2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/debugfs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/bsearch.h>
26 #include <linux/module.h>
27 #include <linux/ftrace.h>
28 #include <linux/sysctl.h>
29 #include <linux/slab.h>
30 #include <linux/ctype.h>
31 #include <linux/sort.h>
32 #include <linux/list.h>
33 #include <linux/hash.h>
34 #include <linux/rcupdate.h>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
60 #define FTRACE_HASH_BITS 7
61 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62 #define FTRACE_HASH_DEFAULT_BITS 10
63 #define FTRACE_HASH_MAX_BITS 12
65 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
67 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_OPS_HASH(opsname) \
69 .func_hash = &opsname.local_hash, \
70 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
71 #define ASSIGN_OPS_HASH(opsname, val) \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #define INIT_OPS_HASH(opsname)
76 #define ASSIGN_OPS_HASH(opsname, val)
79 static struct ftrace_ops ftrace_list_end __read_mostly = {
81 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
82 INIT_OPS_HASH(ftrace_list_end)
85 /* ftrace_enabled is a method to turn ftrace on or off */
86 int ftrace_enabled __read_mostly;
87 static int last_ftrace_enabled;
89 /* Current function tracing op */
90 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
91 /* What to set function_trace_op to */
92 static struct ftrace_ops *set_function_trace_op;
94 /* List for set_ftrace_pid's pids. */
95 LIST_HEAD(ftrace_pids);
97 struct list_head list;
102 * ftrace_disabled is set when an anomaly is discovered.
103 * ftrace_disabled is much stronger than ftrace_enabled.
105 static int ftrace_disabled __read_mostly;
107 static DEFINE_MUTEX(ftrace_lock);
109 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
110 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
111 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
112 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
113 static struct ftrace_ops global_ops;
114 static struct ftrace_ops control_ops;
116 static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
117 struct ftrace_ops *op, struct pt_regs *regs);
119 #if ARCH_SUPPORTS_FTRACE_OPS
120 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
121 struct ftrace_ops *op, struct pt_regs *regs);
123 /* See comment below, where ftrace_ops_list_func is defined */
124 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
125 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
129 * Traverse the ftrace_global_list, invoking all entries. The reason that we
130 * can use rcu_dereference_raw_notrace() is that elements removed from this list
131 * are simply leaked, so there is no need to interact with a grace-period
132 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
133 * concurrent insertions into the ftrace_global_list.
135 * Silly Alpha and silly pointer-speculation compiler optimizations!
137 #define do_for_each_ftrace_op(op, list) \
138 op = rcu_dereference_raw_notrace(list); \
142 * Optimized for just a single item in the list (as that is the normal case).
144 #define while_for_each_ftrace_op(op) \
145 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
146 unlikely((op) != &ftrace_list_end))
148 static inline void ftrace_ops_init(struct ftrace_ops *ops)
150 #ifdef CONFIG_DYNAMIC_FTRACE
151 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
152 mutex_init(&ops->local_hash.regex_lock);
153 ops->func_hash = &ops->local_hash;
154 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
160 * ftrace_nr_registered_ops - return number of ops registered
162 * Returns the number of ftrace_ops registered and tracing functions
164 int ftrace_nr_registered_ops(void)
166 struct ftrace_ops *ops;
169 mutex_lock(&ftrace_lock);
171 for (ops = ftrace_ops_list;
172 ops != &ftrace_list_end; ops = ops->next)
175 mutex_unlock(&ftrace_lock);
180 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
181 struct ftrace_ops *op, struct pt_regs *regs)
183 if (!test_tsk_trace_trace(current))
186 ftrace_pid_function(ip, parent_ip, op, regs);
189 static void set_ftrace_pid_function(ftrace_func_t func)
191 /* do not set ftrace_pid_function to itself! */
192 if (func != ftrace_pid_func)
193 ftrace_pid_function = func;
197 * clear_ftrace_function - reset the ftrace function
199 * This NULLs the ftrace function and in essence stops
200 * tracing. There may be lag
202 void clear_ftrace_function(void)
204 ftrace_trace_function = ftrace_stub;
205 ftrace_pid_function = ftrace_stub;
208 static void control_ops_disable_all(struct ftrace_ops *ops)
212 for_each_possible_cpu(cpu)
213 *per_cpu_ptr(ops->disabled, cpu) = 1;
216 static int control_ops_alloc(struct ftrace_ops *ops)
218 int __percpu *disabled;
220 disabled = alloc_percpu(int);
224 ops->disabled = disabled;
225 control_ops_disable_all(ops);
229 static void ftrace_sync(struct work_struct *work)
232 * This function is just a stub to implement a hard force
233 * of synchronize_sched(). This requires synchronizing
234 * tasks even in userspace and idle.
236 * Yes, function tracing is rude.
240 static void ftrace_sync_ipi(void *data)
242 /* Probably not needed, but do it anyway */
246 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
247 static void update_function_graph_func(void);
249 static inline void update_function_graph_func(void) { }
252 static void update_ftrace_function(void)
257 * Prepare the ftrace_ops that the arch callback will use.
258 * If there's only one ftrace_ops registered, the ftrace_ops_list
259 * will point to the ops we want.
261 set_function_trace_op = ftrace_ops_list;
263 /* If there's no ftrace_ops registered, just call the stub function */
264 if (ftrace_ops_list == &ftrace_list_end) {
268 * If we are at the end of the list and this ops is
269 * recursion safe and not dynamic and the arch supports passing ops,
270 * then have the mcount trampoline call the function directly.
272 } else if (ftrace_ops_list->next == &ftrace_list_end) {
273 func = ftrace_ops_get_func(ftrace_ops_list);
276 /* Just use the default ftrace_ops */
277 set_function_trace_op = &ftrace_list_end;
278 func = ftrace_ops_list_func;
281 update_function_graph_func();
283 /* If there's no change, then do nothing more here */
284 if (ftrace_trace_function == func)
288 * If we are using the list function, it doesn't care
289 * about the function_trace_ops.
291 if (func == ftrace_ops_list_func) {
292 ftrace_trace_function = func;
294 * Don't even bother setting function_trace_ops,
295 * it would be racy to do so anyway.
300 #ifndef CONFIG_DYNAMIC_FTRACE
302 * For static tracing, we need to be a bit more careful.
303 * The function change takes affect immediately. Thus,
304 * we need to coorditate the setting of the function_trace_ops
305 * with the setting of the ftrace_trace_function.
307 * Set the function to the list ops, which will call the
308 * function we want, albeit indirectly, but it handles the
309 * ftrace_ops and doesn't depend on function_trace_op.
311 ftrace_trace_function = ftrace_ops_list_func;
313 * Make sure all CPUs see this. Yes this is slow, but static
314 * tracing is slow and nasty to have enabled.
316 schedule_on_each_cpu(ftrace_sync);
317 /* Now all cpus are using the list ops. */
318 function_trace_op = set_function_trace_op;
319 /* Make sure the function_trace_op is visible on all CPUs */
321 /* Nasty way to force a rmb on all cpus */
322 smp_call_function(ftrace_sync_ipi, NULL, 1);
323 /* OK, we are all set to update the ftrace_trace_function now! */
324 #endif /* !CONFIG_DYNAMIC_FTRACE */
326 ftrace_trace_function = func;
329 int using_ftrace_ops_list_func(void)
331 return ftrace_trace_function == ftrace_ops_list_func;
334 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
338 * We are entering ops into the list but another
339 * CPU might be walking that list. We need to make sure
340 * the ops->next pointer is valid before another CPU sees
341 * the ops pointer included into the list.
343 rcu_assign_pointer(*list, ops);
346 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
348 struct ftrace_ops **p;
351 * If we are removing the last function, then simply point
352 * to the ftrace_stub.
354 if (*list == ops && ops->next == &ftrace_list_end) {
355 *list = &ftrace_list_end;
359 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
370 static void add_ftrace_list_ops(struct ftrace_ops **list,
371 struct ftrace_ops *main_ops,
372 struct ftrace_ops *ops)
374 int first = *list == &ftrace_list_end;
375 add_ftrace_ops(list, ops);
377 add_ftrace_ops(&ftrace_ops_list, main_ops);
380 static int remove_ftrace_list_ops(struct ftrace_ops **list,
381 struct ftrace_ops *main_ops,
382 struct ftrace_ops *ops)
384 int ret = remove_ftrace_ops(list, ops);
385 if (!ret && *list == &ftrace_list_end)
386 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
390 static int __register_ftrace_function(struct ftrace_ops *ops)
392 if (ops->flags & FTRACE_OPS_FL_DELETED)
395 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
398 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
400 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
401 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
402 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
404 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
405 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
408 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
409 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
412 if (!core_kernel_data((unsigned long)ops))
413 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
415 if (ops->flags & FTRACE_OPS_FL_CONTROL) {
416 if (control_ops_alloc(ops))
418 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
420 add_ftrace_ops(&ftrace_ops_list, ops);
423 update_ftrace_function();
428 static int __unregister_ftrace_function(struct ftrace_ops *ops)
432 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
435 if (ops->flags & FTRACE_OPS_FL_CONTROL) {
436 ret = remove_ftrace_list_ops(&ftrace_control_list,
439 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
445 update_ftrace_function();
450 static void ftrace_update_pid_func(void)
452 /* Only do something if we are tracing something */
453 if (ftrace_trace_function == ftrace_stub)
456 update_ftrace_function();
459 #ifdef CONFIG_FUNCTION_PROFILER
460 struct ftrace_profile {
461 struct hlist_node node;
463 unsigned long counter;
464 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
465 unsigned long long time;
466 unsigned long long time_squared;
470 struct ftrace_profile_page {
471 struct ftrace_profile_page *next;
473 struct ftrace_profile records[];
476 struct ftrace_profile_stat {
478 struct hlist_head *hash;
479 struct ftrace_profile_page *pages;
480 struct ftrace_profile_page *start;
481 struct tracer_stat stat;
484 #define PROFILE_RECORDS_SIZE \
485 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
487 #define PROFILES_PER_PAGE \
488 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
490 static int ftrace_profile_enabled __read_mostly;
492 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
493 static DEFINE_MUTEX(ftrace_profile_lock);
495 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
497 #define FTRACE_PROFILE_HASH_BITS 10
498 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
501 function_stat_next(void *v, int idx)
503 struct ftrace_profile *rec = v;
504 struct ftrace_profile_page *pg;
506 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
512 if ((void *)rec >= (void *)&pg->records[pg->index]) {
516 rec = &pg->records[0];
524 static void *function_stat_start(struct tracer_stat *trace)
526 struct ftrace_profile_stat *stat =
527 container_of(trace, struct ftrace_profile_stat, stat);
529 if (!stat || !stat->start)
532 return function_stat_next(&stat->start->records[0], 0);
535 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
536 /* function graph compares on total time */
537 static int function_stat_cmp(void *p1, void *p2)
539 struct ftrace_profile *a = p1;
540 struct ftrace_profile *b = p2;
542 if (a->time < b->time)
544 if (a->time > b->time)
550 /* not function graph compares against hits */
551 static int function_stat_cmp(void *p1, void *p2)
553 struct ftrace_profile *a = p1;
554 struct ftrace_profile *b = p2;
556 if (a->counter < b->counter)
558 if (a->counter > b->counter)
565 static int function_stat_headers(struct seq_file *m)
567 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
568 seq_printf(m, " Function "
571 "--- ---- --- ---\n");
573 seq_printf(m, " Function Hit\n"
579 static int function_stat_show(struct seq_file *m, void *v)
581 struct ftrace_profile *rec = v;
582 char str[KSYM_SYMBOL_LEN];
584 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
585 static struct trace_seq s;
586 unsigned long long avg;
587 unsigned long long stddev;
589 mutex_lock(&ftrace_profile_lock);
591 /* we raced with function_profile_reset() */
592 if (unlikely(rec->counter == 0)) {
597 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
598 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
600 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
603 do_div(avg, rec->counter);
605 /* Sample standard deviation (s^2) */
606 if (rec->counter <= 1)
610 * Apply Welford's method:
611 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
613 stddev = rec->counter * rec->time_squared -
614 rec->time * rec->time;
617 * Divide only 1000 for ns^2 -> us^2 conversion.
618 * trace_print_graph_duration will divide 1000 again.
620 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
624 trace_print_graph_duration(rec->time, &s);
625 trace_seq_puts(&s, " ");
626 trace_print_graph_duration(avg, &s);
627 trace_seq_puts(&s, " ");
628 trace_print_graph_duration(stddev, &s);
629 trace_print_seq(m, &s);
633 mutex_unlock(&ftrace_profile_lock);
638 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
640 struct ftrace_profile_page *pg;
642 pg = stat->pages = stat->start;
645 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
650 memset(stat->hash, 0,
651 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
654 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
656 struct ftrace_profile_page *pg;
661 /* If we already allocated, do nothing */
665 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
669 #ifdef CONFIG_DYNAMIC_FTRACE
670 functions = ftrace_update_tot_cnt;
673 * We do not know the number of functions that exist because
674 * dynamic tracing is what counts them. With past experience
675 * we have around 20K functions. That should be more than enough.
676 * It is highly unlikely we will execute every function in
682 pg = stat->start = stat->pages;
684 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
686 for (i = 1; i < pages; i++) {
687 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
698 unsigned long tmp = (unsigned long)pg;
710 static int ftrace_profile_init_cpu(int cpu)
712 struct ftrace_profile_stat *stat;
715 stat = &per_cpu(ftrace_profile_stats, cpu);
718 /* If the profile is already created, simply reset it */
719 ftrace_profile_reset(stat);
724 * We are profiling all functions, but usually only a few thousand
725 * functions are hit. We'll make a hash of 1024 items.
727 size = FTRACE_PROFILE_HASH_SIZE;
729 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
734 /* Preallocate the function profiling pages */
735 if (ftrace_profile_pages_init(stat) < 0) {
744 static int ftrace_profile_init(void)
749 for_each_possible_cpu(cpu) {
750 ret = ftrace_profile_init_cpu(cpu);
758 /* interrupts must be disabled */
759 static struct ftrace_profile *
760 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
762 struct ftrace_profile *rec;
763 struct hlist_head *hhd;
766 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
767 hhd = &stat->hash[key];
769 if (hlist_empty(hhd))
772 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
780 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
781 struct ftrace_profile *rec)
785 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
786 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
790 * The memory is already allocated, this simply finds a new record to use.
