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 ftrace_sync(struct work_struct *work)
209 * This function is just a stub to implement a hard force
210 * of synchronize_sched(). This requires synchronizing
211 * tasks even in userspace and idle.
213 * Yes, function tracing is rude.
217 static void ftrace_sync_ipi(void *data)
219 /* Probably not needed, but do it anyway */
223 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
224 static void update_function_graph_func(void);
226 /* Both enabled by default (can be cleared by function_graph tracer flags */
227 static bool fgraph_sleep_time = true;
228 static bool fgraph_graph_time = true;
231 static inline void update_function_graph_func(void) { }
235 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
238 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
239 * then it needs to call the list anyway.
241 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
242 FTRACE_FORCE_LIST_FUNC)
243 return ftrace_ops_list_func;
245 return ftrace_ops_get_func(ops);
248 static void update_ftrace_function(void)
253 * Prepare the ftrace_ops that the arch callback will use.
254 * If there's only one ftrace_ops registered, the ftrace_ops_list
255 * will point to the ops we want.
257 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
258 lockdep_is_held(&ftrace_lock));
260 /* If there's no ftrace_ops registered, just call the stub function */
261 if (set_function_trace_op == &ftrace_list_end) {
265 * If we are at the end of the list and this ops is
266 * recursion safe and not dynamic and the arch supports passing ops,
267 * then have the mcount trampoline call the function directly.
269 } else if (rcu_dereference_protected(ftrace_ops_list->next,
270 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
271 func = ftrace_ops_get_list_func(ftrace_ops_list);
274 /* Just use the default ftrace_ops */
275 set_function_trace_op = &ftrace_list_end;
276 func = ftrace_ops_list_func;
279 update_function_graph_func();
281 /* If there's no change, then do nothing more here */
282 if (ftrace_trace_function == func)
286 * If we are using the list function, it doesn't care
287 * about the function_trace_ops.
289 if (func == ftrace_ops_list_func) {
290 ftrace_trace_function = func;
292 * Don't even bother setting function_trace_ops,
293 * it would be racy to do so anyway.
298 #ifndef CONFIG_DYNAMIC_FTRACE
300 * For static tracing, we need to be a bit more careful.
301 * The function change takes affect immediately. Thus,
302 * we need to coorditate the setting of the function_trace_ops
303 * with the setting of the ftrace_trace_function.
305 * Set the function to the list ops, which will call the
306 * function we want, albeit indirectly, but it handles the
307 * ftrace_ops and doesn't depend on function_trace_op.
309 ftrace_trace_function = ftrace_ops_list_func;
311 * Make sure all CPUs see this. Yes this is slow, but static
312 * tracing is slow and nasty to have enabled.
314 schedule_on_each_cpu(ftrace_sync);
315 /* Now all cpus are using the list ops. */
316 function_trace_op = set_function_trace_op;
317 /* Make sure the function_trace_op is visible on all CPUs */
319 /* Nasty way to force a rmb on all cpus */
320 smp_call_function(ftrace_sync_ipi, NULL, 1);
321 /* OK, we are all set to update the ftrace_trace_function now! */
322 #endif /* !CONFIG_DYNAMIC_FTRACE */
324 ftrace_trace_function = func;
327 int using_ftrace_ops_list_func(void)
329 return ftrace_trace_function == ftrace_ops_list_func;
332 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
333 struct ftrace_ops *ops)
335 rcu_assign_pointer(ops->next, *list);
338 * We are entering ops into the list but another
339 * CPU might be walking that list. We need to make sure
340 * the ops->next pointer is valid before another CPU sees
341 * the ops pointer included into the list.
343 rcu_assign_pointer(*list, ops);
346 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
347 struct ftrace_ops *ops)
349 struct ftrace_ops **p;
352 * If we are removing the last function, then simply point
353 * to the ftrace_stub.
355 if (rcu_dereference_protected(*list,
356 lockdep_is_held(&ftrace_lock)) == ops &&
357 rcu_dereference_protected(ops->next,
358 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
359 *list = &ftrace_list_end;
363 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
374 static void ftrace_update_trampoline(struct ftrace_ops *ops);
376 static int __register_ftrace_function(struct ftrace_ops *ops)
378 if (ops->flags & FTRACE_OPS_FL_DELETED)
381 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
384 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
386 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
387 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
388 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
390 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
391 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
394 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
395 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
398 if (!core_kernel_data((unsigned long)ops))
399 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
401 add_ftrace_ops(&ftrace_ops_list, ops);
403 /* Always save the function, and reset at unregistering */
404 ops->saved_func = ops->func;
406 if (ftrace_pids_enabled(ops))
407 ops->func = ftrace_pid_func;
409 ftrace_update_trampoline(ops);
412 update_ftrace_function();
417 static int __unregister_ftrace_function(struct ftrace_ops *ops)
421 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
424 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
430 update_ftrace_function();
432 ops->func = ops->saved_func;
437 static void ftrace_update_pid_func(void)
439 struct ftrace_ops *op;
441 /* Only do something if we are tracing something */
442 if (ftrace_trace_function == ftrace_stub)
445 do_for_each_ftrace_op(op, ftrace_ops_list) {
446 if (op->flags & FTRACE_OPS_FL_PID) {
447 op->func = ftrace_pids_enabled(op) ?
448 ftrace_pid_func : op->saved_func;
449 ftrace_update_trampoline(op);
451 } while_for_each_ftrace_op(op);
453 update_ftrace_function();
456 #ifdef CONFIG_FUNCTION_PROFILER
457 struct ftrace_profile {
458 struct hlist_node node;
460 unsigned long counter;
461 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
462 unsigned long long time;
463 unsigned long long time_squared;
467 struct ftrace_profile_page {
468 struct ftrace_profile_page *next;
470 struct ftrace_profile records[];
473 struct ftrace_profile_stat {
475 struct hlist_head *hash;
476 struct ftrace_profile_page *pages;
477 struct ftrace_profile_page *start;
478 struct tracer_stat stat;
481 #define PROFILE_RECORDS_SIZE \
482 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
484 #define PROFILES_PER_PAGE \
485 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
487 static int ftrace_profile_enabled __read_mostly;
489 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
490 static DEFINE_MUTEX(ftrace_profile_lock);
492 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
494 #define FTRACE_PROFILE_HASH_BITS 10
495 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
498 function_stat_next(void *v, int idx)
500 struct ftrace_profile *rec = v;
501 struct ftrace_profile_page *pg;
503 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
509 if ((void *)rec >= (void *)&pg->records[pg->index]) {
513 rec = &pg->records[0];
521 static void *function_stat_start(struct tracer_stat *trace)
523 struct ftrace_profile_stat *stat =
524 container_of(trace, struct ftrace_profile_stat, stat);
526 if (!stat || !stat->start)
529 return function_stat_next(&stat->start->records[0], 0);
532 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
533 /* function graph compares on total time */
534 static int function_stat_cmp(void *p1, void *p2)
536 struct ftrace_profile *a = p1;
537 struct ftrace_profile *b = p2;
539 if (a->time < b->time)
541 if (a->time > b->time)
547 /* not function graph compares against hits */
548 static int function_stat_cmp(void *p1, void *p2)
550 struct ftrace_profile *a = p1;
551 struct ftrace_profile *b = p2;
553 if (a->counter < b->counter)
555 if (a->counter > b->counter)
562 static int function_stat_headers(struct seq_file *m)
564 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
565 seq_puts(m, " Function "
568 "--- ---- --- ---\n");
570 seq_puts(m, " Function Hit\n"
576 static int function_stat_show(struct seq_file *m, void *v)
578 struct ftrace_profile *rec = v;
579 char str[KSYM_SYMBOL_LEN];
581 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
582 static struct trace_seq s;
583 unsigned long long avg;
584 unsigned long long stddev;
586 mutex_lock(&ftrace_profile_lock);
588 /* we raced with function_profile_reset() */
589 if (unlikely(rec->counter == 0)) {
594 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
596 do_div(avg, rec->counter);
597 if (tracing_thresh && (avg < tracing_thresh))
601 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
602 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
604 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
607 /* Sample standard deviation (s^2) */
608 if (rec->counter <= 1)
612 * Apply Welford's method:
613 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
615 stddev = rec->counter * rec->time_squared -
616 rec->time * rec->time;
619 * Divide only 1000 for ns^2 -> us^2 conversion.
620 * trace_print_graph_duration will divide 1000 again.
622 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
626 trace_print_graph_duration(rec->time, &s);
627 trace_seq_puts(&s, " ");
628 trace_print_graph_duration(avg, &s);
629 trace_seq_puts(&s, " ");
630 trace_print_graph_duration(stddev, &s);
631 trace_print_seq(m, &s);
635 mutex_unlock(&ftrace_profile_lock);
640 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
642 struct ftrace_profile_page *pg;
644 pg = stat->pages = stat->start;
647 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
652 memset(stat->hash, 0,
653 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
656 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
658 struct ftrace_profile_page *pg;
663 /* If we already allocated, do nothing */
667 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
671 #ifdef CONFIG_DYNAMIC_FTRACE
672 functions = ftrace_update_tot_cnt;
675 * We do not know the number of functions that exist because
676 * dynamic tracing is what counts them. With past experience
677 * we have around 20K functions. That should be more than enough.
678 * It is highly unlikely we will execute every function in
684 pg = stat->start = stat->pages;
686 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
688 for (i = 1; i < pages; i++) {
689 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
700 unsigned long tmp = (unsigned long)pg;
712 static int ftrace_profile_init_cpu(int cpu)
714 struct ftrace_profile_stat *stat;
717 stat = &per_cpu(ftrace_profile_stats, cpu);
720 /* If the profile is already created, simply reset it */
721 ftrace_profile_reset(stat);
726 * We are profiling all functions, but usually only a few thousand
727 * functions are hit. We'll make a hash of 1024 items.
729 size = FTRACE_PROFILE_HASH_SIZE;
731 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
736 /* Preallocate the function profiling pages */
737 if (ftrace_profile_pages_init(stat) < 0) {
746 static int ftrace_profile_init(void)
751 for_each_possible_cpu(cpu) {
752 ret = ftrace_profile_init_cpu(cpu);
760 /* interrupts must be disabled */
761 static struct ftrace_profile *
762 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
764 struct ftrace_profile *rec;
765 struct hlist_head *hhd;
768 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
769 hhd = &stat->hash[key];
771 if (hlist_empty(hhd))
774 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
782 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
783 struct ftrace_profile *rec)
787 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
788 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
792 * The memory is already allocated, this simply finds a new record to use.
794 static struct ftrace_profile *
795 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
797 struct ftrace_profile *rec = NULL;
799 /* prevent recursion (from NMIs) */
800 if (atomic_inc_return(&stat->disabled) != 1)
804 * Try to find the function again since an NMI
805 * could have added it
807 rec = ftrace_find_profiled_func(stat, ip);
811 if (stat->pages->index == PROFILES_PER_PAGE) {
812 if (!stat->pages->next)
814 stat->pages = stat->pages->next;
817 rec = &stat->pages->records[stat->pages->index++];
819 ftrace_add_profile(stat, rec);
822 atomic_dec(&stat->disabled);
828 function_profile_call(unsigned long ip, unsigned long parent_ip,
829 struct ftrace_ops *ops, struct pt_regs *regs)
831 struct ftrace_profile_stat *stat;
832 struct ftrace_profile *rec;
835 if (!ftrace_profile_enabled)
838 local_irq_save(flags);
840 stat = this_cpu_ptr(&ftrace_profile_stats);
841 if (!stat->hash || !ftrace_profile_enabled)
844 rec = ftrace_find_profiled_func(stat, ip);
846 rec = ftrace_profile_alloc(stat, ip);
853 local_irq_restore(flags);
856 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
857 static int profile_graph_entry(struct ftrace_graph_ent *trace)
859 int index = trace->depth;
861 function_profile_call(trace->func, 0, NULL, NULL);
863 /* If function graph is shutting down, ret_stack can be NULL */
864 if (!current->ret_stack)
867 if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
868 current->ret_stack[index].subtime = 0;
873 static void profile_graph_return(struct ftrace_graph_ret *trace)
875 struct ftrace_profile_stat *stat;
876 unsigned long long calltime;
877 struct ftrace_profile *rec;
880 local_irq_save(flags);
881 stat = this_cpu_ptr(&ftrace_profile_stats);
882 if (!stat->hash || !ftrace_profile_enabled)
885 /* If the calltime was zero'd ignore it */
886 if (!trace->calltime)
889 calltime = trace->rettime - trace->calltime;
891 if (!fgraph_graph_time) {
894 index = trace->depth;
896 /* Append this call time to the parent time to subtract */
898 current->ret_stack[index - 1].subtime += calltime;
900 if (current->ret_stack[index].subtime < calltime)
901 calltime -= current->ret_stack[index].subtime;
906 rec = ftrace_find_profiled_func(stat, trace->func);
908 rec->time += calltime;
909 rec->time_squared += calltime * calltime;
913 local_irq_restore(flags);
916 static int register_ftrace_profiler(void)
918 return register_ftrace_graph(&profile_graph_return,
919 &profile_graph_entry);
922 static void unregister_ftrace_profiler(void)
924 unregister_ftrace_graph();
927 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
928 .func = function_profile_call,
929 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
930 INIT_OPS_HASH(ftrace_profile_ops)
933 static int register_ftrace_profiler(void)
935 return register_ftrace_function(&ftrace_profile_ops);
938 static void unregister_ftrace_profiler(void)
940 unregister_ftrace_function(&ftrace_profile_ops);
942 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
945 ftrace_profile_write(struct file *filp, const char __user *ubuf,
946 size_t cnt, loff_t *ppos)
951 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
957 mutex_lock(&ftrace_profile_lock);
958 if (ftrace_profile_enabled ^ val) {
960 ret = ftrace_profile_init();
966 ret = register_ftrace_profiler();
971 ftrace_profile_enabled = 1;
973 ftrace_profile_enabled = 0;
975 * unregister_ftrace_profiler calls stop_machine
976 * so this acts like an synchronize_sched.
978 unregister_ftrace_profiler();
982 mutex_unlock(&ftrace_profile_lock);
990 ftrace_profile_read(struct file *filp, char __user *ubuf,
991 size_t cnt, loff_t *ppos)
993 char buf[64]; /* big enough to hold a number */
996 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
997 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1000 static const struct file_operations ftrace_profile_fops = {
1001 .open = tracing_open_generic,
1002 .read = ftrace_profile_read,
1003 .write = ftrace_profile_write,
1004 .llseek = default_llseek,
1007 /* used to initialize the real stat files */
1008 static struct tracer_stat function_stats __initdata = {
1009 .name = "functions",
1010 .stat_start = function_stat_start,
1011 .stat_next = function_stat_next,
1012 .stat_cmp = function_stat_cmp,
1013 .stat_headers = function_stat_headers,
1014 .stat_show = function_stat_show
1017 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1019 struct ftrace_profile_stat *stat;
1020 struct dentry *entry;
1025 for_each_possible_cpu(cpu) {
1026 stat = &per_cpu(ftrace_profile_stats, cpu);
1028 name = kasprintf(GFP_KERNEL, "function%d", cpu);
1031 * The files created are permanent, if something happens
1032 * we still do not free memory.
1035 "Could not allocate stat file for cpu %d\n",
1039 stat->stat = function_stats;
1040 stat->stat.name = name;
1041 ret = register_stat_tracer(&stat->stat);
1044 "Could not register function stat for cpu %d\n",
1051 entry = tracefs_create_file("function_profile_enabled", 0644,
1052 d_tracer, NULL, &ftrace_profile_fops);
1054 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1057 #else /* CONFIG_FUNCTION_PROFILER */
1058 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1061 #endif /* CONFIG_FUNCTION_PROFILER */
1063 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1065 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1066 static int ftrace_graph_active;
1068 # define ftrace_graph_active 0
1071 #ifdef CONFIG_DYNAMIC_FTRACE
1073 static struct ftrace_ops *removed_ops;
1076 * Set when doing a global update, like enabling all recs or disabling them.
1077 * It is not set when just updating a single ftrace_ops.
1079 static bool update_all_ops;
1081 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1082 # error Dynamic ftrace depends on MCOUNT_RECORD
1085 struct ftrace_func_entry {
1086 struct hlist_node hlist;
1090 struct ftrace_func_probe {
1091 struct ftrace_probe_ops *probe_ops;
1092 struct ftrace_ops ops;
1093 struct trace_array *tr;
1094 struct list_head list;
1100 * We make these constant because no one should touch them,
1101 * but they are used as the default "empty hash", to avoid allocating
1102 * it all the time. These are in a read only section such that if
1103 * anyone does try to modify it, it will cause an exception.
1105 static const struct hlist_head empty_buckets[1];
1106 static const struct ftrace_hash empty_hash = {
1107 .buckets = (struct hlist_head *)empty_buckets,
1109 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1111 static struct ftrace_ops global_ops = {
1112 .func = ftrace_stub,
1113 .local_hash.notrace_hash = EMPTY_HASH,
1114 .local_hash.filter_hash = EMPTY_HASH,
1115 INIT_OPS_HASH(global_ops)
1116 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1117 FTRACE_OPS_FL_INITIALIZED |
1122 * This is used by __kernel_text_address() to return true if the
1123 * address is on a dynamically allocated trampoline that would
1124 * not return true for either core_kernel_text() or
1125 * is_module_text_address().
1127 bool is_ftrace_trampoline(unsigned long addr)
1129 struct ftrace_ops *op;
1133 * Some of the ops may be dynamically allocated,
1134 * they are freed after a synchronize_sched().
