4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
8 #include <linux/module.h>
9 #include <linux/mutex.h>
10 #include <linux/ftrace.h>
12 #include "trace_output.h"
14 /* must be a power of 2 */
15 #define EVENT_HASHSIZE 128
17 static DEFINE_MUTEX(trace_event_mutex
);
18 static struct hlist_head event_hash
[EVENT_HASHSIZE
] __read_mostly
;
20 static int next_event_type
= __TRACE_LAST_TYPE
+ 1;
23 * trace_seq_printf - sequence printing of trace information
24 * @s: trace sequence descriptor
25 * @fmt: printf format string
27 * The tracer may use either sequence operations or its own
28 * copy to user routines. To simplify formating of a trace
29 * trace_seq_printf is used to store strings into a special
30 * buffer (@s). Then the output may be either used by
31 * the sequencer or pulled into another buffer.
34 trace_seq_printf(struct trace_seq
*s
, const char *fmt
, ...)
36 int len
= (PAGE_SIZE
- 1) - s
->len
;
44 ret
= vsnprintf(s
->buffer
+ s
->len
, len
, fmt
, ap
);
47 /* If we can't write it all, don't bother writing anything */
57 * trace_seq_puts - trace sequence printing of simple string
58 * @s: trace sequence descriptor
59 * @str: simple string to record
61 * The tracer may use either the sequence operations or its own
62 * copy to user routines. This function records a simple string
63 * into a special buffer (@s) for later retrieval by a sequencer
66 int trace_seq_puts(struct trace_seq
*s
, const char *str
)
68 int len
= strlen(str
);
70 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
73 memcpy(s
->buffer
+ s
->len
, str
, len
);
79 int trace_seq_putc(struct trace_seq
*s
, unsigned char c
)
81 if (s
->len
>= (PAGE_SIZE
- 1))
84 s
->buffer
[s
->len
++] = c
;
89 int trace_seq_putmem(struct trace_seq
*s
, void *mem
, size_t len
)
91 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
94 memcpy(s
->buffer
+ s
->len
, mem
, len
);
100 int trace_seq_putmem_hex(struct trace_seq
*s
, void *mem
, size_t len
)
102 unsigned char hex
[HEX_CHARS
];
103 unsigned char *data
= mem
;
107 for (i
= 0, j
= 0; i
< len
; i
++) {
109 for (i
= len
-1, j
= 0; i
>= 0; i
--) {
111 hex
[j
++] = hex_asc_hi(data
[i
]);
112 hex
[j
++] = hex_asc_lo(data
[i
]);
116 return trace_seq_putmem(s
, hex
, j
);
119 int trace_seq_path(struct trace_seq
*s
, struct path
*path
)
123 if (s
->len
>= (PAGE_SIZE
- 1))
125 p
= d_path(path
, s
->buffer
+ s
->len
, PAGE_SIZE
- s
->len
);
127 p
= mangle_path(s
->buffer
+ s
->len
, p
, "\n");
129 s
->len
= p
- s
->buffer
;
133 s
->buffer
[s
->len
++] = '?';
140 #ifdef CONFIG_KRETPROBES
141 static inline const char *kretprobed(const char *name
)
143 static const char tramp_name
[] = "kretprobe_trampoline";
144 int size
= sizeof(tramp_name
);
146 if (strncmp(tramp_name
, name
, size
) == 0)
147 return "[unknown/kretprobe'd]";
151 static inline const char *kretprobed(const char *name
