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/seq_file.h>
22 #include <linux/tracefs.h>
23 #include <linux/hardirq.h>
24 #include <linux/kthread.h>
25 #include <linux/uaccess.h>
26 #include <linux/bsearch.h>
27 #include <linux/module.h>
28 #include <linux/ftrace.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/ctype.h>
32 #include <linux/sort.h>
33 #include <linux/list.h>
34 #include <linux/hash.h>
35 #include <linux/rcupdate.h>
36 #include <linux/kprobes.h>
37 #include <linux/memory.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 bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1630 struct ftrace_hash *hash;
1631 struct ftrace_hash *other_hash;
1632 struct ftrace_page *pg;
1633 struct dyn_ftrace *rec;
1634 bool update = false;
1638 /* Only update if the ops has been registered */
1639 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1643 * In the filter_hash case:
1644 * If the count is zero, we update all records.
1645 * Otherwise we just update the items in the hash.
1647 * In the notrace_hash case:
1648 * We enable the update in the hash.
1649 * As disabling notrace means enabling the tracing,
1650 * and enabling notrace means disabling, the inc variable
1654 hash = ops->func_hash->filter_hash;
1655 other_hash = ops->func_hash->notrace_hash;
1656 if (ftrace_hash_empty(hash))
1660 hash = ops->func_hash->notrace_hash;
1661 other_hash = ops->func_hash->filter_hash;
1663 * If the notrace hash has no items,
1664 * then there's nothing to do.
1666 if (ftrace_hash_empty(hash))
1670 do_for_each_ftrace_rec(pg, rec) {
1671 int in_other_hash = 0;
1675 if (rec->flags & FTRACE_FL_DISABLED)
1680 * Only the filter_hash affects all records.
1681 * Update if the record is not in the notrace hash.
1683 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1686 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1687 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1690 * If filter_hash is set, we want to match all functions
1691 * that are in the hash but not in the other hash.
1693 * If filter_hash is not set, then we are decrementing.
1694 * That means we match anything that is in the hash
1695 * and also in the other_hash. That is, we need to turn
1696 * off functions in the other hash because they are disabled
1699 if (filter_hash && in_hash && !in_other_hash)
1701 else if (!filter_hash && in_hash &&
1702 (in_other_hash || ftrace_hash_empty(other_hash)))
1710 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1714 * If there's only a single callback registered to a
1715 * function, and the ops has a trampoline registered
1716 * for it, then we can call it directly.
1718 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1719 rec->flags |= FTRACE_FL_TRAMP;
1722 * If we are adding another function callback
1723 * to this function, and the previous had a
1724 * custom trampoline in use, then we need to go
1725 * back to the default trampoline.
1727 rec->flags &= ~FTRACE_FL_TRAMP;
1730 * If any ops wants regs saved for this function
1731 * then all ops will get saved regs.
1733 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1734 rec->flags |= FTRACE_FL_REGS;
1736 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1741 * If the rec had REGS enabled and the ops that is
1742 * being removed had REGS set, then see if there is
1743 * still any ops for this record that wants regs.
1744 * If not, we can stop recording them.
1746 if (ftrace_rec_count(rec) > 0 &&
1747 rec->flags & FTRACE_FL_REGS &&
1748 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1749 if (!test_rec_ops_needs_regs(rec))
1750 rec->flags &= ~FTRACE_FL_REGS;
1754 * If the rec had TRAMP enabled, then it needs to
1755 * be cleared. As TRAMP can only be enabled iff
1756 * there is only a single ops attached to it.
1757 * In otherwords, always disable it on decrementing.
1758 * In the future, we may set it if rec count is
1759 * decremented to one, and the ops that is left
1762 rec->flags &= ~FTRACE_FL_TRAMP;
1765 * flags will be cleared in ftrace_check_record()
1766 * if rec count is zero.
1771 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1772 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1774 /* Shortcut, if we handled all records, we are done. */
1775 if (!all && count == hash->count)
1777 } while_for_each_ftrace_rec();
1782 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1785 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1788 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1791 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1794 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1795 int filter_hash, int inc)
1797 struct ftrace_ops *op;
1799 __ftrace_hash_rec_update(ops, filter_hash, inc);
1801 if (ops->func_hash != &global_ops.local_hash)
1805 * If the ops shares the global_ops hash, then we need to update
1806 * all ops that are enabled and use this hash.
1808 do_for_each_ftrace_op(op, ftrace_ops_list) {
1812 if (op->func_hash == &global_ops.local_hash)
1813 __ftrace_hash_rec_update(op, filter_hash, inc);
1814 } while_for_each_ftrace_op(op);
1817 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1820 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1823 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1826 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1830 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1831 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1832 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1833 * Note that old_hash and new_hash has below meanings
1834 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1835 * - If the hash is EMPTY_HASH, it hits nothing
1836 * - Anything else hits the recs which match the hash entries.
1838 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1839 struct ftrace_hash *old_hash,
1840 struct ftrace_hash *new_hash)
1842 struct ftrace_page *pg;
1843 struct dyn_ftrace *rec, *end = NULL;
1846 /* Only update if the ops has been registered */
1847 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1850 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1854 * Since the IPMODIFY is a very address sensitive action, we do not
1855 * allow ftrace_ops to set all functions to new hash.
1857 if (!new_hash || !old_hash)
1860 /* Update rec->flags */
1861 do_for_each_ftrace_rec(pg, rec) {
1863 if (rec->flags & FTRACE_FL_DISABLED)
1866 /* We need to update only differences of filter_hash */
1867 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1868 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1869 if (in_old == in_new)
1873 /* New entries must ensure no others are using it */
1874 if (rec->flags & FTRACE_FL_IPMODIFY)
1876 rec->flags |= FTRACE_FL_IPMODIFY;
1877 } else /* Removed entry */
1878 rec->flags &= ~FTRACE_FL_IPMODIFY;
1879 } while_for_each_ftrace_rec();
1886 /* Roll back what we did above */
1887 do_for_each_ftrace_rec(pg, rec) {
1889 if (rec->flags & FTRACE_FL_DISABLED)
1895 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1896 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1897 if (in_old == in_new)
1901 rec->flags &= ~FTRACE_FL_IPMODIFY;
1903 rec->flags |= FTRACE_FL_IPMODIFY;
1904 } while_for_each_ftrace_rec();
1910 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1912 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1914 if (ftrace_hash_empty(hash))
1917 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1920 /* Disabling always succeeds */
1921 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1923 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1925 if (ftrace_hash_empty(hash))
1928 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1931 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1932 struct ftrace_hash *new_hash)
1934 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1936 if (ftrace_hash_empty(old_hash))
1939 if (ftrace_hash_empty(new_hash))
1942 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1945 static void print_ip_ins(const char *fmt, const unsigned char *p)
1949 printk(KERN_CONT "%s", fmt);
1951 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1952 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1955 static struct ftrace_ops *
1956 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1957 static struct ftrace_ops *
1958 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1960 enum ftrace_bug_type ftrace_bug_type;
1961 const void *ftrace_expected;
1963 static void print_bug_type(void)
1965 switch (ftrace_bug_type) {
1966 case FTRACE_BUG_UNKNOWN:
1968 case FTRACE_BUG_INIT:
1969 pr_info("Initializing ftrace call sites\n");
1971 case FTRACE_BUG_NOP:
1972 pr_info("Setting ftrace call site to NOP\n");
1974 case FTRACE_BUG_CALL:
1975 pr_info("Setting ftrace call site to call ftrace function\n");
1977 case FTRACE_BUG_UPDATE:
1978 pr_info("Updating ftrace call site to call a different ftrace function\n");
1984 * ftrace_bug - report and shutdown function tracer
1985 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1986 * @rec: The record that failed
1988 * The arch code that enables or disables the function tracing
1989 * can call ftrace_bug() when it has detected a problem in
1990 * modifying the code. @failed should be one of either:
1991 * EFAULT - if the problem happens on reading the @ip address
1992 * EINVAL - if what is read at @ip is not what was expected
1993 * EPERM - if the problem happens on writing to the @ip address
1995 void ftrace_bug(int failed, struct dyn_ftrace *rec)
1997 unsigned long ip = rec ? rec->ip : 0;
2001 FTRACE_WARN_ON_ONCE(1);
2002 pr_info("ftrace faulted on modifying ");
2006 FTRACE_WARN_ON_ONCE(1);
2007 pr_info("ftrace failed to modify ");
2009 print_ip_ins(" actual: ", (unsigned char *)ip);
2011 if (ftrace_expected) {
2012 print_ip_ins(" expected: ", ftrace_expected);
2017 FTRACE_WARN_ON_ONCE(1);
2018 pr_info("ftrace faulted on writing ");
2022 FTRACE_WARN_ON_ONCE(1);
2023 pr_info("ftrace faulted on unknown error ");
2028 struct ftrace_ops *ops = NULL;
2030 pr_info("ftrace record flags: %lx\n", rec->flags);
2031 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2032 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2033 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2034 ops = ftrace_find_tramp_ops_any(rec);
2037 pr_cont("\ttramp: %pS (%pS)",
2038 (void *)ops->trampoline,
2040 ops = ftrace_find_tramp_ops_next(rec, ops);
2043 pr_cont("\ttramp: ERROR!");
2046 ip = ftrace_get_addr_curr(rec);
2047 pr_cont("\n expected tramp: %lx\n", ip);
2051 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2053 unsigned long flag = 0UL;
2055 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2057 if (rec->flags & FTRACE_FL_DISABLED)
2058 return FTRACE_UPDATE_IGNORE;
2061 * If we are updating calls:
2063 * If the record has a ref count, then we need to enable it
2064 * because someone is using it.
2066 * Otherwise we make sure its disabled.
2068 * If we are disabling calls, then disable all records that
2071 if (enable && ftrace_rec_count(rec))
2072 flag = FTRACE_FL_ENABLED;
2075 * If enabling and the REGS flag does not match the REGS_EN, or
2076 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2077 * this record. Set flags to fail the compare against ENABLED.
2080 if (!(rec->flags & FTRACE_FL_REGS) !=
2081 !(rec->flags & FTRACE_FL_REGS_EN))
2082 flag |= FTRACE_FL_REGS;
2084 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2085 !(rec->flags & FTRACE_FL_TRAMP_EN))
2086 flag |= FTRACE_FL_TRAMP;
2089 /* If the state of this record hasn't changed, then do nothing */
2090 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2091 return FTRACE_UPDATE_IGNORE;
2094 /* Save off if rec is being enabled (for return value) */
2095 flag ^= rec->flags & FTRACE_FL_ENABLED;
2098 rec->flags |= FTRACE_FL_ENABLED;
2099 if (flag & FTRACE_FL_REGS) {
2100 if (rec->flags & FTRACE_FL_REGS)
2101 rec->flags |= FTRACE_FL_REGS_EN;
2103 rec->flags &= ~FTRACE_FL_REGS_EN;
2105 if (flag & FTRACE_FL_TRAMP) {
2106 if (rec->flags & FTRACE_FL_TRAMP)
2107 rec->flags |= FTRACE_FL_TRAMP_EN;
2109 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2114 * If this record is being updated from a nop, then
2115 * return UPDATE_MAKE_CALL.
2117 * return UPDATE_MODIFY_CALL to tell the caller to convert
2118 * from the save regs, to a non-save regs function or
2119 * vice versa, or from a trampoline call.
2121 if (flag & FTRACE_FL_ENABLED) {
2122 ftrace_bug_type = FTRACE_BUG_CALL;
2123 return FTRACE_UPDATE_MAKE_CALL;
2126 ftrace_bug_type = FTRACE_BUG_UPDATE;
2127 return FTRACE_UPDATE_MODIFY_CALL;
2131 /* If there's no more users, clear all flags */
2132 if (!ftrace_rec_count(rec))
2136 * Just disable the record, but keep the ops TRAMP
2137 * and REGS states. The _EN flags must be disabled though.
2139 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2143 ftrace_bug_type = FTRACE_BUG_NOP;
2144 return FTRACE_UPDATE_MAKE_NOP;
2148 * ftrace_update_record, set a record that now is tracing or not
2149 * @rec: the record to update
2150 * @enable: set to 1 if the record is tracing, zero to force disable
2152 * The records that represent all functions that can be traced need
2153 * to be updated when tracing has been enabled.
2155 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2157 return ftrace_check_record(rec, enable, 1);
2161 * ftrace_test_record, check if the record has been enabled or not
2162 * @rec: the record to test
2163 * @enable: set to 1 to check if enabled, 0 if it is disabled
2165 * The arch code may need to test if a record is already set to
2166 * tracing to determine how to modify the function code that it
2169 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2171 return ftrace_check_record(rec, enable, 0);
2174 static struct ftrace_ops *
2175 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2177 struct ftrace_ops *op;
2178 unsigned long ip = rec->ip;
2180 do_for_each_ftrace_op(op, ftrace_ops_list) {
2182 if (!op->trampoline)
2185 if (hash_contains_ip(ip, op->func_hash))
2187 } while_for_each_ftrace_op(op);
2192 static struct ftrace_ops *
2193 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2194 struct ftrace_ops *op)
2196 unsigned long ip = rec->ip;
2198 while_for_each_ftrace_op(op) {
2200 if (!op->trampoline)
2203 if (hash_contains_ip(ip, op->func_hash))
2210 static struct ftrace_ops *
2211 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2213 struct ftrace_ops *op;
2214 unsigned long ip = rec->ip;
2217 * Need to check removed ops first.
