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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * trace_events_synth - synthetic trace events
4 *
5 * Copyright (C) 2015, 2020 Tom Zanussi <tom.zanussi@linux.intel.com>
6 */
7
8#include <linux/module.h>
9#include <linux/kallsyms.h>
10#include <linux/security.h>
11#include <linux/mutex.h>
12#include <linux/slab.h>
13#include <linux/stacktrace.h>
14#include <linux/rculist.h>
15#include <linux/tracefs.h>
16
17/* for gfp flag names */
18#include <linux/trace_events.h>
19#include <trace/events/mmflags.h>
20
21#include "trace_synth.h"
22
23#undef ERRORS
24#define ERRORS \
25 C(BAD_NAME, "Illegal name"), \
26 C(INVALID_CMD, "Command must be of the form: <name> field[;field] ..."),\
27 C(INVALID_DYN_CMD, "Command must be of the form: s or -:[synthetic/]<name> field[;field] ..."),\
28 C(EVENT_EXISTS, "Event already exists"), \
29 C(TOO_MANY_FIELDS, "Too many fields"), \
30 C(INCOMPLETE_TYPE, "Incomplete type"), \
31 C(INVALID_TYPE, "Invalid type"), \
32 C(INVALID_FIELD, "Invalid field"), \
33 C(INVALID_ARRAY_SPEC, "Invalid array specification"),
34
35#undef C
36#define C(a, b) SYNTH_ERR_##a
37
38enum { ERRORS };
39
40#undef C
41#define C(a, b) b
42
43static const char *err_text[] = { ERRORS };
44
45static char last_cmd[MAX_FILTER_STR_VAL];
46
47static int errpos(const char *str)
48{
49 return err_pos(last_cmd, str);
50}
51
52static void last_cmd_set(const char *str)
53{
54 if (!str)
55 return;
56
57 strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
58}
59
60static void synth_err(u8 err_type, u8 err_pos)
61{
62 tracing_log_err(NULL, "synthetic_events", last_cmd, err_text,
63 err_type, err_pos);
64}
65
66static int create_synth_event(const char *raw_command);
67static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
68static int synth_event_release(struct dyn_event *ev);
69static bool synth_event_is_busy(struct dyn_event *ev);
70static bool synth_event_match(const char *system, const char *event,
71 int argc, const char **argv, struct dyn_event *ev);
72
73static struct dyn_event_operations synth_event_ops = {
74 .create = create_synth_event,
75 .show = synth_event_show,
76 .is_busy = synth_event_is_busy,
77 .free = synth_event_release,
78 .match = synth_event_match,
79};
80
81static bool is_synth_event(struct dyn_event *ev)
82{
83 return ev->ops == &synth_event_ops;
84}
85
86static struct synth_event *to_synth_event(struct dyn_event *ev)
87{
88 return container_of(ev, struct synth_event, devent);
89}
90
91static bool synth_event_is_busy(struct dyn_event *ev)
92{
93 struct synth_event *event = to_synth_event(ev);
94
95 return event->ref != 0;
96}
97
98static bool synth_event_match(const char *system, const char *event,
99 int argc, const char **argv, struct dyn_event *ev)
100{
101 struct synth_event *sev = to_synth_event(ev);
102
103 return strcmp(sev->name, event) == 0 &&
104 (!system || strcmp(system, SYNTH_SYSTEM) == 0);
105}
106
107struct synth_trace_event {
108 struct trace_entry ent;
109 u64 fields[];
110};
111
112static int synth_event_define_fields(struct trace_event_call *call)
113{
114 struct synth_trace_event trace;
115 int offset = offsetof(typeof(trace), fields);
116 struct synth_event *event = call->data;
117 unsigned int i, size, n_u64;
118 char *name, *type;
119 bool is_signed;
120 int ret = 0;
121
122 for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
123 size = event->fields[i]->size;
124 is_signed = event->fields[i]->is_signed;
125 type = event->fields[i]->type;
126 name = event->fields[i]->name;
127 ret = trace_define_field(call, type, name, offset, size,
128 is_signed, FILTER_OTHER);
129 if (ret)
130 break;
131
132 event->fields[i]->offset = n_u64;
133
134 if (event->fields[i]->is_string && !event->fields[i]->is_dynamic) {
135 offset += STR_VAR_LEN_MAX;
136 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
137 } else {
138 offset += sizeof(u64);
139 n_u64++;
140 }
141 }
142
143 event->n_u64 = n_u64;
144
145 return ret;
146}
147
148static bool synth_field_signed(char *type)
149{
150 if (str_has_prefix(type, "u"))
151 return false;
152 if (strcmp(type, "gfp_t") == 0)
153 return false;
154
155 return true;
156}
157
158static int synth_field_is_string(char *type)
159{
160 if (strstr(type, "char[") != NULL)
161 return true;
162
163 return false;
164}
165
166static int synth_field_string_size(char *type)
167{
168 char buf[4], *end, *start;
169 unsigned int len;
170 int size, err;
171
172 start = strstr(type, "char[");
173 if (start == NULL)
174 return -EINVAL;
175 start += sizeof("char[") - 1;
176
177 end = strchr(type, ']');
178 if (!end || end < start || type + strlen(type) > end + 1)
179 return -EINVAL;
180
181 len = end - start;
182 if (len > 3)
183 return -EINVAL;
184
185 if (len == 0)
186 return 0; /* variable-length string */
187
188 strncpy(buf, start, len);
189 buf[len] = '\0';
190
191 err = kstrtouint(buf, 0, &size);
192 if (err)
193 return err;
194
195 if (size > STR_VAR_LEN_MAX)
196 return -EINVAL;
197
198 return size;
199}
200
201static int synth_field_size(char *type)
202{
203 int size = 0;
204
205 if (strcmp(type, "s64") == 0)
206 size = sizeof(s64);
207 else if (strcmp(type, "u64") == 0)
208 size = sizeof(u64);
209 else if (strcmp(type, "s32") == 0)
210 size = sizeof(s32);
211 else if (strcmp(type, "u32") == 0)
212 size = sizeof(u32);
213 else if (strcmp(type, "s16") == 0)
214 size = sizeof(s16);
215 else if (strcmp(type, "u16") == 0)
216 size = sizeof(u16);
217 else if (strcmp(type, "s8") == 0)
218 size = sizeof(s8);
219 else if (strcmp(type, "u8") == 0)
220 size = sizeof(u8);
221 else if (strcmp(type, "char") == 0)
222 size = sizeof(char);
223 else if (strcmp(type, "unsigned char") == 0)
224 size = sizeof(unsigned char);
225 else if (strcmp(type, "int") == 0)
226 size = sizeof(int);
227 else if (strcmp(type, "unsigned int") == 0)
228 size = sizeof(unsigned int);
229 else if (strcmp(type, "long") == 0)
230 size = sizeof(long);
231 else if (strcmp(type, "unsigned long") == 0)
232 size = sizeof(unsigned long);
233 else if (strcmp(type, "bool") == 0)
234 size = sizeof(bool);
235 else if (strcmp(type, "pid_t") == 0)
236 size = sizeof(pid_t);
237 else if (strcmp(type, "gfp_t") == 0)
238 size = sizeof(gfp_t);
239 else if (synth_field_is_string(type))
240 size = synth_field_string_size(type);
241
242 return size;
243}
244
245static const char *synth_field_fmt(char *type)
246{
247 const char *fmt = "%llu";
248
249 if (strcmp(type, "s64") == 0)
250 fmt = "%lld";
251 else if (strcmp(type, "u64") == 0)
252 fmt = "%llu";
253 else if (strcmp(type, "s32") == 0)
254 fmt = "%d";
255 else if (strcmp(type, "u32") == 0)
256 fmt = "%u";
257 else if (strcmp(type, "s16") == 0)
258 fmt = "%d";
259 else if (strcmp(type, "u16") == 0)
260 fmt = "%u";
261 else if (strcmp(type, "s8") == 0)
262 fmt = "%d";
263 else if (strcmp(type, "u8") == 0)
264 fmt = "%u";
265 else if (strcmp(type, "char") == 0)
266 fmt = "%d";
267 else if (strcmp(type, "unsigned char") == 0)
268 fmt = "%u";
269 else if (strcmp(type, "int") == 0)
270 fmt = "%d";
271 else if (strcmp(type, "unsigned int") == 0)
272 fmt = "%u";
273 else if (strcmp(type, "long") == 0)
274 fmt = "%ld";
275 else if (strcmp(type, "unsigned long") == 0)
276 fmt = "%lu";
277 else if (strcmp(type, "bool") == 0)
278 fmt = "%d";
279 else if (strcmp(type, "pid_t") == 0)
280 fmt = "%d";
281 else if (strcmp(type, "gfp_t") == 0)
282 fmt = "%x";
283 else if (synth_field_is_string(type))
284 fmt = "%.*s";
285
286 return fmt;
287}
288
289static void print_synth_event_num_val(struct trace_seq *s,
290 char *print_fmt, char *name,
291 int size, u64 val, char *space)
292{
293 switch (size) {
294 case 1:
295 trace_seq_printf(s, print_fmt, name, (u8)val, space);
296 break;
297
298 case 2:
299 trace_seq_printf(s, print_fmt, name, (u16)val, space);
300 break;
301
302 case 4:
303 trace_seq_printf(s, print_fmt, name, (u32)val, space);
304 break;
305
306 default:
307 trace_seq_printf(s, print_fmt, name, val, space);
308 break;
309 }
310}
311
312static enum print_line_t print_synth_event(struct trace_iterator *iter,
313 int flags,
314 struct trace_event *event)
315{
316 struct trace_array *tr = iter->tr;
317 struct trace_seq *s = &iter->seq;
318 struct synth_trace_event *entry;
319 struct synth_event *se;
320 unsigned int i, n_u64;
321 char print_fmt[32];
322 const char *fmt;
323
324 entry = (struct synth_trace_event *)iter->ent;
325 se = container_of(event, struct synth_event, call.event);
326
327 trace_seq_printf(s, "%s: ", se->name);
328
329 for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
330 if (trace_seq_has_overflowed(s))
331 goto end;
332
333 fmt = synth_field_fmt(se->fields[i]->type);
334
335 /* parameter types */
336 if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
337 trace_seq_printf(s, "%s ", fmt);
338
339 snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
340
341 /* parameter values */
342 if (se->fields[i]->is_string) {
343 if (se->fields[i]->is_dynamic) {
344 u32 offset, data_offset;
345 char *str_field;
346
347 offset = (u32)entry->fields[n_u64];
348 data_offset = offset & 0xffff;
349
350 str_field = (char *)entry + data_offset;
351
352 trace_seq_printf(s, print_fmt, se->fields[i]->name,
353 STR_VAR_LEN_MAX,
354 str_field,
355 i == se->n_fields - 1 ? "" : " ");
356 n_u64++;
357 } else {
358 trace_seq_printf(s, print_fmt, se->fields[i]->name,
359 STR_VAR_LEN_MAX,
360 (char *)&entry->fields[n_u64],
361 i == se->n_fields - 1 ? "" : " ");
362 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
363 }
364 } else {
365 struct trace_print_flags __flags[] = {
366 __def_gfpflag_names, {-1, NULL} };
367 char *space = (i == se->n_fields - 1 ? "" : " ");
368
369 print_synth_event_num_val(s, print_fmt,
370 se->fields[i]->name,
371 se->fields[i]->size,
372 entry->fields[n_u64],
373 space);
374
375 if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
376 trace_seq_puts(s, " (");
377 trace_print_flags_seq(s, "|",
378 entry->fields[n_u64],
379 __flags);
380 trace_seq_putc(s, ')');
381 }
382 n_u64++;
383 }
384 }
385end:
386 trace_seq_putc(s, '\n');
387
388 return trace_handle_return(s);
389}
390
391static struct trace_event_functions synth_event_funcs = {
392 .trace = print_synth_event
393};
394
395static unsigned int trace_string(struct synth_trace_event *entry,
396 struct synth_event *event,
397 char *str_val,
398 bool is_dynamic,
399 unsigned int data_size,
400 unsigned int *n_u64)
401{
402 unsigned int len = 0;
403 char *str_field;
404
405 if (is_dynamic) {
406 u32 data_offset;
407
408 data_offset = offsetof(typeof(*entry), fields);
409 data_offset += event->n_u64 * sizeof(u64);
410 data_offset += data_size;
411
412 str_field = (char *)entry + data_offset;
413
414 len = strlen(str_val) + 1;
415 strscpy(str_field, str_val, len);
416
417 data_offset |= len << 16;
418 *(u32 *)&entry->fields[*n_u64] = data_offset;
419
420 (*n_u64)++;
421 } else {
422 str_field = (char *)&entry->fields[*n_u64];
423
424 strscpy(str_field, str_val, STR_VAR_LEN_MAX);
425 (*n_u64) += STR_VAR_LEN_MAX / sizeof(u64);
426 }
427
428 return len;
429}
430
431static notrace void trace_event_raw_event_synth(void *__data,
432 u64 *var_ref_vals,
433 unsigned int *var_ref_idx)
434{
435 unsigned int i, n_u64, val_idx, len, data_size = 0;
436 struct trace_event_file *trace_file = __data;
437 struct synth_trace_event *entry;
438 struct trace_event_buffer fbuffer;
439 struct trace_buffer *buffer;
440 struct synth_event *event;
441 int fields_size = 0;
442
443 event = trace_file->event_call->data;
444
445 if (trace_trigger_soft_disabled(trace_file))
446 return;
447
448 fields_size = event->n_u64 * sizeof(u64);
449
450 for (i = 0; i < event->n_dynamic_fields; i++) {
451 unsigned int field_pos = event->dynamic_fields[i]->field_pos;
452 char *str_val;
453
454 val_idx = var_ref_idx[field_pos];
455 str_val = (char *)(long)var_ref_vals[val_idx];
456
457 len = strlen(str_val) + 1;
458
459 fields_size += len;
460 }
461
462 /*
463 * Avoid ring buffer recursion detection, as this event
464 * is being performed within another event.
465 */
466 buffer = trace_file->tr->array_buffer.buffer;
467 ring_buffer_nest_start(buffer);
468
469 entry = trace_event_buffer_reserve(&fbuffer, trace_file,
470 sizeof(*entry) + fields_size);
471 if (!entry)
472 goto out;
473
474 for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
475 val_idx = var_ref_idx[i];
476 if (event->fields[i]->is_string) {
477 char *str_val = (char *)(long)var_ref_vals[val_idx];
478
479 len = trace_string(entry, event, str_val,
480 event->fields[i]->is_dynamic,
481 data_size, &n_u64);
482 data_size += len; /* only dynamic string increments */
483 } else {
484 struct synth_field *field = event->fields[i];
485 u64 val = var_ref_vals[val_idx];
486
487 switch (field->size) {
488 case 1:
489 *(u8 *)&entry->fields[n_u64] = (u8)val;
490 break;
491
492 case 2:
493 *(u16 *)&entry->fields[n_u64] = (u16)val;
494 break;
495
496 case 4:
497 *(u32 *)&entry->fields[n_u64] = (u32)val;
498 break;
499
500 default:
501 entry->fields[n_u64] = val;
502 break;
503 }
504 n_u64++;
505 }
506 }
507
508 trace_event_buffer_commit(&fbuffer);
509out:
510 ring_buffer_nest_end(buffer);
511}
512
513static void free_synth_event_print_fmt(struct trace_event_call *call)
514{
515 if (call) {
516 kfree(call->print_fmt);
517 call->print_fmt = NULL;
518 }
519}
520
521static int __set_synth_event_print_fmt(struct synth_event *event,
522 char *buf, int len)
523{
524 const char *fmt;
525 int pos = 0;
526 int i;
527
528 /* When len=0, we just calculate the needed length */
529#define LEN_OR_ZERO (len ? len - pos : 0)
530
531 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
532 for (i = 0; i < event->n_fields; i++) {
533 fmt = synth_field_fmt(event->fields[i]->type);
534 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
535 event->fields[i]->name, fmt,
536 i == event->n_fields - 1 ? "" : ", ");
537 }
538 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
539
540 for (i = 0; i < event->n_fields; i++) {
541 if (event->fields[i]->is_string &&
542 event->fields[i]->is_dynamic)
543 pos += snprintf(buf + pos, LEN_OR_ZERO,
544 ", __get_str(%s)", event->fields[i]->name);
545 else
546 pos += snprintf(buf + pos, LEN_OR_ZERO,
547 ", REC->%s", event->fields[i]->name);
548 }
549
550#undef LEN_OR_ZERO
551
552 /* return the length of print_fmt */
553 return pos;
554}
555
556static int set_synth_event_print_fmt(struct trace_event_call *call)
557{
558 struct synth_event *event = call->data;
559 char *print_fmt;
560 int len;
561
562 /* First: called with 0 length to calculate the needed length */
563 len = __set_synth_event_print_fmt(event, NULL, 0);
564
565 print_fmt = kmalloc(len + 1, GFP_KERNEL);
566 if (!print_fmt)
567 return -ENOMEM;
568
569 /* Second: actually write the @print_fmt */
570 __set_synth_event_print_fmt(event, print_fmt, len + 1);
571 call->print_fmt = print_fmt;
572
573 return 0;
574}
575
576static void free_synth_field(struct synth_field *field)
577{
578 kfree(field->type);
579 kfree(field->name);
580 kfree(field);
581}
582
583static int check_field_version(const char *prefix, const char *field_type,
584 const char *field_name)
585{
586 /*
587 * For backward compatibility, the old synthetic event command
588 * format did not require semicolons, and in order to not
589 * break user space, that old format must still work. If a new
590 * feature is added, then the format that uses the new feature
591 * will be required to have semicolons, as nothing that uses
592 * the old format would be using the new, yet to be created,
593 * feature. When a new feature is added, this will detect it,
594 * and return a number greater than 1, and require the format
595 * to use semicolons.
