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/tracefs.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;
101 static bool ftrace_pids_enabled(void)
103 return !list_empty(&ftrace_pids);
106 static void ftrace_update_trampoline(struct ftrace_ops *ops);
109 * ftrace_disabled is set when an anomaly is discovered.
110 * ftrace_disabled is much stronger than ftrace_enabled.
112 static int ftrace_disabled __read_mostly;
114 static DEFINE_MUTEX(ftrace_lock);
116 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
117 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
118 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
119 static struct ftrace_ops global_ops;
120 static struct ftrace_ops control_ops;
122 static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
123 struct ftrace_ops *op, struct pt_regs *regs);
125 #if ARCH_SUPPORTS_FTRACE_OPS
126 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
127 struct ftrace_ops *op, struct pt_regs *regs);
129 /* See comment below, where ftrace_ops_list_func is defined */
130 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
131 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
135 * Traverse the ftrace_global_list, invoking all entries. The reason that we
136 * can use rcu_dereference_raw_notrace() is that elements removed from this list
137 * are simply leaked, so there is no need to interact with a grace-period
138 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
139 * concurrent insertions into the ftrace_global_list.
141 * Silly Alpha and silly pointer-speculation compiler optimizations!
143 #define do_for_each_ftrace_op(op, list) \
144 op = rcu_dereference_raw_notrace(list); \
148 * Optimized for just a single item in the list (as that is the normal case).
150 #define while_for_each_ftrace_op(op) \
151 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
152 unlikely((op) != &ftrace_list_end))
154 static inline void ftrace_ops_init(struct ftrace_ops *ops)
156 #ifdef CONFIG_DYNAMIC_FTRACE
157 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
158 mutex_init(&ops->local_hash.regex_lock);
159 ops->func_hash = &ops->local_hash;
160 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
166 * ftrace_nr_registered_ops - return number of ops registered
168 * Returns the number of ftrace_ops registered and tracing functions
170 int ftrace_nr_registered_ops(void)
172 struct ftrace_ops *ops;
175 mutex_lock(&ftrace_lock);
177 for (ops = ftrace_ops_list;
178 ops != &ftrace_list_end; ops = ops->next)
181 mutex_unlock(&ftrace_lock);
186 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
187 struct ftrace_ops *op, struct pt_regs *regs)
189 if (!test_tsk_trace_trace(current))
192 op->saved_func(ip, parent_ip, op, regs);
196 * clear_ftrace_function - reset the ftrace function
198 * This NULLs the ftrace function and in essence stops
199 * tracing. There may be lag
201 void clear_ftrace_function(void)
203 ftrace_trace_function = ftrace_stub;
206 static void control_ops_disable_all(struct ftrace_ops *ops)
210 for_each_possible_cpu(cpu)
211 *per_cpu_ptr(ops->disabled, cpu) = 1;
214 static int control_ops_alloc(struct ftrace_ops *ops)
216 int __percpu *disabled;
218 disabled = alloc_percpu(int);
222 ops->disabled = disabled;
223 control_ops_disable_all(ops);
227 static void ftrace_sync(struct work_struct *work)
230 * This function is just a stub to implement a hard force
231 * of synchronize_sched(). This requires synchronizing
232 * tasks even in userspace and idle.
234 * Yes, function tracing is rude.
238 static void ftrace_sync_ipi(void *data)
240 /* Probably not needed, but do it anyway */
244 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
245 static void update_function_graph_func(void);
247 /* Both enabled by default (can be cleared by function_graph tracer flags */
248 static bool fgraph_sleep_time = true;
249 static bool fgraph_graph_time = true;
252 static inline void update_function_graph_func(void) { }
256 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
259 * If this is a dynamic ops or we force list func,
260 * then it needs to call the list anyway.
262 if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC)
263 return ftrace_ops_list_func;
265 return ftrace_ops_get_func(ops);
268 static void update_ftrace_function(void)
273 * Prepare the ftrace_ops that the arch callback will use.
274 * If there's only one ftrace_ops registered, the ftrace_ops_list
275 * will point to the ops we want.
277 set_function_trace_op = ftrace_ops_list;
279 /* If there's no ftrace_ops registered, just call the stub function */
280 if (ftrace_ops_list == &ftrace_list_end) {
284 * If we are at the end of the list and this ops is
285 * recursion safe and not dynamic and the arch supports passing ops,
286 * then have the mcount trampoline call the function directly.
288 } else if (ftrace_ops_list->next == &ftrace_list_end) {
289 func = ftrace_ops_get_list_func(ftrace_ops_list);
292 /* Just use the default ftrace_ops */
293 set_function_trace_op = &ftrace_list_end;
294 func = ftrace_ops_list_func;
297 update_function_graph_func();
299 /* If there's no change, then do nothing more here */
300 if (ftrace_trace_function == func)
304 * If we are using the list function, it doesn't care
305 * about the function_trace_ops.
307 if (func == ftrace_ops_list_func) {
308 ftrace_trace_function = func;
310 * Don't even bother setting function_trace_ops,
311 * it would be racy to do so anyway.
316 #ifndef CONFIG_DYNAMIC_FTRACE
318 * For static tracing, we need to be a bit more careful.
319 * The function change takes affect immediately. Thus,
320 * we need to coorditate the setting of the function_trace_ops
321 * with the setting of the ftrace_trace_function.
323 * Set the function to the list ops, which will call the
324 * function we want, albeit indirectly, but it handles the
325 * ftrace_ops and doesn't depend on function_trace_op.
327 ftrace_trace_function = ftrace_ops_list_func;
329 * Make sure all CPUs see this. Yes this is slow, but static
330 * tracing is slow and nasty to have enabled.
332 schedule_on_each_cpu(ftrace_sync);
333 /* Now all cpus are using the list ops. */
334 function_trace_op = set_function_trace_op;
335 /* Make sure the function_trace_op is visible on all CPUs */
337 /* Nasty way to force a rmb on all cpus */
338 smp_call_function(ftrace_sync_ipi, NULL, 1);
339 /* OK, we are all set to update the ftrace_trace_function now! */
340 #endif /* !CONFIG_DYNAMIC_FTRACE */
342 ftrace_trace_function = func;
345 int using_ftrace_ops_list_func(void)
347 return ftrace_trace_function == ftrace_ops_list_func;
350 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
354 * We are entering ops into the list but another
355 * CPU might be walking that list. We need to make sure
356 * the ops->next pointer is valid before another CPU sees
357 * the ops pointer included into the list.
359 rcu_assign_pointer(*list, ops);
362 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
364 struct ftrace_ops **p;
367 * If we are removing the last function, then simply point
368 * to the ftrace_stub.
370 if (*list == ops && ops->next == &ftrace_list_end) {
371 *list = &ftrace_list_end;
375 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
386 static void add_ftrace_list_ops(struct ftrace_ops **list,
387 struct ftrace_ops *main_ops,
388 struct ftrace_ops *ops)
390 int first = *list == &ftrace_list_end;
391 add_ftrace_ops(list, ops);
393 add_ftrace_ops(&ftrace_ops_list, main_ops);
396 static int remove_ftrace_list_ops(struct ftrace_ops **list,
397 struct ftrace_ops *main_ops,
398 struct ftrace_ops *ops)
400 int ret = remove_ftrace_ops(list, ops);
401 if (!ret && *list == &ftrace_list_end)
402 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
406 static void ftrace_update_trampoline(struct ftrace_ops *ops);
408 static int __register_ftrace_function(struct ftrace_ops *ops)
410 if (ops->flags & FTRACE_OPS_FL_DELETED)
413 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
416 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
418 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
419 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
420 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
422 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
423 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
426 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
427 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
430 if (!core_kernel_data((unsigned long)ops))
431 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
433 if (ops->flags & FTRACE_OPS_FL_CONTROL) {
434 if (control_ops_alloc(ops))
436 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
437 /* The control_ops needs the trampoline update */
440 add_ftrace_ops(&ftrace_ops_list, ops);
442 /* Always save the function, and reset at unregistering */
443 ops->saved_func = ops->func;
445 if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled())
446 ops->func = ftrace_pid_func;
448 ftrace_update_trampoline(ops);
451 update_ftrace_function();
456 static int __unregister_ftrace_function(struct ftrace_ops *ops)
460 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
463 if (ops->flags & FTRACE_OPS_FL_CONTROL) {
464 ret = remove_ftrace_list_ops(&ftrace_control_list,
467 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
473 update_ftrace_function();
475 ops->func = ops->saved_func;
480 static void ftrace_update_pid_func(void)
482 bool enabled = ftrace_pids_enabled();
483 struct ftrace_ops *op;
485 /* Only do something if we are tracing something */
486 if (ftrace_trace_function == ftrace_stub)
489 do_for_each_ftrace_op(op, ftrace_ops_list) {
490 if (op->flags & FTRACE_OPS_FL_PID) {
491 op->func = enabled ? ftrace_pid_func :
493 ftrace_update_trampoline(op);
495 } while_for_each_ftrace_op(op);
497 update_ftrace_function();
500 #ifdef CONFIG_FUNCTION_PROFILER
501 struct ftrace_profile {
502 struct hlist_node node;
504 unsigned long counter;
505 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
506 unsigned long long time;
507 unsigned long long time_squared;
511 struct ftrace_profile_page {
512 struct ftrace_profile_page *next;
514 struct ftrace_profile records[];
517 struct ftrace_profile_stat {
519 struct hlist_head *hash;
520 struct ftrace_profile_page *pages;
521 struct ftrace_profile_page *start;
522 struct tracer_stat stat;
525 #define PROFILE_RECORDS_SIZE \
526 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
528 #define PROFILES_PER_PAGE \
529 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
531 static int ftrace_profile_enabled __read_mostly;
533 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
534 static DEFINE_MUTEX(ftrace_profile_lock);
536 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
538 #define FTRACE_PROFILE_HASH_BITS 10
539 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
542 function_stat_next(void *v, int idx)
544 struct ftrace_profile *rec = v;
545 struct ftrace_profile_page *pg;
547 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
553 if ((void *)rec >= (void *)&pg->records[pg->index]) {
557 rec = &pg->records[0];
565 static void *function_stat_start(struct tracer_stat *trace)
567 struct ftrace_profile_stat *stat =
568 container_of(trace, struct ftrace_profile_stat, stat);
570 if (!stat || !stat->start)
573 return function_stat_next(&stat->start->records[0], 0);
576 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
577 /* function graph compares on total time */
578 static int function_stat_cmp(void *p1, void *p2)
580 struct ftrace_profile *a = p1;
581 struct ftrace_profile *b = p2;
583 if (a->time < b->time)
585 if (a->time > b->time)
591 /* not function graph compares against hits */
592 static int function_stat_cmp(void *p1, void *p2)
594 struct ftrace_profile *a = p1;
595 struct ftrace_profile *b = p2;
597 if (a->counter < b->counter)
599 if (a->counter > b->counter)
606 static int function_stat_headers(struct seq_file *m)
608 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
609 seq_puts(m, " Function "
612 "--- ---- --- ---\n");
614 seq_puts(m, " Function Hit\n"
620 static int function_stat_show(struct seq_file *m, void *v)
622 struct ftrace_profile *rec = v;
623 char str[KSYM_SYMBOL_LEN];
625 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
626 static struct trace_seq s;
627 unsigned long long avg;
628 unsigned long long stddev;
630 mutex_lock(&ftrace_profile_lock);
632 /* we raced with function_profile_reset() */
633 if (unlikely(rec->counter == 0)) {
638 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
640 do_div(avg, rec->counter);
641 if (tracing_thresh && (avg < tracing_thresh))
645 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
646 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
648 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
651 /* Sample standard deviation (s^2) */
652 if (rec->counter <= 1)
656 * Apply Welford's method:
657 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
659 stddev = rec->counter * rec->time_squared -
660 rec->time * rec->time;
663 * Divide only 1000 for ns^2 -> us^2 conversion.
664 * trace_print_graph_duration will divide 1000 again.
666 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
670 trace_print_graph_duration(rec->time, &s);
671 trace_seq_puts(&s, " ");
672 trace_print_graph_duration(avg, &s);
673 trace_seq_puts(&s, " ");
674 trace_print_graph_duration(stddev, &s);
675 trace_print_seq(m, &s);
679 mutex_unlock(&ftrace_profile_lock);
684 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
686 struct ftrace_profile_page *pg;
688 pg = stat->pages = stat->start;
691 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
696 memset(stat->hash, 0,
697 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
700 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
702 struct ftrace_profile_page *pg;
707 /* If we already allocated, do nothing */
711 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
715 #ifdef CONFIG_DYNAMIC_FTRACE
716 functions = ftrace_update_tot_cnt;
719 * We do not know the number of functions that exist because
720 * dynamic tracing is what counts them. With past experience
721 * we have around 20K functions. That should be more than enough.
722 * It is highly unlikely we will execute every function in
728 pg = stat->start = stat->pages;
730 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
732 for (i = 1; i < pages; i++) {
733 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
744 unsigned long tmp = (unsigned long)pg;
756 static int ftrace_profile_init_cpu(int cpu)
758 struct ftrace_profile_stat *stat;
761 stat = &per_cpu(ftrace_profile_stats, cpu);
764 /* If the profile is already created, simply reset it */
765 ftrace_profile_reset(stat);
770 * We are profiling all functions, but usually only a few thousand
771 * functions are hit. We'll make a hash of 1024 items.
773 size = FTRACE_PROFILE_HASH_SIZE;
775 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
780 /* Preallocate the function profiling pages */
781 if (ftrace_profile_pages_init(stat) < 0) {
790 static int ftrace_profile_init(void)
795 for_each_possible_cpu(cpu) {
796 ret = ftrace_profile_init_cpu(cpu);
804 /* interrupts must be disabled */
805 static struct ftrace_profile *
806 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
808 struct ftrace_profile *rec;
809 struct hlist_head *hhd;
812 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
813 hhd = &stat->hash[key];
815 if (hlist_empty(hhd))
818 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
826 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
827 struct ftrace_profile *rec)
831 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
832 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
836 * The memory is already allocated, this simply finds a new record to use.
