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1/*
2 * probe-file.c : operate ftrace k/uprobe events files
3 *
4 * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 */
17#include <errno.h>
18#include <fcntl.h>
19#include <sys/stat.h>
20#include <sys/types.h>
21#include <sys/uio.h>
22#include <unistd.h>
23#include "util.h"
24#include "event.h"
25#include "strlist.h"
26#include "strfilter.h"
27#include "debug.h"
28#include "cache.h"
29#include "color.h"
30#include "symbol.h"
31#include "thread.h"
32#include <api/fs/tracing_path.h>
33#include "probe-event.h"
34#include "probe-file.h"
35#include "session.h"
36#include "perf_regs.h"
37#include "string2.h"
38
39/* 4096 - 2 ('\n' + '\0') */
40#define MAX_CMDLEN 4094
41
42static void print_open_warning(int err, bool uprobe)
43{
44 char sbuf[STRERR_BUFSIZE];
45
46 if (err == -ENOENT) {
47 const char *config;
48
49 if (uprobe)
50 config = "CONFIG_UPROBE_EVENTS";
51 else
52 config = "CONFIG_KPROBE_EVENTS";
53
54 pr_warning("%cprobe_events file does not exist"
55 " - please rebuild kernel with %s.\n",
56 uprobe ? 'u' : 'k', config);
57 } else if (err == -ENOTSUP)
58 pr_warning("Tracefs or debugfs is not mounted.\n");
59 else
60 pr_warning("Failed to open %cprobe_events: %s\n",
61 uprobe ? 'u' : 'k',
62 str_error_r(-err, sbuf, sizeof(sbuf)));
63}
64
65static void print_both_open_warning(int kerr, int uerr)
66{
67 /* Both kprobes and uprobes are disabled, warn it. */
68 if (kerr == -ENOTSUP && uerr == -ENOTSUP)
69 pr_warning("Tracefs or debugfs is not mounted.\n");
70 else if (kerr == -ENOENT && uerr == -ENOENT)
71 pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
72 "or/and CONFIG_UPROBE_EVENTS.\n");
73 else {
74 char sbuf[STRERR_BUFSIZE];
75 pr_warning("Failed to open kprobe events: %s.\n",
76 str_error_r(-kerr, sbuf, sizeof(sbuf)));
77 pr_warning("Failed to open uprobe events: %s.\n",
78 str_error_r(-uerr, sbuf, sizeof(sbuf)));
79 }
80}
81
82int open_trace_file(const char *trace_file, bool readwrite)
83{
84 char buf[PATH_MAX];
85 int ret;
86
87 ret = e_snprintf(buf, PATH_MAX, "%s/%s",
88 tracing_path, trace_file);
89 if (ret >= 0) {
90 pr_debug("Opening %s write=%d\n", buf, readwrite);
91 if (readwrite && !probe_event_dry_run)
92 ret = open(buf, O_RDWR | O_APPEND, 0);
93 else
94 ret = open(buf, O_RDONLY, 0);
95
96 if (ret < 0)
97 ret = -errno;
98 }
99 return ret;
100}
101
102static int open_kprobe_events(bool readwrite)
103{
104 return open_trace_file("kprobe_events", readwrite);
105}
106
107static int open_uprobe_events(bool readwrite)
108{
109 return open_trace_file("uprobe_events", readwrite);
110}
111
112int probe_file__open(int flag)
113{
114 int fd;
115
116 if (flag & PF_FL_UPROBE)
117 fd = open_uprobe_events(flag & PF_FL_RW);
118 else
119 fd = open_kprobe_events(flag & PF_FL_RW);
120 if (fd < 0)
121 print_open_warning(fd, flag & PF_FL_UPROBE);
122
123 return fd;
124}
125
126int probe_file__open_both(int *kfd, int *ufd, int flag)
127{
128 if (!kfd || !ufd)
129 return -EINVAL;
130
131 *kfd = open_kprobe_events(flag & PF_FL_RW);
132 *ufd = open_uprobe_events(flag & PF_FL_RW);
133 if (*kfd < 0 && *ufd < 0) {
134 print_both_open_warning(*kfd, *ufd);
135 return *kfd;
136 }
137
138 return 0;
139}
140
141/* Get raw string list of current kprobe_events or uprobe_events */
142struct strlist *probe_file__get_rawlist(int fd)
143{
144 int ret, idx, fddup;
145 FILE *fp;
146 char buf[MAX_CMDLEN];
147 char *p;
148 struct strlist *sl;
149
150 if (fd < 0)
151 return NULL;
152
153 sl = strlist__new(NULL, NULL);
154 if (sl == NULL)
155 return NULL;
156
157 fddup = dup(fd);
158 if (fddup < 0)
159 goto out_free_sl;
160
161 fp = fdopen(fddup, "r");
162 if (!fp)
163 goto out_close_fddup;
164
165 while (!feof(fp)) {
166 p = fgets(buf, MAX_CMDLEN, fp);
167 if (!p)
168 break;
169
170 idx = strlen(p) - 1;
171 if (p[idx] == '\n')
172 p[idx] = '\0';
173 ret = strlist__add(sl, buf);
174 if (ret < 0) {
175 pr_debug("strlist__add failed (%d)\n", ret);
176 goto out_close_fp;
177 }
178 }
179 fclose(fp);
180
181 return sl;
182
183out_close_fp:
184 fclose(fp);
185 goto out_free_sl;
186out_close_fddup:
187 close(fddup);
188out_free_sl:
189 strlist__delete(sl);
190 return NULL;
191}
192
193static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
194{
195 char buf[128];
196 struct strlist *sl, *rawlist;
197 struct str_node *ent;
198 struct probe_trace_event tev;
199 int ret = 0;
200
201 memset(&tev, 0, sizeof(tev));
202 rawlist = probe_file__get_rawlist(fd);
203 if (!rawlist)
204 return NULL;
205 sl = strlist__new(NULL, NULL);
206 strlist__for_each_entry(ent, rawlist) {
207 ret = parse_probe_trace_command(ent->s, &tev);
208 if (ret < 0)
209 break;
210 if (include_group) {
211 ret = e_snprintf(buf, 128, "%s:%s", tev.group,
212 tev.event);
213 if (ret >= 0)
214 ret = strlist__add(sl, buf);
215 } else
216 ret = strlist__add(sl, tev.event);
217 clear_probe_trace_event(&tev);
218 if (ret < 0)
219 break;
220 }
221 strlist__delete(rawlist);
222
223 if (ret < 0) {
224 strlist__delete(sl);
225 return NULL;
226 }
227 return sl;
228}
229
230/* Get current perf-probe event names */
231struct strlist *probe_file__get_namelist(int fd)
232{
233 return __probe_file__get_namelist(fd, false);
234}
235
236int probe_file__add_event(int fd, struct probe_trace_event *tev)
237{
238 int ret = 0;
239 char *buf = synthesize_probe_trace_command(tev);
240 char sbuf[STRERR_BUFSIZE];
241
242 if (!buf) {
243 pr_debug("Failed to synthesize probe trace event.\n");
244 return -EINVAL;
245 }
246
247 pr_debug("Writing event: %s\n", buf);
248 if (!probe_event_dry_run) {
249 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
250 ret = -errno;
251 pr_warning("Failed to write event: %s\n",
252 str_error_r(errno, sbuf, sizeof(sbuf)));
