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 <api/fs/fs.h>
26 #include "probe-event.h"
27 #include "probe-file.h"
28 #include "session.h"
29 #include "perf_regs.h"
30 #include "string2.h"
31
32 /* 4096 - 2 ('\n' + '\0') */
33 #define MAX_CMDLEN 4094
34
35 static bool print_common_warning(int err, bool readwrite)
36 {
37 if (err == -EACCES)
38 pr_warning("No permission to %s tracefs.\nPlease %s\n",
39 readwrite ? "write" : "read",
40 readwrite ? "run this command again with sudo." :
41 "try 'sudo mount -o remount,mode=755 /sys/kernel/tracing/'");
42 else
43 return false;
44
45 return true;
46 }
47
48 static bool print_configure_probe_event(int kerr, int uerr)
49 {
50 const char *config, *file;
51
52 if (kerr == -ENOENT && uerr == -ENOENT) {
53 file = "{k,u}probe_events";
54 config = "CONFIG_KPROBE_EVENTS=y and CONFIG_UPROBE_EVENTS=y";
55 } else if (kerr == -ENOENT) {
56 file = "kprobe_events";
57 config = "CONFIG_KPROBE_EVENTS=y";
58 } else if (uerr == -ENOENT) {
59 file = "uprobe_events";
60 config = "CONFIG_UPROBE_EVENTS=y";
61 } else
62 return false;
63
64 if (!debugfs__configured() && !tracefs__configured())
65 pr_warning("Debugfs or tracefs is not mounted\n"
66 "Please try 'sudo mount -t tracefs nodev /sys/kernel/tracing/'\n");
67 else
68 pr_warning("%s/%s does not exist.\nPlease rebuild kernel with %s.\n",
69 tracing_path_mount(), file, config);
70
71 return true;
72 }
73
74 static void print_open_warning(int err, bool uprobe, bool readwrite)
75 {
76 char sbuf[STRERR_BUFSIZE];
77
78 if (print_common_warning(err, readwrite))
79 return;
80
81 if (print_configure_probe_event(uprobe ? 0 : err, uprobe ? err : 0))
82 return;
83
84 pr_warning("Failed to open %s/%cprobe_events: %s\n",
85 tracing_path_mount(), uprobe ? 'u' : 'k',
86 str_error_r(-err, sbuf, sizeof(sbuf)));
87 }
88
89 static void print_both_open_warning(int kerr, int uerr, bool readwrite)
90 {
91 char sbuf[STRERR_BUFSIZE];
92
93 if (kerr == uerr && print_common_warning(kerr, readwrite))
94 return;
95
96 if (print_configure_probe_event(kerr, uerr))
97 return;
98
99 if (kerr < 0)
100 pr_warning("Failed to open %s/kprobe_events: %s.\n",
101 tracing_path_mount(),
102 str_error_r(-kerr, sbuf, sizeof(sbuf)));
103 if (uerr < 0)
104 pr_warning("Failed to open %s/uprobe_events: %s.\n",
105 tracing_path_mount(),
106 str_error_r(-uerr, sbuf, sizeof(sbuf)));
107 }
108
109 int open_trace_file(const char *trace_file, bool readwrite)
110 {
111 char buf[PATH_MAX];
112 int ret;
113
114 ret = e_snprintf(buf, PATH_MAX, "%s/%s", tracing_path_mount(), trace_file);
115 if (ret >= 0) {
116 pr_debug("Opening %s write=%d\n", buf, readwrite);
117 if (readwrite && !probe_event_dry_run)
118 ret = open(buf, O_RDWR | O_APPEND, 0);
119 else
120 ret = open(buf, O_RDONLY, 0);
121
122 if (ret < 0)
123 ret = -errno;
124 }
125 return ret;
126 }
127
128 static int open_kprobe_events(bool readwrite)
129 {
130 return open_trace_file("kprobe_events", readwrite);
131 }
132
133 static int open_uprobe_events(bool readwrite)
134 {
135 return open_trace_file("uprobe_events", readwrite);
136 }
137
138 int probe_file__open(int flag)
139 {
140 int fd;
141
142 if (flag & PF_FL_UPROBE)
143 fd = open_uprobe_events(flag & PF_FL_RW);
144 else
145 fd = open_kprobe_events(flag & PF_FL_RW);
146 if (fd < 0)
147 print_open_warning(fd, flag & PF_FL_UPROBE, flag & PF_FL_RW);
148
149 return fd;
150 }
151
152 int probe_file__open_both(int *kfd, int *ufd, int flag)
153 {
154 if (!kfd || !ufd)
