funcs[*pos];
3595 g_next(struct seq_file *m, void *v, loff_t *pos)
3598 return __g_next(m, pos);
3601 static void *g_start(struct seq_file *m, loff_t *pos)
3603 mutex_lock(&graph_lock);
3605 /* Nothing, tell g_show to print all functions are enabled */
3606 if (!ftrace_graph_filter_enabled && !*pos)
3609 return __g_next(m, pos);
3612 static void g_stop(struct seq_file *m, void *p)
3614 mutex_unlock(&graph_lock);
3617 static int g_show(struct seq_file *m, void *v)
3619 unsigned long *ptr = v;
3624 if (ptr == (unsigned long *)1) {
3625 seq_printf(m, "#### all functions enabled ####\n");
3629 seq_printf(m, "%ps\n", (void *)*ptr);
3634 static const struct seq_operations ftrace_graph_seq_ops = {
3642 ftrace_graph_open(struct inode *inode, struct file *file)
3646 if (unlikely(ftrace_disabled))
3649 mutex_lock(&graph_lock);
3650 if ((file->f_mode & FMODE_WRITE) &&
3651 (file->f_flags & O_TRUNC)) {
3652 ftrace_graph_filter_enabled = 0;
3653 ftrace_graph_count = 0;
3654 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3656 mutex_unlock(&graph_lock);
3658 if (file->f_mode & FMODE_READ)
3659 ret = seq_open(file, &ftrace_graph_seq_ops);
3665 ftrace_graph_release(struct inode *inode, struct file *file)
3667 if (file->f_mode & FMODE_READ)
3668 seq_release(inode, file);
3673 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3675 struct dyn_ftrace *rec;
3676 struct ftrace_page *pg;
3685 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3686 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3689 search_len = strlen(search);
3691 mutex_lock(&ftrace_lock);
3693 if (unlikely(ftrace_disabled)) {
3694 mutex_unlock(&ftrace_lock);
3698 do_for_each_ftrace_rec(pg, rec) {
3700 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3701 /* if it is in the array */
3703 for (i = 0; i < *idx; i++) {
3704 if (array[i] == rec->ip) {
3713 array[(*idx)++] = rec->ip;
3714 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3719 array[i] = array[--(*idx)];
3725 } while_for_each_ftrace_rec();
3727 mutex_unlock(&ftrace_lock);
3732 ftrace_graph_filter_enabled = 1;
3737 ftrace_graph_write(struct file *file, const char __user *ubuf,
3738 size_t cnt, loff_t *ppos)
3740 struct trace_parser parser;
3746 mutex_lock(&graph_lock);
3748 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3753 read = trace_get_user(&parser, ubuf, cnt, ppos);
3755 if (read >= 0 && trace_parser_loaded((&parser))) {
3756 parser.buffer[parser.idx] = 0;
3758 /* we allow only one expression at a time */
3759 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3768 trace_parser_put(&parser);
3770 mutex_unlock(&graph_lock);
3775 static const struct file_operations ftrace_graph_fops = {
3776 .open = ftrace_graph_open,
3778 .write = ftrace_graph_write,
3779 .release = ftrace_graph_release,
3780 .llseek = seq_lseek,
3782 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3784 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3787 trace_create_file("available_filter_functions", 0444,
3788 d_tracer, NULL, &ftrace_avail_fops);
3790 trace_create_file("enabled_functions", 0444,
3791 d_tracer, NULL, &ftrace_enabled_fops);
3793 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3794 NULL, &ftrace_filter_fops);
3796 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3797 NULL, &ftrace_notrace_fops);
3799 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3800 trace_create_file("set_graph_function", 0444, d_tracer,
3802 &ftrace_graph_fops);
3803 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3808 static int ftrace_cmp_ips(const void *a, const void *b)
3810 const unsigned long *ipa = a;
3811 const unsigned long *ipb = b;
3820 static void ftrace_swap_ips(void *a, void *b, int size)
3822 unsigned long *ipa = a;
3823 unsigned long *ipb = b;
3831 static int ftrace_process_locs(struct module *mod,
3832 unsigned long *start,
3835 struct ftrace_page *start_pg;
3836 struct ftrace_page *pg;
3837 struct dyn_ftrace *rec;
3838 unsigned long count;
3841 unsigned long flags = 0; /* Shut up gcc */
3844 count = end - start;
3849 sort(start, count, sizeof(*start),
3850 ftrace_cmp_ips, ftrace_swap_ips);
3852 start_pg = ftrace_allocate_pages(count);
3856 mutex_lock(&ftrace_lock);
3859 * Core and each module needs their own pages, as
3860 * modules will free them when they are removed.