253 }
254 }
255 free(buf);
256
257 return ret;
258}
259
260static int __del_trace_probe_event(int fd, struct str_node *ent)
261{
262 char *p;
263 char buf[128];
264 int ret;
265
266 /* Convert from perf-probe event to trace-probe event */
267 ret = e_snprintf(buf, 128, "-:%s", ent->s);
268 if (ret < 0)
269 goto error;
270
271 p = strchr(buf + 2, ':');
272 if (!p) {
273 pr_debug("Internal error: %s should have ':' but not.\n",
274 ent->s);
275 ret = -ENOTSUP;
276 goto error;
277 }
278 *p = '/';
279
280 pr_debug("Writing event: %s\n", buf);
281 ret = write(fd, buf, strlen(buf));
282 if (ret < 0) {
283 ret = -errno;
284 goto error;
285 }
286
287 return 0;
288error:
289 pr_warning("Failed to delete event: %s\n",
290 str_error_r(-ret, buf, sizeof(buf)));
291 return ret;
292}
293
294int probe_file__get_events(int fd, struct strfilter *filter,
295 struct strlist *plist)
296{
297 struct strlist *namelist;
298 struct str_node *ent;
299 const char *p;
300 int ret = -ENOENT;
301
302 if (!plist)
303 return -EINVAL;
304
305 namelist = __probe_file__get_namelist(fd, true);
306 if (!namelist)
307 return -ENOENT;
308
309 strlist__for_each_entry(ent, namelist) {
310 p = strchr(ent->s, ':');
311 if ((p && strfilter__compare(filter, p + 1)) ||
312 strfilter__compare(filter, ent->s)) {
313 strlist__add(plist, ent->s);
314 ret = 0;
315 }
316 }
317 strlist__delete(namelist);
318
319 return ret;
320}
321
322int probe_file__del_strlist(int fd, struct strlist *namelist)
323{
324 int ret = 0;
325 struct str_node *ent;
326
327 strlist__for_each_entry(ent, namelist) {
328 ret = __del_trace_probe_event(fd, ent);
329 if (ret < 0)
330 break;
331 }
332 return ret;
333}
334
335int probe_file__del_events(int fd, struct strfilter *filter)
336{
337 struct strlist *namelist;
338 int ret;
339
340 namelist = strlist__new(NULL, NULL);
341 if (!namelist)
342 return -ENOMEM;
343
344 ret = probe_file__get_events(fd, filter, namelist);
345 if (ret < 0)
346 return ret;
347
348 ret = probe_file__del_strlist(fd, namelist);
349 strlist__delete(namelist);
350
351 return ret;
352}
353
354/* Caller must ensure to remove this entry from list */
355static void probe_cache_entry__delete(struct probe_cache_entry *entry)
356{
357 if (entry) {
358 BUG_ON(!list_empty(&entry->node));
359
360 strlist__delete(entry->tevlist);
361 clear_perf_probe_event(&entry->pev);
362 zfree(&entry->spev);
363 free(entry);
364 }
365}
366
367static struct probe_cache_entry *
368probe_cache_entry__new(struct perf_probe_event *pev)
369{
370 struct probe_cache_entry *entry = zalloc(sizeof(*entry));
371
372 if (entry) {
373 INIT_LIST_HEAD(&entry->node);
374 entry->tevlist = strlist__new(NULL, NULL);
375 if (!entry->tevlist)
376 zfree(&entry);
377 else if (pev) {
378 entry->spev = synthesize_perf_probe_command(pev);
379 if (!entry->spev ||
380 perf_probe_event__copy(&entry->pev, pev) < 0) {
381 probe_cache_entry__delete(entry);
382 return NULL;
383 }
384 }
385 }
386
387 return entry;
388}
389
390int probe_cache_entry__get_event(struct probe_cache_entry *entry,
391 struct probe_trace_event **tevs)
392{
393 struct probe_trace_event *tev;
394 struct str_node *node;
395 int ret, i;
396
397 ret = strlist__nr_entries(entry->tevlist);
398 if (ret > probe_conf.max_probes)
399 return -E2BIG;
400
401 *tevs = zalloc(ret * sizeof(*tev));
402 if (!*tevs)
403 return -ENOMEM;
404
405 i = 0;
406 strlist__for_each_entry(node, entry->tevlist) {
407 tev = &(*tevs)[i++];
408 ret = parse_probe_trace_command(node->s, tev);
409 if (ret < 0)
410 break;
411 }
412 return i;
413}
414
415/* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
416static int probe_cache__open(struct probe_cache *pcache, const char *target,
417 struct nsinfo *nsi)
418{
419 char cpath[PATH_MAX];
420 char sbuildid[SBUILD_ID_SIZE];
421 char *dir_name = NULL;
422 bool is_kallsyms = false;
423 int ret, fd;
424 struct nscookie nsc;
425
426 if (target && build_id_cache__cached(target)) {
427 /* This is a cached buildid */
428 strncpy(sbuildid, target, SBUILD_ID_SIZE);
429 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
430 goto found;
431 }
432
433 if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
434 target = DSO__NAME_KALLSYMS;
435 is_kallsyms = true;
436 ret = sysfs__sprintf_build_id("/", sbuildid);
437 } else {
438 nsinfo__mountns_enter(nsi, &nsc);
439 ret = filename__sprintf_build_id(target, sbuildid);
440 nsinfo__mountns_exit(&nsc);
441 }
442
443 if (ret < 0) {
444 pr_debug("Failed to get build-id from %s.\n", target);
445 return ret;
446 }
447
448 /* If we have no buildid cache, make it */
449 if (!build_id_cache__cached(sbuildid)) {
450 ret = build_id_cache__add_s(sbuildid, target, nsi,
451 is_kallsyms, NULL);
452 if (ret < 0) {
453 pr_debug("Failed to add build-id cache: %s\n", target);
454 return ret;
455 }
456 }
457
458 dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
459 false);
460found:
461 if (!dir_name) {
462 pr_debug("Failed to get cache from %s\n", target);
463 return -ENOMEM;
464 }
465
466 snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
467 fd = open(cpath, O_CREAT | O_RDWR, 0644);
468 if (fd < 0)
469 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
470 free(dir_name);
471 pcache->fd = fd;
472
473 return fd;
474}
475
476static int probe_cache__load(struct probe_cache *pcache)
477{
478 struct probe_cache_entry *entry = NULL;
479 char buf[MAX_CMDLEN], *p;
480 int ret = 0, fddup;
481 FILE *fp;
482
483 fddup = dup(pcache->fd);
484 if (fddup < 0)
485 return -errno;
486 fp = fdopen(fddup, "r");
487 if (!fp) {
488 close(fddup);
489 return -EINVAL;
490 }
491
492 while (!feof(fp)) {
493 if (!fgets(buf, MAX_CMDLEN, fp))
494 break;
495 p = strchr(buf, '\n');
496 if (p)
497 *p = '\0';