838 static struct ftrace_profile *
839 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
841 struct ftrace_profile *rec = NULL;
843 /* prevent recursion (from NMIs) */
844 if (atomic_inc_return(&stat->disabled) != 1)
848 * Try to find the function again since an NMI
849 * could have added it
851 rec = ftrace_find_profiled_func(stat, ip);
855 if (stat->pages->index == PROFILES_PER_PAGE) {
856 if (!stat->pages->next)
858 stat->pages = stat->pages->next;
861 rec = &stat->pages->records[stat->pages->index++];
863 ftrace_add_profile(stat, rec);
866 atomic_dec(&stat->disabled);
872 function_profile_call(unsigned long ip, unsigned long parent_ip,
873 struct ftrace_ops *ops, struct pt_regs *regs)
875 struct ftrace_profile_stat *stat;
876 struct ftrace_profile *rec;
879 if (!ftrace_profile_enabled)
882 local_irq_save(flags);
884 stat = this_cpu_ptr(&ftrace_profile_stats);
885 if (!stat->hash || !ftrace_profile_enabled)
888 rec = ftrace_find_profiled_func(stat, ip);
890 rec = ftrace_profile_alloc(stat, ip);
897 local_irq_restore(flags);
900 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
901 static int profile_graph_entry(struct ftrace_graph_ent *trace)
903 function_profile_call(trace->func, 0, NULL, NULL);
907 static void profile_graph_return(struct ftrace_graph_ret *trace)
909 struct ftrace_profile_stat *stat;
910 unsigned long long calltime;
911 struct ftrace_profile *rec;
914 local_irq_save(flags);
915 stat = this_cpu_ptr(&ftrace_profile_stats);
916 if (!stat->hash || !ftrace_profile_enabled)
919 /* If the calltime was zero'd ignore it */
920 if (!trace->calltime)
923 calltime = trace->rettime - trace->calltime;
925 if (!fgraph_graph_time) {
928 index = trace->depth;
930 /* Append this call time to the parent time to subtract */
932 current->ret_stack[index - 1].subtime += calltime;
934 if (current->ret_stack[index].subtime < calltime)
935 calltime -= current->ret_stack[index].subtime;
940 rec = ftrace_find_profiled_func(stat, trace->func);
942 rec->time += calltime;
943 rec->time_squared += calltime * calltime;
947 local_irq_restore(flags);
950 static int register_ftrace_profiler(void)
952 return register_ftrace_graph(&profile_graph_return,
953 &profile_graph_entry);
956 static void unregister_ftrace_profiler(void)
958 unregister_ftrace_graph();
961 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
962 .func = function_profile_call,
963 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
964 INIT_OPS_HASH(ftrace_profile_ops)
967 static int register_ftrace_profiler(void)
969 return register_ftrace_function(&ftrace_profile_ops);
972 static void unregister_ftrace_profiler(void)
974 unregister_ftrace_function(&ftrace_profile_ops);
976 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
979 ftrace_profile_write(struct file *filp, const char __user *ubuf,
980 size_t cnt, loff_t *ppos)
985 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
991 mutex_lock(&ftrace_profile_lock);
992 if (ftrace_profile_enabled ^ val) {
994 ret = ftrace_profile_init();
1000 ret = register_ftrace_profiler();
1005 ftrace_profile_enabled = 1;
1007 ftrace_profile_enabled = 0;
1009 * unregister_ftrace_profiler calls stop_machine
1010 * so this acts like an synchronize_sched.
1012 unregister_ftrace_profiler();
1016 mutex_unlock(&ftrace_profile_lock);
1024 ftrace_profile_read(struct file *filp, char __user *ubuf,
1025 size_t cnt, loff_t *ppos)
1027 char buf[64]; /* big enough to hold a number */
1030 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
1031 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1034 static const struct file_operations ftrace_profile_fops = {
1035 .open = tracing_open_generic,
1036 .read = ftrace_profile_read,
1037 .write = ftrace_profile_write,
1038 .llseek = default_llseek,
1041 /* used to initialize the real stat files */
1042 static struct tracer_stat function_stats __initdata = {
1043 .name = "functions",
1044 .stat_start = function_stat_start,
1045 .stat_next = function_stat_next,
1046 .stat_cmp = function_stat_cmp,
1047 .stat_headers = function_stat_headers,
1048 .stat_show = function_stat_show
1051 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1053 struct ftrace_profile_stat *stat;
1054 struct dentry *entry;
1059 for_each_possible_cpu(cpu) {
1060 stat = &per_cpu(ftrace_profile_stats, cpu);
1062 /* allocate enough for function name + cpu number */
1063 name = kmalloc(32, GFP_KERNEL);
1066 * The files created are permanent, if something happens
1067 * we still do not free memory.
1070 "Could not allocate stat file for cpu %d\n",
1074 stat->stat = function_stats;
1075 snprintf(name, 32, "function%d", cpu);
1076 stat->stat.name = name;
1077 ret = register_stat_tracer(&stat->stat);
1080 "Could not register function stat for cpu %d\n",
1087 entry = tracefs_create_file("function_profile_enabled", 0644,
1088 d_tracer, NULL, &ftrace_profile_fops);
1090 pr_warning("Could not create tracefs "
1091 "'function_profile_enabled' entry\n");
1094 #else /* CONFIG_FUNCTION_PROFILER */
1095 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1098 #endif /* CONFIG_FUNCTION_PROFILER */
1100 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1102 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1103 static int ftrace_graph_active;
1105 # define ftrace_graph_active 0
1108 #ifdef CONFIG_DYNAMIC_FTRACE
1110 static struct ftrace_ops *removed_ops;
1113 * Set when doing a global update, like enabling all recs or disabling them.
1114 * It is not set when just updating a single ftrace_ops.
1116 static bool update_all_ops;
1118 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1119 # error Dynamic ftrace depends on MCOUNT_RECORD
1122 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1124 struct ftrace_func_probe {
1125 struct hlist_node node;
1126 struct ftrace_probe_ops *ops;
1127 unsigned long flags;
1130 struct list_head free_list;
1133 struct ftrace_func_entry {
1134 struct hlist_node hlist;
1138 struct ftrace_hash {
1139 unsigned long size_bits;
1140 struct hlist_head *buckets;
1141 unsigned long count;
1142 struct rcu_head rcu;
1146 * We make these constant because no one should touch them,
1147 * but they are used as the default "empty hash", to avoid allocating
1148 * it all the time. These are in a read only section such that if
1149 * anyone does try to modify it, it will cause an exception.
1151 static const struct hlist_head empty_buckets[1];
1152 static const struct ftrace_hash empty_hash = {
1153 .buckets = (struct hlist_head *)empty_buckets,
1155 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1157 static struct ftrace_ops global_ops = {
1158 .func = ftrace_stub,
1159 .local_hash.notrace_hash = EMPTY_HASH,
1160 .local_hash.filter_hash = EMPTY_HASH,
1161 INIT_OPS_HASH(global_ops)
1162 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1163 FTRACE_OPS_FL_INITIALIZED |
1168 * This is used by __kernel_text_address() to return true if the
1169 * address is on a dynamically allocated trampoline that would
1170 * not return true for either core_kernel_text() or
1171 * is_module_text_address().
1173 bool is_ftrace_trampoline(unsigned long addr)
1175 struct ftrace_ops *op;
1179 * Some of the ops may be dynamically allocated,
1180 * they are freed after a synchronize_sched().
1182 preempt_disable_notrace();
1184 do_for_each_ftrace_op(op, ftrace_ops_list) {
1186 * This is to check for dynamically allocated trampolines.
1187 * Trampolines that are in kernel text will have
1188 * core_kernel_text() return true.
1190 if (op->trampoline && op->trampoline_size)
1191 if (addr >= op->trampoline &&
1192 addr < op->trampoline + op->trampoline_size) {
1196 } while_for_each_ftrace_op(op);
1199 preempt_enable_notrace();
1204 struct ftrace_page {
1205 struct ftrace_page *next;
1206 struct dyn_ftrace *records;
1211 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1212 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1214 /* estimate from running different kernels */
1215 #define NR_TO_INIT 10000
1217 static struct ftrace_page *ftrace_pages_start;
1218 static struct ftrace_page *ftrace_pages;
1220 static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
1222 return !hash || !hash->count;
1225 static struct ftrace_func_entry *
1226 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1229 struct ftrace_func_entry *entry;
1230 struct hlist_head *hhd;
1232 if (ftrace_hash_empty(hash))
1235 if (hash->size_bits > 0)
1236 key = hash_long(ip, hash->size_bits);
1240 hhd = &hash->buckets[key];
1242 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1243 if (entry->ip == ip)
1249 static void __add_hash_entry(struct ftrace_hash *hash,
1250 struct ftrace_func_entry *entry)
1252 struct hlist_head *hhd;
1255 if (hash->size_bits)
1256 key = hash_long(entry->ip, hash->size_bits);
1260 hhd = &hash->buckets[key];
1261 hlist_add_head(&entry->hlist, hhd);
1265 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1267 struct ftrace_func_entry *entry;
1269 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1274 __add_hash_entry(hash, entry);
1280 free_hash_entry(struct ftrace_hash *hash,
1281 struct ftrace_func_entry *entry)
1283 hlist_del(&entry->hlist);
1289 remove_hash_entry(struct ftrace_hash *hash,
1290 struct ftrace_func_entry *entry)
1292 hlist_del(&entry->hlist);
1296 static void ftrace_hash_clear(struct ftrace_hash *hash)
1298 struct hlist_head *hhd;
1299 struct hlist_node *tn;
1300 struct ftrace_func_entry *entry;
1301 int size = 1 << hash->size_bits;
1307 for (i = 0; i < size; i++) {
1308 hhd = &hash->buckets[i];
1309 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1310 free_hash_entry(hash, entry);
1312 FTRACE_WARN_ON(hash->count);
1315 static void free_ftrace_hash(struct ftrace_hash *hash)
1317 if (!hash || hash == EMPTY_HASH)
1319 ftrace_hash_clear(hash);
1320 kfree(hash->buckets);
1324 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1326 struct ftrace_hash *hash;
1328 hash = container_of(rcu, struct ftrace_hash, rcu);
1329 free_ftrace_hash(hash);
1332 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1334 if (!hash || hash == EMPTY_HASH)
1336 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1339 void ftrace_free_filter(struct ftrace_ops *ops)
1341 ftrace_ops_init(ops);
1342 free_ftrace_hash(ops->func_hash->filter_hash);
1343 free_ftrace_hash(ops->func_hash->notrace_hash);
1346 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1348 struct ftrace_hash *hash;
1351 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1355 size = 1 << size_bits;
1356 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1358 if (!hash->buckets) {
1363 hash->size_bits = size_bits;
1368 static struct ftrace_hash *
1369 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1371 struct ftrace_func_entry *entry;
1372 struct ftrace_hash *new_hash;
1377 new_hash = alloc_ftrace_hash(size_bits);
1382 if (ftrace_hash_empty(hash))
1385 size = 1 << hash->size_bits;
1386 for (i = 0; i < size; i++) {
1387 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1388 ret = add_hash_entry(new_hash, entry->ip);
1394 FTRACE_WARN_ON(new_hash->count != hash->count);
1399 free_ftrace_hash(new_hash);
1404 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1406 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1408 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1409 struct ftrace_hash *new_hash);
1412 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1413 struct ftrace_hash **dst, struct ftrace_hash *src)
1415 struct ftrace_func_entry *entry;
1416 struct hlist_node *tn;
1417 struct hlist_head *hhd;
1418 struct ftrace_hash *new_hash;
1419 int size = src->count;
1424 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1425 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1429 * If the new source is empty, just free dst and assign it
1433 new_hash = EMPTY_HASH;
1438 * Make the hash size about 1/2 the # found
1440 for (size /= 2; size; size >>= 1)
1443 /* Don't allocate too much */
1444 if (bits > FTRACE_HASH_MAX_BITS)
1445 bits = FTRACE_HASH_MAX_BITS;
1447 new_hash = alloc_ftrace_hash(bits);
1451 size = 1 << src->size_bits;
1452 for (i = 0; i < size; i++) {
1453 hhd = &src->buckets[i];
1454 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1455 remove_hash_entry(src, entry);
1456 __add_hash_entry(new_hash, entry);
1461 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1463 /* IPMODIFY should be updated only when filter_hash updating */
1464 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1466 free_ftrace_hash(new_hash);
1472 * Remove the current set, update the hash and add
1475 ftrace_hash_rec_disable_modify(ops, enable);
1477 rcu_assign_pointer(*dst, new_hash);
1479 ftrace_hash_rec_enable_modify(ops, enable);
1484 static bool hash_contains_ip(unsigned long ip,
1485 struct ftrace_ops_hash *hash)
1488 * The function record is a match if it exists in the filter
1489 * hash and not in the notrace hash. Note, an emty hash is
1490 * considered a match for the filter hash, but an empty
1491 * notrace hash is considered not in the notrace hash.
1493 return (ftrace_hash_empty(hash->filter_hash) ||
1494 ftrace_lookup_ip(hash->filter_hash, ip)) &&
1495 (ftrace_hash_empty(hash->notrace_hash) ||
1496 !ftrace_lookup_ip(hash->notrace_hash, ip));
1500 * Test the hashes for this ops to see if we want to call
1501 * the ops->func or not.
1503 * It's a match if the ip is in the ops->filter_hash or
1504 * the filter_hash does not exist or is empty,
1506 * the ip is not in the ops->notrace_hash.
1508 * This needs to be called with preemption disabled as
1509 * the hashes are freed with call_rcu_sched().
1512 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1514 struct ftrace_ops_hash hash;
1517 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1519 * There's a small race when adding ops that the ftrace handler
1520 * that wants regs, may be called without them. We can not
1521 * allow that handler to be called if regs is NULL.
1523 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1527 hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
1528 hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
1530 if (hash_contains_ip(ip, &hash))
1539 * This is a double for. Do not use 'break' to break out of the loop,
1540 * you must use a goto.
1542 #define do_for_each_ftrace_rec(pg, rec) \
1543 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1545 for (_____i = 0; _____i < pg->index; _____i++) { \
1546 rec = &pg->records[_____i];
1548 #define while_for_each_ftrace_rec() \
1553 static int ftrace_cmp_recs(const void *a, const void *b)
1555 const struct dyn_ftrace *key = a;
1556 const struct dyn_ftrace *rec = b;
1558 if (key->flags < rec->ip)
1560 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1565 static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1567 struct ftrace_page *pg;
1568 struct dyn_ftrace *rec;
1569 struct dyn_ftrace key;
1572 key.flags = end; /* overload flags, as it is unsigned long */
1574 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1575 if (end < pg->records[0].ip ||
1576 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1578 rec = bsearch(&key, pg->records, pg->index,
1579 sizeof(struct dyn_ftrace),
1589 * ftrace_location - return true if the ip giving is a traced location
1590 * @ip: the instruction pointer to check
1592 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1593 * That is, the instruction that is either a NOP or call to
1594 * the function tracer. It checks the ftrace internal tables to
1595 * determine if the address belongs or not.
1597 unsigned long ftrace_location(unsigned long ip)
1599 return ftrace_location_range(ip, ip);
1603 * ftrace_text_reserved - return true if range contains an ftrace location
1604 * @start: start of range to search
1605 * @end: end of range to search (inclusive). @end points to the last byte to check.
1607 * Returns 1 if @start and @end contains a ftrace location.
1608 * That is, the instruction that is either a NOP or call to
1609 * the function tracer. It checks the ftrace internal tables to
1610 * determine if the address belongs or not.
1612 int ftrace_text_reserved(const void *start, const void *end)
1616 ret = ftrace_location_range((unsigned long)start,
1617 (unsigned long)end);
1622 /* Test if ops registered to this rec needs regs */
1623 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1625 struct ftrace_ops *ops;
1626 bool keep_regs = false;
1628 for (ops = ftrace_ops_list;
1629 ops != &ftrace_list_end; ops = ops->next) {
1630 /* pass rec in as regs to have non-NULL val */
1631 if (ftrace_ops_test(ops, rec->ip, rec)) {
1632 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1642 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1646 struct ftrace_hash *hash;
1647 struct ftrace_hash *other_hash;
1648 struct ftrace_page *pg;
1649 struct dyn_ftrace *rec;
1653 /* Only update if the ops has been registered */
1654 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1658 * In the filter_hash case:
1659 * If the count is zero, we update all records.
1660 * Otherwise we just update the items in the hash.
