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/sched/task.h>
19 #include <linux/kallsyms.h>
20 #include <linux/seq_file.h>
21 #include <linux/suspend.h>
22 #include <linux/tracefs.h>
23 #include <linux/hardirq.h>
24 #include <linux/kthread.h>
25 #include <linux/uaccess.h>
26 #include <linux/bsearch.h>
27 #include <linux/module.h>
28 #include <linux/ftrace.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/ctype.h>
32 #include <linux/sort.h>
33 #include <linux/list.h>
34 #include <linux/hash.h>
35 #include <linux/rcupdate.h>
37 #include <trace/events/sched.h>
39 #include <asm/sections.h>
40 #include <asm/setup.h>
42 #include "trace_output.h"
43 #include "trace_stat.h"
45 #define FTRACE_WARN_ON(cond) \
53 #define FTRACE_WARN_ON_ONCE(cond) \
56 if (WARN_ON_ONCE(___r)) \
61 /* hash bits for specific function selection */
62 #define FTRACE_HASH_BITS 7
63 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
64 #define FTRACE_HASH_DEFAULT_BITS 10
65 #define FTRACE_HASH_MAX_BITS 12
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 static bool ftrace_pids_enabled(struct ftrace_ops
*ops
)
96 struct trace_array
*tr
;
98 if (!(ops
->flags
& FTRACE_OPS_FL_PID
) || !ops
->private)
103 return tr
->function_pids
!= NULL
;
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_ops_list __read_mostly
= &ftrace_list_end
;
117 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
118 static struct ftrace_ops global_ops
;
120 #if ARCH_SUPPORTS_FTRACE_OPS
121 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
122 struct ftrace_ops
*op
, struct pt_regs
*regs
);
124 /* See comment below, where ftrace_ops_list_func is defined */
125 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
126 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
130 * Traverse the ftrace_global_list, invoking all entries. The reason that we
131 * can use rcu_dereference_raw_notrace() is that elements removed from this list
132 * are simply leaked, so there is no need to interact with a grace-period
133 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
134 * concurrent insertions into the ftrace_global_list.
136 * Silly Alpha and silly pointer-speculation compiler optimizations!
138 #define do_for_each_ftrace_op(op, list) \
139 op = rcu_dereference_raw_notrace(list); \
143 * Optimized for just a single item in the list (as that is the normal case).
145 #define while_for_each_ftrace_op(op) \
146 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
147 unlikely((op) != &ftrace_list_end))
149 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
151 #ifdef CONFIG_DYNAMIC_FTRACE
152 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
153 mutex_init(&ops
->local_hash
.regex_lock
);
154 ops
->func_hash
= &ops
->local_hash
;
155 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
161 * ftrace_nr_registered_ops - return number of ops registered
163 * Returns the number of ftrace_ops registered and tracing functions
165 int ftrace_nr_registered_ops(void)
167 struct ftrace_ops
*ops
;
170 mutex_lock(&ftrace_lock
);
172 for (ops
= ftrace_ops_list
;
173 ops
!= &ftrace_list_end
; ops
= ops
->next
)
176 mutex_unlock(&ftrace_lock
);
181 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
182 struct ftrace_ops
*op
, struct pt_regs
*regs
)
184 struct trace_array
*tr
= op
->private;
186 if (tr
&& this_cpu_read(tr
->trace_buffer
.data
->ftrace_ignore_pid
))
189 op
->saved_func(ip
, parent_ip
, op
, regs
);
193 * clear_ftrace_function - reset the ftrace function
195 * This NULLs the ftrace function and in essence stops
196 * tracing. There may be lag
198 void clear_ftrace_function(void)
200 ftrace_trace_function
= ftrace_stub
;
203 static void per_cpu_ops_disable_all(struct ftrace_ops
*ops
)
207 for_each_possible_cpu(cpu
)
208 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
211 static int per_cpu_ops_alloc(struct ftrace_ops
*ops
)
213 int __percpu
*disabled
;
215 if (WARN_ON_ONCE(!(ops
->flags
& FTRACE_OPS_FL_PER_CPU
)))
218 disabled
= alloc_percpu(int);
222 ops
->disabled
= disabled
;
223 per_cpu_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, RCU, or per CPU ops, or we force list func,
260 * then it needs to call the list anyway.
262 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
|
263 FTRACE_OPS_FL_RCU
) || FTRACE_FORCE_LIST_FUNC
)
264 return ftrace_ops_list_func
;
266 return ftrace_ops_get_func(ops
);
269 static void update_ftrace_function(void)
274 * Prepare the ftrace_ops that the arch callback will use.
275 * If there's only one ftrace_ops registered, the ftrace_ops_list
276 * will point to the ops we want.
278 set_function_trace_op
= ftrace_ops_list
;
280 /* If there's no ftrace_ops registered, just call the stub function */
281 if (ftrace_ops_list
== &ftrace_list_end
) {
285 * If we are at the end of the list and this ops is
286 * recursion safe and not dynamic and the arch supports passing ops,
287 * then have the mcount trampoline call the function directly.
289 } else if (ftrace_ops_list
->next
== &ftrace_list_end
) {
290 func
= ftrace_ops_get_list_func(ftrace_ops_list
);
293 /* Just use the default ftrace_ops */
294 set_function_trace_op
= &ftrace_list_end
;
295 func
= ftrace_ops_list_func
;
298 update_function_graph_func();
300 /* If there's no change, then do nothing more here */
301 if (ftrace_trace_function
== func
)
305 * If we are using the list function, it doesn't care
306 * about the function_trace_ops.
308 if (func
== ftrace_ops_list_func
) {
309 ftrace_trace_function
= func
;
311 * Don't even bother setting function_trace_ops,
312 * it would be racy to do so anyway.
317 #ifndef CONFIG_DYNAMIC_FTRACE
319 * For static tracing, we need to be a bit more careful.
320 * The function change takes affect immediately. Thus,
321 * we need to coorditate the setting of the function_trace_ops
322 * with the setting of the ftrace_trace_function.
324 * Set the function to the list ops, which will call the
325 * function we want, albeit indirectly, but it handles the
326 * ftrace_ops and doesn't depend on function_trace_op.
328 ftrace_trace_function
= ftrace_ops_list_func
;
330 * Make sure all CPUs see this. Yes this is slow, but static
331 * tracing is slow and nasty to have enabled.
333 schedule_on_each_cpu(ftrace_sync
);
334 /* Now all cpus are using the list ops. */
335 function_trace_op
= set_function_trace_op
;
336 /* Make sure the function_trace_op is visible on all CPUs */
338 /* Nasty way to force a rmb on all cpus */
339 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
340 /* OK, we are all set to update the ftrace_trace_function now! */
341 #endif /* !CONFIG_DYNAMIC_FTRACE */
343 ftrace_trace_function
= func
;
346 int using_ftrace_ops_list_func(void)
348 return ftrace_trace_function
== ftrace_ops_list_func
;
351 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
355 * We are entering ops into the list but another
356 * CPU might be walking that list. We need to make sure
357 * the ops->next pointer is valid before another CPU sees
358 * the ops pointer included into the list.
360 rcu_assign_pointer(*list
, ops
);
363 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
365 struct ftrace_ops
**p
;
368 * If we are removing the last function, then simply point
369 * to the ftrace_stub.
371 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
372 *list
= &ftrace_list_end
;
376 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
387 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
389 static int __register_ftrace_function(struct ftrace_ops
*ops
)
391 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
394 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
397 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
399 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
400 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
401 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
403 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
404 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
407 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
408 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
411 if (!core_kernel_data((unsigned long)ops
))
412 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
414 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
) {
415 if (per_cpu_ops_alloc(ops
))
419 add_ftrace_ops(&ftrace_ops_list
, ops
);
421 /* Always save the function, and reset at unregistering */
422 ops
->saved_func
= ops
->func
;
424 if (ftrace_pids_enabled(ops
))
425 ops
->func
= ftrace_pid_func
;
427 ftrace_update_trampoline(ops
);
430 update_ftrace_function();
435 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
439 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
442 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
448 update_ftrace_function();
450 ops
->func
= ops
->saved_func
;
455 static void ftrace_update_pid_func(void)
457 struct ftrace_ops
*op
;
459 /* Only do something if we are tracing something */
460 if (ftrace_trace_function
== ftrace_stub
)
463 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
464 if (op
->flags
& FTRACE_OPS_FL_PID
) {
465 op
->func
= ftrace_pids_enabled(op
) ?
466 ftrace_pid_func
: op
->saved_func
;
467 ftrace_update_trampoline(op
);
469 } while_for_each_ftrace_op(op
);
471 update_ftrace_function();
474 #ifdef CONFIG_FUNCTION_PROFILER
475 struct ftrace_profile
{
476 struct hlist_node node
;
478 unsigned long counter
;
479 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
480 unsigned long long time
;
481 unsigned long long time_squared
;
485 struct ftrace_profile_page
{
486 struct ftrace_profile_page
*next
;
488 struct ftrace_profile records
[];
491 struct ftrace_profile_stat
{
493 struct hlist_head
*hash
;
494 struct ftrace_profile_page
*pages
;
495 struct ftrace_profile_page
*start
;
496 struct tracer_stat stat
;
499 #define PROFILE_RECORDS_SIZE \
500 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
502 #define PROFILES_PER_PAGE \
503 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
505 static int ftrace_profile_enabled __read_mostly
;
507 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
508 static DEFINE_MUTEX(ftrace_profile_lock
);
510 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
512 #define FTRACE_PROFILE_HASH_BITS 10
513 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
516 function_stat_next(void *v
, int idx
)
518 struct ftrace_profile
*rec
= v
;
519 struct ftrace_profile_page
*pg
;
521 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
527 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
531 rec
= &pg
->records
[0];
539 static void *function_stat_start(struct tracer_stat
*trace
)
541 struct ftrace_profile_stat
*stat
=
542 container_of(trace
, struct ftrace_profile_stat
, stat
);
544 if (!stat
|| !stat
->start
)
547 return function_stat_next(&stat
->start
->records
[0], 0);
550 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
551 /* function graph compares on total time */
552 static int function_stat_cmp(void *p1
, void *p2
)
554 struct ftrace_profile
*a
= p1
;
555 struct ftrace_profile
*b
= p2
;
557 if (a
->time
< b
->time
)
559 if (a
->time
> b
->time
)
565 /* not function graph compares against hits */
566 static int function_stat_cmp(void *p1
, void *p2
)
568 struct ftrace_profile
*a
= p1
;
569 struct ftrace_profile
*b
= p2
;
571 if (a
->counter
< b
->counter
)
573 if (a
->counter
> b
->counter
)
580 static int function_stat_headers(struct seq_file
*m
)
582 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
583 seq_puts(m
, " Function "
586 "--- ---- --- ---\n");
588 seq_puts(m
, " Function Hit\n"
594 static int function_stat_show(struct seq_file
*m
, void *v
)
596 struct ftrace_profile
*rec
= v
;
597 char str
[KSYM_SYMBOL_LEN
];
599 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
600 static struct trace_seq s
;
601 unsigned long long avg
;
602 unsigned long long stddev
;
604 mutex_lock(&ftrace_profile_lock
);
606 /* we raced with function_profile_reset() */
607 if (unlikely(rec
->counter
== 0)) {
612 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
614 do_div(avg
, rec
->counter
);
615 if (tracing_thresh
&& (avg
< tracing_thresh
))
619 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
620 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
622 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
625 /* Sample standard deviation (s^2) */
626 if (rec
->counter
<= 1)
630 * Apply Welford's method:
631 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
633 stddev
= rec
->counter
* rec
->time_squared
-
634 rec
->time
* rec
->time
;
637 * Divide only 1000 for ns^2 -> us^2 conversion.
638 * trace_print_graph_duration will divide 1000 again.
640 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
644 trace_print_graph_duration(rec
->time
, &s
);
645 trace_seq_puts(&s
, " ");
646 trace_print_graph_duration(avg
, &s
);
647 trace_seq_puts(&s
, " ");
648 trace_print_graph_duration(stddev
, &s
);
649 trace_print_seq(m
, &s
);
653 mutex_unlock(&ftrace_profile_lock
);
658 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
660 struct ftrace_profile_page
*pg
;
662 pg
= stat
->pages
= stat
->start
;
665 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
670 memset(stat
->hash
, 0,
671 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
674 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
676 struct ftrace_profile_page
*pg
;
681 /* If we already allocated, do nothing */
685 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
689 #ifdef CONFIG_DYNAMIC_FTRACE
690 functions
= ftrace_update_tot_cnt
;
693 * We do not know the number of functions that exist because
694 * dynamic tracing is what counts them. With past experience
695 * we have around 20K functions. That should be more than enough.
696 * It is highly unlikely we will execute every function in
702 pg
= stat
->start
= stat
->pages
;
704 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
706 for (i
= 1; i
< pages
; i
++) {
707 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
718 unsigned long tmp
= (unsigned long)pg
;
730 static int ftrace_profile_init_cpu(int cpu
)
732 struct ftrace_profile_stat
*stat
;
735 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
738 /* If the profile is already created, simply reset it */
739 ftrace_profile_reset(stat
);
744 * We are profiling all functions, but usually only a few thousand
745 * functions are hit. We'll make a hash of 1024 items.
747 size
= FTRACE_PROFILE_HASH_SIZE
;
749 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
754 /* Preallocate the function profiling pages */
755 if (ftrace_profile_pages_init(stat
) < 0) {
764 static int ftrace_profile_init(void)
769 for_each_possible_cpu(cpu
) {
770 ret
= ftrace_profile_init_cpu(cpu
);
778 /* interrupts must be disabled */
779 static struct ftrace_profile
*
780 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
782 struct ftrace_profile
*rec
;
783 struct hlist_head
*hhd
;
786 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
787 hhd
= &stat
->hash
[key
];
789 if (hlist_empty(hhd
))
792 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
800 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
801 struct ftrace_profile
*rec
)
805 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
806 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
810 * The memory is already allocated, this simply finds a new record to use.
812 static struct ftrace_profile
*
813 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
815 struct ftrace_profile
*rec
= NULL
;
817 /* prevent recursion (from NMIs) */
818 if (atomic_inc_return(&stat
->disabled
) != 1)
822 * Try to find the function again since an NMI
823 * could have added it
825 rec
= ftrace_find_profiled_func(stat
, ip
);
829 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
830 if (!stat
->pages
->next
)
832 stat
->pages
= stat
->pages
->next
;
835 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
837 ftrace_add_profile(stat
, rec
);
840 atomic_dec(&stat
->disabled
);
846 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
847 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
849 struct ftrace_profile_stat
*stat
;
850 struct ftrace_profile
*rec
;
853 if (!ftrace_profile_enabled
)
856 local_irq_save(flags
);
858 stat
= this_cpu_ptr(&ftrace_profile_stats
);
859 if (!stat
->hash
|| !ftrace_profile_enabled
)
862 rec
= ftrace_find_profiled_func(stat
, ip
);
864 rec
= ftrace_profile_alloc(stat
, ip
);
871 local_irq_restore(flags
);
874 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
875 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
877 int index
= trace
->depth
;
879 function_profile_call(trace
->func
, 0, NULL
, NULL
);
881 if (index
>= 0 && index
< FTRACE_RETFUNC_DEPTH
)
882 current
->ret_stack
[index
].subtime
= 0;
887 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
889 struct ftrace_profile_stat
*stat
;
890 unsigned long long calltime
;
891 struct ftrace_profile
*rec
;
894 local_irq_save(flags
);
895 stat
= this_cpu_ptr(&ftrace_profile_stats
);
896 if (!stat
->hash
|| !ftrace_profile_enabled
)
899 /* If the calltime was zero'd ignore it */
900 if (!trace
->calltime
)
903 calltime
= trace
->rettime
- trace
->calltime
;
905 if (!fgraph_graph_time
) {
908 index
= trace
->depth
;
910 /* Append this call time to the parent time to subtract */
912 current
->ret_stack
[index
- 1].subtime
+= calltime
;
914 if (current
->ret_stack
[index
].subtime
< calltime
)
915 calltime
-= current
->ret_stack
[index
].subtime
;
920 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
922 rec
->time
+= calltime
;
923 rec
->time_squared
+= calltime
* calltime
;
927 local_irq_restore(flags
);
930 static int register_ftrace_profiler(void)
932 return register_ftrace_graph(&profile_graph_return
,
933 &profile_graph_entry
);
936 static void unregister_ftrace_profiler(void)
938 unregister_ftrace_graph();
941 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
942 .func
= function_profile_call
,
943 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
944 INIT_OPS_HASH(ftrace_profile_ops
)
947 static int register_ftrace_profiler(void)
949 return register_ftrace_function(&ftrace_profile_ops
);
952 static void unregister_ftrace_profiler(void)
954 unregister_ftrace_function(&ftrace_profile_ops
);
956 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
959 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
960 size_t cnt
, loff_t
*ppos
)
965 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
971 mutex_lock(&ftrace_profile_lock
);
972 if (ftrace_profile_enabled
^ val
) {
974 ret
= ftrace_profile_init();
980 ret
= register_ftrace_profiler();
985 ftrace_profile_enabled
= 1;
987 ftrace_profile_enabled
= 0;
989 * unregister_ftrace_profiler calls stop_machine
990 * so this acts like an synchronize_sched.
