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 *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 = ftrace_ops_list;
173 ops != &ftrace_list_end; ops = ops->next)
176 mutex_unlock(&ftrace_lock);
181 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
182 struct ftrace_ops *op, struct pt_regs *regs)
184 struct trace_array *tr = op->private;
186 if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
189 op->saved_func(ip, parent_ip, op, regs);
193 * clear_ftrace_function - reset the ftrace function
195 * This NULLs the ftrace function and in essence stops
196 * tracing. There may be lag
198 void clear_ftrace_function(void)
200 ftrace_trace_function = ftrace_stub;
203 static void per_cpu_ops_disable_all(struct ftrace_ops *ops)
207 for_each_possible_cpu(cpu)
208 *per_cpu_ptr(ops->disabled, cpu) = 1;
211 static int per_cpu_ops_alloc(struct ftrace_ops *ops)
213 int __percpu *disabled;
215 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
218 disabled = alloc_percpu(int);
222 ops->disabled = disabled;
223 per_cpu_ops_disable_all(ops);
227 static void ftrace_sync(struct work_struct *work)
230 * This function is just a stub to implement a hard force
231 * of synchronize_sched(). This requires synchronizing
232 * tasks even in userspace and idle.
234 * Yes, function tracing is rude.
238 static void ftrace_sync_ipi(void *data)
240 /* Probably not needed, but do it anyway */
244 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
245 static void update_function_graph_func(void);
247 /* Both enabled by default (can be cleared by function_graph tracer flags */
248 static bool fgraph_sleep_time = true;
249 static bool fgraph_graph_time = true;
252 static inline void update_function_graph_func(void) { }
256 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
259 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
260 * then it needs to call the list anyway.
262 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU |
263 FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC)
264 return ftrace_ops_list_func;
266 return ftrace_ops_get_func(ops);
269 static void update_ftrace_function(void)
274 * Prepare the ftrace_ops that the arch callback will use.
275 * If there's only one ftrace_ops registered, the ftrace_ops_list
276 * will point to the ops we want.
278 set_function_trace_op = ftrace_ops_list;
280 /* If there's no ftrace_ops registered, just call the stub function */
281 if (ftrace_ops_list == &ftrace_list_end) {
285 * If we are at the end of the list and this ops is
286 * recursion safe and not dynamic and the arch supports passing ops,
287 * then have the mcount trampoline call the function directly.
289 } else if (ftrace_ops_list->next == &ftrace_list_end) {
290 func = ftrace_ops_get_list_func(ftrace_ops_list);
293 /* Just use the default ftrace_ops */
294 set_function_trace_op = &ftrace_list_end;
295 func = ftrace_ops_list_func;
298 update_function_graph_func();
300 /* If there's no change, then do nothing more here */
301 if (ftrace_trace_function == func)
305 * If we are using the list function, it doesn't care
306 * about the function_trace_ops.
308 if (func == ftrace_ops_list_func) {
309 ftrace_trace_function = func;
311 * Don't even bother setting function_trace_ops,
312 * it would be racy to do so anyway.
317 #ifndef CONFIG_DYNAMIC_FTRACE
319 * For static tracing, we need to be a bit more careful.
320 * The function change takes affect immediately. Thus,
321 * we need to coorditate the setting of the function_trace_ops
322 * with the setting of the ftrace_trace_function.
324 * Set the function to the list ops, which will call the
325 * function we want, albeit indirectly, but it handles the
326 * ftrace_ops and doesn't depend on function_trace_op.
328 ftrace_trace_function = ftrace_ops_list_func;
330 * Make sure all CPUs see this. Yes this is slow, but static
331 * tracing is slow and nasty to have enabled.
333 schedule_on_each_cpu(ftrace_sync);
334 /* Now all cpus are using the list ops. */
335 function_trace_op = set_function_trace_op;
336 /* Make sure the function_trace_op is visible on all CPUs */
338 /* Nasty way to force a rmb on all cpus */
339 smp_call_function(ftrace_sync_ipi, NULL, 1);
340 /* OK, we are all set to update the ftrace_trace_function now! */
341 #endif /* !CONFIG_DYNAMIC_FTRACE */
343 ftrace_trace_function = func;
346 int using_ftrace_ops_list_func(void)
348 return ftrace_trace_function == ftrace_ops_list_func;
351 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
355 * We are entering ops into the list but another
356 * CPU might be walking that list. We need to make sure
357 * the ops->next pointer is valid before another CPU sees
358 * the ops pointer included into the list.
360 rcu_assign_pointer(*list, ops);
363 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
365 struct ftrace_ops **p;
368 * If we are removing the last function, then simply point
369 * to the ftrace_stub.
371 if (*list == ops && ops->next == &ftrace_list_end) {
372 *list = &ftrace_list_end;
376 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
387 static void ftrace_update_trampoline(struct ftrace_ops *ops);
389 static int __register_ftrace_function(struct ftrace_ops *ops)
391 if (ops->flags & FTRACE_OPS_FL_DELETED)
394 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
397 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
399 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
400 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
401 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
403 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
404 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
407 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
408 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
411 if (!core_kernel_data((unsigned long)ops))
412 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
414 if (ops->flags & FTRACE_OPS_FL_PER_CPU) {
415 if (per_cpu_ops_alloc(ops))
419 add_ftrace_ops(&ftrace_ops_list, ops);
421 /* Always save the function, and reset at unregistering */
422 ops->saved_func = ops->func;
424 if (ftrace_pids_enabled(ops))
425 ops->func = ftrace_pid_func;
427 ftrace_update_trampoline(ops);
430 update_ftrace_function();
435 static int __unregister_ftrace_function(struct ftrace_ops *ops)
439 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
442 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
448 update_ftrace_function();
450 ops->func = ops->saved_func;
455 static void ftrace_update_pid_func(void)
457 struct ftrace_ops *op;
459 /* Only do something if we are tracing something */
460 if (ftrace_trace_function == ftrace_stub)
463 do_for_each_ftrace_op(op, ftrace_ops_list) {
464 if (op->flags & FTRACE_OPS_FL_PID) {
465 op->func = ftrace_pids_enabled(op) ?
466 ftrace_pid_func : op->saved_func;
467 ftrace_update_trampoline(op);
469 } while_for_each_ftrace_op(op);
471 update_ftrace_function();
474 #ifdef CONFIG_FUNCTION_PROFILER
475 struct ftrace_profile {
476 struct hlist_node node;
478 unsigned long counter;
479 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
480 unsigned long long time;
481 unsigned long long time_squared;
485 struct ftrace_profile_page {
486 struct ftrace_profile_page *next;
488 struct ftrace_profile records[];
491 struct ftrace_profile_stat {
493 struct hlist_head *hash;
494 struct ftrace_profile_page *pages;
495 struct ftrace_profile_page *start;
496 struct tracer_stat stat;
499 #define PROFILE_RECORDS_SIZE \
500 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
502 #define PROFILES_PER_PAGE \
503 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
505 static int ftrace_profile_enabled __read_mostly;
507 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
508 static DEFINE_MUTEX(ftrace_profile_lock);
510 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
512 #define FTRACE_PROFILE_HASH_BITS 10
513 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
516 function_stat_next(void *v, int idx)
518 struct ftrace_profile *rec = v;
519 struct ftrace_profile_page *pg;
521 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
527 if ((void *)rec >= (void *)&pg->records[pg->index]) {
531 rec = &pg->records[0];
539 static void *function_stat_start(struct tracer_stat *trace)
541 struct ftrace_profile_stat *stat =
542 container_of(trace, struct ftrace_profile_stat, stat);
544 if (!stat || !stat->start)
547 return function_stat_next(&stat->start->records[0], 0);
550 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
551 /* function graph compares on total time */
552 static int function_stat_cmp(void *p1, void *p2)
554 struct ftrace_profile *a = p1;
555 struct ftrace_profile *b = p2;
557 if (a->time < b->time)
559 if (a->time > b->time)
565 /* not function graph compares against hits */
566 static int function_stat_cmp(void *p1, void *p2)
568 struct ftrace_profile *a = p1;
569 struct ftrace_profile *b = p2;
571 if (a->counter < b->counter)
573 if (a->counter > b->counter)
580 static int function_stat_headers(struct seq_file *m)
582 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
583 seq_puts(m, " Function "
586 "--- ---- --- ---\n");
588 seq_puts(m, " Function Hit\n"
594 static int function_stat_show(struct seq_file *m, void *v)
596 struct ftrace_profile *rec = v;
597 char str[KSYM_SYMBOL_LEN];
599 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
600 static struct trace_seq s;
601 unsigned long long avg;
602 unsigned long long stddev;
604 mutex_lock(&ftrace_profile_lock);
606 /* we raced with function_profile_reset() */
607 if (unlikely(rec->counter == 0)) {
612 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
614 do_div(avg, rec->counter);
615 if (tracing_thresh && (avg < tracing_thresh))
619 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
620 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
622 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
625 /* Sample standard deviation (s^2) */
626 if (rec->counter <= 1)
630 * Apply Welford's method:
631 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
633 stddev = rec->counter * rec->time_squared -
634 rec->time * rec->time;
637 * Divide only 1000 for ns^2 -> us^2 conversion.
638 * trace_print_graph_duration will divide 1000 again.
640 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
644 trace_print_graph_duration(rec->time, &s);
645 trace_seq_puts(&s, " ");
646 trace_print_graph_duration(avg, &s);
647 trace_seq_puts(&s, " ");
648 trace_print_graph_duration(stddev, &s);
649 trace_print_seq(m, &s);
653 mutex_unlock(&ftrace_profile_lock);
658 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
660 struct ftrace_profile_page *pg;
662 pg = stat->pages = stat->start;
665 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
670 memset(stat->hash, 0,
671 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
674 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
676 struct ftrace_profile_page *pg;
681 /* If we already allocated, do nothing */
685 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
689 #ifdef CONFIG_DYNAMIC_FTRACE
690 functions = ftrace_update_tot_cnt;
693 * We do not know the number of functions that exist because
694 * dynamic tracing is what counts them. With past experience
695 * we have around 20K functions. That should be more than enough.
696 * It is highly unlikely we will execute every function in
702 pg = stat->start = stat->pages;
704 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
706 for (i = 1; i < pages; i++) {
707 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
718 unsigned long tmp = (unsigned long)pg;
730 static int ftrace_profile_init_cpu(int cpu)
732 struct ftrace_profile_stat *stat;
735 stat = &per_cpu(ftrace_profile_stats, cpu);
738 /* If the profile is already created, simply reset it */
739 ftrace_profile_reset(stat);
744 * We are profiling all functions, but usually only a few thousand
745 * functions are hit. We'll make a hash of 1024 items.
747 size = FTRACE_PROFILE_HASH_SIZE;
749 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
754 /* Preallocate the function profiling pages */
755 if (ftrace_profile_pages_init(stat) < 0) {
764 static int ftrace_profile_init(void)
769 for_each_possible_cpu(cpu) {
770 ret = ftrace_profile_init_cpu(cpu);
778 /* interrupts must be disabled */
779 static struct ftrace_profile *
780 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
782 struct ftrace_profile *rec;
783 struct hlist_head *hhd;
786 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
787 hhd = &stat->hash[key];
789 if (hlist_empty(hhd))
792 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
800 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
801 struct ftrace_profile *rec)
805 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
806 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
810 * The memory is already allocated, this simply finds a new record to use.
812 static struct ftrace_profile *
813 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
815 struct ftrace_profile *rec = NULL;
817 /* prevent recursion (from NMIs) */
818 if (atomic_inc_return(&stat->disabled) != 1)
822 * Try to find the function again since an NMI
823 * could have added it
825 rec = ftrace_find_profiled_func(stat, ip);
829 if (stat->pages->index == PROFILES_PER_PAGE) {
830 if (!stat->pages->next)
832 stat->pages = stat->pages->next;
835 rec = &stat->pages->records[stat->pages->index++];
837 ftrace_add_profile(stat, rec);
840 atomic_dec(&stat->disabled);
846 function_profile_call(unsigned long ip, unsigned long parent_ip,
847 struct ftrace_ops *ops, struct pt_regs *regs)
849 struct ftrace_profile_stat *stat;
850 struct ftrace_profile *rec;
853 if (!ftrace_profile_enabled)
856 local_irq_save(flags);
858 stat = this_cpu_ptr(&ftrace_profile_stats);
859 if (!stat->hash || !ftrace_profile_enabled)
862 rec = ftrace_find_profiled_func(stat, ip);
864 rec = ftrace_profile_alloc(stat, ip);
871 local_irq_restore(flags);
874 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
875 static int profile_graph_entry(struct ftrace_graph_ent *trace)
877 int index = trace->depth;
879 function_profile_call(trace->func, 0, NULL, NULL);
881 if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
882 current->ret_stack[index].subtime = 0;
887 static void profile_graph_return(struct ftrace_graph_ret *trace)
889 struct ftrace_profile_stat *stat;
890 unsigned long long calltime;
891 struct ftrace_profile *rec;
894 local_irq_save(flags);
895 stat = this_cpu_ptr(&ftrace_profile_stats);
896 if (!stat->hash || !ftrace_profile_enabled)
899 /* If the calltime was zero'd ignore it */
900 if (!trace->calltime)
903 calltime = trace->rettime - trace->calltime;
905 if (!fgraph_graph_time) {
908 index = trace->depth;
910 /* Append this call time to the parent time to subtract */
912 current->ret_stack[index - 1].subtime += calltime;
914 if (current->ret_stack[index].subtime < calltime)
915 calltime -= current->ret_stack[index].subtime;
920 rec = ftrace_find_profiled_func(stat, trace->func);
922 rec->time += calltime;
923 rec->time_squared += calltime * calltime;
927 local_irq_restore(flags);
930 static int register_ftrace_profiler(void)
932 return register_ftrace_graph(&profile_graph_return,
933 &profile_graph_entry);
936 static void unregister_ftrace_profiler(void)
938 unregister_ftrace_graph();
941 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
942 .func = function_profile_call,
943 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
944 INIT_OPS_HASH(ftrace_profile_ops)
947 static int register_ftrace_profiler(void)
949 return register_ftrace_function(&ftrace_profile_ops);
952 static void unregister_ftrace_profiler(void)
954 unregister_ftrace_function(&ftrace_profile_ops);
956 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
959 ftrace_profile_write(struct file *filp, const char __user *ubuf,
960 size_t cnt, loff_t *ppos)
965 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
971 mutex_lock(&ftrace_profile_lock);
972 if (ftrace_profile_enabled ^ val) {
974 ret = ftrace_profile_init();
980 ret = register_ftrace_profiler();
985 ftrace_profile_enabled = 1;
987 ftrace_profile_enabled = 0;
989 * unregister_ftrace_profiler calls stop_machine
990 * so this acts like an synchronize_sched.
992 unregister_ftrace_profiler();
996 mutex_unlock(&ftrace_profile_lock);
1004 ftrace_profile_read(struct file *filp, char __user *ubuf,
1005 size_t cnt, loff_t *ppos)
1007 char buf[64]; /* big enough to hold a number */
1010 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
1011 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1014 static const struct file_operations ftrace_profile_fops = {
1015 .open = tracing_open_generic,
1016 .read = ftrace_profile_read,
1017 .write = ftrace_profile_write,
1018 .llseek = default_llseek,
1021 /* used to initialize the real stat files */
1022 static struct tracer_stat function_stats __initdata = {
1023 .name = "functions",
1024 .stat_start = function_stat_start,
1025 .stat_next = function_stat_next,
1026 .stat_cmp = function_stat_cmp,
1027 .stat_headers = function_stat_headers,
1028 .stat_show = function_stat_show
1031 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1033 struct ftrace_profile_stat *stat;
1034 struct dentry *entry;
1039 for_each_possible_cpu(cpu) {
1040 stat = &per_cpu(ftrace_profile_stats, cpu);
1042 name = kasprintf(GFP_KERNEL, "function%d", cpu);
1045 * The files created are permanent, if something happens
1046 * we still do not free memory.
