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 static bool ftrace_pids_enabled(struct ftrace_ops
*ops
)
94 struct trace_array
*tr
;
96 if (!(ops
->flags
& FTRACE_OPS_FL_PID
) || !ops
->private)
101 return tr
->function_pids
!= NULL
;
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 struct trace_array
*tr
= op
->private;
184 if (tr
&& this_cpu_read(tr
->trace_buffer
.data
->ftrace_ignore_pid
))
187 op
->saved_func(ip
, parent_ip
, op
, regs
);
191 * clear_ftrace_function - reset the ftrace function
193 * This NULLs the ftrace function and in essence stops
194 * tracing. There may be lag
196 void clear_ftrace_function(void)
198 ftrace_trace_function
= ftrace_stub
;
201 static void per_cpu_ops_disable_all(struct ftrace_ops
*ops
)
205 for_each_possible_cpu(cpu
)
206 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
209 static int per_cpu_ops_alloc(struct ftrace_ops
*ops
)
211 int __percpu
*disabled
;
213 if (WARN_ON_ONCE(!(ops
->flags
& FTRACE_OPS_FL_PER_CPU
)))
216 disabled
= alloc_percpu(int);
220 ops
->disabled
= disabled
;
221 per_cpu_ops_disable_all(ops
);
225 static void ftrace_sync(struct work_struct
*work
)
228 * This function is just a stub to implement a hard force
229 * of synchronize_sched(). This requires synchronizing
230 * tasks even in userspace and idle.
232 * Yes, function tracing is rude.
236 static void ftrace_sync_ipi(void *data
)
238 /* Probably not needed, but do it anyway */
242 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
243 static void update_function_graph_func(void);
245 /* Both enabled by default (can be cleared by function_graph tracer flags */
246 static bool fgraph_sleep_time
= true;
247 static bool fgraph_graph_time
= true;
250 static inline void update_function_graph_func(void) { }
254 static ftrace_func_t
ftrace_ops_get_list_func(struct ftrace_ops
*ops
)
257 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
258 * then it needs to call the list anyway.
260 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
|
261 FTRACE_OPS_FL_RCU
) || FTRACE_FORCE_LIST_FUNC
)
262 return ftrace_ops_list_func
;
264 return ftrace_ops_get_func(ops
);
267 static void update_ftrace_function(void)
272 * Prepare the ftrace_ops that the arch callback will use.
273 * If there's only one ftrace_ops registered, the ftrace_ops_list
274 * will point to the ops we want.
276 set_function_trace_op
= ftrace_ops_list
;
278 /* If there's no ftrace_ops registered, just call the stub function */
279 if (ftrace_ops_list
== &ftrace_list_end
) {
283 * If we are at the end of the list and this ops is
284 * recursion safe and not dynamic and the arch supports passing ops,
285 * then have the mcount trampoline call the function directly.
287 } else if (ftrace_ops_list
->next
== &ftrace_list_end
) {
288 func
= ftrace_ops_get_list_func(ftrace_ops_list
);
291 /* Just use the default ftrace_ops */
292 set_function_trace_op
= &ftrace_list_end
;
293 func
= ftrace_ops_list_func
;
296 update_function_graph_func();
298 /* If there's no change, then do nothing more here */
299 if (ftrace_trace_function
== func
)
303 * If we are using the list function, it doesn't care
304 * about the function_trace_ops.
306 if (func
== ftrace_ops_list_func
) {
307 ftrace_trace_function
= func
;
309 * Don't even bother setting function_trace_ops,
310 * it would be racy to do so anyway.
315 #ifndef CONFIG_DYNAMIC_FTRACE
317 * For static tracing, we need to be a bit more careful.
318 * The function change takes affect immediately. Thus,
319 * we need to coorditate the setting of the function_trace_ops
320 * with the setting of the ftrace_trace_function.
322 * Set the function to the list ops, which will call the
323 * function we want, albeit indirectly, but it handles the
324 * ftrace_ops and doesn't depend on function_trace_op.
326 ftrace_trace_function
= ftrace_ops_list_func
;
328 * Make sure all CPUs see this. Yes this is slow, but static
329 * tracing is slow and nasty to have enabled.
331 schedule_on_each_cpu(ftrace_sync
);
332 /* Now all cpus are using the list ops. */
333 function_trace_op
= set_function_trace_op
;
334 /* Make sure the function_trace_op is visible on all CPUs */
336 /* Nasty way to force a rmb on all cpus */
337 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
338 /* OK, we are all set to update the ftrace_trace_function now! */
339 #endif /* !CONFIG_DYNAMIC_FTRACE */
341 ftrace_trace_function
= func
;
344 int using_ftrace_ops_list_func(void)
346 return ftrace_trace_function
== ftrace_ops_list_func
;
349 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
353 * We are entering ops into the list but another
354 * CPU might be walking that list. We need to make sure
355 * the ops->next pointer is valid before another CPU sees
356 * the ops pointer included into the list.
358 rcu_assign_pointer(*list
, ops
);
361 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
363 struct ftrace_ops
**p
;
366 * If we are removing the last function, then simply point
367 * to the ftrace_stub.
369 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
370 *list
= &ftrace_list_end
;
374 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
385 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
387 static int __register_ftrace_function(struct ftrace_ops
*ops
)
389 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
392 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
395 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
397 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
398 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
399 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
401 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
402 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
405 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
406 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
409 if (!core_kernel_data((unsigned long)ops
))
410 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
412 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
) {
413 if (per_cpu_ops_alloc(ops
))
417 add_ftrace_ops(&ftrace_ops_list
, ops
);
419 /* Always save the function, and reset at unregistering */
420 ops
->saved_func
= ops
->func
;
422 if (ftrace_pids_enabled(ops
))
423 ops
->func
= ftrace_pid_func
;
425 ftrace_update_trampoline(ops
);
428 update_ftrace_function();
433 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
437 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
440 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
446 update_ftrace_function();
448 ops
->func
= ops
->saved_func
;
453 static void ftrace_update_pid_func(void)
455 struct ftrace_ops
*op
;
457 /* Only do something if we are tracing something */
458 if (ftrace_trace_function
== ftrace_stub
)
461 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
462 if (op
->flags
& FTRACE_OPS_FL_PID
) {
463 op
->func
= ftrace_pids_enabled(op
) ?
464 ftrace_pid_func
: op
->saved_func
;
465 ftrace_update_trampoline(op
);
467 } while_for_each_ftrace_op(op
);
469 update_ftrace_function();
472 #ifdef CONFIG_FUNCTION_PROFILER
473 struct ftrace_profile
{
474 struct hlist_node node
;
476 unsigned long counter
;
477 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
478 unsigned long long time
;
479 unsigned long long time_squared
;
483 struct ftrace_profile_page
{
484 struct ftrace_profile_page
*next
;
486 struct ftrace_profile records
[];
489 struct ftrace_profile_stat
{
491 struct hlist_head
*hash
;
492 struct ftrace_profile_page
*pages
;
493 struct ftrace_profile_page
*start
;
494 struct tracer_stat stat
;
497 #define PROFILE_RECORDS_SIZE \
498 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
500 #define PROFILES_PER_PAGE \
501 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
503 static int ftrace_profile_enabled __read_mostly
;
505 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
506 static DEFINE_MUTEX(ftrace_profile_lock
);
508 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
510 #define FTRACE_PROFILE_HASH_BITS 10
511 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
514 function_stat_next(void *v
, int idx
)
516 struct ftrace_profile
*rec
= v
;
517 struct ftrace_profile_page
*pg
;
519 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
525 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
529 rec
= &pg
->records
[0];
537 static void *function_stat_start(struct tracer_stat
*trace
)
539 struct ftrace_profile_stat
*stat
=
540 container_of(trace
, struct ftrace_profile_stat
, stat
);
542 if (!stat
|| !stat
->start
)
545 return function_stat_next(&stat
->start
->records
[0], 0);
548 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
549 /* function graph compares on total time */
550 static int function_stat_cmp(void *p1
, void *p2
)
552 struct ftrace_profile
*a
= p1
;
553 struct ftrace_profile
*b
= p2
;
555 if (a
->time
< b
->time
)
557 if (a
->time
> b
->time
)
563 /* not function graph compares against hits */
564 static int function_stat_cmp(void *p1
, void *p2
)
566 struct ftrace_profile
*a
= p1
;
567 struct ftrace_profile
*b
= p2
;
569 if (a
->counter
< b
->counter
)
571 if (a
->counter
> b
->counter
)
578 static int function_stat_headers(struct seq_file
*m
)
580 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
581 seq_puts(m
, " Function "
584 "--- ---- --- ---\n");
586 seq_puts(m
, " Function Hit\n"
592 static int function_stat_show(struct seq_file
*m
, void *v
)
594 struct ftrace_profile
*rec
= v
;
595 char str
[KSYM_SYMBOL_LEN
];
597 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
598 static struct trace_seq s
;
599 unsigned long long avg
;
600 unsigned long long stddev
;
602 mutex_lock(&ftrace_profile_lock
);
604 /* we raced with function_profile_reset() */
605 if (unlikely(rec
->counter
== 0)) {
610 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
612 do_div(avg
, rec
->counter
);
613 if (tracing_thresh
&& (avg
< tracing_thresh
))
617 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
618 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
620 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
623 /* Sample standard deviation (s^2) */
624 if (rec
->counter
<= 1)
628 * Apply Welford's method:
629 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
631 stddev
= rec
->counter
* rec
->time_squared
-
632 rec
->time
* rec
->time
;
635 * Divide only 1000 for ns^2 -> us^2 conversion.
636 * trace_print_graph_duration will divide 1000 again.
638 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
642 trace_print_graph_duration(rec
->time
, &s
);
643 trace_seq_puts(&s
, " ");
644 trace_print_graph_duration(avg
, &s
);
645 trace_seq_puts(&s
, " ");
646 trace_print_graph_duration(stddev
, &s
);
647 trace_print_seq(m
, &s
);
651 mutex_unlock(&ftrace_profile_lock
);
656 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
658 struct ftrace_profile_page
*pg
;
660 pg
= stat
->pages
= stat
->start
;
663 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
668 memset(stat
->hash
, 0,
669 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
672 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
674 struct ftrace_profile_page
*pg
;
679 /* If we already allocated, do nothing */
683 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
687 #ifdef CONFIG_DYNAMIC_FTRACE
688 functions
= ftrace_update_tot_cnt
;
691 * We do not know the number of functions that exist because
692 * dynamic tracing is what counts them. With past experience
693 * we have around 20K functions. That should be more than enough.
694 * It is highly unlikely we will execute every function in
700 pg
= stat
->start
= stat
->pages
;
702 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
704 for (i
= 1; i
< pages
; i
++) {
705 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
716 unsigned long tmp
= (unsigned long)pg
;
728 static int ftrace_profile_init_cpu(int cpu
)
730 struct ftrace_profile_stat
*stat
;
733 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
736 /* If the profile is already created, simply reset it */
737 ftrace_profile_reset(stat
);
742 * We are profiling all functions, but usually only a few thousand
743 * functions are hit. We'll make a hash of 1024 items.
745 size
= FTRACE_PROFILE_HASH_SIZE
;
747 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
752 /* Preallocate the function profiling pages */
753 if (ftrace_profile_pages_init(stat
) < 0) {
762 static int ftrace_profile_init(void)
767 for_each_possible_cpu(cpu
) {
768 ret
= ftrace_profile_init_cpu(cpu
);
776 /* interrupts must be disabled */
777 static struct ftrace_profile
*
778 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
780 struct ftrace_profile
*rec
;
781 struct hlist_head
*hhd
;
784 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
785 hhd
= &stat
->hash
[key
];
787 if (hlist_empty(hhd
))
790 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
798 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
799 struct ftrace_profile
*rec
)
803 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
804 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
808 * The memory is already allocated, this simply finds a new record to use.
810 static struct ftrace_profile
*
811 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
813 struct ftrace_profile
*rec
= NULL
;
815 /* prevent recursion (from NMIs) */
816 if (atomic_inc_return(&stat
->disabled
) != 1)
820 * Try to find the function again since an NMI
821 * could have added it
823 rec
= ftrace_find_profiled_func(stat
, ip
);
827 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
828 if (!stat
->pages
->next
)
830 stat
->pages
= stat
->pages
->next
;
833 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
835 ftrace_add_profile(stat
, rec
);
838 atomic_dec(&stat
->disabled
);
844 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
845 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
847 struct ftrace_profile_stat
*stat
;
848 struct ftrace_profile
*rec
;
851 if (!ftrace_profile_enabled
)
854 local_irq_save(flags
);
856 stat
= this_cpu_ptr(&ftrace_profile_stats
);
857 if (!stat
->hash
|| !ftrace_profile_enabled
)
860 rec
= ftrace_find_profiled_func(stat
, ip
);
862 rec
= ftrace_profile_alloc(stat
, ip
);
869 local_irq_restore(flags
);
872 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
873 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
875 int index
= trace
->depth
;
877 function_profile_call(trace
->func
, 0, NULL
, NULL
);
879 if (index
>= 0 && index
< FTRACE_RETFUNC_DEPTH
)
880 current
->ret_stack
[index
].subtime
= 0;
885 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
887 struct ftrace_profile_stat
*stat
;
888 unsigned long long calltime
;
889 struct ftrace_profile
*rec
;
892 local_irq_save(flags
);
893 stat
= this_cpu_ptr(&ftrace_profile_stats
);
894 if (!stat
->hash
|| !ftrace_profile_enabled
)
897 /* If the calltime was zero'd ignore it */
898 if (!trace
->calltime
)
901 calltime
= trace
->rettime
- trace
->calltime
;
903 if (!fgraph_graph_time
) {
906 index
= trace
->depth
;
908 /* Append this call time to the parent time to subtract */
910 current
->ret_stack
[index
- 1].subtime
+= calltime
;
912 if (current
->ret_stack
[index
].subtime
< calltime
)
913 calltime
-= current
->ret_stack
[index
].subtime
;
918 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
920 rec
->time
+= calltime
;
921 rec
->time_squared
+= calltime
* calltime
;
925 local_irq_restore(flags
);
928 static int register_ftrace_profiler(void)
930 return register_ftrace_graph(&profile_graph_return
,
931 &profile_graph_entry
);
934 static void unregister_ftrace_profiler(void)
936 unregister_ftrace_graph();
939 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
940 .func
= function_profile_call
,
941 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
942 INIT_OPS_HASH(ftrace_profile_ops
)
945 static int register_ftrace_profiler(void)
947 return register_ftrace_function(&ftrace_profile_ops
);
950 static void unregister_ftrace_profiler(void)
952 unregister_ftrace_function(&ftrace_profile_ops
);
954 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
957 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
958 size_t cnt
, loff_t
*ppos
)
963 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
969 mutex_lock(&ftrace_profile_lock
);
970 if (ftrace_profile_enabled
^ val
) {
972 ret
= ftrace_profile_init();
978 ret
= register_ftrace_profiler();
983 ftrace_profile_enabled
= 1;
985 ftrace_profile_enabled
= 0;
987 * unregister_ftrace_profiler calls stop_machine
988 * so this acts like an synchronize_sched.
