2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/debugfs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/bsearch.h>
26 #include <linux/module.h>
27 #include <linux/ftrace.h>
28 #include <linux/sysctl.h>
29 #include <linux/slab.h>
30 #include <linux/ctype.h>
31 #include <linux/sort.h>
32 #include <linux/list.h>
33 #include <linux/hash.h>
34 #include <linux/rcupdate.h>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
60 #define FTRACE_HASH_BITS 7
61 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62 #define FTRACE_HASH_DEFAULT_BITS 10
63 #define FTRACE_HASH_MAX_BITS 12
65 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
67 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_OPS_HASH(opsname) \
69 .func_hash = &opsname.local_hash, \
70 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
71 #define ASSIGN_OPS_HASH(opsname, val) \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #define INIT_OPS_HASH(opsname)
76 #define ASSIGN_OPS_HASH(opsname, val)
79 static struct ftrace_ops ftrace_list_end __read_mostly
= {
81 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
82 INIT_OPS_HASH(ftrace_list_end
)
85 /* ftrace_enabled is a method to turn ftrace on or off */
86 int ftrace_enabled __read_mostly
;
87 static int last_ftrace_enabled
;
89 /* Current function tracing op */
90 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
91 /* What to set function_trace_op to */
92 static struct ftrace_ops
*set_function_trace_op
;
94 /* List for set_ftrace_pid's pids. */
95 LIST_HEAD(ftrace_pids
);
97 struct list_head list
;
102 * ftrace_disabled is set when an anomaly is discovered.
103 * ftrace_disabled is much stronger than ftrace_enabled.
105 static int ftrace_disabled __read_mostly
;
107 static DEFINE_MUTEX(ftrace_lock
);
109 static struct ftrace_ops
*ftrace_control_list __read_mostly
= &ftrace_list_end
;
110 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
111 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
112 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
113 static struct ftrace_ops global_ops
;
114 static struct ftrace_ops control_ops
;
116 static void ftrace_ops_recurs_func(unsigned long ip
, unsigned long parent_ip
,
117 struct ftrace_ops
*op
, struct pt_regs
*regs
);
119 #if ARCH_SUPPORTS_FTRACE_OPS
120 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
121 struct ftrace_ops
*op
, struct pt_regs
*regs
);
123 /* See comment below, where ftrace_ops_list_func is defined */
124 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
125 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
129 * Traverse the ftrace_global_list, invoking all entries. The reason that we
130 * can use rcu_dereference_raw_notrace() is that elements removed from this list
131 * are simply leaked, so there is no need to interact with a grace-period
132 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
133 * concurrent insertions into the ftrace_global_list.
135 * Silly Alpha and silly pointer-speculation compiler optimizations!
137 #define do_for_each_ftrace_op(op, list) \
138 op = rcu_dereference_raw_notrace(list); \
142 * Optimized for just a single item in the list (as that is the normal case).
144 #define while_for_each_ftrace_op(op) \
145 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
146 unlikely((op) != &ftrace_list_end))
148 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
150 #ifdef CONFIG_DYNAMIC_FTRACE
151 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
152 mutex_init(&ops
->local_hash
.regex_lock
);
153 ops
->func_hash
= &ops
->local_hash
;
154 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
160 * ftrace_nr_registered_ops - return number of ops registered
162 * Returns the number of ftrace_ops registered and tracing functions
164 int ftrace_nr_registered_ops(void)
166 struct ftrace_ops
*ops
;
169 mutex_lock(&ftrace_lock
);
171 for (ops
= ftrace_ops_list
;
172 ops
!= &ftrace_list_end
; ops
= ops
->next
)
175 mutex_unlock(&ftrace_lock
);
180 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
181 struct ftrace_ops
*op
, struct pt_regs
*regs
)
183 if (!test_tsk_trace_trace(current
))
186 ftrace_pid_function(ip
, parent_ip
, op
, regs
);
189 static void set_ftrace_pid_function(ftrace_func_t func
)
191 /* do not set ftrace_pid_function to itself! */
192 if (func
!= ftrace_pid_func
)
193 ftrace_pid_function
= func
;
197 * clear_ftrace_function - reset the ftrace function
199 * This NULLs the ftrace function and in essence stops
200 * tracing. There may be lag
202 void clear_ftrace_function(void)
204 ftrace_trace_function
= ftrace_stub
;
205 ftrace_pid_function
= ftrace_stub
;
208 static void control_ops_disable_all(struct ftrace_ops
*ops
)
212 for_each_possible_cpu(cpu
)
213 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
216 static int control_ops_alloc(struct ftrace_ops
*ops
)
218 int __percpu
*disabled
;
220 disabled
= alloc_percpu(int);
224 ops
->disabled
= disabled
;
225 control_ops_disable_all(ops
);
229 static void ftrace_sync(struct work_struct
*work
)
232 * This function is just a stub to implement a hard force
233 * of synchronize_sched(). This requires synchronizing
234 * tasks even in userspace and idle.
236 * Yes, function tracing is rude.
240 static void ftrace_sync_ipi(void *data
)
242 /* Probably not needed, but do it anyway */
246 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
247 static void update_function_graph_func(void);
249 static inline void update_function_graph_func(void) { }
252 static void update_ftrace_function(void)
257 * Prepare the ftrace_ops that the arch callback will use.
258 * If there's only one ftrace_ops registered, the ftrace_ops_list
259 * will point to the ops we want.
261 set_function_trace_op
= ftrace_ops_list
;
263 /* If there's no ftrace_ops registered, just call the stub function */
264 if (ftrace_ops_list
== &ftrace_list_end
) {
268 * If we are at the end of the list and this ops is
269 * recursion safe and not dynamic and the arch supports passing ops,
270 * then have the mcount trampoline call the function directly.
272 } else if (ftrace_ops_list
->next
== &ftrace_list_end
) {
273 func
= ftrace_ops_get_func(ftrace_ops_list
);
276 /* Just use the default ftrace_ops */
277 set_function_trace_op
= &ftrace_list_end
;
278 func
= ftrace_ops_list_func
;
281 update_function_graph_func();
283 /* If there's no change, then do nothing more here */
284 if (ftrace_trace_function
== func
)
288 * If we are using the list function, it doesn't care
289 * about the function_trace_ops.
291 if (func
== ftrace_ops_list_func
) {
292 ftrace_trace_function
= func
;
294 * Don't even bother setting function_trace_ops,
295 * it would be racy to do so anyway.
300 #ifndef CONFIG_DYNAMIC_FTRACE
302 * For static tracing, we need to be a bit more careful.
303 * The function change takes affect immediately. Thus,
304 * we need to coorditate the setting of the function_trace_ops
305 * with the setting of the ftrace_trace_function.
307 * Set the function to the list ops, which will call the
308 * function we want, albeit indirectly, but it handles the
309 * ftrace_ops and doesn't depend on function_trace_op.
311 ftrace_trace_function
= ftrace_ops_list_func
;
313 * Make sure all CPUs see this. Yes this is slow, but static
314 * tracing is slow and nasty to have enabled.
316 schedule_on_each_cpu(ftrace_sync
);
317 /* Now all cpus are using the list ops. */
318 function_trace_op
= set_function_trace_op
;
319 /* Make sure the function_trace_op is visible on all CPUs */
321 /* Nasty way to force a rmb on all cpus */
322 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
323 /* OK, we are all set to update the ftrace_trace_function now! */
324 #endif /* !CONFIG_DYNAMIC_FTRACE */
326 ftrace_trace_function
= func
;
329 int using_ftrace_ops_list_func(void)
331 return ftrace_trace_function
== ftrace_ops_list_func
;
334 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
338 * We are entering ops into the list but another
339 * CPU might be walking that list. We need to make sure
340 * the ops->next pointer is valid before another CPU sees
341 * the ops pointer included into the list.
343 rcu_assign_pointer(*list
, ops
);
346 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
348 struct ftrace_ops
**p
;
351 * If we are removing the last function, then simply point
352 * to the ftrace_stub.
354 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
355 *list
= &ftrace_list_end
;
359 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
370 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
371 struct ftrace_ops
*main_ops
,
372 struct ftrace_ops
*ops
)
374 int first
= *list
== &ftrace_list_end
;
375 add_ftrace_ops(list
, ops
);
377 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
380 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
381 struct ftrace_ops
*main_ops
,
382 struct ftrace_ops
*ops
)
384 int ret
= remove_ftrace_ops(list
, ops
);
385 if (!ret
&& *list
== &ftrace_list_end
)
386 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
390 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
392 static int __register_ftrace_function(struct ftrace_ops
*ops
)
394 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
397 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
400 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
402 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
403 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
404 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
406 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
407 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
410 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
411 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
414 if (!core_kernel_data((unsigned long)ops
))
415 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
417 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
418 if (control_ops_alloc(ops
))
420 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
421 /* The control_ops needs the trampoline update */
424 add_ftrace_ops(&ftrace_ops_list
, ops
);
426 ftrace_update_trampoline(ops
);
429 update_ftrace_function();
434 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
438 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
441 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
442 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
445 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
451 update_ftrace_function();
456 static void ftrace_update_pid_func(void)
458 /* Only do something if we are tracing something */
459 if (ftrace_trace_function
== ftrace_stub
)
462 update_ftrace_function();
465 #ifdef CONFIG_FUNCTION_PROFILER
466 struct ftrace_profile
{
467 struct hlist_node node
;
469 unsigned long counter
;
470 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
471 unsigned long long time
;
472 unsigned long long time_squared
;
476 struct ftrace_profile_page
{
477 struct ftrace_profile_page
*next
;
479 struct ftrace_profile records
[];
482 struct ftrace_profile_stat
{
484 struct hlist_head
*hash
;
485 struct ftrace_profile_page
*pages
;
486 struct ftrace_profile_page
*start
;
487 struct tracer_stat stat
;
490 #define PROFILE_RECORDS_SIZE \
491 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
493 #define PROFILES_PER_PAGE \
494 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
496 static int ftrace_profile_enabled __read_mostly
;
498 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
499 static DEFINE_MUTEX(ftrace_profile_lock
);
501 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
503 #define FTRACE_PROFILE_HASH_BITS 10
504 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
507 function_stat_next(void *v
, int idx
)
509 struct ftrace_profile
*rec
= v
;
510 struct ftrace_profile_page
*pg
;
512 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
518 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
522 rec
= &pg
->records
[0];
530 static void *function_stat_start(struct tracer_stat
*trace
)
532 struct ftrace_profile_stat
*stat
=
533 container_of(trace
, struct ftrace_profile_stat
, stat
);
535 if (!stat
|| !stat
->start
)
538 return function_stat_next(&stat
->start
->records
[0], 0);
541 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
542 /* function graph compares on total time */
543 static int function_stat_cmp(void *p1
, void *p2
)
545 struct ftrace_profile
*a
= p1
;
546 struct ftrace_profile
*b
= p2
;
548 if (a
->time
< b
->time
)
550 if (a
->time
> b
->time
)
556 /* not function graph compares against hits */
557 static int function_stat_cmp(void *p1
, void *p2
)
559 struct ftrace_profile
*a
= p1
;
560 struct ftrace_profile
*b
= p2
;
562 if (a
->counter
< b
->counter
)
564 if (a
->counter
> b
->counter
)
571 static int function_stat_headers(struct seq_file
*m
)
573 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
574 seq_puts(m
, " Function "
577 "--- ---- --- ---\n");
579 seq_puts(m
, " Function Hit\n"
585 static int function_stat_show(struct seq_file
*m
, void *v
)
587 struct ftrace_profile
*rec
= v
;
588 char str
[KSYM_SYMBOL_LEN
];
590 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
591 static struct trace_seq s
;
592 unsigned long long avg
;
593 unsigned long long stddev
;
595 mutex_lock(&ftrace_profile_lock
);
597 /* we raced with function_profile_reset() */
598 if (unlikely(rec
->counter
== 0)) {
603 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
604 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
606 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
609 do_div(avg
, rec
->counter
);
611 /* Sample standard deviation (s^2) */
612 if (rec
->counter
<= 1)
616 * Apply Welford's method:
617 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
619 stddev
= rec
->counter
* rec
->time_squared
-
620 rec
->time
* rec
->time
;
623 * Divide only 1000 for ns^2 -> us^2 conversion.
624 * trace_print_graph_duration will divide 1000 again.
626 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
630 trace_print_graph_duration(rec
->time
, &s
);
631 trace_seq_puts(&s
, " ");
632 trace_print_graph_duration(avg
, &s
);
633 trace_seq_puts(&s
, " ");
634 trace_print_graph_duration(stddev
, &s
);
635 trace_print_seq(m
, &s
);
639 mutex_unlock(&ftrace_profile_lock
);
644 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
646 struct ftrace_profile_page
*pg
;
648 pg
= stat
->pages
= stat
->start
;
651 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
656 memset(stat
->hash
, 0,
657 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
660 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
662 struct ftrace_profile_page
*pg
;
667 /* If we already allocated, do nothing */
671 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
675 #ifdef CONFIG_DYNAMIC_FTRACE
676 functions
= ftrace_update_tot_cnt
;
679 * We do not know the number of functions that exist because
680 * dynamic tracing is what counts them. With past experience
681 * we have around 20K functions. That should be more than enough.
682 * It is highly unlikely we will execute every function in
688 pg
= stat
->start
= stat
->pages
;
690 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
692 for (i
= 1; i
< pages
; i
++) {
693 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
704 unsigned long tmp
= (unsigned long)pg
;
716 static int ftrace_profile_init_cpu(int cpu
)
718 struct ftrace_profile_stat
*stat
;
721 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
724 /* If the profile is already created, simply reset it */
725 ftrace_profile_reset(stat
);
730 * We are profiling all functions, but usually only a few thousand
731 * functions are hit. We'll make a hash of 1024 items.
733 size
= FTRACE_PROFILE_HASH_SIZE
;
735 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
740 /* Preallocate the function profiling pages */
741 if (ftrace_profile_pages_init(stat
) < 0) {
750 static int ftrace_profile_init(void)
755 for_each_possible_cpu(cpu
) {
756 ret
= ftrace_profile_init_cpu(cpu
);
764 /* interrupts must be disabled */
765 static struct ftrace_profile
*
766 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
768 struct ftrace_profile
*rec
;
769 struct hlist_head
*hhd
;
772 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
773 hhd
= &stat
->hash
[key
];
775 if (hlist_empty(hhd
))
778 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
786 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
787 struct ftrace_profile
*rec
)
791 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
792 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
796 * The memory is already allocated, this simply finds a new record to use.