1049 "Could not allocate stat file for cpu %d\n",
1053 stat->stat = function_stats;
1054 stat->stat.name = name;
1055 ret = register_stat_tracer(&stat->stat);
1058 "Could not register function stat for cpu %d\n",
1065 entry = tracefs_create_file("function_profile_enabled", 0644,
1066 d_tracer, NULL, &ftrace_profile_fops);
1068 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1071 #else /* CONFIG_FUNCTION_PROFILER */
1072 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1075 #endif /* CONFIG_FUNCTION_PROFILER */
1077 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1079 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1080 static int ftrace_graph_active;
1082 # define ftrace_graph_active 0
1085 #ifdef CONFIG_DYNAMIC_FTRACE
1087 static struct ftrace_ops *removed_ops;
1090 * Set when doing a global update, like enabling all recs or disabling them.
1091 * It is not set when just updating a single ftrace_ops.
1093 static bool update_all_ops;
1095 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1096 # error Dynamic ftrace depends on MCOUNT_RECORD
1099 struct ftrace_func_entry {
1100 struct hlist_node hlist;
1104 struct ftrace_func_probe {
1105 struct ftrace_probe_ops *probe_ops;
1106 struct ftrace_ops ops;
1107 struct trace_array *tr;
1108 struct list_head list;
1114 * We make these constant because no one should touch them,
1115 * but they are used as the default "empty hash", to avoid allocating
1116 * it all the time. These are in a read only section such that if
1117 * anyone does try to modify it, it will cause an exception.
1119 static const struct hlist_head empty_buckets[1];
1120 static const struct ftrace_hash empty_hash = {
1121 .buckets = (struct hlist_head *)empty_buckets,
1123 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1125 static struct ftrace_ops global_ops = {
1126 .func = ftrace_stub,
1127 .local_hash.notrace_hash = EMPTY_HASH,
1128 .local_hash.filter_hash = EMPTY_HASH,
1129 INIT_OPS_HASH(global_ops)
1130 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1131 FTRACE_OPS_FL_INITIALIZED |
1136 * This is used by __kernel_text_address() to return true if the
1137 * address is on a dynamically allocated trampoline that would
1138 * not return true for either core_kernel_text() or
1139 * is_module_text_address().
1141 bool is_ftrace_trampoline(unsigned long addr)
1143 struct ftrace_ops *op;
1147 * Some of the ops may be dynamically allocated,
1148 * they are freed after a synchronize_sched().
1150 preempt_disable_notrace();
1152 do_for_each_ftrace_op(op, ftrace_ops_list) {
1154 * This is to check for dynamically allocated trampolines.
1155 * Trampolines that are in kernel text will have
1156 * core_kernel_text() return true.
1158 if (op->trampoline && op->trampoline_size)
1159 if (addr >= op->trampoline &&
1160 addr < op->trampoline + op->trampoline_size) {
1164 } while_for_each_ftrace_op(op);
1167 preempt_enable_notrace();
1172 struct ftrace_page {
1173 struct ftrace_page *next;
1174 struct dyn_ftrace *records;
1179 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1180 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1182 /* estimate from running different kernels */
1183 #define NR_TO_INIT 10000
1185 static struct ftrace_page *ftrace_pages_start;
1186 static struct ftrace_page *ftrace_pages;
1188 static __always_inline unsigned long
1189 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1191 if (hash->size_bits > 0)
1192 return hash_long(ip, hash->size_bits);
1197 /* Only use this function if ftrace_hash_empty() has already been tested */
1198 static __always_inline struct ftrace_func_entry *
1199 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1202 struct ftrace_func_entry *entry;
1203 struct hlist_head *hhd;
1205 key = ftrace_hash_key(hash, ip);
1206 hhd = &hash->buckets[key];
1208 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1209 if (entry->ip == ip)
1216 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1217 * @hash: The hash to look at
1218 * @ip: The instruction pointer to test
1220 * Search a given @hash to see if a given instruction pointer (@ip)
1223 * Returns the entry that holds the @ip if found. NULL otherwise.
1225 struct ftrace_func_entry *
1226 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1228 if (ftrace_hash_empty(hash))
1231 return __ftrace_lookup_ip(hash, ip);
1234 static void __add_hash_entry(struct ftrace_hash *hash,
1235 struct ftrace_func_entry *entry)
1237 struct hlist_head *hhd;
1240 key = ftrace_hash_key(hash, entry->ip);
1241 hhd = &hash->buckets[key];
1242 hlist_add_head(&entry->hlist, hhd);
1246 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1248 struct ftrace_func_entry *entry;
1250 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1255 __add_hash_entry(hash, entry);
1261 free_hash_entry(struct ftrace_hash *hash,
1262 struct ftrace_func_entry *entry)
1264 hlist_del(&entry->hlist);
1270 remove_hash_entry(struct ftrace_hash *hash,
1271 struct ftrace_func_entry *entry)
1273 hlist_del_rcu(&entry->hlist);
1277 static void ftrace_hash_clear(struct ftrace_hash *hash)
1279 struct hlist_head *hhd;
1280 struct hlist_node *tn;
1281 struct ftrace_func_entry *entry;
1282 int size = 1 << hash->size_bits;
1288 for (i = 0; i < size; i++) {
1289 hhd = &hash->buckets[i];
1290 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1291 free_hash_entry(hash, entry);
1293 FTRACE_WARN_ON(hash->count);
1296 static void free_ftrace_hash(struct ftrace_hash *hash)
1298 if (!hash || hash == EMPTY_HASH)
1300 ftrace_hash_clear(hash);
1301 kfree(hash->buckets);
1305 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1307 struct ftrace_hash *hash;
1309 hash = container_of(rcu, struct ftrace_hash, rcu);
1310 free_ftrace_hash(hash);
1313 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1315 if (!hash || hash == EMPTY_HASH)
1317 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1320 void ftrace_free_filter(struct ftrace_ops *ops)
1322 ftrace_ops_init(ops);
1323 free_ftrace_hash(ops->func_hash->filter_hash);
1324 free_ftrace_hash(ops->func_hash->notrace_hash);
1327 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1329 struct ftrace_hash *hash;
1332 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1336 size = 1 << size_bits;
1337 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1339 if (!hash->buckets) {
1344 hash->size_bits = size_bits;
1349 static struct ftrace_hash *
1350 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1352 struct ftrace_func_entry *entry;
1353 struct ftrace_hash *new_hash;
1358 new_hash = alloc_ftrace_hash(size_bits);
1363 if (ftrace_hash_empty(hash))
1366 size = 1 << hash->size_bits;
1367 for (i = 0; i < size; i++) {
1368 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1369 ret = add_hash_entry(new_hash, entry->ip);
1375 FTRACE_WARN_ON(new_hash->count != hash->count);
1380 free_ftrace_hash(new_hash);
1385 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1387 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1389 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1390 struct ftrace_hash *new_hash);
1392 static struct ftrace_hash *
1393 __ftrace_hash_move(struct ftrace_hash *src)
1395 struct ftrace_func_entry *entry;
1396 struct hlist_node *tn;
1397 struct hlist_head *hhd;
1398 struct ftrace_hash *new_hash;
1399 int size = src->count;
1404 * If the new source is empty, just return the empty_hash.
1410 * Make the hash size about 1/2 the # found
1412 for (size /= 2; size; size >>= 1)
1415 /* Don't allocate too much */
1416 if (bits > FTRACE_HASH_MAX_BITS)
1417 bits = FTRACE_HASH_MAX_BITS;
1419 new_hash = alloc_ftrace_hash(bits);
1423 size = 1 << src->size_bits;
1424 for (i = 0; i < size; i++) {
1425 hhd = &src->buckets[i];
1426 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1427 remove_hash_entry(src, entry);
1428 __add_hash_entry(new_hash, entry);
1436 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1437 struct ftrace_hash **dst, struct ftrace_hash *src)
1439 struct ftrace_hash *new_hash;
1442 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1443 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1446 new_hash = __ftrace_hash_move(src);
1450 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1452 /* IPMODIFY should be updated only when filter_hash updating */
1453 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1455 free_ftrace_hash(new_hash);
1461 * Remove the current set, update the hash and add
1464 ftrace_hash_rec_disable_modify(ops, enable);
1466 rcu_assign_pointer(*dst, new_hash);
1468 ftrace_hash_rec_enable_modify(ops, enable);
1473 static bool hash_contains_ip(unsigned long ip,
1474 struct ftrace_ops_hash *hash)
1477 * The function record is a match if it exists in the filter
1478 * hash and not in the notrace hash. Note, an emty hash is
1479 * considered a match for the filter hash, but an empty
1480 * notrace hash is considered not in the notrace hash.
1482 return (ftrace_hash_empty(hash->filter_hash) ||
1483 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1484 (ftrace_hash_empty(hash->notrace_hash) ||
1485 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1489 * Test the hashes for this ops to see if we want to call
1490 * the ops->func or not.
1492 * It's a match if the ip is in the ops->filter_hash or
1493 * the filter_hash does not exist or is empty,
1495 * the ip is not in the ops->notrace_hash.
1497 * This needs to be called with preemption disabled as
1498 * the hashes are freed with call_rcu_sched().
1501 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1503 struct ftrace_ops_hash hash;
1506 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1508 * There's a small race when adding ops that the ftrace handler
1509 * that wants regs, may be called without them. We can not
1510 * allow that handler to be called if regs is NULL.
1512 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1516 hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
1517 hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
1519 if (hash_contains_ip(ip, &hash))
1528 * This is a double for. Do not use 'break' to break out of the loop,
1529 * you must use a goto.
1531 #define do_for_each_ftrace_rec(pg, rec) \
1532 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1534 for (_____i = 0; _____i < pg->index; _____i++) { \
1535 rec = &pg->records[_____i];
1537 #define while_for_each_ftrace_rec() \
1542 static int ftrace_cmp_recs(const void *a, const void *b)
1544 const struct dyn_ftrace *key = a;
1545 const struct dyn_ftrace *rec = b;
1547 if (key->flags < rec->ip)
1549 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1555 * ftrace_location_range - return the first address of a traced location
1556 * if it touches the given ip range
1557 * @start: start of range to search.
1558 * @end: end of range to search (inclusive). @end points to the last byte
1561 * Returns rec->ip if the related ftrace location is a least partly within
1562 * the given address range. That is, the first address of the instruction
1563 * that is either a NOP or call to the function tracer. It checks the ftrace
1564 * internal tables to determine if the address belongs or not.
1566 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1568 struct ftrace_page *pg;
1569 struct dyn_ftrace *rec;
1570 struct dyn_ftrace key;
1573 key.flags = end; /* overload flags, as it is unsigned long */
1575 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1576 if (end < pg->records[0].ip ||
1577 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1579 rec = bsearch(&key, pg->records, pg->index,
1580 sizeof(struct dyn_ftrace),
1590 * ftrace_location - return true if the ip giving is a traced location
1591 * @ip: the instruction pointer to check
1593 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1594 * That is, the instruction that is either a NOP or call to
1595 * the function tracer. It checks the ftrace internal tables to
1596 * determine if the address belongs or not.
1598 unsigned long ftrace_location(unsigned long ip)
1600 return ftrace_location_range(ip, ip);
1604 * ftrace_text_reserved - return true if range contains an ftrace location
1605 * @start: start of range to search
1606 * @end: end of range to search (inclusive). @end points to the last byte to check.
1608 * Returns 1 if @start and @end contains a ftrace location.
1609 * That is, the instruction that is either a NOP or call to
1610 * the function tracer. It checks the ftrace internal tables to
1611 * determine if the address belongs or not.
1613 int ftrace_text_reserved(const void *start, const void *end)
1617 ret = ftrace_location_range((unsigned long)start,
1618 (unsigned long)end);
1623 /* Test if ops registered to this rec needs regs */
1624 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1626 struct ftrace_ops *ops;
1627 bool keep_regs = false;
1629 for (ops = ftrace_ops_list;
1630 ops != &ftrace_list_end; ops = ops->next) {
1631 /* pass rec in as regs to have non-NULL val */
1632 if (ftrace_ops_test(ops, rec->ip, rec)) {
1633 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1643 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1647 struct ftrace_hash *hash;
1648 struct ftrace_hash *other_hash;
1649 struct ftrace_page *pg;
1650 struct dyn_ftrace *rec;
1651 bool update = false;
1655 /* Only update if the ops has been registered */
1656 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1660 * In the filter_hash case:
1661 * If the count is zero, we update all records.
1662 * Otherwise we just update the items in the hash.
1664 * In the notrace_hash case:
1665 * We enable the update in the hash.
1666 * As disabling notrace means enabling the tracing,
1667 * and enabling notrace means disabling, the inc variable
1671 hash = ops->func_hash->filter_hash;
1672 other_hash = ops->func_hash->notrace_hash;
1673 if (ftrace_hash_empty(hash))
1677 hash = ops->func_hash->notrace_hash;
1678 other_hash = ops->func_hash->filter_hash;
1680 * If the notrace hash has no items,
1681 * then there's nothing to do.
1683 if (ftrace_hash_empty(hash))
1687 do_for_each_ftrace_rec(pg, rec) {
1688 int in_other_hash = 0;
1692 if (rec->flags & FTRACE_FL_DISABLED)
1697 * Only the filter_hash affects all records.
1698 * Update if the record is not in the notrace hash.
1700 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1703 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1704 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1707 * If filter_hash is set, we want to match all functions
1708 * that are in the hash but not in the other hash.
1710 * If filter_hash is not set, then we are decrementing.
1711 * That means we match anything that is in the hash
1712 * and also in the other_hash. That is, we need to turn
1713 * off functions in the other hash because they are disabled
1716 if (filter_hash && in_hash && !in_other_hash)
1718 else if (!filter_hash && in_hash &&
1719 (in_other_hash || ftrace_hash_empty(other_hash)))
1727 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1731 * If there's only a single callback registered to a
1732 * function, and the ops has a trampoline registered
1733 * for it, then we can call it directly.
1735 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1736 rec->flags |= FTRACE_FL_TRAMP;
1739 * If we are adding another function callback
1740 * to this function, and the previous had a
1741 * custom trampoline in use, then we need to go
1742 * back to the default trampoline.
1744 rec->flags &= ~FTRACE_FL_TRAMP;
1747 * If any ops wants regs saved for this function
1748 * then all ops will get saved regs.
1750 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1751 rec->flags |= FTRACE_FL_REGS;
1753 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1758 * If the rec had REGS enabled and the ops that is
1759 * being removed had REGS set, then see if there is
1760 * still any ops for this record that wants regs.
1761 * If not, we can stop recording them.
1763 if (ftrace_rec_count(rec) > 0 &&
1764 rec->flags & FTRACE_FL_REGS &&
1765 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1766 if (!test_rec_ops_needs_regs(rec))
1767 rec->flags &= ~FTRACE_FL_REGS;
1771 * If the rec had TRAMP enabled, then it needs to
1772 * be cleared. As TRAMP can only be enabled iff
1773 * there is only a single ops attached to it.
1774 * In otherwords, always disable it on decrementing.
1775 * In the future, we may set it if rec count is
1776 * decremented to one, and the ops that is left
1779 rec->flags &= ~FTRACE_FL_TRAMP;
1782 * flags will be cleared in ftrace_check_record()
1783 * if rec count is zero.
1788 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1789 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1791 /* Shortcut, if we handled all records, we are done. */
1792 if (!all && count == hash->count)
1794 } while_for_each_ftrace_rec();
1799 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1802 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1805 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1808 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1811 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1812 int filter_hash, int inc)
1814 struct ftrace_ops *op;
1816 __ftrace_hash_rec_update(ops, filter_hash, inc);
1818 if (ops->func_hash != &global_ops.local_hash)
1822 * If the ops shares the global_ops hash, then we need to update
1823 * all ops that are enabled and use this hash.
1825 do_for_each_ftrace_op(op, ftrace_ops_list) {
1829 if (op->func_hash == &global_ops.local_hash)
1830 __ftrace_hash_rec_update(op, filter_hash, inc);
1831 } while_for_each_ftrace_op(op);
1834 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1837 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1840 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1843 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1847 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1848 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1849 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1850 * Note that old_hash and new_hash has below meanings
1851 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1852 * - If the hash is EMPTY_HASH, it hits nothing
1853 * - Anything else hits the recs which match the hash entries.
1855 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1856 struct ftrace_hash *old_hash,
1857 struct ftrace_hash *new_hash)
1859 struct ftrace_page *pg;
1860 struct dyn_ftrace *rec, *end = NULL;
1863 /* Only update if the ops has been registered */
1864 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1867 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1871 * Since the IPMODIFY is a very address sensitive action, we do not
1872 * allow ftrace_ops to set all functions to new hash.