990 unregister_ftrace_profiler();
994 mutex_unlock(&ftrace_profile_lock
);
1002 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
1003 size_t cnt
, loff_t
*ppos
)
1005 char buf
[64]; /* big enough to hold a number */
1008 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1009 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1012 static const struct file_operations ftrace_profile_fops
= {
1013 .open
= tracing_open_generic
,
1014 .read
= ftrace_profile_read
,
1015 .write
= ftrace_profile_write
,
1016 .llseek
= default_llseek
,
1019 /* used to initialize the real stat files */
1020 static struct tracer_stat function_stats __initdata
= {
1021 .name
= "functions",
1022 .stat_start
= function_stat_start
,
1023 .stat_next
= function_stat_next
,
1024 .stat_cmp
= function_stat_cmp
,
1025 .stat_headers
= function_stat_headers
,
1026 .stat_show
= function_stat_show
1029 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1031 struct ftrace_profile_stat
*stat
;
1032 struct dentry
*entry
;
1037 for_each_possible_cpu(cpu
) {
1038 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1040 name
= kasprintf(GFP_KERNEL
, "function%d", cpu
);
1043 * The files created are permanent, if something happens
1044 * we still do not free memory.
1047 "Could not allocate stat file for cpu %d\n",
1051 stat
->stat
= function_stats
;
1052 stat
->stat
.name
= name
;
1053 ret
= register_stat_tracer(&stat
->stat
);
1056 "Could not register function stat for cpu %d\n",
1063 entry
= tracefs_create_file("function_profile_enabled", 0644,
1064 d_tracer
, NULL
, &ftrace_profile_fops
);
1066 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1069 #else /* CONFIG_FUNCTION_PROFILER */
1070 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1073 #endif /* CONFIG_FUNCTION_PROFILER */
1075 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1077 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1078 static int ftrace_graph_active
;
1080 # define ftrace_graph_active 0
1083 #ifdef CONFIG_DYNAMIC_FTRACE
1085 static struct ftrace_ops
*removed_ops
;
1088 * Set when doing a global update, like enabling all recs or disabling them.
1089 * It is not set when just updating a single ftrace_ops.
1091 static bool update_all_ops
;
1093 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1094 # error Dynamic ftrace depends on MCOUNT_RECORD
1097 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1099 struct ftrace_func_probe
{
1100 struct hlist_node node
;
1101 struct ftrace_probe_ops
*ops
;
1102 unsigned long flags
;
1105 struct list_head free_list
;
1108 struct ftrace_func_entry
{
1109 struct hlist_node hlist
;
1113 struct ftrace_hash
{
1114 unsigned long size_bits
;
1115 struct hlist_head
*buckets
;
1116 unsigned long count
;
1117 struct rcu_head rcu
;
1121 * We make these constant because no one should touch them,
1122 * but they are used as the default "empty hash", to avoid allocating
1123 * it all the time. These are in a read only section such that if
1124 * anyone does try to modify it, it will cause an exception.
1126 static const struct hlist_head empty_buckets
[1];
1127 static const struct ftrace_hash empty_hash
= {
1128 .buckets
= (struct hlist_head
*)empty_buckets
,
1130 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1132 static struct ftrace_ops global_ops
= {
1133 .func
= ftrace_stub
,
1134 .local_hash
.notrace_hash
= EMPTY_HASH
,
1135 .local_hash
.filter_hash
= EMPTY_HASH
,
1136 INIT_OPS_HASH(global_ops
)
1137 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1138 FTRACE_OPS_FL_INITIALIZED
|
1143 * This is used by __kernel_text_address() to return true if the
1144 * address is on a dynamically allocated trampoline that would
1145 * not return true for either core_kernel_text() or
1146 * is_module_text_address().
1148 bool is_ftrace_trampoline(unsigned long addr
)
1150 struct ftrace_ops
*op
;
1154 * Some of the ops may be dynamically allocated,
1155 * they are freed after a synchronize_sched().
1157 preempt_disable_notrace();
1159 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1161 * This is to check for dynamically allocated trampolines.
1162 * Trampolines that are in kernel text will have
1163 * core_kernel_text() return true.
1165 if (op
->trampoline
&& op
->trampoline_size
)
1166 if (addr
>= op
->trampoline
&&
1167 addr
< op
->trampoline
+ op
->trampoline_size
) {
1171 } while_for_each_ftrace_op(op
);
1174 preempt_enable_notrace();
1179 struct ftrace_page
{
1180 struct ftrace_page
*next
;
1181 struct dyn_ftrace
*records
;
1186 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1187 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1189 /* estimate from running different kernels */
1190 #define NR_TO_INIT 10000
1192 static struct ftrace_page
*ftrace_pages_start
;
1193 static struct ftrace_page
*ftrace_pages
;
1195 static bool __always_inline
ftrace_hash_empty(struct ftrace_hash
*hash
)
1197 return !hash
|| !hash
->count
;
1200 static struct ftrace_func_entry
*
1201 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1204 struct ftrace_func_entry
*entry
;
1205 struct hlist_head
*hhd
;
1207 if (ftrace_hash_empty(hash
))
1210 if (hash
->size_bits
> 0)
1211 key
= hash_long(ip
, hash
->size_bits
);
1215 hhd
= &hash
->buckets
[key
];
1217 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1218 if (entry
->ip
== ip
)
1224 static void __add_hash_entry(struct ftrace_hash
*hash
,
1225 struct ftrace_func_entry
*entry
)
1227 struct hlist_head
*hhd
;
1230 if (hash
->size_bits
)
1231 key
= hash_long(entry
->ip
, hash
->size_bits
);
1235 hhd
= &hash
->buckets
[key
];
1236 hlist_add_head(&entry
->hlist
, hhd
);
1240 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1242 struct ftrace_func_entry
*entry
;
1244 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1249 __add_hash_entry(hash
, entry
);
1255 free_hash_entry(struct ftrace_hash
*hash
,
1256 struct ftrace_func_entry
*entry
)
1258 hlist_del(&entry
->hlist
);
1264 remove_hash_entry(struct ftrace_hash
*hash
,
1265 struct ftrace_func_entry
*entry
)
1267 hlist_del(&entry
->hlist
);
1271 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1273 struct hlist_head
*hhd
;
1274 struct hlist_node
*tn
;
1275 struct ftrace_func_entry
*entry
;
1276 int size
= 1 << hash
->size_bits
;
1282 for (i
= 0; i
< size
; i
++) {
1283 hhd
= &hash
->buckets
[i
];
1284 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1285 free_hash_entry(hash
, entry
);
1287 FTRACE_WARN_ON(hash
->count
);
1290 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1292 if (!hash
|| hash
== EMPTY_HASH
)
1294 ftrace_hash_clear(hash
);
1295 kfree(hash
->buckets
);
1299 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1301 struct ftrace_hash
*hash
;
1303 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1304 free_ftrace_hash(hash
);
1307 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1309 if (!hash
|| hash
== EMPTY_HASH
)
1311 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1314 void ftrace_free_filter(struct ftrace_ops
*ops
)
1316 ftrace_ops_init(ops
);
1317 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1318 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1321 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1323 struct ftrace_hash
*hash
;
1326 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1330 size
= 1 << size_bits
;
1331 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1333 if (!hash
->buckets
) {
1338 hash
->size_bits
= size_bits
;
1343 static struct ftrace_hash
*
1344 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1346 struct ftrace_func_entry
*entry
;
1347 struct ftrace_hash
*new_hash
;
1352 new_hash
= alloc_ftrace_hash(size_bits
);
1357 if (ftrace_hash_empty(hash
))
1360 size
= 1 << hash
->size_bits
;
1361 for (i
= 0; i
< size
; i
++) {
1362 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1363 ret
= add_hash_entry(new_hash
, entry
->ip
);
1369 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1374 free_ftrace_hash(new_hash
);
1379 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1381 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1383 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1384 struct ftrace_hash
*new_hash
);
1387 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1388 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1390 struct ftrace_func_entry
*entry
;
1391 struct hlist_node
*tn
;
1392 struct hlist_head
*hhd
;
1393 struct ftrace_hash
*new_hash
;
1394 int size
= src
->count
;
1399 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1400 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1404 * If the new source is empty, just free dst and assign it
1408 new_hash
= EMPTY_HASH
;
1413 * Make the hash size about 1/2 the # found
1415 for (size
/= 2; size
; size
>>= 1)
1418 /* Don't allocate too much */
1419 if (bits
> FTRACE_HASH_MAX_BITS
)
1420 bits
= FTRACE_HASH_MAX_BITS
;
1422 new_hash
= alloc_ftrace_hash(bits
);
1426 size
= 1 << src
->size_bits
;
1427 for (i
= 0; i
< size
; i
++) {
1428 hhd
= &src
->buckets
[i
];
1429 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1430 remove_hash_entry(src
, entry
);
1431 __add_hash_entry(new_hash
, entry
);
1436 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1438 /* IPMODIFY should be updated only when filter_hash updating */
1439 ret
= ftrace_hash_ipmodify_update(ops
, new_hash
);
1441 free_ftrace_hash(new_hash
);
1447 * Remove the current set, update the hash and add
1450 ftrace_hash_rec_disable_modify(ops
, enable
);
1452 rcu_assign_pointer(*dst
, new_hash
);
1454 ftrace_hash_rec_enable_modify(ops
, enable
);
1459 static bool hash_contains_ip(unsigned long ip
,
1460 struct ftrace_ops_hash
*hash
)
1463 * The function record is a match if it exists in the filter
1464 * hash and not in the notrace hash. Note, an emty hash is
1465 * considered a match for the filter hash, but an empty
1466 * notrace hash is considered not in the notrace hash.
1468 return (ftrace_hash_empty(hash
->filter_hash
) ||
1469 ftrace_lookup_ip(hash
->filter_hash
, ip
)) &&
1470 (ftrace_hash_empty(hash
->notrace_hash
) ||
1471 !ftrace_lookup_ip(hash
->notrace_hash
, ip
));
1475 * Test the hashes for this ops to see if we want to call
1476 * the ops->func or not.
1478 * It's a match if the ip is in the ops->filter_hash or
1479 * the filter_hash does not exist or is empty,
1481 * the ip is not in the ops->notrace_hash.
1483 * This needs to be called with preemption disabled as
1484 * the hashes are freed with call_rcu_sched().
1487 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1489 struct ftrace_ops_hash hash
;
1492 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1494 * There's a small race when adding ops that the ftrace handler
1495 * that wants regs, may be called without them. We can not
1496 * allow that handler to be called if regs is NULL.
1498 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1502 hash
.filter_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->filter_hash
);
1503 hash
.notrace_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->notrace_hash
);
1505 if (hash_contains_ip(ip
, &hash
))
1514 * This is a double for. Do not use 'break' to break out of the loop,
1515 * you must use a goto.
1517 #define do_for_each_ftrace_rec(pg, rec) \
1518 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1520 for (_____i = 0; _____i < pg->index; _____i++) { \
1521 rec = &pg->records[_____i];
1523 #define while_for_each_ftrace_rec() \
1528 static int ftrace_cmp_recs(const void *a
, const void *b
)
1530 const struct dyn_ftrace
*key
= a
;
1531 const struct dyn_ftrace
*rec
= b
;
1533 if (key
->flags
< rec
->ip
)
1535 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1541 * ftrace_location_range - return the first address of a traced location
1542 * if it touches the given ip range
1543 * @start: start of range to search.
1544 * @end: end of range to search (inclusive). @end points to the last byte
1547 * Returns rec->ip if the related ftrace location is a least partly within
1548 * the given address range. That is, the first address of the instruction
1549 * that is either a NOP or call to the function tracer. It checks the ftrace
1550 * internal tables to determine if the address belongs or not.
1552 unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1554 struct ftrace_page
*pg
;
1555 struct dyn_ftrace
*rec
;
1556 struct dyn_ftrace key
;
1559 key
.flags
= end
; /* overload flags, as it is unsigned long */
1561 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1562 if (end
< pg
->records
[0].ip
||
1563 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1565 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1566 sizeof(struct dyn_ftrace
),
1576 * ftrace_location - return true if the ip giving is a traced location
1577 * @ip: the instruction pointer to check
1579 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1580 * That is, the instruction that is either a NOP or call to
1581 * the function tracer. It checks the ftrace internal tables to
1582 * determine if the address belongs or not.
1584 unsigned long ftrace_location(unsigned long ip
)
1586 return ftrace_location_range(ip
, ip
);
1590 * ftrace_text_reserved - return true if range contains an ftrace location
1591 * @start: start of range to search
1592 * @end: end of range to search (inclusive). @end points to the last byte to check.
1594 * Returns 1 if @start and @end contains a ftrace location.
1595 * That is, the instruction that is either a NOP or call to
1596 * the function tracer. It checks the ftrace internal tables to
1597 * determine if the address belongs or not.
1599 int ftrace_text_reserved(const void *start
, const void *end
)
1603 ret
= ftrace_location_range((unsigned long)start
,
1604 (unsigned long)end
);
1609 /* Test if ops registered to this rec needs regs */
1610 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1612 struct ftrace_ops
*ops
;
1613 bool keep_regs
= false;
1615 for (ops
= ftrace_ops_list
;
1616 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1617 /* pass rec in as regs to have non-NULL val */
1618 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1619 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1629 static bool __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1633 struct ftrace_hash
*hash
;
1634 struct ftrace_hash
*other_hash
;
1635 struct ftrace_page
*pg
;
1636 struct dyn_ftrace
*rec
;
1637 bool update
= false;
1641 /* Only update if the ops has been registered */
1642 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1646 * In the filter_hash case:
1647 * If the count is zero, we update all records.
1648 * Otherwise we just update the items in the hash.
1650 * In the notrace_hash case:
1651 * We enable the update in the hash.
1652 * As disabling notrace means enabling the tracing,
1653 * and enabling notrace means disabling, the inc variable
1657 hash
= ops
->func_hash
->filter_hash
;
1658 other_hash
= ops
->func_hash
->notrace_hash
;
1659 if (ftrace_hash_empty(hash
))
1663 hash
= ops
->func_hash
->notrace_hash
;
1664 other_hash
= ops
->func_hash
->filter_hash
;
1666 * If the notrace hash has no items,
1667 * then there's nothing to do.
1669 if (ftrace_hash_empty(hash
))
1673 do_for_each_ftrace_rec(pg
, rec
) {
1674 int in_other_hash
= 0;
1678 if (rec
->flags
& FTRACE_FL_DISABLED
)
1683 * Only the filter_hash affects all records.
1684 * Update if the record is not in the notrace hash.
1686 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1689 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1690 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1693 * If filter_hash is set, we want to match all functions
1694 * that are in the hash but not in the other hash.
1696 * If filter_hash is not set, then we are decrementing.
1697 * That means we match anything that is in the hash
1698 * and also in the other_hash. That is, we need to turn
1699 * off functions in the other hash because they are disabled
1702 if (filter_hash
&& in_hash
&& !in_other_hash
)
1704 else if (!filter_hash
&& in_hash
&&
1705 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1713 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1717 * If there's only a single callback registered to a
1718 * function, and the ops has a trampoline registered
1719 * for it, then we can call it directly.
