2 * Infrastructure for profiling code inserted by 'gcc -pg'.
7 * Originally ported from the -rt patch by:
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/sched/task.h>
19 #include <linux/kallsyms.h>
20 #include <linux/seq_file.h>
21 #include <linux/suspend.h>
22 #include <linux/tracefs.h>
23 #include <linux/hardirq.h>
24 #include <linux/kthread.h>
25 #include <linux/uaccess.h>
26 #include <linux/bsearch.h>
27 #include <linux/module.h>
28 #include <linux/ftrace.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/ctype.h>
32 #include <linux/sort.h>
33 #include <linux/list.h>
34 #include <linux/hash.h>
35 #include <linux/rcupdate.h>
37 #include <trace/events/sched.h>
39 #include <asm/sections.h>
40 #include <asm/setup.h>
42 #include "trace_output.h"
43 #include "trace_stat.h"
45 #define FTRACE_WARN_ON(cond) \
53 #define FTRACE_WARN_ON_ONCE(cond) \
56 if (WARN_ON_ONCE(___r)) \
61 /* hash bits for specific function selection */
62 #define FTRACE_HASH_BITS 7
63 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
64 #define FTRACE_HASH_DEFAULT_BITS 10
65 #define FTRACE_HASH_MAX_BITS 12
67 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_OPS_HASH(opsname) \
69 .func_hash = &opsname.local_hash, \
70 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
71 #define ASSIGN_OPS_HASH(opsname, val) \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #define INIT_OPS_HASH(opsname)
76 #define ASSIGN_OPS_HASH(opsname, val)
79 static struct ftrace_ops ftrace_list_end __read_mostly = {
81 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
82 INIT_OPS_HASH(ftrace_list_end)
85 /* ftrace_enabled is a method to turn ftrace on or off */
86 int ftrace_enabled __read_mostly;
87 static int last_ftrace_enabled;
89 /* Current function tracing op */
90 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
91 /* What to set function_trace_op to */
92 static struct ftrace_ops *set_function_trace_op;
94 static bool ftrace_pids_enabled(struct ftrace_ops *ops)
96 struct trace_array *tr;
98 if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
103 return tr->function_pids != NULL;
106 static void ftrace_update_trampoline(struct ftrace_ops *ops);
109 * ftrace_disabled is set when an anomaly is discovered.
110 * ftrace_disabled is much stronger than ftrace_enabled.
112 static int ftrace_disabled __read_mostly;
114 static DEFINE_MUTEX(ftrace_lock);
116 static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
117 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
118 static struct ftrace_ops global_ops;
120 #if ARCH_SUPPORTS_FTRACE_OPS
121 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
122 struct ftrace_ops *op, struct pt_regs *regs);
124 /* See comment below, where ftrace_ops_list_func is defined */
125 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
126 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
130 * Traverse the ftrace_global_list, invoking all entries. The reason that we
131 * can use rcu_dereference_raw_notrace() is that elements removed from this list
132 * are simply leaked, so there is no need to interact with a grace-period
133 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
134 * concurrent insertions into the ftrace_global_list.
136 * Silly Alpha and silly pointer-speculation compiler optimizations!
138 #define do_for_each_ftrace_op(op, list) \
139 op = rcu_dereference_raw_notrace(list); \
143 * Optimized for just a single item in the list (as that is the normal case).
145 #define while_for_each_ftrace_op(op) \
146 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
147 unlikely((op) != &ftrace_list_end))
149 static inline void ftrace_ops_init(struct ftrace_ops *ops)
151 #ifdef CONFIG_DYNAMIC_FTRACE
152 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
153 mutex_init(&ops->local_hash.regex_lock);
154 ops->func_hash = &ops->local_hash;
155 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
161 * ftrace_nr_registered_ops - return number of ops registered
163 * Returns the number of ftrace_ops registered and tracing functions
165 int ftrace_nr_registered_ops(void)
167 struct ftrace_ops *ops;
170 mutex_lock(&ftrace_lock);
172 for (ops = rcu_dereference_protected(ftrace_ops_list,
173 lockdep_is_held(&ftrace_lock));
174 ops != &ftrace_list_end;
175 ops = rcu_dereference_protected(ops->next,
176 lockdep_is_held(&ftrace_lock)))
179 mutex_unlock(&ftrace_lock);
184 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
185 struct ftrace_ops *op, struct pt_regs *regs)
187 struct trace_array *tr = op->private;
189 if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
192 op->saved_func(ip, parent_ip, op, regs);
196 * clear_ftrace_function - reset the ftrace function
198 * This NULLs the ftrace function and in essence stops
199 * tracing. There may be lag
201 void clear_ftrace_function(void)
203 ftrace_trace_function = ftrace_stub;
206 static void ftrace_sync(struct work_struct *work)
209 * This function is just a stub to implement a hard force
210 * of synchronize_sched(). This requires synchronizing
211 * tasks even in userspace and idle.
213 * Yes, function tracing is rude.
217 static void ftrace_sync_ipi(void *data)
219 /* Probably not needed, but do it anyway */
223 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
224 static void update_function_graph_func(void);
226 /* Both enabled by default (can be cleared by function_graph tracer flags */
227 static bool fgraph_sleep_time = true;
228 static bool fgraph_graph_time = true;
231 static inline void update_function_graph_func(void) { }
235 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
238 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
239 * then it needs to call the list anyway.
241 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
242 FTRACE_FORCE_LIST_FUNC)
243 return ftrace_ops_list_func;
245 return ftrace_ops_get_func(ops);
248 static void update_ftrace_function(void)
253 * Prepare the ftrace_ops that the arch callback will use.
254 * If there's only one ftrace_ops registered, the ftrace_ops_list
255 * will point to the ops we want.
257 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
258 lockdep_is_held(&ftrace_lock));
260 /* If there's no ftrace_ops registered, just call the stub function */
261 if (set_function_trace_op == &ftrace_list_end) {
265 * If we are at the end of the list and this ops is
266 * recursion safe and not dynamic and the arch supports passing ops,
267 * then have the mcount trampoline call the function directly.
269 } else if (rcu_dereference_protected(ftrace_ops_list->next,
270 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
271 func = ftrace_ops_get_list_func(ftrace_ops_list);
274 /* Just use the default ftrace_ops */
275 set_function_trace_op = &ftrace_list_end;
276 func = ftrace_ops_list_func;
279 update_function_graph_func();
281 /* If there's no change, then do nothing more here */
282 if (ftrace_trace_function == func)
286 * If we are using the list function, it doesn't care
287 * about the function_trace_ops.
289 if (func == ftrace_ops_list_func) {
290 ftrace_trace_function = func;
292 * Don't even bother setting function_trace_ops,
293 * it would be racy to do so anyway.
298 #ifndef CONFIG_DYNAMIC_FTRACE
300 * For static tracing, we need to be a bit more careful.
301 * The function change takes affect immediately. Thus,
302 * we need to coorditate the setting of the function_trace_ops
303 * with the setting of the ftrace_trace_function.
305 * Set the function to the list ops, which will call the
306 * function we want, albeit indirectly, but it handles the
307 * ftrace_ops and doesn't depend on function_trace_op.
309 ftrace_trace_function = ftrace_ops_list_func;
311 * Make sure all CPUs see this. Yes this is slow, but static
312 * tracing is slow and nasty to have enabled.
314 schedule_on_each_cpu(ftrace_sync);
315 /* Now all cpus are using the list ops. */
316 function_trace_op = set_function_trace_op;
317 /* Make sure the function_trace_op is visible on all CPUs */
319 /* Nasty way to force a rmb on all cpus */
320 smp_call_function(ftrace_sync_ipi, NULL, 1);
321 /* OK, we are all set to update the ftrace_trace_function now! */
322 #endif /* !CONFIG_DYNAMIC_FTRACE */
324 ftrace_trace_function = func;
327 int using_ftrace_ops_list_func(void)
329 return ftrace_trace_function == ftrace_ops_list_func;
332 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
333 struct ftrace_ops *ops)
335 rcu_assign_pointer(ops->next, *list);
338 * We are entering ops into the list but another
339 * CPU might be walking that list. We need to make sure
340 * the ops->next pointer is valid before another CPU sees
341 * the ops pointer included into the list.
343 rcu_assign_pointer(*list, ops);
346 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
347 struct ftrace_ops *ops)
349 struct ftrace_ops **p;
352 * If we are removing the last function, then simply point
353 * to the ftrace_stub.
355 if (rcu_dereference_protected(*list,
356 lockdep_is_held(&ftrace_lock)) == ops &&
357 rcu_dereference_protected(ops->next,
358 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
359 *list = &ftrace_list_end;
363 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
374 static void ftrace_update_trampoline(struct ftrace_ops *ops);
376 static int __register_ftrace_function(struct ftrace_ops *ops)
378 if (ops->flags & FTRACE_OPS_FL_DELETED)
381 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
384 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
386 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
387 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
388 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
390 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
391 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
394 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
395 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
398 if (!core_kernel_data((unsigned long)ops))
399 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
401 add_ftrace_ops(&ftrace_ops_list, ops);
403 /* Always save the function, and reset at unregistering */
404 ops->saved_func = ops->func;
406 if (ftrace_pids_enabled(ops))
407 ops->func = ftrace_pid_func;
409 ftrace_update_trampoline(ops);
412 update_ftrace_function();
417 static int __unregister_ftrace_function(struct ftrace_ops *ops)
421 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
424 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
430 update_ftrace_function();
432 ops->func = ops->saved_func;
437 static void ftrace_update_pid_func(void)
439 struct ftrace_ops *op;
441 /* Only do something if we are tracing something */
442 if (ftrace_trace_function == ftrace_stub)
445 do_for_each_ftrace_op(op, ftrace_ops_list) {
446 if (op->flags & FTRACE_OPS_FL_PID) {
447 op->func = ftrace_pids_enabled(op) ?
448 ftrace_pid_func : op->saved_func;
449 ftrace_update_trampoline(op);
451 } while_for_each_ftrace_op(op);
453 update_ftrace_function();
456 #ifdef CONFIG_FUNCTION_PROFILER
457 struct ftrace_profile {
458 struct hlist_node node;
460 unsigned long counter;
461 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
462 unsigned long long time;
463 unsigned long long time_squared;
467 struct ftrace_profile_page {
468 struct ftrace_profile_page *next;
470 struct ftrace_profile records[];
473 struct ftrace_profile_stat {
475 struct hlist_head *hash;
476 struct ftrace_profile_page *pages;
477 struct ftrace_profile_page *start;
478 struct tracer_stat stat;
481 #define PROFILE_RECORDS_SIZE \
482 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
484 #define PROFILES_PER_PAGE \
485 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
487 static int ftrace_profile_enabled __read_mostly;
489 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
490 static DEFINE_MUTEX(ftrace_profile_lock);
492 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
494 #define FTRACE_PROFILE_HASH_BITS 10
495 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
498 function_stat_next(void *v, int idx)
500 struct ftrace_profile *rec = v;
501 struct ftrace_profile_page *pg;
503 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
509 if ((void *)rec >= (void *)&pg->records[pg->index]) {
513 rec = &pg->records[0];
521 static void *function_stat_start(struct tracer_stat *trace)
523 struct ftrace_profile_stat *stat =
524 container_of(trace, struct ftrace_profile_stat, stat);
526 if (!stat || !stat->start)
529 return function_stat_next(&stat->start->records[0], 0);
532 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
533 /* function graph compares on total time */
534 static int function_stat_cmp(void *p1, void *p2)
536 struct ftrace_profile *a = p1;
537 struct ftrace_profile *b = p2;
539 if (a->time < b->time)
541 if (a->time > b->time)
547 /* not function graph compares against hits */
548 static int function_stat_cmp(void *p1, void *p2)
550 struct ftrace_profile *a = p1;
551 struct ftrace_profile *b = p2;
553 if (a->counter < b->counter)
555 if (a->counter > b->counter)
562 static int function_stat_headers(struct seq_file *m)
564 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
565 seq_puts(m, " Function "
568 "--- ---- --- ---\n");
570 seq_puts(m, " Function Hit\n"
576 static int function_stat_show(struct seq_file *m, void *v)
578 struct ftrace_profile *rec = v;
579 char str[KSYM_SYMBOL_LEN];
581 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
582 static struct trace_seq s;
583 unsigned long long avg;
584 unsigned long long stddev;
586 mutex_lock(&ftrace_profile_lock);
588 /* we raced with function_profile_reset() */
589 if (unlikely(rec->counter == 0)) {
594 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
596 do_div(avg, rec->counter);
597 if (tracing_thresh && (avg < tracing_thresh))
601 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
602 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
604 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
607 /* Sample standard deviation (s^2) */
608 if (rec->counter <= 1)
612 * Apply Welford's method:
613 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
615 stddev = rec->counter * rec->time_squared -
616 rec->time * rec->time;
619 * Divide only 1000 for ns^2 -> us^2 conversion.
620 * trace_print_graph_duration will divide 1000 again.
622 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
626 trace_print_graph_duration(rec->time, &s);
627 trace_seq_puts(&s, " ");
628 trace_print_graph_duration(avg, &s);
629 trace_seq_puts(&s, " ");
630 trace_print_graph_duration(stddev, &s);
631 trace_print_seq(m, &s);
635 mutex_unlock(&ftrace_profile_lock);
640 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
642 struct ftrace_profile_page *pg;
644 pg = stat->pages = stat->start;
647 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
652 memset(stat->hash, 0,
653 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
656 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
658 struct ftrace_profile_page *pg;
663 /* If we already allocated, do nothing */
667 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
671 #ifdef CONFIG_DYNAMIC_FTRACE
672 functions = ftrace_update_tot_cnt;
675 * We do not know the number of functions that exist because
676 * dynamic tracing is what counts them. With past experience
677 * we have around 20K functions. That should be more than enough.
678 * It is highly unlikely we will execute every function in
684 pg = stat->start = stat->pages;
686 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
688 for (i = 1; i < pages; i++) {
689 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
700 unsigned long tmp = (unsigned long)pg;
712 static int ftrace_profile_init_cpu(int cpu)
714 struct ftrace_profile_stat *stat;
717 stat = &per_cpu(ftrace_profile_stats, cpu);
720 /* If the profile is already created, simply reset it */
721 ftrace_profile_reset(stat);
726 * We are profiling all functions, but usually only a few thousand
727 * functions are hit. We'll make a hash of 1024 items.
729 size = FTRACE_PROFILE_HASH_SIZE;
731 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
736 /* Preallocate the function profiling pages */
737 if (ftrace_profile_pages_init(stat) < 0) {
746 static int ftrace_profile_init(void)
751 for_each_possible_cpu(cpu) {
752 ret = ftrace_profile_init_cpu(cpu);
760 /* interrupts must be disabled */
761 static struct ftrace_profile *
762 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
764 struct ftrace_profile *rec;
765 struct hlist_head *hhd;
768 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
769 hhd = &stat->hash[key];
771 if (hlist_empty(hhd))
774 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
782 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
783 struct ftrace_profile *rec)
787 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
788 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
792 * The memory is already allocated, this simply finds a new record to use.
794 static struct ftrace_profile *
795 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
797 struct ftrace_profile *rec = NULL;
799 /* prevent recursion (from NMIs) */
800 if (atomic_inc_return(&stat->disabled) != 1)
804 * Try to find the function again since an NMI
805 * could have added it
807 rec = ftrace_find_profiled_func(stat, ip);
811 if (stat->pages->index == PROFILES_PER_PAGE) {
812 if (!stat->pages->next)
814 stat->pages = stat->pages->next;
817 rec = &stat->pages->records[stat->pages->index++];
819 ftrace_add_profile(stat, rec);
822 atomic_dec(&stat->disabled);
828 function_profile_call(unsigned long ip, unsigned long parent_ip,
829 struct ftrace_ops *ops, struct pt_regs *regs)
831 struct ftrace_profile_stat *stat;
832 struct ftrace_profile *rec;
835 if (!ftrace_profile_enabled)
838 local_irq_save(flags);
840 stat = this_cpu_ptr(&ftrace_profile_stats);
841 if (!stat->hash || !ftrace_profile_enabled)
844 rec = ftrace_find_profiled_func(stat, ip);
846 rec = ftrace_profile_alloc(stat, ip);
853 local_irq_restore(flags);
856 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
857 static int profile_graph_entry(struct ftrace_graph_ent *trace)
859 int index = trace->depth;
861 function_profile_call(trace->func, 0, NULL, NULL);
863 /* If function graph is shutting down, ret_stack can be NULL */
864 if (!current->ret_stack)
867 if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
868 current->ret_stack[index].subtime = 0;
873 static void profile_graph_return(struct ftrace_graph_ret *trace)
875 struct ftrace_profile_stat *stat;
876 unsigned long long calltime;
877 struct ftrace_profile *rec;
880 local_irq_save(flags);
881 stat = this_cpu_ptr(&ftrace_profile_stats);
882 if (!stat->hash || !ftrace_profile_enabled)
885 /* If the calltime was zero'd ignore it */
886 if (!trace->calltime)
889 calltime = trace->rettime - trace->calltime;
891 if (!fgraph_graph_time) {
894 index = trace->depth;
896 /* Append this call time to the parent time to subtract */
898 current->ret_stack[index - 1].subtime += calltime;
900 if (current->ret_stack[index].subtime < calltime)
901 calltime -= current->ret_stack[index].subtime;
906 rec = ftrace_find_profiled_func(stat, trace->func);
908 rec->time += calltime;
909 rec->time_squared += calltime * calltime;
913 local_irq_restore(flags);
916 static int register_ftrace_profiler(void)
918 return register_ftrace_graph(&profile_graph_return,
919 &profile_graph_entry);
922 static void unregister_ftrace_profiler(void)
924 unregister_ftrace_graph();
927 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
928 .func = function_profile_call,
929 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
930 INIT_OPS_HASH(ftrace_profile_ops)
933 static int register_ftrace_profiler(void)
935 return register_ftrace_function(&ftrace_profile_ops);
938 static void unregister_ftrace_profiler(void)
940 unregister_ftrace_function(&ftrace_profile_ops);
942 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
945 ftrace_profile_write(struct file *filp, const char __user *ubuf,
946 size_t cnt, loff_t *ppos)
951 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
957 mutex_lock(&ftrace_profile_lock);
958 if (ftrace_profile_enabled ^ val) {
960 ret = ftrace_profile_init();
966 ret = register_ftrace_profiler();
971 ftrace_profile_enabled = 1;
973 ftrace_profile_enabled = 0;
975 * unregister_ftrace_profiler calls stop_machine
976 * so this acts like an synchronize_sched.