992 unregister_ftrace_profiler();
996 mutex_unlock(&ftrace_profile_lock
);
1004 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
1005 size_t cnt
, loff_t
*ppos
)
1007 char buf
[64]; /* big enough to hold a number */
1010 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1011 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1014 static const struct file_operations ftrace_profile_fops
= {
1015 .open
= tracing_open_generic
,
1016 .read
= ftrace_profile_read
,
1017 .write
= ftrace_profile_write
,
1018 .llseek
= default_llseek
,
1021 /* used to initialize the real stat files */
1022 static struct tracer_stat function_stats __initdata
= {
1023 .name
= "functions",
1024 .stat_start
= function_stat_start
,
1025 .stat_next
= function_stat_next
,
1026 .stat_cmp
= function_stat_cmp
,
1027 .stat_headers
= function_stat_headers
,
1028 .stat_show
= function_stat_show
1031 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1033 struct ftrace_profile_stat
*stat
;
1034 struct dentry
*entry
;
1039 for_each_possible_cpu(cpu
) {
1040 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1042 name
= kasprintf(GFP_KERNEL
, "function%d", cpu
);
1045 * The files created are permanent, if something happens
1046 * we still do not free memory.
1049 "Could not allocate stat file for cpu %d\n",
1053 stat
->stat
= function_stats
;
1054 stat
->stat
.name
= name
;
1055 ret
= register_stat_tracer(&stat
->stat
);
1058 "Could not register function stat for cpu %d\n",
1065 entry
= tracefs_create_file("function_profile_enabled", 0644,
1066 d_tracer
, NULL
, &ftrace_profile_fops
);
1068 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1071 #else /* CONFIG_FUNCTION_PROFILER */
1072 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1075 #endif /* CONFIG_FUNCTION_PROFILER */
1077 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1079 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1080 static int ftrace_graph_active
;
1082 # define ftrace_graph_active 0
1085 #ifdef CONFIG_DYNAMIC_FTRACE
1087 static struct ftrace_ops
*removed_ops
;
1090 * Set when doing a global update, like enabling all recs or disabling them.
1091 * It is not set when just updating a single ftrace_ops.
1093 static bool update_all_ops
;
1095 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1096 # error Dynamic ftrace depends on MCOUNT_RECORD
1099 struct ftrace_func_entry
{
1100 struct hlist_node hlist
;
1104 struct ftrace_func_probe
{
1105 struct ftrace_probe_ops
*probe_ops
;
1106 struct ftrace_ops ops
;
1107 struct trace_array
*tr
;
1108 struct list_head list
;
1114 * We make these constant because no one should touch them,
1115 * but they are used as the default "empty hash", to avoid allocating
1116 * it all the time. These are in a read only section such that if
1117 * anyone does try to modify it, it will cause an exception.
1119 static const struct hlist_head empty_buckets
[1];
1120 static const struct ftrace_hash empty_hash
= {
1121 .buckets
= (struct hlist_head
*)empty_buckets
,
1123 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1125 static struct ftrace_ops global_ops
= {
1126 .func
= ftrace_stub
,
1127 .local_hash
.notrace_hash
= EMPTY_HASH
,
1128 .local_hash
.filter_hash
= EMPTY_HASH
,
1129 INIT_OPS_HASH(global_ops
)
1130 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1131 FTRACE_OPS_FL_INITIALIZED
|
1136 * This is used by __kernel_text_address() to return true if the
1137 * address is on a dynamically allocated trampoline that would
1138 * not return true for either core_kernel_text() or
1139 * is_module_text_address().
1141 bool is_ftrace_trampoline(unsigned long addr
)
1143 struct ftrace_ops
*op
;
1147 * Some of the ops may be dynamically allocated,
1148 * they are freed after a synchronize_sched().
1150 preempt_disable_notrace();
1152 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1154 * This is to check for dynamically allocated trampolines.
1155 * Trampolines that are in kernel text will have
1156 * core_kernel_text() return true.
1158 if (op
->trampoline
&& op
->trampoline_size
)
1159 if (addr
>= op
->trampoline
&&
1160 addr
< op
->trampoline
+ op
->trampoline_size
) {
1164 } while_for_each_ftrace_op(op
);
1167 preempt_enable_notrace();
1172 struct ftrace_page
{
1173 struct ftrace_page
*next
;
1174 struct dyn_ftrace
*records
;
1179 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1180 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1182 /* estimate from running different kernels */
1183 #define NR_TO_INIT 10000
1185 static struct ftrace_page
*ftrace_pages_start
;
1186 static struct ftrace_page
*ftrace_pages
;
1188 static __always_inline
unsigned long
1189 ftrace_hash_key(struct ftrace_hash
*hash
, unsigned long ip
)
1191 if (hash
->size_bits
> 0)
1192 return hash_long(ip
, hash
->size_bits
);
1197 /* Only use this function if ftrace_hash_empty() has already been tested */
1198 static __always_inline
struct ftrace_func_entry
*
1199 __ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1202 struct ftrace_func_entry
*entry
;
1203 struct hlist_head
*hhd
;
1205 key
= ftrace_hash_key(hash
, ip
);
1206 hhd
= &hash
->buckets
[key
];
1208 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1209 if (entry
->ip
== ip
)
1216 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1217 * @hash: The hash to look at
1218 * @ip: The instruction pointer to test
1220 * Search a given @hash to see if a given instruction pointer (@ip)
1223 * Returns the entry that holds the @ip if found. NULL otherwise.
1225 struct ftrace_func_entry
*
1226 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1228 if (ftrace_hash_empty(hash
))
1231 return __ftrace_lookup_ip(hash
, ip
);
1234 static void __add_hash_entry(struct ftrace_hash
*hash
,
1235 struct ftrace_func_entry
*entry
)
1237 struct hlist_head
*hhd
;
1240 key
= ftrace_hash_key(hash
, entry
->ip
);
1241 hhd
= &hash
->buckets
[key
];
1242 hlist_add_head(&entry
->hlist
, hhd
);
1246 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1248 struct ftrace_func_entry
*entry
;
1250 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1255 __add_hash_entry(hash
, entry
);
1261 free_hash_entry(struct ftrace_hash
*hash
,
1262 struct ftrace_func_entry
*entry
)
1264 hlist_del(&entry
->hlist
);
1270 remove_hash_entry(struct ftrace_hash
*hash
,
1271 struct ftrace_func_entry
*entry
)
1273 hlist_del_rcu(&entry
->hlist
);
1277 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1279 struct hlist_head
*hhd
;
1280 struct hlist_node
*tn
;
1281 struct ftrace_func_entry
*entry
;
1282 int size
= 1 << hash
->size_bits
;
1288 for (i
= 0; i
< size
; i
++) {
1289 hhd
= &hash
->buckets
[i
];
1290 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1291 free_hash_entry(hash
, entry
);
1293 FTRACE_WARN_ON(hash
->count
);
1296 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1298 if (!hash
|| hash
== EMPTY_HASH
)
1300 ftrace_hash_clear(hash
);
1301 kfree(hash
->buckets
);
1305 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1307 struct ftrace_hash
*hash
;
1309 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1310 free_ftrace_hash(hash
);
1313 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1315 if (!hash
|| hash
== EMPTY_HASH
)
1317 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1320 void ftrace_free_filter(struct ftrace_ops
*ops
)
1322 ftrace_ops_init(ops
);
1323 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1324 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1327 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1329 struct ftrace_hash
*hash
;
1332 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1336 size
= 1 << size_bits
;
1337 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1339 if (!hash
->buckets
) {
1344 hash
->size_bits
= size_bits
;
1349 static struct ftrace_hash
*
1350 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1352 struct ftrace_func_entry
*entry
;
1353 struct ftrace_hash
*new_hash
;
1358 new_hash
= alloc_ftrace_hash(size_bits
);
1363 if (ftrace_hash_empty(hash
))
1366 size
= 1 << hash
->size_bits
;
1367 for (i
= 0; i
< size
; i
++) {
1368 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1369 ret
= add_hash_entry(new_hash
, entry
->ip
);
1375 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1380 free_ftrace_hash(new_hash
);
1385 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1387 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1389 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1390 struct ftrace_hash
*new_hash
);
1392 static struct ftrace_hash
*
1393 __ftrace_hash_move(struct ftrace_hash
*src
)
1395 struct ftrace_func_entry
*entry
;
1396 struct hlist_node
*tn
;
1397 struct hlist_head
*hhd
;
1398 struct ftrace_hash
*new_hash
;
1399 int size
= src
->count
;
1404 * If the new source is empty, just return the empty_hash.
1410 * Make the hash size about 1/2 the # found
1412 for (size
/= 2; size
; size
>>= 1)
1415 /* Don't allocate too much */
1416 if (bits
> FTRACE_HASH_MAX_BITS
)
1417 bits
= FTRACE_HASH_MAX_BITS
;
1419 new_hash
= alloc_ftrace_hash(bits
);
1423 size
= 1 << src
->size_bits
;
1424 for (i
= 0; i
< size
; i
++) {
1425 hhd
= &src
->buckets
[i
];
1426 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1427 remove_hash_entry(src
, entry
);
1428 __add_hash_entry(new_hash
, entry
);
1436 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1437 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1439 struct ftrace_hash
*new_hash
;
1442 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1443 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1446 new_hash
= __ftrace_hash_move(src
);
1450 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1452 /* IPMODIFY should be updated only when filter_hash updating */
1453 ret
= ftrace_hash_ipmodify_update(ops
, new_hash
);
1455 free_ftrace_hash(new_hash
);
1461 * Remove the current set, update the hash and add
1464 ftrace_hash_rec_disable_modify(ops
, enable
);
1466 rcu_assign_pointer(*dst
, new_hash
);
1468 ftrace_hash_rec_enable_modify(ops
, enable
);
1473 static bool hash_contains_ip(unsigned long ip
,
1474 struct ftrace_ops_hash
*hash
)
1477 * The function record is a match if it exists in the filter
1478 * hash and not in the notrace hash. Note, an emty hash is
1479 * considered a match for the filter hash, but an empty
1480 * notrace hash is considered not in the notrace hash.
1482 return (ftrace_hash_empty(hash
->filter_hash
) ||
1483 __ftrace_lookup_ip(hash
->filter_hash
, ip
)) &&
1484 (ftrace_hash_empty(hash
->notrace_hash
) ||
1485 !__ftrace_lookup_ip(hash
->notrace_hash
, ip
));
1489 * Test the hashes for this ops to see if we want to call
1490 * the ops->func or not.
1492 * It's a match if the ip is in the ops->filter_hash or
1493 * the filter_hash does not exist or is empty,
1495 * the ip is not in the ops->notrace_hash.
1497 * This needs to be called with preemption disabled as
1498 * the hashes are freed with call_rcu_sched().
1501 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1503 struct ftrace_ops_hash hash
;
1506 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1508 * There's a small race when adding ops that the ftrace handler
1509 * that wants regs, may be called without them. We can not
1510 * allow that handler to be called if regs is NULL.
1512 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1516 hash
.filter_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->filter_hash
);
1517 hash
.notrace_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->notrace_hash
);
1519 if (hash_contains_ip(ip
, &hash
))
1528 * This is a double for. Do not use 'break' to break out of the loop,
1529 * you must use a goto.
1531 #define do_for_each_ftrace_rec(pg, rec) \
1532 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1534 for (_____i = 0; _____i < pg->index; _____i++) { \
1535 rec = &pg->records[_____i];
1537 #define while_for_each_ftrace_rec() \
1542 static int ftrace_cmp_recs(const void *a
, const void *b
)
1544 const struct dyn_ftrace
*key
= a
;
1545 const struct dyn_ftrace
*rec
= b
;
1547 if (key
->flags
< rec
->ip
)
1549 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1555 * ftrace_location_range - return the first address of a traced location
1556 * if it touches the given ip range
1557 * @start: start of range to search.
1558 * @end: end of range to search (inclusive). @end points to the last byte
1561 * Returns rec->ip if the related ftrace location is a least partly within
1562 * the given address range. That is, the first address of the instruction
1563 * that is either a NOP or call to the function tracer. It checks the ftrace
1564 * internal tables to determine if the address belongs or not.
1566 unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1568 struct ftrace_page
*pg
;
1569 struct dyn_ftrace
*rec
;
1570 struct dyn_ftrace key
;
1573 key
.flags
= end
; /* overload flags, as it is unsigned long */
1575 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1576 if (end
< pg
->records
[0].ip
||
1577 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1579 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1580 sizeof(struct dyn_ftrace
),
1590 * ftrace_location - return true if the ip giving is a traced location
1591 * @ip: the instruction pointer to check
1593 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1594 * That is, the instruction that is either a NOP or call to
1595 * the function tracer. It checks the ftrace internal tables to
1596 * determine if the address belongs or not.
1598 unsigned long ftrace_location(unsigned long ip
)
1600 return ftrace_location_range(ip
, ip
);
1604 * ftrace_text_reserved - return true if range contains an ftrace location
1605 * @start: start of range to search
1606 * @end: end of range to search (inclusive). @end points to the last byte to check.
1608 * Returns 1 if @start and @end contains a ftrace location.
1609 * That is, the instruction that is either a NOP or call to
1610 * the function tracer. It checks the ftrace internal tables to
1611 * determine if the address belongs or not.
1613 int ftrace_text_reserved(const void *start
, const void *end
)
1617 ret
= ftrace_location_range((unsigned long)start
,
1618 (unsigned long)end
);
1623 /* Test if ops registered to this rec needs regs */
1624 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1626 struct ftrace_ops
*ops
;
1627 bool keep_regs
= false;
1629 for (ops
= ftrace_ops_list
;
1630 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1631 /* pass rec in as regs to have non-NULL val */
1632 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1633 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1643 static bool __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1647 struct ftrace_hash
*hash
;
1648 struct ftrace_hash
*other_hash
;
1649 struct ftrace_page
*pg
;
1650 struct dyn_ftrace
*rec
;
1651 bool update
= false;
1655 /* Only update if the ops has been registered */
1656 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1660 * In the filter_hash case:
1661 * If the count is zero, we update all records.
1662 * Otherwise we just update the items in the hash.
1664 * In the notrace_hash case:
1665 * We enable the update in the hash.
1666 * As disabling notrace means enabling the tracing,
1667 * and enabling notrace means disabling, the inc variable
1671 hash
= ops
->func_hash
->filter_hash
;
1672 other_hash
= ops
->func_hash
->notrace_hash
;
1673 if (ftrace_hash_empty(hash
))
1677 hash
= ops
->func_hash
->notrace_hash
;
1678 other_hash
= ops
->func_hash
->filter_hash
;
1680 * If the notrace hash has no items,
1681 * then there's nothing to do.
1683 if (ftrace_hash_empty(hash
))
1687 do_for_each_ftrace_rec(pg
, rec
) {
1688 int in_other_hash
= 0;
1692 if (rec
->flags
& FTRACE_FL_DISABLED
)
1697 * Only the filter_hash affects all records.
1698 * Update if the record is not in the notrace hash.
1700 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1703 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1704 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1707 * If filter_hash is set, we want to match all functions
1708 * that are in the hash but not in the other hash.
1710 * If filter_hash is not set, then we are decrementing.
1711 * That means we match anything that is in the hash
1712 * and also in the other_hash. That is, we need to turn
1713 * off functions in the other hash because they are disabled
1716 if (filter_hash
&& in_hash
&& !in_other_hash
)
1718 else if (!filter_hash
&& in_hash
&&
1719 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1727 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1731 * If there's only a single callback registered to a
1732 * function, and the ops has a trampoline registered
1733 * for it, then we can call it directly.
1735 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1736 rec
->flags
|= FTRACE_FL_TRAMP
;
1739 * If we are adding another function callback
1740 * to this function, and the previous had a
1741 * custom trampoline in use, then we need to go
1742 * back to the default trampoline.
1744 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1747 * If any ops wants regs saved for this function
1748 * then all ops will get saved regs.
1750 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1751 rec
->flags
|= FTRACE_FL_REGS
;
1753 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1758 * If the rec had REGS enabled and the ops that is
1759 * being removed had REGS set, then see if there is
1760 * still any ops for this record that wants regs.
1761 * If not, we can stop recording them.
1763 if (ftrace_rec_count(rec
) > 0 &&
1764 rec
->flags
& FTRACE_FL_REGS
&&
1765 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1766 if (!test_rec_ops_needs_regs(rec
))
1767 rec
->flags
&= ~FTRACE_FL_REGS
;
1771 * If the rec had TRAMP enabled, then it needs to
1772 * be cleared. As TRAMP can only be enabled iff
1773 * there is only a single ops attached to it.
1774 * In otherwords, always disable it on decrementing.
1775 * In the future, we may set it if rec count is
1776 * decremented to one, and the ops that is left
1779 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1782 * flags will be cleared in ftrace_check_record()
1783 * if rec count is zero.
1788 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1789 update
|= ftrace_test_record(rec
, 1) != FTRACE_UPDATE_IGNORE
;
1791 /* Shortcut, if we handled all records, we are done. */
1792 if (!all
&& count
== hash
->count
)
1794 } while_for_each_ftrace_rec();
1799 static bool ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1802 return __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1805 static bool ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1808 return __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1811 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1812 int filter_hash
, int inc
)
1814 struct ftrace_ops
*op
;
1816 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1818 if (ops
->func_hash
!= &global_ops
.local_hash
)
1822 * If the ops shares the global_ops hash, then we need to update
1823 * all ops that are enabled and use this hash.