2218 * If they are being removed, and this rec has a tramp,
2219 * and this rec is in the ops list, then it would be the
2220 * one with the tramp.
2223 if (hash_contains_ip(ip, &removed_ops->old_hash))
2228 * Need to find the current trampoline for a rec.
2229 * Now, a trampoline is only attached to a rec if there
2230 * was a single 'ops' attached to it. But this can be called
2231 * when we are adding another op to the rec or removing the
2232 * current one. Thus, if the op is being added, we can
2233 * ignore it because it hasn't attached itself to the rec
2236 * If an ops is being modified (hooking to different functions)
2237 * then we don't care about the new functions that are being
2238 * added, just the old ones (that are probably being removed).
2240 * If we are adding an ops to a function that already is using
2241 * a trampoline, it needs to be removed (trampolines are only
2242 * for single ops connected), then an ops that is not being
2243 * modified also needs to be checked.
2245 do_for_each_ftrace_op(op, ftrace_ops_list) {
2247 if (!op->trampoline)
2251 * If the ops is being added, it hasn't gotten to
2252 * the point to be removed from this tree yet.
2254 if (op->flags & FTRACE_OPS_FL_ADDING)
2259 * If the ops is being modified and is in the old
2260 * hash, then it is probably being removed from this
2263 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2264 hash_contains_ip(ip, &op->old_hash))
2267 * If the ops is not being added or modified, and it's
2268 * in its normal filter hash, then this must be the one
2271 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2272 hash_contains_ip(ip, op->func_hash))
2275 } while_for_each_ftrace_op(op);
2280 static struct ftrace_ops *
2281 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2283 struct ftrace_ops *op;
2284 unsigned long ip = rec->ip;
2286 do_for_each_ftrace_op(op, ftrace_ops_list) {
2287 /* pass rec in as regs to have non-NULL val */
2288 if (hash_contains_ip(ip, op->func_hash))
2290 } while_for_each_ftrace_op(op);
2296 * ftrace_get_addr_new - Get the call address to set to
2297 * @rec: The ftrace record descriptor
2299 * If the record has the FTRACE_FL_REGS set, that means that it
2300 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2301 * is not not set, then it wants to convert to the normal callback.
2303 * Returns the address of the trampoline to set to
2305 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2307 struct ftrace_ops *ops;
2309 /* Trampolines take precedence over regs */
2310 if (rec->flags & FTRACE_FL_TRAMP) {
2311 ops = ftrace_find_tramp_ops_new(rec);
2312 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2313 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2314 (void *)rec->ip, (void *)rec->ip, rec->flags);
2315 /* Ftrace is shutting down, return anything */
2316 return (unsigned long)FTRACE_ADDR;
2318 return ops->trampoline;
2321 if (rec->flags & FTRACE_FL_REGS)
2322 return (unsigned long)FTRACE_REGS_ADDR;
2324 return (unsigned long)FTRACE_ADDR;
2328 * ftrace_get_addr_curr - Get the call address that is already there
2329 * @rec: The ftrace record descriptor
2331 * The FTRACE_FL_REGS_EN is set when the record already points to
2332 * a function that saves all the regs. Basically the '_EN' version
2333 * represents the current state of the function.
2335 * Returns the address of the trampoline that is currently being called
2337 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2339 struct ftrace_ops *ops;
2341 /* Trampolines take precedence over regs */
2342 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2343 ops = ftrace_find_tramp_ops_curr(rec);
2344 if (FTRACE_WARN_ON(!ops)) {
2345 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2346 (void *)rec->ip, (void *)rec->ip);
2347 /* Ftrace is shutting down, return anything */
2348 return (unsigned long)FTRACE_ADDR;
2350 return ops->trampoline;
2353 if (rec->flags & FTRACE_FL_REGS_EN)
2354 return (unsigned long)FTRACE_REGS_ADDR;
2356 return (unsigned long)FTRACE_ADDR;
2360 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2362 unsigned long ftrace_old_addr;
2363 unsigned long ftrace_addr;
2366 ftrace_addr = ftrace_get_addr_new(rec);
2368 /* This needs to be done before we call ftrace_update_record */
2369 ftrace_old_addr = ftrace_get_addr_curr(rec);
2371 ret = ftrace_update_record(rec, enable);
2373 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2376 case FTRACE_UPDATE_IGNORE:
2379 case FTRACE_UPDATE_MAKE_CALL:
2380 ftrace_bug_type = FTRACE_BUG_CALL;
2381 return ftrace_make_call(rec, ftrace_addr);
2383 case FTRACE_UPDATE_MAKE_NOP:
2384 ftrace_bug_type = FTRACE_BUG_NOP;
2385 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2387 case FTRACE_UPDATE_MODIFY_CALL:
2388 ftrace_bug_type = FTRACE_BUG_UPDATE;
2389 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2392 return -1; /* unknown ftrace bug */
2395 void __weak ftrace_replace_code(int mod_flags)
2397 struct dyn_ftrace *rec;
2398 struct ftrace_page *pg;
2399 int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2400 int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2403 if (unlikely(ftrace_disabled))
2406 do_for_each_ftrace_rec(pg, rec) {
2408 if (rec->flags & FTRACE_FL_DISABLED)
2411 failed = __ftrace_replace_code(rec, enable);
2413 ftrace_bug(failed, rec);
2414 /* Stop processing */
2419 } while_for_each_ftrace_rec();
2422 struct ftrace_rec_iter {
2423 struct ftrace_page *pg;
2428 * ftrace_rec_iter_start, start up iterating over traced functions
2430 * Returns an iterator handle that is used to iterate over all
2431 * the records that represent address locations where functions
2434 * May return NULL if no records are available.
2436 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2439 * We only use a single iterator.
2440 * Protected by the ftrace_lock mutex.
2442 static struct ftrace_rec_iter ftrace_rec_iter;
2443 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2445 iter->pg = ftrace_pages_start;
2448 /* Could have empty pages */
2449 while (iter->pg && !iter->pg->index)
2450 iter->pg = iter->pg->next;
2459 * ftrace_rec_iter_next, get the next record to process.
2460 * @iter: The handle to the iterator.
2462 * Returns the next iterator after the given iterator @iter.
2464 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2468 if (iter->index >= iter->pg->index) {
2469 iter->pg = iter->pg->next;
2472 /* Could have empty pages */
2473 while (iter->pg && !iter->pg->index)
2474 iter->pg = iter->pg->next;
2484 * ftrace_rec_iter_record, get the record at the iterator location
2485 * @iter: The current iterator location
2487 * Returns the record that the current @iter is at.
2489 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2491 return &iter->pg->records[iter->index];
2495 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2499 if (unlikely(ftrace_disabled))
2502 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2504 ftrace_bug_type = FTRACE_BUG_INIT;
2505 ftrace_bug(ret, rec);
2512 * archs can override this function if they must do something
2513 * before the modifying code is performed.
2515 int __weak ftrace_arch_code_modify_prepare(void)
2521 * archs can override this function if they must do something
2522 * after the modifying code is performed.
2524 int __weak ftrace_arch_code_modify_post_process(void)
2529 void ftrace_modify_all_code(int command)
2531 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2535 if (command & FTRACE_MAY_SLEEP)
2536 mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2539 * If the ftrace_caller calls a ftrace_ops func directly,
2540 * we need to make sure that it only traces functions it
2541 * expects to trace. When doing the switch of functions,
2542 * we need to update to the ftrace_ops_list_func first
2543 * before the transition between old and new calls are set,
2544 * as the ftrace_ops_list_func will check the ops hashes
2545 * to make sure the ops are having the right functions
2549 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2550 if (FTRACE_WARN_ON(err))
2554 if (command & FTRACE_UPDATE_CALLS)
2555 ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
2556 else if (command & FTRACE_DISABLE_CALLS)
2557 ftrace_replace_code(mod_flags);
2559 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2560 function_trace_op = set_function_trace_op;
2562 /* If irqs are disabled, we are in stop machine */
2563 if (!irqs_disabled())
2564 smp_call_function(ftrace_sync_ipi, NULL, 1);
2565 err = ftrace_update_ftrace_func(ftrace_trace_function);
2566 if (FTRACE_WARN_ON(err))
2570 if (command & FTRACE_START_FUNC_RET)
2571 err = ftrace_enable_ftrace_graph_caller();
2572 else if (command & FTRACE_STOP_FUNC_RET)
2573 err = ftrace_disable_ftrace_graph_caller();
2574 FTRACE_WARN_ON(err);
2577 static int __ftrace_modify_code(void *data)
2579 int *command = data;
2581 ftrace_modify_all_code(*command);
2587 * ftrace_run_stop_machine, go back to the stop machine method
2588 * @command: The command to tell ftrace what to do
2590 * If an arch needs to fall back to the stop machine method, the
2591 * it can call this function.
2593 void ftrace_run_stop_machine(int command)
2595 stop_machine(__ftrace_modify_code, &command, NULL);
2599 * arch_ftrace_update_code, modify the code to trace or not trace
2600 * @command: The command that needs to be done
2602 * Archs can override this function if it does not need to
2603 * run stop_machine() to modify code.
2605 void __weak arch_ftrace_update_code(int command)
2607 ftrace_run_stop_machine(command);
2610 static void ftrace_run_update_code(int command)
2614 mutex_lock(&text_mutex);
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 mutex_unlock(&text_mutex);
2636 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2637 struct ftrace_ops_hash *old_hash)
2639 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2640 ops->old_hash.filter_hash = old_hash->filter_hash;
2641 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2642 ftrace_run_update_code(command);
2643 ops->old_hash.filter_hash = NULL;
2644 ops->old_hash.notrace_hash = NULL;
2645 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2648 static ftrace_func_t saved_ftrace_func;
2649 static int ftrace_start_up;
2651 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2655 static void ftrace_startup_enable(int command)
2657 if (saved_ftrace_func != ftrace_trace_function) {
2658 saved_ftrace_func = ftrace_trace_function;
2659 command |= FTRACE_UPDATE_TRACE_FUNC;
2662 if (!command || !ftrace_enabled)
2665 ftrace_run_update_code(command);
2668 static void ftrace_startup_all(int command)
2670 update_all_ops = true;
2671 ftrace_startup_enable(command);
2672 update_all_ops = false;
2675 int ftrace_startup(struct ftrace_ops *ops, int command)
2679 if (unlikely(ftrace_disabled))
2682 ret = __register_ftrace_function(ops);
2689 * Note that ftrace probes uses this to start up
2690 * and modify functions it will probe. But we still
2691 * set the ADDING flag for modification, as probes
2692 * do not have trampolines. If they add them in the
2693 * future, then the probes will need to distinguish
2694 * between adding and updating probes.
2696 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2698 ret = ftrace_hash_ipmodify_enable(ops);
2700 /* Rollback registration process */
2701 __unregister_ftrace_function(ops);
2703 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2707 if (ftrace_hash_rec_enable(ops, 1))
2708 command |= FTRACE_UPDATE_CALLS;
2710 ftrace_startup_enable(command);
2712 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2717 int ftrace_shutdown(struct ftrace_ops *ops, int command)
2721 if (unlikely(ftrace_disabled))
2724 ret = __unregister_ftrace_function(ops);
2730 * Just warn in case of unbalance, no need to kill ftrace, it's not
2731 * critical but the ftrace_call callers may be never nopped again after
2732 * further ftrace uses.
2734 WARN_ON_ONCE(ftrace_start_up < 0);
2736 /* Disabling ipmodify never fails */
2737 ftrace_hash_ipmodify_disable(ops);
2739 if (ftrace_hash_rec_disable(ops, 1))
2740 command |= FTRACE_UPDATE_CALLS;
2742 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2744 if (saved_ftrace_func != ftrace_trace_function) {
2745 saved_ftrace_func = ftrace_trace_function;
2746 command |= FTRACE_UPDATE_TRACE_FUNC;
2749 if (!command || !ftrace_enabled) {
2751 * If these are dynamic or per_cpu ops, they still
2752 * need their data freed. Since, function tracing is
2753 * not currently active, we can just free them
2754 * without synchronizing all CPUs.
2756 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2763 * If the ops uses a trampoline, then it needs to be
2764 * tested first on update.
2766 ops->flags |= FTRACE_OPS_FL_REMOVING;
2769 /* The trampoline logic checks the old hashes */
2770 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2771 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2773 ftrace_run_update_code(command);
2776 * If there's no more ops registered with ftrace, run a
2777 * sanity check to make sure all rec flags are cleared.
2779 if (rcu_dereference_protected(ftrace_ops_list,
2780 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2781 struct ftrace_page *pg;
2782 struct dyn_ftrace *rec;
2784 do_for_each_ftrace_rec(pg, rec) {
2785 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2786 pr_warn(" %pS flags:%lx\n",
2787 (void *)rec->ip, rec->flags);
2788 } while_for_each_ftrace_rec();
2791 ops->old_hash.filter_hash = NULL;
2792 ops->old_hash.notrace_hash = NULL;
2795 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2798 * Dynamic ops may be freed, we must make sure that all
2799 * callers are done before leaving this function.
2800 * The same goes for freeing the per_cpu data of the per_cpu
2803 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2805 * We need to do a hard force of sched synchronization.