1721 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1722 rec
->flags
|= FTRACE_FL_TRAMP
;
1725 * If we are adding another function callback
1726 * to this function, and the previous had a
1727 * custom trampoline in use, then we need to go
1728 * back to the default trampoline.
1730 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1733 * If any ops wants regs saved for this function
1734 * then all ops will get saved regs.
1736 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1737 rec
->flags
|= FTRACE_FL_REGS
;
1739 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1744 * If the rec had REGS enabled and the ops that is
1745 * being removed had REGS set, then see if there is
1746 * still any ops for this record that wants regs.
1747 * If not, we can stop recording them.
1749 if (ftrace_rec_count(rec
) > 0 &&
1750 rec
->flags
& FTRACE_FL_REGS
&&
1751 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1752 if (!test_rec_ops_needs_regs(rec
))
1753 rec
->flags
&= ~FTRACE_FL_REGS
;
1757 * If the rec had TRAMP enabled, then it needs to
1758 * be cleared. As TRAMP can only be enabled iff
1759 * there is only a single ops attached to it.
1760 * In otherwords, always disable it on decrementing.
1761 * In the future, we may set it if rec count is
1762 * decremented to one, and the ops that is left
1765 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1768 * flags will be cleared in ftrace_check_record()
1769 * if rec count is zero.
1774 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1775 update
|= ftrace_test_record(rec
, 1) != FTRACE_UPDATE_IGNORE
;
1777 /* Shortcut, if we handled all records, we are done. */
1778 if (!all
&& count
== hash
->count
)
1780 } while_for_each_ftrace_rec();
1785 static bool ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1788 return __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1791 static bool ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1794 return __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1797 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1798 int filter_hash
, int inc
)
1800 struct ftrace_ops
*op
;
1802 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1804 if (ops
->func_hash
!= &global_ops
.local_hash
)
1808 * If the ops shares the global_ops hash, then we need to update
1809 * all ops that are enabled and use this hash.
1811 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1815 if (op
->func_hash
== &global_ops
.local_hash
)
1816 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1817 } while_for_each_ftrace_op(op
);
1820 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1823 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1826 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1829 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1833 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1834 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1835 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1836 * Note that old_hash and new_hash has below meanings
1837 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1838 * - If the hash is EMPTY_HASH, it hits nothing
1839 * - Anything else hits the recs which match the hash entries.
1841 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1842 struct ftrace_hash
*old_hash
,
1843 struct ftrace_hash
*new_hash
)
1845 struct ftrace_page
*pg
;
1846 struct dyn_ftrace
*rec
, *end
= NULL
;
1849 /* Only update if the ops has been registered */
1850 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1853 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1857 * Since the IPMODIFY is a very address sensitive action, we do not
1858 * allow ftrace_ops to set all functions to new hash.
1860 if (!new_hash
|| !old_hash
)
1863 /* Update rec->flags */
1864 do_for_each_ftrace_rec(pg
, rec
) {
1866 if (rec
->flags
& FTRACE_FL_DISABLED
)
1869 /* We need to update only differences of filter_hash */
1870 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1871 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1872 if (in_old
== in_new
)
1876 /* New entries must ensure no others are using it */
1877 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1879 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1880 } else /* Removed entry */
1881 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1882 } while_for_each_ftrace_rec();
1889 /* Roll back what we did above */
1890 do_for_each_ftrace_rec(pg
, rec
) {
1892 if (rec
->flags
& FTRACE_FL_DISABLED
)
1898 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1899 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1900 if (in_old
== in_new
)
1904 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1906 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1907 } while_for_each_ftrace_rec();
1913 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
1915 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1917 if (ftrace_hash_empty(hash
))
1920 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
1923 /* Disabling always succeeds */
1924 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
1926 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1928 if (ftrace_hash_empty(hash
))
1931 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
1934 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1935 struct ftrace_hash
*new_hash
)
1937 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
1939 if (ftrace_hash_empty(old_hash
))
1942 if (ftrace_hash_empty(new_hash
))
1945 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
1948 static void print_ip_ins(const char *fmt
, const unsigned char *p
)
1952 printk(KERN_CONT
"%s", fmt
);
1954 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1955 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1958 static struct ftrace_ops
*
1959 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
1960 static struct ftrace_ops
*
1961 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
);
1963 enum ftrace_bug_type ftrace_bug_type
;
1964 const void *ftrace_expected
;
1966 static void print_bug_type(void)
1968 switch (ftrace_bug_type
) {
1969 case FTRACE_BUG_UNKNOWN
:
1971 case FTRACE_BUG_INIT
:
1972 pr_info("Initializing ftrace call sites\n");
1974 case FTRACE_BUG_NOP
:
1975 pr_info("Setting ftrace call site to NOP\n");
1977 case FTRACE_BUG_CALL
:
1978 pr_info("Setting ftrace call site to call ftrace function\n");
1980 case FTRACE_BUG_UPDATE
:
1981 pr_info("Updating ftrace call site to call a different ftrace function\n");
1987 * ftrace_bug - report and shutdown function tracer
1988 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1989 * @rec: The record that failed
1991 * The arch code that enables or disables the function tracing
1992 * can call ftrace_bug() when it has detected a problem in
1993 * modifying the code. @failed should be one of either:
1994 * EFAULT - if the problem happens on reading the @ip address
1995 * EINVAL - if what is read at @ip is not what was expected
1996 * EPERM - if the problem happens on writting to the @ip address
1998 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
2000 unsigned long ip
= rec
? rec
->ip
: 0;
2004 FTRACE_WARN_ON_ONCE(1);
2005 pr_info("ftrace faulted on modifying ");
2009 FTRACE_WARN_ON_ONCE(1);
2010 pr_info("ftrace failed to modify ");
2012 print_ip_ins(" actual: ", (unsigned char *)ip
);
2014 if (ftrace_expected
) {
2015 print_ip_ins(" expected: ", ftrace_expected
);
2020 FTRACE_WARN_ON_ONCE(1);
2021 pr_info("ftrace faulted on writing ");
2025 FTRACE_WARN_ON_ONCE(1);
2026 pr_info("ftrace faulted on unknown error ");
2031 struct ftrace_ops
*ops
= NULL
;
2033 pr_info("ftrace record flags: %lx\n", rec
->flags
);
2034 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
2035 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2036 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2037 ops
= ftrace_find_tramp_ops_any(rec
);
2040 pr_cont("\ttramp: %pS (%pS)",
2041 (void *)ops
->trampoline
,
2043 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
2046 pr_cont("\ttramp: ERROR!");
2049 ip
= ftrace_get_addr_curr(rec
);
2050 pr_cont("\n expected tramp: %lx\n", ip
);
2054 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
2056 unsigned long flag
= 0UL;
2058 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2060 if (rec
->flags
& FTRACE_FL_DISABLED
)
2061 return FTRACE_UPDATE_IGNORE
;
2064 * If we are updating calls:
2066 * If the record has a ref count, then we need to enable it
2067 * because someone is using it.
2069 * Otherwise we make sure its disabled.
2071 * If we are disabling calls, then disable all records that
2074 if (enable
&& ftrace_rec_count(rec
))
2075 flag
= FTRACE_FL_ENABLED
;
2078 * If enabling and the REGS flag does not match the REGS_EN, or
2079 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2080 * this record. Set flags to fail the compare against ENABLED.
2083 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
2084 !(rec
->flags
& FTRACE_FL_REGS_EN
))
2085 flag
|= FTRACE_FL_REGS
;
2087 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
2088 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
2089 flag
|= FTRACE_FL_TRAMP
;
2092 /* If the state of this record hasn't changed, then do nothing */
2093 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2094 return FTRACE_UPDATE_IGNORE
;
2097 /* Save off if rec is being enabled (for return value) */
2098 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2101 rec
->flags
|= FTRACE_FL_ENABLED
;
2102 if (flag
& FTRACE_FL_REGS
) {
2103 if (rec
->flags
& FTRACE_FL_REGS
)
2104 rec
->flags
|= FTRACE_FL_REGS_EN
;
2106 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2108 if (flag
& FTRACE_FL_TRAMP
) {
2109 if (rec
->flags
& FTRACE_FL_TRAMP
)
2110 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2112 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2117 * If this record is being updated from a nop, then
2118 * return UPDATE_MAKE_CALL.
2120 * return UPDATE_MODIFY_CALL to tell the caller to convert
2121 * from the save regs, to a non-save regs function or
2122 * vice versa, or from a trampoline call.
2124 if (flag
& FTRACE_FL_ENABLED
) {
2125 ftrace_bug_type
= FTRACE_BUG_CALL
;
2126 return FTRACE_UPDATE_MAKE_CALL
;
2129 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2130 return FTRACE_UPDATE_MODIFY_CALL
;
2134 /* If there's no more users, clear all flags */
2135 if (!ftrace_rec_count(rec
))
2139 * Just disable the record, but keep the ops TRAMP
2140 * and REGS states. The _EN flags must be disabled though.
2142 rec
->flags
&= ~(FTRACE_FL_ENABLED
| FTRACE_FL_TRAMP_EN
|
2146 ftrace_bug_type
= FTRACE_BUG_NOP
;
2147 return FTRACE_UPDATE_MAKE_NOP
;
2151 * ftrace_update_record, set a record that now is tracing or not
2152 * @rec: the record to update
2153 * @enable: set to 1 if the record is tracing, zero to force disable
2155 * The records that represent all functions that can be traced need
2156 * to be updated when tracing has been enabled.
2158 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2160 return ftrace_check_record(rec
, enable
, 1);
2164 * ftrace_test_record, check if the record has been enabled or not
2165 * @rec: the record to test
2166 * @enable: set to 1 to check if enabled, 0 if it is disabled
2168 * The arch code may need to test if a record is already set to
2169 * tracing to determine how to modify the function code that it
2172 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2174 return ftrace_check_record(rec
, enable
, 0);
2177 static struct ftrace_ops
*
2178 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2180 struct ftrace_ops
*op
;
2181 unsigned long ip
= rec
->ip
;
2183 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2185 if (!op
->trampoline
)
2188 if (hash_contains_ip(ip
, op
->func_hash
))
2190 } while_for_each_ftrace_op(op
);
2195 static struct ftrace_ops
*
2196 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
,
2197 struct ftrace_ops
*op
)
2199 unsigned long ip
= rec
->ip
;
2201 while_for_each_ftrace_op(op
) {
2203 if (!op
->trampoline
)
2206 if (hash_contains_ip(ip
, op
->func_hash
))
2213 static struct ftrace_ops
*
2214 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2216 struct ftrace_ops
*op
;
2217 unsigned long ip
= rec
->ip
;
2220 * Need to check removed ops first.
2221 * If they are being removed, and this rec has a tramp,
2222 * and this rec is in the ops list, then it would be the
2223 * one with the tramp.
2226 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2231 * Need to find the current trampoline for a rec.
2232 * Now, a trampoline is only attached to a rec if there
2233 * was a single 'ops' attached to it. But this can be called
2234 * when we are adding another op to the rec or removing the
2235 * current one. Thus, if the op is being added, we can
2236 * ignore it because it hasn't attached itself to the rec
2239 * If an ops is being modified (hooking to different functions)
2240 * then we don't care about the new functions that are being
2241 * added, just the old ones (that are probably being removed).
2243 * If we are adding an ops to a function that already is using
2244 * a trampoline, it needs to be removed (trampolines are only
2245 * for single ops connected), then an ops that is not being
2246 * modified also needs to be checked.
2248 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2250 if (!op
->trampoline
)
2254 * If the ops is being added, it hasn't gotten to
2255 * the point to be removed from this tree yet.
2257 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2262 * If the ops is being modified and is in the old
2263 * hash, then it is probably being removed from this
2266 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2267 hash_contains_ip(ip
, &op
->old_hash
))
2270 * If the ops is not being added or modified, and it's
2271 * in its normal filter hash, then this must be the one
2274 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2275 hash_contains_ip(ip
, op
->func_hash
))
2278 } while_for_each_ftrace_op(op
);
2283 static struct ftrace_ops
*
2284 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2286 struct ftrace_ops
*op
;
2287 unsigned long ip
= rec
->ip
;
2289 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2290 /* pass rec in as regs to have non-NULL val */
2291 if (hash_contains_ip(ip
, op
->func_hash
))
2293 } while_for_each_ftrace_op(op
);
2299 * ftrace_get_addr_new - Get the call address to set to
2300 * @rec: The ftrace record descriptor
2302 * If the record has the FTRACE_FL_REGS set, that means that it
2303 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2304 * is not not set, then it wants to convert to the normal callback.
2306 * Returns the address of the trampoline to set to
2308 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2310 struct ftrace_ops
*ops
;
2312 /* Trampolines take precedence over regs */
2313 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2314 ops
= ftrace_find_tramp_ops_new(rec
);
2315 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2316 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2317 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2318 /* Ftrace is shutting down, return anything */
2319 return (unsigned long)FTRACE_ADDR
;
2321 return ops
->trampoline
;
2324 if (rec
->flags
& FTRACE_FL_REGS
)
2325 return (unsigned long)FTRACE_REGS_ADDR
;
2327 return (unsigned long)FTRACE_ADDR
;
2331 * ftrace_get_addr_curr - Get the call address that is already there
2332 * @rec: The ftrace record descriptor
2334 * The FTRACE_FL_REGS_EN is set when the record already points to
2335 * a function that saves all the regs. Basically the '_EN' version
2336 * represents the current state of the function.
2338 * Returns the address of the trampoline that is currently being called
2340 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2342 struct ftrace_ops
*ops
;
2344 /* Trampolines take precedence over regs */
2345 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2346 ops
= ftrace_find_tramp_ops_curr(rec
);
2347 if (FTRACE_WARN_ON(!ops
)) {
2348 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2349 (void *)rec
->ip
, (void *)rec
->ip
);
2350 /* Ftrace is shutting down, return anything */
2351 return (unsigned long)FTRACE_ADDR
;
2353 return ops
->trampoline
;
2356 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2357 return (unsigned long)FTRACE_REGS_ADDR
;
2359 return (unsigned long)FTRACE_ADDR
;
2363 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2365 unsigned long ftrace_old_addr
;
2366 unsigned long ftrace_addr
;
2369 ftrace_addr
= ftrace_get_addr_new(rec
);
2371 /* This needs to be done before we call ftrace_update_record */
2372 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2374 ret
= ftrace_update_record(rec
, enable
);
2376 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2379 case FTRACE_UPDATE_IGNORE
:
2382 case FTRACE_UPDATE_MAKE_CALL
:
2383 ftrace_bug_type
= FTRACE_BUG_CALL
;
2384 return ftrace_make_call(rec
, ftrace_addr
);
2386 case FTRACE_UPDATE_MAKE_NOP
:
2387 ftrace_bug_type
= FTRACE_BUG_NOP
;
2388 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2390 case FTRACE_UPDATE_MODIFY_CALL
:
2391 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2392 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2395 return -1; /* unknow ftrace bug */
2398 void __weak
ftrace_replace_code(int enable
)
2400 struct dyn_ftrace
*rec
;
2401 struct ftrace_page
*pg
;
2404 if (unlikely(ftrace_disabled
))
2407 do_for_each_ftrace_rec(pg
, rec
) {
2409 if (rec
->flags
& FTRACE_FL_DISABLED
)
2412 failed
= __ftrace_replace_code(rec
, enable
);
2414 ftrace_bug(failed
, rec
);
2415 /* Stop processing */
2418 } while_for_each_ftrace_rec();
2421 struct ftrace_rec_iter
{
2422 struct ftrace_page
*pg
;
2427 * ftrace_rec_iter_start, start up iterating over traced functions
2429 * Returns an iterator handle that is used to iterate over all
2430 * the records that represent address locations where functions
2433 * May return NULL if no records are available.
