Merge tag '4.3-rc-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
[sfrench/cifs-2.6.git] / kernel / trace / trace_output.c
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 + 1;
24
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
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
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 *
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 *
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 *
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 *
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 *
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 *
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
223         for (i = 0; i < buf_len; i++)
224                 trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
225                                  buf[i]);
226         trace_seq_putc(p, 0);
227
228         return ret;
229 }
230 EXPORT_SYMBOL(trace_print_hex_seq);
231
232 const char *
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 int trace_raw_output_prep(struct trace_iterator *iter,
278                           struct trace_event *trace_event)
279 {
280         struct trace_event_call *event;
281         struct trace_seq *s = &iter->seq;
282         struct trace_seq *p = &iter->tmp_seq;
283         struct trace_entry *entry;
284
285         event = container_of(trace_event, struct trace_event_call, event);
286         entry = iter->ent;
287
288         if (entry->type != event->event.type) {
289                 WARN_ON_ONCE(1);
290                 return TRACE_TYPE_UNHANDLED;
291         }
292
293         trace_seq_init(p);
294         trace_seq_printf(s, "%s: ", trace_event_name(event));
295
296         return trace_handle_return(s);
297 }
298 EXPORT_SYMBOL(trace_raw_output_prep);
299
300 static int trace_output_raw(struct trace_iterator *iter, char *name,
301                             char *fmt, va_list ap)
302 {
303         struct trace_seq *s = &iter->seq;
304
305         trace_seq_printf(s, "%s: ", name);
306         trace_seq_vprintf(s, fmt, ap);
307
308         return trace_handle_return(s);
309 }
310
311 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
312 {
313         va_list ap;
314         int ret;
315
316         va_start(ap, fmt);
317         ret = trace_output_raw(iter, name, fmt, ap);
318         va_end(ap);
319
320         return ret;
321 }
322 EXPORT_SYMBOL_GPL(trace_output_call);
323
324 #ifdef CONFIG_KRETPROBES
325 static inline const char *kretprobed(const char *name)
326 {
327         static const char tramp_name[] = "kretprobe_trampoline";
328         int size = sizeof(tramp_name);
329
330         if (strncmp(tramp_name, name, size) == 0)
331                 return "[unknown/kretprobe'd]";
332         return name;
333 }
334 #else
335 static inline const char *kretprobed(const char *name)
336 {
337         return name;
338 }
339 #endif /* CONFIG_KRETPROBES */
340
341 static void
342 seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
343 {
344 #ifdef CONFIG_KALLSYMS
345         char str[KSYM_SYMBOL_LEN];
346         const char *name;
347
348         if (offset)
349                 sprint_symbol(str, address);
350         else
351                 kallsyms_lookup(address, NULL, NULL, NULL, str);
352         name = kretprobed(str);
353
354         if (name && strlen(name)) {
355                 trace_seq_puts(s, name);
356                 return;
357         }
358 #endif
359         trace_seq_printf(s, "0x%08lx", address);
360 }
361
362 #ifndef CONFIG_64BIT
363 # define IP_FMT "%08lx"
364 #else
365 # define IP_FMT "%016lx"
366 #endif
367
368 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
369                              unsigned long ip, unsigned long sym_flags)
370 {
371         struct file *file = NULL;
372         unsigned long vmstart = 0;
373         int ret = 1;
374
375         if (s->full)
376                 return 0;
377
378         if (mm) {
379                 const struct vm_area_struct *vma;
380
381                 down_read(&mm->mmap_sem);
382                 vma = find_vma(mm, ip);
383                 if (vma) {
384                         file = vma->vm_file;
385                         vmstart = vma->vm_start;
386                 }
387                 if (file) {
388                         ret = trace_seq_path(s, &file->f_path);
389                         if (ret)
390                                 trace_seq_printf(s, "[+0x%lx]",
391                                                  ip - vmstart);
392                 }
393                 up_read(&mm->mmap_sem);
394         }
395         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
396                 trace_seq_printf(s, " <" IP_FMT ">", ip);
397         return !trace_seq_has_overflowed(s);
398 }
399
400 int
401 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
402 {
403         if (!ip) {
404                 trace_seq_putc(s, '0');
405                 goto out;
406         }
407
408         seq_print_sym(s, ip, sym_flags & TRACE_ITER_SYM_OFFSET);
409
410         if (sym_flags & TRACE_ITER_SYM_ADDR)
411                 trace_seq_printf(s, " <" IP_FMT ">", ip);
412
413  out:
414         return !trace_seq_has_overflowed(s);
415 }
416
417 /**
418  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
419  * @s: trace seq struct to write to
420  * @entry: The trace entry field from the ring buffer
421  *
422  * Prints the generic fields of irqs off, in hard or softirq, preempt
423  * count.