596 */
597 return 1;
598}
599
600static struct synth_field *parse_synth_field(int argc, char **argv,
601 int *consumed, int *field_version)
602{
603 const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
604 struct synth_field *field;
605 int len, ret = -ENOMEM;
606 struct seq_buf s;
607 ssize_t size;
608
609 if (!strcmp(field_type, "unsigned")) {
610 if (argc < 3) {
611 synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type));
612 return ERR_PTR(-EINVAL);
613 }
614 prefix = "unsigned ";
615 field_type = argv[1];
616 field_name = argv[2];
617 *consumed += 3;
618 } else {
619 field_name = argv[1];
620 *consumed += 2;
621 }
622
623 if (!field_name) {
624 synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type));
625 return ERR_PTR(-EINVAL);
626 }
627
628 *field_version = check_field_version(prefix, field_type, field_name);
629
630 field = kzalloc(sizeof(*field), GFP_KERNEL);
631 if (!field)
632 return ERR_PTR(-ENOMEM);
633
634 len = strlen(field_name);
635 array = strchr(field_name, '[');
636 if (array)
637 len -= strlen(array);
638
639 field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
640 if (!field->name)
641 goto free;
642
643 if (!is_good_name(field->name)) {
644 synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name));
645 ret = -EINVAL;
646 goto free;
647 }
648
649 len = strlen(field_type) + 1;
650
651 if (array)
652 len += strlen(array);
653
654 if (prefix)
655 len += strlen(prefix);
656
657 field->type = kzalloc(len, GFP_KERNEL);
658 if (!field->type)
659 goto free;
660
661 seq_buf_init(&s, field->type, len);
662 if (prefix)
663 seq_buf_puts(&s, prefix);
664 seq_buf_puts(&s, field_type);
665 if (array)
666 seq_buf_puts(&s, array);
667 if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
668 goto free;
669
670 s.buffer[s.len] = '\0';
671
672 size = synth_field_size(field->type);
673 if (size < 0) {
674 if (array)
675 synth_err(SYNTH_ERR_INVALID_ARRAY_SPEC, errpos(field_name));
676 else
677 synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
678 ret = -EINVAL;
679 goto free;
680 } else if (size == 0) {
681 if (synth_field_is_string(field->type)) {
682 char *type;
683
684 len = sizeof("__data_loc ") + strlen(field->type) + 1;
685 type = kzalloc(len, GFP_KERNEL);
686 if (!type)
687 goto free;
688
689 seq_buf_init(&s, type, len);
690 seq_buf_puts(&s, "__data_loc ");
691 seq_buf_puts(&s, field->type);
692
693 if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
694 goto free;
695 s.buffer[s.len] = '\0';
696
697 kfree(field->type);
698 field->type = type;
699
700 field->is_dynamic = true;
701 size = sizeof(u64);
702 } else {
703 synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
704 ret = -EINVAL;
705 goto free;
706 }
707 }
708 field->size = size;
709
710 if (synth_field_is_string(field->type))
711 field->is_string = true;
712
713 field->is_signed = synth_field_signed(field->type);
714 out:
715 return field;
716 free:
717 free_synth_field(field);
718 field = ERR_PTR(ret);
719 goto out;
720}
721
722static void free_synth_tracepoint(struct tracepoint *tp)
723{
724 if (!tp)
725 return;
726
727 kfree(tp->name);
728 kfree(tp);
729}
730
731static struct tracepoint *alloc_synth_tracepoint(char *name)
732{
733 struct tracepoint *tp;
734
735 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
736 if (!tp)
737 return ERR_PTR(-ENOMEM);
738
739 tp->name = kstrdup(name, GFP_KERNEL);
740 if (!tp->name) {
741 kfree(tp);
742 return ERR_PTR(-ENOMEM);
743 }
744
745 return tp;
746}
747
748struct synth_event *find_synth_event(const char *name)
749{
750 struct dyn_event *pos;
751 struct synth_event *event;
752
753 for_each_dyn_event(pos) {
754 if (!is_synth_event(pos))
755 continue;
756 event = to_synth_event(pos);
757 if (strcmp(event->name, name) == 0)
758 return event;
759 }
760
761 return NULL;
762}
763
764static struct trace_event_fields synth_event_fields_array[] = {
765 { .type = TRACE_FUNCTION_TYPE,
766 .define_fields = synth_event_define_fields },
767 {}
768};
769
770static int register_synth_event(struct synth_event *event)
771{
772 struct trace_event_call *call = &event->call;
773 int ret = 0;
774
775 event->call.class = &event->class;
776 event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
777 if (!event->class.system) {
778 ret = -ENOMEM;
779 goto out;
780 }
781
782 event->tp = alloc_synth_tracepoint(event->name);
783 if (IS_ERR(event->tp)) {
784 ret = PTR_ERR(event->tp);
785 event->tp = NULL;
786 goto out;
787 }
788
789 INIT_LIST_HEAD(&call->class->fields);
790 call->event.funcs = &synth_event_funcs;
791 call->class->fields_array = synth_event_fields_array;
792
793 ret = register_trace_event(&call->event);
794 if (!ret) {
795 ret = -ENODEV;
796 goto out;
797 }
798 call->flags = TRACE_EVENT_FL_TRACEPOINT;
799 call->class->reg = trace_event_reg;
800 call->class->probe = trace_event_raw_event_synth;
801 call->data = event;
802 call->tp = event->tp;
803
804 ret = trace_add_event_call(call);
805 if (ret) {
806 pr_warn("Failed to register synthetic event: %s\n",
807 trace_event_name(call));
808 goto err;
809 }
810
811 ret = set_synth_event_print_fmt(call);
812 if (ret < 0) {
813 trace_remove_event_call(call);
814 goto err;
815 }
816 out:
817 return ret;
818 err:
819 unregister_trace_event(&call->event);
820 goto out;
821}
822
823static int unregister_synth_event(struct synth_event *event)
824{
825 struct trace_event_call *call = &event->call;
826 int ret;
827
828 ret = trace_remove_event_call(call);
829
830 return ret;
831}
832
833static void free_synth_event(struct synth_event *event)
834{
835 unsigned int i;
836
837 if (!event)
838 return;
839
840 for (i = 0; i < event->n_fields; i++)
841 free_synth_field(event->fields[i]);
842
843 kfree(event->fields);
844 kfree(event->dynamic_fields);
845 kfree(event->name);
846 kfree(event->class.system);
847 free_synth_tracepoint(event->tp);
848 free_synth_event_print_fmt(&event->call);
849 kfree(event);
850}
851
852static struct synth_event *alloc_synth_event(const char *name, int n_fields,
853 struct synth_field **fields)
854{
855 unsigned int i, j, n_dynamic_fields = 0;
856 struct synth_event *event;
857
858 event = kzalloc(sizeof(*event), GFP_KERNEL);
859 if (!event) {
860 event = ERR_PTR(-ENOMEM);
861 goto out;
862 }
863
864 event->name = kstrdup(name, GFP_KERNEL);
865 if (!event->name) {
866 kfree(event);
867 event = ERR_PTR(-ENOMEM);
868 goto out;
869 }
870
871 event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
872 if (!event->fields) {
873 free_synth_event(event);
874 event = ERR_PTR(-ENOMEM);
875 goto out;
876 }
877
878 for (i = 0; i < n_fields; i++)
879 if (fields[i]->is_dynamic)
880 n_dynamic_fields++;
881
882 if (n_dynamic_fields) {
883 event->dynamic_fields = kcalloc(n_dynamic_fields,
884 sizeof(*event->dynamic_fields),
885 GFP_KERNEL);
886 if (!event->dynamic_fields) {
887 free_synth_event(event);
888 event = ERR_PTR(-ENOMEM);
889 goto out;
890 }
891 }
892
893 dyn_event_init(&event->devent, &synth_event_ops);
894
895 for (i = 0, j = 0; i < n_fields; i++) {
896 fields[i]->field_pos = i;
897 event->fields[i] = fields[i];
898
899 if (fields[i]->is_dynamic)
900 event->dynamic_fields[j++] = fields[i];
901 }
902 event->n_dynamic_fields = j;
903 event->n_fields = n_fields;
904 out:
905 return event;
906}
907
908static int synth_event_check_arg_fn(void *data)
909{
910 struct dynevent_arg_pair *arg_pair = data;
911 int size;
912
913 size = synth_field_size((char *)arg_pair->lhs);
914 if (size == 0) {
915 if (strstr((char *)arg_pair->lhs, "["))
916 return 0;
917 }
918
919 return size ? 0 : -EINVAL;
920}
921
922/**
923 * synth_event_add_field - Add a new field to a synthetic event cmd
924 * @cmd: A pointer to the dynevent_cmd struct representing the new event
925 * @type: The type of the new field to add
926 * @name: The name of the new field to add
927 *
928 * Add a new field to a synthetic event cmd object. Field ordering is in
929 * the same order the fields are added.