498 /* #perf_probe_event or %sdt_event */
499 if (buf[0] == '#' || buf[0] == '%') {
500 entry = probe_cache_entry__new(NULL);
501 if (!entry) {
502 ret = -ENOMEM;
503 goto out;
504 }
505 if (buf[0] == '%')
506 entry->sdt = true;
507 entry->spev = strdup(buf + 1);
508 if (entry->spev)
509 ret = parse_perf_probe_command(buf + 1,
510 &entry->pev);
511 else
512 ret = -ENOMEM;
513 if (ret < 0) {
514 probe_cache_entry__delete(entry);
515 goto out;
516 }
517 list_add_tail(&entry->node, &pcache->entries);
518 } else { /* trace_probe_event */
519 if (!entry) {
520 ret = -EINVAL;
521 goto out;
522 }
523 strlist__add(entry->tevlist, buf);
524 }
525 }
526out:
527 fclose(fp);
528 return ret;
529}
530
531static struct probe_cache *probe_cache__alloc(void)
532{
533 struct probe_cache *pcache = zalloc(sizeof(*pcache));
534
535 if (pcache) {
536 INIT_LIST_HEAD(&pcache->entries);
537 pcache->fd = -EINVAL;
538 }
539 return pcache;
540}
541
542void probe_cache__purge(struct probe_cache *pcache)
543{
544 struct probe_cache_entry *entry, *n;
545
546 list_for_each_entry_safe(entry, n, &pcache->entries, node) {
547 list_del_init(&entry->node);
548 probe_cache_entry__delete(entry);
549 }
550}
551
552void probe_cache__delete(struct probe_cache *pcache)
553{
554 if (!pcache)
555 return;
556
557 probe_cache__purge(pcache);
558 if (pcache->fd > 0)
559 close(pcache->fd);
560 free(pcache);
561}
562
563struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
564{
565 struct probe_cache *pcache = probe_cache__alloc();
566 int ret;
567
568 if (!pcache)
569 return NULL;
570
571 ret = probe_cache__open(pcache, target, nsi);
572 if (ret < 0) {
573 pr_debug("Cache open error: %d\n", ret);
574 goto out_err;
575 }
576
577 ret = probe_cache__load(pcache);
578 if (ret < 0) {
579 pr_debug("Cache read error: %d\n", ret);
580 goto out_err;
581 }
582
583 return pcache;
584
585out_err:
586 probe_cache__delete(pcache);
587 return NULL;
588}
589
590static bool streql(const char *a, const char *b)
591{
592 if (a == b)
593 return true;
594
595 if (!a || !b)
596 return false;
597
598 return !strcmp(a, b);
599}
600
601struct probe_cache_entry *
602probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
603{
604 struct probe_cache_entry *entry = NULL;
605 char *cmd = synthesize_perf_probe_command(pev);
606
607 if (!cmd)
608 return NULL;
609
610 for_each_probe_cache_entry(entry, pcache) {
611 if (pev->sdt) {
612 if (entry->pev.event &&
613 streql(entry->pev.event, pev->event) &&
614 (!pev->group ||
615 streql(entry->pev.group, pev->group)))
616 goto found;
617
618 continue;
619 }
620 /* Hit if same event name or same command-string */
621 if ((pev->event &&
622 (streql(entry->pev.group, pev->group) &&
623 streql(entry->pev.event, pev->event))) ||
624 (!strcmp(entry->spev, cmd)))
625 goto found;
626 }
627 entry = NULL;
628
629found:
630 free(cmd);
631 return entry;
632}
633
634struct probe_cache_entry *
635probe_cache__find_by_name(struct probe_cache *pcache,
636 const char *group, const char *event)
637{
638 struct probe_cache_entry *entry = NULL;
639
640 for_each_probe_cache_entry(entry, pcache) {
641 /* Hit if same event name or same command-string */
642 if (streql(entry->pev.group, group) &&
643 streql(entry->pev.event, event))
644 goto found;
645 }
646 entry = NULL;
647
648found:
649 return entry;
650}
651
652int probe_cache__add_entry(struct probe_cache *pcache,
653 struct perf_probe_event *pev,
654 struct probe_trace_event *tevs, int ntevs)
655{
656 struct probe_cache_entry *entry = NULL;
657 char *command;
658 int i, ret = 0;
659
660 if (!pcache || !pev || !tevs || ntevs <= 0) {
661 ret = -EINVAL;
662 goto out_err;
663 }
664
665 /* Remove old cache entry */
666 entry = probe_cache__find(pcache, pev);
667 if (entry) {
668 list_del_init(&entry->node);
669 probe_cache_entry__delete(entry);
670 }
671
672 ret = -ENOMEM;
673 entry = probe_cache_entry__new(pev);
674 if (!entry)
675 goto out_err;
676
677 for (i = 0; i < ntevs; i++) {
678 if (!tevs[i].point.symbol)
679 continue;
680
681 command = synthesize_probe_trace_command(&tevs[i]);
682 if (!command)
683 goto out_err;
684 strlist__add(entry->tevlist, command);
685 free(command);
686 }
687 list_add_tail(&entry->node, &pcache->entries);
688 pr_debug("Added probe cache: %d\n", ntevs);
689 return 0;
690
691out_err:
692 pr_debug("Failed to add probe caches\n");
693 probe_cache_entry__delete(entry);
694 return ret;
695}
696
697#ifdef HAVE_GELF_GETNOTE_SUPPORT
698static unsigned long long sdt_note__get_addr(struct sdt_note *note)
699{
700 return note->bit32 ? (unsigned long long)note->addr.a32[0]
701 : (unsigned long long)note->addr.a64[0];
702}
703
704static const char * const type_to_suffix[] = {
705 ":s64", "", "", "", ":s32", "", ":s16", ":s8",
706 "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
707};
708
709/*
710 * Isolate the string number and convert it into a decimal value;
711 * this will be an index to get suffix of the uprobe name (defining
712 * the type)
713 */
714static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
715{
716 long type_idx;
717
718 type_idx = strtol(n_ptr, NULL, 10);
719 if (type_idx < -8 || type_idx > 8) {
720 pr_debug4("Failed to get a valid sdt type\n");
721 return -1;
722 }
723
724 *suffix = type_to_suffix[type_idx + 8];
725 return 0;
726}
727
728static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
729{
730 char *op, *desc = strdup(arg), *new_op = NULL;
731 const char *suffix = "";
732 int ret = -1;
733
734 if (desc == NULL) {
735 pr_debug4("Allocation error\n");
736 return ret;
737 }
738
739 /*
740 * Argument is in N@OP format. N is size of the argument and OP is
741 * the actual assembly operand. N can be omitted; in that case
742 * argument is just OP(without @).