792 static struct ftrace_profile *
793 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
795 struct ftrace_profile *rec = NULL;
797 /* prevent recursion (from NMIs) */
798 if (atomic_inc_return(&stat->disabled) != 1)
802 * Try to find the function again since an NMI
803 * could have added it
805 rec = ftrace_find_profiled_func(stat, ip);
809 if (stat->pages->index == PROFILES_PER_PAGE) {
810 if (!stat->pages->next)
812 stat->pages = stat->pages->next;
815 rec = &stat->pages->records[stat->pages->index++];
817 ftrace_add_profile(stat, rec);
820 atomic_dec(&stat->disabled);
826 function_profile_call(unsigned long ip, unsigned long parent_ip,
827 struct ftrace_ops *ops, struct pt_regs *regs)
829 struct ftrace_profile_stat *stat;
830 struct ftrace_profile *rec;
833 if (!ftrace_profile_enabled)
836 local_irq_save(flags);
838 stat = this_cpu_ptr(&ftrace_profile_stats);
839 if (!stat->hash || !ftrace_profile_enabled)
842 rec = ftrace_find_profiled_func(stat, ip);
844 rec = ftrace_profile_alloc(stat, ip);
851 local_irq_restore(flags);
854 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
855 static int profile_graph_entry(struct ftrace_graph_ent *trace)
857 function_profile_call(trace->func, 0, NULL, NULL);
861 static void profile_graph_return(struct ftrace_graph_ret *trace)
863 struct ftrace_profile_stat *stat;
864 unsigned long long calltime;
865 struct ftrace_profile *rec;
868 local_irq_save(flags);
869 stat = this_cpu_ptr(&ftrace_profile_stats);
870 if (!stat->hash || !ftrace_profile_enabled)
873 /* If the calltime was zero'd ignore it */
874 if (!trace->calltime)
877 calltime = trace->rettime - trace->calltime;
879 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
882 index = trace->depth;
884 /* Append this call time to the parent time to subtract */
886 current->ret_stack[index - 1].subtime += calltime;
888 if (current->ret_stack[index].subtime < calltime)
889 calltime -= current->ret_stack[index].subtime;
894 rec = ftrace_find_profiled_func(stat, trace->func);
896 rec->time += calltime;
897 rec->time_squared += calltime * calltime;
901 local_irq_restore(flags);
904 static int register_ftrace_profiler(void)
906 return register_ftrace_graph(&profile_graph_return,
907 &profile_graph_entry);
910 static void unregister_ftrace_profiler(void)
912 unregister_ftrace_graph();
915 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
916 .func = function_profile_call,
917 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
918 INIT_OPS_HASH(ftrace_profile_ops)
921 static int register_ftrace_profiler(void)
923 return register_ftrace_function(&ftrace_profile_ops);
926 static void unregister_ftrace_profiler(void)
928 unregister_ftrace_function(&ftrace_profile_ops);
930 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
933 ftrace_profile_write(struct file *filp, const char __user *ubuf,
934 size_t cnt, loff_t *ppos)
939 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
945 mutex_lock(&ftrace_profile_lock);
946 if (ftrace_profile_enabled ^ val) {
948 ret = ftrace_profile_init();
954 ret = register_ftrace_profiler();
959 ftrace_profile_enabled = 1;
961 ftrace_profile_enabled = 0;
963 * unregister_ftrace_profiler calls stop_machine
964 * so this acts like an synchronize_sched.
966 unregister_ftrace_profiler();
970 mutex_unlock(&ftrace_profile_lock);
978 ftrace_profile_read(struct file *filp, char __user *ubuf,
979 size_t cnt, loff_t *ppos)
981 char buf[64]; /* big enough to hold a number */
984 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
985 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
988 static const struct file_operations ftrace_profile_fops = {
989 .open = tracing_open_generic,
990 .read = ftrace_profile_read,
991 .write = ftrace_profile_write,
992 .llseek = default_llseek,
995 /* used to initialize the real stat files */
996 static struct tracer_stat function_stats __initdata = {
998 .stat_start = function_stat_start,
999 .stat_next = function_stat_next,
1000 .stat_cmp = function_stat_cmp,
1001 .stat_headers = function_stat_headers,
1002 .stat_show = function_stat_show
1005 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1007 struct ftrace_profile_stat *stat;
1008 struct dentry *entry;
1013 for_each_possible_cpu(cpu) {
1014 stat = &per_cpu(ftrace_profile_stats, cpu);
1016 /* allocate enough for function name + cpu number */
1017 name = kmalloc(32, GFP_KERNEL);
1020 * The files created are permanent, if something happens
1021 * we still do not free memory.
1024 "Could not allocate stat file for cpu %d\n",
1028 stat->stat = function_stats;
1029 snprintf(name, 32, "function%d", cpu);
1030 stat->stat.name = name;
1031 ret = register_stat_tracer(&stat->stat);
1034 "Could not register function stat for cpu %d\n",
1041 entry = debugfs_create_file("function_profile_enabled", 0644,
1042 d_tracer, NULL, &ftrace_profile_fops);
1044 pr_warning("Could not create debugfs "
1045 "'function_profile_enabled' entry\n");
1048 #else /* CONFIG_FUNCTION_PROFILER */
1049 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1052 #endif /* CONFIG_FUNCTION_PROFILER */
1054 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1056 #ifdef CONFIG_DYNAMIC_FTRACE
1058 static struct ftrace_ops *removed_ops;
1061 * Set when doing a global update, like enabling all recs or disabling them.
1062 * It is not set when just updating a single ftrace_ops.
1064 static bool update_all_ops;
1066 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1067 # error Dynamic ftrace depends on MCOUNT_RECORD
1070 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1072 struct ftrace_func_probe {
1073 struct hlist_node node;
1074 struct ftrace_probe_ops *ops;
1075 unsigned long flags;
1078 struct list_head free_list;
1081 struct ftrace_func_entry {
1082 struct hlist_node hlist;
1086 struct ftrace_hash {
1087 unsigned long size_bits;
1088 struct hlist_head *buckets;
1089 unsigned long count;
1090 struct rcu_head rcu;
1094 * We make these constant because no one should touch them,
1095 * but they are used as the default "empty hash", to avoid allocating
1096 * it all the time. These are in a read only section such that if
1097 * anyone does try to modify it, it will cause an exception.
1099 static const struct hlist_head empty_buckets[1];
1100 static const struct ftrace_hash empty_hash = {
1101 .buckets = (struct hlist_head *)empty_buckets,
1103 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1105 static struct ftrace_ops global_ops = {
1106 .func = ftrace_stub,
1107 .local_hash.notrace_hash = EMPTY_HASH,
1108 .local_hash.filter_hash = EMPTY_HASH,
1109 INIT_OPS_HASH(global_ops)
1110 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1111 FTRACE_OPS_FL_INITIALIZED,
1114 struct ftrace_page {
1115 struct ftrace_page *next;
1116 struct dyn_ftrace *records;
1121 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1122 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1124 /* estimate from running different kernels */
1125 #define NR_TO_INIT 10000
1127 static struct ftrace_page *ftrace_pages_start;
1128 static struct ftrace_page *ftrace_pages;
1130 static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
1132 return !hash || !hash->count;
1135 static struct ftrace_func_entry *
1136 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1139 struct ftrace_func_entry *entry;
1140 struct hlist_head *hhd;
1142 if (ftrace_hash_empty(hash))
1145 if (hash->size_bits > 0)
1146 key = hash_long(ip, hash->size_bits);
1150 hhd = &hash->buckets[key];
1152 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1153 if (entry->ip == ip)
1159 static void __add_hash_entry(struct ftrace_hash *hash,
1160 struct ftrace_func_entry *entry)
1162 struct hlist_head *hhd;
1165 if (hash->size_bits)
1166 key = hash_long(entry->ip, hash->size_bits);
1170 hhd = &hash->buckets[key];
1171 hlist_add_head(&entry->hlist, hhd);
1175 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1177 struct ftrace_func_entry *entry;
1179 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1184 __add_hash_entry(hash, entry);
1190 free_hash_entry(struct ftrace_hash *hash,
1191 struct ftrace_func_entry *entry)
1193 hlist_del(&entry->hlist);
1199 remove_hash_entry(struct ftrace_hash *hash,
1200 struct ftrace_func_entry *entry)
1202 hlist_del(&entry->hlist);
1206 static void ftrace_hash_clear(struct ftrace_hash *hash)
1208 struct hlist_head *hhd;
1209 struct hlist_node *tn;
1210 struct ftrace_func_entry *entry;
1211 int size = 1 << hash->size_bits;
1217 for (i = 0; i < size; i++) {
1218 hhd = &hash->buckets[i];
1219 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1220 free_hash_entry(hash, entry);
1222 FTRACE_WARN_ON(hash->count);
1225 static void free_ftrace_hash(struct ftrace_hash *hash)
1227 if (!hash || hash == EMPTY_HASH)
1229 ftrace_hash_clear(hash);
1230 kfree(hash->buckets);
1234 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1236 struct ftrace_hash *hash;
1238 hash = container_of(rcu, struct ftrace_hash, rcu);
1239 free_ftrace_hash(hash);
1242 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1244 if (!hash || hash == EMPTY_HASH)
1246 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1249 void ftrace_free_filter(struct ftrace_ops *ops)
1251 ftrace_ops_init(ops);
1252 free_ftrace_hash(ops->func_hash->filter_hash);
1253 free_ftrace_hash(ops->func_hash->notrace_hash);
1256 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1258 struct ftrace_hash *hash;
1261 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1265 size = 1 << size_bits;
1266 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1268 if (!hash->buckets) {
1273 hash->size_bits = size_bits;
1278 static struct ftrace_hash *
1279 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1281 struct ftrace_func_entry *entry;
1282 struct ftrace_hash *new_hash;
1287 new_hash = alloc_ftrace_hash(size_bits);
1292 if (ftrace_hash_empty(hash))
1295 size = 1 << hash->size_bits;
1296 for (i = 0; i < size; i++) {
1297 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1298 ret = add_hash_entry(new_hash, entry->ip);
1304 FTRACE_WARN_ON(new_hash->count != hash->count);
1309 free_ftrace_hash(new_hash);
1314 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1316 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1319 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1320 struct ftrace_hash **dst, struct ftrace_hash *src)
1322 struct ftrace_func_entry *entry;
1323 struct hlist_node *tn;
1324 struct hlist_head *hhd;
1325 struct ftrace_hash *new_hash;
1326 int size = src->count;
1331 * If the new source is empty, just free dst and assign it
1335 new_hash = EMPTY_HASH;
1340 * Make the hash size about 1/2 the # found
1342 for (size /= 2; size; size >>= 1)
1345 /* Don't allocate too much */
1346 if (bits > FTRACE_HASH_MAX_BITS)
1347 bits = FTRACE_HASH_MAX_BITS;
1349 new_hash = alloc_ftrace_hash(bits);
1353 size = 1 << src->size_bits;
1354 for (i = 0; i < size; i++) {
1355 hhd = &src->buckets[i];
1356 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1357 remove_hash_entry(src, entry);
1358 __add_hash_entry(new_hash, entry);
1364 * Remove the current set, update the hash and add
1367 ftrace_hash_rec_disable_modify(ops, enable);
1369 rcu_assign_pointer(*dst, new_hash);
1371 ftrace_hash_rec_enable_modify(ops, enable);
1376 static bool hash_contains_ip(unsigned long ip,
1377 struct ftrace_ops_hash *hash)
1380 * The function record is a match if it exists in the filter
1381 * hash and not in the notrace hash. Note, an emty hash is
1382 * considered a match for the filter hash, but an empty
1383 * notrace hash is considered not in the notrace hash.
1385 return (ftrace_hash_empty(hash->filter_hash) ||
1386 ftrace_lookup_ip(hash->filter_hash, ip)) &&
1387 (ftrace_hash_empty(hash->notrace_hash) ||
1388 !ftrace_lookup_ip(hash->notrace_hash, ip));
1392 * Test the hashes for this ops to see if we want to call
1393 * the ops->func or not.
1395 * It's a match if the ip is in the ops->filter_hash or
1396 * the filter_hash does not exist or is empty,
1398 * the ip is not in the ops->notrace_hash.
1400 * This needs to be called with preemption disabled as
1401 * the hashes are freed with call_rcu_sched().
1404 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1406 struct ftrace_ops_hash hash;
1409 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1411 * There's a small race when adding ops that the ftrace handler
1412 * that wants regs, may be called without them. We can not
1413 * allow that handler to be called if regs is NULL.
1415 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1419 hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
1420 hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
1422 if (hash_contains_ip(ip, &hash))
1431 * This is a double for. Do not use 'break' to break out of the loop,
1432 * you must use a goto.
1434 #define do_for_each_ftrace_rec(pg, rec) \
1435 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1437 for (_____i = 0; _____i < pg->index; _____i++) { \
1438 rec = &pg->records[_____i];
1440 #define while_for_each_ftrace_rec() \
1445 static int ftrace_cmp_recs(const void *a, const void *b)
1447 const struct dyn_ftrace *key = a;
1448 const struct dyn_ftrace *rec = b;
1450 if (key->flags < rec->ip)
1452 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1457 static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1459 struct ftrace_page *pg;
1460 struct dyn_ftrace *rec;
1461 struct dyn_ftrace key;
1464 key.flags = end; /* overload flags, as it is unsigned long */
1466 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1467 if (end < pg->records[0].ip ||
1468 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1470 rec = bsearch(&key, pg->records, pg->index,
1471 sizeof(struct dyn_ftrace),
1481 * ftrace_location - return true if the ip giving is a traced location
1482 * @ip: the instruction pointer to check
1484 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1485 * That is, the instruction that is either a NOP or call to
1486 * the function tracer. It checks the ftrace internal tables to
1487 * determine if the address belongs or not.
1489 unsigned long ftrace_location(unsigned long ip)
1491 return ftrace_location_range(ip, ip);
1495 * ftrace_text_reserved - return true if range contains an ftrace location
1496 * @start: start of range to search
1497 * @end: end of range to search (inclusive). @end points to the last byte to check.