978 unregister_ftrace_profiler();
982 mutex_unlock(&ftrace_profile_lock);
990 ftrace_profile_read(struct file *filp, char __user *ubuf,
991 size_t cnt, loff_t *ppos)
993 char buf[64]; /* big enough to hold a number */
996 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
997 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1000 static const struct file_operations ftrace_profile_fops = {
1001 .open = tracing_open_generic,
1002 .read = ftrace_profile_read,
1003 .write = ftrace_profile_write,
1004 .llseek = default_llseek,
1007 /* used to initialize the real stat files */
1008 static struct tracer_stat function_stats __initdata = {
1009 .name = "functions",
1010 .stat_start = function_stat_start,
1011 .stat_next = function_stat_next,
1012 .stat_cmp = function_stat_cmp,
1013 .stat_headers = function_stat_headers,
1014 .stat_show = function_stat_show
1017 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1019 struct ftrace_profile_stat *stat;
1020 struct dentry *entry;
1025 for_each_possible_cpu(cpu) {
1026 stat = &per_cpu(ftrace_profile_stats, cpu);
1028 name = kasprintf(GFP_KERNEL, "function%d", cpu);
1031 * The files created are permanent, if something happens
1032 * we still do not free memory.
1035 "Could not allocate stat file for cpu %d\n",
1039 stat->stat = function_stats;
1040 stat->stat.name = name;
1041 ret = register_stat_tracer(&stat->stat);
1044 "Could not register function stat for cpu %d\n",
1051 entry = tracefs_create_file("function_profile_enabled", 0644,
1052 d_tracer, NULL, &ftrace_profile_fops);
1054 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1057 #else /* CONFIG_FUNCTION_PROFILER */
1058 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1061 #endif /* CONFIG_FUNCTION_PROFILER */
1063 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1065 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1066 static int ftrace_graph_active;
1068 # define ftrace_graph_active 0
1071 #ifdef CONFIG_DYNAMIC_FTRACE
1073 static struct ftrace_ops *removed_ops;
1076 * Set when doing a global update, like enabling all recs or disabling them.
1077 * It is not set when just updating a single ftrace_ops.
1079 static bool update_all_ops;
1081 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1082 # error Dynamic ftrace depends on MCOUNT_RECORD
1085 struct ftrace_func_entry {
1086 struct hlist_node hlist;
1090 struct ftrace_func_probe {
1091 struct ftrace_probe_ops *probe_ops;
1092 struct ftrace_ops ops;
1093 struct trace_array *tr;
1094 struct list_head list;
1100 * We make these constant because no one should touch them,
1101 * but they are used as the default "empty hash", to avoid allocating
1102 * it all the time. These are in a read only section such that if
1103 * anyone does try to modify it, it will cause an exception.
1105 static const struct hlist_head empty_buckets[1];
1106 static const struct ftrace_hash empty_hash = {
1107 .buckets = (struct hlist_head *)empty_buckets,
1109 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1111 static struct ftrace_ops global_ops = {
1112 .func = ftrace_stub,
1113 .local_hash.notrace_hash = EMPTY_HASH,
1114 .local_hash.filter_hash = EMPTY_HASH,
1115 INIT_OPS_HASH(global_ops)
1116 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1117 FTRACE_OPS_FL_INITIALIZED |
1122 * Used by the stack undwinder to know about dynamic ftrace trampolines.
1124 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1126 struct ftrace_ops *op = NULL;
1129 * Some of the ops may be dynamically allocated,
1130 * they are freed after a synchronize_sched().
1132 preempt_disable_notrace();
1134 do_for_each_ftrace_op(op, ftrace_ops_list) {
1136 * This is to check for dynamically allocated trampolines.
1137 * Trampolines that are in kernel text will have
1138 * core_kernel_text() return true.
1140 if (op->trampoline && op->trampoline_size)
1141 if (addr >= op->trampoline &&
1142 addr < op->trampoline + op->trampoline_size) {
1143 preempt_enable_notrace();
1146 } while_for_each_ftrace_op(op);
1147 preempt_enable_notrace();
1153 * This is used by __kernel_text_address() to return true if the
1154 * address is on a dynamically allocated trampoline that would
1155 * not return true for either core_kernel_text() or
1156 * is_module_text_address().
1158 bool is_ftrace_trampoline(unsigned long addr)
1160 return ftrace_ops_trampoline(addr) != NULL;
1163 struct ftrace_page {
1164 struct ftrace_page *next;
1165 struct dyn_ftrace *records;
1170 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1171 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1173 /* estimate from running different kernels */
1174 #define NR_TO_INIT 10000
1176 static struct ftrace_page *ftrace_pages_start;
1177 static struct ftrace_page *ftrace_pages;
1179 static __always_inline unsigned long
1180 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1182 if (hash->size_bits > 0)
1183 return hash_long(ip, hash->size_bits);
1188 /* Only use this function if ftrace_hash_empty() has already been tested */
1189 static __always_inline struct ftrace_func_entry *
1190 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1193 struct ftrace_func_entry *entry;
1194 struct hlist_head *hhd;
1196 key = ftrace_hash_key(hash, ip);
1197 hhd = &hash->buckets[key];
1199 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1200 if (entry->ip == ip)
1207 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1208 * @hash: The hash to look at
1209 * @ip: The instruction pointer to test
1211 * Search a given @hash to see if a given instruction pointer (@ip)
1214 * Returns the entry that holds the @ip if found. NULL otherwise.
1216 struct ftrace_func_entry *
1217 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1219 if (ftrace_hash_empty(hash))
1222 return __ftrace_lookup_ip(hash, ip);
1225 static void __add_hash_entry(struct ftrace_hash *hash,
1226 struct ftrace_func_entry *entry)
1228 struct hlist_head *hhd;
1231 key = ftrace_hash_key(hash, entry->ip);
1232 hhd = &hash->buckets[key];
1233 hlist_add_head(&entry->hlist, hhd);
1237 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1239 struct ftrace_func_entry *entry;
1241 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1246 __add_hash_entry(hash, entry);
1252 free_hash_entry(struct ftrace_hash *hash,
1253 struct ftrace_func_entry *entry)
1255 hlist_del(&entry->hlist);
1261 remove_hash_entry(struct ftrace_hash *hash,
1262 struct ftrace_func_entry *entry)
1264 hlist_del_rcu(&entry->hlist);
1268 static void ftrace_hash_clear(struct ftrace_hash *hash)
1270 struct hlist_head *hhd;
1271 struct hlist_node *tn;
1272 struct ftrace_func_entry *entry;
1273 int size = 1 << hash->size_bits;
1279 for (i = 0; i < size; i++) {
1280 hhd = &hash->buckets[i];
1281 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1282 free_hash_entry(hash, entry);
1284 FTRACE_WARN_ON(hash->count);
1287 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1289 list_del(&ftrace_mod->list);
1290 kfree(ftrace_mod->module);
1291 kfree(ftrace_mod->func);
1295 static void clear_ftrace_mod_list(struct list_head *head)
1297 struct ftrace_mod_load *p, *n;
1299 /* stack tracer isn't supported yet */
1303 mutex_lock(&ftrace_lock);
1304 list_for_each_entry_safe(p, n, head, list)
1306 mutex_unlock(&ftrace_lock);
1309 static void free_ftrace_hash(struct ftrace_hash *hash)
1311 if (!hash || hash == EMPTY_HASH)
1313 ftrace_hash_clear(hash);
1314 kfree(hash->buckets);
1318 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1320 struct ftrace_hash *hash;
1322 hash = container_of(rcu, struct ftrace_hash, rcu);
1323 free_ftrace_hash(hash);
1326 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1328 if (!hash || hash == EMPTY_HASH)
1330 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1333 void ftrace_free_filter(struct ftrace_ops *ops)
1335 ftrace_ops_init(ops);
1336 free_ftrace_hash(ops->func_hash->filter_hash);
1337 free_ftrace_hash(ops->func_hash->notrace_hash);
1340 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1342 struct ftrace_hash *hash;
1345 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1349 size = 1 << size_bits;
1350 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1352 if (!hash->buckets) {
1357 hash->size_bits = size_bits;
1363 static int ftrace_add_mod(struct trace_array *tr,
1364 const char *func, const char *module,
1367 struct ftrace_mod_load *ftrace_mod;
1368 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1370 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1374 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1375 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1376 ftrace_mod->enable = enable;
1378 if (!ftrace_mod->func || !ftrace_mod->module)
1381 list_add(&ftrace_mod->list, mod_head);
1386 free_ftrace_mod(ftrace_mod);
1391 static struct ftrace_hash *
1392 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1394 struct ftrace_func_entry *entry;
1395 struct ftrace_hash *new_hash;
1400 new_hash = alloc_ftrace_hash(size_bits);
1405 new_hash->flags = hash->flags;
1408 if (ftrace_hash_empty(hash))
1411 size = 1 << hash->size_bits;
1412 for (i = 0; i < size; i++) {
1413 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1414 ret = add_hash_entry(new_hash, entry->ip);
1420 FTRACE_WARN_ON(new_hash->count != hash->count);
1425 free_ftrace_hash(new_hash);
1430 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1432 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1434 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1435 struct ftrace_hash *new_hash);
1437 static struct ftrace_hash *
1438 __ftrace_hash_move(struct ftrace_hash *src)
1440 struct ftrace_func_entry *entry;
1441 struct hlist_node *tn;
1442 struct hlist_head *hhd;
1443 struct ftrace_hash *new_hash;
1444 int size = src->count;
1449 * If the new source is empty, just return the empty_hash.
1451 if (ftrace_hash_empty(src))
1455 * Make the hash size about 1/2 the # found
1457 for (size /= 2; size; size >>= 1)
1460 /* Don't allocate too much */
1461 if (bits > FTRACE_HASH_MAX_BITS)
1462 bits = FTRACE_HASH_MAX_BITS;
1464 new_hash = alloc_ftrace_hash(bits);
1468 new_hash->flags = src->flags;
1470 size = 1 << src->size_bits;
1471 for (i = 0; i < size; i++) {
1472 hhd = &src->buckets[i];
1473 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1474 remove_hash_entry(src, entry);
1475 __add_hash_entry(new_hash, entry);
1483 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1484 struct ftrace_hash **dst, struct ftrace_hash *src)
1486 struct ftrace_hash *new_hash;
1489 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1490 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1493 new_hash = __ftrace_hash_move(src);
1497 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1499 /* IPMODIFY should be updated only when filter_hash updating */
1500 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1502 free_ftrace_hash(new_hash);
1508 * Remove the current set, update the hash and add
1511 ftrace_hash_rec_disable_modify(ops, enable);
1513 rcu_assign_pointer(*dst, new_hash);
1515 ftrace_hash_rec_enable_modify(ops, enable);
1520 static bool hash_contains_ip(unsigned long ip,
1521 struct ftrace_ops_hash *hash)
1524 * The function record is a match if it exists in the filter
1525 * hash and not in the notrace hash. Note, an emty hash is
1526 * considered a match for the filter hash, but an empty
1527 * notrace hash is considered not in the notrace hash.
1529 return (ftrace_hash_empty(hash->filter_hash) ||
1530 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1531 (ftrace_hash_empty(hash->notrace_hash) ||
1532 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1536 * Test the hashes for this ops to see if we want to call
1537 * the ops->func or not.
1539 * It's a match if the ip is in the ops->filter_hash or
1540 * the filter_hash does not exist or is empty,
1542 * the ip is not in the ops->notrace_hash.
1544 * This needs to be called with preemption disabled as
1545 * the hashes are freed with call_rcu_sched().
1548 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1550 struct ftrace_ops_hash hash;
1553 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1555 * There's a small race when adding ops that the ftrace handler
1556 * that wants regs, may be called without them. We can not
1557 * allow that handler to be called if regs is NULL.
1559 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1563 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1564 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1566 if (hash_contains_ip(ip, &hash))
1575 * This is a double for. Do not use 'break' to break out of the loop,
1576 * you must use a goto.
1578 #define do_for_each_ftrace_rec(pg, rec) \
1579 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1581 for (_____i = 0; _____i < pg->index; _____i++) { \
1582 rec = &pg->records[_____i];
1584 #define while_for_each_ftrace_rec() \
1589 static int ftrace_cmp_recs(const void *a, const void *b)
1591 const struct dyn_ftrace *key = a;
1592 const struct dyn_ftrace *rec = b;
1594 if (key->flags < rec->ip)
1596 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1602 * ftrace_location_range - return the first address of a traced location
1603 * if it touches the given ip range
1604 * @start: start of range to search.
1605 * @end: end of range to search (inclusive). @end points to the last byte
1608 * Returns rec->ip if the related ftrace location is a least partly within
1609 * the given address range. That is, the first address of the instruction
1610 * that is either a NOP or call to the function tracer. It checks the ftrace
1611 * internal tables to determine if the address belongs or not.
1613 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1615 struct ftrace_page *pg;
1616 struct dyn_ftrace *rec;
1617 struct dyn_ftrace key;
1620 key.flags = end; /* overload flags, as it is unsigned long */
1622 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1623 if (end < pg->records[0].ip ||
1624 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1626 rec = bsearch(&key, pg->records, pg->index,
1627 sizeof(struct dyn_ftrace),
1637 * ftrace_location - return true if the ip giving is a traced location
1638 * @ip: the instruction pointer to check
1640 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1641 * That is, the instruction that is either a NOP or call to
1642 * the function tracer. It checks the ftrace internal tables to
1643 * determine if the address belongs or not.
1645 unsigned long ftrace_location(unsigned long ip)
1647 return ftrace_location_range(ip, ip);
1651 * ftrace_text_reserved - return true if range contains an ftrace location
1652 * @start: start of range to search
1653 * @end: end of range to search (inclusive). @end points to the last byte to check.
1655 * Returns 1 if @start and @end contains a ftrace location.
1656 * That is, the instruction that is either a NOP or call to
1657 * the function tracer. It checks the ftrace internal tables to
1658 * determine if the address belongs or not.
1660 int ftrace_text_reserved(const void *start, const void *end)
1664 ret = ftrace_location_range((unsigned long)start,
1665 (unsigned long)end);
1670 /* Test if ops registered to this rec needs regs */
1671 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1673 struct ftrace_ops *ops;
1674 bool keep_regs = false;
1676 for (ops = ftrace_ops_list;
1677 ops != &ftrace_list_end; ops = ops->next) {
1678 /* pass rec in as regs to have non-NULL val */
1679 if (ftrace_ops_test(ops, rec->ip, rec)) {
1680 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1690 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1694 struct ftrace_hash *hash;
1695 struct ftrace_hash *other_hash;
1696 struct ftrace_page *pg;
1697 struct dyn_ftrace *rec;
1698 bool update = false;
1702 /* Only update if the ops has been registered */
1703 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1707 * In the filter_hash case:
1708 * If the count is zero, we update all records.
1709 * Otherwise we just update the items in the hash.
1711 * In the notrace_hash case:
1712 * We enable the update in the hash.
1713 * As disabling notrace means enabling the tracing,
1714 * and enabling notrace means disabling, the inc variable
1718 hash = ops->func_hash->filter_hash;
1719 other_hash = ops->func_hash->notrace_hash;
1720 if (ftrace_hash_empty(hash))
1724 hash = ops->func_hash->notrace_hash;
1725 other_hash = ops->func_hash->filter_hash;
1727 * If the notrace hash has no items,
1728 * then there's nothing to do.
1730 if (ftrace_hash_empty(hash))
1734 do_for_each_ftrace_rec(pg, rec) {
1735 int in_other_hash = 0;
1739 if (rec->flags & FTRACE_FL_DISABLED)
1744 * Only the filter_hash affects all records.
1745 * Update if the record is not in the notrace hash.
1747 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1750 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1751 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1754 * If filter_hash is set, we want to match all functions
1755 * that are in the hash but not in the other hash.
1757 * If filter_hash is not set, then we are decrementing.
1758 * That means we match anything that is in the hash
1759 * and also in the other_hash. That is, we need to turn
1760 * off functions in the other hash because they are disabled
1763 if (filter_hash && in_hash && !in_other_hash)
1765 else if (!filter_hash && in_hash &&
1766 (in_other_hash || ftrace_hash_empty(other_hash)))
1774 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1778 * If there's only a single callback registered to a
1779 * function, and the ops has a trampoline registered
1780 * for it, then we can call it directly.
1782 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1783 rec->flags |= FTRACE_FL_TRAMP;
1786 * If we are adding another function callback
1787 * to this function, and the previous had a
1788 * custom trampoline in use, then we need to go
1789 * back to the default trampoline.
1791 rec->flags &= ~FTRACE_FL_TRAMP;
1794 * If any ops wants regs saved for this function
1795 * then all ops will get saved regs.
1797 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1798 rec->flags |= FTRACE_FL_REGS;
1800 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1805 * If the rec had REGS enabled and the ops that is
1806 * being removed had REGS set, then see if there is
1807 * still any ops for this record that wants regs.
1808 * If not, we can stop recording them.
1810 if (ftrace_rec_count(rec) > 0 &&
1811 rec->flags & FTRACE_FL_REGS &&
1812 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1813 if (!test_rec_ops_needs_regs(rec))
1814 rec->flags &= ~FTRACE_FL_REGS;
1818 * If the rec had TRAMP enabled, then it needs to
1819 * be cleared. As TRAMP can only be enabled iff
1820 * there is only a single ops attached to it.
1821 * In otherwords, always disable it on decrementing.
1822 * In the future, we may set it if rec count is
1823 * decremented to one, and the ops that is left
1826 rec->flags &= ~FTRACE_FL_TRAMP;
1829 * flags will be cleared in ftrace_check_record()
1830 * if rec count is zero.