743 */
744 op = strchr(desc, '@');
745 if (op) {
746 op[0] = '\0';
747 op++;
748
749 if (sdt_arg_parse_size(desc, &suffix))
750 goto error;
751 } else {
752 op = desc;
753 }
754
755 ret = arch_sdt_arg_parse_op(op, &new_op);
756
757 if (ret < 0)
758 goto error;
759
760 if (ret == SDT_ARG_VALID) {
761 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
762 if (ret < 0)
763 goto error;
764 }
765
766 ret = 0;
767error:
768 free(desc);
769 free(new_op);
770 return ret;
771}
772
773static char *synthesize_sdt_probe_command(struct sdt_note *note,
774 const char *pathname,
775 const char *sdtgrp)
776{
777 struct strbuf buf;
778 char *ret = NULL, **args;
779 int i, args_count;
780
781 if (strbuf_init(&buf, 32) < 0)
782 return NULL;
783
784 if (strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
785 sdtgrp, note->name, pathname,
786 sdt_note__get_addr(note)) < 0)
787 goto error;
788
789 if (!note->args)
790 goto out;
791
792 if (note->args) {
793 args = argv_split(note->args, &args_count);
794
795 for (i = 0; i < args_count; ++i) {
796 if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
797 goto error;
798 }
799 }
800
801out:
802 ret = strbuf_detach(&buf, NULL);
803error:
804 strbuf_release(&buf);
805 return ret;
806}
807
808int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
809{
810 struct probe_cache_entry *entry = NULL;
811 struct list_head sdtlist;
812 struct sdt_note *note;
813 char *buf;
814 char sdtgrp[64];
815 int ret;
816
817 INIT_LIST_HEAD(&sdtlist);
818 ret = get_sdt_note_list(&sdtlist, pathname);
819 if (ret < 0) {
820 pr_debug4("Failed to get sdt note: %d\n", ret);
821 return ret;
822 }
823 list_for_each_entry(note, &sdtlist, note_list) {
824 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
825 if (ret < 0)
826 break;
827 /* Try to find same-name entry */
828 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
829 if (!entry) {
830 entry = probe_cache_entry__new(NULL);
831 if (!entry) {
832 ret = -ENOMEM;
833 break;
834 }
835 entry->sdt = true;
836 ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
837 note->name, note->name);
838 if (ret < 0)
839 break;
840 entry->pev.event = strdup(note->name);
841 entry->pev.group = strdup(sdtgrp);
842 list_add_tail(&entry->node, &pcache->entries);
843 }
844 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
845 if (!buf) {
846 ret = -ENOMEM;
847 break;
848 }
849
850 strlist__add(entry->tevlist, buf);
851 free(buf);
852 entry = NULL;
853 }
854 if (entry) {
855 list_del_init(&entry->node);
856 probe_cache_entry__delete(entry);
857 }
858 cleanup_sdt_note_list(&sdtlist);
859 return ret;
860}
861#endif
862
863static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
864{
865 struct str_node *snode;
866 struct stat st;
867 struct iovec iov[3];
868 const char *prefix = entry->sdt ? "%" : "#";
869 int ret;
870 /* Save stat for rollback */
871 ret = fstat(fd, &st);
872 if (ret < 0)
873 return ret;
874
875 pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
876 iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
877 iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
878 iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
879 ret = writev(fd, iov, 3);
880 if (ret < (int)iov[1].iov_len + 2)
881 goto rollback;
882
883 strlist__for_each_entry(snode, entry->tevlist) {
884 iov[0].iov_base = (void *)snode->s;
885 iov[0].iov_len = strlen(snode->s);
886 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
887 ret = writev(fd, iov, 2);
888 if (ret < (int)iov[0].iov_len + 1)
889 goto rollback;
890 }
891 return 0;
892
893rollback:
894 /* Rollback to avoid cache file corruption */
895 if (ret > 0)
896 ret = -1;
897 if (ftruncate(fd, st.st_size) < 0)
898 ret = -2;
899
900 return ret;
901}
902
903int probe_cache__commit(struct probe_cache *pcache)
904{
905 struct probe_cache_entry *entry;
906 int ret = 0;
907
908 /* TBD: if we do not update existing entries, skip it */
909 ret = lseek(pcache->fd, 0, SEEK_SET);
910 if (ret < 0)
911 goto out;
912
913 ret = ftruncate(pcache->fd, 0);
914 if (ret < 0)
915 goto out;
916
917 for_each_probe_cache_entry(entry, pcache) {
918 ret = probe_cache_entry__write(entry, pcache->fd);
919 pr_debug("Cache committed: %d\n", ret);
920 if (ret < 0)
921 break;
922 }
923out:
924 return ret;
925}
926
927static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
928 struct strfilter *filter)
929{
930 char buf[128], *ptr = entry->spev;
931
932 if (entry->pev.event) {
933 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
934 ptr = buf;
935 }
936 return strfilter__compare(filter, ptr);
937}
938
939int probe_cache__filter_purge(struct probe_cache *pcache,
940 struct strfilter *filter)
941{
942 struct probe_cache_entry *entry, *tmp;
943
944 list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
945 if (probe_cache_entry__compare(entry, filter)) {
946 pr_info("Removed cached event: %s\n", entry->spev);
947 list_del_init(&entry->node);
948 probe_cache_entry__delete(entry);
949 }
950 }
951 return 0;
952}
953
954static int probe_cache__show_entries(struct probe_cache *pcache,
955 struct strfilter *filter)
956{
957 struct probe_cache_entry *entry;
958
959 for_each_probe_cache_entry(entry, pcache) {
960 if (probe_cache_entry__compare(entry, filter))
961 printf("%s\n", entry->spev);
962 }
963 return 0;
964}
965
966/* Show all cached probes */
967int probe_cache__show_all_caches(struct strfilter *filter)
968{
969 struct probe_cache *pcache;
970 struct strlist *bidlist;
971 struct str_node *nd;
972 char *buf = strfilter__string(filter);
973
974 pr_debug("list cache with filter: %s\n", buf);
975 free(buf);
976
977 bidlist = build_id_cache__list_all(true);
978 if (!bidlist) {
979 pr_debug("Failed to get buildids: %d\n", errno);
980 return -EINVAL;
981 }
982 strlist__for_each_entry(nd, bidlist) {
983 pcache = probe_cache__new(nd->s, NULL);
984 if (!pcache)
985 continue;
986 if (!list_empty(&pcache->entries)) {
987 buf = build_id_cache__origname(nd->s);
988 printf("%s (%s):\n", buf, nd->s);
989 free(buf);
990 probe_cache__show_entries(pcache, filter);
991 }
992 probe_cache__delete(pcache);
993 }
994 strlist__delete(bidlist);
995
996 return 0;
997}
998
999enum ftrace_readme {
1000 FTRACE_README_PROBE_TYPE_X = 0,
1001 FTRACE_README_KRETPROBE_OFFSET,
1002 FTRACE_README_END,
1003};
1004
1005static struct {
