1 // SPDX-License-Identifier: GPL-2.0
3 * Infrastructure for profiling code inserted by 'gcc -pg'.
5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
8 * Originally ported from the -rt patch by:
9 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
11 * Based on code in the latency_tracer, that is:
13 * Copyright (C) 2004-2006 Ingo Molnar
14 * Copyright (C) 2004 Nadia Yvette Chambers
17 #include <linux/stop_machine.h>
18 #include <linux/clocksource.h>
19 #include <linux/sched/task.h>
20 #include <linux/kallsyms.h>
21 #include <linux/security.h>
22 #include <linux/seq_file.h>
23 #include <linux/tracefs.h>
24 #include <linux/hardirq.h>
25 #include <linux/kthread.h>
26 #include <linux/uaccess.h>
27 #include <linux/bsearch.h>
28 #include <linux/module.h>
29 #include <linux/ftrace.h>
30 #include <linux/sysctl.h>
31 #include <linux/slab.h>
32 #include <linux/ctype.h>
33 #include <linux/sort.h>
34 #include <linux/list.h>
35 #include <linux/hash.h>
36 #include <linux/rcupdate.h>
37 #include <linux/kprobes.h>
39 #include <trace/events/sched.h>
41 #include <asm/sections.h>
42 #include <asm/setup.h>
44 #include "ftrace_internal.h"
45 #include "trace_output.h"
46 #include "trace_stat.h"
48 #define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__"
50 #define FTRACE_WARN_ON(cond) \
58 #define FTRACE_WARN_ON_ONCE(cond) \
61 if (WARN_ON_ONCE(___r)) \
66 /* hash bits for specific function selection */
67 #define FTRACE_HASH_DEFAULT_BITS 10
68 #define FTRACE_HASH_MAX_BITS 12
70 #ifdef CONFIG_DYNAMIC_FTRACE
71 #define INIT_OPS_HASH(opsname) \
72 .func_hash = &opsname.local_hash, \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #define INIT_OPS_HASH(opsname)
79 FTRACE_MODIFY_ENABLE_FL = (1 << 0),
80 FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
83 struct ftrace_ops ftrace_list_end __read_mostly = {
85 .flags = FTRACE_OPS_FL_STUB,
86 INIT_OPS_HASH(ftrace_list_end)
89 /* ftrace_enabled is a method to turn ftrace on or off */
90 int ftrace_enabled __read_mostly;
91 static int __maybe_unused last_ftrace_enabled;
93 /* Current function tracing op */
94 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
95 /* What to set function_trace_op to */
96 static struct ftrace_ops *set_function_trace_op;
98 static bool ftrace_pids_enabled(struct ftrace_ops *ops)
100 struct trace_array *tr;
102 if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
107 return tr->function_pids != NULL || tr->function_no_pids != NULL;
110 static void ftrace_update_trampoline(struct ftrace_ops *ops);
113 * ftrace_disabled is set when an anomaly is discovered.
114 * ftrace_disabled is much stronger than ftrace_enabled.
116 static int ftrace_disabled __read_mostly;
118 DEFINE_MUTEX(ftrace_lock);
120 struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
121 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
122 struct ftrace_ops global_ops;
124 /* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */
125 void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
126 struct ftrace_ops *op, struct ftrace_regs *fregs);
128 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
130 * Stub used to invoke the list ops without requiring a separate trampoline.
132 const struct ftrace_ops ftrace_list_ops = {
133 .func = ftrace_ops_list_func,
134 .flags = FTRACE_OPS_FL_STUB,
137 static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip,
138 struct ftrace_ops *op,
139 struct ftrace_regs *fregs)
145 * Stub used when a call site is disabled. May be called transiently by threads
146 * which have made it into ftrace_caller but haven't yet recovered the ops at
147 * the point the call site is disabled.
149 const struct ftrace_ops ftrace_nop_ops = {
150 .func = ftrace_ops_nop_func,
151 .flags = FTRACE_OPS_FL_STUB,
155 static inline void ftrace_ops_init(struct ftrace_ops *ops)
157 #ifdef CONFIG_DYNAMIC_FTRACE
158 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
159 mutex_init(&ops->local_hash.regex_lock);
160 ops->func_hash = &ops->local_hash;
161 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
166 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
167 struct ftrace_ops *op, struct ftrace_regs *fregs)
169 struct trace_array *tr = op->private;
173 pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
174 if (pid == FTRACE_PID_IGNORE)
176 if (pid != FTRACE_PID_TRACE &&
181 op->saved_func(ip, parent_ip, op, fregs);
184 static void ftrace_sync_ipi(void *data)
186 /* Probably not needed, but do it anyway */
190 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
193 * If this is a dynamic or RCU ops, or we force list func,
194 * then it needs to call the list anyway.
196 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
197 FTRACE_FORCE_LIST_FUNC)
198 return ftrace_ops_list_func;
200 return ftrace_ops_get_func(ops);
203 static void update_ftrace_function(void)
208 * Prepare the ftrace_ops that the arch callback will use.
209 * If there's only one ftrace_ops registered, the ftrace_ops_list
210 * will point to the ops we want.
212 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
213 lockdep_is_held(&ftrace_lock));
215 /* If there's no ftrace_ops registered, just call the stub function */
216 if (set_function_trace_op == &ftrace_list_end) {
220 * If we are at the end of the list and this ops is
221 * recursion safe and not dynamic and the arch supports passing ops,
222 * then have the mcount trampoline call the function directly.
224 } else if (rcu_dereference_protected(ftrace_ops_list->next,
225 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
226 func = ftrace_ops_get_list_func(ftrace_ops_list);
229 /* Just use the default ftrace_ops */
230 set_function_trace_op = &ftrace_list_end;
231 func = ftrace_ops_list_func;
234 update_function_graph_func();
236 /* If there's no change, then do nothing more here */
237 if (ftrace_trace_function == func)
241 * If we are using the list function, it doesn't care
242 * about the function_trace_ops.
244 if (func == ftrace_ops_list_func) {
245 ftrace_trace_function = func;
247 * Don't even bother setting function_trace_ops,
248 * it would be racy to do so anyway.
253 #ifndef CONFIG_DYNAMIC_FTRACE
255 * For static tracing, we need to be a bit more careful.
256 * The function change takes affect immediately. Thus,
257 * we need to coordinate the setting of the function_trace_ops
258 * with the setting of the ftrace_trace_function.
260 * Set the function to the list ops, which will call the
261 * function we want, albeit indirectly, but it handles the
262 * ftrace_ops and doesn't depend on function_trace_op.
264 ftrace_trace_function = ftrace_ops_list_func;
266 * Make sure all CPUs see this. Yes this is slow, but static
267 * tracing is slow and nasty to have enabled.
269 synchronize_rcu_tasks_rude();
270 /* Now all cpus are using the list ops. */
271 function_trace_op = set_function_trace_op;
272 /* Make sure the function_trace_op is visible on all CPUs */
274 /* Nasty way to force a rmb on all cpus */
275 smp_call_function(ftrace_sync_ipi, NULL, 1);
276 /* OK, we are all set to update the ftrace_trace_function now! */
277 #endif /* !CONFIG_DYNAMIC_FTRACE */
279 ftrace_trace_function = func;
282 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
283 struct ftrace_ops *ops)
285 rcu_assign_pointer(ops->next, *list);
288 * We are entering ops into the list but another
289 * CPU might be walking that list. We need to make sure
290 * the ops->next pointer is valid before another CPU sees
291 * the ops pointer included into the list.
293 rcu_assign_pointer(*list, ops);
296 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
297 struct ftrace_ops *ops)
299 struct ftrace_ops **p;
302 * If we are removing the last function, then simply point
303 * to the ftrace_stub.
305 if (rcu_dereference_protected(*list,
306 lockdep_is_held(&ftrace_lock)) == ops &&
307 rcu_dereference_protected(ops->next,
308 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
309 *list = &ftrace_list_end;
313 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
324 static void ftrace_update_trampoline(struct ftrace_ops *ops);
326 int __register_ftrace_function(struct ftrace_ops *ops)
328 if (ops->flags & FTRACE_OPS_FL_DELETED)
331 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
334 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
336 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
337 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
338 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
340 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
341 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
344 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
345 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
347 if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT))
350 if (!is_kernel_core_data((unsigned long)ops))
351 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
353 add_ftrace_ops(&ftrace_ops_list, ops);
355 /* Always save the function, and reset at unregistering */
356 ops->saved_func = ops->func;
358 if (ftrace_pids_enabled(ops))
359 ops->func = ftrace_pid_func;
361 ftrace_update_trampoline(ops);
364 update_ftrace_function();
369 int __unregister_ftrace_function(struct ftrace_ops *ops)
373 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
376 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
382 update_ftrace_function();
384 ops->func = ops->saved_func;
389 static void ftrace_update_pid_func(void)
391 struct ftrace_ops *op;
393 /* Only do something if we are tracing something */
394 if (ftrace_trace_function == ftrace_stub)
397 do_for_each_ftrace_op(op, ftrace_ops_list) {
398 if (op->flags & FTRACE_OPS_FL_PID) {
399 op->func = ftrace_pids_enabled(op) ?
400 ftrace_pid_func : op->saved_func;
401 ftrace_update_trampoline(op);
403 } while_for_each_ftrace_op(op);
405 update_ftrace_function();
408 #ifdef CONFIG_FUNCTION_PROFILER
409 struct ftrace_profile {
410 struct hlist_node node;
412 unsigned long counter;
413 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
414 unsigned long long time;
415 unsigned long long time_squared;
419 struct ftrace_profile_page {
420 struct ftrace_profile_page *next;
422 struct ftrace_profile records[];
425 struct ftrace_profile_stat {
427 struct hlist_head *hash;
428 struct ftrace_profile_page *pages;
429 struct ftrace_profile_page *start;
430 struct tracer_stat stat;
433 #define PROFILE_RECORDS_SIZE \
434 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
436 #define PROFILES_PER_PAGE \
437 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
439 static int ftrace_profile_enabled __read_mostly;
441 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
442 static DEFINE_MUTEX(ftrace_profile_lock);
444 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
446 #define FTRACE_PROFILE_HASH_BITS 10
447 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
450 function_stat_next(void *v, int idx)
452 struct ftrace_profile *rec = v;
453 struct ftrace_profile_page *pg;
455 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
461 if ((void *)rec >= (void *)&pg->records[pg->index]) {
465 rec = &pg->records[0];
473 static void *function_stat_start(struct tracer_stat *trace)
475 struct ftrace_profile_stat *stat =
476 container_of(trace, struct ftrace_profile_stat, stat);
478 if (!stat || !stat->start)
481 return function_stat_next(&stat->start->records[0], 0);
484 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
485 /* function graph compares on total time */
486 static int function_stat_cmp(const void *p1, const void *p2)
488 const struct ftrace_profile *a = p1;
489 const struct ftrace_profile *b = p2;
491 if (a->time < b->time)
493 if (a->time > b->time)
499 /* not function graph compares against hits */
500 static int function_stat_cmp(const void *p1, const void *p2)
502 const struct ftrace_profile *a = p1;
503 const struct ftrace_profile *b = p2;
505 if (a->counter < b->counter)
507 if (a->counter > b->counter)
514 static int function_stat_headers(struct seq_file *m)
516 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
517 seq_puts(m, " Function "
520 "--- ---- --- ---\n");
522 seq_puts(m, " Function Hit\n"
528 static int function_stat_show(struct seq_file *m, void *v)
530 struct ftrace_profile *rec = v;
531 char str[KSYM_SYMBOL_LEN];
533 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
534 static struct trace_seq s;
535 unsigned long long avg;
536 unsigned long long stddev;
538 mutex_lock(&ftrace_profile_lock);
540 /* we raced with function_profile_reset() */
541 if (unlikely(rec->counter == 0)) {
546 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
547 avg = div64_ul(rec->time, rec->counter);
548 if (tracing_thresh && (avg < tracing_thresh))
552 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
553 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
555 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
558 /* Sample standard deviation (s^2) */
559 if (rec->counter <= 1)
563 * Apply Welford's method:
564 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
566 stddev = rec->counter * rec->time_squared -
567 rec->time * rec->time;
570 * Divide only 1000 for ns^2 -> us^2 conversion.
571 * trace_print_graph_duration will divide 1000 again.
573 stddev = div64_ul(stddev,
574 rec->counter * (rec->counter - 1) * 1000);
578 trace_print_graph_duration(rec->time, &s);
579 trace_seq_puts(&s, " ");
580 trace_print_graph_duration(avg, &s);
581 trace_seq_puts(&s, " ");
582 trace_print_graph_duration(stddev, &s);
583 trace_print_seq(m, &s);
587 mutex_unlock(&ftrace_profile_lock);
592 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
594 struct ftrace_profile_page *pg;
596 pg = stat->pages = stat->start;
599 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
604 memset(stat->hash, 0,
605 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
608 static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
610 struct ftrace_profile_page *pg;
615 /* If we already allocated, do nothing */
619 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
623 #ifdef CONFIG_DYNAMIC_FTRACE
624 functions = ftrace_update_tot_cnt;
627 * We do not know the number of functions that exist because
628 * dynamic tracing is what counts them. With past experience
629 * we have around 20K functions. That should be more than enough.
630 * It is highly unlikely we will execute every function in
636 pg = stat->start = stat->pages;
638 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
640 for (i = 1; i < pages; i++) {
641 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
652 unsigned long tmp = (unsigned long)pg;
664 static int ftrace_profile_init_cpu(int cpu)
666 struct ftrace_profile_stat *stat;
669 stat = &per_cpu(ftrace_profile_stats, cpu);
672 /* If the profile is already created, simply reset it */
673 ftrace_profile_reset(stat);
678 * We are profiling all functions, but usually only a few thousand
679 * functions are hit. We'll make a hash of 1024 items.
681 size = FTRACE_PROFILE_HASH_SIZE;
683 stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
688 /* Preallocate the function profiling pages */
689 if (ftrace_profile_pages_init(stat) < 0) {
698 static int ftrace_profile_init(void)
703 for_each_possible_cpu(cpu) {
704 ret = ftrace_profile_init_cpu(cpu);
712 /* interrupts must be disabled */
713 static struct ftrace_profile *
714 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
716 struct ftrace_profile *rec;
717 struct hlist_head *hhd;
720 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
721 hhd = &stat->hash[key];
723 if (hlist_empty(hhd))
726 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
734 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
735 struct ftrace_profile *rec)
739 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
740 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
744 * The memory is already allocated, this simply finds a new record to use.
746 static struct ftrace_profile *
747 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
749 struct ftrace_profile *rec = NULL;
751 /* prevent recursion (from NMIs) */
752 if (atomic_inc_return(&stat->disabled) != 1)
756 * Try to find the function again since an NMI
757 * could have added it
759 rec = ftrace_find_profiled_func(stat, ip);
763 if (stat->pages->index == PROFILES_PER_PAGE) {
764 if (!stat->pages->next)
766 stat->pages = stat->pages->next;
769 rec = &stat->pages->records[stat->pages->index++];
771 ftrace_add_profile(stat, rec);
774 atomic_dec(&stat->disabled);
780 function_profile_call(unsigned long ip, unsigned long parent_ip,
781 struct ftrace_ops *ops, struct ftrace_regs *fregs)
783 struct ftrace_profile_stat *stat;
784 struct ftrace_profile *rec;
787 if (!ftrace_profile_enabled)
790 local_irq_save(flags);
792 stat = this_cpu_ptr(&ftrace_profile_stats);
793 if (!stat->hash || !ftrace_profile_enabled)
796 rec = ftrace_find_profiled_func(stat, ip);
798 rec = ftrace_profile_alloc(stat, ip);
805 local_irq_restore(flags);
808 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
809 static bool fgraph_graph_time = true;
811 void ftrace_graph_graph_time_control(bool enable)
813 fgraph_graph_time = enable;
816 static int profile_graph_entry(struct ftrace_graph_ent *trace)
818 struct ftrace_ret_stack *ret_stack;
820 function_profile_call(trace->func, 0, NULL, NULL);
822 /* If function graph is shutting down, ret_stack can be NULL */
823 if (!current->ret_stack)
826 ret_stack = ftrace_graph_get_ret_stack(current, 0);
828 ret_stack->subtime = 0;
833 static void profile_graph_return(struct ftrace_graph_ret *trace)
835 struct ftrace_ret_stack *ret_stack;
836 struct ftrace_profile_stat *stat;
837 unsigned long long calltime;
838 struct ftrace_profile *rec;
841 local_irq_save(flags);
842 stat = this_cpu_ptr(&ftrace_profile_stats);
843 if (!stat->hash || !ftrace_profile_enabled)
846 /* If the calltime was zero'd ignore it */
847 if (!trace->calltime)
850 calltime = trace->rettime - trace->calltime;
852 if (!fgraph_graph_time) {
854 /* Append this call time to the parent time to subtract */
855 ret_stack = ftrace_graph_get_ret_stack(current, 1);
857 ret_stack->subtime += calltime;
859 ret_stack = ftrace_graph_get_ret_stack(current, 0);
860 if (ret_stack && ret_stack->subtime < calltime)
861 calltime -= ret_stack->subtime;
866 rec = ftrace_find_profiled_func(stat, trace->func);
868 rec->time += calltime;
869 rec->time_squared += calltime * calltime;
873 local_irq_restore(flags);
876 static struct fgraph_ops fprofiler_ops = {
877 .entryfunc = &profile_graph_entry,
878 .retfunc = &profile_graph_return,
881 static int register_ftrace_profiler(void)
883 return register_ftrace_graph(&fprofiler_ops);
886 static void unregister_ftrace_profiler(void)
888 unregister_ftrace_graph(&fprofiler_ops);
891 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
892 .func = function_profile_call,
893 .flags = FTRACE_OPS_FL_INITIALIZED,
894 INIT_OPS_HASH(ftrace_profile_ops)
897 static int register_ftrace_profiler(void)
899 return register_ftrace_function(&ftrace_profile_ops);
902 static void unregister_ftrace_profiler(void)
904 unregister_ftrace_function(&ftrace_profile_ops);
906 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
909 ftrace_profile_write(struct file *filp, const char __user *ubuf,
910 size_t cnt, loff_t *ppos)
915 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
921 mutex_lock(&ftrace_profile_lock);
922 if (ftrace_profile_enabled ^ val) {
924 ret = ftrace_profile_init();
930 ret = register_ftrace_profiler();
935 ftrace_profile_enabled = 1;
937 ftrace_profile_enabled = 0;
939 * unregister_ftrace_profiler calls stop_machine
940 * so this acts like an synchronize_rcu.
942 unregister_ftrace_profiler();
946 mutex_unlock(&ftrace_profile_lock);
954 ftrace_profile_read(struct file *filp, char __user *ubuf,
955 size_t cnt, loff_t *ppos)
957 char buf[64]; /* big enough to hold a number */
960 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
961 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
964 static const struct file_operations ftrace_profile_fops = {
965 .open = tracing_open_generic,
966 .read = ftrace_profile_read,
967 .write = ftrace_profile_write,
968 .llseek = default_llseek,
971 /* used to initialize the real stat files */
972 static struct tracer_stat function_stats __initdata = {
974 .stat_start = function_stat_start,
975 .stat_next = function_stat_next,
976 .stat_cmp = function_stat_cmp,
977 .stat_headers = function_stat_headers,
978 .stat_show = function_stat_show
981 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
983 struct ftrace_profile_stat *stat;
988 for_each_possible_cpu(cpu) {
989 stat = &per_cpu(ftrace_profile_stats, cpu);
991 name = kasprintf(GFP_KERNEL, "function%d", cpu);
994 * The files created are permanent, if something happens
995 * we still do not free memory.
998 "Could not allocate stat file for cpu %d\n",
1002 stat->stat = function_stats;
1003 stat->stat.name = name;
1004 ret = register_stat_tracer(&stat->stat);
1007 "Could not register function stat for cpu %d\n",
1014 trace_create_file("function_profile_enabled",
1015 TRACE_MODE_WRITE, d_tracer, NULL,
1016 &ftrace_profile_fops);
1019 #else /* CONFIG_FUNCTION_PROFILER */
1020 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1023 #endif /* CONFIG_FUNCTION_PROFILER */
1025 #ifdef CONFIG_DYNAMIC_FTRACE
1027 static struct ftrace_ops *removed_ops;
1030 * Set when doing a global update, like enabling all recs or disabling them.
1031 * It is not set when just updating a single ftrace_ops.
1033 static bool update_all_ops;
1035 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1036 # error Dynamic ftrace depends on MCOUNT_RECORD
1039 struct ftrace_func_probe {
1040 struct ftrace_probe_ops *probe_ops;
1041 struct ftrace_ops ops;
1042 struct trace_array *tr;
1043 struct list_head list;
1049 * We make these constant because no one should touch them,
1050 * but they are used as the default "empty hash", to avoid allocating
1051 * it all the time. These are in a read only section such that if
1052 * anyone does try to modify it, it will cause an exception.
1054 static const struct hlist_head empty_buckets[1];
1055 static const struct ftrace_hash empty_hash = {
1056 .buckets = (struct hlist_head *)empty_buckets,
1058 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1060 struct ftrace_ops global_ops = {
1061 .func = ftrace_stub,
1062 .local_hash.notrace_hash = EMPTY_HASH,
1063 .local_hash.filter_hash = EMPTY_HASH,
1064 INIT_OPS_HASH(global_ops)
1065 .flags = FTRACE_OPS_FL_INITIALIZED |
1070 * Used by the stack unwinder to know about dynamic ftrace trampolines.
1072 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1074 struct ftrace_ops *op = NULL;
1077 * Some of the ops may be dynamically allocated,
1078 * they are freed after a synchronize_rcu().
1080 preempt_disable_notrace();
1082 do_for_each_ftrace_op(op, ftrace_ops_list) {
1084 * This is to check for dynamically allocated trampolines.
1085 * Trampolines that are in kernel text will have
1086 * core_kernel_text() return true.
