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_WARN_ON(cond) \
56 #define FTRACE_WARN_ON_ONCE(cond) \
59 if (WARN_ON_ONCE(___r)) \
64 /* hash bits for specific function selection */
65 #define FTRACE_HASH_BITS 7
66 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
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_RECURSION_SAFE | 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 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;
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 #if ARCH_SUPPORTS_FTRACE_OPS
125 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
126 struct ftrace_ops *op, struct pt_regs *regs);
128 /* See comment below, where ftrace_ops_list_func is defined */
129 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
130 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
133 static inline void ftrace_ops_init(struct ftrace_ops *ops)
135 #ifdef CONFIG_DYNAMIC_FTRACE
136 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
137 mutex_init(&ops->local_hash.regex_lock);
138 ops->func_hash = &ops->local_hash;
139 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
144 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
145 struct ftrace_ops *op, struct pt_regs *regs)
147 struct trace_array *tr = op->private;
149 if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
152 op->saved_func(ip, parent_ip, op, regs);
155 static void ftrace_sync(struct work_struct *work)
158 * This function is just a stub to implement a hard force
159 * of synchronize_rcu(). This requires synchronizing
160 * tasks even in userspace and idle.
162 * Yes, function tracing is rude.
166 static void ftrace_sync_ipi(void *data)
168 /* Probably not needed, but do it anyway */
172 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
175 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
176 * then it needs to call the list anyway.
178 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
179 FTRACE_FORCE_LIST_FUNC)
180 return ftrace_ops_list_func;
182 return ftrace_ops_get_func(ops);
185 static void update_ftrace_function(void)
190 * Prepare the ftrace_ops that the arch callback will use.
191 * If there's only one ftrace_ops registered, the ftrace_ops_list
192 * will point to the ops we want.
194 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
195 lockdep_is_held(&ftrace_lock));
197 /* If there's no ftrace_ops registered, just call the stub function */
198 if (set_function_trace_op == &ftrace_list_end) {
202 * If we are at the end of the list and this ops is
203 * recursion safe and not dynamic and the arch supports passing ops,
204 * then have the mcount trampoline call the function directly.
206 } else if (rcu_dereference_protected(ftrace_ops_list->next,
207 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
208 func = ftrace_ops_get_list_func(ftrace_ops_list);
211 /* Just use the default ftrace_ops */
212 set_function_trace_op = &ftrace_list_end;
213 func = ftrace_ops_list_func;
216 update_function_graph_func();
218 /* If there's no change, then do nothing more here */
219 if (ftrace_trace_function == func)
223 * If we are using the list function, it doesn't care
224 * about the function_trace_ops.
226 if (func == ftrace_ops_list_func) {
227 ftrace_trace_function = func;
229 * Don't even bother setting function_trace_ops,
230 * it would be racy to do so anyway.
235 #ifndef CONFIG_DYNAMIC_FTRACE
237 * For static tracing, we need to be a bit more careful.
238 * The function change takes affect immediately. Thus,
239 * we need to coorditate the setting of the function_trace_ops
240 * with the setting of the ftrace_trace_function.
242 * Set the function to the list ops, which will call the
243 * function we want, albeit indirectly, but it handles the
244 * ftrace_ops and doesn't depend on function_trace_op.
246 ftrace_trace_function = ftrace_ops_list_func;
248 * Make sure all CPUs see this. Yes this is slow, but static
249 * tracing is slow and nasty to have enabled.
251 schedule_on_each_cpu(ftrace_sync);
252 /* Now all cpus are using the list ops. */
253 function_trace_op = set_function_trace_op;
254 /* Make sure the function_trace_op is visible on all CPUs */
256 /* Nasty way to force a rmb on all cpus */
257 smp_call_function(ftrace_sync_ipi, NULL, 1);
258 /* OK, we are all set to update the ftrace_trace_function now! */
259 #endif /* !CONFIG_DYNAMIC_FTRACE */
261 ftrace_trace_function = func;
264 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
265 struct ftrace_ops *ops)
267 rcu_assign_pointer(ops->next, *list);
270 * We are entering ops into the list but another
271 * CPU might be walking that list. We need to make sure
272 * the ops->next pointer is valid before another CPU sees
273 * the ops pointer included into the list.
275 rcu_assign_pointer(*list, ops);
278 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
279 struct ftrace_ops *ops)
281 struct ftrace_ops **p;
284 * If we are removing the last function, then simply point
285 * to the ftrace_stub.
287 if (rcu_dereference_protected(*list,
288 lockdep_is_held(&ftrace_lock)) == ops &&
289 rcu_dereference_protected(ops->next,
290 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
291 *list = &ftrace_list_end;
295 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
306 static void ftrace_update_trampoline(struct ftrace_ops *ops);
308 int __register_ftrace_function(struct ftrace_ops *ops)
310 if (ops->flags & FTRACE_OPS_FL_DELETED)
313 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
316 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
318 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
319 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
320 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
322 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
323 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
326 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
327 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
330 if (!core_kernel_data((unsigned long)ops))
331 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
333 add_ftrace_ops(&ftrace_ops_list, ops);
335 /* Always save the function, and reset at unregistering */
336 ops->saved_func = ops->func;
338 if (ftrace_pids_enabled(ops))
339 ops->func = ftrace_pid_func;
341 ftrace_update_trampoline(ops);
344 update_ftrace_function();
349 int __unregister_ftrace_function(struct ftrace_ops *ops)
353 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
356 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
362 update_ftrace_function();
364 ops->func = ops->saved_func;
369 static void ftrace_update_pid_func(void)
371 struct ftrace_ops *op;
373 /* Only do something if we are tracing something */
374 if (ftrace_trace_function == ftrace_stub)
377 do_for_each_ftrace_op(op, ftrace_ops_list) {
378 if (op->flags & FTRACE_OPS_FL_PID) {
379 op->func = ftrace_pids_enabled(op) ?
380 ftrace_pid_func : op->saved_func;
381 ftrace_update_trampoline(op);
383 } while_for_each_ftrace_op(op);
385 update_ftrace_function();
388 #ifdef CONFIG_FUNCTION_PROFILER
389 struct ftrace_profile {
390 struct hlist_node node;
392 unsigned long counter;
393 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
394 unsigned long long time;
395 unsigned long long time_squared;
399 struct ftrace_profile_page {
400 struct ftrace_profile_page *next;
402 struct ftrace_profile records[];
405 struct ftrace_profile_stat {
407 struct hlist_head *hash;
408 struct ftrace_profile_page *pages;
409 struct ftrace_profile_page *start;
410 struct tracer_stat stat;
413 #define PROFILE_RECORDS_SIZE \
414 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
416 #define PROFILES_PER_PAGE \
417 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
419 static int ftrace_profile_enabled __read_mostly;
421 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
422 static DEFINE_MUTEX(ftrace_profile_lock);
424 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
426 #define FTRACE_PROFILE_HASH_BITS 10
427 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
430 function_stat_next(void *v, int idx)
432 struct ftrace_profile *rec = v;
433 struct ftrace_profile_page *pg;
435 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
441 if ((void *)rec >= (void *)&pg->records[pg->index]) {
445 rec = &pg->records[0];
453 static void *function_stat_start(struct tracer_stat *trace)
455 struct ftrace_profile_stat *stat =
456 container_of(trace, struct ftrace_profile_stat, stat);
458 if (!stat || !stat->start)
461 return function_stat_next(&stat->start->records[0], 0);
464 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
465 /* function graph compares on total time */
466 static int function_stat_cmp(void *p1, void *p2)
468 struct ftrace_profile *a = p1;
469 struct ftrace_profile *b = p2;
471 if (a->time < b->time)
473 if (a->time > b->time)
479 /* not function graph compares against hits */
480 static int function_stat_cmp(void *p1, void *p2)
482 struct ftrace_profile *a = p1;
483 struct ftrace_profile *b = p2;
485 if (a->counter < b->counter)
487 if (a->counter > b->counter)
494 static int function_stat_headers(struct seq_file *m)
496 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
497 seq_puts(m, " Function "
500 "--- ---- --- ---\n");
502 seq_puts(m, " Function Hit\n"
508 static int function_stat_show(struct seq_file *m, void *v)
510 struct ftrace_profile *rec = v;
511 char str[KSYM_SYMBOL_LEN];
513 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
514 static struct trace_seq s;
515 unsigned long long avg;
516 unsigned long long stddev;
518 mutex_lock(&ftrace_profile_lock);
520 /* we raced with function_profile_reset() */
521 if (unlikely(rec->counter == 0)) {
526 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
528 do_div(avg, rec->counter);
529 if (tracing_thresh && (avg < tracing_thresh))
533 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
534 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
536 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
539 /* Sample standard deviation (s^2) */
540 if (rec->counter <= 1)
544 * Apply Welford's method:
545 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
547 stddev = rec->counter * rec->time_squared -
548 rec->time * rec->time;
551 * Divide only 1000 for ns^2 -> us^2 conversion.
552 * trace_print_graph_duration will divide 1000 again.
554 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
558 trace_print_graph_duration(rec->time, &s);
559 trace_seq_puts(&s, " ");
560 trace_print_graph_duration(avg, &s);
561 trace_seq_puts(&s, " ");
562 trace_print_graph_duration(stddev, &s);
563 trace_print_seq(m, &s);
567 mutex_unlock(&ftrace_profile_lock);
572 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
574 struct ftrace_profile_page *pg;
576 pg = stat->pages = stat->start;
579 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
584 memset(stat->hash, 0,
585 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
588 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
590 struct ftrace_profile_page *pg;
595 /* If we already allocated, do nothing */
599 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
603 #ifdef CONFIG_DYNAMIC_FTRACE
604 functions = ftrace_update_tot_cnt;
607 * We do not know the number of functions that exist because
608 * dynamic tracing is what counts them. With past experience
609 * we have around 20K functions. That should be more than enough.
610 * It is highly unlikely we will execute every function in
616 pg = stat->start = stat->pages;
618 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
620 for (i = 1; i < pages; i++) {
621 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
632 unsigned long tmp = (unsigned long)pg;
644 static int ftrace_profile_init_cpu(int cpu)
646 struct ftrace_profile_stat *stat;
649 stat = &per_cpu(ftrace_profile_stats, cpu);
652 /* If the profile is already created, simply reset it */
653 ftrace_profile_reset(stat);
658 * We are profiling all functions, but usually only a few thousand
659 * functions are hit. We'll make a hash of 1024 items.
661 size = FTRACE_PROFILE_HASH_SIZE;
663 stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
668 /* Preallocate the function profiling pages */
669 if (ftrace_profile_pages_init(stat) < 0) {
678 static int ftrace_profile_init(void)
683 for_each_possible_cpu(cpu) {
684 ret = ftrace_profile_init_cpu(cpu);
692 /* interrupts must be disabled */
693 static struct ftrace_profile *
694 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
696 struct ftrace_profile *rec;
697 struct hlist_head *hhd;
700 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
701 hhd = &stat->hash[key];
703 if (hlist_empty(hhd))
706 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
714 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
715 struct ftrace_profile *rec)
719 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
720 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
724 * The memory is already allocated, this simply finds a new record to use.
726 static struct ftrace_profile *
727 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
729 struct ftrace_profile *rec = NULL;
731 /* prevent recursion (from NMIs) */
732 if (atomic_inc_return(&stat->disabled) != 1)
736 * Try to find the function again since an NMI
737 * could have added it
739 rec = ftrace_find_profiled_func(stat, ip);
743 if (stat->pages->index == PROFILES_PER_PAGE) {
744 if (!stat->pages->next)
746 stat->pages = stat->pages->next;
749 rec = &stat->pages->records[stat->pages->index++];
751 ftrace_add_profile(stat, rec);
754 atomic_dec(&stat->disabled);
760 function_profile_call(unsigned long ip, unsigned long parent_ip,
761 struct ftrace_ops *ops, struct pt_regs *regs)
763 struct ftrace_profile_stat *stat;
764 struct ftrace_profile *rec;
767 if (!ftrace_profile_enabled)
770 local_irq_save(flags);
772 stat = this_cpu_ptr(&ftrace_profile_stats);
773 if (!stat->hash || !ftrace_profile_enabled)
776 rec = ftrace_find_profiled_func(stat, ip);
778 rec = ftrace_profile_alloc(stat, ip);
785 local_irq_restore(flags);
788 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
789 static bool fgraph_graph_time = true;
791 void ftrace_graph_graph_time_control(bool enable)
793 fgraph_graph_time = enable;
796 static int profile_graph_entry(struct ftrace_graph_ent *trace)
798 struct ftrace_ret_stack *ret_stack;
800 function_profile_call(trace->func, 0, NULL, NULL);
802 /* If function graph is shutting down, ret_stack can be NULL */
803 if (!current->ret_stack)
806 ret_stack = ftrace_graph_get_ret_stack(current, 0);
808 ret_stack->subtime = 0;
813 static void profile_graph_return(struct ftrace_graph_ret *trace)
815 struct ftrace_ret_stack *ret_stack;
816 struct ftrace_profile_stat *stat;
817 unsigned long long calltime;
818 struct ftrace_profile *rec;
821 local_irq_save(flags);
822 stat = this_cpu_ptr(&ftrace_profile_stats);
823 if (!stat->hash || !ftrace_profile_enabled)
826 /* If the calltime was zero'd ignore it */
827 if (!trace->calltime)
830 calltime = trace->rettime - trace->calltime;
832 if (!fgraph_graph_time) {
834 /* Append this call time to the parent time to subtract */
835 ret_stack = ftrace_graph_get_ret_stack(current, 1);
837 ret_stack->subtime += calltime;
839 ret_stack = ftrace_graph_get_ret_stack(current, 0);
840 if (ret_stack && ret_stack->subtime < calltime)
841 calltime -= ret_stack->subtime;
846 rec = ftrace_find_profiled_func(stat, trace->func);
848 rec->time += calltime;
849 rec->time_squared += calltime * calltime;
853 local_irq_restore(flags);
856 static struct fgraph_ops fprofiler_ops = {
857 .entryfunc = &profile_graph_entry,
858 .retfunc = &profile_graph_return,
861 static int register_ftrace_profiler(void)
863 return register_ftrace_graph(&fprofiler_ops);
866 static void unregister_ftrace_profiler(void)
868 unregister_ftrace_graph(&fprofiler_ops);
871 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
872 .func = function_profile_call,
873 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
874 INIT_OPS_HASH(ftrace_profile_ops)
877 static int register_ftrace_profiler(void)
879 return register_ftrace_function(&ftrace_profile_ops);
882 static void unregister_ftrace_profiler(void)
884 unregister_ftrace_function(&ftrace_profile_ops);
886 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
889 ftrace_profile_write(struct file *filp, const char __user *ubuf,
890 size_t cnt, loff_t *ppos)
895 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
901 mutex_lock(&ftrace_profile_lock);
902 if (ftrace_profile_enabled ^ val) {
904 ret = ftrace_profile_init();
910 ret = register_ftrace_profiler();
915 ftrace_profile_enabled = 1;
917 ftrace_profile_enabled = 0;
919 * unregister_ftrace_profiler calls stop_machine
920 * so this acts like an synchronize_rcu.
922 unregister_ftrace_profiler();
926 mutex_unlock(&ftrace_profile_lock);
934 ftrace_profile_read(struct file *filp, char __user *ubuf,
935 size_t cnt, loff_t *ppos)
937 char buf[64]; /* big enough to hold a number */
940 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
941 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
944 static const struct file_operations ftrace_profile_fops = {
945 .open = tracing_open_generic,
946 .read = ftrace_profile_read,
947 .write = ftrace_profile_write,
948 .llseek = default_llseek,
951 /* used to initialize the real stat files */
952 static struct tracer_stat function_stats __initdata = {
954 .stat_start = function_stat_start,
955 .stat_next = function_stat_next,
956 .stat_cmp = function_stat_cmp,
957 .stat_headers = function_stat_headers,
958 .stat_show = function_stat_show
961 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
963 struct ftrace_profile_stat *stat;
964 struct dentry *entry;
969 for_each_possible_cpu(cpu) {
970 stat = &per_cpu(ftrace_profile_stats, cpu);
972 name = kasprintf(GFP_KERNEL, "function%d", cpu);
975 * The files created are permanent, if something happens
976 * we still do not free memory.
979 "Could not allocate stat file for cpu %d\n",
983 stat->stat = function_stats;
984 stat->stat.name = name;
985 ret = register_stat_tracer(&stat->stat);
988 "Could not register function stat for cpu %d\n",
995 entry = tracefs_create_file("function_profile_enabled", 0644,
996 d_tracer, NULL, &ftrace_profile_fops);
998 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1001 #else /* CONFIG_FUNCTION_PROFILER */
1002 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1005 #endif /* CONFIG_FUNCTION_PROFILER */
1007 #ifdef CONFIG_DYNAMIC_FTRACE
1009 static struct ftrace_ops *removed_ops;
1012 * Set when doing a global update, like enabling all recs or disabling them.
1013 * It is not set when just updating a single ftrace_ops.
