2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/tracefs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/bsearch.h>
26 #include <linux/module.h>
27 #include <linux/ftrace.h>
28 #include <linux/sysctl.h>
29 #include <linux/slab.h>
30 #include <linux/ctype.h>
31 #include <linux/sort.h>
32 #include <linux/list.h>
33 #include <linux/hash.h>
34 #include <linux/rcupdate.h>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
60 #define FTRACE_HASH_BITS 7
61 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62 #define FTRACE_HASH_DEFAULT_BITS 10
63 #define FTRACE_HASH_MAX_BITS 12
65 #ifdef CONFIG_DYNAMIC_FTRACE
66 #define INIT_OPS_HASH(opsname) \
67 .func_hash = &opsname.local_hash, \
68 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
69 #define ASSIGN_OPS_HASH(opsname, val) \
71 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
73 #define INIT_OPS_HASH(opsname)
74 #define ASSIGN_OPS_HASH(opsname, val)
77 static struct ftrace_ops ftrace_list_end __read_mostly
= {
79 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
80 INIT_OPS_HASH(ftrace_list_end
)
83 /* ftrace_enabled is a method to turn ftrace on or off */
84 int ftrace_enabled __read_mostly
;
85 static int last_ftrace_enabled
;
87 /* Current function tracing op */
88 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
89 /* What to set function_trace_op to */
90 static struct ftrace_ops
*set_function_trace_op
;
92 /* List for set_ftrace_pid's pids. */
93 LIST_HEAD(ftrace_pids
);
95 struct list_head list
;
99 static bool ftrace_pids_enabled(void)
101 return !list_empty(&ftrace_pids
);
104 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
107 * ftrace_disabled is set when an anomaly is discovered.
108 * ftrace_disabled is much stronger than ftrace_enabled.
110 static int ftrace_disabled __read_mostly
;
112 static DEFINE_MUTEX(ftrace_lock
);
114 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
115 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
116 static struct ftrace_ops global_ops
;
118 #if ARCH_SUPPORTS_FTRACE_OPS
119 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
120 struct ftrace_ops
*op
, struct pt_regs
*regs
);
122 /* See comment below, where ftrace_ops_list_func is defined */
123 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
124 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
128 * Traverse the ftrace_global_list, invoking all entries. The reason that we
129 * can use rcu_dereference_raw_notrace() is that elements removed from this list
130 * are simply leaked, so there is no need to interact with a grace-period
131 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
132 * concurrent insertions into the ftrace_global_list.
134 * Silly Alpha and silly pointer-speculation compiler optimizations!
136 #define do_for_each_ftrace_op(op, list) \
137 op = rcu_dereference_raw_notrace(list); \
141 * Optimized for just a single item in the list (as that is the normal case).
143 #define while_for_each_ftrace_op(op) \
144 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
145 unlikely((op) != &ftrace_list_end))
147 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
149 #ifdef CONFIG_DYNAMIC_FTRACE
150 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
151 mutex_init(&ops
->local_hash
.regex_lock
);
152 ops
->func_hash
= &ops
->local_hash
;
153 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
159 * ftrace_nr_registered_ops - return number of ops registered
161 * Returns the number of ftrace_ops registered and tracing functions
163 int ftrace_nr_registered_ops(void)
165 struct ftrace_ops
*ops
;
168 mutex_lock(&ftrace_lock
);
170 for (ops
= ftrace_ops_list
;
171 ops
!= &ftrace_list_end
; ops
= ops
->next
)
174 mutex_unlock(&ftrace_lock
);
179 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
180 struct ftrace_ops
*op
, struct pt_regs
*regs
)
182 if (!test_tsk_trace_trace(current
))
185 op
->saved_func(ip
, parent_ip
, op
, regs
);
189 * clear_ftrace_function - reset the ftrace function
191 * This NULLs the ftrace function and in essence stops
192 * tracing. There may be lag
194 void clear_ftrace_function(void)
196 ftrace_trace_function
= ftrace_stub
;
199 static void per_cpu_ops_disable_all(struct ftrace_ops
*ops
)
203 for_each_possible_cpu(cpu
)
204 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
207 static int per_cpu_ops_alloc(struct ftrace_ops
*ops
)
209 int __percpu
*disabled
;
211 if (WARN_ON_ONCE(!(ops
->flags
& FTRACE_OPS_FL_PER_CPU
)))
214 disabled
= alloc_percpu(int);
218 ops
->disabled
= disabled
;
219 per_cpu_ops_disable_all(ops
);
223 static void ftrace_sync(struct work_struct
*work
)
226 * This function is just a stub to implement a hard force
227 * of synchronize_sched(). This requires synchronizing
228 * tasks even in userspace and idle.
230 * Yes, function tracing is rude.
234 static void ftrace_sync_ipi(void *data
)
236 /* Probably not needed, but do it anyway */
240 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
241 static void update_function_graph_func(void);
243 /* Both enabled by default (can be cleared by function_graph tracer flags */
244 static bool fgraph_sleep_time
= true;
245 static bool fgraph_graph_time
= true;
248 static inline void update_function_graph_func(void) { }
252 static ftrace_func_t
ftrace_ops_get_list_func(struct ftrace_ops
*ops
)
255 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
256 * then it needs to call the list anyway.
258 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
|
259 FTRACE_OPS_FL_RCU
) || FTRACE_FORCE_LIST_FUNC
)
260 return ftrace_ops_list_func
;
262 return ftrace_ops_get_func(ops
);
265 static void update_ftrace_function(void)
270 * Prepare the ftrace_ops that the arch callback will use.
271 * If there's only one ftrace_ops registered, the ftrace_ops_list
272 * will point to the ops we want.
274 set_function_trace_op
= ftrace_ops_list
;
276 /* If there's no ftrace_ops registered, just call the stub function */
277 if (ftrace_ops_list
== &ftrace_list_end
) {
281 * If we are at the end of the list and this ops is
282 * recursion safe and not dynamic and the arch supports passing ops,
283 * then have the mcount trampoline call the function directly.
285 } else if (ftrace_ops_list
->next
== &ftrace_list_end
) {
286 func
= ftrace_ops_get_list_func(ftrace_ops_list
);
289 /* Just use the default ftrace_ops */
290 set_function_trace_op
= &ftrace_list_end
;
291 func
= ftrace_ops_list_func
;
294 update_function_graph_func();
296 /* If there's no change, then do nothing more here */
297 if (ftrace_trace_function
== func
)
301 * If we are using the list function, it doesn't care
302 * about the function_trace_ops.
304 if (func
== ftrace_ops_list_func
) {
305 ftrace_trace_function
= func
;
307 * Don't even bother setting function_trace_ops,
308 * it would be racy to do so anyway.
313 #ifndef CONFIG_DYNAMIC_FTRACE
315 * For static tracing, we need to be a bit more careful.
316 * The function change takes affect immediately. Thus,
317 * we need to coorditate the setting of the function_trace_ops
318 * with the setting of the ftrace_trace_function.
320 * Set the function to the list ops, which will call the
321 * function we want, albeit indirectly, but it handles the
322 * ftrace_ops and doesn't depend on function_trace_op.
324 ftrace_trace_function
= ftrace_ops_list_func
;
326 * Make sure all CPUs see this. Yes this is slow, but static
327 * tracing is slow and nasty to have enabled.
329 schedule_on_each_cpu(ftrace_sync
);
330 /* Now all cpus are using the list ops. */
331 function_trace_op
= set_function_trace_op
;
332 /* Make sure the function_trace_op is visible on all CPUs */
334 /* Nasty way to force a rmb on all cpus */
335 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
336 /* OK, we are all set to update the ftrace_trace_function now! */
337 #endif /* !CONFIG_DYNAMIC_FTRACE */
339 ftrace_trace_function
= func
;
342 int using_ftrace_ops_list_func(void)
344 return ftrace_trace_function
== ftrace_ops_list_func
;
347 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
351 * We are entering ops into the list but another
352 * CPU might be walking that list. We need to make sure
353 * the ops->next pointer is valid before another CPU sees
354 * the ops pointer included into the list.
356 rcu_assign_pointer(*list
, ops
);
359 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
361 struct ftrace_ops
**p
;
364 * If we are removing the last function, then simply point
365 * to the ftrace_stub.
367 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
368 *list
= &ftrace_list_end
;
372 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
383 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
385 static int __register_ftrace_function(struct ftrace_ops
*ops
)
387 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
390 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
393 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
395 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
396 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
397 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
399 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
400 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
403 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
404 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
407 if (!core_kernel_data((unsigned long)ops
))
408 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
410 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
) {
411 if (per_cpu_ops_alloc(ops
))
415 add_ftrace_ops(&ftrace_ops_list
, ops
);
417 /* Always save the function, and reset at unregistering */
418 ops
->saved_func
= ops
->func
;
420 if (ops
->flags
& FTRACE_OPS_FL_PID
&& ftrace_pids_enabled())
421 ops
->func
= ftrace_pid_func
;
423 ftrace_update_trampoline(ops
);
426 update_ftrace_function();
431 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
435 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
438 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
444 update_ftrace_function();
446 ops
->func
= ops
->saved_func
;
451 static void ftrace_update_pid_func(void)
453 bool enabled
= ftrace_pids_enabled();
454 struct ftrace_ops
*op
;
456 /* Only do something if we are tracing something */
457 if (ftrace_trace_function
== ftrace_stub
)
460 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
461 if (op
->flags
& FTRACE_OPS_FL_PID
) {
462 op
->func
= enabled
? ftrace_pid_func
:
464 ftrace_update_trampoline(op
);
466 } while_for_each_ftrace_op(op
);
468 update_ftrace_function();
471 #ifdef CONFIG_FUNCTION_PROFILER
472 struct ftrace_profile
{
473 struct hlist_node node
;
475 unsigned long counter
;
476 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
477 unsigned long long time
;
478 unsigned long long time_squared
;
482 struct ftrace_profile_page
{
483 struct ftrace_profile_page
*next
;
485 struct ftrace_profile records
[];
488 struct ftrace_profile_stat
{
490 struct hlist_head
*hash
;
491 struct ftrace_profile_page
*pages
;
492 struct ftrace_profile_page
*start
;
493 struct tracer_stat stat
;
496 #define PROFILE_RECORDS_SIZE \
497 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
499 #define PROFILES_PER_PAGE \
500 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
502 static int ftrace_profile_enabled __read_mostly
;
504 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
505 static DEFINE_MUTEX(ftrace_profile_lock
);
507 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
509 #define FTRACE_PROFILE_HASH_BITS 10
510 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
513 function_stat_next(void *v
, int idx
)
515 struct ftrace_profile
*rec
= v
;
516 struct ftrace_profile_page
*pg
;
518 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
524 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
528 rec
= &pg
->records
[0];
536 static void *function_stat_start(struct tracer_stat
*trace
)
538 struct ftrace_profile_stat
*stat
=
539 container_of(trace
, struct ftrace_profile_stat
, stat
);
541 if (!stat
|| !stat
->start
)
544 return function_stat_next(&stat
->start
->records
[0], 0);
547 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
548 /* function graph compares on total time */
549 static int function_stat_cmp(void *p1
, void *p2
)
551 struct ftrace_profile
*a
= p1
;
552 struct ftrace_profile
*b
= p2
;
554 if (a
->time
< b
->time
)
556 if (a
->time
> b
->time
)
562 /* not function graph compares against hits */
563 static int function_stat_cmp(void *p1
, void *p2
)
565 struct ftrace_profile
*a
= p1
;
566 struct ftrace_profile
*b
= p2
;
568 if (a
->counter
< b
->counter
)
570 if (a
->counter
> b
->counter
)
577 static int function_stat_headers(struct seq_file
*m
)
579 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
580 seq_puts(m
, " Function "
583 "--- ---- --- ---\n");
585 seq_puts(m
, " Function Hit\n"
591 static int function_stat_show(struct seq_file
*m
, void *v
)
593 struct ftrace_profile
*rec
= v
;
594 char str
[KSYM_SYMBOL_LEN
];
596 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
597 static struct trace_seq s
;
598 unsigned long long avg
;
599 unsigned long long stddev
;
601 mutex_lock(&ftrace_profile_lock
);
603 /* we raced with function_profile_reset() */
604 if (unlikely(rec
->counter
== 0)) {
609 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
611 do_div(avg
, rec
->counter
);
612 if (tracing_thresh
&& (avg
< tracing_thresh
))
616 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
617 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
619 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
622 /* Sample standard deviation (s^2) */
623 if (rec
->counter
<= 1)
627 * Apply Welford's method:
628 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
630 stddev
= rec
->counter
* rec
->time_squared
-
631 rec
->time
* rec
->time
;
634 * Divide only 1000 for ns^2 -> us^2 conversion.
635 * trace_print_graph_duration will divide 1000 again.
637 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
641 trace_print_graph_duration(rec
->time
, &s
);
642 trace_seq_puts(&s
, " ");
643 trace_print_graph_duration(avg
, &s
);
644 trace_seq_puts(&s
, " ");
645 trace_print_graph_duration(stddev
, &s
);
646 trace_print_seq(m
, &s
);
650 mutex_unlock(&ftrace_profile_lock
);
655 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
657 struct ftrace_profile_page
*pg
;
659 pg
= stat
->pages
= stat
->start
;
662 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
667 memset(stat
->hash
, 0,
668 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
671 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
673 struct ftrace_profile_page
*pg
;
678 /* If we already allocated, do nothing */
682 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
686 #ifdef CONFIG_DYNAMIC_FTRACE
687 functions
= ftrace_update_tot_cnt
;
690 * We do not know the number of functions that exist because
691 * dynamic tracing is what counts them. With past experience
692 * we have around 20K functions. That should be more than enough.
693 * It is highly unlikely we will execute every function in
699 pg
= stat
->start
= stat
->pages
;
701 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
703 for (i
= 1; i
< pages
; i
++) {
704 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
715 unsigned long tmp
= (unsigned long)pg
;
727 static int ftrace_profile_init_cpu(int cpu
)
729 struct ftrace_profile_stat
*stat
;
732 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
735 /* If the profile is already created, simply reset it */
736 ftrace_profile_reset(stat
);
741 * We are profiling all functions, but usually only a few thousand
742 * functions are hit. We'll make a hash of 1024 items.
744 size
= FTRACE_PROFILE_HASH_SIZE
;
746 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
751 /* Preallocate the function profiling pages */
752 if (ftrace_profile_pages_init(stat
) < 0) {
761 static int ftrace_profile_init(void)
766 for_each_possible_cpu(cpu
) {
767 ret
= ftrace_profile_init_cpu(cpu
);
775 /* interrupts must be disabled */
776 static struct ftrace_profile
*
777 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
779 struct ftrace_profile
*rec
;
780 struct hlist_head
*hhd
;
783 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
784 hhd
= &stat
->hash
[key
];
786 if (hlist_empty(hhd
))
789 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
797 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
798 struct ftrace_profile
*rec
)
802 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
803 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
807 * The memory is already allocated, this simply finds a new record to use.