798 static struct ftrace_profile
*
799 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
801 struct ftrace_profile
*rec
= NULL
;
803 /* prevent recursion (from NMIs) */
804 if (atomic_inc_return(&stat
->disabled
) != 1)
808 * Try to find the function again since an NMI
809 * could have added it
811 rec
= ftrace_find_profiled_func(stat
, ip
);
815 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
816 if (!stat
->pages
->next
)
818 stat
->pages
= stat
->pages
->next
;
821 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
823 ftrace_add_profile(stat
, rec
);
826 atomic_dec(&stat
->disabled
);
832 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
833 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
835 struct ftrace_profile_stat
*stat
;
836 struct ftrace_profile
*rec
;
839 if (!ftrace_profile_enabled
)
842 local_irq_save(flags
);
844 stat
= this_cpu_ptr(&ftrace_profile_stats
);
845 if (!stat
->hash
|| !ftrace_profile_enabled
)
848 rec
= ftrace_find_profiled_func(stat
, ip
);
850 rec
= ftrace_profile_alloc(stat
, ip
);
857 local_irq_restore(flags
);
860 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
861 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
863 function_profile_call(trace
->func
, 0, NULL
, NULL
);
867 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
869 struct ftrace_profile_stat
*stat
;
870 unsigned long long calltime
;
871 struct ftrace_profile
*rec
;
874 local_irq_save(flags
);
875 stat
= this_cpu_ptr(&ftrace_profile_stats
);
876 if (!stat
->hash
|| !ftrace_profile_enabled
)
879 /* If the calltime was zero'd ignore it */
880 if (!trace
->calltime
)
883 calltime
= trace
->rettime
- trace
->calltime
;
885 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
888 index
= trace
->depth
;
890 /* Append this call time to the parent time to subtract */
892 current
->ret_stack
[index
- 1].subtime
+= calltime
;
894 if (current
->ret_stack
[index
].subtime
< calltime
)
895 calltime
-= current
->ret_stack
[index
].subtime
;
900 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
902 rec
->time
+= calltime
;
903 rec
->time_squared
+= calltime
* calltime
;
907 local_irq_restore(flags
);
910 static int register_ftrace_profiler(void)
912 return register_ftrace_graph(&profile_graph_return
,
913 &profile_graph_entry
);
916 static void unregister_ftrace_profiler(void)
918 unregister_ftrace_graph();
921 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
922 .func
= function_profile_call
,
923 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
924 INIT_OPS_HASH(ftrace_profile_ops
)
927 static int register_ftrace_profiler(void)
929 return register_ftrace_function(&ftrace_profile_ops
);
932 static void unregister_ftrace_profiler(void)
934 unregister_ftrace_function(&ftrace_profile_ops
);
936 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
939 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
940 size_t cnt
, loff_t
*ppos
)
945 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
951 mutex_lock(&ftrace_profile_lock
);
952 if (ftrace_profile_enabled
^ val
) {
954 ret
= ftrace_profile_init();
960 ret
= register_ftrace_profiler();
965 ftrace_profile_enabled
= 1;
967 ftrace_profile_enabled
= 0;
969 * unregister_ftrace_profiler calls stop_machine
970 * so this acts like an synchronize_sched.
972 unregister_ftrace_profiler();
976 mutex_unlock(&ftrace_profile_lock
);
984 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
985 size_t cnt
, loff_t
*ppos
)
987 char buf
[64]; /* big enough to hold a number */
990 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
991 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
994 static const struct file_operations ftrace_profile_fops
= {
995 .open
= tracing_open_generic
,
996 .read
= ftrace_profile_read
,
997 .write
= ftrace_profile_write
,
998 .llseek
= default_llseek
,
1001 /* used to initialize the real stat files */
1002 static struct tracer_stat function_stats __initdata
= {
1003 .name
= "functions",
1004 .stat_start
= function_stat_start
,
1005 .stat_next
= function_stat_next
,
1006 .stat_cmp
= function_stat_cmp
,
1007 .stat_headers
= function_stat_headers
,
1008 .stat_show
= function_stat_show
1011 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1013 struct ftrace_profile_stat
*stat
;
1014 struct dentry
*entry
;
1019 for_each_possible_cpu(cpu
) {
1020 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1022 /* allocate enough for function name + cpu number */
1023 name
= kmalloc(32, GFP_KERNEL
);
1026 * The files created are permanent, if something happens
1027 * we still do not free memory.
1030 "Could not allocate stat file for cpu %d\n",
1034 stat
->stat
= function_stats
;
1035 snprintf(name
, 32, "function%d", cpu
);
1036 stat
->stat
.name
= name
;
1037 ret
= register_stat_tracer(&stat
->stat
);
1040 "Could not register function stat for cpu %d\n",
1047 entry
= debugfs_create_file("function_profile_enabled", 0644,
1048 d_tracer
, NULL
, &ftrace_profile_fops
);
1050 pr_warning("Could not create debugfs "
1051 "'function_profile_enabled' entry\n");
1054 #else /* CONFIG_FUNCTION_PROFILER */
1055 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1058 #endif /* CONFIG_FUNCTION_PROFILER */
1060 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1062 #ifdef CONFIG_DYNAMIC_FTRACE
1064 static struct ftrace_ops
*removed_ops
;
1067 * Set when doing a global update, like enabling all recs or disabling them.
1068 * It is not set when just updating a single ftrace_ops.
1070 static bool update_all_ops
;
1072 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1073 # error Dynamic ftrace depends on MCOUNT_RECORD
1076 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1078 struct ftrace_func_probe
{
1079 struct hlist_node node
;
1080 struct ftrace_probe_ops
*ops
;
1081 unsigned long flags
;
1084 struct list_head free_list
;
1087 struct ftrace_func_entry
{
1088 struct hlist_node hlist
;
1092 struct ftrace_hash
{
1093 unsigned long size_bits
;
1094 struct hlist_head
*buckets
;
1095 unsigned long count
;
1096 struct rcu_head rcu
;
1100 * We make these constant because no one should touch them,
1101 * but they are used as the default "empty hash", to avoid allocating
1102 * it all the time. These are in a read only section such that if
1103 * anyone does try to modify it, it will cause an exception.
1105 static const struct hlist_head empty_buckets
[1];
1106 static const struct ftrace_hash empty_hash
= {
1107 .buckets
= (struct hlist_head
*)empty_buckets
,
1109 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1111 static struct ftrace_ops global_ops
= {
1112 .func
= ftrace_stub
,
1113 .local_hash
.notrace_hash
= EMPTY_HASH
,
1114 .local_hash
.filter_hash
= EMPTY_HASH
,
1115 INIT_OPS_HASH(global_ops
)
1116 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1117 FTRACE_OPS_FL_INITIALIZED
,
1121 * This is used by __kernel_text_address() to return true if the
1122 * address is on a dynamically allocated trampoline that would
1123 * not return true for either core_kernel_text() or
1124 * is_module_text_address().
1126 bool is_ftrace_trampoline(unsigned long addr
)
1128 struct ftrace_ops
*op
;
1132 * Some of the ops may be dynamically allocated,
1133 * they are freed after a synchronize_sched().
1135 preempt_disable_notrace();
1137 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1139 * This is to check for dynamically allocated trampolines.
1140 * Trampolines that are in kernel text will have
1141 * core_kernel_text() return true.
1143 if (op
->trampoline
&& op
->trampoline_size
)
1144 if (addr
>= op
->trampoline
&&
1145 addr
< op
->trampoline
+ op
->trampoline_size
) {
1149 } while_for_each_ftrace_op(op
);
1152 preempt_enable_notrace();
1157 struct ftrace_page
{
1158 struct ftrace_page
*next
;
1159 struct dyn_ftrace
*records
;
1164 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1165 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1167 /* estimate from running different kernels */
1168 #define NR_TO_INIT 10000
1170 static struct ftrace_page
*ftrace_pages_start
;
1171 static struct ftrace_page
*ftrace_pages
;
1173 static bool __always_inline
ftrace_hash_empty(struct ftrace_hash
*hash
)
1175 return !hash
|| !hash
->count
;
1178 static struct ftrace_func_entry
*
1179 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1182 struct ftrace_func_entry
*entry
;
1183 struct hlist_head
*hhd
;
1185 if (ftrace_hash_empty(hash
))
1188 if (hash
->size_bits
> 0)
1189 key
= hash_long(ip
, hash
->size_bits
);
1193 hhd
= &hash
->buckets
[key
];
1195 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1196 if (entry
->ip
== ip
)
1202 static void __add_hash_entry(struct ftrace_hash
*hash
,
1203 struct ftrace_func_entry
*entry
)
1205 struct hlist_head
*hhd
;
1208 if (hash
->size_bits
)
1209 key
= hash_long(entry
->ip
, hash
->size_bits
);
1213 hhd
= &hash
->buckets
[key
];
1214 hlist_add_head(&entry
->hlist
, hhd
);
1218 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1220 struct ftrace_func_entry
*entry
;
1222 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1227 __add_hash_entry(hash
, entry
);
1233 free_hash_entry(struct ftrace_hash
*hash
,
1234 struct ftrace_func_entry
*entry
)
1236 hlist_del(&entry
->hlist
);
1242 remove_hash_entry(struct ftrace_hash
*hash
,
1243 struct ftrace_func_entry
*entry
)
1245 hlist_del(&entry
->hlist
);
1249 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1251 struct hlist_head
*hhd
;
1252 struct hlist_node
*tn
;
1253 struct ftrace_func_entry
*entry
;
1254 int size
= 1 << hash
->size_bits
;
1260 for (i
= 0; i
< size
; i
++) {
1261 hhd
= &hash
->buckets
[i
];
1262 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1263 free_hash_entry(hash
, entry
);
1265 FTRACE_WARN_ON(hash
->count
);
1268 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1270 if (!hash
|| hash
== EMPTY_HASH
)
1272 ftrace_hash_clear(hash
);
1273 kfree(hash
->buckets
);
1277 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1279 struct ftrace_hash
*hash
;
1281 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1282 free_ftrace_hash(hash
);
1285 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1287 if (!hash
|| hash
== EMPTY_HASH
)
1289 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1292 void ftrace_free_filter(struct ftrace_ops
*ops
)
1294 ftrace_ops_init(ops
);
1295 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1296 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1299 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1301 struct ftrace_hash
*hash
;
1304 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1308 size
= 1 << size_bits
;
1309 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1311 if (!hash
->buckets
) {
1316 hash
->size_bits
= size_bits
;
1321 static struct ftrace_hash
*
1322 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1324 struct ftrace_func_entry
*entry
;
1325 struct ftrace_hash
*new_hash
;
1330 new_hash
= alloc_ftrace_hash(size_bits
);
1335 if (ftrace_hash_empty(hash
))
1338 size
= 1 << hash
->size_bits
;
1339 for (i
= 0; i
< size
; i
++) {
1340 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1341 ret
= add_hash_entry(new_hash
, entry
->ip
);
1347 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1352 free_ftrace_hash(new_hash
);
1357 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1359 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1361 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1362 struct ftrace_hash
*new_hash
);
1365 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1366 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1368 struct ftrace_func_entry
*entry
;
1369 struct hlist_node
*tn
;
1370 struct hlist_head
*hhd
;
1371 struct ftrace_hash
*new_hash
;
1372 int size
= src
->count
;
1377 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1378 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1382 * If the new source is empty, just free dst and assign it
1386 new_hash
= EMPTY_HASH
;
1391 * Make the hash size about 1/2 the # found
1393 for (size
/= 2; size
; size
>>= 1)
1396 /* Don't allocate too much */
1397 if (bits
> FTRACE_HASH_MAX_BITS
)
1398 bits
= FTRACE_HASH_MAX_BITS
;
1400 new_hash
= alloc_ftrace_hash(bits
);
1404 size
= 1 << src
->size_bits
;
1405 for (i
= 0; i
< size
; i
++) {
1406 hhd
= &src
->buckets
[i
];
1407 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1408 remove_hash_entry(src
, entry
);
1409 __add_hash_entry(new_hash
, entry
);
1414 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1416 /* IPMODIFY should be updated only when filter_hash updating */
1417 ret
= ftrace_hash_ipmodify_update(ops
, new_hash
);
1419 free_ftrace_hash(new_hash
);
1425 * Remove the current set, update the hash and add
1428 ftrace_hash_rec_disable_modify(ops
, enable
);
1430 rcu_assign_pointer(*dst
, new_hash
);
1432 ftrace_hash_rec_enable_modify(ops
, enable
);
1437 static bool hash_contains_ip(unsigned long ip
,
1438 struct ftrace_ops_hash
*hash
)
1441 * The function record is a match if it exists in the filter
1442 * hash and not in the notrace hash. Note, an emty hash is
1443 * considered a match for the filter hash, but an empty
1444 * notrace hash is considered not in the notrace hash.
1446 return (ftrace_hash_empty(hash
->filter_hash
) ||
1447 ftrace_lookup_ip(hash
->filter_hash
, ip
)) &&
1448 (ftrace_hash_empty(hash
->notrace_hash
) ||
1449 !ftrace_lookup_ip(hash
->notrace_hash
, ip
));
1453 * Test the hashes for this ops to see if we want to call
1454 * the ops->func or not.
1456 * It's a match if the ip is in the ops->filter_hash or
1457 * the filter_hash does not exist or is empty,
1459 * the ip is not in the ops->notrace_hash.
1461 * This needs to be called with preemption disabled as
1462 * the hashes are freed with call_rcu_sched().
1465 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1467 struct ftrace_ops_hash hash
;
1470 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1472 * There's a small race when adding ops that the ftrace handler
1473 * that wants regs, may be called without them. We can not
1474 * allow that handler to be called if regs is NULL.
1476 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1480 hash
.filter_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->filter_hash
);
1481 hash
.notrace_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->notrace_hash
);
1483 if (hash_contains_ip(ip
, &hash
))
1492 * This is a double for. Do not use 'break' to break out of the loop,
1493 * you must use a goto.
1495 #define do_for_each_ftrace_rec(pg, rec) \
1496 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1498 for (_____i = 0; _____i < pg->index; _____i++) { \
1499 rec = &pg->records[_____i];
1501 #define while_for_each_ftrace_rec() \
1506 static int ftrace_cmp_recs(const void *a
, const void *b
)
1508 const struct dyn_ftrace
*key
= a
;
1509 const struct dyn_ftrace
*rec
= b
;
1511 if (key
->flags
< rec
->ip
)
1513 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1518 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1520 struct ftrace_page
*pg
;
1521 struct dyn_ftrace
*rec
;
1522 struct dyn_ftrace key
;
1525 key
.flags
= end
; /* overload flags, as it is unsigned long */
1527 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1528 if (end
< pg
->records
[0].ip
||
1529 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1531 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1532 sizeof(struct dyn_ftrace
),
1542 * ftrace_location - return true if the ip giving is a traced location
1543 * @ip: the instruction pointer to check
1545 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1546 * That is, the instruction that is either a NOP or call to
1547 * the function tracer. It checks the ftrace internal tables to
1548 * determine if the address belongs or not.