1136 preempt_disable_notrace();
1138 do_for_each_ftrace_op(op, ftrace_ops_list) {
1140 * This is to check for dynamically allocated trampolines.
1141 * Trampolines that are in kernel text will have
1142 * core_kernel_text() return true.
1144 if (op->trampoline && op->trampoline_size)
1145 if (addr >= op->trampoline &&
1146 addr < op->trampoline + op->trampoline_size) {
1150 } while_for_each_ftrace_op(op);
1153 preempt_enable_notrace();
1158 struct ftrace_page {
1159 struct ftrace_page *next;
1160 struct dyn_ftrace *records;
1165 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1166 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1168 /* estimate from running different kernels */
1169 #define NR_TO_INIT 10000
1171 static struct ftrace_page *ftrace_pages_start;
1172 static struct ftrace_page *ftrace_pages;
1174 static __always_inline unsigned long
1175 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1177 if (hash->size_bits > 0)
1178 return hash_long(ip, hash->size_bits);
1183 /* Only use this function if ftrace_hash_empty() has already been tested */
1184 static __always_inline struct ftrace_func_entry *
1185 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1188 struct ftrace_func_entry *entry;
1189 struct hlist_head *hhd;
1191 key = ftrace_hash_key(hash, ip);
1192 hhd = &hash->buckets[key];
1194 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1195 if (entry->ip == ip)
1202 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1203 * @hash: The hash to look at
1204 * @ip: The instruction pointer to test
1206 * Search a given @hash to see if a given instruction pointer (@ip)
1209 * Returns the entry that holds the @ip if found. NULL otherwise.
1211 struct ftrace_func_entry *
1212 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1214 if (ftrace_hash_empty(hash))
1217 return __ftrace_lookup_ip(hash, ip);
1220 static void __add_hash_entry(struct ftrace_hash *hash,
1221 struct ftrace_func_entry *entry)
1223 struct hlist_head *hhd;
1226 key = ftrace_hash_key(hash, entry->ip);
1227 hhd = &hash->buckets[key];
1228 hlist_add_head(&entry->hlist, hhd);
1232 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1234 struct ftrace_func_entry *entry;
1236 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1241 __add_hash_entry(hash, entry);
1247 free_hash_entry(struct ftrace_hash *hash,
1248 struct ftrace_func_entry *entry)
1250 hlist_del(&entry->hlist);
1256 remove_hash_entry(struct ftrace_hash *hash,
1257 struct ftrace_func_entry *entry)
1259 hlist_del_rcu(&entry->hlist);
1263 static void ftrace_hash_clear(struct ftrace_hash *hash)
1265 struct hlist_head *hhd;
1266 struct hlist_node *tn;
1267 struct ftrace_func_entry *entry;
1268 int size = 1 << hash->size_bits;
1274 for (i = 0; i < size; i++) {
1275 hhd = &hash->buckets[i];
1276 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1277 free_hash_entry(hash, entry);
1279 FTRACE_WARN_ON(hash->count);
1282 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1284 list_del(&ftrace_mod->list);
1285 kfree(ftrace_mod->module);
1286 kfree(ftrace_mod->func);
1290 static void clear_ftrace_mod_list(struct list_head *head)
1292 struct ftrace_mod_load *p, *n;
1294 /* stack tracer isn't supported yet */
1298 mutex_lock(&ftrace_lock);
1299 list_for_each_entry_safe(p, n, head, list)
1301 mutex_unlock(&ftrace_lock);
1304 static void free_ftrace_hash(struct ftrace_hash *hash)
1306 if (!hash || hash == EMPTY_HASH)
1308 ftrace_hash_clear(hash);
1309 kfree(hash->buckets);
1313 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1315 struct ftrace_hash *hash;
1317 hash = container_of(rcu, struct ftrace_hash, rcu);
1318 free_ftrace_hash(hash);
1321 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1323 if (!hash || hash == EMPTY_HASH)
1325 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1328 void ftrace_free_filter(struct ftrace_ops *ops)
1330 ftrace_ops_init(ops);
1331 free_ftrace_hash(ops->func_hash->filter_hash);
1332 free_ftrace_hash(ops->func_hash->notrace_hash);
1335 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1337 struct ftrace_hash *hash;
1340 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1344 size = 1 << size_bits;
1345 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1347 if (!hash->buckets) {
1352 hash->size_bits = size_bits;
1358 static int ftrace_add_mod(struct trace_array *tr,
1359 const char *func, const char *module,
1362 struct ftrace_mod_load *ftrace_mod;
1363 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1365 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1369 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1370 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1371 ftrace_mod->enable = enable;
1373 if (!ftrace_mod->func || !ftrace_mod->module)
1376 list_add(&ftrace_mod->list, mod_head);
1381 free_ftrace_mod(ftrace_mod);
1386 static struct ftrace_hash *
1387 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1389 struct ftrace_func_entry *entry;
1390 struct ftrace_hash *new_hash;
1395 new_hash = alloc_ftrace_hash(size_bits);
1400 new_hash->flags = hash->flags;
1403 if (ftrace_hash_empty(hash))
1406 size = 1 << hash->size_bits;
1407 for (i = 0; i < size; i++) {
1408 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1409 ret = add_hash_entry(new_hash, entry->ip);
1415 FTRACE_WARN_ON(new_hash->count != hash->count);
1420 free_ftrace_hash(new_hash);
1425 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1427 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1429 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1430 struct ftrace_hash *new_hash);
1432 static struct ftrace_hash *
1433 __ftrace_hash_move(struct ftrace_hash *src)
1435 struct ftrace_func_entry *entry;
1436 struct hlist_node *tn;
1437 struct hlist_head *hhd;
1438 struct ftrace_hash *new_hash;
1439 int size = src->count;
1444 * If the new source is empty, just return the empty_hash.
1446 if (ftrace_hash_empty(src))
1450 * Make the hash size about 1/2 the # found
1452 for (size /= 2; size; size >>= 1)
1455 /* Don't allocate too much */
1456 if (bits > FTRACE_HASH_MAX_BITS)
1457 bits = FTRACE_HASH_MAX_BITS;
1459 new_hash = alloc_ftrace_hash(bits);
1463 new_hash->flags = src->flags;
1465 size = 1 << src->size_bits;
1466 for (i = 0; i < size; i++) {
1467 hhd = &src->buckets[i];
1468 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1469 remove_hash_entry(src, entry);
1470 __add_hash_entry(new_hash, entry);
1478 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1479 struct ftrace_hash **dst, struct ftrace_hash *src)
1481 struct ftrace_hash *new_hash;
1484 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1485 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1488 new_hash = __ftrace_hash_move(src);
1492 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1494 /* IPMODIFY should be updated only when filter_hash updating */
1495 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1497 free_ftrace_hash(new_hash);
1503 * Remove the current set, update the hash and add
1506 ftrace_hash_rec_disable_modify(ops, enable);
1508 rcu_assign_pointer(*dst, new_hash);
1510 ftrace_hash_rec_enable_modify(ops, enable);
1515 static bool hash_contains_ip(unsigned long ip,
1516 struct ftrace_ops_hash *hash)
1519 * The function record is a match if it exists in the filter
1520 * hash and not in the notrace hash. Note, an emty hash is
1521 * considered a match for the filter hash, but an empty
1522 * notrace hash is considered not in the notrace hash.
1524 return (ftrace_hash_empty(hash->filter_hash) ||
1525 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1526 (ftrace_hash_empty(hash->notrace_hash) ||
1527 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1531 * Test the hashes for this ops to see if we want to call
1532 * the ops->func or not.
1534 * It's a match if the ip is in the ops->filter_hash or
1535 * the filter_hash does not exist or is empty,
1537 * the ip is not in the ops->notrace_hash.
1539 * This needs to be called with preemption disabled as
1540 * the hashes are freed with call_rcu_sched().
1543 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1545 struct ftrace_ops_hash hash;
1548 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1550 * There's a small race when adding ops that the ftrace handler
1551 * that wants regs, may be called without them. We can not
1552 * allow that handler to be called if regs is NULL.
1554 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1558 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1559 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1561 if (hash_contains_ip(ip, &hash))
1570 * This is a double for. Do not use 'break' to break out of the loop,
1571 * you must use a goto.
1573 #define do_for_each_ftrace_rec(pg, rec) \
1574 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1576 for (_____i = 0; _____i < pg->index; _____i++) { \
1577 rec = &pg->records[_____i];
1579 #define while_for_each_ftrace_rec() \
1584 static int ftrace_cmp_recs(const void *a, const void *b)
1586 const struct dyn_ftrace *key = a;
1587 const struct dyn_ftrace *rec = b;
1589 if (key->flags < rec->ip)
1591 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1597 * ftrace_location_range - return the first address of a traced location
1598 * if it touches the given ip range
1599 * @start: start of range to search.
1600 * @end: end of range to search (inclusive). @end points to the last byte
1603 * Returns rec->ip if the related ftrace location is a least partly within
1604 * the given address range. That is, the first address of the instruction
1605 * that is either a NOP or call to the function tracer. It checks the ftrace
1606 * internal tables to determine if the address belongs or not.
1608 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1610 struct ftrace_page *pg;
1611 struct dyn_ftrace *rec;
1612 struct dyn_ftrace key;
1615 key.flags = end; /* overload flags, as it is unsigned long */
1617 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1618 if (end < pg->records[0].ip ||
1619 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1621 rec = bsearch(&key, pg->records, pg->index,
1622 sizeof(struct dyn_ftrace),
1632 * ftrace_location - return true if the ip giving is a traced location
1633 * @ip: the instruction pointer to check
1635 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1636 * That is, the instruction that is either a NOP or call to
1637 * the function tracer. It checks the ftrace internal tables to
1638 * determine if the address belongs or not.
1640 unsigned long ftrace_location(unsigned long ip)
1642 return ftrace_location_range(ip, ip);
1646 * ftrace_text_reserved - return true if range contains an ftrace location
1647 * @start: start of range to search
1648 * @end: end of range to search (inclusive). @end points to the last byte to check.
1650 * Returns 1 if @start and @end contains a ftrace location.
1651 * That is, the instruction that is either a NOP or call to
1652 * the function tracer. It checks the ftrace internal tables to
1653 * determine if the address belongs or not.
1655 int ftrace_text_reserved(const void *start, const void *end)
1659 ret = ftrace_location_range((unsigned long)start,
1660 (unsigned long)end);
1665 /* Test if ops registered to this rec needs regs */
1666 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1668 struct ftrace_ops *ops;
1669 bool keep_regs = false;
1671 for (ops = ftrace_ops_list;
1672 ops != &ftrace_list_end; ops = ops->next) {
1673 /* pass rec in as regs to have non-NULL val */
1674 if (ftrace_ops_test(ops, rec->ip, rec)) {
1675 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1685 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1689 struct ftrace_hash *hash;
1690 struct ftrace_hash *other_hash;
1691 struct ftrace_page *pg;
1692 struct dyn_ftrace *rec;
1693 bool update = false;
1697 /* Only update if the ops has been registered */
1698 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1702 * In the filter_hash case:
1703 * If the count is zero, we update all records.
1704 * Otherwise we just update the items in the hash.
1706 * In the notrace_hash case:
1707 * We enable the update in the hash.
1708 * As disabling notrace means enabling the tracing,
1709 * and enabling notrace means disabling, the inc variable
1713 hash = ops->func_hash->filter_hash;
1714 other_hash = ops->func_hash->notrace_hash;
1715 if (ftrace_hash_empty(hash))
1719 hash = ops->func_hash->notrace_hash;
1720 other_hash = ops->func_hash->filter_hash;
1722 * If the notrace hash has no items,
1723 * then there's nothing to do.
1725 if (ftrace_hash_empty(hash))
1729 do_for_each_ftrace_rec(pg, rec) {
1730 int in_other_hash = 0;
1734 if (rec->flags & FTRACE_FL_DISABLED)
1739 * Only the filter_hash affects all records.
1740 * Update if the record is not in the notrace hash.
1742 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1745 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1746 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1749 * If filter_hash is set, we want to match all functions
1750 * that are in the hash but not in the other hash.
1752 * If filter_hash is not set, then we are decrementing.
1753 * That means we match anything that is in the hash
1754 * and also in the other_hash. That is, we need to turn
1755 * off functions in the other hash because they are disabled
1758 if (filter_hash && in_hash && !in_other_hash)
1760 else if (!filter_hash && in_hash &&
1761 (in_other_hash || ftrace_hash_empty(other_hash)))
1769 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1773 * If there's only a single callback registered to a
1774 * function, and the ops has a trampoline registered
1775 * for it, then we can call it directly.
1777 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1778 rec->flags |= FTRACE_FL_TRAMP;
1781 * If we are adding another function callback
1782 * to this function, and the previous had a
1783 * custom trampoline in use, then we need to go
1784 * back to the default trampoline.
1786 rec->flags &= ~FTRACE_FL_TRAMP;
1789 * If any ops wants regs saved for this function
1790 * then all ops will get saved regs.
1792 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1793 rec->flags |= FTRACE_FL_REGS;
1795 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1800 * If the rec had REGS enabled and the ops that is
1801 * being removed had REGS set, then see if there is
1802 * still any ops for this record that wants regs.
1803 * If not, we can stop recording them.
1805 if (ftrace_rec_count(rec) > 0 &&
1806 rec->flags & FTRACE_FL_REGS &&
1807 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1808 if (!test_rec_ops_needs_regs(rec))
1809 rec->flags &= ~FTRACE_FL_REGS;
1813 * If the rec had TRAMP enabled, then it needs to
1814 * be cleared. As TRAMP can only be enabled iff
1815 * there is only a single ops attached to it.
1816 * In otherwords, always disable it on decrementing.
1817 * In the future, we may set it if rec count is
1818 * decremented to one, and the ops that is left
1821 rec->flags &= ~FTRACE_FL_TRAMP;
1824 * flags will be cleared in ftrace_check_record()
1825 * if rec count is zero.
1830 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1831 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1833 /* Shortcut, if we handled all records, we are done. */
1834 if (!all && count == hash->count)
1836 } while_for_each_ftrace_rec();
1841 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1844 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1847 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1850 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1853 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1854 int filter_hash, int inc)
1856 struct ftrace_ops *op;
1858 __ftrace_hash_rec_update(ops, filter_hash, inc);
1860 if (ops->func_hash != &global_ops.local_hash)
1864 * If the ops shares the global_ops hash, then we need to update
1865 * all ops that are enabled and use this hash.
1867 do_for_each_ftrace_op(op, ftrace_ops_list) {
1871 if (op->func_hash == &global_ops.local_hash)
1872 __ftrace_hash_rec_update(op, filter_hash, inc);
1873 } while_for_each_ftrace_op(op);
1876 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1879 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1882 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1885 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1889 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1890 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1891 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1892 * Note that old_hash and new_hash has below meanings
1893 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1894 * - If the hash is EMPTY_HASH, it hits nothing
1895 * - Anything else hits the recs which match the hash entries.
1897 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1898 struct ftrace_hash *old_hash,
1899 struct ftrace_hash *new_hash)
1901 struct ftrace_page *pg;
1902 struct dyn_ftrace *rec, *end = NULL;
1905 /* Only update if the ops has been registered */
1906 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1909 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1913 * Since the IPMODIFY is a very address sensitive action, we do not
1914 * allow ftrace_ops to set all functions to new hash.
1916 if (!new_hash || !old_hash)
1919 /* Update rec->flags */
1920 do_for_each_ftrace_rec(pg, rec) {
1922 if (rec->flags & FTRACE_FL_DISABLED)
1925 /* We need to update only differences of filter_hash */
1926 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1927 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1928 if (in_old == in_new)
1932 /* New entries must ensure no others are using it */
1933 if (rec->flags & FTRACE_FL_IPMODIFY)
1935 rec->flags |= FTRACE_FL_IPMODIFY;
1936 } else /* Removed entry */
1937 rec->flags &= ~FTRACE_FL_IPMODIFY;
1938 } while_for_each_ftrace_rec();
1945 /* Roll back what we did above */
1946 do_for_each_ftrace_rec(pg, rec) {
1948 if (rec->flags & FTRACE_FL_DISABLED)
1954 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1955 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1956 if (in_old == in_new)
1960 rec->flags &= ~FTRACE_FL_IPMODIFY;
1962 rec->flags |= FTRACE_FL_IPMODIFY;
1963 } while_for_each_ftrace_rec();
1969 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1971 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1973 if (ftrace_hash_empty(hash))
1976 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1979 /* Disabling always succeeds */
1980 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1982 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1984 if (ftrace_hash_empty(hash))
1987 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1990 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1991 struct ftrace_hash *new_hash)
1993 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1995 if (ftrace_hash_empty(old_hash))
1998 if (ftrace_hash_empty(new_hash))
2001 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
2004 static void print_ip_ins(const char *fmt, const unsigned char *p)
2008 printk(KERN_CONT "%s", fmt);
2010 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
2011 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
2014 static struct ftrace_ops *
2015 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
2016 static struct ftrace_ops *
2017 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
2019 enum ftrace_bug_type ftrace_bug_type;
2020 const void *ftrace_expected;
2022 static void print_bug_type(void)
2024 switch (ftrace_bug_type) {
2025 case FTRACE_BUG_UNKNOWN:
2027 case FTRACE_BUG_INIT:
2028 pr_info("Initializing ftrace call sites\n");
2030 case FTRACE_BUG_NOP:
2031 pr_info("Setting ftrace call site to NOP\n");
2033 case FTRACE_BUG_CALL:
2034 pr_info("Setting ftrace call site to call ftrace function\n");
2036 case FTRACE_BUG_UPDATE:
2037 pr_info("Updating ftrace call site to call a different ftrace function\n");
2043 * ftrace_bug - report and shutdown function tracer
2044 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2045 * @rec: The record that failed
2047 * The arch code that enables or disables the function tracing
2048 * can call ftrace_bug() when it has detected a problem in
2049 * modifying the code. @failed should be one of either:
2050 * EFAULT - if the problem happens on reading the @ip address
2051 * EINVAL - if what is read at @ip is not what was expected
2052 * EPERM - if the problem happens on writting to the @ip address
2054 void ftrace_bug(int failed, struct dyn_ftrace *rec)
2056 unsigned long ip = rec ? rec->ip : 0;
2060 FTRACE_WARN_ON_ONCE(1);
2061 pr_info("ftrace faulted on modifying ");
2065 FTRACE_WARN_ON_ONCE(1);
2066 pr_info("ftrace failed to modify ");
2068 print_ip_ins(" actual: ", (unsigned char *)ip);
2070 if (ftrace_expected) {
2071 print_ip_ins(" expected: ", ftrace_expected);
2076 FTRACE_WARN_ON_ONCE(1);
2077 pr_info("ftrace faulted on writing ");
2081 FTRACE_WARN_ON_ONCE(1);
2082 pr_info("ftrace faulted on unknown error ");
2087 struct ftrace_ops *ops = NULL;
2089 pr_info("ftrace record flags: %lx\n", rec->flags);
2090 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2091 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2092 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2093 ops = ftrace_find_tramp_ops_any(rec);
2096 pr_cont("\ttramp: %pS (%pS)",
2097 (void *)ops->trampoline,
2099 ops = ftrace_find_tramp_ops_next(rec, ops);
2102 pr_cont("\ttramp: ERROR!");
2105 ip = ftrace_get_addr_curr(rec);
2106 pr_cont("\n expected tramp: %lx\n", ip);
2110 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2112 unsigned long flag = 0UL;
2114 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2116 if (rec->flags & FTRACE_FL_DISABLED)
2117 return FTRACE_UPDATE_IGNORE;
2120 * If we are updating calls:
2122 * If the record has a ref count, then we need to enable it
2123 * because someone is using it.
