1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * trace_output.c
4 *
5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 *
7 */
8 #include <linux/module.h>
9 #include <linux/mutex.h>
10 #include <linux/ftrace.h>
11 #include <linux/sched/clock.h>
12 #include <linux/sched/mm.h>
13
14 #include "trace_output.h"
15
16 /* must be a power of 2 */
17 #define EVENT_HASHSIZE 128
18
19 DECLARE_RWSEM(trace_event_sem);
20
21 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
22
23 static int next_event_type = __TRACE_LAST_TYPE;
24
trace_print_bputs_msg_only(struct trace_iterator * iter)25 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
26 {
27 struct trace_seq *s = &iter->seq;
28 struct trace_entry *entry = iter->ent;
29 struct bputs_entry *field;
30
31 trace_assign_type(field, entry);
32
33 trace_seq_puts(s, field->str);
34
35 return trace_handle_return(s);
36 }
37
trace_print_bprintk_msg_only(struct trace_iterator * iter)38 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
39 {
40 struct trace_seq *s = &iter->seq;
41 struct trace_entry *entry = iter->ent;
42 struct bprint_entry *field;
43
44 trace_assign_type(field, entry);
45
46 trace_seq_bprintf(s, field->fmt, field->buf);
47
48 return trace_handle_return(s);
49 }
50
trace_print_printk_msg_only(struct trace_iterator * iter)51 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
52 {
53 struct trace_seq *s = &iter->seq;
54 struct trace_entry *entry = iter->ent;
55 struct print_entry *field;
56
57 trace_assign_type(field, entry);
58
59 trace_seq_puts(s, field->buf);
60
61 return trace_handle_return(s);
62 }
63
64 const char *
trace_print_flags_seq(struct trace_seq * p,const char * delim,unsigned long flags,const struct trace_print_flags * flag_array)65 trace_print_flags_seq(struct trace_seq *p, const char *delim,
66 unsigned long flags,
67 const struct trace_print_flags *flag_array)
68 {
69 unsigned long mask;
70 const char *str;
71 const char *ret = trace_seq_buffer_ptr(p);
72 int i, first = 1;
73
74 for (i = 0; flag_array[i].name && flags; i++) {
75
76 mask = flag_array[i].mask;
77 if ((flags & mask) != mask)
78 continue;
79
80 str = flag_array[i].name;
81 flags &= ~mask;
82 if (!first && delim)
83 trace_seq_puts(p, delim);
84 else
85 first = 0;
86 trace_seq_puts(p, str);
87 }
88
89 /* check for left over flags */
90 if (flags) {
91 if (!first && delim)
92 trace_seq_puts(p, delim);
93 trace_seq_printf(p, "0x%lx", flags);
94 }
95
96 trace_seq_putc(p, 0);
97
98 return ret;
99 }
100 EXPORT_SYMBOL(trace_print_flags_seq);
101
102 const char *
trace_print_symbols_seq(struct trace_seq * p,unsigned long val,const struct trace_print_flags * symbol_array)103 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
104 const struct trace_print_flags *symbol_array)
105 {
106 int i;
107 const char *ret = trace_seq_buffer_ptr(p);
108
109 for (i = 0; symbol_array[i].name; i++) {
110
111 if (val != symbol_array[i].mask)
112 continue;
113
114 trace_seq_puts(p, symbol_array[i].name);
115 break;
116 }
117
118 if (ret == (const char *)(trace_seq_buffer_ptr(p)))
119 trace_seq_printf(p, "0x%lx", val);
120
121 trace_seq_putc(p, 0);
122
123 return ret;
124 }
125 EXPORT_SYMBOL(trace_print_symbols_seq);
126
127 #if BITS_PER_LONG == 32
128 const char *
trace_print_flags_seq_u64(struct trace_seq * p,const char * delim,unsigned long long flags,const struct trace_print_flags_u64 * flag_array)129 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
130 unsigned long long flags,
131 const struct trace_print_flags_u64 *flag_array)
132 {
133 unsigned long long mask;
134 const char *str;
135 const char *ret = trace_seq_buffer_ptr(p);
136 int i, first = 1;
137
138 for (i = 0; flag_array[i].name && flags; i++) {
139
140 mask = flag_array[i].mask;
141 if ((flags & mask) != mask)
142 continue;
143
144 str = flag_array[i].name;
145 flags &= ~mask;
146 if (!first && delim)
147 trace_seq_puts(p, delim);
148 else
149 first = 0;
150 trace_seq_puts(p, str);
151 }
152
153 /* check for left over flags */
154 if (flags) {
155 if (!first && delim)
156 trace_seq_puts(p, delim);
157 trace_seq_printf(p, "0x%llx", flags);
158 }
159
160 trace_seq_putc(p, 0);
161
162 return ret;
163 }
164 EXPORT_SYMBOL(trace_print_flags_seq_u64);
165
166 const char *
trace_print_symbols_seq_u64(struct trace_seq * p,unsigned long long val,const struct trace_print_flags_u64 * symbol_array)167 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
168 const struct trace_print_flags_u64 *symbol_array)
169 {
170 int i;
171 const char *ret = trace_seq_buffer_ptr(p);
172
173 for (i = 0; symbol_array[i].name; i++) {
174
175 if (val != symbol_array[i].mask)
176 continue;
177
178 trace_seq_puts(p, symbol_array[i].name);
179 break;
180 }
181
182 if (ret == (const char *)(trace_seq_buffer_ptr(p)))
183 trace_seq_printf(p, "0x%llx", val);
184
185 trace_seq_putc(p, 0);
186
187 return ret;
188 }
189 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
190 #endif
191
192 const char *
trace_print_bitmask_seq(struct trace_seq * p,void * bitmask_ptr,unsigned int bitmask_size)193 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
194 unsigned int bitmask_size)
195 {
196 const char *ret = trace_seq_buffer_ptr(p);
197
198 trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
199 trace_seq_putc(p, 0);
200
201 return ret;
202 }
203 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
204
205 /**
206 * trace_print_hex_seq - print buffer as hex sequence
207 * @p: trace seq struct to write to
208 * @buf: The buffer to print
209 * @buf_len: Length of @buf in bytes
210 * @concatenate: Print @buf as single hex string or with spacing
211 *
212 * Prints the passed buffer as a hex sequence either as a whole,
213 * single hex string if @concatenate is true or with spacing after
214 * each byte in case @concatenate is false.