809 static struct ftrace_profile
*
810 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
812 struct ftrace_profile
*rec
= NULL
;
814 /* prevent recursion (from NMIs) */
815 if (atomic_inc_return(&stat
->disabled
) != 1)
819 * Try to find the function again since an NMI
820 * could have added it
822 rec
= ftrace_find_profiled_func(stat
, ip
);
826 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
827 if (!stat
->pages
->next
)
829 stat
->pages
= stat
->pages
->next
;
832 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
834 ftrace_add_profile(stat
, rec
);
837 atomic_dec(&stat
->disabled
);
843 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
844 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
846 struct ftrace_profile_stat
*stat
;
847 struct ftrace_profile
*rec
;
850 if (!ftrace_profile_enabled
)
853 local_irq_save(flags
);
855 stat
= this_cpu_ptr(&ftrace_profile_stats
);
856 if (!stat
->hash
|| !ftrace_profile_enabled
)
859 rec
= ftrace_find_profiled_func(stat
, ip
);
861 rec
= ftrace_profile_alloc(stat
, ip
);
868 local_irq_restore(flags
);
871 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
872 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
874 function_profile_call(trace
->func
, 0, NULL
, NULL
);
878 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
880 struct ftrace_profile_stat
*stat
;
881 unsigned long long calltime
;
882 struct ftrace_profile
*rec
;
885 local_irq_save(flags
);
886 stat
= this_cpu_ptr(&ftrace_profile_stats
);
887 if (!stat
->hash
|| !ftrace_profile_enabled
)
890 /* If the calltime was zero'd ignore it */
891 if (!trace
->calltime
)
894 calltime
= trace
->rettime
- trace
->calltime
;
896 if (!fgraph_graph_time
) {
899 index
= trace
->depth
;
901 /* Append this call time to the parent time to subtract */
903 current
->ret_stack
[index
- 1].subtime
+= calltime
;
905 if (current
->ret_stack
[index
].subtime
< calltime
)
906 calltime
-= current
->ret_stack
[index
].subtime
;
911 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
913 rec
->time
+= calltime
;
914 rec
->time_squared
+= calltime
* calltime
;
918 local_irq_restore(flags
);
921 static int register_ftrace_profiler(void)
923 return register_ftrace_graph(&profile_graph_return
,
924 &profile_graph_entry
);
927 static void unregister_ftrace_profiler(void)
929 unregister_ftrace_graph();
932 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
933 .func
= function_profile_call
,
934 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
935 INIT_OPS_HASH(ftrace_profile_ops
)
938 static int register_ftrace_profiler(void)
940 return register_ftrace_function(&ftrace_profile_ops
);
943 static void unregister_ftrace_profiler(void)
945 unregister_ftrace_function(&ftrace_profile_ops
);
947 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
950 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
951 size_t cnt
, loff_t
*ppos
)
956 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
962 mutex_lock(&ftrace_profile_lock
);
963 if (ftrace_profile_enabled
^ val
) {
965 ret
= ftrace_profile_init();
971 ret
= register_ftrace_profiler();
976 ftrace_profile_enabled
= 1;
978 ftrace_profile_enabled
= 0;
980 * unregister_ftrace_profiler calls stop_machine
981 * so this acts like an synchronize_sched.
983 unregister_ftrace_profiler();
987 mutex_unlock(&ftrace_profile_lock
);
995 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
996 size_t cnt
, loff_t
*ppos
)
998 char buf
[64]; /* big enough to hold a number */
1001 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1002 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1005 static const struct file_operations ftrace_profile_fops
= {
1006 .open
= tracing_open_generic
,
1007 .read
= ftrace_profile_read
,
1008 .write
= ftrace_profile_write
,
1009 .llseek
= default_llseek
,
1012 /* used to initialize the real stat files */
1013 static struct tracer_stat function_stats __initdata
= {
1014 .name
= "functions",
1015 .stat_start
= function_stat_start
,
1016 .stat_next
= function_stat_next
,
1017 .stat_cmp
= function_stat_cmp
,
1018 .stat_headers
= function_stat_headers
,
1019 .stat_show
= function_stat_show
1022 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1024 struct ftrace_profile_stat
*stat
;
1025 struct dentry
*entry
;
1030 for_each_possible_cpu(cpu
) {
1031 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1033 /* allocate enough for function name + cpu number */
1034 name
= kmalloc(32, GFP_KERNEL
);
1037 * The files created are permanent, if something happens
1038 * we still do not free memory.
1041 "Could not allocate stat file for cpu %d\n",
1045 stat
->stat
= function_stats
;
1046 snprintf(name
, 32, "function%d", cpu
);
1047 stat
->stat
.name
= name
;
1048 ret
= register_stat_tracer(&stat
->stat
);
1051 "Could not register function stat for cpu %d\n",
1058 entry
= tracefs_create_file("function_profile_enabled", 0644,
1059 d_tracer
, NULL
, &ftrace_profile_fops
);
1061 pr_warning("Could not create tracefs "
1062 "'function_profile_enabled' entry\n");
1065 #else /* CONFIG_FUNCTION_PROFILER */
1066 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1069 #endif /* CONFIG_FUNCTION_PROFILER */
1071 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1073 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1074 static int ftrace_graph_active
;
1076 # define ftrace_graph_active 0
1079 #ifdef CONFIG_DYNAMIC_FTRACE
1081 static struct ftrace_ops
*removed_ops
;
1084 * Set when doing a global update, like enabling all recs or disabling them.
1085 * It is not set when just updating a single ftrace_ops.
1087 static bool update_all_ops
;
1089 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1090 # error Dynamic ftrace depends on MCOUNT_RECORD
1093 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1095 struct ftrace_func_probe
{
1096 struct hlist_node node
;
1097 struct ftrace_probe_ops
*ops
;
1098 unsigned long flags
;
1101 struct list_head free_list
;
1104 struct ftrace_func_entry
{
1105 struct hlist_node hlist
;
1109 struct ftrace_hash
{
1110 unsigned long size_bits
;
1111 struct hlist_head
*buckets
;
1112 unsigned long count
;
1113 struct rcu_head rcu
;
1117 * We make these constant because no one should touch them,
1118 * but they are used as the default "empty hash", to avoid allocating
1119 * it all the time. These are in a read only section such that if
1120 * anyone does try to modify it, it will cause an exception.
1122 static const struct hlist_head empty_buckets
[1];
1123 static const struct ftrace_hash empty_hash
= {
1124 .buckets
= (struct hlist_head
*)empty_buckets
,
1126 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1128 static struct ftrace_ops global_ops
= {
1129 .func
= ftrace_stub
,
1130 .local_hash
.notrace_hash
= EMPTY_HASH
,
1131 .local_hash
.filter_hash
= EMPTY_HASH
,
1132 INIT_OPS_HASH(global_ops
)
1133 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1134 FTRACE_OPS_FL_INITIALIZED
|
1139 * This is used by __kernel_text_address() to return true if the
1140 * address is on a dynamically allocated trampoline that would
1141 * not return true for either core_kernel_text() or
1142 * is_module_text_address().
1144 bool is_ftrace_trampoline(unsigned long addr
)
1146 struct ftrace_ops
*op
;
1150 * Some of the ops may be dynamically allocated,
1151 * they are freed after a synchronize_sched().
1153 preempt_disable_notrace();
1155 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1157 * This is to check for dynamically allocated trampolines.
1158 * Trampolines that are in kernel text will have
1159 * core_kernel_text() return true.
1161 if (op
->trampoline
&& op
->trampoline_size
)
1162 if (addr
>= op
->trampoline
&&
1163 addr
< op
->trampoline
+ op
->trampoline_size
) {
1167 } while_for_each_ftrace_op(op
);
1170 preempt_enable_notrace();
1175 struct ftrace_page
{
1176 struct ftrace_page
*next
;
1177 struct dyn_ftrace
*records
;
1182 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1183 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1185 /* estimate from running different kernels */
1186 #define NR_TO_INIT 10000
1188 static struct ftrace_page
*ftrace_pages_start
;
1189 static struct ftrace_page
*ftrace_pages
;
1191 static bool __always_inline
ftrace_hash_empty(struct ftrace_hash
*hash
)
1193 return !hash
|| !hash
->count
;
1196 static struct ftrace_func_entry
*
1197 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1200 struct ftrace_func_entry
*entry
;
1201 struct hlist_head
*hhd
;
1203 if (ftrace_hash_empty(hash
))
1206 if (hash
->size_bits
> 0)
1207 key
= hash_long(ip
, hash
->size_bits
);
1211 hhd
= &hash
->buckets
[key
];
1213 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1214 if (entry
->ip
== ip
)
1220 static void __add_hash_entry(struct ftrace_hash
*hash
,
1221 struct ftrace_func_entry
*entry
)
1223 struct hlist_head
*hhd
;
1226 if (hash
->size_bits
)
1227 key
= hash_long(entry
->ip
, hash
->size_bits
);
1231 hhd
= &hash
->buckets
[key
];
1232 hlist_add_head(&entry
->hlist
, hhd
);
1236 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1238 struct ftrace_func_entry
*entry
;
1240 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1245 __add_hash_entry(hash
, entry
);
1251 free_hash_entry(struct ftrace_hash
*hash
,
1252 struct ftrace_func_entry
*entry
)
1254 hlist_del(&entry
->hlist
);
1260 remove_hash_entry(struct ftrace_hash
*hash
,
1261 struct ftrace_func_entry
*entry
)
1263 hlist_del(&entry
->hlist
);
1267 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1269 struct hlist_head
*hhd
;
1270 struct hlist_node
*tn
;
1271 struct ftrace_func_entry
*entry
;
1272 int size
= 1 << hash
->size_bits
;
1278 for (i
= 0; i
< size
; i
++) {
1279 hhd
= &hash
->buckets
[i
];
1280 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1281 free_hash_entry(hash
, entry
);
1283 FTRACE_WARN_ON(hash
->count
);
1286 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1288 if (!hash
|| hash
== EMPTY_HASH
)
1290 ftrace_hash_clear(hash
);
1291 kfree(hash
->buckets
);
1295 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1297 struct ftrace_hash
*hash
;
1299 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1300 free_ftrace_hash(hash
);
1303 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1305 if (!hash
|| hash
== EMPTY_HASH
)
1307 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1310 void ftrace_free_filter(struct ftrace_ops
*ops
)
1312 ftrace_ops_init(ops
);
1313 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1314 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1317 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1319 struct ftrace_hash
*hash
;
1322 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1326 size
= 1 << size_bits
;
1327 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1329 if (!hash
->buckets
) {
1334 hash
->size_bits
= size_bits
;
1339 static struct ftrace_hash
*
1340 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1342 struct ftrace_func_entry
*entry
;
1343 struct ftrace_hash
*new_hash
;
1348 new_hash
= alloc_ftrace_hash(size_bits
);
1353 if (ftrace_hash_empty(hash
))
1356 size
= 1 << hash
->size_bits
;
1357 for (i
= 0; i
< size
; i
++) {
1358 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1359 ret
= add_hash_entry(new_hash
, entry
->ip
);
1365 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1370 free_ftrace_hash(new_hash
);
1375 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1377 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1379 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1380 struct ftrace_hash
*new_hash
);
1383 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1384 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1386 struct ftrace_func_entry
*entry
;
1387 struct hlist_node
*tn
;
1388 struct hlist_head
*hhd
;
1389 struct ftrace_hash
*new_hash
;
1390 int size
= src
->count
;
1395 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1396 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1400 * If the new source is empty, just free dst and assign it
1404 new_hash
= EMPTY_HASH
;
1409 * Make the hash size about 1/2 the # found
1411 for (size
/= 2; size
; size
>>= 1)
1414 /* Don't allocate too much */
1415 if (bits
> FTRACE_HASH_MAX_BITS
)
1416 bits
= FTRACE_HASH_MAX_BITS
;
1418 new_hash
= alloc_ftrace_hash(bits
);
1422 size
= 1 << src
->size_bits
;
1423 for (i
= 0; i
< size
; i
++) {
1424 hhd
= &src
->buckets
[i
];
1425 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1426 remove_hash_entry(src
, entry
);
1427 __add_hash_entry(new_hash
, entry
);
1432 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1434 /* IPMODIFY should be updated only when filter_hash updating */
1435 ret
= ftrace_hash_ipmodify_update(ops
, new_hash
);
1437 free_ftrace_hash(new_hash
);
1443 * Remove the current set, update the hash and add
1446 ftrace_hash_rec_disable_modify(ops
, enable
);
1448 rcu_assign_pointer(*dst
, new_hash
);
1450 ftrace_hash_rec_enable_modify(ops
, enable
);
1455 static bool hash_contains_ip(unsigned long ip
,
1456 struct ftrace_ops_hash
*hash
)
1459 * The function record is a match if it exists in the filter
1460 * hash and not in the notrace hash. Note, an emty hash is
1461 * considered a match for the filter hash, but an empty
1462 * notrace hash is considered not in the notrace hash.
1464 return (ftrace_hash_empty(hash
->filter_hash
) ||
1465 ftrace_lookup_ip(hash
->filter_hash
, ip
)) &&
1466 (ftrace_hash_empty(hash
->notrace_hash
) ||
1467 !ftrace_lookup_ip(hash
->notrace_hash
, ip
));
1471 * Test the hashes for this ops to see if we want to call
1472 * the ops->func or not.
1474 * It's a match if the ip is in the ops->filter_hash or
1475 * the filter_hash does not exist or is empty,
1477 * the ip is not in the ops->notrace_hash.
1479 * This needs to be called with preemption disabled as
1480 * the hashes are freed with call_rcu_sched().
1483 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1485 struct ftrace_ops_hash hash
;
1488 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1490 * There's a small race when adding ops that the ftrace handler
1491 * that wants regs, may be called without them. We can not
1492 * allow that handler to be called if regs is NULL.
1494 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1498 hash
.filter_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->filter_hash
);
1499 hash
.notrace_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->notrace_hash
);
1501 if (hash_contains_ip(ip
, &hash
))
1510 * This is a double for. Do not use 'break' to break out of the loop,
1511 * you must use a goto.
1513 #define do_for_each_ftrace_rec(pg, rec) \
1514 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1516 for (_____i = 0; _____i < pg->index; _____i++) { \
1517 rec = &pg->records[_____i];
1519 #define while_for_each_ftrace_rec() \
1524 static int ftrace_cmp_recs(const void *a
, const void *b
)
1526 const struct dyn_ftrace
*key
= a
;
1527 const struct dyn_ftrace
*rec
= b
;
1529 if (key
->flags
< rec
->ip
)
1531 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1536 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1538 struct ftrace_page
*pg
;
1539 struct dyn_ftrace
*rec
;
1540 struct dyn_ftrace key
;
1543 key
.flags
= end
; /* overload flags, as it is unsigned long */
1545 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1546 if (end
< pg
->records
[0].ip
||
1547 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1549 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1550 sizeof(struct dyn_ftrace
),
1560 * ftrace_location - return true if the ip giving is a traced location
1561 * @ip: the instruction pointer to check
1563 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1564 * That is, the instruction that is either a NOP or call to
1565 * the function tracer. It checks the ftrace internal tables to
1566 * determine if the address belongs or not.