3861 * Force a new page to be allocated for modules.
3864 WARN_ON(ftrace_pages || ftrace_pages_start);
3865 /* First initialization */
3866 ftrace_pages = ftrace_pages_start = start_pg;
3871 if (WARN_ON(ftrace_pages->next)) {
3872 /* Hmm, we have free pages? */
3873 while (ftrace_pages->next)
3874 ftrace_pages = ftrace_pages->next;
3877 ftrace_pages->next = start_pg;
3883 addr = ftrace_call_adjust(*p++);
3885 * Some architecture linkers will pad between
3886 * the different mcount_loc sections of different
3887 * object files to satisfy alignments.
3888 * Skip any NULL pointers.
3893 if (pg->index == pg->size) {
3894 /* We should have allocated enough */
3895 if (WARN_ON(!pg->next))
3900 rec = &pg->records[pg->index++];
3904 /* We should have used all pages */
3907 /* Assign the last page to ftrace_pages */
3910 /* These new locations need to be initialized */
3911 ftrace_new_pgs = start_pg;
3914 * We only need to disable interrupts on start up
3915 * because we are modifying code that an interrupt
3916 * may execute, and the modification is not atomic.
3917 * But for modules, nothing runs the code we modify
3918 * until we are finished with it, and there's no
3919 * reason to cause large interrupt latencies while we do it.
3922 local_irq_save(flags);
3923 ftrace_update_code(mod);
3925 local_irq_restore(flags);
3928 mutex_unlock(&ftrace_lock);
3933 #ifdef CONFIG_MODULES
3935 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
3937 void ftrace_release_mod(struct module *mod)
3939 struct dyn_ftrace *rec;
3940 struct ftrace_page **last_pg;
3941 struct ftrace_page *pg;
3944 mutex_lock(&ftrace_lock);
3946 if (ftrace_disabled)
3950 * Each module has its own ftrace_pages, remove
3951 * them from the list.
3953 last_pg = &ftrace_pages_start;
3954 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
3955 rec = &pg->records[0];
3956 if (within_module_core(rec->ip, mod)) {
3958 * As core pages are first, the first
3959 * page should never be a module page.
3961 if (WARN_ON(pg == ftrace_pages_start))
3964 /* Check if we are deleting the last page */
3965 if (pg == ftrace_pages)
3966 ftrace_pages = next_to_ftrace_page(last_pg);
3968 *last_pg = pg->next;
3969 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3970 free_pages((unsigned long)pg->records, order);
3973 last_pg = &pg->next;
3976 mutex_unlock(&ftrace_lock);
3979 static void ftrace_init_module(struct module *mod,
3980 unsigned long *start, unsigned long *end)
3982 if (ftrace_disabled || start == end)
3984 ftrace_process_locs(mod, start, end);
3987 static int ftrace_module_notify(struct notifier_block *self,
3988 unsigned long val, void *data)
3990 struct module *mod = data;
3993 case MODULE_STATE_COMING:
3994 ftrace_init_module(mod, mod->ftrace_callsites,
3995 mod->ftrace_callsites +
3996 mod->num_ftrace_callsites);
3998 case MODULE_STATE_GOING:
3999 ftrace_release_mod(mod);
4006 static int ftrace_module_notify(struct notifier_block *self,
4007 unsigned long val, void *data)
4011 #endif /* CONFIG_MODULES */
4013 struct notifier_block ftrace_module_nb = {
4014 .notifier_call = ftrace_module_notify,
4015 .priority = INT_MAX, /* Run before anything that can use kprobes */
4018 extern unsigned long __start_mcount_loc[];
4019 extern unsigned long __stop_mcount_loc[];
4021 void __init ftrace_init(void)
4023 unsigned long count, addr, flags;
4026 /* Keep the ftrace pointer to the stub */
4027 addr = (unsigned long)ftrace_stub;
4029 local_irq_save(flags);
