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);
289 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
291 static int task_state_char(unsigned long state)
293 int bit = state ? __ffs(state) + 1 : 0;
295 return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
299 * ftrace_find_event - find a registered event
300 * @type: the type of event to look for
302 * Returns an event of type @type otherwise NULL
304 struct trace_event *ftrace_find_event(int type)
306 struct trace_event *event;
307 struct hlist_node *n;
310 key = type & (EVENT_HASHSIZE - 1);
312 hlist_for_each_entry_rcu(event, n, &event_hash[key], node) {
313 if (event->type == type)
321 * register_ftrace_event - register output for an event type
322 * @event: the event type to register
324 * Event types are stored in a hash and this hash is used to
325 * find a way to print an event. If the @event->type is set
326 * then it will use that type, otherwise it will assign a
329 * If you assign your own type, please make sure it is added
330 * to the trace_type enum in trace.h, to avoid collisions
331 * with the dynamic types.
333 * Returns the event type number or zero on error.
335 int register_ftrace_event(struct trace_event *event)
340 mutex_lock(&trace_event_mutex);
343 event->type = next_event_type++;
344 else if (event->type > __TRACE_LAST_TYPE) {
345 printk(KERN_WARNING "Need to add type to trace.h\n");
349 if (ftrace_find_event(event->type))
352 key = event->type & (EVENT_HASHSIZE - 1);
354 hlist_add_head_rcu(&event->node, &event_hash[key]);
358 mutex_unlock(&trace_event_mutex);
364 * unregister_ftrace_event - remove a no longer used event
365 * @event: the event to remove
367 int unregister_ftrace_event(struct trace_event *event)
369 mutex_lock(&trace_event_mutex);
370 hlist_del(&event->node);
371 mutex_unlock(&trace_event_mutex);
381 trace_nop_print(struct trace_seq *s, struct trace_entry *entry, int flags)
388 trace_fn_latency(struct trace_seq *s, struct trace_entry *entry, int flags)
390 struct ftrace_entry *field;
392 trace_assign_type(field, entry);
394 if (!seq_print_ip_sym(s, field->ip, flags))
396 if (!trace_seq_puts(s, " ("))
398 if (!seq_print_ip_sym(s, field->parent_ip, flags))
400 if (!trace_seq_puts(s, ")\n"))
406 return TRACE_TYPE_PARTIAL_LINE;
410 trace_fn_trace(struct trace_seq *s, struct trace_entry *entry, int flags)
412 struct ftrace_entry *field;
414 trace_assign_type(field, entry);
416 if (!seq_print_ip_sym(s, field->ip, flags))
419 if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
420 if (!trace_seq_printf(s, " <-"))
422 if (!seq_print_ip_sym(s,
427 if (!trace_seq_printf(s, "\n"))
433 return TRACE_TYPE_PARTIAL_LINE;
437 trace_fn_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
439 struct ftrace_entry *field;
441 trace_assign_type(field, entry);
443 if (!trace_seq_printf(s, "%lx %lx\n",
446 return TRACE_TYPE_PARTIAL_LINE;
452 trace_fn_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
454 struct ftrace_entry *field;
456 trace_assign_type(field, entry);
458 SEQ_PUT_HEX_FIELD_RET(s, field->ip);
459 SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
465 trace_fn_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
467 struct ftrace_entry *field;
469 trace_assign_type(field, entry);
471 SEQ_PUT_FIELD_RET(s, field->ip);
472 SEQ_PUT_FIELD_RET(s, field->parent_ip);
477 static struct trace_event trace_fn_event = {
479 .trace = trace_fn_trace,
480 .latency_trace = trace_fn_latency,
483 .binary = trace_fn_bin,
486 /* TRACE_CTX an TRACE_WAKE */
488 trace_ctxwake_print(struct trace_seq *s, struct trace_entry *entry, int flags,
491 struct ctx_switch_entry *field;
495 trace_assign_type(field, entry);
497 T = task_state_char(field->next_state);
498 S = task_state_char(field->prev_state);
499 comm = trace_find_cmdline(field->next_pid);
500 if (!trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
508 return TRACE_TYPE_PARTIAL_LINE;
514 trace_ctx_print(struct trace_seq *s, struct trace_entry *entry, int flags)
516 return trace_ctxwake_print(s, entry, flags, "==>");
520 trace_wake_print(struct trace_seq *s, struct trace_entry *entry, int flags)
522 return trace_ctxwake_print(s, entry, flags, " +");
526 trace_ctxwake_raw(struct trace_seq *s, struct trace_entry *entry, int flags,
529 struct ctx_switch_entry *field;
532 trace_assign_type(field, entry);
535 task_state_char(field->prev_state);
536 T = task_state_char(field->next_state);
537 if (!trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
545 return TRACE_TYPE_PARTIAL_LINE;
551 trace_ctx_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
553 return trace_ctxwake_raw(s, entry, flags, 0);
557 trace_wake_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
559 return trace_ctxwake_raw(s, entry, flags, '+');
564 trace_ctxwake_hex(struct trace_seq *s, struct trace_entry *entry, int flags,