1568 unsigned long ftrace_location(unsigned long ip
)
1570 return ftrace_location_range(ip
, ip
);
1574 * ftrace_text_reserved - return true if range contains an ftrace location
1575 * @start: start of range to search
1576 * @end: end of range to search (inclusive). @end points to the last byte to check.
1578 * Returns 1 if @start and @end contains a ftrace location.
1579 * That is, the instruction that is either a NOP or call to
1580 * the function tracer. It checks the ftrace internal tables to
1581 * determine if the address belongs or not.
1583 int ftrace_text_reserved(const void *start
, const void *end
)
1587 ret
= ftrace_location_range((unsigned long)start
,
1588 (unsigned long)end
);
1593 /* Test if ops registered to this rec needs regs */
1594 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1596 struct ftrace_ops
*ops
;
1597 bool keep_regs
= false;
1599 for (ops
= ftrace_ops_list
;
1600 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1601 /* pass rec in as regs to have non-NULL val */
1602 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1603 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1613 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1617 struct ftrace_hash
*hash
;
1618 struct ftrace_hash
*other_hash
;
1619 struct ftrace_page
*pg
;
1620 struct dyn_ftrace
*rec
;
1624 /* Only update if the ops has been registered */
1625 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1629 * In the filter_hash case:
1630 * If the count is zero, we update all records.
1631 * Otherwise we just update the items in the hash.
1633 * In the notrace_hash case:
1634 * We enable the update in the hash.
1635 * As disabling notrace means enabling the tracing,
1636 * and enabling notrace means disabling, the inc variable
1640 hash
= ops
->func_hash
->filter_hash
;
1641 other_hash
= ops
->func_hash
->notrace_hash
;
1642 if (ftrace_hash_empty(hash
))
1646 hash
= ops
->func_hash
->notrace_hash
;
1647 other_hash
= ops
->func_hash
->filter_hash
;
1649 * If the notrace hash has no items,
1650 * then there's nothing to do.
1652 if (ftrace_hash_empty(hash
))
1656 do_for_each_ftrace_rec(pg
, rec
) {
1657 int in_other_hash
= 0;
1663 * Only the filter_hash affects all records.
1664 * Update if the record is not in the notrace hash.
1666 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1669 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1670 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1673 * If filter_hash is set, we want to match all functions
1674 * that are in the hash but not in the other hash.
1676 * If filter_hash is not set, then we are decrementing.
1677 * That means we match anything that is in the hash
1678 * and also in the other_hash. That is, we need to turn
1679 * off functions in the other hash because they are disabled
1682 if (filter_hash
&& in_hash
&& !in_other_hash
)
1684 else if (!filter_hash
&& in_hash
&&
1685 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1693 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1697 * If there's only a single callback registered to a
1698 * function, and the ops has a trampoline registered
1699 * for it, then we can call it directly.
1701 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1702 rec
->flags
|= FTRACE_FL_TRAMP
;
1705 * If we are adding another function callback
1706 * to this function, and the previous had a
1707 * custom trampoline in use, then we need to go
1708 * back to the default trampoline.
1710 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1713 * If any ops wants regs saved for this function
1714 * then all ops will get saved regs.
1716 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1717 rec
->flags
|= FTRACE_FL_REGS
;
1719 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1724 * If the rec had REGS enabled and the ops that is
1725 * being removed had REGS set, then see if there is
1726 * still any ops for this record that wants regs.
1727 * If not, we can stop recording them.
1729 if (ftrace_rec_count(rec
) > 0 &&
1730 rec
->flags
& FTRACE_FL_REGS
&&
1731 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1732 if (!test_rec_ops_needs_regs(rec
))
1733 rec
->flags
&= ~FTRACE_FL_REGS
;
1737 * If the rec had TRAMP enabled, then it needs to
1738 * be cleared. As TRAMP can only be enabled iff
1739 * there is only a single ops attached to it.
1740 * In otherwords, always disable it on decrementing.
1741 * In the future, we may set it if rec count is
1742 * decremented to one, and the ops that is left
1745 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1748 * flags will be cleared in ftrace_check_record()
1749 * if rec count is zero.
1753 /* Shortcut, if we handled all records, we are done. */
1754 if (!all
&& count
== hash
->count
)
1756 } while_for_each_ftrace_rec();
1759 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1762 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1765 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1768 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1771 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1772 int filter_hash
, int inc
)
1774 struct ftrace_ops
*op
;
1776 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1778 if (ops
->func_hash
!= &global_ops
.local_hash
)
1782 * If the ops shares the global_ops hash, then we need to update
1783 * all ops that are enabled and use this hash.
1785 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1789 if (op
->func_hash
== &global_ops
.local_hash
)
1790 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1791 } while_for_each_ftrace_op(op
);
1794 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1797 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1800 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1803 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1807 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1808 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1809 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1810 * Note that old_hash and new_hash has below meanings
1811 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1812 * - If the hash is EMPTY_HASH, it hits nothing
1813 * - Anything else hits the recs which match the hash entries.
1815 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1816 struct ftrace_hash
*old_hash
,
1817 struct ftrace_hash
*new_hash
)
1819 struct ftrace_page
*pg
;
1820 struct dyn_ftrace
*rec
, *end
= NULL
;
1823 /* Only update if the ops has been registered */
1824 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1827 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1831 * Since the IPMODIFY is a very address sensitive action, we do not
1832 * allow ftrace_ops to set all functions to new hash.
1834 if (!new_hash
|| !old_hash
)
1837 /* Update rec->flags */
1838 do_for_each_ftrace_rec(pg
, rec
) {
1839 /* We need to update only differences of filter_hash */
1840 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1841 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1842 if (in_old
== in_new
)
1846 /* New entries must ensure no others are using it */
1847 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1849 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1850 } else /* Removed entry */
1851 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1852 } while_for_each_ftrace_rec();
1859 /* Roll back what we did above */
1860 do_for_each_ftrace_rec(pg
, rec
) {
1864 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1865 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1866 if (in_old
== in_new
)
1870 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1872 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1873 } while_for_each_ftrace_rec();
1879 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
1881 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1883 if (ftrace_hash_empty(hash
))
1886 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
1889 /* Disabling always succeeds */
1890 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
1892 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1894 if (ftrace_hash_empty(hash
))
1897 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
1900 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1901 struct ftrace_hash
*new_hash
)
1903 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
1905 if (ftrace_hash_empty(old_hash
))
1908 if (ftrace_hash_empty(new_hash
))
1911 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
1914 static void print_ip_ins(const char *fmt
, const unsigned char *p
)
1918 printk(KERN_CONT
"%s", fmt
);
1920 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1921 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1924 static struct ftrace_ops
*
1925 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
1926 static struct ftrace_ops
*
1927 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
);
1929 enum ftrace_bug_type ftrace_bug_type
;
1930 const void *ftrace_expected
;
1932 static void print_bug_type(void)
1934 switch (ftrace_bug_type
) {
1935 case FTRACE_BUG_UNKNOWN
:
1937 case FTRACE_BUG_INIT
:
1938 pr_info("Initializing ftrace call sites\n");
1940 case FTRACE_BUG_NOP
:
1941 pr_info("Setting ftrace call site to NOP\n");
1943 case FTRACE_BUG_CALL
:
1944 pr_info("Setting ftrace call site to call ftrace function\n");
1946 case FTRACE_BUG_UPDATE
:
1947 pr_info("Updating ftrace call site to call a different ftrace function\n");
1953 * ftrace_bug - report and shutdown function tracer
1954 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1955 * @rec: The record that failed
1957 * The arch code that enables or disables the function tracing
1958 * can call ftrace_bug() when it has detected a problem in
1959 * modifying the code. @failed should be one of either:
1960 * EFAULT - if the problem happens on reading the @ip address
1961 * EINVAL - if what is read at @ip is not what was expected
1962 * EPERM - if the problem happens on writting to the @ip address
1964 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
1966 unsigned long ip
= rec
? rec
->ip
: 0;
1970 FTRACE_WARN_ON_ONCE(1);
1971 pr_info("ftrace faulted on modifying ");
1975 FTRACE_WARN_ON_ONCE(1);
1976 pr_info("ftrace failed to modify ");
1978 print_ip_ins(" actual: ", (unsigned char *)ip
);
1980 if (ftrace_expected
) {
1981 print_ip_ins(" expected: ", ftrace_expected
);
1986 FTRACE_WARN_ON_ONCE(1);
1987 pr_info("ftrace faulted on writing ");
1991 FTRACE_WARN_ON_ONCE(1);
1992 pr_info("ftrace faulted on unknown error ");
1997 struct ftrace_ops
*ops
= NULL
;
1999 pr_info("ftrace record flags: %lx\n", rec
->flags
);
2000 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
2001 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2002 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2003 ops
= ftrace_find_tramp_ops_any(rec
);
2006 pr_cont("\ttramp: %pS (%pS)",
2007 (void *)ops
->trampoline
,
2009 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
2012 pr_cont("\ttramp: ERROR!");
2015 ip
= ftrace_get_addr_curr(rec
);
2016 pr_cont("\n expected tramp: %lx\n", ip
);
2020 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
2022 unsigned long flag
= 0UL;
2024 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2027 * If we are updating calls:
2029 * If the record has a ref count, then we need to enable it
2030 * because someone is using it.
2032 * Otherwise we make sure its disabled.
2034 * If we are disabling calls, then disable all records that
2037 if (enable
&& ftrace_rec_count(rec
))
2038 flag
= FTRACE_FL_ENABLED
;
2041 * If enabling and the REGS flag does not match the REGS_EN, or
2042 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2043 * this record. Set flags to fail the compare against ENABLED.
2046 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
2047 !(rec
->flags
& FTRACE_FL_REGS_EN
))
2048 flag
|= FTRACE_FL_REGS
;
2050 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
2051 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
2052 flag
|= FTRACE_FL_TRAMP
;
2055 /* If the state of this record hasn't changed, then do nothing */
2056 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2057 return FTRACE_UPDATE_IGNORE
;
2060 /* Save off if rec is being enabled (for return value) */
2061 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2064 rec
->flags
|= FTRACE_FL_ENABLED
;
2065 if (flag
& FTRACE_FL_REGS
) {
2066 if (rec
->flags
& FTRACE_FL_REGS
)
2067 rec
->flags
|= FTRACE_FL_REGS_EN
;
2069 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2071 if (flag
& FTRACE_FL_TRAMP
) {
2072 if (rec
->flags
& FTRACE_FL_TRAMP
)
2073 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2075 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2080 * If this record is being updated from a nop, then
2081 * return UPDATE_MAKE_CALL.
2083 * return UPDATE_MODIFY_CALL to tell the caller to convert
2084 * from the save regs, to a non-save regs function or
2085 * vice versa, or from a trampoline call.
2087 if (flag
& FTRACE_FL_ENABLED
) {
2088 ftrace_bug_type
= FTRACE_BUG_CALL
;
2089 return FTRACE_UPDATE_MAKE_CALL
;
2092 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2093 return FTRACE_UPDATE_MODIFY_CALL
;
2097 /* If there's no more users, clear all flags */
2098 if (!ftrace_rec_count(rec
))
2102 * Just disable the record, but keep the ops TRAMP
2103 * and REGS states. The _EN flags must be disabled though.
2105 rec
->flags
&= ~(FTRACE_FL_ENABLED
| FTRACE_FL_TRAMP_EN
|
2109 ftrace_bug_type
= FTRACE_BUG_NOP
;
2110 return FTRACE_UPDATE_MAKE_NOP
;
2114 * ftrace_update_record, set a record that now is tracing or not
2115 * @rec: the record to update
2116 * @enable: set to 1 if the record is tracing, zero to force disable
2118 * The records that represent all functions that can be traced need
2119 * to be updated when tracing has been enabled.
2121 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2123 return ftrace_check_record(rec
, enable
, 1);
2127 * ftrace_test_record, check if the record has been enabled or not
2128 * @rec: the record to test
2129 * @enable: set to 1 to check if enabled, 0 if it is disabled
2131 * The arch code may need to test if a record is already set to
2132 * tracing to determine how to modify the function code that it
2135 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2137 return ftrace_check_record(rec
, enable
, 0);
2140 static struct ftrace_ops
*
2141 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2143 struct ftrace_ops
*op
;
2144 unsigned long ip
= rec
->ip
;
2146 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2148 if (!op
->trampoline
)
2151 if (hash_contains_ip(ip
, op
->func_hash
))
2153 } while_for_each_ftrace_op(op
);
2158 static struct ftrace_ops
*
2159 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
,
2160 struct ftrace_ops
*op
)
2162 unsigned long ip
= rec
->ip
;
2164 while_for_each_ftrace_op(op
) {
2166 if (!op
->trampoline
)
2169 if (hash_contains_ip(ip
, op
->func_hash
))
2176 static struct ftrace_ops
*
2177 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2179 struct ftrace_ops
*op
;
2180 unsigned long ip
= rec
->ip
;
2183 * Need to check removed ops first.
2184 * If they are being removed, and this rec has a tramp,
2185 * and this rec is in the ops list, then it would be the
2186 * one with the tramp.
2189 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2194 * Need to find the current trampoline for a rec.
2195 * Now, a trampoline is only attached to a rec if there
2196 * was a single 'ops' attached to it. But this can be called
2197 * when we are adding another op to the rec or removing the
2198 * current one. Thus, if the op is being added, we can
2199 * ignore it because it hasn't attached itself to the rec
2202 * If an ops is being modified (hooking to different functions)
2203 * then we don't care about the new functions that are being
2204 * added, just the old ones (that are probably being removed).
2206 * If we are adding an ops to a function that already is using
2207 * a trampoline, it needs to be removed (trampolines are only
2208 * for single ops connected), then an ops that is not being
2209 * modified also needs to be checked.
2211 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2213 if (!op
->trampoline
)
2217 * If the ops is being added, it hasn't gotten to
2218 * the point to be removed from this tree yet.
2220 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2225 * If the ops is being modified and is in the old
2226 * hash, then it is probably being removed from this
2229 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2230 hash_contains_ip(ip
, &op
->old_hash
))
2233 * If the ops is not being added or modified, and it's
2234 * in its normal filter hash, then this must be the one
2237 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2238 hash_contains_ip(ip
, op
->func_hash
))
2241 } while_for_each_ftrace_op(op
);
2246 static struct ftrace_ops
*
2247 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2249 struct ftrace_ops
*op
;
2250 unsigned long ip
= rec
->ip
;
2252 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2253 /* pass rec in as regs to have non-NULL val */
2254 if (hash_contains_ip(ip
, op
->func_hash
))
2256 } while_for_each_ftrace_op(op
);
2262 * ftrace_get_addr_new - Get the call address to set to
2263 * @rec: The ftrace record descriptor
2265 * If the record has the FTRACE_FL_REGS set, that means that it
2266 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2267 * is not not set, then it wants to convert to the normal callback.