1015 static bool update_all_ops;
1017 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1018 # error Dynamic ftrace depends on MCOUNT_RECORD
1021 struct ftrace_func_entry {
1022 struct hlist_node hlist;
1026 struct ftrace_func_probe {
1027 struct ftrace_probe_ops *probe_ops;
1028 struct ftrace_ops ops;
1029 struct trace_array *tr;
1030 struct list_head list;
1036 * We make these constant because no one should touch them,
1037 * but they are used as the default "empty hash", to avoid allocating
1038 * it all the time. These are in a read only section such that if
1039 * anyone does try to modify it, it will cause an exception.
1041 static const struct hlist_head empty_buckets[1];
1042 static const struct ftrace_hash empty_hash = {
1043 .buckets = (struct hlist_head *)empty_buckets,
1045 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1047 struct ftrace_ops global_ops = {
1048 .func = ftrace_stub,
1049 .local_hash.notrace_hash = EMPTY_HASH,
1050 .local_hash.filter_hash = EMPTY_HASH,
1051 INIT_OPS_HASH(global_ops)
1052 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1053 FTRACE_OPS_FL_INITIALIZED |
1058 * Used by the stack undwinder to know about dynamic ftrace trampolines.
1060 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1062 struct ftrace_ops *op = NULL;
1065 * Some of the ops may be dynamically allocated,
1066 * they are freed after a synchronize_rcu().
1068 preempt_disable_notrace();
1070 do_for_each_ftrace_op(op, ftrace_ops_list) {
1072 * This is to check for dynamically allocated trampolines.
1073 * Trampolines that are in kernel text will have
1074 * core_kernel_text() return true.
1076 if (op->trampoline && op->trampoline_size)
1077 if (addr >= op->trampoline &&
1078 addr < op->trampoline + op->trampoline_size) {
1079 preempt_enable_notrace();
1082 } while_for_each_ftrace_op(op);
1083 preempt_enable_notrace();
1089 * This is used by __kernel_text_address() to return true if the
1090 * address is on a dynamically allocated trampoline that would
1091 * not return true for either core_kernel_text() or
1092 * is_module_text_address().
1094 bool is_ftrace_trampoline(unsigned long addr)
1096 return ftrace_ops_trampoline(addr) != NULL;
1099 struct ftrace_page {
1100 struct ftrace_page *next;
1101 struct dyn_ftrace *records;
1106 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1107 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1109 /* estimate from running different kernels */
1110 #define NR_TO_INIT 10000
1112 static struct ftrace_page *ftrace_pages_start;
1113 static struct ftrace_page *ftrace_pages;
1115 static __always_inline unsigned long
1116 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1118 if (hash->size_bits > 0)
1119 return hash_long(ip, hash->size_bits);
1124 /* Only use this function if ftrace_hash_empty() has already been tested */
1125 static __always_inline struct ftrace_func_entry *
1126 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1129 struct ftrace_func_entry *entry;
1130 struct hlist_head *hhd;
1132 key = ftrace_hash_key(hash, ip);
1133 hhd = &hash->buckets[key];
1135 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1136 if (entry->ip == ip)
1143 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1144 * @hash: The hash to look at
1145 * @ip: The instruction pointer to test
1147 * Search a given @hash to see if a given instruction pointer (@ip)
1150 * Returns the entry that holds the @ip if found. NULL otherwise.
1152 struct ftrace_func_entry *
1153 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1155 if (ftrace_hash_empty(hash))
1158 return __ftrace_lookup_ip(hash, ip);
1161 static void __add_hash_entry(struct ftrace_hash *hash,
1162 struct ftrace_func_entry *entry)
1164 struct hlist_head *hhd;
1167 key = ftrace_hash_key(hash, entry->ip);
1168 hhd = &hash->buckets[key];
1169 hlist_add_head(&entry->hlist, hhd);
1173 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1175 struct ftrace_func_entry *entry;
1177 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1182 __add_hash_entry(hash, entry);
1188 free_hash_entry(struct ftrace_hash *hash,
1189 struct ftrace_func_entry *entry)
1191 hlist_del(&entry->hlist);
1197 remove_hash_entry(struct ftrace_hash *hash,
1198 struct ftrace_func_entry *entry)
1200 hlist_del_rcu(&entry->hlist);
1204 static void ftrace_hash_clear(struct ftrace_hash *hash)
1206 struct hlist_head *hhd;
1207 struct hlist_node *tn;
1208 struct ftrace_func_entry *entry;
1209 int size = 1 << hash->size_bits;
1215 for (i = 0; i < size; i++) {
1216 hhd = &hash->buckets[i];
1217 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1218 free_hash_entry(hash, entry);
1220 FTRACE_WARN_ON(hash->count);
1223 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1225 list_del(&ftrace_mod->list);
1226 kfree(ftrace_mod->module);
1227 kfree(ftrace_mod->func);
1231 static void clear_ftrace_mod_list(struct list_head *head)
1233 struct ftrace_mod_load *p, *n;
1235 /* stack tracer isn't supported yet */
1239 mutex_lock(&ftrace_lock);
1240 list_for_each_entry_safe(p, n, head, list)
1242 mutex_unlock(&ftrace_lock);
1245 static void free_ftrace_hash(struct ftrace_hash *hash)
1247 if (!hash || hash == EMPTY_HASH)
1249 ftrace_hash_clear(hash);
1250 kfree(hash->buckets);
1254 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1256 struct ftrace_hash *hash;
1258 hash = container_of(rcu, struct ftrace_hash, rcu);
1259 free_ftrace_hash(hash);
1262 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1264 if (!hash || hash == EMPTY_HASH)
1266 call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
1269 void ftrace_free_filter(struct ftrace_ops *ops)
1271 ftrace_ops_init(ops);
1272 free_ftrace_hash(ops->func_hash->filter_hash);
1273 free_ftrace_hash(ops->func_hash->notrace_hash);
1276 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1278 struct ftrace_hash *hash;
1281 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1285 size = 1 << size_bits;
1286 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1288 if (!hash->buckets) {
1293 hash->size_bits = size_bits;
1299 static int ftrace_add_mod(struct trace_array *tr,
1300 const char *func, const char *module,
1303 struct ftrace_mod_load *ftrace_mod;
1304 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1306 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1310 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1311 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1312 ftrace_mod->enable = enable;
1314 if (!ftrace_mod->func || !ftrace_mod->module)
1317 list_add(&ftrace_mod->list, mod_head);
1322 free_ftrace_mod(ftrace_mod);
1327 static struct ftrace_hash *
1328 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1330 struct ftrace_func_entry *entry;
1331 struct ftrace_hash *new_hash;
1336 new_hash = alloc_ftrace_hash(size_bits);
1341 new_hash->flags = hash->flags;
1344 if (ftrace_hash_empty(hash))
1347 size = 1 << hash->size_bits;
1348 for (i = 0; i < size; i++) {
1349 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1350 ret = add_hash_entry(new_hash, entry->ip);
1356 FTRACE_WARN_ON(new_hash->count != hash->count);
1361 free_ftrace_hash(new_hash);
1366 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1368 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1370 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1371 struct ftrace_hash *new_hash);
1373 static struct ftrace_hash *
1374 __ftrace_hash_move(struct ftrace_hash *src)
1376 struct ftrace_func_entry *entry;
1377 struct hlist_node *tn;
1378 struct hlist_head *hhd;
1379 struct ftrace_hash *new_hash;
1380 int size = src->count;
1385 * If the new source is empty, just return the empty_hash.
1387 if (ftrace_hash_empty(src))
1391 * Make the hash size about 1/2 the # found
1393 for (size /= 2; size; size >>= 1)
1396 /* Don't allocate too much */
1397 if (bits > FTRACE_HASH_MAX_BITS)
1398 bits = FTRACE_HASH_MAX_BITS;
1400 new_hash = alloc_ftrace_hash(bits);
1404 new_hash->flags = src->flags;
1406 size = 1 << src->size_bits;
1407 for (i = 0; i < size; i++) {
1408 hhd = &src->buckets[i];
1409 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1410 remove_hash_entry(src, entry);
1411 __add_hash_entry(new_hash, entry);
1419 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1420 struct ftrace_hash **dst, struct ftrace_hash *src)
1422 struct ftrace_hash *new_hash;
1425 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1426 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1429 new_hash = __ftrace_hash_move(src);
1433 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1435 /* IPMODIFY should be updated only when filter_hash updating */
1436 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1438 free_ftrace_hash(new_hash);
1444 * Remove the current set, update the hash and add
1447 ftrace_hash_rec_disable_modify(ops, enable);
1449 rcu_assign_pointer(*dst, new_hash);
1451 ftrace_hash_rec_enable_modify(ops, enable);
1456 static bool hash_contains_ip(unsigned long ip,
1457 struct ftrace_ops_hash *hash)
1460 * The function record is a match if it exists in the filter
1461 * hash and not in the notrace hash. Note, an emty hash is
1462 * considered a match for the filter hash, but an empty
1463 * notrace hash is considered not in the notrace hash.
1465 return (ftrace_hash_empty(hash->filter_hash) ||
1466 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1467 (ftrace_hash_empty(hash->notrace_hash) ||
1468 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1472 * Test the hashes for this ops to see if we want to call
1473 * the ops->func or not.
1475 * It's a match if the ip is in the ops->filter_hash or
1476 * the filter_hash does not exist or is empty,
1478 * the ip is not in the ops->notrace_hash.
1480 * This needs to be called with preemption disabled as
1481 * the hashes are freed with call_rcu().
1484 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1486 struct ftrace_ops_hash hash;
1489 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1491 * There's a small race when adding ops that the ftrace handler
1492 * that wants regs, may be called without them. We can not
1493 * allow that handler to be called if regs is NULL.
1495 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1499 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1500 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1502 if (hash_contains_ip(ip, &hash))
1511 * This is a double for. Do not use 'break' to break out of the loop,
1512 * you must use a goto.
1514 #define do_for_each_ftrace_rec(pg, rec) \
1515 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1517 for (_____i = 0; _____i < pg->index; _____i++) { \
1518 rec = &pg->records[_____i];
1520 #define while_for_each_ftrace_rec() \
1525 static int ftrace_cmp_recs(const void *a, const void *b)
1527 const struct dyn_ftrace *key = a;
1528 const struct dyn_ftrace *rec = b;
1530 if (key->flags < rec->ip)
1532 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1538 * ftrace_location_range - return the first address of a traced location
1539 * if it touches the given ip range
1540 * @start: start of range to search.
1541 * @end: end of range to search (inclusive). @end points to the last byte
1544 * Returns rec->ip if the related ftrace location is a least partly within
1545 * the given address range. That is, the first address of the instruction
1546 * that is either a NOP or call to the function tracer. It checks the ftrace
1547 * internal tables to determine if the address belongs or not.
1549 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1551 struct ftrace_page *pg;
1552 struct dyn_ftrace *rec;
1553 struct dyn_ftrace key;
1556 key.flags = end; /* overload flags, as it is unsigned long */
1558 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1559 if (end < pg->records[0].ip ||
1560 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1562 rec = bsearch(&key, pg->records, pg->index,
1563 sizeof(struct dyn_ftrace),
1573 * ftrace_location - return true if the ip giving is a traced location
1574 * @ip: the instruction pointer to check
1576 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1577 * That is, the instruction that is either a NOP or call to
1578 * the function tracer. It checks the ftrace internal tables to
1579 * determine if the address belongs or not.
1581 unsigned long ftrace_location(unsigned long ip)
1583 return ftrace_location_range(ip, ip);
1587 * ftrace_text_reserved - return true if range contains an ftrace location
1588 * @start: start of range to search
1589 * @end: end of range to search (inclusive). @end points to the last byte to check.
1591 * Returns 1 if @start and @end contains a ftrace location.
1592 * That is, the instruction that is either a NOP or call to
1593 * the function tracer. It checks the ftrace internal tables to
1594 * determine if the address belongs or not.
1596 int ftrace_text_reserved(const void *start, const void *end)
1600 ret = ftrace_location_range((unsigned long)start,
1601 (unsigned long)end);
1606 /* Test if ops registered to this rec needs regs */
1607 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1609 struct ftrace_ops *ops;
1610 bool keep_regs = false;
1612 for (ops = ftrace_ops_list;
1613 ops != &ftrace_list_end; ops = ops->next) {
1614 /* pass rec in as regs to have non-NULL val */
1615 if (ftrace_ops_test(ops, rec->ip, rec)) {
1616 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1626 static struct ftrace_ops *
1627 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1628 static struct ftrace_ops *
1629 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1631 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1635 struct ftrace_hash *hash;
1636 struct ftrace_hash *other_hash;
1637 struct ftrace_page *pg;
1638 struct dyn_ftrace *rec;
1639 bool update = false;
1643 /* Only update if the ops has been registered */
1644 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1648 * In the filter_hash case:
1649 * If the count is zero, we update all records.
1650 * Otherwise we just update the items in the hash.
1652 * In the notrace_hash case:
1653 * We enable the update in the hash.
1654 * As disabling notrace means enabling the tracing,
1655 * and enabling notrace means disabling, the inc variable
1659 hash = ops->func_hash->filter_hash;
1660 other_hash = ops->func_hash->notrace_hash;
1661 if (ftrace_hash_empty(hash))
1665 hash = ops->func_hash->notrace_hash;
1666 other_hash = ops->func_hash->filter_hash;
1668 * If the notrace hash has no items,
1669 * then there's nothing to do.
1671 if (ftrace_hash_empty(hash))
1675 do_for_each_ftrace_rec(pg, rec) {
1676 int in_other_hash = 0;
1680 if (rec->flags & FTRACE_FL_DISABLED)
1685 * Only the filter_hash affects all records.
1686 * Update if the record is not in the notrace hash.
1688 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1691 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1692 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1695 * If filter_hash is set, we want to match all functions
1696 * that are in the hash but not in the other hash.
1698 * If filter_hash is not set, then we are decrementing.
1699 * That means we match anything that is in the hash
1700 * and also in the other_hash. That is, we need to turn
1701 * off functions in the other hash because they are disabled
1704 if (filter_hash && in_hash && !in_other_hash)
1706 else if (!filter_hash && in_hash &&
1707 (in_other_hash || ftrace_hash_empty(other_hash)))
1715 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1719 * If there's only a single callback registered to a
1720 * function, and the ops has a trampoline registered
1721 * for it, then we can call it directly.
1723 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1724 rec->flags |= FTRACE_FL_TRAMP;
1727 * If we are adding another function callback
1728 * to this function, and the previous had a
1729 * custom trampoline in use, then we need to go
1730 * back to the default trampoline.
1732 rec->flags &= ~FTRACE_FL_TRAMP;
1735 * If any ops wants regs saved for this function
1736 * then all ops will get saved regs.
1738 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1739 rec->flags |= FTRACE_FL_REGS;
1741 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1746 * If the rec had REGS enabled and the ops that is
1747 * being removed had REGS set, then see if there is
1748 * still any ops for this record that wants regs.
1749 * If not, we can stop recording them.
1751 if (ftrace_rec_count(rec) > 0 &&
1752 rec->flags & FTRACE_FL_REGS &&
1753 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1754 if (!test_rec_ops_needs_regs(rec))
1755 rec->flags &= ~FTRACE_FL_REGS;
1759 * The TRAMP needs to be set only if rec count
1760 * is decremented to one, and the ops that is
1761 * left has a trampoline. As TRAMP can only be
1762 * enabled if there is only a single ops attached
1765 if (ftrace_rec_count(rec) == 1 &&
1766 ftrace_find_tramp_ops_any(rec))
1767 rec->flags |= FTRACE_FL_TRAMP;
1769 rec->flags &= ~FTRACE_FL_TRAMP;
1772 * flags will be cleared in ftrace_check_record()
1773 * if rec count is zero.
1778 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1779 update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
1781 /* Shortcut, if we handled all records, we are done. */
1782 if (!all && count == hash->count)
1784 } while_for_each_ftrace_rec();
1789 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1792 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1795 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1798 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1801 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1802 int filter_hash, int inc)
1804 struct ftrace_ops *op;
1806 __ftrace_hash_rec_update(ops, filter_hash, inc);
1808 if (ops->func_hash != &global_ops.local_hash)
1812 * If the ops shares the global_ops hash, then we need to update
1813 * all ops that are enabled and use this hash.
1815 do_for_each_ftrace_op(op, ftrace_ops_list) {
1819 if (op->func_hash == &global_ops.local_hash)
1820 __ftrace_hash_rec_update(op, filter_hash, inc);
1821 } while_for_each_ftrace_op(op);
1824 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1827 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1830 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1833 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1837 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1838 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1839 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1840 * Note that old_hash and new_hash has below meanings
1841 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1842 * - If the hash is EMPTY_HASH, it hits nothing
1843 * - Anything else hits the recs which match the hash entries.
1845 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1846 struct ftrace_hash *old_hash,
1847 struct ftrace_hash *new_hash)
1849 struct ftrace_page *pg;
1850 struct dyn_ftrace *rec, *end = NULL;
1853 /* Only update if the ops has been registered */
1854 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1857 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1861 * Since the IPMODIFY is a very address sensitive action, we do not
1862 * allow ftrace_ops to set all functions to new hash.