1088 if (op->trampoline && op->trampoline_size)
1089 if (addr >= op->trampoline &&
1090 addr < op->trampoline + op->trampoline_size) {
1091 preempt_enable_notrace();
1094 } while_for_each_ftrace_op(op);
1095 preempt_enable_notrace();
1101 * This is used by __kernel_text_address() to return true if the
1102 * address is on a dynamically allocated trampoline that would
1103 * not return true for either core_kernel_text() or
1104 * is_module_text_address().
1106 bool is_ftrace_trampoline(unsigned long addr)
1108 return ftrace_ops_trampoline(addr) != NULL;
1111 struct ftrace_page {
1112 struct ftrace_page *next;
1113 struct dyn_ftrace *records;
1118 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1119 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1121 static struct ftrace_page *ftrace_pages_start;
1122 static struct ftrace_page *ftrace_pages;
1124 static __always_inline unsigned long
1125 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1127 if (hash->size_bits > 0)
1128 return hash_long(ip, hash->size_bits);
1133 /* Only use this function if ftrace_hash_empty() has already been tested */
1134 static __always_inline struct ftrace_func_entry *
1135 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1138 struct ftrace_func_entry *entry;
1139 struct hlist_head *hhd;
1141 key = ftrace_hash_key(hash, ip);
1142 hhd = &hash->buckets[key];
1144 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1145 if (entry->ip == ip)
1152 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1153 * @hash: The hash to look at
1154 * @ip: The instruction pointer to test
1156 * Search a given @hash to see if a given instruction pointer (@ip)
1159 * Returns the entry that holds the @ip if found. NULL otherwise.
1161 struct ftrace_func_entry *
1162 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1164 if (ftrace_hash_empty(hash))
1167 return __ftrace_lookup_ip(hash, ip);
1170 static void __add_hash_entry(struct ftrace_hash *hash,
1171 struct ftrace_func_entry *entry)
1173 struct hlist_head *hhd;
1176 key = ftrace_hash_key(hash, entry->ip);
1177 hhd = &hash->buckets[key];
1178 hlist_add_head(&entry->hlist, hhd);
1182 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1184 struct ftrace_func_entry *entry;
1186 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1191 __add_hash_entry(hash, entry);
1197 free_hash_entry(struct ftrace_hash *hash,
1198 struct ftrace_func_entry *entry)
1200 hlist_del(&entry->hlist);
1206 remove_hash_entry(struct ftrace_hash *hash,
1207 struct ftrace_func_entry *entry)
1209 hlist_del_rcu(&entry->hlist);
1213 static void ftrace_hash_clear(struct ftrace_hash *hash)
1215 struct hlist_head *hhd;
1216 struct hlist_node *tn;
1217 struct ftrace_func_entry *entry;
1218 int size = 1 << hash->size_bits;
1224 for (i = 0; i < size; i++) {
1225 hhd = &hash->buckets[i];
1226 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1227 free_hash_entry(hash, entry);
1229 FTRACE_WARN_ON(hash->count);
1232 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1234 list_del(&ftrace_mod->list);
1235 kfree(ftrace_mod->module);
1236 kfree(ftrace_mod->func);
1240 static void clear_ftrace_mod_list(struct list_head *head)
1242 struct ftrace_mod_load *p, *n;
1244 /* stack tracer isn't supported yet */
1248 mutex_lock(&ftrace_lock);
1249 list_for_each_entry_safe(p, n, head, list)
1251 mutex_unlock(&ftrace_lock);
1254 static void free_ftrace_hash(struct ftrace_hash *hash)
1256 if (!hash || hash == EMPTY_HASH)
1258 ftrace_hash_clear(hash);
1259 kfree(hash->buckets);
1263 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1265 struct ftrace_hash *hash;
1267 hash = container_of(rcu, struct ftrace_hash, rcu);
1268 free_ftrace_hash(hash);
1271 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1273 if (!hash || hash == EMPTY_HASH)
1275 call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
1279 * ftrace_free_filter - remove all filters for an ftrace_ops
1280 * @ops - the ops to remove the filters from
1282 void ftrace_free_filter(struct ftrace_ops *ops)
1284 ftrace_ops_init(ops);
1285 free_ftrace_hash(ops->func_hash->filter_hash);
1286 free_ftrace_hash(ops->func_hash->notrace_hash);
1288 EXPORT_SYMBOL_GPL(ftrace_free_filter);
1290 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1292 struct ftrace_hash *hash;
1295 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1299 size = 1 << size_bits;
1300 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1302 if (!hash->buckets) {
1307 hash->size_bits = size_bits;
1313 static int ftrace_add_mod(struct trace_array *tr,
1314 const char *func, const char *module,
1317 struct ftrace_mod_load *ftrace_mod;
1318 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1320 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1324 INIT_LIST_HEAD(&ftrace_mod->list);
1325 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1326 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1327 ftrace_mod->enable = enable;
1329 if (!ftrace_mod->func || !ftrace_mod->module)
1332 list_add(&ftrace_mod->list, mod_head);
1337 free_ftrace_mod(ftrace_mod);
1342 static struct ftrace_hash *
1343 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1345 struct ftrace_func_entry *entry;
1346 struct ftrace_hash *new_hash;
1351 new_hash = alloc_ftrace_hash(size_bits);
1356 new_hash->flags = hash->flags;
1359 if (ftrace_hash_empty(hash))
1362 size = 1 << hash->size_bits;
1363 for (i = 0; i < size; i++) {
1364 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1365 ret = add_hash_entry(new_hash, entry->ip);
1371 FTRACE_WARN_ON(new_hash->count != hash->count);
1376 free_ftrace_hash(new_hash);
1381 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1383 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1385 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1386 struct ftrace_hash *new_hash);
1388 static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
1390 struct ftrace_func_entry *entry;
1391 struct ftrace_hash *new_hash;
1392 struct hlist_head *hhd;
1393 struct hlist_node *tn;
1398 * Use around half the size (max bit of it), but
1399 * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits).
1401 bits = fls(size / 2);
1403 /* Don't allocate too much */
1404 if (bits > FTRACE_HASH_MAX_BITS)
1405 bits = FTRACE_HASH_MAX_BITS;
1407 new_hash = alloc_ftrace_hash(bits);
1411 new_hash->flags = src->flags;
1413 size = 1 << src->size_bits;
1414 for (i = 0; i < size; i++) {
1415 hhd = &src->buckets[i];
1416 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1417 remove_hash_entry(src, entry);
1418 __add_hash_entry(new_hash, entry);
1424 static struct ftrace_hash *
1425 __ftrace_hash_move(struct ftrace_hash *src)
1427 int size = src->count;
1430 * If the new source is empty, just return the empty_hash.
1432 if (ftrace_hash_empty(src))
1435 return dup_hash(src, size);
1439 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1440 struct ftrace_hash **dst, struct ftrace_hash *src)
1442 struct ftrace_hash *new_hash;
1445 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1446 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1449 new_hash = __ftrace_hash_move(src);
1453 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1455 /* IPMODIFY should be updated only when filter_hash updating */
1456 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1458 free_ftrace_hash(new_hash);
1464 * Remove the current set, update the hash and add
1467 ftrace_hash_rec_disable_modify(ops, enable);
1469 rcu_assign_pointer(*dst, new_hash);
1471 ftrace_hash_rec_enable_modify(ops, enable);
1476 static bool hash_contains_ip(unsigned long ip,
1477 struct ftrace_ops_hash *hash)
1480 * The function record is a match if it exists in the filter
1481 * hash and not in the notrace hash. Note, an empty hash is
1482 * considered a match for the filter hash, but an empty
1483 * notrace hash is considered not in the notrace hash.
1485 return (ftrace_hash_empty(hash->filter_hash) ||
1486 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1487 (ftrace_hash_empty(hash->notrace_hash) ||
1488 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1492 * Test the hashes for this ops to see if we want to call
1493 * the ops->func or not.
1495 * It's a match if the ip is in the ops->filter_hash or
1496 * the filter_hash does not exist or is empty,
1498 * the ip is not in the ops->notrace_hash.
1500 * This needs to be called with preemption disabled as
1501 * the hashes are freed with call_rcu().
1504 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1506 struct ftrace_ops_hash hash;
1509 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1511 * There's a small race when adding ops that the ftrace handler
1512 * that wants regs, may be called without them. We can not
1513 * allow that handler to be called if regs is NULL.
1515 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1519 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1520 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1522 if (hash_contains_ip(ip, &hash))
1531 * This is a double for. Do not use 'break' to break out of the loop,
1532 * you must use a goto.
1534 #define do_for_each_ftrace_rec(pg, rec) \
1535 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1537 for (_____i = 0; _____i < pg->index; _____i++) { \
1538 rec = &pg->records[_____i];
1540 #define while_for_each_ftrace_rec() \
1545 static int ftrace_cmp_recs(const void *a, const void *b)
1547 const struct dyn_ftrace *key = a;
1548 const struct dyn_ftrace *rec = b;
1550 if (key->flags < rec->ip)
1552 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1557 static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
1559 struct ftrace_page *pg;
1560 struct dyn_ftrace *rec = NULL;
1561 struct dyn_ftrace key;
1564 key.flags = end; /* overload flags, as it is unsigned long */
1566 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1567 if (pg->index == 0 ||
1568 end < pg->records[0].ip ||
1569 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1571 rec = bsearch(&key, pg->records, pg->index,
1572 sizeof(struct dyn_ftrace),
1581 * ftrace_location_range - return the first address of a traced location
1582 * if it touches the given ip range
1583 * @start: start of range to search.
1584 * @end: end of range to search (inclusive). @end points to the last byte
1587 * Returns rec->ip if the related ftrace location is a least partly within
1588 * the given address range. That is, the first address of the instruction
1589 * that is either a NOP or call to the function tracer. It checks the ftrace
1590 * internal tables to determine if the address belongs or not.
1592 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1594 struct dyn_ftrace *rec;
1596 rec = lookup_rec(start, end);
1604 * ftrace_location - return the ftrace location
1605 * @ip: the instruction pointer to check
1607 * If @ip matches the ftrace location, return @ip.
1608 * If @ip matches sym+0, return sym's ftrace location.
1609 * Otherwise, return 0.
1611 unsigned long ftrace_location(unsigned long ip)
1613 struct dyn_ftrace *rec;
1614 unsigned long offset;
1617 rec = lookup_rec(ip, ip);
1619 if (!kallsyms_lookup_size_offset(ip, &size, &offset))
1622 /* map sym+0 to __fentry__ */
1624 rec = lookup_rec(ip, ip + size - 1);
1635 * ftrace_text_reserved - return true if range contains an ftrace location
1636 * @start: start of range to search
1637 * @end: end of range to search (inclusive). @end points to the last byte to check.
1639 * Returns 1 if @start and @end contains a ftrace location.
1640 * That is, the instruction that is either a NOP or call to
1641 * the function tracer. It checks the ftrace internal tables to
1642 * determine if the address belongs or not.
1644 int ftrace_text_reserved(const void *start, const void *end)
1648 ret = ftrace_location_range((unsigned long)start,
1649 (unsigned long)end);
1654 /* Test if ops registered to this rec needs regs */
1655 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1657 struct ftrace_ops *ops;
1658 bool keep_regs = false;
1660 for (ops = ftrace_ops_list;
1661 ops != &ftrace_list_end; ops = ops->next) {
1662 /* pass rec in as regs to have non-NULL val */
1663 if (ftrace_ops_test(ops, rec->ip, rec)) {
1664 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1674 static struct ftrace_ops *
1675 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1676 static struct ftrace_ops *
1677 ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude);
1678 static struct ftrace_ops *
1679 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1681 static bool skip_record(struct dyn_ftrace *rec)
1684 * At boot up, weak functions are set to disable. Function tracing
1685 * can be enabled before they are, and they still need to be disabled now.
1686 * If the record is disabled, still continue if it is marked as already
1687 * enabled (this is needed to keep the accounting working).
1689 return rec->flags & FTRACE_FL_DISABLED &&
1690 !(rec->flags & FTRACE_FL_ENABLED);
1693 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1697 struct ftrace_hash *hash;
1698 struct ftrace_hash *other_hash;
1699 struct ftrace_page *pg;
1700 struct dyn_ftrace *rec;
1701 bool update = false;
1705 /* Only update if the ops has been registered */
1706 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1710 * In the filter_hash case:
1711 * If the count is zero, we update all records.
1712 * Otherwise we just update the items in the hash.
1714 * In the notrace_hash case:
1715 * We enable the update in the hash.
1716 * As disabling notrace means enabling the tracing,
1717 * and enabling notrace means disabling, the inc variable
1721 hash = ops->func_hash->filter_hash;
1722 other_hash = ops->func_hash->notrace_hash;
1723 if (ftrace_hash_empty(hash))
1727 hash = ops->func_hash->notrace_hash;
1728 other_hash = ops->func_hash->filter_hash;
1730 * If the notrace hash has no items,
1731 * then there's nothing to do.
1733 if (ftrace_hash_empty(hash))
1737 do_for_each_ftrace_rec(pg, rec) {
1738 int in_other_hash = 0;
1742 if (skip_record(rec))
1747 * Only the filter_hash affects all records.
1748 * Update if the record is not in the notrace hash.
1750 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1753 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1754 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1757 * If filter_hash is set, we want to match all functions
1758 * that are in the hash but not in the other hash.
1760 * If filter_hash is not set, then we are decrementing.
1761 * That means we match anything that is in the hash
1762 * and also in the other_hash. That is, we need to turn
1763 * off functions in the other hash because they are disabled
1766 if (filter_hash && in_hash && !in_other_hash)
1768 else if (!filter_hash && in_hash &&
1769 (in_other_hash || ftrace_hash_empty(other_hash)))
1777 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1780 if (ops->flags & FTRACE_OPS_FL_DIRECT)
1781 rec->flags |= FTRACE_FL_DIRECT;
1784 * If there's only a single callback registered to a
1785 * function, and the ops has a trampoline registered
1786 * for it, then we can call it directly.
1788 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1789 rec->flags |= FTRACE_FL_TRAMP;
1792 * If we are adding another function callback
1793 * to this function, and the previous had a
1794 * custom trampoline in use, then we need to go
1795 * back to the default trampoline.
1797 rec->flags &= ~FTRACE_FL_TRAMP;
1800 * If any ops wants regs saved for this function
1801 * then all ops will get saved regs.
1803 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1804 rec->flags |= FTRACE_FL_REGS;
1806 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1811 * Only the internal direct_ops should have the
1812 * DIRECT flag set. Thus, if it is removing a
1813 * function, then that function should no longer
1816 if (ops->flags & FTRACE_OPS_FL_DIRECT)
1817 rec->flags &= ~FTRACE_FL_DIRECT;
1820 * If the rec had REGS enabled and the ops that is
1821 * being removed had REGS set, then see if there is
1822 * still any ops for this record that wants regs.
1823 * If not, we can stop recording them.
1825 if (ftrace_rec_count(rec) > 0 &&
1826 rec->flags & FTRACE_FL_REGS &&
1827 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1828 if (!test_rec_ops_needs_regs(rec))
1829 rec->flags &= ~FTRACE_FL_REGS;
1833 * The TRAMP needs to be set only if rec count
1834 * is decremented to one, and the ops that is
1835 * left has a trampoline. As TRAMP can only be
1836 * enabled if there is only a single ops attached
1839 if (ftrace_rec_count(rec) == 1 &&
1840 ftrace_find_tramp_ops_any_other(rec, ops))
1841 rec->flags |= FTRACE_FL_TRAMP;
1843 rec->flags &= ~FTRACE_FL_TRAMP;
1846 * flags will be cleared in ftrace_check_record()
1847 * if rec count is zero.
1852 * If the rec has a single associated ops, and ops->func can be
1853 * called directly, allow the call site to call via the ops.
1855 if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) &&
1856 ftrace_rec_count(rec) == 1 &&
1857 ftrace_ops_get_func(ops) == ops->func)
1858 rec->flags |= FTRACE_FL_CALL_OPS;
1860 rec->flags &= ~FTRACE_FL_CALL_OPS;
1864 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1865 update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
1867 /* Shortcut, if we handled all records, we are done. */
1868 if (!all && count == hash->count)
1870 } while_for_each_ftrace_rec();
1875 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1878 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1881 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1884 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1887 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1888 int filter_hash, int inc)
1890 struct ftrace_ops *op;
1892 __ftrace_hash_rec_update(ops, filter_hash, inc);
1894 if (ops->func_hash != &global_ops.local_hash)
1898 * If the ops shares the global_ops hash, then we need to update
1899 * all ops that are enabled and use this hash.
1901 do_for_each_ftrace_op(op, ftrace_ops_list) {
1905 if (op->func_hash == &global_ops.local_hash)
1906 __ftrace_hash_rec_update(op, filter_hash, inc);
1907 } while_for_each_ftrace_op(op);
1910 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1913 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1916 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1919 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1923 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1924 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1925 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1926 * Note that old_hash and new_hash has below meanings
1927 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1928 * - If the hash is EMPTY_HASH, it hits nothing
1929 * - Anything else hits the recs which match the hash entries.
1931 * DIRECT ops does not have IPMODIFY flag, but we still need to check it
1932 * against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call
1933 * ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with
1934 * IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate
1935 * the return value to the caller and eventually to the owner of the DIRECT
1938 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1939 struct ftrace_hash *old_hash,
1940 struct ftrace_hash *new_hash)
1942 struct ftrace_page *pg;
1943 struct dyn_ftrace *rec, *end = NULL;
1945 bool is_ipmodify, is_direct;
1947 /* Only update if the ops has been registered */
1948 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1951 is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY;
1952 is_direct = ops->flags & FTRACE_OPS_FL_DIRECT;
1954 /* neither IPMODIFY nor DIRECT, skip */
1955 if (!is_ipmodify && !is_direct)
1958 if (WARN_ON_ONCE(is_ipmodify && is_direct))
1962 * Since the IPMODIFY and DIRECT are very address sensitive
1963 * actions, we do not allow ftrace_ops to set all functions to new
1966 if (!new_hash || !old_hash)
1969 /* Update rec->flags */
1970 do_for_each_ftrace_rec(pg, rec) {
1972 if (rec->flags & FTRACE_FL_DISABLED)
1975 /* We need to update only differences of filter_hash */
1976 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1977 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1978 if (in_old == in_new)
1982 if (rec->flags & FTRACE_FL_IPMODIFY) {
1985 /* Cannot have two ipmodify on same rec */
1989 FTRACE_WARN_ON(rec->flags & FTRACE_FL_DIRECT);
1992 * Another ops with IPMODIFY is already
1993 * attached. We are now attaching a direct
1994 * ops. Run SHARE_IPMODIFY_SELF, to check
1995 * whether sharing is supported.
1999 ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF);
2002 } else if (is_ipmodify) {
2003 rec->flags |= FTRACE_FL_IPMODIFY;
2005 } else if (is_ipmodify) {
2006 rec->flags &= ~FTRACE_FL_IPMODIFY;
2008 } while_for_each_ftrace_rec();
2015 /* Roll back what we did above */
2016 do_for_each_ftrace_rec(pg, rec) {
2018 if (rec->flags & FTRACE_FL_DISABLED)
2024 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
2025 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
2026 if (in_old == in_new)
2030 rec->flags &= ~FTRACE_FL_IPMODIFY;
2032 rec->flags |= FTRACE_FL_IPMODIFY;
2033 } while_for_each_ftrace_rec();
2039 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
2041 struct ftrace_hash *hash = ops->func_hash->filter_hash;
2043 if (ftrace_hash_empty(hash))
2046 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
2049 /* Disabling always succeeds */
2050 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
2052 struct ftrace_hash *hash = ops->func_hash->filter_hash;
2054 if (ftrace_hash_empty(hash))
2057 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
2060 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
2061 struct ftrace_hash *new_hash)
2063 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
2065 if (ftrace_hash_empty(old_hash))
2068 if (ftrace_hash_empty(new_hash))
2071 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
2074 static void print_ip_ins(const char *fmt, const unsigned char *p)
2076 char ins[MCOUNT_INSN_SIZE];
2078 if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
2079 printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
2083 printk(KERN_CONT "%s", fmt);
2084 pr_cont("%*phC", MCOUNT_INSN_SIZE, ins);
2087 enum ftrace_bug_type ftrace_bug_type;
2088 const void *ftrace_expected;
2090 static void print_bug_type(void)
2092 switch (ftrace_bug_type) {
2093 case FTRACE_BUG_UNKNOWN:
2095 case FTRACE_BUG_INIT:
2096 pr_info("Initializing ftrace call sites\n");
2098 case FTRACE_BUG_NOP:
2099 pr_info("Setting ftrace call site to NOP\n");
2101 case FTRACE_BUG_CALL:
2102 pr_info("Setting ftrace call site to call ftrace function\n");
2104 case FTRACE_BUG_UPDATE:
2105 pr_info("Updating ftrace call site to call a different ftrace function\n");
2111 * ftrace_bug - report and shutdown function tracer
2112 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2113 * @rec: The record that failed
2115 * The arch code that enables or disables the function tracing
2116 * can call ftrace_bug() when it has detected a problem in
2117 * modifying the code. @failed should be one of either:
2118 * EFAULT - if the problem happens on reading the @ip address
2119 * EINVAL - if what is read at @ip is not what was expected
2120 * EPERM - if the problem happens on writing to the @ip address
2122 void ftrace_bug(int failed, struct dyn_ftrace *rec)
2124 unsigned long ip = rec ? rec->ip : 0;
2126 pr_info("------------[ ftrace bug ]------------\n");
2130 pr_info("ftrace faulted on modifying ");
2131 print_ip_sym(KERN_INFO, ip);
2134 pr_info("ftrace failed to modify ");
2135 print_ip_sym(KERN_INFO, ip);
2136 print_ip_ins(" actual: ", (unsigned char *)ip);
2138 if (ftrace_expected) {
2139 print_ip_ins(" expected: ", ftrace_expected);
2144 pr_info("ftrace faulted on writing ");
2145 print_ip_sym(KERN_INFO, ip);
2148 pr_info("ftrace faulted on unknown error ");
2149 print_ip_sym(KERN_INFO, ip);
2153 struct ftrace_ops *ops = NULL;
2155 pr_info("ftrace record flags: %lx\n", rec->flags);
2156 pr_cont(" (%ld)%s%s", ftrace_rec_count(rec),
2157 rec->flags & FTRACE_FL_REGS ? " R" : " ",
2158 rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ");
2159 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2160 ops = ftrace_find_tramp_ops_any(rec);
2163 pr_cont("\ttramp: %pS (%pS)",
2164 (void *)ops->trampoline,
2166 ops = ftrace_find_tramp_ops_next(rec, ops);
2169 pr_cont("\ttramp: ERROR!");
2172 ip = ftrace_get_addr_curr(rec);
2173 pr_cont("\n expected tramp: %lx\n", ip);
2176 FTRACE_WARN_ON_ONCE(1);
2179 static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
2181 unsigned long flag = 0UL;
2183 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2185 if (skip_record(rec))
2186 return FTRACE_UPDATE_IGNORE;
2189 * If we are updating calls:
2191 * If the record has a ref count, then we need to enable it
2192 * because someone is using it.