215 */
216 const char *
trace_print_hex_seq(struct trace_seq * p,const unsigned char * buf,int buf_len,bool concatenate)217 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
218 bool concatenate)
219 {
220 int i;
221 const char *ret = trace_seq_buffer_ptr(p);
222 const char *fmt = concatenate ? "%*phN" : "%*ph";
223
224 for (i = 0; i < buf_len; i += 16)
225 trace_seq_printf(p, fmt, min(buf_len - i, 16), &buf[i]);
226 trace_seq_putc(p, 0);
227
228 return ret;
229 }
230 EXPORT_SYMBOL(trace_print_hex_seq);
231
232 const char *
trace_print_array_seq(struct trace_seq * p,const void * buf,int count,size_t el_size)233 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
234 size_t el_size)
235 {
236 const char *ret = trace_seq_buffer_ptr(p);
237 const char *prefix = "";
238 void *ptr = (void *)buf;
239 size_t buf_len = count * el_size;
240
241 trace_seq_putc(p, '{');
242
243 while (ptr < buf + buf_len) {
244 switch (el_size) {
245 case 1:
246 trace_seq_printf(p, "%s0x%x", prefix,
247 *(u8 *)ptr);
248 break;
249 case 2:
250 trace_seq_printf(p, "%s0x%x", prefix,
251 *(u16 *)ptr);
252 break;
253 case 4:
254 trace_seq_printf(p, "%s0x%x", prefix,
255 *(u32 *)ptr);
256 break;
257 case 8:
258 trace_seq_printf(p, "%s0x%llx", prefix,
259 *(u64 *)ptr);
260 break;
261 default:
262 trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
263 *(u8 *)ptr);
264 el_size = 1;
265 }
266 prefix = ",";
267 ptr += el_size;
268 }
269
270 trace_seq_putc(p, '}');
271 trace_seq_putc(p, 0);
272
273 return ret;
274 }
275 EXPORT_SYMBOL(trace_print_array_seq);
276
277 const char *
trace_print_hex_dump_seq(struct trace_seq * p,const char * prefix_str,int prefix_type,int rowsize,int groupsize,const void * buf,size_t len,bool ascii)278 trace_print_hex_dump_seq(struct trace_seq *p, const char *prefix_str,
279 int prefix_type, int rowsize, int groupsize,
280 const void *buf, size_t len, bool ascii)
281 {
282 const char *ret = trace_seq_buffer_ptr(p);
283
284 trace_seq_putc(p, '\n');
285 trace_seq_hex_dump(p, prefix_str, prefix_type,
286 rowsize, groupsize, buf, len, ascii);
287 trace_seq_putc(p, 0);
288 return ret;
289 }
290 EXPORT_SYMBOL(trace_print_hex_dump_seq);
291
trace_raw_output_prep(struct trace_iterator * iter,struct trace_event * trace_event)292 int trace_raw_output_prep(struct trace_iterator *iter,
293 struct trace_event *trace_event)
294 {
295 struct trace_event_call *event;
296 struct trace_seq *s = &iter->seq;
297 struct trace_seq *p = &iter->tmp_seq;
298 struct trace_entry *entry;
299
300 event = container_of(trace_event, struct trace_event_call, event);
301 entry = iter->ent;
302
303 if (entry->type != event->event.type) {
304 WARN_ON_ONCE(1);
305 return TRACE_TYPE_UNHANDLED;
306 }
307
308 trace_seq_init(p);
309 trace_seq_printf(s, "%s: ", trace_event_name(event));
310
311 return trace_handle_return(s);
312 }
313 EXPORT_SYMBOL(trace_raw_output_prep);
314
trace_output_raw(struct trace_iterator * iter,char * name,char * fmt,va_list ap)315 static int trace_output_raw(struct trace_iterator *iter, char *name,
316 char *fmt, va_list ap)
317 {
318 struct trace_seq *s = &iter->seq;
319
320 trace_seq_printf(s, "%s: ", name);
321 trace_seq_vprintf(s, fmt, ap);
322
323 return trace_handle_return(s);
324 }
325
trace_output_call(struct trace_iterator * iter,char * name,char * fmt,...)326 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
327 {
328 va_list ap;
329 int ret;
330
331 va_start(ap, fmt);
332 ret = trace_output_raw(iter, name, fmt, ap);
333 va_end(ap);
334
335 return ret;
336 }
337 EXPORT_SYMBOL_GPL(trace_output_call);
338
339 #ifdef CONFIG_KRETPROBES
kretprobed(const char * name)340 static inline const char *kretprobed(const char *name)
341 {
342 static const char tramp_name[] = "kretprobe_trampoline";
343 int size = sizeof(tramp_name);
344
345 if (strncmp(tramp_name, name, size) == 0)
346 return "[unknown/kretprobe'd]";
347 return name;
348 }
349 #else
kretprobed(const char * name)350 static inline const char *kretprobed(const char *name)
351 {
352 return name;
353 }
354 #endif /* CONFIG_KRETPROBES */
355
356 static void
seq_print_sym(struct trace_seq * s,unsigned long address,bool offset)357 seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
358 {
359 #ifdef CONFIG_KALLSYMS
360 char str[KSYM_SYMBOL_LEN];
361 const char *name;
362
363 if (offset)
364 sprint_symbol(str, address);
365 else
366 kallsyms_lookup(address, NULL, NULL, NULL, str);
367 name = kretprobed(str);
368
369 if (name && strlen(name)) {
370 trace_seq_puts(s, name);
371 return;
372 }
373 #endif
374 trace_seq_printf(s, "0x%08lx", address);
375 }
376
377 #ifndef CONFIG_64BIT
378 # define IP_FMT "%08lx"