2125 * Otherwise we make sure its disabled.
2127 * If we are disabling calls, then disable all records that
2130 if (enable && ftrace_rec_count(rec))
2131 flag = FTRACE_FL_ENABLED;
2134 * If enabling and the REGS flag does not match the REGS_EN, or
2135 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2136 * this record. Set flags to fail the compare against ENABLED.
2139 if (!(rec->flags & FTRACE_FL_REGS) !=
2140 !(rec->flags & FTRACE_FL_REGS_EN))
2141 flag |= FTRACE_FL_REGS;
2143 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2144 !(rec->flags & FTRACE_FL_TRAMP_EN))
2145 flag |= FTRACE_FL_TRAMP;
2148 /* If the state of this record hasn't changed, then do nothing */
2149 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2150 return FTRACE_UPDATE_IGNORE;
2153 /* Save off if rec is being enabled (for return value) */
2154 flag ^= rec->flags & FTRACE_FL_ENABLED;
2157 rec->flags |= FTRACE_FL_ENABLED;
2158 if (flag & FTRACE_FL_REGS) {
2159 if (rec->flags & FTRACE_FL_REGS)
2160 rec->flags |= FTRACE_FL_REGS_EN;
2162 rec->flags &= ~FTRACE_FL_REGS_EN;
2164 if (flag & FTRACE_FL_TRAMP) {
2165 if (rec->flags & FTRACE_FL_TRAMP)
2166 rec->flags |= FTRACE_FL_TRAMP_EN;
2168 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2173 * If this record is being updated from a nop, then
2174 * return UPDATE_MAKE_CALL.
2176 * return UPDATE_MODIFY_CALL to tell the caller to convert
2177 * from the save regs, to a non-save regs function or
2178 * vice versa, or from a trampoline call.
2180 if (flag & FTRACE_FL_ENABLED) {
2181 ftrace_bug_type = FTRACE_BUG_CALL;
2182 return FTRACE_UPDATE_MAKE_CALL;
2185 ftrace_bug_type = FTRACE_BUG_UPDATE;
2186 return FTRACE_UPDATE_MODIFY_CALL;
2190 /* If there's no more users, clear all flags */
2191 if (!ftrace_rec_count(rec))
2195 * Just disable the record, but keep the ops TRAMP
2196 * and REGS states. The _EN flags must be disabled though.
2198 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2202 ftrace_bug_type = FTRACE_BUG_NOP;
2203 return FTRACE_UPDATE_MAKE_NOP;
2207 * ftrace_update_record, set a record that now is tracing or not
2208 * @rec: the record to update
2209 * @enable: set to 1 if the record is tracing, zero to force disable
2211 * The records that represent all functions that can be traced need
2212 * to be updated when tracing has been enabled.
2214 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2216 return ftrace_check_record(rec, enable, 1);
2220 * ftrace_test_record, check if the record has been enabled or not
2221 * @rec: the record to test
2222 * @enable: set to 1 to check if enabled, 0 if it is disabled
2224 * The arch code may need to test if a record is already set to
2225 * tracing to determine how to modify the function code that it
2228 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2230 return ftrace_check_record(rec, enable, 0);
2233 static struct ftrace_ops *
2234 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2236 struct ftrace_ops *op;
2237 unsigned long ip = rec->ip;
2239 do_for_each_ftrace_op(op, ftrace_ops_list) {
2241 if (!op->trampoline)
2244 if (hash_contains_ip(ip, op->func_hash))
2246 } while_for_each_ftrace_op(op);
2251 static struct ftrace_ops *
2252 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2253 struct ftrace_ops *op)
2255 unsigned long ip = rec->ip;
2257 while_for_each_ftrace_op(op) {
2259 if (!op->trampoline)
2262 if (hash_contains_ip(ip, op->func_hash))
2269 static struct ftrace_ops *
2270 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2272 struct ftrace_ops *op;
2273 unsigned long ip = rec->ip;
2276 * Need to check removed ops first.
2277 * If they are being removed, and this rec has a tramp,
2278 * and this rec is in the ops list, then it would be the
2279 * one with the tramp.
2282 if (hash_contains_ip(ip, &removed_ops->old_hash))
2287 * Need to find the current trampoline for a rec.
2288 * Now, a trampoline is only attached to a rec if there
2289 * was a single 'ops' attached to it. But this can be called
2290 * when we are adding another op to the rec or removing the
2291 * current one. Thus, if the op is being added, we can
2292 * ignore it because it hasn't attached itself to the rec
2295 * If an ops is being modified (hooking to different functions)
2296 * then we don't care about the new functions that are being
2297 * added, just the old ones (that are probably being removed).
2299 * If we are adding an ops to a function that already is using
2300 * a trampoline, it needs to be removed (trampolines are only
2301 * for single ops connected), then an ops that is not being
2302 * modified also needs to be checked.
2304 do_for_each_ftrace_op(op, ftrace_ops_list) {
2306 if (!op->trampoline)
2310 * If the ops is being added, it hasn't gotten to
2311 * the point to be removed from this tree yet.
2313 if (op->flags & FTRACE_OPS_FL_ADDING)
2318 * If the ops is being modified and is in the old
2319 * hash, then it is probably being removed from this
2322 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2323 hash_contains_ip(ip, &op->old_hash))
2326 * If the ops is not being added or modified, and it's
2327 * in its normal filter hash, then this must be the one
2330 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2331 hash_contains_ip(ip, op->func_hash))
2334 } while_for_each_ftrace_op(op);
2339 static struct ftrace_ops *
2340 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2342 struct ftrace_ops *op;
2343 unsigned long ip = rec->ip;
2345 do_for_each_ftrace_op(op, ftrace_ops_list) {
2346 /* pass rec in as regs to have non-NULL val */
2347 if (hash_contains_ip(ip, op->func_hash))
2349 } while_for_each_ftrace_op(op);
2355 * ftrace_get_addr_new - Get the call address to set to
2356 * @rec: The ftrace record descriptor
2358 * If the record has the FTRACE_FL_REGS set, that means that it
2359 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2360 * is not not set, then it wants to convert to the normal callback.
2362 * Returns the address of the trampoline to set to
2364 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2366 struct ftrace_ops *ops;
2368 /* Trampolines take precedence over regs */
2369 if (rec->flags & FTRACE_FL_TRAMP) {
2370 ops = ftrace_find_tramp_ops_new(rec);
2371 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2372 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2373 (void *)rec->ip, (void *)rec->ip, rec->flags);
2374 /* Ftrace is shutting down, return anything */
2375 return (unsigned long)FTRACE_ADDR;
2377 return ops->trampoline;
2380 if (rec->flags & FTRACE_FL_REGS)
2381 return (unsigned long)FTRACE_REGS_ADDR;
2383 return (unsigned long)FTRACE_ADDR;
2387 * ftrace_get_addr_curr - Get the call address that is already there
2388 * @rec: The ftrace record descriptor
2390 * The FTRACE_FL_REGS_EN is set when the record already points to
2391 * a function that saves all the regs. Basically the '_EN' version
2392 * represents the current state of the function.
2394 * Returns the address of the trampoline that is currently being called
2396 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2398 struct ftrace_ops *ops;
2400 /* Trampolines take precedence over regs */
2401 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2402 ops = ftrace_find_tramp_ops_curr(rec);
2403 if (FTRACE_WARN_ON(!ops)) {
2404 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2405 (void *)rec->ip, (void *)rec->ip);
2406 /* Ftrace is shutting down, return anything */
2407 return (unsigned long)FTRACE_ADDR;
2409 return ops->trampoline;
2412 if (rec->flags & FTRACE_FL_REGS_EN)
2413 return (unsigned long)FTRACE_REGS_ADDR;
2415 return (unsigned long)FTRACE_ADDR;
2419 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2421 unsigned long ftrace_old_addr;
2422 unsigned long ftrace_addr;
2425 ftrace_addr = ftrace_get_addr_new(rec);
2427 /* This needs to be done before we call ftrace_update_record */
2428 ftrace_old_addr = ftrace_get_addr_curr(rec);
2430 ret = ftrace_update_record(rec, enable);
2432 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2435 case FTRACE_UPDATE_IGNORE:
2438 case FTRACE_UPDATE_MAKE_CALL:
2439 ftrace_bug_type = FTRACE_BUG_CALL;
2440 return ftrace_make_call(rec, ftrace_addr);
2442 case FTRACE_UPDATE_MAKE_NOP:
2443 ftrace_bug_type = FTRACE_BUG_NOP;
2444 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2446 case FTRACE_UPDATE_MODIFY_CALL:
2447 ftrace_bug_type = FTRACE_BUG_UPDATE;
2448 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2451 return -1; /* unknow ftrace bug */
2454 void __weak ftrace_replace_code(int enable)
2456 struct dyn_ftrace *rec;
2457 struct ftrace_page *pg;
2460 if (unlikely(ftrace_disabled))
2463 do_for_each_ftrace_rec(pg, rec) {
2465 if (rec->flags & FTRACE_FL_DISABLED)
2468 failed = __ftrace_replace_code(rec, enable);
2470 ftrace_bug(failed, rec);
2471 /* Stop processing */
2474 } while_for_each_ftrace_rec();
2477 struct ftrace_rec_iter {
2478 struct ftrace_page *pg;
2483 * ftrace_rec_iter_start, start up iterating over traced functions
2485 * Returns an iterator handle that is used to iterate over all
2486 * the records that represent address locations where functions
2489 * May return NULL if no records are available.
2491 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2494 * We only use a single iterator.
2495 * Protected by the ftrace_lock mutex.
2497 static struct ftrace_rec_iter ftrace_rec_iter;
2498 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2500 iter->pg = ftrace_pages_start;
2503 /* Could have empty pages */
2504 while (iter->pg && !iter->pg->index)
2505 iter->pg = iter->pg->next;
2514 * ftrace_rec_iter_next, get the next record to process.
2515 * @iter: The handle to the iterator.
2517 * Returns the next iterator after the given iterator @iter.
2519 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2523 if (iter->index >= iter->pg->index) {
2524 iter->pg = iter->pg->next;
2527 /* Could have empty pages */
2528 while (iter->pg && !iter->pg->index)
2529 iter->pg = iter->pg->next;
2539 * ftrace_rec_iter_record, get the record at the iterator location
2540 * @iter: The current iterator location
2542 * Returns the record that the current @iter is at.
2544 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2546 return &iter->pg->records[iter->index];
2550 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2554 if (unlikely(ftrace_disabled))
2557 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2559 ftrace_bug_type = FTRACE_BUG_INIT;
2560 ftrace_bug(ret, rec);
2567 * archs can override this function if they must do something
2568 * before the modifying code is performed.
2570 int __weak ftrace_arch_code_modify_prepare(void)
2576 * archs can override this function if they must do something
2577 * after the modifying code is performed.
2579 int __weak ftrace_arch_code_modify_post_process(void)
2584 void ftrace_modify_all_code(int command)
2586 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2590 * If the ftrace_caller calls a ftrace_ops func directly,
2591 * we need to make sure that it only traces functions it
2592 * expects to trace. When doing the switch of functions,
2593 * we need to update to the ftrace_ops_list_func first
2594 * before the transition between old and new calls are set,
2595 * as the ftrace_ops_list_func will check the ops hashes
2596 * to make sure the ops are having the right functions
2600 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2601 if (FTRACE_WARN_ON(err))
2605 if (command & FTRACE_UPDATE_CALLS)
2606 ftrace_replace_code(1);
2607 else if (command & FTRACE_DISABLE_CALLS)
2608 ftrace_replace_code(0);
2610 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2611 function_trace_op = set_function_trace_op;
2613 /* If irqs are disabled, we are in stop machine */
2614 if (!irqs_disabled())
2615 smp_call_function(ftrace_sync_ipi, NULL, 1);
2616 err = ftrace_update_ftrace_func(ftrace_trace_function);
2617 if (FTRACE_WARN_ON(err))
2621 if (command & FTRACE_START_FUNC_RET)
2622 err = ftrace_enable_ftrace_graph_caller();
2623 else if (command & FTRACE_STOP_FUNC_RET)
2624 err = ftrace_disable_ftrace_graph_caller();
2625 FTRACE_WARN_ON(err);
2628 static int __ftrace_modify_code(void *data)
2630 int *command = data;
2632 ftrace_modify_all_code(*command);
2638 * ftrace_run_stop_machine, go back to the stop machine method
2639 * @command: The command to tell ftrace what to do
2641 * If an arch needs to fall back to the stop machine method, the
2642 * it can call this function.
2644 void ftrace_run_stop_machine(int command)
2646 stop_machine(__ftrace_modify_code, &command, NULL);
2650 * arch_ftrace_update_code, modify the code to trace or not trace
2651 * @command: The command that needs to be done
2653 * Archs can override this function if it does not need to
2654 * run stop_machine() to modify code.
2656 void __weak arch_ftrace_update_code(int command)
2658 ftrace_run_stop_machine(command);
2661 static void ftrace_run_update_code(int command)
2665 ret = ftrace_arch_code_modify_prepare();
2666 FTRACE_WARN_ON(ret);
2671 * By default we use stop_machine() to modify the code.
2672 * But archs can do what ever they want as long as it
2673 * is safe. The stop_machine() is the safest, but also
2674 * produces the most overhead.
2676 arch_ftrace_update_code(command);
2678 ret = ftrace_arch_code_modify_post_process();
2679 FTRACE_WARN_ON(ret);
2682 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2683 struct ftrace_ops_hash *old_hash)
2685 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2686 ops->old_hash.filter_hash = old_hash->filter_hash;
2687 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2688 ftrace_run_update_code(command);
2689 ops->old_hash.filter_hash = NULL;
2690 ops->old_hash.notrace_hash = NULL;
2691 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2694 static ftrace_func_t saved_ftrace_func;
2695 static int ftrace_start_up;
2697 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2701 static void ftrace_startup_enable(int command)
2703 if (saved_ftrace_func != ftrace_trace_function) {
2704 saved_ftrace_func = ftrace_trace_function;
2705 command |= FTRACE_UPDATE_TRACE_FUNC;
2708 if (!command || !ftrace_enabled)
2711 ftrace_run_update_code(command);
2714 static void ftrace_startup_all(int command)
2716 update_all_ops = true;
2717 ftrace_startup_enable(command);
2718 update_all_ops = false;
2721 static int ftrace_startup(struct ftrace_ops *ops, int command)
2725 if (unlikely(ftrace_disabled))
2728 ret = __register_ftrace_function(ops);
2735 * Note that ftrace probes uses this to start up
2736 * and modify functions it will probe. But we still
2737 * set the ADDING flag for modification, as probes
2738 * do not have trampolines. If they add them in the
2739 * future, then the probes will need to distinguish
2740 * between adding and updating probes.
2742 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2744 ret = ftrace_hash_ipmodify_enable(ops);
2746 /* Rollback registration process */
2747 __unregister_ftrace_function(ops);
2749 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2753 if (ftrace_hash_rec_enable(ops, 1))
2754 command |= FTRACE_UPDATE_CALLS;
2756 ftrace_startup_enable(command);
2758 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2763 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2767 if (unlikely(ftrace_disabled))
2770 ret = __unregister_ftrace_function(ops);
2776 * Just warn in case of unbalance, no need to kill ftrace, it's not
2777 * critical but the ftrace_call callers may be never nopped again after
2778 * further ftrace uses.