1499 * Returns 1 if @start and @end contains a ftrace location.
1500 * That is, the instruction that is either a NOP or call to
1501 * the function tracer. It checks the ftrace internal tables to
1502 * determine if the address belongs or not.
1504 int ftrace_text_reserved(const void *start, const void *end)
1508 ret = ftrace_location_range((unsigned long)start,
1509 (unsigned long)end);
1514 /* Test if ops registered to this rec needs regs */
1515 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1517 struct ftrace_ops *ops;
1518 bool keep_regs = false;
1520 for (ops = ftrace_ops_list;
1521 ops != &ftrace_list_end; ops = ops->next) {
1522 /* pass rec in as regs to have non-NULL val */
1523 if (ftrace_ops_test(ops, rec->ip, rec)) {
1524 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1534 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1538 struct ftrace_hash *hash;
1539 struct ftrace_hash *other_hash;
1540 struct ftrace_page *pg;
1541 struct dyn_ftrace *rec;
1545 /* Only update if the ops has been registered */
1546 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1550 * In the filter_hash case:
1551 * If the count is zero, we update all records.
1552 * Otherwise we just update the items in the hash.
1554 * In the notrace_hash case:
1555 * We enable the update in the hash.
1556 * As disabling notrace means enabling the tracing,
1557 * and enabling notrace means disabling, the inc variable
1561 hash = ops->func_hash->filter_hash;
1562 other_hash = ops->func_hash->notrace_hash;
1563 if (ftrace_hash_empty(hash))
1567 hash = ops->func_hash->notrace_hash;
1568 other_hash = ops->func_hash->filter_hash;
1570 * If the notrace hash has no items,
1571 * then there's nothing to do.
1573 if (ftrace_hash_empty(hash))
1577 do_for_each_ftrace_rec(pg, rec) {
1578 int in_other_hash = 0;
1584 * Only the filter_hash affects all records.
1585 * Update if the record is not in the notrace hash.
1587 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1590 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1591 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1594 * If filter_hash is set, we want to match all functions
1595 * that are in the hash but not in the other hash.
1597 * If filter_hash is not set, then we are decrementing.
1598 * That means we match anything that is in the hash
1599 * and also in the other_hash. That is, we need to turn
1600 * off functions in the other hash because they are disabled
1603 if (filter_hash && in_hash && !in_other_hash)
1605 else if (!filter_hash && in_hash &&
1606 (in_other_hash || ftrace_hash_empty(other_hash)))
1614 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1618 * If there's only a single callback registered to a
1619 * function, and the ops has a trampoline registered
1620 * for it, then we can call it directly.
1622 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1623 rec->flags |= FTRACE_FL_TRAMP;
1626 * If we are adding another function callback
1627 * to this function, and the previous had a
1628 * custom trampoline in use, then we need to go
1629 * back to the default trampoline.
1631 rec->flags &= ~FTRACE_FL_TRAMP;
1634 * If any ops wants regs saved for this function
1635 * then all ops will get saved regs.
1637 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1638 rec->flags |= FTRACE_FL_REGS;
1640 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1645 * If the rec had REGS enabled and the ops that is
1646 * being removed had REGS set, then see if there is
1647 * still any ops for this record that wants regs.
1648 * If not, we can stop recording them.
1650 if (ftrace_rec_count(rec) > 0 &&
1651 rec->flags & FTRACE_FL_REGS &&
1652 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1653 if (!test_rec_ops_needs_regs(rec))
1654 rec->flags &= ~FTRACE_FL_REGS;
1658 * If the rec had TRAMP enabled, then it needs to
1659 * be cleared. As TRAMP can only be enabled iff
1660 * there is only a single ops attached to it.
1661 * In otherwords, always disable it on decrementing.
1662 * In the future, we may set it if rec count is
1663 * decremented to one, and the ops that is left
1666 rec->flags &= ~FTRACE_FL_TRAMP;
1669 * flags will be cleared in ftrace_check_record()
1670 * if rec count is zero.
1674 /* Shortcut, if we handled all records, we are done. */
1675 if (!all && count == hash->count)
1677 } while_for_each_ftrace_rec();
1680 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1683 __ftrace_hash_rec_update(ops, filter_hash, 0);
1686 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1689 __ftrace_hash_rec_update(ops, filter_hash, 1);
1692 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1693 int filter_hash, int inc)
1695 struct ftrace_ops *op;
1697 __ftrace_hash_rec_update(ops, filter_hash, inc);
1699 if (ops->func_hash != &global_ops.local_hash)
1703 * If the ops shares the global_ops hash, then we need to update
1704 * all ops that are enabled and use this hash.
1706 do_for_each_ftrace_op(op, ftrace_ops_list) {
1710 if (op->func_hash == &global_ops.local_hash)
1711 __ftrace_hash_rec_update(op, filter_hash, inc);
1712 } while_for_each_ftrace_op(op);
1715 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1718 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1721 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1724 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1727 static void print_ip_ins(const char *fmt, unsigned char *p)
1731 printk(KERN_CONT "%s", fmt);
1733 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1734 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1738 * ftrace_bug - report and shutdown function tracer
1739 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1740 * @ip: The address that failed
1742 * The arch code that enables or disables the function tracing
1743 * can call ftrace_bug() when it has detected a problem in
1744 * modifying the code. @failed should be one of either:
1745 * EFAULT - if the problem happens on reading the @ip address
1746 * EINVAL - if what is read at @ip is not what was expected
1747 * EPERM - if the problem happens on writting to the @ip address
1749 void ftrace_bug(int failed, unsigned long ip)
1753 FTRACE_WARN_ON_ONCE(1);
1754 pr_info("ftrace faulted on modifying ");
1758 FTRACE_WARN_ON_ONCE(1);
1759 pr_info("ftrace failed to modify ");
1761 print_ip_ins(" actual: ", (unsigned char *)ip);
1762 printk(KERN_CONT "\n");
1765 FTRACE_WARN_ON_ONCE(1);
1766 pr_info("ftrace faulted on writing ");
1770 FTRACE_WARN_ON_ONCE(1);
1771 pr_info("ftrace faulted on unknown error ");
1776 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
1778 unsigned long flag = 0UL;
1781 * If we are updating calls:
1783 * If the record has a ref count, then we need to enable it
1784 * because someone is using it.
1786 * Otherwise we make sure its disabled.
1788 * If we are disabling calls, then disable all records that
1791 if (enable && ftrace_rec_count(rec))
1792 flag = FTRACE_FL_ENABLED;
1795 * If enabling and the REGS flag does not match the REGS_EN, or
1796 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
1797 * this record. Set flags to fail the compare against ENABLED.
1800 if (!(rec->flags & FTRACE_FL_REGS) !=
1801 !(rec->flags & FTRACE_FL_REGS_EN))
1802 flag |= FTRACE_FL_REGS;
1804 if (!(rec->flags & FTRACE_FL_TRAMP) !=
1805 !(rec->flags & FTRACE_FL_TRAMP_EN))
1806 flag |= FTRACE_FL_TRAMP;
1809 /* If the state of this record hasn't changed, then do nothing */
1810 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1811 return FTRACE_UPDATE_IGNORE;
1814 /* Save off if rec is being enabled (for return value) */
1815 flag ^= rec->flags & FTRACE_FL_ENABLED;
1818 rec->flags |= FTRACE_FL_ENABLED;
1819 if (flag & FTRACE_FL_REGS) {
1820 if (rec->flags & FTRACE_FL_REGS)
1821 rec->flags |= FTRACE_FL_REGS_EN;
1823 rec->flags &= ~FTRACE_FL_REGS_EN;
1825 if (flag & FTRACE_FL_TRAMP) {
1826 if (rec->flags & FTRACE_FL_TRAMP)
1827 rec->flags |= FTRACE_FL_TRAMP_EN;
1829 rec->flags &= ~FTRACE_FL_TRAMP_EN;
1834 * If this record is being updated from a nop, then
1835 * return UPDATE_MAKE_CALL.
1837 * return UPDATE_MODIFY_CALL to tell the caller to convert
1838 * from the save regs, to a non-save regs function or
1839 * vice versa, or from a trampoline call.
1841 if (flag & FTRACE_FL_ENABLED)
1842 return FTRACE_UPDATE_MAKE_CALL;
1844 return FTRACE_UPDATE_MODIFY_CALL;
1848 /* If there's no more users, clear all flags */
1849 if (!ftrace_rec_count(rec))
1852 /* Just disable the record (keep REGS state) */
1853 rec->flags &= ~FTRACE_FL_ENABLED;
1856 return FTRACE_UPDATE_MAKE_NOP;
1860 * ftrace_update_record, set a record that now is tracing or not
1861 * @rec: the record to update
1862 * @enable: set to 1 if the record is tracing, zero to force disable
1864 * The records that represent all functions that can be traced need
1865 * to be updated when tracing has been enabled.
1867 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1869 return ftrace_check_record(rec, enable, 1);
1873 * ftrace_test_record, check if the record has been enabled or not
1874 * @rec: the record to test
1875 * @enable: set to 1 to check if enabled, 0 if it is disabled
1877 * The arch code may need to test if a record is already set to
1878 * tracing to determine how to modify the function code that it
1881 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1883 return ftrace_check_record(rec, enable, 0);
1886 static struct ftrace_ops *
1887 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
1889 struct ftrace_ops *op;
1890 unsigned long ip = rec->ip;
1892 do_for_each_ftrace_op(op, ftrace_ops_list) {
1894 if (!op->trampoline)
1897 if (hash_contains_ip(ip, op->func_hash))
1899 } while_for_each_ftrace_op(op);
1904 static struct ftrace_ops *
1905 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
1907 struct ftrace_ops *op;
1908 unsigned long ip = rec->ip;
1911 * Need to check removed ops first.
1912 * If they are being removed, and this rec has a tramp,
1913 * and this rec is in the ops list, then it would be the
1914 * one with the tramp.
1917 if (hash_contains_ip(ip, &removed_ops->old_hash))
1922 * Need to find the current trampoline for a rec.
1923 * Now, a trampoline is only attached to a rec if there
1924 * was a single 'ops' attached to it. But this can be called
1925 * when we are adding another op to the rec or removing the
1926 * current one. Thus, if the op is being added, we can
1927 * ignore it because it hasn't attached itself to the rec
1928 * yet. That means we just need to find the op that has a
1929 * trampoline and is not beeing added.
1931 do_for_each_ftrace_op(op, ftrace_ops_list) {
1933 if (!op->trampoline)
1937 * If the ops is being added, it hasn't gotten to
1938 * the point to be removed from this tree yet.
1940 if (op->flags & FTRACE_OPS_FL_ADDING)
1944 * If the ops is not being added and has a trampoline,
1945 * then it must be the one that we want!
1947 if (hash_contains_ip(ip, op->func_hash))
1950 /* If the ops is being modified, it may be in the old hash. */
1951 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
1952 hash_contains_ip(ip, &op->old_hash))
1955 } while_for_each_ftrace_op(op);
1960 static struct ftrace_ops *
1961 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
1963 struct ftrace_ops *op;
1964 unsigned long ip = rec->ip;
1966 do_for_each_ftrace_op(op, ftrace_ops_list) {
1967 /* pass rec in as regs to have non-NULL val */
1968 if (hash_contains_ip(ip, op->func_hash))
1970 } while_for_each_ftrace_op(op);
1976 * ftrace_get_addr_new - Get the call address to set to
1977 * @rec: The ftrace record descriptor
1979 * If the record has the FTRACE_FL_REGS set, that means that it
1980 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
1981 * is not not set, then it wants to convert to the normal callback.
1983 * Returns the address of the trampoline to set to
1985 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
1987 struct ftrace_ops *ops;
1989 /* Trampolines take precedence over regs */
1990 if (rec->flags & FTRACE_FL_TRAMP) {
1991 ops = ftrace_find_tramp_ops_new(rec);
1992 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
1993 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
1994 (void *)rec->ip, (void *)rec->ip, rec->flags);
1995 /* Ftrace is shutting down, return anything */
1996 return (unsigned long)FTRACE_ADDR;
1998 return ops->trampoline;
2001 if (rec->flags & FTRACE_FL_REGS)
2002 return (unsigned long)FTRACE_REGS_ADDR;
2004 return (unsigned long)FTRACE_ADDR;
2008 * ftrace_get_addr_curr - Get the call address that is already there
2009 * @rec: The ftrace record descriptor
2011 * The FTRACE_FL_REGS_EN is set when the record already points to
2012 * a function that saves all the regs. Basically the '_EN' version
2013 * represents the current state of the function.
2015 * Returns the address of the trampoline that is currently being called
2017 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2019 struct ftrace_ops *ops;
2021 /* Trampolines take precedence over regs */
2022 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2023 ops = ftrace_find_tramp_ops_curr(rec);
2024 if (FTRACE_WARN_ON(!ops)) {
2025 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
2026 (void *)rec->ip, (void *)rec->ip);
2027 /* Ftrace is shutting down, return anything */
2028 return (unsigned long)FTRACE_ADDR;
2030 return ops->trampoline;
2033 if (rec->flags & FTRACE_FL_REGS_EN)
2034 return (unsigned long)FTRACE_REGS_ADDR;
2036 return (unsigned long)FTRACE_ADDR;
2040 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2042 unsigned long ftrace_old_addr;
2043 unsigned long ftrace_addr;
2046 ftrace_addr = ftrace_get_addr_new(rec);
2048 /* This needs to be done before we call ftrace_update_record */
2049 ftrace_old_addr = ftrace_get_addr_curr(rec);
2051 ret = ftrace_update_record(rec, enable);
2054 case FTRACE_UPDATE_IGNORE:
2057 case FTRACE_UPDATE_MAKE_CALL:
2058 return ftrace_make_call(rec, ftrace_addr);
2060 case FTRACE_UPDATE_MAKE_NOP:
2061 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2063 case FTRACE_UPDATE_MODIFY_CALL:
2064 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2067 return -1; /* unknow ftrace bug */
2070 void __weak ftrace_replace_code(int enable)
2072 struct dyn_ftrace *rec;
2073 struct ftrace_page *pg;
2076 if (unlikely(ftrace_disabled))
2079 do_for_each_ftrace_rec(pg, rec) {
2080 failed = __ftrace_replace_code(rec, enable);
2082 ftrace_bug(failed, rec->ip);
2083 /* Stop processing */
2086 } while_for_each_ftrace_rec();
2089 struct ftrace_rec_iter {
2090 struct ftrace_page *pg;
2095 * ftrace_rec_iter_start, start up iterating over traced functions
2097 * Returns an iterator handle that is used to iterate over all
2098 * the records that represent address locations where functions
2101 * May return NULL if no records are available.