379 #else
380 # define IP_FMT "%016lx"
381 #endif
382
seq_print_user_ip(struct trace_seq * s,struct mm_struct * mm,unsigned long ip,unsigned long sym_flags)383 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
384 unsigned long ip, unsigned long sym_flags)
385 {
386 struct file *file = NULL;
387 unsigned long vmstart = 0;
388 int ret = 1;
389
390 if (s->full)
391 return 0;
392
393 if (mm) {
394 const struct vm_area_struct *vma;
395
396 mmap_read_lock(mm);
397 vma = find_vma(mm, ip);
398 if (vma) {
399 file = vma->vm_file;
400 vmstart = vma->vm_start;
401 }
402 if (file) {
403 ret = trace_seq_path(s, &file->f_path);
404 if (ret)
405 trace_seq_printf(s, "[+0x%lx]",
406 ip - vmstart);
407 }
408 mmap_read_unlock(mm);
409 }
410 if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
411 trace_seq_printf(s, " <" IP_FMT ">", ip);
412 return !trace_seq_has_overflowed(s);
413 }
414
415 int
seq_print_ip_sym(struct trace_seq * s,unsigned long ip,unsigned long sym_flags)416 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
417 {
418 if (!ip) {
419 trace_seq_putc(s, '0');
420 goto out;
421 }
422
423 seq_print_sym(s, ip, sym_flags & TRACE_ITER_SYM_OFFSET);
424
425 if (sym_flags & TRACE_ITER_SYM_ADDR)
426 trace_seq_printf(s, " <" IP_FMT ">", ip);
427
428 out:
429 return !trace_seq_has_overflowed(s);
430 }
431
432 /**
433 * trace_print_lat_fmt - print the irq, preempt and lockdep fields
434 * @s: trace seq struct to write to
435 * @entry: The trace entry field from the ring buffer
436 *
437 * Prints the generic fields of irqs off, in hard or softirq, preempt
438 * count.
439 */
trace_print_lat_fmt(struct trace_seq * s,struct trace_entry * entry)440 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
441 {
442 char hardsoft_irq;
443 char need_resched;
444 char irqs_off;
445 int hardirq;
446 int softirq;
447 int nmi;
448
449 nmi = entry->flags & TRACE_FLAG_NMI;
450 hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
451 softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
452
453 irqs_off =
454 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
455 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
456 '.';
457
458 switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
459 TRACE_FLAG_PREEMPT_RESCHED)) {
460 case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
461 need_resched = 'N';
462 break;
463 case TRACE_FLAG_NEED_RESCHED:
464 need_resched = 'n';
465 break;
466 case TRACE_FLAG_PREEMPT_RESCHED:
467 need_resched = 'p';
468 break;
469 default:
470 need_resched = '.';
471 break;
472 }
473
474 hardsoft_irq =
475 (nmi && hardirq) ? 'Z' :
476 nmi ? 'z' :
477 (hardirq && softirq) ? 'H' :
478 hardirq ? 'h' :
479 softirq ? 's' :
480 '.' ;
481
482 trace_seq_printf(s, "%c%c%c",
483 irqs_off, need_resched, hardsoft_irq);
484
485 if (entry->preempt_count)
486 trace_seq_printf(s, "%x", entry->preempt_count);
487 else
488 trace_seq_putc(s, '.');
489
490 return !trace_seq_has_overflowed(s);
491 }
492
493 static int
lat_print_generic(struct trace_seq * s,struct trace_entry * entry,int cpu)494 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
495 {
496 char comm[TASK_COMM_LEN];
497
498 trace_find_cmdline(entry->pid, comm);
499
500 trace_seq_printf(s, "%8.8s-%-7d %3d",
501 comm, entry->pid, cpu);
502
503 return trace_print_lat_fmt(s, entry);
504 }
505
506 #undef MARK
507 #define MARK(v, s) {.val = v, .sym = s}
508 /* trace overhead mark */
509 static const struct trace_mark {
510 unsigned long long val; /* unit: nsec */
511 char sym;
512 } mark[] = {
513 MARK(1000000000ULL , '$'), /* 1 sec */
514 MARK(100000000ULL , '@'), /* 100 msec */
515 MARK(10000000ULL , '*'), /* 10 msec */
516 MARK(1000000ULL , '#'), /* 1000 usecs */
517 MARK(100000ULL , '!'), /* 100 usecs */
518 MARK(10000ULL , '+'), /* 10 usecs */
519 };
520 #undef MARK
521
trace_find_mark(unsigned long long d)522 char trace_find_mark(unsigned long long d)
523 {
524 int i;
525 int size = ARRAY_SIZE(mark);
526
527 for (i = 0; i < size; i++) {
528 if (d > mark[i].val)
529 break;
530 }
531
532 return (i == size) ? ' ' : mark[i].sym;
533 }
534
535 static int
lat_print_timestamp(struct trace_iterator * iter,u64 next_ts)536 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
537 {
538 struct trace_array *tr = iter->tr;
539 unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
540 unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
541 unsigned long long abs_ts = iter->ts - iter->array_buffer->time_start;
542 unsigned long long rel_ts = next_ts - iter->ts;
543 struct trace_seq *s = &iter->seq;
544
545 if (in_ns) {
546 abs_ts = ns2usecs(abs_ts);
547 rel_ts = ns2usecs(rel_ts);
548 }
549
550 if (verbose && in_ns) {