1835 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1836 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1838 /* Shortcut, if we handled all records, we are done. */
1839 if (!all && count == hash->count)
1841 } while_for_each_ftrace_rec();
1846 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1849 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1852 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1855 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1858 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1859 int filter_hash, int inc)
1861 struct ftrace_ops *op;
1863 __ftrace_hash_rec_update(ops, filter_hash, inc);
1865 if (ops->func_hash != &global_ops.local_hash)
1869 * If the ops shares the global_ops hash, then we need to update
1870 * all ops that are enabled and use this hash.
1872 do_for_each_ftrace_op(op, ftrace_ops_list) {
1876 if (op->func_hash == &global_ops.local_hash)
1877 __ftrace_hash_rec_update(op, filter_hash, inc);
1878 } while_for_each_ftrace_op(op);
1881 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1884 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1887 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1890 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1894 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1895 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1896 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1897 * Note that old_hash and new_hash has below meanings
1898 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1899 * - If the hash is EMPTY_HASH, it hits nothing
1900 * - Anything else hits the recs which match the hash entries.
1902 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1903 struct ftrace_hash *old_hash,
1904 struct ftrace_hash *new_hash)
1906 struct ftrace_page *pg;
1907 struct dyn_ftrace *rec, *end = NULL;
1910 /* Only update if the ops has been registered */
1911 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1914 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1918 * Since the IPMODIFY is a very address sensitive action, we do not
1919 * allow ftrace_ops to set all functions to new hash.
1921 if (!new_hash || !old_hash)
1924 /* Update rec->flags */
1925 do_for_each_ftrace_rec(pg, rec) {
1927 if (rec->flags & FTRACE_FL_DISABLED)
1930 /* We need to update only differences of filter_hash */
1931 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1932 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1933 if (in_old == in_new)
1937 /* New entries must ensure no others are using it */
1938 if (rec->flags & FTRACE_FL_IPMODIFY)
1940 rec->flags |= FTRACE_FL_IPMODIFY;
1941 } else /* Removed entry */
1942 rec->flags &= ~FTRACE_FL_IPMODIFY;
1943 } while_for_each_ftrace_rec();
1950 /* Roll back what we did above */
1951 do_for_each_ftrace_rec(pg, rec) {
1953 if (rec->flags & FTRACE_FL_DISABLED)
1959 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1960 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1961 if (in_old == in_new)
1965 rec->flags &= ~FTRACE_FL_IPMODIFY;
1967 rec->flags |= FTRACE_FL_IPMODIFY;
1968 } while_for_each_ftrace_rec();
1974 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1976 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1978 if (ftrace_hash_empty(hash))
1981 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1984 /* Disabling always succeeds */
1985 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1987 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1989 if (ftrace_hash_empty(hash))
1992 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1995 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1996 struct ftrace_hash *new_hash)
1998 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
2000 if (ftrace_hash_empty(old_hash))
2003 if (ftrace_hash_empty(new_hash))
2006 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
2009 static void print_ip_ins(const char *fmt, const unsigned char *p)
2013 printk(KERN_CONT "%s", fmt);
2015 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
2016 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
2019 static struct ftrace_ops *
2020 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
2021 static struct ftrace_ops *
2022 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
2024 enum ftrace_bug_type ftrace_bug_type;
2025 const void *ftrace_expected;
2027 static void print_bug_type(void)
2029 switch (ftrace_bug_type) {
2030 case FTRACE_BUG_UNKNOWN:
2032 case FTRACE_BUG_INIT:
2033 pr_info("Initializing ftrace call sites\n");
2035 case FTRACE_BUG_NOP:
2036 pr_info("Setting ftrace call site to NOP\n");
2038 case FTRACE_BUG_CALL:
2039 pr_info("Setting ftrace call site to call ftrace function\n");
2041 case FTRACE_BUG_UPDATE:
2042 pr_info("Updating ftrace call site to call a different ftrace function\n");
2048 * ftrace_bug - report and shutdown function tracer
2049 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2050 * @rec: The record that failed
2052 * The arch code that enables or disables the function tracing
2053 * can call ftrace_bug() when it has detected a problem in
2054 * modifying the code. @failed should be one of either:
2055 * EFAULT - if the problem happens on reading the @ip address
2056 * EINVAL - if what is read at @ip is not what was expected
2057 * EPERM - if the problem happens on writting to the @ip address
2059 void ftrace_bug(int failed, struct dyn_ftrace *rec)
2061 unsigned long ip = rec ? rec->ip : 0;
2065 FTRACE_WARN_ON_ONCE(1);
2066 pr_info("ftrace faulted on modifying ");
2070 FTRACE_WARN_ON_ONCE(1);
2071 pr_info("ftrace failed to modify ");
2073 print_ip_ins(" actual: ", (unsigned char *)ip);
2075 if (ftrace_expected) {
2076 print_ip_ins(" expected: ", ftrace_expected);
2081 FTRACE_WARN_ON_ONCE(1);
2082 pr_info("ftrace faulted on writing ");
2086 FTRACE_WARN_ON_ONCE(1);
2087 pr_info("ftrace faulted on unknown error ");
2092 struct ftrace_ops *ops = NULL;
2094 pr_info("ftrace record flags: %lx\n", rec->flags);
2095 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2096 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2097 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2098 ops = ftrace_find_tramp_ops_any(rec);
2101 pr_cont("\ttramp: %pS (%pS)",
2102 (void *)ops->trampoline,
2104 ops = ftrace_find_tramp_ops_next(rec, ops);
2107 pr_cont("\ttramp: ERROR!");
2110 ip = ftrace_get_addr_curr(rec);
2111 pr_cont("\n expected tramp: %lx\n", ip);
2115 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2117 unsigned long flag = 0UL;
2119 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2121 if (rec->flags & FTRACE_FL_DISABLED)
2122 return FTRACE_UPDATE_IGNORE;
2125 * If we are updating calls:
2127 * If the record has a ref count, then we need to enable it
2128 * because someone is using it.
2130 * Otherwise we make sure its disabled.
2132 * If we are disabling calls, then disable all records that
2135 if (enable && ftrace_rec_count(rec))
2136 flag = FTRACE_FL_ENABLED;
2139 * If enabling and the REGS flag does not match the REGS_EN, or
2140 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2141 * this record. Set flags to fail the compare against ENABLED.
2144 if (!(rec->flags & FTRACE_FL_REGS) !=
2145 !(rec->flags & FTRACE_FL_REGS_EN))
2146 flag |= FTRACE_FL_REGS;
2148 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2149 !(rec->flags & FTRACE_FL_TRAMP_EN))
2150 flag |= FTRACE_FL_TRAMP;
2153 /* If the state of this record hasn't changed, then do nothing */
2154 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2155 return FTRACE_UPDATE_IGNORE;
2158 /* Save off if rec is being enabled (for return value) */
2159 flag ^= rec->flags & FTRACE_FL_ENABLED;
2162 rec->flags |= FTRACE_FL_ENABLED;
2163 if (flag & FTRACE_FL_REGS) {
2164 if (rec->flags & FTRACE_FL_REGS)
2165 rec->flags |= FTRACE_FL_REGS_EN;
2167 rec->flags &= ~FTRACE_FL_REGS_EN;
2169 if (flag & FTRACE_FL_TRAMP) {
2170 if (rec->flags & FTRACE_FL_TRAMP)
2171 rec->flags |= FTRACE_FL_TRAMP_EN;
2173 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2178 * If this record is being updated from a nop, then
2179 * return UPDATE_MAKE_CALL.
2181 * return UPDATE_MODIFY_CALL to tell the caller to convert
2182 * from the save regs, to a non-save regs function or
2183 * vice versa, or from a trampoline call.
2185 if (flag & FTRACE_FL_ENABLED) {
2186 ftrace_bug_type = FTRACE_BUG_CALL;
2187 return FTRACE_UPDATE_MAKE_CALL;
2190 ftrace_bug_type = FTRACE_BUG_UPDATE;
2191 return FTRACE_UPDATE_MODIFY_CALL;
2195 /* If there's no more users, clear all flags */
2196 if (!ftrace_rec_count(rec))
2200 * Just disable the record, but keep the ops TRAMP
2201 * and REGS states. The _EN flags must be disabled though.
2203 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2207 ftrace_bug_type = FTRACE_BUG_NOP;
2208 return FTRACE_UPDATE_MAKE_NOP;
2212 * ftrace_update_record, set a record that now is tracing or not
2213 * @rec: the record to update
2214 * @enable: set to 1 if the record is tracing, zero to force disable
2216 * The records that represent all functions that can be traced need
2217 * to be updated when tracing has been enabled.
2219 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2221 return ftrace_check_record(rec, enable, 1);
2225 * ftrace_test_record, check if the record has been enabled or not
2226 * @rec: the record to test
2227 * @enable: set to 1 to check if enabled, 0 if it is disabled
2229 * The arch code may need to test if a record is already set to
2230 * tracing to determine how to modify the function code that it
2233 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2235 return ftrace_check_record(rec, enable, 0);
2238 static struct ftrace_ops *
2239 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2241 struct ftrace_ops *op;
2242 unsigned long ip = rec->ip;
2244 do_for_each_ftrace_op(op, ftrace_ops_list) {
2246 if (!op->trampoline)
2249 if (hash_contains_ip(ip, op->func_hash))
2251 } while_for_each_ftrace_op(op);
2256 static struct ftrace_ops *
2257 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2258 struct ftrace_ops *op)
2260 unsigned long ip = rec->ip;
2262 while_for_each_ftrace_op(op) {
2264 if (!op->trampoline)
2267 if (hash_contains_ip(ip, op->func_hash))
2274 static struct ftrace_ops *
2275 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2277 struct ftrace_ops *op;
2278 unsigned long ip = rec->ip;
2281 * Need to check removed ops first.
2282 * If they are being removed, and this rec has a tramp,
2283 * and this rec is in the ops list, then it would be the
2284 * one with the tramp.
2287 if (hash_contains_ip(ip, &removed_ops->old_hash))
2292 * Need to find the current trampoline for a rec.
2293 * Now, a trampoline is only attached to a rec if there
2294 * was a single 'ops' attached to it. But this can be called
2295 * when we are adding another op to the rec or removing the
2296 * current one. Thus, if the op is being added, we can
2297 * ignore it because it hasn't attached itself to the rec
2300 * If an ops is being modified (hooking to different functions)
2301 * then we don't care about the new functions that are being
2302 * added, just the old ones (that are probably being removed).
2304 * If we are adding an ops to a function that already is using
2305 * a trampoline, it needs to be removed (trampolines are only
2306 * for single ops connected), then an ops that is not being
2307 * modified also needs to be checked.
2309 do_for_each_ftrace_op(op, ftrace_ops_list) {
2311 if (!op->trampoline)
2315 * If the ops is being added, it hasn't gotten to
2316 * the point to be removed from this tree yet.
2318 if (op->flags & FTRACE_OPS_FL_ADDING)
2323 * If the ops is being modified and is in the old
2324 * hash, then it is probably being removed from this
2327 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2328 hash_contains_ip(ip, &op->old_hash))
2331 * If the ops is not being added or modified, and it's
2332 * in its normal filter hash, then this must be the one
2335 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2336 hash_contains_ip(ip, op->func_hash))
2339 } while_for_each_ftrace_op(op);
2344 static struct ftrace_ops *
2345 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2347 struct ftrace_ops *op;
2348 unsigned long ip = rec->ip;
2350 do_for_each_ftrace_op(op, ftrace_ops_list) {
2351 /* pass rec in as regs to have non-NULL val */
2352 if (hash_contains_ip(ip, op->func_hash))
2354 } while_for_each_ftrace_op(op);
2360 * ftrace_get_addr_new - Get the call address to set to
2361 * @rec: The ftrace record descriptor
2363 * If the record has the FTRACE_FL_REGS set, that means that it
2364 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2365 * is not not set, then it wants to convert to the normal callback.
2367 * Returns the address of the trampoline to set to
2369 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2371 struct ftrace_ops *ops;
2373 /* Trampolines take precedence over regs */
2374 if (rec->flags & FTRACE_FL_TRAMP) {
2375 ops = ftrace_find_tramp_ops_new(rec);
2376 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2377 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2378 (void *)rec->ip, (void *)rec->ip, rec->flags);
2379 /* Ftrace is shutting down, return anything */
2380 return (unsigned long)FTRACE_ADDR;
2382 return ops->trampoline;
2385 if (rec->flags & FTRACE_FL_REGS)
2386 return (unsigned long)FTRACE_REGS_ADDR;
2388 return (unsigned long)FTRACE_ADDR;
2392 * ftrace_get_addr_curr - Get the call address that is already there
2393 * @rec: The ftrace record descriptor
2395 * The FTRACE_FL_REGS_EN is set when the record already points to
2396 * a function that saves all the regs. Basically the '_EN' version
2397 * represents the current state of the function.
2399 * Returns the address of the trampoline that is currently being called
2401 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2403 struct ftrace_ops *ops;
2405 /* Trampolines take precedence over regs */
2406 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2407 ops = ftrace_find_tramp_ops_curr(rec);
2408 if (FTRACE_WARN_ON(!ops)) {
2409 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2410 (void *)rec->ip, (void *)rec->ip);
2411 /* Ftrace is shutting down, return anything */
2412 return (unsigned long)FTRACE_ADDR;
2414 return ops->trampoline;
2417 if (rec->flags & FTRACE_FL_REGS_EN)
2418 return (unsigned long)FTRACE_REGS_ADDR;
2420 return (unsigned long)FTRACE_ADDR;
2424 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2426 unsigned long ftrace_old_addr;
2427 unsigned long ftrace_addr;
2430 ftrace_addr = ftrace_get_addr_new(rec);
2432 /* This needs to be done before we call ftrace_update_record */
2433 ftrace_old_addr = ftrace_get_addr_curr(rec);
2435 ret = ftrace_update_record(rec, enable);
2437 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2440 case FTRACE_UPDATE_IGNORE:
2443 case FTRACE_UPDATE_MAKE_CALL:
2444 ftrace_bug_type = FTRACE_BUG_CALL;
2445 return ftrace_make_call(rec, ftrace_addr);
2447 case FTRACE_UPDATE_MAKE_NOP:
2448 ftrace_bug_type = FTRACE_BUG_NOP;
2449 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2451 case FTRACE_UPDATE_MODIFY_CALL:
2452 ftrace_bug_type = FTRACE_BUG_UPDATE;
2453 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2456 return -1; /* unknow ftrace bug */
2459 void __weak ftrace_replace_code(int enable)
2461 struct dyn_ftrace *rec;
2462 struct ftrace_page *pg;
2465 if (unlikely(ftrace_disabled))
2468 do_for_each_ftrace_rec(pg, rec) {
2470 if (rec->flags & FTRACE_FL_DISABLED)
2473 failed = __ftrace_replace_code(rec, enable);
2475 ftrace_bug(failed, rec);
2476 /* Stop processing */
2479 } while_for_each_ftrace_rec();
2482 struct ftrace_rec_iter {
2483 struct ftrace_page *pg;
2488 * ftrace_rec_iter_start, start up iterating over traced functions
2490 * Returns an iterator handle that is used to iterate over all
2491 * the records that represent address locations where functions
2494 * May return NULL if no records are available.
2496 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2499 * We only use a single iterator.
2500 * Protected by the ftrace_lock mutex.
2502 static struct ftrace_rec_iter ftrace_rec_iter;
2503 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2505 iter->pg = ftrace_pages_start;
2508 /* Could have empty pages */
2509 while (iter->pg && !iter->pg->index)
2510 iter->pg = iter->pg->next;
2519 * ftrace_rec_iter_next, get the next record to process.
2520 * @iter: The handle to the iterator.
2522 * Returns the next iterator after the given iterator @iter.
2524 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2528 if (iter->index >= iter->pg->index) {
2529 iter->pg = iter->pg->next;
2532 /* Could have empty pages */
2533 while (iter->pg && !iter->pg->index)
2534 iter->pg = iter->pg->next;
2544 * ftrace_rec_iter_record, get the record at the iterator location
2545 * @iter: The current iterator location
2547 * Returns the record that the current @iter is at.
2549 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2551 return &iter->pg->records[iter->index];
2555 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2559 if (unlikely(ftrace_disabled))
2562 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2564 ftrace_bug_type = FTRACE_BUG_INIT;
2565 ftrace_bug(ret, rec);
2572 * archs can override this function if they must do something
2573 * before the modifying code is performed.
2575 int __weak ftrace_arch_code_modify_prepare(void)
2581 * archs can override this function if they must do something
2582 * after the modifying code is performed.
2584 int __weak ftrace_arch_code_modify_post_process(void)
2589 void ftrace_modify_all_code(int command)
2591 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2595 * If the ftrace_caller calls a ftrace_ops func directly,
2596 * we need to make sure that it only traces functions it
2597 * expects to trace. When doing the switch of functions,
2598 * we need to update to the ftrace_ops_list_func first
2599 * before the transition between old and new calls are set,
2600 * as the ftrace_ops_list_func will check the ops hashes
2601 * to make sure the ops are having the right functions
2605 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2606 if (FTRACE_WARN_ON(err))
2610 if (command & FTRACE_UPDATE_CALLS)
2611 ftrace_replace_code(1);
2612 else if (command & FTRACE_DISABLE_CALLS)
2613 ftrace_replace_code(0);
2615 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2616 function_trace_op = set_function_trace_op;
2618 /* If irqs are disabled, we are in stop machine */
2619 if (!irqs_disabled())
2620 smp_call_function(ftrace_sync_ipi, NULL, 1);
2621 err = ftrace_update_ftrace_func(ftrace_trace_function);
2622 if (FTRACE_WARN_ON(err))
2626 if (command & FTRACE_START_FUNC_RET)
2627 err = ftrace_enable_ftrace_graph_caller();
2628 else if (command & FTRACE_STOP_FUNC_RET)
2629 err = ftrace_disable_ftrace_graph_caller();
2630 FTRACE_WARN_ON(err);
2633 static int __ftrace_modify_code(void *data)
2635 int *command = data;
2637 ftrace_modify_all_code(*command);
2643 * ftrace_run_stop_machine, go back to the stop machine method
2644 * @command: The command to tell ftrace what to do
2646 * If an arch needs to fall back to the stop machine method, the
2647 * it can call this function.