155 return -EINVAL;
156
157 *kfd = open_kprobe_events(flag & PF_FL_RW);
158 *ufd = open_uprobe_events(flag & PF_FL_RW);
159 if (*kfd < 0 && *ufd < 0) {
160 print_both_open_warning(*kfd, *ufd, flag & PF_FL_RW);
161 return *kfd;
162 }
163
164 return 0;
165 }
166
167 /* Get raw string list of current kprobe_events or uprobe_events */
168 struct strlist *probe_file__get_rawlist(int fd)
169 {
170 int ret, idx, fddup;
171 FILE *fp;
172 char buf[MAX_CMDLEN];
173 char *p;
174 struct strlist *sl;
175
176 if (fd < 0)
177 return NULL;
178
179 sl = strlist__new(NULL, NULL);
180 if (sl == NULL)
181 return NULL;
182
183 fddup = dup(fd);
184 if (fddup < 0)
185 goto out_free_sl;
186
187 fp = fdopen(fddup, "r");
188 if (!fp)
189 goto out_close_fddup;
190
191 while (!feof(fp)) {
192 p = fgets(buf, MAX_CMDLEN, fp);
193 if (!p)
194 break;
195
196 idx = strlen(p) - 1;
197 if (p[idx] == '\n')
198 p[idx] = '\0';
199 ret = strlist__add(sl, buf);
200 if (ret < 0) {
201 pr_debug("strlist__add failed (%d)\n", ret);
202 goto out_close_fp;
203 }
204 }
205 fclose(fp);
206
207 return sl;
208
209 out_close_fp:
210 fclose(fp);
211 goto out_free_sl;
212 out_close_fddup:
213 close(fddup);
214 out_free_sl:
215 strlist__delete(sl);
216 return NULL;
217 }
218
219 static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
220 {
221 char buf[128];
222 struct strlist *sl, *rawlist;
223 struct str_node *ent;
224 struct probe_trace_event tev;
225 int ret = 0;
226
227 memset(&tev, 0, sizeof(tev));
228 rawlist = probe_file__get_rawlist(fd);
229 if (!rawlist)
230 return NULL;
231 sl = strlist__new(NULL, NULL);
232 strlist__for_each_entry(ent, rawlist) {
233 ret = parse_probe_trace_command(ent->s, &tev);
234 if (ret < 0)
235 break;
236 if (include_group) {
237 ret = e_snprintf(buf, 128, "%s:%s", tev.group,
238 tev.event);
239 if (ret >= 0)
240 ret = strlist__add(sl, buf);
241 } else
242 ret = strlist__add(sl, tev.event);
243 clear_probe_trace_event(&tev);
244 /* Skip if there is same name multi-probe event in the list */
245 if (ret == -EEXIST)
246 ret = 0;
247 if (ret < 0)
248 break;
249 }
250 strlist__delete(rawlist);
251
252 if (ret < 0) {
253 strlist__delete(sl);
254 return NULL;
255 }
256 return sl;
257 }
258
259 /* Get current perf-probe event names */
260 struct strlist *probe_file__get_namelist(int fd)
261 {
262 return __probe_file__get_namelist(fd, false);
263 }
264
265 int probe_file__add_event(int fd, struct probe_trace_event *tev)
266 {
267 int ret = 0;
268 char *buf = synthesize_probe_trace_command(tev);
269 char sbuf[STRERR_BUFSIZE];
270
271 if (!buf) {
272 pr_debug("Failed to synthesize probe trace event.\n");
273 return -EINVAL;
274 }
275
276 pr_debug("Writing event: %s\n", buf);
277 if (!probe_event_dry_run) {
278 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
279 ret = -errno;
280 pr_warning("Failed to write event: %s\n",
281 str_error_r(errno, sbuf, sizeof(sbuf)));
282 }
283 }
284 free(buf);
285
286 return ret;
287 }
288
289 static int __del_trace_probe_event(int fd, struct str_node *ent)
290 {
291 char *p;
292 char buf[128];
293 int ret;
294
295 /* Convert from perf-probe event to trace-probe event */
296 ret = e_snprintf(buf, 128, "-:%s", ent->s);
297 if (ret < 0)
298 goto error;
299
300 p = strchr(buf + 2, ':');
301 if (!p) {
302 pr_debug("Internal error: %s should have ':' but not.\n",
303 ent->s);
304 ret = -ENOTSUP;
305 goto error;
306 }
307 *p = '/';
308
309 pr_debug("Writing event: %s\n", buf);