2103 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2106 * We only use a single iterator.
2107 * Protected by the ftrace_lock mutex.
2109 static struct ftrace_rec_iter ftrace_rec_iter;
2110 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2112 iter->pg = ftrace_pages_start;
2115 /* Could have empty pages */
2116 while (iter->pg && !iter->pg->index)
2117 iter->pg = iter->pg->next;
2126 * ftrace_rec_iter_next, get the next record to process.
2127 * @iter: The handle to the iterator.
2129 * Returns the next iterator after the given iterator @iter.
2131 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2135 if (iter->index >= iter->pg->index) {
2136 iter->pg = iter->pg->next;
2139 /* Could have empty pages */
2140 while (iter->pg && !iter->pg->index)
2141 iter->pg = iter->pg->next;
2151 * ftrace_rec_iter_record, get the record at the iterator location
2152 * @iter: The current iterator location
2154 * Returns the record that the current @iter is at.
2156 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2158 return &iter->pg->records[iter->index];
2162 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2169 if (unlikely(ftrace_disabled))
2172 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2174 ftrace_bug(ret, ip);
2181 * archs can override this function if they must do something
2182 * before the modifying code is performed.
2184 int __weak ftrace_arch_code_modify_prepare(void)
2190 * archs can override this function if they must do something
2191 * after the modifying code is performed.
2193 int __weak ftrace_arch_code_modify_post_process(void)
2198 void ftrace_modify_all_code(int command)
2200 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2204 * If the ftrace_caller calls a ftrace_ops func directly,
2205 * we need to make sure that it only traces functions it
2206 * expects to trace. When doing the switch of functions,
2207 * we need to update to the ftrace_ops_list_func first
2208 * before the transition between old and new calls are set,
2209 * as the ftrace_ops_list_func will check the ops hashes
2210 * to make sure the ops are having the right functions
2214 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2215 if (FTRACE_WARN_ON(err))
2219 if (command & FTRACE_UPDATE_CALLS)
2220 ftrace_replace_code(1);
2221 else if (command & FTRACE_DISABLE_CALLS)
2222 ftrace_replace_code(0);
2224 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2225 function_trace_op = set_function_trace_op;
2227 /* If irqs are disabled, we are in stop machine */
2228 if (!irqs_disabled())
2229 smp_call_function(ftrace_sync_ipi, NULL, 1);
2230 err = ftrace_update_ftrace_func(ftrace_trace_function);
2231 if (FTRACE_WARN_ON(err))
2235 if (command & FTRACE_START_FUNC_RET)
2236 err = ftrace_enable_ftrace_graph_caller();
2237 else if (command & FTRACE_STOP_FUNC_RET)
2238 err = ftrace_disable_ftrace_graph_caller();
2239 FTRACE_WARN_ON(err);
2242 static int __ftrace_modify_code(void *data)
2244 int *command = data;
2246 ftrace_modify_all_code(*command);
2252 * ftrace_run_stop_machine, go back to the stop machine method
2253 * @command: The command to tell ftrace what to do
2255 * If an arch needs to fall back to the stop machine method, the
2256 * it can call this function.
2258 void ftrace_run_stop_machine(int command)
2260 stop_machine(__ftrace_modify_code, &command, NULL);
2264 * arch_ftrace_update_code, modify the code to trace or not trace
2265 * @command: The command that needs to be done
2267 * Archs can override this function if it does not need to
2268 * run stop_machine() to modify code.
2270 void __weak arch_ftrace_update_code(int command)
2272 ftrace_run_stop_machine(command);
2275 static void ftrace_run_update_code(int command)
2279 ret = ftrace_arch_code_modify_prepare();
2280 FTRACE_WARN_ON(ret);
2285 * By default we use stop_machine() to modify the code.
2286 * But archs can do what ever they want as long as it
2287 * is safe. The stop_machine() is the safest, but also
2288 * produces the most overhead.
2290 arch_ftrace_update_code(command);
2292 ret = ftrace_arch_code_modify_post_process();
2293 FTRACE_WARN_ON(ret);
2296 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command)
2298 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2299 ftrace_run_update_code(command);
2300 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2303 static ftrace_func_t saved_ftrace_func;
2304 static int ftrace_start_up;
2306 static void control_ops_free(struct ftrace_ops *ops)
2308 free_percpu(ops->disabled);
2311 static void ftrace_startup_enable(int command)
2313 if (saved_ftrace_func != ftrace_trace_function) {
2314 saved_ftrace_func = ftrace_trace_function;
2315 command |= FTRACE_UPDATE_TRACE_FUNC;
2318 if (!command || !ftrace_enabled)
2321 ftrace_run_update_code(command);
2324 static void ftrace_startup_all(int command)
2326 update_all_ops = true;
2327 ftrace_startup_enable(command);
2328 update_all_ops = false;
2331 static int ftrace_startup(struct ftrace_ops *ops, int command)
2335 if (unlikely(ftrace_disabled))
2338 ret = __register_ftrace_function(ops);
2343 command |= FTRACE_UPDATE_CALLS;
2346 * Note that ftrace probes uses this to start up
2347 * and modify functions it will probe. But we still
2348 * set the ADDING flag for modification, as probes
2349 * do not have trampolines. If they add them in the
2350 * future, then the probes will need to distinguish
2351 * between adding and updating probes.
2353 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2355 ftrace_hash_rec_enable(ops, 1);
2357 ftrace_startup_enable(command);
2359 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2364 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2368 if (unlikely(ftrace_disabled))
2371 ret = __unregister_ftrace_function(ops);
2377 * Just warn in case of unbalance, no need to kill ftrace, it's not
2378 * critical but the ftrace_call callers may be never nopped again after
2379 * further ftrace uses.
2381 WARN_ON_ONCE(ftrace_start_up < 0);
2383 ftrace_hash_rec_disable(ops, 1);
2385 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2387 command |= FTRACE_UPDATE_CALLS;
2389 if (saved_ftrace_func != ftrace_trace_function) {
2390 saved_ftrace_func = ftrace_trace_function;
2391 command |= FTRACE_UPDATE_TRACE_FUNC;
2394 if (!command || !ftrace_enabled) {
2396 * If these are control ops, they still need their
2397 * per_cpu field freed. Since, function tracing is
2398 * not currently active, we can just free them
2399 * without synchronizing all CPUs.
2401 if (ops->flags & FTRACE_OPS_FL_CONTROL)
2402 control_ops_free(ops);
2407 * If the ops uses a trampoline, then it needs to be
2408 * tested first on update.
2410 ops->flags |= FTRACE_OPS_FL_REMOVING;
2413 /* The trampoline logic checks the old hashes */
2414 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2415 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2417 ftrace_run_update_code(command);
2420 * If there's no more ops registered with ftrace, run a
2421 * sanity check to make sure all rec flags are cleared.
2423 if (ftrace_ops_list == &ftrace_list_end) {
2424 struct ftrace_page *pg;
2425 struct dyn_ftrace *rec;
2427 do_for_each_ftrace_rec(pg, rec) {
2428 if (FTRACE_WARN_ON_ONCE(rec->flags))
2429 pr_warn(" %pS flags:%lx\n",
2430 (void *)rec->ip, rec->flags);
2431 } while_for_each_ftrace_rec();
2434 ops->old_hash.filter_hash = NULL;
2435 ops->old_hash.notrace_hash = NULL;
2438 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2441 * Dynamic ops may be freed, we must make sure that all
2442 * callers are done before leaving this function.
2443 * The same goes for freeing the per_cpu data of the control
2446 * Again, normal synchronize_sched() is not good enough.
2447 * We need to do a hard force of sched synchronization.
2448 * This is because we use preempt_disable() to do RCU, but
2449 * the function tracers can be called where RCU is not watching
2450 * (like before user_exit()). We can not rely on the RCU
2451 * infrastructure to do the synchronization, thus we must do it
2454 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
2455 schedule_on_each_cpu(ftrace_sync);
2457 if (ops->flags & FTRACE_OPS_FL_CONTROL)
2458 control_ops_free(ops);
2464 static void ftrace_startup_sysctl(void)
2466 if (unlikely(ftrace_disabled))
2469 /* Force update next time */
2470 saved_ftrace_func = NULL;
2471 /* ftrace_start_up is true if we want ftrace running */
2472 if (ftrace_start_up)
2473 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
2476 static void ftrace_shutdown_sysctl(void)
2478 if (unlikely(ftrace_disabled))
2481 /* ftrace_start_up is true if ftrace is running */
2482 if (ftrace_start_up)
2483 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
2486 static cycle_t ftrace_update_time;
2487 unsigned long ftrace_update_tot_cnt;
2489 static inline int ops_traces_mod(struct ftrace_ops *ops)
2492 * Filter_hash being empty will default to trace module.
2493 * But notrace hash requires a test of individual module functions.
2495 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2496 ftrace_hash_empty(ops->func_hash->notrace_hash);
2500 * Check if the current ops references the record.
2502 * If the ops traces all functions, then it was already accounted for.
2503 * If the ops does not trace the current record function, skip it.
2504 * If the ops ignores the function via notrace filter, skip it.
2507 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2509 /* If ops isn't enabled, ignore it */
2510 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2513 /* If ops traces all mods, we already accounted for it */
2514 if (ops_traces_mod(ops))
2517 /* The function must be in the filter */
2518 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2519 !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2522 /* If in notrace hash, we ignore it too */
2523 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2529 static int referenced_filters(struct dyn_ftrace *rec)
2531 struct ftrace_ops *ops;
2534 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
2535 if (ops_references_rec(ops, rec))
2542 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2544 struct ftrace_page *pg;
2545 struct dyn_ftrace *p;
2546 cycle_t start, stop;
2547 unsigned long update_cnt = 0;
2548 unsigned long ref = 0;
2553 * When adding a module, we need to check if tracers are
2554 * currently enabled and if they are set to trace all functions.
2555 * If they are, we need to enable the module functions as well
2556 * as update the reference counts for those function records.
2559 struct ftrace_ops *ops;
2561 for (ops = ftrace_ops_list;
2562 ops != &ftrace_list_end; ops = ops->next) {
2563 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
2564 if (ops_traces_mod(ops))
2572 start = ftrace_now(raw_smp_processor_id());
2574 for (pg = new_pgs; pg; pg = pg->next) {
2576 for (i = 0; i < pg->index; i++) {
2579 /* If something went wrong, bail without enabling anything */
2580 if (unlikely(ftrace_disabled))
2583 p = &pg->records[i];
2585 cnt += referenced_filters(p);
2589 * Do the initial record conversion from mcount jump
2590 * to the NOP instructions.
2592 if (!ftrace_code_disable(mod, p))
2598 * If the tracing is enabled, go ahead and enable the record.
2600 * The reason not to enable the record immediatelly is the
2601 * inherent check of ftrace_make_nop/ftrace_make_call for
2602 * correct previous instructions. Making first the NOP
2603 * conversion puts the module to the correct state, thus
2604 * passing the ftrace_make_call check.
2606 if (ftrace_start_up && cnt) {
2607 int failed = __ftrace_replace_code(p, 1);
2609 ftrace_bug(failed, p->ip);
2614 stop = ftrace_now(raw_smp_processor_id());
2615 ftrace_update_time = stop - start;
2616 ftrace_update_tot_cnt += update_cnt;
2621 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2626 if (WARN_ON(!count))
2629 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2632 * We want to fill as much as possible. No more than a page
2635 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2639 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2642 /* if we can't allocate this size, try something smaller */
2649 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2658 static struct ftrace_page *
2659 ftrace_allocate_pages(unsigned long num_to_init)
2661 struct ftrace_page *start_pg;
2662 struct ftrace_page *pg;
2669 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2674 * Try to allocate as much as possible in one continues
2675 * location that fills in all of the space. We want to
2676 * waste as little space as possible.
2679 cnt = ftrace_allocate_records(pg, num_to_init);
2687 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2699 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2700 free_pages((unsigned long)pg->records, order);
2701 start_pg = pg->next;
2705 pr_info("ftrace: FAILED to allocate memory for functions\n");
2709 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2711 struct ftrace_iterator {
2714 struct ftrace_page *pg;
2715 struct dyn_ftrace *func;
2716 struct ftrace_func_probe *probe;
2717 struct trace_parser parser;
2718 struct ftrace_hash *hash;
2719 struct ftrace_ops *ops;
2726 t_hash_next(struct seq_file *m, loff_t *pos)
2728 struct ftrace_iterator *iter = m->private;
2729 struct hlist_node *hnd = NULL;
2730 struct hlist_head *hhd;
2736 hnd = &iter->probe->node;
2738 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2741 hhd = &ftrace_func_hash[iter->hidx];
2743 if (hlist_empty(hhd)) {
2759 if (WARN_ON_ONCE(!hnd))
2762 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2767 static void *t_hash_start(struct seq_file *m, loff_t *pos)
2769 struct ftrace_iterator *iter = m->private;
2773 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2776 if (iter->func_pos > *pos)
2780 for (l = 0; l <= (*pos - iter->func_pos); ) {
2781 p = t_hash_next(m, &l);
2788 /* Only set this if we have an item */
2789 iter->flags |= FTRACE_ITER_HASH;
2795 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2797 struct ftrace_func_probe *rec;
2800 if (WARN_ON_ONCE(!rec))
2803 if (rec->ops->print)
2804 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2806 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2809 seq_printf(m, ":%p", rec->data);
2816 t_next(struct seq_file *m, void *v, loff_t *pos)
2818 struct ftrace_iterator *iter = m->private;
2819 struct ftrace_ops *ops = iter->ops;
2820 struct dyn_ftrace *rec = NULL;
2822 if (unlikely(ftrace_disabled))
2825 if (iter->flags & FTRACE_ITER_HASH)
2826 return t_hash_next(m, pos);
2829 iter->pos = iter->func_pos = *pos;
2831 if (iter->flags & FTRACE_ITER_PRINTALL)
2832 return t_hash_start(m, pos);
2835 if (iter->idx >= iter->pg->index) {
2836 if (iter->pg->next) {
2837 iter->pg = iter->pg->next;
2842 rec = &iter->pg->records[iter->idx++];
2843 if (((iter->flags & FTRACE_ITER_FILTER) &&
2844 !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) ||
2846 ((iter->flags & FTRACE_ITER_NOTRACE) &&
2847 !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) ||
2849 ((iter->flags & FTRACE_ITER_ENABLED) &&
2850 !(rec->flags & FTRACE_FL_ENABLED))) {
2858 return t_hash_start(m, pos);
2865 static void reset_iter_read(struct ftrace_iterator *iter)
2869 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
2872 static void *t_start(struct seq_file *m, loff_t *pos)
2874 struct ftrace_iterator *iter = m->private;
2875 struct ftrace_ops *ops = iter->ops;
2879 mutex_lock(&ftrace_lock);
2881 if (unlikely(ftrace_disabled))
2885 * If an lseek was done, then reset and start from beginning.