2435 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2438 * We only use a single iterator.
2439 * Protected by the ftrace_lock mutex.
2441 static struct ftrace_rec_iter ftrace_rec_iter
;
2442 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2444 iter
->pg
= ftrace_pages_start
;
2447 /* Could have empty pages */
2448 while (iter
->pg
&& !iter
->pg
->index
)
2449 iter
->pg
= iter
->pg
->next
;
2458 * ftrace_rec_iter_next, get the next record to process.
2459 * @iter: The handle to the iterator.
2461 * Returns the next iterator after the given iterator @iter.
2463 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2467 if (iter
->index
>= iter
->pg
->index
) {
2468 iter
->pg
= iter
->pg
->next
;
2471 /* Could have empty pages */
2472 while (iter
->pg
&& !iter
->pg
->index
)
2473 iter
->pg
= iter
->pg
->next
;
2483 * ftrace_rec_iter_record, get the record at the iterator location
2484 * @iter: The current iterator location
2486 * Returns the record that the current @iter is at.
2488 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2490 return &iter
->pg
->records
[iter
->index
];
2494 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2498 if (unlikely(ftrace_disabled
))
2501 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2503 ftrace_bug_type
= FTRACE_BUG_INIT
;
2504 ftrace_bug(ret
, rec
);
2511 * archs can override this function if they must do something
2512 * before the modifying code is performed.
2514 int __weak
ftrace_arch_code_modify_prepare(void)
2520 * archs can override this function if they must do something
2521 * after the modifying code is performed.
2523 int __weak
ftrace_arch_code_modify_post_process(void)
2528 void ftrace_modify_all_code(int command
)
2530 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2534 * If the ftrace_caller calls a ftrace_ops func directly,
2535 * we need to make sure that it only traces functions it
2536 * expects to trace. When doing the switch of functions,
2537 * we need to update to the ftrace_ops_list_func first
2538 * before the transition between old and new calls are set,
2539 * as the ftrace_ops_list_func will check the ops hashes
2540 * to make sure the ops are having the right functions
2544 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2545 if (FTRACE_WARN_ON(err
))
2549 if (command
& FTRACE_UPDATE_CALLS
)
2550 ftrace_replace_code(1);
2551 else if (command
& FTRACE_DISABLE_CALLS
)
2552 ftrace_replace_code(0);
2554 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2555 function_trace_op
= set_function_trace_op
;
2557 /* If irqs are disabled, we are in stop machine */
2558 if (!irqs_disabled())
2559 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2560 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2561 if (FTRACE_WARN_ON(err
))
2565 if (command
& FTRACE_START_FUNC_RET
)
2566 err
= ftrace_enable_ftrace_graph_caller();
2567 else if (command
& FTRACE_STOP_FUNC_RET
)
2568 err
= ftrace_disable_ftrace_graph_caller();
2569 FTRACE_WARN_ON(err
);
2572 static int __ftrace_modify_code(void *data
)
2574 int *command
= data
;
2576 ftrace_modify_all_code(*command
);
2582 * ftrace_run_stop_machine, go back to the stop machine method
2583 * @command: The command to tell ftrace what to do
2585 * If an arch needs to fall back to the stop machine method, the
2586 * it can call this function.
2588 void ftrace_run_stop_machine(int command
)
2590 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2594 * arch_ftrace_update_code, modify the code to trace or not trace
2595 * @command: The command that needs to be done
2597 * Archs can override this function if it does not need to
2598 * run stop_machine() to modify code.
2600 void __weak
arch_ftrace_update_code(int command
)
2602 ftrace_run_stop_machine(command
);
2605 static void ftrace_run_update_code(int command
)
2609 ret
= ftrace_arch_code_modify_prepare();
2610 FTRACE_WARN_ON(ret
);
2615 * By default we use stop_machine() to modify the code.
2616 * But archs can do what ever they want as long as it
2617 * is safe. The stop_machine() is the safest, but also
2618 * produces the most overhead.
2620 arch_ftrace_update_code(command
);
2622 ret
= ftrace_arch_code_modify_post_process();
2623 FTRACE_WARN_ON(ret
);
2626 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2627 struct ftrace_ops_hash
*old_hash
)
2629 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2630 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2631 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2632 ftrace_run_update_code(command
);
2633 ops
->old_hash
.filter_hash
= NULL
;
2634 ops
->old_hash
.notrace_hash
= NULL
;
2635 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2638 static ftrace_func_t saved_ftrace_func
;
2639 static int ftrace_start_up
;
2641 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2645 static void per_cpu_ops_free(struct ftrace_ops
*ops
)
2647 free_percpu(ops
->disabled
);
2650 static void ftrace_startup_enable(int command
)
2652 if (saved_ftrace_func
!= ftrace_trace_function
) {
2653 saved_ftrace_func
= ftrace_trace_function
;
2654 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2657 if (!command
|| !ftrace_enabled
)
2660 ftrace_run_update_code(command
);
2663 static void ftrace_startup_all(int command
)
2665 update_all_ops
= true;
2666 ftrace_startup_enable(command
);
2667 update_all_ops
= false;
2670 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2674 if (unlikely(ftrace_disabled
))
2677 ret
= __register_ftrace_function(ops
);
2684 * Note that ftrace probes uses this to start up
2685 * and modify functions it will probe. But we still
2686 * set the ADDING flag for modification, as probes
2687 * do not have trampolines. If they add them in the
2688 * future, then the probes will need to distinguish
2689 * between adding and updating probes.
2691 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2693 ret
= ftrace_hash_ipmodify_enable(ops
);
2695 /* Rollback registration process */
2696 __unregister_ftrace_function(ops
);
2698 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2702 if (ftrace_hash_rec_enable(ops
, 1))
2703 command
|= FTRACE_UPDATE_CALLS
;
2705 ftrace_startup_enable(command
);
2707 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2712 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2716 if (unlikely(ftrace_disabled
))
2719 ret
= __unregister_ftrace_function(ops
);
2725 * Just warn in case of unbalance, no need to kill ftrace, it's not
2726 * critical but the ftrace_call callers may be never nopped again after
2727 * further ftrace uses.
2729 WARN_ON_ONCE(ftrace_start_up
< 0);
2731 /* Disabling ipmodify never fails */
2732 ftrace_hash_ipmodify_disable(ops
);
2734 if (ftrace_hash_rec_disable(ops
, 1))
2735 command
|= FTRACE_UPDATE_CALLS
;
2737 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2739 if (saved_ftrace_func
!= ftrace_trace_function
) {
2740 saved_ftrace_func
= ftrace_trace_function
;
2741 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2744 if (!command
|| !ftrace_enabled
) {
2746 * If these are per_cpu ops, they still need their
2747 * per_cpu field freed. Since, function tracing is
2748 * not currently active, we can just free them
2749 * without synchronizing all CPUs.
2751 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2752 per_cpu_ops_free(ops
);
2757 * If the ops uses a trampoline, then it needs to be
2758 * tested first on update.
2760 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2763 /* The trampoline logic checks the old hashes */
2764 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2765 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2767 ftrace_run_update_code(command
);
2770 * If there's no more ops registered with ftrace, run a
2771 * sanity check to make sure all rec flags are cleared.
2773 if (ftrace_ops_list
== &ftrace_list_end
) {
2774 struct ftrace_page
*pg
;
2775 struct dyn_ftrace
*rec
;
2777 do_for_each_ftrace_rec(pg
, rec
) {
2778 if (FTRACE_WARN_ON_ONCE(rec
->flags
& ~FTRACE_FL_DISABLED
))
2779 pr_warn(" %pS flags:%lx\n",
2780 (void *)rec
->ip
, rec
->flags
);
2781 } while_for_each_ftrace_rec();
2784 ops
->old_hash
.filter_hash
= NULL
;
2785 ops
->old_hash
.notrace_hash
= NULL
;
2788 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2791 * Dynamic ops may be freed, we must make sure that all
2792 * callers are done before leaving this function.
2793 * The same goes for freeing the per_cpu data of the per_cpu
2796 * Again, normal synchronize_sched() is not good enough.
2797 * We need to do a hard force of sched synchronization.
2798 * This is because we use preempt_disable() to do RCU, but
2799 * the function tracers can be called where RCU is not watching
2800 * (like before user_exit()). We can not rely on the RCU
2801 * infrastructure to do the synchronization, thus we must do it
2804 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
)) {
2805 schedule_on_each_cpu(ftrace_sync
);
2807 arch_ftrace_trampoline_free(ops
);
2809 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2810 per_cpu_ops_free(ops
);
2816 static void ftrace_startup_sysctl(void)
2820 if (unlikely(ftrace_disabled
))
2823 /* Force update next time */
2824 saved_ftrace_func
= NULL
;
2825 /* ftrace_start_up is true if we want ftrace running */
2826 if (ftrace_start_up
) {
2827 command
= FTRACE_UPDATE_CALLS
;
2828 if (ftrace_graph_active
)
2829 command
|= FTRACE_START_FUNC_RET
;
2830 ftrace_startup_enable(command
);
2834 static void ftrace_shutdown_sysctl(void)
2838 if (unlikely(ftrace_disabled
))
2841 /* ftrace_start_up is true if ftrace is running */
2842 if (ftrace_start_up
) {
2843 command
= FTRACE_DISABLE_CALLS
;
2844 if (ftrace_graph_active
)
2845 command
|= FTRACE_STOP_FUNC_RET
;
2846 ftrace_run_update_code(command
);
2850 static cycle_t ftrace_update_time
;
2851 unsigned long ftrace_update_tot_cnt
;
2853 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2856 * Filter_hash being empty will default to trace module.
2857 * But notrace hash requires a test of individual module functions.
2859 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2860 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2864 * Check if the current ops references the record.
2866 * If the ops traces all functions, then it was already accounted for.
2867 * If the ops does not trace the current record function, skip it.
2868 * If the ops ignores the function via notrace filter, skip it.
2871 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2873 /* If ops isn't enabled, ignore it */
2874 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2877 /* If ops traces all then it includes this function */
2878 if (ops_traces_mod(ops
))
2881 /* The function must be in the filter */
2882 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2883 !ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2886 /* If in notrace hash, we ignore it too */
2887 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2893 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2895 struct ftrace_page
*pg
;
2896 struct dyn_ftrace
*p
;
2897 cycle_t start
, stop
;
2898 unsigned long update_cnt
= 0;
2899 unsigned long rec_flags
= 0;
2902 start
= ftrace_now(raw_smp_processor_id());
2905 * When a module is loaded, this function is called to convert
2906 * the calls to mcount in its text to nops, and also to create
2907 * an entry in the ftrace data. Now, if ftrace is activated
2908 * after this call, but before the module sets its text to
2909 * read-only, the modification of enabling ftrace can fail if
2910 * the read-only is done while ftrace is converting the calls.
2911 * To prevent this, the module's records are set as disabled
2912 * and will be enabled after the call to set the module's text
2916 rec_flags
|= FTRACE_FL_DISABLED
;
2918 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2920 for (i
= 0; i
< pg
->index
; i
++) {
2922 /* If something went wrong, bail without enabling anything */
2923 if (unlikely(ftrace_disabled
))
2926 p
= &pg
->records
[i
];
2927 p
->flags
= rec_flags
;
2930 * Do the initial record conversion from mcount jump
2931 * to the NOP instructions.
2933 if (!ftrace_code_disable(mod
, p
))
2940 stop
= ftrace_now(raw_smp_processor_id());
2941 ftrace_update_time
= stop
- start
;
2942 ftrace_update_tot_cnt
+= update_cnt
;
2947 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2952 if (WARN_ON(!count
))
2955 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2958 * We want to fill as much as possible. No more than a page
2961 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2965 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2968 /* if we can't allocate this size, try something smaller */
2975 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2984 static struct ftrace_page
*
2985 ftrace_allocate_pages(unsigned long num_to_init
)
2987 struct ftrace_page
*start_pg
;
2988 struct ftrace_page
*pg
;
2995 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3000 * Try to allocate as much as possible in one continues
3001 * location that fills in all of the space. We want to
3002 * waste as little space as possible.
3005 cnt
= ftrace_allocate_records(pg
, num_to_init
);
3013 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3025 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3026 free_pages((unsigned long)pg
->records
, order
);
3027 start_pg
= pg
->next
;
3031 pr_info("ftrace: FAILED to allocate memory for functions\n");
3035 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3037 struct ftrace_iterator
{
3040 struct ftrace_page
*pg
;
3041 struct dyn_ftrace
*func
;
3042 struct ftrace_func_probe
*probe
;
3043 struct trace_parser parser
;
3044 struct ftrace_hash
*hash
;
3045 struct ftrace_ops
*ops
;
3052 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
3054 struct ftrace_iterator
*iter
= m
->private;
3055 struct hlist_node
*hnd
= NULL
;
3056 struct hlist_head
*hhd
;
3062 hnd
= &iter
->probe
->node
;
3064 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
3067 hhd
= &ftrace_func_hash
[iter
->hidx
];
3069 if (hlist_empty(hhd
)) {
3085 if (WARN_ON_ONCE(!hnd
))
3088 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
3093 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
3095 struct ftrace_iterator
*iter
= m
->private;
3099 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
3102 if (iter
->func_pos
> *pos
)
3106 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3107 p
= t_hash_next(m
, &l
);
3114 /* Only set this if we have an item */
3115 iter
->flags
|= FTRACE_ITER_HASH
;
3121 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3123 struct ftrace_func_probe
*rec
;
3126 if (WARN_ON_ONCE(!rec
))
3129 if (rec
->ops
->print
)
3130 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
3132 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
3135 seq_printf(m
, ":%p", rec
->data
);
3142 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3144 struct ftrace_iterator
*iter
= m
->private;
3145 struct ftrace_ops
*ops
= iter
->ops
;
3146 struct dyn_ftrace
*rec
= NULL
;
3148 if (unlikely(ftrace_disabled
))
3151 if (iter
->flags
& FTRACE_ITER_HASH
)
3152 return t_hash_next(m
, pos
);
3155 iter
->pos
= iter
->func_pos
= *pos
;
3157 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
3158 return t_hash_start(m
, pos
);
3161 if (iter
->idx
>= iter
->pg
->index
) {
3162 if (iter
->pg
->next
) {
3163 iter
->pg
= iter
->pg
->next
;
3168 rec
= &iter
->pg
->records
[iter
->idx
++];
3169 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
3170 !(ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))) ||
3172 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
3173 !ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
)) ||
3175 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3176 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3184 return t_hash_start(m
, pos
);
3191 static void reset_iter_read(struct ftrace_iterator
*iter
)
3195 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
3198 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3200 struct ftrace_iterator
*iter
= m
->private;
3201 struct ftrace_ops
*ops
= iter
->ops
;
3205 mutex_lock(&ftrace_lock
);
3207 if (unlikely(ftrace_disabled
))
3211 * If an lseek was done, then reset and start from beginning.
