Loading...
Note: File does not exist in v3.1.
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}