2194 * Otherwise we make sure its disabled.
2196 * If we are disabling calls, then disable all records that
2199 if (enable && ftrace_rec_count(rec))
2200 flag = FTRACE_FL_ENABLED;
2203 * If enabling and the REGS flag does not match the REGS_EN, or
2204 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2205 * this record. Set flags to fail the compare against ENABLED.
2206 * Same for direct calls.
2209 if (!(rec->flags & FTRACE_FL_REGS) !=
2210 !(rec->flags & FTRACE_FL_REGS_EN))
2211 flag |= FTRACE_FL_REGS;
2213 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2214 !(rec->flags & FTRACE_FL_TRAMP_EN))
2215 flag |= FTRACE_FL_TRAMP;
2218 * Direct calls are special, as count matters.
2219 * We must test the record for direct, if the
2220 * DIRECT and DIRECT_EN do not match, but only
2221 * if the count is 1. That's because, if the
2222 * count is something other than one, we do not
2223 * want the direct enabled (it will be done via the
2224 * direct helper). But if DIRECT_EN is set, and
2225 * the count is not one, we need to clear it.
2228 if (ftrace_rec_count(rec) == 1) {
2229 if (!(rec->flags & FTRACE_FL_DIRECT) !=
2230 !(rec->flags & FTRACE_FL_DIRECT_EN))
2231 flag |= FTRACE_FL_DIRECT;
2232 } else if (rec->flags & FTRACE_FL_DIRECT_EN) {
2233 flag |= FTRACE_FL_DIRECT;
2237 * Ops calls are special, as count matters.
2238 * As with direct calls, they must only be enabled when count
2239 * is one, otherwise they'll be handled via the list ops.
2241 if (ftrace_rec_count(rec) == 1) {
2242 if (!(rec->flags & FTRACE_FL_CALL_OPS) !=
2243 !(rec->flags & FTRACE_FL_CALL_OPS_EN))
2244 flag |= FTRACE_FL_CALL_OPS;
2245 } else if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
2246 flag |= FTRACE_FL_CALL_OPS;
2250 /* If the state of this record hasn't changed, then do nothing */
2251 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2252 return FTRACE_UPDATE_IGNORE;
2255 /* Save off if rec is being enabled (for return value) */
2256 flag ^= rec->flags & FTRACE_FL_ENABLED;
2259 rec->flags |= FTRACE_FL_ENABLED;
2260 if (flag & FTRACE_FL_REGS) {
2261 if (rec->flags & FTRACE_FL_REGS)
2262 rec->flags |= FTRACE_FL_REGS_EN;
2264 rec->flags &= ~FTRACE_FL_REGS_EN;
2266 if (flag & FTRACE_FL_TRAMP) {
2267 if (rec->flags & FTRACE_FL_TRAMP)
2268 rec->flags |= FTRACE_FL_TRAMP_EN;
2270 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2273 if (flag & FTRACE_FL_DIRECT) {
2275 * If there's only one user (direct_ops helper)
2276 * then we can call the direct function
2277 * directly (no ftrace trampoline).
2279 if (ftrace_rec_count(rec) == 1) {
2280 if (rec->flags & FTRACE_FL_DIRECT)
2281 rec->flags |= FTRACE_FL_DIRECT_EN;
2283 rec->flags &= ~FTRACE_FL_DIRECT_EN;
2286 * Can only call directly if there's
2287 * only one callback to the function.
2289 rec->flags &= ~FTRACE_FL_DIRECT_EN;
2293 if (flag & FTRACE_FL_CALL_OPS) {
2294 if (ftrace_rec_count(rec) == 1) {
2295 if (rec->flags & FTRACE_FL_CALL_OPS)
2296 rec->flags |= FTRACE_FL_CALL_OPS_EN;
2298 rec->flags &= ~FTRACE_FL_CALL_OPS_EN;
2301 * Can only call directly if there's
2302 * only one set of associated ops.
2304 rec->flags &= ~FTRACE_FL_CALL_OPS_EN;
2310 * If this record is being updated from a nop, then
2311 * return UPDATE_MAKE_CALL.
2313 * return UPDATE_MODIFY_CALL to tell the caller to convert
2314 * from the save regs, to a non-save regs function or
2315 * vice versa, or from a trampoline call.
2317 if (flag & FTRACE_FL_ENABLED) {
2318 ftrace_bug_type = FTRACE_BUG_CALL;
2319 return FTRACE_UPDATE_MAKE_CALL;
2322 ftrace_bug_type = FTRACE_BUG_UPDATE;
2323 return FTRACE_UPDATE_MODIFY_CALL;
2327 /* If there's no more users, clear all flags */
2328 if (!ftrace_rec_count(rec))
2329 rec->flags &= FTRACE_FL_DISABLED;
2332 * Just disable the record, but keep the ops TRAMP
2333 * and REGS states. The _EN flags must be disabled though.
2335 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2336 FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN |
2337 FTRACE_FL_CALL_OPS_EN);
2340 ftrace_bug_type = FTRACE_BUG_NOP;
2341 return FTRACE_UPDATE_MAKE_NOP;
2345 * ftrace_update_record - set a record that now is tracing or not
2346 * @rec: the record to update
2347 * @enable: set to true if the record is tracing, false to force disable
2349 * The records that represent all functions that can be traced need
2350 * to be updated when tracing has been enabled.
2352 int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
2354 return ftrace_check_record(rec, enable, true);
2358 * ftrace_test_record - check if the record has been enabled or not
2359 * @rec: the record to test
2360 * @enable: set to true to check if enabled, false if it is disabled
2362 * The arch code may need to test if a record is already set to
2363 * tracing to determine how to modify the function code that it
2366 int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
2368 return ftrace_check_record(rec, enable, false);
2371 static struct ftrace_ops *
2372 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2374 struct ftrace_ops *op;
2375 unsigned long ip = rec->ip;
2377 do_for_each_ftrace_op(op, ftrace_ops_list) {
2379 if (!op->trampoline)
2382 if (hash_contains_ip(ip, op->func_hash))
2384 } while_for_each_ftrace_op(op);
2389 static struct ftrace_ops *
2390 ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude)
2392 struct ftrace_ops *op;
2393 unsigned long ip = rec->ip;
2395 do_for_each_ftrace_op(op, ftrace_ops_list) {
2397 if (op == op_exclude || !op->trampoline)
2400 if (hash_contains_ip(ip, op->func_hash))
2402 } while_for_each_ftrace_op(op);
2407 static struct ftrace_ops *
2408 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2409 struct ftrace_ops *op)
2411 unsigned long ip = rec->ip;
2413 while_for_each_ftrace_op(op) {
2415 if (!op->trampoline)
2418 if (hash_contains_ip(ip, op->func_hash))
2425 static struct ftrace_ops *
2426 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2428 struct ftrace_ops *op;
2429 unsigned long ip = rec->ip;
2432 * Need to check removed ops first.
2433 * If they are being removed, and this rec has a tramp,
2434 * and this rec is in the ops list, then it would be the
2435 * one with the tramp.
2438 if (hash_contains_ip(ip, &removed_ops->old_hash))
2443 * Need to find the current trampoline for a rec.
2444 * Now, a trampoline is only attached to a rec if there
2445 * was a single 'ops' attached to it. But this can be called
2446 * when we are adding another op to the rec or removing the
2447 * current one. Thus, if the op is being added, we can
2448 * ignore it because it hasn't attached itself to the rec
2451 * If an ops is being modified (hooking to different functions)
2452 * then we don't care about the new functions that are being
2453 * added, just the old ones (that are probably being removed).
2455 * If we are adding an ops to a function that already is using
2456 * a trampoline, it needs to be removed (trampolines are only
2457 * for single ops connected), then an ops that is not being
2458 * modified also needs to be checked.
2460 do_for_each_ftrace_op(op, ftrace_ops_list) {
2462 if (!op->trampoline)
2466 * If the ops is being added, it hasn't gotten to
2467 * the point to be removed from this tree yet.
2469 if (op->flags & FTRACE_OPS_FL_ADDING)
2474 * If the ops is being modified and is in the old
2475 * hash, then it is probably being removed from this
2478 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2479 hash_contains_ip(ip, &op->old_hash))
2482 * If the ops is not being added or modified, and it's
2483 * in its normal filter hash, then this must be the one
2486 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2487 hash_contains_ip(ip, op->func_hash))
2490 } while_for_each_ftrace_op(op);
2495 static struct ftrace_ops *
2496 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2498 struct ftrace_ops *op;
2499 unsigned long ip = rec->ip;
2501 do_for_each_ftrace_op(op, ftrace_ops_list) {
2502 /* pass rec in as regs to have non-NULL val */
2503 if (hash_contains_ip(ip, op->func_hash))
2505 } while_for_each_ftrace_op(op);
2511 ftrace_find_unique_ops(struct dyn_ftrace *rec)
2513 struct ftrace_ops *op, *found = NULL;
2514 unsigned long ip = rec->ip;
2516 do_for_each_ftrace_op(op, ftrace_ops_list) {
2518 if (hash_contains_ip(ip, op->func_hash)) {
2524 } while_for_each_ftrace_op(op);
2529 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
2530 /* Protected by rcu_tasks for reading, and direct_mutex for writing */
2531 static struct ftrace_hash *direct_functions = EMPTY_HASH;
2532 static DEFINE_MUTEX(direct_mutex);
2533 int ftrace_direct_func_count;
2536 * Search the direct_functions hash to see if the given instruction pointer
2537 * has a direct caller attached to it.
2539 unsigned long ftrace_find_rec_direct(unsigned long ip)
2541 struct ftrace_func_entry *entry;
2543 entry = __ftrace_lookup_ip(direct_functions, ip);
2547 return entry->direct;
2550 static struct ftrace_func_entry*
2551 ftrace_add_rec_direct(unsigned long ip, unsigned long addr,
2552 struct ftrace_hash **free_hash)
2554 struct ftrace_func_entry *entry;
2556 if (ftrace_hash_empty(direct_functions) ||
2557 direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
2558 struct ftrace_hash *new_hash;
2559 int size = ftrace_hash_empty(direct_functions) ? 0 :
2560 direct_functions->count + 1;
2565 new_hash = dup_hash(direct_functions, size);
2569 *free_hash = direct_functions;
2570 direct_functions = new_hash;
2573 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2578 entry->direct = addr;
2579 __add_hash_entry(direct_functions, entry);
2583 static void call_direct_funcs(unsigned long ip, unsigned long pip,
2584 struct ftrace_ops *ops, struct ftrace_regs *fregs)
2586 unsigned long addr = READ_ONCE(ops->direct_call);
2591 arch_ftrace_set_direct_caller(fregs, addr);
2593 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
2596 * ftrace_get_addr_new - Get the call address to set to
2597 * @rec: The ftrace record descriptor
2599 * If the record has the FTRACE_FL_REGS set, that means that it
2600 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2601 * is not set, then it wants to convert to the normal callback.
2603 * Returns the address of the trampoline to set to
2605 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2607 struct ftrace_ops *ops;
2610 if ((rec->flags & FTRACE_FL_DIRECT) &&
2611 (ftrace_rec_count(rec) == 1)) {
2612 addr = ftrace_find_rec_direct(rec->ip);
2618 /* Trampolines take precedence over regs */
2619 if (rec->flags & FTRACE_FL_TRAMP) {
2620 ops = ftrace_find_tramp_ops_new(rec);
2621 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2622 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2623 (void *)rec->ip, (void *)rec->ip, rec->flags);
2624 /* Ftrace is shutting down, return anything */
2625 return (unsigned long)FTRACE_ADDR;
2627 return ops->trampoline;
2630 if (rec->flags & FTRACE_FL_REGS)
2631 return (unsigned long)FTRACE_REGS_ADDR;
2633 return (unsigned long)FTRACE_ADDR;
2637 * ftrace_get_addr_curr - Get the call address that is already there
2638 * @rec: The ftrace record descriptor
2640 * The FTRACE_FL_REGS_EN is set when the record already points to
2641 * a function that saves all the regs. Basically the '_EN' version
2642 * represents the current state of the function.
2644 * Returns the address of the trampoline that is currently being called
2646 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2648 struct ftrace_ops *ops;
2651 /* Direct calls take precedence over trampolines */
2652 if (rec->flags & FTRACE_FL_DIRECT_EN) {
2653 addr = ftrace_find_rec_direct(rec->ip);
2659 /* Trampolines take precedence over regs */
2660 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2661 ops = ftrace_find_tramp_ops_curr(rec);
2662 if (FTRACE_WARN_ON(!ops)) {
2663 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2664 (void *)rec->ip, (void *)rec->ip);
2665 /* Ftrace is shutting down, return anything */
2666 return (unsigned long)FTRACE_ADDR;
2668 return ops->trampoline;
2671 if (rec->flags & FTRACE_FL_REGS_EN)
2672 return (unsigned long)FTRACE_REGS_ADDR;
2674 return (unsigned long)FTRACE_ADDR;
2678 __ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
2680 unsigned long ftrace_old_addr;
2681 unsigned long ftrace_addr;
2684 ftrace_addr = ftrace_get_addr_new(rec);
2686 /* This needs to be done before we call ftrace_update_record */
2687 ftrace_old_addr = ftrace_get_addr_curr(rec);
2689 ret = ftrace_update_record(rec, enable);
2691 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2694 case FTRACE_UPDATE_IGNORE:
2697 case FTRACE_UPDATE_MAKE_CALL:
2698 ftrace_bug_type = FTRACE_BUG_CALL;
2699 return ftrace_make_call(rec, ftrace_addr);
2701 case FTRACE_UPDATE_MAKE_NOP:
2702 ftrace_bug_type = FTRACE_BUG_NOP;
2703 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2705 case FTRACE_UPDATE_MODIFY_CALL:
2706 ftrace_bug_type = FTRACE_BUG_UPDATE;
2707 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2710 return -1; /* unknown ftrace bug */
2713 void __weak ftrace_replace_code(int mod_flags)
2715 struct dyn_ftrace *rec;
2716 struct ftrace_page *pg;
2717 bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2718 int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2721 if (unlikely(ftrace_disabled))
2724 do_for_each_ftrace_rec(pg, rec) {
2726 if (skip_record(rec))
2729 failed = __ftrace_replace_code(rec, enable);
2731 ftrace_bug(failed, rec);
2732 /* Stop processing */
2737 } while_for_each_ftrace_rec();
2740 struct ftrace_rec_iter {
2741 struct ftrace_page *pg;
2746 * ftrace_rec_iter_start - start up iterating over traced functions
2748 * Returns an iterator handle that is used to iterate over all
2749 * the records that represent address locations where functions
2752 * May return NULL if no records are available.
2754 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2757 * We only use a single iterator.
2758 * Protected by the ftrace_lock mutex.
2760 static struct ftrace_rec_iter ftrace_rec_iter;
2761 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2763 iter->pg = ftrace_pages_start;
2766 /* Could have empty pages */
2767 while (iter->pg && !iter->pg->index)
2768 iter->pg = iter->pg->next;
2777 * ftrace_rec_iter_next - get the next record to process.
2778 * @iter: The handle to the iterator.
2780 * Returns the next iterator after the given iterator @iter.
2782 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2786 if (iter->index >= iter->pg->index) {
2787 iter->pg = iter->pg->next;
2790 /* Could have empty pages */
2791 while (iter->pg && !iter->pg->index)
2792 iter->pg = iter->pg->next;
2802 * ftrace_rec_iter_record - get the record at the iterator location
2803 * @iter: The current iterator location
2805 * Returns the record that the current @iter is at.
2807 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2809 return &iter->pg->records[iter->index];
2813 ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
2817 if (unlikely(ftrace_disabled))
2820 ret = ftrace_init_nop(mod, rec);
2822 ftrace_bug_type = FTRACE_BUG_INIT;
2823 ftrace_bug(ret, rec);
2830 * archs can override this function if they must do something
2831 * before the modifying code is performed.
2833 void __weak ftrace_arch_code_modify_prepare(void)
2838 * archs can override this function if they must do something
2839 * after the modifying code is performed.
2841 void __weak ftrace_arch_code_modify_post_process(void)
2845 static int update_ftrace_func(ftrace_func_t func)
2847 static ftrace_func_t save_func;
2849 /* Avoid updating if it hasn't changed */
2850 if (func == save_func)
2855 return ftrace_update_ftrace_func(func);
2858 void ftrace_modify_all_code(int command)
2860 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2864 if (command & FTRACE_MAY_SLEEP)
2865 mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2868 * If the ftrace_caller calls a ftrace_ops func directly,
2869 * we need to make sure that it only traces functions it
2870 * expects to trace. When doing the switch of functions,
2871 * we need to update to the ftrace_ops_list_func first
2872 * before the transition between old and new calls are set,
2873 * as the ftrace_ops_list_func will check the ops hashes
2874 * to make sure the ops are having the right functions
2878 err = update_ftrace_func(ftrace_ops_list_func);
2879 if (FTRACE_WARN_ON(err))
2883 if (command & FTRACE_UPDATE_CALLS)
2884 ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
2885 else if (command & FTRACE_DISABLE_CALLS)
2886 ftrace_replace_code(mod_flags);
2888 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2889 function_trace_op = set_function_trace_op;
2891 /* If irqs are disabled, we are in stop machine */
2892 if (!irqs_disabled())
2893 smp_call_function(ftrace_sync_ipi, NULL, 1);
2894 err = update_ftrace_func(ftrace_trace_function);
2895 if (FTRACE_WARN_ON(err))
2899 if (command & FTRACE_START_FUNC_RET)
2900 err = ftrace_enable_ftrace_graph_caller();
2901 else if (command & FTRACE_STOP_FUNC_RET)
2902 err = ftrace_disable_ftrace_graph_caller();
2903 FTRACE_WARN_ON(err);
2906 static int __ftrace_modify_code(void *data)
2908 int *command = data;
2910 ftrace_modify_all_code(*command);
2916 * ftrace_run_stop_machine - go back to the stop machine method
2917 * @command: The command to tell ftrace what to do
2919 * If an arch needs to fall back to the stop machine method, the
2920 * it can call this function.
2922 void ftrace_run_stop_machine(int command)
2924 stop_machine(__ftrace_modify_code, &command, NULL);
2928 * arch_ftrace_update_code - modify the code to trace or not trace
2929 * @command: The command that needs to be done
2931 * Archs can override this function if it does not need to
2932 * run stop_machine() to modify code.
2934 void __weak arch_ftrace_update_code(int command)
2936 ftrace_run_stop_machine(command);
2939 static void ftrace_run_update_code(int command)
2941 ftrace_arch_code_modify_prepare();
2944 * By default we use stop_machine() to modify the code.
2945 * But archs can do what ever they want as long as it
2946 * is safe. The stop_machine() is the safest, but also
2947 * produces the most overhead.
2949 arch_ftrace_update_code(command);
2951 ftrace_arch_code_modify_post_process();
2954 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2955 struct ftrace_ops_hash *old_hash)
2957 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2958 ops->old_hash.filter_hash = old_hash->filter_hash;
2959 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2960 ftrace_run_update_code(command);
2961 ops->old_hash.filter_hash = NULL;
2962 ops->old_hash.notrace_hash = NULL;
2963 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2966 static ftrace_func_t saved_ftrace_func;
2967 static int ftrace_start_up;
2969 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2973 /* List of trace_ops that have allocated trampolines */
2974 static LIST_HEAD(ftrace_ops_trampoline_list);
2976 static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
2978 lockdep_assert_held(&ftrace_lock);
2979 list_add_rcu(&ops->list, &ftrace_ops_trampoline_list);
2982 static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
2984 lockdep_assert_held(&ftrace_lock);
2985 list_del_rcu(&ops->list);
2990 * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
2991 * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
2994 #define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
2995 #define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
2997 static void ftrace_trampoline_free(struct ftrace_ops *ops)
2999 if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
3002 * Record the text poke event before the ksymbol unregister
3005 perf_event_text_poke((void *)ops->trampoline,
3006 (void *)ops->trampoline,
3007 ops->trampoline_size, NULL, 0);
3008 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
3009 ops->trampoline, ops->trampoline_size,
3010 true, FTRACE_TRAMPOLINE_SYM);
3011 /* Remove from kallsyms after the perf events */
3012 ftrace_remove_trampoline_from_kallsyms(ops);
3015 arch_ftrace_trampoline_free(ops);
3018 static void ftrace_startup_enable(int command)
3020 if (saved_ftrace_func != ftrace_trace_function) {
3021 saved_ftrace_func = ftrace_trace_function;
3022 command |= FTRACE_UPDATE_TRACE_FUNC;
3025 if (!command || !ftrace_enabled)
3028 ftrace_run_update_code(command);
3031 static void ftrace_startup_all(int command)
3033 update_all_ops = true;
3034 ftrace_startup_enable(command);
3035 update_all_ops = false;
3038 int ftrace_startup(struct ftrace_ops *ops, int command)
3042 if (unlikely(ftrace_disabled))
3045 ret = __register_ftrace_function(ops);
3052 * Note that ftrace probes uses this to start up
3053 * and modify functions it will probe. But we still
3054 * set the ADDING flag for modification, as probes
3055 * do not have trampolines. If they add them in the
3056 * future, then the probes will need to distinguish
3057 * between adding and updating probes.