3213 if (*pos
< iter
->pos
)
3214 reset_iter_read(iter
);
3217 * For set_ftrace_filter reading, if we have the filter
3218 * off, we can short cut and just print out that all
3219 * functions are enabled.
3221 if ((iter
->flags
& FTRACE_ITER_FILTER
&&
3222 ftrace_hash_empty(ops
->func_hash
->filter_hash
)) ||
3223 (iter
->flags
& FTRACE_ITER_NOTRACE
&&
3224 ftrace_hash_empty(ops
->func_hash
->notrace_hash
))) {
3226 return t_hash_start(m
, pos
);
3227 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3228 /* reset in case of seek/pread */
3229 iter
->flags
&= ~FTRACE_ITER_HASH
;
3233 if (iter
->flags
& FTRACE_ITER_HASH
)
3234 return t_hash_start(m
, pos
);
3237 * Unfortunately, we need to restart at ftrace_pages_start
3238 * every time we let go of the ftrace_mutex. This is because
3239 * those pointers can change without the lock.
3241 iter
->pg
= ftrace_pages_start
;
3243 for (l
= 0; l
<= *pos
; ) {
3244 p
= t_next(m
, p
, &l
);
3250 return t_hash_start(m
, pos
);
3255 static void t_stop(struct seq_file
*m
, void *p
)
3257 mutex_unlock(&ftrace_lock
);
3261 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3266 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3267 struct dyn_ftrace
*rec
)
3271 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3273 seq_printf(m
, " ->%pS", ptr
);
3276 static int t_show(struct seq_file
*m
, void *v
)
3278 struct ftrace_iterator
*iter
= m
->private;
3279 struct dyn_ftrace
*rec
;
3281 if (iter
->flags
& FTRACE_ITER_HASH
)
3282 return t_hash_show(m
, iter
);
3284 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3285 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3286 seq_puts(m
, "#### no functions disabled ####\n");
3288 seq_puts(m
, "#### all functions enabled ####\n");
3297 seq_printf(m
, "%ps", (void *)rec
->ip
);
3298 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3299 struct ftrace_ops
*ops
;
3301 seq_printf(m
, " (%ld)%s%s",
3302 ftrace_rec_count(rec
),
3303 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3304 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3305 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3306 ops
= ftrace_find_tramp_ops_any(rec
);
3309 seq_printf(m
, "\ttramp: %pS (%pS)",
3310 (void *)ops
->trampoline
,
3312 add_trampoline_func(m
, ops
, rec
);
3313 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
3316 seq_puts(m
, "\ttramp: ERROR!");
3318 add_trampoline_func(m
, NULL
, rec
);
3327 static const struct seq_operations show_ftrace_seq_ops
= {
3335 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3337 struct ftrace_iterator
*iter
;
3339 if (unlikely(ftrace_disabled
))
3342 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3344 iter
->pg
= ftrace_pages_start
;
3345 iter
->ops
= &global_ops
;
3348 return iter
? 0 : -ENOMEM
;
3352 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3354 struct ftrace_iterator
*iter
;
3356 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3358 iter
->pg
= ftrace_pages_start
;
3359 iter
->flags
= FTRACE_ITER_ENABLED
;
3360 iter
->ops
= &global_ops
;
3363 return iter
? 0 : -ENOMEM
;
3367 * ftrace_regex_open - initialize function tracer filter files
3368 * @ops: The ftrace_ops that hold the hash filters
3369 * @flag: The type of filter to process
3370 * @inode: The inode, usually passed in to your open routine
3371 * @file: The file, usually passed in to your open routine
3373 * ftrace_regex_open() initializes the filter files for the
3374 * @ops. Depending on @flag it may process the filter hash or
3375 * the notrace hash of @ops. With this called from the open
3376 * routine, you can use ftrace_filter_write() for the write
3377 * routine if @flag has FTRACE_ITER_FILTER set, or
3378 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3379 * tracing_lseek() should be used as the lseek routine, and
3380 * release must call ftrace_regex_release().
3383 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3384 struct inode
*inode
, struct file
*file
)
3386 struct ftrace_iterator
*iter
;
3387 struct ftrace_hash
*hash
;
3390 ftrace_ops_init(ops
);
3392 if (unlikely(ftrace_disabled
))
3395 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3399 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3407 mutex_lock(&ops
->func_hash
->regex_lock
);
3409 if (flag
& FTRACE_ITER_NOTRACE
)
3410 hash
= ops
->func_hash
->notrace_hash
;
3412 hash
= ops
->func_hash
->filter_hash
;
3414 if (file
->f_mode
& FMODE_WRITE
) {
3415 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3417 if (file
->f_flags
& O_TRUNC
)
3418 iter
->hash
= alloc_ftrace_hash(size_bits
);
3420 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3423 trace_parser_put(&iter
->parser
);
3430 if (file
->f_mode
& FMODE_READ
) {
3431 iter
->pg
= ftrace_pages_start
;
3433 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3435 struct seq_file
*m
= file
->private_data
;
3439 free_ftrace_hash(iter
->hash
);
3440 trace_parser_put(&iter
->parser
);
3444 file
->private_data
= iter
;
3447 mutex_unlock(&ops
->func_hash
->regex_lock
);
3453 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3455 struct ftrace_ops
*ops
= inode
->i_private
;
3457 return ftrace_regex_open(ops
,
3458 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
3463 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3465 struct ftrace_ops
*ops
= inode
->i_private
;
3467 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3471 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3472 struct ftrace_glob
{
3479 * If symbols in an architecture don't correspond exactly to the user-visible
3480 * name of what they represent, it is possible to define this function to
3481 * perform the necessary adjustments.
3483 char * __weak
arch_ftrace_match_adjust(char *str
, const char *search
)
3488 static int ftrace_match(char *str
, struct ftrace_glob
*g
)
3493 str
= arch_ftrace_match_adjust(str
, g
->search
);
3497 if (strcmp(str
, g
->search
) == 0)
3500 case MATCH_FRONT_ONLY
:
3501 if (strncmp(str
, g
->search
, g
->len
) == 0)
3504 case MATCH_MIDDLE_ONLY
:
3505 if (strstr(str
, g
->search
))
3508 case MATCH_END_ONLY
:
3510 if (slen
>= g
->len
&&
3511 memcmp(str
+ slen
- g
->len
, g
->search
, g
->len
) == 0)
3520 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int clear_filter
)
3522 struct ftrace_func_entry
*entry
;
3525 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3527 /* Do nothing if it doesn't exist */
3531 free_hash_entry(hash
, entry
);
3533 /* Do nothing if it exists */
3537 ret
= add_hash_entry(hash
, rec
->ip
);
3543 ftrace_match_record(struct dyn_ftrace
*rec
, struct ftrace_glob
*func_g
,
3544 struct ftrace_glob
*mod_g
, int exclude_mod
)
3546 char str
[KSYM_SYMBOL_LEN
];
3549 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3552 int mod_matches
= (modname
) ? ftrace_match(modname
, mod_g
) : 0;
3554 /* blank module name to match all modules */
3556 /* blank module globbing: modname xor exclude_mod */
3557 if ((!exclude_mod
) != (!modname
))
3562 /* not matching the module */
3563 if (!modname
|| !mod_matches
) {
3570 if (mod_matches
&& exclude_mod
)
3574 /* blank search means to match all funcs in the mod */
3579 return ftrace_match(str
, func_g
);
3583 match_records(struct ftrace_hash
*hash
, char *func
, int len
, char *mod
)
3585 struct ftrace_page
*pg
;
3586 struct dyn_ftrace
*rec
;
3587 struct ftrace_glob func_g
= { .type
= MATCH_FULL
};
3588 struct ftrace_glob mod_g
= { .type
= MATCH_FULL
};
3589 struct ftrace_glob
*mod_match
= (mod
) ? &mod_g
: NULL
;
3590 int exclude_mod
= 0;
3596 func_g
.type
= filter_parse_regex(func
, len
, &func_g
.search
,
3598 func_g
.len
= strlen(func_g
.search
);
3602 mod_g
.type
= filter_parse_regex(mod
, strlen(mod
),
3603 &mod_g
.search
, &exclude_mod
);
3604 mod_g
.len
= strlen(mod_g
.search
);
3607 mutex_lock(&ftrace_lock
);
3609 if (unlikely(ftrace_disabled
))
3612 do_for_each_ftrace_rec(pg
, rec
) {
3614 if (rec
->flags
& FTRACE_FL_DISABLED
)
3617 if (ftrace_match_record(rec
, &func_g
, mod_match
, exclude_mod
)) {
3618 ret
= enter_record(hash
, rec
, clear_filter
);
3625 } while_for_each_ftrace_rec();
3627 mutex_unlock(&ftrace_lock
);
3633 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3635 return match_records(hash
, buff
, len
, NULL
);
3640 * We register the module command as a template to show others how
3641 * to register the a command as well.
3645 ftrace_mod_callback(struct ftrace_hash
*hash
,
3646 char *func
, char *cmd
, char *module
, int enable
)
3651 * cmd == 'mod' because we only registered this func
3652 * for the 'mod' ftrace_func_command.
3653 * But if you register one func with multiple commands,
3654 * you can tell which command was used by the cmd
3657 ret
= match_records(hash
, func
, strlen(func
), module
);
3665 static struct ftrace_func_command ftrace_mod_cmd
= {
3667 .func
= ftrace_mod_callback
,
3670 static int __init
ftrace_mod_cmd_init(void)
3672 return register_ftrace_command(&ftrace_mod_cmd
);
3674 core_initcall(ftrace_mod_cmd_init
);
3676 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3677 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3679 struct ftrace_func_probe
*entry
;
3680 struct hlist_head
*hhd
;
3683 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3685 hhd
= &ftrace_func_hash
[key
];
3687 if (hlist_empty(hhd
))
3691 * Disable preemption for these calls to prevent a RCU grace
3692 * period. This syncs the hash iteration and freeing of items
3693 * on the hash. rcu_read_lock is too dangerous here.
3695 preempt_disable_notrace();
3696 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3697 if (entry
->ip
== ip
)
3698 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3700 preempt_enable_notrace();
3703 static struct ftrace_ops trace_probe_ops __read_mostly
=
3705 .func
= function_trace_probe_call
,
3706 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3707 INIT_OPS_HASH(trace_probe_ops
)
3710 static int ftrace_probe_registered
;
3712 static void __enable_ftrace_function_probe(struct ftrace_ops_hash
*old_hash
)
3717 if (ftrace_probe_registered
) {
3718 /* still need to update the function call sites */
3720 ftrace_run_modify_code(&trace_probe_ops
, FTRACE_UPDATE_CALLS
,
3725 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3726 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3730 /* Nothing registered? */
3731 if (i
== FTRACE_FUNC_HASHSIZE
)
3734 ret
= ftrace_startup(&trace_probe_ops
, 0);
3736 ftrace_probe_registered
= 1;
3739 static void __disable_ftrace_function_probe(void)
3743 if (!ftrace_probe_registered
)
3746 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3747 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3752 /* no more funcs left */
3753 ftrace_shutdown(&trace_probe_ops
, 0);
3755 ftrace_probe_registered
= 0;
3759 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3761 if (entry
->ops
->free
)
3762 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3767 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3770 struct ftrace_ops_hash old_hash_ops
;
3771 struct ftrace_func_probe
*entry
;
3772 struct ftrace_glob func_g
;
3773 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3774 struct ftrace_hash
*old_hash
= *orig_hash
;
3775 struct ftrace_hash
*hash
;
3776 struct ftrace_page
*pg
;
3777 struct dyn_ftrace
*rec
;
3783 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
3784 &func_g
.search
, ¬);
3785 func_g
.len
= strlen(func_g
.search
);
3787 /* we do not support '!' for function probes */
3791 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3793 old_hash_ops
.filter_hash
= old_hash
;
3794 /* Probes only have filters */
3795 old_hash_ops
.notrace_hash
= NULL
;
3797 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
3803 if (unlikely(ftrace_disabled
)) {
3808 mutex_lock(&ftrace_lock
);
3810 do_for_each_ftrace_rec(pg
, rec
) {
3812 if (rec
->flags
& FTRACE_FL_DISABLED
)
3815 if (!ftrace_match_record(rec
, &func_g
, NULL
, 0))
3818 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3820 /* If we did not process any, then return error */
3831 * The caller might want to do something special
3832 * for each function we find. We call the callback
3833 * to give the caller an opportunity to do so.
3836 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3837 /* caller does not like this func */
3843 ret
= enter_record(hash
, rec
, 0);
3851 entry
->ip
= rec
->ip
;
3853 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3854 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3856 } while_for_each_ftrace_rec();
3858 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3860 __enable_ftrace_function_probe(&old_hash_ops
);
3863 free_ftrace_hash_rcu(old_hash
);
3868 mutex_unlock(&ftrace_lock
);
3870 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3871 free_ftrace_hash(hash
);
3877 PROBE_TEST_FUNC
= 1,
3882 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3883 void *data
, int flags
)
3885 struct ftrace_func_entry
*rec_entry
;
3886 struct ftrace_func_probe
*entry
;
3887 struct ftrace_func_probe
*p
;
3888 struct ftrace_glob func_g
;
3889 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3890 struct ftrace_hash
*old_hash
= *orig_hash
;
3891 struct list_head free_list
;
3892 struct ftrace_hash
*hash
;
3893 struct hlist_node
*tmp
;
3894 char str
[KSYM_SYMBOL_LEN
];
3897 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3898 func_g
.search
= NULL
;
3902 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
3903 &func_g
.search
, ¬);
3904 func_g
.len
= strlen(func_g
.search
);
3905 func_g
.search
= glob
;
3907 /* we do not support '!' for function probes */
3912 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3914 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3916 /* Hmm, should report this somehow */
3919 INIT_LIST_HEAD(&free_list
);
3921 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3922 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3924 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3926 /* break up if statements for readability */
3927 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3930 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3933 /* do this last, since it is the most expensive */
3934 if (func_g
.search
) {
3935 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3937 if (!ftrace_match(str
, &func_g
))
3941 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3942 /* It is possible more than one entry had this ip */
3944 free_hash_entry(hash
, rec_entry
);
3946 hlist_del_rcu(&entry
->node
);
3947 list_add(&entry
->free_list
, &free_list
);
3950 mutex_lock(&ftrace_lock
);
3951 __disable_ftrace_function_probe();
3953 * Remove after the disable is called. Otherwise, if the last
3954 * probe is removed, a null hash means *all enabled*.