)
155 #endif /* CONFIG_KRETPROBES */
158 seq_print_sym_short(struct trace_seq
*s
, const char *fmt
, unsigned long address
)
160 #ifdef CONFIG_KALLSYMS
161 char str
[KSYM_SYMBOL_LEN
];
164 kallsyms_lookup(address
, NULL
, NULL
, NULL
, str
);
166 name
= kretprobed(str
);
168 return trace_seq_printf(s
, fmt
, name
);
174 seq_print_sym_offset(struct trace_seq
*s
, const char *fmt
,
175 unsigned long address
)
177 #ifdef CONFIG_KALLSYMS
178 char str
[KSYM_SYMBOL_LEN
];
181 sprint_symbol(str
, address
);
182 name
= kretprobed(str
);
184 return trace_seq_printf(s
, fmt
, name
);
190 # define IP_FMT "%08lx"
192 # define IP_FMT "%016lx"
195 int seq_print_user_ip(struct trace_seq
*s
, struct mm_struct
*mm
,
196 unsigned long ip
, unsigned long sym_flags
)
198 struct file
*file
= NULL
;
199 unsigned long vmstart
= 0;
203 const struct vm_area_struct
*vma
;
205 down_read(&mm
->mmap_sem
);
206 vma
= find_vma(mm
, ip
);
209 vmstart
= vma
->vm_start
;
212 ret
= trace_seq_path(s
, &file
->f_path
);
214 ret
= trace_seq_printf(s
, "[+0x%lx]",
217 up_read(&mm
->mmap_sem
);
219 if (ret
&& ((sym_flags
& TRACE_ITER_SYM_ADDR
) || !file
))
220 ret
= trace_seq_printf(s
, " <" IP_FMT
">", ip
);
225 seq_print_userip_objs(const struct userstack_entry
*entry
, struct trace_seq
*s
,
226 unsigned long sym_flags
)
228 struct mm_struct
*mm
= NULL
;
232 if (trace_flags
& TRACE_ITER_SYM_USEROBJ
) {
233 struct task_struct
*task
;
235 * we do the lookup on the thread group leader,
236 * since individual threads might have already quit!
239 task
= find_task_by_vpid(entry
->ent
.tgid
);
241 mm
= get_task_mm(task
);
245 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
246 unsigned long ip
= entry
->caller
[i
];
248 if (ip
== ULONG_MAX
|| !ret
)
251 ret
= trace_seq_puts(s
, " <- ");
254 ret
= trace_seq_puts(s
, "??");
260 ret
= seq_print_user_ip(s
, mm
, ip
, sym_flags
);
269 seq_print_ip_sym(struct trace_seq
*s
, unsigned long ip
, unsigned long sym_flags
)
274 return trace_seq_printf(s
, "0");
276 if (sym_flags
& TRACE_ITER_SYM_OFFSET
)
277 ret
= seq_print_sym_offset(s
, "%s", ip
);
279 ret
= seq_print_sym_short(s
, "%s", ip
);
284 if (sym_flags
& TRACE_ITER_SYM_ADDR
)
285 ret
= trace_seq_printf(s
, " <" IP_FMT
">", ip
);
290 lat_print_generic(struct trace_seq
*s
, struct trace_entry
*entry
, int cpu
)
292 int hardirq
, softirq
;
295 comm
= trace_find_cmdline(entry
->pid
);
296 hardirq
= entry
->flags
& TRACE_FLAG_HARDIRQ
;
297 softirq
= entry
->flags
& TRACE_FLAG_SOFTIRQ
;
299 if (!trace_seq_printf(s
, "%8.8s-%-5d %3d%c%c%c",
300 comm
, entry
->pid
, cpu
,
301 (entry
->flags
& TRACE_FLAG_IRQS_OFF
) ? 'd' :
302 (entry
->flags
& TRACE_FLAG_IRQS_NOSUPPORT
) ?
304 (entry
->flags
& TRACE_FLAG_NEED_RESCHED
) ?
306 (hardirq
&& softirq
) ? 'H' :
307 hardirq
? 'h' : softirq
? 's' : '.'))
