2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/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 per_cpu_ops_disable_all(struct ftrace_ops *ops)
210 for_each_possible_cpu(cpu)
211 *per_cpu_ptr(ops->disabled, cpu) = 1;
214 static int per_cpu_ops_alloc(struct ftrace_ops *ops)
216 int __percpu *disabled;
218 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
221 disabled = alloc_percpu(int);
225 ops->disabled = disabled;
226 per_cpu_ops_disable_all(ops);
230 static void ftrace_sync(struct work_struct *work)
233 * This function is just a stub to implement a hard force
234 * of synchronize_sched(). This requires synchronizing
235 * tasks even in userspace and idle.
237 * Yes, function tracing is rude.
241 static void ftrace_sync_ipi(void *data)
243 /* Probably not needed, but do it anyway */
247 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
248 static void update_function_graph_func(void);
250 /* Both enabled by default (can be cleared by function_graph tracer flags */
251 static bool fgraph_sleep_time = true;
252 static bool fgraph_graph_time = true;
255 static inline void update_function_graph_func(void) { }
259 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
262 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
263 * then it needs to call the list anyway.
265 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU |
266 FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC)
267 return ftrace_ops_list_func;
269 return ftrace_ops_get_func(ops);
272 static void update_ftrace_function(void)
277 * Prepare the ftrace_ops that the arch callback will use.
278 * If there's only one ftrace_ops registered, the ftrace_ops_list
279 * will point to the ops we want.
281 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
282 lockdep_is_held(&ftrace_lock));
284 /* If there's no ftrace_ops registered, just call the stub function */
285 if (set_function_trace_op == &ftrace_list_end) {
289 * If we are at the end of the list and this ops is
290 * recursion safe and not dynamic and the arch supports passing ops,
291 * then have the mcount trampoline call the function directly.
293 } else if (rcu_dereference_protected(ftrace_ops_list->next,
294 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
295 func = ftrace_ops_get_list_func(ftrace_ops_list);
298 /* Just use the default ftrace_ops */
299 set_function_trace_op = &ftrace_list_end;
300 func = ftrace_ops_list_func;
303 update_function_graph_func();
305 /* If there's no change, then do nothing more here */
306 if (ftrace_trace_function == func)
310 * If we are using the list function, it doesn't care
311 * about the function_trace_ops.
313 if (func == ftrace_ops_list_func) {
314 ftrace_trace_function = func;
316 * Don't even bother setting function_trace_ops,
317 * it would be racy to do so anyway.
322 #ifndef CONFIG_DYNAMIC_FTRACE
324 * For static tracing, we need to be a bit more careful.
325 * The function change takes affect immediately. Thus,
326 * we need to coorditate the setting of the function_trace_ops
327 * with the setting of the ftrace_trace_function.
329 * Set the function to the list ops, which will call the
330 * function we want, albeit indirectly, but it handles the
331 * ftrace_ops and doesn't depend on function_trace_op.
333 ftrace_trace_function = ftrace_ops_list_func;
335 * Make sure all CPUs see this. Yes this is slow, but static
336 * tracing is slow and nasty to have enabled.
338 schedule_on_each_cpu(ftrace_sync);
339 /* Now all cpus are using the list ops. */
340 function_trace_op = set_function_trace_op;
341 /* Make sure the function_trace_op is visible on all CPUs */
343 /* Nasty way to force a rmb on all cpus */
344 smp_call_function(ftrace_sync_ipi, NULL, 1);
345 /* OK, we are all set to update the ftrace_trace_function now! */
346 #endif /* !CONFIG_DYNAMIC_FTRACE */
348 ftrace_trace_function = func;
351 int using_ftrace_ops_list_func(void)
353 return ftrace_trace_function == ftrace_ops_list_func;
356 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
357 struct ftrace_ops *ops)
359 rcu_assign_pointer(ops->next, *list);
362 * We are entering ops into the list but another
363 * CPU might be walking that list. We need to make sure
364 * the ops->next pointer is valid before another CPU sees
365 * the ops pointer included into the list.
367 rcu_assign_pointer(*list, ops);
370 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
371 struct ftrace_ops *ops)
373 struct ftrace_ops **p;
376 * If we are removing the last function, then simply point
377 * to the ftrace_stub.
379 if (rcu_dereference_protected(*list,
380 lockdep_is_held(&ftrace_lock)) == ops &&
381 rcu_dereference_protected(ops->next,
382 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
383 *list = &ftrace_list_end;
387 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
398 static void ftrace_update_trampoline(struct ftrace_ops *ops);
400 static int __register_ftrace_function(struct ftrace_ops *ops)
402 if (ops->flags & FTRACE_OPS_FL_DELETED)
405 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
408 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
410 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
411 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
412 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
414 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
415 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
418 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
419 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
422 if (!core_kernel_data((unsigned long)ops))
423 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
425 if (ops->flags & FTRACE_OPS_FL_PER_CPU) {
426 if (per_cpu_ops_alloc(ops))
430 add_ftrace_ops(&ftrace_ops_list, ops);
432 /* Always save the function, and reset at unregistering */
433 ops->saved_func = ops->func;
435 if (ftrace_pids_enabled(ops))
436 ops->func = ftrace_pid_func;
438 ftrace_update_trampoline(ops);
441 update_ftrace_function();
446 static int __unregister_ftrace_function(struct ftrace_ops *ops)
450 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
453 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
459 update_ftrace_function();
461 ops->func = ops->saved_func;
466 static void ftrace_update_pid_func(void)
468 struct ftrace_ops *op;
470 /* Only do something if we are tracing something */
471 if (ftrace_trace_function == ftrace_stub)
474 do_for_each_ftrace_op(op, ftrace_ops_list) {
475 if (op->flags & FTRACE_OPS_FL_PID) {
476 op->func = ftrace_pids_enabled(op) ?
477 ftrace_pid_func : op->saved_func;
478 ftrace_update_trampoline(op);
480 } while_for_each_ftrace_op(op);
482 update_ftrace_function();
485 #ifdef CONFIG_FUNCTION_PROFILER
486 struct ftrace_profile {
487 struct hlist_node node;
489 unsigned long counter;
490 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
491 unsigned long long time;
492 unsigned long long time_squared;
496 struct ftrace_profile_page {
497 struct ftrace_profile_page *next;
499 struct ftrace_profile records[];
502 struct ftrace_profile_stat {
504 struct hlist_head *hash;
505 struct ftrace_profile_page *pages;
506 struct ftrace_profile_page *start;
507 struct tracer_stat stat;
510 #define PROFILE_RECORDS_SIZE \
511 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
513 #define PROFILES_PER_PAGE \
514 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
516 static int ftrace_profile_enabled __read_mostly;
518 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
519 static DEFINE_MUTEX(ftrace_profile_lock);
521 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
523 #define FTRACE_PROFILE_HASH_BITS 10
524 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
527 function_stat_next(void *v, int idx)
529 struct ftrace_profile *rec = v;
530 struct ftrace_profile_page *pg;
532 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
538 if ((void *)rec >= (void *)&pg->records[pg->index]) {
542 rec = &pg->records[0];
550 static void *function_stat_start(struct tracer_stat *trace)
552 struct ftrace_profile_stat *stat =
553 container_of(trace, struct ftrace_profile_stat, stat);
555 if (!stat || !stat->start)
558 return function_stat_next(&stat->start->records[0], 0);
561 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
562 /* function graph compares on total time */
563 static int function_stat_cmp(void *p1, void *p2)
565 struct ftrace_profile *a = p1;
566 struct ftrace_profile *b = p2;
568 if (a->time < b->time)
570 if (a->time > b->time)
576 /* not function graph compares against hits */
577 static int function_stat_cmp(void *p1, void *p2)
579 struct ftrace_profile *a = p1;
580 struct ftrace_profile *b = p2;
582 if (a->counter < b->counter)
584 if (a->counter > b->counter)
591 static int function_stat_headers(struct seq_file *m)
593 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
594 seq_puts(m, " Function "
597 "--- ---- --- ---\n");
599 seq_puts(m, " Function Hit\n"
605 static int function_stat_show(struct seq_file *m, void *v)
607 struct ftrace_profile *rec = v;
608 char str[KSYM_SYMBOL_LEN];
610 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
611 static struct trace_seq s;
612 unsigned long long avg;
613 unsigned long long stddev;
615 mutex_lock(&ftrace_profile_lock);
617 /* we raced with function_profile_reset() */
618 if (unlikely(rec->counter == 0)) {
623 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
625 do_div(avg, rec->counter);
626 if (tracing_thresh && (avg < tracing_thresh))
630 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
631 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
633 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
636 /* Sample standard deviation (s^2) */
637 if (rec->counter <= 1)
641 * Apply Welford's method:
642 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
644 stddev = rec->counter * rec->time_squared -
645 rec->time * rec->time;
648 * Divide only 1000 for ns^2 -> us^2 conversion.
649 * trace_print_graph_duration will divide 1000 again.
651 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
655 trace_print_graph_duration(rec->time, &s);
656 trace_seq_puts(&s, " ");
657 trace_print_graph_duration(avg, &s);
658 trace_seq_puts(&s, " ");
659 trace_print_graph_duration(stddev, &s);
660 trace_print_seq(m, &s);
664 mutex_unlock(&ftrace_profile_lock);
669 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
671 struct ftrace_profile_page *pg;
673 pg = stat->pages = stat->start;
676 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
681 memset(stat->hash, 0,
682 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
685 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
687 struct ftrace_profile_page *pg;
692 /* If we already allocated, do nothing */
696 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
700 #ifdef CONFIG_DYNAMIC_FTRACE
701 functions = ftrace_update_tot_cnt;
704 * We do not know the number of functions that exist because
705 * dynamic tracing is what counts them. With past experience
706 * we have around 20K functions. That should be more than enough.
707 * It is highly unlikely we will execute every function in
713 pg = stat->start = stat->pages;
715 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
717 for (i = 1; i < pages; i++) {
718 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
729 unsigned long tmp = (unsigned long)pg;
741 static int ftrace_profile_init_cpu(int cpu)
743 struct ftrace_profile_stat *stat;
746 stat = &per_cpu(ftrace_profile_stats, cpu);
749 /* If the profile is already created, simply reset it */
750 ftrace_profile_reset(stat);
755 * We are profiling all functions, but usually only a few thousand
756 * functions are hit. We'll make a hash of 1024 items.
758 size = FTRACE_PROFILE_HASH_SIZE;
760 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
765 /* Preallocate the function profiling pages */
766 if (ftrace_profile_pages_init(stat) < 0) {
775 static int ftrace_profile_init(void)
780 for_each_possible_cpu(cpu) {
781 ret = ftrace_profile_init_cpu(cpu);
789 /* interrupts must be disabled */
790 static struct ftrace_profile *
791 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
793 struct ftrace_profile *rec;
794 struct hlist_head *hhd;
797 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
798 hhd = &stat->hash[key];
800 if (hlist_empty(hhd))
803 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
811 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
812 struct ftrace_profile *rec)
816 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
817 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
821 * The memory is already allocated, this simply finds a new record to use.
823 static struct ftrace_profile *
824 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
826 struct ftrace_profile *rec = NULL;
828 /* prevent recursion (from NMIs) */
829 if (atomic_inc_return(&stat->disabled) != 1)
833 * Try to find the function again since an NMI
834 * could have added it
836 rec = ftrace_find_profiled_func(stat, ip);
840 if (stat->pages->index == PROFILES_PER_PAGE) {
841 if (!stat->pages->next)
843 stat->pages = stat->pages->next;
846 rec = &stat->pages->records[stat->pages->index++];
848 ftrace_add_profile(stat, rec);
851 atomic_dec(&stat->disabled);
857 function_profile_call(unsigned long ip, unsigned long parent_ip,
858 struct ftrace_ops *ops, struct pt_regs *regs)
860 struct ftrace_profile_stat *stat;
861 struct ftrace_profile *rec;
864 if (!ftrace_profile_enabled)
867 local_irq_save(flags);
869 stat = this_cpu_ptr(&ftrace_profile_stats);
870 if (!stat->hash || !ftrace_profile_enabled)
873 rec = ftrace_find_profiled_func(stat, ip);
875 rec = ftrace_profile_alloc(stat, ip);
882 local_irq_restore(flags);
885 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
886 static int profile_graph_entry(struct ftrace_graph_ent *trace)
888 int index = trace->depth;
890 function_profile_call(trace->func, 0, NULL, NULL);
892 /* If function graph is shutting down, ret_stack can be NULL */
893 if (!current->ret_stack)
896 if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
897 current->ret_stack[index].subtime = 0;
902 static void profile_graph_return(struct ftrace_graph_ret *trace)
904 struct ftrace_profile_stat *stat;
905 unsigned long long calltime;
906 struct ftrace_profile *rec;
909 local_irq_save(flags);
910 stat = this_cpu_ptr(&ftrace_profile_stats);
911 if (!stat->hash || !ftrace_profile_enabled)
914 /* If the calltime was zero'd ignore it */
915 if (!trace->calltime)
918 calltime = trace->rettime - trace->calltime;
920 if (!fgraph_graph_time) {
923 index = trace->depth;
925 /* Append this call time to the parent time to subtract */
927 current->ret_stack[index - 1].subtime += calltime;
929 if (current->ret_stack[index].subtime < calltime)
930 calltime -= current->ret_stack[index].subtime;
935 rec = ftrace_find_profiled_func(stat, trace->func);
937 rec->time += calltime;
938 rec->time_squared += calltime * calltime;
942 local_irq_restore(flags);
945 static int register_ftrace_profiler(void)
947 return register_ftrace_graph(&profile_graph_return,
948 &profile_graph_entry);
951 static void unregister_ftrace_profiler(void)
953 unregister_ftrace_graph();
956 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
957 .func = function_profile_call,
958 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
959 INIT_OPS_HASH(ftrace_profile_ops)
962 static int register_ftrace_profiler(void)
964 return register_ftrace_function(&ftrace_profile_ops);
967 static void unregister_ftrace_profiler(void)
969 unregister_ftrace_function(&ftrace_profile_ops);
971 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
974 ftrace_profile_write(struct file *filp, const char __user *ubuf,
975 size_t cnt, loff_t *ppos)
980 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
986 mutex_lock(&ftrace_profile_lock);
987 if (ftrace_profile_enabled ^ val) {
989 ret = ftrace_profile_init();
995 ret = register_ftrace_profiler();
1000 ftrace_profile_enabled = 1;
1002 ftrace_profile_enabled = 0;
1004 * unregister_ftrace_profiler calls stop_machine
1005 * so this acts like an synchronize_sched.
1007 unregister_ftrace_profiler();
1011 mutex_unlock(&ftrace_profile_lock);
1019 ftrace_profile_read(struct file *filp, char __user *ubuf,
1020 size_t cnt, loff_t *ppos)
1022 char buf[64]; /* big enough to hold a number */
1025 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
1026 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1029 static const struct file_operations ftrace_profile_fops = {
1030 .open = tracing_open_generic,
1031 .read = ftrace_profile_read,
1032 .write = ftrace_profile_write,
1033 .llseek = default_llseek,
1036 /* used to initialize the real stat files */
1037 static struct tracer_stat function_stats __initdata = {
1038 .name = "functions",
1039 .stat_start = function_stat_start,
1040 .stat_next = function_stat_next,
1041 .stat_cmp = function_stat_cmp,
1042 .stat_headers = function_stat_headers,
1043 .stat_show = function_stat_show
1046 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1048 struct ftrace_profile_stat *stat;
1049 struct dentry *entry;
1054 for_each_possible_cpu(cpu) {
1055 stat = &per_cpu(ftrace_profile_stats, cpu);
1057 name = kasprintf(GFP_KERNEL, "function%d", cpu);
1060 * The files created are permanent, if something happens
1061 * we still do not free memory.
1064 "Could not allocate stat file for cpu %d\n",
1068 stat->stat = function_stats;
1069 stat->stat.name = name;
1070 ret = register_stat_tracer(&stat->stat);
1073 "Could not register function stat for cpu %d\n",
1080 entry = tracefs_create_file("function_profile_enabled", 0644,
1081 d_tracer, NULL, &ftrace_profile_fops);
1083 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1086 #else /* CONFIG_FUNCTION_PROFILER */
1087 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1090 #endif /* CONFIG_FUNCTION_PROFILER */
1092 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1094 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1095 static int ftrace_graph_active;
1097 # define ftrace_graph_active 0
1100 #ifdef CONFIG_DYNAMIC_FTRACE
1102 static struct ftrace_ops *removed_ops;
1105 * Set when doing a global update, like enabling all recs or disabling them.
1106 * It is not set when just updating a single ftrace_ops.
1108 static bool update_all_ops;
1110 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1111 # error Dynamic ftrace depends on MCOUNT_RECORD
1114 struct ftrace_func_entry {
1115 struct hlist_node hlist;
1119 struct ftrace_func_probe {
1120 struct ftrace_probe_ops *probe_ops;
1121 struct ftrace_ops ops;
1122 struct trace_array *tr;
1123 struct list_head list;
1129 * We make these constant because no one should touch them,
1130 * but they are used as the default "empty hash", to avoid allocating
1131 * it all the time. These are in a read only section such that if
1132 * anyone does try to modify it, it will cause an exception.