3956 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3957 synchronize_sched();
3959 free_ftrace_hash_rcu(old_hash
);
3961 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3962 list_del(&entry
->free_list
);
3963 ftrace_free_entry(entry
);
3965 mutex_unlock(&ftrace_lock
);
3968 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3969 free_ftrace_hash(hash
);
3973 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3976 __unregister_ftrace_function_probe(glob
, ops
, data
,
3977 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3981 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3983 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3986 void unregister_ftrace_function_probe_all(char *glob
)
3988 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3991 static LIST_HEAD(ftrace_commands
);
3992 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3995 * Currently we only register ftrace commands from __init, so mark this
3998 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
4000 struct ftrace_func_command
*p
;
4003 mutex_lock(&ftrace_cmd_mutex
);
4004 list_for_each_entry(p
, &ftrace_commands
, list
) {
4005 if (strcmp(cmd
->name
, p
->name
) == 0) {
4010 list_add(&cmd
->list
, &ftrace_commands
);
4012 mutex_unlock(&ftrace_cmd_mutex
);
4018 * Currently we only unregister ftrace commands from __init, so mark
4021 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
4023 struct ftrace_func_command
*p
, *n
;
4026 mutex_lock(&ftrace_cmd_mutex
);
4027 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
4028 if (strcmp(cmd
->name
, p
->name
) == 0) {
4030 list_del_init(&p
->list
);
4035 mutex_unlock(&ftrace_cmd_mutex
);
4040 static int ftrace_process_regex(struct ftrace_hash
*hash
,
4041 char *buff
, int len
, int enable
)
4043 char *func
, *command
, *next
= buff
;
4044 struct ftrace_func_command
*p
;
4047 func
= strsep(&next
, ":");
4050 ret
= ftrace_match_records(hash
, func
, len
);
4060 command
= strsep(&next
, ":");
4062 mutex_lock(&ftrace_cmd_mutex
);
4063 list_for_each_entry(p
, &ftrace_commands
, list
) {
4064 if (strcmp(p
->name
, command
) == 0) {
4065 ret
= p
->func(hash
, func
, command
, next
, enable
);
4070 mutex_unlock(&ftrace_cmd_mutex
);
4076 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
4077 size_t cnt
, loff_t
*ppos
, int enable
)
4079 struct ftrace_iterator
*iter
;
4080 struct trace_parser
*parser
;
4086 if (file
->f_mode
& FMODE_READ
) {
4087 struct seq_file
*m
= file
->private_data
;
4090 iter
= file
->private_data
;
4092 if (unlikely(ftrace_disabled
))
4095 /* iter->hash is a local copy, so we don't need regex_lock */
4097 parser
= &iter
->parser
;
4098 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
4100 if (read
>= 0 && trace_parser_loaded(parser
) &&
4101 !trace_parser_cont(parser
)) {
4102 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
4103 parser
->idx
, enable
);
4104 trace_parser_clear(parser
);
4115 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
4116 size_t cnt
, loff_t
*ppos
)
4118 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
4122 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
4123 size_t cnt
, loff_t
*ppos
)
4125 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
4129 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
4131 struct ftrace_func_entry
*entry
;
4133 if (!ftrace_location(ip
))
4137 entry
= ftrace_lookup_ip(hash
, ip
);
4140 free_hash_entry(hash
, entry
);
4144 return add_hash_entry(hash
, ip
);
4147 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
4148 struct ftrace_ops_hash
*old_hash
)
4150 struct ftrace_ops
*op
;
4152 if (!ftrace_enabled
)
4155 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
4156 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
4161 * If this is the shared global_ops filter, then we need to
4162 * check if there is another ops that shares it, is enabled.
4163 * If so, we still need to run the modify code.
4165 if (ops
->func_hash
!= &global_ops
.local_hash
)
4168 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4169 if (op
->func_hash
== &global_ops
.local_hash
&&
4170 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
4171 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
4172 /* Only need to do this once */
4175 } while_for_each_ftrace_op(op
);
4179 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4180 unsigned long ip
, int remove
, int reset
, int enable
)
4182 struct ftrace_hash
**orig_hash
;
4183 struct ftrace_ops_hash old_hash_ops
;
4184 struct ftrace_hash
*old_hash
;
4185 struct ftrace_hash
*hash
;
4188 if (unlikely(ftrace_disabled
))
4191 mutex_lock(&ops
->func_hash
->regex_lock
);
4194 orig_hash
= &ops
->func_hash
->filter_hash
;
4196 orig_hash
= &ops
->func_hash
->notrace_hash
;
4199 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4201 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4205 goto out_regex_unlock
;
4208 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4210 goto out_regex_unlock
;
4213 ret
= ftrace_match_addr(hash
, ip
, remove
);
4215 goto out_regex_unlock
;
4218 mutex_lock(&ftrace_lock
);
4219 old_hash
= *orig_hash
;
4220 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
4221 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
4222 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
4224 ftrace_ops_update_code(ops
, &old_hash_ops
);
4225 free_ftrace_hash_rcu(old_hash
);
4227 mutex_unlock(&ftrace_lock
);
4230 mutex_unlock(&ops
->func_hash
->regex_lock
);
4232 free_ftrace_hash(hash
);
4237 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4238 int reset
, int enable
)
4240 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
4244 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4245 * @ops - the ops to set the filter with
4246 * @ip - the address to add to or remove from the filter.
4247 * @remove - non zero to remove the ip from the filter
4248 * @reset - non zero to reset all filters before applying this filter.
4250 * Filters denote which functions should be enabled when tracing is enabled
4251 * If @ip is NULL, it failes to update filter.
4253 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4254 int remove
, int reset
)
4256 ftrace_ops_init(ops
);
4257 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4259 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4262 * ftrace_ops_set_global_filter - setup ops to use global filters
4263 * @ops - the ops which will use the global filters
4265 * ftrace users who need global function trace filtering should call this.
4266 * It can set the global filter only if ops were not initialized before.
4268 void ftrace_ops_set_global_filter(struct ftrace_ops
*ops
)
4270 if (ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)
4273 ftrace_ops_init(ops
);
4274 ops
->func_hash
= &global_ops
.local_hash
;
4276 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter
);
4279 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4280 int reset
, int enable
)
4282 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4286 * ftrace_set_filter - set a function to filter on in ftrace
4287 * @ops - the ops to set the filter with
4288 * @buf - the string that holds the function filter text.
4289 * @len - the length of the string.
4290 * @reset - non zero to reset all filters before applying this filter.
4292 * Filters denote which functions should be enabled when tracing is enabled.
4293 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4295 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4298 ftrace_ops_init(ops
);
4299 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4301 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4304 * ftrace_set_notrace - set a function to not trace in ftrace
4305 * @ops - the ops to set the notrace filter with
4306 * @buf - the string that holds the function notrace text.
4307 * @len - the length of the string.
4308 * @reset - non zero to reset all filters before applying this filter.
4310 * Notrace Filters denote which functions should not be enabled when tracing
4311 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4314 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4317 ftrace_ops_init(ops
);
4318 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4320 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4322 * ftrace_set_global_filter - set a function to filter on with global tracers
4323 * @buf - the string that holds the function filter text.
4324 * @len - the length of the string.
4325 * @reset - non zero to reset all filters before applying this filter.
4327 * Filters denote which functions should be enabled when tracing is enabled.
4328 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4330 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4332 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4334 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4337 * ftrace_set_global_notrace - set a function to not trace with global tracers
4338 * @buf - the string that holds the function notrace text.
4339 * @len - the length of the string.
4340 * @reset - non zero to reset all filters before applying this filter.
4342 * Notrace Filters denote which functions should not be enabled when tracing
4343 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4346 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4348 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4350 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4353 * command line interface to allow users to set filters on boot up.
4355 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4356 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4357 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4359 /* Used by function selftest to not test if filter is set */
4360 bool ftrace_filter_param __initdata
;
4362 static int __init
set_ftrace_notrace(char *str
)
4364 ftrace_filter_param
= true;
4365 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4368 __setup("ftrace_notrace=", set_ftrace_notrace
);
4370 static int __init
set_ftrace_filter(char *str
)
4372 ftrace_filter_param
= true;
4373 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4376 __setup("ftrace_filter=", set_ftrace_filter
);
4378 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4379 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4380 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4381 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
4383 static unsigned long save_global_trampoline
;
4384 static unsigned long save_global_flags
;
4386 static int __init
set_graph_function(char *str
)
4388 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4391 __setup("ftrace_graph_filter=", set_graph_function
);
4393 static int __init
set_graph_notrace_function(char *str
)
4395 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4398 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4400 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4404 unsigned long *table
= ftrace_graph_funcs
;
4405 int *count
= &ftrace_graph_count
;
4408 table
= ftrace_graph_notrace_funcs
;
4409 count
= &ftrace_graph_notrace_count
;
4413 func
= strsep(&buf
, ",");
4414 /* we allow only one expression at a time */
4415 ret
= ftrace_set_func(table
, count
, FTRACE_GRAPH_MAX_FUNCS
, func
);
4417 printk(KERN_DEBUG
"ftrace: function %s not "
4418 "traceable\n", func
);
4421 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4424 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
4428 ftrace_ops_init(ops
);
4431 func
= strsep(&buf
, ",");
4432 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
4436 static void __init
set_ftrace_early_filters(void)
4438 if (ftrace_filter_buf
[0])
4439 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4440 if (ftrace_notrace_buf
[0])
4441 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4442 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4443 if (ftrace_graph_buf
[0])
4444 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4445 if (ftrace_graph_notrace_buf
[0])
4446 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4447 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4450 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4452 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4453 struct ftrace_ops_hash old_hash_ops
;
4454 struct ftrace_iterator
*iter
;
4455 struct ftrace_hash
**orig_hash
;
4456 struct ftrace_hash
*old_hash
;
4457 struct trace_parser
*parser
;
4461 if (file
->f_mode
& FMODE_READ
) {
4463 seq_release(inode
, file
);
4465 iter
= file
->private_data
;
4467 parser
= &iter
->parser
;
4468 if (trace_parser_loaded(parser
)) {
4469 parser
->buffer
[parser
->idx
] = 0;
4470 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4473 trace_parser_put(parser
);
4475 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4477 if (file
->f_mode
& FMODE_WRITE
) {
4478 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
4481 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
4483 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
4485 mutex_lock(&ftrace_lock
);
4486 old_hash
= *orig_hash
;
4487 old_hash_ops
.filter_hash
= iter
->ops
->func_hash
->filter_hash
;
4488 old_hash_ops
.notrace_hash
= iter
->ops
->func_hash
->notrace_hash
;
4489 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
4490 orig_hash
, iter
->hash
);
4492 ftrace_ops_update_code(iter
->ops
, &old_hash_ops
);
4493 free_ftrace_hash_rcu(old_hash
);
4495 mutex_unlock(&ftrace_lock
);
4498 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
4499 free_ftrace_hash(iter
->hash
);
4505 static const struct file_operations ftrace_avail_fops
= {
4506 .open
= ftrace_avail_open
,
4508 .llseek
= seq_lseek
,
4509 .release
= seq_release_private
,
4512 static const struct file_operations ftrace_enabled_fops
= {
4513 .open
= ftrace_enabled_open
,
4515 .llseek
= seq_lseek
,
4516 .release
= seq_release_private
,
4519 static const struct file_operations ftrace_filter_fops
= {
4520 .open
= ftrace_filter_open
,
4522 .write
= ftrace_filter_write
,
4523 .llseek
= tracing_lseek
,
4524 .release
= ftrace_regex_release
,
4527 static const struct file_operations ftrace_notrace_fops
= {
4528 .open
= ftrace_notrace_open
,
4530 .write
= ftrace_notrace_write
,
4531 .llseek
= tracing_lseek
,
4532 .release
= ftrace_regex_release
,
4535 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4537 static DEFINE_MUTEX(graph_lock
);
4539 int ftrace_graph_count
;
4540 int ftrace_graph_notrace_count
;
4541 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4542 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4544 struct ftrace_graph_data
{
4545 unsigned long *table
;
4548 const struct seq_operations
*seq_ops
;
4552 __g_next(struct seq_file
*m
, loff_t
*pos
)
4554 struct ftrace_graph_data
*fgd
= m
->private;
4556 if (*pos
>= *fgd
->count
)
4558 return &fgd
->table
[*pos
];
4562 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4565 return __g_next(m
, pos
);
4568 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4570 struct ftrace_graph_data
*fgd
= m
->private;
4572 mutex_lock(&graph_lock
);
4574 /* Nothing, tell g_show to print all functions are enabled */
4575 if (!*fgd
->count
&& !*pos
)
4578 return __g_next(m
, pos
);
4581 static void g_stop(struct seq_file
*m
, void *p
)
4583 mutex_unlock(&graph_lock
);
4586 static int g_show(struct seq_file
*m
, void *v
)
4588 unsigned long *ptr
= v
;
4593 if (ptr
== (unsigned long *)1) {
4594 struct ftrace_graph_data
*fgd
= m
->private;
4596 if (fgd
->table
== ftrace_graph_funcs
)
4597 seq_puts(m
, "#### all functions enabled ####\n");
4599 seq_puts(m
, "#### no functions disabled ####\n");
4603 seq_printf(m
, "%ps\n", (void *)*ptr
);
4608 static const struct seq_operations ftrace_graph_seq_ops
= {
4616 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4617 struct ftrace_graph_data
*fgd
)
4621 mutex_lock(&graph_lock
);
4622 if ((file
->f_mode
& FMODE_WRITE
) &&
4623 (file
->f_flags
& O_TRUNC
)) {
4625 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
4627 mutex_unlock(&graph_lock
);
4629 if (file
->f_mode
& FMODE_READ
) {
4630 ret
= seq_open(file
, fgd
->seq_ops
);
4632 struct seq_file
*m
= file
->private_data
;
4636 file
->private_data
= fgd
;
4642 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4644 struct ftrace_graph_data
*fgd
;
4646 if (unlikely(ftrace_disabled
))
4649 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4653 fgd
->table
= ftrace_graph_funcs
;
4654 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4655 fgd
->count
= &ftrace_graph_count
;
4656 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4658 return __ftrace_graph_open(inode
, file
, fgd
);
4662 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4664 struct ftrace_graph_data
*fgd
;
4666 if (unlikely(ftrace_disabled
))
4669 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4673 fgd
->table
= ftrace_graph_notrace_funcs
;
4674 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4675 fgd
->count
= &ftrace_graph_notrace_count
;
4676 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4678 return __ftrace_graph_open(inode
, file
, fgd
);
4682 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
4684 if (file
->f_mode
& FMODE_READ
) {
4685 struct seq_file
*m
= file
->private_data
;
4688 seq_release(inode
, file
);
4690 kfree(file
->private_data
);
4697 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
4699 struct ftrace_glob func_g
;
4700 struct dyn_ftrace
*rec
;
4701 struct ftrace_page
*pg
;
4708 func_g
.type
= filter_parse_regex(buffer
, strlen(buffer
),
4709 &func_g
.search
, ¬);
4710 if (!not && *idx
>= size
)
4713 func_g
.len
= strlen(func_g
.search
);
4715 mutex_lock(&ftrace_lock
);
4717 if (unlikely(ftrace_disabled
)) {
4718 mutex_unlock(&ftrace_lock
);
4722 do_for_each_ftrace_rec(pg
, rec
) {
4724 if (rec
->flags
& FTRACE_FL_DISABLED
)
4727 if (ftrace_match_record(rec
, &func_g
, NULL
, 0)) {
4728 /* if it is in the array */
4730 for (i
= 0; i
< *idx
; i
++) {
4731 if (array
[i
] == rec
->ip
) {
4740 array
[(*idx
)++] = rec
->ip
;
4746 array
[i
] = array
[--(*idx
)];
4752 } while_for_each_ftrace_rec();
4754 mutex_unlock(&ftrace_lock
);
4763 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4764 size_t cnt
, loff_t
*ppos
)
4766 struct trace_parser parser
;
4767 ssize_t read
, ret
= 0;
4768 struct ftrace_graph_data
*fgd
= file
->private_data
;
4773 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4776 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4778 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4779 parser
.buffer
[parser
.idx
] = 0;
4781 mutex_lock(&graph_lock
);
4783 /* we allow only one expression at a time */
4784 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4787 mutex_unlock(&graph_lock
);
4793 trace_parser_put(&parser
);
4798 static const struct file_operations ftrace_graph_fops
= {
4799 .open
= ftrace_graph_open
,
4801 .write
= ftrace_graph_write
,
4802 .llseek
= tracing_lseek
,
4803 .release
= ftrace_graph_release
,
4806 static const struct file_operations ftrace_graph_notrace_fops
= {
4807 .open
= ftrace_graph_notrace_open
,
4809 .write
= ftrace_graph_write
,
4810 .llseek
= tracing_lseek
,
4811 .release
= ftrace_graph_release
,
4813 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4815 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
4816 struct dentry
*parent
)
4819 trace_create_file("set_ftrace_filter", 0644, parent
,
4820 ops
, &ftrace_filter_fops
);
4822 trace_create_file("set_ftrace_notrace", 0644, parent
,
4823 ops
, &ftrace_notrace_fops
);
4827 * The name "destroy_filter_files" is really a misnomer. Although
4828 * in the future, it may actualy delete the files, but this is
4829 * really intended to make sure the ops passed in are disabled
4830 * and that when this function returns, the caller is free to
4833 * The "destroy" name is only to match the "create" name that this
4834 * should be paired with.