1864 if (!new_hash || !old_hash)
1867 /* Update rec->flags */
1868 do_for_each_ftrace_rec(pg, rec) {
1870 if (rec->flags & FTRACE_FL_DISABLED)
1873 /* We need to update only differences of filter_hash */
1874 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1875 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1876 if (in_old == in_new)
1880 /* New entries must ensure no others are using it */
1881 if (rec->flags & FTRACE_FL_IPMODIFY)
1883 rec->flags |= FTRACE_FL_IPMODIFY;
1884 } else /* Removed entry */
1885 rec->flags &= ~FTRACE_FL_IPMODIFY;
1886 } while_for_each_ftrace_rec();
1893 /* Roll back what we did above */
1894 do_for_each_ftrace_rec(pg, rec) {
1896 if (rec->flags & FTRACE_FL_DISABLED)
1902 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1903 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1904 if (in_old == in_new)
1908 rec->flags &= ~FTRACE_FL_IPMODIFY;
1910 rec->flags |= FTRACE_FL_IPMODIFY;
1911 } while_for_each_ftrace_rec();
1917 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1919 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1921 if (ftrace_hash_empty(hash))
1924 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1927 /* Disabling always succeeds */
1928 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1930 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1932 if (ftrace_hash_empty(hash))
1935 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1938 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1939 struct ftrace_hash *new_hash)
1941 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1943 if (ftrace_hash_empty(old_hash))
1946 if (ftrace_hash_empty(new_hash))
1949 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1952 static void print_ip_ins(const char *fmt, const unsigned char *p)
1956 printk(KERN_CONT "%s", fmt);
1958 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1959 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1962 enum ftrace_bug_type ftrace_bug_type;
1963 const void *ftrace_expected;
1965 static void print_bug_type(void)
1967 switch (ftrace_bug_type) {
1968 case FTRACE_BUG_UNKNOWN:
1970 case FTRACE_BUG_INIT:
1971 pr_info("Initializing ftrace call sites\n");
1973 case FTRACE_BUG_NOP:
1974 pr_info("Setting ftrace call site to NOP\n");
1976 case FTRACE_BUG_CALL:
1977 pr_info("Setting ftrace call site to call ftrace function\n");
1979 case FTRACE_BUG_UPDATE:
1980 pr_info("Updating ftrace call site to call a different ftrace function\n");
1986 * ftrace_bug - report and shutdown function tracer
1987 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1988 * @rec: The record that failed
1990 * The arch code that enables or disables the function tracing
1991 * can call ftrace_bug() when it has detected a problem in
1992 * modifying the code. @failed should be one of either:
1993 * EFAULT - if the problem happens on reading the @ip address
1994 * EINVAL - if what is read at @ip is not what was expected
1995 * EPERM - if the problem happens on writing to the @ip address
1997 void ftrace_bug(int failed, struct dyn_ftrace *rec)
1999 unsigned long ip = rec ? rec->ip : 0;
2003 FTRACE_WARN_ON_ONCE(1);
2004 pr_info("ftrace faulted on modifying ");
2008 FTRACE_WARN_ON_ONCE(1);
2009 pr_info("ftrace failed to modify ");
2011 print_ip_ins(" actual: ", (unsigned char *)ip);
2013 if (ftrace_expected) {
2014 print_ip_ins(" expected: ", ftrace_expected);
2019 FTRACE_WARN_ON_ONCE(1);
2020 pr_info("ftrace faulted on writing ");
2024 FTRACE_WARN_ON_ONCE(1);
2025 pr_info("ftrace faulted on unknown error ");
2030 struct ftrace_ops *ops = NULL;
2032 pr_info("ftrace record flags: %lx\n", rec->flags);
2033 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2034 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2035 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2036 ops = ftrace_find_tramp_ops_any(rec);
2039 pr_cont("\ttramp: %pS (%pS)",
2040 (void *)ops->trampoline,
2042 ops = ftrace_find_tramp_ops_next(rec, ops);
2045 pr_cont("\ttramp: ERROR!");
2048 ip = ftrace_get_addr_curr(rec);
2049 pr_cont("\n expected tramp: %lx\n", ip);
2053 static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
2055 unsigned long flag = 0UL;
2057 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2059 if (rec->flags & FTRACE_FL_DISABLED)
2060 return FTRACE_UPDATE_IGNORE;
2063 * If we are updating calls:
2065 * If the record has a ref count, then we need to enable it
2066 * because someone is using it.
2068 * Otherwise we make sure its disabled.
2070 * If we are disabling calls, then disable all records that
2073 if (enable && ftrace_rec_count(rec))
2074 flag = FTRACE_FL_ENABLED;
2077 * If enabling and the REGS flag does not match the REGS_EN, or
2078 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2079 * this record. Set flags to fail the compare against ENABLED.
2082 if (!(rec->flags & FTRACE_FL_REGS) !=
2083 !(rec->flags & FTRACE_FL_REGS_EN))
2084 flag |= FTRACE_FL_REGS;
2086 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2087 !(rec->flags & FTRACE_FL_TRAMP_EN))
2088 flag |= FTRACE_FL_TRAMP;
2091 /* If the state of this record hasn't changed, then do nothing */
2092 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2093 return FTRACE_UPDATE_IGNORE;
2096 /* Save off if rec is being enabled (for return value) */
2097 flag ^= rec->flags & FTRACE_FL_ENABLED;
2100 rec->flags |= FTRACE_FL_ENABLED;
2101 if (flag & FTRACE_FL_REGS) {
2102 if (rec->flags & FTRACE_FL_REGS)
2103 rec->flags |= FTRACE_FL_REGS_EN;
2105 rec->flags &= ~FTRACE_FL_REGS_EN;
2107 if (flag & FTRACE_FL_TRAMP) {
2108 if (rec->flags & FTRACE_FL_TRAMP)
2109 rec->flags |= FTRACE_FL_TRAMP_EN;
2111 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2116 * If this record is being updated from a nop, then
2117 * return UPDATE_MAKE_CALL.
2119 * return UPDATE_MODIFY_CALL to tell the caller to convert
2120 * from the save regs, to a non-save regs function or
2121 * vice versa, or from a trampoline call.
2123 if (flag & FTRACE_FL_ENABLED) {
2124 ftrace_bug_type = FTRACE_BUG_CALL;
2125 return FTRACE_UPDATE_MAKE_CALL;
2128 ftrace_bug_type = FTRACE_BUG_UPDATE;
2129 return FTRACE_UPDATE_MODIFY_CALL;
2133 /* If there's no more users, clear all flags */
2134 if (!ftrace_rec_count(rec))
2138 * Just disable the record, but keep the ops TRAMP
2139 * and REGS states. The _EN flags must be disabled though.
2141 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2145 ftrace_bug_type = FTRACE_BUG_NOP;
2146 return FTRACE_UPDATE_MAKE_NOP;
2150 * ftrace_update_record, set a record that now is tracing or not
2151 * @rec: the record to update
2152 * @enable: set to true if the record is tracing, false to force disable
2154 * The records that represent all functions that can be traced need
2155 * to be updated when tracing has been enabled.
2157 int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
2159 return ftrace_check_record(rec, enable, true);
2163 * ftrace_test_record, check if the record has been enabled or not
2164 * @rec: the record to test
2165 * @enable: set to true to check if enabled, false if it is disabled
2167 * The arch code may need to test if a record is already set to
2168 * tracing to determine how to modify the function code that it
2171 int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
2173 return ftrace_check_record(rec, enable, false);
2176 static struct ftrace_ops *
2177 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2179 struct ftrace_ops *op;
2180 unsigned long ip = rec->ip;
2182 do_for_each_ftrace_op(op, ftrace_ops_list) {
2184 if (!op->trampoline)
2187 if (hash_contains_ip(ip, op->func_hash))
2189 } while_for_each_ftrace_op(op);
2194 static struct ftrace_ops *
2195 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2196 struct ftrace_ops *op)
2198 unsigned long ip = rec->ip;
2200 while_for_each_ftrace_op(op) {
2202 if (!op->trampoline)
2205 if (hash_contains_ip(ip, op->func_hash))
2212 static struct ftrace_ops *
2213 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2215 struct ftrace_ops *op;
2216 unsigned long ip = rec->ip;
2219 * Need to check removed ops first.
2220 * If they are being removed, and this rec has a tramp,
2221 * and this rec is in the ops list, then it would be the
2222 * one with the tramp.
2225 if (hash_contains_ip(ip, &removed_ops->old_hash))
2230 * Need to find the current trampoline for a rec.
2231 * Now, a trampoline is only attached to a rec if there
2232 * was a single 'ops' attached to it. But this can be called
2233 * when we are adding another op to the rec or removing the
2234 * current one. Thus, if the op is being added, we can
2235 * ignore it because it hasn't attached itself to the rec
2238 * If an ops is being modified (hooking to different functions)
2239 * then we don't care about the new functions that are being
2240 * added, just the old ones (that are probably being removed).
2242 * If we are adding an ops to a function that already is using
2243 * a trampoline, it needs to be removed (trampolines are only
2244 * for single ops connected), then an ops that is not being
2245 * modified also needs to be checked.
2247 do_for_each_ftrace_op(op, ftrace_ops_list) {
2249 if (!op->trampoline)
2253 * If the ops is being added, it hasn't gotten to
2254 * the point to be removed from this tree yet.
2256 if (op->flags & FTRACE_OPS_FL_ADDING)
2261 * If the ops is being modified and is in the old
2262 * hash, then it is probably being removed from this
2265 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2266 hash_contains_ip(ip, &op->old_hash))
2269 * If the ops is not being added or modified, and it's
2270 * in its normal filter hash, then this must be the one
2273 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2274 hash_contains_ip(ip, op->func_hash))
2277 } while_for_each_ftrace_op(op);
2282 static struct ftrace_ops *
2283 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2285 struct ftrace_ops *op;
2286 unsigned long ip = rec->ip;
2288 do_for_each_ftrace_op(op, ftrace_ops_list) {
2289 /* pass rec in as regs to have non-NULL val */
2290 if (hash_contains_ip(ip, op->func_hash))
2292 } while_for_each_ftrace_op(op);
2298 * ftrace_get_addr_new - Get the call address to set to
2299 * @rec: The ftrace record descriptor
2301 * If the record has the FTRACE_FL_REGS set, that means that it
2302 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2303 * is not not set, then it wants to convert to the normal callback.
2305 * Returns the address of the trampoline to set to
2307 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2309 struct ftrace_ops *ops;
2311 /* Trampolines take precedence over regs */
2312 if (rec->flags & FTRACE_FL_TRAMP) {
2313 ops = ftrace_find_tramp_ops_new(rec);
2314 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2315 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2316 (void *)rec->ip, (void *)rec->ip, rec->flags);
2317 /* Ftrace is shutting down, return anything */
2318 return (unsigned long)FTRACE_ADDR;
2320 return ops->trampoline;
2323 if (rec->flags & FTRACE_FL_REGS)
2324 return (unsigned long)FTRACE_REGS_ADDR;
2326 return (unsigned long)FTRACE_ADDR;
2330 * ftrace_get_addr_curr - Get the call address that is already there
2331 * @rec: The ftrace record descriptor
2333 * The FTRACE_FL_REGS_EN is set when the record already points to
2334 * a function that saves all the regs. Basically the '_EN' version
2335 * represents the current state of the function.
2337 * Returns the address of the trampoline that is currently being called
2339 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2341 struct ftrace_ops *ops;
2343 /* Trampolines take precedence over regs */
2344 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2345 ops = ftrace_find_tramp_ops_curr(rec);
2346 if (FTRACE_WARN_ON(!ops)) {
2347 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2348 (void *)rec->ip, (void *)rec->ip);
2349 /* Ftrace is shutting down, return anything */
2350 return (unsigned long)FTRACE_ADDR;
2352 return ops->trampoline;
2355 if (rec->flags & FTRACE_FL_REGS_EN)
2356 return (unsigned long)FTRACE_REGS_ADDR;
2358 return (unsigned long)FTRACE_ADDR;
2362 __ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
2364 unsigned long ftrace_old_addr;
2365 unsigned long ftrace_addr;
2368 ftrace_addr = ftrace_get_addr_new(rec);
2370 /* This needs to be done before we call ftrace_update_record */
2371 ftrace_old_addr = ftrace_get_addr_curr(rec);
2373 ret = ftrace_update_record(rec, enable);
2375 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2378 case FTRACE_UPDATE_IGNORE:
2381 case FTRACE_UPDATE_MAKE_CALL:
2382 ftrace_bug_type = FTRACE_BUG_CALL;
2383 return ftrace_make_call(rec, ftrace_addr);
2385 case FTRACE_UPDATE_MAKE_NOP:
2386 ftrace_bug_type = FTRACE_BUG_NOP;
2387 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2389 case FTRACE_UPDATE_MODIFY_CALL:
2390 ftrace_bug_type = FTRACE_BUG_UPDATE;
2391 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2394 return -1; /* unknown ftrace bug */
2397 void __weak ftrace_replace_code(int mod_flags)
2399 struct dyn_ftrace *rec;
2400 struct ftrace_page *pg;
2401 bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2402 int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2405 if (unlikely(ftrace_disabled))
2408 do_for_each_ftrace_rec(pg, rec) {
2410 if (rec->flags & FTRACE_FL_DISABLED)
2413 failed = __ftrace_replace_code(rec, enable);
2415 ftrace_bug(failed, rec);
2416 /* Stop processing */
2421 } while_for_each_ftrace_rec();
2424 struct ftrace_rec_iter {
2425 struct ftrace_page *pg;
2430 * ftrace_rec_iter_start, start up iterating over traced functions
2432 * Returns an iterator handle that is used to iterate over all
2433 * the records that represent address locations where functions
2436 * May return NULL if no records are available.
2438 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2441 * We only use a single iterator.
2442 * Protected by the ftrace_lock mutex.
2444 static struct ftrace_rec_iter ftrace_rec_iter;
2445 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2447 iter->pg = ftrace_pages_start;
2450 /* Could have empty pages */
2451 while (iter->pg && !iter->pg->index)
2452 iter->pg = iter->pg->next;
2461 * ftrace_rec_iter_next, get the next record to process.
2462 * @iter: The handle to the iterator.
2464 * Returns the next iterator after the given iterator @iter.
2466 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2470 if (iter->index >= iter->pg->index) {
2471 iter->pg = iter->pg->next;
2474 /* Could have empty pages */
2475 while (iter->pg && !iter->pg->index)
2476 iter->pg = iter->pg->next;
2486 * ftrace_rec_iter_record, get the record at the iterator location
2487 * @iter: The current iterator location
2489 * Returns the record that the current @iter is at.
2491 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2493 return &iter->pg->records[iter->index];
2497 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2501 if (unlikely(ftrace_disabled))
2504 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2506 ftrace_bug_type = FTRACE_BUG_INIT;
2507 ftrace_bug(ret, rec);
2514 * archs can override this function if they must do something
2515 * before the modifying code is performed.
2517 int __weak ftrace_arch_code_modify_prepare(void)
2523 * archs can override this function if they must do something
2524 * after the modifying code is performed.
2526 int __weak ftrace_arch_code_modify_post_process(void)
2531 void ftrace_modify_all_code(int command)
2533 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2537 if (command & FTRACE_MAY_SLEEP)
2538 mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2541 * If the ftrace_caller calls a ftrace_ops func directly,
2542 * we need to make sure that it only traces functions it
2543 * expects to trace. When doing the switch of functions,
2544 * we need to update to the ftrace_ops_list_func first
2545 * before the transition between old and new calls are set,
2546 * as the ftrace_ops_list_func will check the ops hashes
2547 * to make sure the ops are having the right functions
2551 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2552 if (FTRACE_WARN_ON(err))
2556 if (command & FTRACE_UPDATE_CALLS)
2557 ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
2558 else if (command & FTRACE_DISABLE_CALLS)
2559 ftrace_replace_code(mod_flags);
2561 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2562 function_trace_op = set_function_trace_op;
2564 /* If irqs are disabled, we are in stop machine */
2565 if (!irqs_disabled())
2566 smp_call_function(ftrace_sync_ipi, NULL, 1);
2567 err = ftrace_update_ftrace_func(ftrace_trace_function);
2568 if (FTRACE_WARN_ON(err))
2572 if (command & FTRACE_START_FUNC_RET)
2573 err = ftrace_enable_ftrace_graph_caller();
2574 else if (command & FTRACE_STOP_FUNC_RET)
2575 err = ftrace_disable_ftrace_graph_caller();
2576 FTRACE_WARN_ON(err);
2579 static int __ftrace_modify_code(void *data)
2581 int *command = data;
2583 ftrace_modify_all_code(*command);
2589 * ftrace_run_stop_machine, go back to the stop machine method
2590 * @command: The command to tell ftrace what to do
2592 * If an arch needs to fall back to the stop machine method, the
2593 * it can call this function.
2595 void ftrace_run_stop_machine(int command)
2597 stop_machine(__ftrace_modify_code, &command, NULL);
2601 * arch_ftrace_update_code, modify the code to trace or not trace
2602 * @command: The command that needs to be done
2604 * Archs can override this function if it does not need to
2605 * run stop_machine() to modify code.