1825 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1829 if (op
->func_hash
== &global_ops
.local_hash
)
1830 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1831 } while_for_each_ftrace_op(op
);
1834 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1837 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1840 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1843 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1847 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1848 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1849 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1850 * Note that old_hash and new_hash has below meanings
1851 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1852 * - If the hash is EMPTY_HASH, it hits nothing
1853 * - Anything else hits the recs which match the hash entries.
1855 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1856 struct ftrace_hash
*old_hash
,
1857 struct ftrace_hash
*new_hash
)
1859 struct ftrace_page
*pg
;
1860 struct dyn_ftrace
*rec
, *end
= NULL
;
1863 /* Only update if the ops has been registered */
1864 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1867 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1871 * Since the IPMODIFY is a very address sensitive action, we do not
1872 * allow ftrace_ops to set all functions to new hash.
1874 if (!new_hash
|| !old_hash
)
1877 /* Update rec->flags */
1878 do_for_each_ftrace_rec(pg
, rec
) {
1880 if (rec
->flags
& FTRACE_FL_DISABLED
)
1883 /* We need to update only differences of filter_hash */
1884 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1885 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1886 if (in_old
== in_new
)
1890 /* New entries must ensure no others are using it */
1891 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1893 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1894 } else /* Removed entry */
1895 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1896 } while_for_each_ftrace_rec();
1903 /* Roll back what we did above */
1904 do_for_each_ftrace_rec(pg
, rec
) {
1906 if (rec
->flags
& FTRACE_FL_DISABLED
)
1912 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1913 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1914 if (in_old
== in_new
)
1918 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1920 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1921 } while_for_each_ftrace_rec();
1927 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
1929 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1931 if (ftrace_hash_empty(hash
))
1934 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
1937 /* Disabling always succeeds */
1938 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
1940 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1942 if (ftrace_hash_empty(hash
))
1945 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
1948 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1949 struct ftrace_hash
*new_hash
)
1951 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
1953 if (ftrace_hash_empty(old_hash
))
1956 if (ftrace_hash_empty(new_hash
))
1959 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
1962 static void print_ip_ins(const char *fmt
, const unsigned char *p
)
1966 printk(KERN_CONT
"%s", fmt
);
1968 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1969 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1972 static struct ftrace_ops
*
1973 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
1974 static struct ftrace_ops
*
1975 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
);
1977 enum ftrace_bug_type ftrace_bug_type
;
1978 const void *ftrace_expected
;
1980 static void print_bug_type(void)
1982 switch (ftrace_bug_type
) {
1983 case FTRACE_BUG_UNKNOWN
:
1985 case FTRACE_BUG_INIT
:
1986 pr_info("Initializing ftrace call sites\n");
1988 case FTRACE_BUG_NOP
:
1989 pr_info("Setting ftrace call site to NOP\n");
1991 case FTRACE_BUG_CALL
:
1992 pr_info("Setting ftrace call site to call ftrace function\n");
1994 case FTRACE_BUG_UPDATE
:
1995 pr_info("Updating ftrace call site to call a different ftrace function\n");
2001 * ftrace_bug - report and shutdown function tracer
2002 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2003 * @rec: The record that failed
2005 * The arch code that enables or disables the function tracing
2006 * can call ftrace_bug() when it has detected a problem in
2007 * modifying the code. @failed should be one of either:
2008 * EFAULT - if the problem happens on reading the @ip address
2009 * EINVAL - if what is read at @ip is not what was expected
2010 * EPERM - if the problem happens on writting to the @ip address
2012 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
2014 unsigned long ip
= rec
? rec
->ip
: 0;
2018 FTRACE_WARN_ON_ONCE(1);
2019 pr_info("ftrace faulted on modifying ");
2023 FTRACE_WARN_ON_ONCE(1);
2024 pr_info("ftrace failed to modify ");
2026 print_ip_ins(" actual: ", (unsigned char *)ip
);
2028 if (ftrace_expected
) {
2029 print_ip_ins(" expected: ", ftrace_expected
);
2034 FTRACE_WARN_ON_ONCE(1);
2035 pr_info("ftrace faulted on writing ");
2039 FTRACE_WARN_ON_ONCE(1);
2040 pr_info("ftrace faulted on unknown error ");
2045 struct ftrace_ops
*ops
= NULL
;
2047 pr_info("ftrace record flags: %lx\n", rec
->flags
);
2048 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
2049 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2050 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2051 ops
= ftrace_find_tramp_ops_any(rec
);
2054 pr_cont("\ttramp: %pS (%pS)",
2055 (void *)ops
->trampoline
,
2057 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
2060 pr_cont("\ttramp: ERROR!");
2063 ip
= ftrace_get_addr_curr(rec
);
2064 pr_cont("\n expected tramp: %lx\n", ip
);
2068 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
2070 unsigned long flag
= 0UL;
2072 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2074 if (rec
->flags
& FTRACE_FL_DISABLED
)
2075 return FTRACE_UPDATE_IGNORE
;
2078 * If we are updating calls:
2080 * If the record has a ref count, then we need to enable it
2081 * because someone is using it.
2083 * Otherwise we make sure its disabled.
2085 * If we are disabling calls, then disable all records that
2088 if (enable
&& ftrace_rec_count(rec
))
2089 flag
= FTRACE_FL_ENABLED
;
2092 * If enabling and the REGS flag does not match the REGS_EN, or
2093 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2094 * this record. Set flags to fail the compare against ENABLED.
2097 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
2098 !(rec
->flags
& FTRACE_FL_REGS_EN
))
2099 flag
|= FTRACE_FL_REGS
;
2101 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
2102 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
2103 flag
|= FTRACE_FL_TRAMP
;
2106 /* If the state of this record hasn't changed, then do nothing */
2107 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2108 return FTRACE_UPDATE_IGNORE
;
2111 /* Save off if rec is being enabled (for return value) */
2112 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2115 rec
->flags
|= FTRACE_FL_ENABLED
;
2116 if (flag
& FTRACE_FL_REGS
) {
2117 if (rec
->flags
& FTRACE_FL_REGS
)
2118 rec
->flags
|= FTRACE_FL_REGS_EN
;
2120 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2122 if (flag
& FTRACE_FL_TRAMP
) {
2123 if (rec
->flags
& FTRACE_FL_TRAMP
)
2124 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2126 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2131 * If this record is being updated from a nop, then
2132 * return UPDATE_MAKE_CALL.
2134 * return UPDATE_MODIFY_CALL to tell the caller to convert
2135 * from the save regs, to a non-save regs function or
2136 * vice versa, or from a trampoline call.
2138 if (flag
& FTRACE_FL_ENABLED
) {
2139 ftrace_bug_type
= FTRACE_BUG_CALL
;
2140 return FTRACE_UPDATE_MAKE_CALL
;
2143 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2144 return FTRACE_UPDATE_MODIFY_CALL
;
2148 /* If there's no more users, clear all flags */
2149 if (!ftrace_rec_count(rec
))
2153 * Just disable the record, but keep the ops TRAMP
2154 * and REGS states. The _EN flags must be disabled though.
2156 rec
->flags
&= ~(FTRACE_FL_ENABLED
| FTRACE_FL_TRAMP_EN
|
2160 ftrace_bug_type
= FTRACE_BUG_NOP
;
2161 return FTRACE_UPDATE_MAKE_NOP
;
2165 * ftrace_update_record, set a record that now is tracing or not
2166 * @rec: the record to update
2167 * @enable: set to 1 if the record is tracing, zero to force disable
2169 * The records that represent all functions that can be traced need
2170 * to be updated when tracing has been enabled.
2172 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2174 return ftrace_check_record(rec
, enable
, 1);
2178 * ftrace_test_record, check if the record has been enabled or not
2179 * @rec: the record to test
2180 * @enable: set to 1 to check if enabled, 0 if it is disabled
2182 * The arch code may need to test if a record is already set to
2183 * tracing to determine how to modify the function code that it
2186 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2188 return ftrace_check_record(rec
, enable
, 0);
2191 static struct ftrace_ops
*
2192 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2194 struct ftrace_ops
*op
;
2195 unsigned long ip
= rec
->ip
;
2197 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2199 if (!op
->trampoline
)
2202 if (hash_contains_ip(ip
, op
->func_hash
))
2204 } while_for_each_ftrace_op(op
);
2209 static struct ftrace_ops
*
2210 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
,
2211 struct ftrace_ops
*op
)
2213 unsigned long ip
= rec
->ip
;
2215 while_for_each_ftrace_op(op
) {
2217 if (!op
->trampoline
)
2220 if (hash_contains_ip(ip
, op
->func_hash
))
2227 static struct ftrace_ops
*
2228 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2230 struct ftrace_ops
*op
;
2231 unsigned long ip
= rec
->ip
;
2234 * Need to check removed ops first.
2235 * If they are being removed, and this rec has a tramp,
2236 * and this rec is in the ops list, then it would be the
2237 * one with the tramp.
2240 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2245 * Need to find the current trampoline for a rec.
2246 * Now, a trampoline is only attached to a rec if there
2247 * was a single 'ops' attached to it. But this can be called
2248 * when we are adding another op to the rec or removing the
2249 * current one. Thus, if the op is being added, we can
2250 * ignore it because it hasn't attached itself to the rec
2253 * If an ops is being modified (hooking to different functions)
2254 * then we don't care about the new functions that are being
2255 * added, just the old ones (that are probably being removed).
2257 * If we are adding an ops to a function that already is using
2258 * a trampoline, it needs to be removed (trampolines are only
2259 * for single ops connected), then an ops that is not being
2260 * modified also needs to be checked.
2262 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2264 if (!op
->trampoline
)
2268 * If the ops is being added, it hasn't gotten to
2269 * the point to be removed from this tree yet.
2271 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2276 * If the ops is being modified and is in the old
2277 * hash, then it is probably being removed from this
2280 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2281 hash_contains_ip(ip
, &op
->old_hash
))
2284 * If the ops is not being added or modified, and it's
2285 * in its normal filter hash, then this must be the one
2288 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2289 hash_contains_ip(ip
, op
->func_hash
))
2292 } while_for_each_ftrace_op(op
);
2297 static struct ftrace_ops
*
2298 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2300 struct ftrace_ops
*op
;
2301 unsigned long ip
= rec
->ip
;
2303 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2304 /* pass rec in as regs to have non-NULL val */
2305 if (hash_contains_ip(ip
, op
->func_hash
))
2307 } while_for_each_ftrace_op(op
);
2313 * ftrace_get_addr_new - Get the call address to set to
2314 * @rec: The ftrace record descriptor
2316 * If the record has the FTRACE_FL_REGS set, that means that it
2317 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2318 * is not not set, then it wants to convert to the normal callback.
2320 * Returns the address of the trampoline to set to
2322 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2324 struct ftrace_ops
*ops
;
2326 /* Trampolines take precedence over regs */
2327 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2328 ops
= ftrace_find_tramp_ops_new(rec
);
2329 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2330 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2331 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2332 /* Ftrace is shutting down, return anything */
2333 return (unsigned long)FTRACE_ADDR
;
2335 return ops
->trampoline
;
2338 if (rec
->flags
& FTRACE_FL_REGS
)
2339 return (unsigned long)FTRACE_REGS_ADDR
;
2341 return (unsigned long)FTRACE_ADDR
;
2345 * ftrace_get_addr_curr - Get the call address that is already there
2346 * @rec: The ftrace record descriptor
2348 * The FTRACE_FL_REGS_EN is set when the record already points to
2349 * a function that saves all the regs. Basically the '_EN' version
2350 * represents the current state of the function.
2352 * Returns the address of the trampoline that is currently being called
2354 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2356 struct ftrace_ops
*ops
;
2358 /* Trampolines take precedence over regs */
2359 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2360 ops
= ftrace_find_tramp_ops_curr(rec
);
2361 if (FTRACE_WARN_ON(!ops
)) {
2362 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2363 (void *)rec
->ip
, (void *)rec
->ip
);
2364 /* Ftrace is shutting down, return anything */
2365 return (unsigned long)FTRACE_ADDR
;
2367 return ops
->trampoline
;
2370 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2371 return (unsigned long)FTRACE_REGS_ADDR
;
2373 return (unsigned long)FTRACE_ADDR
;
2377 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2379 unsigned long ftrace_old_addr
;
2380 unsigned long ftrace_addr
;
2383 ftrace_addr
= ftrace_get_addr_new(rec
);
2385 /* This needs to be done before we call ftrace_update_record */
2386 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2388 ret
= ftrace_update_record(rec
, enable
);
2390 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2393 case FTRACE_UPDATE_IGNORE
:
2396 case FTRACE_UPDATE_MAKE_CALL
:
2397 ftrace_bug_type
= FTRACE_BUG_CALL
;
2398 return ftrace_make_call(rec
, ftrace_addr
);
2400 case FTRACE_UPDATE_MAKE_NOP
:
2401 ftrace_bug_type
= FTRACE_BUG_NOP
;
2402 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2404 case FTRACE_UPDATE_MODIFY_CALL
:
2405 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2406 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2409 return -1; /* unknow ftrace bug */
2412 void __weak
ftrace_replace_code(int enable
)
2414 struct dyn_ftrace
*rec
;
2415 struct ftrace_page
*pg
;
2418 if (unlikely(ftrace_disabled
))
2421 do_for_each_ftrace_rec(pg
, rec
) {
2423 if (rec
->flags
& FTRACE_FL_DISABLED
)
2426 failed
= __ftrace_replace_code(rec
, enable
);
2428 ftrace_bug(failed
, rec
);
2429 /* Stop processing */
2432 } while_for_each_ftrace_rec();
2435 struct ftrace_rec_iter
{
2436 struct ftrace_page
*pg
;
2441 * ftrace_rec_iter_start, start up iterating over traced functions
2443 * Returns an iterator handle that is used to iterate over all
2444 * the records that represent address locations where functions
2447 * May return NULL if no records are available.
2449 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2452 * We only use a single iterator.
2453 * Protected by the ftrace_lock mutex.
2455 static struct ftrace_rec_iter ftrace_rec_iter
;
2456 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2458 iter
->pg
= ftrace_pages_start
;
2461 /* Could have empty pages */
2462 while (iter
->pg
&& !iter
->pg
->index
)
2463 iter
->pg
= iter
->pg
->next
;
2472 * ftrace_rec_iter_next, get the next record to process.
2473 * @iter: The handle to the iterator.
2475 * Returns the next iterator after the given iterator @iter.
2477 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2481 if (iter
->index
>= iter
->pg
->index
) {
2482 iter
->pg
= iter
->pg
->next
;
2485 /* Could have empty pages */
2486 while (iter
->pg
&& !iter
->pg
->index
)
2487 iter
->pg
= iter
->pg
->next
;
2497 * ftrace_rec_iter_record, get the record at the iterator location
2498 * @iter: The current iterator location
2500 * Returns the record that the current @iter is at.
2502 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2504 return &iter
->pg
->records
[iter
->index
];
2508 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2512 if (unlikely(ftrace_disabled
))
2515 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2517 ftrace_bug_type
= FTRACE_BUG_INIT
;
2518 ftrace_bug(ret
, rec
);
2525 * archs can override this function if they must do something
2526 * before the modifying code is performed.
2528 int __weak
ftrace_arch_code_modify_prepare(void)
2534 * archs can override this function if they must do something
2535 * after the modifying code is performed.
2537 int __weak
ftrace_arch_code_modify_post_process(void)
2542 void ftrace_modify_all_code(int command
)
2544 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2548 * If the ftrace_caller calls a ftrace_ops func directly,
2549 * we need to make sure that it only traces functions it
2550 * expects to trace. When doing the switch of functions,
2551 * we need to update to the ftrace_ops_list_func first
2552 * before the transition between old and new calls are set,
2553 * as the ftrace_ops_list_func will check the ops hashes
2554 * to make sure the ops are having the right functions
2558 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2559 if (FTRACE_WARN_ON(err
))
2563 if (command
& FTRACE_UPDATE_CALLS
)
2564 ftrace_replace_code(1);
2565 else if (command
& FTRACE_DISABLE_CALLS
)
2566 ftrace_replace_code(0);
2568 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2569 function_trace_op
= set_function_trace_op
;
2571 /* If irqs are disabled, we are in stop machine */
2572 if (!irqs_disabled())
2573 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2574 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2575 if (FTRACE_WARN_ON(err
))
2579 if (command
& FTRACE_START_FUNC_RET
)
2580 err
= ftrace_enable_ftrace_graph_caller();
2581 else if (command
& FTRACE_STOP_FUNC_RET
)
2582 err
= ftrace_disable_ftrace_graph_caller();
2583 FTRACE_WARN_ON(err
);
2586 static int __ftrace_modify_code(void *data
)
2588 int *command
= data
;
2590 ftrace_modify_all_code(*command
);
2596 * ftrace_run_stop_machine, go back to the stop machine method
2597 * @command: The command to tell ftrace what to do
2599 * If an arch needs to fall back to the stop machine method, the
2600 * it can call this function.
2602 void ftrace_run_stop_machine(int command
)
2604 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2608 * arch_ftrace_update_code, modify the code to trace or not trace
2609 * @command: The command that needs to be done
2611 * Archs can override this function if it does not need to
2612 * run stop_machine() to modify code.