424  */
425 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
426 {
427         char hardsoft_irq;
428         char need_resched;
429         char irqs_off;
430         int hardirq;
431         int softirq;
432         int nmi;
433
434         nmi = entry->flags & TRACE_FLAG_NMI;
435         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
436         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
437
438         irqs_off =
439                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
440                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
441                 '.';
442
443         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
444                                 TRACE_FLAG_PREEMPT_RESCHED)) {
445         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
446                 need_resched = 'N';
447                 break;
448         case TRACE_FLAG_NEED_RESCHED:
449                 need_resched = 'n';
450                 break;
451         case TRACE_FLAG_PREEMPT_RESCHED:
452                 need_resched = 'p';
453                 break;
454         default:
455                 need_resched = '.';
456                 break;
457         }
458
459         hardsoft_irq =
460                 (nmi && hardirq)     ? 'Z' :
461                 nmi                  ? 'z' :
462                 (hardirq && softirq) ? 'H' :
463                 hardirq              ? 'h' :
464                 softirq              ? 's' :
465                                        '.' ;
466
467         trace_seq_printf(s, "%c%c%c",
468                          irqs_off, need_resched, hardsoft_irq);
469
470         if (entry->preempt_count)
471                 trace_seq_printf(s, "%x", entry->preempt_count);
472         else
473                 trace_seq_putc(s, '.');
474
475         return !trace_seq_has_overflowed(s);
476 }
477
478 static int
479 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
480 {
481         char comm[TASK_COMM_LEN];
482
483         trace_find_cmdline(entry->pid, comm);
484
485         trace_seq_printf(s, "%8.8s-%-5d %3d",
486                          comm, entry->pid, cpu);
487
488         return trace_print_lat_fmt(s, entry);
489 }
490
491 #undef MARK
492 #define MARK(v, s) {.val = v, .sym = s}
493 /* trace overhead mark */
494 static const struct trace_mark {
495         unsigned long long      val; /* unit: nsec */
496         char                    sym;
497 } mark[] = {
498         MARK(1000000000ULL      , '$'), /* 1 sec */
499         MARK(100000000ULL       , '@'), /* 100 msec */
500         MARK(10000000ULL        , '*'), /* 10 msec */
501         MARK(1000000ULL         , '#'), /* 1000 usecs */
502         MARK(100000ULL          , '!'), /* 100 usecs */
503         MARK(10000ULL           , '+'), /* 10 usecs */
504 };
505 #undef MARK
506
507 char trace_find_mark(unsigned long long d)
508 {
509         int i;
510         int size = ARRAY_SIZE(mark);
511
512         for (i = 0; i < size; i++) {
513                 if (d > mark[i].val)
514                         break;
515         }
516
517         return (i == size) ? ' ' : mark[i].sym;
518 }
519
520 static int
521 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
522 {
523         struct trace_array *tr = iter->tr;
524         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
525         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
526         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
527         unsigned long long rel_ts = next_ts - iter->ts;
528         struct trace_seq *s = &iter->seq;
529
530         if (in_ns) {
531                 abs_ts = ns2usecs(abs_ts);
532                 rel_ts = ns2usecs(rel_ts);
533         }
534
535         if (verbose && in_ns) {
536                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
537                 unsigned long abs_msec = (unsigned long)abs_ts;
538                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
539                 unsigned long rel_msec = (unsigned long)rel_ts;
540
541                 trace_seq_printf(
542                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
543                         ns2usecs(iter->ts),
544                         abs_msec, abs_usec,
545                         rel_msec, rel_usec);
546
547         } else if (verbose && !in_ns) {