930 *
931 * See synth_field_size() for available types. If field_name contains
932 * [n] the field is considered to be an array.
933 *
934 * Return: 0 if successful, error otherwise.
935 */
936int synth_event_add_field(struct dynevent_cmd *cmd, const char *type,
937 const char *name)
938{
939 struct dynevent_arg_pair arg_pair;
940 int ret;
941
942 if (cmd->type != DYNEVENT_TYPE_SYNTH)
943 return -EINVAL;
944
945 if (!type || !name)
946 return -EINVAL;
947
948 dynevent_arg_pair_init(&arg_pair, 0, ';');
949
950 arg_pair.lhs = type;
951 arg_pair.rhs = name;
952
953 ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn);
954 if (ret)
955 return ret;
956
957 if (++cmd->n_fields > SYNTH_FIELDS_MAX)
958 ret = -EINVAL;
959
960 return ret;
961}
962EXPORT_SYMBOL_GPL(synth_event_add_field);
963
964/**
965 * synth_event_add_field_str - Add a new field to a synthetic event cmd
966 * @cmd: A pointer to the dynevent_cmd struct representing the new event
967 * @type_name: The type and name of the new field to add, as a single string
968 *
969 * Add a new field to a synthetic event cmd object, as a single
970 * string. The @type_name string is expected to be of the form 'type
971 * name', which will be appended by ';'. No sanity checking is done -
972 * what's passed in is assumed to already be well-formed. Field
973 * ordering is in the same order the fields are added.
974 *
975 * See synth_field_size() for available types. If field_name contains
976 * [n] the field is considered to be an array.
977 *
978 * Return: 0 if successful, error otherwise.
979 */
980int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name)
981{
982 struct dynevent_arg arg;
983 int ret;
984
985 if (cmd->type != DYNEVENT_TYPE_SYNTH)
986 return -EINVAL;
987
988 if (!type_name)
989 return -EINVAL;
990
991 dynevent_arg_init(&arg, ';');
992
993 arg.str = type_name;
994
995 ret = dynevent_arg_add(cmd, &arg, NULL);
996 if (ret)
997 return ret;
998
999 if (++cmd->n_fields > SYNTH_FIELDS_MAX)
1000 ret = -EINVAL;
1001
1002 return ret;
1003}
1004EXPORT_SYMBOL_GPL(synth_event_add_field_str);
1005
1006/**
1007 * synth_event_add_fields - Add multiple fields to a synthetic event cmd
1008 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1009 * @fields: An array of type/name field descriptions
1010 * @n_fields: The number of field descriptions contained in the fields array
1011 *
1012 * Add a new set of fields to a synthetic event cmd object. The event
1013 * fields that will be defined for the event should be passed in as an
1014 * array of struct synth_field_desc, and the number of elements in the
1015 * array passed in as n_fields. Field ordering will retain the
1016 * ordering given in the fields array.
1017 *
1018 * See synth_field_size() for available types. If field_name contains
1019 * [n] the field is considered to be an array.
1020 *
1021 * Return: 0 if successful, error otherwise.
1022 */
1023int synth_event_add_fields(struct dynevent_cmd *cmd,
1024 struct synth_field_desc *fields,
1025 unsigned int n_fields)
1026{
1027 unsigned int i;
1028 int ret = 0;
1029
1030 for (i = 0; i < n_fields; i++) {
1031 if (fields[i].type == NULL || fields[i].name == NULL) {
1032 ret = -EINVAL;
1033 break;
1034 }
1035
1036 ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
1037 if (ret)
1038 break;
1039 }
1040
1041 return ret;
1042}
1043EXPORT_SYMBOL_GPL(synth_event_add_fields);
1044
1045/**
1046 * __synth_event_gen_cmd_start - Start a synthetic event command from arg list
1047 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1048 * @name: The name of the synthetic event
1049 * @mod: The module creating the event, NULL if not created from a module
1050 * @args: Variable number of arg (pairs), one pair for each field
1051 *
1052 * NOTE: Users normally won't want to call this function directly, but
1053 * rather use the synth_event_gen_cmd_start() wrapper, which
1054 * automatically adds a NULL to the end of the arg list. If this
1055 * function is used directly, make sure the last arg in the variable
1056 * arg list is NULL.
1057 *
1058 * Generate a synthetic event command to be executed by
1059 * synth_event_gen_cmd_end(). This function can be used to generate
1060 * the complete command or only the first part of it; in the latter
1061 * case, synth_event_add_field(), synth_event_add_field_str(), or
1062 * synth_event_add_fields() can be used to add more fields following
1063 * this.
1064 *
1065 * There should be an even number variable args, each pair consisting
1066 * of a type followed by a field name.
1067 *
1068 * See synth_field_size() for available types. If field_name contains
1069 * [n] the field is considered to be an array.
1070 *
1071 * Return: 0 if successful, error otherwise.
1072 */
1073int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name,
1074 struct module *mod, ...)
1075{
1076 struct dynevent_arg arg;
1077 va_list args;
1078 int ret;
1079
1080 cmd->event_name = name;
1081 cmd->private_data = mod;
1082
1083 if (cmd->type != DYNEVENT_TYPE_SYNTH)
1084 return -EINVAL;
1085
1086 dynevent_arg_init(&arg, 0);
1087 arg.str = name;
1088 ret = dynevent_arg_add(cmd, &arg, NULL);
1089 if (ret)
1090 return ret;
1091
1092 va_start(args, mod);
1093 for (;;) {
1094 const char *type, *name;
1095
1096 type = va_arg(args, const char *);
1097 if (!type)
1098 break;
1099 name = va_arg(args, const char *);
1100 if (!name)
1101 break;
1102
1103 if (++cmd->n_fields > SYNTH_FIELDS_MAX) {
1104 ret = -EINVAL;
1105 break;
1106 }
1107
1108 ret = synth_event_add_field(cmd, type, name);
1109 if (ret)
1110 break;
1111 }
1112 va_end(args);
1113
1114 return ret;
1115}
1116EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
1117
1118/**
1119 * synth_event_gen_cmd_array_start - Start synthetic event command from an array
1120 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1121 * @name: The name of the synthetic event
1122 * @fields: An array of type/name field descriptions
1123 * @n_fields: The number of field descriptions contained in the fields array
1124 *
1125 * Generate a synthetic event command to be executed by
1126 * synth_event_gen_cmd_end(). This function can be used to generate
1127 * the complete command or only the first part of it; in the latter
1128 * case, synth_event_add_field(), synth_event_add_field_str(), or
1129 * synth_event_add_fields() can be used to add more fields following
1130 * this.
1131 *
1132 * The event fields that will be defined for the event should be
1133 * passed in as an array of struct synth_field_desc, and the number of
1134 * elements in the array passed in as n_fields. Field ordering will
1135 * retain the ordering given in the fields array.