2614 void __weak
arch_ftrace_update_code(int command
)
2616 ftrace_run_stop_machine(command
);
2619 static void ftrace_run_update_code(int command
)
2623 ret
= ftrace_arch_code_modify_prepare();
2624 FTRACE_WARN_ON(ret
);
2629 * By default we use stop_machine() to modify the code.
2630 * But archs can do what ever they want as long as it
2631 * is safe. The stop_machine() is the safest, but also
2632 * produces the most overhead.
2634 arch_ftrace_update_code(command
);
2636 ret
= ftrace_arch_code_modify_post_process();
2637 FTRACE_WARN_ON(ret
);
2640 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2641 struct ftrace_ops_hash
*old_hash
)
2643 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2644 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2645 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2646 ftrace_run_update_code(command
);
2647 ops
->old_hash
.filter_hash
= NULL
;
2648 ops
->old_hash
.notrace_hash
= NULL
;
2649 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2652 static ftrace_func_t saved_ftrace_func
;
2653 static int ftrace_start_up
;
2655 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2659 static void per_cpu_ops_free(struct ftrace_ops
*ops
)
2661 free_percpu(ops
->disabled
);
2664 static void ftrace_startup_enable(int command
)
2666 if (saved_ftrace_func
!= ftrace_trace_function
) {
2667 saved_ftrace_func
= ftrace_trace_function
;
2668 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2671 if (!command
|| !ftrace_enabled
)
2674 ftrace_run_update_code(command
);
2677 static void ftrace_startup_all(int command
)
2679 update_all_ops
= true;
2680 ftrace_startup_enable(command
);
2681 update_all_ops
= false;
2684 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2688 if (unlikely(ftrace_disabled
))
2691 ret
= __register_ftrace_function(ops
);
2698 * Note that ftrace probes uses this to start up
2699 * and modify functions it will probe. But we still
2700 * set the ADDING flag for modification, as probes
2701 * do not have trampolines. If they add them in the
2702 * future, then the probes will need to distinguish
2703 * between adding and updating probes.
2705 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2707 ret
= ftrace_hash_ipmodify_enable(ops
);
2709 /* Rollback registration process */
2710 __unregister_ftrace_function(ops
);
2712 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2716 if (ftrace_hash_rec_enable(ops
, 1))
2717 command
|= FTRACE_UPDATE_CALLS
;
2719 ftrace_startup_enable(command
);
2721 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2726 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2730 if (unlikely(ftrace_disabled
))
2733 ret
= __unregister_ftrace_function(ops
);
2739 * Just warn in case of unbalance, no need to kill ftrace, it's not
2740 * critical but the ftrace_call callers may be never nopped again after
2741 * further ftrace uses.
2743 WARN_ON_ONCE(ftrace_start_up
< 0);
2745 /* Disabling ipmodify never fails */
2746 ftrace_hash_ipmodify_disable(ops
);
2748 if (ftrace_hash_rec_disable(ops
, 1))
2749 command
|= FTRACE_UPDATE_CALLS
;
2751 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2753 if (saved_ftrace_func
!= ftrace_trace_function
) {
2754 saved_ftrace_func
= ftrace_trace_function
;
2755 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2758 if (!command
|| !ftrace_enabled
) {
2760 * If these are per_cpu ops, they still need their
2761 * per_cpu field freed. Since, function tracing is
2762 * not currently active, we can just free them
2763 * without synchronizing all CPUs.
2765 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2766 per_cpu_ops_free(ops
);
2771 * If the ops uses a trampoline, then it needs to be
2772 * tested first on update.
2774 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2777 /* The trampoline logic checks the old hashes */
2778 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2779 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2781 ftrace_run_update_code(command
);
2784 * If there's no more ops registered with ftrace, run a
2785 * sanity check to make sure all rec flags are cleared.
2787 if (ftrace_ops_list
== &ftrace_list_end
) {
2788 struct ftrace_page
*pg
;
2789 struct dyn_ftrace
*rec
;
2791 do_for_each_ftrace_rec(pg
, rec
) {
2792 if (FTRACE_WARN_ON_ONCE(rec
->flags
& ~FTRACE_FL_DISABLED
))
2793 pr_warn(" %pS flags:%lx\n",
2794 (void *)rec
->ip
, rec
->flags
);
2795 } while_for_each_ftrace_rec();
2798 ops
->old_hash
.filter_hash
= NULL
;
2799 ops
->old_hash
.notrace_hash
= NULL
;
2802 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2805 * Dynamic ops may be freed, we must make sure that all
2806 * callers are done before leaving this function.
2807 * The same goes for freeing the per_cpu data of the per_cpu
2810 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
)) {
2812 * We need to do a hard force of sched synchronization.
2813 * This is because we use preempt_disable() to do RCU, but
2814 * the function tracers can be called where RCU is not watching
2815 * (like before user_exit()). We can not rely on the RCU
2816 * infrastructure to do the synchronization, thus we must do it
2819 schedule_on_each_cpu(ftrace_sync
);
2822 * When the kernel is preeptive, tasks can be preempted
2823 * while on a ftrace trampoline. Just scheduling a task on
2824 * a CPU is not good enough to flush them. Calling
2825 * synchornize_rcu_tasks() will wait for those tasks to
2826 * execute and either schedule voluntarily or enter user space.
2828 if (IS_ENABLED(CONFIG_PREEMPT
))
2829 synchronize_rcu_tasks();
2831 arch_ftrace_trampoline_free(ops
);
2833 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2834 per_cpu_ops_free(ops
);
2840 static void ftrace_startup_sysctl(void)
2844 if (unlikely(ftrace_disabled
))
2847 /* Force update next time */
2848 saved_ftrace_func
= NULL
;
2849 /* ftrace_start_up is true if we want ftrace running */
2850 if (ftrace_start_up
) {
2851 command
= FTRACE_UPDATE_CALLS
;
2852 if (ftrace_graph_active
)
2853 command
|= FTRACE_START_FUNC_RET
;
2854 ftrace_startup_enable(command
);
2858 static void ftrace_shutdown_sysctl(void)
2862 if (unlikely(ftrace_disabled
))
2865 /* ftrace_start_up is true if ftrace is running */
2866 if (ftrace_start_up
) {
2867 command
= FTRACE_DISABLE_CALLS
;
2868 if (ftrace_graph_active
)
2869 command
|= FTRACE_STOP_FUNC_RET
;
2870 ftrace_run_update_code(command
);
2874 static u64 ftrace_update_time
;
2875 unsigned long ftrace_update_tot_cnt
;
2877 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2880 * Filter_hash being empty will default to trace module.
2881 * But notrace hash requires a test of individual module functions.
2883 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2884 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2888 * Check if the current ops references the record.
2890 * If the ops traces all functions, then it was already accounted for.
2891 * If the ops does not trace the current record function, skip it.
2892 * If the ops ignores the function via notrace filter, skip it.
2895 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2897 /* If ops isn't enabled, ignore it */
2898 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2901 /* If ops traces all then it includes this function */
2902 if (ops_traces_mod(ops
))
2905 /* The function must be in the filter */
2906 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2907 !__ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2910 /* If in notrace hash, we ignore it too */
2911 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2917 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2919 struct ftrace_page
*pg
;
2920 struct dyn_ftrace
*p
;
2922 unsigned long update_cnt
= 0;
2923 unsigned long rec_flags
= 0;
2926 start
= ftrace_now(raw_smp_processor_id());
2929 * When a module is loaded, this function is called to convert
2930 * the calls to mcount in its text to nops, and also to create
2931 * an entry in the ftrace data. Now, if ftrace is activated
2932 * after this call, but before the module sets its text to
2933 * read-only, the modification of enabling ftrace can fail if
2934 * the read-only is done while ftrace is converting the calls.
2935 * To prevent this, the module's records are set as disabled
2936 * and will be enabled after the call to set the module's text
2940 rec_flags
|= FTRACE_FL_DISABLED
;
2942 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2944 for (i
= 0; i
< pg
->index
; i
++) {
2946 /* If something went wrong, bail without enabling anything */
2947 if (unlikely(ftrace_disabled
))
2950 p
= &pg
->records
[i
];
2951 p
->flags
= rec_flags
;
2954 * Do the initial record conversion from mcount jump
2955 * to the NOP instructions.
2957 if (!ftrace_code_disable(mod
, p
))
2964 stop
= ftrace_now(raw_smp_processor_id());
2965 ftrace_update_time
= stop
- start
;
2966 ftrace_update_tot_cnt
+= update_cnt
;
2971 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2976 if (WARN_ON(!count
))
2979 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2982 * We want to fill as much as possible. No more than a page
2985 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2989 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2992 /* if we can't allocate this size, try something smaller */
2999 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
3008 static struct ftrace_page
*
3009 ftrace_allocate_pages(unsigned long num_to_init
)
3011 struct ftrace_page
*start_pg
;
3012 struct ftrace_page
*pg
;
3019 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3024 * Try to allocate as much as possible in one continues
3025 * location that fills in all of the space. We want to
3026 * waste as little space as possible.
3029 cnt
= ftrace_allocate_records(pg
, num_to_init
);
3037 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3049 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3050 free_pages((unsigned long)pg
->records
, order
);
3051 start_pg
= pg
->next
;
3055 pr_info("ftrace: FAILED to allocate memory for functions\n");
3059 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3061 struct ftrace_iterator
{
3064 struct ftrace_page
*pg
;
3065 struct dyn_ftrace
*func
;
3066 struct ftrace_func_probe
*probe
;
3067 struct ftrace_func_entry
*probe_entry
;
3068 struct trace_parser parser
;
3069 struct ftrace_hash
*hash
;
3070 struct ftrace_ops
*ops
;
3077 t_probe_next(struct seq_file
*m
, loff_t
*pos
)
3079 struct ftrace_iterator
*iter
= m
->private;
3080 struct trace_array
*tr
= iter
->ops
->private;
3081 struct list_head
*func_probes
;
3082 struct ftrace_hash
*hash
;
3083 struct list_head
*next
;
3084 struct hlist_node
*hnd
= NULL
;
3085 struct hlist_head
*hhd
;
3094 func_probes
= &tr
->func_probes
;
3095 if (list_empty(func_probes
))
3099 next
= func_probes
->next
;
3100 iter
->probe
= list_entry(next
, struct ftrace_func_probe
, list
);
3103 if (iter
->probe_entry
)
3104 hnd
= &iter
->probe_entry
->hlist
;
3106 hash
= iter
->probe
->ops
.func_hash
->filter_hash
;
3107 size
= 1 << hash
->size_bits
;
3110 if (iter
->pidx
>= size
) {
3111 if (iter
->probe
->list
.next
== func_probes
)
3113 next
= iter
->probe
->list
.next
;
3114 iter
->probe
= list_entry(next
, struct ftrace_func_probe
, list
);
3115 hash
= iter
->probe
->ops
.func_hash
->filter_hash
;
3116 size
= 1 << hash
->size_bits
;
3120 hhd
= &hash
->buckets
[iter
->pidx
];
3122 if (hlist_empty(hhd
)) {
3138 if (WARN_ON_ONCE(!hnd
))
3141 iter
->probe_entry
= hlist_entry(hnd
, struct ftrace_func_entry
, hlist
);
3146 static void *t_probe_start(struct seq_file
*m
, loff_t
*pos
)
3148 struct ftrace_iterator
*iter
= m
->private;
3152 if (!(iter
->flags
& FTRACE_ITER_DO_PROBES
))
3155 if (iter
->func_pos
> *pos
)
3159 iter
->probe_entry
= NULL
;
3161 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3162 p
= t_probe_next(m
, &l
);
3169 /* Only set this if we have an item */
3170 iter
->flags
|= FTRACE_ITER_PROBE
;
3176 t_probe_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3178 struct ftrace_func_entry
*probe_entry
;
3179 struct ftrace_probe_ops
*probe_ops
;
3180 struct ftrace_func_probe
*probe
;
3182 probe
= iter
->probe
;
3183 probe_entry
= iter
->probe_entry
;
3185 if (WARN_ON_ONCE(!probe
|| !probe_entry
))
3188 probe_ops
= probe
->probe_ops
;
3190 if (probe_ops
->print
)
3191 return probe_ops
->print(m
, probe_entry
->ip
, probe_ops
, probe
->data
);
3193 seq_printf(m
, "%ps:%ps\n", (void *)probe_entry
->ip
,
3194 (void *)probe_ops
->func
);
3200 t_func_next(struct seq_file
*m
, loff_t
*pos
)
3202 struct ftrace_iterator
*iter
= m
->private;
3203 struct dyn_ftrace
*rec
= NULL
;
3208 if (iter
->idx
>= iter
->pg
->index
) {
3209 if (iter
->pg
->next
) {
3210 iter
->pg
= iter
->pg
->next
;
3215 rec
= &iter
->pg
->records
[iter
->idx
++];
3216 if (((iter
->flags
& (FTRACE_ITER_FILTER
| FTRACE_ITER_NOTRACE
)) &&
3217 !ftrace_lookup_ip(iter
->hash
, rec
->ip
)) ||
3219 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3220 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3230 iter
->pos
= iter
->func_pos
= *pos
;
3237 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3239 struct ftrace_iterator
*iter
= m
->private;
3240 loff_t l
= *pos
; /* t_hash_start() must use original pos */
3243 if (unlikely(ftrace_disabled
))
3246 if (iter
->flags
& FTRACE_ITER_PROBE
)
3247 return t_probe_next(m
, pos
);
3249 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3250 /* next must increment pos, and t_probe_start does not */
3252 return t_probe_start(m
, &l
);
3255 ret
= t_func_next(m
, pos
);
3258 return t_probe_start(m
, &l
);
3263 static void reset_iter_read(struct ftrace_iterator
*iter
)
3267 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_PROBE
);
3270 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3272 struct ftrace_iterator
*iter
= m
->private;
3276 mutex_lock(&ftrace_lock
);
3278 if (unlikely(ftrace_disabled
))
3282 * If an lseek was done, then reset and start from beginning.
3284 if (*pos
< iter
->pos
)
3285 reset_iter_read(iter
);
3288 * For set_ftrace_filter reading, if we have the filter
3289 * off, we can short cut and just print out that all
3290 * functions are enabled.
3292 if ((iter
->flags
& (FTRACE_ITER_FILTER
| FTRACE_ITER_NOTRACE
)) &&
3293 ftrace_hash_empty(iter
->hash
)) {
3294 iter
->func_pos
= 1; /* Account for the message */
3296 return t_probe_start(m
, pos
);
3297 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3298 /* reset in case of seek/pread */
3299 iter
->flags
&= ~FTRACE_ITER_PROBE
;
3303 if (iter
->flags
& FTRACE_ITER_PROBE
)
3304 return t_probe_start(m
, pos
);
3307 * Unfortunately, we need to restart at ftrace_pages_start
3308 * every time we let go of the ftrace_mutex. This is because
3309 * those pointers can change without the lock.
3311 iter
->pg
= ftrace_pages_start
;
3313 for (l
= 0; l
<= *pos
; ) {
3314 p
= t_func_next(m
, &l
);
3320 return t_probe_start(m
, pos
);
3325 static void t_stop(struct seq_file
*m
, void *p
)
3327 mutex_unlock(&ftrace_lock
);
3331 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3336 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3337 struct dyn_ftrace
*rec
)
3341 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3343 seq_printf(m
, " ->%pS", ptr
);
3346 static int t_show(struct seq_file
*m
, void *v
)
3348 struct ftrace_iterator
*iter
= m
->private;
3349 struct dyn_ftrace
*rec
;
3351 if (iter
->flags
& FTRACE_ITER_PROBE
)
3352 return t_probe_show(m
, iter
);
3354 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3355 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3356 seq_puts(m
, "#### no functions disabled ####\n");
3358 seq_puts(m
, "#### all functions enabled ####\n");
3367 seq_printf(m
, "%ps", (void *)rec
->ip
);
3368 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3369 struct ftrace_ops
*ops
;
3371 seq_printf(m
, " (%ld)%s%s",
3372 ftrace_rec_count(rec
),
3373 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3374 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3375 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3376 ops
= ftrace_find_tramp_ops_any(rec
);
3379 seq_printf(m
, "\ttramp: %pS (%pS)",
3380 (void *)ops
->trampoline
,
3382 add_trampoline_func(m
, ops
, rec
);
3383 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
3386 seq_puts(m
, "\ttramp: ERROR!");
3388 add_trampoline_func(m
, NULL
, rec
);
3397 static const struct seq_operations show_ftrace_seq_ops
= {
3405 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3407 struct ftrace_iterator
*iter
;
3409 if (unlikely(ftrace_disabled
))
3412 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3416 iter
->pg
= ftrace_pages_start
;
3417 iter
->ops
= &global_ops
;
3423 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3425 struct ftrace_iterator
*iter
;
3427 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3431 iter
->pg
= ftrace_pages_start
;
3432 iter
->flags
= FTRACE_ITER_ENABLED
;
3433 iter
->ops
= &global_ops
;
3439 * ftrace_regex_open - initialize function tracer filter files
3440 * @ops: The ftrace_ops that hold the hash filters
3441 * @flag: The type of filter to process
3442 * @inode: The inode, usually passed in to your open routine
3443 * @file: The file, usually passed in to your open routine
3445 * ftrace_regex_open() initializes the filter files for the
3446 * @ops. Depending on @flag it may process the filter hash or
3447 * the notrace hash of @ops. With this called from the open
3448 * routine, you can use ftrace_filter_write() for the write
3449 * routine if @flag has FTRACE_ITER_FILTER set, or
3450 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3451 * tracing_lseek() should be used as the lseek routine, and
3452 * release must call ftrace_regex_release().