2607 void __weak arch_ftrace_update_code(int command)
2609 ftrace_run_stop_machine(command);
2612 static void ftrace_run_update_code(int command)
2616 ret = ftrace_arch_code_modify_prepare();
2617 FTRACE_WARN_ON(ret);
2622 * By default we use stop_machine() to modify the code.
2623 * But archs can do what ever they want as long as it
2624 * is safe. The stop_machine() is the safest, but also
2625 * produces the most overhead.
2627 arch_ftrace_update_code(command);
2629 ret = ftrace_arch_code_modify_post_process();
2630 FTRACE_WARN_ON(ret);
2633 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2634 struct ftrace_ops_hash *old_hash)
2636 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2637 ops->old_hash.filter_hash = old_hash->filter_hash;
2638 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2639 ftrace_run_update_code(command);
2640 ops->old_hash.filter_hash = NULL;
2641 ops->old_hash.notrace_hash = NULL;
2642 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2645 static ftrace_func_t saved_ftrace_func;
2646 static int ftrace_start_up;
2648 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2652 static void ftrace_startup_enable(int command)
2654 if (saved_ftrace_func != ftrace_trace_function) {
2655 saved_ftrace_func = ftrace_trace_function;
2656 command |= FTRACE_UPDATE_TRACE_FUNC;
2659 if (!command || !ftrace_enabled)
2662 ftrace_run_update_code(command);
2665 static void ftrace_startup_all(int command)
2667 update_all_ops = true;
2668 ftrace_startup_enable(command);
2669 update_all_ops = false;
2672 int ftrace_startup(struct ftrace_ops *ops, int command)
2676 if (unlikely(ftrace_disabled))
2679 ret = __register_ftrace_function(ops);
2686 * Note that ftrace probes uses this to start up
2687 * and modify functions it will probe. But we still
2688 * set the ADDING flag for modification, as probes
2689 * do not have trampolines. If they add them in the
2690 * future, then the probes will need to distinguish
2691 * between adding and updating probes.
2693 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2695 ret = ftrace_hash_ipmodify_enable(ops);
2697 /* Rollback registration process */
2698 __unregister_ftrace_function(ops);
2700 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2704 if (ftrace_hash_rec_enable(ops, 1))
2705 command |= FTRACE_UPDATE_CALLS;
2707 ftrace_startup_enable(command);
2709 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2714 int ftrace_shutdown(struct ftrace_ops *ops, int command)
2718 if (unlikely(ftrace_disabled))
2721 ret = __unregister_ftrace_function(ops);
2727 * Just warn in case of unbalance, no need to kill ftrace, it's not
2728 * critical but the ftrace_call callers may be never nopped again after
2729 * further ftrace uses.
2731 WARN_ON_ONCE(ftrace_start_up < 0);
2733 /* Disabling ipmodify never fails */
2734 ftrace_hash_ipmodify_disable(ops);
2736 if (ftrace_hash_rec_disable(ops, 1))
2737 command |= FTRACE_UPDATE_CALLS;
2739 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2741 if (saved_ftrace_func != ftrace_trace_function) {
2742 saved_ftrace_func = ftrace_trace_function;
2743 command |= FTRACE_UPDATE_TRACE_FUNC;
2746 if (!command || !ftrace_enabled) {
2748 * If these are dynamic or per_cpu ops, they still
2749 * need their data freed. Since, function tracing is
2750 * not currently active, we can just free them
2751 * without synchronizing all CPUs.
2753 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2760 * If the ops uses a trampoline, then it needs to be
2761 * tested first on update.
2763 ops->flags |= FTRACE_OPS_FL_REMOVING;
2766 /* The trampoline logic checks the old hashes */
2767 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2768 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2770 ftrace_run_update_code(command);
2773 * If there's no more ops registered with ftrace, run a
2774 * sanity check to make sure all rec flags are cleared.
2776 if (rcu_dereference_protected(ftrace_ops_list,
2777 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2778 struct ftrace_page *pg;
2779 struct dyn_ftrace *rec;
2781 do_for_each_ftrace_rec(pg, rec) {
2782 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2783 pr_warn(" %pS flags:%lx\n",
2784 (void *)rec->ip, rec->flags);
2785 } while_for_each_ftrace_rec();
2788 ops->old_hash.filter_hash = NULL;
2789 ops->old_hash.notrace_hash = NULL;
2792 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2795 * Dynamic ops may be freed, we must make sure that all
2796 * callers are done before leaving this function.
2797 * The same goes for freeing the per_cpu data of the per_cpu
2800 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2802 * We need to do a hard force of sched synchronization.
2803 * This is because we use preempt_disable() to do RCU, but
2804 * the function tracers can be called where RCU is not watching
2805 * (like before user_exit()). We can not rely on the RCU
2806 * infrastructure to do the synchronization, thus we must do it
2809 schedule_on_each_cpu(ftrace_sync);
2812 * When the kernel is preeptive, tasks can be preempted
2813 * while on a ftrace trampoline. Just scheduling a task on
2814 * a CPU is not good enough to flush them. Calling
2815 * synchornize_rcu_tasks() will wait for those tasks to
2816 * execute and either schedule voluntarily or enter user space.
2818 if (IS_ENABLED(CONFIG_PREEMPTION))
2819 synchronize_rcu_tasks();
2822 arch_ftrace_trampoline_free(ops);
2828 static void ftrace_startup_sysctl(void)
2832 if (unlikely(ftrace_disabled))
2835 /* Force update next time */
2836 saved_ftrace_func = NULL;
2837 /* ftrace_start_up is true if we want ftrace running */
2838 if (ftrace_start_up) {
2839 command = FTRACE_UPDATE_CALLS;
2840 if (ftrace_graph_active)
2841 command |= FTRACE_START_FUNC_RET;
2842 ftrace_startup_enable(command);
2846 static void ftrace_shutdown_sysctl(void)
2850 if (unlikely(ftrace_disabled))
2853 /* ftrace_start_up is true if ftrace is running */
2854 if (ftrace_start_up) {
2855 command = FTRACE_DISABLE_CALLS;
2856 if (ftrace_graph_active)
2857 command |= FTRACE_STOP_FUNC_RET;
2858 ftrace_run_update_code(command);
2862 static u64 ftrace_update_time;
2863 unsigned long ftrace_update_tot_cnt;
2865 static inline int ops_traces_mod(struct ftrace_ops *ops)
2868 * Filter_hash being empty will default to trace module.
2869 * But notrace hash requires a test of individual module functions.
2871 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2872 ftrace_hash_empty(ops->func_hash->notrace_hash);
2876 * Check if the current ops references the record.
2878 * If the ops traces all functions, then it was already accounted for.
2879 * If the ops does not trace the current record function, skip it.
2880 * If the ops ignores the function via notrace filter, skip it.
2883 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2885 /* If ops isn't enabled, ignore it */
2886 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2889 /* If ops traces all then it includes this function */
2890 if (ops_traces_mod(ops))
2893 /* The function must be in the filter */
2894 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2895 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2898 /* If in notrace hash, we ignore it too */
2899 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2905 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2907 struct ftrace_page *pg;
2908 struct dyn_ftrace *p;
2910 unsigned long update_cnt = 0;
2911 unsigned long rec_flags = 0;
2914 start = ftrace_now(raw_smp_processor_id());
2917 * When a module is loaded, this function is called to convert
2918 * the calls to mcount in its text to nops, and also to create
2919 * an entry in the ftrace data. Now, if ftrace is activated
2920 * after this call, but before the module sets its text to
2921 * read-only, the modification of enabling ftrace can fail if
2922 * the read-only is done while ftrace is converting the calls.
2923 * To prevent this, the module's records are set as disabled
2924 * and will be enabled after the call to set the module's text
2928 rec_flags |= FTRACE_FL_DISABLED;
2930 for (pg = new_pgs; pg; pg = pg->next) {
2932 for (i = 0; i < pg->index; i++) {
2934 /* If something went wrong, bail without enabling anything */
2935 if (unlikely(ftrace_disabled))
2938 p = &pg->records[i];
2939 p->flags = rec_flags;
2942 * Do the initial record conversion from mcount jump
2943 * to the NOP instructions.
2945 if (!__is_defined(CC_USING_NOP_MCOUNT) &&
2946 !ftrace_code_disable(mod, p))
2953 stop = ftrace_now(raw_smp_processor_id());
2954 ftrace_update_time = stop - start;
2955 ftrace_update_tot_cnt += update_cnt;
2960 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2965 if (WARN_ON(!count))
2968 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2971 * We want to fill as much as possible. No more than a page
2974 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2978 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2981 /* if we can't allocate this size, try something smaller */
2988 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2997 static struct ftrace_page *
2998 ftrace_allocate_pages(unsigned long num_to_init)
3000 struct ftrace_page *start_pg;
3001 struct ftrace_page *pg;
3008 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3013 * Try to allocate as much as possible in one continues
3014 * location that fills in all of the space. We want to
3015 * waste as little space as possible.
3018 cnt = ftrace_allocate_records(pg, num_to_init);
3026 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3038 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3039 free_pages((unsigned long)pg->records, order);
3040 start_pg = pg->next;
3044 pr_info("ftrace: FAILED to allocate memory for functions\n");
3048 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3050 struct ftrace_iterator {
3054 struct ftrace_page *pg;
3055 struct dyn_ftrace *func;
3056 struct ftrace_func_probe *probe;
3057 struct ftrace_func_entry *probe_entry;
3058 struct trace_parser parser;
3059 struct ftrace_hash *hash;
3060 struct ftrace_ops *ops;
3061 struct trace_array *tr;
3062 struct list_head *mod_list;
3069 t_probe_next(struct seq_file *m, loff_t *pos)
3071 struct ftrace_iterator *iter = m->private;
3072 struct trace_array *tr = iter->ops->private;
3073 struct list_head *func_probes;
3074 struct ftrace_hash *hash;
3075 struct list_head *next;
3076 struct hlist_node *hnd = NULL;
3077 struct hlist_head *hhd;
3086 func_probes = &tr->func_probes;
3087 if (list_empty(func_probes))
3091 next = func_probes->next;
3092 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3095 if (iter->probe_entry)
3096 hnd = &iter->probe_entry->hlist;
3098 hash = iter->probe->ops.func_hash->filter_hash;
3101 * A probe being registered may temporarily have an empty hash
3102 * and it's at the end of the func_probes list.
3104 if (!hash || hash == EMPTY_HASH)
3107 size = 1 << hash->size_bits;
3110 if (iter->pidx >= size) {
3111 if (iter->probe->list.next == func_probes)
3113 next = iter->probe->list.next;
3114 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3115 hash = iter->probe->ops.func_hash->filter_hash;
3116 size = 1 << hash->size_bits;
3120 hhd = &hash->buckets[iter->pidx];
3122 if (hlist_empty(hhd)) {
3138 if (WARN_ON_ONCE(!hnd))
3141 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3146 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3148 struct ftrace_iterator *iter = m->private;
3152 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3155 if (iter->mod_pos > *pos)
3159 iter->probe_entry = NULL;
3161 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3162 p = t_probe_next(m, &l);
3169 /* Only set this if we have an item */
3170 iter->flags |= FTRACE_ITER_PROBE;
3176 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3178 struct ftrace_func_entry *probe_entry;
3179 struct ftrace_probe_ops *probe_ops;
3180 struct ftrace_func_probe *probe;
3182 probe = iter->probe;
3183 probe_entry = iter->probe_entry;
3185 if (WARN_ON_ONCE(!probe || !probe_entry))
3188 probe_ops = probe->probe_ops;
3190 if (probe_ops->print)
3191 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3193 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3194 (void *)probe_ops->func);
3200 t_mod_next(struct seq_file *m, loff_t *pos)
3202 struct ftrace_iterator *iter = m->private;
3203 struct trace_array *tr = iter->tr;
3208 iter->mod_list = iter->mod_list->next;
3210 if (iter->mod_list == &tr->mod_trace ||
3211 iter->mod_list == &tr->mod_notrace) {
3212 iter->flags &= ~FTRACE_ITER_MOD;
3216 iter->mod_pos = *pos;
3221 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3223 struct ftrace_iterator *iter = m->private;
3227 if (iter->func_pos > *pos)
3230 iter->mod_pos = iter->func_pos;
3232 /* probes are only available if tr is set */
3236 for (l = 0; l <= (*pos - iter->func_pos); ) {
3237 p = t_mod_next(m, &l);
3242 iter->flags &= ~FTRACE_ITER_MOD;
3243 return t_probe_start(m, pos);
3246 /* Only set this if we have an item */
3247 iter->flags |= FTRACE_ITER_MOD;
3253 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3255 struct ftrace_mod_load *ftrace_mod;
3256 struct trace_array *tr = iter->tr;
3258 if (WARN_ON_ONCE(!iter->mod_list) ||
3259 iter->mod_list == &tr->mod_trace ||
3260 iter->mod_list == &tr->mod_notrace)
3263 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3265 if (ftrace_mod->func)
3266 seq_printf(m, "%s", ftrace_mod->func);
3270 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3276 t_func_next(struct seq_file *m, loff_t *pos)
3278 struct ftrace_iterator *iter = m->private;
3279 struct dyn_ftrace *rec = NULL;
3284 if (iter->idx >= iter->pg->index) {
3285 if (iter->pg->next) {
3286 iter->pg = iter->pg->next;
3291 rec = &iter->pg->records[iter->idx++];
3292 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3293 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3295 ((iter->flags & FTRACE_ITER_ENABLED) &&
3296 !(rec->flags & FTRACE_FL_ENABLED))) {
3306 iter->pos = iter->func_pos = *pos;
3313 t_next(struct seq_file *m, void *v, loff_t *pos)
3315 struct ftrace_iterator *iter = m->private;
3316 loff_t l = *pos; /* t_probe_start() must use original pos */
3319 if (unlikely(ftrace_disabled))
3322 if (iter->flags & FTRACE_ITER_PROBE)
3323 return t_probe_next(m, pos);
3325 if (iter->flags & FTRACE_ITER_MOD)
3326 return t_mod_next(m, pos);
3328 if (iter->flags & FTRACE_ITER_PRINTALL) {
3329 /* next must increment pos, and t_probe_start does not */
3331 return t_mod_start(m, &l);
3334 ret = t_func_next(m, pos);
3337 return t_mod_start(m, &l);
3342 static void reset_iter_read(struct ftrace_iterator *iter)
3346 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3349 static void *t_start(struct seq_file *m, loff_t *pos)
3351 struct ftrace_iterator *iter = m->private;
3355 mutex_lock(&ftrace_lock);
3357 if (unlikely(ftrace_disabled))
3361 * If an lseek was done, then reset and start from beginning.
3363 if (*pos < iter->pos)
3364 reset_iter_read(iter);
3367 * For set_ftrace_filter reading, if we have the filter
3368 * off, we can short cut and just print out that all
3369 * functions are enabled.
3371 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3372 ftrace_hash_empty(iter->hash)) {
3373 iter->func_pos = 1; /* Account for the message */
3375 return t_mod_start(m, pos);
3376 iter->flags |= FTRACE_ITER_PRINTALL;
3377 /* reset in case of seek/pread */
3378 iter->flags &= ~FTRACE_ITER_PROBE;
3382 if (iter->flags & FTRACE_ITER_MOD)
3383 return t_mod_start(m, pos);
3386 * Unfortunately, we need to restart at ftrace_pages_start
3387 * every time we let go of the ftrace_mutex. This is because
3388 * those pointers can change without the lock.
3390 iter->pg = ftrace_pages_start;
3392 for (l = 0; l <= *pos; ) {
3393 p = t_func_next(m, &l);
3399 return t_mod_start(m, pos);
3404 static void t_stop(struct seq_file *m, void *p)
3406 mutex_unlock(&ftrace_lock);
3410 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3415 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3416 struct dyn_ftrace *rec)
3420 ptr = arch_ftrace_trampoline_func(ops, rec);
3422 seq_printf(m, " ->%pS", ptr);
3425 static int t_show(struct seq_file *m, void *v)
3427 struct ftrace_iterator *iter = m->private;
3428 struct dyn_ftrace *rec;
3430 if (iter->flags & FTRACE_ITER_PROBE)
3431 return t_probe_show(m, iter);
3433 if (iter->flags & FTRACE_ITER_MOD)
3434 return t_mod_show(m, iter);
3436 if (iter->flags & FTRACE_ITER_PRINTALL) {
3437 if (iter->flags & FTRACE_ITER_NOTRACE)
3438 seq_puts(m, "#### no functions disabled ####\n");
3440 seq_puts(m, "#### all functions enabled ####\n");
3449 seq_printf(m, "%ps", (void *)rec->ip);
3450 if (iter->flags & FTRACE_ITER_ENABLED) {
3451 struct ftrace_ops *ops;
3453 seq_printf(m, " (%ld)%s%s",
3454 ftrace_rec_count(rec),
3455 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3456 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3457 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3458 ops = ftrace_find_tramp_ops_any(rec);
3461 seq_printf(m, "\ttramp: %pS (%pS)",
3462 (void *)ops->trampoline,
3464 add_trampoline_func(m, ops, rec);
3465 ops = ftrace_find_tramp_ops_next(rec, ops);
3468 seq_puts(m, "\ttramp: ERROR!");
3470 add_trampoline_func(m, NULL, rec);
3479 static const struct seq_operations show_ftrace_seq_ops = {
3487 ftrace_avail_open(struct inode *inode, struct file *file)
3489 struct ftrace_iterator *iter;
3492 ret = security_locked_down(LOCKDOWN_TRACEFS);
3496 if (unlikely(ftrace_disabled))
3499 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3503 iter->pg = ftrace_pages_start;
3504 iter->ops = &global_ops;
3510 ftrace_enabled_open(struct inode *inode, struct file *file)
3512 struct ftrace_iterator *iter;
3515 * This shows us what functions are currently being
3516 * traced and by what. Not sure if we want lockdown
3517 * to hide such critical information for an admin.