1662 * In the notrace_hash case:
1663 * We enable the update in the hash.
1664 * As disabling notrace means enabling the tracing,
1665 * and enabling notrace means disabling, the inc variable
1669 hash = ops->func_hash->filter_hash;
1670 other_hash = ops->func_hash->notrace_hash;
1671 if (ftrace_hash_empty(hash))
1675 hash = ops->func_hash->notrace_hash;
1676 other_hash = ops->func_hash->filter_hash;
1678 * If the notrace hash has no items,
1679 * then there's nothing to do.
1681 if (ftrace_hash_empty(hash))
1685 do_for_each_ftrace_rec(pg, rec) {
1686 int in_other_hash = 0;
1692 * Only the filter_hash affects all records.
1693 * Update if the record is not in the notrace hash.
1695 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1698 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1699 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1702 * If filter_hash is set, we want to match all functions
1703 * that are in the hash but not in the other hash.
1705 * If filter_hash is not set, then we are decrementing.
1706 * That means we match anything that is in the hash
1707 * and also in the other_hash. That is, we need to turn
1708 * off functions in the other hash because they are disabled
1711 if (filter_hash && in_hash && !in_other_hash)
1713 else if (!filter_hash && in_hash &&
1714 (in_other_hash || ftrace_hash_empty(other_hash)))
1722 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1726 * If there's only a single callback registered to a
1727 * function, and the ops has a trampoline registered
1728 * for it, then we can call it directly.
1730 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1731 rec->flags |= FTRACE_FL_TRAMP;
1734 * If we are adding another function callback
1735 * to this function, and the previous had a
1736 * custom trampoline in use, then we need to go
1737 * back to the default trampoline.
1739 rec->flags &= ~FTRACE_FL_TRAMP;
1742 * If any ops wants regs saved for this function
1743 * then all ops will get saved regs.
1745 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1746 rec->flags |= FTRACE_FL_REGS;
1748 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1753 * If the rec had REGS enabled and the ops that is
1754 * being removed had REGS set, then see if there is
1755 * still any ops for this record that wants regs.
1756 * If not, we can stop recording them.
1758 if (ftrace_rec_count(rec) > 0 &&
1759 rec->flags & FTRACE_FL_REGS &&
1760 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1761 if (!test_rec_ops_needs_regs(rec))
1762 rec->flags &= ~FTRACE_FL_REGS;
1766 * If the rec had TRAMP enabled, then it needs to
1767 * be cleared. As TRAMP can only be enabled iff
1768 * there is only a single ops attached to it.
1769 * In otherwords, always disable it on decrementing.
1770 * In the future, we may set it if rec count is
1771 * decremented to one, and the ops that is left
1774 rec->flags &= ~FTRACE_FL_TRAMP;
1777 * flags will be cleared in ftrace_check_record()
1778 * if rec count is zero.
1782 /* Shortcut, if we handled all records, we are done. */
1783 if (!all && count == hash->count)
1785 } while_for_each_ftrace_rec();
1788 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1791 __ftrace_hash_rec_update(ops, filter_hash, 0);
1794 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1797 __ftrace_hash_rec_update(ops, filter_hash, 1);
1800 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1801 int filter_hash, int inc)
1803 struct ftrace_ops *op;
1805 __ftrace_hash_rec_update(ops, filter_hash, inc);
1807 if (ops->func_hash != &global_ops.local_hash)
1811 * If the ops shares the global_ops hash, then we need to update
1812 * all ops that are enabled and use this hash.
1814 do_for_each_ftrace_op(op, ftrace_ops_list) {
1818 if (op->func_hash == &global_ops.local_hash)
1819 __ftrace_hash_rec_update(op, filter_hash, inc);
1820 } while_for_each_ftrace_op(op);
1823 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1826 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1829 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1832 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1836 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1837 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1838 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1839 * Note that old_hash and new_hash has below meanings
1840 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1841 * - If the hash is EMPTY_HASH, it hits nothing
1842 * - Anything else hits the recs which match the hash entries.
1844 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1845 struct ftrace_hash *old_hash,
1846 struct ftrace_hash *new_hash)
1848 struct ftrace_page *pg;
1849 struct dyn_ftrace *rec, *end = NULL;
1852 /* Only update if the ops has been registered */
1853 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1856 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1860 * Since the IPMODIFY is a very address sensitive action, we do not
1861 * allow ftrace_ops to set all functions to new hash.
1863 if (!new_hash || !old_hash)
1866 /* Update rec->flags */
1867 do_for_each_ftrace_rec(pg, rec) {
1868 /* We need to update only differences of filter_hash */
1869 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1870 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1871 if (in_old == in_new)
1875 /* New entries must ensure no others are using it */
1876 if (rec->flags & FTRACE_FL_IPMODIFY)
1878 rec->flags |= FTRACE_FL_IPMODIFY;
1879 } else /* Removed entry */
1880 rec->flags &= ~FTRACE_FL_IPMODIFY;
1881 } while_for_each_ftrace_rec();
1888 /* Roll back what we did above */
1889 do_for_each_ftrace_rec(pg, rec) {
1893 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1894 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1895 if (in_old == in_new)
1899 rec->flags &= ~FTRACE_FL_IPMODIFY;
1901 rec->flags |= FTRACE_FL_IPMODIFY;
1902 } while_for_each_ftrace_rec();
1908 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1910 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1912 if (ftrace_hash_empty(hash))
1915 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1918 /* Disabling always succeeds */
1919 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1921 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1923 if (ftrace_hash_empty(hash))
1926 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1929 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1930 struct ftrace_hash *new_hash)
1932 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1934 if (ftrace_hash_empty(old_hash))
1937 if (ftrace_hash_empty(new_hash))
1940 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1943 static void print_ip_ins(const char *fmt, const unsigned char *p)
1947 printk(KERN_CONT "%s", fmt);
1949 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1950 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1953 static struct ftrace_ops *
1954 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1955 static struct ftrace_ops *
1956 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1958 enum ftrace_bug_type ftrace_bug_type;
1959 const void *ftrace_expected;
1961 static void print_bug_type(void)
1963 switch (ftrace_bug_type) {
1964 case FTRACE_BUG_UNKNOWN:
1966 case FTRACE_BUG_INIT:
1967 pr_info("Initializing ftrace call sites\n");
1969 case FTRACE_BUG_NOP:
1970 pr_info("Setting ftrace call site to NOP\n");
1972 case FTRACE_BUG_CALL:
1973 pr_info("Setting ftrace call site to call ftrace function\n");
1975 case FTRACE_BUG_UPDATE:
1976 pr_info("Updating ftrace call site to call a different ftrace function\n");
1982 * ftrace_bug - report and shutdown function tracer
1983 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1984 * @rec: The record that failed
1986 * The arch code that enables or disables the function tracing
1987 * can call ftrace_bug() when it has detected a problem in
1988 * modifying the code. @failed should be one of either:
1989 * EFAULT - if the problem happens on reading the @ip address
1990 * EINVAL - if what is read at @ip is not what was expected
1991 * EPERM - if the problem happens on writting to the @ip address
1993 void ftrace_bug(int failed, struct dyn_ftrace *rec)
1995 unsigned long ip = rec ? rec->ip : 0;
1999 FTRACE_WARN_ON_ONCE(1);
2000 pr_info("ftrace faulted on modifying ");
2004 FTRACE_WARN_ON_ONCE(1);
2005 pr_info("ftrace failed to modify ");
2007 print_ip_ins(" actual: ", (unsigned char *)ip);
2009 if (ftrace_expected) {
2010 print_ip_ins(" expected: ", ftrace_expected);
2015 FTRACE_WARN_ON_ONCE(1);
2016 pr_info("ftrace faulted on writing ");
2020 FTRACE_WARN_ON_ONCE(1);
2021 pr_info("ftrace faulted on unknown error ");
2026 struct ftrace_ops *ops = NULL;
2028 pr_info("ftrace record flags: %lx\n", rec->flags);
2029 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2030 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2031 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2032 ops = ftrace_find_tramp_ops_any(rec);
2035 pr_cont("\ttramp: %pS (%pS)",
2036 (void *)ops->trampoline,
2038 ops = ftrace_find_tramp_ops_next(rec, ops);
2041 pr_cont("\ttramp: ERROR!");
2044 ip = ftrace_get_addr_curr(rec);
2045 pr_cont("\n expected tramp: %lx\n", ip);
2049 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2051 unsigned long flag = 0UL;
2053 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2056 * If we are updating calls:
2058 * If the record has a ref count, then we need to enable it
2059 * because someone is using it.
2061 * Otherwise we make sure its disabled.
2063 * If we are disabling calls, then disable all records that
2066 if (enable && ftrace_rec_count(rec))
2067 flag = FTRACE_FL_ENABLED;
2070 * If enabling and the REGS flag does not match the REGS_EN, or
2071 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2072 * this record. Set flags to fail the compare against ENABLED.
2075 if (!(rec->flags & FTRACE_FL_REGS) !=
2076 !(rec->flags & FTRACE_FL_REGS_EN))
2077 flag |= FTRACE_FL_REGS;
2079 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2080 !(rec->flags & FTRACE_FL_TRAMP_EN))
2081 flag |= FTRACE_FL_TRAMP;
2084 /* If the state of this record hasn't changed, then do nothing */
2085 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2086 return FTRACE_UPDATE_IGNORE;
2089 /* Save off if rec is being enabled (for return value) */
2090 flag ^= rec->flags & FTRACE_FL_ENABLED;
2093 rec->flags |= FTRACE_FL_ENABLED;
2094 if (flag & FTRACE_FL_REGS) {
2095 if (rec->flags & FTRACE_FL_REGS)
2096 rec->flags |= FTRACE_FL_REGS_EN;
2098 rec->flags &= ~FTRACE_FL_REGS_EN;
2100 if (flag & FTRACE_FL_TRAMP) {
2101 if (rec->flags & FTRACE_FL_TRAMP)
2102 rec->flags |= FTRACE_FL_TRAMP_EN;
2104 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2109 * If this record is being updated from a nop, then
2110 * return UPDATE_MAKE_CALL.
2112 * return UPDATE_MODIFY_CALL to tell the caller to convert
2113 * from the save regs, to a non-save regs function or
2114 * vice versa, or from a trampoline call.
2116 if (flag & FTRACE_FL_ENABLED) {
2117 ftrace_bug_type = FTRACE_BUG_CALL;
2118 return FTRACE_UPDATE_MAKE_CALL;
2121 ftrace_bug_type = FTRACE_BUG_UPDATE;
2122 return FTRACE_UPDATE_MODIFY_CALL;
2126 /* If there's no more users, clear all flags */
2127 if (!ftrace_rec_count(rec))
2131 * Just disable the record, but keep the ops TRAMP
2132 * and REGS states. The _EN flags must be disabled though.
2134 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2138 ftrace_bug_type = FTRACE_BUG_NOP;
2139 return FTRACE_UPDATE_MAKE_NOP;
2143 * ftrace_update_record, set a record that now is tracing or not
2144 * @rec: the record to update
2145 * @enable: set to 1 if the record is tracing, zero to force disable
2147 * The records that represent all functions that can be traced need
2148 * to be updated when tracing has been enabled.
2150 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2152 return ftrace_check_record(rec, enable, 1);
2156 * ftrace_test_record, check if the record has been enabled or not
2157 * @rec: the record to test
2158 * @enable: set to 1 to check if enabled, 0 if it is disabled
2160 * The arch code may need to test if a record is already set to
2161 * tracing to determine how to modify the function code that it
2164 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2166 return ftrace_check_record(rec, enable, 0);
2169 static struct ftrace_ops *
2170 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2172 struct ftrace_ops *op;
2173 unsigned long ip = rec->ip;
2175 do_for_each_ftrace_op(op, ftrace_ops_list) {
2177 if (!op->trampoline)
2180 if (hash_contains_ip(ip, op->func_hash))
2182 } while_for_each_ftrace_op(op);
2187 static struct ftrace_ops *
2188 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2189 struct ftrace_ops *op)
2191 unsigned long ip = rec->ip;
2193 while_for_each_ftrace_op(op) {
2195 if (!op->trampoline)
2198 if (hash_contains_ip(ip, op->func_hash))
2205 static struct ftrace_ops *
2206 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2208 struct ftrace_ops *op;
2209 unsigned long ip = rec->ip;
2212 * Need to check removed ops first.
2213 * If they are being removed, and this rec has a tramp,
2214 * and this rec is in the ops list, then it would be the
2215 * one with the tramp.
2218 if (hash_contains_ip(ip, &removed_ops->old_hash))
2223 * Need to find the current trampoline for a rec.
2224 * Now, a trampoline is only attached to a rec if there
2225 * was a single 'ops' attached to it. But this can be called
2226 * when we are adding another op to the rec or removing the
2227 * current one. Thus, if the op is being added, we can
2228 * ignore it because it hasn't attached itself to the rec
2231 * If an ops is being modified (hooking to different functions)
2232 * then we don't care about the new functions that are being
2233 * added, just the old ones (that are probably being removed).
2235 * If we are adding an ops to a function that already is using
2236 * a trampoline, it needs to be removed (trampolines are only
2237 * for single ops connected), then an ops that is not being
2238 * modified also needs to be checked.
2240 do_for_each_ftrace_op(op, ftrace_ops_list) {
2242 if (!op->trampoline)
2246 * If the ops is being added, it hasn't gotten to
2247 * the point to be removed from this tree yet.
2249 if (op->flags & FTRACE_OPS_FL_ADDING)
2254 * If the ops is being modified and is in the old
2255 * hash, then it is probably being removed from this
2258 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2259 hash_contains_ip(ip, &op->old_hash))
2262 * If the ops is not being added or modified, and it's
2263 * in its normal filter hash, then this must be the one
2266 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2267 hash_contains_ip(ip, op->func_hash))
2270 } while_for_each_ftrace_op(op);
2275 static struct ftrace_ops *
2276 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2278 struct ftrace_ops *op;
2279 unsigned long ip = rec->ip;
2281 do_for_each_ftrace_op(op, ftrace_ops_list) {
2282 /* pass rec in as regs to have non-NULL val */
2283 if (hash_contains_ip(ip, op->func_hash))
2285 } while_for_each_ftrace_op(op);
2291 * ftrace_get_addr_new - Get the call address to set to
2292 * @rec: The ftrace record descriptor
2294 * If the record has the FTRACE_FL_REGS set, that means that it
2295 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2296 * is not not set, then it wants to convert to the normal callback.
2298 * Returns the address of the trampoline to set to
2300 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2302 struct ftrace_ops *ops;
2304 /* Trampolines take precedence over regs */
2305 if (rec->flags & FTRACE_FL_TRAMP) {
2306 ops = ftrace_find_tramp_ops_new(rec);
2307 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2308 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2309 (void *)rec->ip, (void *)rec->ip, rec->flags);
2310 /* Ftrace is shutting down, return anything */
2311 return (unsigned long)FTRACE_ADDR;
2313 return ops->trampoline;
2316 if (rec->flags & FTRACE_FL_REGS)
2317 return (unsigned long)FTRACE_REGS_ADDR;
2319 return (unsigned long)FTRACE_ADDR;
2323 * ftrace_get_addr_curr - Get the call address that is already there
2324 * @rec: The ftrace record descriptor
2326 * The FTRACE_FL_REGS_EN is set when the record already points to
2327 * a function that saves all the regs. Basically the '_EN' version
2328 * represents the current state of the function.