2649 void ftrace_run_stop_machine(int command)
2651 stop_machine(__ftrace_modify_code, &command, NULL);
2655 * arch_ftrace_update_code, modify the code to trace or not trace
2656 * @command: The command that needs to be done
2658 * Archs can override this function if it does not need to
2659 * run stop_machine() to modify code.
2661 void __weak arch_ftrace_update_code(int command)
2663 ftrace_run_stop_machine(command);
2666 static void ftrace_run_update_code(int command)
2670 ret = ftrace_arch_code_modify_prepare();
2671 FTRACE_WARN_ON(ret);
2676 * By default we use stop_machine() to modify the code.
2677 * But archs can do what ever they want as long as it
2678 * is safe. The stop_machine() is the safest, but also
2679 * produces the most overhead.
2681 arch_ftrace_update_code(command);
2683 ret = ftrace_arch_code_modify_post_process();
2684 FTRACE_WARN_ON(ret);
2687 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2688 struct ftrace_ops_hash *old_hash)
2690 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2691 ops->old_hash.filter_hash = old_hash->filter_hash;
2692 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2693 ftrace_run_update_code(command);
2694 ops->old_hash.filter_hash = NULL;
2695 ops->old_hash.notrace_hash = NULL;
2696 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2699 static ftrace_func_t saved_ftrace_func;
2700 static int ftrace_start_up;
2702 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2706 static void ftrace_startup_enable(int command)
2708 if (saved_ftrace_func != ftrace_trace_function) {
2709 saved_ftrace_func = ftrace_trace_function;
2710 command |= FTRACE_UPDATE_TRACE_FUNC;
2713 if (!command || !ftrace_enabled)
2716 ftrace_run_update_code(command);
2719 static void ftrace_startup_all(int command)
2721 update_all_ops = true;
2722 ftrace_startup_enable(command);
2723 update_all_ops = false;
2726 static int ftrace_startup(struct ftrace_ops *ops, int command)
2730 if (unlikely(ftrace_disabled))
2733 ret = __register_ftrace_function(ops);
2740 * Note that ftrace probes uses this to start up
2741 * and modify functions it will probe. But we still
2742 * set the ADDING flag for modification, as probes
2743 * do not have trampolines. If they add them in the
2744 * future, then the probes will need to distinguish
2745 * between adding and updating probes.
2747 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2749 ret = ftrace_hash_ipmodify_enable(ops);
2751 /* Rollback registration process */
2752 __unregister_ftrace_function(ops);
2754 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2758 if (ftrace_hash_rec_enable(ops, 1))
2759 command |= FTRACE_UPDATE_CALLS;
2761 ftrace_startup_enable(command);
2763 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2768 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2772 if (unlikely(ftrace_disabled))
2775 ret = __unregister_ftrace_function(ops);
2781 * Just warn in case of unbalance, no need to kill ftrace, it's not
2782 * critical but the ftrace_call callers may be never nopped again after
2783 * further ftrace uses.
2785 WARN_ON_ONCE(ftrace_start_up < 0);
2787 /* Disabling ipmodify never fails */
2788 ftrace_hash_ipmodify_disable(ops);
2790 if (ftrace_hash_rec_disable(ops, 1))
2791 command |= FTRACE_UPDATE_CALLS;
2793 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2795 if (saved_ftrace_func != ftrace_trace_function) {
2796 saved_ftrace_func = ftrace_trace_function;
2797 command |= FTRACE_UPDATE_TRACE_FUNC;
2800 if (!command || !ftrace_enabled) {
2802 * If these are dynamic or per_cpu ops, they still
2803 * need their data freed. Since, function tracing is
2804 * not currently active, we can just free them
2805 * without synchronizing all CPUs.
2807 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2814 * If the ops uses a trampoline, then it needs to be
2815 * tested first on update.
2817 ops->flags |= FTRACE_OPS_FL_REMOVING;
2820 /* The trampoline logic checks the old hashes */
2821 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2822 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2824 ftrace_run_update_code(command);
2827 * If there's no more ops registered with ftrace, run a
2828 * sanity check to make sure all rec flags are cleared.
2830 if (rcu_dereference_protected(ftrace_ops_list,
2831 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2832 struct ftrace_page *pg;
2833 struct dyn_ftrace *rec;
2835 do_for_each_ftrace_rec(pg, rec) {
2836 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2837 pr_warn(" %pS flags:%lx\n",
2838 (void *)rec->ip, rec->flags);
2839 } while_for_each_ftrace_rec();
2842 ops->old_hash.filter_hash = NULL;
2843 ops->old_hash.notrace_hash = NULL;
2846 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2849 * Dynamic ops may be freed, we must make sure that all
2850 * callers are done before leaving this function.
2851 * The same goes for freeing the per_cpu data of the per_cpu
2854 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2856 * We need to do a hard force of sched synchronization.
2857 * This is because we use preempt_disable() to do RCU, but
2858 * the function tracers can be called where RCU is not watching
2859 * (like before user_exit()). We can not rely on the RCU
2860 * infrastructure to do the synchronization, thus we must do it
2863 schedule_on_each_cpu(ftrace_sync);
2866 * When the kernel is preeptive, tasks can be preempted
2867 * while on a ftrace trampoline. Just scheduling a task on
2868 * a CPU is not good enough to flush them. Calling
2869 * synchornize_rcu_tasks() will wait for those tasks to
2870 * execute and either schedule voluntarily or enter user space.
2872 if (IS_ENABLED(CONFIG_PREEMPT))
2873 synchronize_rcu_tasks();
2876 arch_ftrace_trampoline_free(ops);
2882 static void ftrace_startup_sysctl(void)
2886 if (unlikely(ftrace_disabled))
2889 /* Force update next time */
2890 saved_ftrace_func = NULL;
2891 /* ftrace_start_up is true if we want ftrace running */
2892 if (ftrace_start_up) {
2893 command = FTRACE_UPDATE_CALLS;
2894 if (ftrace_graph_active)
2895 command |= FTRACE_START_FUNC_RET;
2896 ftrace_startup_enable(command);
2900 static void ftrace_shutdown_sysctl(void)
2904 if (unlikely(ftrace_disabled))
2907 /* ftrace_start_up is true if ftrace is running */
2908 if (ftrace_start_up) {
2909 command = FTRACE_DISABLE_CALLS;
2910 if (ftrace_graph_active)
2911 command |= FTRACE_STOP_FUNC_RET;
2912 ftrace_run_update_code(command);
2916 static u64 ftrace_update_time;
2917 unsigned long ftrace_update_tot_cnt;
2919 static inline int ops_traces_mod(struct ftrace_ops *ops)
2922 * Filter_hash being empty will default to trace module.
2923 * But notrace hash requires a test of individual module functions.
2925 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2926 ftrace_hash_empty(ops->func_hash->notrace_hash);
2930 * Check if the current ops references the record.
2932 * If the ops traces all functions, then it was already accounted for.
2933 * If the ops does not trace the current record function, skip it.
2934 * If the ops ignores the function via notrace filter, skip it.
2937 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2939 /* If ops isn't enabled, ignore it */
2940 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2943 /* If ops traces all then it includes this function */
2944 if (ops_traces_mod(ops))
2947 /* The function must be in the filter */
2948 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2949 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2952 /* If in notrace hash, we ignore it too */
2953 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2959 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2961 struct ftrace_page *pg;
2962 struct dyn_ftrace *p;
2964 unsigned long update_cnt = 0;
2965 unsigned long rec_flags = 0;
2968 start = ftrace_now(raw_smp_processor_id());
2971 * When a module is loaded, this function is called to convert
2972 * the calls to mcount in its text to nops, and also to create
2973 * an entry in the ftrace data. Now, if ftrace is activated
2974 * after this call, but before the module sets its text to
2975 * read-only, the modification of enabling ftrace can fail if
2976 * the read-only is done while ftrace is converting the calls.
2977 * To prevent this, the module's records are set as disabled
2978 * and will be enabled after the call to set the module's text
2982 rec_flags |= FTRACE_FL_DISABLED;
2984 for (pg = new_pgs; pg; pg = pg->next) {
2986 for (i = 0; i < pg->index; i++) {
2988 /* If something went wrong, bail without enabling anything */
2989 if (unlikely(ftrace_disabled))
2992 p = &pg->records[i];
2993 p->flags = rec_flags;
2996 * Do the initial record conversion from mcount jump
2997 * to the NOP instructions.
2999 if (!ftrace_code_disable(mod, p))
3006 stop = ftrace_now(raw_smp_processor_id());
3007 ftrace_update_time = stop - start;
3008 ftrace_update_tot_cnt += update_cnt;
3013 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3018 if (WARN_ON(!count))
3021 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
3024 * We want to fill as much as possible. No more than a page
3027 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
3031 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3034 /* if we can't allocate this size, try something smaller */
3041 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3050 static struct ftrace_page *
3051 ftrace_allocate_pages(unsigned long num_to_init)
3053 struct ftrace_page *start_pg;
3054 struct ftrace_page *pg;
3061 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3066 * Try to allocate as much as possible in one continues
3067 * location that fills in all of the space. We want to
3068 * waste as little space as possible.
3071 cnt = ftrace_allocate_records(pg, num_to_init);
3079 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3091 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3092 free_pages((unsigned long)pg->records, order);
3093 start_pg = pg->next;
3097 pr_info("ftrace: FAILED to allocate memory for functions\n");
3101 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3103 struct ftrace_iterator {
3107 struct ftrace_page *pg;
3108 struct dyn_ftrace *func;
3109 struct ftrace_func_probe *probe;
3110 struct ftrace_func_entry *probe_entry;
3111 struct trace_parser parser;
3112 struct ftrace_hash *hash;
3113 struct ftrace_ops *ops;
3114 struct trace_array *tr;
3115 struct list_head *mod_list;
3122 t_probe_next(struct seq_file *m, loff_t *pos)
3124 struct ftrace_iterator *iter = m->private;
3125 struct trace_array *tr = iter->ops->private;
3126 struct list_head *func_probes;
3127 struct ftrace_hash *hash;
3128 struct list_head *next;
3129 struct hlist_node *hnd = NULL;
3130 struct hlist_head *hhd;
3139 func_probes = &tr->func_probes;
3140 if (list_empty(func_probes))
3144 next = func_probes->next;
3145 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3148 if (iter->probe_entry)
3149 hnd = &iter->probe_entry->hlist;
3151 hash = iter->probe->ops.func_hash->filter_hash;
3152 size = 1 << hash->size_bits;
3155 if (iter->pidx >= size) {
3156 if (iter->probe->list.next == func_probes)
3158 next = iter->probe->list.next;
3159 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3160 hash = iter->probe->ops.func_hash->filter_hash;
3161 size = 1 << hash->size_bits;
3165 hhd = &hash->buckets[iter->pidx];
3167 if (hlist_empty(hhd)) {
3183 if (WARN_ON_ONCE(!hnd))
3186 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3191 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3193 struct ftrace_iterator *iter = m->private;
3197 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3200 if (iter->mod_pos > *pos)
3204 iter->probe_entry = NULL;
3206 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3207 p = t_probe_next(m, &l);
3214 /* Only set this if we have an item */
3215 iter->flags |= FTRACE_ITER_PROBE;
3221 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3223 struct ftrace_func_entry *probe_entry;
3224 struct ftrace_probe_ops *probe_ops;
3225 struct ftrace_func_probe *probe;
3227 probe = iter->probe;
3228 probe_entry = iter->probe_entry;
3230 if (WARN_ON_ONCE(!probe || !probe_entry))
3233 probe_ops = probe->probe_ops;
3235 if (probe_ops->print)
3236 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3238 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3239 (void *)probe_ops->func);
3245 t_mod_next(struct seq_file *m, loff_t *pos)
3247 struct ftrace_iterator *iter = m->private;
3248 struct trace_array *tr = iter->tr;
3253 iter->mod_list = iter->mod_list->next;
3255 if (iter->mod_list == &tr->mod_trace ||
3256 iter->mod_list == &tr->mod_notrace) {
3257 iter->flags &= ~FTRACE_ITER_MOD;
3261 iter->mod_pos = *pos;
3266 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3268 struct ftrace_iterator *iter = m->private;
3272 if (iter->func_pos > *pos)
3275 iter->mod_pos = iter->func_pos;
3277 /* probes are only available if tr is set */
3281 for (l = 0; l <= (*pos - iter->func_pos); ) {
3282 p = t_mod_next(m, &l);
3287 iter->flags &= ~FTRACE_ITER_MOD;
3288 return t_probe_start(m, pos);
3291 /* Only set this if we have an item */
3292 iter->flags |= FTRACE_ITER_MOD;
3298 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3300 struct ftrace_mod_load *ftrace_mod;
3301 struct trace_array *tr = iter->tr;
3303 if (WARN_ON_ONCE(!iter->mod_list) ||
3304 iter->mod_list == &tr->mod_trace ||
3305 iter->mod_list == &tr->mod_notrace)
3308 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3310 if (ftrace_mod->func)
3311 seq_printf(m, "%s", ftrace_mod->func);
3315 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3321 t_func_next(struct seq_file *m, loff_t *pos)
3323 struct ftrace_iterator *iter = m->private;
3324 struct dyn_ftrace *rec = NULL;
3329 if (iter->idx >= iter->pg->index) {
3330 if (iter->pg->next) {
3331 iter->pg = iter->pg->next;
3336 rec = &iter->pg->records[iter->idx++];
3337 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3338 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3340 ((iter->flags & FTRACE_ITER_ENABLED) &&
3341 !(rec->flags & FTRACE_FL_ENABLED))) {
3351 iter->pos = iter->func_pos = *pos;
3358 t_next(struct seq_file *m, void *v, loff_t *pos)
3360 struct ftrace_iterator *iter = m->private;
3361 loff_t l = *pos; /* t_probe_start() must use original pos */
3364 if (unlikely(ftrace_disabled))
3367 if (iter->flags & FTRACE_ITER_PROBE)
3368 return t_probe_next(m, pos);
3370 if (iter->flags & FTRACE_ITER_MOD)
3371 return t_mod_next(m, pos);
3373 if (iter->flags & FTRACE_ITER_PRINTALL) {
3374 /* next must increment pos, and t_probe_start does not */
3376 return t_mod_start(m, &l);
3379 ret = t_func_next(m, pos);
3382 return t_mod_start(m, &l);
3387 static void reset_iter_read(struct ftrace_iterator *iter)
3391 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3394 static void *t_start(struct seq_file *m, loff_t *pos)
3396 struct ftrace_iterator *iter = m->private;
3400 mutex_lock(&ftrace_lock);
3402 if (unlikely(ftrace_disabled))
3406 * If an lseek was done, then reset and start from beginning.
3408 if (*pos < iter->pos)
3409 reset_iter_read(iter);
3412 * For set_ftrace_filter reading, if we have the filter
3413 * off, we can short cut and just print out that all
3414 * functions are enabled.
3416 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3417 ftrace_hash_empty(iter->hash)) {
3418 iter->func_pos = 1; /* Account for the message */
3420 return t_mod_start(m, pos);
3421 iter->flags |= FTRACE_ITER_PRINTALL;
3422 /* reset in case of seek/pread */
3423 iter->flags &= ~FTRACE_ITER_PROBE;
3427 if (iter->flags & FTRACE_ITER_MOD)
3428 return t_mod_start(m, pos);
3431 * Unfortunately, we need to restart at ftrace_pages_start
3432 * every time we let go of the ftrace_mutex. This is because
3433 * those pointers can change without the lock.
3435 iter->pg = ftrace_pages_start;
3437 for (l = 0; l <= *pos; ) {
3438 p = t_func_next(m, &l);
3444 return t_mod_start(m, pos);
3449 static void t_stop(struct seq_file *m, void *p)
3451 mutex_unlock(&ftrace_lock);
3455 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3460 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3461 struct dyn_ftrace *rec)
3465 ptr = arch_ftrace_trampoline_func(ops, rec);
3467 seq_printf(m, " ->%pS", ptr);
3470 static int t_show(struct seq_file *m, void *v)
3472 struct ftrace_iterator *iter = m->private;
3473 struct dyn_ftrace *rec;
3475 if (iter->flags & FTRACE_ITER_PROBE)
3476 return t_probe_show(m, iter);
3478 if (iter->flags & FTRACE_ITER_MOD)
3479 return t_mod_show(m, iter);
3481 if (iter->flags & FTRACE_ITER_PRINTALL) {
3482 if (iter->flags & FTRACE_ITER_NOTRACE)
3483 seq_puts(m, "#### no functions disabled ####\n");
3485 seq_puts(m, "#### all functions enabled ####\n");
3494 seq_printf(m, "%ps", (void *)rec->ip);
3495 if (iter->flags & FTRACE_ITER_ENABLED) {
3496 struct ftrace_ops *ops;
3498 seq_printf(m, " (%ld)%s%s",
3499 ftrace_rec_count(rec),
3500 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3501 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3502 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3503 ops = ftrace_find_tramp_ops_any(rec);
3506 seq_printf(m, "\ttramp: %pS (%pS)",
3507 (void *)ops->trampoline,
3509 add_trampoline_func(m, ops, rec);
3510 ops = ftrace_find_tramp_ops_next(rec, ops);
3513 seq_puts(m, "\ttramp: ERROR!");
3515 add_trampoline_func(m, NULL, rec);
3524 static const struct seq_operations show_ftrace_seq_ops = {
3532 ftrace_avail_open(struct inode *inode, struct file *file)
3534 struct ftrace_iterator *iter;
3536 if (unlikely(ftrace_disabled))
3539 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3543 iter->pg = ftrace_pages_start;
3544 iter->ops = &global_ops;
3550 ftrace_enabled_open(struct inode *inode, struct file *file)
3552 struct ftrace_iterator *iter;
3554 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3558 iter->pg = ftrace_pages_start;
3559 iter->flags = FTRACE_ITER_ENABLED;
3560 iter->ops = &global_ops;
3566 * ftrace_regex_open - initialize function tracer filter files
3567 * @ops: The ftrace_ops that hold the hash filters
3568 * @flag: The type of filter to process
3569 * @inode: The inode, usually passed in to your open routine
3570 * @file: The file, usually passed in to your open routine
3572 * ftrace_regex_open() initializes the filter files for the
3573 * @ops. Depending on @flag it may process the filter hash or
3574 * the notrace hash of @ops. With this called from the open
3575 * routine, you can use ftrace_filter_write() for the write
3576 * routine if @flag has FTRACE_ITER_FILTER set, or
3577 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3578 * tracing_lseek() should be used as the lseek routine, and
3579 * release must call ftrace_regex_release().