4836 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
4838 mutex_lock(&ftrace_lock
);
4839 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
4840 ftrace_shutdown(ops
, 0);
4841 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
4842 mutex_unlock(&ftrace_lock
);
4845 static __init
int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
)
4848 trace_create_file("available_filter_functions", 0444,
4849 d_tracer
, NULL
, &ftrace_avail_fops
);
4851 trace_create_file("enabled_functions", 0444,
4852 d_tracer
, NULL
, &ftrace_enabled_fops
);
4854 ftrace_create_filter_files(&global_ops
, d_tracer
);
4856 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4857 trace_create_file("set_graph_function", 0444, d_tracer
,
4859 &ftrace_graph_fops
);
4860 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4862 &ftrace_graph_notrace_fops
);
4863 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4868 static int ftrace_cmp_ips(const void *a
, const void *b
)
4870 const unsigned long *ipa
= a
;
4871 const unsigned long *ipb
= b
;
4880 static int ftrace_process_locs(struct module
*mod
,
4881 unsigned long *start
,
4884 struct ftrace_page
*start_pg
;
4885 struct ftrace_page
*pg
;
4886 struct dyn_ftrace
*rec
;
4887 unsigned long count
;
4890 unsigned long flags
= 0; /* Shut up gcc */
4893 count
= end
- start
;
4898 sort(start
, count
, sizeof(*start
),
4899 ftrace_cmp_ips
, NULL
);
4901 start_pg
= ftrace_allocate_pages(count
);
4905 mutex_lock(&ftrace_lock
);
4908 * Core and each module needs their own pages, as
4909 * modules will free them when they are removed.
4910 * Force a new page to be allocated for modules.
4913 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4914 /* First initialization */
4915 ftrace_pages
= ftrace_pages_start
= start_pg
;
4920 if (WARN_ON(ftrace_pages
->next
)) {
4921 /* Hmm, we have free pages? */
4922 while (ftrace_pages
->next
)
4923 ftrace_pages
= ftrace_pages
->next
;
4926 ftrace_pages
->next
= start_pg
;
4932 addr
= ftrace_call_adjust(*p
++);
4934 * Some architecture linkers will pad between
4935 * the different mcount_loc sections of different
4936 * object files to satisfy alignments.
4937 * Skip any NULL pointers.
4942 if (pg
->index
== pg
->size
) {
4943 /* We should have allocated enough */
4944 if (WARN_ON(!pg
->next
))
4949 rec
= &pg
->records
[pg
->index
++];
4953 /* We should have used all pages */
4956 /* Assign the last page to ftrace_pages */
4960 * We only need to disable interrupts on start up
4961 * because we are modifying code that an interrupt
4962 * may execute, and the modification is not atomic.
4963 * But for modules, nothing runs the code we modify
4964 * until we are finished with it, and there's no
4965 * reason to cause large interrupt latencies while we do it.
4968 local_irq_save(flags
);
4969 ftrace_update_code(mod
, start_pg
);
4971 local_irq_restore(flags
);
4974 mutex_unlock(&ftrace_lock
);
4979 #ifdef CONFIG_MODULES
4981 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4983 static int referenced_filters(struct dyn_ftrace
*rec
)
4985 struct ftrace_ops
*ops
;
4988 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
4989 if (ops_references_rec(ops
, rec
))
4996 void ftrace_release_mod(struct module
*mod
)
4998 struct dyn_ftrace
*rec
;
4999 struct ftrace_page
**last_pg
;
5000 struct ftrace_page
*pg
;
5003 mutex_lock(&ftrace_lock
);
5005 if (ftrace_disabled
)
5009 * Each module has its own ftrace_pages, remove
5010 * them from the list.
5012 last_pg
= &ftrace_pages_start
;
5013 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
5014 rec
= &pg
->records
[0];
5015 if (within_module_core(rec
->ip
, mod
)) {
5017 * As core pages are first, the first
5018 * page should never be a module page.
5020 if (WARN_ON(pg
== ftrace_pages_start
))
5023 /* Check if we are deleting the last page */
5024 if (pg
== ftrace_pages
)
5025 ftrace_pages
= next_to_ftrace_page(last_pg
);
5027 *last_pg
= pg
->next
;
5028 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
5029 free_pages((unsigned long)pg
->records
, order
);
5032 last_pg
= &pg
->next
;
5035 mutex_unlock(&ftrace_lock
);
5038 void ftrace_module_enable(struct module
*mod
)
5040 struct dyn_ftrace
*rec
;
5041 struct ftrace_page
*pg
;
5043 mutex_lock(&ftrace_lock
);
5045 if (ftrace_disabled
)
5049 * If the tracing is enabled, go ahead and enable the record.
5051 * The reason not to enable the record immediatelly is the
5052 * inherent check of ftrace_make_nop/ftrace_make_call for
5053 * correct previous instructions. Making first the NOP
5054 * conversion puts the module to the correct state, thus
5055 * passing the ftrace_make_call check.
5057 * We also delay this to after the module code already set the
5058 * text to read-only, as we now need to set it back to read-write
5059 * so that we can modify the text.
5061 if (ftrace_start_up
)
5062 ftrace_arch_code_modify_prepare();
5064 do_for_each_ftrace_rec(pg
, rec
) {
5067 * do_for_each_ftrace_rec() is a double loop.
5068 * module text shares the pg. If a record is
5069 * not part of this module, then skip this pg,
5070 * which the "break" will do.
5072 if (!within_module_core(rec
->ip
, mod
))
5078 * When adding a module, we need to check if tracers are
5079 * currently enabled and if they are, and can trace this record,
5080 * we need to enable the module functions as well as update the
5081 * reference counts for those function records.
5083 if (ftrace_start_up
)
5084 cnt
+= referenced_filters(rec
);
5086 /* This clears FTRACE_FL_DISABLED */
5089 if (ftrace_start_up
&& cnt
) {
5090 int failed
= __ftrace_replace_code(rec
, 1);
5092 ftrace_bug(failed
, rec
);
5097 } while_for_each_ftrace_rec();
5100 if (ftrace_start_up
)
5101 ftrace_arch_code_modify_post_process();
5104 mutex_unlock(&ftrace_lock
);
5107 void ftrace_module_init(struct module
*mod
)
5109 if (ftrace_disabled
|| !mod
->num_ftrace_callsites
)
5112 ftrace_process_locs(mod
, mod
->ftrace_callsites
,
5113 mod
->ftrace_callsites
+ mod
->num_ftrace_callsites
);
5115 #endif /* CONFIG_MODULES */
5117 void __init
ftrace_init(void)
5119 extern unsigned long __start_mcount_loc
[];
5120 extern unsigned long __stop_mcount_loc
[];
5121 unsigned long count
, flags
;
5124 local_irq_save(flags
);
5125 ret
= ftrace_dyn_arch_init();
5126 local_irq_restore(flags
);
5130 count
= __stop_mcount_loc
- __start_mcount_loc
;
5132 pr_info("ftrace: No functions to be traced?\n");
5136 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5137 count
, count
/ ENTRIES_PER_PAGE
+ 1);
5139 last_ftrace_enabled
= ftrace_enabled
= 1;
5141 ret
= ftrace_process_locs(NULL
,
5145 set_ftrace_early_filters();
5149 ftrace_disabled
= 1;
5152 /* Do nothing if arch does not support this */
5153 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
5157 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5161 * Currently there's no safe way to free a trampoline when the kernel
5162 * is configured with PREEMPT. That is because a task could be preempted
5163 * when it jumped to the trampoline, it may be preempted for a long time
5164 * depending on the system load, and currently there's no way to know
5165 * when it will be off the trampoline. If the trampoline is freed
5166 * too early, when the task runs again, it will be executing on freed
5169 #ifdef CONFIG_PREEMPT
5170 /* Currently, only non dynamic ops can have a trampoline */
5171 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
5175 arch_ftrace_update_trampoline(ops
);
5180 static struct ftrace_ops global_ops
= {
5181 .func
= ftrace_stub
,
5182 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5183 FTRACE_OPS_FL_INITIALIZED
|
5187 static int __init
ftrace_nodyn_init(void)
5192 core_initcall(ftrace_nodyn_init
);
5194 static inline int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
) { return 0; }
5195 static inline void ftrace_startup_enable(int command
) { }
5196 static inline void ftrace_startup_all(int command
) { }
5197 /* Keep as macros so we do not need to define the commands */
5198 # define ftrace_startup(ops, command) \
5200 int ___ret = __register_ftrace_function(ops); \
5202 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5205 # define ftrace_shutdown(ops, command) \
5207 int ___ret = __unregister_ftrace_function(ops); \
5209 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5213 # define ftrace_startup_sysctl() do { } while (0)
5214 # define ftrace_shutdown_sysctl() do { } while (0)
5217 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
5222 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5226 #endif /* CONFIG_DYNAMIC_FTRACE */
5228 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
5230 tr
->ops
= &global_ops
;
5231 tr
->ops
->private = tr
;
5234 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
5236 /* If we filter on pids, update to use the pid function */
5237 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
5238 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
5239 printk("ftrace ops had %pS for function\n",
5242 tr
->ops
->func
= func
;
5243 tr
->ops
->private = tr
;
5246 void ftrace_reset_array_ops(struct trace_array
*tr
)
5248 tr
->ops
->func
= ftrace_stub
;
5252 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5253 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
5255 struct ftrace_ops
*op
;
5258 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5263 * Some of the ops may be dynamically allocated,
5264 * they must be freed after a synchronize_sched().
5266 preempt_disable_notrace();
5268 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5270 * Check the following for each ops before calling their func:
5271 * if RCU flag is set, then rcu_is_watching() must be true
5272 * if PER_CPU is set, then ftrace_function_local_disable()
5274 * Otherwise test if the ip matches the ops filter
5276 * If any of the above fails then the op->func() is not executed.
5278 if ((!(op
->flags
& FTRACE_OPS_FL_RCU
) || rcu_is_watching()) &&
5279 (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5280 !ftrace_function_local_disabled(op
)) &&
5281 ftrace_ops_test(op
, ip
, regs
)) {
5283 if (FTRACE_WARN_ON(!op
->func
)) {
5284 pr_warn("op=%p %pS\n", op
, op
);
5287 op
->func(ip
, parent_ip
, op
, regs
);
5289 } while_for_each_ftrace_op(op
);
5291 preempt_enable_notrace();
5292 trace_clear_recursion(bit
);
5296 * Some archs only support passing ip and parent_ip. Even though
5297 * the list function ignores the op parameter, we do not want any
5298 * C side effects, where a function is called without the caller
5299 * sending a third parameter.
5300 * Archs are to support both the regs and ftrace_ops at the same time.
5301 * If they support ftrace_ops, it is assumed they support regs.
5302 * If call backs want to use regs, they must either check for regs
5303 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5304 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5305 * An architecture can pass partial regs with ftrace_ops and still
5306 * set the ARCH_SUPPORTS_FTRACE_OPS.
5308 #if ARCH_SUPPORTS_FTRACE_OPS
5309 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5310 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5312 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
5315 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
5317 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
5322 * If there's only one function registered but it does not support
5323 * recursion, needs RCU protection and/or requires per cpu handling, then
5324 * this function will be called by the mcount trampoline.
5326 static void ftrace_ops_assist_func(unsigned long ip
, unsigned long parent_ip
,
5327 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5331 if ((op
->flags
& FTRACE_OPS_FL_RCU
) && !rcu_is_watching())
5334 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5338 preempt_disable_notrace();
5340 if (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5341 !ftrace_function_local_disabled(op
)) {
5342 op
->func(ip
, parent_ip
, op
, regs
);
5345 preempt_enable_notrace();
5346 trace_clear_recursion(bit
);
5350 * ftrace_ops_get_func - get the function a trampoline should call
5351 * @ops: the ops to get the function for
5353 * Normally the mcount trampoline will call the ops->func, but there
5354 * are times that it should not. For example, if the ops does not
5355 * have its own recursion protection, then it should call the
5356 * ftrace_ops_recurs_func() instead.
5358 * Returns the function that the trampoline should call for @ops.
5360 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
5363 * If the function does not handle recursion, needs to be RCU safe,
5364 * or does per cpu logic, then we need to call the assist handler.