3518 * Although, perhaps it can show information we don't
3519 * want people to see, but if something is tracing
3520 * something, we probably want to know about it.
3523 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3527 iter->pg = ftrace_pages_start;
3528 iter->flags = FTRACE_ITER_ENABLED;
3529 iter->ops = &global_ops;
3535 * ftrace_regex_open - initialize function tracer filter files
3536 * @ops: The ftrace_ops that hold the hash filters
3537 * @flag: The type of filter to process
3538 * @inode: The inode, usually passed in to your open routine
3539 * @file: The file, usually passed in to your open routine
3541 * ftrace_regex_open() initializes the filter files for the
3542 * @ops. Depending on @flag it may process the filter hash or
3543 * the notrace hash of @ops. With this called from the open
3544 * routine, you can use ftrace_filter_write() for the write
3545 * routine if @flag has FTRACE_ITER_FILTER set, or
3546 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3547 * tracing_lseek() should be used as the lseek routine, and
3548 * release must call ftrace_regex_release().
3551 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3552 struct inode *inode, struct file *file)
3554 struct ftrace_iterator *iter;
3555 struct ftrace_hash *hash;
3556 struct list_head *mod_head;
3557 struct trace_array *tr = ops->private;
3560 ftrace_ops_init(ops);
3562 if (unlikely(ftrace_disabled))
3565 if (tracing_check_open_get_tr(tr))
3568 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3572 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX))
3579 mutex_lock(&ops->func_hash->regex_lock);
3581 if (flag & FTRACE_ITER_NOTRACE) {
3582 hash = ops->func_hash->notrace_hash;
3583 mod_head = tr ? &tr->mod_notrace : NULL;
3585 hash = ops->func_hash->filter_hash;
3586 mod_head = tr ? &tr->mod_trace : NULL;
3589 iter->mod_list = mod_head;
3591 if (file->f_mode & FMODE_WRITE) {
3592 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3594 if (file->f_flags & O_TRUNC) {
3595 iter->hash = alloc_ftrace_hash(size_bits);
3596 clear_ftrace_mod_list(mod_head);
3598 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3602 trace_parser_put(&iter->parser);
3610 if (file->f_mode & FMODE_READ) {
3611 iter->pg = ftrace_pages_start;
3613 ret = seq_open(file, &show_ftrace_seq_ops);
3615 struct seq_file *m = file->private_data;
3619 free_ftrace_hash(iter->hash);
3620 trace_parser_put(&iter->parser);
3623 file->private_data = iter;
3626 mutex_unlock(&ops->func_hash->regex_lock);
3632 trace_array_put(tr);
3639 ftrace_filter_open(struct inode *inode, struct file *file)
3641 struct ftrace_ops *ops = inode->i_private;
3643 /* Checks for tracefs lockdown */
3644 return ftrace_regex_open(ops,
3645 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3650 ftrace_notrace_open(struct inode *inode, struct file *file)
3652 struct ftrace_ops *ops = inode->i_private;
3654 /* Checks for tracefs lockdown */
3655 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3659 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3660 struct ftrace_glob {
3667 * If symbols in an architecture don't correspond exactly to the user-visible
3668 * name of what they represent, it is possible to define this function to
3669 * perform the necessary adjustments.
3671 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3676 static int ftrace_match(char *str, struct ftrace_glob *g)
3681 str = arch_ftrace_match_adjust(str, g->search);
3685 if (strcmp(str, g->search) == 0)
3688 case MATCH_FRONT_ONLY:
3689 if (strncmp(str, g->search, g->len) == 0)
3692 case MATCH_MIDDLE_ONLY:
3693 if (strstr(str, g->search))
3696 case MATCH_END_ONLY:
3698 if (slen >= g->len &&
3699 memcmp(str + slen - g->len, g->search, g->len) == 0)
3703 if (glob_match(g->search, str))
3712 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3714 struct ftrace_func_entry *entry;
3717 entry = ftrace_lookup_ip(hash, rec->ip);
3719 /* Do nothing if it doesn't exist */
3723 free_hash_entry(hash, entry);
3725 /* Do nothing if it exists */
3729 ret = add_hash_entry(hash, rec->ip);
3735 add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
3738 long index = simple_strtoul(func_g->search, NULL, 0);
3739 struct ftrace_page *pg;
3740 struct dyn_ftrace *rec;
3742 /* The index starts at 1 */
3746 do_for_each_ftrace_rec(pg, rec) {
3747 if (pg->index <= index) {
3749 /* this is a double loop, break goes to the next page */
3752 rec = &pg->records[index];
3753 enter_record(hash, rec, clear_filter);
3755 } while_for_each_ftrace_rec();
3760 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3761 struct ftrace_glob *mod_g, int exclude_mod)
3763 char str[KSYM_SYMBOL_LEN];
3766 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3769 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3771 /* blank module name to match all modules */
3773 /* blank module globbing: modname xor exclude_mod */
3774 if (!exclude_mod != !modname)
3780 * exclude_mod is set to trace everything but the given
3781 * module. If it is set and the module matches, then
3782 * return 0. If it is not set, and the module doesn't match
3783 * also return 0. Otherwise, check the function to see if
3786 if (!mod_matches == !exclude_mod)
3789 /* blank search means to match all funcs in the mod */
3794 return ftrace_match(str, func_g);
3798 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3800 struct ftrace_page *pg;
3801 struct dyn_ftrace *rec;
3802 struct ftrace_glob func_g = { .type = MATCH_FULL };
3803 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3804 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3805 int exclude_mod = 0;
3808 int clear_filter = 0;
3811 func_g.type = filter_parse_regex(func, len, &func_g.search,
3813 func_g.len = strlen(func_g.search);
3817 mod_g.type = filter_parse_regex(mod, strlen(mod),
3818 &mod_g.search, &exclude_mod);
3819 mod_g.len = strlen(mod_g.search);
3822 mutex_lock(&ftrace_lock);
3824 if (unlikely(ftrace_disabled))
3827 if (func_g.type == MATCH_INDEX) {
3828 found = add_rec_by_index(hash, &func_g, clear_filter);
3832 do_for_each_ftrace_rec(pg, rec) {
3834 if (rec->flags & FTRACE_FL_DISABLED)
3837 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3838 ret = enter_record(hash, rec, clear_filter);
3845 } while_for_each_ftrace_rec();
3847 mutex_unlock(&ftrace_lock);
3853 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3855 return match_records(hash, buff, len, NULL);
3858 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3859 struct ftrace_ops_hash *old_hash)
3861 struct ftrace_ops *op;
3863 if (!ftrace_enabled)
3866 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3867 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3872 * If this is the shared global_ops filter, then we need to
3873 * check if there is another ops that shares it, is enabled.
3874 * If so, we still need to run the modify code.
3876 if (ops->func_hash != &global_ops.local_hash)
3879 do_for_each_ftrace_op(op, ftrace_ops_list) {
3880 if (op->func_hash == &global_ops.local_hash &&
3881 op->flags & FTRACE_OPS_FL_ENABLED) {
3882 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3883 /* Only need to do this once */
3886 } while_for_each_ftrace_op(op);
3889 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3890 struct ftrace_hash **orig_hash,
3891 struct ftrace_hash *hash,
3894 struct ftrace_ops_hash old_hash_ops;
3895 struct ftrace_hash *old_hash;
3898 old_hash = *orig_hash;
3899 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3900 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3901 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3903 ftrace_ops_update_code(ops, &old_hash_ops);
3904 free_ftrace_hash_rcu(old_hash);
3909 static bool module_exists(const char *module)
3911 /* All modules have the symbol __this_module */
3912 static const char this_mod[] = "__this_module";
3913 char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
3917 n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
3919 if (n > sizeof(modname) - 1)
3922 val = module_kallsyms_lookup_name(modname);
3926 static int cache_mod(struct trace_array *tr,
3927 const char *func, char *module, int enable)
3929 struct ftrace_mod_load *ftrace_mod, *n;
3930 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3933 mutex_lock(&ftrace_lock);
3935 /* We do not cache inverse filters */
3936 if (func[0] == '!') {
3940 /* Look to remove this hash */
3941 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3942 if (strcmp(ftrace_mod->module, module) != 0)
3945 /* no func matches all */
3946 if (strcmp(func, "*") == 0 ||
3947 (ftrace_mod->func &&
3948 strcmp(ftrace_mod->func, func) == 0)) {
3950 free_ftrace_mod(ftrace_mod);
3958 /* We only care about modules that have not been loaded yet */
3959 if (module_exists(module))
3962 /* Save this string off, and execute it when the module is loaded */
3963 ret = ftrace_add_mod(tr, func, module, enable);
3965 mutex_unlock(&ftrace_lock);
3971 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3972 int reset, int enable);
3974 #ifdef CONFIG_MODULES
3975 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3976 char *mod, bool enable)
3978 struct ftrace_mod_load *ftrace_mod, *n;
3979 struct ftrace_hash **orig_hash, *new_hash;
3980 LIST_HEAD(process_mods);
3984 mutex_lock(&ops->func_hash->regex_lock);
3987 orig_hash = &ops->func_hash->filter_hash;
3989 orig_hash = &ops->func_hash->notrace_hash;
3991 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3994 goto out; /* warn? */
3996 mutex_lock(&ftrace_lock);
3998 list_for_each_entry_safe(ftrace_mod, n, head, list) {
4000 if (strcmp(ftrace_mod->module, mod) != 0)
4003 if (ftrace_mod->func)
4004 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
4006 func = kstrdup("*", GFP_KERNEL);
4008 if (!func) /* warn? */
4011 list_del(&ftrace_mod->list);
4012 list_add(&ftrace_mod->list, &process_mods);
4014 /* Use the newly allocated func, as it may be "*" */
4015 kfree(ftrace_mod->func);
4016 ftrace_mod->func = func;
4019 mutex_unlock(&ftrace_lock);
4021 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4023 func = ftrace_mod->func;
4025 /* Grabs ftrace_lock, which is why we have this extra step */
4026 match_records(new_hash, func, strlen(func), mod);
4027 free_ftrace_mod(ftrace_mod);
4030 if (enable && list_empty(head))
4031 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4033 mutex_lock(&ftrace_lock);
4035 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4037 mutex_unlock(&ftrace_lock);
4040 mutex_unlock(&ops->func_hash->regex_lock);
4042 free_ftrace_hash(new_hash);
4045 static void process_cached_mods(const char *mod_name)
4047 struct trace_array *tr;
4050 mod = kstrdup(mod_name, GFP_KERNEL);
4054 mutex_lock(&trace_types_lock);
4055 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4056 if (!list_empty(&tr->mod_trace))
4057 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4058 if (!list_empty(&tr->mod_notrace))
4059 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4061 mutex_unlock(&trace_types_lock);
4068 * We register the module command as a template to show others how
4069 * to register the a command as well.
4073 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4074 char *func_orig, char *cmd, char *module, int enable)
4079 /* match_records() modifies func, and we need the original */
4080 func = kstrdup(func_orig, GFP_KERNEL);
4085 * cmd == 'mod' because we only registered this func
4086 * for the 'mod' ftrace_func_command.
4087 * But if you register one func with multiple commands,
4088 * you can tell which command was used by the cmd
4091 ret = match_records(hash, func, strlen(func), module);
4095 return cache_mod(tr, func_orig, module, enable);
4101 static struct ftrace_func_command ftrace_mod_cmd = {
4103 .func = ftrace_mod_callback,
4106 static int __init ftrace_mod_cmd_init(void)
4108 return register_ftrace_command(&ftrace_mod_cmd);
4110 core_initcall(ftrace_mod_cmd_init);
4112 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4113 struct ftrace_ops *op, struct pt_regs *pt_regs)
4115 struct ftrace_probe_ops *probe_ops;
4116 struct ftrace_func_probe *probe;
4118 probe = container_of(op, struct ftrace_func_probe, ops);
4119 probe_ops = probe->probe_ops;
4122 * Disable preemption for these calls to prevent a RCU grace
4123 * period. This syncs the hash iteration and freeing of items
4124 * on the hash. rcu_read_lock is too dangerous here.
4126 preempt_disable_notrace();
4127 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4128 preempt_enable_notrace();
4131 struct ftrace_func_map {
4132 struct ftrace_func_entry entry;
4136 struct ftrace_func_mapper {
4137 struct ftrace_hash hash;
4141 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4143 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4145 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4147 struct ftrace_hash *hash;
4150 * The mapper is simply a ftrace_hash, but since the entries
4151 * in the hash are not ftrace_func_entry type, we define it
4152 * as a separate structure.
4154 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4155 return (struct ftrace_func_mapper *)hash;
4159 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4160 * @mapper: The mapper that has the ip maps
4161 * @ip: the instruction pointer to find the data for
4163 * Returns the data mapped to @ip if found otherwise NULL. The return
4164 * is actually the address of the mapper data pointer. The address is
4165 * returned for use cases where the data is no bigger than a long, and
4166 * the user can use the data pointer as its data instead of having to
4167 * allocate more memory for the reference.
4169 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4172 struct ftrace_func_entry *entry;
4173 struct ftrace_func_map *map;
4175 entry = ftrace_lookup_ip(&mapper->hash, ip);
4179 map = (struct ftrace_func_map *)entry;
4184 * ftrace_func_mapper_add_ip - Map some data to an ip
4185 * @mapper: The mapper that has the ip maps
4186 * @ip: The instruction pointer address to map @data to
4187 * @data: The data to map to @ip
4189 * Returns 0 on succes otherwise an error.
4191 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4192 unsigned long ip, void *data)
4194 struct ftrace_func_entry *entry;
4195 struct ftrace_func_map *map;
4197 entry = ftrace_lookup_ip(&mapper->hash, ip);
4201 map = kmalloc(sizeof(*map), GFP_KERNEL);
4208 __add_hash_entry(&mapper->hash, &map->entry);
4214 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4215 * @mapper: The mapper that has the ip maps
4216 * @ip: The instruction pointer address to remove the data from
4218 * Returns the data if it is found, otherwise NULL.
4219 * Note, if the data pointer is used as the data itself, (see
4220 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4221 * if the data pointer was set to zero.
4223 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4226 struct ftrace_func_entry *entry;
4227 struct ftrace_func_map *map;
4230 entry = ftrace_lookup_ip(&mapper->hash, ip);
4234 map = (struct ftrace_func_map *)entry;
4237 remove_hash_entry(&mapper->hash, entry);
4244 * free_ftrace_func_mapper - free a mapping of ips and data
4245 * @mapper: The mapper that has the ip maps
4246 * @free_func: A function to be called on each data item.
4248 * This is used to free the function mapper. The @free_func is optional
4249 * and can be used if the data needs to be freed as well.
4251 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4252 ftrace_mapper_func free_func)
4254 struct ftrace_func_entry *entry;
4255 struct ftrace_func_map *map;
4256 struct hlist_head *hhd;
4262 if (free_func && mapper->hash.count) {
4263 size = 1 << mapper->hash.size_bits;
4264 for (i = 0; i < size; i++) {
4265 hhd = &mapper->hash.buckets[i];
4266 hlist_for_each_entry(entry, hhd, hlist) {
4267 map = (struct ftrace_func_map *)entry;
4272 free_ftrace_hash(&mapper->hash);
4275 static void release_probe(struct ftrace_func_probe *probe)
4277 struct ftrace_probe_ops *probe_ops;
4279 mutex_lock(&ftrace_lock);
4281 WARN_ON(probe->ref <= 0);
4283 /* Subtract the ref that was used to protect this instance */
4287 probe_ops = probe->probe_ops;
4289 * Sending zero as ip tells probe_ops to free
4290 * the probe->data itself
4292 if (probe_ops->free)
4293 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4294 list_del(&probe->list);
4297 mutex_unlock(&ftrace_lock);
4300 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4303 * Add one ref to keep it from being freed when releasing the
4304 * ftrace_lock mutex.
4310 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4311 struct ftrace_probe_ops *probe_ops,
4314 struct ftrace_func_entry *entry;
4315 struct ftrace_func_probe *probe;
4316 struct ftrace_hash **orig_hash;
4317 struct ftrace_hash *old_hash;
4318 struct ftrace_hash *hash;
4327 /* We do not support '!' for function probes */
4328 if (WARN_ON(glob[0] == '!'))