548                 trace_seq_printf(
549                         s, "[%016llx] %lld (+%lld): ",
550                         iter->ts, abs_ts, rel_ts);
551
552         } else if (!verbose && in_ns) {
553                 trace_seq_printf(
554                         s, " %4lldus%c: ",
555                         abs_ts,
556                         trace_find_mark(rel_ts * NSEC_PER_USEC));
557
558         } else { /* !verbose && !in_ns */
559                 trace_seq_printf(s, " %4lld: ", abs_ts);
560         }
561
562         return !trace_seq_has_overflowed(s);
563 }
564
565 int trace_print_context(struct trace_iterator *iter)
566 {
567         struct trace_array *tr = iter->tr;
568         struct trace_seq *s = &iter->seq;
569         struct trace_entry *entry = iter->ent;
570         unsigned long long t;
571         unsigned long secs, usec_rem;
572         char comm[TASK_COMM_LEN];
573
574         trace_find_cmdline(entry->pid, comm);
575
576         trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
577
578         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
579                 unsigned int tgid = trace_find_tgid(entry->pid);
580
581                 if (!tgid)
582                         trace_seq_printf(s, "(-----) ");
583                 else
584                         trace_seq_printf(s, "(%5d) ", tgid);
585         }
586
587         trace_seq_printf(s, "[%03d] ", iter->cpu);
588
589         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
590                 trace_print_lat_fmt(s, entry);
591
592         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
593                 t = ns2usecs(iter->ts);
594                 usec_rem = do_div(t, USEC_PER_SEC);
595                 secs = (unsigned long)t;
596                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
597         } else
598                 trace_seq_printf(s, " %12llu: ", iter->ts);
599
600         return !trace_seq_has_overflowed(s);
601 }
602
603 int trace_print_lat_context(struct trace_iterator *iter)
604 {
605         struct trace_array *tr = iter->tr;
606         /* trace_find_next_entry will reset ent_size */
607         int ent_size = iter->ent_size;
608         struct trace_seq *s = &iter->seq;
609         u64 next_ts;
610         struct trace_entry *entry = iter->ent,
611                            *next_entry = trace_find_next_entry(iter, NULL,
612                                                                &next_ts);
613         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
614
615         /* Restore the original ent_size */
616         iter->ent_size = ent_size;
617
618         if (!next_entry)
619                 next_ts = iter->ts;
620
621         if (verbose) {
622                 char comm[TASK_COMM_LEN];
623
624                 trace_find_cmdline(entry->pid, comm);
625
626                 trace_seq_printf(
627                         s, "%16s %5d %3d %d %08x %08lx ",
628                         comm, entry->pid, iter->cpu, entry->flags,
629                         entry->preempt_count, iter->idx);
630         } else {
631                 lat_print_generic(s, entry, iter->cpu);
632         }
633
634         lat_print_timestamp(iter, next_ts);
635
636         return !trace_seq_has_overflowed(s);
637 }
638
639 /**
640  * ftrace_find_event - find a registered event
641  * @type: the type of event to look for
642  *
643  * Returns an event of type @type otherwise NULL
644  * Called with trace_event_read_lock() held.
645  */
646 struct trace_event *ftrace_find_event(int type)
647 {
648         struct trace_event *event;
649         unsigned key;
650
651         key = type & (EVENT_HASHSIZE - 1);
652
653         hlist_for_each_entry(event, &event_hash[key], node) {
654                 if (event->type == type)
655                         return event;
656         }
657
658         return NULL;
659 }
660
661 static LIST_HEAD(ftrace_event_list);
662
663 static int trace_search_list(struct list_head **list)
664 {
665         struct trace_event *e;
666         int last = __TRACE_LAST_TYPE;
667
668         if (list_empty(&ftrace_event_list)) {
669                 *list = &ftrace_event_list;
670                 return last + 1;
671         }
672
673         /*
674          * We used up all possible max events,
675          * lets see if somebody freed one.