2269 * Returns the address of the trampoline to set to
2271 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2273 struct ftrace_ops
*ops
;
2275 /* Trampolines take precedence over regs */
2276 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2277 ops
= ftrace_find_tramp_ops_new(rec
);
2278 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2279 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2280 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2281 /* Ftrace is shutting down, return anything */
2282 return (unsigned long)FTRACE_ADDR
;
2284 return ops
->trampoline
;
2287 if (rec
->flags
& FTRACE_FL_REGS
)
2288 return (unsigned long)FTRACE_REGS_ADDR
;
2290 return (unsigned long)FTRACE_ADDR
;
2294 * ftrace_get_addr_curr - Get the call address that is already there
2295 * @rec: The ftrace record descriptor
2297 * The FTRACE_FL_REGS_EN is set when the record already points to
2298 * a function that saves all the regs. Basically the '_EN' version
2299 * represents the current state of the function.
2301 * Returns the address of the trampoline that is currently being called
2303 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2305 struct ftrace_ops
*ops
;
2307 /* Trampolines take precedence over regs */
2308 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2309 ops
= ftrace_find_tramp_ops_curr(rec
);
2310 if (FTRACE_WARN_ON(!ops
)) {
2311 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
2312 (void *)rec
->ip
, (void *)rec
->ip
);
2313 /* Ftrace is shutting down, return anything */
2314 return (unsigned long)FTRACE_ADDR
;
2316 return ops
->trampoline
;
2319 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2320 return (unsigned long)FTRACE_REGS_ADDR
;
2322 return (unsigned long)FTRACE_ADDR
;
2326 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2328 unsigned long ftrace_old_addr
;
2329 unsigned long ftrace_addr
;
2332 ftrace_addr
= ftrace_get_addr_new(rec
);
2334 /* This needs to be done before we call ftrace_update_record */
2335 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2337 ret
= ftrace_update_record(rec
, enable
);
2339 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2342 case FTRACE_UPDATE_IGNORE
:
2345 case FTRACE_UPDATE_MAKE_CALL
:
2346 ftrace_bug_type
= FTRACE_BUG_CALL
;
2347 return ftrace_make_call(rec
, ftrace_addr
);
2349 case FTRACE_UPDATE_MAKE_NOP
:
2350 ftrace_bug_type
= FTRACE_BUG_NOP
;
2351 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2353 case FTRACE_UPDATE_MODIFY_CALL
:
2354 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2355 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2358 return -1; /* unknow ftrace bug */
2361 void __weak
ftrace_replace_code(int enable
)
2363 struct dyn_ftrace
*rec
;
2364 struct ftrace_page
*pg
;
2367 if (unlikely(ftrace_disabled
))
2370 do_for_each_ftrace_rec(pg
, rec
) {
2371 failed
= __ftrace_replace_code(rec
, enable
);
2373 ftrace_bug(failed
, rec
);
2374 /* Stop processing */
2377 } while_for_each_ftrace_rec();
2380 struct ftrace_rec_iter
{
2381 struct ftrace_page
*pg
;
2386 * ftrace_rec_iter_start, start up iterating over traced functions
2388 * Returns an iterator handle that is used to iterate over all
2389 * the records that represent address locations where functions
2392 * May return NULL if no records are available.
2394 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2397 * We only use a single iterator.
2398 * Protected by the ftrace_lock mutex.
2400 static struct ftrace_rec_iter ftrace_rec_iter
;
2401 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2403 iter
->pg
= ftrace_pages_start
;
2406 /* Could have empty pages */
2407 while (iter
->pg
&& !iter
->pg
->index
)
2408 iter
->pg
= iter
->pg
->next
;
2417 * ftrace_rec_iter_next, get the next record to process.
2418 * @iter: The handle to the iterator.
2420 * Returns the next iterator after the given iterator @iter.
2422 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2426 if (iter
->index
>= iter
->pg
->index
) {
2427 iter
->pg
= iter
->pg
->next
;
2430 /* Could have empty pages */
2431 while (iter
->pg
&& !iter
->pg
->index
)
2432 iter
->pg
= iter
->pg
->next
;
2442 * ftrace_rec_iter_record, get the record at the iterator location
2443 * @iter: The current iterator location
2445 * Returns the record that the current @iter is at.
2447 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2449 return &iter
->pg
->records
[iter
->index
];
2453 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2457 if (unlikely(ftrace_disabled
))
2460 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2462 ftrace_bug_type
= FTRACE_BUG_INIT
;
2463 ftrace_bug(ret
, rec
);
2470 * archs can override this function if they must do something
2471 * before the modifying code is performed.
2473 int __weak
ftrace_arch_code_modify_prepare(void)
2479 * archs can override this function if they must do something
2480 * after the modifying code is performed.
2482 int __weak
ftrace_arch_code_modify_post_process(void)
2487 void ftrace_modify_all_code(int command
)
2489 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2493 * If the ftrace_caller calls a ftrace_ops func directly,
2494 * we need to make sure that it only traces functions it
2495 * expects to trace. When doing the switch of functions,
2496 * we need to update to the ftrace_ops_list_func first
2497 * before the transition between old and new calls are set,
2498 * as the ftrace_ops_list_func will check the ops hashes
2499 * to make sure the ops are having the right functions
2503 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2504 if (FTRACE_WARN_ON(err
))
2508 if (command
& FTRACE_UPDATE_CALLS
)
2509 ftrace_replace_code(1);
2510 else if (command
& FTRACE_DISABLE_CALLS
)
2511 ftrace_replace_code(0);
2513 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2514 function_trace_op
= set_function_trace_op
;
2516 /* If irqs are disabled, we are in stop machine */
2517 if (!irqs_disabled())
2518 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2519 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2520 if (FTRACE_WARN_ON(err
))
2524 if (command
& FTRACE_START_FUNC_RET
)
2525 err
= ftrace_enable_ftrace_graph_caller();
2526 else if (command
& FTRACE_STOP_FUNC_RET
)
2527 err
= ftrace_disable_ftrace_graph_caller();
2528 FTRACE_WARN_ON(err
);
2531 static int __ftrace_modify_code(void *data
)
2533 int *command
= data
;
2535 ftrace_modify_all_code(*command
);
2541 * ftrace_run_stop_machine, go back to the stop machine method
2542 * @command: The command to tell ftrace what to do
2544 * If an arch needs to fall back to the stop machine method, the
2545 * it can call this function.
2547 void ftrace_run_stop_machine(int command
)
2549 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2553 * arch_ftrace_update_code, modify the code to trace or not trace
2554 * @command: The command that needs to be done
2556 * Archs can override this function if it does not need to
2557 * run stop_machine() to modify code.
2559 void __weak
arch_ftrace_update_code(int command
)
2561 ftrace_run_stop_machine(command
);
2564 static void ftrace_run_update_code(int command
)
2568 ret
= ftrace_arch_code_modify_prepare();
2569 FTRACE_WARN_ON(ret
);
2574 * By default we use stop_machine() to modify the code.
2575 * But archs can do what ever they want as long as it
2576 * is safe. The stop_machine() is the safest, but also
2577 * produces the most overhead.
2579 arch_ftrace_update_code(command
);
2581 ret
= ftrace_arch_code_modify_post_process();
2582 FTRACE_WARN_ON(ret
);
2585 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2586 struct ftrace_ops_hash
*old_hash
)
2588 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2589 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2590 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2591 ftrace_run_update_code(command
);
2592 ops
->old_hash
.filter_hash
= NULL
;
2593 ops
->old_hash
.notrace_hash
= NULL
;
2594 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2597 static ftrace_func_t saved_ftrace_func
;
2598 static int ftrace_start_up
;
2600 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2604 static void per_cpu_ops_free(struct ftrace_ops
*ops
)
2606 free_percpu(ops
->disabled
);
2609 static void ftrace_startup_enable(int command
)
2611 if (saved_ftrace_func
!= ftrace_trace_function
) {
2612 saved_ftrace_func
= ftrace_trace_function
;
2613 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2616 if (!command
|| !ftrace_enabled
)
2619 ftrace_run_update_code(command
);
2622 static void ftrace_startup_all(int command
)
2624 update_all_ops
= true;
2625 ftrace_startup_enable(command
);
2626 update_all_ops
= false;
2629 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2633 if (unlikely(ftrace_disabled
))
2636 ret
= __register_ftrace_function(ops
);
2641 command
|= FTRACE_UPDATE_CALLS
;
2644 * Note that ftrace probes uses this to start up
2645 * and modify functions it will probe. But we still
2646 * set the ADDING flag for modification, as probes
2647 * do not have trampolines. If they add them in the
2648 * future, then the probes will need to distinguish
2649 * between adding and updating probes.
2651 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2653 ret
= ftrace_hash_ipmodify_enable(ops
);
2655 /* Rollback registration process */
2656 __unregister_ftrace_function(ops
);
2658 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2662 ftrace_hash_rec_enable(ops
, 1);
2664 ftrace_startup_enable(command
);
2666 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2671 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2675 if (unlikely(ftrace_disabled
))
2678 ret
= __unregister_ftrace_function(ops
);
2684 * Just warn in case of unbalance, no need to kill ftrace, it's not
2685 * critical but the ftrace_call callers may be never nopped again after
2686 * further ftrace uses.
2688 WARN_ON_ONCE(ftrace_start_up
< 0);
2690 /* Disabling ipmodify never fails */
2691 ftrace_hash_ipmodify_disable(ops
);
2692 ftrace_hash_rec_disable(ops
, 1);
2694 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2696 command
|= FTRACE_UPDATE_CALLS
;
2698 if (saved_ftrace_func
!= ftrace_trace_function
) {
2699 saved_ftrace_func
= ftrace_trace_function
;
2700 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2703 if (!command
|| !ftrace_enabled
) {
2705 * If these are per_cpu ops, they still need their
2706 * per_cpu field freed. Since, function tracing is
2707 * not currently active, we can just free them
2708 * without synchronizing all CPUs.
2710 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2711 per_cpu_ops_free(ops
);
2716 * If the ops uses a trampoline, then it needs to be
2717 * tested first on update.
2719 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2722 /* The trampoline logic checks the old hashes */
2723 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2724 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2726 ftrace_run_update_code(command
);
2729 * If there's no more ops registered with ftrace, run a
2730 * sanity check to make sure all rec flags are cleared.
2732 if (ftrace_ops_list
== &ftrace_list_end
) {
2733 struct ftrace_page
*pg
;
2734 struct dyn_ftrace
*rec
;
2736 do_for_each_ftrace_rec(pg
, rec
) {
2737 if (FTRACE_WARN_ON_ONCE(rec
->flags
))
2738 pr_warn(" %pS flags:%lx\n",
2739 (void *)rec
->ip
, rec
->flags
);
2740 } while_for_each_ftrace_rec();
2743 ops
->old_hash
.filter_hash
= NULL
;
2744 ops
->old_hash
.notrace_hash
= NULL
;
2747 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2750 * Dynamic ops may be freed, we must make sure that all
2751 * callers are done before leaving this function.
2752 * The same goes for freeing the per_cpu data of the per_cpu
2755 * Again, normal synchronize_sched() is not good enough.
2756 * We need to do a hard force of sched synchronization.
2757 * This is because we use preempt_disable() to do RCU, but
2758 * the function tracers can be called where RCU is not watching
2759 * (like before user_exit()). We can not rely on the RCU
2760 * infrastructure to do the synchronization, thus we must do it
2763 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
)) {
2764 schedule_on_each_cpu(ftrace_sync
);
2766 arch_ftrace_trampoline_free(ops
);
2768 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2769 per_cpu_ops_free(ops
);
2775 static void ftrace_startup_sysctl(void)
2779 if (unlikely(ftrace_disabled
))
2782 /* Force update next time */
2783 saved_ftrace_func
= NULL
;
2784 /* ftrace_start_up is true if we want ftrace running */
2785 if (ftrace_start_up
) {
2786 command
= FTRACE_UPDATE_CALLS
;
2787 if (ftrace_graph_active
)
2788 command
|= FTRACE_START_FUNC_RET
;
2789 ftrace_startup_enable(command
);
2793 static void ftrace_shutdown_sysctl(void)
2797 if (unlikely(ftrace_disabled
))
2800 /* ftrace_start_up is true if ftrace is running */
2801 if (ftrace_start_up
) {
2802 command
= FTRACE_DISABLE_CALLS
;
2803 if (ftrace_graph_active
)
2804 command
|= FTRACE_STOP_FUNC_RET
;
2805 ftrace_run_update_code(command
);
2809 static cycle_t ftrace_update_time
;
2810 unsigned long ftrace_update_tot_cnt
;
2812 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2815 * Filter_hash being empty will default to trace module.
2816 * But notrace hash requires a test of individual module functions.
2818 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2819 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2823 * Check if the current ops references the record.
2825 * If the ops traces all functions, then it was already accounted for.
2826 * If the ops does not trace the current record function, skip it.
2827 * If the ops ignores the function via notrace filter, skip it.
2830 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2832 /* If ops isn't enabled, ignore it */
2833 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2836 /* If ops traces all mods, we already accounted for it */
2837 if (ops_traces_mod(ops
))
2840 /* The function must be in the filter */
2841 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2842 !ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2845 /* If in notrace hash, we ignore it too */
2846 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2852 static int referenced_filters(struct dyn_ftrace
*rec
)
2854 struct ftrace_ops
*ops
;
2857 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2858 if (ops_references_rec(ops
, rec
))
2865 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2867 struct ftrace_page
*pg
;
2868 struct dyn_ftrace
*p
;
2869 cycle_t start
, stop
;
2870 unsigned long update_cnt
= 0;
2871 unsigned long ref
= 0;
2876 * When adding a module, we need to check if tracers are
2877 * currently enabled and if they are set to trace all functions.
2878 * If they are, we need to enable the module functions as well
2879 * as update the reference counts for those function records.
2882 struct ftrace_ops
*ops
;
2884 for (ops
= ftrace_ops_list
;
2885 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2886 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
2887 if (ops_traces_mod(ops
))
2895 start
= ftrace_now(raw_smp_processor_id());
2897 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2899 for (i
= 0; i
< pg
->index
; i
++) {
2902 /* If something went wrong, bail without enabling anything */
2903 if (unlikely(ftrace_disabled
))
2906 p
= &pg
->records
[i
];
2908 cnt
+= referenced_filters(p
);
2912 * Do the initial record conversion from mcount jump
2913 * to the NOP instructions.
2915 if (!ftrace_code_disable(mod
, p
))
2921 * If the tracing is enabled, go ahead and enable the record.
2923 * The reason not to enable the record immediatelly is the
2924 * inherent check of ftrace_make_nop/ftrace_make_call for
2925 * correct previous instructions. Making first the NOP
2926 * conversion puts the module to the correct state, thus
2927 * passing the ftrace_make_call check.