310 if (entry
->preempt_count
)
311 return trace_seq_printf(s
, "%x", entry
->preempt_count
);
312 return trace_seq_puts(s
, ".");
315 static unsigned long preempt_mark_thresh
= 100;
318 lat_print_timestamp(struct trace_seq
*s
, u64 abs_usecs
,
319 unsigned long rel_usecs
)
321 return trace_seq_printf(s
, " %4lldus%c: ", abs_usecs
,
322 rel_usecs
> preempt_mark_thresh
? '!' :
323 rel_usecs
> 1 ? '+' : ' ');
326 int trace_print_context(struct trace_iterator
*iter
)
328 struct trace_seq
*s
= &iter
->seq
;
329 struct trace_entry
*entry
= iter
->ent
;
330 char *comm
= trace_find_cmdline(entry
->pid
);
331 unsigned long long t
= ns2usecs(iter
->ts
);
332 unsigned long usec_rem
= do_div(t
, USEC_PER_SEC
);
333 unsigned long secs
= (unsigned long)t
;
335 return trace_seq_printf(s
, "%16s-%-5d [%03d] %5lu.%06lu: ",
336 comm
, entry
->pid
, entry
->cpu
, secs
, usec_rem
);
339 int trace_print_lat_context(struct trace_iterator
*iter
)
343 struct trace_seq
*s
= &iter
->seq
;
344 struct trace_entry
*entry
= iter
->ent
,
345 *next_entry
= trace_find_next_entry(iter
, NULL
,
347 unsigned long verbose
= (trace_flags
& TRACE_ITER_VERBOSE
);
348 unsigned long abs_usecs
= ns2usecs(iter
->ts
- iter
->tr
->time_start
);
349 unsigned long rel_usecs
;
353 rel_usecs
= ns2usecs(next_ts
- iter
->ts
);
356 char *comm
= trace_find_cmdline(entry
->pid
);
357 ret
= trace_seq_printf(s
, "%16s %5d %3d %d %08x %08lx [%08lx]"
358 " %ld.%03ldms (+%ld.%03ldms): ", comm
,
359 entry
->pid
, entry
->cpu
, entry
->flags
,
360 entry
->preempt_count
, iter
->idx
,
362 abs_usecs
/ USEC_PER_MSEC
,
363 abs_usecs
% USEC_PER_MSEC
,
364 rel_usecs
/ USEC_PER_MSEC
,
365 rel_usecs
% USEC_PER_MSEC
);
367 ret
= lat_print_generic(s
, entry
, entry
->cpu
);
369 ret
= lat_print_timestamp(s
, abs_usecs
, rel_usecs
);
375 static const char state_to_char
[] = TASK_STATE_TO_CHAR_STR
;
377 static int task_state_char(unsigned long state
)
379 int bit
= state
? __ffs(state
) + 1 : 0;
381 return bit
< sizeof(state_to_char
) - 1 ? state_to_char
[bit
] : '?';
385 * ftrace_find_event - find a registered event
386 * @type: the type of event to look for
388 * Returns an event of type @type otherwise NULL
390 struct trace_event
*ftrace_find_event(int type
)
392 struct trace_event
*event
;
393 struct hlist_node
*n
;
396 key
= type
& (EVENT_HASHSIZE
- 1);
398 hlist_for_each_entry_rcu(event
, n
, &event_hash
[key
], node
) {
399 if (event
->type
== type
)
407 * register_ftrace_event - register output for an event type
408 * @event: the event type to register
410 * Event types are stored in a hash and this hash is used to
411 * find a way to print an event. If the @event->type is set
412 * then it will use that type, otherwise it will assign a
415 * If you assign your own type, please make sure it is added
416 * to the trace_type enum in trace.h, to avoid collisions
417 * with the dynamic types.
419 * Returns the event type number or zero on error.