3455 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3456 struct inode
*inode
, struct file
*file
)
3458 struct ftrace_iterator
*iter
;
3459 struct ftrace_hash
*hash
;
3462 ftrace_ops_init(ops
);
3464 if (unlikely(ftrace_disabled
))
3467 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3471 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3479 mutex_lock(&ops
->func_hash
->regex_lock
);
3481 if (flag
& FTRACE_ITER_NOTRACE
)
3482 hash
= ops
->func_hash
->notrace_hash
;
3484 hash
= ops
->func_hash
->filter_hash
;
3486 if (file
->f_mode
& FMODE_WRITE
) {
3487 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3489 if (file
->f_flags
& O_TRUNC
)
3490 iter
->hash
= alloc_ftrace_hash(size_bits
);
3492 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3495 trace_parser_put(&iter
->parser
);
3503 if (file
->f_mode
& FMODE_READ
) {
3504 iter
->pg
= ftrace_pages_start
;
3506 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3508 struct seq_file
*m
= file
->private_data
;
3512 free_ftrace_hash(iter
->hash
);
3513 trace_parser_put(&iter
->parser
);
3517 file
->private_data
= iter
;
3520 mutex_unlock(&ops
->func_hash
->regex_lock
);
3526 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3528 struct ftrace_ops
*ops
= inode
->i_private
;
3530 return ftrace_regex_open(ops
,
3531 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_PROBES
,
3536 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3538 struct ftrace_ops
*ops
= inode
->i_private
;
3540 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3544 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3545 struct ftrace_glob
{
3552 * If symbols in an architecture don't correspond exactly to the user-visible
3553 * name of what they represent, it is possible to define this function to
3554 * perform the necessary adjustments.
3556 char * __weak
arch_ftrace_match_adjust(char *str
, const char *search
)
3561 static int ftrace_match(char *str
, struct ftrace_glob
*g
)
3566 str
= arch_ftrace_match_adjust(str
, g
->search
);
3570 if (strcmp(str
, g
->search
) == 0)
3573 case MATCH_FRONT_ONLY
:
3574 if (strncmp(str
, g
->search
, g
->len
) == 0)
3577 case MATCH_MIDDLE_ONLY
:
3578 if (strstr(str
, g
->search
))
3581 case MATCH_END_ONLY
:
3583 if (slen
>= g
->len
&&
3584 memcmp(str
+ slen
- g
->len
, g
->search
, g
->len
) == 0)
3588 if (glob_match(g
->search
, str
))
3597 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int clear_filter
)
3599 struct ftrace_func_entry
*entry
;
3602 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3604 /* Do nothing if it doesn't exist */
3608 free_hash_entry(hash
, entry
);
3610 /* Do nothing if it exists */
3614 ret
= add_hash_entry(hash
, rec
->ip
);
3620 ftrace_match_record(struct dyn_ftrace
*rec
, struct ftrace_glob
*func_g
,
3621 struct ftrace_glob
*mod_g
, int exclude_mod
)
3623 char str
[KSYM_SYMBOL_LEN
];
3626 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3629 int mod_matches
= (modname
) ? ftrace_match(modname
, mod_g
) : 0;
3631 /* blank module name to match all modules */
3633 /* blank module globbing: modname xor exclude_mod */
3634 if (!exclude_mod
!= !modname
)
3640 * exclude_mod is set to trace everything but the given
3641 * module. If it is set and the module matches, then
3642 * return 0. If it is not set, and the module doesn't match
3643 * also return 0. Otherwise, check the function to see if
3646 if (!mod_matches
== !exclude_mod
)
3649 /* blank search means to match all funcs in the mod */
3654 return ftrace_match(str
, func_g
);
3658 match_records(struct ftrace_hash
*hash
, char *func
, int len
, char *mod
)
3660 struct ftrace_page
*pg
;
3661 struct dyn_ftrace
*rec
;
3662 struct ftrace_glob func_g
= { .type
= MATCH_FULL
};
3663 struct ftrace_glob mod_g
= { .type
= MATCH_FULL
};
3664 struct ftrace_glob
*mod_match
= (mod
) ? &mod_g
: NULL
;
3665 int exclude_mod
= 0;
3671 func_g
.type
= filter_parse_regex(func
, len
, &func_g
.search
,
3673 func_g
.len
= strlen(func_g
.search
);
3677 mod_g
.type
= filter_parse_regex(mod
, strlen(mod
),
3678 &mod_g
.search
, &exclude_mod
);
3679 mod_g
.len
= strlen(mod_g
.search
);
3682 mutex_lock(&ftrace_lock
);
3684 if (unlikely(ftrace_disabled
))
3687 do_for_each_ftrace_rec(pg
, rec
) {
3689 if (rec
->flags
& FTRACE_FL_DISABLED
)
3692 if (ftrace_match_record(rec
, &func_g
, mod_match
, exclude_mod
)) {
3693 ret
= enter_record(hash
, rec
, clear_filter
);
3700 } while_for_each_ftrace_rec();
3702 mutex_unlock(&ftrace_lock
);
3708 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3710 return match_records(hash
, buff
, len
, NULL
);
3713 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
3714 struct ftrace_ops_hash
*old_hash
)
3716 struct ftrace_ops
*op
;
3718 if (!ftrace_enabled
)
3721 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
3722 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
3727 * If this is the shared global_ops filter, then we need to
3728 * check if there is another ops that shares it, is enabled.
3729 * If so, we still need to run the modify code.
3731 if (ops
->func_hash
!= &global_ops
.local_hash
)
3734 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
3735 if (op
->func_hash
== &global_ops
.local_hash
&&
3736 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
3737 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
3738 /* Only need to do this once */
3741 } while_for_each_ftrace_op(op
);
3744 static int ftrace_hash_move_and_update_ops(struct ftrace_ops
*ops
,
3745 struct ftrace_hash
**orig_hash
,
3746 struct ftrace_hash
*hash
,
3749 struct ftrace_ops_hash old_hash_ops
;
3750 struct ftrace_hash
*old_hash
;
3753 old_hash
= *orig_hash
;
3754 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
3755 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
3756 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3758 ftrace_ops_update_code(ops
, &old_hash_ops
);
3759 free_ftrace_hash_rcu(old_hash
);
3765 * We register the module command as a template to show others how
3766 * to register the a command as well.
3770 ftrace_mod_callback(struct trace_array
*tr
, struct ftrace_hash
*hash
,
3771 char *func
, char *cmd
, char *module
, int enable
)
3776 * cmd == 'mod' because we only registered this func
3777 * for the 'mod' ftrace_func_command.
3778 * But if you register one func with multiple commands,
3779 * you can tell which command was used by the cmd
3782 ret
= match_records(hash
, func
, strlen(func
), module
);
3790 static struct ftrace_func_command ftrace_mod_cmd
= {
3792 .func
= ftrace_mod_callback
,
3795 static int __init
ftrace_mod_cmd_init(void)
3797 return register_ftrace_command(&ftrace_mod_cmd
);
3799 core_initcall(ftrace_mod_cmd_init
);
3801 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3802 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3804 struct ftrace_probe_ops
*probe_ops
;
3805 struct ftrace_func_probe
*probe
;
3807 probe
= container_of(op
, struct ftrace_func_probe
, ops
);
3808 probe_ops
= probe
->probe_ops
;
3811 * Disable preemption for these calls to prevent a RCU grace
3812 * period. This syncs the hash iteration and freeing of items
3813 * on the hash. rcu_read_lock is too dangerous here.
3815 preempt_disable_notrace();
3816 probe_ops
->func(ip
, parent_ip
, probe
->tr
, probe_ops
, probe
->data
);
3817 preempt_enable_notrace();
3820 struct ftrace_func_map
{
3821 struct ftrace_func_entry entry
;
3825 struct ftrace_func_mapper
{
3826 struct ftrace_hash hash
;
3830 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
3832 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
3834 struct ftrace_func_mapper
*allocate_ftrace_func_mapper(void)
3836 struct ftrace_hash
*hash
;
3839 * The mapper is simply a ftrace_hash, but since the entries
3840 * in the hash are not ftrace_func_entry type, we define it
3841 * as a separate structure.
3843 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
3844 return (struct ftrace_func_mapper
*)hash
;
3848 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
3849 * @mapper: The mapper that has the ip maps
3850 * @ip: the instruction pointer to find the data for
3852 * Returns the data mapped to @ip if found otherwise NULL. The return
3853 * is actually the address of the mapper data pointer. The address is
3854 * returned for use cases where the data is no bigger than a long, and
3855 * the user can use the data pointer as its data instead of having to
3856 * allocate more memory for the reference.
3858 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper
*mapper
,
3861 struct ftrace_func_entry
*entry
;
3862 struct ftrace_func_map
*map
;
3864 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
3868 map
= (struct ftrace_func_map
*)entry
;
3873 * ftrace_func_mapper_add_ip - Map some data to an ip
3874 * @mapper: The mapper that has the ip maps
3875 * @ip: The instruction pointer address to map @data to
3876 * @data: The data to map to @ip
3878 * Returns 0 on succes otherwise an error.
3880 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper
*mapper
,
3881 unsigned long ip
, void *data
)
3883 struct ftrace_func_entry
*entry
;
3884 struct ftrace_func_map
*map
;
3886 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
3890 map
= kmalloc(sizeof(*map
), GFP_KERNEL
);
3897 __add_hash_entry(&mapper
->hash
, &map
->entry
);
3903 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
3904 * @mapper: The mapper that has the ip maps
3905 * @ip: The instruction pointer address to remove the data from
3907 * Returns the data if it is found, otherwise NULL.
3908 * Note, if the data pointer is used as the data itself, (see
3909 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
3910 * if the data pointer was set to zero.
3912 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper
*mapper
,
3915 struct ftrace_func_entry
*entry
;
3916 struct ftrace_func_map
*map
;
3919 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
3923 map
= (struct ftrace_func_map
*)entry
;
3926 remove_hash_entry(&mapper
->hash
, entry
);
3933 * free_ftrace_func_mapper - free a mapping of ips and data
3934 * @mapper: The mapper that has the ip maps
3935 * @free_func: A function to be called on each data item.
3937 * This is used to free the function mapper. The @free_func is optional
3938 * and can be used if the data needs to be freed as well.
3940 void free_ftrace_func_mapper(struct ftrace_func_mapper
*mapper
,
3941 ftrace_mapper_func free_func
)
3943 struct ftrace_func_entry
*entry
;
3944 struct ftrace_func_map
*map
;
3945 struct hlist_head
*hhd
;
3946 int size
= 1 << mapper
->hash
.size_bits
;
3949 if (free_func
&& mapper
->hash
.count
) {
3950 for (i
= 0; i
< size
; i
++) {
3951 hhd
= &mapper
->hash
.buckets
[i
];
3952 hlist_for_each_entry(entry
, hhd
, hlist
) {
3953 map
= (struct ftrace_func_map
*)entry
;
3958 free_ftrace_hash(&mapper
->hash
);
3961 static void release_probe(struct ftrace_func_probe
*probe
)
3963 struct ftrace_probe_ops
*probe_ops
;
3965 mutex_lock(&ftrace_lock
);
3967 WARN_ON(probe
->ref
<= 0);
3969 /* Subtract the ref that was used to protect this instance */
3973 probe_ops
= probe
->probe_ops
;
3975 * Sending zero as ip tells probe_ops to free
3976 * the probe->data itself
3978 if (probe_ops
->free
)
3979 probe_ops
->free(probe_ops
, probe
->tr
, 0, probe
->data
);
3980 list_del(&probe
->list
);
3983 mutex_unlock(&ftrace_lock
);
3986 static void acquire_probe_locked(struct ftrace_func_probe
*probe
)
3989 * Add one ref to keep it from being freed when releasing the
3990 * ftrace_lock mutex.
3996 register_ftrace_function_probe(char *glob
, struct trace_array
*tr
,
3997 struct ftrace_probe_ops
*probe_ops
,
4000 struct ftrace_func_entry
*entry
;
4001 struct ftrace_func_probe
*probe
;
4002 struct ftrace_hash
**orig_hash
;
4003 struct ftrace_hash
*old_hash
;
4004 struct ftrace_hash
*hash
;
4013 /* We do not support '!' for function probes */
4014 if (WARN_ON(glob
[0] == '!'))
4018 mutex_lock(&ftrace_lock
);
4019 /* Check if the probe_ops is already registered */
4020 list_for_each_entry(probe
, &tr
->func_probes
, list
) {
4021 if (probe
->probe_ops
== probe_ops
)
4024 if (&probe
->list
== &tr
->func_probes
) {
4025 probe
= kzalloc(sizeof(*probe
), GFP_KERNEL
);
4027 mutex_unlock(&ftrace_lock
);
4030 probe
->probe_ops
= probe_ops
;
4031 probe
->ops
.func
= function_trace_probe_call
;
4033 ftrace_ops_init(&probe
->ops
);
4034 list_add(&probe
->list
, &tr
->func_probes
);
4037 acquire_probe_locked(probe
);
4039 mutex_unlock(&ftrace_lock
);
4041 mutex_lock(&probe
->ops
.func_hash
->regex_lock
);
4043 orig_hash
= &probe
->ops
.func_hash
->filter_hash
;
4044 old_hash
= *orig_hash
;
4045 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
4047 ret
= ftrace_match_records(hash
, glob
, strlen(glob
));
4049 /* Nothing found? */
4056 size
= 1 << hash
->size_bits
;
4057 for (i
= 0; i
< size
; i
++) {
4058 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
4059 if (ftrace_lookup_ip(old_hash
, entry
->ip
))
4062 * The caller might want to do something special
4063 * for each function we find. We call the callback
4064 * to give the caller an opportunity to do so.