2887 if (*pos < iter->pos)
2888 reset_iter_read(iter);
2891 * For set_ftrace_filter reading, if we have the filter
2892 * off, we can short cut and just print out that all
2893 * functions are enabled.
2895 if ((iter->flags & FTRACE_ITER_FILTER &&
2896 ftrace_hash_empty(ops->func_hash->filter_hash)) ||
2897 (iter->flags & FTRACE_ITER_NOTRACE &&
2898 ftrace_hash_empty(ops->func_hash->notrace_hash))) {
2900 return t_hash_start(m, pos);
2901 iter->flags |= FTRACE_ITER_PRINTALL;
2902 /* reset in case of seek/pread */
2903 iter->flags &= ~FTRACE_ITER_HASH;
2907 if (iter->flags & FTRACE_ITER_HASH)
2908 return t_hash_start(m, pos);
2911 * Unfortunately, we need to restart at ftrace_pages_start
2912 * every time we let go of the ftrace_mutex. This is because
2913 * those pointers can change without the lock.
2915 iter->pg = ftrace_pages_start;
2917 for (l = 0; l <= *pos; ) {
2918 p = t_next(m, p, &l);
2924 return t_hash_start(m, pos);
2929 static void t_stop(struct seq_file *m, void *p)
2931 mutex_unlock(&ftrace_lock);
2934 static int t_show(struct seq_file *m, void *v)
2936 struct ftrace_iterator *iter = m->private;
2937 struct dyn_ftrace *rec;
2939 if (iter->flags & FTRACE_ITER_HASH)
2940 return t_hash_show(m, iter);
2942 if (iter->flags & FTRACE_ITER_PRINTALL) {
2943 if (iter->flags & FTRACE_ITER_NOTRACE)
2944 seq_printf(m, "#### no functions disabled ####\n");
2946 seq_printf(m, "#### all functions enabled ####\n");
2955 seq_printf(m, "%ps", (void *)rec->ip);
2956 if (iter->flags & FTRACE_ITER_ENABLED) {
2957 seq_printf(m, " (%ld)%s",
2958 ftrace_rec_count(rec),
2959 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2960 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2961 struct ftrace_ops *ops;
2963 ops = ftrace_find_tramp_ops_any(rec);
2965 seq_printf(m, "\ttramp: %pS",
2966 (void *)ops->trampoline);
2968 seq_printf(m, "\ttramp: ERROR!");
2972 seq_printf(m, "\n");
2977 static const struct seq_operations show_ftrace_seq_ops = {
2985 ftrace_avail_open(struct inode *inode, struct file *file)
2987 struct ftrace_iterator *iter;
2989 if (unlikely(ftrace_disabled))
2992 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2994 iter->pg = ftrace_pages_start;
2995 iter->ops = &global_ops;
2998 return iter ? 0 : -ENOMEM;
3002 ftrace_enabled_open(struct inode *inode, struct file *file)
3004 struct ftrace_iterator *iter;
3006 if (unlikely(ftrace_disabled))
3009 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3011 iter->pg = ftrace_pages_start;
3012 iter->flags = FTRACE_ITER_ENABLED;
3013 iter->ops = &global_ops;
3016 return iter ? 0 : -ENOMEM;
3020 * ftrace_regex_open - initialize function tracer filter files
3021 * @ops: The ftrace_ops that hold the hash filters
3022 * @flag: The type of filter to process
3023 * @inode: The inode, usually passed in to your open routine
3024 * @file: The file, usually passed in to your open routine
3026 * ftrace_regex_open() initializes the filter files for the
3027 * @ops. Depending on @flag it may process the filter hash or
3028 * the notrace hash of @ops. With this called from the open
3029 * routine, you can use ftrace_filter_write() for the write
3030 * routine if @flag has FTRACE_ITER_FILTER set, or
3031 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3032 * tracing_lseek() should be used as the lseek routine, and
3033 * release must call ftrace_regex_release().
3036 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3037 struct inode *inode, struct file *file)
3039 struct ftrace_iterator *iter;
3040 struct ftrace_hash *hash;
3043 ftrace_ops_init(ops);
3045 if (unlikely(ftrace_disabled))
3048 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3052 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3060 mutex_lock(&ops->func_hash->regex_lock);
3062 if (flag & FTRACE_ITER_NOTRACE)
3063 hash = ops->func_hash->notrace_hash;
3065 hash = ops->func_hash->filter_hash;
3067 if (file->f_mode & FMODE_WRITE) {
3068 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3070 if (file->f_flags & O_TRUNC)
3071 iter->hash = alloc_ftrace_hash(size_bits);
3073 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3076 trace_parser_put(&iter->parser);
3083 if (file->f_mode & FMODE_READ) {
3084 iter->pg = ftrace_pages_start;
3086 ret = seq_open(file, &show_ftrace_seq_ops);
3088 struct seq_file *m = file->private_data;
3092 free_ftrace_hash(iter->hash);
3093 trace_parser_put(&iter->parser);
3097 file->private_data = iter;
3100 mutex_unlock(&ops->func_hash->regex_lock);
3106 ftrace_filter_open(struct inode *inode, struct file *file)
3108 struct ftrace_ops *ops = inode->i_private;
3110 return ftrace_regex_open(ops,
3111 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
3116 ftrace_notrace_open(struct inode *inode, struct file *file)
3118 struct ftrace_ops *ops = inode->i_private;
3120 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3124 static int ftrace_match(char *str, char *regex, int len, int type)
3131 if (strcmp(str, regex) == 0)
3134 case MATCH_FRONT_ONLY:
3135 if (strncmp(str, regex, len) == 0)
3138 case MATCH_MIDDLE_ONLY:
3139 if (strstr(str, regex))
3142 case MATCH_END_ONLY:
3144 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
3153 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
3155 struct ftrace_func_entry *entry;
3158 entry = ftrace_lookup_ip(hash, rec->ip);
3160 /* Do nothing if it doesn't exist */
3164 free_hash_entry(hash, entry);
3166 /* Do nothing if it exists */
3170 ret = add_hash_entry(hash, rec->ip);
3176 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
3177 char *regex, int len, int type)
3179 char str[KSYM_SYMBOL_LEN];
3182 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3185 /* module lookup requires matching the module */
3186 if (!modname || strcmp(modname, mod))
3189 /* blank search means to match all funcs in the mod */
3194 return ftrace_match(str, regex, len, type);
3198 match_records(struct ftrace_hash *hash, char *buff,
3199 int len, char *mod, int not)
3201 unsigned search_len = 0;
3202 struct ftrace_page *pg;
3203 struct dyn_ftrace *rec;
3204 int type = MATCH_FULL;
3205 char *search = buff;
3210 type = filter_parse_regex(buff, len, &search, ¬);
3211 search_len = strlen(search);
3214 mutex_lock(&ftrace_lock);
3216 if (unlikely(ftrace_disabled))
3219 do_for_each_ftrace_rec(pg, rec) {
3220 if (ftrace_match_record(rec, mod, search, search_len, type)) {
3221 ret = enter_record(hash, rec, not);
3228 } while_for_each_ftrace_rec();
3230 mutex_unlock(&ftrace_lock);
3236 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3238 return match_records(hash, buff, len, NULL, 0);
3242 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
3246 /* blank or '*' mean the same */
3247 if (strcmp(buff, "*") == 0)
3250 /* handle the case of 'dont filter this module' */
3251 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
3256 return match_records(hash, buff, strlen(buff), mod, not);
3260 * We register the module command as a template to show others how
3261 * to register the a command as well.
3265 ftrace_mod_callback(struct ftrace_hash *hash,
3266 char *func, char *cmd, char *param, int enable)
3272 * cmd == 'mod' because we only registered this func
3273 * for the 'mod' ftrace_func_command.
3274 * But if you register one func with multiple commands,
3275 * you can tell which command was used by the cmd
3279 /* we must have a module name */
3283 mod = strsep(¶m, ":");
3287 ret = ftrace_match_module_records(hash, func, mod);
3296 static struct ftrace_func_command ftrace_mod_cmd = {
3298 .func = ftrace_mod_callback,
3301 static int __init ftrace_mod_cmd_init(void)
3303 return register_ftrace_command(&ftrace_mod_cmd);
3305 core_initcall(ftrace_mod_cmd_init);
3307 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
3308 struct ftrace_ops *op, struct pt_regs *pt_regs)
3310 struct ftrace_func_probe *entry;
3311 struct hlist_head *hhd;
3314 key = hash_long(ip, FTRACE_HASH_BITS);
3316 hhd = &ftrace_func_hash[key];
3318 if (hlist_empty(hhd))
3322 * Disable preemption for these calls to prevent a RCU grace
3323 * period. This syncs the hash iteration and freeing of items
3324 * on the hash. rcu_read_lock is too dangerous here.
3326 preempt_disable_notrace();
3327 hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
3328 if (entry->ip == ip)
3329 entry->ops->func(ip, parent_ip, &entry->data);
3331 preempt_enable_notrace();
3334 static struct ftrace_ops trace_probe_ops __read_mostly =
3336 .func = function_trace_probe_call,
3337 .flags = FTRACE_OPS_FL_INITIALIZED,
3338 INIT_OPS_HASH(trace_probe_ops)
3341 static int ftrace_probe_registered;
3343 static void __enable_ftrace_function_probe(void)
3348 if (ftrace_probe_registered) {
3349 /* still need to update the function call sites */
3351 ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS);
3355 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3356 struct hlist_head *hhd = &ftrace_func_hash[i];
3360 /* Nothing registered? */
3361 if (i == FTRACE_FUNC_HASHSIZE)
3364 ret = ftrace_startup(&trace_probe_ops, 0);
3366 ftrace_probe_registered = 1;
3369 static void __disable_ftrace_function_probe(void)
3373 if (!ftrace_probe_registered)
3376 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3377 struct hlist_head *hhd = &ftrace_func_hash[i];
3382 /* no more funcs left */
3383 ftrace_shutdown(&trace_probe_ops, 0);
3385 ftrace_probe_registered = 0;
3389 static void ftrace_free_entry(struct ftrace_func_probe *entry)
3391 if (entry->ops->free)
3392 entry->ops->free(entry->ops, entry->ip, &entry->data);
3397 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3400 struct ftrace_func_probe *entry;
3401 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
3402 struct ftrace_hash *old_hash = *orig_hash;
3403 struct ftrace_hash *hash;
3404 struct ftrace_page *pg;
3405 struct dyn_ftrace *rec;
3412 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3413 len = strlen(search);
3415 /* we do not support '!' for function probes */
3419 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
3421 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
3427 if (unlikely(ftrace_disabled)) {
3432 mutex_lock(&ftrace_lock);
3434 do_for_each_ftrace_rec(pg, rec) {
3436 if (!ftrace_match_record(rec, NULL, search, len, type))
3439 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3441 /* If we did not process any, then return error */
3452 * The caller might want to do something special
3453 * for each function we find. We call the callback
3454 * to give the caller an opportunity to do so.
3457 if (ops->init(ops, rec->ip, &entry->data) < 0) {
3458 /* caller does not like this func */
3464 ret = enter_record(hash, rec, 0);
3472 entry->ip = rec->ip;
3474 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3475 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3477 } while_for_each_ftrace_rec();
3479 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3481 free_ftrace_hash_rcu(old_hash);
3485 __enable_ftrace_function_probe();
3488 mutex_unlock(&ftrace_lock);
3490 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
3491 free_ftrace_hash(hash);
3497 PROBE_TEST_FUNC = 1,
3502 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3503 void *data, int flags)
3505 struct ftrace_func_entry *rec_entry;
3506 struct ftrace_func_probe *entry;
3507 struct ftrace_func_probe *p;
3508 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
3509 struct ftrace_hash *old_hash = *orig_hash;
3510 struct list_head free_list;
3511 struct ftrace_hash *hash;
3512 struct hlist_node *tmp;
3513 char str[KSYM_SYMBOL_LEN];
3514 int type = MATCH_FULL;
3519 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
3524 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3525 len = strlen(search);
3527 /* we do not support '!' for function probes */
3532 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
3534 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3536 /* Hmm, should report this somehow */
3539 INIT_LIST_HEAD(&free_list);
3541 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3542 struct hlist_head *hhd = &ftrace_func_hash[i];
3544 hlist_for_each_entry_safe(entry, tmp, hhd, node) {
3546 /* break up if statements for readability */
3547 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
3550 if ((flags & PROBE_TEST_DATA) && entry->data != data)
3553 /* do this last, since it is the most expensive */
3555 kallsyms_lookup(entry->ip, NULL, NULL,
3557 if (!ftrace_match(str, glob, len, type))
3561 rec_entry = ftrace_lookup_ip(hash, entry->ip);
3562 /* It is possible more than one entry had this ip */
3564 free_hash_entry(hash, rec_entry);
3566 hlist_del_rcu(&entry->node);
3567 list_add(&entry->free_list, &free_list);
3570 mutex_lock(&ftrace_lock);
3571 __disable_ftrace_function_probe();
3573 * Remove after the disable is called. Otherwise, if the last
3574 * probe is removed, a null hash means *all enabled*.