3059 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
3061 ret = ftrace_hash_ipmodify_enable(ops);
3063 /* Rollback registration process */
3064 __unregister_ftrace_function(ops);
3066 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3067 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
3068 ftrace_trampoline_free(ops);
3072 if (ftrace_hash_rec_enable(ops, 1))
3073 command |= FTRACE_UPDATE_CALLS;
3075 ftrace_startup_enable(command);
3078 * If ftrace is in an undefined state, we just remove ops from list
3079 * to prevent the NULL pointer, instead of totally rolling it back and
3080 * free trampoline, because those actions could cause further damage.
3082 if (unlikely(ftrace_disabled)) {
3083 __unregister_ftrace_function(ops);
3087 ops->flags &= ~FTRACE_OPS_FL_ADDING;
3092 int ftrace_shutdown(struct ftrace_ops *ops, int command)
3096 if (unlikely(ftrace_disabled))
3099 ret = __unregister_ftrace_function(ops);
3105 * Just warn in case of unbalance, no need to kill ftrace, it's not
3106 * critical but the ftrace_call callers may be never nopped again after
3107 * further ftrace uses.
3109 WARN_ON_ONCE(ftrace_start_up < 0);
3111 /* Disabling ipmodify never fails */
3112 ftrace_hash_ipmodify_disable(ops);
3114 if (ftrace_hash_rec_disable(ops, 1))
3115 command |= FTRACE_UPDATE_CALLS;
3117 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3119 if (saved_ftrace_func != ftrace_trace_function) {
3120 saved_ftrace_func = ftrace_trace_function;
3121 command |= FTRACE_UPDATE_TRACE_FUNC;
3124 if (!command || !ftrace_enabled)
3128 * If the ops uses a trampoline, then it needs to be
3129 * tested first on update.
3131 ops->flags |= FTRACE_OPS_FL_REMOVING;
3134 /* The trampoline logic checks the old hashes */
3135 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
3136 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
3138 ftrace_run_update_code(command);
3141 * If there's no more ops registered with ftrace, run a
3142 * sanity check to make sure all rec flags are cleared.
3144 if (rcu_dereference_protected(ftrace_ops_list,
3145 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
3146 struct ftrace_page *pg;
3147 struct dyn_ftrace *rec;
3149 do_for_each_ftrace_rec(pg, rec) {
3150 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
3151 pr_warn(" %pS flags:%lx\n",
3152 (void *)rec->ip, rec->flags);
3153 } while_for_each_ftrace_rec();
3156 ops->old_hash.filter_hash = NULL;
3157 ops->old_hash.notrace_hash = NULL;
3160 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
3164 * Dynamic ops may be freed, we must make sure that all
3165 * callers are done before leaving this function.
3167 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
3169 * We need to do a hard force of sched synchronization.
3170 * This is because we use preempt_disable() to do RCU, but
3171 * the function tracers can be called where RCU is not watching
3172 * (like before user_exit()). We can not rely on the RCU
3173 * infrastructure to do the synchronization, thus we must do it
3176 synchronize_rcu_tasks_rude();
3179 * When the kernel is preemptive, tasks can be preempted
3180 * while on a ftrace trampoline. Just scheduling a task on
3181 * a CPU is not good enough to flush them. Calling
3182 * synchronize_rcu_tasks() will wait for those tasks to
3183 * execute and either schedule voluntarily or enter user space.
3185 if (IS_ENABLED(CONFIG_PREEMPTION))
3186 synchronize_rcu_tasks();
3188 ftrace_trampoline_free(ops);
3194 static u64 ftrace_update_time;
3195 unsigned long ftrace_update_tot_cnt;
3196 unsigned long ftrace_number_of_pages;
3197 unsigned long ftrace_number_of_groups;
3199 static inline int ops_traces_mod(struct ftrace_ops *ops)
3202 * Filter_hash being empty will default to trace module.
3203 * But notrace hash requires a test of individual module functions.
3205 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
3206 ftrace_hash_empty(ops->func_hash->notrace_hash);
3209 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
3211 bool init_nop = ftrace_need_init_nop();
3212 struct ftrace_page *pg;
3213 struct dyn_ftrace *p;
3215 unsigned long update_cnt = 0;
3216 unsigned long rec_flags = 0;
3219 start = ftrace_now(raw_smp_processor_id());
3222 * When a module is loaded, this function is called to convert
3223 * the calls to mcount in its text to nops, and also to create
3224 * an entry in the ftrace data. Now, if ftrace is activated
3225 * after this call, but before the module sets its text to
3226 * read-only, the modification of enabling ftrace can fail if
3227 * the read-only is done while ftrace is converting the calls.
3228 * To prevent this, the module's records are set as disabled
3229 * and will be enabled after the call to set the module's text
3233 rec_flags |= FTRACE_FL_DISABLED;
3235 for (pg = new_pgs; pg; pg = pg->next) {
3237 for (i = 0; i < pg->index; i++) {
3239 /* If something went wrong, bail without enabling anything */
3240 if (unlikely(ftrace_disabled))
3243 p = &pg->records[i];
3244 p->flags = rec_flags;
3247 * Do the initial record conversion from mcount jump
3248 * to the NOP instructions.
3250 if (init_nop && !ftrace_nop_initialize(mod, p))
3257 stop = ftrace_now(raw_smp_processor_id());
3258 ftrace_update_time = stop - start;
3259 ftrace_update_tot_cnt += update_cnt;
3264 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3270 if (WARN_ON(!count))
3273 /* We want to fill as much as possible, with no empty pages */
3274 pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
3275 order = fls(pages) - 1;
3278 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3281 /* if we can't allocate this size, try something smaller */
3288 ftrace_number_of_pages += 1 << order;
3289 ftrace_number_of_groups++;
3291 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3300 static struct ftrace_page *
3301 ftrace_allocate_pages(unsigned long num_to_init)
3303 struct ftrace_page *start_pg;
3304 struct ftrace_page *pg;
3310 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3315 * Try to allocate as much as possible in one continues
3316 * location that fills in all of the space. We want to
3317 * waste as little space as possible.
3320 cnt = ftrace_allocate_records(pg, num_to_init);
3328 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3341 free_pages((unsigned long)pg->records, pg->order);
3342 ftrace_number_of_pages -= 1 << pg->order;
3344 start_pg = pg->next;
3347 ftrace_number_of_groups--;
3349 pr_info("ftrace: FAILED to allocate memory for functions\n");
3353 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3355 struct ftrace_iterator {
3359 struct ftrace_page *pg;
3360 struct dyn_ftrace *func;
3361 struct ftrace_func_probe *probe;
3362 struct ftrace_func_entry *probe_entry;
3363 struct trace_parser parser;
3364 struct ftrace_hash *hash;
3365 struct ftrace_ops *ops;
3366 struct trace_array *tr;
3367 struct list_head *mod_list;
3374 t_probe_next(struct seq_file *m, loff_t *pos)
3376 struct ftrace_iterator *iter = m->private;
3377 struct trace_array *tr = iter->ops->private;
3378 struct list_head *func_probes;
3379 struct ftrace_hash *hash;
3380 struct list_head *next;
3381 struct hlist_node *hnd = NULL;
3382 struct hlist_head *hhd;
3391 func_probes = &tr->func_probes;
3392 if (list_empty(func_probes))
3396 next = func_probes->next;
3397 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3400 if (iter->probe_entry)
3401 hnd = &iter->probe_entry->hlist;
3403 hash = iter->probe->ops.func_hash->filter_hash;
3406 * A probe being registered may temporarily have an empty hash
3407 * and it's at the end of the func_probes list.
3409 if (!hash || hash == EMPTY_HASH)
3412 size = 1 << hash->size_bits;
3415 if (iter->pidx >= size) {
3416 if (iter->probe->list.next == func_probes)
3418 next = iter->probe->list.next;
3419 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3420 hash = iter->probe->ops.func_hash->filter_hash;
3421 size = 1 << hash->size_bits;
3425 hhd = &hash->buckets[iter->pidx];
3427 if (hlist_empty(hhd)) {
3443 if (WARN_ON_ONCE(!hnd))
3446 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3451 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3453 struct ftrace_iterator *iter = m->private;
3457 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3460 if (iter->mod_pos > *pos)
3464 iter->probe_entry = NULL;
3466 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3467 p = t_probe_next(m, &l);
3474 /* Only set this if we have an item */
3475 iter->flags |= FTRACE_ITER_PROBE;
3481 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3483 struct ftrace_func_entry *probe_entry;
3484 struct ftrace_probe_ops *probe_ops;
3485 struct ftrace_func_probe *probe;
3487 probe = iter->probe;
3488 probe_entry = iter->probe_entry;
3490 if (WARN_ON_ONCE(!probe || !probe_entry))
3493 probe_ops = probe->probe_ops;
3495 if (probe_ops->print)
3496 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3498 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3499 (void *)probe_ops->func);
3505 t_mod_next(struct seq_file *m, loff_t *pos)
3507 struct ftrace_iterator *iter = m->private;
3508 struct trace_array *tr = iter->tr;
3513 iter->mod_list = iter->mod_list->next;
3515 if (iter->mod_list == &tr->mod_trace ||
3516 iter->mod_list == &tr->mod_notrace) {
3517 iter->flags &= ~FTRACE_ITER_MOD;
3521 iter->mod_pos = *pos;
3526 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3528 struct ftrace_iterator *iter = m->private;
3532 if (iter->func_pos > *pos)
3535 iter->mod_pos = iter->func_pos;
3537 /* probes are only available if tr is set */
3541 for (l = 0; l <= (*pos - iter->func_pos); ) {
3542 p = t_mod_next(m, &l);
3547 iter->flags &= ~FTRACE_ITER_MOD;
3548 return t_probe_start(m, pos);
3551 /* Only set this if we have an item */
3552 iter->flags |= FTRACE_ITER_MOD;
3558 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3560 struct ftrace_mod_load *ftrace_mod;
3561 struct trace_array *tr = iter->tr;
3563 if (WARN_ON_ONCE(!iter->mod_list) ||
3564 iter->mod_list == &tr->mod_trace ||
3565 iter->mod_list == &tr->mod_notrace)
3568 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3570 if (ftrace_mod->func)
3571 seq_printf(m, "%s", ftrace_mod->func);
3575 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3581 t_func_next(struct seq_file *m, loff_t *pos)
3583 struct ftrace_iterator *iter = m->private;
3584 struct dyn_ftrace *rec = NULL;
3589 if (iter->idx >= iter->pg->index) {
3590 if (iter->pg->next) {
3591 iter->pg = iter->pg->next;
3596 rec = &iter->pg->records[iter->idx++];
3597 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3598 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3600 ((iter->flags & FTRACE_ITER_ENABLED) &&
3601 !(rec->flags & FTRACE_FL_ENABLED))) {
3611 iter->pos = iter->func_pos = *pos;
3618 t_next(struct seq_file *m, void *v, loff_t *pos)
3620 struct ftrace_iterator *iter = m->private;
3621 loff_t l = *pos; /* t_probe_start() must use original pos */
3624 if (unlikely(ftrace_disabled))
3627 if (iter->flags & FTRACE_ITER_PROBE)
3628 return t_probe_next(m, pos);
3630 if (iter->flags & FTRACE_ITER_MOD)
3631 return t_mod_next(m, pos);
3633 if (iter->flags & FTRACE_ITER_PRINTALL) {
3634 /* next must increment pos, and t_probe_start does not */
3636 return t_mod_start(m, &l);
3639 ret = t_func_next(m, pos);
3642 return t_mod_start(m, &l);
3647 static void reset_iter_read(struct ftrace_iterator *iter)
3651 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3654 static void *t_start(struct seq_file *m, loff_t *pos)
3656 struct ftrace_iterator *iter = m->private;
3660 mutex_lock(&ftrace_lock);
3662 if (unlikely(ftrace_disabled))
3666 * If an lseek was done, then reset and start from beginning.
3668 if (*pos < iter->pos)
3669 reset_iter_read(iter);
3672 * For set_ftrace_filter reading, if we have the filter
3673 * off, we can short cut and just print out that all
3674 * functions are enabled.
3676 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3677 ftrace_hash_empty(iter->hash)) {
3678 iter->func_pos = 1; /* Account for the message */
3680 return t_mod_start(m, pos);
3681 iter->flags |= FTRACE_ITER_PRINTALL;
3682 /* reset in case of seek/pread */
3683 iter->flags &= ~FTRACE_ITER_PROBE;
3687 if (iter->flags & FTRACE_ITER_MOD)
3688 return t_mod_start(m, pos);
3691 * Unfortunately, we need to restart at ftrace_pages_start
3692 * every time we let go of the ftrace_mutex. This is because
3693 * those pointers can change without the lock.
3695 iter->pg = ftrace_pages_start;
3697 for (l = 0; l <= *pos; ) {
3698 p = t_func_next(m, &l);
3704 return t_mod_start(m, pos);
3709 static void t_stop(struct seq_file *m, void *p)
3711 mutex_unlock(&ftrace_lock);
3715 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3720 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3721 struct dyn_ftrace *rec)
3725 ptr = arch_ftrace_trampoline_func(ops, rec);
3727 seq_printf(m, " ->%pS", ptr);
3730 #ifdef FTRACE_MCOUNT_MAX_OFFSET
3732 * Weak functions can still have an mcount/fentry that is saved in
3733 * the __mcount_loc section. These can be detected by having a
3734 * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the
3735 * symbol found by kallsyms is not the function that the mcount/fentry
3736 * is part of. The offset is much greater in these cases.
3738 * Test the record to make sure that the ip points to a valid kallsyms
3739 * and if not, mark it disabled.
3741 static int test_for_valid_rec(struct dyn_ftrace *rec)
3743 char str[KSYM_SYMBOL_LEN];
3744 unsigned long offset;
3747 ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str);
3749 /* Weak functions can cause invalid addresses */
3750 if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
3751 rec->flags |= FTRACE_FL_DISABLED;
3757 static struct workqueue_struct *ftrace_check_wq __initdata;
3758 static struct work_struct ftrace_check_work __initdata;
3761 * Scan all the mcount/fentry entries to make sure they are valid.
3763 static __init void ftrace_check_work_func(struct work_struct *work)
3765 struct ftrace_page *pg;
3766 struct dyn_ftrace *rec;
3768 mutex_lock(&ftrace_lock);
3769 do_for_each_ftrace_rec(pg, rec) {
3770 test_for_valid_rec(rec);
3771 } while_for_each_ftrace_rec();
3772 mutex_unlock(&ftrace_lock);
3775 static int __init ftrace_check_for_weak_functions(void)
3777 INIT_WORK(&ftrace_check_work, ftrace_check_work_func);
3779 ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0);
3781 queue_work(ftrace_check_wq, &ftrace_check_work);
3785 static int __init ftrace_check_sync(void)
3787 /* Make sure the ftrace_check updates are finished */
3788 if (ftrace_check_wq)
3789 destroy_workqueue(ftrace_check_wq);
3793 late_initcall_sync(ftrace_check_sync);
3794 subsys_initcall(ftrace_check_for_weak_functions);
3796 static int print_rec(struct seq_file *m, unsigned long ip)
3798 unsigned long offset;
3799 char str[KSYM_SYMBOL_LEN];
3803 ret = kallsyms_lookup(ip, NULL, &offset, &modname, str);
3804 /* Weak functions can cause invalid addresses */
3805 if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
3806 snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld",
3807 FTRACE_INVALID_FUNCTION, offset);
3813 seq_printf(m, " [%s]", modname);
3814 return ret == NULL ? -1 : 0;
3817 static inline int test_for_valid_rec(struct dyn_ftrace *rec)
3822 static inline int print_rec(struct seq_file *m, unsigned long ip)
3824 seq_printf(m, "%ps", (void *)ip);
3829 static int t_show(struct seq_file *m, void *v)
3831 struct ftrace_iterator *iter = m->private;
3832 struct dyn_ftrace *rec;
3834 if (iter->flags & FTRACE_ITER_PROBE)
3835 return t_probe_show(m, iter);
3837 if (iter->flags & FTRACE_ITER_MOD)
3838 return t_mod_show(m, iter);
3840 if (iter->flags & FTRACE_ITER_PRINTALL) {
3841 if (iter->flags & FTRACE_ITER_NOTRACE)
3842 seq_puts(m, "#### no functions disabled ####\n");
3844 seq_puts(m, "#### all functions enabled ####\n");
3853 if (print_rec(m, rec->ip)) {
3854 /* This should only happen when a rec is disabled */
3855 WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED));
3860 if (iter->flags & FTRACE_ITER_ENABLED) {
3861 struct ftrace_ops *ops;
3863 seq_printf(m, " (%ld)%s%s%s%s",
3864 ftrace_rec_count(rec),
3865 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3866 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ",
3867 rec->flags & FTRACE_FL_DIRECT ? " D" : " ",
3868 rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ");
3869 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3870 ops = ftrace_find_tramp_ops_any(rec);
3873 seq_printf(m, "\ttramp: %pS (%pS)",
3874 (void *)ops->trampoline,
3876 add_trampoline_func(m, ops, rec);
3877 ops = ftrace_find_tramp_ops_next(rec, ops);
3880 seq_puts(m, "\ttramp: ERROR!");
3882 add_trampoline_func(m, NULL, rec);
3884 if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
3885 ops = ftrace_find_unique_ops(rec);
3887 seq_printf(m, "\tops: %pS (%pS)",
3890 seq_puts(m, "\tops: ERROR!");
3893 if (rec->flags & FTRACE_FL_DIRECT) {
3894 unsigned long direct;
3896 direct = ftrace_find_rec_direct(rec->ip);
3898 seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
3907 static const struct seq_operations show_ftrace_seq_ops = {
3915 ftrace_avail_open(struct inode *inode, struct file *file)
3917 struct ftrace_iterator *iter;
3920 ret = security_locked_down(LOCKDOWN_TRACEFS);
3924 if (unlikely(ftrace_disabled))
3927 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3931 iter->pg = ftrace_pages_start;
3932 iter->ops = &global_ops;
3938 ftrace_enabled_open(struct inode *inode, struct file *file)
3940 struct ftrace_iterator *iter;
3943 * This shows us what functions are currently being
3944 * traced and by what. Not sure if we want lockdown
3945 * to hide such critical information for an admin.
3946 * Although, perhaps it can show information we don't
3947 * want people to see, but if something is tracing
3948 * something, we probably want to know about it.
3951 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3955 iter->pg = ftrace_pages_start;
3956 iter->flags = FTRACE_ITER_ENABLED;
3957 iter->ops = &global_ops;
3963 * ftrace_regex_open - initialize function tracer filter files
3964 * @ops: The ftrace_ops that hold the hash filters
3965 * @flag: The type of filter to process
3966 * @inode: The inode, usually passed in to your open routine
3967 * @file: The file, usually passed in to your open routine
3969 * ftrace_regex_open() initializes the filter files for the
3970 * @ops. Depending on @flag it may process the filter hash or
3971 * the notrace hash of @ops. With this called from the open
3972 * routine, you can use ftrace_filter_write() for the write
3973 * routine if @flag has FTRACE_ITER_FILTER set, or
3974 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3975 * tracing_lseek() should be used as the lseek routine, and
3976 * release must call ftrace_regex_release().
3979 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3980 struct inode *inode, struct file *file)
3982 struct ftrace_iterator *iter;
3983 struct ftrace_hash *hash;
3984 struct list_head *mod_head;
3985 struct trace_array *tr = ops->private;
3988 ftrace_ops_init(ops);
3990 if (unlikely(ftrace_disabled))
3993 if (tracing_check_open_get_tr(tr))
3996 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
4000 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX))
4007 mutex_lock(&ops->func_hash->regex_lock);
4009 if (flag & FTRACE_ITER_NOTRACE) {
4010 hash = ops->func_hash->notrace_hash;
4011 mod_head = tr ? &tr->mod_notrace : NULL;
4013 hash = ops->func_hash->filter_hash;
4014 mod_head = tr ? &tr->mod_trace : NULL;
4017 iter->mod_list = mod_head;
4019 if (file->f_mode & FMODE_WRITE) {
4020 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
4022 if (file->f_flags & O_TRUNC) {
4023 iter->hash = alloc_ftrace_hash(size_bits);
4024 clear_ftrace_mod_list(mod_head);
4026 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
4030 trace_parser_put(&iter->parser);
4038 if (file->f_mode & FMODE_READ) {
4039 iter->pg = ftrace_pages_start;
4041 ret = seq_open(file, &show_ftrace_seq_ops);
4043 struct seq_file *m = file->private_data;
4047 free_ftrace_hash(iter->hash);
4048 trace_parser_put(&iter->parser);
4051 file->private_data = iter;
4054 mutex_unlock(&ops->func_hash->regex_lock);
4060 trace_array_put(tr);
4067 ftrace_filter_open(struct inode *inode, struct file *file)
4069 struct ftrace_ops *ops = inode->i_private;
4071 /* Checks for tracefs lockdown */
4072 return ftrace_regex_open(ops,
4073 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
4078 ftrace_notrace_open(struct inode *inode, struct file *file)
4080 struct ftrace_ops *ops = inode->i_private;
4082 /* Checks for tracefs lockdown */
4083 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
4087 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
4088 struct ftrace_glob {
4095 * If symbols in an architecture don't correspond exactly to the user-visible
4096 * name of what they represent, it is possible to define this function to
4097 * perform the necessary adjustments.