2780 WARN_ON_ONCE(ftrace_start_up < 0);
2782 /* Disabling ipmodify never fails */
2783 ftrace_hash_ipmodify_disable(ops);
2785 if (ftrace_hash_rec_disable(ops, 1))
2786 command |= FTRACE_UPDATE_CALLS;
2788 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2790 if (saved_ftrace_func != ftrace_trace_function) {
2791 saved_ftrace_func = ftrace_trace_function;
2792 command |= FTRACE_UPDATE_TRACE_FUNC;
2795 if (!command || !ftrace_enabled) {
2797 * If these are dynamic or per_cpu ops, they still
2798 * need their data freed. Since, function tracing is
2799 * not currently active, we can just free them
2800 * without synchronizing all CPUs.
2802 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2809 * If the ops uses a trampoline, then it needs to be
2810 * tested first on update.
2812 ops->flags |= FTRACE_OPS_FL_REMOVING;
2815 /* The trampoline logic checks the old hashes */
2816 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2817 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2819 ftrace_run_update_code(command);
2822 * If there's no more ops registered with ftrace, run a
2823 * sanity check to make sure all rec flags are cleared.
2825 if (rcu_dereference_protected(ftrace_ops_list,
2826 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2827 struct ftrace_page *pg;
2828 struct dyn_ftrace *rec;
2830 do_for_each_ftrace_rec(pg, rec) {
2831 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2832 pr_warn(" %pS flags:%lx\n",
2833 (void *)rec->ip, rec->flags);
2834 } while_for_each_ftrace_rec();
2837 ops->old_hash.filter_hash = NULL;
2838 ops->old_hash.notrace_hash = NULL;
2841 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2844 * Dynamic ops may be freed, we must make sure that all
2845 * callers are done before leaving this function.
2846 * The same goes for freeing the per_cpu data of the per_cpu
2849 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2851 * We need to do a hard force of sched synchronization.
2852 * This is because we use preempt_disable() to do RCU, but
2853 * the function tracers can be called where RCU is not watching
2854 * (like before user_exit()). We can not rely on the RCU
2855 * infrastructure to do the synchronization, thus we must do it
2858 schedule_on_each_cpu(ftrace_sync);
2861 * When the kernel is preeptive, tasks can be preempted
2862 * while on a ftrace trampoline. Just scheduling a task on
2863 * a CPU is not good enough to flush them. Calling
2864 * synchornize_rcu_tasks() will wait for those tasks to
2865 * execute and either schedule voluntarily or enter user space.
2867 if (IS_ENABLED(CONFIG_PREEMPT))
2868 synchronize_rcu_tasks();
2871 arch_ftrace_trampoline_free(ops);
2877 static void ftrace_startup_sysctl(void)
2881 if (unlikely(ftrace_disabled))
2884 /* Force update next time */
2885 saved_ftrace_func = NULL;
2886 /* ftrace_start_up is true if we want ftrace running */
2887 if (ftrace_start_up) {
2888 command = FTRACE_UPDATE_CALLS;
2889 if (ftrace_graph_active)
2890 command |= FTRACE_START_FUNC_RET;
2891 ftrace_startup_enable(command);
2895 static void ftrace_shutdown_sysctl(void)
2899 if (unlikely(ftrace_disabled))
2902 /* ftrace_start_up is true if ftrace is running */
2903 if (ftrace_start_up) {
2904 command = FTRACE_DISABLE_CALLS;
2905 if (ftrace_graph_active)
2906 command |= FTRACE_STOP_FUNC_RET;
2907 ftrace_run_update_code(command);
2911 static u64 ftrace_update_time;
2912 unsigned long ftrace_update_tot_cnt;
2914 static inline int ops_traces_mod(struct ftrace_ops *ops)
2917 * Filter_hash being empty will default to trace module.
2918 * But notrace hash requires a test of individual module functions.
2920 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2921 ftrace_hash_empty(ops->func_hash->notrace_hash);
2925 * Check if the current ops references the record.
2927 * If the ops traces all functions, then it was already accounted for.
2928 * If the ops does not trace the current record function, skip it.
2929 * If the ops ignores the function via notrace filter, skip it.
2932 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2934 /* If ops isn't enabled, ignore it */
2935 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2938 /* If ops traces all then it includes this function */
2939 if (ops_traces_mod(ops))
2942 /* The function must be in the filter */
2943 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2944 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2947 /* If in notrace hash, we ignore it too */
2948 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2954 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2956 struct ftrace_page *pg;
2957 struct dyn_ftrace *p;
2959 unsigned long update_cnt = 0;
2960 unsigned long rec_flags = 0;
2963 start = ftrace_now(raw_smp_processor_id());
2966 * When a module is loaded, this function is called to convert
2967 * the calls to mcount in its text to nops, and also to create
2968 * an entry in the ftrace data. Now, if ftrace is activated
2969 * after this call, but before the module sets its text to
2970 * read-only, the modification of enabling ftrace can fail if
2971 * the read-only is done while ftrace is converting the calls.
2972 * To prevent this, the module's records are set as disabled
2973 * and will be enabled after the call to set the module's text
2977 rec_flags |= FTRACE_FL_DISABLED;
2979 for (pg = new_pgs; pg; pg = pg->next) {
2981 for (i = 0; i < pg->index; i++) {
2983 /* If something went wrong, bail without enabling anything */
2984 if (unlikely(ftrace_disabled))
2987 p = &pg->records[i];
2988 p->flags = rec_flags;
2991 * Do the initial record conversion from mcount jump
2992 * to the NOP instructions.
2994 if (!ftrace_code_disable(mod, p))
3001 stop = ftrace_now(raw_smp_processor_id());
3002 ftrace_update_time = stop - start;
3003 ftrace_update_tot_cnt += update_cnt;
3008 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3013 if (WARN_ON(!count))
3016 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
3019 * We want to fill as much as possible. No more than a page
3022 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
3026 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3029 /* if we can't allocate this size, try something smaller */
3036 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3045 static struct ftrace_page *
3046 ftrace_allocate_pages(unsigned long num_to_init)
3048 struct ftrace_page *start_pg;
3049 struct ftrace_page *pg;
3056 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3061 * Try to allocate as much as possible in one continues
3062 * location that fills in all of the space. We want to
3063 * waste as little space as possible.
3066 cnt = ftrace_allocate_records(pg, num_to_init);
3074 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3086 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3087 free_pages((unsigned long)pg->records, order);
3088 start_pg = pg->next;
3092 pr_info("ftrace: FAILED to allocate memory for functions\n");
3096 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3098 struct ftrace_iterator {
3102 struct ftrace_page *pg;
3103 struct dyn_ftrace *func;
3104 struct ftrace_func_probe *probe;
3105 struct ftrace_func_entry *probe_entry;
3106 struct trace_parser parser;
3107 struct ftrace_hash *hash;
3108 struct ftrace_ops *ops;
3109 struct trace_array *tr;
3110 struct list_head *mod_list;
3117 t_probe_next(struct seq_file *m, loff_t *pos)
3119 struct ftrace_iterator *iter = m->private;
3120 struct trace_array *tr = iter->ops->private;
3121 struct list_head *func_probes;
3122 struct ftrace_hash *hash;
3123 struct list_head *next;
3124 struct hlist_node *hnd = NULL;
3125 struct hlist_head *hhd;
3134 func_probes = &tr->func_probes;
3135 if (list_empty(func_probes))
3139 next = func_probes->next;
3140 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3143 if (iter->probe_entry)
3144 hnd = &iter->probe_entry->hlist;
3146 hash = iter->probe->ops.func_hash->filter_hash;
3147 size = 1 << hash->size_bits;
3150 if (iter->pidx >= size) {
3151 if (iter->probe->list.next == func_probes)
3153 next = iter->probe->list.next;
3154 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3155 hash = iter->probe->ops.func_hash->filter_hash;
3156 size = 1 << hash->size_bits;
3160 hhd = &hash->buckets[iter->pidx];
3162 if (hlist_empty(hhd)) {
3178 if (WARN_ON_ONCE(!hnd))
3181 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3186 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3188 struct ftrace_iterator *iter = m->private;
3192 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3195 if (iter->mod_pos > *pos)
3199 iter->probe_entry = NULL;
3201 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3202 p = t_probe_next(m, &l);
3209 /* Only set this if we have an item */
3210 iter->flags |= FTRACE_ITER_PROBE;
3216 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3218 struct ftrace_func_entry *probe_entry;
3219 struct ftrace_probe_ops *probe_ops;
3220 struct ftrace_func_probe *probe;
3222 probe = iter->probe;
3223 probe_entry = iter->probe_entry;
3225 if (WARN_ON_ONCE(!probe || !probe_entry))
3228 probe_ops = probe->probe_ops;
3230 if (probe_ops->print)
3231 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3233 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3234 (void *)probe_ops->func);
3240 t_mod_next(struct seq_file *m, loff_t *pos)
3242 struct ftrace_iterator *iter = m->private;
3243 struct trace_array *tr = iter->tr;
3248 iter->mod_list = iter->mod_list->next;
3250 if (iter->mod_list == &tr->mod_trace ||
3251 iter->mod_list == &tr->mod_notrace) {
3252 iter->flags &= ~FTRACE_ITER_MOD;
3256 iter->mod_pos = *pos;
3261 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3263 struct ftrace_iterator *iter = m->private;
3267 if (iter->func_pos > *pos)
3270 iter->mod_pos = iter->func_pos;
3272 /* probes are only available if tr is set */
3276 for (l = 0; l <= (*pos - iter->func_pos); ) {
3277 p = t_mod_next(m, &l);
3282 iter->flags &= ~FTRACE_ITER_MOD;
3283 return t_probe_start(m, pos);
3286 /* Only set this if we have an item */
3287 iter->flags |= FTRACE_ITER_MOD;
3293 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3295 struct ftrace_mod_load *ftrace_mod;
3296 struct trace_array *tr = iter->tr;
3298 if (WARN_ON_ONCE(!iter->mod_list) ||
3299 iter->mod_list == &tr->mod_trace ||
3300 iter->mod_list == &tr->mod_notrace)
3303 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3305 if (ftrace_mod->func)
3306 seq_printf(m, "%s", ftrace_mod->func);
3310 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3316 t_func_next(struct seq_file *m, loff_t *pos)
3318 struct ftrace_iterator *iter = m->private;
3319 struct dyn_ftrace *rec = NULL;
3324 if (iter->idx >= iter->pg->index) {
3325 if (iter->pg->next) {
3326 iter->pg = iter->pg->next;
3331 rec = &iter->pg->records[iter->idx++];
3332 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3333 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3335 ((iter->flags & FTRACE_ITER_ENABLED) &&
3336 !(rec->flags & FTRACE_FL_ENABLED))) {
3346 iter->pos = iter->func_pos = *pos;
3353 t_next(struct seq_file *m, void *v, loff_t *pos)
3355 struct ftrace_iterator *iter = m->private;
3356 loff_t l = *pos; /* t_probe_start() must use original pos */
3359 if (unlikely(ftrace_disabled))
3362 if (iter->flags & FTRACE_ITER_PROBE)
3363 return t_probe_next(m, pos);
3365 if (iter->flags & FTRACE_ITER_MOD)
3366 return t_mod_next(m, pos);
3368 if (iter->flags & FTRACE_ITER_PRINTALL) {
3369 /* next must increment pos, and t_probe_start does not */
3371 return t_mod_start(m, &l);
3374 ret = t_func_next(m, pos);
3377 return t_mod_start(m, &l);
3382 static void reset_iter_read(struct ftrace_iterator *iter)
3386 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3389 static void *t_start(struct seq_file *m, loff_t *pos)
3391 struct ftrace_iterator *iter = m->private;
3395 mutex_lock(&ftrace_lock);
3397 if (unlikely(ftrace_disabled))
3401 * If an lseek was done, then reset and start from beginning.
3403 if (*pos < iter->pos)
3404 reset_iter_read(iter);
3407 * For set_ftrace_filter reading, if we have the filter
3408 * off, we can short cut and just print out that all
3409 * functions are enabled.
3411 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3412 ftrace_hash_empty(iter->hash)) {
3413 iter->func_pos = 1; /* Account for the message */
3415 return t_mod_start(m, pos);
3416 iter->flags |= FTRACE_ITER_PRINTALL;
3417 /* reset in case of seek/pread */
3418 iter->flags &= ~FTRACE_ITER_PROBE;
3422 if (iter->flags & FTRACE_ITER_MOD)
3423 return t_mod_start(m, pos);
3426 * Unfortunately, we need to restart at ftrace_pages_start
3427 * every time we let go of the ftrace_mutex. This is because
3428 * those pointers can change without the lock.
3430 iter->pg = ftrace_pages_start;
3432 for (l = 0; l <= *pos; ) {
3433 p = t_func_next(m, &l);
3439 return t_mod_start(m, pos);
3444 static void t_stop(struct seq_file *m, void *p)
3446 mutex_unlock(&ftrace_lock);
3450 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3455 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3456 struct dyn_ftrace *rec)
3460 ptr = arch_ftrace_trampoline_func(ops, rec);
3462 seq_printf(m, " ->%pS", ptr);
3465 static int t_show(struct seq_file *m, void *v)
3467 struct ftrace_iterator *iter = m->private;
3468 struct dyn_ftrace *rec;
3470 if (iter->flags & FTRACE_ITER_PROBE)
3471 return t_probe_show(m, iter);
3473 if (iter->flags & FTRACE_ITER_MOD)
3474 return t_mod_show(m, iter);
3476 if (iter->flags & FTRACE_ITER_PRINTALL) {
3477 if (iter->flags & FTRACE_ITER_NOTRACE)
3478 seq_puts(m, "#### no functions disabled ####\n");
3480 seq_puts(m, "#### all functions enabled ####\n");
3489 seq_printf(m, "%ps", (void *)rec->ip);
3490 if (iter->flags & FTRACE_ITER_ENABLED) {
3491 struct ftrace_ops *ops;
3493 seq_printf(m, " (%ld)%s%s",
3494 ftrace_rec_count(rec),
3495 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3496 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3497 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3498 ops = ftrace_find_tramp_ops_any(rec);
3501 seq_printf(m, "\ttramp: %pS (%pS)",
3502 (void *)ops->trampoline,
3504 add_trampoline_func(m, ops, rec);
3505 ops = ftrace_find_tramp_ops_next(rec, ops);
3508 seq_puts(m, "\ttramp: ERROR!");
3510 add_trampoline_func(m, NULL, rec);
3519 static const struct seq_operations show_ftrace_seq_ops = {
3527 ftrace_avail_open(struct inode *inode, struct file *file)
3529 struct ftrace_iterator *iter;
3531 if (unlikely(ftrace_disabled))
3534 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3538 iter->pg = ftrace_pages_start;
3539 iter->ops = &global_ops;
3545 ftrace_enabled_open(struct inode *inode, struct file *file)
3547 struct ftrace_iterator *iter;
3549 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3553 iter->pg = ftrace_pages_start;
3554 iter->flags = FTRACE_ITER_ENABLED;
3555 iter->ops = &global_ops;
3561 * ftrace_regex_open - initialize function tracer filter files
3562 * @ops: The ftrace_ops that hold the hash filters
3563 * @flag: The type of filter to process
3564 * @inode: The inode, usually passed in to your open routine
3565 * @file: The file, usually passed in to your open routine
3567 * ftrace_regex_open() initializes the filter files for the
3568 * @ops. Depending on @flag it may process the filter hash or
3569 * the notrace hash of @ops. With this called from the open
3570 * routine, you can use ftrace_filter_write() for the write
3571 * routine if @flag has FTRACE_ITER_FILTER set, or
3572 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3573 * tracing_lseek() should be used as the lseek routine, and
3574 * release must call ftrace_regex_release().
3577 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3578 struct inode *inode, struct file *file)
3580 struct ftrace_iterator *iter;
3581 struct ftrace_hash *hash;
3582 struct list_head *mod_head;
3583 struct trace_array *tr = ops->private;
3586 ftrace_ops_init(ops);
3588 if (unlikely(ftrace_disabled))
3591 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3595 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3604 mutex_lock(&ops->func_hash->regex_lock);
3606 if (flag & FTRACE_ITER_NOTRACE) {
3607 hash = ops->func_hash->notrace_hash;
3608 mod_head = tr ? &tr->mod_notrace : NULL;
3610 hash = ops->func_hash->filter_hash;
3611 mod_head = tr ? &tr->mod_trace : NULL;
3614 iter->mod_list = mod_head;
3616 if (file->f_mode & FMODE_WRITE) {
3617 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3619 if (file->f_flags & O_TRUNC) {
3620 iter->hash = alloc_ftrace_hash(size_bits);
3621 clear_ftrace_mod_list(mod_head);
3623 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3627 trace_parser_put(&iter->parser);
3635 if (file->f_mode & FMODE_READ) {
3636 iter->pg = ftrace_pages_start;
3638 ret = seq_open(file, &show_ftrace_seq_ops);
3640 struct seq_file *m = file->private_data;
3644 free_ftrace_hash(iter->hash);
3645 trace_parser_put(&iter->parser);
3649 file->private_data = iter;
3652 mutex_unlock(&ops->func_hash->regex_lock);
3658 ftrace_filter_open(struct inode *inode, struct file *file)
3660 struct ftrace_ops *ops = inode->i_private;
3662 return ftrace_regex_open(ops,
3663 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3668 ftrace_notrace_open(struct inode *inode, struct file *file)
3670 struct ftrace_ops *ops = inode->i_private;
3672 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3676 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3677 struct ftrace_glob {
3684 * If symbols in an architecture don't correspond exactly to the user-visible
3685 * name of what they represent, it is possible to define this function to
3686 * perform the necessary adjustments.