3576 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3577 synchronize_sched();
3579 free_ftrace_hash_rcu(old_hash);
3581 list_for_each_entry_safe(entry, p, &free_list, free_list) {
3582 list_del(&entry->free_list);
3583 ftrace_free_entry(entry);
3585 mutex_unlock(&ftrace_lock);
3588 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
3589 free_ftrace_hash(hash);
3593 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3596 __unregister_ftrace_function_probe(glob, ops, data,
3597 PROBE_TEST_FUNC | PROBE_TEST_DATA);
3601 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
3603 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
3606 void unregister_ftrace_function_probe_all(char *glob)
3608 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
3611 static LIST_HEAD(ftrace_commands);
3612 static DEFINE_MUTEX(ftrace_cmd_mutex);
3615 * Currently we only register ftrace commands from __init, so mark this
3618 __init int register_ftrace_command(struct ftrace_func_command *cmd)
3620 struct ftrace_func_command *p;
3623 mutex_lock(&ftrace_cmd_mutex);
3624 list_for_each_entry(p, &ftrace_commands, list) {
3625 if (strcmp(cmd->name, p->name) == 0) {
3630 list_add(&cmd->list, &ftrace_commands);
3632 mutex_unlock(&ftrace_cmd_mutex);
3638 * Currently we only unregister ftrace commands from __init, so mark
3641 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
3643 struct ftrace_func_command *p, *n;
3646 mutex_lock(&ftrace_cmd_mutex);
3647 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3648 if (strcmp(cmd->name, p->name) == 0) {
3650 list_del_init(&p->list);
3655 mutex_unlock(&ftrace_cmd_mutex);
3660 static int ftrace_process_regex(struct ftrace_hash *hash,
3661 char *buff, int len, int enable)
3663 char *func, *command, *next = buff;
3664 struct ftrace_func_command *p;
3667 func = strsep(&next, ":");
3670 ret = ftrace_match_records(hash, func, len);
3680 command = strsep(&next, ":");
3682 mutex_lock(&ftrace_cmd_mutex);
3683 list_for_each_entry(p, &ftrace_commands, list) {
3684 if (strcmp(p->name, command) == 0) {
3685 ret = p->func(hash, func, command, next, enable);
3690 mutex_unlock(&ftrace_cmd_mutex);
3696 ftrace_regex_write(struct file *file, const char __user *ubuf,
3697 size_t cnt, loff_t *ppos, int enable)
3699 struct ftrace_iterator *iter;
3700 struct trace_parser *parser;
3706 if (file->f_mode & FMODE_READ) {
3707 struct seq_file *m = file->private_data;
3710 iter = file->private_data;
3712 if (unlikely(ftrace_disabled))
3715 /* iter->hash is a local copy, so we don't need regex_lock */
3717 parser = &iter->parser;
3718 read = trace_get_user(parser, ubuf, cnt, ppos);
3720 if (read >= 0 && trace_parser_loaded(parser) &&
3721 !trace_parser_cont(parser)) {
3722 ret = ftrace_process_regex(iter->hash, parser->buffer,
3723 parser->idx, enable);
3724 trace_parser_clear(parser);
3735 ftrace_filter_write(struct file *file, const char __user *ubuf,
3736 size_t cnt, loff_t *ppos)
3738 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3742 ftrace_notrace_write(struct file *file, const char __user *ubuf,
3743 size_t cnt, loff_t *ppos)
3745 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3749 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
3751 struct ftrace_func_entry *entry;
3753 if (!ftrace_location(ip))
3757 entry = ftrace_lookup_ip(hash, ip);
3760 free_hash_entry(hash, entry);
3764 return add_hash_entry(hash, ip);
3767 static void ftrace_ops_update_code(struct ftrace_ops *ops)
3769 if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
3770 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS);
3774 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
3775 unsigned long ip, int remove, int reset, int enable)
3777 struct ftrace_hash **orig_hash;
3778 struct ftrace_hash *old_hash;
3779 struct ftrace_hash *hash;
3782 if (unlikely(ftrace_disabled))
3785 mutex_lock(&ops->func_hash->regex_lock);
3788 orig_hash = &ops->func_hash->filter_hash;
3790 orig_hash = &ops->func_hash->notrace_hash;
3793 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
3795 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3799 goto out_regex_unlock;
3802 if (buf && !ftrace_match_records(hash, buf, len)) {
3804 goto out_regex_unlock;
3807 ret = ftrace_match_addr(hash, ip, remove);
3809 goto out_regex_unlock;
3812 mutex_lock(&ftrace_lock);
3813 old_hash = *orig_hash;
3814 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3816 ftrace_ops_update_code(ops);
3817 free_ftrace_hash_rcu(old_hash);
3819 mutex_unlock(&ftrace_lock);
3822 mutex_unlock(&ops->func_hash->regex_lock);
3824 free_ftrace_hash(hash);
3829 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
3830 int reset, int enable)
3832 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
3836 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3837 * @ops - the ops to set the filter with
3838 * @ip - the address to add to or remove from the filter.
3839 * @remove - non zero to remove the ip from the filter
3840 * @reset - non zero to reset all filters before applying this filter.
3842 * Filters denote which functions should be enabled when tracing is enabled
3843 * If @ip is NULL, it failes to update filter.
3845 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
3846 int remove, int reset)
3848 ftrace_ops_init(ops);
3849 return ftrace_set_addr(ops, ip, remove, reset, 1);
3851 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
3854 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3855 int reset, int enable)
3857 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
3861 * ftrace_set_filter - set a function to filter on in ftrace
3862 * @ops - the ops to set the filter with
3863 * @buf - the string that holds the function filter text.
3864 * @len - the length of the string.
3865 * @reset - non zero to reset all filters before applying this filter.
3867 * Filters denote which functions should be enabled when tracing is enabled.
3868 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3870 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
3873 ftrace_ops_init(ops);
3874 return ftrace_set_regex(ops, buf, len, reset, 1);
3876 EXPORT_SYMBOL_GPL(ftrace_set_filter);
3879 * ftrace_set_notrace - set a function to not trace in ftrace
3880 * @ops - the ops to set the notrace filter with
3881 * @buf - the string that holds the function notrace text.
3882 * @len - the length of the string.
3883 * @reset - non zero to reset all filters before applying this filter.
3885 * Notrace Filters denote which functions should not be enabled when tracing
3886 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3889 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
3892 ftrace_ops_init(ops);
3893 return ftrace_set_regex(ops, buf, len, reset, 0);
3895 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3897 * ftrace_set_global_filter - set a function to filter on with global tracers
3898 * @buf - the string that holds the function filter text.
3899 * @len - the length of the string.
3900 * @reset - non zero to reset all filters before applying this filter.
3902 * Filters denote which functions should be enabled when tracing is enabled.
3903 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3905 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3907 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3909 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3912 * ftrace_set_global_notrace - set a function to not trace with global tracers
3913 * @buf - the string that holds the function notrace text.
3914 * @len - the length of the string.
3915 * @reset - non zero to reset all filters before applying this filter.
3917 * Notrace Filters denote which functions should not be enabled when tracing
3918 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3921 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
3923 ftrace_set_regex(&global_ops, buf, len, reset, 0);
3925 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
3928 * command line interface to allow users to set filters on boot up.
3930 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3931 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3932 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3934 /* Used by function selftest to not test if filter is set */
3935 bool ftrace_filter_param __initdata;
3937 static int __init set_ftrace_notrace(char *str)
3939 ftrace_filter_param = true;
3940 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3943 __setup("ftrace_notrace=", set_ftrace_notrace);
3945 static int __init set_ftrace_filter(char *str)
3947 ftrace_filter_param = true;
3948 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3951 __setup("ftrace_filter=", set_ftrace_filter);
3953 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3954 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3955 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3956 static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
3958 static int __init set_graph_function(char *str)
3960 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3963 __setup("ftrace_graph_filter=", set_graph_function);
3965 static int __init set_graph_notrace_function(char *str)
3967 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
3970 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
3972 static void __init set_ftrace_early_graph(char *buf, int enable)
3976 unsigned long *table = ftrace_graph_funcs;
3977 int *count = &ftrace_graph_count;
3980 table = ftrace_graph_notrace_funcs;
3981 count = &ftrace_graph_notrace_count;
3985 func = strsep(&buf, ",");
3986 /* we allow only one expression at a time */
3987 ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);
3989 printk(KERN_DEBUG "ftrace: function %s not "
3990 "traceable\n", func);
3993 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3996 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4000 ftrace_ops_init(ops);
4003 func = strsep(&buf, ",");
4004 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4008 static void __init set_ftrace_early_filters(void)
4010 if (ftrace_filter_buf[0])
4011 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4012 if (ftrace_notrace_buf[0])
4013 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4014 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4015 if (ftrace_graph_buf[0])
4016 set_ftrace_early_graph(ftrace_graph_buf, 1);
4017 if (ftrace_graph_notrace_buf[0])
4018 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4019 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4022 int ftrace_regex_release(struct inode *inode, struct file *file)
4024 struct seq_file *m = (struct seq_file *)file->private_data;
4025 struct ftrace_iterator *iter;
4026 struct ftrace_hash **orig_hash;
4027 struct ftrace_hash *old_hash;
4028 struct trace_parser *parser;
4032 if (file->f_mode & FMODE_READ) {
4034 seq_release(inode, file);
4036 iter = file->private_data;
4038 parser = &iter->parser;
4039 if (trace_parser_loaded(parser)) {
4040 parser->buffer[parser->idx] = 0;
4041 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
4044 trace_parser_put(parser);
4046 mutex_lock(&iter->ops->func_hash->regex_lock);
4048 if (file->f_mode & FMODE_WRITE) {
4049 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
4052 orig_hash = &iter->ops->func_hash->filter_hash;
4054 orig_hash = &iter->ops->func_hash->notrace_hash;
4056 mutex_lock(&ftrace_lock);
4057 old_hash = *orig_hash;
4058 ret = ftrace_hash_move(iter->ops, filter_hash,
4059 orig_hash, iter->hash);
4061 ftrace_ops_update_code(iter->ops);
4062 free_ftrace_hash_rcu(old_hash);
4064 mutex_unlock(&ftrace_lock);
4067 mutex_unlock(&iter->ops->func_hash->regex_lock);
4068 free_ftrace_hash(iter->hash);
4074 static const struct file_operations ftrace_avail_fops = {
4075 .open = ftrace_avail_open,
4077 .llseek = seq_lseek,
4078 .release = seq_release_private,
4081 static const struct file_operations ftrace_enabled_fops = {
4082 .open = ftrace_enabled_open,
4084 .llseek = seq_lseek,
4085 .release = seq_release_private,
4088 static const struct file_operations ftrace_filter_fops = {
4089 .open = ftrace_filter_open,
4091 .write = ftrace_filter_write,
4092 .llseek = tracing_lseek,
4093 .release = ftrace_regex_release,
4096 static const struct file_operations ftrace_notrace_fops = {
4097 .open = ftrace_notrace_open,
4099 .write = ftrace_notrace_write,
4100 .llseek = tracing_lseek,
4101 .release = ftrace_regex_release,
4104 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4106 static DEFINE_MUTEX(graph_lock);
4108 int ftrace_graph_count;
4109 int ftrace_graph_notrace_count;
4110 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
4111 unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
4113 struct ftrace_graph_data {
4114 unsigned long *table;
4117 const struct seq_operations *seq_ops;
4121 __g_next(struct seq_file *m, loff_t *pos)
4123 struct ftrace_graph_data *fgd = m->private;
4125 if (*pos >= *fgd->count)
4127 return &fgd->table[*pos];
4131 g_next(struct seq_file *m, void *v, loff_t *pos)
4134 return __g_next(m, pos);
4137 static void *g_start(struct seq_file *m, loff_t *pos)
4139 struct ftrace_graph_data *fgd = m->private;
4141 mutex_lock(&graph_lock);
4143 /* Nothing, tell g_show to print all functions are enabled */
4144 if (!*fgd->count && !*pos)
4147 return __g_next(m, pos);
4150 static void g_stop(struct seq_file *m, void *p)
4152 mutex_unlock(&graph_lock);
4155 static int g_show(struct seq_file *m, void *v)
4157 unsigned long *ptr = v;
4162 if (ptr == (unsigned long *)1) {
4163 struct ftrace_graph_data *fgd = m->private;
4165 if (fgd->table == ftrace_graph_funcs)
4166 seq_printf(m, "#### all functions enabled ####\n");
4168 seq_printf(m, "#### no functions disabled ####\n");
4172 seq_printf(m, "%ps\n", (void *)*ptr);
4177 static const struct seq_operations ftrace_graph_seq_ops = {
4185 __ftrace_graph_open(struct inode *inode, struct file *file,
4186 struct ftrace_graph_data *fgd)
4190 mutex_lock(&graph_lock);
4191 if ((file->f_mode & FMODE_WRITE) &&
4192 (file->f_flags & O_TRUNC)) {
4194 memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
4196 mutex_unlock(&graph_lock);
4198 if (file->f_mode & FMODE_READ) {
4199 ret = seq_open(file, fgd->seq_ops);
4201 struct seq_file *m = file->private_data;
4205 file->private_data = fgd;
4211 ftrace_graph_open(struct inode *inode, struct file *file)
4213 struct ftrace_graph_data *fgd;
4215 if (unlikely(ftrace_disabled))
4218 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4222 fgd->table = ftrace_graph_funcs;
4223 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4224 fgd->count = &ftrace_graph_count;
4225 fgd->seq_ops = &ftrace_graph_seq_ops;
4227 return __ftrace_graph_open(inode, file, fgd);
4231 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
4233 struct ftrace_graph_data *fgd;
4235 if (unlikely(ftrace_disabled))
4238 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4242 fgd->table = ftrace_graph_notrace_funcs;
4243 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4244 fgd->count = &ftrace_graph_notrace_count;
4245 fgd->seq_ops = &ftrace_graph_seq_ops;
4247 return __ftrace_graph_open(inode, file, fgd);
4251 ftrace_graph_release(struct inode *inode, struct file *file)
4253 if (file->f_mode & FMODE_READ) {
4254 struct seq_file *m = file->private_data;
4257 seq_release(inode, file);
4259 kfree(file->private_data);
4266 ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
4268 struct dyn_ftrace *rec;
4269 struct ftrace_page *pg;
4278 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
4279 if (!not && *idx >= size)
4282 search_len = strlen(search);
4284 mutex_lock(&ftrace_lock);
4286 if (unlikely(ftrace_disabled)) {
4287 mutex_unlock(&ftrace_lock);
4291 do_for_each_ftrace_rec(pg, rec) {
4293 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
4294 /* if it is in the array */
4296 for (i = 0; i < *idx; i++) {
4297 if (array[i] == rec->ip) {
4306 array[(*idx)++] = rec->ip;
4312 array[i] = array[--(*idx)];
4318 } while_for_each_ftrace_rec();
4320 mutex_unlock(&ftrace_lock);
4329 ftrace_graph_write(struct file *file, const char __user *ubuf,
4330 size_t cnt, loff_t *ppos)
4332 struct trace_parser parser;
4333 ssize_t read, ret = 0;
4334 struct ftrace_graph_data *fgd = file->private_data;
4339 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
4342 read = trace_get_user(&parser, ubuf, cnt, ppos);
4344 if (read >= 0 && trace_parser_loaded((&parser))) {
4345 parser.buffer[parser.idx] = 0;
4347 mutex_lock(&graph_lock);
4349 /* we allow only one expression at a time */
4350 ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
4353 mutex_unlock(&graph_lock);
4359 trace_parser_put(&parser);
4364 static const struct file_operations ftrace_graph_fops = {
4365 .open = ftrace_graph_open,
4367 .write = ftrace_graph_write,
4368 .llseek = tracing_lseek,
4369 .release = ftrace_graph_release,
4372 static const struct file_operations ftrace_graph_notrace_fops = {
4373 .open = ftrace_graph_notrace_open,
4375 .write = ftrace_graph_write,
4376 .llseek = tracing_lseek,
4377 .release = ftrace_graph_release,
4379 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4381 void ftrace_create_filter_files(struct ftrace_ops *ops,
4382 struct dentry *parent)
4385 trace_create_file("set_ftrace_filter", 0644, parent,
4386 ops, &ftrace_filter_fops);
4388 trace_create_file("set_ftrace_notrace", 0644, parent,
4389 ops, &ftrace_notrace_fops);
4393 * The name "destroy_filter_files" is really a misnomer. Although
4394 * in the future, it may actualy delete the files, but this is
4395 * really intended to make sure the ops passed in are disabled
4396 * and that when this function returns, the caller is free to
4399 * The "destroy" name is only to match the "create" name that this
4400 * should be paired with.