1006 const char *pattern;
1007 bool avail;
1008} ftrace_readme_table[] = {
1009#define DEFINE_TYPE(idx, pat) \
1010 [idx] = {.pattern = pat, .avail = false}
1011 DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1012 DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1013};
1014
1015static bool scan_ftrace_readme(enum ftrace_readme type)
1016{
1017 int fd;
1018 FILE *fp;
1019 char *buf = NULL;
1020 size_t len = 0;
1021 bool ret = false;
1022 static bool scanned = false;
1023
1024 if (scanned)
1025 goto result;
1026
1027 fd = open_trace_file("README", false);
1028 if (fd < 0)
1029 return ret;
1030
1031 fp = fdopen(fd, "r");
1032 if (!fp) {
1033 close(fd);
1034 return ret;
1035 }
1036
1037 while (getline(&buf, &len, fp) > 0)
1038 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1039 if (!ftrace_readme_table[i].avail)
1040 ftrace_readme_table[i].avail =
1041 strglobmatch(buf, ftrace_readme_table[i].pattern);
1042 scanned = true;
1043
1044 fclose(fp);
1045 free(buf);
1046
1047result:
1048 if (type >= FTRACE_README_END)
1049 return false;
1050
1051 return ftrace_readme_table[type].avail;
1052}
1053
1054bool probe_type_is_available(enum probe_type type)
1055{
1056 if (type >= PROBE_TYPE_END)
1057 return false;
1058 else if (type == PROBE_TYPE_X)
1059 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1060
1061 return true;
1062}
1063
1064bool kretprobe_offset_is_supported(void)
1065{
1066 return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1067}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * probe-file.c : operate ftrace k/uprobe events files
4 *
5 * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
6 */
7#include <errno.h>
8#include <fcntl.h>
9#include <sys/stat.h>
10#include <sys/types.h>
11#include <sys/uio.h>
12#include <unistd.h>
13#include <linux/zalloc.h>
14#include "namespaces.h"
15#include "event.h"
16#include "strlist.h"
17#include "strfilter.h"
18#include "debug.h"
19#include "build-id.h"
20#include "dso.h"
21#include "color.h"
22#include "symbol.h"
23#include "strbuf.h"
24#include <api/fs/tracing_path.h>
25#include "probe-event.h"
26#include "probe-file.h"
27#include "session.h"
28#include "perf_regs.h"
29#include "string2.h"
30
31/* 4096 - 2 ('\n' + '\0') */
32#define MAX_CMDLEN 4094
33
34static void print_open_warning(int err, bool uprobe)
35{
36 char sbuf[STRERR_BUFSIZE];
37
38 if (err == -ENOENT) {
39 const char *config;
40
41 if (uprobe)
42 config = "CONFIG_UPROBE_EVENTS";
43 else
44 config = "CONFIG_KPROBE_EVENTS";
45
46 pr_warning("%cprobe_events file does not exist"
47 " - please rebuild kernel with %s.\n",
48 uprobe ? 'u' : 'k', config);
49 } else if (err == -ENOTSUP)
50 pr_warning("Tracefs or debugfs is not mounted.\n");
51 else
52 pr_warning("Failed to open %cprobe_events: %s\n",
53 uprobe ? 'u' : 'k',
54 str_error_r(-err, sbuf, sizeof(sbuf)));
55}
56
57static void print_both_open_warning(int kerr, int uerr)
58{
59 /* Both kprobes and uprobes are disabled, warn it. */
60 if (kerr == -ENOTSUP && uerr == -ENOTSUP)
61 pr_warning("Tracefs or debugfs is not mounted.\n");
62 else if (kerr == -ENOENT && uerr == -ENOENT)
63 pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
64 "or/and CONFIG_UPROBE_EVENTS.\n");
65 else {
66 char sbuf[STRERR_BUFSIZE];
67 pr_warning("Failed to open kprobe events: %s.\n",
68 str_error_r(-kerr, sbuf, sizeof(sbuf)));
69 pr_warning("Failed to open uprobe events: %s.\n",
70 str_error_r(-uerr, sbuf, sizeof(sbuf)));
71 }
72}
73
74int open_trace_file(const char *trace_file, bool readwrite)
75{
76 char buf[PATH_MAX];
77 int ret;
78
79 ret = e_snprintf(buf, PATH_MAX, "%s/%s", tracing_path_mount(), trace_file);
80 if (ret >= 0) {
81 pr_debug("Opening %s write=%d\n", buf, readwrite);
82 if (readwrite && !probe_event_dry_run)
83 ret = open(buf, O_RDWR | O_APPEND, 0);
84 else
85 ret = open(buf, O_RDONLY, 0);
86
87 if (ret < 0)
88 ret = -errno;
89 }
90 return ret;
91}
92
93static int open_kprobe_events(bool readwrite)
94{
95 return open_trace_file("kprobe_events", readwrite);
96}
97
98static int open_uprobe_events(bool readwrite)
99{
100 return open_trace_file("uprobe_events", readwrite);
101}
102
103int probe_file__open(int flag)
104{
105 int fd;
106
107 if (flag & PF_FL_UPROBE)
108 fd = open_uprobe_events(flag & PF_FL_RW);
109 else
110 fd = open_kprobe_events(flag & PF_FL_RW);
111 if (fd < 0)
112 print_open_warning(fd, flag & PF_FL_UPROBE);
113
114 return fd;
115}
116
117int probe_file__open_both(int *kfd, int *ufd, int flag)
118{
119 if (!kfd || !ufd)
120 return -EINVAL;
121
122 *kfd = open_kprobe_events(flag & PF_FL_RW);
123 *ufd = open_uprobe_events(flag & PF_FL_RW);
124 if (*kfd < 0 && *ufd < 0) {
125 print_both_open_warning(*kfd, *ufd);
126 return *kfd;
127 }
128
129 return 0;
130}
131
132/* Get raw string list of current kprobe_events or uprobe_events */
133struct strlist *probe_file__get_rawlist(int fd)
134{
135 int ret, idx, fddup;
136 FILE *fp;
137 char buf[MAX_CMDLEN];
138 char *p;
139 struct strlist *sl;
140
141 if (fd < 0)
142 return NULL;
143
144 sl = strlist__new(NULL, NULL);
145 if (sl == NULL)
146 return NULL;
147
148 fddup = dup(fd);
149 if (fddup < 0)
150 goto out_free_sl;
151
152 fp = fdopen(fddup, "r");
153 if (!fp)
154 goto out_close_fddup;
155
156 while (!feof(fp)) {
157 p = fgets(buf, MAX_CMDLEN, fp);
158 if (!p)
159 break;
160
161 idx = strlen(p) - 1;
162 if (p[idx] == '\n')
163 p[idx] = '\0';
164 ret = strlist__add(sl, buf);
165 if (ret < 0) {
166 pr_debug("strlist__add failed (%d)\n", ret);
167 goto out_close_fp;
168 }
169 }
170 fclose(fp);
171
172 return sl;
173
174out_close_fp:
175 fclose(fp);
176 goto out_free_sl;
177out_close_fddup:
178 close(fddup);
179out_free_sl:
180 strlist__delete(sl);
181 return NULL;
182}
183
184static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
185{
186 char buf[128];
187 struct strlist *sl, *rawlist;
188 struct str_node *ent;
189 struct probe_trace_event tev;
190 int ret = 0;
191
192 memset(&tev, 0, sizeof(tev));
193 rawlist = probe_file__get_rawlist(fd);
194 if (!rawlist)
195 return NULL;
196 sl = strlist__new(NULL, NULL);
197 strlist__for_each_entry(ent, rawlist) {
198 ret = parse_probe_trace_command(ent->s, &tev);
199 if (ret < 0)
200 break;
201 if (include_group) {
202 ret = e_snprintf(buf, 128, "%s:%s", tev.group,
203 tev.event);
204 if (ret >= 0)
205 ret = strlist__add(sl, buf);