3582 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3583 struct inode *inode, struct file *file)
3585 struct ftrace_iterator *iter;
3586 struct ftrace_hash *hash;
3587 struct list_head *mod_head;
3588 struct trace_array *tr = ops->private;
3591 ftrace_ops_init(ops);
3593 if (unlikely(ftrace_disabled))
3596 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3600 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3609 mutex_lock(&ops->func_hash->regex_lock);
3611 if (flag & FTRACE_ITER_NOTRACE) {
3612 hash = ops->func_hash->notrace_hash;
3613 mod_head = tr ? &tr->mod_notrace : NULL;
3615 hash = ops->func_hash->filter_hash;
3616 mod_head = tr ? &tr->mod_trace : NULL;
3619 iter->mod_list = mod_head;
3621 if (file->f_mode & FMODE_WRITE) {
3622 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3624 if (file->f_flags & O_TRUNC) {
3625 iter->hash = alloc_ftrace_hash(size_bits);
3626 clear_ftrace_mod_list(mod_head);
3628 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3632 trace_parser_put(&iter->parser);
3640 if (file->f_mode & FMODE_READ) {
3641 iter->pg = ftrace_pages_start;
3643 ret = seq_open(file, &show_ftrace_seq_ops);
3645 struct seq_file *m = file->private_data;
3649 free_ftrace_hash(iter->hash);
3650 trace_parser_put(&iter->parser);
3654 file->private_data = iter;
3657 mutex_unlock(&ops->func_hash->regex_lock);
3663 ftrace_filter_open(struct inode *inode, struct file *file)
3665 struct ftrace_ops *ops = inode->i_private;
3667 return ftrace_regex_open(ops,
3668 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3673 ftrace_notrace_open(struct inode *inode, struct file *file)
3675 struct ftrace_ops *ops = inode->i_private;
3677 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3681 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3682 struct ftrace_glob {
3689 * If symbols in an architecture don't correspond exactly to the user-visible
3690 * name of what they represent, it is possible to define this function to
3691 * perform the necessary adjustments.
3693 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3698 static int ftrace_match(char *str, struct ftrace_glob *g)
3703 str = arch_ftrace_match_adjust(str, g->search);
3707 if (strcmp(str, g->search) == 0)
3710 case MATCH_FRONT_ONLY:
3711 if (strncmp(str, g->search, g->len) == 0)
3714 case MATCH_MIDDLE_ONLY:
3715 if (strstr(str, g->search))
3718 case MATCH_END_ONLY:
3720 if (slen >= g->len &&
3721 memcmp(str + slen - g->len, g->search, g->len) == 0)
3725 if (glob_match(g->search, str))
3734 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3736 struct ftrace_func_entry *entry;
3739 entry = ftrace_lookup_ip(hash, rec->ip);
3741 /* Do nothing if it doesn't exist */
3745 free_hash_entry(hash, entry);
3747 /* Do nothing if it exists */
3751 ret = add_hash_entry(hash, rec->ip);
3757 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3758 struct ftrace_glob *mod_g, int exclude_mod)
3760 char str[KSYM_SYMBOL_LEN];
3763 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3766 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3768 /* blank module name to match all modules */
3770 /* blank module globbing: modname xor exclude_mod */
3771 if (!exclude_mod != !modname)
3777 * exclude_mod is set to trace everything but the given
3778 * module. If it is set and the module matches, then
3779 * return 0. If it is not set, and the module doesn't match
3780 * also return 0. Otherwise, check the function to see if
3783 if (!mod_matches == !exclude_mod)
3786 /* blank search means to match all funcs in the mod */
3791 return ftrace_match(str, func_g);
3795 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3797 struct ftrace_page *pg;
3798 struct dyn_ftrace *rec;
3799 struct ftrace_glob func_g = { .type = MATCH_FULL };
3800 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3801 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3802 int exclude_mod = 0;
3805 int clear_filter = 0;
3808 func_g.type = filter_parse_regex(func, len, &func_g.search,
3810 func_g.len = strlen(func_g.search);
3814 mod_g.type = filter_parse_regex(mod, strlen(mod),
3815 &mod_g.search, &exclude_mod);
3816 mod_g.len = strlen(mod_g.search);
3819 mutex_lock(&ftrace_lock);
3821 if (unlikely(ftrace_disabled))
3824 do_for_each_ftrace_rec(pg, rec) {
3826 if (rec->flags & FTRACE_FL_DISABLED)
3829 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3830 ret = enter_record(hash, rec, clear_filter);
3837 } while_for_each_ftrace_rec();
3839 mutex_unlock(&ftrace_lock);
3845 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3847 return match_records(hash, buff, len, NULL);
3850 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3851 struct ftrace_ops_hash *old_hash)
3853 struct ftrace_ops *op;
3855 if (!ftrace_enabled)
3858 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3859 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3864 * If this is the shared global_ops filter, then we need to
3865 * check if there is another ops that shares it, is enabled.
3866 * If so, we still need to run the modify code.
3868 if (ops->func_hash != &global_ops.local_hash)
3871 do_for_each_ftrace_op(op, ftrace_ops_list) {
3872 if (op->func_hash == &global_ops.local_hash &&
3873 op->flags & FTRACE_OPS_FL_ENABLED) {
3874 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3875 /* Only need to do this once */
3878 } while_for_each_ftrace_op(op);
3881 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3882 struct ftrace_hash **orig_hash,
3883 struct ftrace_hash *hash,
3886 struct ftrace_ops_hash old_hash_ops;
3887 struct ftrace_hash *old_hash;
3890 old_hash = *orig_hash;
3891 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3892 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3893 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3895 ftrace_ops_update_code(ops, &old_hash_ops);
3896 free_ftrace_hash_rcu(old_hash);
3901 static bool module_exists(const char *module)
3903 /* All modules have the symbol __this_module */
3904 const char this_mod[] = "__this_module";
3905 char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
3909 n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
3911 if (n > sizeof(modname) - 1)
3914 val = module_kallsyms_lookup_name(modname);
3918 static int cache_mod(struct trace_array *tr,
3919 const char *func, char *module, int enable)
3921 struct ftrace_mod_load *ftrace_mod, *n;
3922 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3925 mutex_lock(&ftrace_lock);
3927 /* We do not cache inverse filters */
3928 if (func[0] == '!') {
3932 /* Look to remove this hash */
3933 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3934 if (strcmp(ftrace_mod->module, module) != 0)
3937 /* no func matches all */
3938 if (strcmp(func, "*") == 0 ||
3939 (ftrace_mod->func &&
3940 strcmp(ftrace_mod->func, func) == 0)) {
3942 free_ftrace_mod(ftrace_mod);
3950 /* We only care about modules that have not been loaded yet */
3951 if (module_exists(module))
3954 /* Save this string off, and execute it when the module is loaded */
3955 ret = ftrace_add_mod(tr, func, module, enable);
3957 mutex_unlock(&ftrace_lock);
3963 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3964 int reset, int enable);
3966 #ifdef CONFIG_MODULES
3967 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3968 char *mod, bool enable)
3970 struct ftrace_mod_load *ftrace_mod, *n;
3971 struct ftrace_hash **orig_hash, *new_hash;
3972 LIST_HEAD(process_mods);
3976 mutex_lock(&ops->func_hash->regex_lock);
3979 orig_hash = &ops->func_hash->filter_hash;
3981 orig_hash = &ops->func_hash->notrace_hash;
3983 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3986 goto out; /* warn? */
3988 mutex_lock(&ftrace_lock);
3990 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3992 if (strcmp(ftrace_mod->module, mod) != 0)
3995 if (ftrace_mod->func)
3996 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
3998 func = kstrdup("*", GFP_KERNEL);
4000 if (!func) /* warn? */
4003 list_del(&ftrace_mod->list);
4004 list_add(&ftrace_mod->list, &process_mods);
4006 /* Use the newly allocated func, as it may be "*" */
4007 kfree(ftrace_mod->func);
4008 ftrace_mod->func = func;
4011 mutex_unlock(&ftrace_lock);
4013 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4015 func = ftrace_mod->func;
4017 /* Grabs ftrace_lock, which is why we have this extra step */
4018 match_records(new_hash, func, strlen(func), mod);
4019 free_ftrace_mod(ftrace_mod);
4022 if (enable && list_empty(head))
4023 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4025 mutex_lock(&ftrace_lock);
4027 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4029 mutex_unlock(&ftrace_lock);
4032 mutex_unlock(&ops->func_hash->regex_lock);
4034 free_ftrace_hash(new_hash);
4037 static void process_cached_mods(const char *mod_name)
4039 struct trace_array *tr;
4042 mod = kstrdup(mod_name, GFP_KERNEL);
4046 mutex_lock(&trace_types_lock);
4047 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4048 if (!list_empty(&tr->mod_trace))
4049 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4050 if (!list_empty(&tr->mod_notrace))
4051 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4053 mutex_unlock(&trace_types_lock);
4060 * We register the module command as a template to show others how
4061 * to register the a command as well.
4065 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4066 char *func_orig, char *cmd, char *module, int enable)
4071 /* match_records() modifies func, and we need the original */
4072 func = kstrdup(func_orig, GFP_KERNEL);
4077 * cmd == 'mod' because we only registered this func
4078 * for the 'mod' ftrace_func_command.
4079 * But if you register one func with multiple commands,
4080 * you can tell which command was used by the cmd
4083 ret = match_records(hash, func, strlen(func), module);
4087 return cache_mod(tr, func_orig, module, enable);
4093 static struct ftrace_func_command ftrace_mod_cmd = {
4095 .func = ftrace_mod_callback,
4098 static int __init ftrace_mod_cmd_init(void)
4100 return register_ftrace_command(&ftrace_mod_cmd);
4102 core_initcall(ftrace_mod_cmd_init);
4104 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4105 struct ftrace_ops *op, struct pt_regs *pt_regs)
4107 struct ftrace_probe_ops *probe_ops;
4108 struct ftrace_func_probe *probe;
4110 probe = container_of(op, struct ftrace_func_probe, ops);
4111 probe_ops = probe->probe_ops;
4114 * Disable preemption for these calls to prevent a RCU grace
4115 * period. This syncs the hash iteration and freeing of items
4116 * on the hash. rcu_read_lock is too dangerous here.
4118 preempt_disable_notrace();
4119 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4120 preempt_enable_notrace();
4123 struct ftrace_func_map {
4124 struct ftrace_func_entry entry;
4128 struct ftrace_func_mapper {
4129 struct ftrace_hash hash;
4133 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4135 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4137 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4139 struct ftrace_hash *hash;
4142 * The mapper is simply a ftrace_hash, but since the entries
4143 * in the hash are not ftrace_func_entry type, we define it
4144 * as a separate structure.
4146 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4147 return (struct ftrace_func_mapper *)hash;
4151 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4152 * @mapper: The mapper that has the ip maps
4153 * @ip: the instruction pointer to find the data for
4155 * Returns the data mapped to @ip if found otherwise NULL. The return
4156 * is actually the address of the mapper data pointer. The address is
4157 * returned for use cases where the data is no bigger than a long, and
4158 * the user can use the data pointer as its data instead of having to
4159 * allocate more memory for the reference.
4161 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4164 struct ftrace_func_entry *entry;
4165 struct ftrace_func_map *map;
4167 entry = ftrace_lookup_ip(&mapper->hash, ip);
4171 map = (struct ftrace_func_map *)entry;
4176 * ftrace_func_mapper_add_ip - Map some data to an ip
4177 * @mapper: The mapper that has the ip maps
4178 * @ip: The instruction pointer address to map @data to
4179 * @data: The data to map to @ip
4181 * Returns 0 on succes otherwise an error.
4183 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4184 unsigned long ip, void *data)
4186 struct ftrace_func_entry *entry;
4187 struct ftrace_func_map *map;
4189 entry = ftrace_lookup_ip(&mapper->hash, ip);
4193 map = kmalloc(sizeof(*map), GFP_KERNEL);
4200 __add_hash_entry(&mapper->hash, &map->entry);
4206 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4207 * @mapper: The mapper that has the ip maps
4208 * @ip: The instruction pointer address to remove the data from
4210 * Returns the data if it is found, otherwise NULL.
4211 * Note, if the data pointer is used as the data itself, (see
4212 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4213 * if the data pointer was set to zero.
4215 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4218 struct ftrace_func_entry *entry;
4219 struct ftrace_func_map *map;
4222 entry = ftrace_lookup_ip(&mapper->hash, ip);
4226 map = (struct ftrace_func_map *)entry;
4229 remove_hash_entry(&mapper->hash, entry);
4236 * free_ftrace_func_mapper - free a mapping of ips and data
4237 * @mapper: The mapper that has the ip maps
4238 * @free_func: A function to be called on each data item.
4240 * This is used to free the function mapper. The @free_func is optional
4241 * and can be used if the data needs to be freed as well.
4243 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4244 ftrace_mapper_func free_func)
4246 struct ftrace_func_entry *entry;
4247 struct ftrace_func_map *map;
4248 struct hlist_head *hhd;
4249 int size = 1 << mapper->hash.size_bits;
4252 if (free_func && mapper->hash.count) {
4253 for (i = 0; i < size; i++) {
4254 hhd = &mapper->hash.buckets[i];
4255 hlist_for_each_entry(entry, hhd, hlist) {
4256 map = (struct ftrace_func_map *)entry;
4261 free_ftrace_hash(&mapper->hash);
4264 static void release_probe(struct ftrace_func_probe *probe)
4266 struct ftrace_probe_ops *probe_ops;
4268 mutex_lock(&ftrace_lock);
4270 WARN_ON(probe->ref <= 0);
4272 /* Subtract the ref that was used to protect this instance */
4276 probe_ops = probe->probe_ops;
4278 * Sending zero as ip tells probe_ops to free
4279 * the probe->data itself
4281 if (probe_ops->free)
4282 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4283 list_del(&probe->list);
4286 mutex_unlock(&ftrace_lock);
4289 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4292 * Add one ref to keep it from being freed when releasing the
4293 * ftrace_lock mutex.
4299 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4300 struct ftrace_probe_ops *probe_ops,
4303 struct ftrace_func_entry *entry;
4304 struct ftrace_func_probe *probe;
4305 struct ftrace_hash **orig_hash;
4306 struct ftrace_hash *old_hash;
4307 struct ftrace_hash *hash;
4316 /* We do not support '!' for function probes */
4317 if (WARN_ON(glob[0] == '!'))
4321 mutex_lock(&ftrace_lock);
4322 /* Check if the probe_ops is already registered */
4323 list_for_each_entry(probe, &tr->func_probes, list) {
4324 if (probe->probe_ops == probe_ops)
4327 if (&probe->list == &tr->func_probes) {
4328 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4330 mutex_unlock(&ftrace_lock);
4333 probe->probe_ops = probe_ops;
4334 probe->ops.func = function_trace_probe_call;
4336 ftrace_ops_init(&probe->ops);
4337 list_add(&probe->list, &tr->func_probes);
4340 acquire_probe_locked(probe);
4342 mutex_unlock(&ftrace_lock);
4344 mutex_lock(&probe->ops.func_hash->regex_lock);
4346 orig_hash = &probe->ops.func_hash->filter_hash;
4347 old_hash = *orig_hash;
4348 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4350 ret = ftrace_match_records(hash, glob, strlen(glob));
4352 /* Nothing found? */
4359 size = 1 << hash->size_bits;
4360 for (i = 0; i < size; i++) {
4361 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4362 if (ftrace_lookup_ip(old_hash, entry->ip))
4365 * The caller might want to do something special
4366 * for each function we find. We call the callback
4367 * to give the caller an opportunity to do so.