3688 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3693 static int ftrace_match(char *str, struct ftrace_glob *g)
3698 str = arch_ftrace_match_adjust(str, g->search);
3702 if (strcmp(str, g->search) == 0)
3705 case MATCH_FRONT_ONLY:
3706 if (strncmp(str, g->search, g->len) == 0)
3709 case MATCH_MIDDLE_ONLY:
3710 if (strstr(str, g->search))
3713 case MATCH_END_ONLY:
3715 if (slen >= g->len &&
3716 memcmp(str + slen - g->len, g->search, g->len) == 0)
3720 if (glob_match(g->search, str))
3729 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3731 struct ftrace_func_entry *entry;
3734 entry = ftrace_lookup_ip(hash, rec->ip);
3736 /* Do nothing if it doesn't exist */
3740 free_hash_entry(hash, entry);
3742 /* Do nothing if it exists */
3746 ret = add_hash_entry(hash, rec->ip);
3752 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3753 struct ftrace_glob *mod_g, int exclude_mod)
3755 char str[KSYM_SYMBOL_LEN];
3758 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3761 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3763 /* blank module name to match all modules */
3765 /* blank module globbing: modname xor exclude_mod */
3766 if (!exclude_mod != !modname)
3772 * exclude_mod is set to trace everything but the given
3773 * module. If it is set and the module matches, then
3774 * return 0. If it is not set, and the module doesn't match
3775 * also return 0. Otherwise, check the function to see if
3778 if (!mod_matches == !exclude_mod)
3781 /* blank search means to match all funcs in the mod */
3786 return ftrace_match(str, func_g);
3790 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3792 struct ftrace_page *pg;
3793 struct dyn_ftrace *rec;
3794 struct ftrace_glob func_g = { .type = MATCH_FULL };
3795 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3796 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3797 int exclude_mod = 0;
3800 int clear_filter = 0;
3803 func_g.type = filter_parse_regex(func, len, &func_g.search,
3805 func_g.len = strlen(func_g.search);
3809 mod_g.type = filter_parse_regex(mod, strlen(mod),
3810 &mod_g.search, &exclude_mod);
3811 mod_g.len = strlen(mod_g.search);
3814 mutex_lock(&ftrace_lock);
3816 if (unlikely(ftrace_disabled))
3819 do_for_each_ftrace_rec(pg, rec) {
3821 if (rec->flags & FTRACE_FL_DISABLED)
3824 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3825 ret = enter_record(hash, rec, clear_filter);
3832 } while_for_each_ftrace_rec();
3834 mutex_unlock(&ftrace_lock);
3840 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3842 return match_records(hash, buff, len, NULL);
3845 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3846 struct ftrace_ops_hash *old_hash)
3848 struct ftrace_ops *op;
3850 if (!ftrace_enabled)
3853 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3854 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3859 * If this is the shared global_ops filter, then we need to
3860 * check if there is another ops that shares it, is enabled.
3861 * If so, we still need to run the modify code.
3863 if (ops->func_hash != &global_ops.local_hash)
3866 do_for_each_ftrace_op(op, ftrace_ops_list) {
3867 if (op->func_hash == &global_ops.local_hash &&
3868 op->flags & FTRACE_OPS_FL_ENABLED) {
3869 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3870 /* Only need to do this once */
3873 } while_for_each_ftrace_op(op);
3876 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3877 struct ftrace_hash **orig_hash,
3878 struct ftrace_hash *hash,
3881 struct ftrace_ops_hash old_hash_ops;
3882 struct ftrace_hash *old_hash;
3885 old_hash = *orig_hash;
3886 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3887 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3888 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3890 ftrace_ops_update_code(ops, &old_hash_ops);
3891 free_ftrace_hash_rcu(old_hash);
3896 static bool module_exists(const char *module)
3898 /* All modules have the symbol __this_module */
3899 const char this_mod[] = "__this_module";
3900 const int modname_size = MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 1;
3901 char modname[modname_size + 1];
3905 n = snprintf(modname, modname_size + 1, "%s:%s", module, this_mod);
3907 if (n > modname_size)
3910 val = module_kallsyms_lookup_name(modname);
3914 static int cache_mod(struct trace_array *tr,
3915 const char *func, char *module, int enable)
3917 struct ftrace_mod_load *ftrace_mod, *n;
3918 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3921 mutex_lock(&ftrace_lock);
3923 /* We do not cache inverse filters */
3924 if (func[0] == '!') {
3928 /* Look to remove this hash */
3929 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3930 if (strcmp(ftrace_mod->module, module) != 0)
3933 /* no func matches all */
3934 if (strcmp(func, "*") == 0 ||
3935 (ftrace_mod->func &&
3936 strcmp(ftrace_mod->func, func) == 0)) {
3938 free_ftrace_mod(ftrace_mod);
3946 /* We only care about modules that have not been loaded yet */
3947 if (module_exists(module))
3950 /* Save this string off, and execute it when the module is loaded */
3951 ret = ftrace_add_mod(tr, func, module, enable);
3953 mutex_unlock(&ftrace_lock);
3959 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3960 int reset, int enable);
3962 #ifdef CONFIG_MODULES
3963 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3964 char *mod, bool enable)
3966 struct ftrace_mod_load *ftrace_mod, *n;
3967 struct ftrace_hash **orig_hash, *new_hash;
3968 LIST_HEAD(process_mods);
3972 mutex_lock(&ops->func_hash->regex_lock);
3975 orig_hash = &ops->func_hash->filter_hash;
3977 orig_hash = &ops->func_hash->notrace_hash;
3979 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3982 goto out; /* warn? */
3984 mutex_lock(&ftrace_lock);
3986 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3988 if (strcmp(ftrace_mod->module, mod) != 0)
3991 if (ftrace_mod->func)
3992 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
3994 func = kstrdup("*", GFP_KERNEL);
3996 if (!func) /* warn? */
3999 list_del(&ftrace_mod->list);
4000 list_add(&ftrace_mod->list, &process_mods);
4002 /* Use the newly allocated func, as it may be "*" */
4003 kfree(ftrace_mod->func);
4004 ftrace_mod->func = func;
4007 mutex_unlock(&ftrace_lock);
4009 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4011 func = ftrace_mod->func;
4013 /* Grabs ftrace_lock, which is why we have this extra step */
4014 match_records(new_hash, func, strlen(func), mod);
4015 free_ftrace_mod(ftrace_mod);
4018 if (enable && list_empty(head))
4019 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4021 mutex_lock(&ftrace_lock);
4023 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4025 mutex_unlock(&ftrace_lock);
4028 mutex_unlock(&ops->func_hash->regex_lock);
4030 free_ftrace_hash(new_hash);
4033 static void process_cached_mods(const char *mod_name)
4035 struct trace_array *tr;
4038 mod = kstrdup(mod_name, GFP_KERNEL);
4042 mutex_lock(&trace_types_lock);
4043 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4044 if (!list_empty(&tr->mod_trace))
4045 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4046 if (!list_empty(&tr->mod_notrace))
4047 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4049 mutex_unlock(&trace_types_lock);
4056 * We register the module command as a template to show others how
4057 * to register the a command as well.
4061 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4062 char *func_orig, char *cmd, char *module, int enable)
4067 /* match_records() modifies func, and we need the original */
4068 func = kstrdup(func_orig, GFP_KERNEL);
4073 * cmd == 'mod' because we only registered this func
4074 * for the 'mod' ftrace_func_command.
4075 * But if you register one func with multiple commands,
4076 * you can tell which command was used by the cmd
4079 ret = match_records(hash, func, strlen(func), module);
4083 return cache_mod(tr, func_orig, module, enable);
4089 static struct ftrace_func_command ftrace_mod_cmd = {
4091 .func = ftrace_mod_callback,
4094 static int __init ftrace_mod_cmd_init(void)
4096 return register_ftrace_command(&ftrace_mod_cmd);
4098 core_initcall(ftrace_mod_cmd_init);
4100 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4101 struct ftrace_ops *op, struct pt_regs *pt_regs)
4103 struct ftrace_probe_ops *probe_ops;
4104 struct ftrace_func_probe *probe;
4106 probe = container_of(op, struct ftrace_func_probe, ops);
4107 probe_ops = probe->probe_ops;
4110 * Disable preemption for these calls to prevent a RCU grace
4111 * period. This syncs the hash iteration and freeing of items
4112 * on the hash. rcu_read_lock is too dangerous here.
4114 preempt_disable_notrace();
4115 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4116 preempt_enable_notrace();
4119 struct ftrace_func_map {
4120 struct ftrace_func_entry entry;
4124 struct ftrace_func_mapper {
4125 struct ftrace_hash hash;
4129 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4131 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4133 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4135 struct ftrace_hash *hash;
4138 * The mapper is simply a ftrace_hash, but since the entries
4139 * in the hash are not ftrace_func_entry type, we define it
4140 * as a separate structure.
4142 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4143 return (struct ftrace_func_mapper *)hash;
4147 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4148 * @mapper: The mapper that has the ip maps
4149 * @ip: the instruction pointer to find the data for
4151 * Returns the data mapped to @ip if found otherwise NULL. The return
4152 * is actually the address of the mapper data pointer. The address is
4153 * returned for use cases where the data is no bigger than a long, and
4154 * the user can use the data pointer as its data instead of having to
4155 * allocate more memory for the reference.
4157 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4160 struct ftrace_func_entry *entry;
4161 struct ftrace_func_map *map;
4163 entry = ftrace_lookup_ip(&mapper->hash, ip);
4167 map = (struct ftrace_func_map *)entry;
4172 * ftrace_func_mapper_add_ip - Map some data to an ip
4173 * @mapper: The mapper that has the ip maps
4174 * @ip: The instruction pointer address to map @data to
4175 * @data: The data to map to @ip
4177 * Returns 0 on succes otherwise an error.
4179 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4180 unsigned long ip, void *data)
4182 struct ftrace_func_entry *entry;
4183 struct ftrace_func_map *map;
4185 entry = ftrace_lookup_ip(&mapper->hash, ip);
4189 map = kmalloc(sizeof(*map), GFP_KERNEL);
4196 __add_hash_entry(&mapper->hash, &map->entry);
4202 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4203 * @mapper: The mapper that has the ip maps
4204 * @ip: The instruction pointer address to remove the data from
4206 * Returns the data if it is found, otherwise NULL.
4207 * Note, if the data pointer is used as the data itself, (see
4208 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4209 * if the data pointer was set to zero.
4211 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4214 struct ftrace_func_entry *entry;
4215 struct ftrace_func_map *map;
4218 entry = ftrace_lookup_ip(&mapper->hash, ip);
4222 map = (struct ftrace_func_map *)entry;
4225 remove_hash_entry(&mapper->hash, entry);
4232 * free_ftrace_func_mapper - free a mapping of ips and data
4233 * @mapper: The mapper that has the ip maps
4234 * @free_func: A function to be called on each data item.
4236 * This is used to free the function mapper. The @free_func is optional
4237 * and can be used if the data needs to be freed as well.
4239 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4240 ftrace_mapper_func free_func)
4242 struct ftrace_func_entry *entry;
4243 struct ftrace_func_map *map;
4244 struct hlist_head *hhd;
4245 int size = 1 << mapper->hash.size_bits;
4248 if (free_func && mapper->hash.count) {
4249 for (i = 0; i < size; i++) {
4250 hhd = &mapper->hash.buckets[i];
4251 hlist_for_each_entry(entry, hhd, hlist) {
4252 map = (struct ftrace_func_map *)entry;
4257 free_ftrace_hash(&mapper->hash);
4260 static void release_probe(struct ftrace_func_probe *probe)
4262 struct ftrace_probe_ops *probe_ops;
4264 mutex_lock(&ftrace_lock);
4266 WARN_ON(probe->ref <= 0);
4268 /* Subtract the ref that was used to protect this instance */
4272 probe_ops = probe->probe_ops;
4274 * Sending zero as ip tells probe_ops to free
4275 * the probe->data itself
4277 if (probe_ops->free)
4278 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4279 list_del(&probe->list);
4282 mutex_unlock(&ftrace_lock);
4285 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4288 * Add one ref to keep it from being freed when releasing the
4289 * ftrace_lock mutex.
4295 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4296 struct ftrace_probe_ops *probe_ops,
4299 struct ftrace_func_entry *entry;
4300 struct ftrace_func_probe *probe;
4301 struct ftrace_hash **orig_hash;
4302 struct ftrace_hash *old_hash;
4303 struct ftrace_hash *hash;
4312 /* We do not support '!' for function probes */
4313 if (WARN_ON(glob[0] == '!'))
4317 mutex_lock(&ftrace_lock);
4318 /* Check if the probe_ops is already registered */
4319 list_for_each_entry(probe, &tr->func_probes, list) {
4320 if (probe->probe_ops == probe_ops)
4323 if (&probe->list == &tr->func_probes) {
4324 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4326 mutex_unlock(&ftrace_lock);
4329 probe->probe_ops = probe_ops;
4330 probe->ops.func = function_trace_probe_call;
4332 ftrace_ops_init(&probe->ops);
4333 list_add(&probe->list, &tr->func_probes);
4336 acquire_probe_locked(probe);
4338 mutex_unlock(&ftrace_lock);
4340 mutex_lock(&probe->ops.func_hash->regex_lock);
4342 orig_hash = &probe->ops.func_hash->filter_hash;
4343 old_hash = *orig_hash;
4344 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4346 ret = ftrace_match_records(hash, glob, strlen(glob));
4348 /* Nothing found? */
4355 size = 1 << hash->size_bits;
4356 for (i = 0; i < size; i++) {
4357 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4358 if (ftrace_lookup_ip(old_hash, entry->ip))
4361 * The caller might want to do something special
4362 * for each function we find. We call the callback
4363 * to give the caller an opportunity to do so.
4365 if (probe_ops->init) {
4366 ret = probe_ops->init(probe_ops, tr,
4370 if (probe_ops->free && count)
4371 probe_ops->free(probe_ops, tr,
4381 mutex_lock(&ftrace_lock);
4384 /* Nothing was added? */
4389 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4394 /* One ref for each new function traced */
4395 probe->ref += count;
4397 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4398 ret = ftrace_startup(&probe->ops, 0);
4401 mutex_unlock(&ftrace_lock);
4406 mutex_unlock(&probe->ops.func_hash->regex_lock);
4407 free_ftrace_hash(hash);
4409 release_probe(probe);
4414 if (!probe_ops->free || !count)
4417 /* Failed to do the move, need to call the free functions */
4418 for (i = 0; i < size; i++) {
4419 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4420 if (ftrace_lookup_ip(old_hash, entry->ip))
4422 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4429 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4430 struct ftrace_probe_ops *probe_ops)
4432 struct ftrace_ops_hash old_hash_ops;
4433 struct ftrace_func_entry *entry;
4434 struct ftrace_func_probe *probe;
4435 struct ftrace_glob func_g;
4436 struct ftrace_hash **orig_hash;
4437 struct ftrace_hash *old_hash;
4438 struct ftrace_hash *hash = NULL;
4439 struct hlist_node *tmp;
4440 struct hlist_head hhd;
4441 char str[KSYM_SYMBOL_LEN];
4443 int i, ret = -ENODEV;
4446 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4447 func_g.search = NULL;
4451 func_g.type = filter_parse_regex(glob, strlen(glob),
4452 &func_g.search, ¬);
4453 func_g.len = strlen(func_g.search);
4454 func_g.search = glob;
4456 /* we do not support '!' for function probes */
4461 mutex_lock(&ftrace_lock);
4462 /* Check if the probe_ops is already registered */
4463 list_for_each_entry(probe, &tr->func_probes, list) {
4464 if (probe->probe_ops == probe_ops)
4467 if (&probe->list == &tr->func_probes)
4468 goto err_unlock_ftrace;
4471 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4472 goto err_unlock_ftrace;
4474 acquire_probe_locked(probe);
4476 mutex_unlock(&ftrace_lock);
4478 mutex_lock(&probe->ops.func_hash->regex_lock);
4480 orig_hash = &probe->ops.func_hash->filter_hash;
4481 old_hash = *orig_hash;
4483 if (ftrace_hash_empty(old_hash))
4486 old_hash_ops.filter_hash = old_hash;
4487 /* Probes only have filters */
4488 old_hash_ops.notrace_hash = NULL;
4491 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4495 INIT_HLIST_HEAD(&hhd);
4497 size = 1 << hash->size_bits;
4498 for (i = 0; i < size; i++) {
4499 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4501 if (func_g.search) {
4502 kallsyms_lookup(entry->ip, NULL, NULL,
4504 if (!ftrace_match(str, &func_g))
4508 remove_hash_entry(hash, entry);
4509 hlist_add_head(&entry->hlist, &hhd);
4513 /* Nothing found? */
4519 mutex_lock(&ftrace_lock);
4521 WARN_ON(probe->ref < count);
4523 probe->ref -= count;
4525 if (ftrace_hash_empty(hash))
4526 ftrace_shutdown(&probe->ops, 0);
4528 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4531 /* still need to update the function call sites */
4532 if (ftrace_enabled && !ftrace_hash_empty(hash))
4533 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4535 synchronize_sched();
4537 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4538 hlist_del(&entry->hlist);
4539 if (probe_ops->free)
4540 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4543 mutex_unlock(&ftrace_lock);
4546 mutex_unlock(&probe->ops.func_hash->regex_lock);
4547 free_ftrace_hash(hash);
4549 release_probe(probe);
4554 mutex_unlock(&ftrace_lock);
4558 void clear_ftrace_function_probes(struct trace_array *tr)
4560 struct ftrace_func_probe *probe, *n;
4562 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4563 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4566 static LIST_HEAD(ftrace_commands);
4567 static DEFINE_MUTEX(ftrace_cmd_mutex);
4570 * Currently we only register ftrace commands from __init, so mark this
4573 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4575 struct ftrace_func_command *p;
4578 mutex_lock(&ftrace_cmd_mutex);
4579 list_for_each_entry(p, &ftrace_commands, list) {
4580 if (strcmp(cmd->name, p->name) == 0) {
4585 list_add(&cmd->list, &ftrace_commands);
4587 mutex_unlock(&ftrace_cmd_mutex);
4593 * Currently we only unregister ftrace commands from __init, so mark
4596 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4598 struct ftrace_func_command *p, *n;
4601 mutex_lock(&ftrace_cmd_mutex);
4602 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4603 if (strcmp(cmd->name, p->name) == 0) {
4605 list_del_init(&p->list);
4610 mutex_unlock(&ftrace_cmd_mutex);
4615 static int ftrace_process_regex(struct ftrace_iterator *iter,
4616 char *buff, int len, int enable)
4618 struct ftrace_hash *hash = iter->hash;
4619 struct trace_array *tr = iter->ops->private;
4620 char *func, *command, *next = buff;
4621 struct ftrace_func_command *p;
4624 func = strsep(&next, ":");
4627 ret = ftrace_match_records(hash, func, len);
4637 command = strsep(&next, ":");
4639 mutex_lock(&ftrace_cmd_mutex);
4640 list_for_each_entry(p, &ftrace_commands, list) {
4641 if (strcmp(p->name, command) == 0) {
4642 ret = p->func(tr, hash, func, command, next, enable);
4647 mutex_unlock(&ftrace_cmd_mutex);
4653 ftrace_regex_write(struct file *file, const char __user *ubuf,
4654 size_t cnt, loff_t *ppos, int enable)
4656 struct ftrace_iterator *iter;
4657 struct trace_parser *parser;
4663 if (file->f_mode & FMODE_READ) {
4664 struct seq_file *m = file->private_data;
4667 iter = file->private_data;
4669 if (unlikely(ftrace_disabled))
4672 /* iter->hash is a local copy, so we don't need regex_lock */
4674 parser = &iter->parser;
4675 read = trace_get_user(parser, ubuf, cnt, ppos);
4677 if (read >= 0 && trace_parser_loaded(parser) &&
4678 !trace_parser_cont(parser)) {
4679 ret = ftrace_process_regex(iter, parser->buffer,
4680 parser->idx, enable);
4681 trace_parser_clear(parser);
4692 ftrace_filter_write(struct file *file, const char __user *ubuf,
4693 size_t cnt, loff_t *ppos)
4695 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4699 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4700 size_t cnt, loff_t *ppos)
4702 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4706 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4708 struct ftrace_func_entry *entry;
4710 if (!ftrace_location(ip))
4714 entry = ftrace_lookup_ip(hash, ip);
4717 free_hash_entry(hash, entry);
4721 return add_hash_entry(hash, ip);
4725 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4726 unsigned long ip, int remove, int reset, int enable)
4728 struct ftrace_hash **orig_hash;
4729 struct ftrace_hash *hash;
4732 if (unlikely(ftrace_disabled))
4735 mutex_lock(&ops->func_hash->regex_lock);
4738 orig_hash = &ops->func_hash->filter_hash;
4740 orig_hash = &ops->func_hash->notrace_hash;
4743 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4745 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4749 goto out_regex_unlock;
4752 if (buf && !ftrace_match_records(hash, buf, len)) {
4754 goto out_regex_unlock;
4757 ret = ftrace_match_addr(hash, ip, remove);
4759 goto out_regex_unlock;
4762 mutex_lock(&ftrace_lock);
4763 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4764 mutex_unlock(&ftrace_lock);
4767 mutex_unlock(&ops->func_hash->regex_lock);
4769 free_ftrace_hash(hash);
4774 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4775 int reset, int enable)
4777 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4781 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4782 * @ops - the ops to set the filter with
4783 * @ip - the address to add to or remove from the filter.