551 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
552 unsigned long abs_msec = (unsigned long)abs_ts;
553 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
554 unsigned long rel_msec = (unsigned long)rel_ts;
555
556 trace_seq_printf(
557 s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
558 ns2usecs(iter->ts),
559 abs_msec, abs_usec,
560 rel_msec, rel_usec);
561
562 } else if (verbose && !in_ns) {
563 trace_seq_printf(
564 s, "[%016llx] %lld (+%lld): ",
565 iter->ts, abs_ts, rel_ts);
566
567 } else if (!verbose && in_ns) {
568 trace_seq_printf(
569 s, " %4lldus%c: ",
570 abs_ts,
571 trace_find_mark(rel_ts * NSEC_PER_USEC));
572
573 } else { /* !verbose && !in_ns */
574 trace_seq_printf(s, " %4lld: ", abs_ts);
575 }
576
577 return !trace_seq_has_overflowed(s);
578 }
579
trace_print_context(struct trace_iterator * iter)580 int trace_print_context(struct trace_iterator *iter)
581 {
582 struct trace_array *tr = iter->tr;
583 struct trace_seq *s = &iter->seq;
584 struct trace_entry *entry = iter->ent;
585 unsigned long long t;
586 unsigned long secs, usec_rem;
587 char comm[TASK_COMM_LEN];
588
589 trace_find_cmdline(entry->pid, comm);
590
591 trace_seq_printf(s, "%16s-%-7d ", comm, entry->pid);
592
593 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
594 unsigned int tgid = trace_find_tgid(entry->pid);
595
596 if (!tgid)
597 trace_seq_printf(s, "(-------) ");
598 else
599 trace_seq_printf(s, "(%7d) ", tgid);
600 }
601
602 trace_seq_printf(s, "[%03d] ", iter->cpu);
603
604 if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
605 trace_print_lat_fmt(s, entry);
606
607 if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
608 t = ns2usecs(iter->ts);
609 usec_rem = do_div(t, USEC_PER_SEC);
610 secs = (unsigned long)t;
611 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
612 } else
613 trace_seq_printf(s, " %12llu: ", iter->ts);
614
615 return !trace_seq_has_overflowed(s);
616 }
617
trace_print_lat_context(struct trace_iterator * iter)618 int trace_print_lat_context(struct trace_iterator *iter)
619 {
620 struct trace_entry *entry, *next_entry;
621 struct trace_array *tr = iter->tr;
622 struct trace_seq *s = &iter->seq;
623 unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
624 u64 next_ts;
625
626 next_entry = trace_find_next_entry(iter, NULL, &next_ts);
627 if (!next_entry)
628 next_ts = iter->ts;
629
630 /* trace_find_next_entry() may change iter->ent */
631 entry = iter->ent;
632
633 if (verbose) {
634 char comm[TASK_COMM_LEN];
635
636 trace_find_cmdline(entry->pid, comm);
637
638 trace_seq_printf(
639 s, "%16s %7d %3d %d %08x %08lx ",
640 comm, entry->pid, iter->cpu, entry->flags,
641 entry->preempt_count, iter->idx);
642 } else {
643 lat_print_generic(s, entry, iter->cpu);
644 }
645
646 lat_print_timestamp(iter, next_ts);
647
648 return !trace_seq_has_overflowed(s);
649 }
650
651 /**
652 * ftrace_find_event - find a registered event
653 * @type: the type of event to look for
654 *
655 * Returns an event of type @type otherwise NULL
656 * Called with trace_event_read_lock() held.
657 */
ftrace_find_event(int type)658 struct trace_event *ftrace_find_event(int type)
659 {
660 struct trace_event *event;
661 unsigned key;
662
663 key = type & (EVENT_HASHSIZE - 1);
664
665 hlist_for_each_entry(event, &event_hash[key], node) {
666 if (event->type == type)
667 return event;
668 }
669
670 return NULL;
671 }
672
673 static LIST_HEAD(ftrace_event_list);
674
trace_search_list(struct list_head ** list)675 static int trace_search_list(struct list_head **list)
676 {
677 struct trace_event *e;
678 int next = __TRACE_LAST_TYPE;
679
680 if (list_empty(&ftrace_event_list)) {
681 *list = &ftrace_event_list;
682 return next;
683 }
684
685 /*
686 * We used up all possible max events,
687 * lets see if somebody freed one.
688 */
689 list_for_each_entry(e, &ftrace_event_list, list) {
690 if (e->type != next)
691 break;
692 next++;
693 }
694
695 /* Did we used up all 65 thousand events??? */
696 if (next > TRACE_EVENT_TYPE_MAX)
697 return 0;
698
699 *list = &e->list;
700 return next;
701 }
702
trace_event_read_lock(void)703 void trace_event_read_lock(void)
704 {
705 down_read(&trace_event_sem);
706 }
707
trace_event_read_unlock(void)708 void trace_event_read_unlock(void)
709 {
710 up_read(&trace_event_sem);
711 }
712
713 /**
714 * register_trace_event - register output for an event type
715 * @event: the event type to register
716 *
717 * Event types are stored in a hash and this hash is used to
718 * find a way to print an event. If the @event->type is set
719 * then it will use that type, otherwise it will assign a
720 * type to use.