4369 if (probe_ops->init) {
4370 ret = probe_ops->init(probe_ops, tr,
4374 if (probe_ops->free && count)
4375 probe_ops->free(probe_ops, tr,
4385 mutex_lock(&ftrace_lock);
4388 /* Nothing was added? */
4393 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4398 /* One ref for each new function traced */
4399 probe->ref += count;
4401 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4402 ret = ftrace_startup(&probe->ops, 0);
4405 mutex_unlock(&ftrace_lock);
4410 mutex_unlock(&probe->ops.func_hash->regex_lock);
4411 free_ftrace_hash(hash);
4413 release_probe(probe);
4418 if (!probe_ops->free || !count)
4421 /* Failed to do the move, need to call the free functions */
4422 for (i = 0; i < size; i++) {
4423 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4424 if (ftrace_lookup_ip(old_hash, entry->ip))
4426 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4433 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4434 struct ftrace_probe_ops *probe_ops)
4436 struct ftrace_ops_hash old_hash_ops;
4437 struct ftrace_func_entry *entry;
4438 struct ftrace_func_probe *probe;
4439 struct ftrace_glob func_g;
4440 struct ftrace_hash **orig_hash;
4441 struct ftrace_hash *old_hash;
4442 struct ftrace_hash *hash = NULL;
4443 struct hlist_node *tmp;
4444 struct hlist_head hhd;
4445 char str[KSYM_SYMBOL_LEN];
4447 int i, ret = -ENODEV;
4450 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4451 func_g.search = NULL;
4455 func_g.type = filter_parse_regex(glob, strlen(glob),
4456 &func_g.search, ¬);
4457 func_g.len = strlen(func_g.search);
4459 /* we do not support '!' for function probes */
4464 mutex_lock(&ftrace_lock);
4465 /* Check if the probe_ops is already registered */
4466 list_for_each_entry(probe, &tr->func_probes, list) {
4467 if (probe->probe_ops == probe_ops)
4470 if (&probe->list == &tr->func_probes)
4471 goto err_unlock_ftrace;
4474 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4475 goto err_unlock_ftrace;
4477 acquire_probe_locked(probe);
4479 mutex_unlock(&ftrace_lock);
4481 mutex_lock(&probe->ops.func_hash->regex_lock);
4483 orig_hash = &probe->ops.func_hash->filter_hash;
4484 old_hash = *orig_hash;
4486 if (ftrace_hash_empty(old_hash))
4489 old_hash_ops.filter_hash = old_hash;
4490 /* Probes only have filters */
4491 old_hash_ops.notrace_hash = NULL;
4494 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4498 INIT_HLIST_HEAD(&hhd);
4500 size = 1 << hash->size_bits;
4501 for (i = 0; i < size; i++) {
4502 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4504 if (func_g.search) {
4505 kallsyms_lookup(entry->ip, NULL, NULL,
4507 if (!ftrace_match(str, &func_g))
4511 remove_hash_entry(hash, entry);
4512 hlist_add_head(&entry->hlist, &hhd);
4516 /* Nothing found? */
4522 mutex_lock(&ftrace_lock);
4524 WARN_ON(probe->ref < count);
4526 probe->ref -= count;
4528 if (ftrace_hash_empty(hash))
4529 ftrace_shutdown(&probe->ops, 0);
4531 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4534 /* still need to update the function call sites */
4535 if (ftrace_enabled && !ftrace_hash_empty(hash))
4536 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4538 synchronize_sched();
4540 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4541 hlist_del(&entry->hlist);
4542 if (probe_ops->free)
4543 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4546 mutex_unlock(&ftrace_lock);
4549 mutex_unlock(&probe->ops.func_hash->regex_lock);
4550 free_ftrace_hash(hash);
4552 release_probe(probe);
4557 mutex_unlock(&ftrace_lock);
4561 void clear_ftrace_function_probes(struct trace_array *tr)
4563 struct ftrace_func_probe *probe, *n;
4565 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4566 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4569 static LIST_HEAD(ftrace_commands);
4570 static DEFINE_MUTEX(ftrace_cmd_mutex);
4573 * Currently we only register ftrace commands from __init, so mark this
4576 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4578 struct ftrace_func_command *p;
4581 mutex_lock(&ftrace_cmd_mutex);
4582 list_for_each_entry(p, &ftrace_commands, list) {
4583 if (strcmp(cmd->name, p->name) == 0) {
4588 list_add(&cmd->list, &ftrace_commands);
4590 mutex_unlock(&ftrace_cmd_mutex);
4596 * Currently we only unregister ftrace commands from __init, so mark
4599 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4601 struct ftrace_func_command *p, *n;
4604 mutex_lock(&ftrace_cmd_mutex);
4605 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4606 if (strcmp(cmd->name, p->name) == 0) {
4608 list_del_init(&p->list);
4613 mutex_unlock(&ftrace_cmd_mutex);
4618 static int ftrace_process_regex(struct ftrace_iterator *iter,
4619 char *buff, int len, int enable)
4621 struct ftrace_hash *hash = iter->hash;
4622 struct trace_array *tr = iter->ops->private;
4623 char *func, *command, *next = buff;
4624 struct ftrace_func_command *p;
4627 func = strsep(&next, ":");
4630 ret = ftrace_match_records(hash, func, len);
4640 command = strsep(&next, ":");
4642 mutex_lock(&ftrace_cmd_mutex);
4643 list_for_each_entry(p, &ftrace_commands, list) {
4644 if (strcmp(p->name, command) == 0) {
4645 ret = p->func(tr, hash, func, command, next, enable);
4650 mutex_unlock(&ftrace_cmd_mutex);
4656 ftrace_regex_write(struct file *file, const char __user *ubuf,
4657 size_t cnt, loff_t *ppos, int enable)
4659 struct ftrace_iterator *iter;
4660 struct trace_parser *parser;
4666 if (file->f_mode & FMODE_READ) {
4667 struct seq_file *m = file->private_data;
4670 iter = file->private_data;
4672 if (unlikely(ftrace_disabled))
4675 /* iter->hash is a local copy, so we don't need regex_lock */
4677 parser = &iter->parser;
4678 read = trace_get_user(parser, ubuf, cnt, ppos);
4680 if (read >= 0 && trace_parser_loaded(parser) &&
4681 !trace_parser_cont(parser)) {
4682 ret = ftrace_process_regex(iter, parser->buffer,
4683 parser->idx, enable);
4684 trace_parser_clear(parser);
4695 ftrace_filter_write(struct file *file, const char __user *ubuf,
4696 size_t cnt, loff_t *ppos)
4698 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4702 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4703 size_t cnt, loff_t *ppos)
4705 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4709 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4711 struct ftrace_func_entry *entry;
4713 if (!ftrace_location(ip))
4717 entry = ftrace_lookup_ip(hash, ip);
4720 free_hash_entry(hash, entry);
4724 return add_hash_entry(hash, ip);
4728 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4729 unsigned long ip, int remove, int reset, int enable)
4731 struct ftrace_hash **orig_hash;
4732 struct ftrace_hash *hash;
4735 if (unlikely(ftrace_disabled))
4738 mutex_lock(&ops->func_hash->regex_lock);
4741 orig_hash = &ops->func_hash->filter_hash;
4743 orig_hash = &ops->func_hash->notrace_hash;
4746 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4748 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4752 goto out_regex_unlock;
4755 if (buf && !ftrace_match_records(hash, buf, len)) {
4757 goto out_regex_unlock;
4760 ret = ftrace_match_addr(hash, ip, remove);
4762 goto out_regex_unlock;
4765 mutex_lock(&ftrace_lock);
4766 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4767 mutex_unlock(&ftrace_lock);
4770 mutex_unlock(&ops->func_hash->regex_lock);
4772 free_ftrace_hash(hash);
4777 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4778 int reset, int enable)
4780 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4784 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4785 * @ops - the ops to set the filter with
4786 * @ip - the address to add to or remove from the filter.
4787 * @remove - non zero to remove the ip from the filter
4788 * @reset - non zero to reset all filters before applying this filter.
4790 * Filters denote which functions should be enabled when tracing is enabled
4791 * If @ip is NULL, it failes to update filter.
4793 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4794 int remove, int reset)
4796 ftrace_ops_init(ops);
4797 return ftrace_set_addr(ops, ip, remove, reset, 1);
4799 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4802 * ftrace_ops_set_global_filter - setup ops to use global filters
4803 * @ops - the ops which will use the global filters
4805 * ftrace users who need global function trace filtering should call this.
4806 * It can set the global filter only if ops were not initialized before.
4808 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4810 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4813 ftrace_ops_init(ops);
4814 ops->func_hash = &global_ops.local_hash;
4816 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4819 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4820 int reset, int enable)
4822 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4826 * ftrace_set_filter - set a function to filter on in ftrace
4827 * @ops - the ops to set the filter with
4828 * @buf - the string that holds the function filter text.
4829 * @len - the length of the string.
4830 * @reset - non zero to reset all filters before applying this filter.
4832 * Filters denote which functions should be enabled when tracing is enabled.
4833 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4835 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4838 ftrace_ops_init(ops);
4839 return ftrace_set_regex(ops, buf, len, reset, 1);
4841 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4844 * ftrace_set_notrace - set a function to not trace in ftrace
4845 * @ops - the ops to set the notrace filter with
4846 * @buf - the string that holds the function notrace text.
4847 * @len - the length of the string.
4848 * @reset - non zero to reset all filters before applying this filter.
4850 * Notrace Filters denote which functions should not be enabled when tracing
4851 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4854 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4857 ftrace_ops_init(ops);
4858 return ftrace_set_regex(ops, buf, len, reset, 0);
4860 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4862 * ftrace_set_global_filter - set a function to filter on with global tracers
4863 * @buf - the string that holds the function filter text.
4864 * @len - the length of the string.
4865 * @reset - non zero to reset all filters before applying this filter.
4867 * Filters denote which functions should be enabled when tracing is enabled.
4868 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4870 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4872 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4874 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4877 * ftrace_set_global_notrace - set a function to not trace with global tracers
4878 * @buf - the string that holds the function notrace text.
4879 * @len - the length of the string.
4880 * @reset - non zero to reset all filters before applying this filter.
4882 * Notrace Filters denote which functions should not be enabled when tracing
4883 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4886 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4888 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4890 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4893 * command line interface to allow users to set filters on boot up.
4895 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4896 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4897 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4899 /* Used by function selftest to not test if filter is set */
4900 bool ftrace_filter_param __initdata;
4902 static int __init set_ftrace_notrace(char *str)
4904 ftrace_filter_param = true;
4905 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4908 __setup("ftrace_notrace=", set_ftrace_notrace);
4910 static int __init set_ftrace_filter(char *str)
4912 ftrace_filter_param = true;
4913 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4916 __setup("ftrace_filter=", set_ftrace_filter);
4918 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4919 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4920 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4921 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4923 static int __init set_graph_function(char *str)
4925 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4928 __setup("ftrace_graph_filter=", set_graph_function);
4930 static int __init set_graph_notrace_function(char *str)
4932 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4935 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4937 static int __init set_graph_max_depth_function(char *str)
4941 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4944 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4946 static void __init set_ftrace_early_graph(char *buf, int enable)
4950 struct ftrace_hash *hash;
4952 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4957 func = strsep(&buf, ",");
4958 /* we allow only one expression at a time */
4959 ret = ftrace_graph_set_hash(hash, func);
4961 printk(KERN_DEBUG "ftrace: function %s not "
4962 "traceable\n", func);
4966 ftrace_graph_hash = hash;
4968 ftrace_graph_notrace_hash = hash;
4970 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4973 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4977 ftrace_ops_init(ops);
4980 func = strsep(&buf, ",");
4981 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4985 static void __init set_ftrace_early_filters(void)
4987 if (ftrace_filter_buf[0])
4988 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4989 if (ftrace_notrace_buf[0])
4990 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4991 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4992 if (ftrace_graph_buf[0])
4993 set_ftrace_early_graph(ftrace_graph_buf, 1);
4994 if (ftrace_graph_notrace_buf[0])
4995 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4996 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4999 int ftrace_regex_release(struct inode *inode, struct file *file)
5001 struct seq_file *m = (struct seq_file *)file->private_data;
5002 struct ftrace_iterator *iter;
5003 struct ftrace_hash **orig_hash;
5004 struct trace_parser *parser;
5008 if (file->f_mode & FMODE_READ) {
5010 seq_release(inode, file);
5012 iter = file->private_data;
5014 parser = &iter->parser;
5015 if (trace_parser_loaded(parser)) {
5016 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5019 trace_parser_put(parser);
5021 mutex_lock(&iter->ops->func_hash->regex_lock);
5023 if (file->f_mode & FMODE_WRITE) {
5024 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5027 orig_hash = &iter->ops->func_hash->filter_hash;
5028 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5029 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5031 orig_hash = &iter->ops->func_hash->notrace_hash;
5033 mutex_lock(&ftrace_lock);
5034 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5035 iter->hash, filter_hash);
5036 mutex_unlock(&ftrace_lock);
5038 /* For read only, the hash is the ops hash */
5042 mutex_unlock(&iter->ops->func_hash->regex_lock);
5043 free_ftrace_hash(iter->hash);
5049 static const struct file_operations ftrace_avail_fops = {
5050 .open = ftrace_avail_open,
5052 .llseek = seq_lseek,
5053 .release = seq_release_private,
5056 static const struct file_operations ftrace_enabled_fops = {
5057 .open = ftrace_enabled_open,
5059 .llseek = seq_lseek,
5060 .release = seq_release_private,
5063 static const struct file_operations ftrace_filter_fops = {
5064 .open = ftrace_filter_open,
5066 .write = ftrace_filter_write,
5067 .llseek = tracing_lseek,
5068 .release = ftrace_regex_release,
5071 static const struct file_operations ftrace_notrace_fops = {
5072 .open = ftrace_notrace_open,
5074 .write = ftrace_notrace_write,
5075 .llseek = tracing_lseek,
5076 .release = ftrace_regex_release,
5079 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5081 static DEFINE_MUTEX(graph_lock);
5083 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5084 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5086 enum graph_filter_type {
5087 GRAPH_FILTER_NOTRACE = 0,
5088 GRAPH_FILTER_FUNCTION,
5091 #define FTRACE_GRAPH_EMPTY ((void *)1)
5093 struct ftrace_graph_data {
5094 struct ftrace_hash *hash;
5095 struct ftrace_func_entry *entry;
5096 int idx; /* for hash table iteration */
5097 enum graph_filter_type type;
5098 struct ftrace_hash *new_hash;
5099 const struct seq_operations *seq_ops;
5100 struct trace_parser parser;
5104 __g_next(struct seq_file *m, loff_t *pos)
5106 struct ftrace_graph_data *fgd = m->private;
5107 struct ftrace_func_entry *entry = fgd->entry;
5108 struct hlist_head *head;
5109 int i, idx = fgd->idx;
5111 if (*pos >= fgd->hash->count)
5115 hlist_for_each_entry_continue(entry, hlist) {
5123 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5124 head = &fgd->hash->buckets[i];
5125 hlist_for_each_entry(entry, head, hlist) {
5135 g_next(struct seq_file *m, void *v, loff_t *pos)
5138 return __g_next(m, pos);
5141 static void *g_start(struct seq_file *m, loff_t *pos)
5143 struct ftrace_graph_data *fgd = m->private;
5145 mutex_lock(&graph_lock);
5147 if (fgd->type == GRAPH_FILTER_FUNCTION)
5148 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5149 lockdep_is_held(&graph_lock));
5151 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5152 lockdep_is_held(&graph_lock));
5154 /* Nothing, tell g_show to print all functions are enabled */
5155 if (ftrace_hash_empty(fgd->hash) && !*pos)
5156 return FTRACE_GRAPH_EMPTY;
5160 return __g_next(m, pos);
5163 static void g_stop(struct seq_file *m, void *p)
5165 mutex_unlock(&graph_lock);
5168 static int g_show(struct seq_file *m, void *v)
5170 struct ftrace_func_entry *entry = v;
5175 if (entry == FTRACE_GRAPH_EMPTY) {
5176 struct ftrace_graph_data *fgd = m->private;
5178 if (fgd->type == GRAPH_FILTER_FUNCTION)
5179 seq_puts(m, "#### all functions enabled ####\n");
5181 seq_puts(m, "#### no functions disabled ####\n");
5185 seq_printf(m, "%ps\n", (void *)entry->ip);
5190 static const struct seq_operations ftrace_graph_seq_ops = {
5198 __ftrace_graph_open(struct inode *inode, struct file *file,
5199 struct ftrace_graph_data *fgd)
5202 struct ftrace_hash *new_hash = NULL;
5204 if (file->f_mode & FMODE_WRITE) {
5205 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5207 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5210 if (file->f_flags & O_TRUNC)
5211 new_hash = alloc_ftrace_hash(size_bits);
5213 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5221 if (file->f_mode & FMODE_READ) {
5222 ret = seq_open(file, &ftrace_graph_seq_ops);
5224 struct seq_file *m = file->private_data;
5228 free_ftrace_hash(new_hash);
5232 file->private_data = fgd;
5235 if (ret < 0 && file->f_mode & FMODE_WRITE)
5236 trace_parser_put(&fgd->parser);
5238 fgd->new_hash = new_hash;
5241 * All uses of fgd->hash must be taken with the graph_lock
5242 * held. The graph_lock is going to be released, so force
5243 * fgd->hash to be reinitialized when it is taken again.
5251 ftrace_graph_open(struct inode *inode, struct file *file)
5253 struct ftrace_graph_data *fgd;
5256 if (unlikely(ftrace_disabled))
5259 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5263 mutex_lock(&graph_lock);
5265 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5266 lockdep_is_held(&graph_lock));
5267 fgd->type = GRAPH_FILTER_FUNCTION;
5268 fgd->seq_ops = &ftrace_graph_seq_ops;
5270 ret = __ftrace_graph_open(inode, file, fgd);
5274 mutex_unlock(&graph_lock);
5279 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5281 struct ftrace_graph_data *fgd;
5284 if (unlikely(ftrace_disabled))
5287 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5291 mutex_lock(&graph_lock);
5293 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5294 lockdep_is_held(&graph_lock));
5295 fgd->type = GRAPH_FILTER_NOTRACE;
5296 fgd->seq_ops = &ftrace_graph_seq_ops;
5298 ret = __ftrace_graph_open(inode, file, fgd);
5302 mutex_unlock(&graph_lock);
5307 ftrace_graph_release(struct inode *inode, struct file *file)
5309 struct ftrace_graph_data *fgd;
5310 struct ftrace_hash *old_hash, *new_hash;
5311 struct trace_parser *parser;
5314 if (file->f_mode & FMODE_READ) {
5315 struct seq_file *m = file->private_data;
5318 seq_release(inode, file);
5320 fgd = file->private_data;
5324 if (file->f_mode & FMODE_WRITE) {
5326 parser = &fgd->parser;
5328 if (trace_parser_loaded((parser))) {
5329 ret = ftrace_graph_set_hash(fgd->new_hash,
5333 trace_parser_put(parser);
5335 new_hash = __ftrace_hash_move(fgd->new_hash);
5341 mutex_lock(&graph_lock);
5343 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5344 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5345 lockdep_is_held(&graph_lock));
5346 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5348 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5349 lockdep_is_held(&graph_lock));
5350 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5353 mutex_unlock(&graph_lock);
5355 /* Wait till all users are no longer using the old hash */
5356 synchronize_sched();
5358 free_ftrace_hash(old_hash);
5362 free_ftrace_hash(fgd->new_hash);
5369 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5371 struct ftrace_glob func_g;
5372 struct dyn_ftrace *rec;
5373 struct ftrace_page *pg;
5374 struct ftrace_func_entry *entry;
5379 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5380 &func_g.search, ¬);
5382 func_g.len = strlen(func_g.search);
5384 mutex_lock(&ftrace_lock);
5386 if (unlikely(ftrace_disabled)) {
5387 mutex_unlock(&ftrace_lock);
5391 do_for_each_ftrace_rec(pg, rec) {
5393 if (rec->flags & FTRACE_FL_DISABLED)
5396 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5397 entry = ftrace_lookup_ip(hash, rec->ip);
5404 if (add_hash_entry(hash, rec->ip) < 0)
5408 free_hash_entry(hash, entry);
5413 } while_for_each_ftrace_rec();
5415 mutex_unlock(&ftrace_lock);
5424 ftrace_graph_write(struct file *file, const char __user *ubuf,
5425 size_t cnt, loff_t *ppos)
5427 ssize_t read, ret = 0;
5428 struct ftrace_graph_data *fgd = file->private_data;
5429 struct trace_parser *parser;
5434 /* Read mode uses seq functions */
5435 if (file->f_mode & FMODE_READ) {
5436 struct seq_file *m = file->private_data;
5440 parser = &fgd->parser;
5442 read = trace_get_user(parser, ubuf, cnt, ppos);
5444 if (read >= 0 && trace_parser_loaded(parser) &&
5445 !trace_parser_cont(parser)) {
5447 ret = ftrace_graph_set_hash(fgd->new_hash,
5449 trace_parser_clear(parser);
5458 static const struct file_operations ftrace_graph_fops = {
5459 .open = ftrace_graph_open,
5461 .write = ftrace_graph_write,
5462 .llseek = tracing_lseek,
5463 .release = ftrace_graph_release,
5466 static const struct file_operations ftrace_graph_notrace_fops = {
5467 .open = ftrace_graph_notrace_open,
5469 .write = ftrace_graph_write,
5470 .llseek = tracing_lseek,
5471 .release = ftrace_graph_release,
5473 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5475 void ftrace_create_filter_files(struct ftrace_ops *ops,
5476 struct dentry *parent)
5479 trace_create_file("set_ftrace_filter", 0644, parent,
5480 ops, &ftrace_filter_fops);
5482 trace_create_file("set_ftrace_notrace", 0644, parent,
5483 ops, &ftrace_notrace_fops);
5487 * The name "destroy_filter_files" is really a misnomer. Although
5488 * in the future, it may actualy delete the files, but this is
5489 * really intended to make sure the ops passed in are disabled
5490 * and that when this function returns, the caller is free to
5493 * The "destroy" name is only to match the "create" name that this
5494 * should be paired with.