4030 ftrace_dyn_arch_init(&addr);
4031 local_irq_restore(flags);
4033 /* ftrace_dyn_arch_init places the return code in addr */
4037 count = __stop_mcount_loc - __start_mcount_loc;
4039 ret = ftrace_dyn_table_alloc(count);
4043 last_ftrace_enabled = ftrace_enabled = 1;
4045 ret = ftrace_process_locs(NULL,
4049 ret = register_module_notifier(&ftrace_module_nb);
4051 pr_warning("Failed to register trace ftrace module notifier\n");
4053 set_ftrace_early_filters();
4057 ftrace_disabled = 1;
4062 static struct ftrace_ops global_ops = {
4063 .func = ftrace_stub,
4064 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
4067 static int __init ftrace_nodyn_init(void)
4072 core_initcall(ftrace_nodyn_init);
4074 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
4075 static inline void ftrace_startup_enable(int command) { }
4076 /* Keep as macros so we do not need to define the commands */
4077 # define ftrace_startup(ops, command) \
4079 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4082 # define ftrace_shutdown(ops, command) do { } while (0)
4083 # define ftrace_startup_sysctl() do { } while (0)
4084 # define ftrace_shutdown_sysctl() do { } while (0)
4087 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
4092 #endif /* CONFIG_DYNAMIC_FTRACE */
4095 ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
4096 struct ftrace_ops *op, struct pt_regs *regs)
4098 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
4102 * Some of the ops may be dynamically allocated,
4103 * they must be freed after a synchronize_sched().
4105 preempt_disable_notrace();
4106 trace_recursion_set(TRACE_CONTROL_BIT);
4107 op = rcu_dereference_raw(ftrace_control_list);
4108 while (op != &ftrace_list_end) {
4109 if (!ftrace_function_local_disabled(op) &&
4110 ftrace_ops_test(op, ip))
4111 op->func(ip, parent_ip, op, regs);
4113 op = rcu_dereference_raw(op->next);
4115 trace_recursion_clear(TRACE_CONTROL_BIT);
4116 preempt_enable_notrace();
4119 static struct ftrace_ops control_ops = {
4120 .func = ftrace_ops_control_func,
4121 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
4125 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4126 struct ftrace_ops *ignored, struct pt_regs *regs)
4128 struct ftrace_ops *op;
4130 if (function_trace_stop)
4133 if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
4136 trace_recursion_set(TRACE_INTERNAL_BIT);
4138 * Some of the ops may be dynamically allocated,
4139 * they must be freed after a synchronize_sched().
4141 preempt_disable_notrace();
4142 op = rcu_dereference_raw(ftrace_ops_list);
4143 while (op != &ftrace_list_end) {
4144 if (ftrace_ops_test(op, ip))
4145 op->func(ip, parent_ip, op, regs);
4146 op = rcu_dereference_raw(op->next);
4148 preempt_enable_notrace();
4149 trace_recursion_clear(TRACE_INTERNAL_BIT);
4153 * Some archs only support passing ip and parent_ip. Even though
4154 * the list function ignores the op parameter, we do not want any
4155 * C side effects, where a function is called without the caller
4156 * sending a third parameter.
4157 * Archs are to support both the regs and ftrace_ops at the same time.
4158 * If they support ftrace_ops, it is assumed they support regs.
4159 * If call backs want to use regs, they must either check for regs
4160 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4161 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4162 * An architecture can pass partial regs with ftrace_ops and still
4163 * set the ARCH_SUPPORT_FTARCE_OPS.