721 *
722 * If you assign your own type, please make sure it is added
723 * to the trace_type enum in trace.h, to avoid collisions
724 * with the dynamic types.
725 *
726 * Returns the event type number or zero on error.
727 */
register_trace_event(struct trace_event * event)728 int register_trace_event(struct trace_event *event)
729 {
730 unsigned key;
731 int ret = 0;
732
733 down_write(&trace_event_sem);
734
735 if (WARN_ON(!event))
736 goto out;
737
738 if (WARN_ON(!event->funcs))
739 goto out;
740
741 INIT_LIST_HEAD(&event->list);
742
743 if (!event->type) {
744 struct list_head *list = NULL;
745
746 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
747
748 event->type = trace_search_list(&list);
749 if (!event->type)
750 goto out;
751
752 } else {
753
754 event->type = next_event_type++;
755 list = &ftrace_event_list;
756 }
757
758 if (WARN_ON(ftrace_find_event(event->type)))
759 goto out;
760
761 list_add_tail(&event->list, list);
762
763 } else if (event->type > __TRACE_LAST_TYPE) {
764 printk(KERN_WARNING "Need to add type to trace.h\n");
765 WARN_ON(1);
766 goto out;
767 } else {
768 /* Is this event already used */
769 if (ftrace_find_event(event->type))
770 goto out;
771 }
772
773 if (event->funcs->trace == NULL)
774 event->funcs->trace = trace_nop_print;
775 if (event->funcs->raw == NULL)
776 event->funcs->raw = trace_nop_print;
777 if (event->funcs->hex == NULL)
778 event->funcs->hex = trace_nop_print;
779 if (event->funcs->binary == NULL)
780 event->funcs->binary = trace_nop_print;
781
782 key = event->type & (EVENT_HASHSIZE - 1);
783
784 hlist_add_head(&event->node, &event_hash[key]);
785
786 ret = event->type;
787 out:
788 up_write(&trace_event_sem);
789
790 return ret;
791 }
792 EXPORT_SYMBOL_GPL(register_trace_event);
793
794 /*
795 * Used by module code with the trace_event_sem held for write.
796 */
__unregister_trace_event(struct trace_event * event)797 int __unregister_trace_event(struct trace_event *event)
798 {
799 hlist_del(&event->node);
800 list_del(&event->list);
801 return 0;
802 }
803
804 /**
805 * unregister_trace_event - remove a no longer used event
806 * @event: the event to remove
807 */
unregister_trace_event(struct trace_event * event)808 int unregister_trace_event(struct trace_event *event)
809 {
810 down_write(&trace_event_sem);
811 __unregister_trace_event(event);
812 up_write(&trace_event_sem);
813
814 return 0;
815 }
816 EXPORT_SYMBOL_GPL(unregister_trace_event);
817
818 /*
819 * Standard events
820 */
821
trace_nop_print(struct trace_iterator * iter,int flags,struct trace_event * event)822 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
823 struct trace_event *event)
824 {
825 trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
826
827 return trace_handle_return(&iter->seq);
828 }
829
830 /* TRACE_FN */
trace_fn_trace(struct trace_iterator * iter,int flags,struct trace_event * event)831 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
832 struct trace_event *event)
833 {
834 struct ftrace_entry *field;
835 struct trace_seq *s = &iter->seq;
836
837 trace_assign_type(field, iter->ent);
838
839 seq_print_ip_sym(s, field->ip, flags);
840
841 if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
842 trace_seq_puts(s, " <-");
843 seq_print_ip_sym(s, field->parent_ip, flags);
844 }
845
846 trace_seq_putc(s, '\n');
847
848 return trace_handle_return(s);
849 }
850
trace_fn_raw(struct trace_iterator * iter,int flags,struct trace_event * event)851 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
852 struct trace_event *event)
853 {
854 struct ftrace_entry *field;
855
856 trace_assign_type(field, iter->ent);
857
858 trace_seq_printf(&iter->seq, "%lx %lx\n",
859 field->ip,
860 field->parent_ip);
861
862 return trace_handle_return(&iter->seq);
863 }
864
trace_fn_hex(struct trace_iterator * iter,int flags,struct trace_event * event)865 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
866 struct trace_event *event)
867 {
868 struct ftrace_entry *field;
869 struct trace_seq *s = &iter->seq;
870
871 trace_assign_type(field, iter->ent);
872
873 SEQ_PUT_HEX_FIELD(s, field->ip);
874 SEQ_PUT_HEX_FIELD(s, field->parent_ip);
875
876 return trace_handle_return(s);
877 }
878
trace_fn_bin(struct trace_iterator * iter,int flags,struct trace_event * event)879 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
880 struct trace_event *event)
881 {
882 struct ftrace_entry *field;
883 struct trace_seq *s = &iter->seq;
884
885 trace_assign_type(field, iter->ent);
886
887 SEQ_PUT_FIELD(s, field->ip);
888 SEQ_PUT_FIELD(s, field->parent_ip);
889
890 return trace_handle_return(s);
891 }
892
893 static struct trace_event_functions trace_fn_funcs = {
894 .trace = trace_fn_trace,
895 .raw = trace_fn_raw,
896 .hex = trace_fn_hex,
897 .binary = trace_fn_bin,
898 };
899
900 static struct trace_event trace_fn_event = {
901 .type = TRACE_FN,
902 .funcs = &trace_fn_funcs,
903 };
904
905 /* TRACE_CTX an TRACE_WAKE */
trace_ctxwake_print(struct trace_iterator * iter,char * delim)906 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
907 char *delim)
908 {
909 struct ctx_switch_entry *field;
910 char comm[TASK_COMM_LEN];
911 int S, T;
912
913
914 trace_assign_type(field, iter->ent);
915
916 T = task_index_to_char(field->next_state);
917 S = task_index_to_char(field->prev_state);
918 trace_find_cmdline(field->next_pid, comm);
919 trace_seq_printf(&iter->seq,
920 " %7d:%3d:%c %s [%03d] %7d:%3d:%c %s\n",
921 field->prev_pid,
922 field->prev_prio,
923 S, delim,
924 field->next_cpu,
925 field->next_pid,
926 field->next_prio,
927 T, comm);
928
929 return trace_handle_return(&iter->seq);
930 }
931