206 } else
207 ret = strlist__add(sl, tev.event);
208 clear_probe_trace_event(&tev);
209 if (ret < 0)
210 break;
211 }
212 strlist__delete(rawlist);
213
214 if (ret < 0) {
215 strlist__delete(sl);
216 return NULL;
217 }
218 return sl;
219}
220
221/* Get current perf-probe event names */
222struct strlist *probe_file__get_namelist(int fd)
223{
224 return __probe_file__get_namelist(fd, false);
225}
226
227int probe_file__add_event(int fd, struct probe_trace_event *tev)
228{
229 int ret = 0;
230 char *buf = synthesize_probe_trace_command(tev);
231 char sbuf[STRERR_BUFSIZE];
232
233 if (!buf) {
234 pr_debug("Failed to synthesize probe trace event.\n");
235 return -EINVAL;
236 }
237
238 pr_debug("Writing event: %s\n", buf);
239 if (!probe_event_dry_run) {
240 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
241 ret = -errno;
242 pr_warning("Failed to write event: %s\n",
243 str_error_r(errno, sbuf, sizeof(sbuf)));
244 }
245 }
246 free(buf);
247
248 return ret;
249}
250
251static int __del_trace_probe_event(int fd, struct str_node *ent)
252{
253 char *p;
254 char buf[128];
255 int ret;
256
257 /* Convert from perf-probe event to trace-probe event */
258 ret = e_snprintf(buf, 128, "-:%s", ent->s);
259 if (ret < 0)
260 goto error;
261
262 p = strchr(buf + 2, ':');
263 if (!p) {
264 pr_debug("Internal error: %s should have ':' but not.\n",
265 ent->s);
266 ret = -ENOTSUP;
267 goto error;
268 }
269 *p = '/';
270
271 pr_debug("Writing event: %s\n", buf);
272 ret = write(fd, buf, strlen(buf));
273 if (ret < 0) {
274 ret = -errno;
275 goto error;
276 }
277
278 return 0;
279error:
280 pr_warning("Failed to delete event: %s\n",
281 str_error_r(-ret, buf, sizeof(buf)));
282 return ret;
283}
284
285int probe_file__get_events(int fd, struct strfilter *filter,
286 struct strlist *plist)
287{
288 struct strlist *namelist;
289 struct str_node *ent;
290 const char *p;
291 int ret = -ENOENT;
292
293 if (!plist)
294 return -EINVAL;
295
296 namelist = __probe_file__get_namelist(fd, true);
297 if (!namelist)
298 return -ENOENT;
299
300 strlist__for_each_entry(ent, namelist) {
301 p = strchr(ent->s, ':');
302 if ((p && strfilter__compare(filter, p + 1)) ||
303 strfilter__compare(filter, ent->s)) {
304 strlist__add(plist, ent->s);
305 ret = 0;
306 }
307 }
308 strlist__delete(namelist);
309
310 return ret;
311}
312
313int probe_file__del_strlist(int fd, struct strlist *namelist)
314{
315 int ret = 0;
316 struct str_node *ent;
317
318 strlist__for_each_entry(ent, namelist) {
319 ret = __del_trace_probe_event(fd, ent);
320 if (ret < 0)
321 break;
322 }
323 return ret;
324}
325
326int probe_file__del_events(int fd, struct strfilter *filter)
327{
328 struct strlist *namelist;
329 int ret;
330
331 namelist = strlist__new(NULL, NULL);
332 if (!namelist)
333 return -ENOMEM;
334
335 ret = probe_file__get_events(fd, filter, namelist);
336 if (ret < 0)
337 return ret;
338
339 ret = probe_file__del_strlist(fd, namelist);
340 strlist__delete(namelist);
341
342 return ret;
343}
344
345/* Caller must ensure to remove this entry from list */
346static void probe_cache_entry__delete(struct probe_cache_entry *entry)
347{
348 if (entry) {
349 BUG_ON(!list_empty(&entry->node));
350
351 strlist__delete(entry->tevlist);
352 clear_perf_probe_event(&entry->pev);
353 zfree(&entry->spev);
354 free(entry);
355 }
356}
357
358static struct probe_cache_entry *
359probe_cache_entry__new(struct perf_probe_event *pev)
360{
361 struct probe_cache_entry *entry = zalloc(sizeof(*entry));
362
363 if (entry) {
364 INIT_LIST_HEAD(&entry->node);
365 entry->tevlist = strlist__new(NULL, NULL);
366 if (!entry->tevlist)
367 zfree(&entry);
368 else if (pev) {
369 entry->spev = synthesize_perf_probe_command(pev);
370 if (!entry->spev ||
371 perf_probe_event__copy(&entry->pev, pev) < 0) {
372 probe_cache_entry__delete(entry);
373 return NULL;
374 }
375 }
376 }
377
378 return entry;
379}
380
381int probe_cache_entry__get_event(struct probe_cache_entry *entry,
382 struct probe_trace_event **tevs)
383{
384 struct probe_trace_event *tev;
385 struct str_node *node;
386 int ret, i;
387
388 ret = strlist__nr_entries(entry->tevlist);
389 if (ret > probe_conf.max_probes)
390 return -E2BIG;
391
392 *tevs = zalloc(ret * sizeof(*tev));
393 if (!*tevs)
394 return -ENOMEM;
395
396 i = 0;
397 strlist__for_each_entry(node, entry->tevlist) {
398 tev = &(*tevs)[i++];
399 ret = parse_probe_trace_command(node->s, tev);
400 if (ret < 0)
401 break;
402 }
403 return i;
404}
405
406/* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
407static int probe_cache__open(struct probe_cache *pcache, const char *target,
408 struct nsinfo *nsi)
409{
410 char cpath[PATH_MAX];
411 char sbuildid[SBUILD_ID_SIZE];
412 char *dir_name = NULL;
413 bool is_kallsyms = false;
414 int ret, fd;
415 struct nscookie nsc;
416
417 if (target && build_id_cache__cached(target)) {
418 /* This is a cached buildid */
419 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
420 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
421 goto found;
422 }
423
424 if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
425 target = DSO__NAME_KALLSYMS;
426 is_kallsyms = true;
427 ret = sysfs__sprintf_build_id("/", sbuildid);
428 } else {
429 nsinfo__mountns_enter(nsi, &nsc);
430 ret = filename__sprintf_build_id(target, sbuildid);
431 nsinfo__mountns_exit(&nsc);
432 }
433
434 if (ret < 0) {
435 pr_debug("Failed to get build-id from %s.\n", target);
436 return ret;
437 }
438
439 /* If we have no buildid cache, make it */
440 if (!build_id_cache__cached(sbuildid)) {
441 ret = build_id_cache__add_s(sbuildid, target, nsi,
442 is_kallsyms, NULL);
443 if (ret < 0) {
444 pr_debug("Failed to add build-id cache: %s\n", target);
445 return ret;
446 }
447 }
448
449 dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
450 false);
451found:
452 if (!dir_name) {
453 pr_debug("Failed to get cache from %s\n", target);
454 return -ENOMEM;
455 }
456
457 snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
458 fd = open(cpath, O_CREAT | O_RDWR, 0644);
459 if (fd < 0)
460 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
461 free(dir_name);
462 pcache->fd = fd;
463
464 return fd;
465}
466
467static int probe_cache__load(struct probe_cache *pcache)
468{
469 struct probe_cache_entry *entry = NULL;
470 char buf[MAX_CMDLEN], *p;