4165 #if ARCH_SUPPORTS_FTRACE_OPS
4166 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4167 struct ftrace_ops *op, struct pt_regs *regs)
4169 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
4172 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
4174 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
4178 static void clear_ftrace_swapper(void)
4180 struct task_struct *p;
4184 for_each_online_cpu(cpu) {
4186 clear_tsk_trace_trace(p);
4191 static void set_ftrace_swapper(void)
4193 struct task_struct *p;
4197 for_each_online_cpu(cpu) {
4199 set_tsk_trace_trace(p);
4204 static void clear_ftrace_pid(struct pid *pid)
4206 struct task_struct *p;
4209 do_each_pid_task(pid, PIDTYPE_PID, p) {
4210 clear_tsk_trace_trace(p);
4211 } while_each_pid_task(pid, PIDTYPE_PID, p);
4217 static void set_ftrace_pid(struct pid *pid)
4219 struct task_struct *p;
4222 do_each_pid_task(pid, PIDTYPE_PID, p) {
4223 set_tsk_trace_trace(p);
4224 } while_each_pid_task(pid, PIDTYPE_PID, p);
4228 static void clear_ftrace_pid_task(struct pid *pid)
4230 if (pid == ftrace_swapper_pid)
4231 clear_ftrace_swapper();
4233 clear_ftrace_pid(pid);
4236 static void set_ftrace_pid_task(struct pid *pid)
4238 if (pid == ftrace_swapper_pid)
4239 set_ftrace_swapper();
4241 set_ftrace_pid(pid);
4244 static int ftrace_pid_add(int p)
4247 struct ftrace_pid *fpid;
4250 mutex_lock(&ftrace_lock);
4253 pid = ftrace_swapper_pid;
4255 pid = find_get_pid(p);
4262 list_for_each_entry(fpid, &ftrace_pids, list)
4263 if (fpid->pid == pid)
4268 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4272 list_add(&fpid->list, &ftrace_pids);
4275 set_ftrace_pid_task(pid);
4277 ftrace_update_pid_func();
4278 ftrace_startup_enable(0);
4280 mutex_unlock(&ftrace_lock);
4284 if (pid != ftrace_swapper_pid)
4288 mutex_unlock(&ftrace_lock);
4292 static void ftrace_pid_reset(void)
4294 struct ftrace_pid *fpid, *safe;
4296 mutex_lock(&ftrace_lock);
4297 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
4298 struct pid *pid = fpid->pid;
4300 clear_ftrace_pid_task(pid);
4302 list_del(&fpid->list);
4306 ftrace_update_pid_func();
4307 ftrace_startup_enable(0);
4309 mutex_unlock(&ftrace_lock);
4312 static void *fpid_start(struct seq_file *m, loff_t *pos)
4314 mutex_lock(&ftrace_lock);
4316 if (list_empty(&ftrace_pids) && (!*pos))
4319 return seq_list_start(&ftrace_pids, *pos);
4322 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
4327 return seq_list_next(v, &ftrace_pids, pos);
4330 static void fpid_stop(struct seq_file *m, void *p)
4332 mutex_unlock(&ftrace_lock);
4335 static int fpid_show(struct seq_file *m, void *v)
4337 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
4339 if (v == (void *)1) {
4340 seq_printf(m, "no pid\n");
4344 if (fpid->pid == ftrace_swapper_pid)
4345 seq_printf(m, "swapper tasks\n");
4347 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
4352 static const struct seq_operations ftrace_pid_sops = {
4353 .start = fpid_start,
4360 ftrace_pid_open(struct inode *inode, struct file *file)
4364 if ((file->f_mode & FMODE_WRITE) &&
4365 (file->f_flags & O_TRUNC))
4368 if (file->f_mode & FMODE_READ)
4369 ret = seq_open(file, &ftrace_pid_sops);
4375 ftrace_pid_write(struct file *filp, const char __user *ubuf,
4376 size_t cnt, loff_t *ppos)
4382 if (cnt >= sizeof(buf))
4385 if (copy_from_user(&buf, ubuf, cnt))
4391 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4392 * to clean the filter quietly.
4394 tmp = strstrip(buf);
4395 if (strlen(tmp) == 0)
4398 ret = kstrtol(tmp, 10, &val);
4402 ret = ftrace_pid_add(val);
4404 return ret ? ret : cnt;
4408 ftrace_pid_release(struct inode *inode, struct file *file)
4410 if (file->f_mode & FMODE_READ)
4411 seq_release(inode, file);
4416 static const struct file_operations ftrace_pid_fops = {
4417 .open = ftrace_pid_open,
4418 .write = ftrace_pid_write,
4420 .llseek = seq_lseek,
4421 .release = ftrace_pid_release,
4424 static __init int ftrace_init_debugfs(void)
4426 struct dentry *d_tracer;
4428 d_tracer = tracing_init_dentry();
4432 ftrace_init_dyn_debugfs(d_tracer);
4434 trace_create_file("set_ftrace_pid", 0644, d_tracer,
4435 NULL, &ftrace_pid_fops);
4437 ftrace_profile_debugfs(d_tracer);
4441 fs_initcall(ftrace_init_debugfs);
4444 * ftrace_kill - kill ftrace
4446 * This function should be used by panic code. It stops ftrace
4447 * but in a not so nice way. If you need to simply kill ftrace
4448 * from a non-atomic section, use ftrace_kill.