2806 * This is because we use preempt_disable() to do RCU, but
2807 * the function tracers can be called where RCU is not watching
2808 * (like before user_exit()). We can not rely on the RCU
2809 * infrastructure to do the synchronization, thus we must do it
2812 schedule_on_each_cpu(ftrace_sync);
2815 * When the kernel is preeptive, tasks can be preempted
2816 * while on a ftrace trampoline. Just scheduling a task on
2817 * a CPU is not good enough to flush them. Calling
2818 * synchornize_rcu_tasks() will wait for those tasks to
2819 * execute and either schedule voluntarily or enter user space.
2821 if (IS_ENABLED(CONFIG_PREEMPT))
2822 synchronize_rcu_tasks();
2825 arch_ftrace_trampoline_free(ops);
2831 static void ftrace_startup_sysctl(void)
2835 if (unlikely(ftrace_disabled))
2838 /* Force update next time */
2839 saved_ftrace_func = NULL;
2840 /* ftrace_start_up is true if we want ftrace running */
2841 if (ftrace_start_up) {
2842 command = FTRACE_UPDATE_CALLS;
2843 if (ftrace_graph_active)
2844 command |= FTRACE_START_FUNC_RET;
2845 ftrace_startup_enable(command);
2849 static void ftrace_shutdown_sysctl(void)
2853 if (unlikely(ftrace_disabled))
2856 /* ftrace_start_up is true if ftrace is running */
2857 if (ftrace_start_up) {
2858 command = FTRACE_DISABLE_CALLS;
2859 if (ftrace_graph_active)
2860 command |= FTRACE_STOP_FUNC_RET;
2861 ftrace_run_update_code(command);
2865 static u64 ftrace_update_time;
2866 unsigned long ftrace_update_tot_cnt;
2868 static inline int ops_traces_mod(struct ftrace_ops *ops)
2871 * Filter_hash being empty will default to trace module.
2872 * But notrace hash requires a test of individual module functions.
2874 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2875 ftrace_hash_empty(ops->func_hash->notrace_hash);
2879 * Check if the current ops references the record.
2881 * If the ops traces all functions, then it was already accounted for.
2882 * If the ops does not trace the current record function, skip it.
2883 * If the ops ignores the function via notrace filter, skip it.
2886 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2888 /* If ops isn't enabled, ignore it */
2889 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2892 /* If ops traces all then it includes this function */
2893 if (ops_traces_mod(ops))
2896 /* The function must be in the filter */
2897 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2898 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2901 /* If in notrace hash, we ignore it too */
2902 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2908 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2910 struct ftrace_page *pg;
2911 struct dyn_ftrace *p;
2913 unsigned long update_cnt = 0;
2914 unsigned long rec_flags = 0;
2917 start = ftrace_now(raw_smp_processor_id());
2920 * When a module is loaded, this function is called to convert
2921 * the calls to mcount in its text to nops, and also to create
2922 * an entry in the ftrace data. Now, if ftrace is activated
2923 * after this call, but before the module sets its text to
2924 * read-only, the modification of enabling ftrace can fail if
2925 * the read-only is done while ftrace is converting the calls.
2926 * To prevent this, the module's records are set as disabled
2927 * and will be enabled after the call to set the module's text
2931 rec_flags |= FTRACE_FL_DISABLED;
2933 for (pg = new_pgs; pg; pg = pg->next) {
2935 for (i = 0; i < pg->index; i++) {
2937 /* If something went wrong, bail without enabling anything */
2938 if (unlikely(ftrace_disabled))
2941 p = &pg->records[i];
2942 p->flags = rec_flags;
2945 * Do the initial record conversion from mcount jump
2946 * to the NOP instructions.
2948 if (!__is_defined(CC_USING_NOP_MCOUNT) &&
2949 !ftrace_code_disable(mod, p))
2956 stop = ftrace_now(raw_smp_processor_id());
2957 ftrace_update_time = stop - start;
2958 ftrace_update_tot_cnt += update_cnt;
2963 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2968 if (WARN_ON(!count))
2971 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2974 * We want to fill as much as possible. No more than a page
2977 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2981 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2984 /* if we can't allocate this size, try something smaller */
2991 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3000 static struct ftrace_page *
3001 ftrace_allocate_pages(unsigned long num_to_init)
3003 struct ftrace_page *start_pg;
3004 struct ftrace_page *pg;
3011 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3016 * Try to allocate as much as possible in one continues
3017 * location that fills in all of the space. We want to
3018 * waste as little space as possible.
3021 cnt = ftrace_allocate_records(pg, num_to_init);
3029 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3041 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3042 free_pages((unsigned long)pg->records, order);
3043 start_pg = pg->next;
3047 pr_info("ftrace: FAILED to allocate memory for functions\n");
3051 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3053 struct ftrace_iterator {
3057 struct ftrace_page *pg;
3058 struct dyn_ftrace *func;
3059 struct ftrace_func_probe *probe;
3060 struct ftrace_func_entry *probe_entry;
3061 struct trace_parser parser;
3062 struct ftrace_hash *hash;
3063 struct ftrace_ops *ops;
3064 struct trace_array *tr;
3065 struct list_head *mod_list;
3072 t_probe_next(struct seq_file *m, loff_t *pos)
3074 struct ftrace_iterator *iter = m->private;
3075 struct trace_array *tr = iter->ops->private;
3076 struct list_head *func_probes;
3077 struct ftrace_hash *hash;
3078 struct list_head *next;
3079 struct hlist_node *hnd = NULL;
3080 struct hlist_head *hhd;
3089 func_probes = &tr->func_probes;
3090 if (list_empty(func_probes))
3094 next = func_probes->next;
3095 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3098 if (iter->probe_entry)
3099 hnd = &iter->probe_entry->hlist;
3101 hash = iter->probe->ops.func_hash->filter_hash;
3102 size = 1 << hash->size_bits;
3105 if (iter->pidx >= size) {
3106 if (iter->probe->list.next == func_probes)
3108 next = iter->probe->list.next;
3109 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3110 hash = iter->probe->ops.func_hash->filter_hash;
3111 size = 1 << hash->size_bits;
3115 hhd = &hash->buckets[iter->pidx];
3117 if (hlist_empty(hhd)) {
3133 if (WARN_ON_ONCE(!hnd))
3136 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3141 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3143 struct ftrace_iterator *iter = m->private;
3147 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3150 if (iter->mod_pos > *pos)
3154 iter->probe_entry = NULL;
3156 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3157 p = t_probe_next(m, &l);
3164 /* Only set this if we have an item */
3165 iter->flags |= FTRACE_ITER_PROBE;
3171 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3173 struct ftrace_func_entry *probe_entry;
3174 struct ftrace_probe_ops *probe_ops;
3175 struct ftrace_func_probe *probe;
3177 probe = iter->probe;
3178 probe_entry = iter->probe_entry;
3180 if (WARN_ON_ONCE(!probe || !probe_entry))
3183 probe_ops = probe->probe_ops;
3185 if (probe_ops->print)
3186 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3188 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3189 (void *)probe_ops->func);
3195 t_mod_next(struct seq_file *m, loff_t *pos)
3197 struct ftrace_iterator *iter = m->private;
3198 struct trace_array *tr = iter->tr;
3203 iter->mod_list = iter->mod_list->next;
3205 if (iter->mod_list == &tr->mod_trace ||
3206 iter->mod_list == &tr->mod_notrace) {
3207 iter->flags &= ~FTRACE_ITER_MOD;
3211 iter->mod_pos = *pos;
3216 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3218 struct ftrace_iterator *iter = m->private;
3222 if (iter->func_pos > *pos)
3225 iter->mod_pos = iter->func_pos;
3227 /* probes are only available if tr is set */
3231 for (l = 0; l <= (*pos - iter->func_pos); ) {
3232 p = t_mod_next(m, &l);
3237 iter->flags &= ~FTRACE_ITER_MOD;
3238 return t_probe_start(m, pos);
3241 /* Only set this if we have an item */
3242 iter->flags |= FTRACE_ITER_MOD;
3248 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3250 struct ftrace_mod_load *ftrace_mod;
3251 struct trace_array *tr = iter->tr;
3253 if (WARN_ON_ONCE(!iter->mod_list) ||
3254 iter->mod_list == &tr->mod_trace ||
3255 iter->mod_list == &tr->mod_notrace)
3258 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3260 if (ftrace_mod->func)
3261 seq_printf(m, "%s", ftrace_mod->func);
3265 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3271 t_func_next(struct seq_file *m, loff_t *pos)
3273 struct ftrace_iterator *iter = m->private;
3274 struct dyn_ftrace *rec = NULL;
3279 if (iter->idx >= iter->pg->index) {
3280 if (iter->pg->next) {
3281 iter->pg = iter->pg->next;
3286 rec = &iter->pg->records[iter->idx++];
3287 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3288 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3290 ((iter->flags & FTRACE_ITER_ENABLED) &&
3291 !(rec->flags & FTRACE_FL_ENABLED))) {
3301 iter->pos = iter->func_pos = *pos;
3308 t_next(struct seq_file *m, void *v, loff_t *pos)
3310 struct ftrace_iterator *iter = m->private;
3311 loff_t l = *pos; /* t_probe_start() must use original pos */
3314 if (unlikely(ftrace_disabled))
3317 if (iter->flags & FTRACE_ITER_PROBE)
3318 return t_probe_next(m, pos);
3320 if (iter->flags & FTRACE_ITER_MOD)
3321 return t_mod_next(m, pos);
3323 if (iter->flags & FTRACE_ITER_PRINTALL) {
3324 /* next must increment pos, and t_probe_start does not */
3326 return t_mod_start(m, &l);
3329 ret = t_func_next(m, pos);
3332 return t_mod_start(m, &l);
3337 static void reset_iter_read(struct ftrace_iterator *iter)
3341 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3344 static void *t_start(struct seq_file *m, loff_t *pos)
3346 struct ftrace_iterator *iter = m->private;
3350 mutex_lock(&ftrace_lock);
3352 if (unlikely(ftrace_disabled))
3356 * If an lseek was done, then reset and start from beginning.
3358 if (*pos < iter->pos)
3359 reset_iter_read(iter);
3362 * For set_ftrace_filter reading, if we have the filter
3363 * off, we can short cut and just print out that all
3364 * functions are enabled.
3366 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3367 ftrace_hash_empty(iter->hash)) {
3368 iter->func_pos = 1; /* Account for the message */
3370 return t_mod_start(m, pos);
3371 iter->flags |= FTRACE_ITER_PRINTALL;
3372 /* reset in case of seek/pread */
3373 iter->flags &= ~FTRACE_ITER_PROBE;
3377 if (iter->flags & FTRACE_ITER_MOD)
3378 return t_mod_start(m, pos);
3381 * Unfortunately, we need to restart at ftrace_pages_start
3382 * every time we let go of the ftrace_mutex. This is because
3383 * those pointers can change without the lock.
3385 iter->pg = ftrace_pages_start;
3387 for (l = 0; l <= *pos; ) {
3388 p = t_func_next(m, &l);
3394 return t_mod_start(m, pos);
3399 static void t_stop(struct seq_file *m, void *p)
3401 mutex_unlock(&ftrace_lock);
3405 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3410 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3411 struct dyn_ftrace *rec)
3415 ptr = arch_ftrace_trampoline_func(ops, rec);
3417 seq_printf(m, " ->%pS", ptr);
3420 static int t_show(struct seq_file *m, void *v)
3422 struct ftrace_iterator *iter = m->private;
3423 struct dyn_ftrace *rec;
3425 if (iter->flags & FTRACE_ITER_PROBE)
3426 return t_probe_show(m, iter);
3428 if (iter->flags & FTRACE_ITER_MOD)
3429 return t_mod_show(m, iter);
3431 if (iter->flags & FTRACE_ITER_PRINTALL) {
3432 if (iter->flags & FTRACE_ITER_NOTRACE)
3433 seq_puts(m, "#### no functions disabled ####\n");
3435 seq_puts(m, "#### all functions enabled ####\n");
3444 seq_printf(m, "%ps", (void *)rec->ip);
3445 if (iter->flags & FTRACE_ITER_ENABLED) {
3446 struct ftrace_ops *ops;
3448 seq_printf(m, " (%ld)%s%s",
3449 ftrace_rec_count(rec),
3450 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3451 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3452 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3453 ops = ftrace_find_tramp_ops_any(rec);
3456 seq_printf(m, "\ttramp: %pS (%pS)",
3457 (void *)ops->trampoline,
3459 add_trampoline_func(m, ops, rec);
3460 ops = ftrace_find_tramp_ops_next(rec, ops);
3463 seq_puts(m, "\ttramp: ERROR!");
3465 add_trampoline_func(m, NULL, rec);
3474 static const struct seq_operations show_ftrace_seq_ops = {
3482 ftrace_avail_open(struct inode *inode, struct file *file)
3484 struct ftrace_iterator *iter;
3486 if (unlikely(ftrace_disabled))
3489 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3493 iter->pg = ftrace_pages_start;
3494 iter->ops = &global_ops;
3500 ftrace_enabled_open(struct inode *inode, struct file *file)
3502 struct ftrace_iterator *iter;
3504 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3508 iter->pg = ftrace_pages_start;
3509 iter->flags = FTRACE_ITER_ENABLED;
3510 iter->ops = &global_ops;
3516 * ftrace_regex_open - initialize function tracer filter files
3517 * @ops: The ftrace_ops that hold the hash filters
3518 * @flag: The type of filter to process
3519 * @inode: The inode, usually passed in to your open routine
3520 * @file: The file, usually passed in to your open routine
3522 * ftrace_regex_open() initializes the filter files for the
3523 * @ops. Depending on @flag it may process the filter hash or
3524 * the notrace hash of @ops. With this called from the open
3525 * routine, you can use ftrace_filter_write() for the write
3526 * routine if @flag has FTRACE_ITER_FILTER set, or
3527 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3528 * tracing_lseek() should be used as the lseek routine, and
3529 * release must call ftrace_regex_release().