trace_ctx_print(struct trace_iterator * iter,int flags,struct trace_event * event)932 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
933 struct trace_event *event)
934 {
935 return trace_ctxwake_print(iter, "==>");
936 }
937
trace_wake_print(struct trace_iterator * iter,int flags,struct trace_event * event)938 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
939 int flags, struct trace_event *event)
940 {
941 return trace_ctxwake_print(iter, " +");
942 }
943
trace_ctxwake_raw(struct trace_iterator * iter,char S)944 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
945 {
946 struct ctx_switch_entry *field;
947 int T;
948
949 trace_assign_type(field, iter->ent);
950
951 if (!S)
952 S = task_index_to_char(field->prev_state);
953 T = task_index_to_char(field->next_state);
954 trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
955 field->prev_pid,
956 field->prev_prio,
957 S,
958 field->next_cpu,
959 field->next_pid,
960 field->next_prio,
961 T);
962
963 return trace_handle_return(&iter->seq);
964 }
965
trace_ctx_raw(struct trace_iterator * iter,int flags,struct trace_event * event)966 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
967 struct trace_event *event)
968 {
969 return trace_ctxwake_raw(iter, 0);
970 }
971
trace_wake_raw(struct trace_iterator * iter,int flags,struct trace_event * event)972 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
973 struct trace_event *event)
974 {
975 return trace_ctxwake_raw(iter, '+');
976 }
977
978
trace_ctxwake_hex(struct trace_iterator * iter,char S)979 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
980 {
981 struct ctx_switch_entry *field;
982 struct trace_seq *s = &iter->seq;
983 int T;
984
985 trace_assign_type(field, iter->ent);
986
987 if (!S)
988 S = task_index_to_char(field->prev_state);
989 T = task_index_to_char(field->next_state);
990
991 SEQ_PUT_HEX_FIELD(s, field->prev_pid);
992 SEQ_PUT_HEX_FIELD(s, field->prev_prio);
993 SEQ_PUT_HEX_FIELD(s, S);
994 SEQ_PUT_HEX_FIELD(s, field->next_cpu);
995 SEQ_PUT_HEX_FIELD(s, field->next_pid);
996 SEQ_PUT_HEX_FIELD(s, field->next_prio);
997 SEQ_PUT_HEX_FIELD(s, T);
998
999 return trace_handle_return(s);
1000 }
1001
trace_ctx_hex(struct trace_iterator * iter,int flags,struct trace_event * event)1002 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1003 struct trace_event *event)
1004 {
1005 return trace_ctxwake_hex(iter, 0);
1006 }
1007
trace_wake_hex(struct trace_iterator * iter,int flags,struct trace_event * event)1008 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1009 struct trace_event *event)
1010 {
1011 return trace_ctxwake_hex(iter, '+');
1012 }
1013
trace_ctxwake_bin(struct trace_iterator * iter,int flags,struct trace_event * event)1014 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1015 int flags, struct trace_event *event)
1016 {
1017 struct ctx_switch_entry *field;
1018 struct trace_seq *s = &iter->seq;
1019
1020 trace_assign_type(field, iter->ent);
1021
1022 SEQ_PUT_FIELD(s, field->prev_pid);
1023 SEQ_PUT_FIELD(s, field->prev_prio);
1024 SEQ_PUT_FIELD(s, field->prev_state);
1025 SEQ_PUT_FIELD(s, field->next_cpu);
1026 SEQ_PUT_FIELD(s, field->next_pid);
1027 SEQ_PUT_FIELD(s, field->next_prio);
1028 SEQ_PUT_FIELD(s, field->next_state);
1029
1030 return trace_handle_return(s);
1031 }
1032
1033 static struct trace_event_functions trace_ctx_funcs = {
1034 .trace = trace_ctx_print,
1035 .raw = trace_ctx_raw,
1036 .hex = trace_ctx_hex,
1037 .binary = trace_ctxwake_bin,
1038 };
1039
1040 static struct trace_event trace_ctx_event = {
1041 .type = TRACE_CTX,
1042 .funcs = &trace_ctx_funcs,
1043 };
1044
1045 static struct trace_event_functions trace_wake_funcs = {
1046 .trace = trace_wake_print,
1047 .raw = trace_wake_raw,
1048 .hex = trace_wake_hex,
1049 .binary = trace_ctxwake_bin,
1050 };
1051
1052 static struct trace_event trace_wake_event = {
1053 .type = TRACE_WAKE,
1054 .funcs = &trace_wake_funcs,
1055 };
1056
1057 /* TRACE_STACK */
1058
trace_stack_print(struct trace_iterator * iter,int flags,struct trace_event * event)1059 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1060 int flags, struct trace_event *event)
1061 {
1062 struct stack_entry *field;
1063 struct trace_seq *s = &iter->seq;
1064 unsigned long *p;
1065 unsigned long *end;
1066
1067 trace_assign_type(field, iter->ent);
1068 end = (unsigned long *)((long)iter->ent + iter->ent_size);
1069
1070 trace_seq_puts(s, "<stack trace>\n");
1071
1072 for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {
1073
1074 if (trace_seq_has_overflowed(s))
1075 break;
1076
1077 trace_seq_puts(s, " => ");
1078 seq_print_ip_sym(s, *p, flags);
1079 trace_seq_putc(s, '\n');
1080 }
1081
1082 return trace_handle_return(s);
1083 }
1084
1085 static struct trace_event_functions trace_stack_funcs = {
1086 .trace = trace_stack_print,
1087 };
1088
1089 static struct trace_event trace_stack_event = {
1090 .type = TRACE_STACK,
1091 .funcs = &trace_stack_funcs,
1092 };
1093
1094 /* TRACE_USER_STACK */
trace_user_stack_print(struct trace_iterator * iter,int flags,struct trace_event * event)1095 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1096 int flags, struct trace_event *event)
1097 {
1098 struct trace_array *tr = iter->tr;
1099 struct userstack_entry *field;
1100 struct trace_seq *s = &iter->seq;
1101 struct mm_struct *mm = NULL;
1102 unsigned int i;
1103
1104 trace_assign_type(field, iter->ent);
1105
1106 trace_seq_puts(s, "<user stack trace>\n");
1107
1108 if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1109 struct task_struct *task;
1110 /*
1111 * we do the lookup on the thread group leader,
1112 * since individual threads might have already quit!