4099 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
4104 static int ftrace_match(char *str, struct ftrace_glob *g)
4109 str = arch_ftrace_match_adjust(str, g->search);
4113 if (strcmp(str, g->search) == 0)
4116 case MATCH_FRONT_ONLY:
4117 if (strncmp(str, g->search, g->len) == 0)
4120 case MATCH_MIDDLE_ONLY:
4121 if (strstr(str, g->search))
4124 case MATCH_END_ONLY:
4126 if (slen >= g->len &&
4127 memcmp(str + slen - g->len, g->search, g->len) == 0)
4131 if (glob_match(g->search, str))
4140 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
4142 struct ftrace_func_entry *entry;
4145 entry = ftrace_lookup_ip(hash, rec->ip);
4147 /* Do nothing if it doesn't exist */
4151 free_hash_entry(hash, entry);
4153 /* Do nothing if it exists */
4157 ret = add_hash_entry(hash, rec->ip);
4163 add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
4166 long index = simple_strtoul(func_g->search, NULL, 0);
4167 struct ftrace_page *pg;
4168 struct dyn_ftrace *rec;
4170 /* The index starts at 1 */
4174 do_for_each_ftrace_rec(pg, rec) {
4175 if (pg->index <= index) {
4177 /* this is a double loop, break goes to the next page */
4180 rec = &pg->records[index];
4181 enter_record(hash, rec, clear_filter);
4183 } while_for_each_ftrace_rec();
4187 #ifdef FTRACE_MCOUNT_MAX_OFFSET
4188 static int lookup_ip(unsigned long ip, char **modname, char *str)
4190 unsigned long offset;
4192 kallsyms_lookup(ip, NULL, &offset, modname, str);
4193 if (offset > FTRACE_MCOUNT_MAX_OFFSET)
4198 static int lookup_ip(unsigned long ip, char **modname, char *str)
4200 kallsyms_lookup(ip, NULL, NULL, modname, str);
4206 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
4207 struct ftrace_glob *mod_g, int exclude_mod)
4209 char str[KSYM_SYMBOL_LEN];
4212 if (lookup_ip(rec->ip, &modname, str)) {
4213 /* This should only happen when a rec is disabled */
4214 WARN_ON_ONCE(system_state == SYSTEM_RUNNING &&
4215 !(rec->flags & FTRACE_FL_DISABLED));
4220 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
4222 /* blank module name to match all modules */
4224 /* blank module globbing: modname xor exclude_mod */
4225 if (!exclude_mod != !modname)
4231 * exclude_mod is set to trace everything but the given
4232 * module. If it is set and the module matches, then
4233 * return 0. If it is not set, and the module doesn't match
4234 * also return 0. Otherwise, check the function to see if
4237 if (!mod_matches == !exclude_mod)
4240 /* blank search means to match all funcs in the mod */
4245 return ftrace_match(str, func_g);
4249 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
4251 struct ftrace_page *pg;
4252 struct dyn_ftrace *rec;
4253 struct ftrace_glob func_g = { .type = MATCH_FULL };
4254 struct ftrace_glob mod_g = { .type = MATCH_FULL };
4255 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
4256 int exclude_mod = 0;
4259 int clear_filter = 0;
4262 func_g.type = filter_parse_regex(func, len, &func_g.search,
4264 func_g.len = strlen(func_g.search);
4268 mod_g.type = filter_parse_regex(mod, strlen(mod),
4269 &mod_g.search, &exclude_mod);
4270 mod_g.len = strlen(mod_g.search);
4273 mutex_lock(&ftrace_lock);
4275 if (unlikely(ftrace_disabled))
4278 if (func_g.type == MATCH_INDEX) {
4279 found = add_rec_by_index(hash, &func_g, clear_filter);
4283 do_for_each_ftrace_rec(pg, rec) {
4285 if (rec->flags & FTRACE_FL_DISABLED)
4288 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
4289 ret = enter_record(hash, rec, clear_filter);
4297 } while_for_each_ftrace_rec();
4299 mutex_unlock(&ftrace_lock);
4305 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
4307 return match_records(hash, buff, len, NULL);
4310 static void ftrace_ops_update_code(struct ftrace_ops *ops,
4311 struct ftrace_ops_hash *old_hash)
4313 struct ftrace_ops *op;
4315 if (!ftrace_enabled)
4318 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
4319 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
4324 * If this is the shared global_ops filter, then we need to
4325 * check if there is another ops that shares it, is enabled.
4326 * If so, we still need to run the modify code.
4328 if (ops->func_hash != &global_ops.local_hash)
4331 do_for_each_ftrace_op(op, ftrace_ops_list) {
4332 if (op->func_hash == &global_ops.local_hash &&
4333 op->flags & FTRACE_OPS_FL_ENABLED) {
4334 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
4335 /* Only need to do this once */
4338 } while_for_each_ftrace_op(op);
4341 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
4342 struct ftrace_hash **orig_hash,
4343 struct ftrace_hash *hash,
4346 struct ftrace_ops_hash old_hash_ops;
4347 struct ftrace_hash *old_hash;
4350 old_hash = *orig_hash;
4351 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
4352 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
4353 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
4355 ftrace_ops_update_code(ops, &old_hash_ops);
4356 free_ftrace_hash_rcu(old_hash);
4361 static bool module_exists(const char *module)
4363 /* All modules have the symbol __this_module */
4364 static const char this_mod[] = "__this_module";
4365 char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
4369 n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
4371 if (n > sizeof(modname) - 1)
4374 val = module_kallsyms_lookup_name(modname);
4378 static int cache_mod(struct trace_array *tr,
4379 const char *func, char *module, int enable)
4381 struct ftrace_mod_load *ftrace_mod, *n;
4382 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
4385 mutex_lock(&ftrace_lock);
4387 /* We do not cache inverse filters */
4388 if (func[0] == '!') {
4392 /* Look to remove this hash */
4393 list_for_each_entry_safe(ftrace_mod, n, head, list) {
4394 if (strcmp(ftrace_mod->module, module) != 0)
4397 /* no func matches all */
4398 if (strcmp(func, "*") == 0 ||
4399 (ftrace_mod->func &&
4400 strcmp(ftrace_mod->func, func) == 0)) {
4402 free_ftrace_mod(ftrace_mod);
4410 /* We only care about modules that have not been loaded yet */
4411 if (module_exists(module))
4414 /* Save this string off, and execute it when the module is loaded */
4415 ret = ftrace_add_mod(tr, func, module, enable);
4417 mutex_unlock(&ftrace_lock);
4423 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4424 int reset, int enable);
4426 #ifdef CONFIG_MODULES
4427 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
4428 char *mod, bool enable)
4430 struct ftrace_mod_load *ftrace_mod, *n;
4431 struct ftrace_hash **orig_hash, *new_hash;
4432 LIST_HEAD(process_mods);
4435 mutex_lock(&ops->func_hash->regex_lock);
4438 orig_hash = &ops->func_hash->filter_hash;
4440 orig_hash = &ops->func_hash->notrace_hash;
4442 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
4445 goto out; /* warn? */
4447 mutex_lock(&ftrace_lock);
4449 list_for_each_entry_safe(ftrace_mod, n, head, list) {
4451 if (strcmp(ftrace_mod->module, mod) != 0)
4454 if (ftrace_mod->func)
4455 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
4457 func = kstrdup("*", GFP_KERNEL);
4459 if (!func) /* warn? */
4462 list_move(&ftrace_mod->list, &process_mods);
4464 /* Use the newly allocated func, as it may be "*" */
4465 kfree(ftrace_mod->func);
4466 ftrace_mod->func = func;
4469 mutex_unlock(&ftrace_lock);
4471 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4473 func = ftrace_mod->func;
4475 /* Grabs ftrace_lock, which is why we have this extra step */
4476 match_records(new_hash, func, strlen(func), mod);
4477 free_ftrace_mod(ftrace_mod);
4480 if (enable && list_empty(head))
4481 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4483 mutex_lock(&ftrace_lock);
4485 ftrace_hash_move_and_update_ops(ops, orig_hash,
4487 mutex_unlock(&ftrace_lock);
4490 mutex_unlock(&ops->func_hash->regex_lock);
4492 free_ftrace_hash(new_hash);
4495 static void process_cached_mods(const char *mod_name)
4497 struct trace_array *tr;
4500 mod = kstrdup(mod_name, GFP_KERNEL);
4504 mutex_lock(&trace_types_lock);
4505 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4506 if (!list_empty(&tr->mod_trace))
4507 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4508 if (!list_empty(&tr->mod_notrace))
4509 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4511 mutex_unlock(&trace_types_lock);
4518 * We register the module command as a template to show others how
4519 * to register the a command as well.
4523 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4524 char *func_orig, char *cmd, char *module, int enable)
4529 /* match_records() modifies func, and we need the original */
4530 func = kstrdup(func_orig, GFP_KERNEL);
4535 * cmd == 'mod' because we only registered this func
4536 * for the 'mod' ftrace_func_command.
4537 * But if you register one func with multiple commands,
4538 * you can tell which command was used by the cmd
4541 ret = match_records(hash, func, strlen(func), module);
4545 return cache_mod(tr, func_orig, module, enable);
4551 static struct ftrace_func_command ftrace_mod_cmd = {
4553 .func = ftrace_mod_callback,
4556 static int __init ftrace_mod_cmd_init(void)
4558 return register_ftrace_command(&ftrace_mod_cmd);
4560 core_initcall(ftrace_mod_cmd_init);
4562 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4563 struct ftrace_ops *op, struct ftrace_regs *fregs)
4565 struct ftrace_probe_ops *probe_ops;
4566 struct ftrace_func_probe *probe;
4568 probe = container_of(op, struct ftrace_func_probe, ops);
4569 probe_ops = probe->probe_ops;
4572 * Disable preemption for these calls to prevent a RCU grace
4573 * period. This syncs the hash iteration and freeing of items
4574 * on the hash. rcu_read_lock is too dangerous here.
4576 preempt_disable_notrace();
4577 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4578 preempt_enable_notrace();
4581 struct ftrace_func_map {
4582 struct ftrace_func_entry entry;
4586 struct ftrace_func_mapper {
4587 struct ftrace_hash hash;
4591 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4593 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4595 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4597 struct ftrace_hash *hash;
4600 * The mapper is simply a ftrace_hash, but since the entries
4601 * in the hash are not ftrace_func_entry type, we define it
4602 * as a separate structure.
4604 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4605 return (struct ftrace_func_mapper *)hash;
4609 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4610 * @mapper: The mapper that has the ip maps
4611 * @ip: the instruction pointer to find the data for
4613 * Returns the data mapped to @ip if found otherwise NULL. The return
4614 * is actually the address of the mapper data pointer. The address is
4615 * returned for use cases where the data is no bigger than a long, and
4616 * the user can use the data pointer as its data instead of having to
4617 * allocate more memory for the reference.
4619 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4622 struct ftrace_func_entry *entry;
4623 struct ftrace_func_map *map;
4625 entry = ftrace_lookup_ip(&mapper->hash, ip);
4629 map = (struct ftrace_func_map *)entry;
4634 * ftrace_func_mapper_add_ip - Map some data to an ip
4635 * @mapper: The mapper that has the ip maps
4636 * @ip: The instruction pointer address to map @data to
4637 * @data: The data to map to @ip
4639 * Returns 0 on success otherwise an error.
4641 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4642 unsigned long ip, void *data)
4644 struct ftrace_func_entry *entry;
4645 struct ftrace_func_map *map;
4647 entry = ftrace_lookup_ip(&mapper->hash, ip);
4651 map = kmalloc(sizeof(*map), GFP_KERNEL);
4658 __add_hash_entry(&mapper->hash, &map->entry);
4664 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4665 * @mapper: The mapper that has the ip maps
4666 * @ip: The instruction pointer address to remove the data from
4668 * Returns the data if it is found, otherwise NULL.
4669 * Note, if the data pointer is used as the data itself, (see
4670 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4671 * if the data pointer was set to zero.
4673 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4676 struct ftrace_func_entry *entry;
4677 struct ftrace_func_map *map;
4680 entry = ftrace_lookup_ip(&mapper->hash, ip);
4684 map = (struct ftrace_func_map *)entry;
4687 remove_hash_entry(&mapper->hash, entry);
4694 * free_ftrace_func_mapper - free a mapping of ips and data
4695 * @mapper: The mapper that has the ip maps
4696 * @free_func: A function to be called on each data item.
4698 * This is used to free the function mapper. The @free_func is optional
4699 * and can be used if the data needs to be freed as well.
4701 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4702 ftrace_mapper_func free_func)
4704 struct ftrace_func_entry *entry;
4705 struct ftrace_func_map *map;
4706 struct hlist_head *hhd;
4712 if (free_func && mapper->hash.count) {
4713 size = 1 << mapper->hash.size_bits;
4714 for (i = 0; i < size; i++) {
4715 hhd = &mapper->hash.buckets[i];
4716 hlist_for_each_entry(entry, hhd, hlist) {
4717 map = (struct ftrace_func_map *)entry;
4722 free_ftrace_hash(&mapper->hash);
4725 static void release_probe(struct ftrace_func_probe *probe)
4727 struct ftrace_probe_ops *probe_ops;
4729 mutex_lock(&ftrace_lock);
4731 WARN_ON(probe->ref <= 0);
4733 /* Subtract the ref that was used to protect this instance */
4737 probe_ops = probe->probe_ops;
4739 * Sending zero as ip tells probe_ops to free
4740 * the probe->data itself
4742 if (probe_ops->free)
4743 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4744 list_del(&probe->list);
4747 mutex_unlock(&ftrace_lock);
4750 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4753 * Add one ref to keep it from being freed when releasing the
4754 * ftrace_lock mutex.
4760 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4761 struct ftrace_probe_ops *probe_ops,
4764 struct ftrace_func_probe *probe = NULL, *iter;
4765 struct ftrace_func_entry *entry;
4766 struct ftrace_hash **orig_hash;
4767 struct ftrace_hash *old_hash;
4768 struct ftrace_hash *hash;
4777 /* We do not support '!' for function probes */
4778 if (WARN_ON(glob[0] == '!'))
4782 mutex_lock(&ftrace_lock);
4783 /* Check if the probe_ops is already registered */
4784 list_for_each_entry(iter, &tr->func_probes, list) {
4785 if (iter->probe_ops == probe_ops) {
4791 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4793 mutex_unlock(&ftrace_lock);
4796 probe->probe_ops = probe_ops;
4797 probe->ops.func = function_trace_probe_call;
4799 ftrace_ops_init(&probe->ops);
4800 list_add(&probe->list, &tr->func_probes);
4803 acquire_probe_locked(probe);
4805 mutex_unlock(&ftrace_lock);
4808 * Note, there's a small window here that the func_hash->filter_hash
4809 * may be NULL or empty. Need to be careful when reading the loop.
4811 mutex_lock(&probe->ops.func_hash->regex_lock);
4813 orig_hash = &probe->ops.func_hash->filter_hash;
4814 old_hash = *orig_hash;
4815 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4822 ret = ftrace_match_records(hash, glob, strlen(glob));
4824 /* Nothing found? */
4831 size = 1 << hash->size_bits;
4832 for (i = 0; i < size; i++) {
4833 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4834 if (ftrace_lookup_ip(old_hash, entry->ip))
4837 * The caller might want to do something special
4838 * for each function we find. We call the callback
4839 * to give the caller an opportunity to do so.
4841 if (probe_ops->init) {
4842 ret = probe_ops->init(probe_ops, tr,
4846 if (probe_ops->free && count)
4847 probe_ops->free(probe_ops, tr,
4857 mutex_lock(&ftrace_lock);
4860 /* Nothing was added? */
4865 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4870 /* One ref for each new function traced */
4871 probe->ref += count;
4873 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4874 ret = ftrace_startup(&probe->ops, 0);
4877 mutex_unlock(&ftrace_lock);
4882 mutex_unlock(&probe->ops.func_hash->regex_lock);
4883 free_ftrace_hash(hash);
4885 release_probe(probe);
4890 if (!probe_ops->free || !count)
4893 /* Failed to do the move, need to call the free functions */
4894 for (i = 0; i < size; i++) {
4895 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4896 if (ftrace_lookup_ip(old_hash, entry->ip))
4898 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4905 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4906 struct ftrace_probe_ops *probe_ops)
4908 struct ftrace_func_probe *probe = NULL, *iter;
4909 struct ftrace_ops_hash old_hash_ops;
4910 struct ftrace_func_entry *entry;
4911 struct ftrace_glob func_g;
4912 struct ftrace_hash **orig_hash;
4913 struct ftrace_hash *old_hash;
4914 struct ftrace_hash *hash = NULL;
4915 struct hlist_node *tmp;
4916 struct hlist_head hhd;
4917 char str[KSYM_SYMBOL_LEN];
4919 int i, ret = -ENODEV;
4922 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4923 func_g.search = NULL;
4927 func_g.type = filter_parse_regex(glob, strlen(glob),
4928 &func_g.search, ¬);
4929 func_g.len = strlen(func_g.search);
4931 /* we do not support '!' for function probes */
4936 mutex_lock(&ftrace_lock);
4937 /* Check if the probe_ops is already registered */
4938 list_for_each_entry(iter, &tr->func_probes, list) {
4939 if (iter->probe_ops == probe_ops) {
4945 goto err_unlock_ftrace;
4948 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4949 goto err_unlock_ftrace;
4951 acquire_probe_locked(probe);
4953 mutex_unlock(&ftrace_lock);
4955 mutex_lock(&probe->ops.func_hash->regex_lock);
4957 orig_hash = &probe->ops.func_hash->filter_hash;
4958 old_hash = *orig_hash;
4960 if (ftrace_hash_empty(old_hash))
4963 old_hash_ops.filter_hash = old_hash;
4964 /* Probes only have filters */
4965 old_hash_ops.notrace_hash = NULL;
4968 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4972 INIT_HLIST_HEAD(&hhd);
4974 size = 1 << hash->size_bits;
4975 for (i = 0; i < size; i++) {
4976 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4978 if (func_g.search) {
4979 kallsyms_lookup(entry->ip, NULL, NULL,
4981 if (!ftrace_match(str, &func_g))
4985 remove_hash_entry(hash, entry);
4986 hlist_add_head(&entry->hlist, &hhd);
4990 /* Nothing found? */
4996 mutex_lock(&ftrace_lock);
4998 WARN_ON(probe->ref < count);
5000 probe->ref -= count;
5002 if (ftrace_hash_empty(hash))
5003 ftrace_shutdown(&probe->ops, 0);
5005 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
5008 /* still need to update the function call sites */
5009 if (ftrace_enabled && !ftrace_hash_empty(hash))
5010 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
5014 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
5015 hlist_del(&entry->hlist);
5016 if (probe_ops->free)
5017 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
5020 mutex_unlock(&ftrace_lock);
5023 mutex_unlock(&probe->ops.func_hash->regex_lock);
5024 free_ftrace_hash(hash);
5026 release_probe(probe);
5031 mutex_unlock(&ftrace_lock);
5035 void clear_ftrace_function_probes(struct trace_array *tr)
5037 struct ftrace_func_probe *probe, *n;
5039 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
5040 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
5043 static LIST_HEAD(ftrace_commands);
5044 static DEFINE_MUTEX(ftrace_cmd_mutex);
5047 * Currently we only register ftrace commands from __init, so mark this
5050 __init int register_ftrace_command(struct ftrace_func_command *cmd)
5052 struct ftrace_func_command *p;
5055 mutex_lock(&ftrace_cmd_mutex);
5056 list_for_each_entry(p, &ftrace_commands, list) {
5057 if (strcmp(cmd->name, p->name) == 0) {
5062 list_add(&cmd->list, &ftrace_commands);
5064 mutex_unlock(&ftrace_cmd_mutex);
5070 * Currently we only unregister ftrace commands from __init, so mark
5073 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
5075 struct ftrace_func_command *p, *n;
5078 mutex_lock(&ftrace_cmd_mutex);
5079 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
5080 if (strcmp(cmd->name, p->name) == 0) {
5082 list_del_init(&p->list);
5087 mutex_unlock(&ftrace_cmd_mutex);
5092 static int ftrace_process_regex(struct ftrace_iterator *iter,
5093 char *buff, int len, int enable)
5095 struct ftrace_hash *hash = iter->hash;
5096 struct trace_array *tr = iter->ops->private;
5097 char *func, *command, *next = buff;
5098 struct ftrace_func_command *p;
5101 func = strsep(&next, ":");
5104 ret = ftrace_match_records(hash, func, len);
5114 command = strsep(&next, ":");
5116 mutex_lock(&ftrace_cmd_mutex);
5117 list_for_each_entry(p, &ftrace_commands, list) {
5118 if (strcmp(p->name, command) == 0) {
5119 ret = p->func(tr, hash, func, command, next, enable);
5124 mutex_unlock(&ftrace_cmd_mutex);
5130 ftrace_regex_write(struct file *file, const char __user *ubuf,
5131 size_t cnt, loff_t *ppos, int enable)
5133 struct ftrace_iterator *iter;
5134 struct trace_parser *parser;
5140 if (file->f_mode & FMODE_READ) {
5141 struct seq_file *m = file->private_data;
5144 iter = file->private_data;
5146 if (unlikely(ftrace_disabled))
5149 /* iter->hash is a local copy, so we don't need regex_lock */
5151 parser = &iter->parser;
5152 read = trace_get_user(parser, ubuf, cnt, ppos);
5154 if (read >= 0 && trace_parser_loaded(parser) &&
5155 !trace_parser_cont(parser)) {
5156 ret = ftrace_process_regex(iter, parser->buffer,
5157 parser->idx, enable);
5158 trace_parser_clear(parser);
5169 ftrace_filter_write(struct file *file, const char __user *ubuf,
5170 size_t cnt, loff_t *ppos)
5172 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
5176 ftrace_notrace_write(struct file *file, const char __user *ubuf,
5177 size_t cnt, loff_t *ppos)
5179 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
5183 __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
5185 struct ftrace_func_entry *entry;
5187 ip = ftrace_location(ip);
5192 entry = ftrace_lookup_ip(hash, ip);
5195 free_hash_entry(hash, entry);
5199 return add_hash_entry(hash, ip);
5203 ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips,
5204 unsigned int cnt, int remove)
5209 for (i = 0; i < cnt; i++) {
5210 err = __ftrace_match_addr(hash, ips[i], remove);
5213 * This expects the @hash is a temporary hash and if this
5214 * fails the caller must free the @hash.