3532 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3533 struct inode *inode, struct file *file)
3535 struct ftrace_iterator *iter;
3536 struct ftrace_hash *hash;
3537 struct list_head *mod_head;
3538 struct trace_array *tr = ops->private;
3541 ftrace_ops_init(ops);
3543 if (unlikely(ftrace_disabled))
3546 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3550 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3559 mutex_lock(&ops->func_hash->regex_lock);
3561 if (flag & FTRACE_ITER_NOTRACE) {
3562 hash = ops->func_hash->notrace_hash;
3563 mod_head = tr ? &tr->mod_notrace : NULL;
3565 hash = ops->func_hash->filter_hash;
3566 mod_head = tr ? &tr->mod_trace : NULL;
3569 iter->mod_list = mod_head;
3571 if (file->f_mode & FMODE_WRITE) {
3572 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3574 if (file->f_flags & O_TRUNC) {
3575 iter->hash = alloc_ftrace_hash(size_bits);
3576 clear_ftrace_mod_list(mod_head);
3578 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3582 trace_parser_put(&iter->parser);
3590 if (file->f_mode & FMODE_READ) {
3591 iter->pg = ftrace_pages_start;
3593 ret = seq_open(file, &show_ftrace_seq_ops);
3595 struct seq_file *m = file->private_data;
3599 free_ftrace_hash(iter->hash);
3600 trace_parser_put(&iter->parser);
3604 file->private_data = iter;
3607 mutex_unlock(&ops->func_hash->regex_lock);
3613 ftrace_filter_open(struct inode *inode, struct file *file)
3615 struct ftrace_ops *ops = inode->i_private;
3617 return ftrace_regex_open(ops,
3618 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3623 ftrace_notrace_open(struct inode *inode, struct file *file)
3625 struct ftrace_ops *ops = inode->i_private;
3627 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3631 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3632 struct ftrace_glob {
3639 * If symbols in an architecture don't correspond exactly to the user-visible
3640 * name of what they represent, it is possible to define this function to
3641 * perform the necessary adjustments.
3643 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3648 static int ftrace_match(char *str, struct ftrace_glob *g)
3653 str = arch_ftrace_match_adjust(str, g->search);
3657 if (strcmp(str, g->search) == 0)
3660 case MATCH_FRONT_ONLY:
3661 if (strncmp(str, g->search, g->len) == 0)
3664 case MATCH_MIDDLE_ONLY:
3665 if (strstr(str, g->search))
3668 case MATCH_END_ONLY:
3670 if (slen >= g->len &&
3671 memcmp(str + slen - g->len, g->search, g->len) == 0)
3675 if (glob_match(g->search, str))
3684 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3686 struct ftrace_func_entry *entry;
3689 entry = ftrace_lookup_ip(hash, rec->ip);
3691 /* Do nothing if it doesn't exist */
3695 free_hash_entry(hash, entry);
3697 /* Do nothing if it exists */
3701 ret = add_hash_entry(hash, rec->ip);
3707 add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
3710 long index = simple_strtoul(func_g->search, NULL, 0);
3711 struct ftrace_page *pg;
3712 struct dyn_ftrace *rec;
3714 /* The index starts at 1 */
3718 do_for_each_ftrace_rec(pg, rec) {
3719 if (pg->index <= index) {
3721 /* this is a double loop, break goes to the next page */
3724 rec = &pg->records[index];
3725 enter_record(hash, rec, clear_filter);
3727 } while_for_each_ftrace_rec();
3732 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3733 struct ftrace_glob *mod_g, int exclude_mod)
3735 char str[KSYM_SYMBOL_LEN];
3738 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3741 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3743 /* blank module name to match all modules */
3745 /* blank module globbing: modname xor exclude_mod */
3746 if (!exclude_mod != !modname)
3752 * exclude_mod is set to trace everything but the given
3753 * module. If it is set and the module matches, then
3754 * return 0. If it is not set, and the module doesn't match
3755 * also return 0. Otherwise, check the function to see if
3758 if (!mod_matches == !exclude_mod)
3761 /* blank search means to match all funcs in the mod */
3766 return ftrace_match(str, func_g);
3770 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3772 struct ftrace_page *pg;
3773 struct dyn_ftrace *rec;
3774 struct ftrace_glob func_g = { .type = MATCH_FULL };
3775 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3776 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3777 int exclude_mod = 0;
3780 int clear_filter = 0;
3783 func_g.type = filter_parse_regex(func, len, &func_g.search,
3785 func_g.len = strlen(func_g.search);
3789 mod_g.type = filter_parse_regex(mod, strlen(mod),
3790 &mod_g.search, &exclude_mod);
3791 mod_g.len = strlen(mod_g.search);
3794 mutex_lock(&ftrace_lock);
3796 if (unlikely(ftrace_disabled))
3799 if (func_g.type == MATCH_INDEX) {
3800 found = add_rec_by_index(hash, &func_g, clear_filter);
3804 do_for_each_ftrace_rec(pg, rec) {
3806 if (rec->flags & FTRACE_FL_DISABLED)
3809 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3810 ret = enter_record(hash, rec, clear_filter);
3817 } while_for_each_ftrace_rec();
3819 mutex_unlock(&ftrace_lock);
3825 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3827 return match_records(hash, buff, len, NULL);
3830 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3831 struct ftrace_ops_hash *old_hash)
3833 struct ftrace_ops *op;
3835 if (!ftrace_enabled)
3838 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3839 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3844 * If this is the shared global_ops filter, then we need to
3845 * check if there is another ops that shares it, is enabled.
3846 * If so, we still need to run the modify code.
3848 if (ops->func_hash != &global_ops.local_hash)
3851 do_for_each_ftrace_op(op, ftrace_ops_list) {
3852 if (op->func_hash == &global_ops.local_hash &&
3853 op->flags & FTRACE_OPS_FL_ENABLED) {
3854 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3855 /* Only need to do this once */
3858 } while_for_each_ftrace_op(op);
3861 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3862 struct ftrace_hash **orig_hash,
3863 struct ftrace_hash *hash,
3866 struct ftrace_ops_hash old_hash_ops;
3867 struct ftrace_hash *old_hash;
3870 old_hash = *orig_hash;
3871 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3872 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3873 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3875 ftrace_ops_update_code(ops, &old_hash_ops);
3876 free_ftrace_hash_rcu(old_hash);
3881 static bool module_exists(const char *module)
3883 /* All modules have the symbol __this_module */
3884 static const char this_mod[] = "__this_module";
3885 char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
3889 n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
3891 if (n > sizeof(modname) - 1)
3894 val = module_kallsyms_lookup_name(modname);
3898 static int cache_mod(struct trace_array *tr,
3899 const char *func, char *module, int enable)
3901 struct ftrace_mod_load *ftrace_mod, *n;
3902 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3905 mutex_lock(&ftrace_lock);
3907 /* We do not cache inverse filters */
3908 if (func[0] == '!') {
3912 /* Look to remove this hash */
3913 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3914 if (strcmp(ftrace_mod->module, module) != 0)
3917 /* no func matches all */
3918 if (strcmp(func, "*") == 0 ||
3919 (ftrace_mod->func &&
3920 strcmp(ftrace_mod->func, func) == 0)) {
3922 free_ftrace_mod(ftrace_mod);
3930 /* We only care about modules that have not been loaded yet */
3931 if (module_exists(module))
3934 /* Save this string off, and execute it when the module is loaded */
3935 ret = ftrace_add_mod(tr, func, module, enable);
3937 mutex_unlock(&ftrace_lock);
3943 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3944 int reset, int enable);
3946 #ifdef CONFIG_MODULES
3947 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3948 char *mod, bool enable)
3950 struct ftrace_mod_load *ftrace_mod, *n;
3951 struct ftrace_hash **orig_hash, *new_hash;
3952 LIST_HEAD(process_mods);
3956 mutex_lock(&ops->func_hash->regex_lock);
3959 orig_hash = &ops->func_hash->filter_hash;
3961 orig_hash = &ops->func_hash->notrace_hash;
3963 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3966 goto out; /* warn? */
3968 mutex_lock(&ftrace_lock);
3970 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3972 if (strcmp(ftrace_mod->module, mod) != 0)
3975 if (ftrace_mod->func)
3976 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
3978 func = kstrdup("*", GFP_KERNEL);
3980 if (!func) /* warn? */
3983 list_del(&ftrace_mod->list);
3984 list_add(&ftrace_mod->list, &process_mods);
3986 /* Use the newly allocated func, as it may be "*" */
3987 kfree(ftrace_mod->func);
3988 ftrace_mod->func = func;
3991 mutex_unlock(&ftrace_lock);
3993 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
3995 func = ftrace_mod->func;
3997 /* Grabs ftrace_lock, which is why we have this extra step */
3998 match_records(new_hash, func, strlen(func), mod);
3999 free_ftrace_mod(ftrace_mod);
4002 if (enable && list_empty(head))
4003 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4005 mutex_lock(&ftrace_lock);
4007 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4009 mutex_unlock(&ftrace_lock);
4012 mutex_unlock(&ops->func_hash->regex_lock);
4014 free_ftrace_hash(new_hash);
4017 static void process_cached_mods(const char *mod_name)
4019 struct trace_array *tr;
4022 mod = kstrdup(mod_name, GFP_KERNEL);
4026 mutex_lock(&trace_types_lock);
4027 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4028 if (!list_empty(&tr->mod_trace))
4029 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4030 if (!list_empty(&tr->mod_notrace))
4031 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4033 mutex_unlock(&trace_types_lock);
4040 * We register the module command as a template to show others how
4041 * to register the a command as well.
4045 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4046 char *func_orig, char *cmd, char *module, int enable)
4051 /* match_records() modifies func, and we need the original */
4052 func = kstrdup(func_orig, GFP_KERNEL);
4057 * cmd == 'mod' because we only registered this func
4058 * for the 'mod' ftrace_func_command.
4059 * But if you register one func with multiple commands,
4060 * you can tell which command was used by the cmd
4063 ret = match_records(hash, func, strlen(func), module);
4067 return cache_mod(tr, func_orig, module, enable);
4073 static struct ftrace_func_command ftrace_mod_cmd = {
4075 .func = ftrace_mod_callback,
4078 static int __init ftrace_mod_cmd_init(void)
4080 return register_ftrace_command(&ftrace_mod_cmd);
4082 core_initcall(ftrace_mod_cmd_init);
4084 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4085 struct ftrace_ops *op, struct pt_regs *pt_regs)
4087 struct ftrace_probe_ops *probe_ops;
4088 struct ftrace_func_probe *probe;
4090 probe = container_of(op, struct ftrace_func_probe, ops);
4091 probe_ops = probe->probe_ops;
4094 * Disable preemption for these calls to prevent a RCU grace
4095 * period. This syncs the hash iteration and freeing of items
4096 * on the hash. rcu_read_lock is too dangerous here.
4098 preempt_disable_notrace();
4099 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4100 preempt_enable_notrace();
4103 struct ftrace_func_map {
4104 struct ftrace_func_entry entry;
4108 struct ftrace_func_mapper {
4109 struct ftrace_hash hash;
4113 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4115 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4117 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4119 struct ftrace_hash *hash;
4122 * The mapper is simply a ftrace_hash, but since the entries
4123 * in the hash are not ftrace_func_entry type, we define it
4124 * as a separate structure.
4126 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4127 return (struct ftrace_func_mapper *)hash;
4131 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4132 * @mapper: The mapper that has the ip maps
4133 * @ip: the instruction pointer to find the data for
4135 * Returns the data mapped to @ip if found otherwise NULL. The return
4136 * is actually the address of the mapper data pointer. The address is
4137 * returned for use cases where the data is no bigger than a long, and
4138 * the user can use the data pointer as its data instead of having to
4139 * allocate more memory for the reference.
4141 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4144 struct ftrace_func_entry *entry;
4145 struct ftrace_func_map *map;
4147 entry = ftrace_lookup_ip(&mapper->hash, ip);
4151 map = (struct ftrace_func_map *)entry;
4156 * ftrace_func_mapper_add_ip - Map some data to an ip
4157 * @mapper: The mapper that has the ip maps
4158 * @ip: The instruction pointer address to map @data to
4159 * @data: The data to map to @ip
4161 * Returns 0 on succes otherwise an error.
4163 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4164 unsigned long ip, void *data)
4166 struct ftrace_func_entry *entry;
4167 struct ftrace_func_map *map;
4169 entry = ftrace_lookup_ip(&mapper->hash, ip);
4173 map = kmalloc(sizeof(*map), GFP_KERNEL);
4180 __add_hash_entry(&mapper->hash, &map->entry);
4186 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4187 * @mapper: The mapper that has the ip maps
4188 * @ip: The instruction pointer address to remove the data from
4190 * Returns the data if it is found, otherwise NULL.