310 ret = write(fd, buf, strlen(buf));
311 if (ret < 0) {
312 ret = -errno;
313 goto error;
314 }
315
316 return 0;
317 error:
318 pr_warning("Failed to delete event: %s\n",
319 str_error_r(-ret, buf, sizeof(buf)));
320 return ret;
321 }
322
323 int probe_file__get_events(int fd, struct strfilter *filter,
324 struct strlist *plist)
325 {
326 struct strlist *namelist;
327 struct str_node *ent;
328 const char *p;
329 int ret = -ENOENT;
330
331 if (!plist)
332 return -EINVAL;
333
334 namelist = __probe_file__get_namelist(fd, true);
335 if (!namelist)
336 return -ENOENT;
337
338 strlist__for_each_entry(ent, namelist) {
339 p = strchr(ent->s, ':');
340 if ((p && strfilter__compare(filter, p + 1)) ||
341 strfilter__compare(filter, ent->s)) {
342 ret = strlist__add(plist, ent->s);
343 if (ret == -ENOMEM) {
344 pr_err("strlist__add failed with -ENOMEM\n");
345 goto out;
346 }
347 ret = 0;
348 }
349 }
350 out:
351 strlist__delete(namelist);
352
353 return ret;
354 }
355
356 int probe_file__del_strlist(int fd, struct strlist *namelist)
357 {
358 int ret = 0;
359 struct str_node *ent;
360
361 strlist__for_each_entry(ent, namelist) {
362 ret = __del_trace_probe_event(fd, ent);
363 if (ret < 0)
364 break;
365 }
366 return ret;
367 }
368
369 int probe_file__del_events(int fd, struct strfilter *filter)
370 {
371 struct strlist *namelist;
372 int ret;
373
374 namelist = strlist__new(NULL, NULL);
375 if (!namelist)
376 return -ENOMEM;
377
378 ret = probe_file__get_events(fd, filter, namelist);
379 if (ret < 0)
380 goto out;
381
382 ret = probe_file__del_strlist(fd, namelist);
383 out:
384 strlist__delete(namelist);
385 return ret;
386 }
387
388 /* Caller must ensure to remove this entry from list */
389 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
390 {
391 if (entry) {
392 BUG_ON(!list_empty(&entry->node));
393
394 strlist__delete(entry->tevlist);
395 clear_perf_probe_event(&entry->pev);
396 zfree(&entry->spev);
397 free(entry);
398 }
399 }
400
401 static struct probe_cache_entry *
402 probe_cache_entry__new(struct perf_probe_event *pev)
403 {
404 struct probe_cache_entry *entry = zalloc(sizeof(*entry));
405
406 if (entry) {
407 INIT_LIST_HEAD(&entry->node);
408 entry->tevlist = strlist__new(NULL, NULL);
409 if (!entry->tevlist)
410 zfree(&entry);
411 else if (pev) {
412 entry->spev = synthesize_perf_probe_command(pev);
413 if (!entry->spev ||
414 perf_probe_event__copy(&entry->pev, pev) < 0) {
415 probe_cache_entry__delete(entry);
416 return NULL;
417 }
418 }
419 }
420
421 return entry;
422 }
423
424 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
425 struct probe_trace_event **tevs)
426 {
427 struct probe_trace_event *tev;
428 struct str_node *node;
429 int ret, i;
430
431 ret = strlist__nr_entries(entry->tevlist);
432 if (ret > probe_conf.max_probes)
433 return -E2BIG;
434
435 *tevs = zalloc(ret * sizeof(*tev));
436 if (!*tevs)
437 return -ENOMEM;
438
439 i = 0;
440 strlist__for_each_entry(node, entry->tevlist) {
441 tev = &(*tevs)[i++];
442 ret = parse_probe_trace_command(node->s, tev);
443 if (ret < 0)
444 break;
445 }
446 return i;
447 }
448
449 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
450 static int probe_cache__open(struct probe_cache *pcache, const char *target,
451 struct nsinfo *nsi)
452 {
453 char cpath[PATH_MAX];
454 char sbuildid[SBUILD_ID_SIZE];
455 char *dir_name = NULL;
456 bool is_kallsyms = false;
457 int ret, fd;
458 struct nscookie nsc;
459
460 if (target && build_id_cache__cached(target)) {