1136 *
1137 * See synth_field_size() for available types. If field_name contains
1138 * [n] the field is considered to be an array.
1139 *
1140 * Return: 0 if successful, error otherwise.
1141 */
1142int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name,
1143 struct module *mod,
1144 struct synth_field_desc *fields,
1145 unsigned int n_fields)
1146{
1147 struct dynevent_arg arg;
1148 unsigned int i;
1149 int ret = 0;
1150
1151 cmd->event_name = name;
1152 cmd->private_data = mod;
1153
1154 if (cmd->type != DYNEVENT_TYPE_SYNTH)
1155 return -EINVAL;
1156
1157 if (n_fields > SYNTH_FIELDS_MAX)
1158 return -EINVAL;
1159
1160 dynevent_arg_init(&arg, 0);
1161 arg.str = name;
1162 ret = dynevent_arg_add(cmd, &arg, NULL);
1163 if (ret)
1164 return ret;
1165
1166 for (i = 0; i < n_fields; i++) {
1167 if (fields[i].type == NULL || fields[i].name == NULL)
1168 return -EINVAL;
1169
1170 ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
1171 if (ret)
1172 break;
1173 }
1174
1175 return ret;
1176}
1177EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);
1178
1179static int __create_synth_event(const char *name, const char *raw_fields)
1180{
1181 char **argv, *field_str, *tmp_fields, *saved_fields = NULL;
1182 struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
1183 int consumed, cmd_version = 1, n_fields_this_loop;
1184 int i, argc, n_fields = 0, ret = 0;
1185 struct synth_event *event = NULL;
1186
1187 /*
1188 * Argument syntax:
1189 * - Add synthetic event: <event_name> field[;field] ...
1190 * - Remove synthetic event: !<event_name> field[;field] ...
1191 * where 'field' = type field_name
1192 */
1193
1194 if (name[0] == '\0') {
1195 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1196 return -EINVAL;
1197 }
1198
1199 if (!is_good_name(name)) {
1200 synth_err(SYNTH_ERR_BAD_NAME, errpos(name));
1201 return -EINVAL;
1202 }
1203
1204 mutex_lock(&event_mutex);
1205
1206 event = find_synth_event(name);
1207 if (event) {
1208 synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name));
1209 ret = -EEXIST;
1210 goto err;
1211 }
1212
1213 tmp_fields = saved_fields = kstrdup(raw_fields, GFP_KERNEL);
1214 if (!tmp_fields) {
1215 ret = -ENOMEM;
1216 goto err;
1217 }
1218
1219 while ((field_str = strsep(&tmp_fields, ";")) != NULL) {
1220 argv = argv_split(GFP_KERNEL, field_str, &argc);
1221 if (!argv) {
1222 ret = -ENOMEM;
1223 goto err;
1224 }
1225
1226 if (!argc) {
1227 argv_free(argv);
1228 continue;
1229 }
1230
1231 n_fields_this_loop = 0;
1232 consumed = 0;
1233 while (argc > consumed) {
1234 int field_version;
1235
1236 field = parse_synth_field(argc - consumed,
1237 argv + consumed, &consumed,
1238 &field_version);
1239 if (IS_ERR(field)) {
1240 argv_free(argv);
1241 ret = PTR_ERR(field);
1242 goto err;
1243 }
1244
1245 /*
1246 * Track the highest version of any field we
1247 * found in the command.
1248 */
1249 if (field_version > cmd_version)
1250 cmd_version = field_version;
1251
1252 /*
1253 * Now sort out what is and isn't valid for
1254 * each supported version.
1255 *
1256 * If we see more than 1 field per loop, it
1257 * means we have multiple fields between
1258 * semicolons, and that's something we no
1259 * longer support in a version 2 or greater
1260 * command.
1261 */
1262 if (cmd_version > 1 && n_fields_this_loop >= 1) {
1263 synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str));
1264 ret = -EINVAL;
1265 goto err;
1266 }
1267
1268 fields[n_fields++] = field;
1269 if (n_fields == SYNTH_FIELDS_MAX) {
1270 synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);
1271 ret = -EINVAL;
1272 goto err;
1273 }
1274
1275 n_fields_this_loop++;
1276 }
1277
1278 if (consumed < argc) {
1279 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1280 ret = -EINVAL;
1281 goto err;
1282 }
1283
1284 argv_free(argv);
1285 }
1286
1287 if (n_fields == 0) {
1288 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1289 ret = -EINVAL;
1290 goto err;
1291 }
1292
1293 event = alloc_synth_event(name, n_fields, fields);
1294 if (IS_ERR(event)) {
1295 ret = PTR_ERR(event);
1296 event = NULL;
1297 goto err;
1298 }
1299 ret = register_synth_event(event);
1300 if (!ret)
1301 dyn_event_add(&event->devent);
1302 else
1303 free_synth_event(event);
1304 out:
1305 mutex_unlock(&event_mutex);
1306
1307 kfree(saved_fields);
1308
1309 return ret;
1310 err:
1311 for (i = 0; i < n_fields; i++)
1312 free_synth_field(fields[i]);
1313
1314 goto out;
1315}
1316
1317/**
1318 * synth_event_create - Create a new synthetic event
1319 * @name: The name of the new synthetic event
1320 * @fields: An array of type/name field descriptions
1321 * @n_fields: The number of field descriptions contained in the fields array
1322 * @mod: The module creating the event, NULL if not created from a module
1323 *
1324 * Create a new synthetic event with the given name under the
1325 * trace/events/synthetic/ directory. The event fields that will be
1326 * defined for the event should be passed in as an array of struct
1327 * synth_field_desc, and the number elements in the array passed in as
1328 * n_fields. Field ordering will retain the ordering given in the
1329 * fields array.
1330 *
1331 * If the new synthetic event is being created from a module, the mod
1332 * param must be non-NULL. This will ensure that the trace buffer
1333 * won't contain unreadable events.
1334 *
1335 * The new synth event should be deleted using synth_event_delete()
1336 * function. The new synthetic event can be generated from modules or
1337 * other kernel code using trace_synth_event() and related functions.
1338 *
1339 * Return: 0 if successful, error otherwise.
1340 */
1341int synth_event_create(const char *name, struct synth_field_desc *fields,
1342 unsigned int n_fields, struct module *mod)
1343{
1344 struct dynevent_cmd cmd;
1345 char *buf;
1346 int ret;
1347
1348 buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
1349 if (!buf)
1350 return -ENOMEM;
1351
1352 synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
1353
1354 ret = synth_event_gen_cmd_array_start(&cmd, name, mod,
1355 fields, n_fields);
1356 if (ret)
1357 goto out;
1358
1359 ret = synth_event_gen_cmd_end(&cmd);
1360 out:
1361 kfree(buf);
1362
1363 return ret;
1364}
1365EXPORT_SYMBOL_GPL(synth_event_create);
1366
1367static int destroy_synth_event(struct synth_event *se)
1368{
1369 int ret;
1370
1371 if (se->ref)
1372 ret = -EBUSY;
1373 else {
1374 ret = unregister_synth_event(se);
1375 if (!ret) {
1376 dyn_event_remove(&se->devent);
1377 free_synth_event(se);
1378 }
1379 }
1380
1381 return ret;
1382}
1383
1384/**
1385 * synth_event_delete - Delete a synthetic event
1386 * @event_name: The name of the new synthetic event
1387 *
1388 * Delete a synthetic event that was created with synth_event_create().
1389 *
1390 * Return: 0 if successful, error otherwise.
1391 */
1392int synth_event_delete(const char *event_name)
1393{
1394 struct synth_event *se = NULL;
1395 struct module *mod = NULL;
1396 int ret = -ENOENT;
1397
1398 mutex_lock(&event_mutex);
1399 se = find_synth_event(event_name);
1400 if (se) {
1401 mod = se->mod;
1402 ret = destroy_synth_event(se);
1403 }
1404 mutex_unlock(&event_mutex);
1405
1406 if (mod) {
1407 mutex_lock(&trace_types_lock);
1408 /*
1409 * It is safest to reset the ring buffer if the module
1410 * being unloaded registered any events that were
1411 * used. The only worry is if a new module gets
1412 * loaded, and takes on the same id as the events of
1413 * this module. When printing out the buffer, traced
1414 * events left over from this module may be passed to
1415 * the new module events and unexpected results may
1416 * occur.