4191 * Note, if the data pointer is used as the data itself, (see
4192 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4193 * if the data pointer was set to zero.
4195 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4198 struct ftrace_func_entry *entry;
4199 struct ftrace_func_map *map;
4202 entry = ftrace_lookup_ip(&mapper->hash, ip);
4206 map = (struct ftrace_func_map *)entry;
4209 remove_hash_entry(&mapper->hash, entry);
4216 * free_ftrace_func_mapper - free a mapping of ips and data
4217 * @mapper: The mapper that has the ip maps
4218 * @free_func: A function to be called on each data item.
4220 * This is used to free the function mapper. The @free_func is optional
4221 * and can be used if the data needs to be freed as well.
4223 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4224 ftrace_mapper_func free_func)
4226 struct ftrace_func_entry *entry;
4227 struct ftrace_func_map *map;
4228 struct hlist_head *hhd;
4234 if (free_func && mapper->hash.count) {
4235 size = 1 << mapper->hash.size_bits;
4236 for (i = 0; i < size; i++) {
4237 hhd = &mapper->hash.buckets[i];
4238 hlist_for_each_entry(entry, hhd, hlist) {
4239 map = (struct ftrace_func_map *)entry;
4244 free_ftrace_hash(&mapper->hash);
4247 static void release_probe(struct ftrace_func_probe *probe)
4249 struct ftrace_probe_ops *probe_ops;
4251 mutex_lock(&ftrace_lock);
4253 WARN_ON(probe->ref <= 0);
4255 /* Subtract the ref that was used to protect this instance */
4259 probe_ops = probe->probe_ops;
4261 * Sending zero as ip tells probe_ops to free
4262 * the probe->data itself
4264 if (probe_ops->free)
4265 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4266 list_del(&probe->list);
4269 mutex_unlock(&ftrace_lock);
4272 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4275 * Add one ref to keep it from being freed when releasing the
4276 * ftrace_lock mutex.
4282 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4283 struct ftrace_probe_ops *probe_ops,
4286 struct ftrace_func_entry *entry;
4287 struct ftrace_func_probe *probe;
4288 struct ftrace_hash **orig_hash;
4289 struct ftrace_hash *old_hash;
4290 struct ftrace_hash *hash;
4299 /* We do not support '!' for function probes */
4300 if (WARN_ON(glob[0] == '!'))
4304 mutex_lock(&ftrace_lock);
4305 /* Check if the probe_ops is already registered */
4306 list_for_each_entry(probe, &tr->func_probes, list) {
4307 if (probe->probe_ops == probe_ops)
4310 if (&probe->list == &tr->func_probes) {
4311 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4313 mutex_unlock(&ftrace_lock);
4316 probe->probe_ops = probe_ops;
4317 probe->ops.func = function_trace_probe_call;
4319 ftrace_ops_init(&probe->ops);
4320 list_add(&probe->list, &tr->func_probes);
4323 acquire_probe_locked(probe);
4325 mutex_unlock(&ftrace_lock);
4327 mutex_lock(&probe->ops.func_hash->regex_lock);
4329 orig_hash = &probe->ops.func_hash->filter_hash;
4330 old_hash = *orig_hash;
4331 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4333 ret = ftrace_match_records(hash, glob, strlen(glob));
4335 /* Nothing found? */
4342 size = 1 << hash->size_bits;
4343 for (i = 0; i < size; i++) {
4344 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4345 if (ftrace_lookup_ip(old_hash, entry->ip))
4348 * The caller might want to do something special
4349 * for each function we find. We call the callback
4350 * to give the caller an opportunity to do so.
4352 if (probe_ops->init) {
4353 ret = probe_ops->init(probe_ops, tr,
4357 if (probe_ops->free && count)
4358 probe_ops->free(probe_ops, tr,
4368 mutex_lock(&ftrace_lock);
4371 /* Nothing was added? */
4376 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4381 /* One ref for each new function traced */
4382 probe->ref += count;
4384 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4385 ret = ftrace_startup(&probe->ops, 0);
4388 mutex_unlock(&ftrace_lock);
4393 mutex_unlock(&probe->ops.func_hash->regex_lock);
4394 free_ftrace_hash(hash);
4396 release_probe(probe);
4401 if (!probe_ops->free || !count)
4404 /* Failed to do the move, need to call the free functions */
4405 for (i = 0; i < size; i++) {
4406 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4407 if (ftrace_lookup_ip(old_hash, entry->ip))
4409 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4416 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4417 struct ftrace_probe_ops *probe_ops)
4419 struct ftrace_ops_hash old_hash_ops;
4420 struct ftrace_func_entry *entry;
4421 struct ftrace_func_probe *probe;
4422 struct ftrace_glob func_g;
4423 struct ftrace_hash **orig_hash;
4424 struct ftrace_hash *old_hash;
4425 struct ftrace_hash *hash = NULL;
4426 struct hlist_node *tmp;
4427 struct hlist_head hhd;
4428 char str[KSYM_SYMBOL_LEN];
4430 int i, ret = -ENODEV;
4433 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4434 func_g.search = NULL;
4438 func_g.type = filter_parse_regex(glob, strlen(glob),
4439 &func_g.search, ¬);
4440 func_g.len = strlen(func_g.search);
4442 /* we do not support '!' for function probes */
4447 mutex_lock(&ftrace_lock);
4448 /* Check if the probe_ops is already registered */
4449 list_for_each_entry(probe, &tr->func_probes, list) {
4450 if (probe->probe_ops == probe_ops)
4453 if (&probe->list == &tr->func_probes)
4454 goto err_unlock_ftrace;
4457 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4458 goto err_unlock_ftrace;
4460 acquire_probe_locked(probe);
4462 mutex_unlock(&ftrace_lock);
4464 mutex_lock(&probe->ops.func_hash->regex_lock);
4466 orig_hash = &probe->ops.func_hash->filter_hash;
4467 old_hash = *orig_hash;
4469 if (ftrace_hash_empty(old_hash))
4472 old_hash_ops.filter_hash = old_hash;
4473 /* Probes only have filters */
4474 old_hash_ops.notrace_hash = NULL;
4477 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4481 INIT_HLIST_HEAD(&hhd);
4483 size = 1 << hash->size_bits;
4484 for (i = 0; i < size; i++) {
4485 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4487 if (func_g.search) {
4488 kallsyms_lookup(entry->ip, NULL, NULL,
4490 if (!ftrace_match(str, &func_g))
4494 remove_hash_entry(hash, entry);
4495 hlist_add_head(&entry->hlist, &hhd);
4499 /* Nothing found? */
4505 mutex_lock(&ftrace_lock);
4507 WARN_ON(probe->ref < count);
4509 probe->ref -= count;
4511 if (ftrace_hash_empty(hash))
4512 ftrace_shutdown(&probe->ops, 0);
4514 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4517 /* still need to update the function call sites */
4518 if (ftrace_enabled && !ftrace_hash_empty(hash))
4519 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4523 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4524 hlist_del(&entry->hlist);
4525 if (probe_ops->free)
4526 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4529 mutex_unlock(&ftrace_lock);
4532 mutex_unlock(&probe->ops.func_hash->regex_lock);
4533 free_ftrace_hash(hash);
4535 release_probe(probe);
4540 mutex_unlock(&ftrace_lock);
4544 void clear_ftrace_function_probes(struct trace_array *tr)
4546 struct ftrace_func_probe *probe, *n;
4548 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4549 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4552 static LIST_HEAD(ftrace_commands);
4553 static DEFINE_MUTEX(ftrace_cmd_mutex);
4556 * Currently we only register ftrace commands from __init, so mark this
4559 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4561 struct ftrace_func_command *p;
4564 mutex_lock(&ftrace_cmd_mutex);
4565 list_for_each_entry(p, &ftrace_commands, list) {
4566 if (strcmp(cmd->name, p->name) == 0) {
4571 list_add(&cmd->list, &ftrace_commands);
4573 mutex_unlock(&ftrace_cmd_mutex);
4579 * Currently we only unregister ftrace commands from __init, so mark
4582 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4584 struct ftrace_func_command *p, *n;
4587 mutex_lock(&ftrace_cmd_mutex);
4588 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4589 if (strcmp(cmd->name, p->name) == 0) {
4591 list_del_init(&p->list);
4596 mutex_unlock(&ftrace_cmd_mutex);
4601 static int ftrace_process_regex(struct ftrace_iterator *iter,
4602 char *buff, int len, int enable)
4604 struct ftrace_hash *hash = iter->hash;
4605 struct trace_array *tr = iter->ops->private;
4606 char *func, *command, *next = buff;
4607 struct ftrace_func_command *p;
4610 func = strsep(&next, ":");
4613 ret = ftrace_match_records(hash, func, len);
4623 command = strsep(&next, ":");
4625 mutex_lock(&ftrace_cmd_mutex);
4626 list_for_each_entry(p, &ftrace_commands, list) {
4627 if (strcmp(p->name, command) == 0) {
4628 ret = p->func(tr, hash, func, command, next, enable);
4633 mutex_unlock(&ftrace_cmd_mutex);
4639 ftrace_regex_write(struct file *file, const char __user *ubuf,
4640 size_t cnt, loff_t *ppos, int enable)
4642 struct ftrace_iterator *iter;
4643 struct trace_parser *parser;
4649 if (file->f_mode & FMODE_READ) {
4650 struct seq_file *m = file->private_data;
4653 iter = file->private_data;
4655 if (unlikely(ftrace_disabled))
4658 /* iter->hash is a local copy, so we don't need regex_lock */
4660 parser = &iter->parser;
4661 read = trace_get_user(parser, ubuf, cnt, ppos);
4663 if (read >= 0 && trace_parser_loaded(parser) &&
4664 !trace_parser_cont(parser)) {
4665 ret = ftrace_process_regex(iter, parser->buffer,
4666 parser->idx, enable);
4667 trace_parser_clear(parser);
4678 ftrace_filter_write(struct file *file, const char __user *ubuf,
4679 size_t cnt, loff_t *ppos)
4681 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4685 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4686 size_t cnt, loff_t *ppos)
4688 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4692 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4694 struct ftrace_func_entry *entry;
4696 if (!ftrace_location(ip))
4700 entry = ftrace_lookup_ip(hash, ip);
4703 free_hash_entry(hash, entry);
4707 return add_hash_entry(hash, ip);
4711 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4712 unsigned long ip, int remove, int reset, int enable)
4714 struct ftrace_hash **orig_hash;
4715 struct ftrace_hash *hash;
4718 if (unlikely(ftrace_disabled))
4721 mutex_lock(&ops->func_hash->regex_lock);
4724 orig_hash = &ops->func_hash->filter_hash;
4726 orig_hash = &ops->func_hash->notrace_hash;
4729 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4731 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4735 goto out_regex_unlock;
4738 if (buf && !ftrace_match_records(hash, buf, len)) {
4740 goto out_regex_unlock;
4743 ret = ftrace_match_addr(hash, ip, remove);
4745 goto out_regex_unlock;
4748 mutex_lock(&ftrace_lock);
4749 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4750 mutex_unlock(&ftrace_lock);
4753 mutex_unlock(&ops->func_hash->regex_lock);
4755 free_ftrace_hash(hash);
4760 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4761 int reset, int enable)
4763 return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);
4767 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4768 * @ops - the ops to set the filter with
4769 * @ip - the address to add to or remove from the filter.
4770 * @remove - non zero to remove the ip from the filter
4771 * @reset - non zero to reset all filters before applying this filter.
4773 * Filters denote which functions should be enabled when tracing is enabled
4774 * If @ip is NULL, it failes to update filter.
4776 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4777 int remove, int reset)
4779 ftrace_ops_init(ops);
4780 return ftrace_set_addr(ops, ip, remove, reset, 1);
4782 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4785 * ftrace_ops_set_global_filter - setup ops to use global filters
4786 * @ops - the ops which will use the global filters
4788 * ftrace users who need global function trace filtering should call this.
4789 * It can set the global filter only if ops were not initialized before.
4791 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4793 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4796 ftrace_ops_init(ops);
4797 ops->func_hash = &global_ops.local_hash;
4799 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4802 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4803 int reset, int enable)
4805 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4809 * ftrace_set_filter - set a function to filter on in ftrace
4810 * @ops - the ops to set the filter with
4811 * @buf - the string that holds the function filter text.
4812 * @len - the length of the string.
4813 * @reset - non zero to reset all filters before applying this filter.
4815 * Filters denote which functions should be enabled when tracing is enabled.
4816 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4818 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4821 ftrace_ops_init(ops);
4822 return ftrace_set_regex(ops, buf, len, reset, 1);
4824 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4827 * ftrace_set_notrace - set a function to not trace in ftrace
4828 * @ops - the ops to set the notrace filter with
4829 * @buf - the string that holds the function notrace text.
4830 * @len - the length of the string.
4831 * @reset - non zero to reset all filters before applying this filter.
4833 * Notrace Filters denote which functions should not be enabled when tracing
4834 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4837 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4840 ftrace_ops_init(ops);
4841 return ftrace_set_regex(ops, buf, len, reset, 0);
4843 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4845 * ftrace_set_global_filter - set a function to filter on with global tracers
4846 * @buf - the string that holds the function filter text.
4847 * @len - the length of the string.
4848 * @reset - non zero to reset all filters before applying this filter.