2929 if (ftrace_start_up
&& cnt
) {
2930 int failed
= __ftrace_replace_code(p
, 1);
2932 ftrace_bug(failed
, p
);
2937 stop
= ftrace_now(raw_smp_processor_id());
2938 ftrace_update_time
= stop
- start
;
2939 ftrace_update_tot_cnt
+= update_cnt
;
2944 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2949 if (WARN_ON(!count
))
2952 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2955 * We want to fill as much as possible. No more than a page
2958 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2962 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2965 /* if we can't allocate this size, try something smaller */
2972 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2981 static struct ftrace_page
*
2982 ftrace_allocate_pages(unsigned long num_to_init
)
2984 struct ftrace_page
*start_pg
;
2985 struct ftrace_page
*pg
;
2992 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2997 * Try to allocate as much as possible in one continues
2998 * location that fills in all of the space. We want to
2999 * waste as little space as possible.
3002 cnt
= ftrace_allocate_records(pg
, num_to_init
);
3010 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3022 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3023 free_pages((unsigned long)pg
->records
, order
);
3024 start_pg
= pg
->next
;
3028 pr_info("ftrace: FAILED to allocate memory for functions\n");
3032 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3034 struct ftrace_iterator
{
3037 struct ftrace_page
*pg
;
3038 struct dyn_ftrace
*func
;
3039 struct ftrace_func_probe
*probe
;
3040 struct trace_parser parser
;
3041 struct ftrace_hash
*hash
;
3042 struct ftrace_ops
*ops
;
3049 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
3051 struct ftrace_iterator
*iter
= m
->private;
3052 struct hlist_node
*hnd
= NULL
;
3053 struct hlist_head
*hhd
;
3059 hnd
= &iter
->probe
->node
;
3061 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
3064 hhd
= &ftrace_func_hash
[iter
->hidx
];
3066 if (hlist_empty(hhd
)) {
3082 if (WARN_ON_ONCE(!hnd
))
3085 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
3090 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
3092 struct ftrace_iterator
*iter
= m
->private;
3096 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
3099 if (iter
->func_pos
> *pos
)
3103 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3104 p
= t_hash_next(m
, &l
);
3111 /* Only set this if we have an item */
3112 iter
->flags
|= FTRACE_ITER_HASH
;
3118 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3120 struct ftrace_func_probe
*rec
;
3123 if (WARN_ON_ONCE(!rec
))
3126 if (rec
->ops
->print
)
3127 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
3129 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
3132 seq_printf(m
, ":%p", rec
->data
);
3139 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3141 struct ftrace_iterator
*iter
= m
->private;
3142 struct ftrace_ops
*ops
= iter
->ops
;
3143 struct dyn_ftrace
*rec
= NULL
;
3145 if (unlikely(ftrace_disabled
))
3148 if (iter
->flags
& FTRACE_ITER_HASH
)
3149 return t_hash_next(m
, pos
);
3152 iter
->pos
= iter
->func_pos
= *pos
;
3154 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
3155 return t_hash_start(m
, pos
);
3158 if (iter
->idx
>= iter
->pg
->index
) {
3159 if (iter
->pg
->next
) {
3160 iter
->pg
= iter
->pg
->next
;
3165 rec
= &iter
->pg
->records
[iter
->idx
++];
3166 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
3167 !(ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))) ||
3169 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
3170 !ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
)) ||
3172 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3173 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3181 return t_hash_start(m
, pos
);
3188 static void reset_iter_read(struct ftrace_iterator
*iter
)
3192 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
3195 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3197 struct ftrace_iterator
*iter
= m
->private;
3198 struct ftrace_ops
*ops
= iter
->ops
;
3202 mutex_lock(&ftrace_lock
);
3204 if (unlikely(ftrace_disabled
))
3208 * If an lseek was done, then reset and start from beginning.
3210 if (*pos
< iter
->pos
)
3211 reset_iter_read(iter
);
3214 * For set_ftrace_filter reading, if we have the filter
3215 * off, we can short cut and just print out that all
3216 * functions are enabled.
3218 if ((iter
->flags
& FTRACE_ITER_FILTER
&&
3219 ftrace_hash_empty(ops
->func_hash
->filter_hash
)) ||
3220 (iter
->flags
& FTRACE_ITER_NOTRACE
&&
3221 ftrace_hash_empty(ops
->func_hash
->notrace_hash
))) {
3223 return t_hash_start(m
, pos
);
3224 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3225 /* reset in case of seek/pread */
3226 iter
->flags
&= ~FTRACE_ITER_HASH
;
3230 if (iter
->flags
& FTRACE_ITER_HASH
)
3231 return t_hash_start(m
, pos
);
3234 * Unfortunately, we need to restart at ftrace_pages_start
3235 * every time we let go of the ftrace_mutex. This is because
3236 * those pointers can change without the lock.
3238 iter
->pg
= ftrace_pages_start
;
3240 for (l
= 0; l
<= *pos
; ) {
3241 p
= t_next(m
, p
, &l
);
3247 return t_hash_start(m
, pos
);
3252 static void t_stop(struct seq_file
*m
, void *p
)
3254 mutex_unlock(&ftrace_lock
);
3258 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3263 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3264 struct dyn_ftrace
*rec
)
3268 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3270 seq_printf(m
, " ->%pS", ptr
);
3273 static int t_show(struct seq_file
*m
, void *v
)
3275 struct ftrace_iterator
*iter
= m
->private;
3276 struct dyn_ftrace
*rec
;
3278 if (iter
->flags
& FTRACE_ITER_HASH
)
3279 return t_hash_show(m
, iter
);
3281 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3282 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3283 seq_puts(m
, "#### no functions disabled ####\n");
3285 seq_puts(m
, "#### all functions enabled ####\n");
3294 seq_printf(m
, "%ps", (void *)rec
->ip
);
3295 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3296 struct ftrace_ops
*ops
;
3298 seq_printf(m
, " (%ld)%s%s",
3299 ftrace_rec_count(rec
),
3300 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3301 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3302 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3303 ops
= ftrace_find_tramp_ops_any(rec
);
3306 seq_printf(m
, "\ttramp: %pS (%pS)",
3307 (void *)ops
->trampoline
,
3309 add_trampoline_func(m
, ops
, rec
);
3310 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
3313 seq_puts(m
, "\ttramp: ERROR!");
3315 add_trampoline_func(m
, NULL
, rec
);
3324 static const struct seq_operations show_ftrace_seq_ops
= {
3332 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3334 struct ftrace_iterator
*iter
;
3336 if (unlikely(ftrace_disabled
))
3339 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3341 iter
->pg
= ftrace_pages_start
;
3342 iter
->ops
= &global_ops
;
3345 return iter
? 0 : -ENOMEM
;
3349 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3351 struct ftrace_iterator
*iter
;
3353 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3355 iter
->pg
= ftrace_pages_start
;
3356 iter
->flags
= FTRACE_ITER_ENABLED
;
3357 iter
->ops
= &global_ops
;
3360 return iter
? 0 : -ENOMEM
;
3364 * ftrace_regex_open - initialize function tracer filter files
3365 * @ops: The ftrace_ops that hold the hash filters
3366 * @flag: The type of filter to process
3367 * @inode: The inode, usually passed in to your open routine
3368 * @file: The file, usually passed in to your open routine
3370 * ftrace_regex_open() initializes the filter files for the
3371 * @ops. Depending on @flag it may process the filter hash or
3372 * the notrace hash of @ops. With this called from the open
3373 * routine, you can use ftrace_filter_write() for the write
3374 * routine if @flag has FTRACE_ITER_FILTER set, or
3375 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3376 * tracing_lseek() should be used as the lseek routine, and
3377 * release must call ftrace_regex_release().
3380 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3381 struct inode
*inode
, struct file
*file
)
3383 struct ftrace_iterator
*iter
;
3384 struct ftrace_hash
*hash
;
3387 ftrace_ops_init(ops
);
3389 if (unlikely(ftrace_disabled
))
3392 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3396 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3404 mutex_lock(&ops
->func_hash
->regex_lock
);
3406 if (flag
& FTRACE_ITER_NOTRACE
)
3407 hash
= ops
->func_hash
->notrace_hash
;
3409 hash
= ops
->func_hash
->filter_hash
;
3411 if (file
->f_mode
& FMODE_WRITE
) {
3412 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3414 if (file
->f_flags
& O_TRUNC
)
3415 iter
->hash
= alloc_ftrace_hash(size_bits
);
3417 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3420 trace_parser_put(&iter
->parser
);
3427 if (file
->f_mode
& FMODE_READ
) {
3428 iter
->pg
= ftrace_pages_start
;
3430 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3432 struct seq_file
*m
= file
->private_data
;
3436 free_ftrace_hash(iter
->hash
);
3437 trace_parser_put(&iter
->parser
);
3441 file
->private_data
= iter
;
3444 mutex_unlock(&ops
->func_hash
->regex_lock
);
3450 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3452 struct ftrace_ops
*ops
= inode
->i_private
;
3454 return ftrace_regex_open(ops
,
3455 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
3460 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3462 struct ftrace_ops
*ops
= inode
->i_private
;
3464 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3468 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3469 struct ftrace_glob
{
3475 static int ftrace_match(char *str
, struct ftrace_glob
*g
)
3482 if (strcmp(str
, g
->search
) == 0)
3485 case MATCH_FRONT_ONLY
:
3486 if (strncmp(str
, g
->search
, g
->len
) == 0)
3489 case MATCH_MIDDLE_ONLY
:
3490 if (strstr(str
, g
->search
))
3493 case MATCH_END_ONLY
:
3495 if (slen
>= g
->len
&&
3496 memcmp(str
+ slen
- g
->len
, g
->search
, g
->len
) == 0)
3505 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int clear_filter
)
3507 struct ftrace_func_entry
*entry
;
3510 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3512 /* Do nothing if it doesn't exist */
3516 free_hash_entry(hash
, entry
);
3518 /* Do nothing if it exists */
3522 ret
= add_hash_entry(hash
, rec
->ip
);
3528 ftrace_match_record(struct dyn_ftrace
*rec
, struct ftrace_glob
*func_g
,
3529 struct ftrace_glob
*mod_g
, int exclude_mod
)
3531 char str
[KSYM_SYMBOL_LEN
];
3534 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3537 int mod_matches
= (modname
) ? ftrace_match(modname
, mod_g
) : 0;
3539 /* blank module name to match all modules */
3541 /* blank module globbing: modname xor exclude_mod */
3542 if ((!exclude_mod
) != (!modname
))
3547 /* not matching the module */
3548 if (!modname
|| !mod_matches
) {
3555 if (mod_matches
&& exclude_mod
)
3559 /* blank search means to match all funcs in the mod */
3564 return ftrace_match(str
, func_g
);
3568 match_records(struct ftrace_hash
*hash
, char *func
, int len
, char *mod
)
3570 struct ftrace_page
*pg
;
3571 struct dyn_ftrace
*rec
;
3572 struct ftrace_glob func_g
= { .type
= MATCH_FULL
};
3573 struct ftrace_glob mod_g
= { .type
= MATCH_FULL
};
3574 struct ftrace_glob
*mod_match
= (mod
) ? &mod_g
: NULL
;
3575 int exclude_mod
= 0;
3581 func_g
.type
= filter_parse_regex(func
, len
, &func_g
.search
,
3583 func_g
.len
= strlen(func_g
.search
);
3587 mod_g
.type
= filter_parse_regex(mod
, strlen(mod
),
3588 &mod_g
.search
, &exclude_mod
);
3589 mod_g
.len
= strlen(mod_g
.search
);
3592 mutex_lock(&ftrace_lock
);
3594 if (unlikely(ftrace_disabled
))
3597 do_for_each_ftrace_rec(pg
, rec
) {
3598 if (ftrace_match_record(rec
, &func_g
, mod_match
, exclude_mod
)) {
3599 ret
= enter_record(hash
, rec
, clear_filter
);
3606 } while_for_each_ftrace_rec();
3608 mutex_unlock(&ftrace_lock
);
3614 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3616 return match_records(hash
, buff
, len
, NULL
);
3621 * We register the module command as a template to show others how
3622 * to register the a command as well.
3626 ftrace_mod_callback(struct ftrace_hash
*hash
,
3627 char *func
, char *cmd
, char *module
, int enable
)
3632 * cmd == 'mod' because we only registered this func
3633 * for the 'mod' ftrace_func_command.
3634 * But if you register one func with multiple commands,
3635 * you can tell which command was used by the cmd
3638 ret
= match_records(hash
, func
, strlen(func
), module
);
3646 static struct ftrace_func_command ftrace_mod_cmd
= {
3648 .func
= ftrace_mod_callback
,
3651 static int __init
ftrace_mod_cmd_init(void)
3653 return register_ftrace_command(&ftrace_mod_cmd
);
3655 core_initcall(ftrace_mod_cmd_init
);
3657 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3658 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3660 struct ftrace_func_probe
*entry
;
3661 struct hlist_head
*hhd
;
3664 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3666 hhd
= &ftrace_func_hash
[key
];
3668 if (hlist_empty(hhd
))
3672 * Disable preemption for these calls to prevent a RCU grace
3673 * period. This syncs the hash iteration and freeing of items
3674 * on the hash. rcu_read_lock is too dangerous here.
3676 preempt_disable_notrace();
3677 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3678 if (entry
->ip
== ip
)
3679 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3681 preempt_enable_notrace();
3684 static struct ftrace_ops trace_probe_ops __read_mostly
=
3686 .func
= function_trace_probe_call
,
3687 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3688 INIT_OPS_HASH(trace_probe_ops
)
3691 static int ftrace_probe_registered
;
3693 static void __enable_ftrace_function_probe(struct ftrace_ops_hash
*old_hash
)
3698 if (ftrace_probe_registered
) {
3699 /* still need to update the function call sites */
3701 ftrace_run_modify_code(&trace_probe_ops
, FTRACE_UPDATE_CALLS
,
3706 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3707 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3711 /* Nothing registered? */
3712 if (i
== FTRACE_FUNC_HASHSIZE
)
3715 ret
= ftrace_startup(&trace_probe_ops
, 0);
3717 ftrace_probe_registered
= 1;
3720 static void __disable_ftrace_function_probe(void)
3724 if (!ftrace_probe_registered
)
3727 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3728 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3733 /* no more funcs left */
3734 ftrace_shutdown(&trace_probe_ops
, 0);
3736 ftrace_probe_registered
= 0;
3740 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3742 if (entry
->ops
->free
)
3743 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3748 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3751 struct ftrace_ops_hash old_hash_ops
;
3752 struct ftrace_func_probe
*entry
;
3753 struct ftrace_glob func_g
;
3754 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3755 struct ftrace_hash
*old_hash
= *orig_hash
;
3756 struct ftrace_hash
*hash
;
3757 struct ftrace_page
*pg
;
3758 struct dyn_ftrace
*rec
;
3764 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
3765 &func_g
.search
, ¬);
3766 func_g
.len
= strlen(func_g
.search
);
3768 /* we do not support '!' for function probes */
3772 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3774 old_hash_ops
.filter_hash
= old_hash
;
3775 /* Probes only have filters */
3776 old_hash_ops
.notrace_hash
= NULL
;
3778 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
3784 if (unlikely(ftrace_disabled
)) {
3789 mutex_lock(&ftrace_lock
);
3791 do_for_each_ftrace_rec(pg
, rec
) {
3793 if (!ftrace_match_record(rec
, &func_g
, NULL
, 0))
3796 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3798 /* If we did not process any, then return error */
3809 * The caller might want to do something special
3810 * for each function we find. We call the callback
3811 * to give the caller an opportunity to do so.