4402 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
4404 mutex_lock(&ftrace_lock);
4405 if (ops->flags & FTRACE_OPS_FL_ENABLED)
4406 ftrace_shutdown(ops, 0);
4407 ops->flags |= FTRACE_OPS_FL_DELETED;
4408 mutex_unlock(&ftrace_lock);
4411 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
4414 trace_create_file("available_filter_functions", 0444,
4415 d_tracer, NULL, &ftrace_avail_fops);
4417 trace_create_file("enabled_functions", 0444,
4418 d_tracer, NULL, &ftrace_enabled_fops);
4420 ftrace_create_filter_files(&global_ops, d_tracer);
4422 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4423 trace_create_file("set_graph_function", 0444, d_tracer,
4425 &ftrace_graph_fops);
4426 trace_create_file("set_graph_notrace", 0444, d_tracer,
4428 &ftrace_graph_notrace_fops);
4429 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4434 static int ftrace_cmp_ips(const void *a, const void *b)
4436 const unsigned long *ipa = a;
4437 const unsigned long *ipb = b;
4446 static void ftrace_swap_ips(void *a, void *b, int size)
4448 unsigned long *ipa = a;
4449 unsigned long *ipb = b;
4457 static int ftrace_process_locs(struct module *mod,
4458 unsigned long *start,
4461 struct ftrace_page *start_pg;
4462 struct ftrace_page *pg;
4463 struct dyn_ftrace *rec;
4464 unsigned long count;
4467 unsigned long flags = 0; /* Shut up gcc */
4470 count = end - start;
4475 sort(start, count, sizeof(*start),
4476 ftrace_cmp_ips, ftrace_swap_ips);
4478 start_pg = ftrace_allocate_pages(count);
4482 mutex_lock(&ftrace_lock);
4485 * Core and each module needs their own pages, as
4486 * modules will free them when they are removed.
4487 * Force a new page to be allocated for modules.
4490 WARN_ON(ftrace_pages || ftrace_pages_start);
4491 /* First initialization */
4492 ftrace_pages = ftrace_pages_start = start_pg;
4497 if (WARN_ON(ftrace_pages->next)) {
4498 /* Hmm, we have free pages? */
4499 while (ftrace_pages->next)
4500 ftrace_pages = ftrace_pages->next;
4503 ftrace_pages->next = start_pg;
4509 addr = ftrace_call_adjust(*p++);
4511 * Some architecture linkers will pad between
4512 * the different mcount_loc sections of different
4513 * object files to satisfy alignments.
4514 * Skip any NULL pointers.
4519 if (pg->index == pg->size) {
4520 /* We should have allocated enough */
4521 if (WARN_ON(!pg->next))
4526 rec = &pg->records[pg->index++];
4530 /* We should have used all pages */
4533 /* Assign the last page to ftrace_pages */
4537 * We only need to disable interrupts on start up
4538 * because we are modifying code that an interrupt
4539 * may execute, and the modification is not atomic.
4540 * But for modules, nothing runs the code we modify
4541 * until we are finished with it, and there's no
4542 * reason to cause large interrupt latencies while we do it.
4545 local_irq_save(flags);
4546 ftrace_update_code(mod, start_pg);
4548 local_irq_restore(flags);
4551 mutex_unlock(&ftrace_lock);
4556 #ifdef CONFIG_MODULES
4558 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4560 void ftrace_release_mod(struct module *mod)
4562 struct dyn_ftrace *rec;
4563 struct ftrace_page **last_pg;
4564 struct ftrace_page *pg;
4567 mutex_lock(&ftrace_lock);
4569 if (ftrace_disabled)
4573 * Each module has its own ftrace_pages, remove
4574 * them from the list.
4576 last_pg = &ftrace_pages_start;
4577 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
4578 rec = &pg->records[0];
4579 if (within_module_core(rec->ip, mod)) {
4581 * As core pages are first, the first
4582 * page should never be a module page.
4584 if (WARN_ON(pg == ftrace_pages_start))
4587 /* Check if we are deleting the last page */
4588 if (pg == ftrace_pages)
4589 ftrace_pages = next_to_ftrace_page(last_pg);
4591 *last_pg = pg->next;
4592 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
4593 free_pages((unsigned long)pg->records, order);
4596 last_pg = &pg->next;
4599 mutex_unlock(&ftrace_lock);
4602 static void ftrace_init_module(struct module *mod,
4603 unsigned long *start, unsigned long *end)
4605 if (ftrace_disabled || start == end)
4607 ftrace_process_locs(mod, start, end);
4610 void ftrace_module_init(struct module *mod)
4612 ftrace_init_module(mod, mod->ftrace_callsites,
4613 mod->ftrace_callsites +
4614 mod->num_ftrace_callsites);
4617 static int ftrace_module_notify_exit(struct notifier_block *self,
4618 unsigned long val, void *data)
4620 struct module *mod = data;
4622 if (val == MODULE_STATE_GOING)
4623 ftrace_release_mod(mod);
4628 static int ftrace_module_notify_exit(struct notifier_block *self,
4629 unsigned long val, void *data)
4633 #endif /* CONFIG_MODULES */
4635 struct notifier_block ftrace_module_exit_nb = {
4636 .notifier_call = ftrace_module_notify_exit,
4637 .priority = INT_MIN, /* Run after anything that can remove kprobes */
4640 void __init ftrace_init(void)
4642 extern unsigned long __start_mcount_loc[];
4643 extern unsigned long __stop_mcount_loc[];
4644 unsigned long count, flags;
4647 local_irq_save(flags);
4648 ret = ftrace_dyn_arch_init();
4649 local_irq_restore(flags);
4653 count = __stop_mcount_loc - __start_mcount_loc;
4655 pr_info("ftrace: No functions to be traced?\n");
4659 pr_info("ftrace: allocating %ld entries in %ld pages\n",
4660 count, count / ENTRIES_PER_PAGE + 1);
4662 last_ftrace_enabled = ftrace_enabled = 1;
4664 ret = ftrace_process_locs(NULL,
4668 ret = register_module_notifier(&ftrace_module_exit_nb);
4670 pr_warning("Failed to register trace ftrace module exit notifier\n");
4672 set_ftrace_early_filters();
4676 ftrace_disabled = 1;
4681 static struct ftrace_ops global_ops = {
4682 .func = ftrace_stub,
4683 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
4686 static int __init ftrace_nodyn_init(void)
4691 core_initcall(ftrace_nodyn_init);
4693 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
4694 static inline void ftrace_startup_enable(int command) { }
4695 static inline void ftrace_startup_all(int command) { }
4696 /* Keep as macros so we do not need to define the commands */
4697 # define ftrace_startup(ops, command) \
4699 int ___ret = __register_ftrace_function(ops); \
4701 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4704 # define ftrace_shutdown(ops, command) \
4706 int ___ret = __unregister_ftrace_function(ops); \
4708 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
4712 # define ftrace_startup_sysctl() do { } while (0)
4713 # define ftrace_shutdown_sysctl() do { } while (0)
4716 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
4721 #endif /* CONFIG_DYNAMIC_FTRACE */
4723 __init void ftrace_init_global_array_ops(struct trace_array *tr)
4725 tr->ops = &global_ops;
4726 tr->ops->private = tr;
4729 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
4731 /* If we filter on pids, update to use the pid function */
4732 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
4733 if (WARN_ON(tr->ops->func != ftrace_stub))
4734 printk("ftrace ops had %pS for function\n",
4736 /* Only the top level instance does pid tracing */
4737 if (!list_empty(&ftrace_pids)) {
4738 set_ftrace_pid_function(func);
4739 func = ftrace_pid_func;
4742 tr->ops->func = func;
4743 tr->ops->private = tr;
4746 void ftrace_reset_array_ops(struct trace_array *tr)
4748 tr->ops->func = ftrace_stub;
4752 ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
4753 struct ftrace_ops *op, struct pt_regs *regs)
4755 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
4759 * Some of the ops may be dynamically allocated,
4760 * they must be freed after a synchronize_sched().
4762 preempt_disable_notrace();
4763 trace_recursion_set(TRACE_CONTROL_BIT);
4766 * Control funcs (perf) uses RCU. Only trace if
4767 * RCU is currently active.
4769 if (!rcu_is_watching())
4772 do_for_each_ftrace_op(op, ftrace_control_list) {
4773 if (!(op->flags & FTRACE_OPS_FL_STUB) &&
4774 !ftrace_function_local_disabled(op) &&
4775 ftrace_ops_test(op, ip, regs))
4776 op->func(ip, parent_ip, op, regs);
4777 } while_for_each_ftrace_op(op);
4779 trace_recursion_clear(TRACE_CONTROL_BIT);
4780 preempt_enable_notrace();
4783 static struct ftrace_ops control_ops = {
4784 .func = ftrace_ops_control_func,
4785 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
4786 INIT_OPS_HASH(control_ops)
4790 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4791 struct ftrace_ops *ignored, struct pt_regs *regs)
4793 struct ftrace_ops *op;
4796 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4801 * Some of the ops may be dynamically allocated,
4802 * they must be freed after a synchronize_sched().
4804 preempt_disable_notrace();
4805 do_for_each_ftrace_op(op, ftrace_ops_list) {
4806 if (ftrace_ops_test(op, ip, regs)) {
4807 if (FTRACE_WARN_ON(!op->func)) {
4808 pr_warn("op=%p %pS\n", op, op);
4811 op->func(ip, parent_ip, op, regs);
4813 } while_for_each_ftrace_op(op);
4815 preempt_enable_notrace();
4816 trace_clear_recursion(bit);
4820 * Some archs only support passing ip and parent_ip. Even though
4821 * the list function ignores the op parameter, we do not want any
4822 * C side effects, where a function is called without the caller
4823 * sending a third parameter.
4824 * Archs are to support both the regs and ftrace_ops at the same time.
4825 * If they support ftrace_ops, it is assumed they support regs.
4826 * If call backs want to use regs, they must either check for regs
4827 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4828 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4829 * An architecture can pass partial regs with ftrace_ops and still
4830 * set the ARCH_SUPPORT_FTARCE_OPS.
4832 #if ARCH_SUPPORTS_FTRACE_OPS
4833 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4834 struct ftrace_ops *op, struct pt_regs *regs)
4836 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
4839 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
4841 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
4846 * If there's only one function registered but it does not support
4847 * recursion, this function will be called by the mcount trampoline.
4848 * This function will handle recursion protection.
4850 static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
4851 struct ftrace_ops *op, struct pt_regs *regs)
4855 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4859 op->func(ip, parent_ip, op, regs);
4861 trace_clear_recursion(bit);
4865 * ftrace_ops_get_func - get the function a trampoline should call
4866 * @ops: the ops to get the function for
4868 * Normally the mcount trampoline will call the ops->func, but there
4869 * are times that it should not. For example, if the ops does not
4870 * have its own recursion protection, then it should call the
4871 * ftrace_ops_recurs_func() instead.
4873 * Returns the function that the trampoline should call for @ops.
4875 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
4878 * If this is a dynamic ops or we force list func,
4879 * then it needs to call the list anyway.
4881 if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC)
4882 return ftrace_ops_list_func;
4885 * If the func handles its own recursion, call it directly.
4886 * Otherwise call the recursion protected function that
4887 * will call the ftrace ops function.