4784 * @remove - non zero to remove the ip from the filter
4785 * @reset - non zero to reset all filters before applying this filter.
4787 * Filters denote which functions should be enabled when tracing is enabled
4788 * If @ip is NULL, it failes to update filter.
4790 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4791 int remove, int reset)
4793 ftrace_ops_init(ops);
4794 return ftrace_set_addr(ops, ip, remove, reset, 1);
4796 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4799 * ftrace_ops_set_global_filter - setup ops to use global filters
4800 * @ops - the ops which will use the global filters
4802 * ftrace users who need global function trace filtering should call this.
4803 * It can set the global filter only if ops were not initialized before.
4805 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4807 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4810 ftrace_ops_init(ops);
4811 ops->func_hash = &global_ops.local_hash;
4813 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4816 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4817 int reset, int enable)
4819 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4823 * ftrace_set_filter - set a function to filter on in ftrace
4824 * @ops - the ops to set the filter with
4825 * @buf - the string that holds the function filter text.
4826 * @len - the length of the string.
4827 * @reset - non zero to reset all filters before applying this filter.
4829 * Filters denote which functions should be enabled when tracing is enabled.
4830 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4832 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4835 ftrace_ops_init(ops);
4836 return ftrace_set_regex(ops, buf, len, reset, 1);
4838 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4841 * ftrace_set_notrace - set a function to not trace in ftrace
4842 * @ops - the ops to set the notrace filter with
4843 * @buf - the string that holds the function notrace text.
4844 * @len - the length of the string.
4845 * @reset - non zero to reset all filters before applying this filter.
4847 * Notrace Filters denote which functions should not be enabled when tracing
4848 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4851 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4854 ftrace_ops_init(ops);
4855 return ftrace_set_regex(ops, buf, len, reset, 0);
4857 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4859 * ftrace_set_global_filter - set a function to filter on with global tracers
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 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4869 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4871 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4874 * ftrace_set_global_notrace - set a function to not trace with global tracers
4875 * @buf - the string that holds the function notrace text.
4876 * @len - the length of the string.
4877 * @reset - non zero to reset all filters before applying this filter.
4879 * Notrace Filters denote which functions should not be enabled when tracing
4880 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4883 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4885 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4887 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4890 * command line interface to allow users to set filters on boot up.
4892 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4893 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4894 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4896 /* Used by function selftest to not test if filter is set */
4897 bool ftrace_filter_param __initdata;
4899 static int __init set_ftrace_notrace(char *str)
4901 ftrace_filter_param = true;
4902 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4905 __setup("ftrace_notrace=", set_ftrace_notrace);
4907 static int __init set_ftrace_filter(char *str)
4909 ftrace_filter_param = true;
4910 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4913 __setup("ftrace_filter=", set_ftrace_filter);
4915 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4916 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4917 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4918 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4920 static int __init set_graph_function(char *str)
4922 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4925 __setup("ftrace_graph_filter=", set_graph_function);
4927 static int __init set_graph_notrace_function(char *str)
4929 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4932 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4934 static int __init set_graph_max_depth_function(char *str)
4938 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4941 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4943 static void __init set_ftrace_early_graph(char *buf, int enable)
4947 struct ftrace_hash *hash;
4949 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4954 func = strsep(&buf, ",");
4955 /* we allow only one expression at a time */
4956 ret = ftrace_graph_set_hash(hash, func);
4958 printk(KERN_DEBUG "ftrace: function %s not "
4959 "traceable\n", func);
4963 ftrace_graph_hash = hash;
4965 ftrace_graph_notrace_hash = hash;
4967 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4970 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4974 ftrace_ops_init(ops);
4977 func = strsep(&buf, ",");
4978 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4982 static void __init set_ftrace_early_filters(void)
4984 if (ftrace_filter_buf[0])
4985 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4986 if (ftrace_notrace_buf[0])
4987 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4988 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4989 if (ftrace_graph_buf[0])
4990 set_ftrace_early_graph(ftrace_graph_buf, 1);
4991 if (ftrace_graph_notrace_buf[0])
4992 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4993 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4996 int ftrace_regex_release(struct inode *inode, struct file *file)
4998 struct seq_file *m = (struct seq_file *)file->private_data;
4999 struct ftrace_iterator *iter;
5000 struct ftrace_hash **orig_hash;
5001 struct trace_parser *parser;
5005 if (file->f_mode & FMODE_READ) {
5007 seq_release(inode, file);
5009 iter = file->private_data;
5011 parser = &iter->parser;
5012 if (trace_parser_loaded(parser)) {
5013 parser->buffer[parser->idx] = 0;
5014 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5017 trace_parser_put(parser);
5019 mutex_lock(&iter->ops->func_hash->regex_lock);
5021 if (file->f_mode & FMODE_WRITE) {
5022 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5025 orig_hash = &iter->ops->func_hash->filter_hash;
5026 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5027 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5029 orig_hash = &iter->ops->func_hash->notrace_hash;
5031 mutex_lock(&ftrace_lock);
5032 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5033 iter->hash, filter_hash);
5034 mutex_unlock(&ftrace_lock);
5036 /* For read only, the hash is the ops hash */
5040 mutex_unlock(&iter->ops->func_hash->regex_lock);
5041 free_ftrace_hash(iter->hash);
5047 static const struct file_operations ftrace_avail_fops = {
5048 .open = ftrace_avail_open,
5050 .llseek = seq_lseek,
5051 .release = seq_release_private,
5054 static const struct file_operations ftrace_enabled_fops = {
5055 .open = ftrace_enabled_open,
5057 .llseek = seq_lseek,
5058 .release = seq_release_private,
5061 static const struct file_operations ftrace_filter_fops = {
5062 .open = ftrace_filter_open,
5064 .write = ftrace_filter_write,
5065 .llseek = tracing_lseek,
5066 .release = ftrace_regex_release,
5069 static const struct file_operations ftrace_notrace_fops = {
5070 .open = ftrace_notrace_open,
5072 .write = ftrace_notrace_write,
5073 .llseek = tracing_lseek,
5074 .release = ftrace_regex_release,
5077 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5079 static DEFINE_MUTEX(graph_lock);
5081 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5082 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5084 enum graph_filter_type {
5085 GRAPH_FILTER_NOTRACE = 0,
5086 GRAPH_FILTER_FUNCTION,
5089 #define FTRACE_GRAPH_EMPTY ((void *)1)
5091 struct ftrace_graph_data {
5092 struct ftrace_hash *hash;
5093 struct ftrace_func_entry *entry;
5094 int idx; /* for hash table iteration */
5095 enum graph_filter_type type;
5096 struct ftrace_hash *new_hash;
5097 const struct seq_operations *seq_ops;
5098 struct trace_parser parser;
5102 __g_next(struct seq_file *m, loff_t *pos)
5104 struct ftrace_graph_data *fgd = m->private;
5105 struct ftrace_func_entry *entry = fgd->entry;
5106 struct hlist_head *head;
5107 int i, idx = fgd->idx;
5109 if (*pos >= fgd->hash->count)
5113 hlist_for_each_entry_continue(entry, hlist) {
5121 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5122 head = &fgd->hash->buckets[i];
5123 hlist_for_each_entry(entry, head, hlist) {
5133 g_next(struct seq_file *m, void *v, loff_t *pos)
5136 return __g_next(m, pos);
5139 static void *g_start(struct seq_file *m, loff_t *pos)
5141 struct ftrace_graph_data *fgd = m->private;
5143 mutex_lock(&graph_lock);
5145 if (fgd->type == GRAPH_FILTER_FUNCTION)
5146 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5147 lockdep_is_held(&graph_lock));
5149 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5150 lockdep_is_held(&graph_lock));
5152 /* Nothing, tell g_show to print all functions are enabled */
5153 if (ftrace_hash_empty(fgd->hash) && !*pos)
5154 return FTRACE_GRAPH_EMPTY;
5158 return __g_next(m, pos);
5161 static void g_stop(struct seq_file *m, void *p)
5163 mutex_unlock(&graph_lock);
5166 static int g_show(struct seq_file *m, void *v)
5168 struct ftrace_func_entry *entry = v;
5173 if (entry == FTRACE_GRAPH_EMPTY) {
5174 struct ftrace_graph_data *fgd = m->private;
5176 if (fgd->type == GRAPH_FILTER_FUNCTION)
5177 seq_puts(m, "#### all functions enabled ####\n");
5179 seq_puts(m, "#### no functions disabled ####\n");
5183 seq_printf(m, "%ps\n", (void *)entry->ip);
5188 static const struct seq_operations ftrace_graph_seq_ops = {
5196 __ftrace_graph_open(struct inode *inode, struct file *file,
5197 struct ftrace_graph_data *fgd)
5200 struct ftrace_hash *new_hash = NULL;
5202 if (file->f_mode & FMODE_WRITE) {
5203 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5205 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5208 if (file->f_flags & O_TRUNC)
5209 new_hash = alloc_ftrace_hash(size_bits);
5211 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5219 if (file->f_mode & FMODE_READ) {
5220 ret = seq_open(file, &ftrace_graph_seq_ops);
5222 struct seq_file *m = file->private_data;
5226 free_ftrace_hash(new_hash);
5230 file->private_data = fgd;
5233 if (ret < 0 && file->f_mode & FMODE_WRITE)
5234 trace_parser_put(&fgd->parser);
5236 fgd->new_hash = new_hash;
5239 * All uses of fgd->hash must be taken with the graph_lock
5240 * held. The graph_lock is going to be released, so force
5241 * fgd->hash to be reinitialized when it is taken again.
5249 ftrace_graph_open(struct inode *inode, struct file *file)
5251 struct ftrace_graph_data *fgd;
5254 if (unlikely(ftrace_disabled))
5257 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5261 mutex_lock(&graph_lock);
5263 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5264 lockdep_is_held(&graph_lock));
5265 fgd->type = GRAPH_FILTER_FUNCTION;
5266 fgd->seq_ops = &ftrace_graph_seq_ops;
5268 ret = __ftrace_graph_open(inode, file, fgd);
5272 mutex_unlock(&graph_lock);
5277 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5279 struct ftrace_graph_data *fgd;
5282 if (unlikely(ftrace_disabled))
5285 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5289 mutex_lock(&graph_lock);
5291 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5292 lockdep_is_held(&graph_lock));
5293 fgd->type = GRAPH_FILTER_NOTRACE;
5294 fgd->seq_ops = &ftrace_graph_seq_ops;
5296 ret = __ftrace_graph_open(inode, file, fgd);
5300 mutex_unlock(&graph_lock);
5305 ftrace_graph_release(struct inode *inode, struct file *file)
5307 struct ftrace_graph_data *fgd;
5308 struct ftrace_hash *old_hash, *new_hash;
5309 struct trace_parser *parser;
5312 if (file->f_mode & FMODE_READ) {
5313 struct seq_file *m = file->private_data;
5316 seq_release(inode, file);
5318 fgd = file->private_data;
5322 if (file->f_mode & FMODE_WRITE) {
5324 parser = &fgd->parser;
5326 if (trace_parser_loaded((parser))) {
5327 parser->buffer[parser->idx] = 0;
5328 ret = ftrace_graph_set_hash(fgd->new_hash,
5332 trace_parser_put(parser);
5334 new_hash = __ftrace_hash_move(fgd->new_hash);
5340 mutex_lock(&graph_lock);
5342 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5343 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5344 lockdep_is_held(&graph_lock));
5345 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5347 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5348 lockdep_is_held(&graph_lock));
5349 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5352 mutex_unlock(&graph_lock);
5354 /* Wait till all users are no longer using the old hash */
5355 synchronize_sched();
5357 free_ftrace_hash(old_hash);
5361 free_ftrace_hash(fgd->new_hash);
5368 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5370 struct ftrace_glob func_g;
5371 struct dyn_ftrace *rec;
5372 struct ftrace_page *pg;
5373 struct ftrace_func_entry *entry;
5378 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5379 &func_g.search, ¬);
5381 func_g.len = strlen(func_g.search);
5383 mutex_lock(&ftrace_lock);
5385 if (unlikely(ftrace_disabled)) {
5386 mutex_unlock(&ftrace_lock);
5390 do_for_each_ftrace_rec(pg, rec) {
5392 if (rec->flags & FTRACE_FL_DISABLED)
5395 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5396 entry = ftrace_lookup_ip(hash, rec->ip);
5403 if (add_hash_entry(hash, rec->ip) < 0)
5407 free_hash_entry(hash, entry);
5412 } while_for_each_ftrace_rec();
5414 mutex_unlock(&ftrace_lock);
5423 ftrace_graph_write(struct file *file, const char __user *ubuf,
5424 size_t cnt, loff_t *ppos)
5426 ssize_t read, ret = 0;
5427 struct ftrace_graph_data *fgd = file->private_data;
5428 struct trace_parser *parser;
5433 /* Read mode uses seq functions */
5434 if (file->f_mode & FMODE_READ) {
5435 struct seq_file *m = file->private_data;
5439 parser = &fgd->parser;
5441 read = trace_get_user(parser, ubuf, cnt, ppos);
5443 if (read >= 0 && trace_parser_loaded(parser) &&
5444 !trace_parser_cont(parser)) {
5446 ret = ftrace_graph_set_hash(fgd->new_hash,
5448 trace_parser_clear(parser);
5457 static const struct file_operations ftrace_graph_fops = {
5458 .open = ftrace_graph_open,
5460 .write = ftrace_graph_write,
5461 .llseek = tracing_lseek,
5462 .release = ftrace_graph_release,
5465 static const struct file_operations ftrace_graph_notrace_fops = {
5466 .open = ftrace_graph_notrace_open,
5468 .write = ftrace_graph_write,
5469 .llseek = tracing_lseek,
5470 .release = ftrace_graph_release,
5472 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5474 void ftrace_create_filter_files(struct ftrace_ops *ops,
5475 struct dentry *parent)
5478 trace_create_file("set_ftrace_filter", 0644, parent,
5479 ops, &ftrace_filter_fops);
5481 trace_create_file("set_ftrace_notrace", 0644, parent,
5482 ops, &ftrace_notrace_fops);
5486 * The name "destroy_filter_files" is really a misnomer. Although
5487 * in the future, it may actualy delete the files, but this is
5488 * really intended to make sure the ops passed in are disabled
5489 * and that when this function returns, the caller is free to
5492 * The "destroy" name is only to match the "create" name that this
5493 * should be paired with.