4332 mutex_lock(&ftrace_lock);
4333 /* Check if the probe_ops is already registered */
4334 list_for_each_entry(probe, &tr->func_probes, list) {
4335 if (probe->probe_ops == probe_ops)
4338 if (&probe->list == &tr->func_probes) {
4339 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4341 mutex_unlock(&ftrace_lock);
4344 probe->probe_ops = probe_ops;
4345 probe->ops.func = function_trace_probe_call;
4347 ftrace_ops_init(&probe->ops);
4348 list_add(&probe->list, &tr->func_probes);
4351 acquire_probe_locked(probe);
4353 mutex_unlock(&ftrace_lock);
4356 * Note, there's a small window here that the func_hash->filter_hash
4357 * may be NULL or empty. Need to be carefule when reading the loop.
4359 mutex_lock(&probe->ops.func_hash->regex_lock);
4361 orig_hash = &probe->ops.func_hash->filter_hash;
4362 old_hash = *orig_hash;
4363 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4370 ret = ftrace_match_records(hash, glob, strlen(glob));
4372 /* Nothing found? */
4379 size = 1 << hash->size_bits;
4380 for (i = 0; i < size; i++) {
4381 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4382 if (ftrace_lookup_ip(old_hash, entry->ip))
4385 * The caller might want to do something special
4386 * for each function we find. We call the callback
4387 * to give the caller an opportunity to do so.
4389 if (probe_ops->init) {
4390 ret = probe_ops->init(probe_ops, tr,
4394 if (probe_ops->free && count)
4395 probe_ops->free(probe_ops, tr,
4405 mutex_lock(&ftrace_lock);
4408 /* Nothing was added? */
4413 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4418 /* One ref for each new function traced */
4419 probe->ref += count;
4421 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4422 ret = ftrace_startup(&probe->ops, 0);
4425 mutex_unlock(&ftrace_lock);
4430 mutex_unlock(&probe->ops.func_hash->regex_lock);
4431 free_ftrace_hash(hash);
4433 release_probe(probe);
4438 if (!probe_ops->free || !count)
4441 /* Failed to do the move, need to call the free functions */
4442 for (i = 0; i < size; i++) {
4443 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4444 if (ftrace_lookup_ip(old_hash, entry->ip))
4446 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4453 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4454 struct ftrace_probe_ops *probe_ops)
4456 struct ftrace_ops_hash old_hash_ops;
4457 struct ftrace_func_entry *entry;
4458 struct ftrace_func_probe *probe;
4459 struct ftrace_glob func_g;
4460 struct ftrace_hash **orig_hash;
4461 struct ftrace_hash *old_hash;
4462 struct ftrace_hash *hash = NULL;
4463 struct hlist_node *tmp;
4464 struct hlist_head hhd;
4465 char str[KSYM_SYMBOL_LEN];
4467 int i, ret = -ENODEV;
4470 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4471 func_g.search = NULL;
4475 func_g.type = filter_parse_regex(glob, strlen(glob),
4476 &func_g.search, ¬);
4477 func_g.len = strlen(func_g.search);
4479 /* we do not support '!' for function probes */
4484 mutex_lock(&ftrace_lock);
4485 /* Check if the probe_ops is already registered */
4486 list_for_each_entry(probe, &tr->func_probes, list) {
4487 if (probe->probe_ops == probe_ops)
4490 if (&probe->list == &tr->func_probes)
4491 goto err_unlock_ftrace;
4494 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4495 goto err_unlock_ftrace;
4497 acquire_probe_locked(probe);
4499 mutex_unlock(&ftrace_lock);
4501 mutex_lock(&probe->ops.func_hash->regex_lock);
4503 orig_hash = &probe->ops.func_hash->filter_hash;
4504 old_hash = *orig_hash;
4506 if (ftrace_hash_empty(old_hash))
4509 old_hash_ops.filter_hash = old_hash;
4510 /* Probes only have filters */
4511 old_hash_ops.notrace_hash = NULL;
4514 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4518 INIT_HLIST_HEAD(&hhd);
4520 size = 1 << hash->size_bits;
4521 for (i = 0; i < size; i++) {
4522 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4524 if (func_g.search) {
4525 kallsyms_lookup(entry->ip, NULL, NULL,
4527 if (!ftrace_match(str, &func_g))
4531 remove_hash_entry(hash, entry);
4532 hlist_add_head(&entry->hlist, &hhd);
4536 /* Nothing found? */
4542 mutex_lock(&ftrace_lock);
4544 WARN_ON(probe->ref < count);
4546 probe->ref -= count;
4548 if (ftrace_hash_empty(hash))
4549 ftrace_shutdown(&probe->ops, 0);
4551 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4554 /* still need to update the function call sites */
4555 if (ftrace_enabled && !ftrace_hash_empty(hash))
4556 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4560 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4561 hlist_del(&entry->hlist);
4562 if (probe_ops->free)
4563 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4566 mutex_unlock(&ftrace_lock);
4569 mutex_unlock(&probe->ops.func_hash->regex_lock);
4570 free_ftrace_hash(hash);
4572 release_probe(probe);
4577 mutex_unlock(&ftrace_lock);
4581 void clear_ftrace_function_probes(struct trace_array *tr)
4583 struct ftrace_func_probe *probe, *n;
4585 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4586 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4589 static LIST_HEAD(ftrace_commands);
4590 static DEFINE_MUTEX(ftrace_cmd_mutex);
4593 * Currently we only register ftrace commands from __init, so mark this
4596 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4598 struct ftrace_func_command *p;
4601 mutex_lock(&ftrace_cmd_mutex);
4602 list_for_each_entry(p, &ftrace_commands, list) {
4603 if (strcmp(cmd->name, p->name) == 0) {
4608 list_add(&cmd->list, &ftrace_commands);
4610 mutex_unlock(&ftrace_cmd_mutex);
4616 * Currently we only unregister ftrace commands from __init, so mark
4619 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4621 struct ftrace_func_command *p, *n;
4624 mutex_lock(&ftrace_cmd_mutex);
4625 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4626 if (strcmp(cmd->name, p->name) == 0) {
4628 list_del_init(&p->list);
4633 mutex_unlock(&ftrace_cmd_mutex);
4638 static int ftrace_process_regex(struct ftrace_iterator *iter,
4639 char *buff, int len, int enable)
4641 struct ftrace_hash *hash = iter->hash;
4642 struct trace_array *tr = iter->ops->private;
4643 char *func, *command, *next = buff;
4644 struct ftrace_func_command *p;
4647 func = strsep(&next, ":");
4650 ret = ftrace_match_records(hash, func, len);
4660 command = strsep(&next, ":");
4662 mutex_lock(&ftrace_cmd_mutex);
4663 list_for_each_entry(p, &ftrace_commands, list) {
4664 if (strcmp(p->name, command) == 0) {
4665 ret = p->func(tr, hash, func, command, next, enable);
4670 mutex_unlock(&ftrace_cmd_mutex);
4676 ftrace_regex_write(struct file *file, const char __user *ubuf,
4677 size_t cnt, loff_t *ppos, int enable)
4679 struct ftrace_iterator *iter;
4680 struct trace_parser *parser;
4686 if (file->f_mode & FMODE_READ) {
4687 struct seq_file *m = file->private_data;
4690 iter = file->private_data;
4692 if (unlikely(ftrace_disabled))
4695 /* iter->hash is a local copy, so we don't need regex_lock */
4697 parser = &iter->parser;
4698 read = trace_get_user(parser, ubuf, cnt, ppos);
4700 if (read >= 0 && trace_parser_loaded(parser) &&
4701 !trace_parser_cont(parser)) {
4702 ret = ftrace_process_regex(iter, parser->buffer,
4703 parser->idx, enable);
4704 trace_parser_clear(parser);
4715 ftrace_filter_write(struct file *file, const char __user *ubuf,
4716 size_t cnt, loff_t *ppos)
4718 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4722 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4723 size_t cnt, loff_t *ppos)
4725 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4729 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4731 struct ftrace_func_entry *entry;
4733 if (!ftrace_location(ip))
4737 entry = ftrace_lookup_ip(hash, ip);
4740 free_hash_entry(hash, entry);
4744 return add_hash_entry(hash, ip);
4748 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4749 unsigned long ip, int remove, int reset, int enable)
4751 struct ftrace_hash **orig_hash;
4752 struct ftrace_hash *hash;
4755 if (unlikely(ftrace_disabled))
4758 mutex_lock(&ops->func_hash->regex_lock);
4761 orig_hash = &ops->func_hash->filter_hash;
4763 orig_hash = &ops->func_hash->notrace_hash;
4766 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4768 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4772 goto out_regex_unlock;
4775 if (buf && !ftrace_match_records(hash, buf, len)) {
4777 goto out_regex_unlock;
4780 ret = ftrace_match_addr(hash, ip, remove);
4782 goto out_regex_unlock;
4785 mutex_lock(&ftrace_lock);
4786 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4787 mutex_unlock(&ftrace_lock);
4790 mutex_unlock(&ops->func_hash->regex_lock);
4792 free_ftrace_hash(hash);
4797 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4798 int reset, int enable)
4800 return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);
4804 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4805 * @ops - the ops to set the filter with
4806 * @ip - the address to add to or remove from the filter.
4807 * @remove - non zero to remove the ip from the filter
4808 * @reset - non zero to reset all filters before applying this filter.
4810 * Filters denote which functions should be enabled when tracing is enabled
4811 * If @ip is NULL, it failes to update filter.
4813 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4814 int remove, int reset)
4816 ftrace_ops_init(ops);
4817 return ftrace_set_addr(ops, ip, remove, reset, 1);
4819 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4822 * ftrace_ops_set_global_filter - setup ops to use global filters
4823 * @ops - the ops which will use the global filters
4825 * ftrace users who need global function trace filtering should call this.
4826 * It can set the global filter only if ops were not initialized before.
4828 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4830 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4833 ftrace_ops_init(ops);
4834 ops->func_hash = &global_ops.local_hash;
4836 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4839 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4840 int reset, int enable)
4842 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4846 * ftrace_set_filter - set a function to filter on in ftrace
4847 * @ops - the ops to set the filter with
4848 * @buf - the string that holds the function filter text.
4849 * @len - the length of the string.
4850 * @reset - non zero to reset all filters before applying this filter.
4852 * Filters denote which functions should be enabled when tracing is enabled.
4853 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4855 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4858 ftrace_ops_init(ops);
4859 return ftrace_set_regex(ops, buf, len, reset, 1);
4861 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4864 * ftrace_set_notrace - set a function to not trace in ftrace
4865 * @ops - the ops to set the notrace filter with
4866 * @buf - the string that holds the function notrace text.
4867 * @len - the length of the string.
4868 * @reset - non zero to reset all filters before applying this filter.
4870 * Notrace Filters denote which functions should not be enabled when tracing
4871 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4874 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4877 ftrace_ops_init(ops);
4878 return ftrace_set_regex(ops, buf, len, reset, 0);
4880 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4882 * ftrace_set_global_filter - set a function to filter on with global tracers
4883 * @buf - the string that holds the function filter text.
4884 * @len - the length of the string.
4885 * @reset - non zero to reset all filters before applying this filter.
4887 * Filters denote which functions should be enabled when tracing is enabled.
4888 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4890 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4892 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4894 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4897 * ftrace_set_global_notrace - set a function to not trace with global tracers
4898 * @buf - the string that holds the function notrace text.
4899 * @len - the length of the string.
4900 * @reset - non zero to reset all filters before applying this filter.
4902 * Notrace Filters denote which functions should not be enabled when tracing
4903 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4906 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4908 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4910 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4913 * command line interface to allow users to set filters on boot up.
4915 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4916 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4917 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4919 /* Used by function selftest to not test if filter is set */
4920 bool ftrace_filter_param __initdata;
4922 static int __init set_ftrace_notrace(char *str)
4924 ftrace_filter_param = true;
4925 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4928 __setup("ftrace_notrace=", set_ftrace_notrace);
4930 static int __init set_ftrace_filter(char *str)
4932 ftrace_filter_param = true;
4933 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4936 __setup("ftrace_filter=", set_ftrace_filter);
4938 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4939 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4940 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4941 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4943 static int __init set_graph_function(char *str)
4945 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4948 __setup("ftrace_graph_filter=", set_graph_function);
4950 static int __init set_graph_notrace_function(char *str)
4952 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4955 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4957 static int __init set_graph_max_depth_function(char *str)
4961 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4964 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4966 static void __init set_ftrace_early_graph(char *buf, int enable)
4970 struct ftrace_hash *hash;
4972 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4977 func = strsep(&buf, ",");
4978 /* we allow only one expression at a time */
4979 ret = ftrace_graph_set_hash(hash, func);
4981 printk(KERN_DEBUG "ftrace: function %s not "
4982 "traceable\n", func);
4986 ftrace_graph_hash = hash;
4988 ftrace_graph_notrace_hash = hash;
4990 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4993 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4997 ftrace_ops_init(ops);
5000 func = strsep(&buf, ",");
5001 ftrace_set_regex(ops, func, strlen(func), 0, enable);
5005 static void __init set_ftrace_early_filters(void)
5007 if (ftrace_filter_buf[0])
5008 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
5009 if (ftrace_notrace_buf[0])
5010 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
5011 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5012 if (ftrace_graph_buf[0])
5013 set_ftrace_early_graph(ftrace_graph_buf, 1);
5014 if (ftrace_graph_notrace_buf[0])
5015 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
5016 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5019 int ftrace_regex_release(struct inode *inode, struct file *file)
5021 struct seq_file *m = (struct seq_file *)file->private_data;
5022 struct ftrace_iterator *iter;
5023 struct ftrace_hash **orig_hash;
5024 struct trace_parser *parser;
5028 if (file->f_mode & FMODE_READ) {
5030 seq_release(inode, file);
5032 iter = file->private_data;
5034 parser = &iter->parser;
5035 if (trace_parser_loaded(parser)) {
5036 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5039 trace_parser_put(parser);
5041 mutex_lock(&iter->ops->func_hash->regex_lock);
5043 if (file->f_mode & FMODE_WRITE) {
5044 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5047 orig_hash = &iter->ops->func_hash->filter_hash;
5048 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5049 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5051 orig_hash = &iter->ops->func_hash->notrace_hash;
5053 mutex_lock(&ftrace_lock);
5054 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5055 iter->hash, filter_hash);
5056 mutex_unlock(&ftrace_lock);
5058 /* For read only, the hash is the ops hash */
5062 mutex_unlock(&iter->ops->func_hash->regex_lock);
5063 free_ftrace_hash(iter->hash);
5065 trace_array_put(iter->tr);
5071 static const struct file_operations ftrace_avail_fops = {
5072 .open = ftrace_avail_open,
5074 .llseek = seq_lseek,
5075 .release = seq_release_private,
5078 static const struct file_operations ftrace_enabled_fops = {
5079 .open = ftrace_enabled_open,
5081 .llseek = seq_lseek,
5082 .release = seq_release_private,
5085 static const struct file_operations ftrace_filter_fops = {
5086 .open = ftrace_filter_open,
5088 .write = ftrace_filter_write,
5089 .llseek = tracing_lseek,
5090 .release = ftrace_regex_release,
5093 static const struct file_operations ftrace_notrace_fops = {
5094 .open = ftrace_notrace_open,
5096 .write = ftrace_notrace_write,
5097 .llseek = tracing_lseek,
5098 .release = ftrace_regex_release,
5101 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5103 static DEFINE_MUTEX(graph_lock);
5105 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5106 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5108 enum graph_filter_type {
5109 GRAPH_FILTER_NOTRACE = 0,
5110 GRAPH_FILTER_FUNCTION,
5113 #define FTRACE_GRAPH_EMPTY ((void *)1)
5115 struct ftrace_graph_data {
5116 struct ftrace_hash *hash;
5117 struct ftrace_func_entry *entry;
5118 int idx; /* for hash table iteration */
5119 enum graph_filter_type type;
5120 struct ftrace_hash *new_hash;
5121 const struct seq_operations *seq_ops;
5122 struct trace_parser parser;
5126 __g_next(struct seq_file *m, loff_t *pos)
5128 struct ftrace_graph_data *fgd = m->private;
5129 struct ftrace_func_entry *entry = fgd->entry;
5130 struct hlist_head *head;
5131 int i, idx = fgd->idx;
5133 if (*pos >= fgd->hash->count)
5137 hlist_for_each_entry_continue(entry, hlist) {
5145 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5146 head = &fgd->hash->buckets[i];
5147 hlist_for_each_entry(entry, head, hlist) {
5157 g_next(struct seq_file *m, void *v, loff_t *pos)
5160 return __g_next(m, pos);
5163 static void *g_start(struct seq_file *m, loff_t *pos)
5165 struct ftrace_graph_data *fgd = m->private;
5167 mutex_lock(&graph_lock);
5169 if (fgd->type == GRAPH_FILTER_FUNCTION)
5170 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5171 lockdep_is_held(&graph_lock));
5173 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5174 lockdep_is_held(&graph_lock));
5176 /* Nothing, tell g_show to print all functions are enabled */
5177 if (ftrace_hash_empty(fgd->hash) && !*pos)
5178 return FTRACE_GRAPH_EMPTY;
5182 return __g_next(m, pos);
5185 static void g_stop(struct seq_file *m, void *p)
5187 mutex_unlock(&graph_lock);
5190 static int g_show(struct seq_file *m, void *v)
5192 struct ftrace_func_entry *entry = v;
5197 if (entry == FTRACE_GRAPH_EMPTY) {
5198 struct ftrace_graph_data *fgd = m->private;
5200 if (fgd->type == GRAPH_FILTER_FUNCTION)
5201 seq_puts(m, "#### all functions enabled ####\n");
5203 seq_puts(m, "#### no functions disabled ####\n");
5207 seq_printf(m, "%ps\n", (void *)entry->ip);
5212 static const struct seq_operations ftrace_graph_seq_ops = {
5220 __ftrace_graph_open(struct inode *inode, struct file *file,
5221 struct ftrace_graph_data *fgd)
5224 struct ftrace_hash *new_hash = NULL;
5226 ret = security_locked_down(LOCKDOWN_TRACEFS);
5230 if (file->f_mode & FMODE_WRITE) {
5231 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5233 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5236 if (file->f_flags & O_TRUNC)
5237 new_hash = alloc_ftrace_hash(size_bits);
5239 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5247 if (file->f_mode & FMODE_READ) {
5248 ret = seq_open(file, &ftrace_graph_seq_ops);
5250 struct seq_file *m = file->private_data;
5254 free_ftrace_hash(new_hash);
5258 file->private_data = fgd;
5261 if (ret < 0 && file->f_mode & FMODE_WRITE)
5262 trace_parser_put(&fgd->parser);
5264 fgd->new_hash = new_hash;
5267 * All uses of fgd->hash must be taken with the graph_lock
5268 * held. The graph_lock is going to be released, so force
5269 * fgd->hash to be reinitialized when it is taken again.