3814 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3815 /* caller does not like this func */
3821 ret
= enter_record(hash
, rec
, 0);
3829 entry
->ip
= rec
->ip
;
3831 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3832 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3834 } while_for_each_ftrace_rec();
3836 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3838 __enable_ftrace_function_probe(&old_hash_ops
);
3841 free_ftrace_hash_rcu(old_hash
);
3846 mutex_unlock(&ftrace_lock
);
3848 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3849 free_ftrace_hash(hash
);
3855 PROBE_TEST_FUNC
= 1,
3860 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3861 void *data
, int flags
)
3863 struct ftrace_func_entry
*rec_entry
;
3864 struct ftrace_func_probe
*entry
;
3865 struct ftrace_func_probe
*p
;
3866 struct ftrace_glob func_g
;
3867 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3868 struct ftrace_hash
*old_hash
= *orig_hash
;
3869 struct list_head free_list
;
3870 struct ftrace_hash
*hash
;
3871 struct hlist_node
*tmp
;
3872 char str
[KSYM_SYMBOL_LEN
];
3875 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3876 func_g
.search
= NULL
;
3880 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
3881 &func_g
.search
, ¬);
3882 func_g
.len
= strlen(func_g
.search
);
3883 func_g
.search
= glob
;
3885 /* we do not support '!' for function probes */
3890 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3892 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3894 /* Hmm, should report this somehow */
3897 INIT_LIST_HEAD(&free_list
);
3899 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3900 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3902 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3904 /* break up if statements for readability */
3905 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3908 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3911 /* do this last, since it is the most expensive */
3912 if (func_g
.search
) {
3913 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3915 if (!ftrace_match(str
, &func_g
))
3919 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3920 /* It is possible more than one entry had this ip */
3922 free_hash_entry(hash
, rec_entry
);
3924 hlist_del_rcu(&entry
->node
);
3925 list_add(&entry
->free_list
, &free_list
);
3928 mutex_lock(&ftrace_lock
);
3929 __disable_ftrace_function_probe();
3931 * Remove after the disable is called. Otherwise, if the last
3932 * probe is removed, a null hash means *all enabled*.
3934 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3935 synchronize_sched();
3937 free_ftrace_hash_rcu(old_hash
);
3939 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3940 list_del(&entry
->free_list
);
3941 ftrace_free_entry(entry
);
3943 mutex_unlock(&ftrace_lock
);
3946 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3947 free_ftrace_hash(hash
);
3951 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3954 __unregister_ftrace_function_probe(glob
, ops
, data
,
3955 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3959 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3961 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3964 void unregister_ftrace_function_probe_all(char *glob
)
3966 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3969 static LIST_HEAD(ftrace_commands
);
3970 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3973 * Currently we only register ftrace commands from __init, so mark this
3976 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
3978 struct ftrace_func_command
*p
;
3981 mutex_lock(&ftrace_cmd_mutex
);
3982 list_for_each_entry(p
, &ftrace_commands
, list
) {
3983 if (strcmp(cmd
->name
, p
->name
) == 0) {
3988 list_add(&cmd
->list
, &ftrace_commands
);
3990 mutex_unlock(&ftrace_cmd_mutex
);
3996 * Currently we only unregister ftrace commands from __init, so mark
3999 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
4001 struct ftrace_func_command
*p
, *n
;
4004 mutex_lock(&ftrace_cmd_mutex
);
4005 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
4006 if (strcmp(cmd
->name
, p
->name
) == 0) {
4008 list_del_init(&p
->list
);
4013 mutex_unlock(&ftrace_cmd_mutex
);
4018 static int ftrace_process_regex(struct ftrace_hash
*hash
,
4019 char *buff
, int len
, int enable
)
4021 char *func
, *command
, *next
= buff
;
4022 struct ftrace_func_command
*p
;
4025 func
= strsep(&next
, ":");
4028 ret
= ftrace_match_records(hash
, func
, len
);
4038 command
= strsep(&next
, ":");
4040 mutex_lock(&ftrace_cmd_mutex
);
4041 list_for_each_entry(p
, &ftrace_commands
, list
) {
4042 if (strcmp(p
->name
, command
) == 0) {
4043 ret
= p
->func(hash
, func
, command
, next
, enable
);
4048 mutex_unlock(&ftrace_cmd_mutex
);
4054 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
4055 size_t cnt
, loff_t
*ppos
, int enable
)
4057 struct ftrace_iterator
*iter
;
4058 struct trace_parser
*parser
;
4064 if (file
->f_mode
& FMODE_READ
) {
4065 struct seq_file
*m
= file
->private_data
;
4068 iter
= file
->private_data
;
4070 if (unlikely(ftrace_disabled
))
4073 /* iter->hash is a local copy, so we don't need regex_lock */
4075 parser
= &iter
->parser
;
4076 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
4078 if (read
>= 0 && trace_parser_loaded(parser
) &&
4079 !trace_parser_cont(parser
)) {
4080 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
4081 parser
->idx
, enable
);
4082 trace_parser_clear(parser
);
4093 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
4094 size_t cnt
, loff_t
*ppos
)
4096 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
4100 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
4101 size_t cnt
, loff_t
*ppos
)
4103 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
4107 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
4109 struct ftrace_func_entry
*entry
;
4111 if (!ftrace_location(ip
))
4115 entry
= ftrace_lookup_ip(hash
, ip
);
4118 free_hash_entry(hash
, entry
);
4122 return add_hash_entry(hash
, ip
);
4125 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
4126 struct ftrace_ops_hash
*old_hash
)
4128 struct ftrace_ops
*op
;
4130 if (!ftrace_enabled
)
4133 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
4134 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
4139 * If this is the shared global_ops filter, then we need to
4140 * check if there is another ops that shares it, is enabled.
4141 * If so, we still need to run the modify code.
4143 if (ops
->func_hash
!= &global_ops
.local_hash
)
4146 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4147 if (op
->func_hash
== &global_ops
.local_hash
&&
4148 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
4149 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
4150 /* Only need to do this once */
4153 } while_for_each_ftrace_op(op
);
4157 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4158 unsigned long ip
, int remove
, int reset
, int enable
)
4160 struct ftrace_hash
**orig_hash
;
4161 struct ftrace_ops_hash old_hash_ops
;
4162 struct ftrace_hash
*old_hash
;
4163 struct ftrace_hash
*hash
;
4166 if (unlikely(ftrace_disabled
))
4169 mutex_lock(&ops
->func_hash
->regex_lock
);
4172 orig_hash
= &ops
->func_hash
->filter_hash
;
4174 orig_hash
= &ops
->func_hash
->notrace_hash
;
4177 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4179 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4183 goto out_regex_unlock
;
4186 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4188 goto out_regex_unlock
;
4191 ret
= ftrace_match_addr(hash
, ip
, remove
);
4193 goto out_regex_unlock
;
4196 mutex_lock(&ftrace_lock
);
4197 old_hash
= *orig_hash
;
4198 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
4199 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
4200 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
4202 ftrace_ops_update_code(ops
, &old_hash_ops
);
4203 free_ftrace_hash_rcu(old_hash
);
4205 mutex_unlock(&ftrace_lock
);
4208 mutex_unlock(&ops
->func_hash
->regex_lock
);
4210 free_ftrace_hash(hash
);
4215 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4216 int reset
, int enable
)
4218 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
4222 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4223 * @ops - the ops to set the filter with
4224 * @ip - the address to add to or remove from the filter.
4225 * @remove - non zero to remove the ip from the filter
4226 * @reset - non zero to reset all filters before applying this filter.
4228 * Filters denote which functions should be enabled when tracing is enabled
4229 * If @ip is NULL, it failes to update filter.
4231 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4232 int remove
, int reset
)
4234 ftrace_ops_init(ops
);
4235 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4237 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4240 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4241 int reset
, int enable
)
4243 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4247 * ftrace_set_filter - set a function to filter on in ftrace
4248 * @ops - the ops to set the filter with
4249 * @buf - the string that holds the function filter text.
4250 * @len - the length of the string.
4251 * @reset - non zero to reset all filters before applying this filter.
4253 * Filters denote which functions should be enabled when tracing is enabled.
4254 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4256 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4259 ftrace_ops_init(ops
);
4260 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4262 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4265 * ftrace_set_notrace - set a function to not trace in ftrace
4266 * @ops - the ops to set the notrace filter with
4267 * @buf - the string that holds the function notrace text.
4268 * @len - the length of the string.
4269 * @reset - non zero to reset all filters before applying this filter.
4271 * Notrace Filters denote which functions should not be enabled when tracing
4272 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4275 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4278 ftrace_ops_init(ops
);
4279 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4281 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4283 * ftrace_set_global_filter - set a function to filter on with global tracers
4284 * @buf - the string that holds the function filter text.
4285 * @len - the length of the string.
4286 * @reset - non zero to reset all filters before applying this filter.
4288 * Filters denote which functions should be enabled when tracing is enabled.
4289 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4291 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4293 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4295 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4298 * ftrace_set_global_notrace - set a function to not trace with global tracers
4299 * @buf - the string that holds the function notrace text.
4300 * @len - the length of the string.
4301 * @reset - non zero to reset all filters before applying this filter.
4303 * Notrace Filters denote which functions should not be enabled when tracing
4304 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4307 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4309 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4311 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4314 * command line interface to allow users to set filters on boot up.
4316 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4317 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4318 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4320 /* Used by function selftest to not test if filter is set */
4321 bool ftrace_filter_param __initdata
;
4323 static int __init
set_ftrace_notrace(char *str
)
4325 ftrace_filter_param
= true;
4326 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4329 __setup("ftrace_notrace=", set_ftrace_notrace
);
4331 static int __init
set_ftrace_filter(char *str
)
4333 ftrace_filter_param
= true;
4334 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4337 __setup("ftrace_filter=", set_ftrace_filter
);
4339 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4340 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4341 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4342 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
4344 static unsigned long save_global_trampoline
;
4345 static unsigned long save_global_flags
;
4347 static int __init
set_graph_function(char *str
)
4349 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4352 __setup("ftrace_graph_filter=", set_graph_function
);
4354 static int __init
set_graph_notrace_function(char *str
)
4356 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4359 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4361 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4365 unsigned long *table
= ftrace_graph_funcs
;
4366 int *count
= &ftrace_graph_count
;
4369 table
= ftrace_graph_notrace_funcs
;
4370 count
= &ftrace_graph_notrace_count
;
4374 func
= strsep(&buf
, ",");
4375 /* we allow only one expression at a time */
4376 ret
= ftrace_set_func(table
, count
, FTRACE_GRAPH_MAX_FUNCS
, func
);
4378 printk(KERN_DEBUG
"ftrace: function %s not "
4379 "traceable\n", func
);
4382 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4385 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
4389 ftrace_ops_init(ops
);
4392 func
= strsep(&buf
, ",");
4393 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
4397 static void __init
set_ftrace_early_filters(void)
4399 if (ftrace_filter_buf
[0])
4400 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4401 if (ftrace_notrace_buf
[0])
4402 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4403 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4404 if (ftrace_graph_buf
[0])
4405 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4406 if (ftrace_graph_notrace_buf
[0])
4407 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4408 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4411 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4413 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4414 struct ftrace_ops_hash old_hash_ops
;
4415 struct ftrace_iterator
*iter
;
4416 struct ftrace_hash
**orig_hash
;
4417 struct ftrace_hash
*old_hash
;
4418 struct trace_parser
*parser
;
4422 if (file
->f_mode
& FMODE_READ
) {
4424 seq_release(inode
, file
);
4426 iter
= file
->private_data
;
4428 parser
= &iter
->parser
;
4429 if (trace_parser_loaded(parser
)) {
4430 parser
->buffer
[parser
->idx
] = 0;
4431 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4434 trace_parser_put(parser
);
4436 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4438 if (file
->f_mode
& FMODE_WRITE
) {
4439 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
4442 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
4444 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
4446 mutex_lock(&ftrace_lock
);
4447 old_hash
= *orig_hash
;
4448 old_hash_ops
.filter_hash
= iter
->ops
->func_hash
->filter_hash
;
4449 old_hash_ops
.notrace_hash
= iter
->ops
->func_hash
->notrace_hash
;
4450 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
4451 orig_hash
, iter
->hash
);
4453 ftrace_ops_update_code(iter
->ops
, &old_hash_ops
);
4454 free_ftrace_hash_rcu(old_hash
);
4456 mutex_unlock(&ftrace_lock
);
4459 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
4460 free_ftrace_hash(iter
->hash
);
4466 static const struct file_operations ftrace_avail_fops
= {
4467 .open
= ftrace_avail_open
,
4469 .llseek
= seq_lseek
,
4470 .release
= seq_release_private
,
4473 static const struct file_operations ftrace_enabled_fops
= {
4474 .open
= ftrace_enabled_open
,
4476 .llseek
= seq_lseek
,
4477 .release
= seq_release_private
,
4480 static const struct file_operations ftrace_filter_fops
= {
4481 .open
= ftrace_filter_open
,
4483 .write
= ftrace_filter_write
,
4484 .llseek
= tracing_lseek
,
4485 .release
= ftrace_regex_release
,
4488 static const struct file_operations ftrace_notrace_fops
= {
4489 .open
= ftrace_notrace_open
,
4491 .write
= ftrace_notrace_write
,
4492 .llseek
= tracing_lseek
,
4493 .release
= ftrace_regex_release
,
4496 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4498 static DEFINE_MUTEX(graph_lock
);
4500 int ftrace_graph_count
;
4501 int ftrace_graph_notrace_count
;
4502 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4503 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4505 struct ftrace_graph_data
{
4506 unsigned long *table
;
4509 const struct seq_operations
*seq_ops
;
4513 __g_next(struct seq_file
*m
, loff_t
*pos
)
4515 struct ftrace_graph_data
*fgd
= m
->private;
4517 if (*pos
>= *fgd
->count
)
4519 return &fgd
->table
[*pos
];
4523 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4526 return __g_next(m
, pos
);
4529 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4531 struct ftrace_graph_data
*fgd
= m
->private;
4533 mutex_lock(&graph_lock
);
4535 /* Nothing, tell g_show to print all functions are enabled */
4536 if (!*fgd
->count
&& !*pos
)
4539 return __g_next(m
, pos
);
4542 static void g_stop(struct seq_file
*m
, void *p
)
4544 mutex_unlock(&graph_lock
);
4547 static int g_show(struct seq_file
*m
, void *v
)
4549 unsigned long *ptr
= v
;
4554 if (ptr
== (unsigned long *)1) {
4555 struct ftrace_graph_data
*fgd
= m
->private;
4557 if (fgd
->table
== ftrace_graph_funcs
)
4558 seq_puts(m
, "#### all functions enabled ####\n");
4560 seq_puts(m
, "#### no functions disabled ####\n");
4564 seq_printf(m
, "%ps\n", (void *)*ptr
);
4569 static const struct seq_operations ftrace_graph_seq_ops
= {
4577 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4578 struct ftrace_graph_data
*fgd
)
4582 mutex_lock(&graph_lock
);
4583 if ((file
->f_mode
& FMODE_WRITE
) &&
4584 (file
->f_flags
& O_TRUNC
)) {
4586 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
4588 mutex_unlock(&graph_lock
);
4590 if (file
->f_mode
& FMODE_READ
) {
4591 ret
= seq_open(file
, fgd
->seq_ops
);
4593 struct seq_file
*m
= file
->private_data
;
4597 file
->private_data
= fgd
;
4603 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4605 struct ftrace_graph_data
*fgd
;
4607 if (unlikely(ftrace_disabled
))
4610 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4614 fgd
->table
= ftrace_graph_funcs
;
4615 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4616 fgd
->count
= &ftrace_graph_count
;
4617 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4619 return __ftrace_graph_open(inode
, file
, fgd
);
4623 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4625 struct ftrace_graph_data
*fgd
;
4627 if (unlikely(ftrace_disabled
))
4630 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4634 fgd
->table
= ftrace_graph_notrace_funcs
;
4635 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4636 fgd
->count
= &ftrace_graph_notrace_count
;
4637 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4639 return __ftrace_graph_open(inode
, file
, fgd
);
4643 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
4645 if (file
->f_mode
& FMODE_READ
) {
4646 struct seq_file
*m
= file
->private_data
;
4649 seq_release(inode
, file
);
4651 kfree(file
->private_data
);
4658 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
4660 struct ftrace_glob func_g
;
4661 struct dyn_ftrace
*rec
;
4662 struct ftrace_page
*pg
;
4669 func_g
.type
= filter_parse_regex(buffer
, strlen(buffer
),
4670 &func_g
.search
, ¬);
4671 if (!not && *idx
>= size
)
4674 func_g
.len
= strlen(func_g
.search
);
4676 mutex_lock(&ftrace_lock
);
4678 if (unlikely(ftrace_disabled
)) {
4679 mutex_unlock(&ftrace_lock
);
4683 do_for_each_ftrace_rec(pg
, rec
) {
4685 if (ftrace_match_record(rec
, &func_g
, NULL
, 0)) {
4686 /* if it is in the array */
4688 for (i
= 0; i
< *idx
; i
++) {
4689 if (array
[i
] == rec
->ip
) {
4698 array
[(*idx
)++] = rec
->ip
;
4704 array
[i
] = array
[--(*idx
)];
4710 } while_for_each_ftrace_rec();
4712 mutex_unlock(&ftrace_lock
);
4721 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4722 size_t cnt
, loff_t
*ppos
)
4724 struct trace_parser parser
;
4725 ssize_t read
, ret
= 0;
4726 struct ftrace_graph_data
*fgd
= file
->private_data
;
4731 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4734 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4736 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4737 parser
.buffer
[parser
.idx
] = 0;
4739 mutex_lock(&graph_lock
);
4741 /* we allow only one expression at a time */
4742 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4745 mutex_unlock(&graph_lock
);
4751 trace_parser_put(&parser
);
4756 static const struct file_operations ftrace_graph_fops
= {
4757 .open
= ftrace_graph_open
,
4759 .write
= ftrace_graph_write
,
4760 .llseek
= tracing_lseek
,
4761 .release
= ftrace_graph_release
,
4764 static const struct file_operations ftrace_graph_notrace_fops
= {
4765 .open
= ftrace_graph_notrace_open
,
4767 .write
= ftrace_graph_write
,
4768 .llseek
= tracing_lseek
,
4769 .release
= ftrace_graph_release
,
4771 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4773 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
4774 struct dentry
*parent
)
4777 trace_create_file("set_ftrace_filter", 0644, parent
,
4778 ops
, &ftrace_filter_fops
);
4780 trace_create_file("set_ftrace_notrace", 0644, parent
,
4781 ops
, &ftrace_notrace_fops
);
4785 * The name "destroy_filter_files" is really a misnomer. Although
4786 * in the future, it may actualy delete the files, but this is
4787 * really intended to make sure the ops passed in are disabled
4788 * and that when this function returns, the caller is free to
4791 * The "destroy" name is only to match the "create" name that this
4792 * should be paired with.