1134 static const struct hlist_head empty_buckets[1];
1135 static const struct ftrace_hash empty_hash = {
1136 .buckets = (struct hlist_head *)empty_buckets,
1138 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1140 static struct ftrace_ops global_ops = {
1141 .func = ftrace_stub,
1142 .local_hash.notrace_hash = EMPTY_HASH,
1143 .local_hash.filter_hash = EMPTY_HASH,
1144 INIT_OPS_HASH(global_ops)
1145 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1146 FTRACE_OPS_FL_INITIALIZED |
1151 * This is used by __kernel_text_address() to return true if the
1152 * address is on a dynamically allocated trampoline that would
1153 * not return true for either core_kernel_text() or
1154 * is_module_text_address().
1156 bool is_ftrace_trampoline(unsigned long addr)
1158 struct ftrace_ops *op;
1162 * Some of the ops may be dynamically allocated,
1163 * they are freed after a synchronize_sched().
1165 preempt_disable_notrace();
1167 do_for_each_ftrace_op(op, ftrace_ops_list) {
1169 * This is to check for dynamically allocated trampolines.
1170 * Trampolines that are in kernel text will have
1171 * core_kernel_text() return true.
1173 if (op->trampoline && op->trampoline_size)
1174 if (addr >= op->trampoline &&
1175 addr < op->trampoline + op->trampoline_size) {
1179 } while_for_each_ftrace_op(op);
1182 preempt_enable_notrace();
1187 struct ftrace_page {
1188 struct ftrace_page *next;
1189 struct dyn_ftrace *records;
1194 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1195 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1197 /* estimate from running different kernels */
1198 #define NR_TO_INIT 10000
1200 static struct ftrace_page *ftrace_pages_start;
1201 static struct ftrace_page *ftrace_pages;
1203 static __always_inline unsigned long
1204 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1206 if (hash->size_bits > 0)
1207 return hash_long(ip, hash->size_bits);
1212 /* Only use this function if ftrace_hash_empty() has already been tested */
1213 static __always_inline struct ftrace_func_entry *
1214 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1217 struct ftrace_func_entry *entry;
1218 struct hlist_head *hhd;
1220 key = ftrace_hash_key(hash, ip);
1221 hhd = &hash->buckets[key];
1223 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1224 if (entry->ip == ip)
1231 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1232 * @hash: The hash to look at
1233 * @ip: The instruction pointer to test
1235 * Search a given @hash to see if a given instruction pointer (@ip)
1238 * Returns the entry that holds the @ip if found. NULL otherwise.
1240 struct ftrace_func_entry *
1241 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1243 if (ftrace_hash_empty(hash))
1246 return __ftrace_lookup_ip(hash, ip);
1249 static void __add_hash_entry(struct ftrace_hash *hash,
1250 struct ftrace_func_entry *entry)
1252 struct hlist_head *hhd;
1255 key = ftrace_hash_key(hash, entry->ip);
1256 hhd = &hash->buckets[key];
1257 hlist_add_head(&entry->hlist, hhd);
1261 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1263 struct ftrace_func_entry *entry;
1265 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1270 __add_hash_entry(hash, entry);
1276 free_hash_entry(struct ftrace_hash *hash,
1277 struct ftrace_func_entry *entry)
1279 hlist_del(&entry->hlist);
1285 remove_hash_entry(struct ftrace_hash *hash,
1286 struct ftrace_func_entry *entry)
1288 hlist_del_rcu(&entry->hlist);
1292 static void ftrace_hash_clear(struct ftrace_hash *hash)
1294 struct hlist_head *hhd;
1295 struct hlist_node *tn;
1296 struct ftrace_func_entry *entry;
1297 int size = 1 << hash->size_bits;
1303 for (i = 0; i < size; i++) {
1304 hhd = &hash->buckets[i];
1305 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1306 free_hash_entry(hash, entry);
1308 FTRACE_WARN_ON(hash->count);
1311 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1313 list_del(&ftrace_mod->list);
1314 kfree(ftrace_mod->module);
1315 kfree(ftrace_mod->func);
1319 static void clear_ftrace_mod_list(struct list_head *head)
1321 struct ftrace_mod_load *p, *n;
1323 /* stack tracer isn't supported yet */
1327 mutex_lock(&ftrace_lock);
1328 list_for_each_entry_safe(p, n, head, list)
1330 mutex_unlock(&ftrace_lock);
1333 static void free_ftrace_hash(struct ftrace_hash *hash)
1335 if (!hash || hash == EMPTY_HASH)
1337 ftrace_hash_clear(hash);
1338 kfree(hash->buckets);
1342 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1344 struct ftrace_hash *hash;
1346 hash = container_of(rcu, struct ftrace_hash, rcu);
1347 free_ftrace_hash(hash);
1350 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1352 if (!hash || hash == EMPTY_HASH)
1354 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1357 void ftrace_free_filter(struct ftrace_ops *ops)
1359 ftrace_ops_init(ops);
1360 free_ftrace_hash(ops->func_hash->filter_hash);
1361 free_ftrace_hash(ops->func_hash->notrace_hash);
1364 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1366 struct ftrace_hash *hash;
1369 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1373 size = 1 << size_bits;
1374 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1376 if (!hash->buckets) {
1381 hash->size_bits = size_bits;
1387 static int ftrace_add_mod(struct trace_array *tr,
1388 const char *func, const char *module,
1391 struct ftrace_mod_load *ftrace_mod;
1392 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1394 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1398 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1399 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1400 ftrace_mod->enable = enable;
1402 if (!ftrace_mod->func || !ftrace_mod->module)
1405 list_add(&ftrace_mod->list, mod_head);
1410 free_ftrace_mod(ftrace_mod);
1415 static struct ftrace_hash *
1416 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1418 struct ftrace_func_entry *entry;
1419 struct ftrace_hash *new_hash;
1424 new_hash = alloc_ftrace_hash(size_bits);
1429 new_hash->flags = hash->flags;
1432 if (ftrace_hash_empty(hash))
1435 size = 1 << hash->size_bits;
1436 for (i = 0; i < size; i++) {
1437 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1438 ret = add_hash_entry(new_hash, entry->ip);
1444 FTRACE_WARN_ON(new_hash->count != hash->count);
1449 free_ftrace_hash(new_hash);
1454 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1456 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1458 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1459 struct ftrace_hash *new_hash);
1461 static struct ftrace_hash *
1462 __ftrace_hash_move(struct ftrace_hash *src)
1464 struct ftrace_func_entry *entry;
1465 struct hlist_node *tn;
1466 struct hlist_head *hhd;
1467 struct ftrace_hash *new_hash;
1468 int size = src->count;
1473 * If the new source is empty, just return the empty_hash.
1475 if (ftrace_hash_empty(src))
1479 * Make the hash size about 1/2 the # found
1481 for (size /= 2; size; size >>= 1)
1484 /* Don't allocate too much */
1485 if (bits > FTRACE_HASH_MAX_BITS)
1486 bits = FTRACE_HASH_MAX_BITS;
1488 new_hash = alloc_ftrace_hash(bits);
1492 new_hash->flags = src->flags;
1494 size = 1 << src->size_bits;
1495 for (i = 0; i < size; i++) {
1496 hhd = &src->buckets[i];
1497 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1498 remove_hash_entry(src, entry);
1499 __add_hash_entry(new_hash, entry);
1507 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1508 struct ftrace_hash **dst, struct ftrace_hash *src)
1510 struct ftrace_hash *new_hash;
1513 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1514 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1517 new_hash = __ftrace_hash_move(src);
1521 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1523 /* IPMODIFY should be updated only when filter_hash updating */
1524 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1526 free_ftrace_hash(new_hash);
1532 * Remove the current set, update the hash and add
1535 ftrace_hash_rec_disable_modify(ops, enable);
1537 rcu_assign_pointer(*dst, new_hash);
1539 ftrace_hash_rec_enable_modify(ops, enable);
1544 static bool hash_contains_ip(unsigned long ip,
1545 struct ftrace_ops_hash *hash)
1548 * The function record is a match if it exists in the filter
1549 * hash and not in the notrace hash. Note, an emty hash is
1550 * considered a match for the filter hash, but an empty
1551 * notrace hash is considered not in the notrace hash.
1553 return (ftrace_hash_empty(hash->filter_hash) ||
1554 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1555 (ftrace_hash_empty(hash->notrace_hash) ||
1556 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1560 * Test the hashes for this ops to see if we want to call
1561 * the ops->func or not.
1563 * It's a match if the ip is in the ops->filter_hash or
1564 * the filter_hash does not exist or is empty,
1566 * the ip is not in the ops->notrace_hash.
1568 * This needs to be called with preemption disabled as
1569 * the hashes are freed with call_rcu_sched().
1572 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1574 struct ftrace_ops_hash hash;
1577 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1579 * There's a small race when adding ops that the ftrace handler
1580 * that wants regs, may be called without them. We can not
1581 * allow that handler to be called if regs is NULL.
1583 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1587 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1588 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1590 if (hash_contains_ip(ip, &hash))
1599 * This is a double for. Do not use 'break' to break out of the loop,
1600 * you must use a goto.
1602 #define do_for_each_ftrace_rec(pg, rec) \
1603 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1605 for (_____i = 0; _____i < pg->index; _____i++) { \
1606 rec = &pg->records[_____i];
1608 #define while_for_each_ftrace_rec() \
1613 static int ftrace_cmp_recs(const void *a, const void *b)
1615 const struct dyn_ftrace *key = a;
1616 const struct dyn_ftrace *rec = b;
1618 if (key->flags < rec->ip)
1620 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1626 * ftrace_location_range - return the first address of a traced location
1627 * if it touches the given ip range
1628 * @start: start of range to search.
1629 * @end: end of range to search (inclusive). @end points to the last byte
1632 * Returns rec->ip if the related ftrace location is a least partly within
1633 * the given address range. That is, the first address of the instruction
1634 * that is either a NOP or call to the function tracer. It checks the ftrace
1635 * internal tables to determine if the address belongs or not.
1637 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1639 struct ftrace_page *pg;
1640 struct dyn_ftrace *rec;
1641 struct dyn_ftrace key;
1644 key.flags = end; /* overload flags, as it is unsigned long */
1646 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1647 if (end < pg->records[0].ip ||
1648 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1650 rec = bsearch(&key, pg->records, pg->index,
1651 sizeof(struct dyn_ftrace),
1661 * ftrace_location - return true if the ip giving is a traced location
1662 * @ip: the instruction pointer to check
1664 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1665 * That is, the instruction that is either a NOP or call to
1666 * the function tracer. It checks the ftrace internal tables to
1667 * determine if the address belongs or not.
1669 unsigned long ftrace_location(unsigned long ip)
1671 return ftrace_location_range(ip, ip);
1675 * ftrace_text_reserved - return true if range contains an ftrace location
1676 * @start: start of range to search
1677 * @end: end of range to search (inclusive). @end points to the last byte to check.
1679 * Returns 1 if @start and @end contains a ftrace location.
1680 * That is, the instruction that is either a NOP or call to
1681 * the function tracer. It checks the ftrace internal tables to
1682 * determine if the address belongs or not.
1684 int ftrace_text_reserved(const void *start, const void *end)
1688 ret = ftrace_location_range((unsigned long)start,
1689 (unsigned long)end);
1694 /* Test if ops registered to this rec needs regs */
1695 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1697 struct ftrace_ops *ops;
1698 bool keep_regs = false;
1700 for (ops = ftrace_ops_list;
1701 ops != &ftrace_list_end; ops = ops->next) {
1702 /* pass rec in as regs to have non-NULL val */
1703 if (ftrace_ops_test(ops, rec->ip, rec)) {
1704 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1714 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1718 struct ftrace_hash *hash;
1719 struct ftrace_hash *other_hash;
1720 struct ftrace_page *pg;
1721 struct dyn_ftrace *rec;
1722 bool update = false;
1726 /* Only update if the ops has been registered */
1727 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1731 * In the filter_hash case:
1732 * If the count is zero, we update all records.
1733 * Otherwise we just update the items in the hash.
1735 * In the notrace_hash case:
1736 * We enable the update in the hash.
1737 * As disabling notrace means enabling the tracing,
1738 * and enabling notrace means disabling, the inc variable
1742 hash = ops->func_hash->filter_hash;
1743 other_hash = ops->func_hash->notrace_hash;
1744 if (ftrace_hash_empty(hash))
1748 hash = ops->func_hash->notrace_hash;
1749 other_hash = ops->func_hash->filter_hash;
1751 * If the notrace hash has no items,
1752 * then there's nothing to do.
1754 if (ftrace_hash_empty(hash))
1758 do_for_each_ftrace_rec(pg, rec) {
1759 int in_other_hash = 0;
1763 if (rec->flags & FTRACE_FL_DISABLED)
1768 * Only the filter_hash affects all records.
1769 * Update if the record is not in the notrace hash.
1771 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1774 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1775 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1778 * If filter_hash is set, we want to match all functions
1779 * that are in the hash but not in the other hash.
1781 * If filter_hash is not set, then we are decrementing.
1782 * That means we match anything that is in the hash
1783 * and also in the other_hash. That is, we need to turn
1784 * off functions in the other hash because they are disabled
1787 if (filter_hash && in_hash && !in_other_hash)
1789 else if (!filter_hash && in_hash &&
1790 (in_other_hash || ftrace_hash_empty(other_hash)))
1798 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1802 * If there's only a single callback registered to a
1803 * function, and the ops has a trampoline registered
1804 * for it, then we can call it directly.
1806 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1807 rec->flags |= FTRACE_FL_TRAMP;
1810 * If we are adding another function callback
1811 * to this function, and the previous had a
1812 * custom trampoline in use, then we need to go
1813 * back to the default trampoline.
1815 rec->flags &= ~FTRACE_FL_TRAMP;
1818 * If any ops wants regs saved for this function
1819 * then all ops will get saved regs.
1821 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1822 rec->flags |= FTRACE_FL_REGS;
1824 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1829 * If the rec had REGS enabled and the ops that is
1830 * being removed had REGS set, then see if there is
1831 * still any ops for this record that wants regs.
1832 * If not, we can stop recording them.
1834 if (ftrace_rec_count(rec) > 0 &&
1835 rec->flags & FTRACE_FL_REGS &&
1836 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1837 if (!test_rec_ops_needs_regs(rec))
1838 rec->flags &= ~FTRACE_FL_REGS;
1842 * If the rec had TRAMP enabled, then it needs to
1843 * be cleared. As TRAMP can only be enabled iff
1844 * there is only a single ops attached to it.
1845 * In otherwords, always disable it on decrementing.
1846 * In the future, we may set it if rec count is
1847 * decremented to one, and the ops that is left
1850 rec->flags &= ~FTRACE_FL_TRAMP;
1853 * flags will be cleared in ftrace_check_record()
1854 * if rec count is zero.
1859 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1860 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1862 /* Shortcut, if we handled all records, we are done. */
1863 if (!all && count == hash->count)
1865 } while_for_each_ftrace_rec();
1870 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1873 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1876 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1879 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1882 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1883 int filter_hash, int inc)
1885 struct ftrace_ops *op;
1887 __ftrace_hash_rec_update(ops, filter_hash, inc);
1889 if (ops->func_hash != &global_ops.local_hash)
1893 * If the ops shares the global_ops hash, then we need to update
1894 * all ops that are enabled and use this hash.
1896 do_for_each_ftrace_op(op, ftrace_ops_list) {
1900 if (op->func_hash == &global_ops.local_hash)
1901 __ftrace_hash_rec_update(op, filter_hash, inc);
1902 } while_for_each_ftrace_op(op);
1905 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1908 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1911 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1914 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1918 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1919 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1920 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1921 * Note that old_hash and new_hash has below meanings
1922 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1923 * - If the hash is EMPTY_HASH, it hits nothing
1924 * - Anything else hits the recs which match the hash entries.
1926 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1927 struct ftrace_hash *old_hash,
1928 struct ftrace_hash *new_hash)
1930 struct ftrace_page *pg;
1931 struct dyn_ftrace *rec, *end = NULL;
1934 /* Only update if the ops has been registered */
1935 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1938 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1942 * Since the IPMODIFY is a very address sensitive action, we do not
1943 * allow ftrace_ops to set all functions to new hash.