5277 ftrace_graph_open(struct inode *inode, struct file *file)
5279 struct ftrace_graph_data *fgd;
5282 if (unlikely(ftrace_disabled))
5285 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5289 mutex_lock(&graph_lock);
5291 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5292 lockdep_is_held(&graph_lock));
5293 fgd->type = GRAPH_FILTER_FUNCTION;
5294 fgd->seq_ops = &ftrace_graph_seq_ops;
5296 ret = __ftrace_graph_open(inode, file, fgd);
5300 mutex_unlock(&graph_lock);
5305 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5307 struct ftrace_graph_data *fgd;
5310 if (unlikely(ftrace_disabled))
5313 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5317 mutex_lock(&graph_lock);
5319 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5320 lockdep_is_held(&graph_lock));
5321 fgd->type = GRAPH_FILTER_NOTRACE;
5322 fgd->seq_ops = &ftrace_graph_seq_ops;
5324 ret = __ftrace_graph_open(inode, file, fgd);
5328 mutex_unlock(&graph_lock);
5333 ftrace_graph_release(struct inode *inode, struct file *file)
5335 struct ftrace_graph_data *fgd;
5336 struct ftrace_hash *old_hash, *new_hash;
5337 struct trace_parser *parser;
5340 if (file->f_mode & FMODE_READ) {
5341 struct seq_file *m = file->private_data;
5344 seq_release(inode, file);
5346 fgd = file->private_data;
5350 if (file->f_mode & FMODE_WRITE) {
5352 parser = &fgd->parser;
5354 if (trace_parser_loaded((parser))) {
5355 ret = ftrace_graph_set_hash(fgd->new_hash,
5359 trace_parser_put(parser);
5361 new_hash = __ftrace_hash_move(fgd->new_hash);
5367 mutex_lock(&graph_lock);
5369 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5370 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5371 lockdep_is_held(&graph_lock));
5372 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5374 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5375 lockdep_is_held(&graph_lock));
5376 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5379 mutex_unlock(&graph_lock);
5381 /* Wait till all users are no longer using the old hash */
5384 free_ftrace_hash(old_hash);
5388 free_ftrace_hash(fgd->new_hash);
5395 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5397 struct ftrace_glob func_g;
5398 struct dyn_ftrace *rec;
5399 struct ftrace_page *pg;
5400 struct ftrace_func_entry *entry;
5405 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5406 &func_g.search, ¬);
5408 func_g.len = strlen(func_g.search);
5410 mutex_lock(&ftrace_lock);
5412 if (unlikely(ftrace_disabled)) {
5413 mutex_unlock(&ftrace_lock);
5417 do_for_each_ftrace_rec(pg, rec) {
5419 if (rec->flags & FTRACE_FL_DISABLED)
5422 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5423 entry = ftrace_lookup_ip(hash, rec->ip);
5430 if (add_hash_entry(hash, rec->ip) < 0)
5434 free_hash_entry(hash, entry);
5439 } while_for_each_ftrace_rec();
5441 mutex_unlock(&ftrace_lock);
5450 ftrace_graph_write(struct file *file, const char __user *ubuf,
5451 size_t cnt, loff_t *ppos)
5453 ssize_t read, ret = 0;
5454 struct ftrace_graph_data *fgd = file->private_data;
5455 struct trace_parser *parser;
5460 /* Read mode uses seq functions */
5461 if (file->f_mode & FMODE_READ) {
5462 struct seq_file *m = file->private_data;
5466 parser = &fgd->parser;
5468 read = trace_get_user(parser, ubuf, cnt, ppos);
5470 if (read >= 0 && trace_parser_loaded(parser) &&
5471 !trace_parser_cont(parser)) {
5473 ret = ftrace_graph_set_hash(fgd->new_hash,
5475 trace_parser_clear(parser);
5484 static const struct file_operations ftrace_graph_fops = {
5485 .open = ftrace_graph_open,
5487 .write = ftrace_graph_write,
5488 .llseek = tracing_lseek,
5489 .release = ftrace_graph_release,
5492 static const struct file_operations ftrace_graph_notrace_fops = {
5493 .open = ftrace_graph_notrace_open,
5495 .write = ftrace_graph_write,
5496 .llseek = tracing_lseek,
5497 .release = ftrace_graph_release,
5499 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5501 void ftrace_create_filter_files(struct ftrace_ops *ops,
5502 struct dentry *parent)
5505 trace_create_file("set_ftrace_filter", 0644, parent,
5506 ops, &ftrace_filter_fops);
5508 trace_create_file("set_ftrace_notrace", 0644, parent,
5509 ops, &ftrace_notrace_fops);
5513 * The name "destroy_filter_files" is really a misnomer. Although
5514 * in the future, it may actually delete the files, but this is
5515 * really intended to make sure the ops passed in are disabled
5516 * and that when this function returns, the caller is free to
5519 * The "destroy" name is only to match the "create" name that this
5520 * should be paired with.
5522 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5524 mutex_lock(&ftrace_lock);
5525 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5526 ftrace_shutdown(ops, 0);
5527 ops->flags |= FTRACE_OPS_FL_DELETED;
5528 ftrace_free_filter(ops);
5529 mutex_unlock(&ftrace_lock);
5532 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5535 trace_create_file("available_filter_functions", 0444,
5536 d_tracer, NULL, &ftrace_avail_fops);
5538 trace_create_file("enabled_functions", 0444,
5539 d_tracer, NULL, &ftrace_enabled_fops);
5541 ftrace_create_filter_files(&global_ops, d_tracer);
5543 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5544 trace_create_file("set_graph_function", 0644, d_tracer,
5546 &ftrace_graph_fops);
5547 trace_create_file("set_graph_notrace", 0644, d_tracer,
5549 &ftrace_graph_notrace_fops);
5550 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5555 static int ftrace_cmp_ips(const void *a, const void *b)
5557 const unsigned long *ipa = a;
5558 const unsigned long *ipb = b;
5567 static int ftrace_process_locs(struct module *mod,
5568 unsigned long *start,
5571 struct ftrace_page *start_pg;
5572 struct ftrace_page *pg;
5573 struct dyn_ftrace *rec;
5574 unsigned long count;
5577 unsigned long flags = 0; /* Shut up gcc */
5580 count = end - start;
5585 sort(start, count, sizeof(*start),
5586 ftrace_cmp_ips, NULL);
5588 start_pg = ftrace_allocate_pages(count);
5592 mutex_lock(&ftrace_lock);
5595 * Core and each module needs their own pages, as
5596 * modules will free them when they are removed.
5597 * Force a new page to be allocated for modules.
5600 WARN_ON(ftrace_pages || ftrace_pages_start);
5601 /* First initialization */
5602 ftrace_pages = ftrace_pages_start = start_pg;
5607 if (WARN_ON(ftrace_pages->next)) {
5608 /* Hmm, we have free pages? */
5609 while (ftrace_pages->next)
5610 ftrace_pages = ftrace_pages->next;
5613 ftrace_pages->next = start_pg;
5619 addr = ftrace_call_adjust(*p++);
5621 * Some architecture linkers will pad between
5622 * the different mcount_loc sections of different
5623 * object files to satisfy alignments.
5624 * Skip any NULL pointers.
5629 if (pg->index == pg->size) {
5630 /* We should have allocated enough */
5631 if (WARN_ON(!pg->next))
5636 rec = &pg->records[pg->index++];
5640 /* We should have used all pages */
5643 /* Assign the last page to ftrace_pages */
5647 * We only need to disable interrupts on start up
5648 * because we are modifying code that an interrupt
5649 * may execute, and the modification is not atomic.
5650 * But for modules, nothing runs the code we modify
5651 * until we are finished with it, and there's no
5652 * reason to cause large interrupt latencies while we do it.
5655 local_irq_save(flags);
5656 ftrace_update_code(mod, start_pg);
5658 local_irq_restore(flags);
5661 mutex_unlock(&ftrace_lock);
5666 struct ftrace_mod_func {
5667 struct list_head list;
5673 struct ftrace_mod_map {
5674 struct rcu_head rcu;
5675 struct list_head list;
5677 unsigned long start_addr;
5678 unsigned long end_addr;
5679 struct list_head funcs;
5680 unsigned int num_funcs;
5683 #ifdef CONFIG_MODULES
5685 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5687 static LIST_HEAD(ftrace_mod_maps);
5689 static int referenced_filters(struct dyn_ftrace *rec)
5691 struct ftrace_ops *ops;
5694 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5695 if (ops_references_rec(ops, rec))
5703 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5705 struct ftrace_func_entry *entry;
5706 struct dyn_ftrace *rec;
5709 if (ftrace_hash_empty(hash))
5712 for (i = 0; i < pg->index; i++) {
5713 rec = &pg->records[i];
5714 entry = __ftrace_lookup_ip(hash, rec->ip);
5716 * Do not allow this rec to match again.
5717 * Yeah, it may waste some memory, but will be removed
5718 * if/when the hash is modified again.
5725 /* Clear any records from hashs */
5726 static void clear_mod_from_hashes(struct ftrace_page *pg)
5728 struct trace_array *tr;
5730 mutex_lock(&trace_types_lock);
5731 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5732 if (!tr->ops || !tr->ops->func_hash)
5734 mutex_lock(&tr->ops->func_hash->regex_lock);
5735 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5736 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5737 mutex_unlock(&tr->ops->func_hash->regex_lock);
5739 mutex_unlock(&trace_types_lock);
5742 static void ftrace_free_mod_map(struct rcu_head *rcu)
5744 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5745 struct ftrace_mod_func *mod_func;
5746 struct ftrace_mod_func *n;
5748 /* All the contents of mod_map are now not visible to readers */
5749 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5750 kfree(mod_func->name);
5751 list_del(&mod_func->list);
5758 void ftrace_release_mod(struct module *mod)
5760 struct ftrace_mod_map *mod_map;
5761 struct ftrace_mod_map *n;
5762 struct dyn_ftrace *rec;
5763 struct ftrace_page **last_pg;
5764 struct ftrace_page *tmp_page = NULL;
5765 struct ftrace_page *pg;
5768 mutex_lock(&ftrace_lock);
5770 if (ftrace_disabled)
5773 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5774 if (mod_map->mod == mod) {
5775 list_del_rcu(&mod_map->list);
5776 call_rcu(&mod_map->rcu, ftrace_free_mod_map);
5782 * Each module has its own ftrace_pages, remove
5783 * them from the list.
5785 last_pg = &ftrace_pages_start;
5786 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5787 rec = &pg->records[0];
5788 if (within_module_core(rec->ip, mod) ||
5789 within_module_init(rec->ip, mod)) {
5791 * As core pages are first, the first
5792 * page should never be a module page.
5794 if (WARN_ON(pg == ftrace_pages_start))
5797 /* Check if we are deleting the last page */
5798 if (pg == ftrace_pages)
5799 ftrace_pages = next_to_ftrace_page(last_pg);
5801 ftrace_update_tot_cnt -= pg->index;
5802 *last_pg = pg->next;
5804 pg->next = tmp_page;
5807 last_pg = &pg->next;
5810 mutex_unlock(&ftrace_lock);
5812 for (pg = tmp_page; pg; pg = tmp_page) {
5814 /* Needs to be called outside of ftrace_lock */
5815 clear_mod_from_hashes(pg);
5817 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5818 free_pages((unsigned long)pg->records, order);
5819 tmp_page = pg->next;
5824 void ftrace_module_enable(struct module *mod)
5826 struct dyn_ftrace *rec;
5827 struct ftrace_page *pg;
5829 mutex_lock(&ftrace_lock);
5831 if (ftrace_disabled)
5835 * If the tracing is enabled, go ahead and enable the record.
5837 * The reason not to enable the record immediately is the
5838 * inherent check of ftrace_make_nop/ftrace_make_call for
5839 * correct previous instructions. Making first the NOP
5840 * conversion puts the module to the correct state, thus
5841 * passing the ftrace_make_call check.
5843 * We also delay this to after the module code already set the
5844 * text to read-only, as we now need to set it back to read-write
5845 * so that we can modify the text.
5847 if (ftrace_start_up)
5848 ftrace_arch_code_modify_prepare();
5850 do_for_each_ftrace_rec(pg, rec) {
5853 * do_for_each_ftrace_rec() is a double loop.
5854 * module text shares the pg. If a record is
5855 * not part of this module, then skip this pg,
5856 * which the "break" will do.
5858 if (!within_module_core(rec->ip, mod) &&
5859 !within_module_init(rec->ip, mod))
5865 * When adding a module, we need to check if tracers are
5866 * currently enabled and if they are, and can trace this record,
5867 * we need to enable the module functions as well as update the
5868 * reference counts for those function records.
5870 if (ftrace_start_up)
5871 cnt += referenced_filters(rec);
5873 /* This clears FTRACE_FL_DISABLED */
5876 if (ftrace_start_up && cnt) {
5877 int failed = __ftrace_replace_code(rec, 1);
5879 ftrace_bug(failed, rec);
5884 } while_for_each_ftrace_rec();
5887 if (ftrace_start_up)
5888 ftrace_arch_code_modify_post_process();
5891 mutex_unlock(&ftrace_lock);
5893 process_cached_mods(mod->name);
5896 void ftrace_module_init(struct module *mod)
5898 if (ftrace_disabled || !mod->num_ftrace_callsites)
5901 ftrace_process_locs(mod, mod->ftrace_callsites,
5902 mod->ftrace_callsites + mod->num_ftrace_callsites);
5905 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5906 struct dyn_ftrace *rec)
5908 struct ftrace_mod_func *mod_func;
5909 unsigned long symsize;
5910 unsigned long offset;
5911 char str[KSYM_SYMBOL_LEN];
5915 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5919 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5923 mod_func->name = kstrdup(str, GFP_KERNEL);
5924 if (!mod_func->name) {
5929 mod_func->ip = rec->ip - offset;
5930 mod_func->size = symsize;
5932 mod_map->num_funcs++;
5934 list_add_rcu(&mod_func->list, &mod_map->funcs);
5937 static struct ftrace_mod_map *
5938 allocate_ftrace_mod_map(struct module *mod,
5939 unsigned long start, unsigned long end)
5941 struct ftrace_mod_map *mod_map;
5943 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5948 mod_map->start_addr = start;
5949 mod_map->end_addr = end;
5950 mod_map->num_funcs = 0;
5952 INIT_LIST_HEAD_RCU(&mod_map->funcs);
5954 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5960 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5961 unsigned long addr, unsigned long *size,
5962 unsigned long *off, char *sym)
5964 struct ftrace_mod_func *found_func = NULL;
5965 struct ftrace_mod_func *mod_func;
5967 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5968 if (addr >= mod_func->ip &&
5969 addr < mod_func->ip + mod_func->size) {
5970 found_func = mod_func;
5977 *size = found_func->size;
5979 *off = addr - found_func->ip;
5981 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5983 return found_func->name;
5990 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5991 unsigned long *off, char **modname, char *sym)
5993 struct ftrace_mod_map *mod_map;
5994 const char *ret = NULL;
5996 /* mod_map is freed via call_rcu() */
5998 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5999 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
6002 *modname = mod_map->mod->name;
6011 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
6012 char *type, char *name,
6013 char *module_name, int *exported)
6015 struct ftrace_mod_map *mod_map;
6016 struct ftrace_mod_func *mod_func;
6019 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
6021 if (symnum >= mod_map->num_funcs) {
6022 symnum -= mod_map->num_funcs;
6026 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6032 *value = mod_func->ip;
6034 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
6035 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6048 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6049 struct dyn_ftrace *rec) { }
6050 static inline struct ftrace_mod_map *
6051 allocate_ftrace_mod_map(struct module *mod,
6052 unsigned long start, unsigned long end)
6056 #endif /* CONFIG_MODULES */
6058 struct ftrace_init_func {
6059 struct list_head list;
6063 /* Clear any init ips from hashes */
6065 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6067 struct ftrace_func_entry *entry;
6069 entry = ftrace_lookup_ip(hash, func->ip);
6071 * Do not allow this rec to match again.