1550 unsigned long ftrace_location(unsigned long ip
)
1552 return ftrace_location_range(ip
, ip
);
1556 * ftrace_text_reserved - return true if range contains an ftrace location
1557 * @start: start of range to search
1558 * @end: end of range to search (inclusive). @end points to the last byte to check.
1560 * Returns 1 if @start and @end contains a ftrace location.
1561 * That is, the instruction that is either a NOP or call to
1562 * the function tracer. It checks the ftrace internal tables to
1563 * determine if the address belongs or not.
1565 int ftrace_text_reserved(const void *start
, const void *end
)
1569 ret
= ftrace_location_range((unsigned long)start
,
1570 (unsigned long)end
);
1575 /* Test if ops registered to this rec needs regs */
1576 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1578 struct ftrace_ops
*ops
;
1579 bool keep_regs
= false;
1581 for (ops
= ftrace_ops_list
;
1582 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1583 /* pass rec in as regs to have non-NULL val */
1584 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1585 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1595 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1599 struct ftrace_hash
*hash
;
1600 struct ftrace_hash
*other_hash
;
1601 struct ftrace_page
*pg
;
1602 struct dyn_ftrace
*rec
;
1606 /* Only update if the ops has been registered */
1607 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1611 * In the filter_hash case:
1612 * If the count is zero, we update all records.
1613 * Otherwise we just update the items in the hash.
1615 * In the notrace_hash case:
1616 * We enable the update in the hash.
1617 * As disabling notrace means enabling the tracing,
1618 * and enabling notrace means disabling, the inc variable
1622 hash
= ops
->func_hash
->filter_hash
;
1623 other_hash
= ops
->func_hash
->notrace_hash
;
1624 if (ftrace_hash_empty(hash
))
1628 hash
= ops
->func_hash
->notrace_hash
;
1629 other_hash
= ops
->func_hash
->filter_hash
;
1631 * If the notrace hash has no items,
1632 * then there's nothing to do.
1634 if (ftrace_hash_empty(hash
))
1638 do_for_each_ftrace_rec(pg
, rec
) {
1639 int in_other_hash
= 0;
1645 * Only the filter_hash affects all records.
1646 * Update if the record is not in the notrace hash.
1648 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1651 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1652 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1655 * If filter_hash is set, we want to match all functions
1656 * that are in the hash but not in the other hash.
1658 * If filter_hash is not set, then we are decrementing.
1659 * That means we match anything that is in the hash
1660 * and also in the other_hash. That is, we need to turn
1661 * off functions in the other hash because they are disabled
1664 if (filter_hash
&& in_hash
&& !in_other_hash
)
1666 else if (!filter_hash
&& in_hash
&&
1667 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1675 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1679 * If there's only a single callback registered to a
1680 * function, and the ops has a trampoline registered
1681 * for it, then we can call it directly.
1683 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1684 rec
->flags
|= FTRACE_FL_TRAMP
;
1687 * If we are adding another function callback
1688 * to this function, and the previous had a
1689 * custom trampoline in use, then we need to go
1690 * back to the default trampoline.
1692 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1695 * If any ops wants regs saved for this function
1696 * then all ops will get saved regs.
1698 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1699 rec
->flags
|= FTRACE_FL_REGS
;
1701 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1706 * If the rec had REGS enabled and the ops that is
1707 * being removed had REGS set, then see if there is
1708 * still any ops for this record that wants regs.
1709 * If not, we can stop recording them.
1711 if (ftrace_rec_count(rec
) > 0 &&
1712 rec
->flags
& FTRACE_FL_REGS
&&
1713 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1714 if (!test_rec_ops_needs_regs(rec
))
1715 rec
->flags
&= ~FTRACE_FL_REGS
;
1719 * If the rec had TRAMP enabled, then it needs to
1720 * be cleared. As TRAMP can only be enabled iff
1721 * there is only a single ops attached to it.
1722 * In otherwords, always disable it on decrementing.
1723 * In the future, we may set it if rec count is
1724 * decremented to one, and the ops that is left
1727 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1730 * flags will be cleared in ftrace_check_record()
1731 * if rec count is zero.
1735 /* Shortcut, if we handled all records, we are done. */
1736 if (!all
&& count
== hash
->count
)
1738 } while_for_each_ftrace_rec();
1741 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1744 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1747 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1750 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1753 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1754 int filter_hash
, int inc
)
1756 struct ftrace_ops
*op
;
1758 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1760 if (ops
->func_hash
!= &global_ops
.local_hash
)
1764 * If the ops shares the global_ops hash, then we need to update
1765 * all ops that are enabled and use this hash.
1767 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1771 if (op
->func_hash
== &global_ops
.local_hash
)
1772 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1773 } while_for_each_ftrace_op(op
);
1776 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1779 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1782 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1785 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1789 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1790 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1791 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1792 * Note that old_hash and new_hash has below meanings
1793 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1794 * - If the hash is EMPTY_HASH, it hits nothing
1795 * - Anything else hits the recs which match the hash entries.
1797 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1798 struct ftrace_hash
*old_hash
,
1799 struct ftrace_hash
*new_hash
)
1801 struct ftrace_page
*pg
;
1802 struct dyn_ftrace
*rec
, *end
= NULL
;
1805 /* Only update if the ops has been registered */
1806 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1809 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1813 * Since the IPMODIFY is a very address sensitive action, we do not
1814 * allow ftrace_ops to set all functions to new hash.
1816 if (!new_hash
|| !old_hash
)
1819 /* Update rec->flags */
1820 do_for_each_ftrace_rec(pg
, rec
) {
1821 /* We need to update only differences of filter_hash */
1822 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1823 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1824 if (in_old
== in_new
)
1828 /* New entries must ensure no others are using it */
1829 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1831 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1832 } else /* Removed entry */
1833 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1834 } while_for_each_ftrace_rec();
1841 /* Roll back what we did above */
1842 do_for_each_ftrace_rec(pg
, rec
) {
1846 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1847 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1848 if (in_old
== in_new
)
1852 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1854 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1855 } while_for_each_ftrace_rec();
1861 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
1863 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1865 if (ftrace_hash_empty(hash
))
1868 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
1871 /* Disabling always succeeds */
1872 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
1874 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1876 if (ftrace_hash_empty(hash
))
1879 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
1882 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1883 struct ftrace_hash
*new_hash
)
1885 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
1887 if (ftrace_hash_empty(old_hash
))
1890 if (ftrace_hash_empty(new_hash
))
1893 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
1896 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1900 printk(KERN_CONT
"%s", fmt
);
1902 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1903 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1906 static struct ftrace_ops
*
1907 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
1910 * ftrace_bug - report and shutdown function tracer
1911 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1912 * @rec: The record that failed
1914 * The arch code that enables or disables the function tracing
1915 * can call ftrace_bug() when it has detected a problem in
1916 * modifying the code. @failed should be one of either:
1917 * EFAULT - if the problem happens on reading the @ip address
1918 * EINVAL - if what is read at @ip is not what was expected
1919 * EPERM - if the problem happens on writting to the @ip address
1921 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
1923 unsigned long ip
= rec
? rec
->ip
: 0;
1927 FTRACE_WARN_ON_ONCE(1);
1928 pr_info("ftrace faulted on modifying ");
1932 FTRACE_WARN_ON_ONCE(1);
1933 pr_info("ftrace failed to modify ");
1935 print_ip_ins(" actual: ", (unsigned char *)ip
);
1939 FTRACE_WARN_ON_ONCE(1);
1940 pr_info("ftrace faulted on writing ");
1944 FTRACE_WARN_ON_ONCE(1);
1945 pr_info("ftrace faulted on unknown error ");
1949 struct ftrace_ops
*ops
= NULL
;
1951 pr_info("ftrace record flags: %lx\n", rec
->flags
);
1952 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
1953 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
1954 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
1955 ops
= ftrace_find_tramp_ops_any(rec
);
1957 pr_cont("\ttramp: %pS",
1958 (void *)ops
->trampoline
);
1960 pr_cont("\ttramp: ERROR!");
1963 ip
= ftrace_get_addr_curr(rec
);
1964 pr_cont(" expected tramp: %lx\n", ip
);
1968 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1970 unsigned long flag
= 0UL;
1973 * If we are updating calls:
1975 * If the record has a ref count, then we need to enable it
1976 * because someone is using it.
1978 * Otherwise we make sure its disabled.
1980 * If we are disabling calls, then disable all records that
1983 if (enable
&& ftrace_rec_count(rec
))
1984 flag
= FTRACE_FL_ENABLED
;
1987 * If enabling and the REGS flag does not match the REGS_EN, or
1988 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
1989 * this record. Set flags to fail the compare against ENABLED.
1992 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
1993 !(rec
->flags
& FTRACE_FL_REGS_EN
))
1994 flag
|= FTRACE_FL_REGS
;
1996 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
1997 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
1998 flag
|= FTRACE_FL_TRAMP
;
2001 /* If the state of this record hasn't changed, then do nothing */
2002 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2003 return FTRACE_UPDATE_IGNORE
;
2006 /* Save off if rec is being enabled (for return value) */
2007 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2010 rec
->flags
|= FTRACE_FL_ENABLED
;
2011 if (flag
& FTRACE_FL_REGS
) {
2012 if (rec
->flags
& FTRACE_FL_REGS
)
2013 rec
->flags
|= FTRACE_FL_REGS_EN
;
2015 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2017 if (flag
& FTRACE_FL_TRAMP
) {
2018 if (rec
->flags
& FTRACE_FL_TRAMP
)
2019 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2021 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2026 * If this record is being updated from a nop, then
2027 * return UPDATE_MAKE_CALL.
2029 * return UPDATE_MODIFY_CALL to tell the caller to convert
2030 * from the save regs, to a non-save regs function or
2031 * vice versa, or from a trampoline call.
2033 if (flag
& FTRACE_FL_ENABLED
)
2034 return FTRACE_UPDATE_MAKE_CALL
;
2036 return FTRACE_UPDATE_MODIFY_CALL
;
2040 /* If there's no more users, clear all flags */
2041 if (!ftrace_rec_count(rec
))
2044 /* Just disable the record (keep REGS state) */
2045 rec
->flags
&= ~FTRACE_FL_ENABLED
;
2048 return FTRACE_UPDATE_MAKE_NOP
;
2052 * ftrace_update_record, set a record that now is tracing or not
2053 * @rec: the record to update
2054 * @enable: set to 1 if the record is tracing, zero to force disable
2056 * The records that represent all functions that can be traced need
2057 * to be updated when tracing has been enabled.
2059 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2061 return ftrace_check_record(rec
, enable
, 1);
2065 * ftrace_test_record, check if the record has been enabled or not
2066 * @rec: the record to test
2067 * @enable: set to 1 to check if enabled, 0 if it is disabled
2069 * The arch code may need to test if a record is already set to
2070 * tracing to determine how to modify the function code that it
2073 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2075 return ftrace_check_record(rec
, enable
, 0);
2078 static struct ftrace_ops
*
2079 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2081 struct ftrace_ops
*op
;
2082 unsigned long ip
= rec
->ip
;
2084 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2086 if (!op
->trampoline
)
2089 if (hash_contains_ip(ip
, op
->func_hash
))
2091 } while_for_each_ftrace_op(op
);
2096 static struct ftrace_ops
*
2097 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2099 struct ftrace_ops
*op
;
2100 unsigned long ip
= rec
->ip
;
2103 * Need to check removed ops first.
2104 * If they are being removed, and this rec has a tramp,
2105 * and this rec is in the ops list, then it would be the
2106 * one with the tramp.
2109 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2114 * Need to find the current trampoline for a rec.
2115 * Now, a trampoline is only attached to a rec if there
2116 * was a single 'ops' attached to it. But this can be called
2117 * when we are adding another op to the rec or removing the
2118 * current one. Thus, if the op is being added, we can
2119 * ignore it because it hasn't attached itself to the rec
2122 * If an ops is being modified (hooking to different functions)
2123 * then we don't care about the new functions that are being
2124 * added, just the old ones (that are probably being removed).
2126 * If we are adding an ops to a function that already is using
2127 * a trampoline, it needs to be removed (trampolines are only
2128 * for single ops connected), then an ops that is not being
2129 * modified also needs to be checked.
2131 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2133 if (!op
->trampoline
)
2137 * If the ops is being added, it hasn't gotten to
2138 * the point to be removed from this tree yet.
2140 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2145 * If the ops is being modified and is in the old
2146 * hash, then it is probably being removed from this
2149 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2150 hash_contains_ip(ip
, &op
->old_hash
))
2153 * If the ops is not being added or modified, and it's
2154 * in its normal filter hash, then this must be the one
2157 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2158 hash_contains_ip(ip
, op
->func_hash
))
2161 } while_for_each_ftrace_op(op
);
2166 static struct ftrace_ops
*
2167 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2169 struct ftrace_ops
*op
;
2170 unsigned long ip
= rec
->ip
;
2172 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2173 /* pass rec in as regs to have non-NULL val */
2174 if (hash_contains_ip(ip
, op
->func_hash
))
2176 } while_for_each_ftrace_op(op
);
2182 * ftrace_get_addr_new - Get the call address to set to
2183 * @rec: The ftrace record descriptor
2185 * If the record has the FTRACE_FL_REGS set, that means that it
2186 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2187 * is not not set, then it wants to convert to the normal callback.
2189 * Returns the address of the trampoline to set to
2191 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2193 struct ftrace_ops
*ops
;
2195 /* Trampolines take precedence over regs */
2196 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2197 ops
= ftrace_find_tramp_ops_new(rec
);
2198 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2199 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2200 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2201 /* Ftrace is shutting down, return anything */
2202 return (unsigned long)FTRACE_ADDR
;
2204 return ops
->trampoline
;
2207 if (rec
->flags
& FTRACE_FL_REGS
)
2208 return (unsigned long)FTRACE_REGS_ADDR
;
2210 return (unsigned long)FTRACE_ADDR
;
2214 * ftrace_get_addr_curr - Get the call address that is already there
2215 * @rec: The ftrace record descriptor
2217 * The FTRACE_FL_REGS_EN is set when the record already points to
2218 * a function that saves all the regs. Basically the '_EN' version
2219 * represents the current state of the function.