1945 if (!new_hash || !old_hash)
1948 /* Update rec->flags */
1949 do_for_each_ftrace_rec(pg, rec) {
1951 if (rec->flags & FTRACE_FL_DISABLED)
1954 /* We need to update only differences of filter_hash */
1955 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1956 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1957 if (in_old == in_new)
1961 /* New entries must ensure no others are using it */
1962 if (rec->flags & FTRACE_FL_IPMODIFY)
1964 rec->flags |= FTRACE_FL_IPMODIFY;
1965 } else /* Removed entry */
1966 rec->flags &= ~FTRACE_FL_IPMODIFY;
1967 } while_for_each_ftrace_rec();
1974 /* Roll back what we did above */
1975 do_for_each_ftrace_rec(pg, rec) {
1977 if (rec->flags & FTRACE_FL_DISABLED)
1983 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1984 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1985 if (in_old == in_new)
1989 rec->flags &= ~FTRACE_FL_IPMODIFY;
1991 rec->flags |= FTRACE_FL_IPMODIFY;
1992 } while_for_each_ftrace_rec();
1998 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
2000 struct ftrace_hash *hash = ops->func_hash->filter_hash;
2002 if (ftrace_hash_empty(hash))
2005 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
2008 /* Disabling always succeeds */
2009 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
2011 struct ftrace_hash *hash = ops->func_hash->filter_hash;
2013 if (ftrace_hash_empty(hash))
2016 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
2019 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
2020 struct ftrace_hash *new_hash)
2022 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
2024 if (ftrace_hash_empty(old_hash))
2027 if (ftrace_hash_empty(new_hash))
2030 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
2033 static void print_ip_ins(const char *fmt, const unsigned char *p)
2037 printk(KERN_CONT "%s", fmt);
2039 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
2040 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
2043 static struct ftrace_ops *
2044 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
2045 static struct ftrace_ops *
2046 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
2048 enum ftrace_bug_type ftrace_bug_type;
2049 const void *ftrace_expected;
2051 static void print_bug_type(void)
2053 switch (ftrace_bug_type) {
2054 case FTRACE_BUG_UNKNOWN:
2056 case FTRACE_BUG_INIT:
2057 pr_info("Initializing ftrace call sites\n");
2059 case FTRACE_BUG_NOP:
2060 pr_info("Setting ftrace call site to NOP\n");
2062 case FTRACE_BUG_CALL:
2063 pr_info("Setting ftrace call site to call ftrace function\n");
2065 case FTRACE_BUG_UPDATE:
2066 pr_info("Updating ftrace call site to call a different ftrace function\n");
2072 * ftrace_bug - report and shutdown function tracer
2073 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2074 * @rec: The record that failed
2076 * The arch code that enables or disables the function tracing
2077 * can call ftrace_bug() when it has detected a problem in
2078 * modifying the code. @failed should be one of either:
2079 * EFAULT - if the problem happens on reading the @ip address
2080 * EINVAL - if what is read at @ip is not what was expected
2081 * EPERM - if the problem happens on writting to the @ip address
2083 void ftrace_bug(int failed, struct dyn_ftrace *rec)
2085 unsigned long ip = rec ? rec->ip : 0;
2089 FTRACE_WARN_ON_ONCE(1);
2090 pr_info("ftrace faulted on modifying ");
2094 FTRACE_WARN_ON_ONCE(1);
2095 pr_info("ftrace failed to modify ");
2097 print_ip_ins(" actual: ", (unsigned char *)ip);
2099 if (ftrace_expected) {
2100 print_ip_ins(" expected: ", ftrace_expected);
2105 FTRACE_WARN_ON_ONCE(1);
2106 pr_info("ftrace faulted on writing ");
2110 FTRACE_WARN_ON_ONCE(1);
2111 pr_info("ftrace faulted on unknown error ");
2116 struct ftrace_ops *ops = NULL;
2118 pr_info("ftrace record flags: %lx\n", rec->flags);
2119 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2120 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2121 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2122 ops = ftrace_find_tramp_ops_any(rec);
2125 pr_cont("\ttramp: %pS (%pS)",
2126 (void *)ops->trampoline,
2128 ops = ftrace_find_tramp_ops_next(rec, ops);
2131 pr_cont("\ttramp: ERROR!");
2134 ip = ftrace_get_addr_curr(rec);
2135 pr_cont("\n expected tramp: %lx\n", ip);
2139 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2141 unsigned long flag = 0UL;
2143 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2145 if (rec->flags & FTRACE_FL_DISABLED)
2146 return FTRACE_UPDATE_IGNORE;
2149 * If we are updating calls:
2151 * If the record has a ref count, then we need to enable it
2152 * because someone is using it.
2154 * Otherwise we make sure its disabled.
2156 * If we are disabling calls, then disable all records that
2159 if (enable && ftrace_rec_count(rec))
2160 flag = FTRACE_FL_ENABLED;
2163 * If enabling and the REGS flag does not match the REGS_EN, or
2164 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2165 * this record. Set flags to fail the compare against ENABLED.
2168 if (!(rec->flags & FTRACE_FL_REGS) !=
2169 !(rec->flags & FTRACE_FL_REGS_EN))
2170 flag |= FTRACE_FL_REGS;
2172 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2173 !(rec->flags & FTRACE_FL_TRAMP_EN))
2174 flag |= FTRACE_FL_TRAMP;
2177 /* If the state of this record hasn't changed, then do nothing */
2178 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2179 return FTRACE_UPDATE_IGNORE;
2182 /* Save off if rec is being enabled (for return value) */
2183 flag ^= rec->flags & FTRACE_FL_ENABLED;
2186 rec->flags |= FTRACE_FL_ENABLED;
2187 if (flag & FTRACE_FL_REGS) {
2188 if (rec->flags & FTRACE_FL_REGS)
2189 rec->flags |= FTRACE_FL_REGS_EN;
2191 rec->flags &= ~FTRACE_FL_REGS_EN;
2193 if (flag & FTRACE_FL_TRAMP) {
2194 if (rec->flags & FTRACE_FL_TRAMP)
2195 rec->flags |= FTRACE_FL_TRAMP_EN;
2197 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2202 * If this record is being updated from a nop, then
2203 * return UPDATE_MAKE_CALL.
2205 * return UPDATE_MODIFY_CALL to tell the caller to convert
2206 * from the save regs, to a non-save regs function or
2207 * vice versa, or from a trampoline call.
2209 if (flag & FTRACE_FL_ENABLED) {
2210 ftrace_bug_type = FTRACE_BUG_CALL;
2211 return FTRACE_UPDATE_MAKE_CALL;
2214 ftrace_bug_type = FTRACE_BUG_UPDATE;
2215 return FTRACE_UPDATE_MODIFY_CALL;
2219 /* If there's no more users, clear all flags */
2220 if (!ftrace_rec_count(rec))
2224 * Just disable the record, but keep the ops TRAMP
2225 * and REGS states. The _EN flags must be disabled though.
2227 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2231 ftrace_bug_type = FTRACE_BUG_NOP;
2232 return FTRACE_UPDATE_MAKE_NOP;
2236 * ftrace_update_record, set a record that now is tracing or not
2237 * @rec: the record to update
2238 * @enable: set to 1 if the record is tracing, zero to force disable
2240 * The records that represent all functions that can be traced need
2241 * to be updated when tracing has been enabled.
2243 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2245 return ftrace_check_record(rec, enable, 1);
2249 * ftrace_test_record, check if the record has been enabled or not
2250 * @rec: the record to test
2251 * @enable: set to 1 to check if enabled, 0 if it is disabled
2253 * The arch code may need to test if a record is already set to
2254 * tracing to determine how to modify the function code that it
2257 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2259 return ftrace_check_record(rec, enable, 0);
2262 static struct ftrace_ops *
2263 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2265 struct ftrace_ops *op;
2266 unsigned long ip = rec->ip;
2268 do_for_each_ftrace_op(op, ftrace_ops_list) {
2270 if (!op->trampoline)
2273 if (hash_contains_ip(ip, op->func_hash))
2275 } while_for_each_ftrace_op(op);
2280 static struct ftrace_ops *
2281 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2282 struct ftrace_ops *op)
2284 unsigned long ip = rec->ip;
2286 while_for_each_ftrace_op(op) {
2288 if (!op->trampoline)
2291 if (hash_contains_ip(ip, op->func_hash))
2298 static struct ftrace_ops *
2299 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2301 struct ftrace_ops *op;
2302 unsigned long ip = rec->ip;
2305 * Need to check removed ops first.
2306 * If they are being removed, and this rec has a tramp,
2307 * and this rec is in the ops list, then it would be the
2308 * one with the tramp.
2311 if (hash_contains_ip(ip, &removed_ops->old_hash))
2316 * Need to find the current trampoline for a rec.
2317 * Now, a trampoline is only attached to a rec if there
2318 * was a single 'ops' attached to it. But this can be called
2319 * when we are adding another op to the rec or removing the
2320 * current one. Thus, if the op is being added, we can
2321 * ignore it because it hasn't attached itself to the rec
2324 * If an ops is being modified (hooking to different functions)
2325 * then we don't care about the new functions that are being
2326 * added, just the old ones (that are probably being removed).
2328 * If we are adding an ops to a function that already is using
2329 * a trampoline, it needs to be removed (trampolines are only
2330 * for single ops connected), then an ops that is not being
2331 * modified also needs to be checked.
2333 do_for_each_ftrace_op(op, ftrace_ops_list) {
2335 if (!op->trampoline)
2339 * If the ops is being added, it hasn't gotten to
2340 * the point to be removed from this tree yet.
2342 if (op->flags & FTRACE_OPS_FL_ADDING)
2347 * If the ops is being modified and is in the old
2348 * hash, then it is probably being removed from this
2351 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2352 hash_contains_ip(ip, &op->old_hash))
2355 * If the ops is not being added or modified, and it's
2356 * in its normal filter hash, then this must be the one
2359 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2360 hash_contains_ip(ip, op->func_hash))
2363 } while_for_each_ftrace_op(op);
2368 static struct ftrace_ops *
2369 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2371 struct ftrace_ops *op;
2372 unsigned long ip = rec->ip;
2374 do_for_each_ftrace_op(op, ftrace_ops_list) {
2375 /* pass rec in as regs to have non-NULL val */
2376 if (hash_contains_ip(ip, op->func_hash))
2378 } while_for_each_ftrace_op(op);
2384 * ftrace_get_addr_new - Get the call address to set to
2385 * @rec: The ftrace record descriptor
2387 * If the record has the FTRACE_FL_REGS set, that means that it
2388 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2389 * is not not set, then it wants to convert to the normal callback.
2391 * Returns the address of the trampoline to set to
2393 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2395 struct ftrace_ops *ops;
2397 /* Trampolines take precedence over regs */
2398 if (rec->flags & FTRACE_FL_TRAMP) {
2399 ops = ftrace_find_tramp_ops_new(rec);
2400 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2401 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2402 (void *)rec->ip, (void *)rec->ip, rec->flags);
2403 /* Ftrace is shutting down, return anything */
2404 return (unsigned long)FTRACE_ADDR;
2406 return ops->trampoline;
2409 if (rec->flags & FTRACE_FL_REGS)
2410 return (unsigned long)FTRACE_REGS_ADDR;
2412 return (unsigned long)FTRACE_ADDR;
2416 * ftrace_get_addr_curr - Get the call address that is already there
2417 * @rec: The ftrace record descriptor
2419 * The FTRACE_FL_REGS_EN is set when the record already points to
2420 * a function that saves all the regs. Basically the '_EN' version
2421 * represents the current state of the function.
2423 * Returns the address of the trampoline that is currently being called
2425 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2427 struct ftrace_ops *ops;
2429 /* Trampolines take precedence over regs */
2430 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2431 ops = ftrace_find_tramp_ops_curr(rec);
2432 if (FTRACE_WARN_ON(!ops)) {
2433 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2434 (void *)rec->ip, (void *)rec->ip);
2435 /* Ftrace is shutting down, return anything */
2436 return (unsigned long)FTRACE_ADDR;
2438 return ops->trampoline;
2441 if (rec->flags & FTRACE_FL_REGS_EN)
2442 return (unsigned long)FTRACE_REGS_ADDR;
2444 return (unsigned long)FTRACE_ADDR;
2448 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2450 unsigned long ftrace_old_addr;
2451 unsigned long ftrace_addr;
2454 ftrace_addr = ftrace_get_addr_new(rec);
2456 /* This needs to be done before we call ftrace_update_record */
2457 ftrace_old_addr = ftrace_get_addr_curr(rec);
2459 ret = ftrace_update_record(rec, enable);
2461 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2464 case FTRACE_UPDATE_IGNORE:
2467 case FTRACE_UPDATE_MAKE_CALL:
2468 ftrace_bug_type = FTRACE_BUG_CALL;
2469 return ftrace_make_call(rec, ftrace_addr);
2471 case FTRACE_UPDATE_MAKE_NOP:
2472 ftrace_bug_type = FTRACE_BUG_NOP;
2473 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2475 case FTRACE_UPDATE_MODIFY_CALL:
2476 ftrace_bug_type = FTRACE_BUG_UPDATE;
2477 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2480 return -1; /* unknow ftrace bug */
2483 void __weak ftrace_replace_code(int enable)
2485 struct dyn_ftrace *rec;
2486 struct ftrace_page *pg;
2489 if (unlikely(ftrace_disabled))
2492 do_for_each_ftrace_rec(pg, rec) {
2494 if (rec->flags & FTRACE_FL_DISABLED)
2497 failed = __ftrace_replace_code(rec, enable);
2499 ftrace_bug(failed, rec);
2500 /* Stop processing */
2503 } while_for_each_ftrace_rec();
2506 struct ftrace_rec_iter {
2507 struct ftrace_page *pg;
2512 * ftrace_rec_iter_start, start up iterating over traced functions
2514 * Returns an iterator handle that is used to iterate over all
2515 * the records that represent address locations where functions
2518 * May return NULL if no records are available.
2520 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2523 * We only use a single iterator.
2524 * Protected by the ftrace_lock mutex.
2526 static struct ftrace_rec_iter ftrace_rec_iter;
2527 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2529 iter->pg = ftrace_pages_start;
2532 /* Could have empty pages */
2533 while (iter->pg && !iter->pg->index)
2534 iter->pg = iter->pg->next;
2543 * ftrace_rec_iter_next, get the next record to process.
2544 * @iter: The handle to the iterator.
2546 * Returns the next iterator after the given iterator @iter.
2548 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2552 if (iter->index >= iter->pg->index) {
2553 iter->pg = iter->pg->next;
2556 /* Could have empty pages */
2557 while (iter->pg && !iter->pg->index)
2558 iter->pg = iter->pg->next;
2568 * ftrace_rec_iter_record, get the record at the iterator location
2569 * @iter: The current iterator location
2571 * Returns the record that the current @iter is at.
2573 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2575 return &iter->pg->records[iter->index];
2579 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2583 if (unlikely(ftrace_disabled))
2586 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2588 ftrace_bug_type = FTRACE_BUG_INIT;
2589 ftrace_bug(ret, rec);
2596 * archs can override this function if they must do something
2597 * before the modifying code is performed.
2599 int __weak ftrace_arch_code_modify_prepare(void)
2605 * archs can override this function if they must do something
2606 * after the modifying code is performed.
2608 int __weak ftrace_arch_code_modify_post_process(void)
2613 void ftrace_modify_all_code(int command)
2615 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2619 * If the ftrace_caller calls a ftrace_ops func directly,
2620 * we need to make sure that it only traces functions it
2621 * expects to trace. When doing the switch of functions,
2622 * we need to update to the ftrace_ops_list_func first
2623 * before the transition between old and new calls are set,
2624 * as the ftrace_ops_list_func will check the ops hashes
2625 * to make sure the ops are having the right functions
2629 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2630 if (FTRACE_WARN_ON(err))
2634 if (command & FTRACE_UPDATE_CALLS)
2635 ftrace_replace_code(1);
2636 else if (command & FTRACE_DISABLE_CALLS)
2637 ftrace_replace_code(0);
2639 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2640 function_trace_op = set_function_trace_op;
2642 /* If irqs are disabled, we are in stop machine */
2643 if (!irqs_disabled())
2644 smp_call_function(ftrace_sync_ipi, NULL, 1);
2645 err = ftrace_update_ftrace_func(ftrace_trace_function);
2646 if (FTRACE_WARN_ON(err))
2650 if (command & FTRACE_START_FUNC_RET)
2651 err = ftrace_enable_ftrace_graph_caller();
2652 else if (command & FTRACE_STOP_FUNC_RET)
2653 err = ftrace_disable_ftrace_graph_caller();
2654 FTRACE_WARN_ON(err);
2657 static int __ftrace_modify_code(void *data)
2659 int *command = data;
2661 ftrace_modify_all_code(*command);
2667 * ftrace_run_stop_machine, go back to the stop machine method
2668 * @command: The command to tell ftrace what to do
2670 * If an arch needs to fall back to the stop machine method, the
2671 * it can call this function.
2673 void ftrace_run_stop_machine(int command)
2675 stop_machine(__ftrace_modify_code, &command, NULL);
2679 * arch_ftrace_update_code, modify the code to trace or not trace
2680 * @command: The command that needs to be done
2682 * Archs can override this function if it does not need to
2683 * run stop_machine() to modify code.
2685 void __weak arch_ftrace_update_code(int command)
2687 ftrace_run_stop_machine(command);
2690 static void ftrace_run_update_code(int command)
2694 ret = ftrace_arch_code_modify_prepare();
2695 FTRACE_WARN_ON(ret);
2700 * By default we use stop_machine() to modify the code.