676          */
677         list_for_each_entry(e, &ftrace_event_list, list) {
678                 if (e->type != last + 1)
679                         break;
680                 last++;
681         }
682
683         /* Did we used up all 65 thousand events??? */
684         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
685                 return 0;
686
687         *list = &e->list;
688         return last + 1;
689 }
690
691 void trace_event_read_lock(void)
692 {
693         down_read(&trace_event_sem);
694 }
695
696 void trace_event_read_unlock(void)
697 {
698         up_read(&trace_event_sem);
699 }
700
701 /**
702  * register_trace_event - register output for an event type
703  * @event: the event type to register
704  *
705  * Event types are stored in a hash and this hash is used to
706  * find a way to print an event. If the @event->type is set
707  * then it will use that type, otherwise it will assign a
708  * type to use.
709  *
710  * If you assign your own type, please make sure it is added
711  * to the trace_type enum in trace.h, to avoid collisions
712  * with the dynamic types.
713  *
714  * Returns the event type number or zero on error.
715  */
716 int register_trace_event(struct trace_event *event)
717 {
718         unsigned key;
719         int ret = 0;
720
721         down_write(&trace_event_sem);
722
723         if (WARN_ON(!event))
724                 goto out;
725
726         if (WARN_ON(!event->funcs))
727                 goto out;
728
729         INIT_LIST_HEAD(&event->list);
730
731         if (!event->type) {
732                 struct list_head *list = NULL;
733
734                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
735
736                         event->type = trace_search_list(&list);
737                         if (!event->type)
738                                 goto out;
739
740                 } else {
741
742                         event->type = next_event_type++;
743                         list = &ftrace_event_list;
744                 }
745
746                 if (WARN_ON(ftrace_find_event(event->type)))
747                         goto out;
748
749                 list_add_tail(&event->list, list);
750
751         } else if (event->type > __TRACE_LAST_TYPE) {
752                 printk(KERN_WARNING "Need to add type to trace.h\n");
753                 WARN_ON(1);
754                 goto out;
755         } else {
756                 /* Is this event already used */
757                 if (ftrace_find_event(event->type))
758                         goto out;
759         }
760
761         if (event->funcs->trace == NULL)
762                 event->funcs->trace = trace_nop_print;
763         if (event->funcs->raw == NULL)
764                 event->funcs->raw = trace_nop_print;
765         if (event->funcs->hex == NULL)
766                 event->funcs->hex = trace_nop_print;
767         if (event->funcs->binary == NULL)
768                 event->funcs->binary = trace_nop_print;
769
770         key = event->type & (EVENT_HASHSIZE - 1);
771
772         hlist_add_head(&event->node, &event_hash[key]);
773
774         ret = event->type;
775  out:
776         up_write(&trace_event_sem);
777
778         return ret;
779 }
780 EXPORT_SYMBOL_GPL(register_trace_event);
781
782 /*
783  * Used by module code with the trace_event_sem held for write.
784  */
785 int __unregister_trace_event(struct trace_event *event)
786 {
787         hlist_del(&event->node);
788         list_del(&event->list);
789         return 0;
790 }
791
792 /**
793  * unregister_trace_event - remove a no longer used event
794  * @event: the event to remove
795  */
796 int unregister_trace_event(struct trace_event *event)
797 {
798         down_write(&trace_event_sem);
799         __unregister_trace_event(event);
800         up_write(&trace_event_sem);
801
802         return 0;
803 }
804 EXPORT_SYMBOL_GPL(unregister_trace_event);
805
806 /*
807  * Standard events
808  */
809
810 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
811                                   struct trace_event *event)
812 {
813         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
814
815         return trace_handle_return(&iter->seq);
816 }
817
818 /* TRACE_FN */
819 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
820                                         struct trace_event *event)
821 {
822         struct ftrace_entry *field;
823         struct trace_seq *s = &iter->seq;
824
825         trace_assign_type(field, iter->ent);
826
827         seq_print_ip_sym(s, field->ip, flags);
828