2221 * Returns the address of the trampoline that is currently being called
2223 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2225 struct ftrace_ops
*ops
;
2227 /* Trampolines take precedence over regs */
2228 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2229 ops
= ftrace_find_tramp_ops_curr(rec
);
2230 if (FTRACE_WARN_ON(!ops
)) {
2231 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
2232 (void *)rec
->ip
, (void *)rec
->ip
);
2233 /* Ftrace is shutting down, return anything */
2234 return (unsigned long)FTRACE_ADDR
;
2236 return ops
->trampoline
;
2239 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2240 return (unsigned long)FTRACE_REGS_ADDR
;
2242 return (unsigned long)FTRACE_ADDR
;
2246 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2248 unsigned long ftrace_old_addr
;
2249 unsigned long ftrace_addr
;
2252 ftrace_addr
= ftrace_get_addr_new(rec
);
2254 /* This needs to be done before we call ftrace_update_record */
2255 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2257 ret
= ftrace_update_record(rec
, enable
);
2260 case FTRACE_UPDATE_IGNORE
:
2263 case FTRACE_UPDATE_MAKE_CALL
:
2264 return ftrace_make_call(rec
, ftrace_addr
);
2266 case FTRACE_UPDATE_MAKE_NOP
:
2267 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2269 case FTRACE_UPDATE_MODIFY_CALL
:
2270 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2273 return -1; /* unknow ftrace bug */
2276 void __weak
ftrace_replace_code(int enable
)
2278 struct dyn_ftrace
*rec
;
2279 struct ftrace_page
*pg
;
2282 if (unlikely(ftrace_disabled
))
2285 do_for_each_ftrace_rec(pg
, rec
) {
2286 failed
= __ftrace_replace_code(rec
, enable
);
2288 ftrace_bug(failed
, rec
);
2289 /* Stop processing */
2292 } while_for_each_ftrace_rec();
2295 struct ftrace_rec_iter
{
2296 struct ftrace_page
*pg
;
2301 * ftrace_rec_iter_start, start up iterating over traced functions
2303 * Returns an iterator handle that is used to iterate over all
2304 * the records that represent address locations where functions
2307 * May return NULL if no records are available.
2309 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2312 * We only use a single iterator.
2313 * Protected by the ftrace_lock mutex.
2315 static struct ftrace_rec_iter ftrace_rec_iter
;
2316 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2318 iter
->pg
= ftrace_pages_start
;
2321 /* Could have empty pages */
2322 while (iter
->pg
&& !iter
->pg
->index
)
2323 iter
->pg
= iter
->pg
->next
;
2332 * ftrace_rec_iter_next, get the next record to process.
2333 * @iter: The handle to the iterator.
2335 * Returns the next iterator after the given iterator @iter.
2337 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2341 if (iter
->index
>= iter
->pg
->index
) {
2342 iter
->pg
= iter
->pg
->next
;
2345 /* Could have empty pages */
2346 while (iter
->pg
&& !iter
->pg
->index
)
2347 iter
->pg
= iter
->pg
->next
;
2357 * ftrace_rec_iter_record, get the record at the iterator location
2358 * @iter: The current iterator location
2360 * Returns the record that the current @iter is at.
2362 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2364 return &iter
->pg
->records
[iter
->index
];
2368 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2372 if (unlikely(ftrace_disabled
))
2375 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2377 ftrace_bug(ret
, rec
);
2384 * archs can override this function if they must do something
2385 * before the modifying code is performed.
2387 int __weak
ftrace_arch_code_modify_prepare(void)
2393 * archs can override this function if they must do something
2394 * after the modifying code is performed.
2396 int __weak
ftrace_arch_code_modify_post_process(void)
2401 void ftrace_modify_all_code(int command
)
2403 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2407 * If the ftrace_caller calls a ftrace_ops func directly,
2408 * we need to make sure that it only traces functions it
2409 * expects to trace. When doing the switch of functions,
2410 * we need to update to the ftrace_ops_list_func first
2411 * before the transition between old and new calls are set,
2412 * as the ftrace_ops_list_func will check the ops hashes
2413 * to make sure the ops are having the right functions
2417 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2418 if (FTRACE_WARN_ON(err
))
2422 if (command
& FTRACE_UPDATE_CALLS
)
2423 ftrace_replace_code(1);
2424 else if (command
& FTRACE_DISABLE_CALLS
)
2425 ftrace_replace_code(0);
2427 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2428 function_trace_op
= set_function_trace_op
;
2430 /* If irqs are disabled, we are in stop machine */
2431 if (!irqs_disabled())
2432 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2433 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2434 if (FTRACE_WARN_ON(err
))
2438 if (command
& FTRACE_START_FUNC_RET
)
2439 err
= ftrace_enable_ftrace_graph_caller();
2440 else if (command
& FTRACE_STOP_FUNC_RET
)
2441 err
= ftrace_disable_ftrace_graph_caller();
2442 FTRACE_WARN_ON(err
);
2445 static int __ftrace_modify_code(void *data
)
2447 int *command
= data
;
2449 ftrace_modify_all_code(*command
);
2455 * ftrace_run_stop_machine, go back to the stop machine method
2456 * @command: The command to tell ftrace what to do
2458 * If an arch needs to fall back to the stop machine method, the
2459 * it can call this function.
2461 void ftrace_run_stop_machine(int command
)
2463 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2467 * arch_ftrace_update_code, modify the code to trace or not trace
2468 * @command: The command that needs to be done
2470 * Archs can override this function if it does not need to
2471 * run stop_machine() to modify code.
2473 void __weak
arch_ftrace_update_code(int command
)
2475 ftrace_run_stop_machine(command
);
2478 static void ftrace_run_update_code(int command
)
2482 ret
= ftrace_arch_code_modify_prepare();
2483 FTRACE_WARN_ON(ret
);
2488 * By default we use stop_machine() to modify the code.
2489 * But archs can do what ever they want as long as it
2490 * is safe. The stop_machine() is the safest, but also
2491 * produces the most overhead.
2493 arch_ftrace_update_code(command
);
2495 ret
= ftrace_arch_code_modify_post_process();
2496 FTRACE_WARN_ON(ret
);
2499 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2500 struct ftrace_ops_hash
*old_hash
)
2502 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2503 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2504 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2505 ftrace_run_update_code(command
);
2506 ops
->old_hash
.filter_hash
= NULL
;
2507 ops
->old_hash
.notrace_hash
= NULL
;
2508 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2511 static ftrace_func_t saved_ftrace_func
;
2512 static int ftrace_start_up
;
2514 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2518 static void control_ops_free(struct ftrace_ops
*ops
)
2520 free_percpu(ops
->disabled
);
2523 static void ftrace_startup_enable(int command
)
2525 if (saved_ftrace_func
!= ftrace_trace_function
) {
2526 saved_ftrace_func
= ftrace_trace_function
;
2527 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2530 if (!command
|| !ftrace_enabled
)
2533 ftrace_run_update_code(command
);
2536 static void ftrace_startup_all(int command
)
2538 update_all_ops
= true;
2539 ftrace_startup_enable(command
);
2540 update_all_ops
= false;
2543 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2547 if (unlikely(ftrace_disabled
))
2550 ret
= __register_ftrace_function(ops
);
2555 command
|= FTRACE_UPDATE_CALLS
;
2558 * Note that ftrace probes uses this to start up
2559 * and modify functions it will probe. But we still
2560 * set the ADDING flag for modification, as probes
2561 * do not have trampolines. If they add them in the
2562 * future, then the probes will need to distinguish
2563 * between adding and updating probes.
2565 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2567 ret
= ftrace_hash_ipmodify_enable(ops
);
2569 /* Rollback registration process */
2570 __unregister_ftrace_function(ops
);
2572 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2576 ftrace_hash_rec_enable(ops
, 1);
2578 ftrace_startup_enable(command
);
2580 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2585 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2589 if (unlikely(ftrace_disabled
))
2592 ret
= __unregister_ftrace_function(ops
);
2598 * Just warn in case of unbalance, no need to kill ftrace, it's not
2599 * critical but the ftrace_call callers may be never nopped again after
2600 * further ftrace uses.
2602 WARN_ON_ONCE(ftrace_start_up
< 0);
2604 /* Disabling ipmodify never fails */
2605 ftrace_hash_ipmodify_disable(ops
);
2606 ftrace_hash_rec_disable(ops
, 1);
2608 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2610 command
|= FTRACE_UPDATE_CALLS
;
2612 if (saved_ftrace_func
!= ftrace_trace_function
) {
2613 saved_ftrace_func
= ftrace_trace_function
;
2614 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2617 if (!command
|| !ftrace_enabled
) {
2619 * If these are control ops, they still need their
2620 * per_cpu field freed. Since, function tracing is
2621 * not currently active, we can just free them
2622 * without synchronizing all CPUs.
2624 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2625 control_ops_free(ops
);
2630 * If the ops uses a trampoline, then it needs to be
2631 * tested first on update.
2633 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2636 /* The trampoline logic checks the old hashes */
2637 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2638 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2640 ftrace_run_update_code(command
);
2643 * If there's no more ops registered with ftrace, run a
2644 * sanity check to make sure all rec flags are cleared.
2646 if (ftrace_ops_list
== &ftrace_list_end
) {
2647 struct ftrace_page
*pg
;
2648 struct dyn_ftrace
*rec
;
2650 do_for_each_ftrace_rec(pg
, rec
) {
2651 if (FTRACE_WARN_ON_ONCE(rec
->flags
))
2652 pr_warn(" %pS flags:%lx\n",
2653 (void *)rec
->ip
, rec
->flags
);
2654 } while_for_each_ftrace_rec();
2657 ops
->old_hash
.filter_hash
= NULL
;
2658 ops
->old_hash
.notrace_hash
= NULL
;
2661 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2664 * Dynamic ops may be freed, we must make sure that all
2665 * callers are done before leaving this function.
2666 * The same goes for freeing the per_cpu data of the control
2669 * Again, normal synchronize_sched() is not good enough.
2670 * We need to do a hard force of sched synchronization.
2671 * This is because we use preempt_disable() to do RCU, but
2672 * the function tracers can be called where RCU is not watching
2673 * (like before user_exit()). We can not rely on the RCU
2674 * infrastructure to do the synchronization, thus we must do it
2677 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_CONTROL
)) {
2678 schedule_on_each_cpu(ftrace_sync
);
2680 arch_ftrace_trampoline_free(ops
);
2682 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2683 control_ops_free(ops
);
2689 static void ftrace_startup_sysctl(void)
2691 if (unlikely(ftrace_disabled
))
2694 /* Force update next time */
2695 saved_ftrace_func
= NULL
;
2696 /* ftrace_start_up is true if we want ftrace running */
2697 if (ftrace_start_up
)
2698 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2701 static void ftrace_shutdown_sysctl(void)
2703 if (unlikely(ftrace_disabled
))
2706 /* ftrace_start_up is true if ftrace is running */
2707 if (ftrace_start_up
)
2708 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2711 static cycle_t ftrace_update_time
;
2712 unsigned long ftrace_update_tot_cnt
;
2714 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2717 * Filter_hash being empty will default to trace module.
2718 * But notrace hash requires a test of individual module functions.
2720 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2721 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2725 * Check if the current ops references the record.
2727 * If the ops traces all functions, then it was already accounted for.
2728 * If the ops does not trace the current record function, skip it.
2729 * If the ops ignores the function via notrace filter, skip it.
2732 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2734 /* If ops isn't enabled, ignore it */
2735 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2738 /* If ops traces all mods, we already accounted for it */
2739 if (ops_traces_mod(ops
))
2742 /* The function must be in the filter */
2743 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2744 !ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2747 /* If in notrace hash, we ignore it too */
2748 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2754 static int referenced_filters(struct dyn_ftrace
*rec
)
2756 struct ftrace_ops
*ops
;
2759 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2760 if (ops_references_rec(ops
, rec
))
2767 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2769 struct ftrace_page
*pg
;
2770 struct dyn_ftrace
*p
;
2771 cycle_t start
, stop
;
2772 unsigned long update_cnt
= 0;
2773 unsigned long ref
= 0;
2778 * When adding a module, we need to check if tracers are
2779 * currently enabled and if they are set to trace all functions.
2780 * If they are, we need to enable the module functions as well
2781 * as update the reference counts for those function records.
2784 struct ftrace_ops
*ops
;
2786 for (ops
= ftrace_ops_list
;
2787 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2788 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
2789 if (ops_traces_mod(ops
))
2797 start
= ftrace_now(raw_smp_processor_id());
2799 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2801 for (i
= 0; i
< pg
->index
; i
++) {
2804 /* If something went wrong, bail without enabling anything */
2805 if (unlikely(ftrace_disabled
))
2808 p
= &pg
->records
[i
];
2810 cnt
+= referenced_filters(p
);
2814 * Do the initial record conversion from mcount jump
2815 * to the NOP instructions.
2817 if (!ftrace_code_disable(mod
, p
))
2823 * If the tracing is enabled, go ahead and enable the record.
2825 * The reason not to enable the record immediatelly is the
2826 * inherent check of ftrace_make_nop/ftrace_make_call for
2827 * correct previous instructions. Making first the NOP
2828 * conversion puts the module to the correct state, thus
2829 * passing the ftrace_make_call check.
2831 if (ftrace_start_up
&& cnt
) {
2832 int failed
= __ftrace_replace_code(p
, 1);
2834 ftrace_bug(failed
, p
);
2839 stop
= ftrace_now(raw_smp_processor_id());
2840 ftrace_update_time
= stop
- start
;
2841 ftrace_update_tot_cnt
+= update_cnt
;
2846 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2851 if (WARN_ON(!count
))
2854 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2857 * We want to fill as much as possible. No more than a page
2860 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2864 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2867 /* if we can't allocate this size, try something smaller */
2874 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2883 static struct ftrace_page
*
2884 ftrace_allocate_pages(unsigned long num_to_init
)
2886 struct ftrace_page
*start_pg
;
2887 struct ftrace_page
*pg
;
2894 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2899 * Try to allocate as much as possible in one continues
2900 * location that fills in all of the space. We want to
2901 * waste as little space as possible.