567 struct ctx_switch_entry *field;
570 trace_assign_type(field, entry);
573 task_state_char(field->prev_state);
574 T = task_state_char(field->next_state);
576 SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
577 SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
578 SEQ_PUT_HEX_FIELD_RET(s, S);
579 SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
580 SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
581 SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
582 SEQ_PUT_HEX_FIELD_RET(s, T);
588 trace_ctx_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
590 return trace_ctxwake_hex(s, entry, flags, 0);
594 trace_wake_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
596 return trace_ctxwake_hex(s, entry, flags, '+');
600 trace_ctxwake_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
602 struct ctx_switch_entry *field;
604 trace_assign_type(field, entry);
606 SEQ_PUT_FIELD_RET(s, field->prev_pid);
607 SEQ_PUT_FIELD_RET(s, field->prev_prio);
608 SEQ_PUT_FIELD_RET(s, field->prev_state);
609 SEQ_PUT_FIELD_RET(s, field->next_pid);
610 SEQ_PUT_FIELD_RET(s, field->next_prio);
611 SEQ_PUT_FIELD_RET(s, field->next_state);
616 static struct trace_event trace_ctx_event = {
618 .trace = trace_ctx_print,
619 .latency_trace = trace_ctx_print,
620 .raw = trace_ctx_raw,
621 .hex = trace_ctx_hex,
622 .binary = trace_ctxwake_bin,
625 static struct trace_event trace_wake_event = {
627 .trace = trace_wake_print,
628 .latency_trace = trace_wake_print,
629 .raw = trace_wake_raw,
630 .hex = trace_wake_hex,
631 .binary = trace_ctxwake_bin,
636 trace_special_print(struct trace_seq *s, struct trace_entry *entry, int flags)
638 struct special_entry *field;
640 trace_assign_type(field, entry);
642 if (!trace_seq_printf(s, "# %ld %ld %ld\n",
646 return TRACE_TYPE_PARTIAL_LINE;
652 trace_special_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
654 struct special_entry *field;
656 trace_assign_type(field, entry);
658 SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
659 SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
660 SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
666 trace_special_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
668 struct special_entry *field;
670 trace_assign_type(field, entry);
672 SEQ_PUT_FIELD_RET(s, field->arg1);
673 SEQ_PUT_FIELD_RET(s, field->arg2);
674 SEQ_PUT_FIELD_RET(s, field->arg3);
679 static struct trace_event trace_special_event = {
680 .type = TRACE_SPECIAL,
681 .trace = trace_special_print,
682 .latency_trace = trace_special_print,
683 .raw = trace_special_print,
684 .hex = trace_special_hex,
685 .binary = trace_special_bin,
691 trace_stack_print(struct trace_seq *s, struct trace_entry *entry, int flags)
693 struct stack_entry *field;
696 trace_assign_type(field, entry);
698 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
700 if (!trace_seq_puts(s, " <= "))
703 if (!seq_print_ip_sym(s, field->caller[i], flags))
706 if (!trace_seq_puts(s, "\n"))
713 return TRACE_TYPE_PARTIAL_LINE;
716 static struct trace_event trace_stack_event = {
718 .trace = trace_stack_print,
719 .latency_trace = trace_stack_print,
720 .raw = trace_special_print,
721 .hex = trace_special_hex,
722 .binary = trace_special_bin,
725 /* TRACE_USER_STACK */
727 trace_user_stack_print(struct trace_seq *s, struct trace_entry *entry,
730 struct userstack_entry *field;
732 trace_assign_type(field, entry);
734 if (!seq_print_userip_objs(field, s, flags))
737 if (!trace_seq_putc(s, '\n'))
743 return TRACE_TYPE_PARTIAL_LINE;
746 static struct trace_event trace_user_stack_event = {
747 .type = TRACE_USER_STACK,
748 .trace = trace_user_stack_print,
749 .latency_trace = trace_user_stack_print,
750 .raw = trace_special_print,
751 .hex = trace_special_hex,
752 .binary = trace_special_bin,
757 trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags)
759 struct print_entry *field;
761 trace_assign_type(field, entry);
763 if (!seq_print_ip_sym(s, field->ip, flags))
766 if (!trace_seq_printf(s, ": %s", field->buf))
772 return TRACE_TYPE_PARTIAL_LINE;
776 trace_print_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
778 struct print_entry *field;
780 trace_assign_type(field, entry);
782 if (!trace_seq_printf(s, "# %lx %s", field->ip, field->buf))
788 return TRACE_TYPE_PARTIAL_LINE;
791 static struct trace_event trace_print_event = {
793 .trace = trace_print_print,
794 .latency_trace = trace_print_print,
795 .raw = trace_print_raw,
796 .hex = trace_nop_print,
797 .binary = trace_nop_print,
800 static struct trace_event *events[] __initdata = {
804 &trace_special_event,
806 &trace_user_stack_event,
811 __init static int init_events(void)
813 struct trace_event *event;
816 for (i = 0; events[i]; i++) {
819 ret = register_ftrace_event(event);
821 printk(KERN_WARNING "event %d failed to register\n",
829 device_initcall(init_events);