5496 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5498 mutex_lock(&ftrace_lock);
5499 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5500 ftrace_shutdown(ops, 0);
5501 ops->flags |= FTRACE_OPS_FL_DELETED;
5502 mutex_unlock(&ftrace_lock);
5505 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5508 trace_create_file("available_filter_functions", 0444,
5509 d_tracer, NULL, &ftrace_avail_fops);
5511 trace_create_file("enabled_functions", 0444,
5512 d_tracer, NULL, &ftrace_enabled_fops);
5514 ftrace_create_filter_files(&global_ops, d_tracer);
5516 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5517 trace_create_file("set_graph_function", 0644, d_tracer,
5519 &ftrace_graph_fops);
5520 trace_create_file("set_graph_notrace", 0644, d_tracer,
5522 &ftrace_graph_notrace_fops);
5523 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5528 static int ftrace_cmp_ips(const void *a, const void *b)
5530 const unsigned long *ipa = a;
5531 const unsigned long *ipb = b;
5540 static int ftrace_process_locs(struct module *mod,
5541 unsigned long *start,
5544 struct ftrace_page *start_pg;
5545 struct ftrace_page *pg;
5546 struct dyn_ftrace *rec;
5547 unsigned long count;
5550 unsigned long flags = 0; /* Shut up gcc */
5553 count = end - start;
5558 sort(start, count, sizeof(*start),
5559 ftrace_cmp_ips, NULL);
5561 start_pg = ftrace_allocate_pages(count);
5565 mutex_lock(&ftrace_lock);
5568 * Core and each module needs their own pages, as
5569 * modules will free them when they are removed.
5570 * Force a new page to be allocated for modules.
5573 WARN_ON(ftrace_pages || ftrace_pages_start);
5574 /* First initialization */
5575 ftrace_pages = ftrace_pages_start = start_pg;
5580 if (WARN_ON(ftrace_pages->next)) {
5581 /* Hmm, we have free pages? */
5582 while (ftrace_pages->next)
5583 ftrace_pages = ftrace_pages->next;
5586 ftrace_pages->next = start_pg;
5592 addr = ftrace_call_adjust(*p++);
5594 * Some architecture linkers will pad between
5595 * the different mcount_loc sections of different
5596 * object files to satisfy alignments.
5597 * Skip any NULL pointers.
5602 if (pg->index == pg->size) {
5603 /* We should have allocated enough */
5604 if (WARN_ON(!pg->next))
5609 rec = &pg->records[pg->index++];
5613 /* We should have used all pages */
5616 /* Assign the last page to ftrace_pages */
5620 * We only need to disable interrupts on start up
5621 * because we are modifying code that an interrupt
5622 * may execute, and the modification is not atomic.
5623 * But for modules, nothing runs the code we modify
5624 * until we are finished with it, and there's no
5625 * reason to cause large interrupt latencies while we do it.
5628 local_irq_save(flags);
5629 ftrace_update_code(mod, start_pg);
5631 local_irq_restore(flags);
5634 mutex_unlock(&ftrace_lock);
5639 struct ftrace_mod_func {
5640 struct list_head list;
5646 struct ftrace_mod_map {
5647 struct rcu_head rcu;
5648 struct list_head list;
5650 unsigned long start_addr;
5651 unsigned long end_addr;
5652 struct list_head funcs;
5653 unsigned int num_funcs;
5656 #ifdef CONFIG_MODULES
5658 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5660 static LIST_HEAD(ftrace_mod_maps);
5662 static int referenced_filters(struct dyn_ftrace *rec)
5664 struct ftrace_ops *ops;
5667 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5668 if (ops_references_rec(ops, rec))
5676 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5678 struct ftrace_func_entry *entry;
5679 struct dyn_ftrace *rec;
5682 if (ftrace_hash_empty(hash))
5685 for (i = 0; i < pg->index; i++) {
5686 rec = &pg->records[i];
5687 entry = __ftrace_lookup_ip(hash, rec->ip);
5689 * Do not allow this rec to match again.
5690 * Yeah, it may waste some memory, but will be removed
5691 * if/when the hash is modified again.
5698 /* Clear any records from hashs */
5699 static void clear_mod_from_hashes(struct ftrace_page *pg)
5701 struct trace_array *tr;
5703 mutex_lock(&trace_types_lock);
5704 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5705 if (!tr->ops || !tr->ops->func_hash)
5707 mutex_lock(&tr->ops->func_hash->regex_lock);
5708 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5709 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5710 mutex_unlock(&tr->ops->func_hash->regex_lock);
5712 mutex_unlock(&trace_types_lock);
5715 static void ftrace_free_mod_map(struct rcu_head *rcu)
5717 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5718 struct ftrace_mod_func *mod_func;
5719 struct ftrace_mod_func *n;
5721 /* All the contents of mod_map are now not visible to readers */
5722 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5723 kfree(mod_func->name);
5724 list_del(&mod_func->list);
5731 void ftrace_release_mod(struct module *mod)
5733 struct ftrace_mod_map *mod_map;
5734 struct ftrace_mod_map *n;
5735 struct dyn_ftrace *rec;
5736 struct ftrace_page **last_pg;
5737 struct ftrace_page *tmp_page = NULL;
5738 struct ftrace_page *pg;
5741 mutex_lock(&ftrace_lock);
5743 if (ftrace_disabled)
5746 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5747 if (mod_map->mod == mod) {
5748 list_del_rcu(&mod_map->list);
5749 call_rcu_sched(&mod_map->rcu, ftrace_free_mod_map);
5755 * Each module has its own ftrace_pages, remove
5756 * them from the list.
5758 last_pg = &ftrace_pages_start;
5759 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5760 rec = &pg->records[0];
5761 if (within_module_core(rec->ip, mod) ||
5762 within_module_init(rec->ip, mod)) {
5764 * As core pages are first, the first
5765 * page should never be a module page.
5767 if (WARN_ON(pg == ftrace_pages_start))
5770 /* Check if we are deleting the last page */
5771 if (pg == ftrace_pages)
5772 ftrace_pages = next_to_ftrace_page(last_pg);
5774 ftrace_update_tot_cnt -= pg->index;
5775 *last_pg = pg->next;
5777 pg->next = tmp_page;
5780 last_pg = &pg->next;
5783 mutex_unlock(&ftrace_lock);
5785 for (pg = tmp_page; pg; pg = tmp_page) {
5787 /* Needs to be called outside of ftrace_lock */
5788 clear_mod_from_hashes(pg);
5790 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5791 free_pages((unsigned long)pg->records, order);
5792 tmp_page = pg->next;
5797 void ftrace_module_enable(struct module *mod)
5799 struct dyn_ftrace *rec;
5800 struct ftrace_page *pg;
5802 mutex_lock(&ftrace_lock);
5804 if (ftrace_disabled)
5808 * If the tracing is enabled, go ahead and enable the record.
5810 * The reason not to enable the record immediatelly is the
5811 * inherent check of ftrace_make_nop/ftrace_make_call for
5812 * correct previous instructions. Making first the NOP
5813 * conversion puts the module to the correct state, thus
5814 * passing the ftrace_make_call check.
5816 * We also delay this to after the module code already set the
5817 * text to read-only, as we now need to set it back to read-write
5818 * so that we can modify the text.
5820 if (ftrace_start_up)
5821 ftrace_arch_code_modify_prepare();
5823 do_for_each_ftrace_rec(pg, rec) {
5826 * do_for_each_ftrace_rec() is a double loop.
5827 * module text shares the pg. If a record is
5828 * not part of this module, then skip this pg,
5829 * which the "break" will do.
5831 if (!within_module_core(rec->ip, mod) &&
5832 !within_module_init(rec->ip, mod))
5838 * When adding a module, we need to check if tracers are
5839 * currently enabled and if they are, and can trace this record,
5840 * we need to enable the module functions as well as update the
5841 * reference counts for those function records.
5843 if (ftrace_start_up)
5844 cnt += referenced_filters(rec);
5846 /* This clears FTRACE_FL_DISABLED */
5849 if (ftrace_start_up && cnt) {
5850 int failed = __ftrace_replace_code(rec, 1);
5852 ftrace_bug(failed, rec);
5857 } while_for_each_ftrace_rec();
5860 if (ftrace_start_up)
5861 ftrace_arch_code_modify_post_process();
5864 mutex_unlock(&ftrace_lock);
5866 process_cached_mods(mod->name);
5869 void ftrace_module_init(struct module *mod)
5871 if (ftrace_disabled || !mod->num_ftrace_callsites)
5874 ftrace_process_locs(mod, mod->ftrace_callsites,
5875 mod->ftrace_callsites + mod->num_ftrace_callsites);
5878 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5879 struct dyn_ftrace *rec)
5881 struct ftrace_mod_func *mod_func;
5882 unsigned long symsize;
5883 unsigned long offset;
5884 char str[KSYM_SYMBOL_LEN];
5888 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5892 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5896 mod_func->name = kstrdup(str, GFP_KERNEL);
5897 if (!mod_func->name) {
5902 mod_func->ip = rec->ip - offset;
5903 mod_func->size = symsize;
5905 mod_map->num_funcs++;
5907 list_add_rcu(&mod_func->list, &mod_map->funcs);
5910 static struct ftrace_mod_map *
5911 allocate_ftrace_mod_map(struct module *mod,
5912 unsigned long start, unsigned long end)
5914 struct ftrace_mod_map *mod_map;
5916 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5921 mod_map->start_addr = start;
5922 mod_map->end_addr = end;
5923 mod_map->num_funcs = 0;
5925 INIT_LIST_HEAD_RCU(&mod_map->funcs);
5927 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5933 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5934 unsigned long addr, unsigned long *size,
5935 unsigned long *off, char *sym)
5937 struct ftrace_mod_func *found_func = NULL;
5938 struct ftrace_mod_func *mod_func;
5940 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5941 if (addr >= mod_func->ip &&
5942 addr < mod_func->ip + mod_func->size) {
5943 found_func = mod_func;
5950 *size = found_func->size;
5952 *off = addr - found_func->ip;
5954 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5956 return found_func->name;
5963 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5964 unsigned long *off, char **modname, char *sym)
5966 struct ftrace_mod_map *mod_map;
5967 const char *ret = NULL;
5969 /* mod_map is freed via call_rcu_sched() */
5971 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5972 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
5975 *modname = mod_map->mod->name;
5984 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
5985 char *type, char *name,
5986 char *module_name, int *exported)
5988 struct ftrace_mod_map *mod_map;
5989 struct ftrace_mod_func *mod_func;
5992 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5994 if (symnum >= mod_map->num_funcs) {
5995 symnum -= mod_map->num_funcs;
5999 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6005 *value = mod_func->ip;
6007 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
6008 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6021 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6022 struct dyn_ftrace *rec) { }
6023 static inline struct ftrace_mod_map *
6024 allocate_ftrace_mod_map(struct module *mod,
6025 unsigned long start, unsigned long end)
6029 #endif /* CONFIG_MODULES */
6031 struct ftrace_init_func {
6032 struct list_head list;
6036 /* Clear any init ips from hashes */
6038 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6040 struct ftrace_func_entry *entry;
6042 if (ftrace_hash_empty(hash))
6045 entry = __ftrace_lookup_ip(hash, func->ip);
6048 * Do not allow this rec to match again.
6049 * Yeah, it may waste some memory, but will be removed
6050 * if/when the hash is modified again.
6057 clear_func_from_hashes(struct ftrace_init_func *func)
6059 struct trace_array *tr;
6061 mutex_lock(&trace_types_lock);
6062 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6063 if (!tr->ops || !tr->ops->func_hash)
6065 mutex_lock(&tr->ops->func_hash->regex_lock);
6066 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6067 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6068 mutex_unlock(&tr->ops->func_hash->regex_lock);
6070 mutex_unlock(&trace_types_lock);
6073 static void add_to_clear_hash_list(struct list_head *clear_list,
6074 struct dyn_ftrace *rec)
6076 struct ftrace_init_func *func;
6078 func = kmalloc(sizeof(*func), GFP_KERNEL);
6080 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6085 list_add(&func->list, clear_list);
6088 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6090 unsigned long start = (unsigned long)(start_ptr);
6091 unsigned long end = (unsigned long)(end_ptr);
6092 struct ftrace_page **last_pg = &ftrace_pages_start;
6093 struct ftrace_page *pg;
6094 struct dyn_ftrace *rec;
6095 struct dyn_ftrace key;
6096 struct ftrace_mod_map *mod_map = NULL;
6097 struct ftrace_init_func *func, *func_next;
6098 struct list_head clear_hash;
6101 INIT_LIST_HEAD(&clear_hash);
6104 key.flags = end; /* overload flags, as it is unsigned long */
6106 mutex_lock(&ftrace_lock);
6109 * If we are freeing module init memory, then check if
6110 * any tracer is active. If so, we need to save a mapping of
6111 * the module functions being freed with the address.
6113 if (mod && ftrace_ops_list != &ftrace_list_end)
6114 mod_map = allocate_ftrace_mod_map(mod, start, end);
6116 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6117 if (end < pg->records[0].ip ||
6118 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6121 rec = bsearch(&key, pg->records, pg->index,
6122 sizeof(struct dyn_ftrace),
6127 /* rec will be cleared from hashes after ftrace_lock unlock */
6128 add_to_clear_hash_list(&clear_hash, rec);
6131 save_ftrace_mod_rec(mod_map, rec);
6134 ftrace_update_tot_cnt--;
6136 *last_pg = pg->next;
6137 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6138 free_pages((unsigned long)pg->records, order);
6140 pg = container_of(last_pg, struct ftrace_page, next);
6145 memmove(rec, rec + 1,
6146 (pg->index - (rec - pg->records)) * sizeof(*rec));
6147 /* More than one function may be in this block */
6150 mutex_unlock(&ftrace_lock);
6152 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6153 clear_func_from_hashes(func);
6158 void __init ftrace_free_init_mem(void)
6160 void *start = (void *)(&__init_begin);
6161 void *end = (void *)(&__init_end);
6163 ftrace_free_mem(NULL, start, end);
6166 void __init ftrace_init(void)
6168 extern unsigned long __start_mcount_loc[];
6169 extern unsigned long __stop_mcount_loc[];
6170 unsigned long count, flags;
6173 local_irq_save(flags);
6174 ret = ftrace_dyn_arch_init();
6175 local_irq_restore(flags);
6179 count = __stop_mcount_loc - __start_mcount_loc;
6181 pr_info("ftrace: No functions to be traced?\n");
6185 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6186 count, count / ENTRIES_PER_PAGE + 1);
6188 last_ftrace_enabled = ftrace_enabled = 1;
6190 ret = ftrace_process_locs(NULL,
6194 set_ftrace_early_filters();
6198 ftrace_disabled = 1;
6201 /* Do nothing if arch does not support this */
6202 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6206 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6208 arch_ftrace_update_trampoline(ops);
6211 void ftrace_init_trace_array(struct trace_array *tr)
6213 INIT_LIST_HEAD(&tr->func_probes);
6214 INIT_LIST_HEAD(&tr->mod_trace);
6215 INIT_LIST_HEAD(&tr->mod_notrace);
6219 static struct ftrace_ops global_ops = {
6220 .func = ftrace_stub,
6221 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6222 FTRACE_OPS_FL_INITIALIZED |
6226 static int __init ftrace_nodyn_init(void)
6231 core_initcall(ftrace_nodyn_init);
6233 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6234 static inline void ftrace_startup_enable(int command) { }
6235 static inline void ftrace_startup_all(int command) { }
6236 /* Keep as macros so we do not need to define the commands */
6237 # define ftrace_startup(ops, command) \
6239 int ___ret = __register_ftrace_function(ops); \
6241 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
6244 # define ftrace_shutdown(ops, command) \
6246 int ___ret = __unregister_ftrace_function(ops); \
6248 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
6252 # define ftrace_startup_sysctl() do { } while (0)
6253 # define ftrace_shutdown_sysctl() do { } while (0)
6256 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
6261 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6265 #endif /* CONFIG_DYNAMIC_FTRACE */
6267 __init void ftrace_init_global_array_ops(struct trace_array *tr)
6269 tr->ops = &global_ops;
6270 tr->ops->private = tr;
6271 ftrace_init_trace_array(tr);
6274 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6276 /* If we filter on pids, update to use the pid function */
6277 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6278 if (WARN_ON(tr->ops->func != ftrace_stub))
6279 printk("ftrace ops had %pS for function\n",
6282 tr->ops->func = func;
6283 tr->ops->private = tr;
6286 void ftrace_reset_array_ops(struct trace_array *tr)
6288 tr->ops->func = ftrace_stub;
6292 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6293 struct ftrace_ops *ignored, struct pt_regs *regs)
6295 struct ftrace_ops *op;
6298 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6303 * Some of the ops may be dynamically allocated,
6304 * they must be freed after a synchronize_sched().