4066 if (probe_ops
->init
) {
4067 ret
= probe_ops
->init(probe_ops
, tr
,
4071 if (probe_ops
->free
&& count
)
4072 probe_ops
->free(probe_ops
, tr
,
4082 mutex_lock(&ftrace_lock
);
4085 /* Nothing was added? */
4090 ret
= ftrace_hash_move_and_update_ops(&probe
->ops
, orig_hash
,
4095 /* One ref for each new function traced */
4096 probe
->ref
+= count
;
4098 if (!(probe
->ops
.flags
& FTRACE_OPS_FL_ENABLED
))
4099 ret
= ftrace_startup(&probe
->ops
, 0);
4102 mutex_unlock(&ftrace_lock
);
4107 mutex_unlock(&probe
->ops
.func_hash
->regex_lock
);
4108 free_ftrace_hash(hash
);
4110 release_probe(probe
);
4115 if (!probe_ops
->free
|| !count
)
4118 /* Failed to do the move, need to call the free functions */
4119 for (i
= 0; i
< size
; i
++) {
4120 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
4121 if (ftrace_lookup_ip(old_hash
, entry
->ip
))
4123 probe_ops
->free(probe_ops
, tr
, entry
->ip
, probe
->data
);
4130 unregister_ftrace_function_probe_func(char *glob
, struct trace_array
*tr
,
4131 struct ftrace_probe_ops
*probe_ops
)
4133 struct ftrace_ops_hash old_hash_ops
;
4134 struct ftrace_func_entry
*entry
;
4135 struct ftrace_func_probe
*probe
;
4136 struct ftrace_glob func_g
;
4137 struct ftrace_hash
**orig_hash
;
4138 struct ftrace_hash
*old_hash
;
4139 struct ftrace_hash
*hash
= NULL
;
4140 struct hlist_node
*tmp
;
4141 struct hlist_head hhd
;
4142 char str
[KSYM_SYMBOL_LEN
];
4144 int i
, ret
= -ENODEV
;
4147 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
4148 func_g
.search
= NULL
;
4152 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
4153 &func_g
.search
, ¬);
4154 func_g
.len
= strlen(func_g
.search
);
4155 func_g
.search
= glob
;
4157 /* we do not support '!' for function probes */
4162 mutex_lock(&ftrace_lock
);
4163 /* Check if the probe_ops is already registered */
4164 list_for_each_entry(probe
, &tr
->func_probes
, list
) {
4165 if (probe
->probe_ops
== probe_ops
)
4168 if (&probe
->list
== &tr
->func_probes
)
4169 goto err_unlock_ftrace
;
4172 if (!(probe
->ops
.flags
& FTRACE_OPS_FL_INITIALIZED
))
4173 goto err_unlock_ftrace
;
4175 acquire_probe_locked(probe
);
4177 mutex_unlock(&ftrace_lock
);
4179 mutex_lock(&probe
->ops
.func_hash
->regex_lock
);
4181 orig_hash
= &probe
->ops
.func_hash
->filter_hash
;
4182 old_hash
= *orig_hash
;
4184 if (ftrace_hash_empty(old_hash
))
4187 old_hash_ops
.filter_hash
= old_hash
;
4188 /* Probes only have filters */
4189 old_hash_ops
.notrace_hash
= NULL
;
4192 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
4196 INIT_HLIST_HEAD(&hhd
);
4198 size
= 1 << hash
->size_bits
;
4199 for (i
= 0; i
< size
; i
++) {
4200 hlist_for_each_entry_safe(entry
, tmp
, &hash
->buckets
[i
], hlist
) {
4202 if (func_g
.search
) {
4203 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
4205 if (!ftrace_match(str
, &func_g
))
4209 remove_hash_entry(hash
, entry
);
4210 hlist_add_head(&entry
->hlist
, &hhd
);
4214 /* Nothing found? */
4220 mutex_lock(&ftrace_lock
);
4222 WARN_ON(probe
->ref
< count
);
4224 probe
->ref
-= count
;
4226 if (ftrace_hash_empty(hash
))
4227 ftrace_shutdown(&probe
->ops
, 0);
4229 ret
= ftrace_hash_move_and_update_ops(&probe
->ops
, orig_hash
,
4232 /* still need to update the function call sites */
4233 if (ftrace_enabled
&& !ftrace_hash_empty(hash
))
4234 ftrace_run_modify_code(&probe
->ops
, FTRACE_UPDATE_CALLS
,
4236 synchronize_sched();
4238 hlist_for_each_entry_safe(entry
, tmp
, &hhd
, hlist
) {
4239 hlist_del(&entry
->hlist
);
4240 if (probe_ops
->free
)
4241 probe_ops
->free(probe_ops
, tr
, entry
->ip
, probe
->data
);
4244 mutex_unlock(&ftrace_lock
);
4247 mutex_unlock(&probe
->ops
.func_hash
->regex_lock
);
4248 free_ftrace_hash(hash
);
4250 release_probe(probe
);
4255 mutex_unlock(&ftrace_lock
);
4259 static LIST_HEAD(ftrace_commands
);
4260 static DEFINE_MUTEX(ftrace_cmd_mutex
);
4263 * Currently we only register ftrace commands from __init, so mark this
4266 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
4268 struct ftrace_func_command
*p
;
4271 mutex_lock(&ftrace_cmd_mutex
);
4272 list_for_each_entry(p
, &ftrace_commands
, list
) {
4273 if (strcmp(cmd
->name
, p
->name
) == 0) {
4278 list_add(&cmd
->list
, &ftrace_commands
);
4280 mutex_unlock(&ftrace_cmd_mutex
);
4286 * Currently we only unregister ftrace commands from __init, so mark
4289 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
4291 struct ftrace_func_command
*p
, *n
;
4294 mutex_lock(&ftrace_cmd_mutex
);
4295 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
4296 if (strcmp(cmd
->name
, p
->name
) == 0) {
4298 list_del_init(&p
->list
);
4303 mutex_unlock(&ftrace_cmd_mutex
);
4308 static int ftrace_process_regex(struct ftrace_iterator
*iter
,
4309 char *buff
, int len
, int enable
)
4311 struct ftrace_hash
*hash
= iter
->hash
;
4312 struct trace_array
*tr
= iter
->ops
->private;
4313 char *func
, *command
, *next
= buff
;
4314 struct ftrace_func_command
*p
;
4317 func
= strsep(&next
, ":");
4320 ret
= ftrace_match_records(hash
, func
, len
);
4330 command
= strsep(&next
, ":");
4332 if (WARN_ON_ONCE(!tr
))
4335 mutex_lock(&ftrace_cmd_mutex
);
4336 list_for_each_entry(p
, &ftrace_commands
, list
) {
4337 if (strcmp(p
->name
, command
) == 0) {
4338 ret
= p
->func(tr
, hash
, func
, command
, next
, enable
);
4343 mutex_unlock(&ftrace_cmd_mutex
);
4349 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
4350 size_t cnt
, loff_t
*ppos
, int enable
)
4352 struct ftrace_iterator
*iter
;
4353 struct trace_parser
*parser
;
4359 if (file
->f_mode
& FMODE_READ
) {
4360 struct seq_file
*m
= file
->private_data
;
4363 iter
= file
->private_data
;
4365 if (unlikely(ftrace_disabled
))
4368 /* iter->hash is a local copy, so we don't need regex_lock */
4370 parser
= &iter
->parser
;
4371 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
4373 if (read
>= 0 && trace_parser_loaded(parser
) &&
4374 !trace_parser_cont(parser
)) {
4375 ret
= ftrace_process_regex(iter
, parser
->buffer
,
4376 parser
->idx
, enable
);
4377 trace_parser_clear(parser
);
4388 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
4389 size_t cnt
, loff_t
*ppos
)
4391 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
4395 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
4396 size_t cnt
, loff_t
*ppos
)
4398 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
4402 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
4404 struct ftrace_func_entry
*entry
;
4406 if (!ftrace_location(ip
))
4410 entry
= ftrace_lookup_ip(hash
, ip
);
4413 free_hash_entry(hash
, entry
);
4417 return add_hash_entry(hash
, ip
);
4421 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4422 unsigned long ip
, int remove
, int reset
, int enable
)
4424 struct ftrace_hash
**orig_hash
;
4425 struct ftrace_hash
*hash
;
4428 if (unlikely(ftrace_disabled
))
4431 mutex_lock(&ops
->func_hash
->regex_lock
);
4434 orig_hash
= &ops
->func_hash
->filter_hash
;
4436 orig_hash
= &ops
->func_hash
->notrace_hash
;
4439 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4441 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4445 goto out_regex_unlock
;
4448 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4450 goto out_regex_unlock
;
4453 ret
= ftrace_match_addr(hash
, ip
, remove
);
4455 goto out_regex_unlock
;
4458 mutex_lock(&ftrace_lock
);
4459 ret
= ftrace_hash_move_and_update_ops(ops
, orig_hash
, hash
, enable
);
4460 mutex_unlock(&ftrace_lock
);
4463 mutex_unlock(&ops
->func_hash
->regex_lock
);
4465 free_ftrace_hash(hash
);
4470 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4471 int reset
, int enable
)
4473 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
4477 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4478 * @ops - the ops to set the filter with
4479 * @ip - the address to add to or remove from the filter.
4480 * @remove - non zero to remove the ip from the filter
4481 * @reset - non zero to reset all filters before applying this filter.
4483 * Filters denote which functions should be enabled when tracing is enabled
4484 * If @ip is NULL, it failes to update filter.
4486 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4487 int remove
, int reset
)
4489 ftrace_ops_init(ops
);
4490 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4492 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4495 * ftrace_ops_set_global_filter - setup ops to use global filters
4496 * @ops - the ops which will use the global filters
4498 * ftrace users who need global function trace filtering should call this.
4499 * It can set the global filter only if ops were not initialized before.
4501 void ftrace_ops_set_global_filter(struct ftrace_ops
*ops
)
4503 if (ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)
4506 ftrace_ops_init(ops
);
4507 ops
->func_hash
= &global_ops
.local_hash
;
4509 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter
);
4512 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4513 int reset
, int enable
)
4515 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4519 * ftrace_set_filter - set a function to filter on in ftrace
4520 * @ops - the ops to set the filter with
4521 * @buf - the string that holds the function filter text.
4522 * @len - the length of the string.
4523 * @reset - non zero to reset all filters before applying this filter.
4525 * Filters denote which functions should be enabled when tracing is enabled.
4526 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4528 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4531 ftrace_ops_init(ops
);
4532 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4534 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4537 * ftrace_set_notrace - set a function to not trace in ftrace
4538 * @ops - the ops to set the notrace filter with
4539 * @buf - the string that holds the function notrace text.
4540 * @len - the length of the string.
4541 * @reset - non zero to reset all filters before applying this filter.
4543 * Notrace Filters denote which functions should not be enabled when tracing
4544 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4547 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4550 ftrace_ops_init(ops
);
4551 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4553 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4555 * ftrace_set_global_filter - set a function to filter on with global tracers
4556 * @buf - the string that holds the function filter text.
4557 * @len - the length of the string.
4558 * @reset - non zero to reset all filters before applying this filter.
4560 * Filters denote which functions should be enabled when tracing is enabled.
4561 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4563 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4565 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4567 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4570 * ftrace_set_global_notrace - set a function to not trace with global tracers
4571 * @buf - the string that holds the function notrace text.
4572 * @len - the length of the string.
4573 * @reset - non zero to reset all filters before applying this filter.
4575 * Notrace Filters denote which functions should not be enabled when tracing
4576 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4579 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4581 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4583 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4586 * command line interface to allow users to set filters on boot up.
4588 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4589 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4590 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4592 /* Used by function selftest to not test if filter is set */
4593 bool ftrace_filter_param __initdata
;
4595 static int __init
set_ftrace_notrace(char *str
)
4597 ftrace_filter_param
= true;
4598 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4601 __setup("ftrace_notrace=", set_ftrace_notrace
);
4603 static int __init
set_ftrace_filter(char *str
)
4605 ftrace_filter_param
= true;
4606 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4609 __setup("ftrace_filter=", set_ftrace_filter
);
4611 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4612 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4613 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4614 static int ftrace_graph_set_hash(struct ftrace_hash
*hash
, char *buffer
);
4616 static unsigned long save_global_trampoline
;
4617 static unsigned long save_global_flags
;
4619 static int __init
set_graph_function(char *str
)
4621 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4624 __setup("ftrace_graph_filter=", set_graph_function
);
4626 static int __init
set_graph_notrace_function(char *str
)
4628 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4631 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4633 static int __init
set_graph_max_depth_function(char *str
)
4637 fgraph_max_depth
= simple_strtoul(str
, NULL
, 0);
4640 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function
);
4642 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4646 struct ftrace_hash
*hash
;
4648 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4653 func
= strsep(&buf
, ",");
4654 /* we allow only one expression at a time */
4655 ret
= ftrace_graph_set_hash(hash
, func
);
4657 printk(KERN_DEBUG
"ftrace: function %s not "
4658 "traceable\n", func
);
4662 ftrace_graph_hash
= hash
;
4664 ftrace_graph_notrace_hash
= hash
;
4666 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4669 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
4673 ftrace_ops_init(ops
);
4676 func
= strsep(&buf
, ",");
4677 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
4681 static void __init
set_ftrace_early_filters(void)
4683 if (ftrace_filter_buf
[0])
4684 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4685 if (ftrace_notrace_buf
[0])
4686 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4687 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4688 if (ftrace_graph_buf
[0])
4689 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4690 if (ftrace_graph_notrace_buf
[0])
4691 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4692 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4695 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4697 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4698 struct ftrace_iterator
*iter
;
4699 struct ftrace_hash
**orig_hash
;
4700 struct trace_parser
*parser
;
4704 if (file
->f_mode
& FMODE_READ
) {
4706 seq_release(inode
, file
);
4708 iter
= file
->private_data
;
4710 parser
= &iter
->parser
;
4711 if (trace_parser_loaded(parser
)) {
4712 parser
->buffer
[parser
->idx
] = 0;
4713 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4716 trace_parser_put(parser
);
4718 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4720 if (file
->f_mode
& FMODE_WRITE
) {
4721 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
4724 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
4726 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
4728 mutex_lock(&ftrace_lock
);
4729 ret
= ftrace_hash_move_and_update_ops(iter
->ops
, orig_hash
,
4730 iter
->hash
, filter_hash
);
4731 mutex_unlock(&ftrace_lock
);
4733 /* For read only, the hash is the ops hash */
4737 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
4738 free_ftrace_hash(iter
->hash
);
4744 static const struct file_operations ftrace_avail_fops
= {
4745 .open
= ftrace_avail_open
,
4747 .llseek
= seq_lseek
,
4748 .release
= seq_release_private
,
4751 static const struct file_operations ftrace_enabled_fops
= {
4752 .open
= ftrace_enabled_open
,
4754 .llseek
= seq_lseek
,
4755 .release
= seq_release_private
,
4758 static const struct file_operations ftrace_filter_fops
= {
4759 .open
= ftrace_filter_open
,
4761 .write
= ftrace_filter_write
,
4762 .llseek
= tracing_lseek
,
4763 .release
= ftrace_regex_release
,
4766 static const struct file_operations ftrace_notrace_fops
= {
4767 .open
= ftrace_notrace_open
,
4769 .write
= ftrace_notrace_write
,
4770 .llseek
= tracing_lseek
,
4771 .release
= ftrace_regex_release
,
4774 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4776 static DEFINE_MUTEX(graph_lock
);
4778 struct ftrace_hash
*ftrace_graph_hash
= EMPTY_HASH
;
4779 struct ftrace_hash
*ftrace_graph_notrace_hash
= EMPTY_HASH
;
4781 enum graph_filter_type
{
4782 GRAPH_FILTER_NOTRACE
= 0,
4783 GRAPH_FILTER_FUNCTION
,
4786 #define FTRACE_GRAPH_EMPTY ((void *)1)
4788 struct ftrace_graph_data
{
4789 struct ftrace_hash
*hash
;
4790 struct ftrace_func_entry
*entry
;
4791 int idx
; /* for hash table iteration */
4792 enum graph_filter_type type
;
4793 struct ftrace_hash
*new_hash
;
4794 const struct seq_operations
*seq_ops
;
4795 struct trace_parser parser
;
4799 __g_next(struct seq_file
*m
, loff_t
*pos
)
4801 struct ftrace_graph_data
*fgd
= m
->private;
4802 struct ftrace_func_entry
*entry
= fgd
->entry
;
4803 struct hlist_head
*head
;
4804 int i
, idx
= fgd
->idx
;
4806 if (*pos
>= fgd
->hash
->count
)
4810 hlist_for_each_entry_continue(entry
, hlist
) {
4818 for (i
= idx
; i
< 1 << fgd
->hash
->size_bits
; i
++) {
4819 head
= &fgd
->hash
->buckets
[i
];
4820 hlist_for_each_entry(entry
, head
, hlist
) {
4830 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4833 return __g_next(m
, pos
);
4836 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4838 struct ftrace_graph_data
*fgd
= m
->private;
4840 mutex_lock(&graph_lock
);
4842 if (fgd
->type
== GRAPH_FILTER_FUNCTION
)
4843 fgd
->hash
= rcu_dereference_protected(ftrace_graph_hash
,
4844 lockdep_is_held(&graph_lock
));
4846 fgd
->hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
4847 lockdep_is_held(&graph_lock
));
4849 /* Nothing, tell g_show to print all functions are enabled */
4850 if (ftrace_hash_empty(fgd
->hash
) && !*pos
)
4851 return FTRACE_GRAPH_EMPTY
;
4855 return __g_next(m
, pos
);
4858 static void g_stop(struct seq_file
*m
, void *p
)
4860 mutex_unlock(&graph_lock
);
4863 static int g_show(struct seq_file
*m
, void *v
)
4865 struct ftrace_func_entry
*entry
= v
;
4870 if (entry
== FTRACE_GRAPH_EMPTY
) {
4871 struct ftrace_graph_data
*fgd
= m
->private;
4873 if (fgd
->type
== GRAPH_FILTER_FUNCTION
)
4874 seq_puts(m
, "#### all functions enabled ####\n");
4876 seq_puts(m
, "#### no functions disabled ####\n");
4880 seq_printf(m
, "%ps\n", (void *)entry
->ip
);
4885 static const struct seq_operations ftrace_graph_seq_ops
= {
4893 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4894 struct ftrace_graph_data
*fgd
)
4897 struct ftrace_hash
*new_hash
= NULL
;
4899 if (file
->f_mode
& FMODE_WRITE
) {
4900 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
4902 if (trace_parser_get_init(&fgd
->parser
, FTRACE_BUFF_MAX
))
4905 if (file
->f_flags
& O_TRUNC
)
4906 new_hash
= alloc_ftrace_hash(size_bits
);
4908 new_hash
= alloc_and_copy_ftrace_hash(size_bits
,
4916 if (file
->f_mode
& FMODE_READ
) {
4917 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
4919 struct seq_file
*m
= file
->private_data
;
4923 free_ftrace_hash(new_hash
);
4927 file
->private_data
= fgd
;
4930 if (ret
< 0 && file
->f_mode
& FMODE_WRITE
)
4931 trace_parser_put(&fgd
->parser
);
4933 fgd
->new_hash
= new_hash
;
4936 * All uses of fgd->hash must be taken with the graph_lock
4937 * held. The graph_lock is going to be released, so force
4938 * fgd->hash to be reinitialized when it is taken again.