2330 * Returns the address of the trampoline that is currently being called
2332 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2334 struct ftrace_ops *ops;
2336 /* Trampolines take precedence over regs */
2337 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2338 ops = ftrace_find_tramp_ops_curr(rec);
2339 if (FTRACE_WARN_ON(!ops)) {
2340 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
2341 (void *)rec->ip, (void *)rec->ip);
2342 /* Ftrace is shutting down, return anything */
2343 return (unsigned long)FTRACE_ADDR;
2345 return ops->trampoline;
2348 if (rec->flags & FTRACE_FL_REGS_EN)
2349 return (unsigned long)FTRACE_REGS_ADDR;
2351 return (unsigned long)FTRACE_ADDR;
2355 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2357 unsigned long ftrace_old_addr;
2358 unsigned long ftrace_addr;
2361 ftrace_addr = ftrace_get_addr_new(rec);
2363 /* This needs to be done before we call ftrace_update_record */
2364 ftrace_old_addr = ftrace_get_addr_curr(rec);
2366 ret = ftrace_update_record(rec, enable);
2368 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2371 case FTRACE_UPDATE_IGNORE:
2374 case FTRACE_UPDATE_MAKE_CALL:
2375 ftrace_bug_type = FTRACE_BUG_CALL;
2376 return ftrace_make_call(rec, ftrace_addr);
2378 case FTRACE_UPDATE_MAKE_NOP:
2379 ftrace_bug_type = FTRACE_BUG_NOP;
2380 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2382 case FTRACE_UPDATE_MODIFY_CALL:
2383 ftrace_bug_type = FTRACE_BUG_UPDATE;
2384 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2387 return -1; /* unknow ftrace bug */
2390 void __weak ftrace_replace_code(int enable)
2392 struct dyn_ftrace *rec;
2393 struct ftrace_page *pg;
2396 if (unlikely(ftrace_disabled))
2399 do_for_each_ftrace_rec(pg, rec) {
2400 failed = __ftrace_replace_code(rec, enable);
2402 ftrace_bug(failed, rec);
2403 /* Stop processing */
2406 } while_for_each_ftrace_rec();
2409 struct ftrace_rec_iter {
2410 struct ftrace_page *pg;
2415 * ftrace_rec_iter_start, start up iterating over traced functions
2417 * Returns an iterator handle that is used to iterate over all
2418 * the records that represent address locations where functions
2421 * May return NULL if no records are available.
2423 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2426 * We only use a single iterator.
2427 * Protected by the ftrace_lock mutex.
2429 static struct ftrace_rec_iter ftrace_rec_iter;
2430 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2432 iter->pg = ftrace_pages_start;
2435 /* Could have empty pages */
2436 while (iter->pg && !iter->pg->index)
2437 iter->pg = iter->pg->next;
2446 * ftrace_rec_iter_next, get the next record to process.
2447 * @iter: The handle to the iterator.
2449 * Returns the next iterator after the given iterator @iter.
2451 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2455 if (iter->index >= iter->pg->index) {
2456 iter->pg = iter->pg->next;
2459 /* Could have empty pages */
2460 while (iter->pg && !iter->pg->index)
2461 iter->pg = iter->pg->next;
2471 * ftrace_rec_iter_record, get the record at the iterator location
2472 * @iter: The current iterator location
2474 * Returns the record that the current @iter is at.
2476 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2478 return &iter->pg->records[iter->index];
2482 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2486 if (unlikely(ftrace_disabled))
2489 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2491 ftrace_bug_type = FTRACE_BUG_INIT;
2492 ftrace_bug(ret, rec);
2499 * archs can override this function if they must do something
2500 * before the modifying code is performed.
2502 int __weak ftrace_arch_code_modify_prepare(void)
2508 * archs can override this function if they must do something
2509 * after the modifying code is performed.
2511 int __weak ftrace_arch_code_modify_post_process(void)
2516 void ftrace_modify_all_code(int command)
2518 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2522 * If the ftrace_caller calls a ftrace_ops func directly,
2523 * we need to make sure that it only traces functions it
2524 * expects to trace. When doing the switch of functions,
2525 * we need to update to the ftrace_ops_list_func first
2526 * before the transition between old and new calls are set,
2527 * as the ftrace_ops_list_func will check the ops hashes
2528 * to make sure the ops are having the right functions
2532 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2533 if (FTRACE_WARN_ON(err))
2537 if (command & FTRACE_UPDATE_CALLS)
2538 ftrace_replace_code(1);
2539 else if (command & FTRACE_DISABLE_CALLS)
2540 ftrace_replace_code(0);
2542 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2543 function_trace_op = set_function_trace_op;
2545 /* If irqs are disabled, we are in stop machine */
2546 if (!irqs_disabled())
2547 smp_call_function(ftrace_sync_ipi, NULL, 1);
2548 err = ftrace_update_ftrace_func(ftrace_trace_function);
2549 if (FTRACE_WARN_ON(err))
2553 if (command & FTRACE_START_FUNC_RET)
2554 err = ftrace_enable_ftrace_graph_caller();
2555 else if (command & FTRACE_STOP_FUNC_RET)
2556 err = ftrace_disable_ftrace_graph_caller();
2557 FTRACE_WARN_ON(err);
2560 static int __ftrace_modify_code(void *data)
2562 int *command = data;
2564 ftrace_modify_all_code(*command);
2570 * ftrace_run_stop_machine, go back to the stop machine method
2571 * @command: The command to tell ftrace what to do
2573 * If an arch needs to fall back to the stop machine method, the
2574 * it can call this function.
2576 void ftrace_run_stop_machine(int command)
2578 stop_machine(__ftrace_modify_code, &command, NULL);
2582 * arch_ftrace_update_code, modify the code to trace or not trace
2583 * @command: The command that needs to be done
2585 * Archs can override this function if it does not need to
2586 * run stop_machine() to modify code.
2588 void __weak arch_ftrace_update_code(int command)
2590 ftrace_run_stop_machine(command);
2593 static void ftrace_run_update_code(int command)
2597 ret = ftrace_arch_code_modify_prepare();
2598 FTRACE_WARN_ON(ret);
2603 * By default we use stop_machine() to modify the code.
2604 * But archs can do what ever they want as long as it
2605 * is safe. The stop_machine() is the safest, but also
2606 * produces the most overhead.
2608 arch_ftrace_update_code(command);
2610 ret = ftrace_arch_code_modify_post_process();
2611 FTRACE_WARN_ON(ret);
2614 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2615 struct ftrace_ops_hash *old_hash)
2617 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2618 ops->old_hash.filter_hash = old_hash->filter_hash;
2619 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2620 ftrace_run_update_code(command);
2621 ops->old_hash.filter_hash = NULL;
2622 ops->old_hash.notrace_hash = NULL;
2623 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2626 static ftrace_func_t saved_ftrace_func;
2627 static int ftrace_start_up;
2629 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2633 static void control_ops_free(struct ftrace_ops *ops)
2635 free_percpu(ops->disabled);
2638 static void ftrace_startup_enable(int command)
2640 if (saved_ftrace_func != ftrace_trace_function) {
2641 saved_ftrace_func = ftrace_trace_function;
2642 command |= FTRACE_UPDATE_TRACE_FUNC;
2645 if (!command || !ftrace_enabled)
2648 ftrace_run_update_code(command);
2651 static void ftrace_startup_all(int command)
2653 update_all_ops = true;
2654 ftrace_startup_enable(command);
2655 update_all_ops = false;
2658 static int ftrace_startup(struct ftrace_ops *ops, int command)
2662 if (unlikely(ftrace_disabled))
2665 ret = __register_ftrace_function(ops);
2670 command |= FTRACE_UPDATE_CALLS;
2673 * Note that ftrace probes uses this to start up
2674 * and modify functions it will probe. But we still
2675 * set the ADDING flag for modification, as probes
2676 * do not have trampolines. If they add them in the
2677 * future, then the probes will need to distinguish
2678 * between adding and updating probes.
2680 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2682 ret = ftrace_hash_ipmodify_enable(ops);
2684 /* Rollback registration process */
2685 __unregister_ftrace_function(ops);
2687 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2691 ftrace_hash_rec_enable(ops, 1);
2693 ftrace_startup_enable(command);
2695 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2700 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2704 if (unlikely(ftrace_disabled))
2707 ret = __unregister_ftrace_function(ops);
2713 * Just warn in case of unbalance, no need to kill ftrace, it's not
2714 * critical but the ftrace_call callers may be never nopped again after
2715 * further ftrace uses.
2717 WARN_ON_ONCE(ftrace_start_up < 0);
2719 /* Disabling ipmodify never fails */
2720 ftrace_hash_ipmodify_disable(ops);
2721 ftrace_hash_rec_disable(ops, 1);
2723 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2725 command |= FTRACE_UPDATE_CALLS;
2727 if (saved_ftrace_func != ftrace_trace_function) {
2728 saved_ftrace_func = ftrace_trace_function;
2729 command |= FTRACE_UPDATE_TRACE_FUNC;
2732 if (!command || !ftrace_enabled) {
2734 * If these are control ops, they still need their
2735 * per_cpu field freed. Since, function tracing is
2736 * not currently active, we can just free them
2737 * without synchronizing all CPUs.
2739 if (ops->flags & FTRACE_OPS_FL_CONTROL)
2740 control_ops_free(ops);
2745 * If the ops uses a trampoline, then it needs to be
2746 * tested first on update.
2748 ops->flags |= FTRACE_OPS_FL_REMOVING;
2751 /* The trampoline logic checks the old hashes */
2752 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2753 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2755 ftrace_run_update_code(command);
2758 * If there's no more ops registered with ftrace, run a
2759 * sanity check to make sure all rec flags are cleared.
2761 if (ftrace_ops_list == &ftrace_list_end) {
2762 struct ftrace_page *pg;
2763 struct dyn_ftrace *rec;
2765 do_for_each_ftrace_rec(pg, rec) {
2766 if (FTRACE_WARN_ON_ONCE(rec->flags))
2767 pr_warn(" %pS flags:%lx\n",
2768 (void *)rec->ip, rec->flags);
2769 } while_for_each_ftrace_rec();
2772 ops->old_hash.filter_hash = NULL;
2773 ops->old_hash.notrace_hash = NULL;
2776 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2779 * Dynamic ops may be freed, we must make sure that all
2780 * callers are done before leaving this function.
2781 * The same goes for freeing the per_cpu data of the control
2784 * Again, normal synchronize_sched() is not good enough.
2785 * We need to do a hard force of sched synchronization.
2786 * This is because we use preempt_disable() to do RCU, but
2787 * the function tracers can be called where RCU is not watching
2788 * (like before user_exit()). We can not rely on the RCU
2789 * infrastructure to do the synchronization, thus we must do it
2792 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
2793 schedule_on_each_cpu(ftrace_sync);
2795 arch_ftrace_trampoline_free(ops);
2797 if (ops->flags & FTRACE_OPS_FL_CONTROL)
2798 control_ops_free(ops);
2804 static void ftrace_startup_sysctl(void)
2808 if (unlikely(ftrace_disabled))
2811 /* Force update next time */
2812 saved_ftrace_func = NULL;
2813 /* ftrace_start_up is true if we want ftrace running */
2814 if (ftrace_start_up) {
2815 command = FTRACE_UPDATE_CALLS;
2816 if (ftrace_graph_active)
2817 command |= FTRACE_START_FUNC_RET;
2818 ftrace_startup_enable(command);
2822 static void ftrace_shutdown_sysctl(void)
2826 if (unlikely(ftrace_disabled))
2829 /* ftrace_start_up is true if ftrace is running */
2830 if (ftrace_start_up) {
2831 command = FTRACE_DISABLE_CALLS;
2832 if (ftrace_graph_active)
2833 command |= FTRACE_STOP_FUNC_RET;
2834 ftrace_run_update_code(command);
2838 static cycle_t ftrace_update_time;
2839 unsigned long ftrace_update_tot_cnt;
2841 static inline int ops_traces_mod(struct ftrace_ops *ops)
2844 * Filter_hash being empty will default to trace module.
2845 * But notrace hash requires a test of individual module functions.
2847 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2848 ftrace_hash_empty(ops->func_hash->notrace_hash);
2852 * Check if the current ops references the record.
2854 * If the ops traces all functions, then it was already accounted for.
2855 * If the ops does not trace the current record function, skip it.
2856 * If the ops ignores the function via notrace filter, skip it.
2859 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2861 /* If ops isn't enabled, ignore it */
2862 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2865 /* If ops traces all mods, we already accounted for it */
2866 if (ops_traces_mod(ops))
2869 /* The function must be in the filter */
2870 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2871 !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2874 /* If in notrace hash, we ignore it too */
2875 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2881 static int referenced_filters(struct dyn_ftrace *rec)
2883 struct ftrace_ops *ops;
2886 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
2887 if (ops_references_rec(ops, rec))
2894 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2896 struct ftrace_page *pg;
2897 struct dyn_ftrace *p;
2898 cycle_t start, stop;
2899 unsigned long update_cnt = 0;
2900 unsigned long ref = 0;
2905 * When adding a module, we need to check if tracers are
2906 * currently enabled and if they are set to trace all functions.
2907 * If they are, we need to enable the module functions as well
2908 * as update the reference counts for those function records.
2911 struct ftrace_ops *ops;
2913 for (ops = ftrace_ops_list;
2914 ops != &ftrace_list_end; ops = ops->next) {
2915 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
2916 if (ops_traces_mod(ops))
2924 start = ftrace_now(raw_smp_processor_id());
2926 for (pg = new_pgs; pg; pg = pg->next) {
2928 for (i = 0; i < pg->index; i++) {
2931 /* If something went wrong, bail without enabling anything */
2932 if (unlikely(ftrace_disabled))
2935 p = &pg->records[i];
2937 cnt += referenced_filters(p);
2941 * Do the initial record conversion from mcount jump
2942 * to the NOP instructions.
2944 if (!ftrace_code_disable(mod, p))
2950 * If the tracing is enabled, go ahead and enable the record.
2952 * The reason not to enable the record immediatelly is the
2953 * inherent check of ftrace_make_nop/ftrace_make_call for
2954 * correct previous instructions. Making first the NOP
2955 * conversion puts the module to the correct state, thus
2956 * passing the ftrace_make_call check.
2958 if (ftrace_start_up && cnt) {
2959 int failed = __ftrace_replace_code(p, 1);
2961 ftrace_bug(failed, p);
2966 stop = ftrace_now(raw_smp_processor_id());
2967 ftrace_update_time = stop - start;
2968 ftrace_update_tot_cnt += update_cnt;
2973 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2978 if (WARN_ON(!count))
2981 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2984 * We want to fill as much as possible. No more than a page
2987 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2991 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2994 /* if we can't allocate this size, try something smaller */
3001 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3010 static struct ftrace_page *
3011 ftrace_allocate_pages(unsigned long num_to_init)
3013 struct ftrace_page *start_pg;
3014 struct ftrace_page *pg;
3021 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3026 * Try to allocate as much as possible in one continues
3027 * location that fills in all of the space. We want to
3028 * waste as little space as possible.