6306 preempt_disable_notrace();
6308 do_for_each_ftrace_op(op, ftrace_ops_list) {
6310 * Check the following for each ops before calling their func:
6311 * if RCU flag is set, then rcu_is_watching() must be true
6312 * if PER_CPU is set, then ftrace_function_local_disable()
6314 * Otherwise test if the ip matches the ops filter
6316 * If any of the above fails then the op->func() is not executed.
6318 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6319 ftrace_ops_test(op, ip, regs)) {
6320 if (FTRACE_WARN_ON(!op->func)) {
6321 pr_warn("op=%p %pS\n", op, op);
6324 op->func(ip, parent_ip, op, regs);
6326 } while_for_each_ftrace_op(op);
6328 preempt_enable_notrace();
6329 trace_clear_recursion(bit);
6333 * Some archs only support passing ip and parent_ip. Even though
6334 * the list function ignores the op parameter, we do not want any
6335 * C side effects, where a function is called without the caller
6336 * sending a third parameter.
6337 * Archs are to support both the regs and ftrace_ops at the same time.
6338 * If they support ftrace_ops, it is assumed they support regs.
6339 * If call backs want to use regs, they must either check for regs
6340 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6341 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6342 * An architecture can pass partial regs with ftrace_ops and still
6343 * set the ARCH_SUPPORTS_FTRACE_OPS.
6345 #if ARCH_SUPPORTS_FTRACE_OPS
6346 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6347 struct ftrace_ops *op, struct pt_regs *regs)
6349 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6352 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6354 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6359 * If there's only one function registered but it does not support
6360 * recursion, needs RCU protection and/or requires per cpu handling, then
6361 * this function will be called by the mcount trampoline.
6363 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6364 struct ftrace_ops *op, struct pt_regs *regs)
6368 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6371 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6375 preempt_disable_notrace();
6377 op->func(ip, parent_ip, op, regs);
6379 preempt_enable_notrace();
6380 trace_clear_recursion(bit);
6384 * ftrace_ops_get_func - get the function a trampoline should call
6385 * @ops: the ops to get the function for
6387 * Normally the mcount trampoline will call the ops->func, but there
6388 * are times that it should not. For example, if the ops does not
6389 * have its own recursion protection, then it should call the
6390 * ftrace_ops_assist_func() instead.
6392 * Returns the function that the trampoline should call for @ops.
6394 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6397 * If the function does not handle recursion, needs to be RCU safe,
6398 * or does per cpu logic, then we need to call the assist handler.
6400 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6401 ops->flags & FTRACE_OPS_FL_RCU)
6402 return ftrace_ops_assist_func;
6408 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6409 struct task_struct *prev, struct task_struct *next)
6411 struct trace_array *tr = data;
6412 struct trace_pid_list *pid_list;
6414 pid_list = rcu_dereference_sched(tr->function_pids);
6416 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6417 trace_ignore_this_task(pid_list, next));
6421 ftrace_pid_follow_sched_process_fork(void *data,
6422 struct task_struct *self,
6423 struct task_struct *task)
6425 struct trace_pid_list *pid_list;
6426 struct trace_array *tr = data;
6428 pid_list = rcu_dereference_sched(tr->function_pids);
6429 trace_filter_add_remove_task(pid_list, self, task);
6433 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6435 struct trace_pid_list *pid_list;
6436 struct trace_array *tr = data;
6438 pid_list = rcu_dereference_sched(tr->function_pids);
6439 trace_filter_add_remove_task(pid_list, NULL, task);
6442 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6445 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6447 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6450 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6452 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6457 static void clear_ftrace_pids(struct trace_array *tr)
6459 struct trace_pid_list *pid_list;
6462 pid_list = rcu_dereference_protected(tr->function_pids,
6463 lockdep_is_held(&ftrace_lock));
6467 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6469 for_each_possible_cpu(cpu)
6470 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6472 rcu_assign_pointer(tr->function_pids, NULL);
6474 /* Wait till all users are no longer using pid filtering */
6475 synchronize_sched();
6477 trace_free_pid_list(pid_list);
6480 void ftrace_clear_pids(struct trace_array *tr)
6482 mutex_lock(&ftrace_lock);
6484 clear_ftrace_pids(tr);
6486 mutex_unlock(&ftrace_lock);
6489 static void ftrace_pid_reset(struct trace_array *tr)
6491 mutex_lock(&ftrace_lock);
6492 clear_ftrace_pids(tr);
6494 ftrace_update_pid_func();
6495 ftrace_startup_all(0);
6497 mutex_unlock(&ftrace_lock);
6500 /* Greater than any max PID */
6501 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6503 static void *fpid_start(struct seq_file *m, loff_t *pos)
6506 struct trace_pid_list *pid_list;
6507 struct trace_array *tr = m->private;
6509 mutex_lock(&ftrace_lock);
6510 rcu_read_lock_sched();
6512 pid_list = rcu_dereference_sched(tr->function_pids);
6515 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6517 return trace_pid_start(pid_list, pos);
6520 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6522 struct trace_array *tr = m->private;
6523 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6525 if (v == FTRACE_NO_PIDS)
6528 return trace_pid_next(pid_list, v, pos);
6531 static void fpid_stop(struct seq_file *m, void *p)
6534 rcu_read_unlock_sched();
6535 mutex_unlock(&ftrace_lock);
6538 static int fpid_show(struct seq_file *m, void *v)
6540 if (v == FTRACE_NO_PIDS) {
6541 seq_puts(m, "no pid\n");
6545 return trace_pid_show(m, v);
6548 static const struct seq_operations ftrace_pid_sops = {
6549 .start = fpid_start,
6556 ftrace_pid_open(struct inode *inode, struct file *file)
6558 struct trace_array *tr = inode->i_private;
6562 if (trace_array_get(tr) < 0)
6565 if ((file->f_mode & FMODE_WRITE) &&
6566 (file->f_flags & O_TRUNC))
6567 ftrace_pid_reset(tr);
6569 ret = seq_open(file, &ftrace_pid_sops);
6571 trace_array_put(tr);
6573 m = file->private_data;
6574 /* copy tr over to seq ops */
6581 static void ignore_task_cpu(void *data)
6583 struct trace_array *tr = data;
6584 struct trace_pid_list *pid_list;
6587 * This function is called by on_each_cpu() while the
6588 * event_mutex is held.
6590 pid_list = rcu_dereference_protected(tr->function_pids,
6591 mutex_is_locked(&ftrace_lock));
6593 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6594 trace_ignore_this_task(pid_list, current));
6598 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6599 size_t cnt, loff_t *ppos)
6601 struct seq_file *m = filp->private_data;
6602 struct trace_array *tr = m->private;
6603 struct trace_pid_list *filtered_pids = NULL;
6604 struct trace_pid_list *pid_list;
6610 mutex_lock(&ftrace_lock);
6612 filtered_pids = rcu_dereference_protected(tr->function_pids,
6613 lockdep_is_held(&ftrace_lock));
6615 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6619 rcu_assign_pointer(tr->function_pids, pid_list);
6621 if (filtered_pids) {
6622 synchronize_sched();
6623 trace_free_pid_list(filtered_pids);
6624 } else if (pid_list) {
6625 /* Register a probe to set whether to ignore the tracing of a task */
6626 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6630 * Ignoring of pids is done at task switch. But we have to
6631 * check for those tasks that are currently running.
6632 * Always do this in case a pid was appended or removed.
6634 on_each_cpu(ignore_task_cpu, tr, 1);
6636 ftrace_update_pid_func();
6637 ftrace_startup_all(0);
6639 mutex_unlock(&ftrace_lock);
6648 ftrace_pid_release(struct inode *inode, struct file *file)
6650 struct trace_array *tr = inode->i_private;
6652 trace_array_put(tr);
6654 return seq_release(inode, file);
6657 static const struct file_operations ftrace_pid_fops = {
6658 .open = ftrace_pid_open,
6659 .write = ftrace_pid_write,
6661 .llseek = tracing_lseek,
6662 .release = ftrace_pid_release,
6665 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6667 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6668 tr, &ftrace_pid_fops);
6671 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6672 struct dentry *d_tracer)
6674 /* Only the top level directory has the dyn_tracefs and profile */
6675 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6677 ftrace_init_dyn_tracefs(d_tracer);
6678 ftrace_profile_tracefs(d_tracer);
6682 * ftrace_kill - kill ftrace
6684 * This function should be used by panic code. It stops ftrace
6685 * but in a not so nice way. If you need to simply kill ftrace
6686 * from a non-atomic section, use ftrace_kill.
6688 void ftrace_kill(void)
6690 ftrace_disabled = 1;
6692 clear_ftrace_function();
6696 * Test if ftrace is dead or not.
6698 int ftrace_is_dead(void)
6700 return ftrace_disabled;
6704 * register_ftrace_function - register a function for profiling
6705 * @ops - ops structure that holds the function for profiling.
6707 * Register a function to be called by all functions in the
6710 * Note: @ops->func and all the functions it calls must be labeled
6711 * with "notrace", otherwise it will go into a
6714 int register_ftrace_function(struct ftrace_ops *ops)
6718 ftrace_ops_init(ops);
6720 mutex_lock(&ftrace_lock);
6722 ret = ftrace_startup(ops, 0);
6724 mutex_unlock(&ftrace_lock);
6728 EXPORT_SYMBOL_GPL(register_ftrace_function);
6731 * unregister_ftrace_function - unregister a function for profiling.
6732 * @ops - ops structure that holds the function to unregister
6734 * Unregister a function that was added to be called by ftrace profiling.
6736 int unregister_ftrace_function(struct ftrace_ops *ops)
6740 mutex_lock(&ftrace_lock);
6741 ret = ftrace_shutdown(ops, 0);
6742 mutex_unlock(&ftrace_lock);
6746 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6749 ftrace_enable_sysctl(struct ctl_table *table, int write,
6750 void __user *buffer, size_t *lenp,
6755 mutex_lock(&ftrace_lock);
6757 if (unlikely(ftrace_disabled))
6760 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6762 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6765 last_ftrace_enabled = !!ftrace_enabled;
6767 if (ftrace_enabled) {
6769 /* we are starting ftrace again */
6770 if (rcu_dereference_protected(ftrace_ops_list,
6771 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6772 update_ftrace_function();
6774 ftrace_startup_sysctl();
6777 /* stopping ftrace calls (just send to ftrace_stub) */
6778 ftrace_trace_function = ftrace_stub;
6780 ftrace_shutdown_sysctl();
6784 mutex_unlock(&ftrace_lock);
6788 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6790 static struct ftrace_ops graph_ops = {
6791 .func = ftrace_stub,
6792 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6793 FTRACE_OPS_FL_INITIALIZED |
6796 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6797 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
6798 /* trampoline_size is only needed for dynamically allocated tramps */
6800 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
6803 void ftrace_graph_sleep_time_control(bool enable)
6805 fgraph_sleep_time = enable;
6808 void ftrace_graph_graph_time_control(bool enable)
6810 fgraph_graph_time = enable;
6813 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
6818 /* The callbacks that hook a function */
6819 trace_func_graph_ret_t ftrace_graph_return =
6820 (trace_func_graph_ret_t)ftrace_stub;
6821 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
6822 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
6824 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6825 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
6829 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
6830 struct task_struct *g, *t;
6832 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
6833 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
6834 * sizeof(struct ftrace_ret_stack),
6836 if (!ret_stack_list[i]) {
6844 read_lock(&tasklist_lock);
6845 do_each_thread(g, t) {
6851 if (t->ret_stack == NULL) {
6852 atomic_set(&t->tracing_graph_pause, 0);
6853 atomic_set(&t->trace_overrun, 0);
6854 t->curr_ret_stack = -1;
6855 /* Make sure the tasks see the -1 first: */
6857 t->ret_stack = ret_stack_list[start++];
6859 } while_each_thread(g, t);
6862 read_unlock(&tasklist_lock);
6864 for (i = start; i < end; i++)
6865 kfree(ret_stack_list[i]);
6870 ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
6871 struct task_struct *prev, struct task_struct *next)
6873 unsigned long long timestamp;
6877 * Does the user want to count the time a function was asleep.
6878 * If so, do not update the time stamps.
6880 if (fgraph_sleep_time)
6883 timestamp = trace_clock_local();
6885 prev->ftrace_timestamp = timestamp;
6887 /* only process tasks that we timestamped */
6888 if (!next->ftrace_timestamp)
6892 * Update all the counters in next to make up for the
6893 * time next was sleeping.
6895 timestamp -= next->ftrace_timestamp;
6897 for (index = next->curr_ret_stack; index >= 0; index--)
6898 next->ret_stack[index].calltime += timestamp;
6901 /* Allocate a return stack for each task */
6902 static int start_graph_tracing(void)
6904 struct ftrace_ret_stack **ret_stack_list;
6907 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
6908 sizeof(struct ftrace_ret_stack *),
6911 if (!ret_stack_list)
6914 /* The cpu_boot init_task->ret_stack will never be freed */
6915 for_each_online_cpu(cpu) {
6916 if (!idle_task(cpu)->ret_stack)
6917 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
6921 ret = alloc_retstack_tasklist(ret_stack_list);
6922 } while (ret == -EAGAIN);
6925 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6927 pr_info("ftrace_graph: Couldn't activate tracepoint"
6928 " probe to kernel_sched_switch\n");
6931 kfree(ret_stack_list);
6936 * Hibernation protection.
6937 * The state of the current task is too much unstable during
6938 * suspend/restore to disk. We want to protect against that.
6941 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
6945 case PM_HIBERNATION_PREPARE:
6946 pause_graph_tracing();
6949 case PM_POST_HIBERNATION:
6950 unpause_graph_tracing();
6956 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
6958 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
6960 return __ftrace_graph_entry(trace);
6964 * The function graph tracer should only trace the functions defined
6965 * by set_ftrace_filter and set_ftrace_notrace. If another function
6966 * tracer ops is registered, the graph tracer requires testing the
6967 * function against the global ops, and not just trace any function
6968 * that any ftrace_ops registered.
6970 static void update_function_graph_func(void)
6972 struct ftrace_ops *op;
6973 bool do_test = false;
6976 * The graph and global ops share the same set of functions
6977 * to test. If any other ops is on the list, then
6978 * the graph tracing needs to test if its the function
6981 do_for_each_ftrace_op(op, ftrace_ops_list) {
6982 if (op != &global_ops && op != &graph_ops &&
6983 op != &ftrace_list_end) {
6985 /* in double loop, break out with goto */
6988 } while_for_each_ftrace_op(op);
6991 ftrace_graph_entry = ftrace_graph_entry_test;
6993 ftrace_graph_entry = __ftrace_graph_entry;
6996 static struct notifier_block ftrace_suspend_notifier = {
6997 .notifier_call = ftrace_suspend_notifier_call,
7000 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
7001 trace_func_graph_ent_t entryfunc)
7005 mutex_lock(&ftrace_lock);
7007 /* we currently allow only one tracer registered at a time */
7008 if (ftrace_graph_active) {
7013 register_pm_notifier(&ftrace_suspend_notifier);
7015 ftrace_graph_active++;
7016 ret = start_graph_tracing();
7018 ftrace_graph_active--;
7022 ftrace_graph_return = retfunc;
7025 * Update the indirect function to the entryfunc, and the
7026 * function that gets called to the entry_test first. Then
7027 * call the update fgraph entry function to determine if
7028 * the entryfunc should be called directly or not.
7030 __ftrace_graph_entry = entryfunc;
7031 ftrace_graph_entry = ftrace_graph_entry_test;
7032 update_function_graph_func();
7034 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
7036 mutex_unlock(&ftrace_lock);
7040 void unregister_ftrace_graph(void)
7042 mutex_lock(&ftrace_lock);
7044 if (unlikely(!ftrace_graph_active))
7047 ftrace_graph_active--;
7048 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
7049 ftrace_graph_entry = ftrace_graph_entry_stub;
7050 __ftrace_graph_entry = ftrace_graph_entry_stub;
7051 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
7052 unregister_pm_notifier(&ftrace_suspend_notifier);
7053 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
7056 mutex_unlock(&ftrace_lock);
7059 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
7062 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
7064 atomic_set(&t->tracing_graph_pause, 0);
7065 atomic_set(&t->trace_overrun, 0);
7066 t->ftrace_timestamp = 0;
7067 /* make curr_ret_stack visible before we add the ret_stack */
7069 t->ret_stack = ret_stack;
7073 * Allocate a return stack for the idle task. May be the first
7074 * time through, or it may be done by CPU hotplug online.
7076 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
7078 t->curr_ret_stack = -1;
7080 * The idle task has no parent, it either has its own
7081 * stack or no stack at all.
7084 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
7086 if (ftrace_graph_active) {
7087 struct ftrace_ret_stack *ret_stack;
7089 ret_stack = per_cpu(idle_ret_stack, cpu);
7091 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
7092 * sizeof(struct ftrace_ret_stack),
7096 per_cpu(idle_ret_stack, cpu) = ret_stack;
7098 graph_init_task(t, ret_stack);
7102 /* Allocate a return stack for newly created task */
7103 void ftrace_graph_init_task(struct task_struct *t)
7105 /* Make sure we do not use the parent ret_stack */
7106 t->ret_stack = NULL;
7107 t->curr_ret_stack = -1;
7109 if (ftrace_graph_active) {
7110 struct ftrace_ret_stack *ret_stack;
7112 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
7113 * sizeof(struct ftrace_ret_stack),
7117 graph_init_task(t, ret_stack);
7121 void ftrace_graph_exit_task(struct task_struct *t)
7123 struct ftrace_ret_stack *ret_stack = t->ret_stack;
7125 t->ret_stack = NULL;
7126 /* NULL must become visible to IRQs before we free it: */