5366 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) ||
5367 ops
->flags
& (FTRACE_OPS_FL_RCU
| FTRACE_OPS_FL_PER_CPU
))
5368 return ftrace_ops_assist_func
;
5374 ftrace_filter_pid_sched_switch_probe(void *data
, bool preempt
,
5375 struct task_struct
*prev
, struct task_struct
*next
)
5377 struct trace_array
*tr
= data
;
5378 struct trace_pid_list
*pid_list
;
5380 pid_list
= rcu_dereference_sched(tr
->function_pids
);
5382 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
5383 trace_ignore_this_task(pid_list
, next
));
5386 static void clear_ftrace_pids(struct trace_array
*tr
)
5388 struct trace_pid_list
*pid_list
;
5391 pid_list
= rcu_dereference_protected(tr
->function_pids
,
5392 lockdep_is_held(&ftrace_lock
));
5396 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
5398 for_each_possible_cpu(cpu
)
5399 per_cpu_ptr(tr
->trace_buffer
.data
, cpu
)->ftrace_ignore_pid
= false;
5401 rcu_assign_pointer(tr
->function_pids
, NULL
);
5403 /* Wait till all users are no longer using pid filtering */
5404 synchronize_sched();
5406 trace_free_pid_list(pid_list
);
5409 static void ftrace_pid_reset(struct trace_array
*tr
)
5411 mutex_lock(&ftrace_lock
);
5412 clear_ftrace_pids(tr
);
5414 ftrace_update_pid_func();
5415 ftrace_startup_all(0);
5417 mutex_unlock(&ftrace_lock
);
5420 /* Greater than any max PID */
5421 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
5423 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
5426 struct trace_pid_list
*pid_list
;
5427 struct trace_array
*tr
= m
->private;
5429 mutex_lock(&ftrace_lock
);
5430 rcu_read_lock_sched();
5432 pid_list
= rcu_dereference_sched(tr
->function_pids
);
5435 return !(*pos
) ? FTRACE_NO_PIDS
: NULL
;
5437 return trace_pid_start(pid_list
, pos
);
5440 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5442 struct trace_array
*tr
= m
->private;
5443 struct trace_pid_list
*pid_list
= rcu_dereference_sched(tr
->function_pids
);
5445 if (v
== FTRACE_NO_PIDS
)
5448 return trace_pid_next(pid_list
, v
, pos
);
5451 static void fpid_stop(struct seq_file
*m
, void *p
)
5454 rcu_read_unlock_sched();
5455 mutex_unlock(&ftrace_lock
);
5458 static int fpid_show(struct seq_file
*m
, void *v
)
5460 if (v
== FTRACE_NO_PIDS
) {
5461 seq_puts(m
, "no pid\n");
5465 return trace_pid_show(m
, v
);
5468 static const struct seq_operations ftrace_pid_sops
= {
5469 .start
= fpid_start
,
5476 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
5478 struct trace_array
*tr
= inode
->i_private
;
5482 if (trace_array_get(tr
) < 0)
5485 if ((file
->f_mode
& FMODE_WRITE
) &&
5486 (file
->f_flags
& O_TRUNC
))
5487 ftrace_pid_reset(tr
);
5489 ret
= seq_open(file
, &ftrace_pid_sops
);
5491 trace_array_put(tr
);
5493 m
= file
->private_data
;
5494 /* copy tr over to seq ops */
5501 static void ignore_task_cpu(void *data
)
5503 struct trace_array
*tr
= data
;
5504 struct trace_pid_list
*pid_list
;
5507 * This function is called by on_each_cpu() while the
5508 * event_mutex is held.
5510 pid_list
= rcu_dereference_protected(tr
->function_pids
,
5511 mutex_is_locked(&ftrace_lock
));
5513 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
5514 trace_ignore_this_task(pid_list
, current
));
5518 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
5519 size_t cnt
, loff_t
*ppos
)
5521 struct seq_file
*m
= filp
->private_data
;
5522 struct trace_array
*tr
= m
->private;
5523 struct trace_pid_list
*filtered_pids
= NULL
;
5524 struct trace_pid_list
*pid_list
;
5530 mutex_lock(&ftrace_lock
);
5532 filtered_pids
= rcu_dereference_protected(tr
->function_pids
,
5533 lockdep_is_held(&ftrace_lock
));
5535 ret
= trace_pid_write(filtered_pids
, &pid_list
, ubuf
, cnt
);
5539 rcu_assign_pointer(tr
->function_pids
, pid_list
);
5541 if (filtered_pids
) {
5542 synchronize_sched();
5543 trace_free_pid_list(filtered_pids
);
5544 } else if (pid_list
) {
5545 /* Register a probe to set whether to ignore the tracing of a task */
5546 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
5550 * Ignoring of pids is done at task switch. But we have to
5551 * check for those tasks that are currently running.
5552 * Always do this in case a pid was appended or removed.
5554 on_each_cpu(ignore_task_cpu
, tr
, 1);
5556 ftrace_update_pid_func();
5557 ftrace_startup_all(0);
5559 mutex_unlock(&ftrace_lock
);
5568 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
5570 struct trace_array
*tr
= inode
->i_private
;
5572 trace_array_put(tr
);
5574 return seq_release(inode
, file
);
5577 static const struct file_operations ftrace_pid_fops
= {
5578 .open
= ftrace_pid_open
,
5579 .write
= ftrace_pid_write
,
5581 .llseek
= tracing_lseek
,
5582 .release
= ftrace_pid_release
,
5585 void ftrace_init_tracefs(struct trace_array
*tr
, struct dentry
*d_tracer
)
5587 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
5588 tr
, &ftrace_pid_fops
);
5591 void __init
ftrace_init_tracefs_toplevel(struct trace_array
*tr
,
5592 struct dentry
*d_tracer
)
5594 /* Only the top level directory has the dyn_tracefs and profile */
5595 WARN_ON(!(tr
->flags
& TRACE_ARRAY_FL_GLOBAL
));
5597 ftrace_init_dyn_tracefs(d_tracer
);
5598 ftrace_profile_tracefs(d_tracer
);
5602 * ftrace_kill - kill ftrace
5604 * This function should be used by panic code. It stops ftrace
5605 * but in a not so nice way. If you need to simply kill ftrace
5606 * from a non-atomic section, use ftrace_kill.
5608 void ftrace_kill(void)
5610 ftrace_disabled
= 1;
5612 clear_ftrace_function();
5616 * Test if ftrace is dead or not.
5618 int ftrace_is_dead(void)
5620 return ftrace_disabled
;
5624 * register_ftrace_function - register a function for profiling
5625 * @ops - ops structure that holds the function for profiling.
5627 * Register a function to be called by all functions in the
5630 * Note: @ops->func and all the functions it calls must be labeled
5631 * with "notrace", otherwise it will go into a
5634 int register_ftrace_function(struct ftrace_ops
*ops
)
5638 ftrace_ops_init(ops
);
5640 mutex_lock(&ftrace_lock
);
5642 ret
= ftrace_startup(ops
, 0);
5644 mutex_unlock(&ftrace_lock
);
5648 EXPORT_SYMBOL_GPL(register_ftrace_function
);
5651 * unregister_ftrace_function - unregister a function for profiling.
5652 * @ops - ops structure that holds the function to unregister
5654 * Unregister a function that was added to be called by ftrace profiling.
5656 int unregister_ftrace_function(struct ftrace_ops
*ops
)
5660 mutex_lock(&ftrace_lock
);
5661 ret
= ftrace_shutdown(ops
, 0);
5662 mutex_unlock(&ftrace_lock
);
5666 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
5669 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
5670 void __user
*buffer
, size_t *lenp
,
5675 mutex_lock(&ftrace_lock
);
5677 if (unlikely(ftrace_disabled
))
5680 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
5682 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
5685 last_ftrace_enabled
= !!ftrace_enabled
;
5687 if (ftrace_enabled
) {
5689 /* we are starting ftrace again */
5690 if (ftrace_ops_list
!= &ftrace_list_end
)
5691 update_ftrace_function();
5693 ftrace_startup_sysctl();
5696 /* stopping ftrace calls (just send to ftrace_stub) */
5697 ftrace_trace_function
= ftrace_stub
;
5699 ftrace_shutdown_sysctl();
5703 mutex_unlock(&ftrace_lock
);
5707 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5709 static struct ftrace_ops graph_ops
= {
5710 .func
= ftrace_stub
,
5711 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5712 FTRACE_OPS_FL_INITIALIZED
|
5715 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5716 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
5717 /* trampoline_size is only needed for dynamically allocated tramps */
5719 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
5722 void ftrace_graph_sleep_time_control(bool enable
)
5724 fgraph_sleep_time
= enable
;
5727 void ftrace_graph_graph_time_control(bool enable
)
5729 fgraph_graph_time
= enable
;
5732 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
5737 /* The callbacks that hook a function */
5738 trace_func_graph_ret_t ftrace_graph_return
=
5739 (trace_func_graph_ret_t
)ftrace_stub
;
5740 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
5741 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5743 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5744 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
5748 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
5749 struct task_struct
*g
, *t
;
5751 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
5752 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
5753 * sizeof(struct ftrace_ret_stack
),
5755 if (!ret_stack_list
[i
]) {
5763 read_lock(&tasklist_lock
);
5764 do_each_thread(g
, t
) {
5770 if (t
->ret_stack
== NULL
) {
5771 atomic_set(&t
->tracing_graph_pause
, 0);
5772 atomic_set(&t
->trace_overrun
, 0);
5773 t
->curr_ret_stack
= -1;
5774 /* Make sure the tasks see the -1 first: */
5776 t
->ret_stack
= ret_stack_list
[start
++];
5778 } while_each_thread(g
, t
);
5781 read_unlock(&tasklist_lock
);
5783 for (i
= start
; i
< end
; i
++)
5784 kfree(ret_stack_list
[i
]);
5789 ftrace_graph_probe_sched_switch(void *ignore
, bool preempt
,
5790 struct task_struct
*prev
, struct task_struct
*next
)
5792 unsigned long long timestamp
;
5796 * Does the user want to count the time a function was asleep.
5797 * If so, do not update the time stamps.
5799 if (fgraph_sleep_time
)
5802 timestamp
= trace_clock_local();
5804 prev
->ftrace_timestamp
= timestamp
;
5806 /* only process tasks that we timestamped */
5807 if (!next
->ftrace_timestamp
)
5811 * Update all the counters in next to make up for the
5812 * time next was sleeping.
5814 timestamp
-= next
->ftrace_timestamp
;
5816 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
5817 next
->ret_stack
[index
].calltime
+= timestamp
;
5820 /* Allocate a return stack for each task */
5821 static int start_graph_tracing(void)
5823 struct ftrace_ret_stack
**ret_stack_list
;
5826 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
5827 sizeof(struct ftrace_ret_stack
*),
5830 if (!ret_stack_list
)
5833 /* The cpu_boot init_task->ret_stack will never be freed */
5834 for_each_online_cpu(cpu
) {
5835 if (!idle_task(cpu
)->ret_stack
)
5836 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
5840 ret
= alloc_retstack_tasklist(ret_stack_list
);
5841 } while (ret
== -EAGAIN
);
5844 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5846 pr_info("ftrace_graph: Couldn't activate tracepoint"
5847 " probe to kernel_sched_switch\n");
5850 kfree(ret_stack_list
);
5855 * Hibernation protection.
5856 * The state of the current task is too much unstable during
5857 * suspend/restore to disk. We want to protect against that.
5860 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
5864 case PM_HIBERNATION_PREPARE
:
5865 pause_graph_tracing();
5868 case PM_POST_HIBERNATION
:
5869 unpause_graph_tracing();
5875 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
5877 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
5879 return __ftrace_graph_entry(trace
);
5883 * The function graph tracer should only trace the functions defined
5884 * by set_ftrace_filter and set_ftrace_notrace. If another function
5885 * tracer ops is registered, the graph tracer requires testing the
5886 * function against the global ops, and not just trace any function
5887 * that any ftrace_ops registered.
5889 static void update_function_graph_func(void)
5891 struct ftrace_ops
*op
;
5892 bool do_test
= false;
5895 * The graph and global ops share the same set of functions
5896 * to test. If any other ops is on the list, then
5897 * the graph tracing needs to test if its the function
5900 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5901 if (op
!= &global_ops
&& op
!= &graph_ops
&&
5902 op
!= &ftrace_list_end
) {
5904 /* in double loop, break out with goto */
5907 } while_for_each_ftrace_op(op
);
5910 ftrace_graph_entry
= ftrace_graph_entry_test
;
5912 ftrace_graph_entry
= __ftrace_graph_entry
;
5915 static struct notifier_block ftrace_suspend_notifier
= {
5916 .notifier_call
= ftrace_suspend_notifier_call
,
5919 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5920 trace_func_graph_ent_t entryfunc
)
5924 mutex_lock(&ftrace_lock
);
5926 /* we currently allow only one tracer registered at a time */
5927 if (ftrace_graph_active
) {
5932 register_pm_notifier(&ftrace_suspend_notifier
);
5934 ftrace_graph_active
++;
5935 ret
= start_graph_tracing();
5937 ftrace_graph_active
--;
5941 ftrace_graph_return
= retfunc
;
5944 * Update the indirect function to the entryfunc, and the
5945 * function that gets called to the entry_test first. Then
5946 * call the update fgraph entry function to determine if
5947 * the entryfunc should be called directly or not.
5949 __ftrace_graph_entry
= entryfunc
;
5950 ftrace_graph_entry
= ftrace_graph_entry_test
;
5951 update_function_graph_func();
5953 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
5955 mutex_unlock(&ftrace_lock
);
5959 void unregister_ftrace_graph(void)
5961 mutex_lock(&ftrace_lock
);
5963 if (unlikely(!ftrace_graph_active
))
5966 ftrace_graph_active
--;
5967 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5968 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5969 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5970 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
5971 unregister_pm_notifier(&ftrace_suspend_notifier
);
5972 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5974 #ifdef CONFIG_DYNAMIC_FTRACE
5976 * Function graph does not allocate the trampoline, but
5977 * other global_ops do. We need to reset the ALLOC_TRAMP flag
5980 global_ops
.trampoline
= save_global_trampoline
;
5981 if (save_global_flags
& FTRACE_OPS_FL_ALLOC_TRAMP
)
5982 global_ops
.flags
|= FTRACE_OPS_FL_ALLOC_TRAMP
;
5986 mutex_unlock(&ftrace_lock
);
5989 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5992 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5994 atomic_set(&t
->tracing_graph_pause
, 0);
5995 atomic_set(&t
->trace_overrun
, 0);
5996 t
->ftrace_timestamp
= 0;
5997 /* make curr_ret_stack visible before we add the ret_stack */
5999 t
->ret_stack
= ret_stack
;
6003 * Allocate a return stack for the idle task. May be the first
6004 * time through, or it may be done by CPU hotplug online.
6006 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
6008 t
->curr_ret_stack
= -1;
6010 * The idle task has no parent, it either has its own
6011 * stack or no stack at all.
6014 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
6016 if (ftrace_graph_active
) {
6017 struct ftrace_ret_stack
*ret_stack
;
6019 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
6021 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6022 * sizeof(struct ftrace_ret_stack
),
6026 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
6028 graph_init_task(t
, ret_stack
);
6032 /* Allocate a return stack for newly created task */
6033 void ftrace_graph_init_task(struct task_struct
*t
)
6035 /* Make sure we do not use the parent ret_stack */
6036 t
->ret_stack
= NULL
;
6037 t
->curr_ret_stack
= -1;
6039 if (ftrace_graph_active
) {
6040 struct ftrace_ret_stack
*ret_stack
;
6042 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6043 * sizeof(struct ftrace_ret_stack
),
6047 graph_init_task(t
, ret_stack
);
6051 void ftrace_graph_exit_task(struct task_struct
*t
)
6053 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
6055 t
->ret_stack
= NULL
;
6056 /* NULL must become visible to IRQs before we free it: */