1113 */
1114 rcu_read_lock();
1115 task = find_task_by_vpid(field->tgid);
1116 if (task)
1117 mm = get_task_mm(task);
1118 rcu_read_unlock();
1119 }
1120
1121 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1122 unsigned long ip = field->caller[i];
1123
1124 if (!ip || trace_seq_has_overflowed(s))
1125 break;
1126
1127 trace_seq_puts(s, " => ");
1128 seq_print_user_ip(s, mm, ip, flags);
1129 trace_seq_putc(s, '\n');
1130 }
1131
1132 if (mm)
1133 mmput(mm);
1134
1135 return trace_handle_return(s);
1136 }
1137
1138 static struct trace_event_functions trace_user_stack_funcs = {
1139 .trace = trace_user_stack_print,
1140 };
1141
1142 static struct trace_event trace_user_stack_event = {
1143 .type = TRACE_USER_STACK,
1144 .funcs = &trace_user_stack_funcs,
1145 };
1146
1147 /* TRACE_HWLAT */
1148 static enum print_line_t
trace_hwlat_print(struct trace_iterator * iter,int flags,struct trace_event * event)1149 trace_hwlat_print(struct trace_iterator *iter, int flags,
1150 struct trace_event *event)
1151 {
1152 struct trace_entry *entry = iter->ent;
1153 struct trace_seq *s = &iter->seq;
1154 struct hwlat_entry *field;
1155
1156 trace_assign_type(field, entry);
1157
1158 trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld count:%d",
1159 field->seqnum,
1160 field->duration,
1161 field->outer_duration,
1162 (long long)field->timestamp.tv_sec,
1163 field->timestamp.tv_nsec, field->count);
1164
1165 if (field->nmi_count) {
1166 /*
1167 * The generic sched_clock() is not NMI safe, thus
1168 * we only record the count and not the time.
1169 */
1170 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1171 trace_seq_printf(s, " nmi-total:%llu",
1172 field->nmi_total_ts);
1173 trace_seq_printf(s, " nmi-count:%u",
1174 field->nmi_count);
1175 }
1176
1177 trace_seq_putc(s, '\n');
1178
1179 return trace_handle_return(s);
1180 }
1181
1182
1183 static enum print_line_t
trace_hwlat_raw(struct trace_iterator * iter,int flags,struct trace_event * event)1184 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1185 struct trace_event *event)
1186 {
1187 struct hwlat_entry *field;
1188 struct trace_seq *s = &iter->seq;
1189
1190 trace_assign_type(field, iter->ent);
1191
1192 trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1193 field->duration,
1194 field->outer_duration,
1195 (long long)field->timestamp.tv_sec,
1196 field->timestamp.tv_nsec,
1197 field->seqnum);
1198
1199 return trace_handle_return(s);
1200 }
1201
1202 static struct trace_event_functions trace_hwlat_funcs = {
1203 .trace = trace_hwlat_print,
1204 .raw = trace_hwlat_raw,
1205 };
1206
1207 static struct trace_event trace_hwlat_event = {
1208 .type = TRACE_HWLAT,
1209 .funcs = &trace_hwlat_funcs,
1210 };
1211
1212 /* TRACE_BPUTS */
1213 static enum print_line_t
trace_bputs_print(struct trace_iterator * iter,int flags,struct trace_event * event)1214 trace_bputs_print(struct trace_iterator *iter, int flags,
1215 struct trace_event *event)
1216 {
1217 struct trace_entry *entry = iter->ent;
1218 struct trace_seq *s = &iter->seq;
1219 struct bputs_entry *field;
1220
1221 trace_assign_type(field, entry);
1222
1223 seq_print_ip_sym(s, field->ip, flags);
1224 trace_seq_puts(s, ": ");
1225 trace_seq_puts(s, field->str);
1226
1227 return trace_handle_return(s);
1228 }
1229
1230
1231 static enum print_line_t
trace_bputs_raw(struct trace_iterator * iter,int flags,struct trace_event * event)1232 trace_bputs_raw(struct trace_iterator *iter, int flags,
1233 struct trace_event *event)
1234 {
1235 struct bputs_entry *field;
1236 struct trace_seq *s = &iter->seq;
1237
1238 trace_assign_type(field, iter->ent);
1239
1240 trace_seq_printf(s, ": %lx : ", field->ip);
1241 trace_seq_puts(s, field->str);
1242
1243 return trace_handle_return(s);
1244 }
1245
1246 static struct trace_event_functions trace_bputs_funcs = {
1247 .trace = trace_bputs_print,
1248 .raw = trace_bputs_raw,
1249 };
1250
1251 static struct trace_event trace_bputs_event = {
1252 .type = TRACE_BPUTS,
1253 .funcs = &trace_bputs_funcs,
1254 };
1255
1256 /* TRACE_BPRINT */
1257 static enum print_line_t