3031 cnt = ftrace_allocate_records(pg, num_to_init);
3039 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3051 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3052 free_pages((unsigned long)pg->records, order);
3053 start_pg = pg->next;
3057 pr_info("ftrace: FAILED to allocate memory for functions\n");
3061 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3063 struct ftrace_iterator {
3066 struct ftrace_page *pg;
3067 struct dyn_ftrace *func;
3068 struct ftrace_func_probe *probe;
3069 struct trace_parser parser;
3070 struct ftrace_hash *hash;
3071 struct ftrace_ops *ops;
3078 t_hash_next(struct seq_file *m, loff_t *pos)
3080 struct ftrace_iterator *iter = m->private;
3081 struct hlist_node *hnd = NULL;
3082 struct hlist_head *hhd;
3088 hnd = &iter->probe->node;
3090 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
3093 hhd = &ftrace_func_hash[iter->hidx];
3095 if (hlist_empty(hhd)) {
3111 if (WARN_ON_ONCE(!hnd))
3114 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
3119 static void *t_hash_start(struct seq_file *m, loff_t *pos)
3121 struct ftrace_iterator *iter = m->private;
3125 if (!(iter->flags & FTRACE_ITER_DO_HASH))
3128 if (iter->func_pos > *pos)
3132 for (l = 0; l <= (*pos - iter->func_pos); ) {
3133 p = t_hash_next(m, &l);
3140 /* Only set this if we have an item */
3141 iter->flags |= FTRACE_ITER_HASH;
3147 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
3149 struct ftrace_func_probe *rec;
3152 if (WARN_ON_ONCE(!rec))
3155 if (rec->ops->print)
3156 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
3158 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
3161 seq_printf(m, ":%p", rec->data);
3168 t_next(struct seq_file *m, void *v, loff_t *pos)
3170 struct ftrace_iterator *iter = m->private;
3171 struct ftrace_ops *ops = iter->ops;
3172 struct dyn_ftrace *rec = NULL;
3174 if (unlikely(ftrace_disabled))
3177 if (iter->flags & FTRACE_ITER_HASH)
3178 return t_hash_next(m, pos);
3181 iter->pos = iter->func_pos = *pos;
3183 if (iter->flags & FTRACE_ITER_PRINTALL)
3184 return t_hash_start(m, pos);
3187 if (iter->idx >= iter->pg->index) {
3188 if (iter->pg->next) {
3189 iter->pg = iter->pg->next;
3194 rec = &iter->pg->records[iter->idx++];
3195 if (((iter->flags & FTRACE_ITER_FILTER) &&
3196 !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) ||
3198 ((iter->flags & FTRACE_ITER_NOTRACE) &&
3199 !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) ||
3201 ((iter->flags & FTRACE_ITER_ENABLED) &&
3202 !(rec->flags & FTRACE_FL_ENABLED))) {
3210 return t_hash_start(m, pos);
3217 static void reset_iter_read(struct ftrace_iterator *iter)
3221 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
3224 static void *t_start(struct seq_file *m, loff_t *pos)
3226 struct ftrace_iterator *iter = m->private;
3227 struct ftrace_ops *ops = iter->ops;
3231 mutex_lock(&ftrace_lock);
3233 if (unlikely(ftrace_disabled))
3237 * If an lseek was done, then reset and start from beginning.
3239 if (*pos < iter->pos)
3240 reset_iter_read(iter);
3243 * For set_ftrace_filter reading, if we have the filter
3244 * off, we can short cut and just print out that all
3245 * functions are enabled.
3247 if ((iter->flags & FTRACE_ITER_FILTER &&
3248 ftrace_hash_empty(ops->func_hash->filter_hash)) ||
3249 (iter->flags & FTRACE_ITER_NOTRACE &&
3250 ftrace_hash_empty(ops->func_hash->notrace_hash))) {
3252 return t_hash_start(m, pos);
3253 iter->flags |= FTRACE_ITER_PRINTALL;
3254 /* reset in case of seek/pread */
3255 iter->flags &= ~FTRACE_ITER_HASH;
3259 if (iter->flags & FTRACE_ITER_HASH)
3260 return t_hash_start(m, pos);
3263 * Unfortunately, we need to restart at ftrace_pages_start
3264 * every time we let go of the ftrace_mutex. This is because
3265 * those pointers can change without the lock.
3267 iter->pg = ftrace_pages_start;
3269 for (l = 0; l <= *pos; ) {
3270 p = t_next(m, p, &l);
3276 return t_hash_start(m, pos);
3281 static void t_stop(struct seq_file *m, void *p)
3283 mutex_unlock(&ftrace_lock);
3287 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3292 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3293 struct dyn_ftrace *rec)
3297 ptr = arch_ftrace_trampoline_func(ops, rec);
3299 seq_printf(m, " ->%pS", ptr);
3302 static int t_show(struct seq_file *m, void *v)
3304 struct ftrace_iterator *iter = m->private;
3305 struct dyn_ftrace *rec;
3307 if (iter->flags & FTRACE_ITER_HASH)
3308 return t_hash_show(m, iter);
3310 if (iter->flags & FTRACE_ITER_PRINTALL) {
3311 if (iter->flags & FTRACE_ITER_NOTRACE)
3312 seq_puts(m, "#### no functions disabled ####\n");
3314 seq_puts(m, "#### all functions enabled ####\n");
3323 seq_printf(m, "%ps", (void *)rec->ip);
3324 if (iter->flags & FTRACE_ITER_ENABLED) {
3325 struct ftrace_ops *ops;
3327 seq_printf(m, " (%ld)%s%s",
3328 ftrace_rec_count(rec),
3329 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3330 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3331 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3332 ops = ftrace_find_tramp_ops_any(rec);
3335 seq_printf(m, "\ttramp: %pS (%pS)",
3336 (void *)ops->trampoline,
3338 add_trampoline_func(m, ops, rec);
3339 ops = ftrace_find_tramp_ops_next(rec, ops);
3342 seq_puts(m, "\ttramp: ERROR!");
3344 add_trampoline_func(m, NULL, rec);
3353 static const struct seq_operations show_ftrace_seq_ops = {
3361 ftrace_avail_open(struct inode *inode, struct file *file)
3363 struct ftrace_iterator *iter;
3365 if (unlikely(ftrace_disabled))
3368 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3370 iter->pg = ftrace_pages_start;
3371 iter->ops = &global_ops;
3374 return iter ? 0 : -ENOMEM;
3378 ftrace_enabled_open(struct inode *inode, struct file *file)
3380 struct ftrace_iterator *iter;
3382 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3384 iter->pg = ftrace_pages_start;
3385 iter->flags = FTRACE_ITER_ENABLED;
3386 iter->ops = &global_ops;
3389 return iter ? 0 : -ENOMEM;
3393 * ftrace_regex_open - initialize function tracer filter files
3394 * @ops: The ftrace_ops that hold the hash filters
3395 * @flag: The type of filter to process
3396 * @inode: The inode, usually passed in to your open routine
3397 * @file: The file, usually passed in to your open routine
3399 * ftrace_regex_open() initializes the filter files for the
3400 * @ops. Depending on @flag it may process the filter hash or
3401 * the notrace hash of @ops. With this called from the open
3402 * routine, you can use ftrace_filter_write() for the write
3403 * routine if @flag has FTRACE_ITER_FILTER set, or
3404 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3405 * tracing_lseek() should be used as the lseek routine, and
3406 * release must call ftrace_regex_release().
3409 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3410 struct inode *inode, struct file *file)
3412 struct ftrace_iterator *iter;
3413 struct ftrace_hash *hash;
3416 ftrace_ops_init(ops);
3418 if (unlikely(ftrace_disabled))
3421 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3425 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3433 mutex_lock(&ops->func_hash->regex_lock);
3435 if (flag & FTRACE_ITER_NOTRACE)
3436 hash = ops->func_hash->notrace_hash;
3438 hash = ops->func_hash->filter_hash;
3440 if (file->f_mode & FMODE_WRITE) {
3441 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3443 if (file->f_flags & O_TRUNC)
3444 iter->hash = alloc_ftrace_hash(size_bits);
3446 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3449 trace_parser_put(&iter->parser);
3456 if (file->f_mode & FMODE_READ) {
3457 iter->pg = ftrace_pages_start;
3459 ret = seq_open(file, &show_ftrace_seq_ops);
3461 struct seq_file *m = file->private_data;
3465 free_ftrace_hash(iter->hash);
3466 trace_parser_put(&iter->parser);
3470 file->private_data = iter;
3473 mutex_unlock(&ops->func_hash->regex_lock);
3479 ftrace_filter_open(struct inode *inode, struct file *file)
3481 struct ftrace_ops *ops = inode->i_private;
3483 return ftrace_regex_open(ops,
3484 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
3489 ftrace_notrace_open(struct inode *inode, struct file *file)
3491 struct ftrace_ops *ops = inode->i_private;
3493 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3497 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3498 struct ftrace_glob {
3504 static int ftrace_match(char *str, struct ftrace_glob *g)
3511 if (strcmp(str, g->search) == 0)
3514 case MATCH_FRONT_ONLY:
3515 if (strncmp(str, g->search, g->len) == 0)
3518 case MATCH_MIDDLE_ONLY:
3519 if (strstr(str, g->search))
3522 case MATCH_END_ONLY:
3524 if (slen >= g->len &&
3525 memcmp(str + slen - g->len, g->search, g->len) == 0)
3534 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3536 struct ftrace_func_entry *entry;
3539 entry = ftrace_lookup_ip(hash, rec->ip);
3541 /* Do nothing if it doesn't exist */
3545 free_hash_entry(hash, entry);
3547 /* Do nothing if it exists */
3551 ret = add_hash_entry(hash, rec->ip);
3557 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3558 struct ftrace_glob *mod_g, int exclude_mod)
3560 char str[KSYM_SYMBOL_LEN];
3563 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3566 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3568 /* blank module name to match all modules */
3570 /* blank module globbing: modname xor exclude_mod */
3571 if ((!exclude_mod) != (!modname))
3576 /* not matching the module */
3577 if (!modname || !mod_matches) {
3584 if (mod_matches && exclude_mod)
3588 /* blank search means to match all funcs in the mod */
3593 return ftrace_match(str, func_g);
3597 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3599 struct ftrace_page *pg;
3600 struct dyn_ftrace *rec;
3601 struct ftrace_glob func_g = { .type = MATCH_FULL };
3602 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3603 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3604 int exclude_mod = 0;
3610 func_g.type = filter_parse_regex(func, len, &func_g.search,
3612 func_g.len = strlen(func_g.search);
3616 mod_g.type = filter_parse_regex(mod, strlen(mod),
3617 &mod_g.search, &exclude_mod);
3618 mod_g.len = strlen(mod_g.search);
3621 mutex_lock(&ftrace_lock);
3623 if (unlikely(ftrace_disabled))
3626 do_for_each_ftrace_rec(pg, rec) {
3627 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3628 ret = enter_record(hash, rec, clear_filter);
3635 } while_for_each_ftrace_rec();
3637 mutex_unlock(&ftrace_lock);
3643 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3645 return match_records(hash, buff, len, NULL);
3650 * We register the module command as a template to show others how
3651 * to register the a command as well.
3655 ftrace_mod_callback(struct ftrace_hash *hash,
3656 char *func, char *cmd, char *module, int enable)
3661 * cmd == 'mod' because we only registered this func
3662 * for the 'mod' ftrace_func_command.
3663 * But if you register one func with multiple commands,
3664 * you can tell which command was used by the cmd
3667 ret = match_records(hash, func, strlen(func), module);
3675 static struct ftrace_func_command ftrace_mod_cmd = {
3677 .func = ftrace_mod_callback,
3680 static int __init ftrace_mod_cmd_init(void)
3682 return register_ftrace_command(&ftrace_mod_cmd);
3684 core_initcall(ftrace_mod_cmd_init);
3686 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
3687 struct ftrace_ops *op, struct pt_regs *pt_regs)
3689 struct ftrace_func_probe *entry;
3690 struct hlist_head *hhd;
3693 key = hash_long(ip, FTRACE_HASH_BITS);
3695 hhd = &ftrace_func_hash[key];
3697 if (hlist_empty(hhd))
3701 * Disable preemption for these calls to prevent a RCU grace
3702 * period. This syncs the hash iteration and freeing of items
3703 * on the hash. rcu_read_lock is too dangerous here.
3705 preempt_disable_notrace();
3706 hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
3707 if (entry->ip == ip)
3708 entry->ops->func(ip, parent_ip, &entry->data);
3710 preempt_enable_notrace();
3713 static struct ftrace_ops trace_probe_ops __read_mostly =
3715 .func = function_trace_probe_call,
3716 .flags = FTRACE_OPS_FL_INITIALIZED,
3717 INIT_OPS_HASH(trace_probe_ops)
3720 static int ftrace_probe_registered;
3722 static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash)
3727 if (ftrace_probe_registered) {
3728 /* still need to update the function call sites */
3730 ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
3735 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3736 struct hlist_head *hhd = &ftrace_func_hash[i];
3740 /* Nothing registered? */
3741 if (i == FTRACE_FUNC_HASHSIZE)
3744 ret = ftrace_startup(&trace_probe_ops, 0);
3746 ftrace_probe_registered = 1;
3749 static void __disable_ftrace_function_probe(void)
3753 if (!ftrace_probe_registered)
3756 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3757 struct hlist_head *hhd = &ftrace_func_hash[i];
3762 /* no more funcs left */
3763 ftrace_shutdown(&trace_probe_ops, 0);
3765 ftrace_probe_registered = 0;
3769 static void ftrace_free_entry(struct ftrace_func_probe *entry)
3771 if (entry->ops->free)
3772 entry->ops->free(entry->ops, entry->ip, &entry->data);
3777 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3780 struct ftrace_ops_hash old_hash_ops;
3781 struct ftrace_func_probe *entry;
3782 struct ftrace_glob func_g;
3783 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
3784 struct ftrace_hash *old_hash = *orig_hash;
3785 struct ftrace_hash *hash;
3786 struct ftrace_page *pg;
3787 struct dyn_ftrace *rec;
3793 func_g.type = filter_parse_regex(glob, strlen(glob),
3794 &func_g.search, ¬);
3795 func_g.len = strlen(func_g.search);
3797 /* we do not support '!' for function probes */
3801 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
3803 old_hash_ops.filter_hash = old_hash;
3804 /* Probes only have filters */
3805 old_hash_ops.notrace_hash = NULL;
3807 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
3813 if (unlikely(ftrace_disabled)) {
3818 mutex_lock(&ftrace_lock);
3820 do_for_each_ftrace_rec(pg, rec) {
3822 if (!ftrace_match_record(rec, &func_g, NULL, 0))
3825 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3827 /* If we did not process any, then return error */
3838 * The caller might want to do something special
3839 * for each function we find. We call the callback
3840 * to give the caller an opportunity to do so.
