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;
22 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
24 struct trace_seq *s = &iter->seq;
25 struct trace_entry *entry = iter->ent;
26 struct bprint_entry *field;
29 trace_assign_type(field, entry);
31 ret = trace_seq_bprintf(s, field->fmt, field->buf);
33 return TRACE_TYPE_PARTIAL_LINE;
35 return TRACE_TYPE_HANDLED;
38 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
40 struct trace_seq *s = &iter->seq;
41 struct trace_entry *entry = iter->ent;
42 struct print_entry *field;
45 trace_assign_type(field, entry);
47 ret = trace_seq_printf(s, "%s", field->buf);
49 return TRACE_TYPE_PARTIAL_LINE;
51 return TRACE_TYPE_HANDLED;
55 * trace_seq_printf - sequence printing of trace information
56 * @s: trace sequence descriptor
57 * @fmt: printf format string
59 * The tracer may use either sequence operations or its own
60 * copy to user routines. To simplify formating of a trace
61 * trace_seq_printf is used to store strings into a special
62 * buffer (@s). Then the output may be either used by
63 * the sequencer or pulled into another buffer.
66 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
68 int len = (PAGE_SIZE - 1) - s->len;
76 ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
79 /* If we can't write it all, don't bother writing anything */
88 int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
90 int len = (PAGE_SIZE - 1) - s->len;
96 ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
98 /* If we can't write it all, don't bother writing anything */
108 * trace_seq_puts - trace sequence printing of simple string
109 * @s: trace sequence descriptor
110 * @str: simple string to record
112 * The tracer may use either the sequence operations or its own
113 * copy to user routines. This function records a simple string
114 * into a special buffer (@s) for later retrieval by a sequencer
115 * or other mechanism.
117 int trace_seq_puts(struct trace_seq *s, const char *str)
119 int len = strlen(str);
121 if (len > ((PAGE_SIZE - 1) - s->len))
124 memcpy(s->buffer + s->len, str, len);
130 int trace_seq_putc(struct trace_seq *s, unsigned char c)
132 if (s->len >= (PAGE_SIZE - 1))
135 s->buffer[s->len++] = c;
140 int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
142 if (len > ((PAGE_SIZE - 1) - s->len))
145 memcpy(s->buffer + s->len, mem, len);
151 int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
153 unsigned char hex[HEX_CHARS];
154 unsigned char *data = mem;
158 for (i = 0, j = 0; i < len; i++) {
160 for (i = len-1, j = 0; i >= 0; i--) {
162 hex[j++] = hex_asc_hi(data[i]);
163 hex[j++] = hex_asc_lo(data[i]);
167 return trace_seq_putmem(s, hex, j);
170 int trace_seq_path(struct trace_seq *s, struct path *path)
174 if (s->len >= (PAGE_SIZE - 1))
176 p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
178 p = mangle_path(s->buffer + s->len, p, "\n");
180 s->len = p - s->buffer;
184 s->buffer[s->len++] = '?';
191 #ifdef CONFIG_KRETPROBES
192 static inline const char *kretprobed(const char *name)
194 static const char tramp_name[] = "kretprobe_trampoline";
195 int size = sizeof(tramp_name);
197 if (strncmp(tramp_name, name, size) == 0)
198 return "[unknown/kretprobe'd]";
202 static inline const char *kretprobed(const char *name)
206 #endif /* CONFIG_KRETPROBES */
209 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
211 #ifdef CONFIG_KALLSYMS
212 char str[KSYM_SYMBOL_LEN];
215 kallsyms_lookup(address, NULL, NULL, NULL, str);
217 name = kretprobed(str);
219 return trace_seq_printf(s, fmt, name);
225 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
226 unsigned long address)
228 #ifdef CONFIG_KALLSYMS
229 char str[KSYM_SYMBOL_LEN];
232 sprint_symbol(str, address);
233 name = kretprobed(str);
235 return trace_seq_printf(s, fmt, name);
241 # define IP_FMT "%08lx"
243 # define IP_FMT "%016lx"
246 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
247 unsigned long ip, unsigned long sym_flags)
249 struct file *file = NULL;
250 unsigned long vmstart = 0;
254 const struct vm_area_struct *vma;
256 down_read(&mm->mmap_sem);
257 vma = find_vma(mm, ip);
260 vmstart = vma->vm_start;
263 ret = trace_seq_path(s, &file->f_path);
265 ret = trace_seq_printf(s, "[+0x%lx]",
268 up_read(&mm->mmap_sem);
270 if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
271 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
276 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
277 unsigned long sym_flags)
279 struct mm_struct *mm = NULL;
283 if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
284 struct task_struct *task;
286 * we do the lookup on the thread group leader,
287 * since individual threads might have already quit!