4450 void ftrace_kill(void)
4452 ftrace_disabled = 1;
4454 clear_ftrace_function();
4458 * Test if ftrace is dead or not.
4460 int ftrace_is_dead(void)
4462 return ftrace_disabled;
4466 * register_ftrace_function - register a function for profiling
4467 * @ops - ops structure that holds the function for profiling.
4469 * Register a function to be called by all functions in the
4472 * Note: @ops->func and all the functions it calls must be labeled
4473 * with "notrace", otherwise it will go into a
4476 int register_ftrace_function(struct ftrace_ops *ops)
4480 mutex_lock(&ftrace_lock);
4482 ret = __register_ftrace_function(ops);
4484 ret = ftrace_startup(ops, 0);
4486 mutex_unlock(&ftrace_lock);
4490 EXPORT_SYMBOL_GPL(register_ftrace_function);
4493 * unregister_ftrace_function - unregister a function for profiling.
4494 * @ops - ops structure that holds the function to unregister
4496 * Unregister a function that was added to be called by ftrace profiling.
4498 int unregister_ftrace_function(struct ftrace_ops *ops)
4502 mutex_lock(&ftrace_lock);
4503 ret = __unregister_ftrace_function(ops);
4505 ftrace_shutdown(ops, 0);
4506 mutex_unlock(&ftrace_lock);
4510 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
4513 ftrace_enable_sysctl(struct ctl_table *table, int write,
4514 void __user *buffer, size_t *lenp,
4519 mutex_lock(&ftrace_lock);
4521 if (unlikely(ftrace_disabled))
4524 ret = proc_dointvec(table, write, buffer, lenp, ppos);
4526 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
4529 last_ftrace_enabled = !!ftrace_enabled;
4531 if (ftrace_enabled) {
4533 ftrace_startup_sysctl();
4535 /* we are starting ftrace again */
4536 if (ftrace_ops_list != &ftrace_list_end) {
4537 if (ftrace_ops_list->next == &ftrace_list_end)
4538 ftrace_trace_function = ftrace_ops_list->func;
4540 ftrace_trace_function = ftrace_ops_list_func;
4544 /* stopping ftrace calls (just send to ftrace_stub) */
4545 ftrace_trace_function = ftrace_stub;
4547 ftrace_shutdown_sysctl();
4551 mutex_unlock(&ftrace_lock);
4555 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4557 static int ftrace_graph_active;
4558 static struct notifier_block ftrace_suspend_notifier;
4560 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
4565 /* The callbacks that hook a function */
4566 trace_func_graph_ret_t ftrace_graph_return =
4567 (trace_func_graph_ret_t)ftrace_stub;
4568 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
4570 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4571 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
4575 unsigned long flags;
4576 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
4577 struct task_struct *g, *t;
4579 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
4580 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
4581 * sizeof(struct ftrace_ret_stack),
4583 if (!ret_stack_list[i]) {
4591 read_lock_irqsave(&tasklist_lock, flags);
4592 do_each_thread(g, t) {
4598 if (t->ret_stack == NULL) {
4599 atomic_set(&t->tracing_graph_pause, 0);
4600 atomic_set(&t->trace_overrun, 0);
4601 t->curr_ret_stack = -1;
4602 /* Make sure the tasks see the -1 first: */
4604 t->ret_stack = ret_stack_list[start++];
4606 } while_each_thread(g, t);
4609 read_unlock_irqrestore(&tasklist_lock, flags);
4611 for (i = start; i < end; i++)
4612 kfree(ret_stack_list[i]);
4617 ftrace_graph_probe_sched_switch(void *ignore,
4618 struct task_struct *prev, struct task_struct *next)
4620 unsigned long long timestamp;
4624 * Does the user want to count the time a function was asleep.