4946 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4948 struct ftrace_graph_data
*fgd
;
4951 if (unlikely(ftrace_disabled
))
4954 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4958 mutex_lock(&graph_lock
);
4960 fgd
->hash
= rcu_dereference_protected(ftrace_graph_hash
,
4961 lockdep_is_held(&graph_lock
));
4962 fgd
->type
= GRAPH_FILTER_FUNCTION
;
4963 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4965 ret
= __ftrace_graph_open(inode
, file
, fgd
);
4969 mutex_unlock(&graph_lock
);
4974 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4976 struct ftrace_graph_data
*fgd
;
4979 if (unlikely(ftrace_disabled
))
4982 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4986 mutex_lock(&graph_lock
);
4988 fgd
->hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
4989 lockdep_is_held(&graph_lock
));
4990 fgd
->type
= GRAPH_FILTER_NOTRACE
;
4991 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4993 ret
= __ftrace_graph_open(inode
, file
, fgd
);
4997 mutex_unlock(&graph_lock
);
5002 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
5004 struct ftrace_graph_data
*fgd
;
5005 struct ftrace_hash
*old_hash
, *new_hash
;
5006 struct trace_parser
*parser
;
5009 if (file
->f_mode
& FMODE_READ
) {
5010 struct seq_file
*m
= file
->private_data
;
5013 seq_release(inode
, file
);
5015 fgd
= file
->private_data
;
5019 if (file
->f_mode
& FMODE_WRITE
) {
5021 parser
= &fgd
->parser
;
5023 if (trace_parser_loaded((parser
))) {
5024 parser
->buffer
[parser
->idx
] = 0;
5025 ret
= ftrace_graph_set_hash(fgd
->new_hash
,
5029 trace_parser_put(parser
);
5031 new_hash
= __ftrace_hash_move(fgd
->new_hash
);
5037 mutex_lock(&graph_lock
);
5039 if (fgd
->type
== GRAPH_FILTER_FUNCTION
) {
5040 old_hash
= rcu_dereference_protected(ftrace_graph_hash
,
5041 lockdep_is_held(&graph_lock
));
5042 rcu_assign_pointer(ftrace_graph_hash
, new_hash
);
5044 old_hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5045 lockdep_is_held(&graph_lock
));
5046 rcu_assign_pointer(ftrace_graph_notrace_hash
, new_hash
);
5049 mutex_unlock(&graph_lock
);
5051 /* Wait till all users are no longer using the old hash */
5052 synchronize_sched();
5054 free_ftrace_hash(old_hash
);
5058 kfree(fgd
->new_hash
);
5065 ftrace_graph_set_hash(struct ftrace_hash
*hash
, char *buffer
)
5067 struct ftrace_glob func_g
;
5068 struct dyn_ftrace
*rec
;
5069 struct ftrace_page
*pg
;
5070 struct ftrace_func_entry
*entry
;
5075 func_g
.type
= filter_parse_regex(buffer
, strlen(buffer
),
5076 &func_g
.search
, ¬);
5078 func_g
.len
= strlen(func_g
.search
);
5080 mutex_lock(&ftrace_lock
);
5082 if (unlikely(ftrace_disabled
)) {
5083 mutex_unlock(&ftrace_lock
);
5087 do_for_each_ftrace_rec(pg
, rec
) {
5089 if (rec
->flags
& FTRACE_FL_DISABLED
)
5092 if (ftrace_match_record(rec
, &func_g
, NULL
, 0)) {
5093 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
5100 if (add_hash_entry(hash
, rec
->ip
) < 0)
5104 free_hash_entry(hash
, entry
);
5109 } while_for_each_ftrace_rec();
5111 mutex_unlock(&ftrace_lock
);
5120 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
5121 size_t cnt
, loff_t
*ppos
)
5123 ssize_t read
, ret
= 0;
5124 struct ftrace_graph_data
*fgd
= file
->private_data
;
5125 struct trace_parser
*parser
;
5130 /* Read mode uses seq functions */
5131 if (file
->f_mode
& FMODE_READ
) {
5132 struct seq_file
*m
= file
->private_data
;
5136 parser
= &fgd
->parser
;
5138 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
5140 if (read
>= 0 && trace_parser_loaded(parser
) &&
5141 !trace_parser_cont(parser
)) {
5143 ret
= ftrace_graph_set_hash(fgd
->new_hash
,
5145 trace_parser_clear(parser
);
5154 static const struct file_operations ftrace_graph_fops
= {
5155 .open
= ftrace_graph_open
,
5157 .write
= ftrace_graph_write
,
5158 .llseek
= tracing_lseek
,
5159 .release
= ftrace_graph_release
,
5162 static const struct file_operations ftrace_graph_notrace_fops
= {
5163 .open
= ftrace_graph_notrace_open
,
5165 .write
= ftrace_graph_write
,
5166 .llseek
= tracing_lseek
,
5167 .release
= ftrace_graph_release
,
5169 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5171 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
5172 struct dentry
*parent
)
5175 trace_create_file("set_ftrace_filter", 0644, parent
,
5176 ops
, &ftrace_filter_fops
);
5178 trace_create_file("set_ftrace_notrace", 0644, parent
,
5179 ops
, &ftrace_notrace_fops
);
5183 * The name "destroy_filter_files" is really a misnomer. Although
5184 * in the future, it may actualy delete the files, but this is
5185 * really intended to make sure the ops passed in are disabled
5186 * and that when this function returns, the caller is free to
5189 * The "destroy" name is only to match the "create" name that this
5190 * should be paired with.
5192 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
5194 mutex_lock(&ftrace_lock
);
5195 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
5196 ftrace_shutdown(ops
, 0);
5197 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
5198 mutex_unlock(&ftrace_lock
);
5201 static __init
int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
)
5204 trace_create_file("available_filter_functions", 0444,
5205 d_tracer
, NULL
, &ftrace_avail_fops
);
5207 trace_create_file("enabled_functions", 0444,
5208 d_tracer
, NULL
, &ftrace_enabled_fops
);
5210 ftrace_create_filter_files(&global_ops
, d_tracer
);
5212 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5213 trace_create_file("set_graph_function", 0444, d_tracer
,
5215 &ftrace_graph_fops
);
5216 trace_create_file("set_graph_notrace", 0444, d_tracer
,
5218 &ftrace_graph_notrace_fops
);
5219 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5224 static int ftrace_cmp_ips(const void *a
, const void *b
)
5226 const unsigned long *ipa
= a
;
5227 const unsigned long *ipb
= b
;
5236 static int ftrace_process_locs(struct module
*mod
,
5237 unsigned long *start
,
5240 struct ftrace_page
*start_pg
;
5241 struct ftrace_page
*pg
;
5242 struct dyn_ftrace
*rec
;
5243 unsigned long count
;
5246 unsigned long flags
= 0; /* Shut up gcc */
5249 count
= end
- start
;
5254 sort(start
, count
, sizeof(*start
),
5255 ftrace_cmp_ips
, NULL
);
5257 start_pg
= ftrace_allocate_pages(count
);
5261 mutex_lock(&ftrace_lock
);
5264 * Core and each module needs their own pages, as
5265 * modules will free them when they are removed.
5266 * Force a new page to be allocated for modules.
5269 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
5270 /* First initialization */
5271 ftrace_pages
= ftrace_pages_start
= start_pg
;
5276 if (WARN_ON(ftrace_pages
->next
)) {
5277 /* Hmm, we have free pages? */
5278 while (ftrace_pages
->next
)
5279 ftrace_pages
= ftrace_pages
->next
;
5282 ftrace_pages
->next
= start_pg
;
5288 addr
= ftrace_call_adjust(*p
++);
5290 * Some architecture linkers will pad between
5291 * the different mcount_loc sections of different
5292 * object files to satisfy alignments.
5293 * Skip any NULL pointers.
5298 if (pg
->index
== pg
->size
) {
5299 /* We should have allocated enough */
5300 if (WARN_ON(!pg
->next
))
5305 rec
= &pg
->records
[pg
->index
++];
5309 /* We should have used all pages */
5312 /* Assign the last page to ftrace_pages */
5316 * We only need to disable interrupts on start up
5317 * because we are modifying code that an interrupt
5318 * may execute, and the modification is not atomic.
5319 * But for modules, nothing runs the code we modify
5320 * until we are finished with it, and there's no
5321 * reason to cause large interrupt latencies while we do it.
5324 local_irq_save(flags
);
5325 ftrace_update_code(mod
, start_pg
);
5327 local_irq_restore(flags
);
5330 mutex_unlock(&ftrace_lock
);
5335 #ifdef CONFIG_MODULES
5337 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5339 static int referenced_filters(struct dyn_ftrace
*rec
)
5341 struct ftrace_ops
*ops
;
5344 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
5345 if (ops_references_rec(ops
, rec
))
5352 void ftrace_release_mod(struct module
*mod
)
5354 struct dyn_ftrace
*rec
;
5355 struct ftrace_page
**last_pg
;
5356 struct ftrace_page
*pg
;
5359 mutex_lock(&ftrace_lock
);
5361 if (ftrace_disabled
)
5365 * Each module has its own ftrace_pages, remove
5366 * them from the list.
5368 last_pg
= &ftrace_pages_start
;
5369 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
5370 rec
= &pg
->records
[0];
5371 if (within_module_core(rec
->ip
, mod
)) {
5373 * As core pages are first, the first
5374 * page should never be a module page.
5376 if (WARN_ON(pg
== ftrace_pages_start
))
5379 /* Check if we are deleting the last page */
5380 if (pg
== ftrace_pages
)
5381 ftrace_pages
= next_to_ftrace_page(last_pg
);
5383 *last_pg
= pg
->next
;
5384 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
5385 free_pages((unsigned long)pg
->records
, order
);
5388 last_pg
= &pg
->next
;
5391 mutex_unlock(&ftrace_lock
);
5394 void ftrace_module_enable(struct module
*mod
)
5396 struct dyn_ftrace
*rec
;
5397 struct ftrace_page
*pg
;
5399 mutex_lock(&ftrace_lock
);
5401 if (ftrace_disabled
)
5405 * If the tracing is enabled, go ahead and enable the record.
5407 * The reason not to enable the record immediatelly is the
5408 * inherent check of ftrace_make_nop/ftrace_make_call for
5409 * correct previous instructions. Making first the NOP
5410 * conversion puts the module to the correct state, thus
5411 * passing the ftrace_make_call check.
5413 * We also delay this to after the module code already set the
5414 * text to read-only, as we now need to set it back to read-write
5415 * so that we can modify the text.
5417 if (ftrace_start_up
)
5418 ftrace_arch_code_modify_prepare();
5420 do_for_each_ftrace_rec(pg
, rec
) {
5423 * do_for_each_ftrace_rec() is a double loop.
5424 * module text shares the pg. If a record is
5425 * not part of this module, then skip this pg,
5426 * which the "break" will do.
5428 if (!within_module_core(rec
->ip
, mod
))
5434 * When adding a module, we need to check if tracers are
5435 * currently enabled and if they are, and can trace this record,
5436 * we need to enable the module functions as well as update the
5437 * reference counts for those function records.
5439 if (ftrace_start_up
)
5440 cnt
+= referenced_filters(rec
);
5442 /* This clears FTRACE_FL_DISABLED */
5445 if (ftrace_start_up
&& cnt
) {
5446 int failed
= __ftrace_replace_code(rec
, 1);
5448 ftrace_bug(failed
, rec
);
5453 } while_for_each_ftrace_rec();
5456 if (ftrace_start_up
)
5457 ftrace_arch_code_modify_post_process();
5460 mutex_unlock(&ftrace_lock
);
5463 void ftrace_module_init(struct module
*mod
)
5465 if (ftrace_disabled
|| !mod
->num_ftrace_callsites
)
5468 ftrace_process_locs(mod
, mod
->ftrace_callsites
,
5469 mod
->ftrace_callsites
+ mod
->num_ftrace_callsites
);
5471 #endif /* CONFIG_MODULES */
5473 void __init
ftrace_free_init_mem(void)
5475 unsigned long start
= (unsigned long)(&__init_begin
);
5476 unsigned long end
= (unsigned long)(&__init_end
);
5477 struct ftrace_page
**last_pg
= &ftrace_pages_start
;
5478 struct ftrace_page
*pg
;
5479 struct dyn_ftrace
*rec
;
5480 struct dyn_ftrace key
;
5484 key
.flags
= end
; /* overload flags, as it is unsigned long */
5486 mutex_lock(&ftrace_lock
);
5488 for (pg
= ftrace_pages_start
; pg
; last_pg
= &pg
->next
, pg
= *last_pg
) {
5489 if (end
< pg
->records
[0].ip
||
5490 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
5493 rec
= bsearch(&key
, pg
->records
, pg
->index
,
5494 sizeof(struct dyn_ftrace
),
5500 *last_pg
= pg
->next
;
5501 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
5502 free_pages((unsigned long)pg
->records
, order
);
5504 pg
= container_of(last_pg
, struct ftrace_page
, next
);
5509 memmove(rec
, rec
+ 1,
5510 (pg
->index
- (rec
- pg
->records
)) * sizeof(*rec
));
5511 /* More than one function may be in this block */
5514 mutex_unlock(&ftrace_lock
);
5517 void __init
ftrace_init(void)
5519 extern unsigned long __start_mcount_loc
[];
5520 extern unsigned long __stop_mcount_loc
[];
5521 unsigned long count
, flags
;
5524 local_irq_save(flags
);
5525 ret
= ftrace_dyn_arch_init();
5526 local_irq_restore(flags
);
5530 count
= __stop_mcount_loc
- __start_mcount_loc
;
5532 pr_info("ftrace: No functions to be traced?\n");
5536 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5537 count
, count
/ ENTRIES_PER_PAGE
+ 1);
5539 last_ftrace_enabled
= ftrace_enabled
= 1;
5541 ret
= ftrace_process_locs(NULL
,
5545 set_ftrace_early_filters();
5549 ftrace_disabled
= 1;
5552 /* Do nothing if arch does not support this */
5553 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
5557 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5559 arch_ftrace_update_trampoline(ops
);
5562 void ftrace_init_trace_array(struct trace_array
*tr
)
5564 INIT_LIST_HEAD(&tr
->func_probes
);
5568 static struct ftrace_ops global_ops
= {
5569 .func
= ftrace_stub
,
5570 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5571 FTRACE_OPS_FL_INITIALIZED
|
5575 static int __init
ftrace_nodyn_init(void)
5580 core_initcall(ftrace_nodyn_init
);
5582 static inline int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
) { return 0; }
5583 static inline void ftrace_startup_enable(int command
) { }
5584 static inline void ftrace_startup_all(int command
) { }
5585 /* Keep as macros so we do not need to define the commands */
5586 # define ftrace_startup(ops, command) \
5588 int ___ret = __register_ftrace_function(ops); \
5590 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5593 # define ftrace_shutdown(ops, command) \
5595 int ___ret = __unregister_ftrace_function(ops); \
5597 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5601 # define ftrace_startup_sysctl() do { } while (0)
5602 # define ftrace_shutdown_sysctl() do { } while (0)
5605 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
5610 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5614 #endif /* CONFIG_DYNAMIC_FTRACE */
5616 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
5618 tr
->ops
= &global_ops
;
5619 tr
->ops
->private = tr
;
5620 ftrace_init_trace_array(tr
);
5623 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
5625 /* If we filter on pids, update to use the pid function */
5626 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
5627 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
5628 printk("ftrace ops had %pS for function\n",
5631 tr
->ops
->func
= func
;
5632 tr
->ops
->private = tr
;
5635 void ftrace_reset_array_ops(struct trace_array
*tr
)
5637 tr
->ops
->func
= ftrace_stub
;
5641 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5642 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
5644 struct ftrace_ops
*op
;
5647 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5652 * Some of the ops may be dynamically allocated,
5653 * they must be freed after a synchronize_sched().
5655 preempt_disable_notrace();
5657 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5659 * Check the following for each ops before calling their func:
5660 * if RCU flag is set, then rcu_is_watching() must be true
5661 * if PER_CPU is set, then ftrace_function_local_disable()
5663 * Otherwise test if the ip matches the ops filter
5665 * If any of the above fails then the op->func() is not executed.
5667 if ((!(op
->flags
& FTRACE_OPS_FL_RCU
) || rcu_is_watching()) &&
5668 (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5669 !ftrace_function_local_disabled(op
)) &&
5670 ftrace_ops_test(op
, ip
, regs
)) {
5672 if (FTRACE_WARN_ON(!op
->func
)) {
5673 pr_warn("op=%p %pS\n", op
, op
);
5676 op
->func(ip
, parent_ip
, op
, regs
);
5678 } while_for_each_ftrace_op(op
);
5680 preempt_enable_notrace();
5681 trace_clear_recursion(bit
);
5685 * Some archs only support passing ip and parent_ip. Even though
5686 * the list function ignores the op parameter, we do not want any
5687 * C side effects, where a function is called without the caller
5688 * sending a third parameter.
5689 * Archs are to support both the regs and ftrace_ops at the same time.
5690 * If they support ftrace_ops, it is assumed they support regs.
5691 * If call backs want to use regs, they must either check for regs
5692 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5693 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5694 * An architecture can pass partial regs with ftrace_ops and still
5695 * set the ARCH_SUPPORTS_FTRACE_OPS.
5697 #if ARCH_SUPPORTS_FTRACE_OPS
5698 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5699 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5701 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
5704 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
5706 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
5711 * If there's only one function registered but it does not support
5712 * recursion, needs RCU protection and/or requires per cpu handling, then
5713 * this function will be called by the mcount trampoline.
5715 static void ftrace_ops_assist_func(unsigned long ip
, unsigned long parent_ip
,
5716 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5720 if ((op
->flags
& FTRACE_OPS_FL_RCU
) && !rcu_is_watching())
5723 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5727 preempt_disable_notrace();
5729 if (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5730 !ftrace_function_local_disabled(op
)) {
5731 op
->func(ip
, parent_ip
, op
, regs
);
5734 preempt_enable_notrace();
5735 trace_clear_recursion(bit
);
5739 * ftrace_ops_get_func - get the function a trampoline should call
5740 * @ops: the ops to get the function for
5742 * Normally the mcount trampoline will call the ops->func, but there
5743 * are times that it should not. For example, if the ops does not
5744 * have its own recursion protection, then it should call the
5745 * ftrace_ops_assist_func() instead.