4850 * Filters denote which functions should be enabled when tracing is enabled.
4851 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4853 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4855 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4857 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4860 * ftrace_set_global_notrace - set a function to not trace with global tracers
4861 * @buf - the string that holds the function notrace text.
4862 * @len - the length of the string.
4863 * @reset - non zero to reset all filters before applying this filter.
4865 * Notrace Filters denote which functions should not be enabled when tracing
4866 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4869 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4871 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4873 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4876 * command line interface to allow users to set filters on boot up.
4878 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4879 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4880 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4882 /* Used by function selftest to not test if filter is set */
4883 bool ftrace_filter_param __initdata;
4885 static int __init set_ftrace_notrace(char *str)
4887 ftrace_filter_param = true;
4888 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4891 __setup("ftrace_notrace=", set_ftrace_notrace);
4893 static int __init set_ftrace_filter(char *str)
4895 ftrace_filter_param = true;
4896 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4899 __setup("ftrace_filter=", set_ftrace_filter);
4901 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4902 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4903 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4904 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4906 static int __init set_graph_function(char *str)
4908 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4911 __setup("ftrace_graph_filter=", set_graph_function);
4913 static int __init set_graph_notrace_function(char *str)
4915 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4918 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4920 static int __init set_graph_max_depth_function(char *str)
4924 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4927 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4929 static void __init set_ftrace_early_graph(char *buf, int enable)
4933 struct ftrace_hash *hash;
4935 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4940 func = strsep(&buf, ",");
4941 /* we allow only one expression at a time */
4942 ret = ftrace_graph_set_hash(hash, func);
4944 printk(KERN_DEBUG "ftrace: function %s not "
4945 "traceable\n", func);
4949 ftrace_graph_hash = hash;
4951 ftrace_graph_notrace_hash = hash;
4953 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4956 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4960 ftrace_ops_init(ops);
4963 func = strsep(&buf, ",");
4964 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4968 static void __init set_ftrace_early_filters(void)
4970 if (ftrace_filter_buf[0])
4971 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4972 if (ftrace_notrace_buf[0])
4973 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4974 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4975 if (ftrace_graph_buf[0])
4976 set_ftrace_early_graph(ftrace_graph_buf, 1);
4977 if (ftrace_graph_notrace_buf[0])
4978 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4979 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4982 int ftrace_regex_release(struct inode *inode, struct file *file)
4984 struct seq_file *m = (struct seq_file *)file->private_data;
4985 struct ftrace_iterator *iter;
4986 struct ftrace_hash **orig_hash;
4987 struct trace_parser *parser;
4991 if (file->f_mode & FMODE_READ) {
4993 seq_release(inode, file);
4995 iter = file->private_data;
4997 parser = &iter->parser;
4998 if (trace_parser_loaded(parser)) {
4999 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5002 trace_parser_put(parser);
5004 mutex_lock(&iter->ops->func_hash->regex_lock);
5006 if (file->f_mode & FMODE_WRITE) {
5007 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5010 orig_hash = &iter->ops->func_hash->filter_hash;
5011 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5012 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5014 orig_hash = &iter->ops->func_hash->notrace_hash;
5016 mutex_lock(&ftrace_lock);
5017 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5018 iter->hash, filter_hash);
5019 mutex_unlock(&ftrace_lock);
5021 /* For read only, the hash is the ops hash */
5025 mutex_unlock(&iter->ops->func_hash->regex_lock);
5026 free_ftrace_hash(iter->hash);
5032 static const struct file_operations ftrace_avail_fops = {
5033 .open = ftrace_avail_open,
5035 .llseek = seq_lseek,
5036 .release = seq_release_private,
5039 static const struct file_operations ftrace_enabled_fops = {
5040 .open = ftrace_enabled_open,
5042 .llseek = seq_lseek,
5043 .release = seq_release_private,
5046 static const struct file_operations ftrace_filter_fops = {
5047 .open = ftrace_filter_open,
5049 .write = ftrace_filter_write,
5050 .llseek = tracing_lseek,
5051 .release = ftrace_regex_release,
5054 static const struct file_operations ftrace_notrace_fops = {
5055 .open = ftrace_notrace_open,
5057 .write = ftrace_notrace_write,
5058 .llseek = tracing_lseek,
5059 .release = ftrace_regex_release,
5062 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5064 static DEFINE_MUTEX(graph_lock);
5066 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5067 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5069 enum graph_filter_type {
5070 GRAPH_FILTER_NOTRACE = 0,
5071 GRAPH_FILTER_FUNCTION,
5074 #define FTRACE_GRAPH_EMPTY ((void *)1)
5076 struct ftrace_graph_data {
5077 struct ftrace_hash *hash;
5078 struct ftrace_func_entry *entry;
5079 int idx; /* for hash table iteration */
5080 enum graph_filter_type type;
5081 struct ftrace_hash *new_hash;
5082 const struct seq_operations *seq_ops;
5083 struct trace_parser parser;
5087 __g_next(struct seq_file *m, loff_t *pos)
5089 struct ftrace_graph_data *fgd = m->private;
5090 struct ftrace_func_entry *entry = fgd->entry;
5091 struct hlist_head *head;
5092 int i, idx = fgd->idx;
5094 if (*pos >= fgd->hash->count)
5098 hlist_for_each_entry_continue(entry, hlist) {
5106 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5107 head = &fgd->hash->buckets[i];
5108 hlist_for_each_entry(entry, head, hlist) {
5118 g_next(struct seq_file *m, void *v, loff_t *pos)
5121 return __g_next(m, pos);
5124 static void *g_start(struct seq_file *m, loff_t *pos)
5126 struct ftrace_graph_data *fgd = m->private;
5128 mutex_lock(&graph_lock);
5130 if (fgd->type == GRAPH_FILTER_FUNCTION)
5131 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5132 lockdep_is_held(&graph_lock));
5134 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5135 lockdep_is_held(&graph_lock));
5137 /* Nothing, tell g_show to print all functions are enabled */
5138 if (ftrace_hash_empty(fgd->hash) && !*pos)
5139 return FTRACE_GRAPH_EMPTY;
5143 return __g_next(m, pos);
5146 static void g_stop(struct seq_file *m, void *p)
5148 mutex_unlock(&graph_lock);
5151 static int g_show(struct seq_file *m, void *v)
5153 struct ftrace_func_entry *entry = v;
5158 if (entry == FTRACE_GRAPH_EMPTY) {
5159 struct ftrace_graph_data *fgd = m->private;
5161 if (fgd->type == GRAPH_FILTER_FUNCTION)
5162 seq_puts(m, "#### all functions enabled ####\n");
5164 seq_puts(m, "#### no functions disabled ####\n");
5168 seq_printf(m, "%ps\n", (void *)entry->ip);
5173 static const struct seq_operations ftrace_graph_seq_ops = {
5181 __ftrace_graph_open(struct inode *inode, struct file *file,
5182 struct ftrace_graph_data *fgd)
5185 struct ftrace_hash *new_hash = NULL;
5187 if (file->f_mode & FMODE_WRITE) {
5188 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5190 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5193 if (file->f_flags & O_TRUNC)
5194 new_hash = alloc_ftrace_hash(size_bits);
5196 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5204 if (file->f_mode & FMODE_READ) {
5205 ret = seq_open(file, &ftrace_graph_seq_ops);
5207 struct seq_file *m = file->private_data;
5211 free_ftrace_hash(new_hash);
5215 file->private_data = fgd;
5218 if (ret < 0 && file->f_mode & FMODE_WRITE)
5219 trace_parser_put(&fgd->parser);
5221 fgd->new_hash = new_hash;
5224 * All uses of fgd->hash must be taken with the graph_lock
5225 * held. The graph_lock is going to be released, so force
5226 * fgd->hash to be reinitialized when it is taken again.
5234 ftrace_graph_open(struct inode *inode, struct file *file)
5236 struct ftrace_graph_data *fgd;
5239 if (unlikely(ftrace_disabled))
5242 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5246 mutex_lock(&graph_lock);
5248 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5249 lockdep_is_held(&graph_lock));
5250 fgd->type = GRAPH_FILTER_FUNCTION;
5251 fgd->seq_ops = &ftrace_graph_seq_ops;
5253 ret = __ftrace_graph_open(inode, file, fgd);
5257 mutex_unlock(&graph_lock);
5262 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5264 struct ftrace_graph_data *fgd;
5267 if (unlikely(ftrace_disabled))
5270 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5274 mutex_lock(&graph_lock);
5276 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5277 lockdep_is_held(&graph_lock));
5278 fgd->type = GRAPH_FILTER_NOTRACE;
5279 fgd->seq_ops = &ftrace_graph_seq_ops;
5281 ret = __ftrace_graph_open(inode, file, fgd);
5285 mutex_unlock(&graph_lock);
5290 ftrace_graph_release(struct inode *inode, struct file *file)
5292 struct ftrace_graph_data *fgd;
5293 struct ftrace_hash *old_hash, *new_hash;
5294 struct trace_parser *parser;
5297 if (file->f_mode & FMODE_READ) {
5298 struct seq_file *m = file->private_data;
5301 seq_release(inode, file);
5303 fgd = file->private_data;
5307 if (file->f_mode & FMODE_WRITE) {
5309 parser = &fgd->parser;
5311 if (trace_parser_loaded((parser))) {
5312 ret = ftrace_graph_set_hash(fgd->new_hash,
5316 trace_parser_put(parser);
5318 new_hash = __ftrace_hash_move(fgd->new_hash);
5324 mutex_lock(&graph_lock);
5326 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5327 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5328 lockdep_is_held(&graph_lock));
5329 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5331 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5332 lockdep_is_held(&graph_lock));
5333 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5336 mutex_unlock(&graph_lock);
5338 /* Wait till all users are no longer using the old hash */
5341 free_ftrace_hash(old_hash);
5345 free_ftrace_hash(fgd->new_hash);
5352 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5354 struct ftrace_glob func_g;
5355 struct dyn_ftrace *rec;
5356 struct ftrace_page *pg;
5357 struct ftrace_func_entry *entry;
5362 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5363 &func_g.search, ¬);
5365 func_g.len = strlen(func_g.search);
5367 mutex_lock(&ftrace_lock);
5369 if (unlikely(ftrace_disabled)) {
5370 mutex_unlock(&ftrace_lock);
5374 do_for_each_ftrace_rec(pg, rec) {
5376 if (rec->flags & FTRACE_FL_DISABLED)
5379 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5380 entry = ftrace_lookup_ip(hash, rec->ip);
5387 if (add_hash_entry(hash, rec->ip) < 0)
5391 free_hash_entry(hash, entry);
5396 } while_for_each_ftrace_rec();
5398 mutex_unlock(&ftrace_lock);
5407 ftrace_graph_write(struct file *file, const char __user *ubuf,
5408 size_t cnt, loff_t *ppos)
5410 ssize_t read, ret = 0;
5411 struct ftrace_graph_data *fgd = file->private_data;
5412 struct trace_parser *parser;
5417 /* Read mode uses seq functions */
5418 if (file->f_mode & FMODE_READ) {
5419 struct seq_file *m = file->private_data;
5423 parser = &fgd->parser;
5425 read = trace_get_user(parser, ubuf, cnt, ppos);
5427 if (read >= 0 && trace_parser_loaded(parser) &&
5428 !trace_parser_cont(parser)) {
5430 ret = ftrace_graph_set_hash(fgd->new_hash,
5432 trace_parser_clear(parser);
5441 static const struct file_operations ftrace_graph_fops = {
5442 .open = ftrace_graph_open,
5444 .write = ftrace_graph_write,
5445 .llseek = tracing_lseek,
5446 .release = ftrace_graph_release,
5449 static const struct file_operations ftrace_graph_notrace_fops = {
5450 .open = ftrace_graph_notrace_open,
5452 .write = ftrace_graph_write,
5453 .llseek = tracing_lseek,
5454 .release = ftrace_graph_release,
5456 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5458 void ftrace_create_filter_files(struct ftrace_ops *ops,
5459 struct dentry *parent)
5462 trace_create_file("set_ftrace_filter", 0644, parent,
5463 ops, &ftrace_filter_fops);
5465 trace_create_file("set_ftrace_notrace", 0644, parent,
5466 ops, &ftrace_notrace_fops);
5470 * The name "destroy_filter_files" is really a misnomer. Although
5471 * in the future, it may actually delete the files, but this is
5472 * really intended to make sure the ops passed in are disabled
5473 * and that when this function returns, the caller is free to
5476 * The "destroy" name is only to match the "create" name that this
5477 * should be paired with.
5479 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5481 mutex_lock(&ftrace_lock);
5482 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5483 ftrace_shutdown(ops, 0);
5484 ops->flags |= FTRACE_OPS_FL_DELETED;
5485 ftrace_free_filter(ops);
5486 mutex_unlock(&ftrace_lock);
5489 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5492 trace_create_file("available_filter_functions", 0444,
5493 d_tracer, NULL, &ftrace_avail_fops);
5495 trace_create_file("enabled_functions", 0444,
5496 d_tracer, NULL, &ftrace_enabled_fops);
5498 ftrace_create_filter_files(&global_ops, d_tracer);
5500 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5501 trace_create_file("set_graph_function", 0644, d_tracer,
5503 &ftrace_graph_fops);
5504 trace_create_file("set_graph_notrace", 0644, d_tracer,
5506 &ftrace_graph_notrace_fops);
5507 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5512 static int ftrace_cmp_ips(const void *a, const void *b)
5514 const unsigned long *ipa = a;
5515 const unsigned long *ipb = b;
5524 static int ftrace_process_locs(struct module *mod,
5525 unsigned long *start,
5528 struct ftrace_page *start_pg;
5529 struct ftrace_page *pg;
5530 struct dyn_ftrace *rec;
5531 unsigned long count;
5534 unsigned long flags = 0; /* Shut up gcc */
5537 count = end - start;
5542 sort(start, count, sizeof(*start),
5543 ftrace_cmp_ips, NULL);
5545 start_pg = ftrace_allocate_pages(count);
5549 mutex_lock(&ftrace_lock);
5552 * Core and each module needs their own pages, as
5553 * modules will free them when they are removed.