5495 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5497 mutex_lock(&ftrace_lock);
5498 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5499 ftrace_shutdown(ops, 0);
5500 ops->flags |= FTRACE_OPS_FL_DELETED;
5501 mutex_unlock(&ftrace_lock);
5504 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5507 trace_create_file("available_filter_functions", 0444,
5508 d_tracer, NULL, &ftrace_avail_fops);
5510 trace_create_file("enabled_functions", 0444,
5511 d_tracer, NULL, &ftrace_enabled_fops);
5513 ftrace_create_filter_files(&global_ops, d_tracer);
5515 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5516 trace_create_file("set_graph_function", 0444, d_tracer,
5518 &ftrace_graph_fops);
5519 trace_create_file("set_graph_notrace", 0444, d_tracer,
5521 &ftrace_graph_notrace_fops);
5522 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5527 static int ftrace_cmp_ips(const void *a, const void *b)
5529 const unsigned long *ipa = a;
5530 const unsigned long *ipb = b;
5539 static int ftrace_process_locs(struct module *mod,
5540 unsigned long *start,
5543 struct ftrace_page *start_pg;
5544 struct ftrace_page *pg;
5545 struct dyn_ftrace *rec;
5546 unsigned long count;
5549 unsigned long flags = 0; /* Shut up gcc */
5552 count = end - start;
5557 sort(start, count, sizeof(*start),
5558 ftrace_cmp_ips, NULL);
5560 start_pg = ftrace_allocate_pages(count);
5564 mutex_lock(&ftrace_lock);
5567 * Core and each module needs their own pages, as
5568 * modules will free them when they are removed.
5569 * Force a new page to be allocated for modules.
5572 WARN_ON(ftrace_pages || ftrace_pages_start);
5573 /* First initialization */
5574 ftrace_pages = ftrace_pages_start = start_pg;
5579 if (WARN_ON(ftrace_pages->next)) {
5580 /* Hmm, we have free pages? */
5581 while (ftrace_pages->next)
5582 ftrace_pages = ftrace_pages->next;
5585 ftrace_pages->next = start_pg;
5591 addr = ftrace_call_adjust(*p++);
5593 * Some architecture linkers will pad between
5594 * the different mcount_loc sections of different
5595 * object files to satisfy alignments.
5596 * Skip any NULL pointers.
5601 if (pg->index == pg->size) {
5602 /* We should have allocated enough */
5603 if (WARN_ON(!pg->next))
5608 rec = &pg->records[pg->index++];
5612 /* We should have used all pages */
5615 /* Assign the last page to ftrace_pages */
5619 * We only need to disable interrupts on start up
5620 * because we are modifying code that an interrupt
5621 * may execute, and the modification is not atomic.
5622 * But for modules, nothing runs the code we modify
5623 * until we are finished with it, and there's no
5624 * reason to cause large interrupt latencies while we do it.
5627 local_irq_save(flags);
5628 ftrace_update_code(mod, start_pg);
5630 local_irq_restore(flags);
5633 mutex_unlock(&ftrace_lock);
5638 struct ftrace_mod_func {
5639 struct list_head list;
5645 struct ftrace_mod_map {
5646 struct rcu_head rcu;
5647 struct list_head list;
5649 unsigned long start_addr;
5650 unsigned long end_addr;
5651 struct list_head funcs;
5652 unsigned int num_funcs;
5655 #ifdef CONFIG_MODULES
5657 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5659 static LIST_HEAD(ftrace_mod_maps);
5661 static int referenced_filters(struct dyn_ftrace *rec)
5663 struct ftrace_ops *ops;
5666 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5667 if (ops_references_rec(ops, rec))
5675 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5677 struct ftrace_func_entry *entry;
5678 struct dyn_ftrace *rec;
5681 if (ftrace_hash_empty(hash))
5684 for (i = 0; i < pg->index; i++) {
5685 rec = &pg->records[i];
5686 entry = __ftrace_lookup_ip(hash, rec->ip);
5688 * Do not allow this rec to match again.
5689 * Yeah, it may waste some memory, but will be removed
5690 * if/when the hash is modified again.
5697 /* Clear any records from hashs */
5698 static void clear_mod_from_hashes(struct ftrace_page *pg)
5700 struct trace_array *tr;
5702 mutex_lock(&trace_types_lock);
5703 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5704 if (!tr->ops || !tr->ops->func_hash)
5706 mutex_lock(&tr->ops->func_hash->regex_lock);
5707 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5708 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5709 mutex_unlock(&tr->ops->func_hash->regex_lock);
5711 mutex_unlock(&trace_types_lock);
5714 static void ftrace_free_mod_map(struct rcu_head *rcu)
5716 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5717 struct ftrace_mod_func *mod_func;
5718 struct ftrace_mod_func *n;
5720 /* All the contents of mod_map are now not visible to readers */
5721 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5722 kfree(mod_func->name);
5723 list_del(&mod_func->list);
5730 void ftrace_release_mod(struct module *mod)
5732 struct ftrace_mod_map *mod_map;
5733 struct ftrace_mod_map *n;
5734 struct dyn_ftrace *rec;
5735 struct ftrace_page **last_pg;
5736 struct ftrace_page *tmp_page = NULL;
5737 struct ftrace_page *pg;
5740 mutex_lock(&ftrace_lock);
5742 if (ftrace_disabled)
5745 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5746 if (mod_map->mod == mod) {
5747 list_del_rcu(&mod_map->list);
5748 call_rcu_sched(&mod_map->rcu, ftrace_free_mod_map);
5754 * Each module has its own ftrace_pages, remove
5755 * them from the list.
5757 last_pg = &ftrace_pages_start;
5758 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5759 rec = &pg->records[0];
5760 if (within_module_core(rec->ip, mod) ||
5761 within_module_init(rec->ip, mod)) {
5763 * As core pages are first, the first
5764 * page should never be a module page.
5766 if (WARN_ON(pg == ftrace_pages_start))
5769 /* Check if we are deleting the last page */
5770 if (pg == ftrace_pages)
5771 ftrace_pages = next_to_ftrace_page(last_pg);
5773 ftrace_update_tot_cnt -= pg->index;
5774 *last_pg = pg->next;
5776 pg->next = tmp_page;
5779 last_pg = &pg->next;
5782 mutex_unlock(&ftrace_lock);
5784 for (pg = tmp_page; pg; pg = tmp_page) {
5786 /* Needs to be called outside of ftrace_lock */
5787 clear_mod_from_hashes(pg);
5789 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5790 free_pages((unsigned long)pg->records, order);
5791 tmp_page = pg->next;
5796 void ftrace_module_enable(struct module *mod)
5798 struct dyn_ftrace *rec;
5799 struct ftrace_page *pg;
5801 mutex_lock(&ftrace_lock);
5803 if (ftrace_disabled)
5807 * If the tracing is enabled, go ahead and enable the record.
5809 * The reason not to enable the record immediatelly is the
5810 * inherent check of ftrace_make_nop/ftrace_make_call for
5811 * correct previous instructions. Making first the NOP
5812 * conversion puts the module to the correct state, thus
5813 * passing the ftrace_make_call check.
5815 * We also delay this to after the module code already set the
5816 * text to read-only, as we now need to set it back to read-write
5817 * so that we can modify the text.
5819 if (ftrace_start_up)
5820 ftrace_arch_code_modify_prepare();
5822 do_for_each_ftrace_rec(pg, rec) {
5825 * do_for_each_ftrace_rec() is a double loop.
5826 * module text shares the pg. If a record is
5827 * not part of this module, then skip this pg,
5828 * which the "break" will do.
5830 if (!within_module_core(rec->ip, mod) &&
5831 !within_module_init(rec->ip, mod))
5837 * When adding a module, we need to check if tracers are
5838 * currently enabled and if they are, and can trace this record,
5839 * we need to enable the module functions as well as update the
5840 * reference counts for those function records.
5842 if (ftrace_start_up)
5843 cnt += referenced_filters(rec);
5845 /* This clears FTRACE_FL_DISABLED */
5848 if (ftrace_start_up && cnt) {
5849 int failed = __ftrace_replace_code(rec, 1);
5851 ftrace_bug(failed, rec);
5856 } while_for_each_ftrace_rec();
5859 if (ftrace_start_up)
5860 ftrace_arch_code_modify_post_process();
5863 mutex_unlock(&ftrace_lock);
5865 process_cached_mods(mod->name);
5868 void ftrace_module_init(struct module *mod)
5870 if (ftrace_disabled || !mod->num_ftrace_callsites)
5873 ftrace_process_locs(mod, mod->ftrace_callsites,
5874 mod->ftrace_callsites + mod->num_ftrace_callsites);
5877 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5878 struct dyn_ftrace *rec)
5880 struct ftrace_mod_func *mod_func;
5881 unsigned long symsize;
5882 unsigned long offset;
5883 char str[KSYM_SYMBOL_LEN];
5887 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5891 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5895 mod_func->name = kstrdup(str, GFP_KERNEL);
5896 if (!mod_func->name) {
5901 mod_func->ip = rec->ip - offset;
5902 mod_func->size = symsize;
5904 mod_map->num_funcs++;
5906 list_add_rcu(&mod_func->list, &mod_map->funcs);
5909 static struct ftrace_mod_map *
5910 allocate_ftrace_mod_map(struct module *mod,
5911 unsigned long start, unsigned long end)
5913 struct ftrace_mod_map *mod_map;
5915 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5920 mod_map->start_addr = start;
5921 mod_map->end_addr = end;
5922 mod_map->num_funcs = 0;
5924 INIT_LIST_HEAD_RCU(&mod_map->funcs);
5926 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5932 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5933 unsigned long addr, unsigned long *size,
5934 unsigned long *off, char *sym)
5936 struct ftrace_mod_func *found_func = NULL;
5937 struct ftrace_mod_func *mod_func;
5939 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5940 if (addr >= mod_func->ip &&
5941 addr < mod_func->ip + mod_func->size) {
5942 found_func = mod_func;
5949 *size = found_func->size;
5951 *off = addr - found_func->ip;
5953 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5955 return found_func->name;
5962 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5963 unsigned long *off, char **modname, char *sym)
5965 struct ftrace_mod_map *mod_map;
5966 const char *ret = NULL;
5968 /* mod_map is freed via call_rcu_sched() */
5970 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5971 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
5974 *modname = mod_map->mod->name;
5983 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
5984 char *type, char *name,
5985 char *module_name, int *exported)
5987 struct ftrace_mod_map *mod_map;
5988 struct ftrace_mod_func *mod_func;
5991 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5993 if (symnum >= mod_map->num_funcs) {
5994 symnum -= mod_map->num_funcs;
5998 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6004 *value = mod_func->ip;
6006 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
6007 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6020 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6021 struct dyn_ftrace *rec) { }
6022 static inline struct ftrace_mod_map *
6023 allocate_ftrace_mod_map(struct module *mod,
6024 unsigned long start, unsigned long end)
6028 #endif /* CONFIG_MODULES */
6030 struct ftrace_init_func {
6031 struct list_head list;
6035 /* Clear any init ips from hashes */
6037 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6039 struct ftrace_func_entry *entry;
6041 if (ftrace_hash_empty(hash))
6044 entry = __ftrace_lookup_ip(hash, func->ip);
6047 * Do not allow this rec to match again.
6048 * Yeah, it may waste some memory, but will be removed
6049 * if/when the hash is modified again.
6056 clear_func_from_hashes(struct ftrace_init_func *func)
6058 struct trace_array *tr;
6060 mutex_lock(&trace_types_lock);
6061 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6062 if (!tr->ops || !tr->ops->func_hash)
6064 mutex_lock(&tr->ops->func_hash->regex_lock);
6065 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6066 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6067 mutex_unlock(&tr->ops->func_hash->regex_lock);
6069 mutex_unlock(&trace_types_lock);
6072 static void add_to_clear_hash_list(struct list_head *clear_list,
6073 struct dyn_ftrace *rec)
6075 struct ftrace_init_func *func;
6077 func = kmalloc(sizeof(*func), GFP_KERNEL);
6079 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6084 list_add(&func->list, clear_list);
6087 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6089 unsigned long start = (unsigned long)(start_ptr);
6090 unsigned long end = (unsigned long)(end_ptr);
6091 struct ftrace_page **last_pg = &ftrace_pages_start;
6092 struct ftrace_page *pg;
6093 struct dyn_ftrace *rec;
6094 struct dyn_ftrace key;
6095 struct ftrace_mod_map *mod_map = NULL;
6096 struct ftrace_init_func *func, *func_next;
6097 struct list_head clear_hash;
6100 INIT_LIST_HEAD(&clear_hash);
6103 key.flags = end; /* overload flags, as it is unsigned long */
6105 mutex_lock(&ftrace_lock);
6108 * If we are freeing module init memory, then check if
6109 * any tracer is active. If so, we need to save a mapping of
6110 * the module functions being freed with the address.
6112 if (mod && ftrace_ops_list != &ftrace_list_end)
6113 mod_map = allocate_ftrace_mod_map(mod, start, end);
6115 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6116 if (end < pg->records[0].ip ||
6117 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6120 rec = bsearch(&key, pg->records, pg->index,
6121 sizeof(struct dyn_ftrace),
6126 /* rec will be cleared from hashes after ftrace_lock unlock */
6127 add_to_clear_hash_list(&clear_hash, rec);
6130 save_ftrace_mod_rec(mod_map, rec);
6133 ftrace_update_tot_cnt--;
6135 *last_pg = pg->next;
6136 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6137 free_pages((unsigned long)pg->records, order);
6139 pg = container_of(last_pg, struct ftrace_page, next);
6144 memmove(rec, rec + 1,
6145 (pg->index - (rec - pg->records)) * sizeof(*rec));
6146 /* More than one function may be in this block */
6149 mutex_unlock(&ftrace_lock);
6151 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6152 clear_func_from_hashes(func);
6157 void __init ftrace_free_init_mem(void)
6159 void *start = (void *)(&__init_begin);
6160 void *end = (void *)(&__init_end);
6162 ftrace_free_mem(NULL, start, end);
6165 void __init ftrace_init(void)
6167 extern unsigned long __start_mcount_loc[];
6168 extern unsigned long __stop_mcount_loc[];
6169 unsigned long count, flags;
6172 local_irq_save(flags);
6173 ret = ftrace_dyn_arch_init();
6174 local_irq_restore(flags);
6178 count = __stop_mcount_loc - __start_mcount_loc;
6180 pr_info("ftrace: No functions to be traced?\n");
6184 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6185 count, count / ENTRIES_PER_PAGE + 1);
6187 last_ftrace_enabled = ftrace_enabled = 1;
6189 ret = ftrace_process_locs(NULL,
6193 set_ftrace_early_filters();
6197 ftrace_disabled = 1;
6200 /* Do nothing if arch does not support this */
6201 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6205 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6207 arch_ftrace_update_trampoline(ops);
6210 void ftrace_init_trace_array(struct trace_array *tr)
6212 INIT_LIST_HEAD(&tr->func_probes);
6213 INIT_LIST_HEAD(&tr->mod_trace);
6214 INIT_LIST_HEAD(&tr->mod_notrace);
6218 static struct ftrace_ops global_ops = {
6219 .func = ftrace_stub,
6220 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6221 FTRACE_OPS_FL_INITIALIZED |
6225 static int __init ftrace_nodyn_init(void)
6230 core_initcall(ftrace_nodyn_init);
6232 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6233 static inline void ftrace_startup_enable(int command) { }
6234 static inline void ftrace_startup_all(int command) { }
6235 /* Keep as macros so we do not need to define the commands */
6236 # define ftrace_startup(ops, command) \
6238 int ___ret = __register_ftrace_function(ops); \
6240 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
6243 # define ftrace_shutdown(ops, command) \
6245 int ___ret = __unregister_ftrace_function(ops); \
6247 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
6251 # define ftrace_startup_sysctl() do { } while (0)
6252 # define ftrace_shutdown_sysctl() do { } while (0)
6255 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
6260 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6264 #endif /* CONFIG_DYNAMIC_FTRACE */
6266 __init void ftrace_init_global_array_ops(struct trace_array *tr)
6268 tr->ops = &global_ops;
6269 tr->ops->private = tr;
6270 ftrace_init_trace_array(tr);
6273 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6275 /* If we filter on pids, update to use the pid function */
6276 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6277 if (WARN_ON(tr->ops->func != ftrace_stub))
6278 printk("ftrace ops had %pS for function\n",
6281 tr->ops->func = func;
6282 tr->ops->private = tr;
6285 void ftrace_reset_array_ops(struct trace_array *tr)
6287 tr->ops->func = ftrace_stub;
6291 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6292 struct ftrace_ops *ignored, struct pt_regs *regs)
6294 struct ftrace_ops *op;
6297 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6302 * Some of the ops may be dynamically allocated,
6303 * they must be freed after a synchronize_sched().