1874 if (!new_hash || !old_hash)
1877 /* Update rec->flags */
1878 do_for_each_ftrace_rec(pg, rec) {
1880 if (rec->flags & FTRACE_FL_DISABLED)
1883 /* We need to update only differences of filter_hash */
1884 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1885 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1886 if (in_old == in_new)
1890 /* New entries must ensure no others are using it */
1891 if (rec->flags & FTRACE_FL_IPMODIFY)
1893 rec->flags |= FTRACE_FL_IPMODIFY;
1894 } else /* Removed entry */
1895 rec->flags &= ~FTRACE_FL_IPMODIFY;
1896 } while_for_each_ftrace_rec();
1903 /* Roll back what we did above */
1904 do_for_each_ftrace_rec(pg, rec) {
1906 if (rec->flags & FTRACE_FL_DISABLED)
1912 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1913 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1914 if (in_old == in_new)
1918 rec->flags &= ~FTRACE_FL_IPMODIFY;
1920 rec->flags |= FTRACE_FL_IPMODIFY;
1921 } while_for_each_ftrace_rec();
1927 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1929 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1931 if (ftrace_hash_empty(hash))
1934 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1937 /* Disabling always succeeds */
1938 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1940 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1942 if (ftrace_hash_empty(hash))
1945 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1948 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1949 struct ftrace_hash *new_hash)
1951 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1953 if (ftrace_hash_empty(old_hash))
1956 if (ftrace_hash_empty(new_hash))
1959 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1962 static void print_ip_ins(const char *fmt, const unsigned char *p)
1966 printk(KERN_CONT "%s", fmt);
1968 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1969 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1972 static struct ftrace_ops *
1973 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1974 static struct ftrace_ops *
1975 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1977 enum ftrace_bug_type ftrace_bug_type;
1978 const void *ftrace_expected;
1980 static void print_bug_type(void)
1982 switch (ftrace_bug_type) {
1983 case FTRACE_BUG_UNKNOWN:
1985 case FTRACE_BUG_INIT:
1986 pr_info("Initializing ftrace call sites\n");
1988 case FTRACE_BUG_NOP:
1989 pr_info("Setting ftrace call site to NOP\n");
1991 case FTRACE_BUG_CALL:
1992 pr_info("Setting ftrace call site to call ftrace function\n");
1994 case FTRACE_BUG_UPDATE:
1995 pr_info("Updating ftrace call site to call a different ftrace function\n");
2001 * ftrace_bug - report and shutdown function tracer
2002 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2003 * @rec: The record that failed
2005 * The arch code that enables or disables the function tracing
2006 * can call ftrace_bug() when it has detected a problem in
2007 * modifying the code. @failed should be one of either:
2008 * EFAULT - if the problem happens on reading the @ip address
2009 * EINVAL - if what is read at @ip is not what was expected
2010 * EPERM - if the problem happens on writting to the @ip address
2012 void ftrace_bug(int failed, struct dyn_ftrace *rec)
2014 unsigned long ip = rec ? rec->ip : 0;
2018 FTRACE_WARN_ON_ONCE(1);
2019 pr_info("ftrace faulted on modifying ");
2023 FTRACE_WARN_ON_ONCE(1);
2024 pr_info("ftrace failed to modify ");
2026 print_ip_ins(" actual: ", (unsigned char *)ip);
2028 if (ftrace_expected) {
2029 print_ip_ins(" expected: ", ftrace_expected);
2034 FTRACE_WARN_ON_ONCE(1);
2035 pr_info("ftrace faulted on writing ");
2039 FTRACE_WARN_ON_ONCE(1);
2040 pr_info("ftrace faulted on unknown error ");
2045 struct ftrace_ops *ops = NULL;
2047 pr_info("ftrace record flags: %lx\n", rec->flags);
2048 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2049 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2050 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2051 ops = ftrace_find_tramp_ops_any(rec);
2054 pr_cont("\ttramp: %pS (%pS)",
2055 (void *)ops->trampoline,
2057 ops = ftrace_find_tramp_ops_next(rec, ops);
2060 pr_cont("\ttramp: ERROR!");
2063 ip = ftrace_get_addr_curr(rec);
2064 pr_cont("\n expected tramp: %lx\n", ip);
2068 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2070 unsigned long flag = 0UL;
2072 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2074 if (rec->flags & FTRACE_FL_DISABLED)
2075 return FTRACE_UPDATE_IGNORE;
2078 * If we are updating calls:
2080 * If the record has a ref count, then we need to enable it
2081 * because someone is using it.
2083 * Otherwise we make sure its disabled.
2085 * If we are disabling calls, then disable all records that
2088 if (enable && ftrace_rec_count(rec))
2089 flag = FTRACE_FL_ENABLED;
2092 * If enabling and the REGS flag does not match the REGS_EN, or
2093 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2094 * this record. Set flags to fail the compare against ENABLED.
2097 if (!(rec->flags & FTRACE_FL_REGS) !=
2098 !(rec->flags & FTRACE_FL_REGS_EN))
2099 flag |= FTRACE_FL_REGS;
2101 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2102 !(rec->flags & FTRACE_FL_TRAMP_EN))
2103 flag |= FTRACE_FL_TRAMP;
2106 /* If the state of this record hasn't changed, then do nothing */
2107 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2108 return FTRACE_UPDATE_IGNORE;
2111 /* Save off if rec is being enabled (for return value) */
2112 flag ^= rec->flags & FTRACE_FL_ENABLED;
2115 rec->flags |= FTRACE_FL_ENABLED;
2116 if (flag & FTRACE_FL_REGS) {
2117 if (rec->flags & FTRACE_FL_REGS)
2118 rec->flags |= FTRACE_FL_REGS_EN;
2120 rec->flags &= ~FTRACE_FL_REGS_EN;
2122 if (flag & FTRACE_FL_TRAMP) {
2123 if (rec->flags & FTRACE_FL_TRAMP)
2124 rec->flags |= FTRACE_FL_TRAMP_EN;
2126 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2131 * If this record is being updated from a nop, then
2132 * return UPDATE_MAKE_CALL.
2134 * return UPDATE_MODIFY_CALL to tell the caller to convert
2135 * from the save regs, to a non-save regs function or
2136 * vice versa, or from a trampoline call.
2138 if (flag & FTRACE_FL_ENABLED) {
2139 ftrace_bug_type = FTRACE_BUG_CALL;
2140 return FTRACE_UPDATE_MAKE_CALL;
2143 ftrace_bug_type = FTRACE_BUG_UPDATE;
2144 return FTRACE_UPDATE_MODIFY_CALL;
2148 /* If there's no more users, clear all flags */
2149 if (!ftrace_rec_count(rec))
2153 * Just disable the record, but keep the ops TRAMP
2154 * and REGS states. The _EN flags must be disabled though.
2156 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2160 ftrace_bug_type = FTRACE_BUG_NOP;
2161 return FTRACE_UPDATE_MAKE_NOP;
2165 * ftrace_update_record, set a record that now is tracing or not
2166 * @rec: the record to update
2167 * @enable: set to 1 if the record is tracing, zero to force disable
2169 * The records that represent all functions that can be traced need
2170 * to be updated when tracing has been enabled.
2172 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2174 return ftrace_check_record(rec, enable, 1);
2178 * ftrace_test_record, check if the record has been enabled or not
2179 * @rec: the record to test
2180 * @enable: set to 1 to check if enabled, 0 if it is disabled
2182 * The arch code may need to test if a record is already set to
2183 * tracing to determine how to modify the function code that it
2186 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2188 return ftrace_check_record(rec, enable, 0);
2191 static struct ftrace_ops *
2192 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2194 struct ftrace_ops *op;
2195 unsigned long ip = rec->ip;
2197 do_for_each_ftrace_op(op, ftrace_ops_list) {
2199 if (!op->trampoline)
2202 if (hash_contains_ip(ip, op->func_hash))
2204 } while_for_each_ftrace_op(op);
2209 static struct ftrace_ops *
2210 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2211 struct ftrace_ops *op)
2213 unsigned long ip = rec->ip;
2215 while_for_each_ftrace_op(op) {
2217 if (!op->trampoline)
2220 if (hash_contains_ip(ip, op->func_hash))
2227 static struct ftrace_ops *
2228 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2230 struct ftrace_ops *op;
2231 unsigned long ip = rec->ip;
2234 * Need to check removed ops first.
2235 * If they are being removed, and this rec has a tramp,
2236 * and this rec is in the ops list, then it would be the
2237 * one with the tramp.
2240 if (hash_contains_ip(ip, &removed_ops->old_hash))
2245 * Need to find the current trampoline for a rec.
2246 * Now, a trampoline is only attached to a rec if there
2247 * was a single 'ops' attached to it. But this can be called
2248 * when we are adding another op to the rec or removing the
2249 * current one. Thus, if the op is being added, we can
2250 * ignore it because it hasn't attached itself to the rec
2253 * If an ops is being modified (hooking to different functions)
2254 * then we don't care about the new functions that are being
2255 * added, just the old ones (that are probably being removed).
2257 * If we are adding an ops to a function that already is using
2258 * a trampoline, it needs to be removed (trampolines are only
2259 * for single ops connected), then an ops that is not being
2260 * modified also needs to be checked.
2262 do_for_each_ftrace_op(op, ftrace_ops_list) {
2264 if (!op->trampoline)
2268 * If the ops is being added, it hasn't gotten to
2269 * the point to be removed from this tree yet.
2271 if (op->flags & FTRACE_OPS_FL_ADDING)
2276 * If the ops is being modified and is in the old
2277 * hash, then it is probably being removed from this
2280 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2281 hash_contains_ip(ip, &op->old_hash))
2284 * If the ops is not being added or modified, and it's
2285 * in its normal filter hash, then this must be the one
2288 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2289 hash_contains_ip(ip, op->func_hash))
2292 } while_for_each_ftrace_op(op);
2297 static struct ftrace_ops *
2298 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2300 struct ftrace_ops *op;
2301 unsigned long ip = rec->ip;
2303 do_for_each_ftrace_op(op, ftrace_ops_list) {
2304 /* pass rec in as regs to have non-NULL val */
2305 if (hash_contains_ip(ip, op->func_hash))
2307 } while_for_each_ftrace_op(op);
2313 * ftrace_get_addr_new - Get the call address to set to
2314 * @rec: The ftrace record descriptor
2316 * If the record has the FTRACE_FL_REGS set, that means that it
2317 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2318 * is not not set, then it wants to convert to the normal callback.
2320 * Returns the address of the trampoline to set to
2322 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2324 struct ftrace_ops *ops;
2326 /* Trampolines take precedence over regs */
2327 if (rec->flags & FTRACE_FL_TRAMP) {
2328 ops = ftrace_find_tramp_ops_new(rec);
2329 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2330 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2331 (void *)rec->ip, (void *)rec->ip, rec->flags);
2332 /* Ftrace is shutting down, return anything */
2333 return (unsigned long)FTRACE_ADDR;
2335 return ops->trampoline;
2338 if (rec->flags & FTRACE_FL_REGS)
2339 return (unsigned long)FTRACE_REGS_ADDR;
2341 return (unsigned long)FTRACE_ADDR;
2345 * ftrace_get_addr_curr - Get the call address that is already there
2346 * @rec: The ftrace record descriptor
2348 * The FTRACE_FL_REGS_EN is set when the record already points to
2349 * a function that saves all the regs. Basically the '_EN' version
2350 * represents the current state of the function.
2352 * Returns the address of the trampoline that is currently being called
2354 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2356 struct ftrace_ops *ops;
2358 /* Trampolines take precedence over regs */
2359 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2360 ops = ftrace_find_tramp_ops_curr(rec);
2361 if (FTRACE_WARN_ON(!ops)) {
2362 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2363 (void *)rec->ip, (void *)rec->ip);
2364 /* Ftrace is shutting down, return anything */
2365 return (unsigned long)FTRACE_ADDR;
2367 return ops->trampoline;
2370 if (rec->flags & FTRACE_FL_REGS_EN)
2371 return (unsigned long)FTRACE_REGS_ADDR;
2373 return (unsigned long)FTRACE_ADDR;
2377 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2379 unsigned long ftrace_old_addr;
2380 unsigned long ftrace_addr;
2383 ftrace_addr = ftrace_get_addr_new(rec);
2385 /* This needs to be done before we call ftrace_update_record */
2386 ftrace_old_addr = ftrace_get_addr_curr(rec);
2388 ret = ftrace_update_record(rec, enable);
2390 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2393 case FTRACE_UPDATE_IGNORE:
2396 case FTRACE_UPDATE_MAKE_CALL:
2397 ftrace_bug_type = FTRACE_BUG_CALL;
2398 return ftrace_make_call(rec, ftrace_addr);
2400 case FTRACE_UPDATE_MAKE_NOP:
2401 ftrace_bug_type = FTRACE_BUG_NOP;
2402 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2404 case FTRACE_UPDATE_MODIFY_CALL:
2405 ftrace_bug_type = FTRACE_BUG_UPDATE;
2406 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2409 return -1; /* unknow ftrace bug */
2412 void __weak ftrace_replace_code(int enable)
2414 struct dyn_ftrace *rec;
2415 struct ftrace_page *pg;
2418 if (unlikely(ftrace_disabled))
2421 do_for_each_ftrace_rec(pg, rec) {
2423 if (rec->flags & FTRACE_FL_DISABLED)
2426 failed = __ftrace_replace_code(rec, enable);
2428 ftrace_bug(failed, rec);
2429 /* Stop processing */
2432 } while_for_each_ftrace_rec();
2435 struct ftrace_rec_iter {
2436 struct ftrace_page *pg;
2441 * ftrace_rec_iter_start, start up iterating over traced functions
2443 * Returns an iterator handle that is used to iterate over all
2444 * the records that represent address locations where functions
2447 * May return NULL if no records are available.
2449 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2452 * We only use a single iterator.
2453 * Protected by the ftrace_lock mutex.
2455 static struct ftrace_rec_iter ftrace_rec_iter;
2456 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2458 iter->pg = ftrace_pages_start;
2461 /* Could have empty pages */
2462 while (iter->pg && !iter->pg->index)
2463 iter->pg = iter->pg->next;
2472 * ftrace_rec_iter_next, get the next record to process.
2473 * @iter: The handle to the iterator.
2475 * Returns the next iterator after the given iterator @iter.
2477 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2481 if (iter->index >= iter->pg->index) {
2482 iter->pg = iter->pg->next;
2485 /* Could have empty pages */
2486 while (iter->pg && !iter->pg->index)
2487 iter->pg = iter->pg->next;
2497 * ftrace_rec_iter_record, get the record at the iterator location
2498 * @iter: The current iterator location
2500 * Returns the record that the current @iter is at.
2502 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2504 return &iter->pg->records[iter->index];
2508 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2512 if (unlikely(ftrace_disabled))
2515 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2517 ftrace_bug_type = FTRACE_BUG_INIT;
2518 ftrace_bug(ret, rec);
2525 * archs can override this function if they must do something
2526 * before the modifying code is performed.
2528 int __weak ftrace_arch_code_modify_prepare(void)
2534 * archs can override this function if they must do something
2535 * after the modifying code is performed.
2537 int __weak ftrace_arch_code_modify_post_process(void)
2542 void ftrace_modify_all_code(int command)
2544 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2548 * If the ftrace_caller calls a ftrace_ops func directly,
2549 * we need to make sure that it only traces functions it
2550 * expects to trace. When doing the switch of functions,
2551 * we need to update to the ftrace_ops_list_func first
2552 * before the transition between old and new calls are set,
2553 * as the ftrace_ops_list_func will check the ops hashes
2554 * to make sure the ops are having the right functions
2558 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2559 if (FTRACE_WARN_ON(err))
2563 if (command & FTRACE_UPDATE_CALLS)
2564 ftrace_replace_code(1);
2565 else if (command & FTRACE_DISABLE_CALLS)
2566 ftrace_replace_code(0);
2568 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2569 function_trace_op = set_function_trace_op;
2571 /* If irqs are disabled, we are in stop machine */
2572 if (!irqs_disabled())
2573 smp_call_function(ftrace_sync_ipi, NULL, 1);
2574 err = ftrace_update_ftrace_func(ftrace_trace_function);
2575 if (FTRACE_WARN_ON(err))
2579 if (command & FTRACE_START_FUNC_RET)
2580 err = ftrace_enable_ftrace_graph_caller();
2581 else if (command & FTRACE_STOP_FUNC_RET)
2582 err = ftrace_disable_ftrace_graph_caller();
2583 FTRACE_WARN_ON(err);
2586 static int __ftrace_modify_code(void *data)
2588 int *command = data;
2590 ftrace_modify_all_code(*command);
2596 * ftrace_run_stop_machine, go back to the stop machine method
2597 * @command: The command to tell ftrace what to do
2599 * If an arch needs to fall back to the stop machine method, the
2600 * it can call this function.