4889 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE))
4890 return ftrace_ops_recurs_func;
4895 static void clear_ftrace_swapper(void)
4897 struct task_struct *p;
4901 for_each_online_cpu(cpu) {
4903 clear_tsk_trace_trace(p);
4908 static void set_ftrace_swapper(void)
4910 struct task_struct *p;
4914 for_each_online_cpu(cpu) {
4916 set_tsk_trace_trace(p);
4921 static void clear_ftrace_pid(struct pid *pid)
4923 struct task_struct *p;
4926 do_each_pid_task(pid, PIDTYPE_PID, p) {
4927 clear_tsk_trace_trace(p);
4928 } while_each_pid_task(pid, PIDTYPE_PID, p);
4934 static void set_ftrace_pid(struct pid *pid)
4936 struct task_struct *p;
4939 do_each_pid_task(pid, PIDTYPE_PID, p) {
4940 set_tsk_trace_trace(p);
4941 } while_each_pid_task(pid, PIDTYPE_PID, p);
4945 static void clear_ftrace_pid_task(struct pid *pid)
4947 if (pid == ftrace_swapper_pid)
4948 clear_ftrace_swapper();
4950 clear_ftrace_pid(pid);
4953 static void set_ftrace_pid_task(struct pid *pid)
4955 if (pid == ftrace_swapper_pid)
4956 set_ftrace_swapper();
4958 set_ftrace_pid(pid);
4961 static int ftrace_pid_add(int p)
4964 struct ftrace_pid *fpid;
4967 mutex_lock(&ftrace_lock);
4970 pid = ftrace_swapper_pid;
4972 pid = find_get_pid(p);
4979 list_for_each_entry(fpid, &ftrace_pids, list)
4980 if (fpid->pid == pid)
4985 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4989 list_add(&fpid->list, &ftrace_pids);
4992 set_ftrace_pid_task(pid);
4994 ftrace_update_pid_func();
4996 ftrace_startup_all(0);
4998 mutex_unlock(&ftrace_lock);
5002 if (pid != ftrace_swapper_pid)
5006 mutex_unlock(&ftrace_lock);
5010 static void ftrace_pid_reset(void)
5012 struct ftrace_pid *fpid, *safe;
5014 mutex_lock(&ftrace_lock);
5015 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
5016 struct pid *pid = fpid->pid;
5018 clear_ftrace_pid_task(pid);
5020 list_del(&fpid->list);
5024 ftrace_update_pid_func();
5025 ftrace_startup_all(0);
5027 mutex_unlock(&ftrace_lock);
5030 static void *fpid_start(struct seq_file *m, loff_t *pos)
5032 mutex_lock(&ftrace_lock);
5034 if (list_empty(&ftrace_pids) && (!*pos))
5037 return seq_list_start(&ftrace_pids, *pos);
5040 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
5045 return seq_list_next(v, &ftrace_pids, pos);
5048 static void fpid_stop(struct seq_file *m, void *p)
5050 mutex_unlock(&ftrace_lock);
5053 static int fpid_show(struct seq_file *m, void *v)
5055 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
5057 if (v == (void *)1) {
5058 seq_printf(m, "no pid\n");
5062 if (fpid->pid == ftrace_swapper_pid)
5063 seq_printf(m, "swapper tasks\n");
5065 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
5070 static const struct seq_operations ftrace_pid_sops = {
5071 .start = fpid_start,
5078 ftrace_pid_open(struct inode *inode, struct file *file)
5082 if ((file->f_mode & FMODE_WRITE) &&
5083 (file->f_flags & O_TRUNC))
5086 if (file->f_mode & FMODE_READ)
5087 ret = seq_open(file, &ftrace_pid_sops);
5093 ftrace_pid_write(struct file *filp, const char __user *ubuf,
5094 size_t cnt, loff_t *ppos)
5100 if (cnt >= sizeof(buf))
5103 if (copy_from_user(&buf, ubuf, cnt))
5109 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5110 * to clean the filter quietly.
5112 tmp = strstrip(buf);
5113 if (strlen(tmp) == 0)
5116 ret = kstrtol(tmp, 10, &val);
5120 ret = ftrace_pid_add(val);
5122 return ret ? ret : cnt;
5126 ftrace_pid_release(struct inode *inode, struct file *file)
5128 if (file->f_mode & FMODE_READ)
5129 seq_release(inode, file);
5134 static const struct file_operations ftrace_pid_fops = {
5135 .open = ftrace_pid_open,
5136 .write = ftrace_pid_write,
5138 .llseek = tracing_lseek,
5139 .release = ftrace_pid_release,
5142 static __init int ftrace_init_debugfs(void)
5144 struct dentry *d_tracer;
5146 d_tracer = tracing_init_dentry();
5150 ftrace_init_dyn_debugfs(d_tracer);
5152 trace_create_file("set_ftrace_pid", 0644, d_tracer,
5153 NULL, &ftrace_pid_fops);
5155 ftrace_profile_debugfs(d_tracer);
5159 fs_initcall(ftrace_init_debugfs);
5162 * ftrace_kill - kill ftrace
5164 * This function should be used by panic code. It stops ftrace
5165 * but in a not so nice way. If you need to simply kill ftrace
5166 * from a non-atomic section, use ftrace_kill.
5168 void ftrace_kill(void)
5170 ftrace_disabled = 1;
5172 clear_ftrace_function();
5176 * Test if ftrace is dead or not.
5178 int ftrace_is_dead(void)
5180 return ftrace_disabled;
5184 * register_ftrace_function - register a function for profiling
5185 * @ops - ops structure that holds the function for profiling.
5187 * Register a function to be called by all functions in the
5190 * Note: @ops->func and all the functions it calls must be labeled
5191 * with "notrace", otherwise it will go into a
5194 int register_ftrace_function(struct ftrace_ops *ops)
5198 ftrace_ops_init(ops);
5200 mutex_lock(&ftrace_lock);
5202 ret = ftrace_startup(ops, 0);
5204 mutex_unlock(&ftrace_lock);
5208 EXPORT_SYMBOL_GPL(register_ftrace_function);
5211 * unregister_ftrace_function - unregister a function for profiling.
5212 * @ops - ops structure that holds the function to unregister
5214 * Unregister a function that was added to be called by ftrace profiling.
5216 int unregister_ftrace_function(struct ftrace_ops *ops)
5220 mutex_lock(&ftrace_lock);
5221 ret = ftrace_shutdown(ops, 0);
5222 mutex_unlock(&ftrace_lock);
5226 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
5229 ftrace_enable_sysctl(struct ctl_table *table, int write,
5230 void __user *buffer, size_t *lenp,
5235 mutex_lock(&ftrace_lock);
5237 if (unlikely(ftrace_disabled))
5240 ret = proc_dointvec(table, write, buffer, lenp, ppos);
5242 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
5245 last_ftrace_enabled = !!ftrace_enabled;
5247 if (ftrace_enabled) {
5249 ftrace_startup_sysctl();
5251 /* we are starting ftrace again */
5252 if (ftrace_ops_list != &ftrace_list_end)
5253 update_ftrace_function();
5256 /* stopping ftrace calls (just send to ftrace_stub) */
5257 ftrace_trace_function = ftrace_stub;
5259 ftrace_shutdown_sysctl();
5263 mutex_unlock(&ftrace_lock);
5267 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5269 static struct ftrace_ops graph_ops = {
5270 .func = ftrace_stub,
5271 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5272 FTRACE_OPS_FL_INITIALIZED |
5274 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5275 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
5277 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
5280 static int ftrace_graph_active;
5282 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
5287 /* The callbacks that hook a function */
5288 trace_func_graph_ret_t ftrace_graph_return =
5289 (trace_func_graph_ret_t)ftrace_stub;
5290 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
5291 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
5293 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5294 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
5298 unsigned long flags;
5299 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
5300 struct task_struct *g, *t;
5302 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
5303 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
5304 * sizeof(struct ftrace_ret_stack),
5306 if (!ret_stack_list[i]) {
5314 read_lock_irqsave(&tasklist_lock, flags);
5315 do_each_thread(g, t) {
5321 if (t->ret_stack == NULL) {
5322 atomic_set(&t->tracing_graph_pause, 0);
5323 atomic_set(&t->trace_overrun, 0);
5324 t->curr_ret_stack = -1;
5325 /* Make sure the tasks see the -1 first: */
5327 t->ret_stack = ret_stack_list[start++];
5329 } while_each_thread(g, t);
5332 read_unlock_irqrestore(&tasklist_lock, flags);
5334 for (i = start; i < end; i++)
5335 kfree(ret_stack_list[i]);
5340 ftrace_graph_probe_sched_switch(void *ignore,
5341 struct task_struct *prev, struct task_struct *next)
5343 unsigned long long timestamp;
5347 * Does the user want to count the time a function was asleep.
5348 * If so, do not update the time stamps.
5350 if (trace_flags & TRACE_ITER_SLEEP_TIME)
5353 timestamp = trace_clock_local();
5355 prev->ftrace_timestamp = timestamp;
5357 /* only process tasks that we timestamped */
5358 if (!next->ftrace_timestamp)
5362 * Update all the counters in next to make up for the
5363 * time next was sleeping.
5365 timestamp -= next->ftrace_timestamp;
5367 for (index = next->curr_ret_stack; index >= 0; index--)
5368 next->ret_stack[index].calltime += timestamp;
5371 /* Allocate a return stack for each task */
5372 static int start_graph_tracing(void)
5374 struct ftrace_ret_stack **ret_stack_list;
5377 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
5378 sizeof(struct ftrace_ret_stack *),
5381 if (!ret_stack_list)
5384 /* The cpu_boot init_task->ret_stack will never be freed */
5385 for_each_online_cpu(cpu) {
5386 if (!idle_task(cpu)->ret_stack)
5387 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
5391 ret = alloc_retstack_tasklist(ret_stack_list);
5392 } while (ret == -EAGAIN);
5395 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
5397 pr_info("ftrace_graph: Couldn't activate tracepoint"
5398 " probe to kernel_sched_switch\n");
5401 kfree(ret_stack_list);
5406 * Hibernation protection.
5407 * The state of the current task is too much unstable during
5408 * suspend/restore to disk. We want to protect against that.
5411 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
5415 case PM_HIBERNATION_PREPARE:
5416 pause_graph_tracing();
5419 case PM_POST_HIBERNATION:
5420 unpause_graph_tracing();
5426 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
5428 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
5430 return __ftrace_graph_entry(trace);
5434 * The function graph tracer should only trace the functions defined
5435 * by set_ftrace_filter and set_ftrace_notrace. If another function
5436 * tracer ops is registered, the graph tracer requires testing the
5437 * function against the global ops, and not just trace any function
5438 * that any ftrace_ops registered.
5440 static void update_function_graph_func(void)
5442 struct ftrace_ops *op;
5443 bool do_test = false;
5446 * The graph and global ops share the same set of functions
5447 * to test. If any other ops is on the list, then
5448 * the graph tracing needs to test if its the function
5451 do_for_each_ftrace_op(op, ftrace_ops_list) {
5452 if (op != &global_ops && op != &graph_ops &&
5453 op != &ftrace_list_end) {
5455 /* in double loop, break out with goto */
5458 } while_for_each_ftrace_op(op);
5461 ftrace_graph_entry = ftrace_graph_entry_test;
5463 ftrace_graph_entry = __ftrace_graph_entry;
5466 static struct notifier_block ftrace_suspend_notifier = {
5467 .notifier_call = ftrace_suspend_notifier_call,
5470 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
5471 trace_func_graph_ent_t entryfunc)
5475 mutex_lock(&ftrace_lock);
5477 /* we currently allow only one tracer registered at a time */
5478 if (ftrace_graph_active) {
5483 register_pm_notifier(&ftrace_suspend_notifier);
5485 ftrace_graph_active++;
5486 ret = start_graph_tracing();
5488 ftrace_graph_active--;
5492 ftrace_graph_return = retfunc;
5495 * Update the indirect function to the entryfunc, and the
5496 * function that gets called to the entry_test first. Then
5497 * call the update fgraph entry function to determine if
5498 * the entryfunc should be called directly or not.
5500 __ftrace_graph_entry = entryfunc;
5501 ftrace_graph_entry = ftrace_graph_entry_test;
5502 update_function_graph_func();
5504 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
5507 mutex_unlock(&ftrace_lock);
5511 void unregister_ftrace_graph(void)
5513 mutex_lock(&ftrace_lock);
5515 if (unlikely(!ftrace_graph_active))
5518 ftrace_graph_active--;
5519 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
5520 ftrace_graph_entry = ftrace_graph_entry_stub;
5521 __ftrace_graph_entry = ftrace_graph_entry_stub;
5522 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
5523 unregister_pm_notifier(&ftrace_suspend_notifier);
5524 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
5527 mutex_unlock(&ftrace_lock);
5530 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
5533 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
5535 atomic_set(&t->tracing_graph_pause, 0);
5536 atomic_set(&t->trace_overrun, 0);
5537 t->ftrace_timestamp = 0;
5538 /* make curr_ret_stack visible before we add the ret_stack */
5540 t->ret_stack = ret_stack;
5544 * Allocate a return stack for the idle task. May be the first
5545 * time through, or it may be done by CPU hotplug online.
5547 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
5549 t->curr_ret_stack = -1;
5551 * The idle task has no parent, it either has its own
5552 * stack or no stack at all.
5555 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
5557 if (ftrace_graph_active) {
5558 struct ftrace_ret_stack *ret_stack;
5560 ret_stack = per_cpu(idle_ret_stack, cpu);
5562 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
5563 * sizeof(struct ftrace_ret_stack),
5567 per_cpu(idle_ret_stack, cpu) = ret_stack;
5569 graph_init_task(t, ret_stack);
5573 /* Allocate a return stack for newly created task */
5574 void ftrace_graph_init_task(struct task_struct *t)
5576 /* Make sure we do not use the parent ret_stack */
5577 t->ret_stack = NULL;
5578 t->curr_ret_stack = -1;
5580 if (ftrace_graph_active) {
5581 struct ftrace_ret_stack *ret_stack;
5583 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
5584 * sizeof(struct ftrace_ret_stack),
5588 graph_init_task(t, ret_stack);
5592 void ftrace_graph_exit_task(struct task_struct *t)
5594 struct ftrace_ret_stack *ret_stack = t->ret_stack;
5596 t->ret_stack = NULL;
5597 /* NULL must become visible to IRQs before we free it: */