290 task = find_task_by_vpid(entry->ent.tgid);
292 mm = get_task_mm(task);
296 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
297 unsigned long ip = entry->caller[i];
299 if (ip == ULONG_MAX || !ret)
302 ret = trace_seq_puts(s, " <- ");
305 ret = trace_seq_puts(s, "??");
311 ret = seq_print_user_ip(s, mm, ip, sym_flags);
320 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
325 return trace_seq_printf(s, "0");
327 if (sym_flags & TRACE_ITER_SYM_OFFSET)
328 ret = seq_print_sym_offset(s, "%s", ip);
330 ret = seq_print_sym_short(s, "%s", ip);
335 if (sym_flags & TRACE_ITER_SYM_ADDR)
336 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
341 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
343 int hardirq, softirq;
344 char comm[TASK_COMM_LEN];
346 trace_find_cmdline(entry->pid, comm);
347 hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
348 softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
350 if (!trace_seq_printf(s, "%8.8s-%-5d %3d%c%c%c",
351 comm, entry->pid, cpu,
352 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
353 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
355 (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
357 (hardirq && softirq) ? 'H' :
358 hardirq ? 'h' : softirq ? 's' : '.'))
361 if (entry->preempt_count)
362 return trace_seq_printf(s, "%x", entry->preempt_count);
363 return trace_seq_puts(s, ".");
366 static unsigned long preempt_mark_thresh = 100;
369 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
370 unsigned long rel_usecs)
372 return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
373 rel_usecs > preempt_mark_thresh ? '!' :
374 rel_usecs > 1 ? '+' : ' ');
377 int trace_print_context(struct trace_iterator *iter)
379 struct trace_seq *s = &iter->seq;
380 struct trace_entry *entry = iter->ent;
381 unsigned long long t = ns2usecs(iter->ts);
382 unsigned long usec_rem = do_div(t, USEC_PER_SEC);
383 unsigned long secs = (unsigned long)t;
384 char comm[TASK_COMM_LEN];
386 trace_find_cmdline(entry->pid, comm);
388 return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
389 comm, entry->pid, iter->cpu, secs, usec_rem);
392 int trace_print_lat_context(struct trace_iterator *iter)
396 struct trace_seq *s = &iter->seq;
397 struct trace_entry *entry = iter->ent,
398 *next_entry = trace_find_next_entry(iter, NULL,
400 unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
401 unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
402 unsigned long rel_usecs;
406 rel_usecs = ns2usecs(next_ts - iter->ts);
409 char comm[TASK_COMM_LEN];
411 trace_find_cmdline(entry->pid, comm);
413 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08lx]"
414 " %ld.%03ldms (+%ld.%03ldms): ", comm,
415 entry->pid, iter->cpu, entry->flags,
416 entry->preempt_count, iter->idx,
418 abs_usecs / USEC_PER_MSEC,
419 abs_usecs % USEC_PER_MSEC,
420 rel_usecs / USEC_PER_MSEC,
421 rel_usecs % USEC_PER_MSEC);
423 ret = lat_print_generic(s, entry, iter->cpu);
425 ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
431 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
433 static int task_state_char(unsigned long state)
435 int bit = state ? __ffs(state) + 1 : 0;
437 return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
441 * ftrace_find_event - find a registered event
442 * @type: the type of event to look for
444 * Returns an event of type @type otherwise NULL
446 struct trace_event *ftrace_find_event(int type)
448 struct trace_event *event;
449 struct hlist_node *n;
452 key = type & (EVENT_HASHSIZE - 1);
454 hlist_for_each_entry_rcu(event, n, &event_hash[key], node) {
455 if (event->type == type)
463 * register_ftrace_event - register output for an event type
464 * @event: the event type to register
466 * Event types are stored in a hash and this hash is used to
467 * find a way to print an event. If the @event->type is set
468 * then it will use that type, otherwise it will assign a
471 * If you assign your own type, please make sure it is added
472 * to the trace_type enum in trace.h, to avoid collisions
473 * with the dynamic types.
475 * Returns the event type number or zero on error.