2602 void ftrace_run_stop_machine(int command)
2604 stop_machine(__ftrace_modify_code, &command, NULL);
2608 * arch_ftrace_update_code, modify the code to trace or not trace
2609 * @command: The command that needs to be done
2611 * Archs can override this function if it does not need to
2612 * run stop_machine() to modify code.
2614 void __weak arch_ftrace_update_code(int command)
2616 ftrace_run_stop_machine(command);
2619 static void ftrace_run_update_code(int command)
2623 ret = ftrace_arch_code_modify_prepare();
2624 FTRACE_WARN_ON(ret);
2629 * By default we use stop_machine() to modify the code.
2630 * But archs can do what ever they want as long as it
2631 * is safe. The stop_machine() is the safest, but also
2632 * produces the most overhead.
2634 arch_ftrace_update_code(command);
2636 ret = ftrace_arch_code_modify_post_process();
2637 FTRACE_WARN_ON(ret);
2640 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2641 struct ftrace_ops_hash *old_hash)
2643 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2644 ops->old_hash.filter_hash = old_hash->filter_hash;
2645 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2646 ftrace_run_update_code(command);
2647 ops->old_hash.filter_hash = NULL;
2648 ops->old_hash.notrace_hash = NULL;
2649 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2652 static ftrace_func_t saved_ftrace_func;
2653 static int ftrace_start_up;
2655 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2659 static void per_cpu_ops_free(struct ftrace_ops *ops)
2661 free_percpu(ops->disabled);
2664 static void ftrace_startup_enable(int command)
2666 if (saved_ftrace_func != ftrace_trace_function) {
2667 saved_ftrace_func = ftrace_trace_function;
2668 command |= FTRACE_UPDATE_TRACE_FUNC;
2671 if (!command || !ftrace_enabled)
2674 ftrace_run_update_code(command);
2677 static void ftrace_startup_all(int command)
2679 update_all_ops = true;
2680 ftrace_startup_enable(command);
2681 update_all_ops = false;
2684 static int ftrace_startup(struct ftrace_ops *ops, int command)
2688 if (unlikely(ftrace_disabled))
2691 ret = __register_ftrace_function(ops);
2698 * Note that ftrace probes uses this to start up
2699 * and modify functions it will probe. But we still
2700 * set the ADDING flag for modification, as probes
2701 * do not have trampolines. If they add them in the
2702 * future, then the probes will need to distinguish
2703 * between adding and updating probes.
2705 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2707 ret = ftrace_hash_ipmodify_enable(ops);
2709 /* Rollback registration process */
2710 __unregister_ftrace_function(ops);
2712 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2716 if (ftrace_hash_rec_enable(ops, 1))
2717 command |= FTRACE_UPDATE_CALLS;
2719 ftrace_startup_enable(command);
2721 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2726 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2730 if (unlikely(ftrace_disabled))
2733 ret = __unregister_ftrace_function(ops);
2739 * Just warn in case of unbalance, no need to kill ftrace, it's not
2740 * critical but the ftrace_call callers may be never nopped again after
2741 * further ftrace uses.
2743 WARN_ON_ONCE(ftrace_start_up < 0);
2745 /* Disabling ipmodify never fails */
2746 ftrace_hash_ipmodify_disable(ops);
2748 if (ftrace_hash_rec_disable(ops, 1))
2749 command |= FTRACE_UPDATE_CALLS;
2751 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2753 if (saved_ftrace_func != ftrace_trace_function) {
2754 saved_ftrace_func = ftrace_trace_function;
2755 command |= FTRACE_UPDATE_TRACE_FUNC;
2758 if (!command || !ftrace_enabled) {
2760 * If these are per_cpu ops, they still need their
2761 * per_cpu field freed. Since, function tracing is
2762 * not currently active, we can just free them
2763 * without synchronizing all CPUs.
2765 if (ops->flags & FTRACE_OPS_FL_PER_CPU)
2766 per_cpu_ops_free(ops);
2771 * If the ops uses a trampoline, then it needs to be
2772 * tested first on update.
2774 ops->flags |= FTRACE_OPS_FL_REMOVING;
2777 /* The trampoline logic checks the old hashes */
2778 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2779 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2781 ftrace_run_update_code(command);
2784 * If there's no more ops registered with ftrace, run a
2785 * sanity check to make sure all rec flags are cleared.
2787 if (ftrace_ops_list == &ftrace_list_end) {
2788 struct ftrace_page *pg;
2789 struct dyn_ftrace *rec;
2791 do_for_each_ftrace_rec(pg, rec) {
2792 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2793 pr_warn(" %pS flags:%lx\n",
2794 (void *)rec->ip, rec->flags);
2795 } while_for_each_ftrace_rec();
2798 ops->old_hash.filter_hash = NULL;
2799 ops->old_hash.notrace_hash = NULL;
2802 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2805 * Dynamic ops may be freed, we must make sure that all
2806 * callers are done before leaving this function.
2807 * The same goes for freeing the per_cpu data of the per_cpu
2810 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) {
2812 * We need to do a hard force of sched synchronization.
2813 * This is because we use preempt_disable() to do RCU, but
2814 * the function tracers can be called where RCU is not watching
2815 * (like before user_exit()). We can not rely on the RCU
2816 * infrastructure to do the synchronization, thus we must do it
2819 schedule_on_each_cpu(ftrace_sync);
2822 * When the kernel is preeptive, tasks can be preempted
2823 * while on a ftrace trampoline. Just scheduling a task on
2824 * a CPU is not good enough to flush them. Calling
2825 * synchornize_rcu_tasks() will wait for those tasks to
2826 * execute and either schedule voluntarily or enter user space.
2828 if (IS_ENABLED(CONFIG_PREEMPT))
2829 synchronize_rcu_tasks();
2831 arch_ftrace_trampoline_free(ops);
2833 if (ops->flags & FTRACE_OPS_FL_PER_CPU)
2834 per_cpu_ops_free(ops);
2840 static void ftrace_startup_sysctl(void)
2844 if (unlikely(ftrace_disabled))
2847 /* Force update next time */
2848 saved_ftrace_func = NULL;
2849 /* ftrace_start_up is true if we want ftrace running */
2850 if (ftrace_start_up) {
2851 command = FTRACE_UPDATE_CALLS;
2852 if (ftrace_graph_active)
2853 command |= FTRACE_START_FUNC_RET;
2854 ftrace_startup_enable(command);
2858 static void ftrace_shutdown_sysctl(void)
2862 if (unlikely(ftrace_disabled))
2865 /* ftrace_start_up is true if ftrace is running */
2866 if (ftrace_start_up) {
2867 command = FTRACE_DISABLE_CALLS;
2868 if (ftrace_graph_active)
2869 command |= FTRACE_STOP_FUNC_RET;
2870 ftrace_run_update_code(command);
2874 static u64 ftrace_update_time;
2875 unsigned long ftrace_update_tot_cnt;
2877 static inline int ops_traces_mod(struct ftrace_ops *ops)
2880 * Filter_hash being empty will default to trace module.
2881 * But notrace hash requires a test of individual module functions.
2883 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2884 ftrace_hash_empty(ops->func_hash->notrace_hash);
2888 * Check if the current ops references the record.
2890 * If the ops traces all functions, then it was already accounted for.
2891 * If the ops does not trace the current record function, skip it.
2892 * If the ops ignores the function via notrace filter, skip it.
2895 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2897 /* If ops isn't enabled, ignore it */
2898 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2901 /* If ops traces all then it includes this function */
2902 if (ops_traces_mod(ops))
2905 /* The function must be in the filter */
2906 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2907 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2910 /* If in notrace hash, we ignore it too */
2911 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2917 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2919 struct ftrace_page *pg;
2920 struct dyn_ftrace *p;
2922 unsigned long update_cnt = 0;
2923 unsigned long rec_flags = 0;
2926 start = ftrace_now(raw_smp_processor_id());
2929 * When a module is loaded, this function is called to convert
2930 * the calls to mcount in its text to nops, and also to create
2931 * an entry in the ftrace data. Now, if ftrace is activated
2932 * after this call, but before the module sets its text to
2933 * read-only, the modification of enabling ftrace can fail if
2934 * the read-only is done while ftrace is converting the calls.
2935 * To prevent this, the module's records are set as disabled
2936 * and will be enabled after the call to set the module's text
2940 rec_flags |= FTRACE_FL_DISABLED;
2942 for (pg = new_pgs; pg; pg = pg->next) {
2944 for (i = 0; i < pg->index; i++) {
2946 /* If something went wrong, bail without enabling anything */
2947 if (unlikely(ftrace_disabled))
2950 p = &pg->records[i];
2951 p->flags = rec_flags;
2954 * Do the initial record conversion from mcount jump
2955 * to the NOP instructions.
2957 if (!ftrace_code_disable(mod, p))
2964 stop = ftrace_now(raw_smp_processor_id());
2965 ftrace_update_time = stop - start;
2966 ftrace_update_tot_cnt += update_cnt;
2971 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2976 if (WARN_ON(!count))
2979 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2982 * We want to fill as much as possible. No more than a page
2985 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2989 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2992 /* if we can't allocate this size, try something smaller */
2999 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3008 static struct ftrace_page *
3009 ftrace_allocate_pages(unsigned long num_to_init)
3011 struct ftrace_page *start_pg;
3012 struct ftrace_page *pg;
3019 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3024 * Try to allocate as much as possible in one continues
3025 * location that fills in all of the space. We want to
3026 * waste as little space as possible.
3029 cnt = ftrace_allocate_records(pg, num_to_init);
3037 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3049 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3050 free_pages((unsigned long)pg->records, order);
3051 start_pg = pg->next;
3055 pr_info("ftrace: FAILED to allocate memory for functions\n");
3059 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3061 struct ftrace_iterator {
3064 struct ftrace_page *pg;
3065 struct dyn_ftrace *func;
3066 struct ftrace_func_probe *probe;
3067 struct ftrace_func_entry *probe_entry;
3068 struct trace_parser parser;
3069 struct ftrace_hash *hash;
3070 struct ftrace_ops *ops;
3077 t_probe_next(struct seq_file *m, loff_t *pos)
3079 struct ftrace_iterator *iter = m->private;
3080 struct trace_array *tr = iter->ops->private;
3081 struct list_head *func_probes;
3082 struct ftrace_hash *hash;
3083 struct list_head *next;
3084 struct hlist_node *hnd = NULL;
3085 struct hlist_head *hhd;
3094 func_probes = &tr->func_probes;
3095 if (list_empty(func_probes))
3099 next = func_probes->next;
3100 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3103 if (iter->probe_entry)
3104 hnd = &iter->probe_entry->hlist;
3106 hash = iter->probe->ops.func_hash->filter_hash;
3107 size = 1 << hash->size_bits;
3110 if (iter->pidx >= size) {
3111 if (iter->probe->list.next == func_probes)
3113 next = iter->probe->list.next;
3114 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3115 hash = iter->probe->ops.func_hash->filter_hash;
3116 size = 1 << hash->size_bits;
3120 hhd = &hash->buckets[iter->pidx];
3122 if (hlist_empty(hhd)) {
3138 if (WARN_ON_ONCE(!hnd))
3141 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3146 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3148 struct ftrace_iterator *iter = m->private;
3152 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3155 if (iter->func_pos > *pos)
3159 iter->probe_entry = NULL;
3161 for (l = 0; l <= (*pos - iter->func_pos); ) {
3162 p = t_probe_next(m, &l);
3169 /* Only set this if we have an item */
3170 iter->flags |= FTRACE_ITER_PROBE;
3176 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3178 struct ftrace_func_entry *probe_entry;
3179 struct ftrace_probe_ops *probe_ops;
3180 struct ftrace_func_probe *probe;
3182 probe = iter->probe;
3183 probe_entry = iter->probe_entry;
3185 if (WARN_ON_ONCE(!probe || !probe_entry))
3188 probe_ops = probe->probe_ops;
3190 if (probe_ops->print)
3191 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3193 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3194 (void *)probe_ops->func);
3200 t_func_next(struct seq_file *m, loff_t *pos)
3202 struct ftrace_iterator *iter = m->private;
3203 struct dyn_ftrace *rec = NULL;
3208 if (iter->idx >= iter->pg->index) {
3209 if (iter->pg->next) {
3210 iter->pg = iter->pg->next;
3215 rec = &iter->pg->records[iter->idx++];
3216 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3217 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3219 ((iter->flags & FTRACE_ITER_ENABLED) &&
3220 !(rec->flags & FTRACE_FL_ENABLED))) {
3230 iter->pos = iter->func_pos = *pos;
3237 t_next(struct seq_file *m, void *v, loff_t *pos)
3239 struct ftrace_iterator *iter = m->private;
3240 loff_t l = *pos; /* t_hash_start() must use original pos */
3243 if (unlikely(ftrace_disabled))
3246 if (iter->flags & FTRACE_ITER_PROBE)
3247 return t_probe_next(m, pos);
3249 if (iter->flags & FTRACE_ITER_PRINTALL) {
3250 /* next must increment pos, and t_probe_start does not */
3252 return t_probe_start(m, &l);
3255 ret = t_func_next(m, pos);
3258 return t_probe_start(m, &l);
3263 static void reset_iter_read(struct ftrace_iterator *iter)
3267 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE);
3270 static void *t_start(struct seq_file *m, loff_t *pos)
3272 struct ftrace_iterator *iter = m->private;
3276 mutex_lock(&ftrace_lock);
3278 if (unlikely(ftrace_disabled))
3282 * If an lseek was done, then reset and start from beginning.
3284 if (*pos < iter->pos)
3285 reset_iter_read(iter);
3288 * For set_ftrace_filter reading, if we have the filter
3289 * off, we can short cut and just print out that all
3290 * functions are enabled.
3292 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3293 ftrace_hash_empty(iter->hash)) {
3294 iter->func_pos = 1; /* Account for the message */
3296 return t_probe_start(m, pos);
3297 iter->flags |= FTRACE_ITER_PRINTALL;
3298 /* reset in case of seek/pread */
3299 iter->flags &= ~FTRACE_ITER_PROBE;
3303 if (iter->flags & FTRACE_ITER_PROBE)
3304 return t_probe_start(m, pos);
3307 * Unfortunately, we need to restart at ftrace_pages_start
3308 * every time we let go of the ftrace_mutex. This is because
3309 * those pointers can change without the lock.