421 int register_ftrace_event(struct trace_event
*event
)
426 mutex_lock(&trace_event_mutex
);
429 event
->type
= next_event_type
++;
430 else if (event
->type
> __TRACE_LAST_TYPE
) {
431 printk(KERN_WARNING
"Need to add type to trace.h\n");
435 if (ftrace_find_event(event
->type
))
438 key
= event
->type
& (EVENT_HASHSIZE
- 1);
440 hlist_add_head_rcu(&event
->node
, &event_hash
[key
]);
444 mutex_unlock(&trace_event_mutex
);
450 * unregister_ftrace_event - remove a no longer used event
451 * @event: the event to remove
453 int unregister_ftrace_event(struct trace_event
*event
)
455 mutex_lock(&trace_event_mutex
);
456 hlist_del(&event
->node
);
457 mutex_unlock(&trace_event_mutex
);
466 int trace_nop_print(struct trace_iterator
*iter
, int flags
)
468 return TRACE_TYPE_HANDLED
;
472 static int trace_fn_latency(struct trace_iterator
*iter
, int flags
)
474 struct ftrace_entry
*field
;
475 struct trace_seq
*s
= &iter
->seq
;
477 trace_assign_type(field
, iter
->ent
);
479 if (!seq_print_ip_sym(s
, field
->ip
, flags
))
481 if (!trace_seq_puts(s
, " ("))
483 if (!seq_print_ip_sym(s
, field
->parent_ip
, flags
))
485 if (!trace_seq_puts(s
, ")\n"))
488 return TRACE_TYPE_HANDLED
;
491 return TRACE_TYPE_PARTIAL_LINE
;
494 static int trace_fn_trace(struct trace_iterator
*iter
, int flags
)
496 struct ftrace_entry
*field
;
497 struct trace_seq
*s
= &iter
->seq
;
499 trace_assign_type(field
, iter
->ent
);
501 if (!seq_print_ip_sym(s
, field
->ip
, flags
))
504 if ((flags
& TRACE_ITER_PRINT_PARENT
) && field
->parent_ip
) {
505 if (!trace_seq_printf(s
, " <-"))
507 if (!seq_print_ip_sym(s
,
512 if (!trace_seq_printf(s
, "\n"))
515 return TRACE_TYPE_HANDLED
;
518 return TRACE_TYPE_PARTIAL_LINE
;
521 static int trace_fn_raw(struct trace_iterator
*iter
, int flags
)
523 struct ftrace_entry
*field
;
525 trace_assign_type(field
, iter
->ent
);
527 if (!trace_seq_printf(&iter
->seq
, "%lx %lx\n",
530 return TRACE_TYPE_PARTIAL_LINE
;
532 return TRACE_TYPE_HANDLED
;
535 static int trace_fn_hex(struct trace_iterator
*iter
, int flags
)
537 struct ftrace_entry
*field
;
538 struct trace_seq
*s
= &iter
->seq
;
540 trace_assign_type(field
, iter
->ent
);
542 SEQ_PUT_HEX_FIELD_RET(s
, field
->ip
);
543 SEQ_PUT_HEX_FIELD_RET(s
, field
->parent_ip
);
545 return TRACE_TYPE_HANDLED
;
548 static int trace_fn_bin(struct trace_iterator
*iter
, int flags
)
550 struct ftrace_entry
*field
;
551 struct trace_seq
*s
= &iter
->seq
;
553 trace_assign_type(field
, iter
->ent
);
555 SEQ_PUT_FIELD_RET(s
, field
->ip
);
556 SEQ_PUT_FIELD_RET(s
, field
->parent_ip
);
558 return TRACE_TYPE_HANDLED
;
561 static struct trace_event trace_fn_event
= {
563 .trace
= trace_fn_trace
,
564 .latency_trace
= trace_fn_latency
,
567 .binary
= trace_fn_bin
,
570 /* TRACE_CTX an TRACE_WAKE */
571 static int trace_ctxwake_print(struct trace_iterator
*iter
, char *delim
)
573 struct ctx_switch_entry
*field
;
577 trace_assign_type(field
, iter
->ent
);
579 T
= task_state_char(field
->next_state
);
580 S
= task_state_char(field
->prev_state
);
581 comm
= trace_find_cmdline(field
->next_pid
);
582 if (!trace_seq_printf(&iter
->seq
,
583 " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
591 return TRACE_TYPE_PARTIAL_LINE
;