6305 preempt_disable_notrace();
6307 do_for_each_ftrace_op(op, ftrace_ops_list) {
6309 * Check the following for each ops before calling their func:
6310 * if RCU flag is set, then rcu_is_watching() must be true
6311 * if PER_CPU is set, then ftrace_function_local_disable()
6313 * Otherwise test if the ip matches the ops filter
6315 * If any of the above fails then the op->func() is not executed.
6317 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6318 ftrace_ops_test(op, ip, regs)) {
6319 if (FTRACE_WARN_ON(!op->func)) {
6320 pr_warn("op=%p %pS\n", op, op);
6323 op->func(ip, parent_ip, op, regs);
6325 } while_for_each_ftrace_op(op);
6327 preempt_enable_notrace();
6328 trace_clear_recursion(bit);
6332 * Some archs only support passing ip and parent_ip. Even though
6333 * the list function ignores the op parameter, we do not want any
6334 * C side effects, where a function is called without the caller
6335 * sending a third parameter.
6336 * Archs are to support both the regs and ftrace_ops at the same time.
6337 * If they support ftrace_ops, it is assumed they support regs.
6338 * If call backs want to use regs, they must either check for regs
6339 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6340 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6341 * An architecture can pass partial regs with ftrace_ops and still
6342 * set the ARCH_SUPPORTS_FTRACE_OPS.
6344 #if ARCH_SUPPORTS_FTRACE_OPS
6345 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6346 struct ftrace_ops *op, struct pt_regs *regs)
6348 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6351 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6353 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6358 * If there's only one function registered but it does not support
6359 * recursion, needs RCU protection and/or requires per cpu handling, then
6360 * this function will be called by the mcount trampoline.
6362 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6363 struct ftrace_ops *op, struct pt_regs *regs)
6367 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6370 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6374 preempt_disable_notrace();
6376 op->func(ip, parent_ip, op, regs);
6378 preempt_enable_notrace();
6379 trace_clear_recursion(bit);
6383 * ftrace_ops_get_func - get the function a trampoline should call
6384 * @ops: the ops to get the function for
6386 * Normally the mcount trampoline will call the ops->func, but there
6387 * are times that it should not. For example, if the ops does not
6388 * have its own recursion protection, then it should call the
6389 * ftrace_ops_assist_func() instead.
6391 * Returns the function that the trampoline should call for @ops.
6393 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6396 * If the function does not handle recursion, needs to be RCU safe,
6397 * or does per cpu logic, then we need to call the assist handler.
6399 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6400 ops->flags & FTRACE_OPS_FL_RCU)
6401 return ftrace_ops_assist_func;
6407 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6408 struct task_struct *prev, struct task_struct *next)
6410 struct trace_array *tr = data;
6411 struct trace_pid_list *pid_list;
6413 pid_list = rcu_dereference_sched(tr->function_pids);
6415 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6416 trace_ignore_this_task(pid_list, next));
6420 ftrace_pid_follow_sched_process_fork(void *data,
6421 struct task_struct *self,
6422 struct task_struct *task)
6424 struct trace_pid_list *pid_list;
6425 struct trace_array *tr = data;
6427 pid_list = rcu_dereference_sched(tr->function_pids);
6428 trace_filter_add_remove_task(pid_list, self, task);
6432 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6434 struct trace_pid_list *pid_list;
6435 struct trace_array *tr = data;
6437 pid_list = rcu_dereference_sched(tr->function_pids);
6438 trace_filter_add_remove_task(pid_list, NULL, task);
6441 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6444 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6446 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6449 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6451 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6456 static void clear_ftrace_pids(struct trace_array *tr)
6458 struct trace_pid_list *pid_list;
6461 pid_list = rcu_dereference_protected(tr->function_pids,
6462 lockdep_is_held(&ftrace_lock));
6466 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6468 for_each_possible_cpu(cpu)
6469 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6471 rcu_assign_pointer(tr->function_pids, NULL);
6473 /* Wait till all users are no longer using pid filtering */
6474 synchronize_sched();
6476 trace_free_pid_list(pid_list);
6479 void ftrace_clear_pids(struct trace_array *tr)
6481 mutex_lock(&ftrace_lock);
6483 clear_ftrace_pids(tr);
6485 mutex_unlock(&ftrace_lock);
6488 static void ftrace_pid_reset(struct trace_array *tr)
6490 mutex_lock(&ftrace_lock);
6491 clear_ftrace_pids(tr);
6493 ftrace_update_pid_func();
6494 ftrace_startup_all(0);
6496 mutex_unlock(&ftrace_lock);
6499 /* Greater than any max PID */
6500 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6502 static void *fpid_start(struct seq_file *m, loff_t *pos)
6505 struct trace_pid_list *pid_list;
6506 struct trace_array *tr = m->private;
6508 mutex_lock(&ftrace_lock);
6509 rcu_read_lock_sched();
6511 pid_list = rcu_dereference_sched(tr->function_pids);
6514 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6516 return trace_pid_start(pid_list, pos);
6519 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6521 struct trace_array *tr = m->private;
6522 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6524 if (v == FTRACE_NO_PIDS)
6527 return trace_pid_next(pid_list, v, pos);
6530 static void fpid_stop(struct seq_file *m, void *p)
6533 rcu_read_unlock_sched();
6534 mutex_unlock(&ftrace_lock);
6537 static int fpid_show(struct seq_file *m, void *v)
6539 if (v == FTRACE_NO_PIDS) {
6540 seq_puts(m, "no pid\n");
6544 return trace_pid_show(m, v);
6547 static const struct seq_operations ftrace_pid_sops = {
6548 .start = fpid_start,
6555 ftrace_pid_open(struct inode *inode, struct file *file)
6557 struct trace_array *tr = inode->i_private;
6561 if (trace_array_get(tr) < 0)
6564 if ((file->f_mode & FMODE_WRITE) &&
6565 (file->f_flags & O_TRUNC))
6566 ftrace_pid_reset(tr);
6568 ret = seq_open(file, &ftrace_pid_sops);
6570 trace_array_put(tr);
6572 m = file->private_data;
6573 /* copy tr over to seq ops */
6580 static void ignore_task_cpu(void *data)
6582 struct trace_array *tr = data;
6583 struct trace_pid_list *pid_list;
6586 * This function is called by on_each_cpu() while the
6587 * event_mutex is held.
6589 pid_list = rcu_dereference_protected(tr->function_pids,
6590 mutex_is_locked(&ftrace_lock));
6592 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6593 trace_ignore_this_task(pid_list, current));
6597 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6598 size_t cnt, loff_t *ppos)
6600 struct seq_file *m = filp->private_data;
6601 struct trace_array *tr = m->private;
6602 struct trace_pid_list *filtered_pids = NULL;
6603 struct trace_pid_list *pid_list;
6609 mutex_lock(&ftrace_lock);
6611 filtered_pids = rcu_dereference_protected(tr->function_pids,
6612 lockdep_is_held(&ftrace_lock));
6614 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6618 rcu_assign_pointer(tr->function_pids, pid_list);
6620 if (filtered_pids) {
6621 synchronize_sched();
6622 trace_free_pid_list(filtered_pids);
6623 } else if (pid_list) {
6624 /* Register a probe to set whether to ignore the tracing of a task */
6625 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6629 * Ignoring of pids is done at task switch. But we have to
6630 * check for those tasks that are currently running.
6631 * Always do this in case a pid was appended or removed.
6633 on_each_cpu(ignore_task_cpu, tr, 1);
6635 ftrace_update_pid_func();
6636 ftrace_startup_all(0);
6638 mutex_unlock(&ftrace_lock);
6647 ftrace_pid_release(struct inode *inode, struct file *file)
6649 struct trace_array *tr = inode->i_private;
6651 trace_array_put(tr);
6653 return seq_release(inode, file);
6656 static const struct file_operations ftrace_pid_fops = {
6657 .open = ftrace_pid_open,
6658 .write = ftrace_pid_write,
6660 .llseek = tracing_lseek,
6661 .release = ftrace_pid_release,
6664 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6666 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6667 tr, &ftrace_pid_fops);
6670 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6671 struct dentry *d_tracer)
6673 /* Only the top level directory has the dyn_tracefs and profile */
6674 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6676 ftrace_init_dyn_tracefs(d_tracer);
6677 ftrace_profile_tracefs(d_tracer);
6681 * ftrace_kill - kill ftrace
6683 * This function should be used by panic code. It stops ftrace
6684 * but in a not so nice way. If you need to simply kill ftrace
6685 * from a non-atomic section, use ftrace_kill.
6687 void ftrace_kill(void)
6689 ftrace_disabled = 1;
6691 clear_ftrace_function();
6695 * Test if ftrace is dead or not.
6697 int ftrace_is_dead(void)
6699 return ftrace_disabled;
6703 * register_ftrace_function - register a function for profiling
6704 * @ops - ops structure that holds the function for profiling.
6706 * Register a function to be called by all functions in the
6709 * Note: @ops->func and all the functions it calls must be labeled
6710 * with "notrace", otherwise it will go into a
6713 int register_ftrace_function(struct ftrace_ops *ops)
6717 ftrace_ops_init(ops);
6719 mutex_lock(&ftrace_lock);
6721 ret = ftrace_startup(ops, 0);
6723 mutex_unlock(&ftrace_lock);
6727 EXPORT_SYMBOL_GPL(register_ftrace_function);
6730 * unregister_ftrace_function - unregister a function for profiling.
6731 * @ops - ops structure that holds the function to unregister
6733 * Unregister a function that was added to be called by ftrace profiling.
6735 int unregister_ftrace_function(struct ftrace_ops *ops)
6739 mutex_lock(&ftrace_lock);
6740 ret = ftrace_shutdown(ops, 0);
6741 mutex_unlock(&ftrace_lock);
6745 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6748 ftrace_enable_sysctl(struct ctl_table *table, int write,
6749 void __user *buffer, size_t *lenp,
6754 mutex_lock(&ftrace_lock);
6756 if (unlikely(ftrace_disabled))
6759 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6761 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6764 last_ftrace_enabled = !!ftrace_enabled;
6766 if (ftrace_enabled) {
6768 /* we are starting ftrace again */
6769 if (rcu_dereference_protected(ftrace_ops_list,
6770 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6771 update_ftrace_function();
6773 ftrace_startup_sysctl();
6776 /* stopping ftrace calls (just send to ftrace_stub) */
6777 ftrace_trace_function = ftrace_stub;
6779 ftrace_shutdown_sysctl();
6783 mutex_unlock(&ftrace_lock);
6787 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6789 static struct ftrace_ops graph_ops = {
6790 .func = ftrace_stub,
6791 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6792 FTRACE_OPS_FL_INITIALIZED |
6795 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6796 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
6797 /* trampoline_size is only needed for dynamically allocated tramps */
6799 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
6802 void ftrace_graph_sleep_time_control(bool enable)
6804 fgraph_sleep_time = enable;
6807 void ftrace_graph_graph_time_control(bool enable)
6809 fgraph_graph_time = enable;
6812 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
6817 /* The callbacks that hook a function */
6818 trace_func_graph_ret_t ftrace_graph_return =
6819 (trace_func_graph_ret_t)ftrace_stub;
6820 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
6821 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
6823 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6824 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
6828 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
6829 struct task_struct *g, *t;
6831 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
6832 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
6833 * sizeof(struct ftrace_ret_stack),
6835 if (!ret_stack_list[i]) {
6843 read_lock(&tasklist_lock);
6844 do_each_thread(g, t) {
6850 if (t->ret_stack == NULL) {
6851 atomic_set(&t->tracing_graph_pause, 0);
6852 atomic_set(&t->trace_overrun, 0);
6853 t->curr_ret_stack = -1;
6854 /* Make sure the tasks see the -1 first: */
6856 t->ret_stack = ret_stack_list[start++];
6858 } while_each_thread(g, t);
6861 read_unlock(&tasklist_lock);
6863 for (i = start; i < end; i++)
6864 kfree(ret_stack_list[i]);
6869 ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
6870 struct task_struct *prev, struct task_struct *next)
6872 unsigned long long timestamp;
6876 * Does the user want to count the time a function was asleep.
6877 * If so, do not update the time stamps.
6879 if (fgraph_sleep_time)
6882 timestamp = trace_clock_local();
6884 prev->ftrace_timestamp = timestamp;
6886 /* only process tasks that we timestamped */
6887 if (!next->ftrace_timestamp)
6891 * Update all the counters in next to make up for the
6892 * time next was sleeping.
6894 timestamp -= next->ftrace_timestamp;
6896 for (index = next->curr_ret_stack; index >= 0; index--)
6897 next->ret_stack[index].calltime += timestamp;
6900 /* Allocate a return stack for each task */
6901 static int start_graph_tracing(void)
6903 struct ftrace_ret_stack **ret_stack_list;
6906 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
6907 sizeof(struct ftrace_ret_stack *),
6910 if (!ret_stack_list)
6913 /* The cpu_boot init_task->ret_stack will never be freed */
6914 for_each_online_cpu(cpu) {
6915 if (!idle_task(cpu)->ret_stack)
6916 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
6920 ret = alloc_retstack_tasklist(ret_stack_list);
6921 } while (ret == -EAGAIN);
6924 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6926 pr_info("ftrace_graph: Couldn't activate tracepoint"
6927 " probe to kernel_sched_switch\n");
6930 kfree(ret_stack_list);
6935 * Hibernation protection.
6936 * The state of the current task is too much unstable during
6937 * suspend/restore to disk. We want to protect against that.
6940 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
6944 case PM_HIBERNATION_PREPARE:
6945 pause_graph_tracing();
6948 case PM_POST_HIBERNATION:
6949 unpause_graph_tracing();
6955 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
6957 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
6959 return __ftrace_graph_entry(trace);
6963 * The function graph tracer should only trace the functions defined
6964 * by set_ftrace_filter and set_ftrace_notrace. If another function
6965 * tracer ops is registered, the graph tracer requires testing the
6966 * function against the global ops, and not just trace any function
6967 * that any ftrace_ops registered.
6969 static void update_function_graph_func(void)
6971 struct ftrace_ops *op;
6972 bool do_test = false;
6975 * The graph and global ops share the same set of functions
6976 * to test. If any other ops is on the list, then
6977 * the graph tracing needs to test if its the function
6980 do_for_each_ftrace_op(op, ftrace_ops_list) {
6981 if (op != &global_ops && op != &graph_ops &&
6982 op != &ftrace_list_end) {
6984 /* in double loop, break out with goto */
6987 } while_for_each_ftrace_op(op);
6990 ftrace_graph_entry = ftrace_graph_entry_test;
6992 ftrace_graph_entry = __ftrace_graph_entry;
6995 static struct notifier_block ftrace_suspend_notifier = {
6996 .notifier_call = ftrace_suspend_notifier_call,
6999 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
7000 trace_func_graph_ent_t entryfunc)
7004 mutex_lock(&ftrace_lock);
7006 /* we currently allow only one tracer registered at a time */
7007 if (ftrace_graph_active) {
7012 register_pm_notifier(&ftrace_suspend_notifier);
7014 ftrace_graph_active++;
7015 ret = start_graph_tracing();
7017 ftrace_graph_active--;
7021 ftrace_graph_return = retfunc;
7024 * Update the indirect function to the entryfunc, and the
7025 * function that gets called to the entry_test first. Then
7026 * call the update fgraph entry function to determine if
7027 * the entryfunc should be called directly or not.
7029 __ftrace_graph_entry = entryfunc;
7030 ftrace_graph_entry = ftrace_graph_entry_test;
7031 update_function_graph_func();
7033 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
7035 mutex_unlock(&ftrace_lock);
7039 void unregister_ftrace_graph(void)
7041 mutex_lock(&ftrace_lock);
7043 if (unlikely(!ftrace_graph_active))
7046 ftrace_graph_active--;
7047 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
7048 ftrace_graph_entry = ftrace_graph_entry_stub;
7049 __ftrace_graph_entry = ftrace_graph_entry_stub;
7050 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
7051 unregister_pm_notifier(&ftrace_suspend_notifier);
7052 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
7055 mutex_unlock(&ftrace_lock);
7058 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
7061 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
7063 atomic_set(&t->tracing_graph_pause, 0);
7064 atomic_set(&t->trace_overrun, 0);
7065 t->ftrace_timestamp = 0;
7066 /* make curr_ret_stack visible before we add the ret_stack */
7068 t->ret_stack = ret_stack;
7072 * Allocate a return stack for the idle task. May be the first
7073 * time through, or it may be done by CPU hotplug online.
7075 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
7077 t->curr_ret_stack = -1;
7079 * The idle task has no parent, it either has its own
7080 * stack or no stack at all.
7083 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
7085 if (ftrace_graph_active) {
7086 struct ftrace_ret_stack *ret_stack;
7088 ret_stack = per_cpu(idle_ret_stack, cpu);
7090 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
7091 * sizeof(struct ftrace_ret_stack),
7095 per_cpu(idle_ret_stack, cpu) = ret_stack;
7097 graph_init_task(t, ret_stack);
7101 /* Allocate a return stack for newly created task */
7102 void ftrace_graph_init_task(struct task_struct *t)
7104 /* Make sure we do not use the parent ret_stack */
7105 t->ret_stack = NULL;
7106 t->curr_ret_stack = -1;
7108 if (ftrace_graph_active) {
7109 struct ftrace_ret_stack *ret_stack;
7111 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
7112 * sizeof(struct ftrace_ret_stack),
7116 graph_init_task(t, ret_stack);
7120 void ftrace_graph_exit_task(struct task_struct *t)
7122 struct ftrace_ret_stack *ret_stack = t->ret_stack;
7124 t->ret_stack = NULL;
7125 /* NULL must become visible to IRQs before we free it: */