829         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
830                 trace_seq_puts(s, " <-");
831                 seq_print_ip_sym(s, field->parent_ip, flags);
832         }
833
834         trace_seq_putc(s, '\n');
835
836         return trace_handle_return(s);
837 }
838
839 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
840                                       struct trace_event *event)
841 {
842         struct ftrace_entry *field;
843
844         trace_assign_type(field, iter->ent);
845
846         trace_seq_printf(&iter->seq, "%lx %lx\n",
847                          field->ip,
848                          field->parent_ip);
849
850         return trace_handle_return(&iter->seq);
851 }
852
853 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
854                                       struct trace_event *event)
855 {
856         struct ftrace_entry *field;
857         struct trace_seq *s = &iter->seq;
858
859         trace_assign_type(field, iter->ent);
860
861         SEQ_PUT_HEX_FIELD(s, field->ip);
862         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
863
864         return trace_handle_return(s);
865 }
866
867 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
868                                       struct trace_event *event)
869 {
870         struct ftrace_entry *field;
871         struct trace_seq *s = &iter->seq;
872
873         trace_assign_type(field, iter->ent);
874
875         SEQ_PUT_FIELD(s, field->ip);
876         SEQ_PUT_FIELD(s, field->parent_ip);
877
878         return trace_handle_return(s);
879 }
880
881 static struct trace_event_functions trace_fn_funcs = {
882         .trace          = trace_fn_trace,
883         .raw            = trace_fn_raw,
884         .hex            = trace_fn_hex,
885         .binary         = trace_fn_bin,
886 };
887
888 static struct trace_event trace_fn_event = {
889         .type           = TRACE_FN,
890         .funcs          = &trace_fn_funcs,
891 };
892
893 /* TRACE_CTX an TRACE_WAKE */
894 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
895                                              char *delim)
896 {
897         struct ctx_switch_entry *field;
898         char comm[TASK_COMM_LEN];
899         int S, T;
900
901
902         trace_assign_type(field, iter->ent);
903
904         T = task_index_to_char(field->next_state);
905         S = task_index_to_char(field->prev_state);
906         trace_find_cmdline(field->next_pid, comm);
907         trace_seq_printf(&iter->seq,
908                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
909                          field->prev_pid,
910                          field->prev_prio,
911                          S, delim,
912                          field->next_cpu,
913                          field->next_pid,
914                          field->next_prio,
915                          T, comm);
916
917         return trace_handle_return(&iter->seq);
918 }
919
920 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
921                                          struct trace_event *event)
922 {
923         return trace_ctxwake_print(iter, "==>");
924 }
925
926 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
927                                           int flags, struct trace_event *event)
928 {
929         return trace_ctxwake_print(iter, "  +");
930 }
931
932 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
933 {
934         struct ctx_switch_entry *field;
935         int T;
936
937         trace_assign_type(field, iter->ent);
938
939         if (!S)
940                 S = task_index_to_char(field->prev_state);
941         T = task_index_to_char(field->next_state);
942         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
943                          field->prev_pid,
944                          field->prev_prio,
945                          S,
946                          field->next_cpu,
947                          field->next_pid,
948                          field->next_prio,
949                          T);
950
951         return trace_handle_return(&iter->seq);
952 }
953
954 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
955                                        struct trace_event *event)
956 {
957         return trace_ctxwake_raw(iter, 0);
958 }
959
960 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
961                                         struct trace_event *event)
962 {
963         return trace_ctxwake_raw(iter, '+');
964 }
965
966
967 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
968 {
969         struct ctx_switch_entry *field;