593 return TRACE_TYPE_HANDLED
;
596 static int trace_ctx_print(struct trace_iterator
*iter
, int flags
)
598 return trace_ctxwake_print(iter
, "==>");
601 static int trace_wake_print(struct trace_iterator
*iter
, int flags
)
603 return trace_ctxwake_print(iter
, " +");
606 static int trace_ctxwake_raw(struct trace_iterator
*iter
, char S
)
608 struct ctx_switch_entry
*field
;
611 trace_assign_type(field
, iter
->ent
);
614 task_state_char(field
->prev_state
);
615 T
= task_state_char(field
->next_state
);
616 if (!trace_seq_printf(&iter
->seq
, "%d %d %c %d %d %d %c\n",
624 return TRACE_TYPE_PARTIAL_LINE
;
626 return TRACE_TYPE_HANDLED
;
629 static int trace_ctx_raw(struct trace_iterator
*iter
, int flags
)
631 return trace_ctxwake_raw(iter
, 0);
634 static int trace_wake_raw(struct trace_iterator
*iter
, int flags
)
636 return trace_ctxwake_raw(iter
, '+');
640 static int trace_ctxwake_hex(struct trace_iterator
*iter
, char S
)
642 struct ctx_switch_entry
*field
;
643 struct trace_seq
*s
= &iter
->seq
;
646 trace_assign_type(field
, iter
->ent
);
649 task_state_char(field
->prev_state
);
650 T
= task_state_char(field
->next_state
);
652 SEQ_PUT_HEX_FIELD_RET(s
, field
->prev_pid
);
653 SEQ_PUT_HEX_FIELD_RET(s
, field
->prev_prio
);
654 SEQ_PUT_HEX_FIELD_RET(s
, S
);
655 SEQ_PUT_HEX_FIELD_RET(s
, field
->next_cpu
);
656 SEQ_PUT_HEX_FIELD_RET(s
, field
->next_pid
);
657 SEQ_PUT_HEX_FIELD_RET(s
, field
->next_prio
);
658 SEQ_PUT_HEX_FIELD_RET(s
, T
);
660 return TRACE_TYPE_HANDLED
;
663 static int trace_ctx_hex(struct trace_iterator
*iter
, int flags
)
665 return trace_ctxwake_hex(iter
, 0);
668 static int trace_wake_hex(struct trace_iterator
*iter
, int flags
)
670 return trace_ctxwake_hex(iter
, '+');
673 static int trace_ctxwake_bin(struct trace_iterator
*iter
, int flags
)
675 struct ctx_switch_entry
*field
;
676 struct trace_seq
*s
= &iter
->seq
;
678 trace_assign_type(field
, iter
->ent
);
680 SEQ_PUT_FIELD_RET(s
, field
->prev_pid
);
681 SEQ_PUT_FIELD_RET(s
, field
->prev_prio
);
682 SEQ_PUT_FIELD_RET(s
, field
->prev_state
);
683 SEQ_PUT_FIELD_RET(s
, field
->next_pid
);
684 SEQ_PUT_FIELD_RET(s
, field
->next_prio
);
685 SEQ_PUT_FIELD_RET(s
, field
->next_state
);
687 return TRACE_TYPE_HANDLED
;
690 static struct trace_event trace_ctx_event
= {
692 .trace
= trace_ctx_print
,
693 .latency_trace
= trace_ctx_print
,
694 .raw
= trace_ctx_raw
,
695 .hex
= trace_ctx_hex
,
696 .binary
= trace_ctxwake_bin
,
699 static struct trace_event trace_wake_event
= {
701 .trace
= trace_wake_print
,
702 .latency_trace
= trace_wake_print
,
703 .raw
= trace_wake_raw
,
704 .hex
= trace_wake_hex
,
705 .binary
= trace_ctxwake_bin
,
709 static int trace_special_print(struct trace_iterator
*iter
, int flags
)
711 struct special_entry
*field
;
713 trace_assign_type(field
, iter
->ent
);
715 if (!trace_seq_printf(&iter
->seq
, "# %ld %ld %ld\n",
719 return TRACE_TYPE_PARTIAL_LINE
;
721 return TRACE_TYPE_HANDLED
;
724 static int trace_special_hex(struct trace_iterator
*iter
, int flags
)
726 struct special_entry
*field
;
727 struct trace_seq
*s
= &iter
->seq
;
729 trace_assign_type(field
, iter
->ent
);
731 SEQ_PUT_HEX_FIELD_RET(s
, field
->arg1
);
732 SEQ_PUT_HEX_FIELD_RET(s
, field
->arg2
);