5223 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
5224 unsigned long *ips, unsigned int cnt,
5225 int remove, int reset, int enable)
5227 struct ftrace_hash **orig_hash;
5228 struct ftrace_hash *hash;
5231 if (unlikely(ftrace_disabled))
5234 mutex_lock(&ops->func_hash->regex_lock);
5237 orig_hash = &ops->func_hash->filter_hash;
5239 orig_hash = &ops->func_hash->notrace_hash;
5242 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5244 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
5248 goto out_regex_unlock;
5251 if (buf && !ftrace_match_records(hash, buf, len)) {
5253 goto out_regex_unlock;
5256 ret = ftrace_match_addr(hash, ips, cnt, remove);
5258 goto out_regex_unlock;
5261 mutex_lock(&ftrace_lock);
5262 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
5263 mutex_unlock(&ftrace_lock);
5266 mutex_unlock(&ops->func_hash->regex_lock);
5268 free_ftrace_hash(hash);
5273 ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,
5274 int remove, int reset, int enable)
5276 return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable);
5279 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
5281 struct ftrace_direct_func {
5282 struct list_head next;
5287 static LIST_HEAD(ftrace_direct_funcs);
5289 static int register_ftrace_function_nolock(struct ftrace_ops *ops);
5291 #define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS)
5293 static int check_direct_multi(struct ftrace_ops *ops)
5295 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5297 if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS)
5302 static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr)
5304 struct ftrace_func_entry *entry, *del;
5307 size = 1 << hash->size_bits;
5308 for (i = 0; i < size; i++) {
5309 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5310 del = __ftrace_lookup_ip(direct_functions, entry->ip);
5311 if (del && del->direct == addr) {
5312 remove_hash_entry(direct_functions, del);
5320 * register_ftrace_direct - Call a custom trampoline directly
5321 * for multiple functions registered in @ops
5322 * @ops: The address of the struct ftrace_ops object
5323 * @addr: The address of the trampoline to call at @ops functions
5325 * This is used to connect a direct calls to @addr from the nop locations
5326 * of the functions registered in @ops (with by ftrace_set_filter_ip
5329 * The location that it calls (@addr) must be able to handle a direct call,
5330 * and save the parameters of the function being traced, and restore them
5331 * (or inject new ones if needed), before returning.
5335 * -EINVAL - The @ops object was already registered with this call or
5336 * when there are no functions in @ops object.
5337 * -EBUSY - Another direct function is already attached (there can be only one)
5338 * -ENODEV - @ip does not point to a ftrace nop location (or not supported)
5339 * -ENOMEM - There was an allocation failure.
5341 int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5343 struct ftrace_hash *hash, *free_hash = NULL;
5344 struct ftrace_func_entry *entry, *new;
5345 int err = -EBUSY, size, i;
5347 if (ops->func || ops->trampoline)
5349 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5351 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5354 hash = ops->func_hash->filter_hash;
5355 if (ftrace_hash_empty(hash))
5358 mutex_lock(&direct_mutex);
5360 /* Make sure requested entries are not already registered.. */
5361 size = 1 << hash->size_bits;
5362 for (i = 0; i < size; i++) {
5363 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5364 if (ftrace_find_rec_direct(entry->ip))
5369 /* ... and insert them to direct_functions hash. */
5371 for (i = 0; i < size; i++) {
5372 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5373 new = ftrace_add_rec_direct(entry->ip, addr, &free_hash);
5376 entry->direct = addr;
5380 ops->func = call_direct_funcs;
5381 ops->flags = MULTI_FLAGS;
5382 ops->trampoline = FTRACE_REGS_ADDR;
5383 ops->direct_call = addr;
5385 err = register_ftrace_function_nolock(ops);
5389 remove_direct_functions_hash(hash, addr);
5392 mutex_unlock(&direct_mutex);
5395 synchronize_rcu_tasks();
5396 free_ftrace_hash(free_hash);
5400 EXPORT_SYMBOL_GPL(register_ftrace_direct);
5403 * unregister_ftrace_direct - Remove calls to custom trampoline
5404 * previously registered by register_ftrace_direct for @ops object.
5405 * @ops: The address of the struct ftrace_ops object
5407 * This is used to remove a direct calls to @addr from the nop locations
5408 * of the functions registered in @ops (with by ftrace_set_filter_ip
5413 * -EINVAL - The @ops object was not properly registered.
5415 int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
5418 struct ftrace_hash *hash = ops->func_hash->filter_hash;
5421 if (check_direct_multi(ops))
5423 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5426 mutex_lock(&direct_mutex);
5427 err = unregister_ftrace_function(ops);
5428 remove_direct_functions_hash(hash, addr);
5429 mutex_unlock(&direct_mutex);
5431 /* cleanup for possible another register call */
5433 ops->trampoline = 0;
5436 ftrace_free_filter(ops);
5439 EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
5442 __modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5444 struct ftrace_hash *hash;
5445 struct ftrace_func_entry *entry, *iter;
5446 static struct ftrace_ops tmp_ops = {
5447 .func = ftrace_stub,
5448 .flags = FTRACE_OPS_FL_STUB,
5453 lockdep_assert_held_once(&direct_mutex);
5455 /* Enable the tmp_ops to have the same functions as the direct ops */
5456 ftrace_ops_init(&tmp_ops);
5457 tmp_ops.func_hash = ops->func_hash;
5458 tmp_ops.direct_call = addr;
5460 err = register_ftrace_function_nolock(&tmp_ops);
5465 * Now the ftrace_ops_list_func() is called to do the direct callers.
5466 * We can safely change the direct functions attached to each entry.
5468 mutex_lock(&ftrace_lock);
5470 hash = ops->func_hash->filter_hash;
5471 size = 1 << hash->size_bits;
5472 for (i = 0; i < size; i++) {
5473 hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
5474 entry = __ftrace_lookup_ip(direct_functions, iter->ip);
5477 entry->direct = addr;
5480 /* Prevent store tearing if a trampoline concurrently accesses the value */
5481 WRITE_ONCE(ops->direct_call, addr);
5483 mutex_unlock(&ftrace_lock);
5485 /* Removing the tmp_ops will add the updated direct callers to the functions */
5486 unregister_ftrace_function(&tmp_ops);
5492 * modify_ftrace_direct_nolock - Modify an existing direct 'multi' call
5493 * to call something else
5494 * @ops: The address of the struct ftrace_ops object
5495 * @addr: The address of the new trampoline to call at @ops functions
5497 * This is used to unregister currently registered direct caller and
5498 * register new one @addr on functions registered in @ops object.
5500 * Note there's window between ftrace_shutdown and ftrace_startup calls
5501 * where there will be no callbacks called.
5503 * Caller should already have direct_mutex locked, so we don't lock
5504 * direct_mutex here.
5506 * Returns: zero on success. Non zero on error, which includes:
5507 * -EINVAL - The @ops object was not properly registered.
5509 int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
5511 if (check_direct_multi(ops))
5513 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5516 return __modify_ftrace_direct(ops, addr);
5518 EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock);
5521 * modify_ftrace_direct - Modify an existing direct 'multi' call
5522 * to call something else
5523 * @ops: The address of the struct ftrace_ops object
5524 * @addr: The address of the new trampoline to call at @ops functions
5526 * This is used to unregister currently registered direct caller and
5527 * register new one @addr on functions registered in @ops object.
5529 * Note there's window between ftrace_shutdown and ftrace_startup calls
5530 * where there will be no callbacks called.
5532 * Returns: zero on success. Non zero on error, which includes:
5533 * -EINVAL - The @ops object was not properly registered.
5535 int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5539 if (check_direct_multi(ops))
5541 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5544 mutex_lock(&direct_mutex);
5545 err = __modify_ftrace_direct(ops, addr);
5546 mutex_unlock(&direct_mutex);
5549 EXPORT_SYMBOL_GPL(modify_ftrace_direct);
5550 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
5553 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
5554 * @ops - the ops to set the filter with
5555 * @ip - the address to add to or remove from the filter.
5556 * @remove - non zero to remove the ip from the filter
5557 * @reset - non zero to reset all filters before applying this filter.
5559 * Filters denote which functions should be enabled when tracing is enabled
5560 * If @ip is NULL, it fails to update filter.
5562 * This can allocate memory which must be freed before @ops can be freed,
5563 * either by removing each filtered addr or by using
5564 * ftrace_free_filter(@ops).
5566 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
5567 int remove, int reset)
5569 ftrace_ops_init(ops);
5570 return ftrace_set_addr(ops, &ip, 1, remove, reset, 1);
5572 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
5575 * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses
5576 * @ops - the ops to set the filter with
5577 * @ips - the array of addresses to add to or remove from the filter.
5578 * @cnt - the number of addresses in @ips
5579 * @remove - non zero to remove ips from the filter
5580 * @reset - non zero to reset all filters before applying this filter.
5582 * Filters denote which functions should be enabled when tracing is enabled
5583 * If @ips array or any ip specified within is NULL , it fails to update filter.
5585 * This can allocate memory which must be freed before @ops can be freed,
5586 * either by removing each filtered addr or by using
5587 * ftrace_free_filter(@ops).
5589 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
5590 unsigned int cnt, int remove, int reset)
5592 ftrace_ops_init(ops);
5593 return ftrace_set_addr(ops, ips, cnt, remove, reset, 1);
5595 EXPORT_SYMBOL_GPL(ftrace_set_filter_ips);
5598 * ftrace_ops_set_global_filter - setup ops to use global filters
5599 * @ops - the ops which will use the global filters
5601 * ftrace users who need global function trace filtering should call this.
5602 * It can set the global filter only if ops were not initialized before.
5604 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
5606 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
5609 ftrace_ops_init(ops);
5610 ops->func_hash = &global_ops.local_hash;
5612 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
5615 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
5616 int reset, int enable)
5618 return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable);
5622 * ftrace_set_filter - set a function to filter on in ftrace
5623 * @ops - the ops to set the filter with
5624 * @buf - the string that holds the function filter text.
5625 * @len - the length of the string.
5626 * @reset - non zero to reset all filters before applying this filter.
5628 * Filters denote which functions should be enabled when tracing is enabled.
5629 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
5631 * This can allocate memory which must be freed before @ops can be freed,
5632 * either by removing each filtered addr or by using
5633 * ftrace_free_filter(@ops).
5635 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
5638 ftrace_ops_init(ops);
5639 return ftrace_set_regex(ops, buf, len, reset, 1);
5641 EXPORT_SYMBOL_GPL(ftrace_set_filter);
5644 * ftrace_set_notrace - set a function to not trace in ftrace
5645 * @ops - the ops to set the notrace filter with
5646 * @buf - the string that holds the function notrace text.
5647 * @len - the length of the string.
5648 * @reset - non zero to reset all filters before applying this filter.
5650 * Notrace Filters denote which functions should not be enabled when tracing
5651 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
5654 * This can allocate memory which must be freed before @ops can be freed,
5655 * either by removing each filtered addr or by using
5656 * ftrace_free_filter(@ops).
5658 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
5661 ftrace_ops_init(ops);
5662 return ftrace_set_regex(ops, buf, len, reset, 0);
5664 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
5666 * ftrace_set_global_filter - set a function to filter on with global tracers
5667 * @buf - the string that holds the function filter text.
5668 * @len - the length of the string.
5669 * @reset - non zero to reset all filters before applying this filter.
5671 * Filters denote which functions should be enabled when tracing is enabled.
5672 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
5674 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
5676 ftrace_set_regex(&global_ops, buf, len, reset, 1);
5678 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
5681 * ftrace_set_global_notrace - set a function to not trace with global tracers
5682 * @buf - the string that holds the function notrace text.
5683 * @len - the length of the string.
5684 * @reset - non zero to reset all filters before applying this filter.
5686 * Notrace Filters denote which functions should not be enabled when tracing
5687 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
5690 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
5692 ftrace_set_regex(&global_ops, buf, len, reset, 0);
5694 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
5697 * command line interface to allow users to set filters on boot up.
5699 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
5700 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
5701 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
5703 /* Used by function selftest to not test if filter is set */
5704 bool ftrace_filter_param __initdata;
5706 static int __init set_ftrace_notrace(char *str)
5708 ftrace_filter_param = true;
5709 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
5712 __setup("ftrace_notrace=", set_ftrace_notrace);
5714 static int __init set_ftrace_filter(char *str)
5716 ftrace_filter_param = true;
5717 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
5720 __setup("ftrace_filter=", set_ftrace_filter);
5722 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5723 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
5724 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
5725 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
5727 static int __init set_graph_function(char *str)
5729 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
5732 __setup("ftrace_graph_filter=", set_graph_function);
5734 static int __init set_graph_notrace_function(char *str)
5736 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
5739 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
5741 static int __init set_graph_max_depth_function(char *str)
5745 fgraph_max_depth = simple_strtoul(str, NULL, 0);
5748 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
5750 static void __init set_ftrace_early_graph(char *buf, int enable)
5754 struct ftrace_hash *hash;
5756 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5757 if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
5761 func = strsep(&buf, ",");
5762 /* we allow only one expression at a time */
5763 ret = ftrace_graph_set_hash(hash, func);
5765 printk(KERN_DEBUG "ftrace: function %s not "
5766 "traceable\n", func);
5770 ftrace_graph_hash = hash;
5772 ftrace_graph_notrace_hash = hash;
5774 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5777 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
5781 ftrace_ops_init(ops);
5784 func = strsep(&buf, ",");
5785 ftrace_set_regex(ops, func, strlen(func), 0, enable);
5789 static void __init set_ftrace_early_filters(void)
5791 if (ftrace_filter_buf[0])
5792 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
5793 if (ftrace_notrace_buf[0])
5794 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
5795 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5796 if (ftrace_graph_buf[0])
5797 set_ftrace_early_graph(ftrace_graph_buf, 1);
5798 if (ftrace_graph_notrace_buf[0])
5799 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
5800 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5803 int ftrace_regex_release(struct inode *inode, struct file *file)
5805 struct seq_file *m = (struct seq_file *)file->private_data;
5806 struct ftrace_iterator *iter;
5807 struct ftrace_hash **orig_hash;
5808 struct trace_parser *parser;
5811 if (file->f_mode & FMODE_READ) {
5813 seq_release(inode, file);
5815 iter = file->private_data;
5817 parser = &iter->parser;
5818 if (trace_parser_loaded(parser)) {
5819 int enable = !(iter->flags & FTRACE_ITER_NOTRACE);
5821 ftrace_process_regex(iter, parser->buffer,
5822 parser->idx, enable);
5825 trace_parser_put(parser);
5827 mutex_lock(&iter->ops->func_hash->regex_lock);
5829 if (file->f_mode & FMODE_WRITE) {
5830 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5833 orig_hash = &iter->ops->func_hash->filter_hash;
5835 if (list_empty(&iter->tr->mod_trace))
5836 iter->hash->flags &= ~FTRACE_HASH_FL_MOD;
5838 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5841 orig_hash = &iter->ops->func_hash->notrace_hash;
5843 mutex_lock(&ftrace_lock);
5844 ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5845 iter->hash, filter_hash);
5846 mutex_unlock(&ftrace_lock);
5848 /* For read only, the hash is the ops hash */
5852 mutex_unlock(&iter->ops->func_hash->regex_lock);
5853 free_ftrace_hash(iter->hash);
5855 trace_array_put(iter->tr);
5861 static const struct file_operations ftrace_avail_fops = {
5862 .open = ftrace_avail_open,
5864 .llseek = seq_lseek,
5865 .release = seq_release_private,
5868 static const struct file_operations ftrace_enabled_fops = {
5869 .open = ftrace_enabled_open,
5871 .llseek = seq_lseek,
5872 .release = seq_release_private,
5875 static const struct file_operations ftrace_filter_fops = {
5876 .open = ftrace_filter_open,
5878 .write = ftrace_filter_write,
5879 .llseek = tracing_lseek,
5880 .release = ftrace_regex_release,
5883 static const struct file_operations ftrace_notrace_fops = {
5884 .open = ftrace_notrace_open,
5886 .write = ftrace_notrace_write,
5887 .llseek = tracing_lseek,
5888 .release = ftrace_regex_release,
5891 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5893 static DEFINE_MUTEX(graph_lock);
5895 struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
5896 struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH;
5898 enum graph_filter_type {
5899 GRAPH_FILTER_NOTRACE = 0,
5900 GRAPH_FILTER_FUNCTION,
5903 #define FTRACE_GRAPH_EMPTY ((void *)1)
5905 struct ftrace_graph_data {
5906 struct ftrace_hash *hash;
5907 struct ftrace_func_entry *entry;
5908 int idx; /* for hash table iteration */
5909 enum graph_filter_type type;
5910 struct ftrace_hash *new_hash;
5911 const struct seq_operations *seq_ops;
5912 struct trace_parser parser;
5916 __g_next(struct seq_file *m, loff_t *pos)
5918 struct ftrace_graph_data *fgd = m->private;
5919 struct ftrace_func_entry *entry = fgd->entry;
5920 struct hlist_head *head;
5921 int i, idx = fgd->idx;
5923 if (*pos >= fgd->hash->count)
5927 hlist_for_each_entry_continue(entry, hlist) {
5935 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5936 head = &fgd->hash->buckets[i];
5937 hlist_for_each_entry(entry, head, hlist) {
5947 g_next(struct seq_file *m, void *v, loff_t *pos)
5950 return __g_next(m, pos);
5953 static void *g_start(struct seq_file *m, loff_t *pos)
5955 struct ftrace_graph_data *fgd = m->private;
5957 mutex_lock(&graph_lock);
5959 if (fgd->type == GRAPH_FILTER_FUNCTION)
5960 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5961 lockdep_is_held(&graph_lock));
5963 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5964 lockdep_is_held(&graph_lock));
5966 /* Nothing, tell g_show to print all functions are enabled */
5967 if (ftrace_hash_empty(fgd->hash) && !*pos)
5968 return FTRACE_GRAPH_EMPTY;
5972 return __g_next(m, pos);
5975 static void g_stop(struct seq_file *m, void *p)
5977 mutex_unlock(&graph_lock);
5980 static int g_show(struct seq_file *m, void *v)
5982 struct ftrace_func_entry *entry = v;
5987 if (entry == FTRACE_GRAPH_EMPTY) {
5988 struct ftrace_graph_data *fgd = m->private;
5990 if (fgd->type == GRAPH_FILTER_FUNCTION)
5991 seq_puts(m, "#### all functions enabled ####\n");
5993 seq_puts(m, "#### no functions disabled ####\n");
5997 seq_printf(m, "%ps\n", (void *)entry->ip);
6002 static const struct seq_operations ftrace_graph_seq_ops = {
6010 __ftrace_graph_open(struct inode *inode, struct file *file,
6011 struct ftrace_graph_data *fgd)
6014 struct ftrace_hash *new_hash = NULL;
6016 ret = security_locked_down(LOCKDOWN_TRACEFS);
6020 if (file->f_mode & FMODE_WRITE) {
6021 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
6023 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
6026 if (file->f_flags & O_TRUNC)
6027 new_hash = alloc_ftrace_hash(size_bits);
6029 new_hash = alloc_and_copy_ftrace_hash(size_bits,
6037 if (file->f_mode & FMODE_READ) {
6038 ret = seq_open(file, &ftrace_graph_seq_ops);
6040 struct seq_file *m = file->private_data;
6044 free_ftrace_hash(new_hash);
6048 file->private_data = fgd;
6051 if (ret < 0 && file->f_mode & FMODE_WRITE)
6052 trace_parser_put(&fgd->parser);
6054 fgd->new_hash = new_hash;
6057 * All uses of fgd->hash must be taken with the graph_lock
6058 * held. The graph_lock is going to be released, so force
6059 * fgd->hash to be reinitialized when it is taken again.
6067 ftrace_graph_open(struct inode *inode, struct file *file)
6069 struct ftrace_graph_data *fgd;
6072 if (unlikely(ftrace_disabled))
6075 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
6079 mutex_lock(&graph_lock);
6081 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6082 lockdep_is_held(&graph_lock));
6083 fgd->type = GRAPH_FILTER_FUNCTION;
6084 fgd->seq_ops = &ftrace_graph_seq_ops;
6086 ret = __ftrace_graph_open(inode, file, fgd);
6090 mutex_unlock(&graph_lock);
6095 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
6097 struct ftrace_graph_data *fgd;
6100 if (unlikely(ftrace_disabled))
6103 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
6107 mutex_lock(&graph_lock);
6109 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6110 lockdep_is_held(&graph_lock));
6111 fgd->type = GRAPH_FILTER_NOTRACE;
6112 fgd->seq_ops = &ftrace_graph_seq_ops;
6114 ret = __ftrace_graph_open(inode, file, fgd);
6118 mutex_unlock(&graph_lock);
6123 ftrace_graph_release(struct inode *inode, struct file *file)
6125 struct ftrace_graph_data *fgd;
6126 struct ftrace_hash *old_hash, *new_hash;
6127 struct trace_parser *parser;
6130 if (file->f_mode & FMODE_READ) {
6131 struct seq_file *m = file->private_data;
6134 seq_release(inode, file);
6136 fgd = file->private_data;
6140 if (file->f_mode & FMODE_WRITE) {
6142 parser = &fgd->parser;
6144 if (trace_parser_loaded((parser))) {
6145 ret = ftrace_graph_set_hash(fgd->new_hash,
6149 trace_parser_put(parser);
6151 new_hash = __ftrace_hash_move(fgd->new_hash);
6157 mutex_lock(&graph_lock);
6159 if (fgd->type == GRAPH_FILTER_FUNCTION) {
6160 old_hash = rcu_dereference_protected(ftrace_graph_hash,
6161 lockdep_is_held(&graph_lock));
6162 rcu_assign_pointer(ftrace_graph_hash, new_hash);
6164 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6165 lockdep_is_held(&graph_lock));
6166 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
6169 mutex_unlock(&graph_lock);
6172 * We need to do a hard force of sched synchronization.