trace_bprint_print(struct trace_iterator * iter,int flags,struct trace_event * event)1258 trace_bprint_print(struct trace_iterator *iter, int flags,
1259 struct trace_event *event)
1260 {
1261 struct trace_entry *entry = iter->ent;
1262 struct trace_seq *s = &iter->seq;
1263 struct bprint_entry *field;
1264
1265 trace_assign_type(field, entry);
1266
1267 seq_print_ip_sym(s, field->ip, flags);
1268 trace_seq_puts(s, ": ");
1269 trace_seq_bprintf(s, field->fmt, field->buf);
1270
1271 return trace_handle_return(s);
1272 }
1273
1274
1275 static enum print_line_t
trace_bprint_raw(struct trace_iterator * iter,int flags,struct trace_event * event)1276 trace_bprint_raw(struct trace_iterator *iter, int flags,
1277 struct trace_event *event)
1278 {
1279 struct bprint_entry *field;
1280 struct trace_seq *s = &iter->seq;
1281
1282 trace_assign_type(field, iter->ent);
1283
1284 trace_seq_printf(s, ": %lx : ", field->ip);
1285 trace_seq_bprintf(s, field->fmt, field->buf);
1286
1287 return trace_handle_return(s);
1288 }
1289
1290 static struct trace_event_functions trace_bprint_funcs = {
1291 .trace = trace_bprint_print,
1292 .raw = trace_bprint_raw,
1293 };
1294
1295 static struct trace_event trace_bprint_event = {
1296 .type = TRACE_BPRINT,
1297 .funcs = &trace_bprint_funcs,
1298 };
1299
1300 /* TRACE_PRINT */
trace_print_print(struct trace_iterator * iter,int flags,struct trace_event * event)1301 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1302 int flags, struct trace_event *event)
1303 {
1304 struct print_entry *field;
1305 struct trace_seq *s = &iter->seq;
1306 int max = iter->ent_size - offsetof(struct print_entry, buf);
1307
1308 trace_assign_type(field, iter->ent);
1309
1310 seq_print_ip_sym(s, field->ip, flags);
1311 trace_seq_printf(s, ": %.*s", max, field->buf);
1312
1313 return trace_handle_return(s);
1314 }
1315
trace_print_raw(struct trace_iterator * iter,int flags,struct trace_event * event)1316 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1317 struct trace_event *event)
1318 {
1319 struct print_entry *field;
1320 int max = iter->ent_size - offsetof(struct print_entry, buf);
1321
1322 trace_assign_type(field, iter->ent);
1323
1324 trace_seq_printf(&iter->seq, "# %lx %.*s", field->ip, max, field->buf);
1325
1326 return trace_handle_return(&iter->seq);
1327 }
1328
1329 static struct trace_event_functions trace_print_funcs = {
1330 .trace = trace_print_print,
1331 .raw = trace_print_raw,
1332 };
1333
1334 static struct trace_event trace_print_event = {
1335 .type = TRACE_PRINT,
1336 .funcs = &trace_print_funcs,
1337 };
1338
trace_raw_data(struct trace_iterator * iter,int flags,struct trace_event * event)1339 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1340 struct trace_event *event)
1341 {
1342 struct raw_data_entry *field;
1343 int i;
1344
1345 trace_assign_type(field, iter->ent);
1346
1347 trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1348
1349 for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1350 trace_seq_printf(&iter->seq, " %02x",
1351 (unsigned char)field->buf[i]);
1352
1353 trace_seq_putc(&iter->seq, '\n');
1354
1355 return trace_handle_return(&iter->seq);
1356 }
1357
1358 static struct trace_event_functions trace_raw_data_funcs = {
1359 .trace = trace_raw_data,
1360 .raw = trace_raw_data,
1361 };
1362
1363 static struct trace_event trace_raw_data_event = {
1364 .type = TRACE_RAW_DATA,
1365 .funcs = &trace_raw_data_funcs,
1366 };
1367
1368
1369 static struct trace_event *events[] __initdata = {
1370 &trace_fn_event,
1371 &trace_ctx_event,
1372 &trace_wake_event,
1373 &trace_stack_event,
1374 &trace_user_stack_event,
1375 &trace_bputs_event,
1376 &trace_bprint_event,
1377 &trace_print_event,
1378 &trace_hwlat_event,
1379 &trace_raw_data_event,
1380 NULL
1381 };
1382
init_events(void)1383 __init int init_events(void)
1384 {
1385 struct trace_event *event;
1386 int i, ret;
1387
1388 for (i = 0; events[i]; i++) {
1389 event = events[i];
1390
1391 ret = register_trace_event(event);
1392 if (!ret) {
1393 printk(KERN_WARNING "event %d failed to register\n",
1394 event->type);
1395 WARN_ON_ONCE(1);
1396 }
1397 }
1398
1399 return 0;
1400 }
1401