3311 iter->pg = ftrace_pages_start;
3313 for (l = 0; l <= *pos; ) {
3314 p = t_func_next(m, &l);
3320 return t_probe_start(m, pos);
3325 static void t_stop(struct seq_file *m, void *p)
3327 mutex_unlock(&ftrace_lock);
3331 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3336 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3337 struct dyn_ftrace *rec)
3341 ptr = arch_ftrace_trampoline_func(ops, rec);
3343 seq_printf(m, " ->%pS", ptr);
3346 static int t_show(struct seq_file *m, void *v)
3348 struct ftrace_iterator *iter = m->private;
3349 struct dyn_ftrace *rec;
3351 if (iter->flags & FTRACE_ITER_PROBE)
3352 return t_probe_show(m, iter);
3354 if (iter->flags & FTRACE_ITER_PRINTALL) {
3355 if (iter->flags & FTRACE_ITER_NOTRACE)
3356 seq_puts(m, "#### no functions disabled ####\n");
3358 seq_puts(m, "#### all functions enabled ####\n");
3367 seq_printf(m, "%ps", (void *)rec->ip);
3368 if (iter->flags & FTRACE_ITER_ENABLED) {
3369 struct ftrace_ops *ops;
3371 seq_printf(m, " (%ld)%s%s",
3372 ftrace_rec_count(rec),
3373 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3374 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3375 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3376 ops = ftrace_find_tramp_ops_any(rec);
3379 seq_printf(m, "\ttramp: %pS (%pS)",
3380 (void *)ops->trampoline,
3382 add_trampoline_func(m, ops, rec);
3383 ops = ftrace_find_tramp_ops_next(rec, ops);
3386 seq_puts(m, "\ttramp: ERROR!");
3388 add_trampoline_func(m, NULL, rec);
3397 static const struct seq_operations show_ftrace_seq_ops = {
3405 ftrace_avail_open(struct inode *inode, struct file *file)
3407 struct ftrace_iterator *iter;
3409 if (unlikely(ftrace_disabled))
3412 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3416 iter->pg = ftrace_pages_start;
3417 iter->ops = &global_ops;
3423 ftrace_enabled_open(struct inode *inode, struct file *file)
3425 struct ftrace_iterator *iter;
3427 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3431 iter->pg = ftrace_pages_start;
3432 iter->flags = FTRACE_ITER_ENABLED;
3433 iter->ops = &global_ops;
3439 * ftrace_regex_open - initialize function tracer filter files
3440 * @ops: The ftrace_ops that hold the hash filters
3441 * @flag: The type of filter to process
3442 * @inode: The inode, usually passed in to your open routine
3443 * @file: The file, usually passed in to your open routine
3445 * ftrace_regex_open() initializes the filter files for the
3446 * @ops. Depending on @flag it may process the filter hash or
3447 * the notrace hash of @ops. With this called from the open
3448 * routine, you can use ftrace_filter_write() for the write
3449 * routine if @flag has FTRACE_ITER_FILTER set, or
3450 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3451 * tracing_lseek() should be used as the lseek routine, and
3452 * release must call ftrace_regex_release().
3455 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3456 struct inode *inode, struct file *file)
3458 struct ftrace_iterator *iter;
3459 struct ftrace_hash *hash;
3462 ftrace_ops_init(ops);
3464 if (unlikely(ftrace_disabled))
3467 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3471 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3479 mutex_lock(&ops->func_hash->regex_lock);
3481 if (flag & FTRACE_ITER_NOTRACE)
3482 hash = ops->func_hash->notrace_hash;
3484 hash = ops->func_hash->filter_hash;
3486 if (file->f_mode & FMODE_WRITE) {
3487 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3489 if (file->f_flags & O_TRUNC)
3490 iter->hash = alloc_ftrace_hash(size_bits);
3492 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3495 trace_parser_put(&iter->parser);
3503 if (file->f_mode & FMODE_READ) {
3504 iter->pg = ftrace_pages_start;
3506 ret = seq_open(file, &show_ftrace_seq_ops);
3508 struct seq_file *m = file->private_data;
3512 free_ftrace_hash(iter->hash);
3513 trace_parser_put(&iter->parser);
3517 file->private_data = iter;
3520 mutex_unlock(&ops->func_hash->regex_lock);
3526 ftrace_filter_open(struct inode *inode, struct file *file)
3528 struct ftrace_ops *ops = inode->i_private;
3530 return ftrace_regex_open(ops,
3531 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3536 ftrace_notrace_open(struct inode *inode, struct file *file)
3538 struct ftrace_ops *ops = inode->i_private;
3540 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3544 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3545 struct ftrace_glob {
3552 * If symbols in an architecture don't correspond exactly to the user-visible
3553 * name of what they represent, it is possible to define this function to
3554 * perform the necessary adjustments.
3556 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3561 static int ftrace_match(char *str, struct ftrace_glob *g)
3566 str = arch_ftrace_match_adjust(str, g->search);
3570 if (strcmp(str, g->search) == 0)
3573 case MATCH_FRONT_ONLY:
3574 if (strncmp(str, g->search, g->len) == 0)
3577 case MATCH_MIDDLE_ONLY:
3578 if (strstr(str, g->search))
3581 case MATCH_END_ONLY:
3583 if (slen >= g->len &&
3584 memcmp(str + slen - g->len, g->search, g->len) == 0)
3588 if (glob_match(g->search, str))
3597 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3599 struct ftrace_func_entry *entry;
3602 entry = ftrace_lookup_ip(hash, rec->ip);
3604 /* Do nothing if it doesn't exist */
3608 free_hash_entry(hash, entry);
3610 /* Do nothing if it exists */
3614 ret = add_hash_entry(hash, rec->ip);
3620 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3621 struct ftrace_glob *mod_g, int exclude_mod)
3623 char str[KSYM_SYMBOL_LEN];
3626 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3629 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3631 /* blank module name to match all modules */
3633 /* blank module globbing: modname xor exclude_mod */
3634 if (!exclude_mod != !modname)
3640 * exclude_mod is set to trace everything but the given
3641 * module. If it is set and the module matches, then
3642 * return 0. If it is not set, and the module doesn't match
3643 * also return 0. Otherwise, check the function to see if
3646 if (!mod_matches == !exclude_mod)
3649 /* blank search means to match all funcs in the mod */
3654 return ftrace_match(str, func_g);
3658 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3660 struct ftrace_page *pg;
3661 struct dyn_ftrace *rec;
3662 struct ftrace_glob func_g = { .type = MATCH_FULL };
3663 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3664 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3665 int exclude_mod = 0;
3671 func_g.type = filter_parse_regex(func, len, &func_g.search,
3673 func_g.len = strlen(func_g.search);
3677 mod_g.type = filter_parse_regex(mod, strlen(mod),
3678 &mod_g.search, &exclude_mod);
3679 mod_g.len = strlen(mod_g.search);
3682 mutex_lock(&ftrace_lock);
3684 if (unlikely(ftrace_disabled))
3687 do_for_each_ftrace_rec(pg, rec) {
3689 if (rec->flags & FTRACE_FL_DISABLED)
3692 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3693 ret = enter_record(hash, rec, clear_filter);
3700 } while_for_each_ftrace_rec();
3702 mutex_unlock(&ftrace_lock);
3708 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3710 return match_records(hash, buff, len, NULL);
3713 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3714 struct ftrace_ops_hash *old_hash)
3716 struct ftrace_ops *op;
3718 if (!ftrace_enabled)
3721 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3722 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3727 * If this is the shared global_ops filter, then we need to
3728 * check if there is another ops that shares it, is enabled.
3729 * If so, we still need to run the modify code.
3731 if (ops->func_hash != &global_ops.local_hash)
3734 do_for_each_ftrace_op(op, ftrace_ops_list) {
3735 if (op->func_hash == &global_ops.local_hash &&
3736 op->flags & FTRACE_OPS_FL_ENABLED) {
3737 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3738 /* Only need to do this once */
3741 } while_for_each_ftrace_op(op);
3744 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3745 struct ftrace_hash **orig_hash,
3746 struct ftrace_hash *hash,
3749 struct ftrace_ops_hash old_hash_ops;
3750 struct ftrace_hash *old_hash;
3753 old_hash = *orig_hash;
3754 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3755 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3756 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3758 ftrace_ops_update_code(ops, &old_hash_ops);
3759 free_ftrace_hash_rcu(old_hash);
3765 * We register the module command as a template to show others how
3766 * to register the a command as well.
3770 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
3771 char *func, char *cmd, char *module, int enable)
3776 * cmd == 'mod' because we only registered this func
3777 * for the 'mod' ftrace_func_command.
3778 * But if you register one func with multiple commands,
3779 * you can tell which command was used by the cmd
3782 ret = match_records(hash, func, strlen(func), module);
3790 static struct ftrace_func_command ftrace_mod_cmd = {
3792 .func = ftrace_mod_callback,
3795 static int __init ftrace_mod_cmd_init(void)
3797 return register_ftrace_command(&ftrace_mod_cmd);
3799 core_initcall(ftrace_mod_cmd_init);
3801 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
3802 struct ftrace_ops *op, struct pt_regs *pt_regs)
3804 struct ftrace_probe_ops *probe_ops;
3805 struct ftrace_func_probe *probe;
3807 probe = container_of(op, struct ftrace_func_probe, ops);
3808 probe_ops = probe->probe_ops;
3811 * Disable preemption for these calls to prevent a RCU grace
3812 * period. This syncs the hash iteration and freeing of items
3813 * on the hash. rcu_read_lock is too dangerous here.
3815 preempt_disable_notrace();
3816 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
3817 preempt_enable_notrace();
3820 struct ftrace_func_map {
3821 struct ftrace_func_entry entry;
3825 struct ftrace_func_mapper {
3826 struct ftrace_hash hash;
3830 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
3832 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
3834 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
3836 struct ftrace_hash *hash;
3839 * The mapper is simply a ftrace_hash, but since the entries
3840 * in the hash are not ftrace_func_entry type, we define it
3841 * as a separate structure.
3843 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
3844 return (struct ftrace_func_mapper *)hash;
3848 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
3849 * @mapper: The mapper that has the ip maps
3850 * @ip: the instruction pointer to find the data for
3852 * Returns the data mapped to @ip if found otherwise NULL. The return
3853 * is actually the address of the mapper data pointer. The address is
3854 * returned for use cases where the data is no bigger than a long, and
3855 * the user can use the data pointer as its data instead of having to
3856 * allocate more memory for the reference.
3858 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
3861 struct ftrace_func_entry *entry;
3862 struct ftrace_func_map *map;
3864 entry = ftrace_lookup_ip(&mapper->hash, ip);
3868 map = (struct ftrace_func_map *)entry;
3873 * ftrace_func_mapper_add_ip - Map some data to an ip
3874 * @mapper: The mapper that has the ip maps
3875 * @ip: The instruction pointer address to map @data to
3876 * @data: The data to map to @ip
3878 * Returns 0 on succes otherwise an error.
3880 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
3881 unsigned long ip, void *data)
3883 struct ftrace_func_entry *entry;
3884 struct ftrace_func_map *map;
3886 entry = ftrace_lookup_ip(&mapper->hash, ip);
3890 map = kmalloc(sizeof(*map), GFP_KERNEL);
3897 __add_hash_entry(&mapper->hash, &map->entry);
3903 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
3904 * @mapper: The mapper that has the ip maps
3905 * @ip: The instruction pointer address to remove the data from
3907 * Returns the data if it is found, otherwise NULL.
3908 * Note, if the data pointer is used as the data itself, (see
3909 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
3910 * if the data pointer was set to zero.
3912 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
3915 struct ftrace_func_entry *entry;
3916 struct ftrace_func_map *map;
3919 entry = ftrace_lookup_ip(&mapper->hash, ip);
3923 map = (struct ftrace_func_map *)entry;
3926 remove_hash_entry(&mapper->hash, entry);
3933 * free_ftrace_func_mapper - free a mapping of ips and data
3934 * @mapper: The mapper that has the ip maps
3935 * @free_func: A function to be called on each data item.
3937 * This is used to free the function mapper. The @free_func is optional
3938 * and can be used if the data needs to be freed as well.
3940 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
3941 ftrace_mapper_func free_func)
3943 struct ftrace_func_entry *entry;
3944 struct ftrace_func_map *map;
3945 struct hlist_head *hhd;
3946 int size = 1 << mapper->hash.size_bits;
3949 if (free_func && mapper->hash.count) {
3950 for (i = 0; i < size; i++) {
3951 hhd = &mapper->hash.buckets[i];
3952 hlist_for_each_entry(entry, hhd, hlist) {
3953 map = (struct ftrace_func_map *)entry;
3958 free_ftrace_hash(&mapper->hash);
3961 static void release_probe(struct ftrace_func_probe *probe)
3963 struct ftrace_probe_ops *probe_ops;
3965 mutex_lock(&ftrace_lock);
3967 WARN_ON(probe->ref <= 0);
3969 /* Subtract the ref that was used to protect this instance */
3973 probe_ops = probe->probe_ops;
3975 * Sending zero as ip tells probe_ops to free
3976 * the probe->data itself
3978 if (probe_ops->free)
3979 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
3980 list_del(&probe->list);
3983 mutex_unlock(&ftrace_lock);
3986 static void acquire_probe_locked(struct ftrace_func_probe *probe)
3989 * Add one ref to keep it from being freed when releasing the
3990 * ftrace_lock mutex.
3996 register_ftrace_function_probe(char *glob, struct trace_array *tr,
3997 struct ftrace_probe_ops *probe_ops,
4000 struct ftrace_func_entry *entry;
4001 struct ftrace_func_probe *probe;
4002 struct ftrace_hash **orig_hash;
4003 struct ftrace_hash *old_hash;
4004 struct ftrace_hash *hash;
4013 /* We do not support '!' for function probes */
4014 if (WARN_ON(glob[0] == '!'))
4018 mutex_lock(&ftrace_lock);
4019 /* Check if the probe_ops is already registered */
4020 list_for_each_entry(probe, &tr->func_probes, list) {
4021 if (probe->probe_ops == probe_ops)
4024 if (&probe->list == &tr->func_probes) {
4025 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4027 mutex_unlock(&ftrace_lock);
4030 probe->probe_ops = probe_ops;
4031 probe->ops.func = function_trace_probe_call;
4033 ftrace_ops_init(&probe->ops);
4034 list_add(&probe->list, &tr->func_probes);
4037 acquire_probe_locked(probe);
4039 mutex_unlock(&ftrace_lock);
4041 mutex_lock(&probe->ops.func_hash->regex_lock);
4043 orig_hash = &probe->ops.func_hash->filter_hash;
4044 old_hash = *orig_hash;
4045 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4047 ret = ftrace_match_records(hash, glob, strlen(glob));
4049 /* Nothing found? */
4056 size = 1 << hash->size_bits;
4057 for (i = 0; i < size; i++) {
4058 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4059 if (ftrace_lookup_ip(old_hash, entry->ip))
4062 * The caller might want to do something special
4063 * for each function we find. We call the callback
4064 * to give the caller an opportunity to do so.