471 int ret = 0, fddup;
472 FILE *fp;
473
474 fddup = dup(pcache->fd);
475 if (fddup < 0)
476 return -errno;
477 fp = fdopen(fddup, "r");
478 if (!fp) {
479 close(fddup);
480 return -EINVAL;
481 }
482
483 while (!feof(fp)) {
484 if (!fgets(buf, MAX_CMDLEN, fp))
485 break;
486 p = strchr(buf, '\n');
487 if (p)
488 *p = '\0';
489 /* #perf_probe_event or %sdt_event */
490 if (buf[0] == '#' || buf[0] == '%') {
491 entry = probe_cache_entry__new(NULL);
492 if (!entry) {
493 ret = -ENOMEM;
494 goto out;
495 }
496 if (buf[0] == '%')
497 entry->sdt = true;
498 entry->spev = strdup(buf + 1);
499 if (entry->spev)
500 ret = parse_perf_probe_command(buf + 1,
501 &entry->pev);
502 else
503 ret = -ENOMEM;
504 if (ret < 0) {
505 probe_cache_entry__delete(entry);
506 goto out;
507 }
508 list_add_tail(&entry->node, &pcache->entries);
509 } else { /* trace_probe_event */
510 if (!entry) {
511 ret = -EINVAL;
512 goto out;
513 }
514 strlist__add(entry->tevlist, buf);
515 }
516 }
517out:
518 fclose(fp);
519 return ret;
520}
521
522static struct probe_cache *probe_cache__alloc(void)
523{
524 struct probe_cache *pcache = zalloc(sizeof(*pcache));
525
526 if (pcache) {
527 INIT_LIST_HEAD(&pcache->entries);
528 pcache->fd = -EINVAL;
529 }
530 return pcache;
531}
532
533void probe_cache__purge(struct probe_cache *pcache)
534{
535 struct probe_cache_entry *entry, *n;
536
537 list_for_each_entry_safe(entry, n, &pcache->entries, node) {
538 list_del_init(&entry->node);
539 probe_cache_entry__delete(entry);
540 }
541}
542
543void probe_cache__delete(struct probe_cache *pcache)
544{
545 if (!pcache)
546 return;
547
548 probe_cache__purge(pcache);
549 if (pcache->fd > 0)
550 close(pcache->fd);
551 free(pcache);
552}
553
554struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
555{
556 struct probe_cache *pcache = probe_cache__alloc();
557 int ret;
558
559 if (!pcache)
560 return NULL;
561
562 ret = probe_cache__open(pcache, target, nsi);
563 if (ret < 0) {
564 pr_debug("Cache open error: %d\n", ret);
565 goto out_err;
566 }
567
568 ret = probe_cache__load(pcache);
569 if (ret < 0) {
570 pr_debug("Cache read error: %d\n", ret);
571 goto out_err;
572 }
573
574 return pcache;
575
576out_err:
577 probe_cache__delete(pcache);
578 return NULL;
579}
580
581static bool streql(const char *a, const char *b)
582{
583 if (a == b)
584 return true;
585
586 if (!a || !b)
587 return false;
588
589 return !strcmp(a, b);
590}
591
592struct probe_cache_entry *
593probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
594{
595 struct probe_cache_entry *entry = NULL;
596 char *cmd = synthesize_perf_probe_command(pev);
597
598 if (!cmd)
599 return NULL;
600
601 for_each_probe_cache_entry(entry, pcache) {
602 if (pev->sdt) {
603 if (entry->pev.event &&
604 streql(entry->pev.event, pev->event) &&
605 (!pev->group ||
606 streql(entry->pev.group, pev->group)))
607 goto found;
608
609 continue;
610 }
611 /* Hit if same event name or same command-string */
612 if ((pev->event &&
613 (streql(entry->pev.group, pev->group) &&
614 streql(entry->pev.event, pev->event))) ||
615 (!strcmp(entry->spev, cmd)))
616 goto found;
617 }
618 entry = NULL;
619
620found:
621 free(cmd);
622 return entry;
623}
624
625struct probe_cache_entry *
626probe_cache__find_by_name(struct probe_cache *pcache,
627 const char *group, const char *event)
628{
629 struct probe_cache_entry *entry = NULL;
630
631 for_each_probe_cache_entry(entry, pcache) {
632 /* Hit if same event name or same command-string */
633 if (streql(entry->pev.group, group) &&
634 streql(entry->pev.event, event))
635 goto found;
636 }
637 entry = NULL;
638
639found:
640 return entry;
641}
642
643int probe_cache__add_entry(struct probe_cache *pcache,
644 struct perf_probe_event *pev,
645 struct probe_trace_event *tevs, int ntevs)
646{
647 struct probe_cache_entry *entry = NULL;
648 char *command;
649 int i, ret = 0;
650
651 if (!pcache || !pev || !tevs || ntevs <= 0) {
652 ret = -EINVAL;
653 goto out_err;
654 }
655
656 /* Remove old cache entry */
657 entry = probe_cache__find(pcache, pev);
658 if (entry) {
659 list_del_init(&entry->node);
660 probe_cache_entry__delete(entry);
661 }
662
663 ret = -ENOMEM;
664 entry = probe_cache_entry__new(pev);
665 if (!entry)
666 goto out_err;
667
668 for (i = 0; i < ntevs; i++) {
669 if (!tevs[i].point.symbol)
670 continue;
671
672 command = synthesize_probe_trace_command(&tevs[i]);
673 if (!command)
674 goto out_err;
675 strlist__add(entry->tevlist, command);
676 free(command);
677 }
678 list_add_tail(&entry->node, &pcache->entries);
679 pr_debug("Added probe cache: %d\n", ntevs);
680 return 0;
681
682out_err:
683 pr_debug("Failed to add probe caches\n");
684 probe_cache_entry__delete(entry);
685 return ret;
686}
687
688#ifdef HAVE_GELF_GETNOTE_SUPPORT
689static unsigned long long sdt_note__get_addr(struct sdt_note *note)
690{
691 return note->bit32 ?
692 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
693 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
694}
695
696static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
697{
698 return note->bit32 ?
699 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
700 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
701}
702
703static const char * const type_to_suffix[] = {
704 ":s64", "", "", "", ":s32", "", ":s16", ":s8",
705 "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
706};
707
708/*
709 * Isolate the string number and convert it into a decimal value;
710 * this will be an index to get suffix of the uprobe name (defining
711 * the type)
712 */
713static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
714{
715 long type_idx;
716
717 type_idx = strtol(n_ptr, NULL, 10);
718 if (type_idx < -8 || type_idx > 8) {
719 pr_debug4("Failed to get a valid sdt type\n");
720 return -1;
721 }
722
723 *suffix = type_to_suffix[type_idx + 8];
724 return 0;
725}
726
727static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
728{
729 char *op, *desc = strdup(arg), *new_op = NULL;
730 const char *suffix = "";
731 int ret = -1;
732
733 if (desc == NULL) {
734 pr_debug4("Allocation error\n");
735 return ret;
736 }
737
738 /*
739 * Argument is in N@OP format. N is size of the argument and OP is
740 * the actual assembly operand. N can be omitted; in that case
741 * argument is just OP(without @).