970         struct trace_seq *s = &iter->seq;
971         int T;
972
973         trace_assign_type(field, iter->ent);
974
975         if (!S)
976                 S = task_index_to_char(field->prev_state);
977         T = task_index_to_char(field->next_state);
978
979         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
980         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
981         SEQ_PUT_HEX_FIELD(s, S);
982         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
983         SEQ_PUT_HEX_FIELD(s, field->next_pid);
984         SEQ_PUT_HEX_FIELD(s, field->next_prio);
985         SEQ_PUT_HEX_FIELD(s, T);
986
987         return trace_handle_return(s);
988 }
989
990 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
991                                        struct trace_event *event)
992 {
993         return trace_ctxwake_hex(iter, 0);
994 }
995
996 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
997                                         struct trace_event *event)
998 {
999         return trace_ctxwake_hex(iter, '+');
1000 }
1001
1002 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1003                                            int flags, struct trace_event *event)
1004 {
1005         struct ctx_switch_entry *field;
1006         struct trace_seq *s = &iter->seq;
1007
1008         trace_assign_type(field, iter->ent);
1009
1010         SEQ_PUT_FIELD(s, field->prev_pid);
1011         SEQ_PUT_FIELD(s, field->prev_prio);
1012         SEQ_PUT_FIELD(s, field->prev_state);
1013         SEQ_PUT_FIELD(s, field->next_cpu);
1014         SEQ_PUT_FIELD(s, field->next_pid);
1015         SEQ_PUT_FIELD(s, field->next_prio);
1016         SEQ_PUT_FIELD(s, field->next_state);
1017
1018         return trace_handle_return(s);
1019 }
1020
1021 static struct trace_event_functions trace_ctx_funcs = {
1022         .trace          = trace_ctx_print,
1023         .raw            = trace_ctx_raw,
1024         .hex            = trace_ctx_hex,
1025         .binary         = trace_ctxwake_bin,
1026 };
1027
1028 static struct trace_event trace_ctx_event = {
1029         .type           = TRACE_CTX,
1030         .funcs          = &trace_ctx_funcs,
1031 };
1032
1033 static struct trace_event_functions trace_wake_funcs = {
1034         .trace          = trace_wake_print,
1035         .raw            = trace_wake_raw,
1036         .hex            = trace_wake_hex,
1037         .binary         = trace_ctxwake_bin,
1038 };
1039
1040 static struct trace_event trace_wake_event = {
1041         .type           = TRACE_WAKE,
1042         .funcs          = &trace_wake_funcs,
1043 };
1044
1045 /* TRACE_STACK */
1046
1047 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1048                                            int flags, struct trace_event *event)
1049 {
1050         struct stack_entry *field;
1051         struct trace_seq *s = &iter->seq;
1052         unsigned long *p;
1053         unsigned long *end;
1054
1055         trace_assign_type(field, iter->ent);
1056         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1057
1058         trace_seq_puts(s, "<stack trace>\n");
1059
1060         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1061
1062                 if (trace_seq_has_overflowed(s))
1063                         break;
1064
1065                 trace_seq_puts(s, " => ");
1066                 seq_print_ip_sym(s, *p, flags);
1067                 trace_seq_putc(s, '\n');
1068         }
1069
1070         return trace_handle_return(s);
1071 }
1072
1073 static struct trace_event_functions trace_stack_funcs = {
1074         .trace          = trace_stack_print,
1075 };
1076
1077 static struct trace_event trace_stack_event = {
1078         .type           = TRACE_STACK,
1079         .funcs          = &trace_stack_funcs,
1080 };
1081
1082 /* TRACE_USER_STACK */
1083 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1084                                                 int flags, struct trace_event *event)
1085 {
1086         struct trace_array *tr = iter->tr;
1087         struct userstack_entry *field;
1088         struct trace_seq *s = &iter->seq;
1089         struct mm_struct *mm = NULL;
1090         unsigned int i;
1091
1092         trace_assign_type(field, iter->ent);
1093
1094         trace_seq_puts(s, "<user stack trace>\n");
1095
1096         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1097                 struct task_struct *task;
1098                 /*
1099                  * we do the lookup on the thread group leader,
1100                  * since individual threads might have already quit!