1417 */
1418 tracing_reset_all_online_cpus();
1419 mutex_unlock(&trace_types_lock);
1420 }
1421
1422 return ret;
1423}
1424EXPORT_SYMBOL_GPL(synth_event_delete);
1425
1426static int check_command(const char *raw_command)
1427{
1428 char **argv = NULL, *cmd, *saved_cmd, *name_and_field;
1429 int argc, ret = 0;
1430
1431 cmd = saved_cmd = kstrdup(raw_command, GFP_KERNEL);
1432 if (!cmd)
1433 return -ENOMEM;
1434
1435 name_and_field = strsep(&cmd, ";");
1436 if (!name_and_field) {
1437 ret = -EINVAL;
1438 goto free;
1439 }
1440
1441 if (name_and_field[0] == '!')
1442 goto free;
1443
1444 argv = argv_split(GFP_KERNEL, name_and_field, &argc);
1445 if (!argv) {
1446 ret = -ENOMEM;
1447 goto free;
1448 }
1449 argv_free(argv);
1450
1451 if (argc < 3)
1452 ret = -EINVAL;
1453free:
1454 kfree(saved_cmd);
1455
1456 return ret;
1457}
1458
1459static int create_or_delete_synth_event(const char *raw_command)
1460{
1461 char *name = NULL, *fields, *p;
1462 int ret = 0;
1463
1464 raw_command = skip_spaces(raw_command);
1465 if (raw_command[0] == '\0')
1466 return ret;
1467
1468 last_cmd_set(raw_command);
1469
1470 ret = check_command(raw_command);
1471 if (ret) {
1472 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1473 return ret;
1474 }
1475
1476 p = strpbrk(raw_command, " \t");
1477 if (!p && raw_command[0] != '!') {
1478 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1479 ret = -EINVAL;
1480 goto free;
1481 }
1482
1483 name = kmemdup_nul(raw_command, p ? p - raw_command : strlen(raw_command), GFP_KERNEL);
1484 if (!name)
1485 return -ENOMEM;
1486
1487 if (name[0] == '!') {
1488 ret = synth_event_delete(name + 1);
1489 goto free;
1490 }
1491
1492 fields = skip_spaces(p);
1493
1494 ret = __create_synth_event(name, fields);
1495free:
1496 kfree(name);
1497
1498 return ret;
1499}
1500
1501static int synth_event_run_command(struct dynevent_cmd *cmd)
1502{
1503 struct synth_event *se;
1504 int ret;
1505
1506 ret = create_or_delete_synth_event(cmd->seq.buffer);
1507 if (ret)
1508 return ret;
1509
1510 se = find_synth_event(cmd->event_name);
1511 if (WARN_ON(!se))
1512 return -ENOENT;
1513
1514 se->mod = cmd->private_data;
1515
1516 return ret;
1517}
1518
1519/**
1520 * synth_event_cmd_init - Initialize a synthetic event command object
1521 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1522 * @buf: A pointer to the buffer used to build the command
1523 * @maxlen: The length of the buffer passed in @buf
1524 *
1525 * Initialize a synthetic event command object. Use this before
1526 * calling any of the other dyenvent_cmd functions.
1527 */
1528void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
1529{
1530 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
1531 synth_event_run_command);
1532}
1533EXPORT_SYMBOL_GPL(synth_event_cmd_init);
1534
1535static inline int
1536__synth_event_trace_init(struct trace_event_file *file,
1537 struct synth_event_trace_state *trace_state)
1538{
1539 int ret = 0;
1540
1541 memset(trace_state, '\0', sizeof(*trace_state));
1542
1543 /*
1544 * Normal event tracing doesn't get called at all unless the
1545 * ENABLED bit is set (which attaches the probe thus allowing
1546 * this code to be called, etc). Because this is called
1547 * directly by the user, we don't have that but we still need
1548 * to honor not logging when disabled. For the iterated
1549 * trace case, we save the enabled state upon start and just
1550 * ignore the following data calls.
1551 */
1552 if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
1553 trace_trigger_soft_disabled(file)) {
1554 trace_state->disabled = true;
1555 ret = -ENOENT;
1556 goto out;
1557 }
1558
1559 trace_state->event = file->event_call->data;
1560out:
1561 return ret;
1562}
1563
1564static inline int
1565__synth_event_trace_start(struct trace_event_file *file,
1566 struct synth_event_trace_state *trace_state,
1567 int dynamic_fields_size)
1568{
1569 int entry_size, fields_size = 0;
1570 int ret = 0;
1571
1572 fields_size = trace_state->event->n_u64 * sizeof(u64);
1573 fields_size += dynamic_fields_size;
1574
1575 /*
1576 * Avoid ring buffer recursion detection, as this event
1577 * is being performed within another event.
1578 */
1579 trace_state->buffer = file->tr->array_buffer.buffer;
1580 ring_buffer_nest_start(trace_state->buffer);
1581
1582 entry_size = sizeof(*trace_state->entry) + fields_size;
1583 trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer,
1584 file,
1585 entry_size);
1586 if (!trace_state->entry) {
1587 ring_buffer_nest_end(trace_state->buffer);
1588 ret = -EINVAL;
1589 }
1590
1591 return ret;
1592}
1593
1594static inline void
1595__synth_event_trace_end(struct synth_event_trace_state *trace_state)
1596{
1597 trace_event_buffer_commit(&trace_state->fbuffer);
1598
1599 ring_buffer_nest_end(trace_state->buffer);
1600}
1601
1602/**
1603 * synth_event_trace - Trace a synthetic event
1604 * @file: The trace_event_file representing the synthetic event
1605 * @n_vals: The number of values in vals
1606 * @args: Variable number of args containing the event values
1607 *
1608 * Trace a synthetic event using the values passed in the variable
1609 * argument list.
1610 *
1611 * The argument list should be a list 'n_vals' u64 values. The number
1612 * of vals must match the number of field in the synthetic event, and
1613 * must be in the same order as the synthetic event fields.
1614 *
1615 * All vals should be cast to u64, and string vals are just pointers
1616 * to strings, cast to u64. Strings will be copied into space
1617 * reserved in the event for the string, using these pointers.
1618 *
1619 * Return: 0 on success, err otherwise.
1620 */
1621int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
1622{
1623 unsigned int i, n_u64, len, data_size = 0;
1624 struct synth_event_trace_state state;
1625 va_list args;
1626 int ret;
1627
1628 ret = __synth_event_trace_init(file, &state);
1629 if (ret) {
1630 if (ret == -ENOENT)
1631 ret = 0; /* just disabled, not really an error */
1632 return ret;
1633 }
1634
1635 if (state.event->n_dynamic_fields) {
1636 va_start(args, n_vals);
1637
1638 for (i = 0; i < state.event->n_fields; i++) {
1639 u64 val = va_arg(args, u64);
1640
1641 if (state.event->fields[i]->is_string &&
1642 state.event->fields[i]->is_dynamic) {
1643 char *str_val = (char *)(long)val;
1644
1645 data_size += strlen(str_val) + 1;
1646 }
1647 }
1648
1649 va_end(args);
1650 }
1651
1652 ret = __synth_event_trace_start(file, &state, data_size);
1653 if (ret)
1654 return ret;
1655
1656 if (n_vals != state.event->n_fields) {
1657 ret = -EINVAL;
1658 goto out;
1659 }
1660
1661 data_size = 0;
1662
1663 va_start(args, n_vals);
1664 for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
1665 u64 val;
1666
1667 val = va_arg(args, u64);
1668
1669 if (state.event->fields[i]->is_string) {
1670 char *str_val = (char *)(long)val;
1671
1672 len = trace_string(state.entry, state.event, str_val,
1673 state.event->fields[i]->is_dynamic,
1674 data_size, &n_u64);
1675 data_size += len; /* only dynamic string increments */
1676 } else {
1677 struct synth_field *field = state.event->fields[i];
1678
1679 switch (field->size) {
1680 case 1:
1681 *(u8 *)&state.entry->fields[n_u64] = (u8)val;
1682 break;
1683
1684 case 2:
1685 *(u16 *)&state.entry->fields[n_u64] = (u16)val;
1686 break;
1687
1688 case 4:
1689 *(u32 *)&state.entry->fields[n_u64] = (u32)val;
1690 break;
1691
1692 default:
1693 state.entry->fields[n_u64] = val;
1694 break;
1695 }
1696 n_u64++;
1697 }
1698 }
1699 va_end(args);
1700out:
1701 __synth_event_trace_end(&state);
1702
1703 return ret;
1704}
1705EXPORT_SYMBOL_GPL(synth_event_trace);
1706
1707/**
1708 * synth_event_trace_array - Trace a synthetic event from an array
1709 * @file: The trace_event_file representing the synthetic event
1710 * @vals: Array of values
1711 * @n_vals: The number of values in vals
1712 *
1713 * Trace a synthetic event using the values passed in as 'vals'.