4625 * If so, do not update the time stamps.
4627 if (trace_flags & TRACE_ITER_SLEEP_TIME)
4630 timestamp = trace_clock_local();
4632 prev->ftrace_timestamp = timestamp;
4634 /* only process tasks that we timestamped */
4635 if (!next->ftrace_timestamp)
4639 * Update all the counters in next to make up for the
4640 * time next was sleeping.
4642 timestamp -= next->ftrace_timestamp;
4644 for (index = next->curr_ret_stack; index >= 0; index--)
4645 next->ret_stack[index].calltime += timestamp;
4648 /* Allocate a return stack for each task */
4649 static int start_graph_tracing(void)
4651 struct ftrace_ret_stack **ret_stack_list;
4654 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4655 sizeof(struct ftrace_ret_stack *),
4658 if (!ret_stack_list)
4661 /* The cpu_boot init_task->ret_stack will never be freed */
4662 for_each_online_cpu(cpu) {
4663 if (!idle_task(cpu)->ret_stack)
4664 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
4668 ret = alloc_retstack_tasklist(ret_stack_list);
4669 } while (ret == -EAGAIN);
4672 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4674 pr_info("ftrace_graph: Couldn't activate tracepoint"
4675 " probe to kernel_sched_switch\n");
4678 kfree(ret_stack_list);
4683 * Hibernation protection.
4684 * The state of the current task is too much unstable during
4685 * suspend/restore to disk. We want to protect against that.
4688 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4692 case PM_HIBERNATION_PREPARE:
4693 pause_graph_tracing();
4696 case PM_POST_HIBERNATION:
4697 unpause_graph_tracing();
4703 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4704 trace_func_graph_ent_t entryfunc)
4708 mutex_lock(&ftrace_lock);
4710 /* we currently allow only one tracer registered at a time */
4711 if (ftrace_graph_active) {
4716 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4717 register_pm_notifier(&ftrace_suspend_notifier);
4719 ftrace_graph_active++;
4720 ret = start_graph_tracing();
4722 ftrace_graph_active--;
4726 ftrace_graph_return = retfunc;
4727 ftrace_graph_entry = entryfunc;
4729 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4732 mutex_unlock(&ftrace_lock);
4736 void unregister_ftrace_graph(void)
4738 mutex_lock(&ftrace_lock);
4740 if (unlikely(!ftrace_graph_active))
4743 ftrace_graph_active--;
4744 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4745 ftrace_graph_entry = ftrace_graph_entry_stub;
4746 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4747 unregister_pm_notifier(&ftrace_suspend_notifier);
4748 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4751 mutex_unlock(&ftrace_lock);
4754 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4757 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4759 atomic_set(&t->tracing_graph_pause, 0);
4760 atomic_set(&t->trace_overrun, 0);
4761 t->ftrace_timestamp = 0;
4762 /* make curr_ret_stack visible before we add the ret_stack */
4764 t->ret_stack = ret_stack;
4768 * Allocate a return stack for the idle task. May be the first
4769 * time through, or it may be done by CPU hotplug online.
4771 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4773 t->curr_ret_stack = -1;
4775 * The idle task has no parent, it either has its own
4776 * stack or no stack at all.
4779 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4781 if (ftrace_graph_active) {
4782 struct ftrace_ret_stack *ret_stack;
4784 ret_stack = per_cpu(idle_ret_stack, cpu);
4786 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4787 * sizeof(struct ftrace_ret_stack),
4791 per_cpu(idle_ret_stack, cpu) = ret_stack;
4793 graph_init_task(t, ret_stack);
4797 /* Allocate a return stack for newly created task */
4798 void ftrace_graph_init_task(struct task_struct *t)
4800 /* Make sure we do not use the parent ret_stack */
4801 t->ret_stack = NULL;
4802 t->curr_ret_stack = -1;
4804 if (ftrace_graph_active) {
4805 struct ftrace_ret_stack *ret_stack;
4807 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4808 * sizeof(struct ftrace_ret_stack),
4812 graph_init_task(t, ret_stack);
4816 void ftrace_graph_exit_task(struct task_struct *t)
4818 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4820 t->ret_stack = NULL;
4821 /* NULL must become visible to IRQs before we free it: */
4827 void ftrace_graph_stop(void)