2904 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2912 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2924 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2925 free_pages((unsigned long)pg
->records
, order
);
2926 start_pg
= pg
->next
;
2930 pr_info("ftrace: FAILED to allocate memory for functions\n");
2934 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2936 struct ftrace_iterator
{
2939 struct ftrace_page
*pg
;
2940 struct dyn_ftrace
*func
;
2941 struct ftrace_func_probe
*probe
;
2942 struct trace_parser parser
;
2943 struct ftrace_hash
*hash
;
2944 struct ftrace_ops
*ops
;
2951 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2953 struct ftrace_iterator
*iter
= m
->private;
2954 struct hlist_node
*hnd
= NULL
;
2955 struct hlist_head
*hhd
;
2961 hnd
= &iter
->probe
->node
;
2963 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2966 hhd
= &ftrace_func_hash
[iter
->hidx
];
2968 if (hlist_empty(hhd
)) {
2984 if (WARN_ON_ONCE(!hnd
))
2987 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2992 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2994 struct ftrace_iterator
*iter
= m
->private;
2998 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
3001 if (iter
->func_pos
> *pos
)
3005 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3006 p
= t_hash_next(m
, &l
);
3013 /* Only set this if we have an item */
3014 iter
->flags
|= FTRACE_ITER_HASH
;
3020 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3022 struct ftrace_func_probe
*rec
;
3025 if (WARN_ON_ONCE(!rec
))
3028 if (rec
->ops
->print
)
3029 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
3031 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
3034 seq_printf(m
, ":%p", rec
->data
);
3041 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3043 struct ftrace_iterator
*iter
= m
->private;
3044 struct ftrace_ops
*ops
= iter
->ops
;
3045 struct dyn_ftrace
*rec
= NULL
;
3047 if (unlikely(ftrace_disabled
))
3050 if (iter
->flags
& FTRACE_ITER_HASH
)
3051 return t_hash_next(m
, pos
);
3054 iter
->pos
= iter
->func_pos
= *pos
;
3056 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
3057 return t_hash_start(m
, pos
);
3060 if (iter
->idx
>= iter
->pg
->index
) {
3061 if (iter
->pg
->next
) {
3062 iter
->pg
= iter
->pg
->next
;
3067 rec
= &iter
->pg
->records
[iter
->idx
++];
3068 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
3069 !(ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))) ||
3071 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
3072 !ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
)) ||
3074 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3075 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3083 return t_hash_start(m
, pos
);
3090 static void reset_iter_read(struct ftrace_iterator
*iter
)
3094 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
3097 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3099 struct ftrace_iterator
*iter
= m
->private;
3100 struct ftrace_ops
*ops
= iter
->ops
;
3104 mutex_lock(&ftrace_lock
);
3106 if (unlikely(ftrace_disabled
))
3110 * If an lseek was done, then reset and start from beginning.
3112 if (*pos
< iter
->pos
)
3113 reset_iter_read(iter
);
3116 * For set_ftrace_filter reading, if we have the filter
3117 * off, we can short cut and just print out that all
3118 * functions are enabled.
3120 if ((iter
->flags
& FTRACE_ITER_FILTER
&&
3121 ftrace_hash_empty(ops
->func_hash
->filter_hash
)) ||
3122 (iter
->flags
& FTRACE_ITER_NOTRACE
&&
3123 ftrace_hash_empty(ops
->func_hash
->notrace_hash
))) {
3125 return t_hash_start(m
, pos
);
3126 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3127 /* reset in case of seek/pread */
3128 iter
->flags
&= ~FTRACE_ITER_HASH
;
3132 if (iter
->flags
& FTRACE_ITER_HASH
)
3133 return t_hash_start(m
, pos
);
3136 * Unfortunately, we need to restart at ftrace_pages_start
3137 * every time we let go of the ftrace_mutex. This is because
3138 * those pointers can change without the lock.
3140 iter
->pg
= ftrace_pages_start
;
3142 for (l
= 0; l
<= *pos
; ) {
3143 p
= t_next(m
, p
, &l
);
3149 return t_hash_start(m
, pos
);
3154 static void t_stop(struct seq_file
*m
, void *p
)
3156 mutex_unlock(&ftrace_lock
);
3160 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3165 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3166 struct dyn_ftrace
*rec
)
3170 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3172 seq_printf(m
, " ->%pS", ptr
);
3175 static int t_show(struct seq_file
*m
, void *v
)
3177 struct ftrace_iterator
*iter
= m
->private;
3178 struct dyn_ftrace
*rec
;
3180 if (iter
->flags
& FTRACE_ITER_HASH
)
3181 return t_hash_show(m
, iter
);
3183 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3184 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3185 seq_puts(m
, "#### no functions disabled ####\n");
3187 seq_puts(m
, "#### all functions enabled ####\n");
3196 seq_printf(m
, "%ps", (void *)rec
->ip
);
3197 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3198 struct ftrace_ops
*ops
= NULL
;
3200 seq_printf(m
, " (%ld)%s%s",
3201 ftrace_rec_count(rec
),
3202 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3203 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3204 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3205 ops
= ftrace_find_tramp_ops_any(rec
);
3207 seq_printf(m
, "\ttramp: %pS",
3208 (void *)ops
->trampoline
);
3210 seq_puts(m
, "\ttramp: ERROR!");
3213 add_trampoline_func(m
, ops
, rec
);
3221 static const struct seq_operations show_ftrace_seq_ops
= {
3229 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3231 struct ftrace_iterator
*iter
;
3233 if (unlikely(ftrace_disabled
))
3236 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3238 iter
->pg
= ftrace_pages_start
;
3239 iter
->ops
= &global_ops
;
3242 return iter
? 0 : -ENOMEM
;
3246 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3248 struct ftrace_iterator
*iter
;
3250 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3252 iter
->pg
= ftrace_pages_start
;
3253 iter
->flags
= FTRACE_ITER_ENABLED
;
3254 iter
->ops
= &global_ops
;
3257 return iter
? 0 : -ENOMEM
;
3261 * ftrace_regex_open - initialize function tracer filter files
3262 * @ops: The ftrace_ops that hold the hash filters
3263 * @flag: The type of filter to process
3264 * @inode: The inode, usually passed in to your open routine
3265 * @file: The file, usually passed in to your open routine
3267 * ftrace_regex_open() initializes the filter files for the
3268 * @ops. Depending on @flag it may process the filter hash or
3269 * the notrace hash of @ops. With this called from the open
3270 * routine, you can use ftrace_filter_write() for the write
3271 * routine if @flag has FTRACE_ITER_FILTER set, or
3272 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3273 * tracing_lseek() should be used as the lseek routine, and
3274 * release must call ftrace_regex_release().
3277 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3278 struct inode
*inode
, struct file
*file
)
3280 struct ftrace_iterator
*iter
;
3281 struct ftrace_hash
*hash
;
3284 ftrace_ops_init(ops
);
3286 if (unlikely(ftrace_disabled
))
3289 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3293 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3301 mutex_lock(&ops
->func_hash
->regex_lock
);
3303 if (flag
& FTRACE_ITER_NOTRACE
)
3304 hash
= ops
->func_hash
->notrace_hash
;
3306 hash
= ops
->func_hash
->filter_hash
;
3308 if (file
->f_mode
& FMODE_WRITE
) {
3309 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3311 if (file
->f_flags
& O_TRUNC
)
3312 iter
->hash
= alloc_ftrace_hash(size_bits
);
3314 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3317 trace_parser_put(&iter
->parser
);
3324 if (file
->f_mode
& FMODE_READ
) {
3325 iter
->pg
= ftrace_pages_start
;
3327 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3329 struct seq_file
*m
= file
->private_data
;
3333 free_ftrace_hash(iter
->hash
);
3334 trace_parser_put(&iter
->parser
);
3338 file
->private_data
= iter
;
3341 mutex_unlock(&ops
->func_hash
->regex_lock
);
3347 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3349 struct ftrace_ops
*ops
= inode
->i_private
;
3351 return ftrace_regex_open(ops
,
3352 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
3357 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3359 struct ftrace_ops
*ops
= inode
->i_private
;
3361 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3365 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
3372 if (strcmp(str
, regex
) == 0)
3375 case MATCH_FRONT_ONLY
:
3376 if (strncmp(str
, regex
, len
) == 0)
3379 case MATCH_MIDDLE_ONLY
:
3380 if (strstr(str
, regex
))
3383 case MATCH_END_ONLY
:
3385 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
3394 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
3396 struct ftrace_func_entry
*entry
;
3399 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3401 /* Do nothing if it doesn't exist */
3405 free_hash_entry(hash
, entry
);
3407 /* Do nothing if it exists */
3411 ret
= add_hash_entry(hash
, rec
->ip
);
3417 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
3418 char *regex
, int len
, int type
)
3420 char str
[KSYM_SYMBOL_LEN
];
3423 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3426 /* module lookup requires matching the module */
3427 if (!modname
|| strcmp(modname
, mod
))
3430 /* blank search means to match all funcs in the mod */
3435 return ftrace_match(str
, regex
, len
, type
);
3439 match_records(struct ftrace_hash
*hash
, char *buff
,
3440 int len
, char *mod
, int not)
3442 unsigned search_len
= 0;
3443 struct ftrace_page
*pg
;
3444 struct dyn_ftrace
*rec
;
3445 int type
= MATCH_FULL
;
3446 char *search
= buff
;
3451 type
= filter_parse_regex(buff
, len
, &search
, ¬);
3452 search_len
= strlen(search
);
3455 mutex_lock(&ftrace_lock
);
3457 if (unlikely(ftrace_disabled
))
3460 do_for_each_ftrace_rec(pg
, rec
) {
3461 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
3462 ret
= enter_record(hash
, rec
, not);
3469 } while_for_each_ftrace_rec();
3471 mutex_unlock(&ftrace_lock
);
3477 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3479 return match_records(hash
, buff
, len
, NULL
, 0);
3483 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
3487 /* blank or '*' mean the same */
3488 if (strcmp(buff
, "*") == 0)
3491 /* handle the case of 'dont filter this module' */
3492 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
3497 return match_records(hash
, buff
, strlen(buff
), mod
, not);
3501 * We register the module command as a template to show others how
3502 * to register the a command as well.
3506 ftrace_mod_callback(struct ftrace_hash
*hash
,
3507 char *func
, char *cmd
, char *param
, int enable
)
3513 * cmd == 'mod' because we only registered this func
3514 * for the 'mod' ftrace_func_command.
3515 * But if you register one func with multiple commands,
3516 * you can tell which command was used by the cmd
3520 /* we must have a module name */
3524 mod
= strsep(¶m
, ":");
3528 ret
= ftrace_match_module_records(hash
, func
, mod
);
3537 static struct ftrace_func_command ftrace_mod_cmd
= {
3539 .func
= ftrace_mod_callback
,
3542 static int __init
ftrace_mod_cmd_init(void)
3544 return register_ftrace_command(&ftrace_mod_cmd
);
3546 core_initcall(ftrace_mod_cmd_init
);
3548 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3549 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3551 struct ftrace_func_probe
*entry
;
3552 struct hlist_head
*hhd
;
3555 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3557 hhd
= &ftrace_func_hash
[key
];
3559 if (hlist_empty(hhd
))
3563 * Disable preemption for these calls to prevent a RCU grace
3564 * period. This syncs the hash iteration and freeing of items
3565 * on the hash. rcu_read_lock is too dangerous here.
3567 preempt_disable_notrace();
3568 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3569 if (entry
->ip
== ip
)
3570 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3572 preempt_enable_notrace();
3575 static struct ftrace_ops trace_probe_ops __read_mostly
=
3577 .func
= function_trace_probe_call
,
3578 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3579 INIT_OPS_HASH(trace_probe_ops
)
3582 static int ftrace_probe_registered
;
3584 static void __enable_ftrace_function_probe(struct ftrace_ops_hash
*old_hash
)
3589 if (ftrace_probe_registered
) {
3590 /* still need to update the function call sites */
3592 ftrace_run_modify_code(&trace_probe_ops
, FTRACE_UPDATE_CALLS
,
3597 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3598 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3602 /* Nothing registered? */
3603 if (i
== FTRACE_FUNC_HASHSIZE
)
3606 ret
= ftrace_startup(&trace_probe_ops
, 0);
3608 ftrace_probe_registered
= 1;
3611 static void __disable_ftrace_function_probe(void)
3615 if (!ftrace_probe_registered
)
3618 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3619 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3624 /* no more funcs left */
3625 ftrace_shutdown(&trace_probe_ops
, 0);
3627 ftrace_probe_registered
= 0;
3631 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3633 if (entry
->ops
->free
)
3634 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3639 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3642 struct ftrace_ops_hash old_hash_ops
;
3643 struct ftrace_func_probe
*entry
;
3644 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3645 struct ftrace_hash
*old_hash
= *orig_hash
;
3646 struct ftrace_hash
*hash
;
3647 struct ftrace_page
*pg
;
3648 struct dyn_ftrace
*rec
;
3655 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3656 len
= strlen(search
);
3658 /* we do not support '!' for function probes */
3662 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3664 old_hash_ops
.filter_hash
= old_hash
;
3665 /* Probes only have filters */
3666 old_hash_ops
.notrace_hash
= NULL
;
3668 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
3674 if (unlikely(ftrace_disabled
)) {
3679 mutex_lock(&ftrace_lock
);
3681 do_for_each_ftrace_rec(pg
, rec
) {
3683 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3686 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3688 /* If we did not process any, then return error */
3699 * The caller might want to do something special
3700 * for each function we find. We call the callback
3701 * to give the caller an opportunity to do so.
3704 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3705 /* caller does not like this func */
3711 ret
= enter_record(hash
, rec
, 0);
3719 entry
->ip
= rec
->ip
;
3721 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3722 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3724 } while_for_each_ftrace_rec();
3726 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3728 __enable_ftrace_function_probe(&old_hash_ops
);
3731 free_ftrace_hash_rcu(old_hash
);
3736 mutex_unlock(&ftrace_lock
);
3738 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3739 free_ftrace_hash(hash
);
3745 PROBE_TEST_FUNC
= 1,
3750 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3751 void *data
, int flags
)
3753 struct ftrace_func_entry
*rec_entry
;
3754 struct ftrace_func_probe
*entry
;
3755 struct ftrace_func_probe
*p
;
3756 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3757 struct ftrace_hash
*old_hash
= *orig_hash
;
3758 struct list_head free_list
;
3759 struct ftrace_hash
*hash
;
3760 struct hlist_node
*tmp
;
3761 char str
[KSYM_SYMBOL_LEN
];
3762 int type
= MATCH_FULL
;
3767 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3772 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3773 len
= strlen(search
);
3775 /* we do not support '!' for function probes */
3780 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3782 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3784 /* Hmm, should report this somehow */
3787 INIT_LIST_HEAD(&free_list
);
3789 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3790 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3792 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3794 /* break up if statements for readability */
3795 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3798 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3801 /* do this last, since it is the most expensive */
3803 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3805 if (!ftrace_match(str
, glob
, len
, type
))
3809 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3810 /* It is possible more than one entry had this ip */
3812 free_hash_entry(hash
, rec_entry
);
3814 hlist_del_rcu(&entry
->node
);
3815 list_add(&entry
->free_list
, &free_list
);
3818 mutex_lock(&ftrace_lock
);
3819 __disable_ftrace_function_probe();
3821 * Remove after the disable is called. Otherwise, if the last
3822 * probe is removed, a null hash means *all enabled*.