1714 *
1715 * The 'vals' array is just an array of 'n_vals' u64. The number of
1716 * vals must match the number of field in the synthetic event, and
1717 * must be in the same order as the synthetic event fields.
1718 *
1719 * All vals should be cast to u64, and string vals are just pointers
1720 * to strings, cast to u64. Strings will be copied into space
1721 * reserved in the event for the string, using these pointers.
1722 *
1723 * Return: 0 on success, err otherwise.
1724 */
1725int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
1726 unsigned int n_vals)
1727{
1728 unsigned int i, n_u64, field_pos, len, data_size = 0;
1729 struct synth_event_trace_state state;
1730 char *str_val;
1731 int ret;
1732
1733 ret = __synth_event_trace_init(file, &state);
1734 if (ret) {
1735 if (ret == -ENOENT)
1736 ret = 0; /* just disabled, not really an error */
1737 return ret;
1738 }
1739
1740 if (state.event->n_dynamic_fields) {
1741 for (i = 0; i < state.event->n_dynamic_fields; i++) {
1742 field_pos = state.event->dynamic_fields[i]->field_pos;
1743 str_val = (char *)(long)vals[field_pos];
1744 len = strlen(str_val) + 1;
1745 data_size += len;
1746 }
1747 }
1748
1749 ret = __synth_event_trace_start(file, &state, data_size);
1750 if (ret)
1751 return ret;
1752
1753 if (n_vals != state.event->n_fields) {
1754 ret = -EINVAL;
1755 goto out;
1756 }
1757
1758 data_size = 0;
1759
1760 for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
1761 if (state.event->fields[i]->is_string) {
1762 char *str_val = (char *)(long)vals[i];
1763
1764 len = trace_string(state.entry, state.event, str_val,
1765 state.event->fields[i]->is_dynamic,
1766 data_size, &n_u64);
1767 data_size += len; /* only dynamic string increments */
1768 } else {
1769 struct synth_field *field = state.event->fields[i];
1770 u64 val = vals[i];
1771
1772 switch (field->size) {
1773 case 1:
1774 *(u8 *)&state.entry->fields[n_u64] = (u8)val;
1775 break;
1776
1777 case 2:
1778 *(u16 *)&state.entry->fields[n_u64] = (u16)val;
1779 break;
1780
1781 case 4:
1782 *(u32 *)&state.entry->fields[n_u64] = (u32)val;
1783 break;
1784
1785 default:
1786 state.entry->fields[n_u64] = val;
1787 break;
1788 }
1789 n_u64++;
1790 }
1791 }
1792out:
1793 __synth_event_trace_end(&state);
1794
1795 return ret;
1796}
1797EXPORT_SYMBOL_GPL(synth_event_trace_array);
1798
1799/**
1800 * synth_event_trace_start - Start piecewise synthetic event trace
1801 * @file: The trace_event_file representing the synthetic event
1802 * @trace_state: A pointer to object tracking the piecewise trace state
1803 *
1804 * Start the trace of a synthetic event field-by-field rather than all
1805 * at once.
1806 *
1807 * This function 'opens' an event trace, which means space is reserved
1808 * for the event in the trace buffer, after which the event's
1809 * individual field values can be set through either
1810 * synth_event_add_next_val() or synth_event_add_val().
1811 *
1812 * A pointer to a trace_state object is passed in, which will keep
1813 * track of the current event trace state until the event trace is
1814 * closed (and the event finally traced) using
1815 * synth_event_trace_end().
1816 *
1817 * Note that synth_event_trace_end() must be called after all values
1818 * have been added for each event trace, regardless of whether adding
1819 * all field values succeeded or not.
1820 *
1821 * Note also that for a given event trace, all fields must be added
1822 * using either synth_event_add_next_val() or synth_event_add_val()
1823 * but not both together or interleaved.
1824 *
1825 * Return: 0 on success, err otherwise.
1826 */
1827int synth_event_trace_start(struct trace_event_file *file,
1828 struct synth_event_trace_state *trace_state)
1829{
1830 int ret;
1831
1832 if (!trace_state)
1833 return -EINVAL;
1834
1835 ret = __synth_event_trace_init(file, trace_state);
1836 if (ret) {
1837 if (ret == -ENOENT)
1838 ret = 0; /* just disabled, not really an error */
1839 return ret;
1840 }
1841
1842 if (trace_state->event->n_dynamic_fields)
1843 return -ENOTSUPP;
1844
1845 ret = __synth_event_trace_start(file, trace_state, 0);
1846
1847 return ret;
1848}
1849EXPORT_SYMBOL_GPL(synth_event_trace_start);
1850
1851static int __synth_event_add_val(const char *field_name, u64 val,
1852 struct synth_event_trace_state *trace_state)
1853{
1854 struct synth_field *field = NULL;
1855 struct synth_trace_event *entry;
1856 struct synth_event *event;
1857 int i, ret = 0;
1858
1859 if (!trace_state) {
1860 ret = -EINVAL;
1861 goto out;
1862 }
1863
1864 /* can't mix add_next_synth_val() with add_synth_val() */
1865 if (field_name) {
1866 if (trace_state->add_next) {
1867 ret = -EINVAL;
1868 goto out;
1869 }
1870 trace_state->add_name = true;
1871 } else {
1872 if (trace_state->add_name) {
1873 ret = -EINVAL;
1874 goto out;
1875 }
1876 trace_state->add_next = true;
1877 }
1878
1879 if (trace_state->disabled)
1880 goto out;
1881
1882 event = trace_state->event;
1883 if (trace_state->add_name) {
1884 for (i = 0; i < event->n_fields; i++) {
1885 field = event->fields[i];
1886 if (strcmp(field->name, field_name) == 0)
1887 break;
1888 }
1889 if (!field) {
1890 ret = -EINVAL;
1891 goto out;
1892 }
1893 } else {
1894 if (trace_state->cur_field >= event->n_fields) {
1895 ret = -EINVAL;
1896 goto out;
1897 }
1898 field = event->fields[trace_state->cur_field++];
1899 }
1900
1901 entry = trace_state->entry;
1902 if (field->is_string) {
1903 char *str_val = (char *)(long)val;
1904 char *str_field;
1905
1906 if (field->is_dynamic) { /* add_val can't do dynamic strings */
1907 ret = -EINVAL;
1908 goto out;
1909 }
1910
1911 if (!str_val) {
1912 ret = -EINVAL;
1913 goto out;
1914 }
1915
1916 str_field = (char *)&entry->fields[field->offset];
1917 strscpy(str_field, str_val, STR_VAR_LEN_MAX);
1918 } else {
1919 switch (field->size) {
1920 case 1:
1921 *(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
1922 break;
1923
1924 case 2:
1925 *(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
1926 break;
1927
1928 case 4:
1929 *(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
1930 break;
1931
1932 default:
1933 trace_state->entry->fields[field->offset] = val;
1934 break;
1935 }
1936 }
1937 out:
1938 return ret;
1939}
1940
1941/**
1942 * synth_event_add_next_val - Add the next field's value to an open synth trace
1943 * @val: The value to set the next field to
1944 * @trace_state: A pointer to object tracking the piecewise trace state
1945 *
1946 * Set the value of the next field in an event that's been opened by
1947 * synth_event_trace_start().
1948 *
1949 * The val param should be the value cast to u64. If the value points
1950 * to a string, the val param should be a char * cast to u64.
1951 *
1952 * This function assumes all the fields in an event are to be set one
1953 * after another - successive calls to this function are made, one for
1954 * each field, in the order of the fields in the event, until all
1955 * fields have been set. If you'd rather set each field individually
1956 * without regard to ordering, synth_event_add_val() can be used
1957 * instead.
1958 *
1959 * Note however that synth_event_add_next_val() and
1960 * synth_event_add_val() can't be intermixed for a given event trace -
1961 * one or the other but not both can be used at the same time.
1962 *
1963 * Note also that synth_event_trace_end() must be called after all
1964 * values have been added for each event trace, regardless of whether
1965 * adding all field values succeeded or not.