477 int register_ftrace_event(struct trace_event *event)
482 mutex_lock(&trace_event_mutex);
485 event->type = next_event_type++;
486 else if (event->type > __TRACE_LAST_TYPE) {
487 printk(KERN_WARNING "Need to add type to trace.h\n");
491 if (ftrace_find_event(event->type))
494 if (event->trace == NULL)
495 event->trace = trace_nop_print;
496 if (event->raw == NULL)
497 event->raw = trace_nop_print;
498 if (event->hex == NULL)
499 event->hex = trace_nop_print;
500 if (event->binary == NULL)
501 event->binary = trace_nop_print;
503 key = event->type & (EVENT_HASHSIZE - 1);
505 hlist_add_head_rcu(&event->node, &event_hash[key]);
509 mutex_unlock(&trace_event_mutex);
515 * unregister_ftrace_event - remove a no longer used event
516 * @event: the event to remove
518 int unregister_ftrace_event(struct trace_event *event)
520 mutex_lock(&trace_event_mutex);
521 hlist_del(&event->node);
522 mutex_unlock(&trace_event_mutex);
531 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
533 return TRACE_TYPE_HANDLED;
537 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
539 struct ftrace_entry *field;
540 struct trace_seq *s = &iter->seq;
542 trace_assign_type(field, iter->ent);
544 if (!seq_print_ip_sym(s, field->ip, flags))
547 if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
548 if (!trace_seq_printf(s, " <-"))
550 if (!seq_print_ip_sym(s,
555 if (!trace_seq_printf(s, "\n"))
558 return TRACE_TYPE_HANDLED;
561 return TRACE_TYPE_PARTIAL_LINE;
564 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
566 struct ftrace_entry *field;
568 trace_assign_type(field, iter->ent);
570 if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
573 return TRACE_TYPE_PARTIAL_LINE;
575 return TRACE_TYPE_HANDLED;
578 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
580 struct ftrace_entry *field;
581 struct trace_seq *s = &iter->seq;
583 trace_assign_type(field, iter->ent);
585 SEQ_PUT_HEX_FIELD_RET(s, field->ip);
586 SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
588 return TRACE_TYPE_HANDLED;
591 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
593 struct ftrace_entry *field;
594 struct trace_seq *s = &iter->seq;
596 trace_assign_type(field, iter->ent);
598 SEQ_PUT_FIELD_RET(s, field->ip);
599 SEQ_PUT_FIELD_RET(s, field->parent_ip);
601 return TRACE_TYPE_HANDLED;
604 static struct trace_event trace_fn_event = {
606 .trace = trace_fn_trace,
609 .binary = trace_fn_bin,
612 /* TRACE_CTX an TRACE_WAKE */
613 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
616 struct ctx_switch_entry *field;
617 char comm[TASK_COMM_LEN];
621 trace_assign_type(field, iter->ent);
623 T = task_state_char(field->next_state);
624 S = task_state_char(field->prev_state);
625 trace_find_cmdline(field->next_pid, comm);
626 if (!trace_seq_printf(&iter->seq,
627 " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
635 return TRACE_TYPE_PARTIAL_LINE;
637 return TRACE_TYPE_HANDLED;
640 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
642 return trace_ctxwake_print(iter, "==>");
645 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
648 return trace_ctxwake_print(iter, " +");
651 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
653 struct ctx_switch_entry *field;
656 trace_assign_type(field, iter->ent);
659 task_state_char(field->prev_state);
660 T = task_state_char(field->next_state);
661 if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
669 return TRACE_TYPE_PARTIAL_LINE;
671 return TRACE_TYPE_HANDLED;
674 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
676 return trace_ctxwake_raw(iter, 0);
679 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
681 return trace_ctxwake_raw(iter, '+');
685 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
687 struct ctx_switch_entry *field;
688 struct trace_seq *s = &iter->seq;
691 trace_assign_type(field, iter->ent);
694 task_state_char(field->prev_state);
695 T = task_state_char(field->next_state);
697 SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
698 SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
699 SEQ_PUT_HEX_FIELD_RET(s, S);
700 SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
701 SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
702 SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
703 SEQ_PUT_HEX_FIELD_RET(s, T);
705 return TRACE_TYPE_HANDLED;
708 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
710 return trace_ctxwake_hex(iter, 0);
713 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
715 return trace_ctxwake_hex(iter, '+');
718 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
721 struct ctx_switch_entry *field;
722 struct trace_seq *s = &iter->seq;
724 trace_assign_type(field, iter->ent);
726 SEQ_PUT_FIELD_RET(s, field->prev_pid);
727 SEQ_PUT_FIELD_RET(s, field->prev_prio);
728 SEQ_PUT_FIELD_RET(s, field->prev_state);
729 SEQ_PUT_FIELD_RET(s, field->next_pid);