2701 * But archs can do what ever they want as long as it
2702 * is safe. The stop_machine() is the safest, but also
2703 * produces the most overhead.
2705 arch_ftrace_update_code(command);
2707 ret = ftrace_arch_code_modify_post_process();
2708 FTRACE_WARN_ON(ret);
2711 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2712 struct ftrace_ops_hash *old_hash)
2714 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2715 ops->old_hash.filter_hash = old_hash->filter_hash;
2716 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2717 ftrace_run_update_code(command);
2718 ops->old_hash.filter_hash = NULL;
2719 ops->old_hash.notrace_hash = NULL;
2720 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2723 static ftrace_func_t saved_ftrace_func;
2724 static int ftrace_start_up;
2726 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2730 static void per_cpu_ops_free(struct ftrace_ops *ops)
2732 free_percpu(ops->disabled);
2735 static void ftrace_startup_enable(int command)
2737 if (saved_ftrace_func != ftrace_trace_function) {
2738 saved_ftrace_func = ftrace_trace_function;
2739 command |= FTRACE_UPDATE_TRACE_FUNC;
2742 if (!command || !ftrace_enabled)
2745 ftrace_run_update_code(command);
2748 static void ftrace_startup_all(int command)
2750 update_all_ops = true;
2751 ftrace_startup_enable(command);
2752 update_all_ops = false;
2755 static int ftrace_startup(struct ftrace_ops *ops, int command)
2759 if (unlikely(ftrace_disabled))
2762 ret = __register_ftrace_function(ops);
2769 * Note that ftrace probes uses this to start up
2770 * and modify functions it will probe. But we still
2771 * set the ADDING flag for modification, as probes
2772 * do not have trampolines. If they add them in the
2773 * future, then the probes will need to distinguish
2774 * between adding and updating probes.
2776 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2778 ret = ftrace_hash_ipmodify_enable(ops);
2780 /* Rollback registration process */
2781 __unregister_ftrace_function(ops);
2783 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2787 if (ftrace_hash_rec_enable(ops, 1))
2788 command |= FTRACE_UPDATE_CALLS;
2790 ftrace_startup_enable(command);
2792 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2797 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2801 if (unlikely(ftrace_disabled))
2804 ret = __unregister_ftrace_function(ops);
2810 * Just warn in case of unbalance, no need to kill ftrace, it's not
2811 * critical but the ftrace_call callers may be never nopped again after
2812 * further ftrace uses.
2814 WARN_ON_ONCE(ftrace_start_up < 0);
2816 /* Disabling ipmodify never fails */
2817 ftrace_hash_ipmodify_disable(ops);
2819 if (ftrace_hash_rec_disable(ops, 1))
2820 command |= FTRACE_UPDATE_CALLS;
2822 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2824 if (saved_ftrace_func != ftrace_trace_function) {
2825 saved_ftrace_func = ftrace_trace_function;
2826 command |= FTRACE_UPDATE_TRACE_FUNC;
2829 if (!command || !ftrace_enabled) {
2831 * If these are per_cpu ops, they still need their
2832 * per_cpu field freed. Since, function tracing is
2833 * not currently active, we can just free them
2834 * without synchronizing all CPUs.
2836 if (ops->flags & FTRACE_OPS_FL_PER_CPU)
2837 per_cpu_ops_free(ops);
2842 * If the ops uses a trampoline, then it needs to be
2843 * tested first on update.
2845 ops->flags |= FTRACE_OPS_FL_REMOVING;
2848 /* The trampoline logic checks the old hashes */
2849 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2850 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2852 ftrace_run_update_code(command);
2855 * If there's no more ops registered with ftrace, run a
2856 * sanity check to make sure all rec flags are cleared.
2858 if (rcu_dereference_protected(ftrace_ops_list,
2859 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2860 struct ftrace_page *pg;
2861 struct dyn_ftrace *rec;
2863 do_for_each_ftrace_rec(pg, rec) {
2864 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2865 pr_warn(" %pS flags:%lx\n",
2866 (void *)rec->ip, rec->flags);
2867 } while_for_each_ftrace_rec();
2870 ops->old_hash.filter_hash = NULL;
2871 ops->old_hash.notrace_hash = NULL;
2874 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2877 * Dynamic ops may be freed, we must make sure that all
2878 * callers are done before leaving this function.
2879 * The same goes for freeing the per_cpu data of the per_cpu
2882 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) {
2884 * We need to do a hard force of sched synchronization.
2885 * This is because we use preempt_disable() to do RCU, but
2886 * the function tracers can be called where RCU is not watching
2887 * (like before user_exit()). We can not rely on the RCU
2888 * infrastructure to do the synchronization, thus we must do it
2891 schedule_on_each_cpu(ftrace_sync);
2894 * When the kernel is preeptive, tasks can be preempted
2895 * while on a ftrace trampoline. Just scheduling a task on
2896 * a CPU is not good enough to flush them. Calling
2897 * synchornize_rcu_tasks() will wait for those tasks to
2898 * execute and either schedule voluntarily or enter user space.
2900 if (IS_ENABLED(CONFIG_PREEMPT))
2901 synchronize_rcu_tasks();
2903 arch_ftrace_trampoline_free(ops);
2905 if (ops->flags & FTRACE_OPS_FL_PER_CPU)
2906 per_cpu_ops_free(ops);
2912 static void ftrace_startup_sysctl(void)
2916 if (unlikely(ftrace_disabled))
2919 /* Force update next time */
2920 saved_ftrace_func = NULL;
2921 /* ftrace_start_up is true if we want ftrace running */
2922 if (ftrace_start_up) {
2923 command = FTRACE_UPDATE_CALLS;
2924 if (ftrace_graph_active)
2925 command |= FTRACE_START_FUNC_RET;
2926 ftrace_startup_enable(command);
2930 static void ftrace_shutdown_sysctl(void)
2934 if (unlikely(ftrace_disabled))
2937 /* ftrace_start_up is true if ftrace is running */
2938 if (ftrace_start_up) {
2939 command = FTRACE_DISABLE_CALLS;
2940 if (ftrace_graph_active)
2941 command |= FTRACE_STOP_FUNC_RET;
2942 ftrace_run_update_code(command);
2946 static u64 ftrace_update_time;
2947 unsigned long ftrace_update_tot_cnt;
2949 static inline int ops_traces_mod(struct ftrace_ops *ops)
2952 * Filter_hash being empty will default to trace module.
2953 * But notrace hash requires a test of individual module functions.
2955 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2956 ftrace_hash_empty(ops->func_hash->notrace_hash);
2960 * Check if the current ops references the record.
2962 * If the ops traces all functions, then it was already accounted for.
2963 * If the ops does not trace the current record function, skip it.
2964 * If the ops ignores the function via notrace filter, skip it.
2967 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2969 /* If ops isn't enabled, ignore it */
2970 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2973 /* If ops traces all then it includes this function */
2974 if (ops_traces_mod(ops))
2977 /* The function must be in the filter */
2978 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2979 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2982 /* If in notrace hash, we ignore it too */
2983 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2989 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2991 struct ftrace_page *pg;
2992 struct dyn_ftrace *p;
2994 unsigned long update_cnt = 0;
2995 unsigned long rec_flags = 0;
2998 start = ftrace_now(raw_smp_processor_id());
3001 * When a module is loaded, this function is called to convert
3002 * the calls to mcount in its text to nops, and also to create
3003 * an entry in the ftrace data. Now, if ftrace is activated
3004 * after this call, but before the module sets its text to
3005 * read-only, the modification of enabling ftrace can fail if
3006 * the read-only is done while ftrace is converting the calls.
3007 * To prevent this, the module's records are set as disabled
3008 * and will be enabled after the call to set the module's text
3012 rec_flags |= FTRACE_FL_DISABLED;
3014 for (pg = new_pgs; pg; pg = pg->next) {
3016 for (i = 0; i < pg->index; i++) {
3018 /* If something went wrong, bail without enabling anything */
3019 if (unlikely(ftrace_disabled))
3022 p = &pg->records[i];
3023 p->flags = rec_flags;
3026 * Do the initial record conversion from mcount jump
3027 * to the NOP instructions.
3029 if (!ftrace_code_disable(mod, p))
3036 stop = ftrace_now(raw_smp_processor_id());
3037 ftrace_update_time = stop - start;
3038 ftrace_update_tot_cnt += update_cnt;
3043 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3048 if (WARN_ON(!count))
3051 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
3054 * We want to fill as much as possible. No more than a page
3057 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
3061 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3064 /* if we can't allocate this size, try something smaller */
3071 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3080 static struct ftrace_page *
3081 ftrace_allocate_pages(unsigned long num_to_init)
3083 struct ftrace_page *start_pg;
3084 struct ftrace_page *pg;
3091 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3096 * Try to allocate as much as possible in one continues
3097 * location that fills in all of the space. We want to
3098 * waste as little space as possible.
3101 cnt = ftrace_allocate_records(pg, num_to_init);
3109 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3121 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3122 free_pages((unsigned long)pg->records, order);
3123 start_pg = pg->next;
3127 pr_info("ftrace: FAILED to allocate memory for functions\n");
3131 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3133 struct ftrace_iterator {
3137 struct ftrace_page *pg;
3138 struct dyn_ftrace *func;
3139 struct ftrace_func_probe *probe;
3140 struct ftrace_func_entry *probe_entry;
3141 struct trace_parser parser;
3142 struct ftrace_hash *hash;
3143 struct ftrace_ops *ops;
3144 struct trace_array *tr;
3145 struct list_head *mod_list;
3152 t_probe_next(struct seq_file *m, loff_t *pos)
3154 struct ftrace_iterator *iter = m->private;
3155 struct trace_array *tr = iter->ops->private;
3156 struct list_head *func_probes;
3157 struct ftrace_hash *hash;
3158 struct list_head *next;
3159 struct hlist_node *hnd = NULL;
3160 struct hlist_head *hhd;
3169 func_probes = &tr->func_probes;
3170 if (list_empty(func_probes))
3174 next = func_probes->next;
3175 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3178 if (iter->probe_entry)
3179 hnd = &iter->probe_entry->hlist;
3181 hash = iter->probe->ops.func_hash->filter_hash;
3182 size = 1 << hash->size_bits;
3185 if (iter->pidx >= size) {
3186 if (iter->probe->list.next == func_probes)
3188 next = iter->probe->list.next;
3189 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3190 hash = iter->probe->ops.func_hash->filter_hash;
3191 size = 1 << hash->size_bits;
3195 hhd = &hash->buckets[iter->pidx];
3197 if (hlist_empty(hhd)) {
3213 if (WARN_ON_ONCE(!hnd))
3216 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3221 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3223 struct ftrace_iterator *iter = m->private;
3227 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3230 if (iter->mod_pos > *pos)
3234 iter->probe_entry = NULL;
3236 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3237 p = t_probe_next(m, &l);
3244 /* Only set this if we have an item */
3245 iter->flags |= FTRACE_ITER_PROBE;
3251 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3253 struct ftrace_func_entry *probe_entry;
3254 struct ftrace_probe_ops *probe_ops;
3255 struct ftrace_func_probe *probe;
3257 probe = iter->probe;
3258 probe_entry = iter->probe_entry;
3260 if (WARN_ON_ONCE(!probe || !probe_entry))
3263 probe_ops = probe->probe_ops;
3265 if (probe_ops->print)
3266 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3268 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3269 (void *)probe_ops->func);
3275 t_mod_next(struct seq_file *m, loff_t *pos)
3277 struct ftrace_iterator *iter = m->private;
3278 struct trace_array *tr = iter->tr;
3283 iter->mod_list = iter->mod_list->next;
3285 if (iter->mod_list == &tr->mod_trace ||
3286 iter->mod_list == &tr->mod_notrace) {
3287 iter->flags &= ~FTRACE_ITER_MOD;
3291 iter->mod_pos = *pos;
3296 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3298 struct ftrace_iterator *iter = m->private;
3302 if (iter->func_pos > *pos)
3305 iter->mod_pos = iter->func_pos;
3307 /* probes are only available if tr is set */
3311 for (l = 0; l <= (*pos - iter->func_pos); ) {
3312 p = t_mod_next(m, &l);
3317 iter->flags &= ~FTRACE_ITER_MOD;
3318 return t_probe_start(m, pos);
3321 /* Only set this if we have an item */
3322 iter->flags |= FTRACE_ITER_MOD;
3328 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3330 struct ftrace_mod_load *ftrace_mod;
3331 struct trace_array *tr = iter->tr;
3333 if (WARN_ON_ONCE(!iter->mod_list) ||
3334 iter->mod_list == &tr->mod_trace ||
3335 iter->mod_list == &tr->mod_notrace)
3338 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3340 if (ftrace_mod->func)
3341 seq_printf(m, "%s", ftrace_mod->func);
3345 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3351 t_func_next(struct seq_file *m, loff_t *pos)
3353 struct ftrace_iterator *iter = m->private;
3354 struct dyn_ftrace *rec = NULL;
3359 if (iter->idx >= iter->pg->index) {
3360 if (iter->pg->next) {
3361 iter->pg = iter->pg->next;
3366 rec = &iter->pg->records[iter->idx++];
3367 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3368 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3370 ((iter->flags & FTRACE_ITER_ENABLED) &&
3371 !(rec->flags & FTRACE_FL_ENABLED))) {
3381 iter->pos = iter->func_pos = *pos;
3388 t_next(struct seq_file *m, void *v, loff_t *pos)
3390 struct ftrace_iterator *iter = m->private;
3391 loff_t l = *pos; /* t_probe_start() must use original pos */
3394 if (unlikely(ftrace_disabled))
3397 if (iter->flags & FTRACE_ITER_PROBE)
3398 return t_probe_next(m, pos);
3400 if (iter->flags & FTRACE_ITER_MOD)
3401 return t_mod_next(m, pos);
3403 if (iter->flags & FTRACE_ITER_PRINTALL) {
3404 /* next must increment pos, and t_probe_start does not */
3406 return t_mod_start(m, &l);
3409 ret = t_func_next(m, pos);
3412 return t_mod_start(m, &l);
3417 static void reset_iter_read(struct ftrace_iterator *iter)
3421 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3424 static void *t_start(struct seq_file *m, loff_t *pos)
3426 struct ftrace_iterator *iter = m->private;
3430 mutex_lock(&ftrace_lock);
3432 if (unlikely(ftrace_disabled))
3436 * If an lseek was done, then reset and start from beginning.
3438 if (*pos < iter->pos)
3439 reset_iter_read(iter);
3442 * For set_ftrace_filter reading, if we have the filter
3443 * off, we can short cut and just print out that all
3444 * functions are enabled.
3446 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3447 ftrace_hash_empty(iter->hash)) {
3448 iter->func_pos = 1; /* Account for the message */
3450 return t_mod_start(m, pos);
3451 iter->flags |= FTRACE_ITER_PRINTALL;
3452 /* reset in case of seek/pread */
3453 iter->flags &= ~FTRACE_ITER_PROBE;
3457 if (iter->flags & FTRACE_ITER_MOD)
3458 return t_mod_start(m, pos);
3461 * Unfortunately, we need to restart at ftrace_pages_start
3462 * every time we let go of the ftrace_mutex. This is because
3463 * those pointers can change without the lock.
3465 iter->pg = ftrace_pages_start;
3467 for (l = 0; l <= *pos; ) {
3468 p = t_func_next(m, &l);
3474 return t_mod_start(m, pos);
3479 static void t_stop(struct seq_file *m, void *p)
3481 mutex_unlock(&ftrace_lock);
3485 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3490 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3491 struct dyn_ftrace *rec)
3495 ptr = arch_ftrace_trampoline_func(ops, rec);
3497 seq_printf(m, " ->%pS", ptr);
3500 static int t_show(struct seq_file *m, void *v)
3502 struct ftrace_iterator *iter = m->private;
3503 struct dyn_ftrace *rec;
3505 if (iter->flags & FTRACE_ITER_PROBE)
3506 return t_probe_show(m, iter);
3508 if (iter->flags & FTRACE_ITER_MOD)
3509 return t_mod_show(m, iter);
3511 if (iter->flags & FTRACE_ITER_PRINTALL) {
3512 if (iter->flags & FTRACE_ITER_NOTRACE)
3513 seq_puts(m, "#### no functions disabled ####\n");
3515 seq_puts(m, "#### all functions enabled ####\n");
3524 seq_printf(m, "%ps", (void *)rec->ip);
3525 if (iter->flags & FTRACE_ITER_ENABLED) {
3526 struct ftrace_ops *ops;
3528 seq_printf(m, " (%ld)%s%s",
3529 ftrace_rec_count(rec),
3530 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3531 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3532 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3533 ops = ftrace_find_tramp_ops_any(rec);
3536 seq_printf(m, "\ttramp: %pS (%pS)",
3537 (void *)ops->trampoline,
3539 add_trampoline_func(m, ops, rec);
3540 ops = ftrace_find_tramp_ops_next(rec, ops);
3543 seq_puts(m, "\ttramp: ERROR!");
3545 add_trampoline_func(m, NULL, rec);
3554 static const struct seq_operations show_ftrace_seq_ops = {
3562 ftrace_avail_open(struct inode *inode, struct file *file)
3564 struct ftrace_iterator *iter;
3566 if (unlikely(ftrace_disabled))
3569 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3573 iter->pg = ftrace_pages_start;
3574 iter->ops = &global_ops;
3580 ftrace_enabled_open(struct inode *inode, struct file *file)
3582 struct ftrace_iterator *iter;
3584 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3588 iter->pg = ftrace_pages_start;
3589 iter->flags = FTRACE_ITER_ENABLED;
3590 iter->ops = &global_ops;
3596 * ftrace_regex_open - initialize function tracer filter files
3597 * @ops: The ftrace_ops that hold the hash filters
3598 * @flag: The type of filter to process
3599 * @inode: The inode, usually passed in to your open routine
3600 * @file: The file, usually passed in to your open routine
3602 * ftrace_regex_open() initializes the filter files for the
3603 * @ops. Depending on @flag it may process the filter hash or
3604 * the notrace hash of @ops. With this called from the open
3605 * routine, you can use ftrace_filter_write() for the write
3606 * routine if @flag has FTRACE_ITER_FILTER set, or
3607 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3608 * tracing_lseek() should be used as the lseek routine, and
3609 * release must call ftrace_regex_release().