742 */
743 op = strchr(desc, '@');
744 if (op) {
745 op[0] = '\0';
746 op++;
747
748 if (sdt_arg_parse_size(desc, &suffix))
749 goto error;
750 } else {
751 op = desc;
752 }
753
754 ret = arch_sdt_arg_parse_op(op, &new_op);
755
756 if (ret < 0)
757 goto error;
758
759 if (ret == SDT_ARG_VALID) {
760 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
761 if (ret < 0)
762 goto error;
763 }
764
765 ret = 0;
766error:
767 free(desc);
768 free(new_op);
769 return ret;
770}
771
772static char *synthesize_sdt_probe_command(struct sdt_note *note,
773 const char *pathname,
774 const char *sdtgrp)
775{
776 struct strbuf buf;
777 char *ret = NULL, **args;
778 int i, args_count, err;
779 unsigned long long ref_ctr_offset;
780
781 if (strbuf_init(&buf, 32) < 0)
782 return NULL;
783
784 err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
785 sdtgrp, note->name, pathname,
786 sdt_note__get_addr(note));
787
788 ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
789 if (ref_ctr_offset && err >= 0)
790 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
791
792 if (err < 0)
793 goto error;
794
795 if (!note->args)
796 goto out;
797
798 if (note->args) {
799 args = argv_split(note->args, &args_count);
800
801 for (i = 0; i < args_count; ++i) {
802 if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
803 goto error;
804 }
805 }
806
807out:
808 ret = strbuf_detach(&buf, NULL);
809error:
810 strbuf_release(&buf);
811 return ret;
812}
813
814int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
815{
816 struct probe_cache_entry *entry = NULL;
817 struct list_head sdtlist;
818 struct sdt_note *note;
819 char *buf;
820 char sdtgrp[64];
821 int ret;
822
823 INIT_LIST_HEAD(&sdtlist);
824 ret = get_sdt_note_list(&sdtlist, pathname);
825 if (ret < 0) {
826 pr_debug4("Failed to get sdt note: %d\n", ret);
827 return ret;
828 }
829 list_for_each_entry(note, &sdtlist, note_list) {
830 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
831 if (ret < 0)
832 break;
833 /* Try to find same-name entry */
834 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
835 if (!entry) {
836 entry = probe_cache_entry__new(NULL);
837 if (!entry) {
838 ret = -ENOMEM;
839 break;
840 }
841 entry->sdt = true;
842 ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
843 note->name, note->name);
844 if (ret < 0)
845 break;
846 entry->pev.event = strdup(note->name);
847 entry->pev.group = strdup(sdtgrp);
848 list_add_tail(&entry->node, &pcache->entries);
849 }
850 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
851 if (!buf) {
852 ret = -ENOMEM;
853 break;
854 }
855
856 strlist__add(entry->tevlist, buf);
857 free(buf);
858 entry = NULL;
859 }
860 if (entry) {
861 list_del_init(&entry->node);
862 probe_cache_entry__delete(entry);
863 }
864 cleanup_sdt_note_list(&sdtlist);
865 return ret;
866}
867#endif
868
869static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
870{
871 struct str_node *snode;
872 struct stat st;
873 struct iovec iov[3];
874 const char *prefix = entry->sdt ? "%" : "#";
875 int ret;
876 /* Save stat for rollback */
877 ret = fstat(fd, &st);
878 if (ret < 0)
879 return ret;
880
881 pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
882 iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
883 iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
884 iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
885 ret = writev(fd, iov, 3);
886 if (ret < (int)iov[1].iov_len + 2)
887 goto rollback;
888
889 strlist__for_each_entry(snode, entry->tevlist) {
890 iov[0].iov_base = (void *)snode->s;
891 iov[0].iov_len = strlen(snode->s);
892 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
893 ret = writev(fd, iov, 2);
894 if (ret < (int)iov[0].iov_len + 1)
895 goto rollback;
896 }
897 return 0;
898
899rollback:
900 /* Rollback to avoid cache file corruption */
901 if (ret > 0)
902 ret = -1;
903 if (ftruncate(fd, st.st_size) < 0)
904 ret = -2;
905
906 return ret;
907}
908
909int probe_cache__commit(struct probe_cache *pcache)
910{
911 struct probe_cache_entry *entry;
912 int ret = 0;
913
914 /* TBD: if we do not update existing entries, skip it */
915 ret = lseek(pcache->fd, 0, SEEK_SET);
916 if (ret < 0)
917 goto out;
918
919 ret = ftruncate(pcache->fd, 0);
920 if (ret < 0)
921 goto out;
922
923 for_each_probe_cache_entry(entry, pcache) {
924 ret = probe_cache_entry__write(entry, pcache->fd);
925 pr_debug("Cache committed: %d\n", ret);
926 if (ret < 0)
927 break;
928 }
929out:
930 return ret;
931}
932
933static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
934 struct strfilter *filter)
935{
936 char buf[128], *ptr = entry->spev;
937
938 if (entry->pev.event) {
939 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
940 ptr = buf;
941 }
942 return strfilter__compare(filter, ptr);
943}
944
945int probe_cache__filter_purge(struct probe_cache *pcache,
946 struct strfilter *filter)
947{
948 struct probe_cache_entry *entry, *tmp;
949
950 list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
951 if (probe_cache_entry__compare(entry, filter)) {
952 pr_info("Removed cached event: %s\n", entry->spev);
953 list_del_init(&entry->node);
954 probe_cache_entry__delete(entry);
955 }
956 }
957 return 0;
958}
959
960static int probe_cache__show_entries(struct probe_cache *pcache,
961 struct strfilter *filter)
962{
963 struct probe_cache_entry *entry;
964
965 for_each_probe_cache_entry(entry, pcache) {
966 if (probe_cache_entry__compare(entry, filter))
967 printf("%s\n", entry->spev);
968 }
969 return 0;
970}
971
972/* Show all cached probes */
973int probe_cache__show_all_caches(struct strfilter *filter)
974{
975 struct probe_cache *pcache;
976 struct strlist *bidlist;
977 struct str_node *nd;
978 char *buf = strfilter__string(filter);
979
980 pr_debug("list cache with filter: %s\n", buf);
981 free(buf);
982
983 bidlist = build_id_cache__list_all(true);
984 if (!bidlist) {
985 pr_debug("Failed to get buildids: %d\n", errno);
986 return -EINVAL;
987 }
988 strlist__for_each_entry(nd, bidlist) {
989 pcache = probe_cache__new(nd->s, NULL);
990 if (!pcache)
991 continue;
992 if (!list_empty(&pcache->entries)) {
993 buf = build_id_cache__origname(nd->s);
994 printf("%s (%s):\n", buf, nd->s);
995 free(buf);
996 probe_cache__show_entries(pcache, filter);
997 }
998 probe_cache__delete(pcache);
999 }
1000 strlist__delete(bidlist);
1001
1002 return 0;
1003}
1004
1005enum ftrace_readme {
1006 FTRACE_README_PROBE_TYPE_X = 0,
1007 FTRACE_README_KRETPROBE_OFFSET,
1008 FTRACE_README_UPROBE_REF_CTR,
1009 FTRACE_README_USER_ACCESS,
1010 FTRACE_README_END,
1011};
1012
1013static struct {
1014 const char *pattern;
1015 bool avail;
1016} ftrace_readme_table[] = {
1017#define DEFINE_TYPE(idx, pat) \
1018 [idx] = {.pattern = pat, .avail = false}
1019 DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1020 DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1021 DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1022 DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"),
1023};
1024
1025static bool scan_ftrace_readme(enum ftrace_readme type)
1026{
1027 int fd;
1028 FILE *fp;
1029 char *buf = NULL;
1030 size_t len = 0;
1031 bool ret = false;
1032 static bool scanned = false;
1033
1034 if (scanned)
1035 goto result;
1036
1037 fd = open_trace_file("README", false);
1038 if (fd < 0)
1039 return ret;
1040
1041 fp = fdopen(fd, "r");
1042 if (!fp) {
1043 close(fd);
1044 return ret;
1045 }
1046
1047 while (getline(&buf, &len, fp) > 0)
1048 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1049 if (!ftrace_readme_table[i].avail)
1050 ftrace_readme_table[i].avail =
1051 strglobmatch(buf, ftrace_readme_table[i].pattern);
1052 scanned = true;
1053
1054 fclose(fp);
1055 free(buf);
1056
1057result:
1058 if (type >= FTRACE_README_END)
1059 return false;
1060
1061 return ftrace_readme_table[type].avail;
1062}
1063
1064bool probe_type_is_available(enum probe_type type)
1065{
1066 if (type >= PROBE_TYPE_END)
1067 return false;
1068 else if (type == PROBE_TYPE_X)
1069 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1070
1071 return true;
1072}
1073
1074bool kretprobe_offset_is_supported(void)
1075{
1076 return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1077}
1078
1079bool uprobe_ref_ctr_is_supported(void)
1080{
1081 return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1082}
1083
1084bool user_access_is_supported(void)
1085{
1086 return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1087}