6072 * Yeah, it may waste some memory, but will be removed
6073 * if/when the hash is modified again.
6080 clear_func_from_hashes(struct ftrace_init_func *func)
6082 struct trace_array *tr;
6084 mutex_lock(&trace_types_lock);
6085 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6086 if (!tr->ops || !tr->ops->func_hash)
6088 mutex_lock(&tr->ops->func_hash->regex_lock);
6089 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6090 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6091 mutex_unlock(&tr->ops->func_hash->regex_lock);
6093 mutex_unlock(&trace_types_lock);
6096 static void add_to_clear_hash_list(struct list_head *clear_list,
6097 struct dyn_ftrace *rec)
6099 struct ftrace_init_func *func;
6101 func = kmalloc(sizeof(*func), GFP_KERNEL);
6103 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6108 list_add(&func->list, clear_list);
6111 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6113 unsigned long start = (unsigned long)(start_ptr);
6114 unsigned long end = (unsigned long)(end_ptr);
6115 struct ftrace_page **last_pg = &ftrace_pages_start;
6116 struct ftrace_page *pg;
6117 struct dyn_ftrace *rec;
6118 struct dyn_ftrace key;
6119 struct ftrace_mod_map *mod_map = NULL;
6120 struct ftrace_init_func *func, *func_next;
6121 struct list_head clear_hash;
6124 INIT_LIST_HEAD(&clear_hash);
6127 key.flags = end; /* overload flags, as it is unsigned long */
6129 mutex_lock(&ftrace_lock);
6132 * If we are freeing module init memory, then check if
6133 * any tracer is active. If so, we need to save a mapping of
6134 * the module functions being freed with the address.
6136 if (mod && ftrace_ops_list != &ftrace_list_end)
6137 mod_map = allocate_ftrace_mod_map(mod, start, end);
6139 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6140 if (end < pg->records[0].ip ||
6141 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6144 rec = bsearch(&key, pg->records, pg->index,
6145 sizeof(struct dyn_ftrace),
6150 /* rec will be cleared from hashes after ftrace_lock unlock */
6151 add_to_clear_hash_list(&clear_hash, rec);
6154 save_ftrace_mod_rec(mod_map, rec);
6157 ftrace_update_tot_cnt--;
6159 *last_pg = pg->next;
6160 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6161 free_pages((unsigned long)pg->records, order);
6163 pg = container_of(last_pg, struct ftrace_page, next);
6168 memmove(rec, rec + 1,
6169 (pg->index - (rec - pg->records)) * sizeof(*rec));
6170 /* More than one function may be in this block */
6173 mutex_unlock(&ftrace_lock);
6175 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6176 clear_func_from_hashes(func);
6181 void __init ftrace_free_init_mem(void)
6183 void *start = (void *)(&__init_begin);
6184 void *end = (void *)(&__init_end);
6186 ftrace_free_mem(NULL, start, end);
6189 void __init ftrace_init(void)
6191 extern unsigned long __start_mcount_loc[];
6192 extern unsigned long __stop_mcount_loc[];
6193 unsigned long count, flags;
6196 local_irq_save(flags);
6197 ret = ftrace_dyn_arch_init();
6198 local_irq_restore(flags);
6202 count = __stop_mcount_loc - __start_mcount_loc;
6204 pr_info("ftrace: No functions to be traced?\n");
6208 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6209 count, count / ENTRIES_PER_PAGE + 1);
6211 last_ftrace_enabled = ftrace_enabled = 1;
6213 ret = ftrace_process_locs(NULL,
6217 set_ftrace_early_filters();
6221 ftrace_disabled = 1;
6224 /* Do nothing if arch does not support this */
6225 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6229 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6231 arch_ftrace_update_trampoline(ops);
6234 void ftrace_init_trace_array(struct trace_array *tr)
6236 INIT_LIST_HEAD(&tr->func_probes);
6237 INIT_LIST_HEAD(&tr->mod_trace);
6238 INIT_LIST_HEAD(&tr->mod_notrace);
6242 struct ftrace_ops global_ops = {
6243 .func = ftrace_stub,
6244 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6245 FTRACE_OPS_FL_INITIALIZED |
6249 static int __init ftrace_nodyn_init(void)
6254 core_initcall(ftrace_nodyn_init);
6256 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6257 static inline void ftrace_startup_enable(int command) { }
6258 static inline void ftrace_startup_all(int command) { }
6260 # define ftrace_startup_sysctl() do { } while (0)
6261 # define ftrace_shutdown_sysctl() do { } while (0)
6263 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6267 #endif /* CONFIG_DYNAMIC_FTRACE */
6269 __init void ftrace_init_global_array_ops(struct trace_array *tr)
6271 tr->ops = &global_ops;
6272 tr->ops->private = tr;
6273 ftrace_init_trace_array(tr);
6276 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6278 /* If we filter on pids, update to use the pid function */
6279 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6280 if (WARN_ON(tr->ops->func != ftrace_stub))
6281 printk("ftrace ops had %pS for function\n",
6284 tr->ops->func = func;
6285 tr->ops->private = tr;
6288 void ftrace_reset_array_ops(struct trace_array *tr)
6290 tr->ops->func = ftrace_stub;
6293 static nokprobe_inline void
6294 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6295 struct ftrace_ops *ignored, struct pt_regs *regs)
6297 struct ftrace_ops *op;
6300 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6305 * Some of the ops may be dynamically allocated,
6306 * they must be freed after a synchronize_rcu().
6308 preempt_disable_notrace();
6310 do_for_each_ftrace_op(op, ftrace_ops_list) {
6311 /* Stub functions don't need to be called nor tested */
6312 if (op->flags & FTRACE_OPS_FL_STUB)
6315 * Check the following for each ops before calling their func:
6316 * if RCU flag is set, then rcu_is_watching() must be true
6317 * if PER_CPU is set, then ftrace_function_local_disable()
6319 * Otherwise test if the ip matches the ops filter
6321 * If any of the above fails then the op->func() is not executed.
6323 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6324 ftrace_ops_test(op, ip, regs)) {
6325 if (FTRACE_WARN_ON(!op->func)) {
6326 pr_warn("op=%p %pS\n", op, op);
6329 op->func(ip, parent_ip, op, regs);
6331 } while_for_each_ftrace_op(op);
6333 preempt_enable_notrace();
6334 trace_clear_recursion(bit);
6338 * Some archs only support passing ip and parent_ip. Even though
6339 * the list function ignores the op parameter, we do not want any
6340 * C side effects, where a function is called without the caller
6341 * sending a third parameter.
6342 * Archs are to support both the regs and ftrace_ops at the same time.
6343 * If they support ftrace_ops, it is assumed they support regs.
6344 * If call backs want to use regs, they must either check for regs
6345 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6346 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6347 * An architecture can pass partial regs with ftrace_ops and still
6348 * set the ARCH_SUPPORTS_FTRACE_OPS.
6350 #if ARCH_SUPPORTS_FTRACE_OPS
6351 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6352 struct ftrace_ops *op, struct pt_regs *regs)
6354 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6356 NOKPROBE_SYMBOL(ftrace_ops_list_func);
6358 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6360 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6362 NOKPROBE_SYMBOL(ftrace_ops_no_ops);
6366 * If there's only one function registered but it does not support
6367 * recursion, needs RCU protection and/or requires per cpu handling, then
6368 * this function will be called by the mcount trampoline.
6370 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6371 struct ftrace_ops *op, struct pt_regs *regs)
6375 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6378 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6382 preempt_disable_notrace();
6384 op->func(ip, parent_ip, op, regs);
6386 preempt_enable_notrace();
6387 trace_clear_recursion(bit);
6389 NOKPROBE_SYMBOL(ftrace_ops_assist_func);
6392 * ftrace_ops_get_func - get the function a trampoline should call
6393 * @ops: the ops to get the function for
6395 * Normally the mcount trampoline will call the ops->func, but there
6396 * are times that it should not. For example, if the ops does not
6397 * have its own recursion protection, then it should call the
6398 * ftrace_ops_assist_func() instead.
6400 * Returns the function that the trampoline should call for @ops.
6402 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6405 * If the function does not handle recursion, needs to be RCU safe,
6406 * or does per cpu logic, then we need to call the assist handler.
6408 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6409 ops->flags & FTRACE_OPS_FL_RCU)
6410 return ftrace_ops_assist_func;
6416 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6417 struct task_struct *prev, struct task_struct *next)
6419 struct trace_array *tr = data;
6420 struct trace_pid_list *pid_list;
6422 pid_list = rcu_dereference_sched(tr->function_pids);
6424 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6425 trace_ignore_this_task(pid_list, next));
6429 ftrace_pid_follow_sched_process_fork(void *data,
6430 struct task_struct *self,
6431 struct task_struct *task)
6433 struct trace_pid_list *pid_list;
6434 struct trace_array *tr = data;
6436 pid_list = rcu_dereference_sched(tr->function_pids);
6437 trace_filter_add_remove_task(pid_list, self, task);
6441 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6443 struct trace_pid_list *pid_list;
6444 struct trace_array *tr = data;
6446 pid_list = rcu_dereference_sched(tr->function_pids);
6447 trace_filter_add_remove_task(pid_list, NULL, task);
6450 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6453 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6455 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6458 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6460 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6465 static void clear_ftrace_pids(struct trace_array *tr)
6467 struct trace_pid_list *pid_list;
6470 pid_list = rcu_dereference_protected(tr->function_pids,
6471 lockdep_is_held(&ftrace_lock));
6475 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6477 for_each_possible_cpu(cpu)
6478 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6480 rcu_assign_pointer(tr->function_pids, NULL);
6482 /* Wait till all users are no longer using pid filtering */
6485 trace_free_pid_list(pid_list);
6488 void ftrace_clear_pids(struct trace_array *tr)
6490 mutex_lock(&ftrace_lock);
6492 clear_ftrace_pids(tr);
6494 mutex_unlock(&ftrace_lock);
6497 static void ftrace_pid_reset(struct trace_array *tr)
6499 mutex_lock(&ftrace_lock);
6500 clear_ftrace_pids(tr);
6502 ftrace_update_pid_func();
6503 ftrace_startup_all(0);
6505 mutex_unlock(&ftrace_lock);
6508 /* Greater than any max PID */
6509 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6511 static void *fpid_start(struct seq_file *m, loff_t *pos)
6514 struct trace_pid_list *pid_list;
6515 struct trace_array *tr = m->private;
6517 mutex_lock(&ftrace_lock);
6518 rcu_read_lock_sched();
6520 pid_list = rcu_dereference_sched(tr->function_pids);
6523 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6525 return trace_pid_start(pid_list, pos);
6528 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6530 struct trace_array *tr = m->private;
6531 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6533 if (v == FTRACE_NO_PIDS)
6536 return trace_pid_next(pid_list, v, pos);
6539 static void fpid_stop(struct seq_file *m, void *p)
6542 rcu_read_unlock_sched();
6543 mutex_unlock(&ftrace_lock);
6546 static int fpid_show(struct seq_file *m, void *v)
6548 if (v == FTRACE_NO_PIDS) {
6549 seq_puts(m, "no pid\n");
6553 return trace_pid_show(m, v);
6556 static const struct seq_operations ftrace_pid_sops = {
6557 .start = fpid_start,
6564 ftrace_pid_open(struct inode *inode, struct file *file)
6566 struct trace_array *tr = inode->i_private;
6570 ret = tracing_check_open_get_tr(tr);
6574 if ((file->f_mode & FMODE_WRITE) &&
6575 (file->f_flags & O_TRUNC))
6576 ftrace_pid_reset(tr);
6578 ret = seq_open(file, &ftrace_pid_sops);
6580 trace_array_put(tr);
6582 m = file->private_data;
6583 /* copy tr over to seq ops */
6590 static void ignore_task_cpu(void *data)
6592 struct trace_array *tr = data;
6593 struct trace_pid_list *pid_list;
6596 * This function is called by on_each_cpu() while the
6597 * event_mutex is held.
6599 pid_list = rcu_dereference_protected(tr->function_pids,
6600 mutex_is_locked(&ftrace_lock));
6602 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6603 trace_ignore_this_task(pid_list, current));
6607 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6608 size_t cnt, loff_t *ppos)
6610 struct seq_file *m = filp->private_data;
6611 struct trace_array *tr = m->private;
6612 struct trace_pid_list *filtered_pids = NULL;
6613 struct trace_pid_list *pid_list;
6619 mutex_lock(&ftrace_lock);
6621 filtered_pids = rcu_dereference_protected(tr->function_pids,
6622 lockdep_is_held(&ftrace_lock));
6624 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6628 rcu_assign_pointer(tr->function_pids, pid_list);
6630 if (filtered_pids) {
6632 trace_free_pid_list(filtered_pids);
6633 } else if (pid_list) {
6634 /* Register a probe to set whether to ignore the tracing of a task */
6635 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6639 * Ignoring of pids is done at task switch. But we have to
6640 * check for those tasks that are currently running.
6641 * Always do this in case a pid was appended or removed.
6643 on_each_cpu(ignore_task_cpu, tr, 1);
6645 ftrace_update_pid_func();
6646 ftrace_startup_all(0);
6648 mutex_unlock(&ftrace_lock);
6657 ftrace_pid_release(struct inode *inode, struct file *file)
6659 struct trace_array *tr = inode->i_private;
6661 trace_array_put(tr);
6663 return seq_release(inode, file);
6666 static const struct file_operations ftrace_pid_fops = {
6667 .open = ftrace_pid_open,
6668 .write = ftrace_pid_write,
6670 .llseek = tracing_lseek,
6671 .release = ftrace_pid_release,
6674 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6676 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6677 tr, &ftrace_pid_fops);
6680 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6681 struct dentry *d_tracer)
6683 /* Only the top level directory has the dyn_tracefs and profile */
6684 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6686 ftrace_init_dyn_tracefs(d_tracer);
6687 ftrace_profile_tracefs(d_tracer);
6691 * ftrace_kill - kill ftrace
6693 * This function should be used by panic code. It stops ftrace
6694 * but in a not so nice way. If you need to simply kill ftrace
6695 * from a non-atomic section, use ftrace_kill.
6697 void ftrace_kill(void)
6699 ftrace_disabled = 1;
6701 ftrace_trace_function = ftrace_stub;
6705 * Test if ftrace is dead or not.
6707 int ftrace_is_dead(void)
6709 return ftrace_disabled;
6713 * register_ftrace_function - register a function for profiling
6714 * @ops - ops structure that holds the function for profiling.
6716 * Register a function to be called by all functions in the
6719 * Note: @ops->func and all the functions it calls must be labeled
6720 * with "notrace", otherwise it will go into a
6723 int register_ftrace_function(struct ftrace_ops *ops)
6727 ftrace_ops_init(ops);
6729 mutex_lock(&ftrace_lock);
6731 ret = ftrace_startup(ops, 0);
6733 mutex_unlock(&ftrace_lock);
6737 EXPORT_SYMBOL_GPL(register_ftrace_function);
6740 * unregister_ftrace_function - unregister a function for profiling.
6741 * @ops - ops structure that holds the function to unregister
6743 * Unregister a function that was added to be called by ftrace profiling.
6745 int unregister_ftrace_function(struct ftrace_ops *ops)
6749 mutex_lock(&ftrace_lock);
6750 ret = ftrace_shutdown(ops, 0);
6751 mutex_unlock(&ftrace_lock);
6755 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6758 ftrace_enable_sysctl(struct ctl_table *table, int write,
6759 void __user *buffer, size_t *lenp,
6764 mutex_lock(&ftrace_lock);
6766 if (unlikely(ftrace_disabled))
6769 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6771 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6774 last_ftrace_enabled = !!ftrace_enabled;
6776 if (ftrace_enabled) {
6778 /* we are starting ftrace again */
6779 if (rcu_dereference_protected(ftrace_ops_list,
6780 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6781 update_ftrace_function();
6783 ftrace_startup_sysctl();
6786 /* stopping ftrace calls (just send to ftrace_stub) */
6787 ftrace_trace_function = ftrace_stub;
6789 ftrace_shutdown_sysctl();
6793 mutex_unlock(&ftrace_lock);