3612 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3613 struct inode *inode, struct file *file)
3615 struct ftrace_iterator *iter;
3616 struct ftrace_hash *hash;
3617 struct list_head *mod_head;
3618 struct trace_array *tr = ops->private;
3621 ftrace_ops_init(ops);
3623 if (unlikely(ftrace_disabled))
3626 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3630 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3639 mutex_lock(&ops->func_hash->regex_lock);
3641 if (flag & FTRACE_ITER_NOTRACE) {
3642 hash = ops->func_hash->notrace_hash;
3643 mod_head = tr ? &tr->mod_notrace : NULL;
3645 hash = ops->func_hash->filter_hash;
3646 mod_head = tr ? &tr->mod_trace : NULL;
3649 iter->mod_list = mod_head;
3651 if (file->f_mode & FMODE_WRITE) {
3652 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3654 if (file->f_flags & O_TRUNC) {
3655 iter->hash = alloc_ftrace_hash(size_bits);
3656 clear_ftrace_mod_list(mod_head);
3658 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3662 trace_parser_put(&iter->parser);
3670 if (file->f_mode & FMODE_READ) {
3671 iter->pg = ftrace_pages_start;
3673 ret = seq_open(file, &show_ftrace_seq_ops);
3675 struct seq_file *m = file->private_data;
3679 free_ftrace_hash(iter->hash);
3680 trace_parser_put(&iter->parser);
3684 file->private_data = iter;
3687 mutex_unlock(&ops->func_hash->regex_lock);
3693 ftrace_filter_open(struct inode *inode, struct file *file)
3695 struct ftrace_ops *ops = inode->i_private;
3697 return ftrace_regex_open(ops,
3698 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3703 ftrace_notrace_open(struct inode *inode, struct file *file)
3705 struct ftrace_ops *ops = inode->i_private;
3707 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3711 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3712 struct ftrace_glob {
3719 * If symbols in an architecture don't correspond exactly to the user-visible
3720 * name of what they represent, it is possible to define this function to
3721 * perform the necessary adjustments.
3723 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3728 static int ftrace_match(char *str, struct ftrace_glob *g)
3733 str = arch_ftrace_match_adjust(str, g->search);
3737 if (strcmp(str, g->search) == 0)
3740 case MATCH_FRONT_ONLY:
3741 if (strncmp(str, g->search, g->len) == 0)
3744 case MATCH_MIDDLE_ONLY:
3745 if (strstr(str, g->search))
3748 case MATCH_END_ONLY:
3750 if (slen >= g->len &&
3751 memcmp(str + slen - g->len, g->search, g->len) == 0)
3755 if (glob_match(g->search, str))
3764 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3766 struct ftrace_func_entry *entry;
3769 entry = ftrace_lookup_ip(hash, rec->ip);
3771 /* Do nothing if it doesn't exist */
3775 free_hash_entry(hash, entry);
3777 /* Do nothing if it exists */
3781 ret = add_hash_entry(hash, rec->ip);
3787 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3788 struct ftrace_glob *mod_g, int exclude_mod)
3790 char str[KSYM_SYMBOL_LEN];
3793 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3796 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3798 /* blank module name to match all modules */
3800 /* blank module globbing: modname xor exclude_mod */
3801 if (!exclude_mod != !modname)
3807 * exclude_mod is set to trace everything but the given
3808 * module. If it is set and the module matches, then
3809 * return 0. If it is not set, and the module doesn't match
3810 * also return 0. Otherwise, check the function to see if
3813 if (!mod_matches == !exclude_mod)
3816 /* blank search means to match all funcs in the mod */
3821 return ftrace_match(str, func_g);
3825 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3827 struct ftrace_page *pg;
3828 struct dyn_ftrace *rec;
3829 struct ftrace_glob func_g = { .type = MATCH_FULL };
3830 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3831 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3832 int exclude_mod = 0;
3835 int clear_filter = 0;
3838 func_g.type = filter_parse_regex(func, len, &func_g.search,
3840 func_g.len = strlen(func_g.search);
3844 mod_g.type = filter_parse_regex(mod, strlen(mod),
3845 &mod_g.search, &exclude_mod);
3846 mod_g.len = strlen(mod_g.search);
3849 mutex_lock(&ftrace_lock);
3851 if (unlikely(ftrace_disabled))
3854 do_for_each_ftrace_rec(pg, rec) {
3856 if (rec->flags & FTRACE_FL_DISABLED)
3859 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3860 ret = enter_record(hash, rec, clear_filter);
3867 } while_for_each_ftrace_rec();
3869 mutex_unlock(&ftrace_lock);
3875 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3877 return match_records(hash, buff, len, NULL);
3880 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3881 struct ftrace_ops_hash *old_hash)
3883 struct ftrace_ops *op;
3885 if (!ftrace_enabled)
3888 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3889 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3894 * If this is the shared global_ops filter, then we need to
3895 * check if there is another ops that shares it, is enabled.
3896 * If so, we still need to run the modify code.
3898 if (ops->func_hash != &global_ops.local_hash)
3901 do_for_each_ftrace_op(op, ftrace_ops_list) {
3902 if (op->func_hash == &global_ops.local_hash &&
3903 op->flags & FTRACE_OPS_FL_ENABLED) {
3904 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3905 /* Only need to do this once */
3908 } while_for_each_ftrace_op(op);
3911 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3912 struct ftrace_hash **orig_hash,
3913 struct ftrace_hash *hash,
3916 struct ftrace_ops_hash old_hash_ops;
3917 struct ftrace_hash *old_hash;
3920 old_hash = *orig_hash;
3921 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3922 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3923 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3925 ftrace_ops_update_code(ops, &old_hash_ops);
3926 free_ftrace_hash_rcu(old_hash);
3931 static bool module_exists(const char *module)
3933 /* All modules have the symbol __this_module */
3934 const char this_mod[] = "__this_module";
3935 const int modname_size = MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 1;
3936 char modname[modname_size + 1];
3940 n = snprintf(modname, modname_size + 1, "%s:%s", module, this_mod);
3942 if (n > modname_size)
3945 val = module_kallsyms_lookup_name(modname);
3949 static int cache_mod(struct trace_array *tr,
3950 const char *func, char *module, int enable)
3952 struct ftrace_mod_load *ftrace_mod, *n;
3953 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3956 mutex_lock(&ftrace_lock);
3958 /* We do not cache inverse filters */
3959 if (func[0] == '!') {
3963 /* Look to remove this hash */
3964 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3965 if (strcmp(ftrace_mod->module, module) != 0)
3968 /* no func matches all */
3969 if (strcmp(func, "*") == 0 ||
3970 (ftrace_mod->func &&
3971 strcmp(ftrace_mod->func, func) == 0)) {
3973 free_ftrace_mod(ftrace_mod);
3981 /* We only care about modules that have not been loaded yet */
3982 if (module_exists(module))
3985 /* Save this string off, and execute it when the module is loaded */
3986 ret = ftrace_add_mod(tr, func, module, enable);
3988 mutex_unlock(&ftrace_lock);
3994 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3995 int reset, int enable);
3997 #ifdef CONFIG_MODULES
3998 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3999 char *mod, bool enable)
4001 struct ftrace_mod_load *ftrace_mod, *n;
4002 struct ftrace_hash **orig_hash, *new_hash;
4003 LIST_HEAD(process_mods);
4007 mutex_lock(&ops->func_hash->regex_lock);
4010 orig_hash = &ops->func_hash->filter_hash;
4012 orig_hash = &ops->func_hash->notrace_hash;
4014 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
4017 goto out; /* warn? */
4019 mutex_lock(&ftrace_lock);
4021 list_for_each_entry_safe(ftrace_mod, n, head, list) {
4023 if (strcmp(ftrace_mod->module, mod) != 0)
4026 if (ftrace_mod->func)
4027 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
4029 func = kstrdup("*", GFP_KERNEL);
4031 if (!func) /* warn? */
4034 list_del(&ftrace_mod->list);
4035 list_add(&ftrace_mod->list, &process_mods);
4037 /* Use the newly allocated func, as it may be "*" */
4038 kfree(ftrace_mod->func);
4039 ftrace_mod->func = func;
4042 mutex_unlock(&ftrace_lock);
4044 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4046 func = ftrace_mod->func;
4048 /* Grabs ftrace_lock, which is why we have this extra step */
4049 match_records(new_hash, func, strlen(func), mod);
4050 free_ftrace_mod(ftrace_mod);
4053 if (enable && list_empty(head))
4054 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4056 mutex_lock(&ftrace_lock);
4058 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4060 mutex_unlock(&ftrace_lock);
4063 mutex_unlock(&ops->func_hash->regex_lock);
4065 free_ftrace_hash(new_hash);
4068 static void process_cached_mods(const char *mod_name)
4070 struct trace_array *tr;
4073 mod = kstrdup(mod_name, GFP_KERNEL);
4077 mutex_lock(&trace_types_lock);
4078 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4079 if (!list_empty(&tr->mod_trace))
4080 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4081 if (!list_empty(&tr->mod_notrace))
4082 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4084 mutex_unlock(&trace_types_lock);
4091 * We register the module command as a template to show others how
4092 * to register the a command as well.
4096 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4097 char *func_orig, char *cmd, char *module, int enable)
4102 /* match_records() modifies func, and we need the original */
4103 func = kstrdup(func_orig, GFP_KERNEL);
4108 * cmd == 'mod' because we only registered this func
4109 * for the 'mod' ftrace_func_command.
4110 * But if you register one func with multiple commands,
4111 * you can tell which command was used by the cmd
4114 ret = match_records(hash, func, strlen(func), module);
4118 return cache_mod(tr, func_orig, module, enable);
4124 static struct ftrace_func_command ftrace_mod_cmd = {
4126 .func = ftrace_mod_callback,
4129 static int __init ftrace_mod_cmd_init(void)
4131 return register_ftrace_command(&ftrace_mod_cmd);
4133 core_initcall(ftrace_mod_cmd_init);
4135 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4136 struct ftrace_ops *op, struct pt_regs *pt_regs)
4138 struct ftrace_probe_ops *probe_ops;
4139 struct ftrace_func_probe *probe;
4141 probe = container_of(op, struct ftrace_func_probe, ops);
4142 probe_ops = probe->probe_ops;
4145 * Disable preemption for these calls to prevent a RCU grace
4146 * period. This syncs the hash iteration and freeing of items
4147 * on the hash. rcu_read_lock is too dangerous here.
4149 preempt_disable_notrace();
4150 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4151 preempt_enable_notrace();
4154 struct ftrace_func_map {
4155 struct ftrace_func_entry entry;
4159 struct ftrace_func_mapper {
4160 struct ftrace_hash hash;
4164 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4166 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4168 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4170 struct ftrace_hash *hash;
4173 * The mapper is simply a ftrace_hash, but since the entries
4174 * in the hash are not ftrace_func_entry type, we define it
4175 * as a separate structure.
4177 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4178 return (struct ftrace_func_mapper *)hash;
4182 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4183 * @mapper: The mapper that has the ip maps
4184 * @ip: the instruction pointer to find the data for
4186 * Returns the data mapped to @ip if found otherwise NULL. The return
4187 * is actually the address of the mapper data pointer. The address is
4188 * returned for use cases where the data is no bigger than a long, and
4189 * the user can use the data pointer as its data instead of having to
4190 * allocate more memory for the reference.
4192 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4195 struct ftrace_func_entry *entry;
4196 struct ftrace_func_map *map;
4198 entry = ftrace_lookup_ip(&mapper->hash, ip);
4202 map = (struct ftrace_func_map *)entry;
4207 * ftrace_func_mapper_add_ip - Map some data to an ip
4208 * @mapper: The mapper that has the ip maps
4209 * @ip: The instruction pointer address to map @data to
4210 * @data: The data to map to @ip
4212 * Returns 0 on succes otherwise an error.
4214 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4215 unsigned long ip, void *data)
4217 struct ftrace_func_entry *entry;
4218 struct ftrace_func_map *map;
4220 entry = ftrace_lookup_ip(&mapper->hash, ip);
4224 map = kmalloc(sizeof(*map), GFP_KERNEL);
4231 __add_hash_entry(&mapper->hash, &map->entry);
4237 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4238 * @mapper: The mapper that has the ip maps
4239 * @ip: The instruction pointer address to remove the data from
4241 * Returns the data if it is found, otherwise NULL.
4242 * Note, if the data pointer is used as the data itself, (see
4243 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4244 * if the data pointer was set to zero.
4246 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4249 struct ftrace_func_entry *entry;
4250 struct ftrace_func_map *map;
4253 entry = ftrace_lookup_ip(&mapper->hash, ip);
4257 map = (struct ftrace_func_map *)entry;
4260 remove_hash_entry(&mapper->hash, entry);
4267 * free_ftrace_func_mapper - free a mapping of ips and data
4268 * @mapper: The mapper that has the ip maps
4269 * @free_func: A function to be called on each data item.
4271 * This is used to free the function mapper. The @free_func is optional
4272 * and can be used if the data needs to be freed as well.
4274 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4275 ftrace_mapper_func free_func)
4277 struct ftrace_func_entry *entry;
4278 struct ftrace_func_map *map;
4279 struct hlist_head *hhd;
4280 int size = 1 << mapper->hash.size_bits;
4283 if (free_func && mapper->hash.count) {
4284 for (i = 0; i < size; i++) {
4285 hhd = &mapper->hash.buckets[i];
4286 hlist_for_each_entry(entry, hhd, hlist) {
4287 map = (struct ftrace_func_map *)entry;
4292 free_ftrace_hash(&mapper->hash);
4295 static void release_probe(struct ftrace_func_probe *probe)
4297 struct ftrace_probe_ops *probe_ops;
4299 mutex_lock(&ftrace_lock);
4301 WARN_ON(probe->ref <= 0);
4303 /* Subtract the ref that was used to protect this instance */
4307 probe_ops = probe->probe_ops;
4309 * Sending zero as ip tells probe_ops to free
4310 * the probe->data itself
4312 if (probe_ops->free)
4313 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4314 list_del(&probe->list);
4317 mutex_unlock(&ftrace_lock);
4320 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4323 * Add one ref to keep it from being freed when releasing the
4324 * ftrace_lock mutex.
4330 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4331 struct ftrace_probe_ops *probe_ops,
4334 struct ftrace_func_entry *entry;
4335 struct ftrace_func_probe *probe;
4336 struct ftrace_hash **orig_hash;
4337 struct ftrace_hash *old_hash;
4338 struct ftrace_hash *hash;
4347 /* We do not support '!' for function probes */
4348 if (WARN_ON(glob[0] == '!'))
4352 mutex_lock(&ftrace_lock);
4353 /* Check if the probe_ops is already registered */
4354 list_for_each_entry(probe, &tr->func_probes, list) {
4355 if (probe->probe_ops == probe_ops)
4358 if (&probe->list == &tr->func_probes) {
4359 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4361 mutex_unlock(&ftrace_lock);
4364 probe->probe_ops = probe_ops;
4365 probe->ops.func = function_trace_probe_call;
4367 ftrace_ops_init(&probe->ops);
4368 list_add(&probe->list, &tr->func_probes);
4371 acquire_probe_locked(probe);
4373 mutex_unlock(&ftrace_lock);
4375 mutex_lock(&probe->ops.func_hash->regex_lock);
4377 orig_hash = &probe->ops.func_hash->filter_hash;
4378 old_hash = *orig_hash;
4379 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4381 ret = ftrace_match_records(hash, glob, strlen(glob));
4383 /* Nothing found? */
4390 size = 1 << hash->size_bits;
4391 for (i = 0; i < size; i++) {
4392 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4393 if (ftrace_lookup_ip(old_hash, entry->ip))
4396 * The caller might want to do something special
4397 * for each function we find. We call the callback
4398 * to give the caller an opportunity to do so.