3843 if (ops->init(ops, rec->ip, &entry->data) < 0) {
3844 /* caller does not like this func */
3850 ret = enter_record(hash, rec, 0);
3858 entry->ip = rec->ip;
3860 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3861 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3863 } while_for_each_ftrace_rec();
3865 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3867 __enable_ftrace_function_probe(&old_hash_ops);
3870 free_ftrace_hash_rcu(old_hash);
3875 mutex_unlock(&ftrace_lock);
3877 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
3878 free_ftrace_hash(hash);
3884 PROBE_TEST_FUNC = 1,
3889 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3890 void *data, int flags)
3892 struct ftrace_func_entry *rec_entry;
3893 struct ftrace_func_probe *entry;
3894 struct ftrace_func_probe *p;
3895 struct ftrace_glob func_g;
3896 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
3897 struct ftrace_hash *old_hash = *orig_hash;
3898 struct list_head free_list;
3899 struct ftrace_hash *hash;
3900 struct hlist_node *tmp;
3901 char str[KSYM_SYMBOL_LEN];
3904 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
3905 func_g.search = NULL;
3909 func_g.type = filter_parse_regex(glob, strlen(glob),
3910 &func_g.search, ¬);
3911 func_g.len = strlen(func_g.search);
3912 func_g.search = glob;
3914 /* we do not support '!' for function probes */
3919 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
3921 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3923 /* Hmm, should report this somehow */
3926 INIT_LIST_HEAD(&free_list);
3928 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3929 struct hlist_head *hhd = &ftrace_func_hash[i];
3931 hlist_for_each_entry_safe(entry, tmp, hhd, node) {
3933 /* break up if statements for readability */
3934 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
3937 if ((flags & PROBE_TEST_DATA) && entry->data != data)
3940 /* do this last, since it is the most expensive */
3941 if (func_g.search) {
3942 kallsyms_lookup(entry->ip, NULL, NULL,
3944 if (!ftrace_match(str, &func_g))
3948 rec_entry = ftrace_lookup_ip(hash, entry->ip);
3949 /* It is possible more than one entry had this ip */
3951 free_hash_entry(hash, rec_entry);
3953 hlist_del_rcu(&entry->node);
3954 list_add(&entry->free_list, &free_list);
3957 mutex_lock(&ftrace_lock);
3958 __disable_ftrace_function_probe();
3960 * Remove after the disable is called. Otherwise, if the last
3961 * probe is removed, a null hash means *all enabled*.
3963 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3964 synchronize_sched();
3966 free_ftrace_hash_rcu(old_hash);
3968 list_for_each_entry_safe(entry, p, &free_list, free_list) {
3969 list_del(&entry->free_list);
3970 ftrace_free_entry(entry);
3972 mutex_unlock(&ftrace_lock);
3975 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
3976 free_ftrace_hash(hash);
3980 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3983 __unregister_ftrace_function_probe(glob, ops, data,
3984 PROBE_TEST_FUNC | PROBE_TEST_DATA);
3988 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
3990 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
3993 void unregister_ftrace_function_probe_all(char *glob)
3995 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
3998 static LIST_HEAD(ftrace_commands);
3999 static DEFINE_MUTEX(ftrace_cmd_mutex);
4002 * Currently we only register ftrace commands from __init, so mark this
4005 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4007 struct ftrace_func_command *p;
4010 mutex_lock(&ftrace_cmd_mutex);
4011 list_for_each_entry(p, &ftrace_commands, list) {
4012 if (strcmp(cmd->name, p->name) == 0) {
4017 list_add(&cmd->list, &ftrace_commands);
4019 mutex_unlock(&ftrace_cmd_mutex);
4025 * Currently we only unregister ftrace commands from __init, so mark
4028 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4030 struct ftrace_func_command *p, *n;
4033 mutex_lock(&ftrace_cmd_mutex);
4034 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4035 if (strcmp(cmd->name, p->name) == 0) {
4037 list_del_init(&p->list);
4042 mutex_unlock(&ftrace_cmd_mutex);
4047 static int ftrace_process_regex(struct ftrace_hash *hash,
4048 char *buff, int len, int enable)
4050 char *func, *command, *next = buff;
4051 struct ftrace_func_command *p;
4054 func = strsep(&next, ":");
4057 ret = ftrace_match_records(hash, func, len);
4067 command = strsep(&next, ":");
4069 mutex_lock(&ftrace_cmd_mutex);
4070 list_for_each_entry(p, &ftrace_commands, list) {
4071 if (strcmp(p->name, command) == 0) {
4072 ret = p->func(hash, func, command, next, enable);
4077 mutex_unlock(&ftrace_cmd_mutex);
4083 ftrace_regex_write(struct file *file, const char __user *ubuf,
4084 size_t cnt, loff_t *ppos, int enable)
4086 struct ftrace_iterator *iter;
4087 struct trace_parser *parser;
4093 if (file->f_mode & FMODE_READ) {
4094 struct seq_file *m = file->private_data;
4097 iter = file->private_data;
4099 if (unlikely(ftrace_disabled))
4102 /* iter->hash is a local copy, so we don't need regex_lock */
4104 parser = &iter->parser;
4105 read = trace_get_user(parser, ubuf, cnt, ppos);
4107 if (read >= 0 && trace_parser_loaded(parser) &&
4108 !trace_parser_cont(parser)) {
4109 ret = ftrace_process_regex(iter->hash, parser->buffer,
4110 parser->idx, enable);
4111 trace_parser_clear(parser);
4122 ftrace_filter_write(struct file *file, const char __user *ubuf,
4123 size_t cnt, loff_t *ppos)
4125 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4129 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4130 size_t cnt, loff_t *ppos)
4132 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4136 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4138 struct ftrace_func_entry *entry;
4140 if (!ftrace_location(ip))
4144 entry = ftrace_lookup_ip(hash, ip);
4147 free_hash_entry(hash, entry);
4151 return add_hash_entry(hash, ip);
4154 static void ftrace_ops_update_code(struct ftrace_ops *ops,
4155 struct ftrace_ops_hash *old_hash)
4157 struct ftrace_ops *op;
4159 if (!ftrace_enabled)
4162 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
4163 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
4168 * If this is the shared global_ops filter, then we need to
4169 * check if there is another ops that shares it, is enabled.
4170 * If so, we still need to run the modify code.
4172 if (ops->func_hash != &global_ops.local_hash)
4175 do_for_each_ftrace_op(op, ftrace_ops_list) {
4176 if (op->func_hash == &global_ops.local_hash &&
4177 op->flags & FTRACE_OPS_FL_ENABLED) {
4178 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
4179 /* Only need to do this once */
4182 } while_for_each_ftrace_op(op);
4186 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4187 unsigned long ip, int remove, int reset, int enable)
4189 struct ftrace_hash **orig_hash;
4190 struct ftrace_ops_hash old_hash_ops;
4191 struct ftrace_hash *old_hash;
4192 struct ftrace_hash *hash;
4195 if (unlikely(ftrace_disabled))
4198 mutex_lock(&ops->func_hash->regex_lock);
4201 orig_hash = &ops->func_hash->filter_hash;
4203 orig_hash = &ops->func_hash->notrace_hash;
4206 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4208 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4212 goto out_regex_unlock;
4215 if (buf && !ftrace_match_records(hash, buf, len)) {
4217 goto out_regex_unlock;
4220 ret = ftrace_match_addr(hash, ip, remove);
4222 goto out_regex_unlock;
4225 mutex_lock(&ftrace_lock);
4226 old_hash = *orig_hash;
4227 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
4228 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
4229 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
4231 ftrace_ops_update_code(ops, &old_hash_ops);
4232 free_ftrace_hash_rcu(old_hash);
4234 mutex_unlock(&ftrace_lock);
4237 mutex_unlock(&ops->func_hash->regex_lock);
4239 free_ftrace_hash(hash);
4244 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4245 int reset, int enable)
4247 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4251 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4252 * @ops - the ops to set the filter with
4253 * @ip - the address to add to or remove from the filter.
4254 * @remove - non zero to remove the ip from the filter
4255 * @reset - non zero to reset all filters before applying this filter.
4257 * Filters denote which functions should be enabled when tracing is enabled
4258 * If @ip is NULL, it failes to update filter.
4260 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4261 int remove, int reset)
4263 ftrace_ops_init(ops);
4264 return ftrace_set_addr(ops, ip, remove, reset, 1);
4266 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4269 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4270 int reset, int enable)
4272 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4276 * ftrace_set_filter - set a function to filter on in ftrace
4277 * @ops - the ops to set the filter with
4278 * @buf - the string that holds the function filter text.
4279 * @len - the length of the string.
4280 * @reset - non zero to reset all filters before applying this filter.
4282 * Filters denote which functions should be enabled when tracing is enabled.
4283 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4285 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4288 ftrace_ops_init(ops);
4289 return ftrace_set_regex(ops, buf, len, reset, 1);
4291 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4294 * ftrace_set_notrace - set a function to not trace in ftrace
4295 * @ops - the ops to set the notrace filter with
4296 * @buf - the string that holds the function notrace text.
4297 * @len - the length of the string.
4298 * @reset - non zero to reset all filters before applying this filter.
4300 * Notrace Filters denote which functions should not be enabled when tracing
4301 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4304 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4307 ftrace_ops_init(ops);
4308 return ftrace_set_regex(ops, buf, len, reset, 0);
4310 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4312 * ftrace_set_global_filter - set a function to filter on with global tracers
4313 * @buf - the string that holds the function filter text.
4314 * @len - the length of the string.
4315 * @reset - non zero to reset all filters before applying this filter.
4317 * Filters denote which functions should be enabled when tracing is enabled.
4318 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4320 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4322 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4324 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4327 * ftrace_set_global_notrace - set a function to not trace with global tracers
4328 * @buf - the string that holds the function notrace text.
4329 * @len - the length of the string.
4330 * @reset - non zero to reset all filters before applying this filter.
4332 * Notrace Filters denote which functions should not be enabled when tracing
4333 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4336 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4338 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4340 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4343 * command line interface to allow users to set filters on boot up.
4345 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4346 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4347 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4349 /* Used by function selftest to not test if filter is set */
4350 bool ftrace_filter_param __initdata;
4352 static int __init set_ftrace_notrace(char *str)
4354 ftrace_filter_param = true;
4355 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4358 __setup("ftrace_notrace=", set_ftrace_notrace);
4360 static int __init set_ftrace_filter(char *str)
4362 ftrace_filter_param = true;
4363 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4366 __setup("ftrace_filter=", set_ftrace_filter);
4368 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4369 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4370 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4371 static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
4373 static unsigned long save_global_trampoline;
4374 static unsigned long save_global_flags;
4376 static int __init set_graph_function(char *str)
4378 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4381 __setup("ftrace_graph_filter=", set_graph_function);
4383 static int __init set_graph_notrace_function(char *str)
4385 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4388 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4390 static void __init set_ftrace_early_graph(char *buf, int enable)
4394 unsigned long *table = ftrace_graph_funcs;
4395 int *count = &ftrace_graph_count;
4398 table = ftrace_graph_notrace_funcs;
4399 count = &ftrace_graph_notrace_count;
4403 func = strsep(&buf, ",");
4404 /* we allow only one expression at a time */
4405 ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);
4407 printk(KERN_DEBUG "ftrace: function %s not "
4408 "traceable\n", func);
4411 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4414 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4418 ftrace_ops_init(ops);
4421 func = strsep(&buf, ",");
4422 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4426 static void __init set_ftrace_early_filters(void)
4428 if (ftrace_filter_buf[0])
4429 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4430 if (ftrace_notrace_buf[0])
4431 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4432 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4433 if (ftrace_graph_buf[0])
4434 set_ftrace_early_graph(ftrace_graph_buf, 1);
4435 if (ftrace_graph_notrace_buf[0])
4436 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4437 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4440 int ftrace_regex_release(struct inode *inode, struct file *file)
4442 struct seq_file *m = (struct seq_file *)file->private_data;
4443 struct ftrace_ops_hash old_hash_ops;
4444 struct ftrace_iterator *iter;
4445 struct ftrace_hash **orig_hash;
4446 struct ftrace_hash *old_hash;
4447 struct trace_parser *parser;
4451 if (file->f_mode & FMODE_READ) {
4453 seq_release(inode, file);
4455 iter = file->private_data;
4457 parser = &iter->parser;
4458 if (trace_parser_loaded(parser)) {
4459 parser->buffer[parser->idx] = 0;
4460 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
4463 trace_parser_put(parser);
4465 mutex_lock(&iter->ops->func_hash->regex_lock);
4467 if (file->f_mode & FMODE_WRITE) {
4468 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
4471 orig_hash = &iter->ops->func_hash->filter_hash;
4473 orig_hash = &iter->ops->func_hash->notrace_hash;
4475 mutex_lock(&ftrace_lock);
4476 old_hash = *orig_hash;
4477 old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash;
4478 old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash;
4479 ret = ftrace_hash_move(iter->ops, filter_hash,
4480 orig_hash, iter->hash);
4482 ftrace_ops_update_code(iter->ops, &old_hash_ops);
4483 free_ftrace_hash_rcu(old_hash);
4485 mutex_unlock(&ftrace_lock);
4488 mutex_unlock(&iter->ops->func_hash->regex_lock);
4489 free_ftrace_hash(iter->hash);
4495 static const struct file_operations ftrace_avail_fops = {
4496 .open = ftrace_avail_open,
4498 .llseek = seq_lseek,
4499 .release = seq_release_private,
4502 static const struct file_operations ftrace_enabled_fops = {
4503 .open = ftrace_enabled_open,
4505 .llseek = seq_lseek,
4506 .release = seq_release_private,
4509 static const struct file_operations ftrace_filter_fops = {
4510 .open = ftrace_filter_open,
4512 .write = ftrace_filter_write,
4513 .llseek = tracing_lseek,
4514 .release = ftrace_regex_release,
4517 static const struct file_operations ftrace_notrace_fops = {
4518 .open = ftrace_notrace_open,
4520 .write = ftrace_notrace_write,
4521 .llseek = tracing_lseek,
4522 .release = ftrace_regex_release,
4525 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4527 static DEFINE_MUTEX(graph_lock);
4529 int ftrace_graph_count;
4530 int ftrace_graph_notrace_count;
4531 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
4532 unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
4534 struct ftrace_graph_data {
4535 unsigned long *table;
4538 const struct seq_operations *seq_ops;
4542 __g_next(struct seq_file *m, loff_t *pos)
4544 struct ftrace_graph_data *fgd = m->private;
4546 if (*pos >= *fgd->count)
4548 return &fgd->table[*pos];
4552 g_next(struct seq_file *m, void *v, loff_t *pos)
4555 return __g_next(m, pos);
4558 static void *g_start(struct seq_file *m, loff_t *pos)
4560 struct ftrace_graph_data *fgd = m->private;
4562 mutex_lock(&graph_lock);
4564 /* Nothing, tell g_show to print all functions are enabled */
4565 if (!*fgd->count && !*pos)
4568 return __g_next(m, pos);
4571 static void g_stop(struct seq_file *m, void *p)
4573 mutex_unlock(&graph_lock);
4576 static int g_show(struct seq_file *m, void *v)
4578 unsigned long *ptr = v;
4583 if (ptr == (unsigned long *)1) {
4584 struct ftrace_graph_data *fgd = m->private;
4586 if (fgd->table == ftrace_graph_funcs)
4587 seq_puts(m, "#### all functions enabled ####\n");
4589 seq_puts(m, "#### no functions disabled ####\n");
4593 seq_printf(m, "%ps\n", (void *)*ptr);
4598 static const struct seq_operations ftrace_graph_seq_ops = {
4606 __ftrace_graph_open(struct inode *inode, struct file *file,
4607 struct ftrace_graph_data *fgd)
4611 mutex_lock(&graph_lock);
4612 if ((file->f_mode & FMODE_WRITE) &&
4613 (file->f_flags & O_TRUNC)) {
4615 memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
4617 mutex_unlock(&graph_lock);
4619 if (file->f_mode & FMODE_READ) {
4620 ret = seq_open(file, fgd->seq_ops);
4622 struct seq_file *m = file->private_data;
4626 file->private_data = fgd;
4632 ftrace_graph_open(struct inode *inode, struct file *file)
4634 struct ftrace_graph_data *fgd;
4636 if (unlikely(ftrace_disabled))
4639 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4643 fgd->table = ftrace_graph_funcs;
4644 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4645 fgd->count = &ftrace_graph_count;
4646 fgd->seq_ops = &ftrace_graph_seq_ops;
4648 return __ftrace_graph_open(inode, file, fgd);
4652 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
4654 struct ftrace_graph_data *fgd;
4656 if (unlikely(ftrace_disabled))
4659 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4663 fgd->table = ftrace_graph_notrace_funcs;
4664 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4665 fgd->count = &ftrace_graph_notrace_count;
4666 fgd->seq_ops = &ftrace_graph_seq_ops;
4668 return __ftrace_graph_open(inode, file, fgd);
4672 ftrace_graph_release(struct inode *inode, struct file *file)
4674 if (file->f_mode & FMODE_READ) {
4675 struct seq_file *m = file->private_data;
4678 seq_release(inode, file);
4680 kfree(file->private_data);
4687 ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
4689 struct ftrace_glob func_g;
4690 struct dyn_ftrace *rec;
4691 struct ftrace_page *pg;
4698 func_g.type = filter_parse_regex(buffer, strlen(buffer),
4699 &func_g.search, ¬);
4700 if (!not && *idx >= size)
4703 func_g.len = strlen(func_g.search);
4705 mutex_lock(&ftrace_lock);
4707 if (unlikely(ftrace_disabled)) {
4708 mutex_unlock(&ftrace_lock);
4712 do_for_each_ftrace_rec(pg, rec) {
4714 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
4715 /* if it is in the array */
4717 for (i = 0; i < *idx; i++) {
4718 if (array[i] == rec->ip) {
4727 array[(*idx)++] = rec->ip;
4733 array[i] = array[--(*idx)];
4739 } while_for_each_ftrace_rec();
4741 mutex_unlock(&ftrace_lock);
4750 ftrace_graph_write(struct file *file, const char __user *ubuf,
4751 size_t cnt, loff_t *ppos)
4753 struct trace_parser parser;
4754 ssize_t read, ret = 0;
4755 struct ftrace_graph_data *fgd = file->private_data;
4760 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
4763 read = trace_get_user(&parser, ubuf, cnt, ppos);
4765 if (read >= 0 && trace_parser_loaded((&parser))) {
4766 parser.buffer[parser.idx] = 0;
4768 mutex_lock(&graph_lock);
4770 /* we allow only one expression at a time */
4771 ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
4774 mutex_unlock(&graph_lock);
4780 trace_parser_put(&parser);
4785 static const struct file_operations ftrace_graph_fops = {
4786 .open = ftrace_graph_open,
4788 .write = ftrace_graph_write,
4789 .llseek = tracing_lseek,
4790 .release = ftrace_graph_release,
4793 static const struct file_operations ftrace_graph_notrace_fops = {
4794 .open = ftrace_graph_notrace_open,
4796 .write = ftrace_graph_write,
4797 .llseek = tracing_lseek,
4798 .release = ftrace_graph_release,
4800 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4802 void ftrace_create_filter_files(struct ftrace_ops *ops,
4803 struct dentry *parent)
4806 trace_create_file("set_ftrace_filter", 0644, parent,
4807 ops, &ftrace_filter_fops);
4809 trace_create_file("set_ftrace_notrace", 0644, parent,
4810 ops, &ftrace_notrace_fops);
4814 * The name "destroy_filter_files" is really a misnomer. Although
4815 * in the future, it may actualy delete the files, but this is
4816 * really intended to make sure the ops passed in are disabled
4817 * and that when this function returns, the caller is free to
4820 * The "destroy" name is only to match the "create" name that this
4821 * should be paired with.