5554 * Force a new page to be allocated for modules.
5557 WARN_ON(ftrace_pages || ftrace_pages_start);
5558 /* First initialization */
5559 ftrace_pages = ftrace_pages_start = start_pg;
5564 if (WARN_ON(ftrace_pages->next)) {
5565 /* Hmm, we have free pages? */
5566 while (ftrace_pages->next)
5567 ftrace_pages = ftrace_pages->next;
5570 ftrace_pages->next = start_pg;
5576 addr = ftrace_call_adjust(*p++);
5578 * Some architecture linkers will pad between
5579 * the different mcount_loc sections of different
5580 * object files to satisfy alignments.
5581 * Skip any NULL pointers.
5586 if (pg->index == pg->size) {
5587 /* We should have allocated enough */
5588 if (WARN_ON(!pg->next))
5593 rec = &pg->records[pg->index++];
5597 /* We should have used all pages */
5600 /* Assign the last page to ftrace_pages */
5604 * We only need to disable interrupts on start up
5605 * because we are modifying code that an interrupt
5606 * may execute, and the modification is not atomic.
5607 * But for modules, nothing runs the code we modify
5608 * until we are finished with it, and there's no
5609 * reason to cause large interrupt latencies while we do it.
5612 local_irq_save(flags);
5613 ftrace_update_code(mod, start_pg);
5615 local_irq_restore(flags);
5618 mutex_unlock(&ftrace_lock);
5623 struct ftrace_mod_func {
5624 struct list_head list;
5630 struct ftrace_mod_map {
5631 struct rcu_head rcu;
5632 struct list_head list;
5634 unsigned long start_addr;
5635 unsigned long end_addr;
5636 struct list_head funcs;
5637 unsigned int num_funcs;
5640 #ifdef CONFIG_MODULES
5642 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5644 static LIST_HEAD(ftrace_mod_maps);
5646 static int referenced_filters(struct dyn_ftrace *rec)
5648 struct ftrace_ops *ops;
5651 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5652 if (ops_references_rec(ops, rec))
5660 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5662 struct ftrace_func_entry *entry;
5663 struct dyn_ftrace *rec;
5666 if (ftrace_hash_empty(hash))
5669 for (i = 0; i < pg->index; i++) {
5670 rec = &pg->records[i];
5671 entry = __ftrace_lookup_ip(hash, rec->ip);
5673 * Do not allow this rec to match again.
5674 * Yeah, it may waste some memory, but will be removed
5675 * if/when the hash is modified again.
5682 /* Clear any records from hashs */
5683 static void clear_mod_from_hashes(struct ftrace_page *pg)
5685 struct trace_array *tr;
5687 mutex_lock(&trace_types_lock);
5688 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5689 if (!tr->ops || !tr->ops->func_hash)
5691 mutex_lock(&tr->ops->func_hash->regex_lock);
5692 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5693 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5694 mutex_unlock(&tr->ops->func_hash->regex_lock);
5696 mutex_unlock(&trace_types_lock);
5699 static void ftrace_free_mod_map(struct rcu_head *rcu)
5701 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5702 struct ftrace_mod_func *mod_func;
5703 struct ftrace_mod_func *n;
5705 /* All the contents of mod_map are now not visible to readers */
5706 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5707 kfree(mod_func->name);
5708 list_del(&mod_func->list);
5715 void ftrace_release_mod(struct module *mod)
5717 struct ftrace_mod_map *mod_map;
5718 struct ftrace_mod_map *n;
5719 struct dyn_ftrace *rec;
5720 struct ftrace_page **last_pg;
5721 struct ftrace_page *tmp_page = NULL;
5722 struct ftrace_page *pg;
5725 mutex_lock(&ftrace_lock);
5727 if (ftrace_disabled)
5730 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5731 if (mod_map->mod == mod) {
5732 list_del_rcu(&mod_map->list);
5733 call_rcu(&mod_map->rcu, ftrace_free_mod_map);
5739 * Each module has its own ftrace_pages, remove
5740 * them from the list.
5742 last_pg = &ftrace_pages_start;
5743 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5744 rec = &pg->records[0];
5745 if (within_module_core(rec->ip, mod) ||
5746 within_module_init(rec->ip, mod)) {
5748 * As core pages are first, the first
5749 * page should never be a module page.
5751 if (WARN_ON(pg == ftrace_pages_start))
5754 /* Check if we are deleting the last page */
5755 if (pg == ftrace_pages)
5756 ftrace_pages = next_to_ftrace_page(last_pg);
5758 ftrace_update_tot_cnt -= pg->index;
5759 *last_pg = pg->next;
5761 pg->next = tmp_page;
5764 last_pg = &pg->next;
5767 mutex_unlock(&ftrace_lock);
5769 for (pg = tmp_page; pg; pg = tmp_page) {
5771 /* Needs to be called outside of ftrace_lock */
5772 clear_mod_from_hashes(pg);
5774 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5775 free_pages((unsigned long)pg->records, order);
5776 tmp_page = pg->next;
5781 void ftrace_module_enable(struct module *mod)
5783 struct dyn_ftrace *rec;
5784 struct ftrace_page *pg;
5786 mutex_lock(&ftrace_lock);
5787 mutex_lock(&text_mutex);
5789 if (ftrace_disabled)
5793 * If the tracing is enabled, go ahead and enable the record.
5795 * The reason not to enable the record immediately is the
5796 * inherent check of ftrace_make_nop/ftrace_make_call for
5797 * correct previous instructions. Making first the NOP
5798 * conversion puts the module to the correct state, thus
5799 * passing the ftrace_make_call check.
5801 * We also delay this to after the module code already set the
5802 * text to read-only, as we now need to set it back to read-write
5803 * so that we can modify the text.
5805 if (ftrace_start_up)
5806 ftrace_arch_code_modify_prepare();
5808 do_for_each_ftrace_rec(pg, rec) {
5811 * do_for_each_ftrace_rec() is a double loop.
5812 * module text shares the pg. If a record is
5813 * not part of this module, then skip this pg,
5814 * which the "break" will do.
5816 if (!within_module_core(rec->ip, mod) &&
5817 !within_module_init(rec->ip, mod))
5823 * When adding a module, we need to check if tracers are
5824 * currently enabled and if they are, and can trace this record,
5825 * we need to enable the module functions as well as update the
5826 * reference counts for those function records.
5828 if (ftrace_start_up)
5829 cnt += referenced_filters(rec);
5831 /* This clears FTRACE_FL_DISABLED */
5834 if (ftrace_start_up && cnt) {
5835 int failed = __ftrace_replace_code(rec, 1);
5837 ftrace_bug(failed, rec);
5842 } while_for_each_ftrace_rec();
5845 if (ftrace_start_up)
5846 ftrace_arch_code_modify_post_process();
5849 mutex_unlock(&text_mutex);
5850 mutex_unlock(&ftrace_lock);
5852 process_cached_mods(mod->name);
5855 void ftrace_module_init(struct module *mod)
5857 if (ftrace_disabled || !mod->num_ftrace_callsites)
5860 ftrace_process_locs(mod, mod->ftrace_callsites,
5861 mod->ftrace_callsites + mod->num_ftrace_callsites);
5864 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5865 struct dyn_ftrace *rec)
5867 struct ftrace_mod_func *mod_func;
5868 unsigned long symsize;
5869 unsigned long offset;
5870 char str[KSYM_SYMBOL_LEN];
5874 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5878 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5882 mod_func->name = kstrdup(str, GFP_KERNEL);
5883 if (!mod_func->name) {
5888 mod_func->ip = rec->ip - offset;
5889 mod_func->size = symsize;
5891 mod_map->num_funcs++;
5893 list_add_rcu(&mod_func->list, &mod_map->funcs);
5896 static struct ftrace_mod_map *
5897 allocate_ftrace_mod_map(struct module *mod,
5898 unsigned long start, unsigned long end)
5900 struct ftrace_mod_map *mod_map;
5902 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5907 mod_map->start_addr = start;
5908 mod_map->end_addr = end;
5909 mod_map->num_funcs = 0;
5911 INIT_LIST_HEAD_RCU(&mod_map->funcs);
5913 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5919 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5920 unsigned long addr, unsigned long *size,
5921 unsigned long *off, char *sym)
5923 struct ftrace_mod_func *found_func = NULL;
5924 struct ftrace_mod_func *mod_func;
5926 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5927 if (addr >= mod_func->ip &&
5928 addr < mod_func->ip + mod_func->size) {
5929 found_func = mod_func;
5936 *size = found_func->size;
5938 *off = addr - found_func->ip;
5940 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5942 return found_func->name;
5949 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5950 unsigned long *off, char **modname, char *sym)
5952 struct ftrace_mod_map *mod_map;
5953 const char *ret = NULL;
5955 /* mod_map is freed via call_rcu() */
5957 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5958 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
5961 *modname = mod_map->mod->name;
5970 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
5971 char *type, char *name,
5972 char *module_name, int *exported)
5974 struct ftrace_mod_map *mod_map;
5975 struct ftrace_mod_func *mod_func;
5978 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5980 if (symnum >= mod_map->num_funcs) {
5981 symnum -= mod_map->num_funcs;
5985 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5991 *value = mod_func->ip;
5993 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
5994 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6007 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6008 struct dyn_ftrace *rec) { }
6009 static inline struct ftrace_mod_map *
6010 allocate_ftrace_mod_map(struct module *mod,
6011 unsigned long start, unsigned long end)
6015 #endif /* CONFIG_MODULES */
6017 struct ftrace_init_func {
6018 struct list_head list;
6022 /* Clear any init ips from hashes */
6024 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6026 struct ftrace_func_entry *entry;
6028 if (ftrace_hash_empty(hash))
6031 entry = __ftrace_lookup_ip(hash, func->ip);
6034 * Do not allow this rec to match again.
6035 * Yeah, it may waste some memory, but will be removed
6036 * if/when the hash is modified again.
6043 clear_func_from_hashes(struct ftrace_init_func *func)
6045 struct trace_array *tr;
6047 mutex_lock(&trace_types_lock);
6048 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6049 if (!tr->ops || !tr->ops->func_hash)
6051 mutex_lock(&tr->ops->func_hash->regex_lock);
6052 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6053 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6054 mutex_unlock(&tr->ops->func_hash->regex_lock);
6056 mutex_unlock(&trace_types_lock);
6059 static void add_to_clear_hash_list(struct list_head *clear_list,
6060 struct dyn_ftrace *rec)
6062 struct ftrace_init_func *func;
6064 func = kmalloc(sizeof(*func), GFP_KERNEL);
6066 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6071 list_add(&func->list, clear_list);
6074 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6076 unsigned long start = (unsigned long)(start_ptr);
6077 unsigned long end = (unsigned long)(end_ptr);
6078 struct ftrace_page **last_pg = &ftrace_pages_start;
6079 struct ftrace_page *pg;
6080 struct dyn_ftrace *rec;
6081 struct dyn_ftrace key;
6082 struct ftrace_mod_map *mod_map = NULL;
6083 struct ftrace_init_func *func, *func_next;
6084 struct list_head clear_hash;
6087 INIT_LIST_HEAD(&clear_hash);
6090 key.flags = end; /* overload flags, as it is unsigned long */
6092 mutex_lock(&ftrace_lock);
6095 * If we are freeing module init memory, then check if
6096 * any tracer is active. If so, we need to save a mapping of
6097 * the module functions being freed with the address.