4794 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
4796 mutex_lock(&ftrace_lock
);
4797 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
4798 ftrace_shutdown(ops
, 0);
4799 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
4800 mutex_unlock(&ftrace_lock
);
4803 static __init
int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
)
4806 trace_create_file("available_filter_functions", 0444,
4807 d_tracer
, NULL
, &ftrace_avail_fops
);
4809 trace_create_file("enabled_functions", 0444,
4810 d_tracer
, NULL
, &ftrace_enabled_fops
);
4812 ftrace_create_filter_files(&global_ops
, d_tracer
);
4814 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4815 trace_create_file("set_graph_function", 0444, d_tracer
,
4817 &ftrace_graph_fops
);
4818 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4820 &ftrace_graph_notrace_fops
);
4821 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4826 static int ftrace_cmp_ips(const void *a
, const void *b
)
4828 const unsigned long *ipa
= a
;
4829 const unsigned long *ipb
= b
;
4838 static int ftrace_process_locs(struct module
*mod
,
4839 unsigned long *start
,
4842 struct ftrace_page
*start_pg
;
4843 struct ftrace_page
*pg
;
4844 struct dyn_ftrace
*rec
;
4845 unsigned long count
;
4848 unsigned long flags
= 0; /* Shut up gcc */
4851 count
= end
- start
;
4856 sort(start
, count
, sizeof(*start
),
4857 ftrace_cmp_ips
, NULL
);
4859 start_pg
= ftrace_allocate_pages(count
);
4863 mutex_lock(&ftrace_lock
);
4866 * Core and each module needs their own pages, as
4867 * modules will free them when they are removed.
4868 * Force a new page to be allocated for modules.
4871 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4872 /* First initialization */
4873 ftrace_pages
= ftrace_pages_start
= start_pg
;
4878 if (WARN_ON(ftrace_pages
->next
)) {
4879 /* Hmm, we have free pages? */
4880 while (ftrace_pages
->next
)
4881 ftrace_pages
= ftrace_pages
->next
;
4884 ftrace_pages
->next
= start_pg
;
4890 addr
= ftrace_call_adjust(*p
++);
4892 * Some architecture linkers will pad between
4893 * the different mcount_loc sections of different
4894 * object files to satisfy alignments.
4895 * Skip any NULL pointers.
4900 if (pg
->index
== pg
->size
) {
4901 /* We should have allocated enough */
4902 if (WARN_ON(!pg
->next
))
4907 rec
= &pg
->records
[pg
->index
++];
4911 /* We should have used all pages */
4914 /* Assign the last page to ftrace_pages */
4918 * We only need to disable interrupts on start up
4919 * because we are modifying code that an interrupt
4920 * may execute, and the modification is not atomic.
4921 * But for modules, nothing runs the code we modify
4922 * until we are finished with it, and there's no
4923 * reason to cause large interrupt latencies while we do it.
4926 local_irq_save(flags
);
4927 ftrace_update_code(mod
, start_pg
);
4929 local_irq_restore(flags
);
4932 mutex_unlock(&ftrace_lock
);
4937 #ifdef CONFIG_MODULES
4939 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4941 void ftrace_release_mod(struct module
*mod
)
4943 struct dyn_ftrace
*rec
;
4944 struct ftrace_page
**last_pg
;
4945 struct ftrace_page
*pg
;
4948 mutex_lock(&ftrace_lock
);
4950 if (ftrace_disabled
)
4954 * Each module has its own ftrace_pages, remove
4955 * them from the list.
4957 last_pg
= &ftrace_pages_start
;
4958 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4959 rec
= &pg
->records
[0];
4960 if (within_module_core(rec
->ip
, mod
)) {
4962 * As core pages are first, the first
4963 * page should never be a module page.
4965 if (WARN_ON(pg
== ftrace_pages_start
))
4968 /* Check if we are deleting the last page */
4969 if (pg
== ftrace_pages
)
4970 ftrace_pages
= next_to_ftrace_page(last_pg
);
4972 *last_pg
= pg
->next
;
4973 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4974 free_pages((unsigned long)pg
->records
, order
);
4977 last_pg
= &pg
->next
;
4980 mutex_unlock(&ftrace_lock
);
4983 void ftrace_module_init(struct module
*mod
)
4985 unsigned long *start
= mod
->ftrace_callsites
;
4986 unsigned long *end
= mod
->ftrace_callsites
+
4987 mod
->num_ftrace_callsites
;
4989 if (ftrace_disabled
|| start
== end
)
4992 ftrace_process_locs(mod
, start
, end
);
4995 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4996 unsigned long val
, void *data
)
4998 struct module
*mod
= data
;
5000 if (val
== MODULE_STATE_GOING
)
5001 ftrace_release_mod(mod
);
5006 static int ftrace_module_notify_exit(struct notifier_block
*self
,
5007 unsigned long val
, void *data
)
5011 #endif /* CONFIG_MODULES */
5013 struct notifier_block ftrace_module_exit_nb
= {
5014 .notifier_call
= ftrace_module_notify_exit
,
5015 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
5018 void __init
ftrace_init(void)
5020 extern unsigned long __start_mcount_loc
[];
5021 extern unsigned long __stop_mcount_loc
[];
5022 unsigned long count
, flags
;
5025 local_irq_save(flags
);
5026 ret
= ftrace_dyn_arch_init();
5027 local_irq_restore(flags
);
5031 count
= __stop_mcount_loc
- __start_mcount_loc
;
5033 pr_info("ftrace: No functions to be traced?\n");
5037 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5038 count
, count
/ ENTRIES_PER_PAGE
+ 1);
5040 last_ftrace_enabled
= ftrace_enabled
= 1;
5042 ret
= ftrace_process_locs(NULL
,
5046 ret
= register_module_notifier(&ftrace_module_exit_nb
);
5048 pr_warning("Failed to register trace ftrace module exit notifier\n");
5050 set_ftrace_early_filters();
5054 ftrace_disabled
= 1;
5057 /* Do nothing if arch does not support this */
5058 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
5062 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5066 * Currently there's no safe way to free a trampoline when the kernel
5067 * is configured with PREEMPT. That is because a task could be preempted
5068 * when it jumped to the trampoline, it may be preempted for a long time
5069 * depending on the system load, and currently there's no way to know
5070 * when it will be off the trampoline. If the trampoline is freed
5071 * too early, when the task runs again, it will be executing on freed
5074 #ifdef CONFIG_PREEMPT
5075 /* Currently, only non dynamic ops can have a trampoline */
5076 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
5080 arch_ftrace_update_trampoline(ops
);
5085 static struct ftrace_ops global_ops
= {
5086 .func
= ftrace_stub
,
5087 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5088 FTRACE_OPS_FL_INITIALIZED
|
5092 static int __init
ftrace_nodyn_init(void)
5097 core_initcall(ftrace_nodyn_init
);
5099 static inline int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
) { return 0; }
5100 static inline void ftrace_startup_enable(int command
) { }
5101 static inline void ftrace_startup_all(int command
) { }
5102 /* Keep as macros so we do not need to define the commands */
5103 # define ftrace_startup(ops, command) \
5105 int ___ret = __register_ftrace_function(ops); \
5107 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5110 # define ftrace_shutdown(ops, command) \
5112 int ___ret = __unregister_ftrace_function(ops); \
5114 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5118 # define ftrace_startup_sysctl() do { } while (0)
5119 # define ftrace_shutdown_sysctl() do { } while (0)
5122 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
5127 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5131 #endif /* CONFIG_DYNAMIC_FTRACE */
5133 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
5135 tr
->ops
= &global_ops
;
5136 tr
->ops
->private = tr
;
5139 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
5141 /* If we filter on pids, update to use the pid function */
5142 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
5143 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
5144 printk("ftrace ops had %pS for function\n",
5147 tr
->ops
->func
= func
;
5148 tr
->ops
->private = tr
;
5151 void ftrace_reset_array_ops(struct trace_array
*tr
)
5153 tr
->ops
->func
= ftrace_stub
;
5157 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5158 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
5160 struct ftrace_ops
*op
;
5163 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5168 * Some of the ops may be dynamically allocated,
5169 * they must be freed after a synchronize_sched().
5171 preempt_disable_notrace();
5173 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5175 * Check the following for each ops before calling their func:
5176 * if RCU flag is set, then rcu_is_watching() must be true
5177 * if PER_CPU is set, then ftrace_function_local_disable()
5179 * Otherwise test if the ip matches the ops filter
5181 * If any of the above fails then the op->func() is not executed.
5183 if ((!(op
->flags
& FTRACE_OPS_FL_RCU
) || rcu_is_watching()) &&
5184 (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5185 !ftrace_function_local_disabled(op
)) &&
5186 ftrace_ops_test(op
, ip
, regs
)) {
5188 if (FTRACE_WARN_ON(!op
->func
)) {
5189 pr_warn("op=%p %pS\n", op
, op
);
5192 op
->func(ip
, parent_ip
, op
, regs
);
5194 } while_for_each_ftrace_op(op
);
5196 preempt_enable_notrace();
5197 trace_clear_recursion(bit
);
5201 * Some archs only support passing ip and parent_ip. Even though
5202 * the list function ignores the op parameter, we do not want any
5203 * C side effects, where a function is called without the caller
5204 * sending a third parameter.
5205 * Archs are to support both the regs and ftrace_ops at the same time.
5206 * If they support ftrace_ops, it is assumed they support regs.
5207 * If call backs want to use regs, they must either check for regs
5208 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5209 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5210 * An architecture can pass partial regs with ftrace_ops and still
5211 * set the ARCH_SUPPORTS_FTRACE_OPS.
5213 #if ARCH_SUPPORTS_FTRACE_OPS
5214 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5215 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5217 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
5220 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
5222 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
5227 * If there's only one function registered but it does not support
5228 * recursion, needs RCU protection and/or requires per cpu handling, then
5229 * this function will be called by the mcount trampoline.
5231 static void ftrace_ops_assist_func(unsigned long ip
, unsigned long parent_ip
,
5232 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5236 if ((op
->flags
& FTRACE_OPS_FL_RCU
) && !rcu_is_watching())
5239 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5243 preempt_disable_notrace();
5245 if (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5246 !ftrace_function_local_disabled(op
)) {
5247 op
->func(ip
, parent_ip
, op
, regs
);
5250 preempt_enable_notrace();
5251 trace_clear_recursion(bit
);
5255 * ftrace_ops_get_func - get the function a trampoline should call
5256 * @ops: the ops to get the function for
5258 * Normally the mcount trampoline will call the ops->func, but there
5259 * are times that it should not. For example, if the ops does not
5260 * have its own recursion protection, then it should call the
5261 * ftrace_ops_recurs_func() instead.
5263 * Returns the function that the trampoline should call for @ops.