730 SEQ_PUT_FIELD_RET(s, field->next_prio);
731 SEQ_PUT_FIELD_RET(s, field->next_state);
733 return TRACE_TYPE_HANDLED;
736 static struct trace_event trace_ctx_event = {
738 .trace = trace_ctx_print,
739 .raw = trace_ctx_raw,
740 .hex = trace_ctx_hex,
741 .binary = trace_ctxwake_bin,
744 static struct trace_event trace_wake_event = {
746 .trace = trace_wake_print,
747 .raw = trace_wake_raw,
748 .hex = trace_wake_hex,
749 .binary = trace_ctxwake_bin,
753 static enum print_line_t trace_special_print(struct trace_iterator *iter,
756 struct special_entry *field;
758 trace_assign_type(field, iter->ent);
760 if (!trace_seq_printf(&iter->seq, "# %ld %ld %ld\n",
764 return TRACE_TYPE_PARTIAL_LINE;
766 return TRACE_TYPE_HANDLED;
769 static enum print_line_t trace_special_hex(struct trace_iterator *iter,
772 struct special_entry *field;
773 struct trace_seq *s = &iter->seq;
775 trace_assign_type(field, iter->ent);
777 SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
778 SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
779 SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
781 return TRACE_TYPE_HANDLED;
784 static enum print_line_t trace_special_bin(struct trace_iterator *iter,
787 struct special_entry *field;
788 struct trace_seq *s = &iter->seq;
790 trace_assign_type(field, iter->ent);
792 SEQ_PUT_FIELD_RET(s, field->arg1);
793 SEQ_PUT_FIELD_RET(s, field->arg2);
794 SEQ_PUT_FIELD_RET(s, field->arg3);
796 return TRACE_TYPE_HANDLED;
799 static struct trace_event trace_special_event = {
800 .type = TRACE_SPECIAL,
801 .trace = trace_special_print,
802 .raw = trace_special_print,
803 .hex = trace_special_hex,
804 .binary = trace_special_bin,
809 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
812 struct stack_entry *field;
813 struct trace_seq *s = &iter->seq;
816 trace_assign_type(field, iter->ent);
818 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
820 if (!trace_seq_puts(s, " <= "))
823 if (!seq_print_ip_sym(s, field->caller[i], flags))
826 if (!trace_seq_puts(s, "\n"))
830 return TRACE_TYPE_HANDLED;
833 return TRACE_TYPE_PARTIAL_LINE;
836 static struct trace_event trace_stack_event = {
838 .trace = trace_stack_print,
839 .raw = trace_special_print,
840 .hex = trace_special_hex,
841 .binary = trace_special_bin,
844 /* TRACE_USER_STACK */
845 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
848 struct userstack_entry *field;
849 struct trace_seq *s = &iter->seq;
851 trace_assign_type(field, iter->ent);
853 if (!seq_print_userip_objs(field, s, flags))
856 if (!trace_seq_putc(s, '\n'))
859 return TRACE_TYPE_HANDLED;
862 return TRACE_TYPE_PARTIAL_LINE;
865 static struct trace_event trace_user_stack_event = {
866 .type = TRACE_USER_STACK,
867 .trace = trace_user_stack_print,
868 .raw = trace_special_print,
869 .hex = trace_special_hex,
870 .binary = trace_special_bin,
874 static enum print_line_t
875 trace_bprint_print(struct trace_iterator *iter, int flags)
877 struct trace_entry *entry = iter->ent;
878 struct trace_seq *s = &iter->seq;
879 struct bprint_entry *field;
881 trace_assign_type(field, entry);
883 if (!seq_print_ip_sym(s, field->ip, flags))
886 if (!trace_seq_puts(s, ": "))
889 if (!trace_seq_bprintf(s, field->fmt, field->buf))
892 return TRACE_TYPE_HANDLED;
895 return TRACE_TYPE_PARTIAL_LINE;
899 static enum print_line_t
900 trace_bprint_raw(struct trace_iterator *iter, int flags)
902 struct bprint_entry *field;
903 struct trace_seq *s = &iter->seq;
905 trace_assign_type(field, iter->ent);
907 if (!trace_seq_printf(s, ": %lx : ", field->ip))
910 if (!trace_seq_bprintf(s, field->fmt, field->buf))
913 return TRACE_TYPE_HANDLED;
916 return TRACE_TYPE_PARTIAL_LINE;
920 static struct trace_event trace_bprint_event = {
921 .type = TRACE_BPRINT,
922 .trace = trace_bprint_print,
923 .raw = trace_bprint_raw,
927 static enum print_line_t trace_print_print(struct trace_iterator *iter,
930 struct print_entry *field;
931 struct trace_seq *s = &iter->seq;
933 trace_assign_type(field, iter->ent);
935 if (!seq_print_ip_sym(s, field->ip, flags))
938 if (!trace_seq_printf(s, ": %s", field->buf))
941 return TRACE_TYPE_HANDLED;
944 return TRACE_TYPE_PARTIAL_LINE;
947 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
949 struct print_entry *field;
951 trace_assign_type(field, iter->ent);
953 if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
956 return TRACE_TYPE_HANDLED;
959 return TRACE_TYPE_PARTIAL_LINE;
962 static struct trace_event trace_print_event = {
964 .trace = trace_print_print,
965 .raw = trace_print_raw,
969 static struct trace_event *events[] __initdata = {
973 &trace_special_event,
975 &trace_user_stack_event,
981 __init static int init_events(void)
983 struct trace_event *event;
986 for (i = 0; events[i]; i++) {
989 ret = register_ftrace_event(event);
991 printk(KERN_WARNING "event %d failed to register\n",
999 device_initcall(init_events);