6099 if (mod && ftrace_ops_list != &ftrace_list_end)
6100 mod_map = allocate_ftrace_mod_map(mod, start, end);
6102 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6103 if (end < pg->records[0].ip ||
6104 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6107 rec = bsearch(&key, pg->records, pg->index,
6108 sizeof(struct dyn_ftrace),
6113 /* rec will be cleared from hashes after ftrace_lock unlock */
6114 add_to_clear_hash_list(&clear_hash, rec);
6117 save_ftrace_mod_rec(mod_map, rec);
6120 ftrace_update_tot_cnt--;
6122 *last_pg = pg->next;
6123 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6124 free_pages((unsigned long)pg->records, order);
6126 pg = container_of(last_pg, struct ftrace_page, next);
6131 memmove(rec, rec + 1,
6132 (pg->index - (rec - pg->records)) * sizeof(*rec));
6133 /* More than one function may be in this block */
6136 mutex_unlock(&ftrace_lock);
6138 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6139 clear_func_from_hashes(func);
6144 void __init ftrace_free_init_mem(void)
6146 void *start = (void *)(&__init_begin);
6147 void *end = (void *)(&__init_end);
6149 ftrace_free_mem(NULL, start, end);
6152 void __init ftrace_init(void)
6154 extern unsigned long __start_mcount_loc[];
6155 extern unsigned long __stop_mcount_loc[];
6156 unsigned long count, flags;
6159 local_irq_save(flags);
6160 ret = ftrace_dyn_arch_init();
6161 local_irq_restore(flags);
6165 count = __stop_mcount_loc - __start_mcount_loc;
6167 pr_info("ftrace: No functions to be traced?\n");
6171 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6172 count, count / ENTRIES_PER_PAGE + 1);
6174 last_ftrace_enabled = ftrace_enabled = 1;
6176 ret = ftrace_process_locs(NULL,
6180 set_ftrace_early_filters();
6184 ftrace_disabled = 1;
6187 /* Do nothing if arch does not support this */
6188 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6192 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6194 arch_ftrace_update_trampoline(ops);
6197 void ftrace_init_trace_array(struct trace_array *tr)
6199 INIT_LIST_HEAD(&tr->func_probes);
6200 INIT_LIST_HEAD(&tr->mod_trace);
6201 INIT_LIST_HEAD(&tr->mod_notrace);
6205 struct ftrace_ops global_ops = {
6206 .func = ftrace_stub,
6207 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6208 FTRACE_OPS_FL_INITIALIZED |
6212 static int __init ftrace_nodyn_init(void)
6217 core_initcall(ftrace_nodyn_init);
6219 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6220 static inline void ftrace_startup_enable(int command) { }
6221 static inline void ftrace_startup_all(int command) { }
6223 # define ftrace_startup_sysctl() do { } while (0)
6224 # define ftrace_shutdown_sysctl() do { } while (0)
6226 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6230 #endif /* CONFIG_DYNAMIC_FTRACE */
6232 __init void ftrace_init_global_array_ops(struct trace_array *tr)
6234 tr->ops = &global_ops;
6235 tr->ops->private = tr;
6236 ftrace_init_trace_array(tr);
6239 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6241 /* If we filter on pids, update to use the pid function */
6242 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6243 if (WARN_ON(tr->ops->func != ftrace_stub))
6244 printk("ftrace ops had %pS for function\n",
6247 tr->ops->func = func;
6248 tr->ops->private = tr;
6251 void ftrace_reset_array_ops(struct trace_array *tr)
6253 tr->ops->func = ftrace_stub;
6256 static nokprobe_inline void
6257 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6258 struct ftrace_ops *ignored, struct pt_regs *regs)
6260 struct ftrace_ops *op;
6263 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6268 * Some of the ops may be dynamically allocated,
6269 * they must be freed after a synchronize_rcu().
6271 preempt_disable_notrace();
6273 do_for_each_ftrace_op(op, ftrace_ops_list) {
6274 /* Stub functions don't need to be called nor tested */
6275 if (op->flags & FTRACE_OPS_FL_STUB)
6278 * Check the following for each ops before calling their func:
6279 * if RCU flag is set, then rcu_is_watching() must be true
6280 * if PER_CPU is set, then ftrace_function_local_disable()
6282 * Otherwise test if the ip matches the ops filter
6284 * If any of the above fails then the op->func() is not executed.
6286 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6287 ftrace_ops_test(op, ip, regs)) {
6288 if (FTRACE_WARN_ON(!op->func)) {
6289 pr_warn("op=%p %pS\n", op, op);
6292 op->func(ip, parent_ip, op, regs);
6294 } while_for_each_ftrace_op(op);
6296 preempt_enable_notrace();
6297 trace_clear_recursion(bit);
6301 * Some archs only support passing ip and parent_ip. Even though
6302 * the list function ignores the op parameter, we do not want any
6303 * C side effects, where a function is called without the caller
6304 * sending a third parameter.
6305 * Archs are to support both the regs and ftrace_ops at the same time.
6306 * If they support ftrace_ops, it is assumed they support regs.
6307 * If call backs want to use regs, they must either check for regs
6308 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6309 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6310 * An architecture can pass partial regs with ftrace_ops and still
6311 * set the ARCH_SUPPORTS_FTRACE_OPS.
6313 #if ARCH_SUPPORTS_FTRACE_OPS
6314 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6315 struct ftrace_ops *op, struct pt_regs *regs)
6317 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6319 NOKPROBE_SYMBOL(ftrace_ops_list_func);
6321 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6323 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6325 NOKPROBE_SYMBOL(ftrace_ops_no_ops);
6329 * If there's only one function registered but it does not support
6330 * recursion, needs RCU protection and/or requires per cpu handling, then
6331 * this function will be called by the mcount trampoline.
6333 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6334 struct ftrace_ops *op, struct pt_regs *regs)
6338 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6341 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6345 preempt_disable_notrace();
6347 op->func(ip, parent_ip, op, regs);
6349 preempt_enable_notrace();
6350 trace_clear_recursion(bit);
6352 NOKPROBE_SYMBOL(ftrace_ops_assist_func);
6355 * ftrace_ops_get_func - get the function a trampoline should call
6356 * @ops: the ops to get the function for
6358 * Normally the mcount trampoline will call the ops->func, but there
6359 * are times that it should not. For example, if the ops does not
6360 * have its own recursion protection, then it should call the
6361 * ftrace_ops_assist_func() instead.
6363 * Returns the function that the trampoline should call for @ops.
6365 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6368 * If the function does not handle recursion, needs to be RCU safe,
6369 * or does per cpu logic, then we need to call the assist handler.
6371 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6372 ops->flags & FTRACE_OPS_FL_RCU)
6373 return ftrace_ops_assist_func;
6379 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6380 struct task_struct *prev, struct task_struct *next)
6382 struct trace_array *tr = data;
6383 struct trace_pid_list *pid_list;
6385 pid_list = rcu_dereference_sched(tr->function_pids);
6387 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6388 trace_ignore_this_task(pid_list, next));
6392 ftrace_pid_follow_sched_process_fork(void *data,
6393 struct task_struct *self,
6394 struct task_struct *task)
6396 struct trace_pid_list *pid_list;
6397 struct trace_array *tr = data;
6399 pid_list = rcu_dereference_sched(tr->function_pids);
6400 trace_filter_add_remove_task(pid_list, self, task);
6404 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6406 struct trace_pid_list *pid_list;
6407 struct trace_array *tr = data;
6409 pid_list = rcu_dereference_sched(tr->function_pids);
6410 trace_filter_add_remove_task(pid_list, NULL, task);
6413 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6416 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6418 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6421 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6423 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6428 static void clear_ftrace_pids(struct trace_array *tr)
6430 struct trace_pid_list *pid_list;
6433 pid_list = rcu_dereference_protected(tr->function_pids,
6434 lockdep_is_held(&ftrace_lock));
6438 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6440 for_each_possible_cpu(cpu)
6441 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6443 rcu_assign_pointer(tr->function_pids, NULL);
6445 /* Wait till all users are no longer using pid filtering */
6448 trace_free_pid_list(pid_list);
6451 void ftrace_clear_pids(struct trace_array *tr)
6453 mutex_lock(&ftrace_lock);
6455 clear_ftrace_pids(tr);
6457 mutex_unlock(&ftrace_lock);
6460 static void ftrace_pid_reset(struct trace_array *tr)
6462 mutex_lock(&ftrace_lock);
6463 clear_ftrace_pids(tr);
6465 ftrace_update_pid_func();
6466 ftrace_startup_all(0);
6468 mutex_unlock(&ftrace_lock);
6471 /* Greater than any max PID */
6472 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6474 static void *fpid_start(struct seq_file *m, loff_t *pos)
6477 struct trace_pid_list *pid_list;
6478 struct trace_array *tr = m->private;
6480 mutex_lock(&ftrace_lock);
6481 rcu_read_lock_sched();
6483 pid_list = rcu_dereference_sched(tr->function_pids);
6486 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6488 return trace_pid_start(pid_list, pos);
6491 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6493 struct trace_array *tr = m->private;
6494 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6496 if (v == FTRACE_NO_PIDS)
6499 return trace_pid_next(pid_list, v, pos);
6502 static void fpid_stop(struct seq_file *m, void *p)
6505 rcu_read_unlock_sched();
6506 mutex_unlock(&ftrace_lock);
6509 static int fpid_show(struct seq_file *m, void *v)
6511 if (v == FTRACE_NO_PIDS) {
6512 seq_puts(m, "no pid\n");
6516 return trace_pid_show(m, v);
6519 static const struct seq_operations ftrace_pid_sops = {
6520 .start = fpid_start,
6527 ftrace_pid_open(struct inode *inode, struct file *file)
6529 struct trace_array *tr = inode->i_private;
6533 if (trace_array_get(tr) < 0)
6536 if ((file->f_mode & FMODE_WRITE) &&
6537 (file->f_flags & O_TRUNC))
6538 ftrace_pid_reset(tr);
6540 ret = seq_open(file, &ftrace_pid_sops);
6542 trace_array_put(tr);
6544 m = file->private_data;
6545 /* copy tr over to seq ops */
6552 static void ignore_task_cpu(void *data)
6554 struct trace_array *tr = data;
6555 struct trace_pid_list *pid_list;
6558 * This function is called by on_each_cpu() while the
6559 * event_mutex is held.
6561 pid_list = rcu_dereference_protected(tr->function_pids,
6562 mutex_is_locked(&ftrace_lock));
6564 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6565 trace_ignore_this_task(pid_list, current));
6569 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6570 size_t cnt, loff_t *ppos)
6572 struct seq_file *m = filp->private_data;
6573 struct trace_array *tr = m->private;
6574 struct trace_pid_list *filtered_pids = NULL;
6575 struct trace_pid_list *pid_list;
6581 mutex_lock(&ftrace_lock);
6583 filtered_pids = rcu_dereference_protected(tr->function_pids,
6584 lockdep_is_held(&ftrace_lock));
6586 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6590 rcu_assign_pointer(tr->function_pids, pid_list);
6592 if (filtered_pids) {
6594 trace_free_pid_list(filtered_pids);
6595 } else if (pid_list) {
6596 /* Register a probe to set whether to ignore the tracing of a task */
6597 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6601 * Ignoring of pids is done at task switch. But we have to
6602 * check for those tasks that are currently running.
6603 * Always do this in case a pid was appended or removed.
6605 on_each_cpu(ignore_task_cpu, tr, 1);
6607 ftrace_update_pid_func();
6608 ftrace_startup_all(0);
6610 mutex_unlock(&ftrace_lock);
6619 ftrace_pid_release(struct inode *inode, struct file *file)
6621 struct trace_array *tr = inode->i_private;
6623 trace_array_put(tr);
6625 return seq_release(inode, file);
6628 static const struct file_operations ftrace_pid_fops = {
6629 .open = ftrace_pid_open,
6630 .write = ftrace_pid_write,
6632 .llseek = tracing_lseek,
6633 .release = ftrace_pid_release,
6636 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6638 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6639 tr, &ftrace_pid_fops);
6642 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6643 struct dentry *d_tracer)
6645 /* Only the top level directory has the dyn_tracefs and profile */
6646 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6648 ftrace_init_dyn_tracefs(d_tracer);
6649 ftrace_profile_tracefs(d_tracer);
6653 * ftrace_kill - kill ftrace
6655 * This function should be used by panic code. It stops ftrace
6656 * but in a not so nice way. If you need to simply kill ftrace
6657 * from a non-atomic section, use ftrace_kill.
6659 void ftrace_kill(void)
6661 ftrace_disabled = 1;
6663 ftrace_trace_function = ftrace_stub;
6667 * Test if ftrace is dead or not.
6669 int ftrace_is_dead(void)
6671 return ftrace_disabled;
6675 * register_ftrace_function - register a function for profiling
6676 * @ops - ops structure that holds the function for profiling.
6678 * Register a function to be called by all functions in the
6681 * Note: @ops->func and all the functions it calls must be labeled
6682 * with "notrace", otherwise it will go into a
6685 int register_ftrace_function(struct ftrace_ops *ops)
6689 ftrace_ops_init(ops);
6691 mutex_lock(&ftrace_lock);
6693 ret = ftrace_startup(ops, 0);
6695 mutex_unlock(&ftrace_lock);
6699 EXPORT_SYMBOL_GPL(register_ftrace_function);
6702 * unregister_ftrace_function - unregister a function for profiling.
6703 * @ops - ops structure that holds the function to unregister
6705 * Unregister a function that was added to be called by ftrace profiling.
6707 int unregister_ftrace_function(struct ftrace_ops *ops)
6711 mutex_lock(&ftrace_lock);
6712 ret = ftrace_shutdown(ops, 0);
6713 mutex_unlock(&ftrace_lock);
6717 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6720 ftrace_enable_sysctl(struct ctl_table *table, int write,
6721 void __user *buffer, size_t *lenp,
6726 mutex_lock(&ftrace_lock);
6728 if (unlikely(ftrace_disabled))
6731 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6733 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6736 last_ftrace_enabled = !!ftrace_enabled;
6738 if (ftrace_enabled) {
6740 /* we are starting ftrace again */
6741 if (rcu_dereference_protected(ftrace_ops_list,
6742 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6743 update_ftrace_function();
6745 ftrace_startup_sysctl();
6748 /* stopping ftrace calls (just send to ftrace_stub) */
6749 ftrace_trace_function = ftrace_stub;
6751 ftrace_shutdown_sysctl();
6755 mutex_unlock(&ftrace_lock);