1966 *
1967 * Return: 0 on success, err otherwise.
1968 */
1969int synth_event_add_next_val(u64 val,
1970 struct synth_event_trace_state *trace_state)
1971{
1972 return __synth_event_add_val(NULL, val, trace_state);
1973}
1974EXPORT_SYMBOL_GPL(synth_event_add_next_val);
1975
1976/**
1977 * synth_event_add_val - Add a named field's value to an open synth trace
1978 * @field_name: The name of the synthetic event field value to set
1979 * @val: The value to set the next field to
1980 * @trace_state: A pointer to object tracking the piecewise trace state
1981 *
1982 * Set the value of the named field in an event that's been opened by
1983 * synth_event_trace_start().
1984 *
1985 * The val param should be the value cast to u64. If the value points
1986 * to a string, the val param should be a char * cast to u64.
1987 *
1988 * This function looks up the field name, and if found, sets the field
1989 * to the specified value. This lookup makes this function more
1990 * expensive than synth_event_add_next_val(), so use that or the
1991 * none-piecewise synth_event_trace() instead if efficiency is more
1992 * important.
1993 *
1994 * Note however that synth_event_add_next_val() and
1995 * synth_event_add_val() can't be intermixed for a given event trace -
1996 * one or the other but not both can be used at the same time.
1997 *
1998 * Note also that synth_event_trace_end() must be called after all
1999 * values have been added for each event trace, regardless of whether
2000 * adding all field values succeeded or not.
2001 *
2002 * Return: 0 on success, err otherwise.
2003 */
2004int synth_event_add_val(const char *field_name, u64 val,
2005 struct synth_event_trace_state *trace_state)
2006{
2007 return __synth_event_add_val(field_name, val, trace_state);
2008}
2009EXPORT_SYMBOL_GPL(synth_event_add_val);
2010
2011/**
2012 * synth_event_trace_end - End piecewise synthetic event trace
2013 * @trace_state: A pointer to object tracking the piecewise trace state
2014 *
2015 * End the trace of a synthetic event opened by
2016 * synth_event_trace__start().
2017 *
2018 * This function 'closes' an event trace, which basically means that
2019 * it commits the reserved event and cleans up other loose ends.
2020 *
2021 * A pointer to a trace_state object is passed in, which will keep
2022 * track of the current event trace state opened with
2023 * synth_event_trace_start().
2024 *
2025 * Note that this function must be called after all values have been
2026 * added for each event trace, regardless of whether adding all field
2027 * values succeeded or not.
2028 *
2029 * Return: 0 on success, err otherwise.
2030 */
2031int synth_event_trace_end(struct synth_event_trace_state *trace_state)
2032{
2033 if (!trace_state)
2034 return -EINVAL;
2035
2036 __synth_event_trace_end(trace_state);
2037
2038 return 0;
2039}
2040EXPORT_SYMBOL_GPL(synth_event_trace_end);
2041
2042static int create_synth_event(const char *raw_command)
2043{
2044 char *fields, *p;
2045 const char *name;
2046 int len, ret = 0;
2047
2048 raw_command = skip_spaces(raw_command);
2049 if (raw_command[0] == '\0')
2050 return ret;
2051
2052 last_cmd_set(raw_command);
2053
2054 p = strpbrk(raw_command, " \t");
2055 if (!p) {
2056 synth_err(SYNTH_ERR_INVALID_CMD, 0);
2057 return -EINVAL;
2058 }
2059
2060 fields = skip_spaces(p);
2061
2062 name = raw_command;
2063
2064 if (name[0] != 's' || name[1] != ':')
2065 return -ECANCELED;
2066 name += 2;
2067
2068 /* This interface accepts group name prefix */
2069 if (strchr(name, '/')) {
2070 len = str_has_prefix(name, SYNTH_SYSTEM "/");
2071 if (len == 0) {
2072 synth_err(SYNTH_ERR_INVALID_DYN_CMD, 0);
2073 return -EINVAL;
2074 }
2075 name += len;
2076 }
2077
2078 len = name - raw_command;
2079
2080 ret = check_command(raw_command + len);
2081 if (ret) {
2082 synth_err(SYNTH_ERR_INVALID_CMD, 0);
2083 return ret;
2084 }
2085
2086 name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL);
2087 if (!name)
2088 return -ENOMEM;
2089
2090 ret = __create_synth_event(name, fields);
2091
2092 kfree(name);
2093
2094 return ret;
2095}
2096
2097static int synth_event_release(struct dyn_event *ev)
2098{
2099 struct synth_event *event = to_synth_event(ev);
2100 int ret;
2101
2102 if (event->ref)
2103 return -EBUSY;
2104
2105 ret = unregister_synth_event(event);
2106 if (ret)
2107 return ret;
2108
2109 dyn_event_remove(ev);
2110 free_synth_event(event);
2111 return 0;
2112}
2113
2114static int __synth_event_show(struct seq_file *m, struct synth_event *event)
2115{
2116 struct synth_field *field;
2117 unsigned int i;
2118 char *type, *t;
2119
2120 seq_printf(m, "%s\t", event->name);
2121
2122 for (i = 0; i < event->n_fields; i++) {
2123 field = event->fields[i];
2124
2125 type = field->type;
2126 t = strstr(type, "__data_loc");
2127 if (t) { /* __data_loc belongs in format but not event desc */
2128 t += sizeof("__data_loc");
2129 type = t;
2130 }
2131
2132 /* parameter values */
2133 seq_printf(m, "%s %s%s", type, field->name,
2134 i == event->n_fields - 1 ? "" : "; ");
2135 }
2136
2137 seq_putc(m, '\n');
2138
2139 return 0;
2140}
2141
2142static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
2143{
2144 struct synth_event *event = to_synth_event(ev);
2145
2146 seq_printf(m, "s:%s/", event->class.system);
2147
2148 return __synth_event_show(m, event);
2149}
2150
2151static int synth_events_seq_show(struct seq_file *m, void *v)
2152{
2153 struct dyn_event *ev = v;
2154
2155 if (!is_synth_event(ev))
2156 return 0;
2157
2158 return __synth_event_show(m, to_synth_event(ev));
2159}
2160
2161static const struct seq_operations synth_events_seq_op = {
2162 .start = dyn_event_seq_start,
2163 .next = dyn_event_seq_next,
2164 .stop = dyn_event_seq_stop,
2165 .show = synth_events_seq_show,
2166};
2167
2168static int synth_events_open(struct inode *inode, struct file *file)
2169{
2170 int ret;
2171
2172 ret = security_locked_down(LOCKDOWN_TRACEFS);
2173 if (ret)
2174 return ret;
2175
2176 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
2177 ret = dyn_events_release_all(&synth_event_ops);
2178 if (ret < 0)
2179 return ret;
2180 }
2181
2182 return seq_open(file, &synth_events_seq_op);
2183}
2184
2185static ssize_t synth_events_write(struct file *file,
2186 const char __user *buffer,
2187 size_t count, loff_t *ppos)
2188{
2189 return trace_parse_run_command(file, buffer, count, ppos,
2190 create_or_delete_synth_event);
2191}
2192
2193static const struct file_operations synth_events_fops = {
2194 .open = synth_events_open,
2195 .write = synth_events_write,
2196 .read = seq_read,
2197 .llseek = seq_lseek,
2198 .release = seq_release,
2199};
2200
2201/*
2202 * Register dynevent at core_initcall. This allows kernel to setup kprobe
2203 * events in postcore_initcall without tracefs.
2204 */
2205static __init int trace_events_synth_init_early(void)
2206{
2207 int err = 0;
2208
2209 err = dyn_event_register(&synth_event_ops);
2210 if (err)
2211 pr_warn("Could not register synth_event_ops\n");
2212
2213 return err;
2214}
2215core_initcall(trace_events_synth_init_early);
2216
2217static __init int trace_events_synth_init(void)
2218{
2219 struct dentry *entry = NULL;
2220 int err = 0;
2221 err = tracing_init_dentry();
2222 if (err)
2223 goto err;
2224
2225 entry = tracefs_create_file("synthetic_events", 0644, NULL,
2226 NULL, &synth_events_fops);
2227 if (!entry) {
2228 err = -ENODEV;
2229 goto err;
2230 }
2231
2232 return err;
2233 err:
2234 pr_warn("Could not create tracefs 'synthetic_events' entry\n");
2235
2236 return err;
2237}
2238
2239fs_initcall(trace_events_synth_init);