6173 * This is because we use preempt_disable() to do RCU, but
6174 * the function tracers can be called where RCU is not watching
6175 * (like before user_exit()). We can not rely on the RCU
6176 * infrastructure to do the synchronization, thus we must do it
6179 if (old_hash != EMPTY_HASH)
6180 synchronize_rcu_tasks_rude();
6182 free_ftrace_hash(old_hash);
6186 free_ftrace_hash(fgd->new_hash);
6193 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
6195 struct ftrace_glob func_g;
6196 struct dyn_ftrace *rec;
6197 struct ftrace_page *pg;
6198 struct ftrace_func_entry *entry;
6203 func_g.type = filter_parse_regex(buffer, strlen(buffer),
6204 &func_g.search, ¬);
6206 func_g.len = strlen(func_g.search);
6208 mutex_lock(&ftrace_lock);
6210 if (unlikely(ftrace_disabled)) {
6211 mutex_unlock(&ftrace_lock);
6215 do_for_each_ftrace_rec(pg, rec) {
6217 if (rec->flags & FTRACE_FL_DISABLED)
6220 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
6221 entry = ftrace_lookup_ip(hash, rec->ip);
6228 if (add_hash_entry(hash, rec->ip) < 0)
6232 free_hash_entry(hash, entry);
6237 } while_for_each_ftrace_rec();
6239 mutex_unlock(&ftrace_lock);
6248 ftrace_graph_write(struct file *file, const char __user *ubuf,
6249 size_t cnt, loff_t *ppos)
6251 ssize_t read, ret = 0;
6252 struct ftrace_graph_data *fgd = file->private_data;
6253 struct trace_parser *parser;
6258 /* Read mode uses seq functions */
6259 if (file->f_mode & FMODE_READ) {
6260 struct seq_file *m = file->private_data;
6264 parser = &fgd->parser;
6266 read = trace_get_user(parser, ubuf, cnt, ppos);
6268 if (read >= 0 && trace_parser_loaded(parser) &&
6269 !trace_parser_cont(parser)) {
6271 ret = ftrace_graph_set_hash(fgd->new_hash,
6273 trace_parser_clear(parser);
6282 static const struct file_operations ftrace_graph_fops = {
6283 .open = ftrace_graph_open,
6285 .write = ftrace_graph_write,
6286 .llseek = tracing_lseek,
6287 .release = ftrace_graph_release,
6290 static const struct file_operations ftrace_graph_notrace_fops = {
6291 .open = ftrace_graph_notrace_open,
6293 .write = ftrace_graph_write,
6294 .llseek = tracing_lseek,
6295 .release = ftrace_graph_release,
6297 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6299 void ftrace_create_filter_files(struct ftrace_ops *ops,
6300 struct dentry *parent)
6303 trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent,
6304 ops, &ftrace_filter_fops);
6306 trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent,
6307 ops, &ftrace_notrace_fops);
6311 * The name "destroy_filter_files" is really a misnomer. Although
6312 * in the future, it may actually delete the files, but this is
6313 * really intended to make sure the ops passed in are disabled
6314 * and that when this function returns, the caller is free to
6317 * The "destroy" name is only to match the "create" name that this
6318 * should be paired with.
6320 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
6322 mutex_lock(&ftrace_lock);
6323 if (ops->flags & FTRACE_OPS_FL_ENABLED)
6324 ftrace_shutdown(ops, 0);
6325 ops->flags |= FTRACE_OPS_FL_DELETED;
6326 ftrace_free_filter(ops);
6327 mutex_unlock(&ftrace_lock);
6330 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
6333 trace_create_file("available_filter_functions", TRACE_MODE_READ,
6334 d_tracer, NULL, &ftrace_avail_fops);
6336 trace_create_file("enabled_functions", TRACE_MODE_READ,
6337 d_tracer, NULL, &ftrace_enabled_fops);
6339 ftrace_create_filter_files(&global_ops, d_tracer);
6341 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6342 trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer,
6344 &ftrace_graph_fops);
6345 trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer,
6347 &ftrace_graph_notrace_fops);
6348 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6353 static int ftrace_cmp_ips(const void *a, const void *b)
6355 const unsigned long *ipa = a;
6356 const unsigned long *ipb = b;
6365 #ifdef CONFIG_FTRACE_SORT_STARTUP_TEST
6366 static void test_is_sorted(unsigned long *start, unsigned long count)
6370 for (i = 1; i < count; i++) {
6371 if (WARN(start[i - 1] > start[i],
6372 "[%d] %pS at %lx is not sorted with %pS at %lx\n", i,
6373 (void *)start[i - 1], start[i - 1],
6374 (void *)start[i], start[i]))
6378 pr_info("ftrace section at %px sorted properly\n", start);
6381 static void test_is_sorted(unsigned long *start, unsigned long count)
6386 static int ftrace_process_locs(struct module *mod,
6387 unsigned long *start,
6390 struct ftrace_page *start_pg;
6391 struct ftrace_page *pg;
6392 struct dyn_ftrace *rec;
6393 unsigned long count;
6396 unsigned long flags = 0; /* Shut up gcc */
6399 count = end - start;
6405 * Sorting mcount in vmlinux at build time depend on
6406 * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in
6407 * modules can not be sorted at build time.
6409 if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) {
6410 sort(start, count, sizeof(*start),
6411 ftrace_cmp_ips, NULL);
6413 test_is_sorted(start, count);
6416 start_pg = ftrace_allocate_pages(count);
6420 mutex_lock(&ftrace_lock);
6423 * Core and each module needs their own pages, as
6424 * modules will free them when they are removed.
6425 * Force a new page to be allocated for modules.
6428 WARN_ON(ftrace_pages || ftrace_pages_start);
6429 /* First initialization */
6430 ftrace_pages = ftrace_pages_start = start_pg;
6435 if (WARN_ON(ftrace_pages->next)) {
6436 /* Hmm, we have free pages? */
6437 while (ftrace_pages->next)
6438 ftrace_pages = ftrace_pages->next;
6441 ftrace_pages->next = start_pg;
6447 unsigned long end_offset;
6448 addr = ftrace_call_adjust(*p++);
6450 * Some architecture linkers will pad between
6451 * the different mcount_loc sections of different
6452 * object files to satisfy alignments.
6453 * Skip any NULL pointers.
6458 end_offset = (pg->index+1) * sizeof(pg->records[0]);
6459 if (end_offset > PAGE_SIZE << pg->order) {
6460 /* We should have allocated enough */
6461 if (WARN_ON(!pg->next))
6466 rec = &pg->records[pg->index++];
6470 /* We should have used all pages */
6473 /* Assign the last page to ftrace_pages */
6477 * We only need to disable interrupts on start up
6478 * because we are modifying code that an interrupt
6479 * may execute, and the modification is not atomic.
6480 * But for modules, nothing runs the code we modify
6481 * until we are finished with it, and there's no
6482 * reason to cause large interrupt latencies while we do it.
6485 local_irq_save(flags);
6486 ftrace_update_code(mod, start_pg);
6488 local_irq_restore(flags);
6491 mutex_unlock(&ftrace_lock);
6496 struct ftrace_mod_func {
6497 struct list_head list;
6503 struct ftrace_mod_map {
6504 struct rcu_head rcu;
6505 struct list_head list;
6507 unsigned long start_addr;
6508 unsigned long end_addr;
6509 struct list_head funcs;
6510 unsigned int num_funcs;
6513 static int ftrace_get_trampoline_kallsym(unsigned int symnum,
6514 unsigned long *value, char *type,
6515 char *name, char *module_name,
6518 struct ftrace_ops *op;
6520 list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
6521 if (!op->trampoline || symnum--)
6523 *value = op->trampoline;
6525 strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
6526 strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
6534 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES)
6536 * Check if the current ops references the given ip.
6538 * If the ops traces all functions, then it was already accounted for.
6539 * If the ops does not trace the current record function, skip it.
6540 * If the ops ignores the function via notrace filter, skip it.
6543 ops_references_ip(struct ftrace_ops *ops, unsigned long ip)
6545 /* If ops isn't enabled, ignore it */
6546 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
6549 /* If ops traces all then it includes this function */
6550 if (ops_traces_mod(ops))
6553 /* The function must be in the filter */
6554 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
6555 !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip))
6558 /* If in notrace hash, we ignore it too */
6559 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip))
6566 #ifdef CONFIG_MODULES
6568 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
6570 static LIST_HEAD(ftrace_mod_maps);
6572 static int referenced_filters(struct dyn_ftrace *rec)
6574 struct ftrace_ops *ops;
6577 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
6578 if (ops_references_ip(ops, rec->ip)) {
6579 if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
6581 if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
6584 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
6585 rec->flags |= FTRACE_FL_REGS;
6586 if (cnt == 1 && ops->trampoline)
6587 rec->flags |= FTRACE_FL_TRAMP;
6589 rec->flags &= ~FTRACE_FL_TRAMP;
6597 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
6599 struct ftrace_func_entry *entry;
6600 struct dyn_ftrace *rec;
6603 if (ftrace_hash_empty(hash))
6606 for (i = 0; i < pg->index; i++) {
6607 rec = &pg->records[i];
6608 entry = __ftrace_lookup_ip(hash, rec->ip);
6610 * Do not allow this rec to match again.
6611 * Yeah, it may waste some memory, but will be removed
6612 * if/when the hash is modified again.
6619 /* Clear any records from hashes */
6620 static void clear_mod_from_hashes(struct ftrace_page *pg)
6622 struct trace_array *tr;
6624 mutex_lock(&trace_types_lock);
6625 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6626 if (!tr->ops || !tr->ops->func_hash)
6628 mutex_lock(&tr->ops->func_hash->regex_lock);
6629 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
6630 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
6631 mutex_unlock(&tr->ops->func_hash->regex_lock);
6633 mutex_unlock(&trace_types_lock);
6636 static void ftrace_free_mod_map(struct rcu_head *rcu)
6638 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
6639 struct ftrace_mod_func *mod_func;
6640 struct ftrace_mod_func *n;
6642 /* All the contents of mod_map are now not visible to readers */
6643 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
6644 kfree(mod_func->name);
6645 list_del(&mod_func->list);
6652 void ftrace_release_mod(struct module *mod)
6654 struct ftrace_mod_map *mod_map;
6655 struct ftrace_mod_map *n;
6656 struct dyn_ftrace *rec;
6657 struct ftrace_page **last_pg;
6658 struct ftrace_page *tmp_page = NULL;
6659 struct ftrace_page *pg;
6661 mutex_lock(&ftrace_lock);
6663 if (ftrace_disabled)
6666 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
6667 if (mod_map->mod == mod) {
6668 list_del_rcu(&mod_map->list);
6669 call_rcu(&mod_map->rcu, ftrace_free_mod_map);
6675 * Each module has its own ftrace_pages, remove
6676 * them from the list.
6678 last_pg = &ftrace_pages_start;
6679 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
6680 rec = &pg->records[0];
6681 if (within_module_core(rec->ip, mod) ||
6682 within_module_init(rec->ip, mod)) {
6684 * As core pages are first, the first
6685 * page should never be a module page.
6687 if (WARN_ON(pg == ftrace_pages_start))
6690 /* Check if we are deleting the last page */
6691 if (pg == ftrace_pages)
6692 ftrace_pages = next_to_ftrace_page(last_pg);
6694 ftrace_update_tot_cnt -= pg->index;
6695 *last_pg = pg->next;
6697 pg->next = tmp_page;
6700 last_pg = &pg->next;
6703 mutex_unlock(&ftrace_lock);
6705 for (pg = tmp_page; pg; pg = tmp_page) {
6707 /* Needs to be called outside of ftrace_lock */
6708 clear_mod_from_hashes(pg);
6711 free_pages((unsigned long)pg->records, pg->order);
6712 ftrace_number_of_pages -= 1 << pg->order;
6714 tmp_page = pg->next;
6716 ftrace_number_of_groups--;
6720 void ftrace_module_enable(struct module *mod)
6722 struct dyn_ftrace *rec;
6723 struct ftrace_page *pg;
6725 mutex_lock(&ftrace_lock);
6727 if (ftrace_disabled)
6731 * If the tracing is enabled, go ahead and enable the record.
6733 * The reason not to enable the record immediately is the
6734 * inherent check of ftrace_make_nop/ftrace_make_call for
6735 * correct previous instructions. Making first the NOP
6736 * conversion puts the module to the correct state, thus
6737 * passing the ftrace_make_call check.
6739 * We also delay this to after the module code already set the
6740 * text to read-only, as we now need to set it back to read-write
6741 * so that we can modify the text.
6743 if (ftrace_start_up)
6744 ftrace_arch_code_modify_prepare();
6746 do_for_each_ftrace_rec(pg, rec) {
6749 * do_for_each_ftrace_rec() is a double loop.
6750 * module text shares the pg. If a record is
6751 * not part of this module, then skip this pg,
6752 * which the "break" will do.
6754 if (!within_module_core(rec->ip, mod) &&
6755 !within_module_init(rec->ip, mod))
6758 /* Weak functions should still be ignored */
6759 if (!test_for_valid_rec(rec)) {
6760 /* Clear all other flags. Should not be enabled anyway */
6761 rec->flags = FTRACE_FL_DISABLED;
6768 * When adding a module, we need to check if tracers are
6769 * currently enabled and if they are, and can trace this record,
6770 * we need to enable the module functions as well as update the
6771 * reference counts for those function records.
6773 if (ftrace_start_up)
6774 cnt += referenced_filters(rec);
6776 rec->flags &= ~FTRACE_FL_DISABLED;
6779 if (ftrace_start_up && cnt) {
6780 int failed = __ftrace_replace_code(rec, 1);
6782 ftrace_bug(failed, rec);
6787 } while_for_each_ftrace_rec();
6790 if (ftrace_start_up)
6791 ftrace_arch_code_modify_post_process();
6794 mutex_unlock(&ftrace_lock);
6796 process_cached_mods(mod->name);
6799 void ftrace_module_init(struct module *mod)
6803 if (ftrace_disabled || !mod->num_ftrace_callsites)
6806 ret = ftrace_process_locs(mod, mod->ftrace_callsites,
6807 mod->ftrace_callsites + mod->num_ftrace_callsites);
6809 pr_warn("ftrace: failed to allocate entries for module '%s' functions\n",
6813 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6814 struct dyn_ftrace *rec)
6816 struct ftrace_mod_func *mod_func;
6817 unsigned long symsize;
6818 unsigned long offset;
6819 char str[KSYM_SYMBOL_LEN];
6823 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
6827 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
6831 mod_func->name = kstrdup(str, GFP_KERNEL);
6832 if (!mod_func->name) {
6837 mod_func->ip = rec->ip - offset;
6838 mod_func->size = symsize;
6840 mod_map->num_funcs++;
6842 list_add_rcu(&mod_func->list, &mod_map->funcs);
6845 static struct ftrace_mod_map *
6846 allocate_ftrace_mod_map(struct module *mod,
6847 unsigned long start, unsigned long end)
6849 struct ftrace_mod_map *mod_map;
6851 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
6856 mod_map->start_addr = start;
6857 mod_map->end_addr = end;
6858 mod_map->num_funcs = 0;
6860 INIT_LIST_HEAD_RCU(&mod_map->funcs);
6862 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
6868 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
6869 unsigned long addr, unsigned long *size,
6870 unsigned long *off, char *sym)
6872 struct ftrace_mod_func *found_func = NULL;
6873 struct ftrace_mod_func *mod_func;
6875 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6876 if (addr >= mod_func->ip &&
6877 addr < mod_func->ip + mod_func->size) {
6878 found_func = mod_func;
6885 *size = found_func->size;
6887 *off = addr - found_func->ip;
6889 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
6891 return found_func->name;
6898 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
6899 unsigned long *off, char **modname, char *sym)
6901 struct ftrace_mod_map *mod_map;
6902 const char *ret = NULL;
6904 /* mod_map is freed via call_rcu() */
6906 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
6907 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
6910 *modname = mod_map->mod->name;
6919 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
6920 char *type, char *name,
6921 char *module_name, int *exported)
6923 struct ftrace_mod_map *mod_map;
6924 struct ftrace_mod_func *mod_func;
6928 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
6930 if (symnum >= mod_map->num_funcs) {
6931 symnum -= mod_map->num_funcs;
6935 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6941 *value = mod_func->ip;
6943 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
6944 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6952 ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
6953 module_name, exported);
6959 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6960 struct dyn_ftrace *rec) { }
6961 static inline struct ftrace_mod_map *
6962 allocate_ftrace_mod_map(struct module *mod,
6963 unsigned long start, unsigned long end)
6967 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
6968 char *type, char *name, char *module_name,
6974 ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
6975 module_name, exported);
6979 #endif /* CONFIG_MODULES */
6981 struct ftrace_init_func {
6982 struct list_head list;
6986 /* Clear any init ips from hashes */
6988 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6990 struct ftrace_func_entry *entry;
6992 entry = ftrace_lookup_ip(hash, func->ip);
6994 * Do not allow this rec to match again.
6995 * Yeah, it may waste some memory, but will be removed
6996 * if/when the hash is modified again.
7003 clear_func_from_hashes(struct ftrace_init_func *func)
7005 struct trace_array *tr;
7007 mutex_lock(&trace_types_lock);
7008 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
7009 if (!tr->ops || !tr->ops->func_hash)
7011 mutex_lock(&tr->ops->func_hash->regex_lock);
7012 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
7013 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
7014 mutex_unlock(&tr->ops->func_hash->regex_lock);
7016 mutex_unlock(&trace_types_lock);
7019 static void add_to_clear_hash_list(struct list_head *clear_list,
7020 struct dyn_ftrace *rec)
7022 struct ftrace_init_func *func;
7024 func = kmalloc(sizeof(*func), GFP_KERNEL);
7026 MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
7031 list_add(&func->list, clear_list);
7034 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
7036 unsigned long start = (unsigned long)(start_ptr);
7037 unsigned long end = (unsigned long)(end_ptr);
7038 struct ftrace_page **last_pg = &ftrace_pages_start;
7039 struct ftrace_page *pg;
7040 struct dyn_ftrace *rec;
7041 struct dyn_ftrace key;
7042 struct ftrace_mod_map *mod_map = NULL;
7043 struct ftrace_init_func *func, *func_next;
7044 struct list_head clear_hash;
7046 INIT_LIST_HEAD(&clear_hash);
7049 key.flags = end; /* overload flags, as it is unsigned long */
7051 mutex_lock(&ftrace_lock);
7054 * If we are freeing module init memory, then check if
7055 * any tracer is active. If so, we need to save a mapping of
7056 * the module functions being freed with the address.
7058 if (mod && ftrace_ops_list != &ftrace_list_end)
7059 mod_map = allocate_ftrace_mod_map(mod, start, end);
7061 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
7062 if (end < pg->records[0].ip ||
7063 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
7066 rec = bsearch(&key, pg->records, pg->index,
7067 sizeof(struct dyn_ftrace),
7072 /* rec will be cleared from hashes after ftrace_lock unlock */
7073 add_to_clear_hash_list(&clear_hash, rec);
7076 save_ftrace_mod_rec(mod_map, rec);
7079 ftrace_update_tot_cnt--;
7081 *last_pg = pg->next;
7083 free_pages((unsigned long)pg->records, pg->order);
7084 ftrace_number_of_pages -= 1 << pg->order;
7086 ftrace_number_of_groups--;
7088 pg = container_of(last_pg, struct ftrace_page, next);
7093 memmove(rec, rec + 1,
7094 (pg->index - (rec - pg->records)) * sizeof(*rec));
7095 /* More than one function may be in this block */
7098 mutex_unlock(&ftrace_lock);
7100 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
7101 clear_func_from_hashes(func);
7106 void __init ftrace_free_init_mem(void)
7108 void *start = (void *)(&__init_begin);
7109 void *end = (void *)(&__init_end);
7111 ftrace_boot_snapshot();
7113 ftrace_free_mem(NULL, start, end);
7116 int __init __weak ftrace_dyn_arch_init(void)
7121 void __init ftrace_init(void)
7123 extern unsigned long __start_mcount_loc[];
7124 extern unsigned long __stop_mcount_loc[];
7125 unsigned long count, flags;
7128 local_irq_save(flags);
7129 ret = ftrace_dyn_arch_init();
7130 local_irq_restore(flags);
7134 count = __stop_mcount_loc - __start_mcount_loc;
7136 pr_info("ftrace: No functions to be traced?\n");
7140 pr_info("ftrace: allocating %ld entries in %ld pages\n",
7141 count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
7143 ret = ftrace_process_locs(NULL,
7147 pr_warn("ftrace: failed to allocate entries for functions\n");
7151 pr_info("ftrace: allocated %ld pages with %ld groups\n",
7152 ftrace_number_of_pages, ftrace_number_of_groups);
7154 last_ftrace_enabled = ftrace_enabled = 1;
7156 set_ftrace_early_filters();
7160 ftrace_disabled = 1;
7163 /* Do nothing if arch does not support this */
7164 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
7168 static void ftrace_update_trampoline(struct ftrace_ops *ops)
7170 unsigned long trampoline = ops->trampoline;
7172 arch_ftrace_update_trampoline(ops);
7173 if (ops->trampoline && ops->trampoline != trampoline &&
7174 (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
7175 /* Add to kallsyms before the perf events */
7176 ftrace_add_trampoline_to_kallsyms(ops);
7177 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
7178 ops->trampoline, ops->trampoline_size, false,
7179 FTRACE_TRAMPOLINE_SYM);
7181 * Record the perf text poke event after the ksymbol register
7184 perf_event_text_poke((void *)ops->trampoline, NULL, 0,
7185 (void *)ops->trampoline,
7186 ops->trampoline_size);
7190 void ftrace_init_trace_array(struct trace_array *tr)
7192 INIT_LIST_HEAD(&tr->func_probes);
7193 INIT_LIST_HEAD(&tr->mod_trace);
7194 INIT_LIST_HEAD(&tr->mod_notrace);
7198 struct ftrace_ops global_ops = {
7199 .func = ftrace_stub,
7200 .flags = FTRACE_OPS_FL_INITIALIZED |
7204 static int __init ftrace_nodyn_init(void)
7209 core_initcall(ftrace_nodyn_init);
7211 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
7212 static inline void ftrace_startup_all(int command) { }
7214 static void ftrace_update_trampoline(struct ftrace_ops *ops)
7218 #endif /* CONFIG_DYNAMIC_FTRACE */
7220 __init void ftrace_init_global_array_ops(struct trace_array *tr)
7222 tr->ops = &global_ops;
7223 tr->ops->private = tr;
7224 ftrace_init_trace_array(tr);
7227 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
7229 /* If we filter on pids, update to use the pid function */
7230 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
7231 if (WARN_ON(tr->ops->func != ftrace_stub))
7232 printk("ftrace ops had %pS for function\n",
7235 tr->ops->func = func;
7236 tr->ops->private = tr;
7239 void ftrace_reset_array_ops(struct trace_array *tr)
7241 tr->ops->func = ftrace_stub;
7244 static nokprobe_inline void
7245 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
7246 struct ftrace_ops *ignored, struct ftrace_regs *fregs)
7248 struct pt_regs *regs = ftrace_get_regs(fregs);
7249 struct ftrace_ops *op;
7253 * The ftrace_test_and_set_recursion() will disable preemption,
7254 * which is required since some of the ops may be dynamically
7255 * allocated, they must be freed after a synchronize_rcu().