3824 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3825 synchronize_sched();
3827 free_ftrace_hash_rcu(old_hash
);
3829 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3830 list_del(&entry
->free_list
);
3831 ftrace_free_entry(entry
);
3833 mutex_unlock(&ftrace_lock
);
3836 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3837 free_ftrace_hash(hash
);
3841 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3844 __unregister_ftrace_function_probe(glob
, ops
, data
,
3845 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3849 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3851 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3854 void unregister_ftrace_function_probe_all(char *glob
)
3856 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3859 static LIST_HEAD(ftrace_commands
);
3860 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3863 * Currently we only register ftrace commands from __init, so mark this
3866 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
3868 struct ftrace_func_command
*p
;
3871 mutex_lock(&ftrace_cmd_mutex
);
3872 list_for_each_entry(p
, &ftrace_commands
, list
) {
3873 if (strcmp(cmd
->name
, p
->name
) == 0) {
3878 list_add(&cmd
->list
, &ftrace_commands
);
3880 mutex_unlock(&ftrace_cmd_mutex
);
3886 * Currently we only unregister ftrace commands from __init, so mark
3889 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3891 struct ftrace_func_command
*p
, *n
;
3894 mutex_lock(&ftrace_cmd_mutex
);
3895 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3896 if (strcmp(cmd
->name
, p
->name
) == 0) {
3898 list_del_init(&p
->list
);
3903 mutex_unlock(&ftrace_cmd_mutex
);
3908 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3909 char *buff
, int len
, int enable
)
3911 char *func
, *command
, *next
= buff
;
3912 struct ftrace_func_command
*p
;
3915 func
= strsep(&next
, ":");
3918 ret
= ftrace_match_records(hash
, func
, len
);
3928 command
= strsep(&next
, ":");
3930 mutex_lock(&ftrace_cmd_mutex
);
3931 list_for_each_entry(p
, &ftrace_commands
, list
) {
3932 if (strcmp(p
->name
, command
) == 0) {
3933 ret
= p
->func(hash
, func
, command
, next
, enable
);
3938 mutex_unlock(&ftrace_cmd_mutex
);
3944 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3945 size_t cnt
, loff_t
*ppos
, int enable
)
3947 struct ftrace_iterator
*iter
;
3948 struct trace_parser
*parser
;
3954 if (file
->f_mode
& FMODE_READ
) {
3955 struct seq_file
*m
= file
->private_data
;
3958 iter
= file
->private_data
;
3960 if (unlikely(ftrace_disabled
))
3963 /* iter->hash is a local copy, so we don't need regex_lock */
3965 parser
= &iter
->parser
;
3966 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3968 if (read
>= 0 && trace_parser_loaded(parser
) &&
3969 !trace_parser_cont(parser
)) {
3970 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3971 parser
->idx
, enable
);
3972 trace_parser_clear(parser
);
3983 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3984 size_t cnt
, loff_t
*ppos
)
3986 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3990 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3991 size_t cnt
, loff_t
*ppos
)
3993 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3997 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3999 struct ftrace_func_entry
*entry
;
4001 if (!ftrace_location(ip
))
4005 entry
= ftrace_lookup_ip(hash
, ip
);
4008 free_hash_entry(hash
, entry
);
4012 return add_hash_entry(hash
, ip
);
4015 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
4016 struct ftrace_ops_hash
*old_hash
)
4018 struct ftrace_ops
*op
;
4020 if (!ftrace_enabled
)
4023 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
4024 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
4029 * If this is the shared global_ops filter, then we need to
4030 * check if there is another ops that shares it, is enabled.
4031 * If so, we still need to run the modify code.
4033 if (ops
->func_hash
!= &global_ops
.local_hash
)
4036 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4037 if (op
->func_hash
== &global_ops
.local_hash
&&
4038 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
4039 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
4040 /* Only need to do this once */
4043 } while_for_each_ftrace_op(op
);
4047 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4048 unsigned long ip
, int remove
, int reset
, int enable
)
4050 struct ftrace_hash
**orig_hash
;
4051 struct ftrace_ops_hash old_hash_ops
;
4052 struct ftrace_hash
*old_hash
;
4053 struct ftrace_hash
*hash
;
4056 if (unlikely(ftrace_disabled
))
4059 mutex_lock(&ops
->func_hash
->regex_lock
);
4062 orig_hash
= &ops
->func_hash
->filter_hash
;
4064 orig_hash
= &ops
->func_hash
->notrace_hash
;
4067 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4069 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4073 goto out_regex_unlock
;
4076 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4078 goto out_regex_unlock
;
4081 ret
= ftrace_match_addr(hash
, ip
, remove
);
4083 goto out_regex_unlock
;
4086 mutex_lock(&ftrace_lock
);
4087 old_hash
= *orig_hash
;
4088 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
4089 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
4090 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
4092 ftrace_ops_update_code(ops
, &old_hash_ops
);
4093 free_ftrace_hash_rcu(old_hash
);
4095 mutex_unlock(&ftrace_lock
);
4098 mutex_unlock(&ops
->func_hash
->regex_lock
);
4100 free_ftrace_hash(hash
);
4105 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4106 int reset
, int enable
)
4108 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
4112 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4113 * @ops - the ops to set the filter with
4114 * @ip - the address to add to or remove from the filter.
4115 * @remove - non zero to remove the ip from the filter
4116 * @reset - non zero to reset all filters before applying this filter.
4118 * Filters denote which functions should be enabled when tracing is enabled
4119 * If @ip is NULL, it failes to update filter.
4121 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4122 int remove
, int reset
)
4124 ftrace_ops_init(ops
);
4125 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4127 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4130 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4131 int reset
, int enable
)
4133 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4137 * ftrace_set_filter - set a function to filter on in ftrace
4138 * @ops - the ops to set the filter with
4139 * @buf - the string that holds the function filter text.
4140 * @len - the length of the string.
4141 * @reset - non zero to reset all filters before applying this filter.
4143 * Filters denote which functions should be enabled when tracing is enabled.
4144 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4146 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4149 ftrace_ops_init(ops
);
4150 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4152 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4155 * ftrace_set_notrace - set a function to not trace in ftrace
4156 * @ops - the ops to set the notrace filter with
4157 * @buf - the string that holds the function notrace text.
4158 * @len - the length of the string.
4159 * @reset - non zero to reset all filters before applying this filter.
4161 * Notrace Filters denote which functions should not be enabled when tracing
4162 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4165 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4168 ftrace_ops_init(ops
);
4169 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4171 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4173 * ftrace_set_global_filter - set a function to filter on with global tracers
4174 * @buf - the string that holds the function filter text.
4175 * @len - the length of the string.
4176 * @reset - non zero to reset all filters before applying this filter.
4178 * Filters denote which functions should be enabled when tracing is enabled.
4179 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4181 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4183 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4185 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4188 * ftrace_set_global_notrace - set a function to not trace with global tracers
4189 * @buf - the string that holds the function notrace text.
4190 * @len - the length of the string.
4191 * @reset - non zero to reset all filters before applying this filter.
4193 * Notrace Filters denote which functions should not be enabled when tracing
4194 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4197 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4199 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4201 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4204 * command line interface to allow users to set filters on boot up.
4206 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4207 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4208 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4210 /* Used by function selftest to not test if filter is set */
4211 bool ftrace_filter_param __initdata
;
4213 static int __init
set_ftrace_notrace(char *str
)
4215 ftrace_filter_param
= true;
4216 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4219 __setup("ftrace_notrace=", set_ftrace_notrace
);
4221 static int __init
set_ftrace_filter(char *str
)
4223 ftrace_filter_param
= true;
4224 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4227 __setup("ftrace_filter=", set_ftrace_filter
);
4229 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4230 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4231 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4232 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
4234 static unsigned long save_global_trampoline
;
4235 static unsigned long save_global_flags
;
4237 static int __init
set_graph_function(char *str
)
4239 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4242 __setup("ftrace_graph_filter=", set_graph_function
);
4244 static int __init
set_graph_notrace_function(char *str
)
4246 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4249 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4251 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4255 unsigned long *table
= ftrace_graph_funcs
;
4256 int *count
= &ftrace_graph_count
;
4259 table
= ftrace_graph_notrace_funcs
;
4260 count
= &ftrace_graph_notrace_count
;
4264 func
= strsep(&buf
, ",");
4265 /* we allow only one expression at a time */
4266 ret
= ftrace_set_func(table
, count
, FTRACE_GRAPH_MAX_FUNCS
, func
);
4268 printk(KERN_DEBUG
"ftrace: function %s not "
4269 "traceable\n", func
);
4272 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4275 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
4279 ftrace_ops_init(ops
);
4282 func
= strsep(&buf
, ",");
4283 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
4287 static void __init
set_ftrace_early_filters(void)
4289 if (ftrace_filter_buf
[0])
4290 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4291 if (ftrace_notrace_buf
[0])
4292 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4293 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4294 if (ftrace_graph_buf
[0])
4295 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4296 if (ftrace_graph_notrace_buf
[0])
4297 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4298 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4301 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4303 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4304 struct ftrace_ops_hash old_hash_ops
;
4305 struct ftrace_iterator
*iter
;
4306 struct ftrace_hash
**orig_hash
;
4307 struct ftrace_hash
*old_hash
;
4308 struct trace_parser
*parser
;
4312 if (file
->f_mode
& FMODE_READ
) {
4314 seq_release(inode
, file
);
4316 iter
= file
->private_data
;
4318 parser
= &iter
->parser
;
4319 if (trace_parser_loaded(parser
)) {
4320 parser
->buffer
[parser
->idx
] = 0;
4321 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4324 trace_parser_put(parser
);
4326 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4328 if (file
->f_mode
& FMODE_WRITE
) {
4329 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
4332 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
4334 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
4336 mutex_lock(&ftrace_lock
);
4337 old_hash
= *orig_hash
;
4338 old_hash_ops
.filter_hash
= iter
->ops
->func_hash
->filter_hash
;
4339 old_hash_ops
.notrace_hash
= iter
->ops
->func_hash
->notrace_hash
;
4340 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
4341 orig_hash
, iter
->hash
);
4343 ftrace_ops_update_code(iter
->ops
, &old_hash_ops
);
4344 free_ftrace_hash_rcu(old_hash
);
4346 mutex_unlock(&ftrace_lock
);
4349 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
4350 free_ftrace_hash(iter
->hash
);
4356 static const struct file_operations ftrace_avail_fops
= {
4357 .open
= ftrace_avail_open
,
4359 .llseek
= seq_lseek
,
4360 .release
= seq_release_private
,
4363 static const struct file_operations ftrace_enabled_fops
= {
4364 .open
= ftrace_enabled_open
,
4366 .llseek
= seq_lseek
,
4367 .release
= seq_release_private
,
4370 static const struct file_operations ftrace_filter_fops
= {
4371 .open
= ftrace_filter_open
,
4373 .write
= ftrace_filter_write
,
4374 .llseek
= tracing_lseek
,
4375 .release
= ftrace_regex_release
,
4378 static const struct file_operations ftrace_notrace_fops
= {
4379 .open
= ftrace_notrace_open
,
4381 .write
= ftrace_notrace_write
,
4382 .llseek
= tracing_lseek
,
4383 .release
= ftrace_regex_release
,
4386 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4388 static DEFINE_MUTEX(graph_lock
);
4390 int ftrace_graph_count
;
4391 int ftrace_graph_notrace_count
;
4392 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4393 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4395 struct ftrace_graph_data
{
4396 unsigned long *table
;
4399 const struct seq_operations
*seq_ops
;
4403 __g_next(struct seq_file
*m
, loff_t
*pos
)
4405 struct ftrace_graph_data
*fgd
= m
->private;
4407 if (*pos
>= *fgd
->count
)
4409 return &fgd
->table
[*pos
];
4413 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4416 return __g_next(m
, pos
);
4419 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4421 struct ftrace_graph_data
*fgd
= m
->private;
4423 mutex_lock(&graph_lock
);
4425 /* Nothing, tell g_show to print all functions are enabled */
4426 if (!*fgd
->count
&& !*pos
)
4429 return __g_next(m
, pos
);
4432 static void g_stop(struct seq_file
*m
, void *p
)
4434 mutex_unlock(&graph_lock
);
4437 static int g_show(struct seq_file
*m
, void *v
)
4439 unsigned long *ptr
= v
;
4444 if (ptr
== (unsigned long *)1) {
4445 struct ftrace_graph_data
*fgd
= m
->private;
4447 if (fgd
->table
== ftrace_graph_funcs
)
4448 seq_puts(m
, "#### all functions enabled ####\n");
4450 seq_puts(m
, "#### no functions disabled ####\n");
4454 seq_printf(m
, "%ps\n", (void *)*ptr
);
4459 static const struct seq_operations ftrace_graph_seq_ops
= {
4467 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4468 struct ftrace_graph_data
*fgd
)
4472 mutex_lock(&graph_lock
);
4473 if ((file
->f_mode
& FMODE_WRITE
) &&
4474 (file
->f_flags
& O_TRUNC
)) {
4476 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
4478 mutex_unlock(&graph_lock
);
4480 if (file
->f_mode
& FMODE_READ
) {
4481 ret
= seq_open(file
, fgd
->seq_ops
);
4483 struct seq_file
*m
= file
->private_data
;
4487 file
->private_data
= fgd
;
4493 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4495 struct ftrace_graph_data
*fgd
;
4497 if (unlikely(ftrace_disabled
))
4500 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4504 fgd
->table
= ftrace_graph_funcs
;
4505 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4506 fgd
->count
= &ftrace_graph_count
;
4507 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4509 return __ftrace_graph_open(inode
, file
, fgd
);
4513 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4515 struct ftrace_graph_data
*fgd
;
4517 if (unlikely(ftrace_disabled
))
4520 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4524 fgd
->table
= ftrace_graph_notrace_funcs
;
4525 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4526 fgd
->count
= &ftrace_graph_notrace_count
;
4527 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4529 return __ftrace_graph_open(inode
, file
, fgd
);
4533 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
4535 if (file
->f_mode
& FMODE_READ
) {
4536 struct seq_file
*m
= file
->private_data
;
4539 seq_release(inode
, file
);
4541 kfree(file
->private_data
);
4548 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
4550 struct dyn_ftrace
*rec
;
4551 struct ftrace_page
*pg
;
4560 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
4561 if (!not && *idx
>= size
)
4564 search_len
= strlen(search
);
4566 mutex_lock(&ftrace_lock
);
4568 if (unlikely(ftrace_disabled
)) {
4569 mutex_unlock(&ftrace_lock
);
4573 do_for_each_ftrace_rec(pg
, rec
) {
4575 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
4576 /* if it is in the array */
4578 for (i
= 0; i
< *idx
; i
++) {
4579 if (array
[i
] == rec
->ip
) {
4588 array
[(*idx
)++] = rec
->ip
;
4594 array
[i
] = array
[--(*idx
)];
4600 } while_for_each_ftrace_rec();
4602 mutex_unlock(&ftrace_lock
);
4611 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4612 size_t cnt
, loff_t
*ppos
)
4614 struct trace_parser parser
;
4615 ssize_t read
, ret
= 0;
4616 struct ftrace_graph_data
*fgd
= file
->private_data
;
4621 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4624 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4626 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4627 parser
.buffer
[parser
.idx
] = 0;
4629 mutex_lock(&graph_lock
);
4631 /* we allow only one expression at a time */
4632 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4635 mutex_unlock(&graph_lock
);
4641 trace_parser_put(&parser
);
4646 static const struct file_operations ftrace_graph_fops
= {
4647 .open
= ftrace_graph_open
,
4649 .write
= ftrace_graph_write
,
4650 .llseek
= tracing_lseek
,
4651 .release
= ftrace_graph_release
,
4654 static const struct file_operations ftrace_graph_notrace_fops
= {
4655 .open
= ftrace_graph_notrace_open
,
4657 .write
= ftrace_graph_write
,
4658 .llseek
= tracing_lseek
,
4659 .release
= ftrace_graph_release
,
4661 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4663 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
4664 struct dentry
*parent
)
4667 trace_create_file("set_ftrace_filter", 0644, parent
,
4668 ops
, &ftrace_filter_fops
);
4670 trace_create_file("set_ftrace_notrace", 0644, parent
,
4671 ops
, &ftrace_notrace_fops
);
4675 * The name "destroy_filter_files" is really a misnomer. Although
4676 * in the future, it may actualy delete the files, but this is
4677 * really intended to make sure the ops passed in are disabled
4678 * and that when this function returns, the caller is free to
4681 * The "destroy" name is only to match the "create" name that this
4682 * should be paired with.