4823 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
4825 mutex_lock(&ftrace_lock);
4826 if (ops->flags & FTRACE_OPS_FL_ENABLED)
4827 ftrace_shutdown(ops, 0);
4828 ops->flags |= FTRACE_OPS_FL_DELETED;
4829 mutex_unlock(&ftrace_lock);
4832 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
4835 trace_create_file("available_filter_functions", 0444,
4836 d_tracer, NULL, &ftrace_avail_fops);
4838 trace_create_file("enabled_functions", 0444,
4839 d_tracer, NULL, &ftrace_enabled_fops);
4841 ftrace_create_filter_files(&global_ops, d_tracer);
4843 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4844 trace_create_file("set_graph_function", 0444, d_tracer,
4846 &ftrace_graph_fops);
4847 trace_create_file("set_graph_notrace", 0444, d_tracer,
4849 &ftrace_graph_notrace_fops);
4850 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4855 static int ftrace_cmp_ips(const void *a, const void *b)
4857 const unsigned long *ipa = a;
4858 const unsigned long *ipb = b;
4867 static int ftrace_process_locs(struct module *mod,
4868 unsigned long *start,
4871 struct ftrace_page *start_pg;
4872 struct ftrace_page *pg;
4873 struct dyn_ftrace *rec;
4874 unsigned long count;
4877 unsigned long flags = 0; /* Shut up gcc */
4880 count = end - start;
4885 sort(start, count, sizeof(*start),
4886 ftrace_cmp_ips, NULL);
4888 start_pg = ftrace_allocate_pages(count);
4892 mutex_lock(&ftrace_lock);
4895 * Core and each module needs their own pages, as
4896 * modules will free them when they are removed.
4897 * Force a new page to be allocated for modules.
4900 WARN_ON(ftrace_pages || ftrace_pages_start);
4901 /* First initialization */
4902 ftrace_pages = ftrace_pages_start = start_pg;
4907 if (WARN_ON(ftrace_pages->next)) {
4908 /* Hmm, we have free pages? */
4909 while (ftrace_pages->next)
4910 ftrace_pages = ftrace_pages->next;
4913 ftrace_pages->next = start_pg;
4919 addr = ftrace_call_adjust(*p++);
4921 * Some architecture linkers will pad between
4922 * the different mcount_loc sections of different
4923 * object files to satisfy alignments.
4924 * Skip any NULL pointers.
4929 if (pg->index == pg->size) {
4930 /* We should have allocated enough */
4931 if (WARN_ON(!pg->next))
4936 rec = &pg->records[pg->index++];
4940 /* We should have used all pages */
4943 /* Assign the last page to ftrace_pages */
4947 * We only need to disable interrupts on start up
4948 * because we are modifying code that an interrupt
4949 * may execute, and the modification is not atomic.
4950 * But for modules, nothing runs the code we modify
4951 * until we are finished with it, and there's no
4952 * reason to cause large interrupt latencies while we do it.
4955 local_irq_save(flags);
4956 ftrace_update_code(mod, start_pg);
4958 local_irq_restore(flags);
4961 mutex_unlock(&ftrace_lock);
4966 #ifdef CONFIG_MODULES
4968 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4970 void ftrace_release_mod(struct module *mod)
4972 struct dyn_ftrace *rec;
4973 struct ftrace_page **last_pg;
4974 struct ftrace_page *pg;
4977 mutex_lock(&ftrace_lock);
4979 if (ftrace_disabled)
4983 * Each module has its own ftrace_pages, remove
4984 * them from the list.
4986 last_pg = &ftrace_pages_start;
4987 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
4988 rec = &pg->records[0];
4989 if (within_module_core(rec->ip, mod)) {
4991 * As core pages are first, the first
4992 * page should never be a module page.
4994 if (WARN_ON(pg == ftrace_pages_start))
4997 /* Check if we are deleting the last page */
4998 if (pg == ftrace_pages)
4999 ftrace_pages = next_to_ftrace_page(last_pg);
5001 *last_pg = pg->next;
5002 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5003 free_pages((unsigned long)pg->records, order);
5006 last_pg = &pg->next;
5009 mutex_unlock(&ftrace_lock);
5012 static void ftrace_init_module(struct module *mod,
5013 unsigned long *start, unsigned long *end)
5015 if (ftrace_disabled || start == end)
5017 ftrace_process_locs(mod, start, end);
5020 void ftrace_module_init(struct module *mod)
5022 ftrace_init_module(mod, mod->ftrace_callsites,
5023 mod->ftrace_callsites +
5024 mod->num_ftrace_callsites);
5027 static int ftrace_module_notify_exit(struct notifier_block *self,
5028 unsigned long val, void *data)
5030 struct module *mod = data;
5032 if (val == MODULE_STATE_GOING)
5033 ftrace_release_mod(mod);
5038 static int ftrace_module_notify_exit(struct notifier_block *self,
5039 unsigned long val, void *data)
5043 #endif /* CONFIG_MODULES */
5045 struct notifier_block ftrace_module_exit_nb = {
5046 .notifier_call = ftrace_module_notify_exit,
5047 .priority = INT_MIN, /* Run after anything that can remove kprobes */
5050 void __init ftrace_init(void)
5052 extern unsigned long __start_mcount_loc[];
5053 extern unsigned long __stop_mcount_loc[];
5054 unsigned long count, flags;
5057 local_irq_save(flags);
5058 ret = ftrace_dyn_arch_init();
5059 local_irq_restore(flags);
5063 count = __stop_mcount_loc - __start_mcount_loc;
5065 pr_info("ftrace: No functions to be traced?\n");
5069 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5070 count, count / ENTRIES_PER_PAGE + 1);
5072 last_ftrace_enabled = ftrace_enabled = 1;
5074 ret = ftrace_process_locs(NULL,
5078 ret = register_module_notifier(&ftrace_module_exit_nb);
5080 pr_warning("Failed to register trace ftrace module exit notifier\n");
5082 set_ftrace_early_filters();
5086 ftrace_disabled = 1;
5089 /* Do nothing if arch does not support this */
5090 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
5094 static void ftrace_update_trampoline(struct ftrace_ops *ops)
5098 * Currently there's no safe way to free a trampoline when the kernel
5099 * is configured with PREEMPT. That is because a task could be preempted
5100 * when it jumped to the trampoline, it may be preempted for a long time
5101 * depending on the system load, and currently there's no way to know
5102 * when it will be off the trampoline. If the trampoline is freed
5103 * too early, when the task runs again, it will be executing on freed
5106 #ifdef CONFIG_PREEMPT
5107 /* Currently, only non dynamic ops can have a trampoline */
5108 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
5112 arch_ftrace_update_trampoline(ops);
5117 static struct ftrace_ops global_ops = {
5118 .func = ftrace_stub,
5119 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5120 FTRACE_OPS_FL_INITIALIZED |
5124 static int __init ftrace_nodyn_init(void)
5129 core_initcall(ftrace_nodyn_init);
5131 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
5132 static inline void ftrace_startup_enable(int command) { }
5133 static inline void ftrace_startup_all(int command) { }
5134 /* Keep as macros so we do not need to define the commands */
5135 # define ftrace_startup(ops, command) \
5137 int ___ret = __register_ftrace_function(ops); \
5139 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5142 # define ftrace_shutdown(ops, command) \
5144 int ___ret = __unregister_ftrace_function(ops); \
5146 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5150 # define ftrace_startup_sysctl() do { } while (0)
5151 # define ftrace_shutdown_sysctl() do { } while (0)
5154 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
5159 static void ftrace_update_trampoline(struct ftrace_ops *ops)
5163 #endif /* CONFIG_DYNAMIC_FTRACE */
5165 __init void ftrace_init_global_array_ops(struct trace_array *tr)
5167 tr->ops = &global_ops;
5168 tr->ops->private = tr;
5171 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
5173 /* If we filter on pids, update to use the pid function */
5174 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
5175 if (WARN_ON(tr->ops->func != ftrace_stub))
5176 printk("ftrace ops had %pS for function\n",
5179 tr->ops->func = func;
5180 tr->ops->private = tr;
5183 void ftrace_reset_array_ops(struct trace_array *tr)
5185 tr->ops->func = ftrace_stub;
5189 ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
5190 struct ftrace_ops *op, struct pt_regs *regs)
5192 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
5196 * Some of the ops may be dynamically allocated,
5197 * they must be freed after a synchronize_sched().
5199 preempt_disable_notrace();
5200 trace_recursion_set(TRACE_CONTROL_BIT);
5203 * Control funcs (perf) uses RCU. Only trace if
5204 * RCU is currently active.
5206 if (!rcu_is_watching())
5209 do_for_each_ftrace_op(op, ftrace_control_list) {
5210 if (!(op->flags & FTRACE_OPS_FL_STUB) &&
5211 !ftrace_function_local_disabled(op) &&
5212 ftrace_ops_test(op, ip, regs))
5213 op->func(ip, parent_ip, op, regs);
5214 } while_for_each_ftrace_op(op);
5216 trace_recursion_clear(TRACE_CONTROL_BIT);
5217 preempt_enable_notrace();
5220 static struct ftrace_ops control_ops = {
5221 .func = ftrace_ops_control_func,
5222 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
5223 INIT_OPS_HASH(control_ops)
5227 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
5228 struct ftrace_ops *ignored, struct pt_regs *regs)
5230 struct ftrace_ops *op;
5233 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5238 * Some of the ops may be dynamically allocated,
5239 * they must be freed after a synchronize_sched().
5241 preempt_disable_notrace();
5242 do_for_each_ftrace_op(op, ftrace_ops_list) {
5243 if (ftrace_ops_test(op, ip, regs)) {
5244 if (FTRACE_WARN_ON(!op->func)) {
5245 pr_warn("op=%p %pS\n", op, op);
5248 op->func(ip, parent_ip, op, regs);
5250 } while_for_each_ftrace_op(op);
5252 preempt_enable_notrace();
5253 trace_clear_recursion(bit);
5257 * Some archs only support passing ip and parent_ip. Even though
5258 * the list function ignores the op parameter, we do not want any
5259 * C side effects, where a function is called without the caller
5260 * sending a third parameter.
5261 * Archs are to support both the regs and ftrace_ops at the same time.
5262 * If they support ftrace_ops, it is assumed they support regs.
5263 * If call backs want to use regs, they must either check for regs
5264 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5265 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5266 * An architecture can pass partial regs with ftrace_ops and still
5267 * set the ARCH_SUPPORTS_FTRACE_OPS.
5269 #if ARCH_SUPPORTS_FTRACE_OPS
5270 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
5271 struct ftrace_ops *op, struct pt_regs *regs)
5273 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
5276 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
5278 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
5283 * If there's only one function registered but it does not support
5284 * recursion, this function will be called by the mcount trampoline.
5285 * This function will handle recursion protection.
5287 static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
5288 struct ftrace_ops *op, struct pt_regs *regs)
5292 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5296 op->func(ip, parent_ip, op, regs);
5298 trace_clear_recursion(bit);
5302 * ftrace_ops_get_func - get the function a trampoline should call
5303 * @ops: the ops to get the function for
5305 * Normally the mcount trampoline will call the ops->func, but there
5306 * are times that it should not. For example, if the ops does not
5307 * have its own recursion protection, then it should call the
5308 * ftrace_ops_recurs_func() instead.