5747 * Returns the function that the trampoline should call for @ops.
5749 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
5752 * If the function does not handle recursion, needs to be RCU safe,
5753 * or does per cpu logic, then we need to call the assist handler.
5755 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) ||
5756 ops
->flags
& (FTRACE_OPS_FL_RCU
| FTRACE_OPS_FL_PER_CPU
))
5757 return ftrace_ops_assist_func
;
5763 ftrace_filter_pid_sched_switch_probe(void *data
, bool preempt
,
5764 struct task_struct
*prev
, struct task_struct
*next
)
5766 struct trace_array
*tr
= data
;
5767 struct trace_pid_list
*pid_list
;
5769 pid_list
= rcu_dereference_sched(tr
->function_pids
);
5771 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
5772 trace_ignore_this_task(pid_list
, next
));
5776 ftrace_pid_follow_sched_process_fork(void *data
,
5777 struct task_struct
*self
,
5778 struct task_struct
*task
)
5780 struct trace_pid_list
*pid_list
;
5781 struct trace_array
*tr
= data
;
5783 pid_list
= rcu_dereference_sched(tr
->function_pids
);
5784 trace_filter_add_remove_task(pid_list
, self
, task
);
5788 ftrace_pid_follow_sched_process_exit(void *data
, struct task_struct
*task
)
5790 struct trace_pid_list
*pid_list
;
5791 struct trace_array
*tr
= data
;
5793 pid_list
= rcu_dereference_sched(tr
->function_pids
);
5794 trace_filter_add_remove_task(pid_list
, NULL
, task
);
5797 void ftrace_pid_follow_fork(struct trace_array
*tr
, bool enable
)
5800 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork
,
5802 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit
,
5805 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork
,
5807 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit
,
5812 static void clear_ftrace_pids(struct trace_array
*tr
)
5814 struct trace_pid_list
*pid_list
;
5817 pid_list
= rcu_dereference_protected(tr
->function_pids
,
5818 lockdep_is_held(&ftrace_lock
));
5822 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
5824 for_each_possible_cpu(cpu
)
5825 per_cpu_ptr(tr
->trace_buffer
.data
, cpu
)->ftrace_ignore_pid
= false;
5827 rcu_assign_pointer(tr
->function_pids
, NULL
);
5829 /* Wait till all users are no longer using pid filtering */
5830 synchronize_sched();
5832 trace_free_pid_list(pid_list
);
5835 void ftrace_clear_pids(struct trace_array
*tr
)
5837 mutex_lock(&ftrace_lock
);
5839 clear_ftrace_pids(tr
);
5841 mutex_unlock(&ftrace_lock
);
5844 static void ftrace_pid_reset(struct trace_array
*tr
)
5846 mutex_lock(&ftrace_lock
);
5847 clear_ftrace_pids(tr
);
5849 ftrace_update_pid_func();
5850 ftrace_startup_all(0);
5852 mutex_unlock(&ftrace_lock
);
5855 /* Greater than any max PID */
5856 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
5858 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
5861 struct trace_pid_list
*pid_list
;
5862 struct trace_array
*tr
= m
->private;
5864 mutex_lock(&ftrace_lock
);
5865 rcu_read_lock_sched();
5867 pid_list
= rcu_dereference_sched(tr
->function_pids
);
5870 return !(*pos
) ? FTRACE_NO_PIDS
: NULL
;
5872 return trace_pid_start(pid_list
, pos
);
5875 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5877 struct trace_array
*tr
= m
->private;
5878 struct trace_pid_list
*pid_list
= rcu_dereference_sched(tr
->function_pids
);
5880 if (v
== FTRACE_NO_PIDS
)
5883 return trace_pid_next(pid_list
, v
, pos
);
5886 static void fpid_stop(struct seq_file
*m
, void *p
)
5889 rcu_read_unlock_sched();
5890 mutex_unlock(&ftrace_lock
);
5893 static int fpid_show(struct seq_file
*m
, void *v
)
5895 if (v
== FTRACE_NO_PIDS
) {
5896 seq_puts(m
, "no pid\n");
5900 return trace_pid_show(m
, v
);
5903 static const struct seq_operations ftrace_pid_sops
= {
5904 .start
= fpid_start
,
5911 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
5913 struct trace_array
*tr
= inode
->i_private
;
5917 if (trace_array_get(tr
) < 0)
5920 if ((file
->f_mode
& FMODE_WRITE
) &&
5921 (file
->f_flags
& O_TRUNC
))
5922 ftrace_pid_reset(tr
);
5924 ret
= seq_open(file
, &ftrace_pid_sops
);
5926 trace_array_put(tr
);
5928 m
= file
->private_data
;
5929 /* copy tr over to seq ops */
5936 static void ignore_task_cpu(void *data
)
5938 struct trace_array
*tr
= data
;
5939 struct trace_pid_list
*pid_list
;
5942 * This function is called by on_each_cpu() while the
5943 * event_mutex is held.
5945 pid_list
= rcu_dereference_protected(tr
->function_pids
,
5946 mutex_is_locked(&ftrace_lock
));
5948 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
5949 trace_ignore_this_task(pid_list
, current
));
5953 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
5954 size_t cnt
, loff_t
*ppos
)
5956 struct seq_file
*m
= filp
->private_data
;
5957 struct trace_array
*tr
= m
->private;
5958 struct trace_pid_list
*filtered_pids
= NULL
;
5959 struct trace_pid_list
*pid_list
;
5965 mutex_lock(&ftrace_lock
);
5967 filtered_pids
= rcu_dereference_protected(tr
->function_pids
,
5968 lockdep_is_held(&ftrace_lock
));
5970 ret
= trace_pid_write(filtered_pids
, &pid_list
, ubuf
, cnt
);
5974 rcu_assign_pointer(tr
->function_pids
, pid_list
);
5976 if (filtered_pids
) {
5977 synchronize_sched();
5978 trace_free_pid_list(filtered_pids
);
5979 } else if (pid_list
) {
5980 /* Register a probe to set whether to ignore the tracing of a task */
5981 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
5985 * Ignoring of pids is done at task switch. But we have to
5986 * check for those tasks that are currently running.
5987 * Always do this in case a pid was appended or removed.
5989 on_each_cpu(ignore_task_cpu
, tr
, 1);
5991 ftrace_update_pid_func();
5992 ftrace_startup_all(0);
5994 mutex_unlock(&ftrace_lock
);
6003 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
6005 struct trace_array
*tr
= inode
->i_private
;
6007 trace_array_put(tr
);
6009 return seq_release(inode
, file
);
6012 static const struct file_operations ftrace_pid_fops
= {
6013 .open
= ftrace_pid_open
,
6014 .write
= ftrace_pid_write
,
6016 .llseek
= tracing_lseek
,
6017 .release
= ftrace_pid_release
,
6020 void ftrace_init_tracefs(struct trace_array
*tr
, struct dentry
*d_tracer
)
6022 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
6023 tr
, &ftrace_pid_fops
);
6026 void __init
ftrace_init_tracefs_toplevel(struct trace_array
*tr
,
6027 struct dentry
*d_tracer
)
6029 /* Only the top level directory has the dyn_tracefs and profile */
6030 WARN_ON(!(tr
->flags
& TRACE_ARRAY_FL_GLOBAL
));
6032 ftrace_init_dyn_tracefs(d_tracer
);
6033 ftrace_profile_tracefs(d_tracer
);
6037 * ftrace_kill - kill ftrace
6039 * This function should be used by panic code. It stops ftrace
6040 * but in a not so nice way. If you need to simply kill ftrace
6041 * from a non-atomic section, use ftrace_kill.
6043 void ftrace_kill(void)
6045 ftrace_disabled
= 1;
6047 clear_ftrace_function();
6051 * Test if ftrace is dead or not.
6053 int ftrace_is_dead(void)
6055 return ftrace_disabled
;
6059 * register_ftrace_function - register a function for profiling
6060 * @ops - ops structure that holds the function for profiling.
6062 * Register a function to be called by all functions in the
6065 * Note: @ops->func and all the functions it calls must be labeled
6066 * with "notrace", otherwise it will go into a
6069 int register_ftrace_function(struct ftrace_ops
*ops
)
6073 ftrace_ops_init(ops
);
6075 mutex_lock(&ftrace_lock
);
6077 ret
= ftrace_startup(ops
, 0);
6079 mutex_unlock(&ftrace_lock
);
6083 EXPORT_SYMBOL_GPL(register_ftrace_function
);
6086 * unregister_ftrace_function - unregister a function for profiling.
6087 * @ops - ops structure that holds the function to unregister
6089 * Unregister a function that was added to be called by ftrace profiling.
6091 int unregister_ftrace_function(struct ftrace_ops
*ops
)
6095 mutex_lock(&ftrace_lock
);
6096 ret
= ftrace_shutdown(ops
, 0);
6097 mutex_unlock(&ftrace_lock
);
6101 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
6104 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
6105 void __user
*buffer
, size_t *lenp
,
6110 mutex_lock(&ftrace_lock
);
6112 if (unlikely(ftrace_disabled
))
6115 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
6117 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
6120 last_ftrace_enabled
= !!ftrace_enabled
;
6122 if (ftrace_enabled
) {
6124 /* we are starting ftrace again */
6125 if (ftrace_ops_list
!= &ftrace_list_end
)
6126 update_ftrace_function();
6128 ftrace_startup_sysctl();
6131 /* stopping ftrace calls (just send to ftrace_stub) */
6132 ftrace_trace_function
= ftrace_stub
;
6134 ftrace_shutdown_sysctl();
6138 mutex_unlock(&ftrace_lock
);
6142 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6144 static struct ftrace_ops graph_ops
= {
6145 .func
= ftrace_stub
,
6146 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
6147 FTRACE_OPS_FL_INITIALIZED
|
6150 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6151 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
6152 /* trampoline_size is only needed for dynamically allocated tramps */
6154 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
6157 void ftrace_graph_sleep_time_control(bool enable
)
6159 fgraph_sleep_time
= enable
;
6162 void ftrace_graph_graph_time_control(bool enable
)
6164 fgraph_graph_time
= enable
;
6167 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
6172 /* The callbacks that hook a function */
6173 trace_func_graph_ret_t ftrace_graph_return
=
6174 (trace_func_graph_ret_t
)ftrace_stub
;
6175 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
6176 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
6178 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6179 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
6183 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
6184 struct task_struct
*g
, *t
;
6186 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
6187 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
6188 * sizeof(struct ftrace_ret_stack
),
6190 if (!ret_stack_list
[i
]) {
6198 read_lock(&tasklist_lock
);
6199 do_each_thread(g
, t
) {
6205 if (t
->ret_stack
== NULL
) {
6206 atomic_set(&t
->tracing_graph_pause
, 0);
6207 atomic_set(&t
->trace_overrun
, 0);
6208 t
->curr_ret_stack
= -1;
6209 /* Make sure the tasks see the -1 first: */
6211 t
->ret_stack
= ret_stack_list
[start
++];
6213 } while_each_thread(g
, t
);
6216 read_unlock(&tasklist_lock
);
6218 for (i
= start
; i
< end
; i
++)
6219 kfree(ret_stack_list
[i
]);
6224 ftrace_graph_probe_sched_switch(void *ignore
, bool preempt
,
6225 struct task_struct
*prev
, struct task_struct
*next
)
6227 unsigned long long timestamp
;
6231 * Does the user want to count the time a function was asleep.
6232 * If so, do not update the time stamps.
6234 if (fgraph_sleep_time
)
6237 timestamp
= trace_clock_local();
6239 prev
->ftrace_timestamp
= timestamp
;
6241 /* only process tasks that we timestamped */
6242 if (!next
->ftrace_timestamp
)
6246 * Update all the counters in next to make up for the
6247 * time next was sleeping.
6249 timestamp
-= next
->ftrace_timestamp
;
6251 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
6252 next
->ret_stack
[index
].calltime
+= timestamp
;
6255 /* Allocate a return stack for each task */
6256 static int start_graph_tracing(void)
6258 struct ftrace_ret_stack
**ret_stack_list
;
6261 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
6262 sizeof(struct ftrace_ret_stack
*),
6265 if (!ret_stack_list
)
6268 /* The cpu_boot init_task->ret_stack will never be freed */
6269 for_each_online_cpu(cpu
) {
6270 if (!idle_task(cpu
)->ret_stack
)
6271 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
6275 ret
= alloc_retstack_tasklist(ret_stack_list
);
6276 } while (ret
== -EAGAIN
);
6279 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
6281 pr_info("ftrace_graph: Couldn't activate tracepoint"
6282 " probe to kernel_sched_switch\n");
6285 kfree(ret_stack_list
);
6290 * Hibernation protection.
6291 * The state of the current task is too much unstable during
6292 * suspend/restore to disk. We want to protect against that.
6295 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
6299 case PM_HIBERNATION_PREPARE
:
6300 pause_graph_tracing();
6303 case PM_POST_HIBERNATION
:
6304 unpause_graph_tracing();
6310 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
6312 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
6314 return __ftrace_graph_entry(trace
);
6318 * The function graph tracer should only trace the functions defined
6319 * by set_ftrace_filter and set_ftrace_notrace. If another function
6320 * tracer ops is registered, the graph tracer requires testing the
6321 * function against the global ops, and not just trace any function
6322 * that any ftrace_ops registered.
6324 static void update_function_graph_func(void)
6326 struct ftrace_ops
*op
;
6327 bool do_test
= false;
6330 * The graph and global ops share the same set of functions
6331 * to test. If any other ops is on the list, then
6332 * the graph tracing needs to test if its the function
6335 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
6336 if (op
!= &global_ops
&& op
!= &graph_ops
&&
6337 op
!= &ftrace_list_end
) {
6339 /* in double loop, break out with goto */
6342 } while_for_each_ftrace_op(op
);
6345 ftrace_graph_entry
= ftrace_graph_entry_test
;
6347 ftrace_graph_entry
= __ftrace_graph_entry
;
6350 static struct notifier_block ftrace_suspend_notifier
= {
6351 .notifier_call
= ftrace_suspend_notifier_call
,
6354 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
6355 trace_func_graph_ent_t entryfunc
)
6359 mutex_lock(&ftrace_lock
);
6361 /* we currently allow only one tracer registered at a time */
6362 if (ftrace_graph_active
) {
6367 register_pm_notifier(&ftrace_suspend_notifier
);
6369 ftrace_graph_active
++;
6370 ret
= start_graph_tracing();
6372 ftrace_graph_active
--;
6376 ftrace_graph_return
= retfunc
;
6379 * Update the indirect function to the entryfunc, and the
6380 * function that gets called to the entry_test first. Then
6381 * call the update fgraph entry function to determine if
6382 * the entryfunc should be called directly or not.
6384 __ftrace_graph_entry
= entryfunc
;
6385 ftrace_graph_entry
= ftrace_graph_entry_test
;
6386 update_function_graph_func();
6388 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
6390 mutex_unlock(&ftrace_lock
);
6394 void unregister_ftrace_graph(void)
6396 mutex_lock(&ftrace_lock
);
6398 if (unlikely(!ftrace_graph_active
))
6401 ftrace_graph_active
--;
6402 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
6403 ftrace_graph_entry
= ftrace_graph_entry_stub
;
6404 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
6405 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
6406 unregister_pm_notifier(&ftrace_suspend_notifier
);
6407 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
6409 #ifdef CONFIG_DYNAMIC_FTRACE
6411 * Function graph does not allocate the trampoline, but
6412 * other global_ops do. We need to reset the ALLOC_TRAMP flag
6415 global_ops
.trampoline
= save_global_trampoline
;
6416 if (save_global_flags
& FTRACE_OPS_FL_ALLOC_TRAMP
)
6417 global_ops
.flags
|= FTRACE_OPS_FL_ALLOC_TRAMP
;
6421 mutex_unlock(&ftrace_lock
);
6424 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
6427 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
6429 atomic_set(&t
->tracing_graph_pause
, 0);
6430 atomic_set(&t
->trace_overrun
, 0);
6431 t
->ftrace_timestamp
= 0;
6432 /* make curr_ret_stack visible before we add the ret_stack */
6434 t
->ret_stack
= ret_stack
;
6438 * Allocate a return stack for the idle task. May be the first
6439 * time through, or it may be done by CPU hotplug online.
6441 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
6443 t
->curr_ret_stack
= -1;
6445 * The idle task has no parent, it either has its own
6446 * stack or no stack at all.
6449 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
6451 if (ftrace_graph_active
) {
6452 struct ftrace_ret_stack
*ret_stack
;
6454 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
6456 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6457 * sizeof(struct ftrace_ret_stack
),
6461 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
6463 graph_init_task(t
, ret_stack
);
6467 /* Allocate a return stack for newly created task */
6468 void ftrace_graph_init_task(struct task_struct
*t
)
6470 /* Make sure we do not use the parent ret_stack */
6471 t
->ret_stack
= NULL
;
6472 t
->curr_ret_stack
= -1;
6474 if (ftrace_graph_active
) {
6475 struct ftrace_ret_stack
*ret_stack
;
6477 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6478 * sizeof(struct ftrace_ret_stack
),
6482 graph_init_task(t
, ret_stack
);
6486 void ftrace_graph_exit_task(struct task_struct
*t
)
6488 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
6490 t
->ret_stack
= NULL
;
6491 /* NULL must become visible to IRQs before we free it: */