4684 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
4686 mutex_lock(&ftrace_lock
);
4687 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
4688 ftrace_shutdown(ops
, 0);
4689 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
4690 mutex_unlock(&ftrace_lock
);
4693 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
4696 trace_create_file("available_filter_functions", 0444,
4697 d_tracer
, NULL
, &ftrace_avail_fops
);
4699 trace_create_file("enabled_functions", 0444,
4700 d_tracer
, NULL
, &ftrace_enabled_fops
);
4702 ftrace_create_filter_files(&global_ops
, d_tracer
);
4704 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4705 trace_create_file("set_graph_function", 0444, d_tracer
,
4707 &ftrace_graph_fops
);
4708 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4710 &ftrace_graph_notrace_fops
);
4711 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4716 static int ftrace_cmp_ips(const void *a
, const void *b
)
4718 const unsigned long *ipa
= a
;
4719 const unsigned long *ipb
= b
;
4728 static void ftrace_swap_ips(void *a
, void *b
, int size
)
4730 unsigned long *ipa
= a
;
4731 unsigned long *ipb
= b
;
4739 static int ftrace_process_locs(struct module
*mod
,
4740 unsigned long *start
,
4743 struct ftrace_page
*start_pg
;
4744 struct ftrace_page
*pg
;
4745 struct dyn_ftrace
*rec
;
4746 unsigned long count
;
4749 unsigned long flags
= 0; /* Shut up gcc */
4752 count
= end
- start
;
4757 sort(start
, count
, sizeof(*start
),
4758 ftrace_cmp_ips
, ftrace_swap_ips
);
4760 start_pg
= ftrace_allocate_pages(count
);
4764 mutex_lock(&ftrace_lock
);
4767 * Core and each module needs their own pages, as
4768 * modules will free them when they are removed.
4769 * Force a new page to be allocated for modules.
4772 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4773 /* First initialization */
4774 ftrace_pages
= ftrace_pages_start
= start_pg
;
4779 if (WARN_ON(ftrace_pages
->next
)) {
4780 /* Hmm, we have free pages? */
4781 while (ftrace_pages
->next
)
4782 ftrace_pages
= ftrace_pages
->next
;
4785 ftrace_pages
->next
= start_pg
;
4791 addr
= ftrace_call_adjust(*p
++);
4793 * Some architecture linkers will pad between
4794 * the different mcount_loc sections of different
4795 * object files to satisfy alignments.
4796 * Skip any NULL pointers.
4801 if (pg
->index
== pg
->size
) {
4802 /* We should have allocated enough */
4803 if (WARN_ON(!pg
->next
))
4808 rec
= &pg
->records
[pg
->index
++];
4812 /* We should have used all pages */
4815 /* Assign the last page to ftrace_pages */
4819 * We only need to disable interrupts on start up
4820 * because we are modifying code that an interrupt
4821 * may execute, and the modification is not atomic.
4822 * But for modules, nothing runs the code we modify
4823 * until we are finished with it, and there's no
4824 * reason to cause large interrupt latencies while we do it.
4827 local_irq_save(flags
);
4828 ftrace_update_code(mod
, start_pg
);
4830 local_irq_restore(flags
);
4833 mutex_unlock(&ftrace_lock
);
4838 #ifdef CONFIG_MODULES
4840 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4842 void ftrace_release_mod(struct module
*mod
)
4844 struct dyn_ftrace
*rec
;
4845 struct ftrace_page
**last_pg
;
4846 struct ftrace_page
*pg
;
4849 mutex_lock(&ftrace_lock
);
4851 if (ftrace_disabled
)
4855 * Each module has its own ftrace_pages, remove
4856 * them from the list.
4858 last_pg
= &ftrace_pages_start
;
4859 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4860 rec
= &pg
->records
[0];
4861 if (within_module_core(rec
->ip
, mod
)) {
4863 * As core pages are first, the first
4864 * page should never be a module page.
4866 if (WARN_ON(pg
== ftrace_pages_start
))
4869 /* Check if we are deleting the last page */
4870 if (pg
== ftrace_pages
)
4871 ftrace_pages
= next_to_ftrace_page(last_pg
);
4873 *last_pg
= pg
->next
;
4874 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4875 free_pages((unsigned long)pg
->records
, order
);
4878 last_pg
= &pg
->next
;
4881 mutex_unlock(&ftrace_lock
);
4884 static void ftrace_init_module(struct module
*mod
,
4885 unsigned long *start
, unsigned long *end
)
4887 if (ftrace_disabled
|| start
== end
)
4889 ftrace_process_locs(mod
, start
, end
);
4892 void ftrace_module_init(struct module
*mod
)
4894 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4895 mod
->ftrace_callsites
+
4896 mod
->num_ftrace_callsites
);
4899 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4900 unsigned long val
, void *data
)
4902 struct module
*mod
= data
;
4904 if (val
== MODULE_STATE_GOING
)
4905 ftrace_release_mod(mod
);
4910 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4911 unsigned long val
, void *data
)
4915 #endif /* CONFIG_MODULES */
4917 struct notifier_block ftrace_module_exit_nb
= {
4918 .notifier_call
= ftrace_module_notify_exit
,
4919 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4922 void __init
ftrace_init(void)
4924 extern unsigned long __start_mcount_loc
[];
4925 extern unsigned long __stop_mcount_loc
[];
4926 unsigned long count
, flags
;
4929 local_irq_save(flags
);
4930 ret
= ftrace_dyn_arch_init();
4931 local_irq_restore(flags
);
4935 count
= __stop_mcount_loc
- __start_mcount_loc
;
4937 pr_info("ftrace: No functions to be traced?\n");
4941 pr_info("ftrace: allocating %ld entries in %ld pages\n",
4942 count
, count
/ ENTRIES_PER_PAGE
+ 1);
4944 last_ftrace_enabled
= ftrace_enabled
= 1;
4946 ret
= ftrace_process_locs(NULL
,
4950 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4952 pr_warning("Failed to register trace ftrace module exit notifier\n");
4954 set_ftrace_early_filters();
4958 ftrace_disabled
= 1;
4961 /* Do nothing if arch does not support this */
4962 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
4966 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
4970 * Currently there's no safe way to free a trampoline when the kernel
4971 * is configured with PREEMPT. That is because a task could be preempted
4972 * when it jumped to the trampoline, it may be preempted for a long time
4973 * depending on the system load, and currently there's no way to know
4974 * when it will be off the trampoline. If the trampoline is freed
4975 * too early, when the task runs again, it will be executing on freed
4978 #ifdef CONFIG_PREEMPT
4979 /* Currently, only non dynamic ops can have a trampoline */
4980 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
4984 arch_ftrace_update_trampoline(ops
);
4989 static struct ftrace_ops global_ops
= {
4990 .func
= ftrace_stub
,
4991 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4994 static int __init
ftrace_nodyn_init(void)
4999 core_initcall(ftrace_nodyn_init
);
5001 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
5002 static inline void ftrace_startup_enable(int command
) { }
5003 static inline void ftrace_startup_all(int command
) { }
5004 /* Keep as macros so we do not need to define the commands */
5005 # define ftrace_startup(ops, command) \
5007 int ___ret = __register_ftrace_function(ops); \
5009 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5012 # define ftrace_shutdown(ops, command) \
5014 int ___ret = __unregister_ftrace_function(ops); \
5016 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5020 # define ftrace_startup_sysctl() do { } while (0)
5021 # define ftrace_shutdown_sysctl() do { } while (0)
5024 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
5029 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5033 #endif /* CONFIG_DYNAMIC_FTRACE */
5035 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
5037 tr
->ops
= &global_ops
;
5038 tr
->ops
->private = tr
;
5041 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
5043 /* If we filter on pids, update to use the pid function */
5044 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
5045 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
5046 printk("ftrace ops had %pS for function\n",
5048 /* Only the top level instance does pid tracing */
5049 if (!list_empty(&ftrace_pids
)) {
5050 set_ftrace_pid_function(func
);
5051 func
= ftrace_pid_func
;
5054 tr
->ops
->func
= func
;
5055 tr
->ops
->private = tr
;
5058 void ftrace_reset_array_ops(struct trace_array
*tr
)
5060 tr
->ops
->func
= ftrace_stub
;
5064 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
5065 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5067 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
5071 * Some of the ops may be dynamically allocated,
5072 * they must be freed after a synchronize_sched().
5074 preempt_disable_notrace();
5075 trace_recursion_set(TRACE_CONTROL_BIT
);
5078 * Control funcs (perf) uses RCU. Only trace if
5079 * RCU is currently active.
5081 if (!rcu_is_watching())
5084 do_for_each_ftrace_op(op
, ftrace_control_list
) {
5085 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
5086 !ftrace_function_local_disabled(op
) &&
5087 ftrace_ops_test(op
, ip
, regs
))
5088 op
->func(ip
, parent_ip
, op
, regs
);
5089 } while_for_each_ftrace_op(op
);
5091 trace_recursion_clear(TRACE_CONTROL_BIT
);
5092 preempt_enable_notrace();
5095 static struct ftrace_ops control_ops
= {
5096 .func
= ftrace_ops_control_func
,
5097 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
5098 INIT_OPS_HASH(control_ops
)
5102 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5103 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
5105 struct ftrace_ops
*op
;
5108 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5113 * Some of the ops may be dynamically allocated,
5114 * they must be freed after a synchronize_sched().
5116 preempt_disable_notrace();
5117 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5118 if (ftrace_ops_test(op
, ip
, regs
)) {
5119 if (FTRACE_WARN_ON(!op
->func
)) {
5120 pr_warn("op=%p %pS\n", op
, op
);
5123 op
->func(ip
, parent_ip
, op
, regs
);
5125 } while_for_each_ftrace_op(op
);
5127 preempt_enable_notrace();
5128 trace_clear_recursion(bit
);
5132 * Some archs only support passing ip and parent_ip. Even though
5133 * the list function ignores the op parameter, we do not want any
5134 * C side effects, where a function is called without the caller
5135 * sending a third parameter.
5136 * Archs are to support both the regs and ftrace_ops at the same time.
5137 * If they support ftrace_ops, it is assumed they support regs.
5138 * If call backs want to use regs, they must either check for regs
5139 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5140 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5141 * An architecture can pass partial regs with ftrace_ops and still
5142 * set the ARCH_SUPPORT_FTARCE_OPS.
5144 #if ARCH_SUPPORTS_FTRACE_OPS
5145 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5146 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5148 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
5151 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
5153 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
5158 * If there's only one function registered but it does not support
5159 * recursion, this function will be called by the mcount trampoline.
5160 * This function will handle recursion protection.
5162 static void ftrace_ops_recurs_func(unsigned long ip
, unsigned long parent_ip
,
5163 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5167 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5171 op
->func(ip
, parent_ip
, op
, regs
);
5173 trace_clear_recursion(bit
);
5177 * ftrace_ops_get_func - get the function a trampoline should call
5178 * @ops: the ops to get the function for
5180 * Normally the mcount trampoline will call the ops->func, but there
5181 * are times that it should not. For example, if the ops does not
5182 * have its own recursion protection, then it should call the
5183 * ftrace_ops_recurs_func() instead.
5185 * Returns the function that the trampoline should call for @ops.
5187 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
5190 * If this is a dynamic ops or we force list func,
5191 * then it needs to call the list anyway.
5193 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
|| FTRACE_FORCE_LIST_FUNC
)
5194 return ftrace_ops_list_func
;
5197 * If the func handles its own recursion, call it directly.
5198 * Otherwise call the recursion protected function that
5199 * will call the ftrace ops function.