4066 if (probe_ops->init) {
4067 ret = probe_ops->init(probe_ops, tr,
4071 if (probe_ops->free && count)
4072 probe_ops->free(probe_ops, tr,
4082 mutex_lock(&ftrace_lock);
4085 /* Nothing was added? */
4090 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4095 /* One ref for each new function traced */
4096 probe->ref += count;
4098 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4099 ret = ftrace_startup(&probe->ops, 0);
4102 mutex_unlock(&ftrace_lock);
4107 mutex_unlock(&probe->ops.func_hash->regex_lock);
4108 free_ftrace_hash(hash);
4110 release_probe(probe);
4115 if (!probe_ops->free || !count)
4118 /* Failed to do the move, need to call the free functions */
4119 for (i = 0; i < size; i++) {
4120 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4121 if (ftrace_lookup_ip(old_hash, entry->ip))
4123 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4130 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4131 struct ftrace_probe_ops *probe_ops)
4133 struct ftrace_ops_hash old_hash_ops;
4134 struct ftrace_func_entry *entry;
4135 struct ftrace_func_probe *probe;
4136 struct ftrace_glob func_g;
4137 struct ftrace_hash **orig_hash;
4138 struct ftrace_hash *old_hash;
4139 struct ftrace_hash *hash = NULL;
4140 struct hlist_node *tmp;
4141 struct hlist_head hhd;
4142 char str[KSYM_SYMBOL_LEN];
4144 int i, ret = -ENODEV;
4147 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4148 func_g.search = NULL;
4152 func_g.type = filter_parse_regex(glob, strlen(glob),
4153 &func_g.search, ¬);
4154 func_g.len = strlen(func_g.search);
4155 func_g.search = glob;
4157 /* we do not support '!' for function probes */
4162 mutex_lock(&ftrace_lock);
4163 /* Check if the probe_ops is already registered */
4164 list_for_each_entry(probe, &tr->func_probes, list) {
4165 if (probe->probe_ops == probe_ops)
4168 if (&probe->list == &tr->func_probes)
4169 goto err_unlock_ftrace;
4172 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4173 goto err_unlock_ftrace;
4175 acquire_probe_locked(probe);
4177 mutex_unlock(&ftrace_lock);
4179 mutex_lock(&probe->ops.func_hash->regex_lock);
4181 orig_hash = &probe->ops.func_hash->filter_hash;
4182 old_hash = *orig_hash;
4184 if (ftrace_hash_empty(old_hash))
4187 old_hash_ops.filter_hash = old_hash;
4188 /* Probes only have filters */
4189 old_hash_ops.notrace_hash = NULL;
4192 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4196 INIT_HLIST_HEAD(&hhd);
4198 size = 1 << hash->size_bits;
4199 for (i = 0; i < size; i++) {
4200 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4202 if (func_g.search) {
4203 kallsyms_lookup(entry->ip, NULL, NULL,
4205 if (!ftrace_match(str, &func_g))
4209 remove_hash_entry(hash, entry);
4210 hlist_add_head(&entry->hlist, &hhd);
4214 /* Nothing found? */
4220 mutex_lock(&ftrace_lock);
4222 WARN_ON(probe->ref < count);
4224 probe->ref -= count;
4226 if (ftrace_hash_empty(hash))
4227 ftrace_shutdown(&probe->ops, 0);
4229 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4232 /* still need to update the function call sites */
4233 if (ftrace_enabled && !ftrace_hash_empty(hash))
4234 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4236 synchronize_sched();
4238 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4239 hlist_del(&entry->hlist);
4240 if (probe_ops->free)
4241 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4244 mutex_unlock(&ftrace_lock);
4247 mutex_unlock(&probe->ops.func_hash->regex_lock);
4248 free_ftrace_hash(hash);
4250 release_probe(probe);
4255 mutex_unlock(&ftrace_lock);
4259 void clear_ftrace_function_probes(struct trace_array *tr)
4261 struct ftrace_func_probe *probe, *n;
4263 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4264 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4267 static LIST_HEAD(ftrace_commands);
4268 static DEFINE_MUTEX(ftrace_cmd_mutex);
4271 * Currently we only register ftrace commands from __init, so mark this
4274 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4276 struct ftrace_func_command *p;
4279 mutex_lock(&ftrace_cmd_mutex);
4280 list_for_each_entry(p, &ftrace_commands, list) {
4281 if (strcmp(cmd->name, p->name) == 0) {
4286 list_add(&cmd->list, &ftrace_commands);
4288 mutex_unlock(&ftrace_cmd_mutex);
4294 * Currently we only unregister ftrace commands from __init, so mark
4297 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4299 struct ftrace_func_command *p, *n;
4302 mutex_lock(&ftrace_cmd_mutex);
4303 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4304 if (strcmp(cmd->name, p->name) == 0) {
4306 list_del_init(&p->list);
4311 mutex_unlock(&ftrace_cmd_mutex);
4316 static int ftrace_process_regex(struct ftrace_iterator *iter,
4317 char *buff, int len, int enable)
4319 struct ftrace_hash *hash = iter->hash;
4320 struct trace_array *tr = iter->ops->private;
4321 char *func, *command, *next = buff;
4322 struct ftrace_func_command *p;
4325 func = strsep(&next, ":");
4328 ret = ftrace_match_records(hash, func, len);
4338 command = strsep(&next, ":");
4340 if (WARN_ON_ONCE(!tr))
4343 mutex_lock(&ftrace_cmd_mutex);
4344 list_for_each_entry(p, &ftrace_commands, list) {
4345 if (strcmp(p->name, command) == 0) {
4346 ret = p->func(tr, hash, func, command, next, enable);
4351 mutex_unlock(&ftrace_cmd_mutex);
4357 ftrace_regex_write(struct file *file, const char __user *ubuf,
4358 size_t cnt, loff_t *ppos, int enable)
4360 struct ftrace_iterator *iter;
4361 struct trace_parser *parser;
4367 if (file->f_mode & FMODE_READ) {
4368 struct seq_file *m = file->private_data;
4371 iter = file->private_data;
4373 if (unlikely(ftrace_disabled))
4376 /* iter->hash is a local copy, so we don't need regex_lock */
4378 parser = &iter->parser;
4379 read = trace_get_user(parser, ubuf, cnt, ppos);
4381 if (read >= 0 && trace_parser_loaded(parser) &&
4382 !trace_parser_cont(parser)) {
4383 ret = ftrace_process_regex(iter, parser->buffer,
4384 parser->idx, enable);
4385 trace_parser_clear(parser);
4396 ftrace_filter_write(struct file *file, const char __user *ubuf,
4397 size_t cnt, loff_t *ppos)
4399 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4403 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4404 size_t cnt, loff_t *ppos)
4406 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4410 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4412 struct ftrace_func_entry *entry;
4414 if (!ftrace_location(ip))
4418 entry = ftrace_lookup_ip(hash, ip);
4421 free_hash_entry(hash, entry);
4425 return add_hash_entry(hash, ip);
4429 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4430 unsigned long ip, int remove, int reset, int enable)
4432 struct ftrace_hash **orig_hash;
4433 struct ftrace_hash *hash;
4436 if (unlikely(ftrace_disabled))
4439 mutex_lock(&ops->func_hash->regex_lock);
4442 orig_hash = &ops->func_hash->filter_hash;
4444 orig_hash = &ops->func_hash->notrace_hash;
4447 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4449 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4453 goto out_regex_unlock;
4456 if (buf && !ftrace_match_records(hash, buf, len)) {
4458 goto out_regex_unlock;
4461 ret = ftrace_match_addr(hash, ip, remove);
4463 goto out_regex_unlock;
4466 mutex_lock(&ftrace_lock);
4467 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4468 mutex_unlock(&ftrace_lock);
4471 mutex_unlock(&ops->func_hash->regex_lock);
4473 free_ftrace_hash(hash);
4478 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4479 int reset, int enable)
4481 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4485 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4486 * @ops - the ops to set the filter with
4487 * @ip - the address to add to or remove from the filter.
4488 * @remove - non zero to remove the ip from the filter
4489 * @reset - non zero to reset all filters before applying this filter.
4491 * Filters denote which functions should be enabled when tracing is enabled
4492 * If @ip is NULL, it failes to update filter.
4494 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4495 int remove, int reset)
4497 ftrace_ops_init(ops);
4498 return ftrace_set_addr(ops, ip, remove, reset, 1);
4500 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4503 * ftrace_ops_set_global_filter - setup ops to use global filters
4504 * @ops - the ops which will use the global filters
4506 * ftrace users who need global function trace filtering should call this.
4507 * It can set the global filter only if ops were not initialized before.
4509 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4511 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4514 ftrace_ops_init(ops);
4515 ops->func_hash = &global_ops.local_hash;
4517 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4520 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4521 int reset, int enable)
4523 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4527 * ftrace_set_filter - set a function to filter on in ftrace
4528 * @ops - the ops to set the filter with
4529 * @buf - the string that holds the function filter text.
4530 * @len - the length of the string.
4531 * @reset - non zero to reset all filters before applying this filter.
4533 * Filters denote which functions should be enabled when tracing is enabled.
4534 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4536 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4539 ftrace_ops_init(ops);
4540 return ftrace_set_regex(ops, buf, len, reset, 1);
4542 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4545 * ftrace_set_notrace - set a function to not trace in ftrace
4546 * @ops - the ops to set the notrace filter with
4547 * @buf - the string that holds the function notrace text.
4548 * @len - the length of the string.
4549 * @reset - non zero to reset all filters before applying this filter.
4551 * Notrace Filters denote which functions should not be enabled when tracing
4552 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4555 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4558 ftrace_ops_init(ops);
4559 return ftrace_set_regex(ops, buf, len, reset, 0);
4561 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4563 * ftrace_set_global_filter - set a function to filter on with global tracers
4564 * @buf - the string that holds the function filter text.
4565 * @len - the length of the string.
4566 * @reset - non zero to reset all filters before applying this filter.
4568 * Filters denote which functions should be enabled when tracing is enabled.
4569 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4571 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4573 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4575 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4578 * ftrace_set_global_notrace - set a function to not trace with global tracers
4579 * @buf - the string that holds the function notrace text.
4580 * @len - the length of the string.
4581 * @reset - non zero to reset all filters before applying this filter.
4583 * Notrace Filters denote which functions should not be enabled when tracing
4584 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4587 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4589 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4591 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4594 * command line interface to allow users to set filters on boot up.
4596 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4597 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4598 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4600 /* Used by function selftest to not test if filter is set */
4601 bool ftrace_filter_param __initdata;
4603 static int __init set_ftrace_notrace(char *str)
4605 ftrace_filter_param = true;
4606 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4609 __setup("ftrace_notrace=", set_ftrace_notrace);
4611 static int __init set_ftrace_filter(char *str)
4613 ftrace_filter_param = true;
4614 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4617 __setup("ftrace_filter=", set_ftrace_filter);
4619 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4620 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4621 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4622 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4624 static unsigned long save_global_trampoline;
4625 static unsigned long save_global_flags;
4627 static int __init set_graph_function(char *str)
4629 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4632 __setup("ftrace_graph_filter=", set_graph_function);
4634 static int __init set_graph_notrace_function(char *str)
4636 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4639 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4641 static int __init set_graph_max_depth_function(char *str)
4645 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4648 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4650 static void __init set_ftrace_early_graph(char *buf, int enable)
4654 struct ftrace_hash *hash;
4656 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4661 func = strsep(&buf, ",");
4662 /* we allow only one expression at a time */
4663 ret = ftrace_graph_set_hash(hash, func);
4665 printk(KERN_DEBUG "ftrace: function %s not "
4666 "traceable\n", func);
4670 ftrace_graph_hash = hash;
4672 ftrace_graph_notrace_hash = hash;
4674 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4677 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4681 ftrace_ops_init(ops);
4684 func = strsep(&buf, ",");
4685 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4689 static void __init set_ftrace_early_filters(void)
4691 if (ftrace_filter_buf[0])
4692 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4693 if (ftrace_notrace_buf[0])
4694 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4695 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4696 if (ftrace_graph_buf[0])
4697 set_ftrace_early_graph(ftrace_graph_buf, 1);
4698 if (ftrace_graph_notrace_buf[0])
4699 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4700 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4703 int ftrace_regex_release(struct inode *inode, struct file *file)
4705 struct seq_file *m = (struct seq_file *)file->private_data;
4706 struct ftrace_iterator *iter;
4707 struct ftrace_hash **orig_hash;
4708 struct trace_parser *parser;
4712 if (file->f_mode & FMODE_READ) {
4714 seq_release(inode, file);
4716 iter = file->private_data;
4718 parser = &iter->parser;
4719 if (trace_parser_loaded(parser)) {
4720 parser->buffer[parser->idx] = 0;
4721 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
4724 trace_parser_put(parser);
4726 mutex_lock(&iter->ops->func_hash->regex_lock);
4728 if (file->f_mode & FMODE_WRITE) {
4729 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
4732 orig_hash = &iter->ops->func_hash->filter_hash;
4734 orig_hash = &iter->ops->func_hash->notrace_hash;
4736 mutex_lock(&ftrace_lock);
4737 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
4738 iter->hash, filter_hash);
4739 mutex_unlock(&ftrace_lock);
4741 /* For read only, the hash is the ops hash */
4745 mutex_unlock(&iter->ops->func_hash->regex_lock);
4746 free_ftrace_hash(iter->hash);
4752 static const struct file_operations ftrace_avail_fops = {
4753 .open = ftrace_avail_open,
4755 .llseek = seq_lseek,
4756 .release = seq_release_private,
4759 static const struct file_operations ftrace_enabled_fops = {
4760 .open = ftrace_enabled_open,
4762 .llseek = seq_lseek,
4763 .release = seq_release_private,
4766 static const struct file_operations ftrace_filter_fops = {
4767 .open = ftrace_filter_open,
4769 .write = ftrace_filter_write,
4770 .llseek = tracing_lseek,
4771 .release = ftrace_regex_release,
4774 static const struct file_operations ftrace_notrace_fops = {
4775 .open = ftrace_notrace_open,
4777 .write = ftrace_notrace_write,
4778 .llseek = tracing_lseek,
4779 .release = ftrace_regex_release,
4782 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4784 static DEFINE_MUTEX(graph_lock);
4786 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
4787 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
4789 enum graph_filter_type {
4790 GRAPH_FILTER_NOTRACE = 0,
4791 GRAPH_FILTER_FUNCTION,
4794 #define FTRACE_GRAPH_EMPTY ((void *)1)
4796 struct ftrace_graph_data {
4797 struct ftrace_hash *hash;
4798 struct ftrace_func_entry *entry;
4799 int idx; /* for hash table iteration */
4800 enum graph_filter_type type;
4801 struct ftrace_hash *new_hash;
4802 const struct seq_operations *seq_ops;
4803 struct trace_parser parser;
4807 __g_next(struct seq_file *m, loff_t *pos)
4809 struct ftrace_graph_data *fgd = m->private;
4810 struct ftrace_func_entry *entry = fgd->entry;
4811 struct hlist_head *head;
4812 int i, idx = fgd->idx;
4814 if (*pos >= fgd->hash->count)
4818 hlist_for_each_entry_continue(entry, hlist) {
4826 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
4827 head = &fgd->hash->buckets[i];
4828 hlist_for_each_entry(entry, head, hlist) {
4838 g_next(struct seq_file *m, void *v, loff_t *pos)
4841 return __g_next(m, pos);
4844 static void *g_start(struct seq_file *m, loff_t *pos)
4846 struct ftrace_graph_data *fgd = m->private;
4848 mutex_lock(&graph_lock);
4850 if (fgd->type == GRAPH_FILTER_FUNCTION)
4851 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
4852 lockdep_is_held(&graph_lock));
4854 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
4855 lockdep_is_held(&graph_lock));
4857 /* Nothing, tell g_show to print all functions are enabled */
4858 if (ftrace_hash_empty(fgd->hash) && !*pos)
4859 return FTRACE_GRAPH_EMPTY;
4863 return __g_next(m, pos);
4866 static void g_stop(struct seq_file *m, void *p)
4868 mutex_unlock(&graph_lock);
4871 static int g_show(struct seq_file *m, void *v)
4873 struct ftrace_func_entry *entry = v;
4878 if (entry == FTRACE_GRAPH_EMPTY) {
4879 struct ftrace_graph_data *fgd = m->private;
4881 if (fgd->type == GRAPH_FILTER_FUNCTION)
4882 seq_puts(m, "#### all functions enabled ####\n");
4884 seq_puts(m, "#### no functions disabled ####\n");
4888 seq_printf(m, "%ps\n", (void *)entry->ip);
4893 static const struct seq_operations ftrace_graph_seq_ops = {
4901 __ftrace_graph_open(struct inode *inode, struct file *file,
4902 struct ftrace_graph_data *fgd)
4905 struct ftrace_hash *new_hash = NULL;
4907 if (file->f_mode & FMODE_WRITE) {
4908 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
4910 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
4913 if (file->f_flags & O_TRUNC)
4914 new_hash = alloc_ftrace_hash(size_bits);
4916 new_hash = alloc_and_copy_ftrace_hash(size_bits,
4924 if (file->f_mode & FMODE_READ) {
4925 ret = seq_open(file, &ftrace_graph_seq_ops);
4927 struct seq_file *m = file->private_data;
4931 free_ftrace_hash(new_hash);
4935 file->private_data = fgd;
4938 if (ret < 0 && file->f_mode & FMODE_WRITE)
4939 trace_parser_put(&fgd->parser);
4941 fgd->new_hash = new_hash;
4944 * All uses of fgd->hash must be taken with the graph_lock
4945 * held. The graph_lock is going to be released, so force
4946 * fgd->hash to be reinitialized when it is taken again.