733 SEQ_PUT_HEX_FIELD_RET(s
, field
->arg3
);
735 return TRACE_TYPE_HANDLED
;
738 static int trace_special_bin(struct trace_iterator
*iter
, int flags
)
740 struct special_entry
*field
;
741 struct trace_seq
*s
= &iter
->seq
;
743 trace_assign_type(field
, iter
->ent
);
745 SEQ_PUT_FIELD_RET(s
, field
->arg1
);
746 SEQ_PUT_FIELD_RET(s
, field
->arg2
);
747 SEQ_PUT_FIELD_RET(s
, field
->arg3
);
749 return TRACE_TYPE_HANDLED
;
752 static struct trace_event trace_special_event
= {
753 .type
= TRACE_SPECIAL
,
754 .trace
= trace_special_print
,
755 .latency_trace
= trace_special_print
,
756 .raw
= trace_special_print
,
757 .hex
= trace_special_hex
,
758 .binary
= trace_special_bin
,
763 static int trace_stack_print(struct trace_iterator
*iter
, int flags
)
765 struct stack_entry
*field
;
766 struct trace_seq
*s
= &iter
->seq
;
769 trace_assign_type(field
, iter
->ent
);
771 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
773 if (!trace_seq_puts(s
, " <= "))
776 if (!seq_print_ip_sym(s
, field
->caller
[i
], flags
))
779 if (!trace_seq_puts(s
, "\n"))
783 return TRACE_TYPE_HANDLED
;
786 return TRACE_TYPE_PARTIAL_LINE
;
789 static struct trace_event trace_stack_event
= {
791 .trace
= trace_stack_print
,
792 .latency_trace
= trace_stack_print
,
793 .raw
= trace_special_print
,
794 .hex
= trace_special_hex
,
795 .binary
= trace_special_bin
,
798 /* TRACE_USER_STACK */
799 static int trace_user_stack_print(struct trace_iterator
*iter
, int flags
)
801 struct userstack_entry
*field
;
802 struct trace_seq
*s
= &iter
->seq
;
804 trace_assign_type(field
, iter
->ent
);
806 if (!seq_print_userip_objs(field
, s
, flags
))
809 if (!trace_seq_putc(s
, '\n'))
812 return TRACE_TYPE_HANDLED
;
815 return TRACE_TYPE_PARTIAL_LINE
;
818 static struct trace_event trace_user_stack_event
= {
819 .type
= TRACE_USER_STACK
,
820 .trace
= trace_user_stack_print
,
821 .latency_trace
= trace_user_stack_print
,
822 .raw
= trace_special_print
,
823 .hex
= trace_special_hex
,
824 .binary
= trace_special_bin
,
828 static int trace_print_print(struct trace_iterator
*iter
, int flags
)
830 struct print_entry
*field
;
831 struct trace_seq
*s
= &iter
->seq
;
833 trace_assign_type(field
, iter
->ent
);
835 if (!seq_print_ip_sym(s
, field
->ip
, flags
))
838 if (!trace_seq_printf(s
, ": %s", field
->buf
))
841 return TRACE_TYPE_HANDLED
;
844 return TRACE_TYPE_PARTIAL_LINE
;
847 static int trace_print_raw(struct trace_iterator
*iter
, int flags
)
849 struct print_entry
*field
;
851 trace_assign_type(field
, iter
->ent
);
853 if (!trace_seq_printf(&iter
->seq
, "# %lx %s", field
->ip
, field
->buf
))
856 return TRACE_TYPE_HANDLED
;
859 return TRACE_TYPE_PARTIAL_LINE
;
862 static struct trace_event trace_print_event
= {
864 .trace
= trace_print_print
,
865 .latency_trace
= trace_print_print
,
866 .raw
= trace_print_raw
,
867 .hex
= trace_nop_print
,
868 .binary
= trace_nop_print
,
871 static struct trace_event
*events
[] __initdata
= {
875 &trace_special_event
,
877 &trace_user_stack_event
,
882 __init
static int init_events(void)
884 struct trace_event
*event
;
887 for (i
= 0; events
[i
]; i
++) {
890 ret
= register_ftrace_event(event
);
892 printk(KERN_WARNING
"event %d failed to register\n",
900 device_initcall(init_events
);