5265 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
5268 * If the function does not handle recursion, needs to be RCU safe,
5269 * or does per cpu logic, then we need to call the assist handler.
5271 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) ||
5272 ops
->flags
& (FTRACE_OPS_FL_RCU
| FTRACE_OPS_FL_PER_CPU
))
5273 return ftrace_ops_assist_func
;
5278 static void clear_ftrace_swapper(void)
5280 struct task_struct
*p
;
5284 for_each_online_cpu(cpu
) {
5286 clear_tsk_trace_trace(p
);
5291 static void set_ftrace_swapper(void)
5293 struct task_struct
*p
;
5297 for_each_online_cpu(cpu
) {
5299 set_tsk_trace_trace(p
);
5304 static void clear_ftrace_pid(struct pid
*pid
)
5306 struct task_struct
*p
;
5309 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
5310 clear_tsk_trace_trace(p
);
5311 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
5317 static void set_ftrace_pid(struct pid
*pid
)
5319 struct task_struct
*p
;
5322 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
5323 set_tsk_trace_trace(p
);
5324 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
5328 static void clear_ftrace_pid_task(struct pid
*pid
)
5330 if (pid
== ftrace_swapper_pid
)
5331 clear_ftrace_swapper();
5333 clear_ftrace_pid(pid
);
5336 static void set_ftrace_pid_task(struct pid
*pid
)
5338 if (pid
== ftrace_swapper_pid
)
5339 set_ftrace_swapper();
5341 set_ftrace_pid(pid
);
5344 static int ftrace_pid_add(int p
)
5347 struct ftrace_pid
*fpid
;
5350 mutex_lock(&ftrace_lock
);
5353 pid
= ftrace_swapper_pid
;
5355 pid
= find_get_pid(p
);
5362 list_for_each_entry(fpid
, &ftrace_pids
, list
)
5363 if (fpid
->pid
== pid
)
5368 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
5372 list_add(&fpid
->list
, &ftrace_pids
);
5375 set_ftrace_pid_task(pid
);
5377 ftrace_update_pid_func();
5379 ftrace_startup_all(0);
5381 mutex_unlock(&ftrace_lock
);
5385 if (pid
!= ftrace_swapper_pid
)
5389 mutex_unlock(&ftrace_lock
);
5393 static void ftrace_pid_reset(void)
5395 struct ftrace_pid
*fpid
, *safe
;
5397 mutex_lock(&ftrace_lock
);
5398 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
5399 struct pid
*pid
= fpid
->pid
;
5401 clear_ftrace_pid_task(pid
);
5403 list_del(&fpid
->list
);
5407 ftrace_update_pid_func();
5408 ftrace_startup_all(0);
5410 mutex_unlock(&ftrace_lock
);
5413 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
5415 mutex_lock(&ftrace_lock
);
5417 if (!ftrace_pids_enabled() && (!*pos
))
5420 return seq_list_start(&ftrace_pids
, *pos
);
5423 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5428 return seq_list_next(v
, &ftrace_pids
, pos
);
5431 static void fpid_stop(struct seq_file
*m
, void *p
)
5433 mutex_unlock(&ftrace_lock
);
5436 static int fpid_show(struct seq_file
*m
, void *v
)
5438 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
5440 if (v
== (void *)1) {
5441 seq_puts(m
, "no pid\n");
5445 if (fpid
->pid
== ftrace_swapper_pid
)
5446 seq_puts(m
, "swapper tasks\n");
5448 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
5453 static const struct seq_operations ftrace_pid_sops
= {
5454 .start
= fpid_start
,
5461 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
5465 if ((file
->f_mode
& FMODE_WRITE
) &&
5466 (file
->f_flags
& O_TRUNC
))
5469 if (file
->f_mode
& FMODE_READ
)
5470 ret
= seq_open(file
, &ftrace_pid_sops
);
5476 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
5477 size_t cnt
, loff_t
*ppos
)
5483 if (cnt
>= sizeof(buf
))
5486 if (copy_from_user(&buf
, ubuf
, cnt
))
5492 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5493 * to clean the filter quietly.
5495 tmp
= strstrip(buf
);
5496 if (strlen(tmp
) == 0)
5499 ret
= kstrtol(tmp
, 10, &val
);
5503 ret
= ftrace_pid_add(val
);
5505 return ret
? ret
: cnt
;
5509 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
5511 if (file
->f_mode
& FMODE_READ
)
5512 seq_release(inode
, file
);
5517 static const struct file_operations ftrace_pid_fops
= {
5518 .open
= ftrace_pid_open
,
5519 .write
= ftrace_pid_write
,
5521 .llseek
= tracing_lseek
,
5522 .release
= ftrace_pid_release
,
5525 static __init
int ftrace_init_tracefs(void)
5527 struct dentry
*d_tracer
;
5529 d_tracer
= tracing_init_dentry();
5530 if (IS_ERR(d_tracer
))
5533 ftrace_init_dyn_tracefs(d_tracer
);
5535 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
5536 NULL
, &ftrace_pid_fops
);
5538 ftrace_profile_tracefs(d_tracer
);
5542 fs_initcall(ftrace_init_tracefs
);
5545 * ftrace_kill - kill ftrace
5547 * This function should be used by panic code. It stops ftrace
5548 * but in a not so nice way. If you need to simply kill ftrace
5549 * from a non-atomic section, use ftrace_kill.
5551 void ftrace_kill(void)
5553 ftrace_disabled
= 1;
5555 clear_ftrace_function();
5559 * Test if ftrace is dead or not.
5561 int ftrace_is_dead(void)
5563 return ftrace_disabled
;
5567 * register_ftrace_function - register a function for profiling
5568 * @ops - ops structure that holds the function for profiling.
5570 * Register a function to be called by all functions in the
5573 * Note: @ops->func and all the functions it calls must be labeled
5574 * with "notrace", otherwise it will go into a
5577 int register_ftrace_function(struct ftrace_ops
*ops
)
5581 ftrace_ops_init(ops
);
5583 mutex_lock(&ftrace_lock
);
5585 ret
= ftrace_startup(ops
, 0);
5587 mutex_unlock(&ftrace_lock
);
5591 EXPORT_SYMBOL_GPL(register_ftrace_function
);
5594 * unregister_ftrace_function - unregister a function for profiling.
5595 * @ops - ops structure that holds the function to unregister
5597 * Unregister a function that was added to be called by ftrace profiling.
5599 int unregister_ftrace_function(struct ftrace_ops
*ops
)
5603 mutex_lock(&ftrace_lock
);
5604 ret
= ftrace_shutdown(ops
, 0);
5605 mutex_unlock(&ftrace_lock
);
5609 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
5612 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
5613 void __user
*buffer
, size_t *lenp
,
5618 mutex_lock(&ftrace_lock
);
5620 if (unlikely(ftrace_disabled
))
5623 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
5625 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
5628 last_ftrace_enabled
= !!ftrace_enabled
;
5630 if (ftrace_enabled
) {
5632 /* we are starting ftrace again */
5633 if (ftrace_ops_list
!= &ftrace_list_end
)
5634 update_ftrace_function();
5636 ftrace_startup_sysctl();
5639 /* stopping ftrace calls (just send to ftrace_stub) */
5640 ftrace_trace_function
= ftrace_stub
;
5642 ftrace_shutdown_sysctl();
5646 mutex_unlock(&ftrace_lock
);
5650 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5652 static struct ftrace_ops graph_ops
= {
5653 .func
= ftrace_stub
,
5654 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5655 FTRACE_OPS_FL_INITIALIZED
|
5658 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5659 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
5660 /* trampoline_size is only needed for dynamically allocated tramps */
5662 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
5665 void ftrace_graph_sleep_time_control(bool enable
)
5667 fgraph_sleep_time
= enable
;
5670 void ftrace_graph_graph_time_control(bool enable
)
5672 fgraph_graph_time
= enable
;
5675 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
5680 /* The callbacks that hook a function */
5681 trace_func_graph_ret_t ftrace_graph_return
=
5682 (trace_func_graph_ret_t
)ftrace_stub
;
5683 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
5684 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5686 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5687 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
5691 unsigned long flags
;
5692 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
5693 struct task_struct
*g
, *t
;
5695 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
5696 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
5697 * sizeof(struct ftrace_ret_stack
),
5699 if (!ret_stack_list
[i
]) {
5707 read_lock_irqsave(&tasklist_lock
, flags
);
5708 do_each_thread(g
, t
) {
5714 if (t
->ret_stack
== NULL
) {
5715 atomic_set(&t
->tracing_graph_pause
, 0);
5716 atomic_set(&t
->trace_overrun
, 0);
5717 t
->curr_ret_stack
= -1;
5718 /* Make sure the tasks see the -1 first: */
5720 t
->ret_stack
= ret_stack_list
[start
++];
5722 } while_each_thread(g
, t
);
5725 read_unlock_irqrestore(&tasklist_lock
, flags
);
5727 for (i
= start
; i
< end
; i
++)
5728 kfree(ret_stack_list
[i
]);
5733 ftrace_graph_probe_sched_switch(void *ignore
, bool preempt
,
5734 struct task_struct
*prev
, struct task_struct
*next
)
5736 unsigned long long timestamp
;
5740 * Does the user want to count the time a function was asleep.
5741 * If so, do not update the time stamps.
5743 if (fgraph_sleep_time
)
5746 timestamp
= trace_clock_local();
5748 prev
->ftrace_timestamp
= timestamp
;
5750 /* only process tasks that we timestamped */
5751 if (!next
->ftrace_timestamp
)
5755 * Update all the counters in next to make up for the
5756 * time next was sleeping.
5758 timestamp
-= next
->ftrace_timestamp
;
5760 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
5761 next
->ret_stack
[index
].calltime
+= timestamp
;
5764 /* Allocate a return stack for each task */
5765 static int start_graph_tracing(void)
5767 struct ftrace_ret_stack
**ret_stack_list
;
5770 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
5771 sizeof(struct ftrace_ret_stack
*),
5774 if (!ret_stack_list
)
5777 /* The cpu_boot init_task->ret_stack will never be freed */
5778 for_each_online_cpu(cpu
) {
5779 if (!idle_task(cpu
)->ret_stack
)
5780 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
5784 ret
= alloc_retstack_tasklist(ret_stack_list
);
5785 } while (ret
== -EAGAIN
);
5788 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5790 pr_info("ftrace_graph: Couldn't activate tracepoint"
5791 " probe to kernel_sched_switch\n");
5794 kfree(ret_stack_list
);
5799 * Hibernation protection.
5800 * The state of the current task is too much unstable during
5801 * suspend/restore to disk. We want to protect against that.
5804 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
5808 case PM_HIBERNATION_PREPARE
:
5809 pause_graph_tracing();
5812 case PM_POST_HIBERNATION
:
5813 unpause_graph_tracing();
5819 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
5821 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
5823 return __ftrace_graph_entry(trace
);
5827 * The function graph tracer should only trace the functions defined
5828 * by set_ftrace_filter and set_ftrace_notrace. If another function
5829 * tracer ops is registered, the graph tracer requires testing the
5830 * function against the global ops, and not just trace any function
5831 * that any ftrace_ops registered.
5833 static void update_function_graph_func(void)
5835 struct ftrace_ops
*op
;
5836 bool do_test
= false;
5839 * The graph and global ops share the same set of functions
5840 * to test. If any other ops is on the list, then
5841 * the graph tracing needs to test if its the function
5844 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5845 if (op
!= &global_ops
&& op
!= &graph_ops
&&
5846 op
!= &ftrace_list_end
) {
5848 /* in double loop, break out with goto */
5851 } while_for_each_ftrace_op(op
);
5854 ftrace_graph_entry
= ftrace_graph_entry_test
;
5856 ftrace_graph_entry
= __ftrace_graph_entry
;
5859 static struct notifier_block ftrace_suspend_notifier
= {
5860 .notifier_call
= ftrace_suspend_notifier_call
,
5863 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5864 trace_func_graph_ent_t entryfunc
)
5868 mutex_lock(&ftrace_lock
);
5870 /* we currently allow only one tracer registered at a time */
5871 if (ftrace_graph_active
) {
5876 register_pm_notifier(&ftrace_suspend_notifier
);
5878 ftrace_graph_active
++;
5879 ret
= start_graph_tracing();
5881 ftrace_graph_active
--;
5885 ftrace_graph_return
= retfunc
;
5888 * Update the indirect function to the entryfunc, and the
5889 * function that gets called to the entry_test first. Then
5890 * call the update fgraph entry function to determine if
5891 * the entryfunc should be called directly or not.
5893 __ftrace_graph_entry
= entryfunc
;
5894 ftrace_graph_entry
= ftrace_graph_entry_test
;
5895 update_function_graph_func();
5897 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
5899 mutex_unlock(&ftrace_lock
);
5903 void unregister_ftrace_graph(void)
5905 mutex_lock(&ftrace_lock
);
5907 if (unlikely(!ftrace_graph_active
))
5910 ftrace_graph_active
--;
5911 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5912 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5913 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5914 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
5915 unregister_pm_notifier(&ftrace_suspend_notifier
);
5916 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5918 #ifdef CONFIG_DYNAMIC_FTRACE
5920 * Function graph does not allocate the trampoline, but
5921 * other global_ops do. We need to reset the ALLOC_TRAMP flag
5924 global_ops
.trampoline
= save_global_trampoline
;
5925 if (save_global_flags
& FTRACE_OPS_FL_ALLOC_TRAMP
)
5926 global_ops
.flags
|= FTRACE_OPS_FL_ALLOC_TRAMP
;
5930 mutex_unlock(&ftrace_lock
);
5933 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5936 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5938 atomic_set(&t
->tracing_graph_pause
, 0);
5939 atomic_set(&t
->trace_overrun
, 0);
5940 t
->ftrace_timestamp
= 0;
5941 /* make curr_ret_stack visible before we add the ret_stack */
5943 t
->ret_stack
= ret_stack
;
5947 * Allocate a return stack for the idle task. May be the first
5948 * time through, or it may be done by CPU hotplug online.
5950 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5952 t
->curr_ret_stack
= -1;
5954 * The idle task has no parent, it either has its own
5955 * stack or no stack at all.
5958 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5960 if (ftrace_graph_active
) {
5961 struct ftrace_ret_stack
*ret_stack
;
5963 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5965 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5966 * sizeof(struct ftrace_ret_stack
),
5970 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
5972 graph_init_task(t
, ret_stack
);
5976 /* Allocate a return stack for newly created task */
5977 void ftrace_graph_init_task(struct task_struct
*t
)
5979 /* Make sure we do not use the parent ret_stack */
5980 t
->ret_stack
= NULL
;
5981 t
->curr_ret_stack
= -1;
5983 if (ftrace_graph_active
) {
5984 struct ftrace_ret_stack
*ret_stack
;
5986 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5987 * sizeof(struct ftrace_ret_stack
),
5991 graph_init_task(t
, ret_stack
);
5995 void ftrace_graph_exit_task(struct task_struct
*t
)
5997 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
5999 t
->ret_stack
= NULL
;
6000 /* NULL must become visible to IRQs before we free it: */