4400 if (probe_ops->init) {
4401 ret = probe_ops->init(probe_ops, tr,
4405 if (probe_ops->free && count)
4406 probe_ops->free(probe_ops, tr,
4416 mutex_lock(&ftrace_lock);
4419 /* Nothing was added? */
4424 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4429 /* One ref for each new function traced */
4430 probe->ref += count;
4432 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4433 ret = ftrace_startup(&probe->ops, 0);
4436 mutex_unlock(&ftrace_lock);
4441 mutex_unlock(&probe->ops.func_hash->regex_lock);
4442 free_ftrace_hash(hash);
4444 release_probe(probe);
4449 if (!probe_ops->free || !count)
4452 /* Failed to do the move, need to call the free functions */
4453 for (i = 0; i < size; i++) {
4454 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4455 if (ftrace_lookup_ip(old_hash, entry->ip))
4457 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4464 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4465 struct ftrace_probe_ops *probe_ops)
4467 struct ftrace_ops_hash old_hash_ops;
4468 struct ftrace_func_entry *entry;
4469 struct ftrace_func_probe *probe;
4470 struct ftrace_glob func_g;
4471 struct ftrace_hash **orig_hash;
4472 struct ftrace_hash *old_hash;
4473 struct ftrace_hash *hash = NULL;
4474 struct hlist_node *tmp;
4475 struct hlist_head hhd;
4476 char str[KSYM_SYMBOL_LEN];
4478 int i, ret = -ENODEV;
4481 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4482 func_g.search = NULL;
4486 func_g.type = filter_parse_regex(glob, strlen(glob),
4487 &func_g.search, ¬);
4488 func_g.len = strlen(func_g.search);
4489 func_g.search = glob;
4491 /* we do not support '!' for function probes */
4496 mutex_lock(&ftrace_lock);
4497 /* Check if the probe_ops is already registered */
4498 list_for_each_entry(probe, &tr->func_probes, list) {
4499 if (probe->probe_ops == probe_ops)
4502 if (&probe->list == &tr->func_probes)
4503 goto err_unlock_ftrace;
4506 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4507 goto err_unlock_ftrace;
4509 acquire_probe_locked(probe);
4511 mutex_unlock(&ftrace_lock);
4513 mutex_lock(&probe->ops.func_hash->regex_lock);
4515 orig_hash = &probe->ops.func_hash->filter_hash;
4516 old_hash = *orig_hash;
4518 if (ftrace_hash_empty(old_hash))
4521 old_hash_ops.filter_hash = old_hash;
4522 /* Probes only have filters */
4523 old_hash_ops.notrace_hash = NULL;
4526 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4530 INIT_HLIST_HEAD(&hhd);
4532 size = 1 << hash->size_bits;
4533 for (i = 0; i < size; i++) {
4534 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4536 if (func_g.search) {
4537 kallsyms_lookup(entry->ip, NULL, NULL,
4539 if (!ftrace_match(str, &func_g))
4543 remove_hash_entry(hash, entry);
4544 hlist_add_head(&entry->hlist, &hhd);
4548 /* Nothing found? */
4554 mutex_lock(&ftrace_lock);
4556 WARN_ON(probe->ref < count);
4558 probe->ref -= count;
4560 if (ftrace_hash_empty(hash))
4561 ftrace_shutdown(&probe->ops, 0);
4563 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4566 /* still need to update the function call sites */
4567 if (ftrace_enabled && !ftrace_hash_empty(hash))
4568 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4570 synchronize_sched();
4572 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4573 hlist_del(&entry->hlist);
4574 if (probe_ops->free)
4575 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4578 mutex_unlock(&ftrace_lock);
4581 mutex_unlock(&probe->ops.func_hash->regex_lock);
4582 free_ftrace_hash(hash);
4584 release_probe(probe);
4589 mutex_unlock(&ftrace_lock);
4593 void clear_ftrace_function_probes(struct trace_array *tr)
4595 struct ftrace_func_probe *probe, *n;
4597 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4598 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4601 static LIST_HEAD(ftrace_commands);
4602 static DEFINE_MUTEX(ftrace_cmd_mutex);
4605 * Currently we only register ftrace commands from __init, so mark this
4608 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4610 struct ftrace_func_command *p;
4613 mutex_lock(&ftrace_cmd_mutex);
4614 list_for_each_entry(p, &ftrace_commands, list) {
4615 if (strcmp(cmd->name, p->name) == 0) {
4620 list_add(&cmd->list, &ftrace_commands);
4622 mutex_unlock(&ftrace_cmd_mutex);
4628 * Currently we only unregister ftrace commands from __init, so mark
4631 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4633 struct ftrace_func_command *p, *n;
4636 mutex_lock(&ftrace_cmd_mutex);
4637 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4638 if (strcmp(cmd->name, p->name) == 0) {
4640 list_del_init(&p->list);
4645 mutex_unlock(&ftrace_cmd_mutex);
4650 static int ftrace_process_regex(struct ftrace_iterator *iter,
4651 char *buff, int len, int enable)
4653 struct ftrace_hash *hash = iter->hash;
4654 struct trace_array *tr = iter->ops->private;
4655 char *func, *command, *next = buff;
4656 struct ftrace_func_command *p;
4659 func = strsep(&next, ":");
4662 ret = ftrace_match_records(hash, func, len);
4672 command = strsep(&next, ":");
4674 mutex_lock(&ftrace_cmd_mutex);
4675 list_for_each_entry(p, &ftrace_commands, list) {
4676 if (strcmp(p->name, command) == 0) {
4677 ret = p->func(tr, hash, func, command, next, enable);
4682 mutex_unlock(&ftrace_cmd_mutex);
4688 ftrace_regex_write(struct file *file, const char __user *ubuf,
4689 size_t cnt, loff_t *ppos, int enable)
4691 struct ftrace_iterator *iter;
4692 struct trace_parser *parser;
4698 if (file->f_mode & FMODE_READ) {
4699 struct seq_file *m = file->private_data;
4702 iter = file->private_data;
4704 if (unlikely(ftrace_disabled))
4707 /* iter->hash is a local copy, so we don't need regex_lock */
4709 parser = &iter->parser;
4710 read = trace_get_user(parser, ubuf, cnt, ppos);
4712 if (read >= 0 && trace_parser_loaded(parser) &&
4713 !trace_parser_cont(parser)) {
4714 ret = ftrace_process_regex(iter, parser->buffer,
4715 parser->idx, enable);
4716 trace_parser_clear(parser);
4727 ftrace_filter_write(struct file *file, const char __user *ubuf,
4728 size_t cnt, loff_t *ppos)
4730 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4734 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4735 size_t cnt, loff_t *ppos)
4737 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4741 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4743 struct ftrace_func_entry *entry;
4745 if (!ftrace_location(ip))
4749 entry = ftrace_lookup_ip(hash, ip);
4752 free_hash_entry(hash, entry);
4756 return add_hash_entry(hash, ip);
4760 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4761 unsigned long ip, int remove, int reset, int enable)
4763 struct ftrace_hash **orig_hash;
4764 struct ftrace_hash *hash;
4767 if (unlikely(ftrace_disabled))
4770 mutex_lock(&ops->func_hash->regex_lock);
4773 orig_hash = &ops->func_hash->filter_hash;
4775 orig_hash = &ops->func_hash->notrace_hash;
4778 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4780 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4784 goto out_regex_unlock;
4787 if (buf && !ftrace_match_records(hash, buf, len)) {
4789 goto out_regex_unlock;
4792 ret = ftrace_match_addr(hash, ip, remove);
4794 goto out_regex_unlock;
4797 mutex_lock(&ftrace_lock);
4798 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4799 mutex_unlock(&ftrace_lock);
4802 mutex_unlock(&ops->func_hash->regex_lock);
4804 free_ftrace_hash(hash);
4809 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4810 int reset, int enable)
4812 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4816 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4817 * @ops - the ops to set the filter with
4818 * @ip - the address to add to or remove from the filter.
4819 * @remove - non zero to remove the ip from the filter
4820 * @reset - non zero to reset all filters before applying this filter.
4822 * Filters denote which functions should be enabled when tracing is enabled
4823 * If @ip is NULL, it failes to update filter.
4825 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4826 int remove, int reset)
4828 ftrace_ops_init(ops);
4829 return ftrace_set_addr(ops, ip, remove, reset, 1);
4831 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4834 * ftrace_ops_set_global_filter - setup ops to use global filters
4835 * @ops - the ops which will use the global filters
4837 * ftrace users who need global function trace filtering should call this.
4838 * It can set the global filter only if ops were not initialized before.
4840 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4842 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4845 ftrace_ops_init(ops);
4846 ops->func_hash = &global_ops.local_hash;
4848 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4851 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4852 int reset, int enable)
4854 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4858 * ftrace_set_filter - set a function to filter on in ftrace
4859 * @ops - the ops to set the filter with
4860 * @buf - the string that holds the function filter text.
4861 * @len - the length of the string.
4862 * @reset - non zero to reset all filters before applying this filter.
4864 * Filters denote which functions should be enabled when tracing is enabled.
4865 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4867 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4870 ftrace_ops_init(ops);
4871 return ftrace_set_regex(ops, buf, len, reset, 1);
4873 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4876 * ftrace_set_notrace - set a function to not trace in ftrace
4877 * @ops - the ops to set the notrace filter with
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 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4889 ftrace_ops_init(ops);
4890 return ftrace_set_regex(ops, buf, len, reset, 0);
4892 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4894 * ftrace_set_global_filter - set a function to filter on with global tracers
4895 * @buf - the string that holds the function filter text.
4896 * @len - the length of the string.
4897 * @reset - non zero to reset all filters before applying this filter.
4899 * Filters denote which functions should be enabled when tracing is enabled.
4900 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4902 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4904 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4906 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4909 * ftrace_set_global_notrace - set a function to not trace with global tracers
4910 * @buf - the string that holds the function notrace text.
4911 * @len - the length of the string.
4912 * @reset - non zero to reset all filters before applying this filter.
4914 * Notrace Filters denote which functions should not be enabled when tracing
4915 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4918 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4920 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4922 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4925 * command line interface to allow users to set filters on boot up.
4927 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4928 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4929 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4931 /* Used by function selftest to not test if filter is set */
4932 bool ftrace_filter_param __initdata;
4934 static int __init set_ftrace_notrace(char *str)
4936 ftrace_filter_param = true;
4937 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4940 __setup("ftrace_notrace=", set_ftrace_notrace);
4942 static int __init set_ftrace_filter(char *str)
4944 ftrace_filter_param = true;
4945 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4948 __setup("ftrace_filter=", set_ftrace_filter);
4950 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4951 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4952 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4953 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4955 static unsigned long save_global_trampoline;
4956 static unsigned long save_global_flags;
4958 static int __init set_graph_function(char *str)
4960 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4963 __setup("ftrace_graph_filter=", set_graph_function);
4965 static int __init set_graph_notrace_function(char *str)
4967 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4970 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4972 static int __init set_graph_max_depth_function(char *str)
4976 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4979 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4981 static void __init set_ftrace_early_graph(char *buf, int enable)
4985 struct ftrace_hash *hash;
4987 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4992 func = strsep(&buf, ",");
4993 /* we allow only one expression at a time */
4994 ret = ftrace_graph_set_hash(hash, func);
4996 printk(KERN_DEBUG "ftrace: function %s not "
4997 "traceable\n", func);
5001 ftrace_graph_hash = hash;
5003 ftrace_graph_notrace_hash = hash;
5005 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5008 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
5012 ftrace_ops_init(ops);
5015 func = strsep(&buf, ",");
5016 ftrace_set_regex(ops, func, strlen(func), 0, enable);
5020 static void __init set_ftrace_early_filters(void)
5022 if (ftrace_filter_buf[0])
5023 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
5024 if (ftrace_notrace_buf[0])
5025 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
5026 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5027 if (ftrace_graph_buf[0])
5028 set_ftrace_early_graph(ftrace_graph_buf, 1);
5029 if (ftrace_graph_notrace_buf[0])
5030 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
5031 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5034 int ftrace_regex_release(struct inode *inode, struct file *file)
5036 struct seq_file *m = (struct seq_file *)file->private_data;
5037 struct ftrace_iterator *iter;
5038 struct ftrace_hash **orig_hash;
5039 struct trace_parser *parser;
5043 if (file->f_mode & FMODE_READ) {
5045 seq_release(inode, file);
5047 iter = file->private_data;
5049 parser = &iter->parser;
5050 if (trace_parser_loaded(parser)) {
5051 parser->buffer[parser->idx] = 0;
5052 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5055 trace_parser_put(parser);
5057 mutex_lock(&iter->ops->func_hash->regex_lock);
5059 if (file->f_mode & FMODE_WRITE) {
5060 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5063 orig_hash = &iter->ops->func_hash->filter_hash;
5064 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5065 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5067 orig_hash = &iter->ops->func_hash->notrace_hash;
5069 mutex_lock(&ftrace_lock);
5070 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5071 iter->hash, filter_hash);
5072 mutex_unlock(&ftrace_lock);
5074 /* For read only, the hash is the ops hash */
5078 mutex_unlock(&iter->ops->func_hash->regex_lock);
5079 free_ftrace_hash(iter->hash);
5085 static const struct file_operations ftrace_avail_fops = {
5086 .open = ftrace_avail_open,
5088 .llseek = seq_lseek,
5089 .release = seq_release_private,
5092 static const struct file_operations ftrace_enabled_fops = {
5093 .open = ftrace_enabled_open,
5095 .llseek = seq_lseek,
5096 .release = seq_release_private,
5099 static const struct file_operations ftrace_filter_fops = {
5100 .open = ftrace_filter_open,
5102 .write = ftrace_filter_write,
5103 .llseek = tracing_lseek,
5104 .release = ftrace_regex_release,
5107 static const struct file_operations ftrace_notrace_fops = {
5108 .open = ftrace_notrace_open,
5110 .write = ftrace_notrace_write,
5111 .llseek = tracing_lseek,
5112 .release = ftrace_regex_release,
5115 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5117 static DEFINE_MUTEX(graph_lock);
5119 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5120 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5122 enum graph_filter_type {
5123 GRAPH_FILTER_NOTRACE = 0,
5124 GRAPH_FILTER_FUNCTION,
5127 #define FTRACE_GRAPH_EMPTY ((void *)1)
5129 struct ftrace_graph_data {
5130 struct ftrace_hash *hash;
5131 struct ftrace_func_entry *entry;
5132 int idx; /* for hash table iteration */
5133 enum graph_filter_type type;
5134 struct ftrace_hash *new_hash;
5135 const struct seq_operations *seq_ops;
5136 struct trace_parser parser;
5140 __g_next(struct seq_file *m, loff_t *pos)
5142 struct ftrace_graph_data *fgd = m->private;
5143 struct ftrace_func_entry *entry = fgd->entry;
5144 struct hlist_head *head;
5145 int i, idx = fgd->idx;
5147 if (*pos >= fgd->hash->count)
5151 hlist_for_each_entry_continue(entry, hlist) {
5159 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5160 head = &fgd->hash->buckets[i];
5161 hlist_for_each_entry(entry, head, hlist) {
5171 g_next(struct seq_file *m, void *v, loff_t *pos)
5174 return __g_next(m, pos);
5177 static void *g_start(struct seq_file *m, loff_t *pos)
5179 struct ftrace_graph_data *fgd = m->private;
5181 mutex_lock(&graph_lock);
5183 if (fgd->type == GRAPH_FILTER_FUNCTION)
5184 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5185 lockdep_is_held(&graph_lock));
5187 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5188 lockdep_is_held(&graph_lock));
5190 /* Nothing, tell g_show to print all functions are enabled */
5191 if (ftrace_hash_empty(fgd->hash) && !*pos)
5192 return FTRACE_GRAPH_EMPTY;
5196 return __g_next(m, pos);
5199 static void g_stop(struct seq_file *m, void *p)
5201 mutex_unlock(&graph_lock);
5204 static int g_show(struct seq_file *m, void *v)
5206 struct ftrace_func_entry *entry = v;
5211 if (entry == FTRACE_GRAPH_EMPTY) {
5212 struct ftrace_graph_data *fgd = m->private;
5214 if (fgd->type == GRAPH_FILTER_FUNCTION)
5215 seq_puts(m, "#### all functions enabled ####\n");
5217 seq_puts(m, "#### no functions disabled ####\n");
5221 seq_printf(m, "%ps\n", (void *)entry->ip);
5226 static const struct seq_operations ftrace_graph_seq_ops = {
5234 __ftrace_graph_open(struct inode *inode, struct file *file,
5235 struct ftrace_graph_data *fgd)
5238 struct ftrace_hash *new_hash = NULL;
5240 if (file->f_mode & FMODE_WRITE) {
5241 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5243 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5246 if (file->f_flags & O_TRUNC)
5247 new_hash = alloc_ftrace_hash(size_bits);
5249 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5257 if (file->f_mode & FMODE_READ) {
5258 ret = seq_open(file, &ftrace_graph_seq_ops);
5260 struct seq_file *m = file->private_data;
5264 free_ftrace_hash(new_hash);
5268 file->private_data = fgd;
5271 if (ret < 0 && file->f_mode & FMODE_WRITE)
5272 trace_parser_put(&fgd->parser);
5274 fgd->new_hash = new_hash;
5277 * All uses of fgd->hash must be taken with the graph_lock
5278 * held. The graph_lock is going to be released, so force
5279 * fgd->hash to be reinitialized when it is taken again.