5310 * Returns the function that the trampoline should call for @ops.
5312 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
5315 * If the func handles its own recursion, call it directly.
5316 * Otherwise call the recursion protected function that
5317 * will call the ftrace ops function.
5319 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE))
5320 return ftrace_ops_recurs_func;
5325 static void clear_ftrace_swapper(void)
5327 struct task_struct *p;
5331 for_each_online_cpu(cpu) {
5333 clear_tsk_trace_trace(p);
5338 static void set_ftrace_swapper(void)
5340 struct task_struct *p;
5344 for_each_online_cpu(cpu) {
5346 set_tsk_trace_trace(p);
5351 static void clear_ftrace_pid(struct pid *pid)
5353 struct task_struct *p;
5356 do_each_pid_task(pid, PIDTYPE_PID, p) {
5357 clear_tsk_trace_trace(p);
5358 } while_each_pid_task(pid, PIDTYPE_PID, p);
5364 static void set_ftrace_pid(struct pid *pid)
5366 struct task_struct *p;
5369 do_each_pid_task(pid, PIDTYPE_PID, p) {
5370 set_tsk_trace_trace(p);
5371 } while_each_pid_task(pid, PIDTYPE_PID, p);
5375 static void clear_ftrace_pid_task(struct pid *pid)
5377 if (pid == ftrace_swapper_pid)
5378 clear_ftrace_swapper();
5380 clear_ftrace_pid(pid);
5383 static void set_ftrace_pid_task(struct pid *pid)
5385 if (pid == ftrace_swapper_pid)
5386 set_ftrace_swapper();
5388 set_ftrace_pid(pid);
5391 static int ftrace_pid_add(int p)
5394 struct ftrace_pid *fpid;
5397 mutex_lock(&ftrace_lock);
5400 pid = ftrace_swapper_pid;
5402 pid = find_get_pid(p);
5409 list_for_each_entry(fpid, &ftrace_pids, list)
5410 if (fpid->pid == pid)
5415 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
5419 list_add(&fpid->list, &ftrace_pids);
5422 set_ftrace_pid_task(pid);
5424 ftrace_update_pid_func();
5426 ftrace_startup_all(0);
5428 mutex_unlock(&ftrace_lock);
5432 if (pid != ftrace_swapper_pid)
5436 mutex_unlock(&ftrace_lock);
5440 static void ftrace_pid_reset(void)
5442 struct ftrace_pid *fpid, *safe;
5444 mutex_lock(&ftrace_lock);
5445 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
5446 struct pid *pid = fpid->pid;
5448 clear_ftrace_pid_task(pid);
5450 list_del(&fpid->list);
5454 ftrace_update_pid_func();
5455 ftrace_startup_all(0);
5457 mutex_unlock(&ftrace_lock);
5460 static void *fpid_start(struct seq_file *m, loff_t *pos)
5462 mutex_lock(&ftrace_lock);
5464 if (!ftrace_pids_enabled() && (!*pos))
5467 return seq_list_start(&ftrace_pids, *pos);
5470 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
5475 return seq_list_next(v, &ftrace_pids, pos);
5478 static void fpid_stop(struct seq_file *m, void *p)
5480 mutex_unlock(&ftrace_lock);
5483 static int fpid_show(struct seq_file *m, void *v)
5485 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
5487 if (v == (void *)1) {
5488 seq_puts(m, "no pid\n");
5492 if (fpid->pid == ftrace_swapper_pid)
5493 seq_puts(m, "swapper tasks\n");
5495 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
5500 static const struct seq_operations ftrace_pid_sops = {
5501 .start = fpid_start,
5508 ftrace_pid_open(struct inode *inode, struct file *file)
5512 if ((file->f_mode & FMODE_WRITE) &&
5513 (file->f_flags & O_TRUNC))
5516 if (file->f_mode & FMODE_READ)
5517 ret = seq_open(file, &ftrace_pid_sops);
5523 ftrace_pid_write(struct file *filp, const char __user *ubuf,
5524 size_t cnt, loff_t *ppos)
5530 if (cnt >= sizeof(buf))
5533 if (copy_from_user(&buf, ubuf, cnt))
5539 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5540 * to clean the filter quietly.
5542 tmp = strstrip(buf);
5543 if (strlen(tmp) == 0)
5546 ret = kstrtol(tmp, 10, &val);
5550 ret = ftrace_pid_add(val);
5552 return ret ? ret : cnt;
5556 ftrace_pid_release(struct inode *inode, struct file *file)
5558 if (file->f_mode & FMODE_READ)
5559 seq_release(inode, file);
5564 static const struct file_operations ftrace_pid_fops = {
5565 .open = ftrace_pid_open,
5566 .write = ftrace_pid_write,
5568 .llseek = tracing_lseek,
5569 .release = ftrace_pid_release,
5572 static __init int ftrace_init_tracefs(void)
5574 struct dentry *d_tracer;
5576 d_tracer = tracing_init_dentry();
5577 if (IS_ERR(d_tracer))
5580 ftrace_init_dyn_tracefs(d_tracer);
5582 trace_create_file("set_ftrace_pid", 0644, d_tracer,
5583 NULL, &ftrace_pid_fops);
5585 ftrace_profile_tracefs(d_tracer);
5589 fs_initcall(ftrace_init_tracefs);
5592 * ftrace_kill - kill ftrace
5594 * This function should be used by panic code. It stops ftrace
5595 * but in a not so nice way. If you need to simply kill ftrace
5596 * from a non-atomic section, use ftrace_kill.
5598 void ftrace_kill(void)
5600 ftrace_disabled = 1;
5602 clear_ftrace_function();
5606 * Test if ftrace is dead or not.
5608 int ftrace_is_dead(void)
5610 return ftrace_disabled;
5614 * register_ftrace_function - register a function for profiling
5615 * @ops - ops structure that holds the function for profiling.
5617 * Register a function to be called by all functions in the
5620 * Note: @ops->func and all the functions it calls must be labeled
5621 * with "notrace", otherwise it will go into a
5624 int register_ftrace_function(struct ftrace_ops *ops)
5628 ftrace_ops_init(ops);
5630 mutex_lock(&ftrace_lock);
5632 ret = ftrace_startup(ops, 0);
5634 mutex_unlock(&ftrace_lock);
5638 EXPORT_SYMBOL_GPL(register_ftrace_function);
5641 * unregister_ftrace_function - unregister a function for profiling.
5642 * @ops - ops structure that holds the function to unregister
5644 * Unregister a function that was added to be called by ftrace profiling.
5646 int unregister_ftrace_function(struct ftrace_ops *ops)
5650 mutex_lock(&ftrace_lock);
5651 ret = ftrace_shutdown(ops, 0);
5652 mutex_unlock(&ftrace_lock);
5656 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
5659 ftrace_enable_sysctl(struct ctl_table *table, int write,
5660 void __user *buffer, size_t *lenp,
5665 mutex_lock(&ftrace_lock);
5667 if (unlikely(ftrace_disabled))
5670 ret = proc_dointvec(table, write, buffer, lenp, ppos);
5672 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
5675 last_ftrace_enabled = !!ftrace_enabled;
5677 if (ftrace_enabled) {
5679 /* we are starting ftrace again */
5680 if (ftrace_ops_list != &ftrace_list_end)
5681 update_ftrace_function();
5683 ftrace_startup_sysctl();
5686 /* stopping ftrace calls (just send to ftrace_stub) */
5687 ftrace_trace_function = ftrace_stub;
5689 ftrace_shutdown_sysctl();
5693 mutex_unlock(&ftrace_lock);
5697 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5699 static struct ftrace_ops graph_ops = {
5700 .func = ftrace_stub,
5701 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5702 FTRACE_OPS_FL_INITIALIZED |
5705 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5706 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
5707 /* trampoline_size is only needed for dynamically allocated tramps */
5709 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
5712 void ftrace_graph_sleep_time_control(bool enable)
5714 fgraph_sleep_time = enable;
5717 void ftrace_graph_graph_time_control(bool enable)
5719 fgraph_graph_time = enable;
5722 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
5727 /* The callbacks that hook a function */
5728 trace_func_graph_ret_t ftrace_graph_return =
5729 (trace_func_graph_ret_t)ftrace_stub;
5730 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
5731 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
5733 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5734 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
5738 unsigned long flags;
5739 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
5740 struct task_struct *g, *t;
5742 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
5743 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
5744 * sizeof(struct ftrace_ret_stack),
5746 if (!ret_stack_list[i]) {
5754 read_lock_irqsave(&tasklist_lock, flags);
5755 do_each_thread(g, t) {
5761 if (t->ret_stack == NULL) {
5762 atomic_set(&t->tracing_graph_pause, 0);
5763 atomic_set(&t->trace_overrun, 0);
5764 t->curr_ret_stack = -1;
5765 /* Make sure the tasks see the -1 first: */
5767 t->ret_stack = ret_stack_list[start++];
5769 } while_each_thread(g, t);
5772 read_unlock_irqrestore(&tasklist_lock, flags);
5774 for (i = start; i < end; i++)
5775 kfree(ret_stack_list[i]);
5780 ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
5781 struct task_struct *prev, struct task_struct *next)
5783 unsigned long long timestamp;
5787 * Does the user want to count the time a function was asleep.
5788 * If so, do not update the time stamps.
5790 if (fgraph_sleep_time)
5793 timestamp = trace_clock_local();
5795 prev->ftrace_timestamp = timestamp;
5797 /* only process tasks that we timestamped */
5798 if (!next->ftrace_timestamp)
5802 * Update all the counters in next to make up for the
5803 * time next was sleeping.
5805 timestamp -= next->ftrace_timestamp;
5807 for (index = next->curr_ret_stack; index >= 0; index--)
5808 next->ret_stack[index].calltime += timestamp;
5811 /* Allocate a return stack for each task */
5812 static int start_graph_tracing(void)
5814 struct ftrace_ret_stack **ret_stack_list;
5817 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
5818 sizeof(struct ftrace_ret_stack *),
5821 if (!ret_stack_list)
5824 /* The cpu_boot init_task->ret_stack will never be freed */
5825 for_each_online_cpu(cpu) {
5826 if (!idle_task(cpu)->ret_stack)
5827 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
5831 ret = alloc_retstack_tasklist(ret_stack_list);
5832 } while (ret == -EAGAIN);
5835 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
5837 pr_info("ftrace_graph: Couldn't activate tracepoint"
5838 " probe to kernel_sched_switch\n");
5841 kfree(ret_stack_list);
5846 * Hibernation protection.
5847 * The state of the current task is too much unstable during
5848 * suspend/restore to disk. We want to protect against that.
5851 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
5855 case PM_HIBERNATION_PREPARE:
5856 pause_graph_tracing();
5859 case PM_POST_HIBERNATION:
5860 unpause_graph_tracing();
5866 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
5868 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
5870 return __ftrace_graph_entry(trace);
5874 * The function graph tracer should only trace the functions defined
5875 * by set_ftrace_filter and set_ftrace_notrace. If another function
5876 * tracer ops is registered, the graph tracer requires testing the
5877 * function against the global ops, and not just trace any function
5878 * that any ftrace_ops registered.
5880 static void update_function_graph_func(void)
5882 struct ftrace_ops *op;
5883 bool do_test = false;
5886 * The graph and global ops share the same set of functions
5887 * to test. If any other ops is on the list, then
5888 * the graph tracing needs to test if its the function
5891 do_for_each_ftrace_op(op, ftrace_ops_list) {
5892 if (op != &global_ops && op != &graph_ops &&
5893 op != &ftrace_list_end) {
5895 /* in double loop, break out with goto */
5898 } while_for_each_ftrace_op(op);
5901 ftrace_graph_entry = ftrace_graph_entry_test;
5903 ftrace_graph_entry = __ftrace_graph_entry;
5906 static struct notifier_block ftrace_suspend_notifier = {
5907 .notifier_call = ftrace_suspend_notifier_call,
5910 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
5911 trace_func_graph_ent_t entryfunc)
5915 mutex_lock(&ftrace_lock);
5917 /* we currently allow only one tracer registered at a time */
5918 if (ftrace_graph_active) {
5923 register_pm_notifier(&ftrace_suspend_notifier);
5925 ftrace_graph_active++;
5926 ret = start_graph_tracing();
5928 ftrace_graph_active--;
5932 ftrace_graph_return = retfunc;
5935 * Update the indirect function to the entryfunc, and the
5936 * function that gets called to the entry_test first. Then
5937 * call the update fgraph entry function to determine if
5938 * the entryfunc should be called directly or not.
5940 __ftrace_graph_entry = entryfunc;
5941 ftrace_graph_entry = ftrace_graph_entry_test;
5942 update_function_graph_func();
5944 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
5946 mutex_unlock(&ftrace_lock);
5950 void unregister_ftrace_graph(void)
5952 mutex_lock(&ftrace_lock);
5954 if (unlikely(!ftrace_graph_active))
5957 ftrace_graph_active--;
5958 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
5959 ftrace_graph_entry = ftrace_graph_entry_stub;
5960 __ftrace_graph_entry = ftrace_graph_entry_stub;
5961 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
5962 unregister_pm_notifier(&ftrace_suspend_notifier);
5963 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
5965 #ifdef CONFIG_DYNAMIC_FTRACE
5967 * Function graph does not allocate the trampoline, but
5968 * other global_ops do. We need to reset the ALLOC_TRAMP flag
5971 global_ops.trampoline = save_global_trampoline;
5972 if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP)
5973 global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
5977 mutex_unlock(&ftrace_lock);
5980 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
5983 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
5985 atomic_set(&t->tracing_graph_pause, 0);
5986 atomic_set(&t->trace_overrun, 0);
5987 t->ftrace_timestamp = 0;
5988 /* make curr_ret_stack visible before we add the ret_stack */
5990 t->ret_stack = ret_stack;
5994 * Allocate a return stack for the idle task. May be the first
5995 * time through, or it may be done by CPU hotplug online.
5997 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
5999 t->curr_ret_stack = -1;
6001 * The idle task has no parent, it either has its own
6002 * stack or no stack at all.
6005 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
6007 if (ftrace_graph_active) {
6008 struct ftrace_ret_stack *ret_stack;
6010 ret_stack = per_cpu(idle_ret_stack, cpu);
6012 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6013 * sizeof(struct ftrace_ret_stack),
6017 per_cpu(idle_ret_stack, cpu) = ret_stack;
6019 graph_init_task(t, ret_stack);
6023 /* Allocate a return stack for newly created task */
6024 void ftrace_graph_init_task(struct task_struct *t)
6026 /* Make sure we do not use the parent ret_stack */
6027 t->ret_stack = NULL;
6028 t->curr_ret_stack = -1;
6030 if (ftrace_graph_active) {
6031 struct ftrace_ret_stack *ret_stack;
6033 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6034 * sizeof(struct ftrace_ret_stack),
6038 graph_init_task(t, ret_stack);
6042 void ftrace_graph_exit_task(struct task_struct *t)
6044 struct ftrace_ret_stack *ret_stack = t->ret_stack;
6046 t->ret_stack = NULL;
6047 /* NULL must become visible to IRQs before we free it: */