4954 ftrace_graph_open(struct inode *inode, struct file *file)
4956 struct ftrace_graph_data *fgd;
4959 if (unlikely(ftrace_disabled))
4962 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4966 mutex_lock(&graph_lock);
4968 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
4969 lockdep_is_held(&graph_lock));
4970 fgd->type = GRAPH_FILTER_FUNCTION;
4971 fgd->seq_ops = &ftrace_graph_seq_ops;
4973 ret = __ftrace_graph_open(inode, file, fgd);
4977 mutex_unlock(&graph_lock);
4982 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
4984 struct ftrace_graph_data *fgd;
4987 if (unlikely(ftrace_disabled))
4990 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4994 mutex_lock(&graph_lock);
4996 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
4997 lockdep_is_held(&graph_lock));
4998 fgd->type = GRAPH_FILTER_NOTRACE;
4999 fgd->seq_ops = &ftrace_graph_seq_ops;
5001 ret = __ftrace_graph_open(inode, file, fgd);
5005 mutex_unlock(&graph_lock);
5010 ftrace_graph_release(struct inode *inode, struct file *file)
5012 struct ftrace_graph_data *fgd;
5013 struct ftrace_hash *old_hash, *new_hash;
5014 struct trace_parser *parser;
5017 if (file->f_mode & FMODE_READ) {
5018 struct seq_file *m = file->private_data;
5021 seq_release(inode, file);
5023 fgd = file->private_data;
5027 if (file->f_mode & FMODE_WRITE) {
5029 parser = &fgd->parser;
5031 if (trace_parser_loaded((parser))) {
5032 parser->buffer[parser->idx] = 0;
5033 ret = ftrace_graph_set_hash(fgd->new_hash,
5037 trace_parser_put(parser);
5039 new_hash = __ftrace_hash_move(fgd->new_hash);
5045 mutex_lock(&graph_lock);
5047 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5048 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5049 lockdep_is_held(&graph_lock));
5050 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5052 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5053 lockdep_is_held(&graph_lock));
5054 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5057 mutex_unlock(&graph_lock);
5059 /* Wait till all users are no longer using the old hash */
5060 synchronize_sched();
5062 free_ftrace_hash(old_hash);
5066 kfree(fgd->new_hash);
5073 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5075 struct ftrace_glob func_g;
5076 struct dyn_ftrace *rec;
5077 struct ftrace_page *pg;
5078 struct ftrace_func_entry *entry;
5083 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5084 &func_g.search, ¬);
5086 func_g.len = strlen(func_g.search);
5088 mutex_lock(&ftrace_lock);
5090 if (unlikely(ftrace_disabled)) {
5091 mutex_unlock(&ftrace_lock);
5095 do_for_each_ftrace_rec(pg, rec) {
5097 if (rec->flags & FTRACE_FL_DISABLED)
5100 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5101 entry = ftrace_lookup_ip(hash, rec->ip);
5108 if (add_hash_entry(hash, rec->ip) < 0)
5112 free_hash_entry(hash, entry);
5117 } while_for_each_ftrace_rec();
5119 mutex_unlock(&ftrace_lock);
5128 ftrace_graph_write(struct file *file, const char __user *ubuf,
5129 size_t cnt, loff_t *ppos)
5131 ssize_t read, ret = 0;
5132 struct ftrace_graph_data *fgd = file->private_data;
5133 struct trace_parser *parser;
5138 /* Read mode uses seq functions */
5139 if (file->f_mode & FMODE_READ) {
5140 struct seq_file *m = file->private_data;
5144 parser = &fgd->parser;
5146 read = trace_get_user(parser, ubuf, cnt, ppos);
5148 if (read >= 0 && trace_parser_loaded(parser) &&
5149 !trace_parser_cont(parser)) {
5151 ret = ftrace_graph_set_hash(fgd->new_hash,
5153 trace_parser_clear(parser);
5162 static const struct file_operations ftrace_graph_fops = {
5163 .open = ftrace_graph_open,
5165 .write = ftrace_graph_write,
5166 .llseek = tracing_lseek,
5167 .release = ftrace_graph_release,
5170 static const struct file_operations ftrace_graph_notrace_fops = {
5171 .open = ftrace_graph_notrace_open,
5173 .write = ftrace_graph_write,
5174 .llseek = tracing_lseek,
5175 .release = ftrace_graph_release,
5177 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5179 void ftrace_create_filter_files(struct ftrace_ops *ops,
5180 struct dentry *parent)
5183 trace_create_file("set_ftrace_filter", 0644, parent,
5184 ops, &ftrace_filter_fops);
5186 trace_create_file("set_ftrace_notrace", 0644, parent,
5187 ops, &ftrace_notrace_fops);
5191 * The name "destroy_filter_files" is really a misnomer. Although
5192 * in the future, it may actualy delete the files, but this is
5193 * really intended to make sure the ops passed in are disabled
5194 * and that when this function returns, the caller is free to
5197 * The "destroy" name is only to match the "create" name that this
5198 * should be paired with.
5200 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5202 mutex_lock(&ftrace_lock);
5203 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5204 ftrace_shutdown(ops, 0);
5205 ops->flags |= FTRACE_OPS_FL_DELETED;
5206 mutex_unlock(&ftrace_lock);
5209 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5212 trace_create_file("available_filter_functions", 0444,
5213 d_tracer, NULL, &ftrace_avail_fops);
5215 trace_create_file("enabled_functions", 0444,
5216 d_tracer, NULL, &ftrace_enabled_fops);
5218 ftrace_create_filter_files(&global_ops, d_tracer);
5220 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5221 trace_create_file("set_graph_function", 0444, d_tracer,
5223 &ftrace_graph_fops);
5224 trace_create_file("set_graph_notrace", 0444, d_tracer,
5226 &ftrace_graph_notrace_fops);
5227 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5232 static int ftrace_cmp_ips(const void *a, const void *b)
5234 const unsigned long *ipa = a;
5235 const unsigned long *ipb = b;
5244 static int ftrace_process_locs(struct module *mod,
5245 unsigned long *start,
5248 struct ftrace_page *start_pg;
5249 struct ftrace_page *pg;
5250 struct dyn_ftrace *rec;
5251 unsigned long count;
5254 unsigned long flags = 0; /* Shut up gcc */
5257 count = end - start;
5262 sort(start, count, sizeof(*start),
5263 ftrace_cmp_ips, NULL);
5265 start_pg = ftrace_allocate_pages(count);
5269 mutex_lock(&ftrace_lock);
5272 * Core and each module needs their own pages, as
5273 * modules will free them when they are removed.
5274 * Force a new page to be allocated for modules.
5277 WARN_ON(ftrace_pages || ftrace_pages_start);
5278 /* First initialization */
5279 ftrace_pages = ftrace_pages_start = start_pg;
5284 if (WARN_ON(ftrace_pages->next)) {
5285 /* Hmm, we have free pages? */
5286 while (ftrace_pages->next)
5287 ftrace_pages = ftrace_pages->next;
5290 ftrace_pages->next = start_pg;
5296 addr = ftrace_call_adjust(*p++);
5298 * Some architecture linkers will pad between
5299 * the different mcount_loc sections of different
5300 * object files to satisfy alignments.
5301 * Skip any NULL pointers.
5306 if (pg->index == pg->size) {
5307 /* We should have allocated enough */
5308 if (WARN_ON(!pg->next))
5313 rec = &pg->records[pg->index++];
5317 /* We should have used all pages */
5320 /* Assign the last page to ftrace_pages */
5324 * We only need to disable interrupts on start up
5325 * because we are modifying code that an interrupt
5326 * may execute, and the modification is not atomic.
5327 * But for modules, nothing runs the code we modify
5328 * until we are finished with it, and there's no
5329 * reason to cause large interrupt latencies while we do it.
5332 local_irq_save(flags);
5333 ftrace_update_code(mod, start_pg);
5335 local_irq_restore(flags);
5338 mutex_unlock(&ftrace_lock);
5343 #ifdef CONFIG_MODULES
5345 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5347 static int referenced_filters(struct dyn_ftrace *rec)
5349 struct ftrace_ops *ops;
5352 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5353 if (ops_references_rec(ops, rec))
5360 void ftrace_release_mod(struct module *mod)
5362 struct dyn_ftrace *rec;
5363 struct ftrace_page **last_pg;
5364 struct ftrace_page *pg;
5367 mutex_lock(&ftrace_lock);
5369 if (ftrace_disabled)
5373 * Each module has its own ftrace_pages, remove
5374 * them from the list.
5376 last_pg = &ftrace_pages_start;
5377 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5378 rec = &pg->records[0];
5379 if (within_module_core(rec->ip, mod)) {
5381 * As core pages are first, the first
5382 * page should never be a module page.
5384 if (WARN_ON(pg == ftrace_pages_start))
5387 /* Check if we are deleting the last page */
5388 if (pg == ftrace_pages)
5389 ftrace_pages = next_to_ftrace_page(last_pg);
5391 *last_pg = pg->next;
5392 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5393 free_pages((unsigned long)pg->records, order);
5396 last_pg = &pg->next;
5399 mutex_unlock(&ftrace_lock);
5402 void ftrace_module_enable(struct module *mod)
5404 struct dyn_ftrace *rec;
5405 struct ftrace_page *pg;
5407 mutex_lock(&ftrace_lock);
5409 if (ftrace_disabled)
5413 * If the tracing is enabled, go ahead and enable the record.
5415 * The reason not to enable the record immediatelly is the
5416 * inherent check of ftrace_make_nop/ftrace_make_call for
5417 * correct previous instructions. Making first the NOP
5418 * conversion puts the module to the correct state, thus
5419 * passing the ftrace_make_call check.
5421 * We also delay this to after the module code already set the
5422 * text to read-only, as we now need to set it back to read-write
5423 * so that we can modify the text.
5425 if (ftrace_start_up)
5426 ftrace_arch_code_modify_prepare();
5428 do_for_each_ftrace_rec(pg, rec) {
5431 * do_for_each_ftrace_rec() is a double loop.
5432 * module text shares the pg. If a record is
5433 * not part of this module, then skip this pg,
5434 * which the "break" will do.
5436 if (!within_module_core(rec->ip, mod))
5442 * When adding a module, we need to check if tracers are
5443 * currently enabled and if they are, and can trace this record,
5444 * we need to enable the module functions as well as update the
5445 * reference counts for those function records.
5447 if (ftrace_start_up)
5448 cnt += referenced_filters(rec);
5450 /* This clears FTRACE_FL_DISABLED */
5453 if (ftrace_start_up && cnt) {
5454 int failed = __ftrace_replace_code(rec, 1);
5456 ftrace_bug(failed, rec);
5461 } while_for_each_ftrace_rec();
5464 if (ftrace_start_up)
5465 ftrace_arch_code_modify_post_process();
5468 mutex_unlock(&ftrace_lock);
5471 void ftrace_module_init(struct module *mod)
5473 if (ftrace_disabled || !mod->num_ftrace_callsites)
5476 ftrace_process_locs(mod, mod->ftrace_callsites,
5477 mod->ftrace_callsites + mod->num_ftrace_callsites);
5479 #endif /* CONFIG_MODULES */
5481 void __init ftrace_free_init_mem(void)
5483 unsigned long start = (unsigned long)(&__init_begin);
5484 unsigned long end = (unsigned long)(&__init_end);
5485 struct ftrace_page **last_pg = &ftrace_pages_start;
5486 struct ftrace_page *pg;
5487 struct dyn_ftrace *rec;
5488 struct dyn_ftrace key;
5492 key.flags = end; /* overload flags, as it is unsigned long */
5494 mutex_lock(&ftrace_lock);
5496 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
5497 if (end < pg->records[0].ip ||
5498 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
5501 rec = bsearch(&key, pg->records, pg->index,
5502 sizeof(struct dyn_ftrace),
5508 *last_pg = pg->next;
5509 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5510 free_pages((unsigned long)pg->records, order);
5512 pg = container_of(last_pg, struct ftrace_page, next);
5517 memmove(rec, rec + 1,
5518 (pg->index - (rec - pg->records)) * sizeof(*rec));
5519 /* More than one function may be in this block */
5522 mutex_unlock(&ftrace_lock);
5525 void __init ftrace_init(void)
5527 extern unsigned long __start_mcount_loc[];
5528 extern unsigned long __stop_mcount_loc[];
5529 unsigned long count, flags;
5532 local_irq_save(flags);
5533 ret = ftrace_dyn_arch_init();
5534 local_irq_restore(flags);
5538 count = __stop_mcount_loc - __start_mcount_loc;
5540 pr_info("ftrace: No functions to be traced?\n");
5544 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5545 count, count / ENTRIES_PER_PAGE + 1);
5547 last_ftrace_enabled = ftrace_enabled = 1;
5549 ret = ftrace_process_locs(NULL,
5553 set_ftrace_early_filters();
5557 ftrace_disabled = 1;
5560 /* Do nothing if arch does not support this */
5561 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
5565 static void ftrace_update_trampoline(struct ftrace_ops *ops)
5567 arch_ftrace_update_trampoline(ops);
5570 void ftrace_init_trace_array(struct trace_array *tr)
5572 INIT_LIST_HEAD(&tr->func_probes);
5576 static struct ftrace_ops global_ops = {
5577 .func = ftrace_stub,
5578 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5579 FTRACE_OPS_FL_INITIALIZED |
5583 static int __init ftrace_nodyn_init(void)
5588 core_initcall(ftrace_nodyn_init);
5590 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
5591 static inline void ftrace_startup_enable(int command) { }
5592 static inline void ftrace_startup_all(int command) { }
5593 /* Keep as macros so we do not need to define the commands */
5594 # define ftrace_startup(ops, command) \
5596 int ___ret = __register_ftrace_function(ops); \
5598 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5601 # define ftrace_shutdown(ops, command) \
5603 int ___ret = __unregister_ftrace_function(ops); \
5605 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5609 # define ftrace_startup_sysctl() do { } while (0)
5610 # define ftrace_shutdown_sysctl() do { } while (0)
5613 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
5618 static void ftrace_update_trampoline(struct ftrace_ops *ops)
5622 #endif /* CONFIG_DYNAMIC_FTRACE */
5624 __init void ftrace_init_global_array_ops(struct trace_array *tr)
5626 tr->ops = &global_ops;
5627 tr->ops->private = tr;
5628 ftrace_init_trace_array(tr);
5631 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
5633 /* If we filter on pids, update to use the pid function */
5634 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
5635 if (WARN_ON(tr->ops->func != ftrace_stub))
5636 printk("ftrace ops had %pS for function\n",
5639 tr->ops->func = func;
5640 tr->ops->private = tr;
5643 void ftrace_reset_array_ops(struct trace_array *tr)
5645 tr->ops->func = ftrace_stub;
5649 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
5650 struct ftrace_ops *ignored, struct pt_regs *regs)
5652 struct ftrace_ops *op;
5655 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5660 * Some of the ops may be dynamically allocated,
5661 * they must be freed after a synchronize_sched().
5663 preempt_disable_notrace();
5665 do_for_each_ftrace_op(op, ftrace_ops_list) {
5667 * Check the following for each ops before calling their func:
5668 * if RCU flag is set, then rcu_is_watching() must be true
5669 * if PER_CPU is set, then ftrace_function_local_disable()
5671 * Otherwise test if the ip matches the ops filter
5673 * If any of the above fails then the op->func() is not executed.
5675 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
5676 (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
5677 !ftrace_function_local_disabled(op)) &&
5678 ftrace_ops_test(op, ip, regs)) {
5680 if (FTRACE_WARN_ON(!op->func)) {
5681 pr_warn("op=%p %pS\n", op, op);
5684 op->func(ip, parent_ip, op, regs);
5686 } while_for_each_ftrace_op(op);
5688 preempt_enable_notrace();
5689 trace_clear_recursion(bit);
5693 * Some archs only support passing ip and parent_ip. Even though
5694 * the list function ignores the op parameter, we do not want any
5695 * C side effects, where a function is called without the caller
5696 * sending a third parameter.
5697 * Archs are to support both the regs and ftrace_ops at the same time.
5698 * If they support ftrace_ops, it is assumed they support regs.
5699 * If call backs want to use regs, they must either check for regs
5700 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5701 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5702 * An architecture can pass partial regs with ftrace_ops and still
5703 * set the ARCH_SUPPORTS_FTRACE_OPS.
5705 #if ARCH_SUPPORTS_FTRACE_OPS
5706 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
5707 struct ftrace_ops *op, struct pt_regs *regs)
5709 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
5712 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
5714 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
5719 * If there's only one function registered but it does not support
5720 * recursion, needs RCU protection and/or requires per cpu handling, then
5721 * this function will be called by the mcount trampoline.
5723 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
5724 struct ftrace_ops *op, struct pt_regs *regs)
5728 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
5731 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5735 preempt_disable_notrace();
5737 if (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
5738 !ftrace_function_local_disabled(op)) {
5739 op->func(ip, parent_ip, op, regs);
5742 preempt_enable_notrace();
5743 trace_clear_recursion(bit);
5747 * ftrace_ops_get_func - get the function a trampoline should call
5748 * @ops: the ops to get the function for
5750 * Normally the mcount trampoline will call the ops->func, but there
5751 * are times that it should not. For example, if the ops does not
5752 * have its own recursion protection, then it should call the
5753 * ftrace_ops_assist_func() instead.