5287 ftrace_graph_open(struct inode *inode, struct file *file)
5289 struct ftrace_graph_data *fgd;
5292 if (unlikely(ftrace_disabled))
5295 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5299 mutex_lock(&graph_lock);
5301 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5302 lockdep_is_held(&graph_lock));
5303 fgd->type = GRAPH_FILTER_FUNCTION;
5304 fgd->seq_ops = &ftrace_graph_seq_ops;
5306 ret = __ftrace_graph_open(inode, file, fgd);
5310 mutex_unlock(&graph_lock);
5315 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5317 struct ftrace_graph_data *fgd;
5320 if (unlikely(ftrace_disabled))
5323 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5327 mutex_lock(&graph_lock);
5329 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5330 lockdep_is_held(&graph_lock));
5331 fgd->type = GRAPH_FILTER_NOTRACE;
5332 fgd->seq_ops = &ftrace_graph_seq_ops;
5334 ret = __ftrace_graph_open(inode, file, fgd);
5338 mutex_unlock(&graph_lock);
5343 ftrace_graph_release(struct inode *inode, struct file *file)
5345 struct ftrace_graph_data *fgd;
5346 struct ftrace_hash *old_hash, *new_hash;
5347 struct trace_parser *parser;
5350 if (file->f_mode & FMODE_READ) {
5351 struct seq_file *m = file->private_data;
5354 seq_release(inode, file);
5356 fgd = file->private_data;
5360 if (file->f_mode & FMODE_WRITE) {
5362 parser = &fgd->parser;
5364 if (trace_parser_loaded((parser))) {
5365 parser->buffer[parser->idx] = 0;
5366 ret = ftrace_graph_set_hash(fgd->new_hash,
5370 trace_parser_put(parser);
5372 new_hash = __ftrace_hash_move(fgd->new_hash);
5378 mutex_lock(&graph_lock);
5380 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5381 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5382 lockdep_is_held(&graph_lock));
5383 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5385 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5386 lockdep_is_held(&graph_lock));
5387 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5390 mutex_unlock(&graph_lock);
5392 /* Wait till all users are no longer using the old hash */
5393 synchronize_sched();
5395 free_ftrace_hash(old_hash);
5399 free_ftrace_hash(fgd->new_hash);
5406 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5408 struct ftrace_glob func_g;
5409 struct dyn_ftrace *rec;
5410 struct ftrace_page *pg;
5411 struct ftrace_func_entry *entry;
5416 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5417 &func_g.search, ¬);
5419 func_g.len = strlen(func_g.search);
5421 mutex_lock(&ftrace_lock);
5423 if (unlikely(ftrace_disabled)) {
5424 mutex_unlock(&ftrace_lock);
5428 do_for_each_ftrace_rec(pg, rec) {
5430 if (rec->flags & FTRACE_FL_DISABLED)
5433 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5434 entry = ftrace_lookup_ip(hash, rec->ip);
5441 if (add_hash_entry(hash, rec->ip) < 0)
5445 free_hash_entry(hash, entry);
5450 } while_for_each_ftrace_rec();
5452 mutex_unlock(&ftrace_lock);
5461 ftrace_graph_write(struct file *file, const char __user *ubuf,
5462 size_t cnt, loff_t *ppos)
5464 ssize_t read, ret = 0;
5465 struct ftrace_graph_data *fgd = file->private_data;
5466 struct trace_parser *parser;
5471 /* Read mode uses seq functions */
5472 if (file->f_mode & FMODE_READ) {
5473 struct seq_file *m = file->private_data;
5477 parser = &fgd->parser;
5479 read = trace_get_user(parser, ubuf, cnt, ppos);
5481 if (read >= 0 && trace_parser_loaded(parser) &&
5482 !trace_parser_cont(parser)) {
5484 ret = ftrace_graph_set_hash(fgd->new_hash,
5486 trace_parser_clear(parser);
5495 static const struct file_operations ftrace_graph_fops = {
5496 .open = ftrace_graph_open,
5498 .write = ftrace_graph_write,
5499 .llseek = tracing_lseek,
5500 .release = ftrace_graph_release,
5503 static const struct file_operations ftrace_graph_notrace_fops = {
5504 .open = ftrace_graph_notrace_open,
5506 .write = ftrace_graph_write,
5507 .llseek = tracing_lseek,
5508 .release = ftrace_graph_release,
5510 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5512 void ftrace_create_filter_files(struct ftrace_ops *ops,
5513 struct dentry *parent)
5516 trace_create_file("set_ftrace_filter", 0644, parent,
5517 ops, &ftrace_filter_fops);
5519 trace_create_file("set_ftrace_notrace", 0644, parent,
5520 ops, &ftrace_notrace_fops);
5524 * The name "destroy_filter_files" is really a misnomer. Although
5525 * in the future, it may actualy delete the files, but this is
5526 * really intended to make sure the ops passed in are disabled
5527 * and that when this function returns, the caller is free to
5530 * The "destroy" name is only to match the "create" name that this
5531 * should be paired with.
5533 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5535 mutex_lock(&ftrace_lock);
5536 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5537 ftrace_shutdown(ops, 0);
5538 ops->flags |= FTRACE_OPS_FL_DELETED;
5539 mutex_unlock(&ftrace_lock);
5542 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5545 trace_create_file("available_filter_functions", 0444,
5546 d_tracer, NULL, &ftrace_avail_fops);
5548 trace_create_file("enabled_functions", 0444,
5549 d_tracer, NULL, &ftrace_enabled_fops);
5551 ftrace_create_filter_files(&global_ops, d_tracer);
5553 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5554 trace_create_file("set_graph_function", 0444, d_tracer,
5556 &ftrace_graph_fops);
5557 trace_create_file("set_graph_notrace", 0444, d_tracer,
5559 &ftrace_graph_notrace_fops);
5560 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5565 static int ftrace_cmp_ips(const void *a, const void *b)
5567 const unsigned long *ipa = a;
5568 const unsigned long *ipb = b;
5577 static int ftrace_process_locs(struct module *mod,
5578 unsigned long *start,
5581 struct ftrace_page *start_pg;
5582 struct ftrace_page *pg;
5583 struct dyn_ftrace *rec;
5584 unsigned long count;
5587 unsigned long flags = 0; /* Shut up gcc */
5590 count = end - start;
5595 sort(start, count, sizeof(*start),
5596 ftrace_cmp_ips, NULL);
5598 start_pg = ftrace_allocate_pages(count);
5602 mutex_lock(&ftrace_lock);
5605 * Core and each module needs their own pages, as
5606 * modules will free them when they are removed.
5607 * Force a new page to be allocated for modules.
5610 WARN_ON(ftrace_pages || ftrace_pages_start);
5611 /* First initialization */
5612 ftrace_pages = ftrace_pages_start = start_pg;
5617 if (WARN_ON(ftrace_pages->next)) {
5618 /* Hmm, we have free pages? */
5619 while (ftrace_pages->next)
5620 ftrace_pages = ftrace_pages->next;
5623 ftrace_pages->next = start_pg;
5629 addr = ftrace_call_adjust(*p++);
5631 * Some architecture linkers will pad between
5632 * the different mcount_loc sections of different
5633 * object files to satisfy alignments.
5634 * Skip any NULL pointers.
5639 if (pg->index == pg->size) {
5640 /* We should have allocated enough */
5641 if (WARN_ON(!pg->next))
5646 rec = &pg->records[pg->index++];
5650 /* We should have used all pages */
5653 /* Assign the last page to ftrace_pages */
5657 * We only need to disable interrupts on start up
5658 * because we are modifying code that an interrupt
5659 * may execute, and the modification is not atomic.
5660 * But for modules, nothing runs the code we modify
5661 * until we are finished with it, and there's no
5662 * reason to cause large interrupt latencies while we do it.
5665 local_irq_save(flags);
5666 ftrace_update_code(mod, start_pg);
5668 local_irq_restore(flags);
5671 mutex_unlock(&ftrace_lock);
5676 #ifdef CONFIG_MODULES
5678 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5680 static int referenced_filters(struct dyn_ftrace *rec)
5682 struct ftrace_ops *ops;
5685 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5686 if (ops_references_rec(ops, rec))
5693 void ftrace_release_mod(struct module *mod)
5695 struct dyn_ftrace *rec;
5696 struct ftrace_page **last_pg;
5697 struct ftrace_page *pg;
5700 mutex_lock(&ftrace_lock);
5702 if (ftrace_disabled)
5706 * Each module has its own ftrace_pages, remove
5707 * them from the list.
5709 last_pg = &ftrace_pages_start;
5710 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5711 rec = &pg->records[0];
5712 if (within_module_core(rec->ip, mod)) {
5714 * As core pages are first, the first
5715 * page should never be a module page.
5717 if (WARN_ON(pg == ftrace_pages_start))
5720 /* Check if we are deleting the last page */
5721 if (pg == ftrace_pages)
5722 ftrace_pages = next_to_ftrace_page(last_pg);
5724 ftrace_update_tot_cnt -= pg->index;
5725 *last_pg = pg->next;
5726 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5727 free_pages((unsigned long)pg->records, order);
5730 last_pg = &pg->next;
5733 mutex_unlock(&ftrace_lock);
5736 void ftrace_module_enable(struct module *mod)
5738 struct dyn_ftrace *rec;
5739 struct ftrace_page *pg;
5741 mutex_lock(&ftrace_lock);
5743 if (ftrace_disabled)
5747 * If the tracing is enabled, go ahead and enable the record.
5749 * The reason not to enable the record immediatelly is the
5750 * inherent check of ftrace_make_nop/ftrace_make_call for
5751 * correct previous instructions. Making first the NOP
5752 * conversion puts the module to the correct state, thus
5753 * passing the ftrace_make_call check.
5755 * We also delay this to after the module code already set the
5756 * text to read-only, as we now need to set it back to read-write
5757 * so that we can modify the text.
5759 if (ftrace_start_up)
5760 ftrace_arch_code_modify_prepare();
5762 do_for_each_ftrace_rec(pg, rec) {
5765 * do_for_each_ftrace_rec() is a double loop.
5766 * module text shares the pg. If a record is
5767 * not part of this module, then skip this pg,
5768 * which the "break" will do.
5770 if (!within_module_core(rec->ip, mod))
5776 * When adding a module, we need to check if tracers are
5777 * currently enabled and if they are, and can trace this record,
5778 * we need to enable the module functions as well as update the
5779 * reference counts for those function records.
5781 if (ftrace_start_up)
5782 cnt += referenced_filters(rec);
5784 /* This clears FTRACE_FL_DISABLED */
5787 if (ftrace_start_up && cnt) {
5788 int failed = __ftrace_replace_code(rec, 1);
5790 ftrace_bug(failed, rec);
5795 } while_for_each_ftrace_rec();
5798 if (ftrace_start_up)
5799 ftrace_arch_code_modify_post_process();
5802 mutex_unlock(&ftrace_lock);
5804 process_cached_mods(mod->name);
5807 void ftrace_module_init(struct module *mod)
5809 if (ftrace_disabled || !mod->num_ftrace_callsites)
5812 ftrace_process_locs(mod, mod->ftrace_callsites,
5813 mod->ftrace_callsites + mod->num_ftrace_callsites);
5815 #endif /* CONFIG_MODULES */
5817 void __init ftrace_free_init_mem(void)
5819 unsigned long start = (unsigned long)(&__init_begin);
5820 unsigned long end = (unsigned long)(&__init_end);
5821 struct ftrace_page **last_pg = &ftrace_pages_start;
5822 struct ftrace_page *pg;
5823 struct dyn_ftrace *rec;
5824 struct dyn_ftrace key;
5828 key.flags = end; /* overload flags, as it is unsigned long */
5830 mutex_lock(&ftrace_lock);
5832 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
5833 if (end < pg->records[0].ip ||
5834 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
5837 rec = bsearch(&key, pg->records, pg->index,
5838 sizeof(struct dyn_ftrace),
5843 ftrace_update_tot_cnt--;
5845 *last_pg = pg->next;
5846 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5847 free_pages((unsigned long)pg->records, order);
5849 pg = container_of(last_pg, struct ftrace_page, next);
5854 memmove(rec, rec + 1,
5855 (pg->index - (rec - pg->records)) * sizeof(*rec));
5856 /* More than one function may be in this block */
5859 mutex_unlock(&ftrace_lock);
5862 void __init ftrace_init(void)
5864 extern unsigned long __start_mcount_loc[];
5865 extern unsigned long __stop_mcount_loc[];
5866 unsigned long count, flags;
5869 local_irq_save(flags);
5870 ret = ftrace_dyn_arch_init();
5871 local_irq_restore(flags);
5875 count = __stop_mcount_loc - __start_mcount_loc;
5877 pr_info("ftrace: No functions to be traced?\n");
5881 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5882 count, count / ENTRIES_PER_PAGE + 1);
5884 last_ftrace_enabled = ftrace_enabled = 1;
5886 ret = ftrace_process_locs(NULL,
5890 set_ftrace_early_filters();
5894 ftrace_disabled = 1;
5897 /* Do nothing if arch does not support this */
5898 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
5902 static void ftrace_update_trampoline(struct ftrace_ops *ops)
5904 arch_ftrace_update_trampoline(ops);
5907 void ftrace_init_trace_array(struct trace_array *tr)
5909 INIT_LIST_HEAD(&tr->func_probes);
5910 INIT_LIST_HEAD(&tr->mod_trace);
5911 INIT_LIST_HEAD(&tr->mod_notrace);
5915 static struct ftrace_ops global_ops = {
5916 .func = ftrace_stub,
5917 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5918 FTRACE_OPS_FL_INITIALIZED |
5922 static int __init ftrace_nodyn_init(void)
5927 core_initcall(ftrace_nodyn_init);
5929 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
5930 static inline void ftrace_startup_enable(int command) { }
5931 static inline void ftrace_startup_all(int command) { }
5932 /* Keep as macros so we do not need to define the commands */
5933 # define ftrace_startup(ops, command) \
5935 int ___ret = __register_ftrace_function(ops); \
5937 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5940 # define ftrace_shutdown(ops, command) \
5942 int ___ret = __unregister_ftrace_function(ops); \
5944 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5948 # define ftrace_startup_sysctl() do { } while (0)
5949 # define ftrace_shutdown_sysctl() do { } while (0)
5952 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
5957 static void ftrace_update_trampoline(struct ftrace_ops *ops)
5961 #endif /* CONFIG_DYNAMIC_FTRACE */
5963 __init void ftrace_init_global_array_ops(struct trace_array *tr)
5965 tr->ops = &global_ops;
5966 tr->ops->private = tr;
5967 ftrace_init_trace_array(tr);
5970 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
5972 /* If we filter on pids, update to use the pid function */
5973 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
5974 if (WARN_ON(tr->ops->func != ftrace_stub))
5975 printk("ftrace ops had %pS for function\n",
5978 tr->ops->func = func;
5979 tr->ops->private = tr;
5982 void ftrace_reset_array_ops(struct trace_array *tr)
5984 tr->ops->func = ftrace_stub;
5988 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
5989 struct ftrace_ops *ignored, struct pt_regs *regs)
5991 struct ftrace_ops *op;
5994 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5999 * Some of the ops may be dynamically allocated,
6000 * they must be freed after a synchronize_sched().
6002 preempt_disable_notrace();
6004 do_for_each_ftrace_op(op, ftrace_ops_list) {
6006 * Check the following for each ops before calling their func:
6007 * if RCU flag is set, then rcu_is_watching() must be true
6008 * if PER_CPU is set, then ftrace_function_local_disable()
6010 * Otherwise test if the ip matches the ops filter
6012 * If any of the above fails then the op->func() is not executed.
6014 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6015 (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
6016 !ftrace_function_local_disabled(op)) &&
6017 ftrace_ops_test(op, ip, regs)) {
6019 if (FTRACE_WARN_ON(!op->func)) {
6020 pr_warn("op=%p %pS\n", op, op);
6023 op->func(ip, parent_ip, op, regs);
6025 } while_for_each_ftrace_op(op);
6027 preempt_enable_notrace();
6028 trace_clear_recursion(bit);
6032 * Some archs only support passing ip and parent_ip. Even though
6033 * the list function ignores the op parameter, we do not want any
6034 * C side effects, where a function is called without the caller
6035 * sending a third parameter.
6036 * Archs are to support both the regs and ftrace_ops at the same time.
6037 * If they support ftrace_ops, it is assumed they support regs.