5201 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
))
5202 return ftrace_ops_recurs_func
;
5207 static void clear_ftrace_swapper(void)
5209 struct task_struct
*p
;
5213 for_each_online_cpu(cpu
) {
5215 clear_tsk_trace_trace(p
);
5220 static void set_ftrace_swapper(void)
5222 struct task_struct
*p
;
5226 for_each_online_cpu(cpu
) {
5228 set_tsk_trace_trace(p
);
5233 static void clear_ftrace_pid(struct pid
*pid
)
5235 struct task_struct
*p
;
5238 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
5239 clear_tsk_trace_trace(p
);
5240 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
5246 static void set_ftrace_pid(struct pid
*pid
)
5248 struct task_struct
*p
;
5251 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
5252 set_tsk_trace_trace(p
);
5253 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
5257 static void clear_ftrace_pid_task(struct pid
*pid
)
5259 if (pid
== ftrace_swapper_pid
)
5260 clear_ftrace_swapper();
5262 clear_ftrace_pid(pid
);
5265 static void set_ftrace_pid_task(struct pid
*pid
)
5267 if (pid
== ftrace_swapper_pid
)
5268 set_ftrace_swapper();
5270 set_ftrace_pid(pid
);
5273 static int ftrace_pid_add(int p
)
5276 struct ftrace_pid
*fpid
;
5279 mutex_lock(&ftrace_lock
);
5282 pid
= ftrace_swapper_pid
;
5284 pid
= find_get_pid(p
);
5291 list_for_each_entry(fpid
, &ftrace_pids
, list
)
5292 if (fpid
->pid
== pid
)
5297 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
5301 list_add(&fpid
->list
, &ftrace_pids
);
5304 set_ftrace_pid_task(pid
);
5306 ftrace_update_pid_func();
5308 ftrace_startup_all(0);
5310 mutex_unlock(&ftrace_lock
);
5314 if (pid
!= ftrace_swapper_pid
)
5318 mutex_unlock(&ftrace_lock
);
5322 static void ftrace_pid_reset(void)
5324 struct ftrace_pid
*fpid
, *safe
;
5326 mutex_lock(&ftrace_lock
);
5327 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
5328 struct pid
*pid
= fpid
->pid
;
5330 clear_ftrace_pid_task(pid
);
5332 list_del(&fpid
->list
);
5336 ftrace_update_pid_func();
5337 ftrace_startup_all(0);
5339 mutex_unlock(&ftrace_lock
);
5342 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
5344 mutex_lock(&ftrace_lock
);
5346 if (list_empty(&ftrace_pids
) && (!*pos
))
5349 return seq_list_start(&ftrace_pids
, *pos
);
5352 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5357 return seq_list_next(v
, &ftrace_pids
, pos
);
5360 static void fpid_stop(struct seq_file
*m
, void *p
)
5362 mutex_unlock(&ftrace_lock
);
5365 static int fpid_show(struct seq_file
*m
, void *v
)
5367 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
5369 if (v
== (void *)1) {
5370 seq_puts(m
, "no pid\n");
5374 if (fpid
->pid
== ftrace_swapper_pid
)
5375 seq_puts(m
, "swapper tasks\n");
5377 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
5382 static const struct seq_operations ftrace_pid_sops
= {
5383 .start
= fpid_start
,
5390 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
5394 if ((file
->f_mode
& FMODE_WRITE
) &&
5395 (file
->f_flags
& O_TRUNC
))
5398 if (file
->f_mode
& FMODE_READ
)
5399 ret
= seq_open(file
, &ftrace_pid_sops
);
5405 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
5406 size_t cnt
, loff_t
*ppos
)
5412 if (cnt
>= sizeof(buf
))
5415 if (copy_from_user(&buf
, ubuf
, cnt
))
5421 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5422 * to clean the filter quietly.
5424 tmp
= strstrip(buf
);
5425 if (strlen(tmp
) == 0)
5428 ret
= kstrtol(tmp
, 10, &val
);
5432 ret
= ftrace_pid_add(val
);
5434 return ret
? ret
: cnt
;
5438 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
5440 if (file
->f_mode
& FMODE_READ
)
5441 seq_release(inode
, file
);
5446 static const struct file_operations ftrace_pid_fops
= {
5447 .open
= ftrace_pid_open
,
5448 .write
= ftrace_pid_write
,
5450 .llseek
= tracing_lseek
,
5451 .release
= ftrace_pid_release
,
5454 static __init
int ftrace_init_debugfs(void)
5456 struct dentry
*d_tracer
;
5458 d_tracer
= tracing_init_dentry();
5459 if (IS_ERR(d_tracer
))
5462 ftrace_init_dyn_debugfs(d_tracer
);
5464 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
5465 NULL
, &ftrace_pid_fops
);
5467 ftrace_profile_debugfs(d_tracer
);
5471 fs_initcall(ftrace_init_debugfs
);
5474 * ftrace_kill - kill ftrace
5476 * This function should be used by panic code. It stops ftrace
5477 * but in a not so nice way. If you need to simply kill ftrace
5478 * from a non-atomic section, use ftrace_kill.
5480 void ftrace_kill(void)
5482 ftrace_disabled
= 1;
5484 clear_ftrace_function();
5488 * Test if ftrace is dead or not.
5490 int ftrace_is_dead(void)
5492 return ftrace_disabled
;
5496 * register_ftrace_function - register a function for profiling
5497 * @ops - ops structure that holds the function for profiling.
5499 * Register a function to be called by all functions in the
5502 * Note: @ops->func and all the functions it calls must be labeled
5503 * with "notrace", otherwise it will go into a
5506 int register_ftrace_function(struct ftrace_ops
*ops
)
5510 ftrace_ops_init(ops
);
5512 mutex_lock(&ftrace_lock
);
5514 ret
= ftrace_startup(ops
, 0);
5516 mutex_unlock(&ftrace_lock
);
5520 EXPORT_SYMBOL_GPL(register_ftrace_function
);
5523 * unregister_ftrace_function - unregister a function for profiling.
5524 * @ops - ops structure that holds the function to unregister
5526 * Unregister a function that was added to be called by ftrace profiling.
5528 int unregister_ftrace_function(struct ftrace_ops
*ops
)
5532 mutex_lock(&ftrace_lock
);
5533 ret
= ftrace_shutdown(ops
, 0);
5534 mutex_unlock(&ftrace_lock
);
5538 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
5541 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
5542 void __user
*buffer
, size_t *lenp
,
5547 mutex_lock(&ftrace_lock
);
5549 if (unlikely(ftrace_disabled
))
5552 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
5554 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
5557 last_ftrace_enabled
= !!ftrace_enabled
;
5559 if (ftrace_enabled
) {
5561 ftrace_startup_sysctl();
5563 /* we are starting ftrace again */
5564 if (ftrace_ops_list
!= &ftrace_list_end
)
5565 update_ftrace_function();
5568 /* stopping ftrace calls (just send to ftrace_stub) */
5569 ftrace_trace_function
= ftrace_stub
;
5571 ftrace_shutdown_sysctl();
5575 mutex_unlock(&ftrace_lock
);
5579 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5581 static struct ftrace_ops graph_ops
= {
5582 .func
= ftrace_stub
,
5583 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5584 FTRACE_OPS_FL_INITIALIZED
|
5586 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5587 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
5588 /* trampoline_size is only needed for dynamically allocated tramps */
5590 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
5593 static int ftrace_graph_active
;
5595 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
5600 /* The callbacks that hook a function */
5601 trace_func_graph_ret_t ftrace_graph_return
=
5602 (trace_func_graph_ret_t
)ftrace_stub
;
5603 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
5604 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5606 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5607 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
5611 unsigned long flags
;
5612 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
5613 struct task_struct
*g
, *t
;
5615 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
5616 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
5617 * sizeof(struct ftrace_ret_stack
),
5619 if (!ret_stack_list
[i
]) {
5627 read_lock_irqsave(&tasklist_lock
, flags
);
5628 do_each_thread(g
, t
) {
5634 if (t
->ret_stack
== NULL
) {
5635 atomic_set(&t
->tracing_graph_pause
, 0);
5636 atomic_set(&t
->trace_overrun
, 0);
5637 t
->curr_ret_stack
= -1;
5638 /* Make sure the tasks see the -1 first: */
5640 t
->ret_stack
= ret_stack_list
[start
++];
5642 } while_each_thread(g
, t
);
5645 read_unlock_irqrestore(&tasklist_lock
, flags
);
5647 for (i
= start
; i
< end
; i
++)
5648 kfree(ret_stack_list
[i
]);
5653 ftrace_graph_probe_sched_switch(void *ignore
,
5654 struct task_struct
*prev
, struct task_struct
*next
)
5656 unsigned long long timestamp
;
5660 * Does the user want to count the time a function was asleep.
5661 * If so, do not update the time stamps.
5663 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
5666 timestamp
= trace_clock_local();
5668 prev
->ftrace_timestamp
= timestamp
;
5670 /* only process tasks that we timestamped */
5671 if (!next
->ftrace_timestamp
)
5675 * Update all the counters in next to make up for the
5676 * time next was sleeping.
5678 timestamp
-= next
->ftrace_timestamp
;
5680 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
5681 next
->ret_stack
[index
].calltime
+= timestamp
;
5684 /* Allocate a return stack for each task */
5685 static int start_graph_tracing(void)
5687 struct ftrace_ret_stack
**ret_stack_list
;
5690 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
5691 sizeof(struct ftrace_ret_stack
*),
5694 if (!ret_stack_list
)
5697 /* The cpu_boot init_task->ret_stack will never be freed */
5698 for_each_online_cpu(cpu
) {
5699 if (!idle_task(cpu
)->ret_stack
)
5700 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
5704 ret
= alloc_retstack_tasklist(ret_stack_list
);
5705 } while (ret
== -EAGAIN
);
5708 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5710 pr_info("ftrace_graph: Couldn't activate tracepoint"
5711 " probe to kernel_sched_switch\n");
5714 kfree(ret_stack_list
);
5719 * Hibernation protection.
5720 * The state of the current task is too much unstable during
5721 * suspend/restore to disk. We want to protect against that.
5724 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
5728 case PM_HIBERNATION_PREPARE
:
5729 pause_graph_tracing();
5732 case PM_POST_HIBERNATION
:
5733 unpause_graph_tracing();
5739 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
5741 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
5743 return __ftrace_graph_entry(trace
);
5747 * The function graph tracer should only trace the functions defined
5748 * by set_ftrace_filter and set_ftrace_notrace. If another function
5749 * tracer ops is registered, the graph tracer requires testing the
5750 * function against the global ops, and not just trace any function
5751 * that any ftrace_ops registered.
5753 static void update_function_graph_func(void)
5755 struct ftrace_ops
*op
;
5756 bool do_test
= false;
5759 * The graph and global ops share the same set of functions
5760 * to test. If any other ops is on the list, then
5761 * the graph tracing needs to test if its the function
5764 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5765 if (op
!= &global_ops
&& op
!= &graph_ops
&&
5766 op
!= &ftrace_list_end
) {
5768 /* in double loop, break out with goto */
5771 } while_for_each_ftrace_op(op
);
5774 ftrace_graph_entry
= ftrace_graph_entry_test
;
5776 ftrace_graph_entry
= __ftrace_graph_entry
;
5779 static struct notifier_block ftrace_suspend_notifier
= {
5780 .notifier_call
= ftrace_suspend_notifier_call
,
5783 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5784 trace_func_graph_ent_t entryfunc
)
5788 mutex_lock(&ftrace_lock
);
5790 /* we currently allow only one tracer registered at a time */
5791 if (ftrace_graph_active
) {
5796 register_pm_notifier(&ftrace_suspend_notifier
);
5798 ftrace_graph_active
++;
5799 ret
= start_graph_tracing();
5801 ftrace_graph_active
--;
5805 ftrace_graph_return
= retfunc
;
5808 * Update the indirect function to the entryfunc, and the
5809 * function that gets called to the entry_test first. Then
5810 * call the update fgraph entry function to determine if
5811 * the entryfunc should be called directly or not.
5813 __ftrace_graph_entry
= entryfunc
;
5814 ftrace_graph_entry
= ftrace_graph_entry_test
;
5815 update_function_graph_func();
5817 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
5819 mutex_unlock(&ftrace_lock
);
5823 void unregister_ftrace_graph(void)
5825 mutex_lock(&ftrace_lock
);
5827 if (unlikely(!ftrace_graph_active
))
5830 ftrace_graph_active
--;
5831 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5832 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5833 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5834 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
5835 unregister_pm_notifier(&ftrace_suspend_notifier
);
5836 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5838 #ifdef CONFIG_DYNAMIC_FTRACE
5840 * Function graph does not allocate the trampoline, but
5841 * other global_ops do. We need to reset the ALLOC_TRAMP flag
5844 global_ops
.trampoline
= save_global_trampoline
;
5845 if (save_global_flags
& FTRACE_OPS_FL_ALLOC_TRAMP
)
5846 global_ops
.flags
|= FTRACE_OPS_FL_ALLOC_TRAMP
;
5850 mutex_unlock(&ftrace_lock
);
5853 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5856 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5858 atomic_set(&t
->tracing_graph_pause
, 0);
5859 atomic_set(&t
->trace_overrun
, 0);
5860 t
->ftrace_timestamp
= 0;
5861 /* make curr_ret_stack visible before we add the ret_stack */
5863 t
->ret_stack
= ret_stack
;
5867 * Allocate a return stack for the idle task. May be the first
5868 * time through, or it may be done by CPU hotplug online.
5870 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5872 t
->curr_ret_stack
= -1;
5874 * The idle task has no parent, it either has its own
5875 * stack or no stack at all.
5878 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5880 if (ftrace_graph_active
) {
5881 struct ftrace_ret_stack
*ret_stack
;
5883 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5885 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5886 * sizeof(struct ftrace_ret_stack
),
5890 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
5892 graph_init_task(t
, ret_stack
);
5896 /* Allocate a return stack for newly created task */
5897 void ftrace_graph_init_task(struct task_struct
*t
)
5899 /* Make sure we do not use the parent ret_stack */
5900 t
->ret_stack
= NULL
;
5901 t
->curr_ret_stack
= -1;
5903 if (ftrace_graph_active
) {
5904 struct ftrace_ret_stack
*ret_stack
;
5906 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5907 * sizeof(struct ftrace_ret_stack
),
5911 graph_init_task(t
, ret_stack
);
5915 void ftrace_graph_exit_task(struct task_struct
*t
)
5917 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
5919 t
->ret_stack
= NULL
;
5920 /* NULL must become visible to IRQs before we free it: */