1101                  */
1102                 rcu_read_lock();
1103                 task = find_task_by_vpid(field->tgid);
1104                 if (task)
1105                         mm = get_task_mm(task);
1106                 rcu_read_unlock();
1107         }
1108
1109         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1110                 unsigned long ip = field->caller[i];
1111
1112                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1113                         break;
1114
1115                 trace_seq_puts(s, " => ");
1116
1117                 if (!ip) {
1118                         trace_seq_puts(s, "??");
1119                         trace_seq_putc(s, '\n');
1120                         continue;
1121                 }
1122
1123                 seq_print_user_ip(s, mm, ip, flags);
1124                 trace_seq_putc(s, '\n');
1125         }
1126
1127         if (mm)
1128                 mmput(mm);
1129
1130         return trace_handle_return(s);
1131 }
1132
1133 static struct trace_event_functions trace_user_stack_funcs = {
1134         .trace          = trace_user_stack_print,
1135 };
1136
1137 static struct trace_event trace_user_stack_event = {
1138         .type           = TRACE_USER_STACK,
1139         .funcs          = &trace_user_stack_funcs,
1140 };
1141
1142 /* TRACE_HWLAT */
1143 static enum print_line_t
1144 trace_hwlat_print(struct trace_iterator *iter, int flags,
1145                   struct trace_event *event)
1146 {
1147         struct trace_entry *entry = iter->ent;
1148         struct trace_seq *s = &iter->seq;
1149         struct hwlat_entry *field;
1150
1151         trace_assign_type(field, entry);
1152
1153         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1154                          field->seqnum,
1155                          field->duration,
1156                          field->outer_duration,
1157                          (long long)field->timestamp.tv_sec,
1158                          field->timestamp.tv_nsec);
1159
1160         if (field->nmi_count) {
1161                 /*
1162                  * The generic sched_clock() is not NMI safe, thus
1163                  * we only record the count and not the time.
1164                  */
1165                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1166                         trace_seq_printf(s, " nmi-total:%llu",
1167                                          field->nmi_total_ts);
1168                 trace_seq_printf(s, " nmi-count:%u",
1169                                  field->nmi_count);
1170         }
1171
1172         trace_seq_putc(s, '\n');
1173
1174         return trace_handle_return(s);
1175 }
1176
1177
1178 static enum print_line_t
1179 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1180                 struct trace_event *event)
1181 {
1182         struct hwlat_entry *field;
1183         struct trace_seq *s = &iter->seq;
1184
1185         trace_assign_type(field, iter->ent);
1186
1187         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1188                          field->duration,
1189                          field->outer_duration,
1190                          (long long)field->timestamp.tv_sec,
1191                          field->timestamp.tv_nsec,
1192                          field->seqnum);
1193
1194         return trace_handle_return(s);
1195 }
1196
1197 static struct trace_event_functions trace_hwlat_funcs = {
1198         .trace          = trace_hwlat_print,
1199         .raw            = trace_hwlat_raw,
1200 };
1201
1202 static struct trace_event trace_hwlat_event = {
1203         .type           = TRACE_HWLAT,
1204         .funcs          = &trace_hwlat_funcs,
1205 };
1206
1207 /* TRACE_BPUTS */
1208 static enum print_line_t
1209 trace_bputs_print(struct trace_iterator *iter, int flags,
1210                    struct trace_event *event)
1211 {
1212         struct trace_entry *entry = iter->ent;
1213         struct trace_seq *s = &iter->seq;
1214         struct bputs_entry *field;
1215
1216         trace_assign_type(field, entry);
1217
1218         seq_print_ip_sym(s, field->ip, flags);
1219         trace_seq_puts(s, ": ");
1220         trace_seq_puts(s, field->str);
1221
1222         return trace_handle_return(s);
1223 }
1224
1225
1226 static enum print_line_t
1227 trace_bputs_raw(struct trace_iterator *iter, int flags,
1228                 struct trace_event *event)
1229 {
1230         struct bputs_entry *field;
1231         struct trace_seq *s = &iter->seq;
1232
1233         trace_assign_type(field, iter->ent);
1234
1235         trace_seq_printf(s, ": %lx : ", field->ip);
1236         trace_seq_puts(s, field->str);
1237
1238         return trace_handle_return(s);
1239 }
1240
1241 static struct trace_event_functions trace_bputs_funcs = {
1242         .trace          = trace_bputs_print,