7257 bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
7261 do_for_each_ftrace_op(op, ftrace_ops_list) {
7262 /* Stub functions don't need to be called nor tested */
7263 if (op->flags & FTRACE_OPS_FL_STUB)
7266 * Check the following for each ops before calling their func:
7267 * if RCU flag is set, then rcu_is_watching() must be true
7268 * Otherwise test if the ip matches the ops filter
7270 * If any of the above fails then the op->func() is not executed.
7272 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
7273 ftrace_ops_test(op, ip, regs)) {
7274 if (FTRACE_WARN_ON(!op->func)) {
7275 pr_warn("op=%p %pS\n", op, op);
7278 op->func(ip, parent_ip, op, fregs);
7280 } while_for_each_ftrace_op(op);
7282 trace_clear_recursion(bit);
7286 * Some archs only support passing ip and parent_ip. Even though
7287 * the list function ignores the op parameter, we do not want any
7288 * C side effects, where a function is called without the caller
7289 * sending a third parameter.
7290 * Archs are to support both the regs and ftrace_ops at the same time.
7291 * If they support ftrace_ops, it is assumed they support regs.
7292 * If call backs want to use regs, they must either check for regs
7293 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
7294 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
7295 * An architecture can pass partial regs with ftrace_ops and still
7296 * set the ARCH_SUPPORTS_FTRACE_OPS.
7298 * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be
7299 * arch_ftrace_ops_list_func.
7301 #if ARCH_SUPPORTS_FTRACE_OPS
7302 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
7303 struct ftrace_ops *op, struct ftrace_regs *fregs)
7305 __ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
7308 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
7310 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
7313 NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
7316 * If there's only one function registered but it does not support
7317 * recursion, needs RCU protection, then this function will be called
7318 * by the mcount trampoline.
7320 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
7321 struct ftrace_ops *op, struct ftrace_regs *fregs)
7325 bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
7329 if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
7330 op->func(ip, parent_ip, op, fregs);
7332 trace_clear_recursion(bit);
7334 NOKPROBE_SYMBOL(ftrace_ops_assist_func);
7337 * ftrace_ops_get_func - get the function a trampoline should call
7338 * @ops: the ops to get the function for
7340 * Normally the mcount trampoline will call the ops->func, but there
7341 * are times that it should not. For example, if the ops does not
7342 * have its own recursion protection, then it should call the
7343 * ftrace_ops_assist_func() instead.
7345 * Returns the function that the trampoline should call for @ops.
7347 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
7350 * If the function does not handle recursion or needs to be RCU safe,
7351 * then we need to call the assist handler.
7353 if (ops->flags & (FTRACE_OPS_FL_RECURSION |
7355 return ftrace_ops_assist_func;
7361 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
7362 struct task_struct *prev,
7363 struct task_struct *next,
7364 unsigned int prev_state)
7366 struct trace_array *tr = data;
7367 struct trace_pid_list *pid_list;
7368 struct trace_pid_list *no_pid_list;
7370 pid_list = rcu_dereference_sched(tr->function_pids);
7371 no_pid_list = rcu_dereference_sched(tr->function_no_pids);
7373 if (trace_ignore_this_task(pid_list, no_pid_list, next))
7374 this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7377 this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7382 ftrace_pid_follow_sched_process_fork(void *data,
7383 struct task_struct *self,
7384 struct task_struct *task)
7386 struct trace_pid_list *pid_list;
7387 struct trace_array *tr = data;
7389 pid_list = rcu_dereference_sched(tr->function_pids);
7390 trace_filter_add_remove_task(pid_list, self, task);
7392 pid_list = rcu_dereference_sched(tr->function_no_pids);
7393 trace_filter_add_remove_task(pid_list, self, task);
7397 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
7399 struct trace_pid_list *pid_list;
7400 struct trace_array *tr = data;
7402 pid_list = rcu_dereference_sched(tr->function_pids);
7403 trace_filter_add_remove_task(pid_list, NULL, task);
7405 pid_list = rcu_dereference_sched(tr->function_no_pids);
7406 trace_filter_add_remove_task(pid_list, NULL, task);
7409 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
7412 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
7414 register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit,
7417 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
7419 unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit,
7424 static void clear_ftrace_pids(struct trace_array *tr, int type)
7426 struct trace_pid_list *pid_list;
7427 struct trace_pid_list *no_pid_list;
7430 pid_list = rcu_dereference_protected(tr->function_pids,
7431 lockdep_is_held(&ftrace_lock));
7432 no_pid_list = rcu_dereference_protected(tr->function_no_pids,
7433 lockdep_is_held(&ftrace_lock));
7435 /* Make sure there's something to do */
7436 if (!pid_type_enabled(type, pid_list, no_pid_list))
7439 /* See if the pids still need to be checked after this */
7440 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
7441 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
7442 for_each_possible_cpu(cpu)
7443 per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
7446 if (type & TRACE_PIDS)
7447 rcu_assign_pointer(tr->function_pids, NULL);
7449 if (type & TRACE_NO_PIDS)
7450 rcu_assign_pointer(tr->function_no_pids, NULL);
7452 /* Wait till all users are no longer using pid filtering */
7455 if ((type & TRACE_PIDS) && pid_list)
7456 trace_pid_list_free(pid_list);
7458 if ((type & TRACE_NO_PIDS) && no_pid_list)
7459 trace_pid_list_free(no_pid_list);
7462 void ftrace_clear_pids(struct trace_array *tr)
7464 mutex_lock(&ftrace_lock);
7466 clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
7468 mutex_unlock(&ftrace_lock);
7471 static void ftrace_pid_reset(struct trace_array *tr, int type)
7473 mutex_lock(&ftrace_lock);
7474 clear_ftrace_pids(tr, type);
7476 ftrace_update_pid_func();
7477 ftrace_startup_all(0);
7479 mutex_unlock(&ftrace_lock);
7482 /* Greater than any max PID */
7483 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
7485 static void *fpid_start(struct seq_file *m, loff_t *pos)
7488 struct trace_pid_list *pid_list;
7489 struct trace_array *tr = m->private;
7491 mutex_lock(&ftrace_lock);
7492 rcu_read_lock_sched();
7494 pid_list = rcu_dereference_sched(tr->function_pids);
7497 return !(*pos) ? FTRACE_NO_PIDS : NULL;
7499 return trace_pid_start(pid_list, pos);
7502 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
7504 struct trace_array *tr = m->private;
7505 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
7507 if (v == FTRACE_NO_PIDS) {
7511 return trace_pid_next(pid_list, v, pos);
7514 static void fpid_stop(struct seq_file *m, void *p)
7517 rcu_read_unlock_sched();
7518 mutex_unlock(&ftrace_lock);
7521 static int fpid_show(struct seq_file *m, void *v)
7523 if (v == FTRACE_NO_PIDS) {
7524 seq_puts(m, "no pid\n");
7528 return trace_pid_show(m, v);
7531 static const struct seq_operations ftrace_pid_sops = {
7532 .start = fpid_start,
7538 static void *fnpid_start(struct seq_file *m, loff_t *pos)
7541 struct trace_pid_list *pid_list;
7542 struct trace_array *tr = m->private;
7544 mutex_lock(&ftrace_lock);
7545 rcu_read_lock_sched();
7547 pid_list = rcu_dereference_sched(tr->function_no_pids);
7550 return !(*pos) ? FTRACE_NO_PIDS : NULL;
7552 return trace_pid_start(pid_list, pos);
7555 static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
7557 struct trace_array *tr = m->private;
7558 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
7560 if (v == FTRACE_NO_PIDS) {
7564 return trace_pid_next(pid_list, v, pos);
7567 static const struct seq_operations ftrace_no_pid_sops = {
7568 .start = fnpid_start,
7574 static int pid_open(struct inode *inode, struct file *file, int type)
7576 const struct seq_operations *seq_ops;
7577 struct trace_array *tr = inode->i_private;
7581 ret = tracing_check_open_get_tr(tr);
7585 if ((file->f_mode & FMODE_WRITE) &&
7586 (file->f_flags & O_TRUNC))
7587 ftrace_pid_reset(tr, type);
7591 seq_ops = &ftrace_pid_sops;
7594 seq_ops = &ftrace_no_pid_sops;
7597 trace_array_put(tr);
7602 ret = seq_open(file, seq_ops);
7604 trace_array_put(tr);
7606 m = file->private_data;
7607 /* copy tr over to seq ops */
7615 ftrace_pid_open(struct inode *inode, struct file *file)
7617 return pid_open(inode, file, TRACE_PIDS);
7621 ftrace_no_pid_open(struct inode *inode, struct file *file)
7623 return pid_open(inode, file, TRACE_NO_PIDS);
7626 static void ignore_task_cpu(void *data)
7628 struct trace_array *tr = data;
7629 struct trace_pid_list *pid_list;
7630 struct trace_pid_list *no_pid_list;
7633 * This function is called by on_each_cpu() while the
7634 * event_mutex is held.
7636 pid_list = rcu_dereference_protected(tr->function_pids,
7637 mutex_is_locked(&ftrace_lock));
7638 no_pid_list = rcu_dereference_protected(tr->function_no_pids,
7639 mutex_is_locked(&ftrace_lock));
7641 if (trace_ignore_this_task(pid_list, no_pid_list, current))
7642 this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7645 this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7650 pid_write(struct file *filp, const char __user *ubuf,
7651 size_t cnt, loff_t *ppos, int type)
7653 struct seq_file *m = filp->private_data;
7654 struct trace_array *tr = m->private;
7655 struct trace_pid_list *filtered_pids;
7656 struct trace_pid_list *other_pids;
7657 struct trace_pid_list *pid_list;
7663 mutex_lock(&ftrace_lock);
7667 filtered_pids = rcu_dereference_protected(tr->function_pids,
7668 lockdep_is_held(&ftrace_lock));
7669 other_pids = rcu_dereference_protected(tr->function_no_pids,
7670 lockdep_is_held(&ftrace_lock));
7673 filtered_pids = rcu_dereference_protected(tr->function_no_pids,
7674 lockdep_is_held(&ftrace_lock));
7675 other_pids = rcu_dereference_protected(tr->function_pids,
7676 lockdep_is_held(&ftrace_lock));
7684 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
7690 rcu_assign_pointer(tr->function_pids, pid_list);
7693 rcu_assign_pointer(tr->function_no_pids, pid_list);
7698 if (filtered_pids) {
7700 trace_pid_list_free(filtered_pids);
7701 } else if (pid_list && !other_pids) {
7702 /* Register a probe to set whether to ignore the tracing of a task */
7703 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
7707 * Ignoring of pids is done at task switch. But we have to
7708 * check for those tasks that are currently running.
7709 * Always do this in case a pid was appended or removed.
7711 on_each_cpu(ignore_task_cpu, tr, 1);
7713 ftrace_update_pid_func();
7714 ftrace_startup_all(0);
7716 mutex_unlock(&ftrace_lock);
7725 ftrace_pid_write(struct file *filp, const char __user *ubuf,
7726 size_t cnt, loff_t *ppos)
7728 return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
7732 ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
7733 size_t cnt, loff_t *ppos)
7735 return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
7739 ftrace_pid_release(struct inode *inode, struct file *file)
7741 struct trace_array *tr = inode->i_private;
7743 trace_array_put(tr);
7745 return seq_release(inode, file);
7748 static const struct file_operations ftrace_pid_fops = {
7749 .open = ftrace_pid_open,
7750 .write = ftrace_pid_write,
7752 .llseek = tracing_lseek,
7753 .release = ftrace_pid_release,
7756 static const struct file_operations ftrace_no_pid_fops = {
7757 .open = ftrace_no_pid_open,
7758 .write = ftrace_no_pid_write,
7760 .llseek = tracing_lseek,
7761 .release = ftrace_pid_release,
7764 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
7766 trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer,
7767 tr, &ftrace_pid_fops);
7768 trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE,
7769 d_tracer, tr, &ftrace_no_pid_fops);
7772 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
7773 struct dentry *d_tracer)
7775 /* Only the top level directory has the dyn_tracefs and profile */
7776 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
7778 ftrace_init_dyn_tracefs(d_tracer);
7779 ftrace_profile_tracefs(d_tracer);
7783 * ftrace_kill - kill ftrace
7785 * This function should be used by panic code. It stops ftrace
7786 * but in a not so nice way. If you need to simply kill ftrace
7787 * from a non-atomic section, use ftrace_kill.
7789 void ftrace_kill(void)
7791 ftrace_disabled = 1;
7793 ftrace_trace_function = ftrace_stub;
7797 * ftrace_is_dead - Test if ftrace is dead or not.
7799 * Returns 1 if ftrace is "dead", zero otherwise.
7801 int ftrace_is_dead(void)
7803 return ftrace_disabled;
7806 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
7808 * When registering ftrace_ops with IPMODIFY, it is necessary to make sure
7809 * it doesn't conflict with any direct ftrace_ops. If there is existing
7810 * direct ftrace_ops on a kernel function being patched, call
7811 * FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing.
7813 * @ops: ftrace_ops being registered.
7817 * Negative on failure.
7819 static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
7821 struct ftrace_func_entry *entry;
7822 struct ftrace_hash *hash;
7823 struct ftrace_ops *op;
7826 lockdep_assert_held_once(&direct_mutex);
7828 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7831 hash = ops->func_hash->filter_hash;
7832 size = 1 << hash->size_bits;
7833 for (i = 0; i < size; i++) {
7834 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
7835 unsigned long ip = entry->ip;
7836 bool found_op = false;
7838 mutex_lock(&ftrace_lock);
7839 do_for_each_ftrace_op(op, ftrace_ops_list) {
7840 if (!(op->flags & FTRACE_OPS_FL_DIRECT))
7842 if (ops_references_ip(op, ip)) {
7846 } while_for_each_ftrace_op(op);
7847 mutex_unlock(&ftrace_lock);
7853 ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
7864 * Similar to prepare_direct_functions_for_ipmodify, clean up after ops
7865 * with IPMODIFY is unregistered. The cleanup is optional for most DIRECT
7868 static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
7870 struct ftrace_func_entry *entry;
7871 struct ftrace_hash *hash;
7872 struct ftrace_ops *op;
7875 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7878 mutex_lock(&direct_mutex);
7880 hash = ops->func_hash->filter_hash;
7881 size = 1 << hash->size_bits;
7882 for (i = 0; i < size; i++) {
7883 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
7884 unsigned long ip = entry->ip;
7885 bool found_op = false;
7887 mutex_lock(&ftrace_lock);
7888 do_for_each_ftrace_op(op, ftrace_ops_list) {
7889 if (!(op->flags & FTRACE_OPS_FL_DIRECT))
7891 if (ops_references_ip(op, ip)) {
7895 } while_for_each_ftrace_op(op);
7896 mutex_unlock(&ftrace_lock);
7898 /* The cleanup is optional, ignore any errors */
7899 if (found_op && op->ops_func)
7900 op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
7903 mutex_unlock(&direct_mutex);
7906 #define lock_direct_mutex() mutex_lock(&direct_mutex)
7907 #define unlock_direct_mutex() mutex_unlock(&direct_mutex)
7909 #else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
7911 static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
7916 static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
7920 #define lock_direct_mutex() do { } while (0)
7921 #define unlock_direct_mutex() do { } while (0)
7923 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
7926 * Similar to register_ftrace_function, except we don't lock direct_mutex.
7928 static int register_ftrace_function_nolock(struct ftrace_ops *ops)
7932 ftrace_ops_init(ops);
7934 mutex_lock(&ftrace_lock);
7936 ret = ftrace_startup(ops, 0);
7938 mutex_unlock(&ftrace_lock);
7944 * register_ftrace_function - register a function for profiling
7945 * @ops: ops structure that holds the function for profiling.
7947 * Register a function to be called by all functions in the
7950 * Note: @ops->func and all the functions it calls must be labeled
7951 * with "notrace", otherwise it will go into a
7954 int register_ftrace_function(struct ftrace_ops *ops)
7958 lock_direct_mutex();
7959 ret = prepare_direct_functions_for_ipmodify(ops);
7963 ret = register_ftrace_function_nolock(ops);
7966 unlock_direct_mutex();
7969 EXPORT_SYMBOL_GPL(register_ftrace_function);
7972 * unregister_ftrace_function - unregister a function for profiling.
7973 * @ops: ops structure that holds the function to unregister
7975 * Unregister a function that was added to be called by ftrace profiling.
7977 int unregister_ftrace_function(struct ftrace_ops *ops)
7981 mutex_lock(&ftrace_lock);
7982 ret = ftrace_shutdown(ops, 0);
7983 mutex_unlock(&ftrace_lock);
7985 cleanup_direct_functions_after_ipmodify(ops);
7988 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
7990 static int symbols_cmp(const void *a, const void *b)
7992 const char **str_a = (const char **) a;
7993 const char **str_b = (const char **) b;
7995 return strcmp(*str_a, *str_b);
7998 struct kallsyms_data {
7999 unsigned long *addrs;
8005 /* This function gets called for all kernel and module symbols
8006 * and returns 1 in case we resolved all the requested symbols,
8009 static int kallsyms_callback(void *data, const char *name,
8010 struct module *mod, unsigned long addr)
8012 struct kallsyms_data *args = data;
8016 sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp);
8020 idx = sym - args->syms;
8021 if (args->addrs[idx])
8024 if (!ftrace_location(addr))
8027 args->addrs[idx] = addr;
8029 return args->found == args->cnt ? 1 : 0;
8033 * ftrace_lookup_symbols - Lookup addresses for array of symbols
8035 * @sorted_syms: array of symbols pointers symbols to resolve,
8036 * must be alphabetically sorted
8037 * @cnt: number of symbols/addresses in @syms/@addrs arrays
8038 * @addrs: array for storing resulting addresses
8040 * This function looks up addresses for array of symbols provided in
8041 * @syms array (must be alphabetically sorted) and stores them in
8042 * @addrs array, which needs to be big enough to store at least @cnt
8045 * This function returns 0 if all provided symbols are found,
8048 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
8050 struct kallsyms_data args;
8053 memset(addrs, 0, sizeof(*addrs) * cnt);
8055 args.syms = sorted_syms;
8059 found_all = kallsyms_on_each_symbol(kallsyms_callback, &args);
8062 found_all = module_kallsyms_on_each_symbol(NULL, kallsyms_callback, &args);
8063 return found_all ? 0 : -ESRCH;
8066 #ifdef CONFIG_SYSCTL
8068 #ifdef CONFIG_DYNAMIC_FTRACE
8069 static void ftrace_startup_sysctl(void)
8073 if (unlikely(ftrace_disabled))
8076 /* Force update next time */
8077 saved_ftrace_func = NULL;
8078 /* ftrace_start_up is true if we want ftrace running */
8079 if (ftrace_start_up) {
8080 command = FTRACE_UPDATE_CALLS;
8081 if (ftrace_graph_active)
8082 command |= FTRACE_START_FUNC_RET;
8083 ftrace_startup_enable(command);
8087 static void ftrace_shutdown_sysctl(void)
8091 if (unlikely(ftrace_disabled))
8094 /* ftrace_start_up is true if ftrace is running */
8095 if (ftrace_start_up) {
8096 command = FTRACE_DISABLE_CALLS;
8097 if (ftrace_graph_active)
8098 command |= FTRACE_STOP_FUNC_RET;
8099 ftrace_run_update_code(command);
8103 # define ftrace_startup_sysctl() do { } while (0)
8104 # define ftrace_shutdown_sysctl() do { } while (0)
8105 #endif /* CONFIG_DYNAMIC_FTRACE */
8107 static bool is_permanent_ops_registered(void)
8109 struct ftrace_ops *op;
8111 do_for_each_ftrace_op(op, ftrace_ops_list) {
8112 if (op->flags & FTRACE_OPS_FL_PERMANENT)
8114 } while_for_each_ftrace_op(op);
8120 ftrace_enable_sysctl(struct ctl_table *table, int write,
8121 void *buffer, size_t *lenp, loff_t *ppos)
8125 mutex_lock(&ftrace_lock);
8127 if (unlikely(ftrace_disabled))
8130 ret = proc_dointvec(table, write, buffer, lenp, ppos);
8132 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
8135 if (ftrace_enabled) {
8137 /* we are starting ftrace again */
8138 if (rcu_dereference_protected(ftrace_ops_list,
8139 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
8140 update_ftrace_function();
8142 ftrace_startup_sysctl();
8145 if (is_permanent_ops_registered()) {
8146 ftrace_enabled = true;
8151 /* stopping ftrace calls (just send to ftrace_stub) */
8152 ftrace_trace_function = ftrace_stub;
8154 ftrace_shutdown_sysctl();
8157 last_ftrace_enabled = !!ftrace_enabled;
8159 mutex_unlock(&ftrace_lock);
8163 static struct ctl_table ftrace_sysctls[] = {
8165 .procname = "ftrace_enabled",
8166 .data = &ftrace_enabled,
8167 .maxlen = sizeof(int),
8169 .proc_handler = ftrace_enable_sysctl,
8174 static int __init ftrace_sysctl_init(void)
8176 register_sysctl_init("kernel", ftrace_sysctls);
8179 late_initcall(ftrace_sysctl_init);