6038 * If call backs want to use regs, they must either check for regs
6039 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6040 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6041 * An architecture can pass partial regs with ftrace_ops and still
6042 * set the ARCH_SUPPORTS_FTRACE_OPS.
6044 #if ARCH_SUPPORTS_FTRACE_OPS
6045 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6046 struct ftrace_ops *op, struct pt_regs *regs)
6048 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6051 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6053 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6058 * If there's only one function registered but it does not support
6059 * recursion, needs RCU protection and/or requires per cpu handling, then
6060 * this function will be called by the mcount trampoline.
6062 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6063 struct ftrace_ops *op, struct pt_regs *regs)
6067 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6070 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6074 preempt_disable_notrace();
6076 if (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
6077 !ftrace_function_local_disabled(op)) {
6078 op->func(ip, parent_ip, op, regs);
6081 preempt_enable_notrace();
6082 trace_clear_recursion(bit);
6086 * ftrace_ops_get_func - get the function a trampoline should call
6087 * @ops: the ops to get the function for
6089 * Normally the mcount trampoline will call the ops->func, but there
6090 * are times that it should not. For example, if the ops does not
6091 * have its own recursion protection, then it should call the
6092 * ftrace_ops_assist_func() instead.
6094 * Returns the function that the trampoline should call for @ops.
6096 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6099 * If the function does not handle recursion, needs to be RCU safe,
6100 * or does per cpu logic, then we need to call the assist handler.
6102 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6103 ops->flags & (FTRACE_OPS_FL_RCU | FTRACE_OPS_FL_PER_CPU))
6104 return ftrace_ops_assist_func;
6110 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6111 struct task_struct *prev, struct task_struct *next)
6113 struct trace_array *tr = data;
6114 struct trace_pid_list *pid_list;
6116 pid_list = rcu_dereference_sched(tr->function_pids);
6118 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6119 trace_ignore_this_task(pid_list, next));
6123 ftrace_pid_follow_sched_process_fork(void *data,
6124 struct task_struct *self,
6125 struct task_struct *task)
6127 struct trace_pid_list *pid_list;
6128 struct trace_array *tr = data;
6130 pid_list = rcu_dereference_sched(tr->function_pids);
6131 trace_filter_add_remove_task(pid_list, self, task);
6135 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6137 struct trace_pid_list *pid_list;
6138 struct trace_array *tr = data;
6140 pid_list = rcu_dereference_sched(tr->function_pids);
6141 trace_filter_add_remove_task(pid_list, NULL, task);
6144 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6147 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6149 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6152 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6154 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6159 static void clear_ftrace_pids(struct trace_array *tr)
6161 struct trace_pid_list *pid_list;
6164 pid_list = rcu_dereference_protected(tr->function_pids,
6165 lockdep_is_held(&ftrace_lock));
6169 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6171 for_each_possible_cpu(cpu)
6172 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6174 rcu_assign_pointer(tr->function_pids, NULL);
6176 /* Wait till all users are no longer using pid filtering */
6177 synchronize_sched();
6179 trace_free_pid_list(pid_list);
6182 void ftrace_clear_pids(struct trace_array *tr)
6184 mutex_lock(&ftrace_lock);
6186 clear_ftrace_pids(tr);
6188 mutex_unlock(&ftrace_lock);
6191 static void ftrace_pid_reset(struct trace_array *tr)
6193 mutex_lock(&ftrace_lock);
6194 clear_ftrace_pids(tr);
6196 ftrace_update_pid_func();
6197 ftrace_startup_all(0);
6199 mutex_unlock(&ftrace_lock);
6202 /* Greater than any max PID */
6203 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6205 static void *fpid_start(struct seq_file *m, loff_t *pos)
6208 struct trace_pid_list *pid_list;
6209 struct trace_array *tr = m->private;
6211 mutex_lock(&ftrace_lock);
6212 rcu_read_lock_sched();
6214 pid_list = rcu_dereference_sched(tr->function_pids);
6217 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6219 return trace_pid_start(pid_list, pos);
6222 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6224 struct trace_array *tr = m->private;
6225 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6227 if (v == FTRACE_NO_PIDS)
6230 return trace_pid_next(pid_list, v, pos);
6233 static void fpid_stop(struct seq_file *m, void *p)
6236 rcu_read_unlock_sched();
6237 mutex_unlock(&ftrace_lock);
6240 static int fpid_show(struct seq_file *m, void *v)
6242 if (v == FTRACE_NO_PIDS) {
6243 seq_puts(m, "no pid\n");
6247 return trace_pid_show(m, v);
6250 static const struct seq_operations ftrace_pid_sops = {
6251 .start = fpid_start,
6258 ftrace_pid_open(struct inode *inode, struct file *file)
6260 struct trace_array *tr = inode->i_private;
6264 if (trace_array_get(tr) < 0)
6267 if ((file->f_mode & FMODE_WRITE) &&
6268 (file->f_flags & O_TRUNC))
6269 ftrace_pid_reset(tr);
6271 ret = seq_open(file, &ftrace_pid_sops);
6273 trace_array_put(tr);
6275 m = file->private_data;
6276 /* copy tr over to seq ops */
6283 static void ignore_task_cpu(void *data)
6285 struct trace_array *tr = data;
6286 struct trace_pid_list *pid_list;
6289 * This function is called by on_each_cpu() while the
6290 * event_mutex is held.
6292 pid_list = rcu_dereference_protected(tr->function_pids,
6293 mutex_is_locked(&ftrace_lock));
6295 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6296 trace_ignore_this_task(pid_list, current));
6300 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6301 size_t cnt, loff_t *ppos)
6303 struct seq_file *m = filp->private_data;
6304 struct trace_array *tr = m->private;
6305 struct trace_pid_list *filtered_pids = NULL;
6306 struct trace_pid_list *pid_list;
6312 mutex_lock(&ftrace_lock);
6314 filtered_pids = rcu_dereference_protected(tr->function_pids,
6315 lockdep_is_held(&ftrace_lock));
6317 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6321 rcu_assign_pointer(tr->function_pids, pid_list);
6323 if (filtered_pids) {
6324 synchronize_sched();
6325 trace_free_pid_list(filtered_pids);
6326 } else if (pid_list) {
6327 /* Register a probe to set whether to ignore the tracing of a task */
6328 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6332 * Ignoring of pids is done at task switch. But we have to
6333 * check for those tasks that are currently running.
6334 * Always do this in case a pid was appended or removed.
6336 on_each_cpu(ignore_task_cpu, tr, 1);
6338 ftrace_update_pid_func();
6339 ftrace_startup_all(0);
6341 mutex_unlock(&ftrace_lock);
6350 ftrace_pid_release(struct inode *inode, struct file *file)
6352 struct trace_array *tr = inode->i_private;
6354 trace_array_put(tr);
6356 return seq_release(inode, file);
6359 static const struct file_operations ftrace_pid_fops = {
6360 .open = ftrace_pid_open,
6361 .write = ftrace_pid_write,
6363 .llseek = tracing_lseek,
6364 .release = ftrace_pid_release,
6367 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6369 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6370 tr, &ftrace_pid_fops);
6373 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6374 struct dentry *d_tracer)
6376 /* Only the top level directory has the dyn_tracefs and profile */
6377 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6379 ftrace_init_dyn_tracefs(d_tracer);
6380 ftrace_profile_tracefs(d_tracer);
6384 * ftrace_kill - kill ftrace
6386 * This function should be used by panic code. It stops ftrace
6387 * but in a not so nice way. If you need to simply kill ftrace
6388 * from a non-atomic section, use ftrace_kill.
6390 void ftrace_kill(void)
6392 ftrace_disabled = 1;
6394 clear_ftrace_function();
6398 * Test if ftrace is dead or not.
6400 int ftrace_is_dead(void)
6402 return ftrace_disabled;
6406 * register_ftrace_function - register a function for profiling
6407 * @ops - ops structure that holds the function for profiling.
6409 * Register a function to be called by all functions in the
6412 * Note: @ops->func and all the functions it calls must be labeled
6413 * with "notrace", otherwise it will go into a
6416 int register_ftrace_function(struct ftrace_ops *ops)
6420 ftrace_ops_init(ops);
6422 mutex_lock(&ftrace_lock);
6424 ret = ftrace_startup(ops, 0);
6426 mutex_unlock(&ftrace_lock);
6430 EXPORT_SYMBOL_GPL(register_ftrace_function);
6433 * unregister_ftrace_function - unregister a function for profiling.
6434 * @ops - ops structure that holds the function to unregister
6436 * Unregister a function that was added to be called by ftrace profiling.
6438 int unregister_ftrace_function(struct ftrace_ops *ops)
6442 mutex_lock(&ftrace_lock);
6443 ret = ftrace_shutdown(ops, 0);
6444 mutex_unlock(&ftrace_lock);
6448 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6451 ftrace_enable_sysctl(struct ctl_table *table, int write,
6452 void __user *buffer, size_t *lenp,
6457 mutex_lock(&ftrace_lock);
6459 if (unlikely(ftrace_disabled))
6462 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6464 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6467 last_ftrace_enabled = !!ftrace_enabled;
6469 if (ftrace_enabled) {
6471 /* we are starting ftrace again */
6472 if (rcu_dereference_protected(ftrace_ops_list,
6473 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6474 update_ftrace_function();
6476 ftrace_startup_sysctl();
6479 /* stopping ftrace calls (just send to ftrace_stub) */
6480 ftrace_trace_function = ftrace_stub;
6482 ftrace_shutdown_sysctl();
6486 mutex_unlock(&ftrace_lock);
6490 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6492 static struct ftrace_ops graph_ops = {
6493 .func = ftrace_stub,
6494 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6495 FTRACE_OPS_FL_INITIALIZED |
6498 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6499 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
6500 /* trampoline_size is only needed for dynamically allocated tramps */
6502 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
6505 void ftrace_graph_sleep_time_control(bool enable)
6507 fgraph_sleep_time = enable;
6510 void ftrace_graph_graph_time_control(bool enable)
6512 fgraph_graph_time = enable;
6515 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
6520 /* The callbacks that hook a function */
6521 trace_func_graph_ret_t ftrace_graph_return =
6522 (trace_func_graph_ret_t)ftrace_stub;
6523 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
6524 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
6526 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6527 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
6531 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
6532 struct task_struct *g, *t;
6534 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
6535 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
6536 * sizeof(struct ftrace_ret_stack),
6538 if (!ret_stack_list[i]) {
6546 read_lock(&tasklist_lock);
6547 do_each_thread(g, t) {
6553 if (t->ret_stack == NULL) {
6554 atomic_set(&t->tracing_graph_pause, 0);
6555 atomic_set(&t->trace_overrun, 0);
6556 t->curr_ret_stack = -1;
6557 /* Make sure the tasks see the -1 first: */
6559 t->ret_stack = ret_stack_list[start++];
6561 } while_each_thread(g, t);
6564 read_unlock(&tasklist_lock);
6566 for (i = start; i < end; i++)
6567 kfree(ret_stack_list[i]);
6572 ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
6573 struct task_struct *prev, struct task_struct *next)
6575 unsigned long long timestamp;
6579 * Does the user want to count the time a function was asleep.
6580 * If so, do not update the time stamps.
6582 if (fgraph_sleep_time)
6585 timestamp = trace_clock_local();
6587 prev->ftrace_timestamp = timestamp;
6589 /* only process tasks that we timestamped */
6590 if (!next->ftrace_timestamp)
6594 * Update all the counters in next to make up for the
6595 * time next was sleeping.
6597 timestamp -= next->ftrace_timestamp;
6599 for (index = next->curr_ret_stack; index >= 0; index--)
6600 next->ret_stack[index].calltime += timestamp;
6603 /* Allocate a return stack for each task */
6604 static int start_graph_tracing(void)
6606 struct ftrace_ret_stack **ret_stack_list;
6609 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
6610 sizeof(struct ftrace_ret_stack *),
6613 if (!ret_stack_list)
6616 /* The cpu_boot init_task->ret_stack will never be freed */
6617 for_each_online_cpu(cpu) {
6618 if (!idle_task(cpu)->ret_stack)
6619 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
6623 ret = alloc_retstack_tasklist(ret_stack_list);
6624 } while (ret == -EAGAIN);
6627 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6629 pr_info("ftrace_graph: Couldn't activate tracepoint"
6630 " probe to kernel_sched_switch\n");
6633 kfree(ret_stack_list);
6638 * Hibernation protection.
6639 * The state of the current task is too much unstable during
6640 * suspend/restore to disk. We want to protect against that.
6643 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
6647 case PM_HIBERNATION_PREPARE:
6648 pause_graph_tracing();
6651 case PM_POST_HIBERNATION:
6652 unpause_graph_tracing();
6658 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
6660 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
6662 return __ftrace_graph_entry(trace);
6666 * The function graph tracer should only trace the functions defined
6667 * by set_ftrace_filter and set_ftrace_notrace. If another function
6668 * tracer ops is registered, the graph tracer requires testing the
6669 * function against the global ops, and not just trace any function
6670 * that any ftrace_ops registered.
6672 static void update_function_graph_func(void)
6674 struct ftrace_ops *op;
6675 bool do_test = false;
6678 * The graph and global ops share the same set of functions
6679 * to test. If any other ops is on the list, then
6680 * the graph tracing needs to test if its the function
6683 do_for_each_ftrace_op(op, ftrace_ops_list) {
6684 if (op != &global_ops && op != &graph_ops &&
6685 op != &ftrace_list_end) {
6687 /* in double loop, break out with goto */
6690 } while_for_each_ftrace_op(op);
6693 ftrace_graph_entry = ftrace_graph_entry_test;
6695 ftrace_graph_entry = __ftrace_graph_entry;
6698 static struct notifier_block ftrace_suspend_notifier = {
6699 .notifier_call = ftrace_suspend_notifier_call,
6702 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
6703 trace_func_graph_ent_t entryfunc)
6707 mutex_lock(&ftrace_lock);
6709 /* we currently allow only one tracer registered at a time */
6710 if (ftrace_graph_active) {
6715 register_pm_notifier(&ftrace_suspend_notifier);
6717 ftrace_graph_active++;
6718 ret = start_graph_tracing();
6720 ftrace_graph_active--;
6724 ftrace_graph_return = retfunc;
6727 * Update the indirect function to the entryfunc, and the
6728 * function that gets called to the entry_test first. Then
6729 * call the update fgraph entry function to determine if
6730 * the entryfunc should be called directly or not.
6732 __ftrace_graph_entry = entryfunc;
6733 ftrace_graph_entry = ftrace_graph_entry_test;
6734 update_function_graph_func();
6736 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
6738 mutex_unlock(&ftrace_lock);
6742 void unregister_ftrace_graph(void)
6744 mutex_lock(&ftrace_lock);
6746 if (unlikely(!ftrace_graph_active))
6749 ftrace_graph_active--;
6750 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
6751 ftrace_graph_entry = ftrace_graph_entry_stub;
6752 __ftrace_graph_entry = ftrace_graph_entry_stub;
6753 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
6754 unregister_pm_notifier(&ftrace_suspend_notifier);
6755 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6757 #ifdef CONFIG_DYNAMIC_FTRACE
6759 * Function graph does not allocate the trampoline, but
6760 * other global_ops do. We need to reset the ALLOC_TRAMP flag
6763 global_ops.trampoline = save_global_trampoline;
6764 if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP)
6765 global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
6769 mutex_unlock(&ftrace_lock);
6772 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
6775 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
6777 atomic_set(&t->tracing_graph_pause, 0);
6778 atomic_set(&t->trace_overrun, 0);
6779 t->ftrace_timestamp = 0;
6780 /* make curr_ret_stack visible before we add the ret_stack */
6782 t->ret_stack = ret_stack;
6786 * Allocate a return stack for the idle task. May be the first
6787 * time through, or it may be done by CPU hotplug online.
6789 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
6791 t->curr_ret_stack = -1;
6793 * The idle task has no parent, it either has its own
6794 * stack or no stack at all.
6797 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
6799 if (ftrace_graph_active) {
6800 struct ftrace_ret_stack *ret_stack;
6802 ret_stack = per_cpu(idle_ret_stack, cpu);
6804 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6805 * sizeof(struct ftrace_ret_stack),
6809 per_cpu(idle_ret_stack, cpu) = ret_stack;
6811 graph_init_task(t, ret_stack);
6815 /* Allocate a return stack for newly created task */
6816 void ftrace_graph_init_task(struct task_struct *t)
6818 /* Make sure we do not use the parent ret_stack */
6819 t->ret_stack = NULL;
6820 t->curr_ret_stack = -1;
6822 if (ftrace_graph_active) {
6823 struct ftrace_ret_stack *ret_stack;
6825 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6826 * sizeof(struct ftrace_ret_stack),
6830 graph_init_task(t, ret_stack);
6834 void ftrace_graph_exit_task(struct task_struct *t)
6836 struct ftrace_ret_stack *ret_stack = t->ret_stack;
6838 t->ret_stack = NULL;
6839 /* NULL must become visible to IRQs before we free it: */