5755 * Returns the function that the trampoline should call for @ops.
5757 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
5760 * If the function does not handle recursion, needs to be RCU safe,
5761 * or does per cpu logic, then we need to call the assist handler.
5763 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
5764 ops->flags & (FTRACE_OPS_FL_RCU | FTRACE_OPS_FL_PER_CPU))
5765 return ftrace_ops_assist_func;
5771 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
5772 struct task_struct *prev, struct task_struct *next)
5774 struct trace_array *tr = data;
5775 struct trace_pid_list *pid_list;
5777 pid_list = rcu_dereference_sched(tr->function_pids);
5779 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
5780 trace_ignore_this_task(pid_list, next));
5784 ftrace_pid_follow_sched_process_fork(void *data,
5785 struct task_struct *self,
5786 struct task_struct *task)
5788 struct trace_pid_list *pid_list;
5789 struct trace_array *tr = data;
5791 pid_list = rcu_dereference_sched(tr->function_pids);
5792 trace_filter_add_remove_task(pid_list, self, task);
5796 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
5798 struct trace_pid_list *pid_list;
5799 struct trace_array *tr = data;
5801 pid_list = rcu_dereference_sched(tr->function_pids);
5802 trace_filter_add_remove_task(pid_list, NULL, task);
5805 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
5808 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
5810 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
5813 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
5815 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
5820 static void clear_ftrace_pids(struct trace_array *tr)
5822 struct trace_pid_list *pid_list;
5825 pid_list = rcu_dereference_protected(tr->function_pids,
5826 lockdep_is_held(&ftrace_lock));
5830 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
5832 for_each_possible_cpu(cpu)
5833 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
5835 rcu_assign_pointer(tr->function_pids, NULL);
5837 /* Wait till all users are no longer using pid filtering */
5838 synchronize_sched();
5840 trace_free_pid_list(pid_list);
5843 void ftrace_clear_pids(struct trace_array *tr)
5845 mutex_lock(&ftrace_lock);
5847 clear_ftrace_pids(tr);
5849 mutex_unlock(&ftrace_lock);
5852 static void ftrace_pid_reset(struct trace_array *tr)
5854 mutex_lock(&ftrace_lock);
5855 clear_ftrace_pids(tr);
5857 ftrace_update_pid_func();
5858 ftrace_startup_all(0);
5860 mutex_unlock(&ftrace_lock);
5863 /* Greater than any max PID */
5864 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
5866 static void *fpid_start(struct seq_file *m, loff_t *pos)
5869 struct trace_pid_list *pid_list;
5870 struct trace_array *tr = m->private;
5872 mutex_lock(&ftrace_lock);
5873 rcu_read_lock_sched();
5875 pid_list = rcu_dereference_sched(tr->function_pids);
5878 return !(*pos) ? FTRACE_NO_PIDS : NULL;
5880 return trace_pid_start(pid_list, pos);
5883 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
5885 struct trace_array *tr = m->private;
5886 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
5888 if (v == FTRACE_NO_PIDS)
5891 return trace_pid_next(pid_list, v, pos);
5894 static void fpid_stop(struct seq_file *m, void *p)
5897 rcu_read_unlock_sched();
5898 mutex_unlock(&ftrace_lock);
5901 static int fpid_show(struct seq_file *m, void *v)
5903 if (v == FTRACE_NO_PIDS) {
5904 seq_puts(m, "no pid\n");
5908 return trace_pid_show(m, v);
5911 static const struct seq_operations ftrace_pid_sops = {
5912 .start = fpid_start,
5919 ftrace_pid_open(struct inode *inode, struct file *file)
5921 struct trace_array *tr = inode->i_private;
5925 if (trace_array_get(tr) < 0)
5928 if ((file->f_mode & FMODE_WRITE) &&
5929 (file->f_flags & O_TRUNC))
5930 ftrace_pid_reset(tr);
5932 ret = seq_open(file, &ftrace_pid_sops);
5934 trace_array_put(tr);
5936 m = file->private_data;
5937 /* copy tr over to seq ops */
5944 static void ignore_task_cpu(void *data)
5946 struct trace_array *tr = data;
5947 struct trace_pid_list *pid_list;
5950 * This function is called by on_each_cpu() while the
5951 * event_mutex is held.
5953 pid_list = rcu_dereference_protected(tr->function_pids,
5954 mutex_is_locked(&ftrace_lock));
5956 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
5957 trace_ignore_this_task(pid_list, current));
5961 ftrace_pid_write(struct file *filp, const char __user *ubuf,
5962 size_t cnt, loff_t *ppos)
5964 struct seq_file *m = filp->private_data;
5965 struct trace_array *tr = m->private;
5966 struct trace_pid_list *filtered_pids = NULL;
5967 struct trace_pid_list *pid_list;
5973 mutex_lock(&ftrace_lock);
5975 filtered_pids = rcu_dereference_protected(tr->function_pids,
5976 lockdep_is_held(&ftrace_lock));
5978 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
5982 rcu_assign_pointer(tr->function_pids, pid_list);
5984 if (filtered_pids) {
5985 synchronize_sched();
5986 trace_free_pid_list(filtered_pids);
5987 } else if (pid_list) {
5988 /* Register a probe to set whether to ignore the tracing of a task */
5989 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
5993 * Ignoring of pids is done at task switch. But we have to
5994 * check for those tasks that are currently running.
5995 * Always do this in case a pid was appended or removed.
5997 on_each_cpu(ignore_task_cpu, tr, 1);
5999 ftrace_update_pid_func();
6000 ftrace_startup_all(0);
6002 mutex_unlock(&ftrace_lock);
6011 ftrace_pid_release(struct inode *inode, struct file *file)
6013 struct trace_array *tr = inode->i_private;
6015 trace_array_put(tr);
6017 return seq_release(inode, file);
6020 static const struct file_operations ftrace_pid_fops = {
6021 .open = ftrace_pid_open,
6022 .write = ftrace_pid_write,
6024 .llseek = tracing_lseek,
6025 .release = ftrace_pid_release,
6028 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6030 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6031 tr, &ftrace_pid_fops);
6034 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6035 struct dentry *d_tracer)
6037 /* Only the top level directory has the dyn_tracefs and profile */
6038 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6040 ftrace_init_dyn_tracefs(d_tracer);
6041 ftrace_profile_tracefs(d_tracer);
6045 * ftrace_kill - kill ftrace
6047 * This function should be used by panic code. It stops ftrace
6048 * but in a not so nice way. If you need to simply kill ftrace
6049 * from a non-atomic section, use ftrace_kill.
6051 void ftrace_kill(void)
6053 ftrace_disabled = 1;
6055 clear_ftrace_function();
6059 * Test if ftrace is dead or not.
6061 int ftrace_is_dead(void)
6063 return ftrace_disabled;
6067 * register_ftrace_function - register a function for profiling
6068 * @ops - ops structure that holds the function for profiling.
6070 * Register a function to be called by all functions in the
6073 * Note: @ops->func and all the functions it calls must be labeled
6074 * with "notrace", otherwise it will go into a
6077 int register_ftrace_function(struct ftrace_ops *ops)
6081 ftrace_ops_init(ops);
6083 mutex_lock(&ftrace_lock);
6085 ret = ftrace_startup(ops, 0);
6087 mutex_unlock(&ftrace_lock);
6091 EXPORT_SYMBOL_GPL(register_ftrace_function);
6094 * unregister_ftrace_function - unregister a function for profiling.
6095 * @ops - ops structure that holds the function to unregister
6097 * Unregister a function that was added to be called by ftrace profiling.
6099 int unregister_ftrace_function(struct ftrace_ops *ops)
6103 mutex_lock(&ftrace_lock);
6104 ret = ftrace_shutdown(ops, 0);
6105 mutex_unlock(&ftrace_lock);
6109 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6112 ftrace_enable_sysctl(struct ctl_table *table, int write,
6113 void __user *buffer, size_t *lenp,
6118 mutex_lock(&ftrace_lock);
6120 if (unlikely(ftrace_disabled))
6123 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6125 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6128 last_ftrace_enabled = !!ftrace_enabled;
6130 if (ftrace_enabled) {
6132 /* we are starting ftrace again */
6133 if (ftrace_ops_list != &ftrace_list_end)
6134 update_ftrace_function();
6136 ftrace_startup_sysctl();
6139 /* stopping ftrace calls (just send to ftrace_stub) */
6140 ftrace_trace_function = ftrace_stub;
6142 ftrace_shutdown_sysctl();
6146 mutex_unlock(&ftrace_lock);
6150 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6152 static struct ftrace_ops graph_ops = {
6153 .func = ftrace_stub,
6154 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6155 FTRACE_OPS_FL_INITIALIZED |
6158 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6159 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
6160 /* trampoline_size is only needed for dynamically allocated tramps */
6162 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
6165 void ftrace_graph_sleep_time_control(bool enable)
6167 fgraph_sleep_time = enable;
6170 void ftrace_graph_graph_time_control(bool enable)
6172 fgraph_graph_time = enable;
6175 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
6180 /* The callbacks that hook a function */
6181 trace_func_graph_ret_t ftrace_graph_return =
6182 (trace_func_graph_ret_t)ftrace_stub;
6183 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
6184 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
6186 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6187 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
6191 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
6192 struct task_struct *g, *t;
6194 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
6195 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
6196 * sizeof(struct ftrace_ret_stack),
6198 if (!ret_stack_list[i]) {
6206 read_lock(&tasklist_lock);
6207 do_each_thread(g, t) {
6213 if (t->ret_stack == NULL) {
6214 atomic_set(&t->tracing_graph_pause, 0);
6215 atomic_set(&t->trace_overrun, 0);
6216 t->curr_ret_stack = -1;
6217 /* Make sure the tasks see the -1 first: */
6219 t->ret_stack = ret_stack_list[start++];
6221 } while_each_thread(g, t);
6224 read_unlock(&tasklist_lock);
6226 for (i = start; i < end; i++)
6227 kfree(ret_stack_list[i]);
6232 ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
6233 struct task_struct *prev, struct task_struct *next)
6235 unsigned long long timestamp;
6239 * Does the user want to count the time a function was asleep.
6240 * If so, do not update the time stamps.
6242 if (fgraph_sleep_time)
6245 timestamp = trace_clock_local();
6247 prev->ftrace_timestamp = timestamp;
6249 /* only process tasks that we timestamped */
6250 if (!next->ftrace_timestamp)
6254 * Update all the counters in next to make up for the
6255 * time next was sleeping.
6257 timestamp -= next->ftrace_timestamp;
6259 for (index = next->curr_ret_stack; index >= 0; index--)
6260 next->ret_stack[index].calltime += timestamp;
6263 /* Allocate a return stack for each task */
6264 static int start_graph_tracing(void)
6266 struct ftrace_ret_stack **ret_stack_list;
6269 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
6270 sizeof(struct ftrace_ret_stack *),
6273 if (!ret_stack_list)
6276 /* The cpu_boot init_task->ret_stack will never be freed */
6277 for_each_online_cpu(cpu) {
6278 if (!idle_task(cpu)->ret_stack)
6279 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
6283 ret = alloc_retstack_tasklist(ret_stack_list);
6284 } while (ret == -EAGAIN);
6287 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6289 pr_info("ftrace_graph: Couldn't activate tracepoint"
6290 " probe to kernel_sched_switch\n");
6293 kfree(ret_stack_list);
6298 * Hibernation protection.
6299 * The state of the current task is too much unstable during
6300 * suspend/restore to disk. We want to protect against that.
6303 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
6307 case PM_HIBERNATION_PREPARE:
6308 pause_graph_tracing();
6311 case PM_POST_HIBERNATION:
6312 unpause_graph_tracing();
6318 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
6320 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
6322 return __ftrace_graph_entry(trace);
6326 * The function graph tracer should only trace the functions defined
6327 * by set_ftrace_filter and set_ftrace_notrace. If another function
6328 * tracer ops is registered, the graph tracer requires testing the
6329 * function against the global ops, and not just trace any function
6330 * that any ftrace_ops registered.
6332 static void update_function_graph_func(void)
6334 struct ftrace_ops *op;
6335 bool do_test = false;
6338 * The graph and global ops share the same set of functions
6339 * to test. If any other ops is on the list, then
6340 * the graph tracing needs to test if its the function
6343 do_for_each_ftrace_op(op, ftrace_ops_list) {
6344 if (op != &global_ops && op != &graph_ops &&
6345 op != &ftrace_list_end) {
6347 /* in double loop, break out with goto */
6350 } while_for_each_ftrace_op(op);
6353 ftrace_graph_entry = ftrace_graph_entry_test;
6355 ftrace_graph_entry = __ftrace_graph_entry;
6358 static struct notifier_block ftrace_suspend_notifier = {
6359 .notifier_call = ftrace_suspend_notifier_call,
6362 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
6363 trace_func_graph_ent_t entryfunc)
6367 mutex_lock(&ftrace_lock);
6369 /* we currently allow only one tracer registered at a time */
6370 if (ftrace_graph_active) {
6375 register_pm_notifier(&ftrace_suspend_notifier);
6377 ftrace_graph_active++;
6378 ret = start_graph_tracing();
6380 ftrace_graph_active--;
6384 ftrace_graph_return = retfunc;
6387 * Update the indirect function to the entryfunc, and the
6388 * function that gets called to the entry_test first. Then
6389 * call the update fgraph entry function to determine if
6390 * the entryfunc should be called directly or not.
6392 __ftrace_graph_entry = entryfunc;
6393 ftrace_graph_entry = ftrace_graph_entry_test;
6394 update_function_graph_func();
6396 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
6398 mutex_unlock(&ftrace_lock);
6402 void unregister_ftrace_graph(void)
6404 mutex_lock(&ftrace_lock);
6406 if (unlikely(!ftrace_graph_active))
6409 ftrace_graph_active--;
6410 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
6411 ftrace_graph_entry = ftrace_graph_entry_stub;
6412 __ftrace_graph_entry = ftrace_graph_entry_stub;
6413 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
6414 unregister_pm_notifier(&ftrace_suspend_notifier);
6415 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6417 #ifdef CONFIG_DYNAMIC_FTRACE
6419 * Function graph does not allocate the trampoline, but
6420 * other global_ops do. We need to reset the ALLOC_TRAMP flag
6423 global_ops.trampoline = save_global_trampoline;
6424 if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP)
6425 global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
6429 mutex_unlock(&ftrace_lock);
6432 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
6435 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
6437 atomic_set(&t->tracing_graph_pause, 0);
6438 atomic_set(&t->trace_overrun, 0);
6439 t->ftrace_timestamp = 0;
6440 /* make curr_ret_stack visible before we add the ret_stack */
6442 t->ret_stack = ret_stack;
6446 * Allocate a return stack for the idle task. May be the first
6447 * time through, or it may be done by CPU hotplug online.
6449 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
6451 t->curr_ret_stack = -1;
6453 * The idle task has no parent, it either has its own
6454 * stack or no stack at all.
6457 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
6459 if (ftrace_graph_active) {
6460 struct ftrace_ret_stack *ret_stack;
6462 ret_stack = per_cpu(idle_ret_stack, cpu);
6464 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6465 * sizeof(struct ftrace_ret_stack),
6469 per_cpu(idle_ret_stack, cpu) = ret_stack;
6471 graph_init_task(t, ret_stack);
6475 /* Allocate a return stack for newly created task */
6476 void ftrace_graph_init_task(struct task_struct *t)
6478 /* Make sure we do not use the parent ret_stack */
6479 t->ret_stack = NULL;
6480 t->curr_ret_stack = -1;
6482 if (ftrace_graph_active) {
6483 struct ftrace_ret_stack *ret_stack;
6485 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6486 * sizeof(struct ftrace_ret_stack),
6490 graph_init_task(t, ret_stack);
6494 void ftrace_graph_exit_task(struct task_struct *t)
6496 struct ftrace_ret_stack *ret_stack = t->ret_stack;
6498 t->ret_stack = NULL;
6499 /* NULL must become visible to IRQs before we free it: */