1243         .raw            = trace_bputs_raw,
1244 };
1245
1246 static struct trace_event trace_bputs_event = {
1247         .type           = TRACE_BPUTS,
1248         .funcs          = &trace_bputs_funcs,
1249 };
1250
1251 /* TRACE_BPRINT */
1252 static enum print_line_t
1253 trace_bprint_print(struct trace_iterator *iter, int flags,
1254                    struct trace_event *event)
1255 {
1256         struct trace_entry *entry = iter->ent;
1257         struct trace_seq *s = &iter->seq;
1258         struct bprint_entry *field;
1259
1260         trace_assign_type(field, entry);
1261
1262         seq_print_ip_sym(s, field->ip, flags);
1263         trace_seq_puts(s, ": ");
1264         trace_seq_bprintf(s, field->fmt, field->buf);
1265
1266         return trace_handle_return(s);
1267 }
1268
1269
1270 static enum print_line_t
1271 trace_bprint_raw(struct trace_iterator *iter, int flags,
1272                  struct trace_event *event)
1273 {
1274         struct bprint_entry *field;
1275         struct trace_seq *s = &iter->seq;
1276
1277         trace_assign_type(field, iter->ent);
1278
1279         trace_seq_printf(s, ": %lx : ", field->ip);
1280         trace_seq_bprintf(s, field->fmt, field->buf);
1281
1282         return trace_handle_return(s);
1283 }
1284
1285 static struct trace_event_functions trace_bprint_funcs = {
1286         .trace          = trace_bprint_print,
1287         .raw            = trace_bprint_raw,
1288 };
1289
1290 static struct trace_event trace_bprint_event = {
1291         .type           = TRACE_BPRINT,
1292         .funcs          = &trace_bprint_funcs,
1293 };
1294
1295 /* TRACE_PRINT */
1296 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1297                                            int flags, struct trace_event *event)
1298 {
1299         struct print_entry *field;
1300         struct trace_seq *s = &iter->seq;
1301
1302         trace_assign_type(field, iter->ent);
1303
1304         seq_print_ip_sym(s, field->ip, flags);
1305         trace_seq_printf(s, ": %s", field->buf);
1306
1307         return trace_handle_return(s);
1308 }
1309
1310 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1311                                          struct trace_event *event)
1312 {
1313         struct print_entry *field;
1314
1315         trace_assign_type(field, iter->ent);
1316
1317         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1318
1319         return trace_handle_return(&iter->seq);
1320 }
1321
1322 static struct trace_event_functions trace_print_funcs = {
1323         .trace          = trace_print_print,
1324         .raw            = trace_print_raw,
1325 };
1326
1327 static struct trace_event trace_print_event = {
1328         .type           = TRACE_PRINT,
1329         .funcs          = &trace_print_funcs,
1330 };
1331
1332 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1333                                          struct trace_event *event)
1334 {
1335         struct raw_data_entry *field;
1336         int i;
1337
1338         trace_assign_type(field, iter->ent);
1339
1340         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1341
1342         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1343                 trace_seq_printf(&iter->seq, " %02x",
1344                                  (unsigned char)field->buf[i]);
1345
1346         trace_seq_putc(&iter->seq, '\n');
1347
1348         return trace_handle_return(&iter->seq);
1349 }
1350
1351 static struct trace_event_functions trace_raw_data_funcs = {
1352         .trace          = trace_raw_data,
1353         .raw            = trace_raw_data,
1354 };
1355
1356 static struct trace_event trace_raw_data_event = {
1357         .type           = TRACE_RAW_DATA,
1358         .funcs          = &trace_raw_data_funcs,
1359 };
1360
1361
1362 static struct trace_event *events[] __initdata = {
1363         &trace_fn_event,
1364         &trace_ctx_event,
1365         &trace_wake_event,
1366         &trace_stack_event,
1367         &trace_user_stack_event,
1368         &trace_bputs_event,
1369         &trace_bprint_event,
1370         &trace_print_event,
1371         &trace_hwlat_event,
1372         &trace_raw_data_event,
1373         NULL
1374 };
1375
1376 __init static int init_events(void)
1377 {
1378         struct trace_event *event;
1379         int i, ret;
1380
1381         for (i = 0; events[i]; i++) {
1382                 event = events[i];
1383
1384                 ret = register_trace_event(event);
1385                 if (!ret) {
1386                         printk(KERN_WARNING "event %d failed to register\n",
1387                                event->type);
1388                         WARN_ON_ONCE(1);
1389                 }
1390         }
1391
1392         return 0;
1393 }
1394 early_initcall(init_events);