461 /* This is a cached buildid */
462 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
463 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
464 goto found;
465 }
466
467 if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
468 target = DSO__NAME_KALLSYMS;
469 is_kallsyms = true;
470 ret = sysfs__sprintf_build_id("/", sbuildid);
471 } else {
472 nsinfo__mountns_enter(nsi, &nsc);
473 ret = filename__sprintf_build_id(target, sbuildid);
474 nsinfo__mountns_exit(&nsc);
475 }
476
477 if (ret < 0) {
478 pr_debug("Failed to get build-id from %s.\n", target);
479 return ret;
480 }
481
482 /* If we have no buildid cache, make it */
483 if (!build_id_cache__cached(sbuildid)) {
484 ret = build_id_cache__add_s(sbuildid, target, nsi,
485 is_kallsyms, NULL);
486 if (ret < 0) {
487 pr_debug("Failed to add build-id cache: %s\n", target);
488 return ret;
489 }
490 }
491
492 dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
493 false);
494 found:
495 if (!dir_name) {
496 pr_debug("Failed to get cache from %s\n", target);
497 return -ENOMEM;
498 }
499
500 snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
501 fd = open(cpath, O_CREAT | O_RDWR, 0644);
502 if (fd < 0)
503 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
504 free(dir_name);
505 pcache->fd = fd;
506
507 return fd;
508 }
509
510 static int probe_cache__load(struct probe_cache *pcache)
511 {
512 struct probe_cache_entry *entry = NULL;
513 char buf[MAX_CMDLEN], *p;
514 int ret = 0, fddup;
515 FILE *fp;
516
517 fddup = dup(pcache->fd);
518 if (fddup < 0)
519 return -errno;
520 fp = fdopen(fddup, "r");
521 if (!fp) {
522 close(fddup);
523 return -EINVAL;
524 }
525
526 while (!feof(fp)) {
527 if (!fgets(buf, MAX_CMDLEN, fp))
528 break;
529 p = strchr(buf, '\n');
530 if (p)
531 *p = '\0';
532 /* #perf_probe_event or %sdt_event */
533 if (buf[0] == '#' || buf[0] == '%') {
534 entry = probe_cache_entry__new(NULL);
535 if (!entry) {
536 ret = -ENOMEM;
537 goto out;
538 }
539 if (buf[0] == '%')
540 entry->sdt = true;
541 entry->spev = strdup(buf + 1);
542 if (entry->spev)
543 ret = parse_perf_probe_command(buf + 1,
544 &entry->pev);
545 else
546 ret = -ENOMEM;
547 if (ret < 0) {
548 probe_cache_entry__delete(entry);
549 goto out;
550 }
551 list_add_tail(&entry->node, &pcache->entries);
552 } else { /* trace_probe_event */
553 if (!entry) {
554 ret = -EINVAL;
555 goto out;
556 }
557 ret = strlist__add(entry->tevlist, buf);
558 if (ret == -ENOMEM) {
559 pr_err("strlist__add failed with -ENOMEM\n");
560 goto out;
561 }
562 }
563 }
564 out:
565 fclose(fp);
566 return ret;
567 }
568
569 static struct probe_cache *probe_cache__alloc(void)
570 {
571 struct probe_cache *pcache = zalloc(sizeof(*pcache));
572
573 if (pcache) {
574 INIT_LIST_HEAD(&pcache->entries);
575 pcache->fd = -EINVAL;
576 }
577 return pcache;
578 }
579
580 void probe_cache__purge(struct probe_cache *pcache)
581 {
582 struct probe_cache_entry *entry, *n;
583
584 list_for_each_entry_safe(entry, n, &pcache->entries, node) {
585 list_del_init(&entry->node);
586 probe_cache_entry__delete(entry);
587 }
588 }
589
590 void probe_cache__delete(struct probe_cache *pcache)
591 {
592 if (!pcache)
593 return;
594
595 probe_cache__purge(pcache);
596 if (pcache->fd > 0)
597 close(pcache->fd);
598 free(pcache);
599 }
600
601 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
602 {
603 struct probe_cache *pcache = probe_cache__alloc();
604 int ret;
605
606 if (!pcache)
607 return NULL;
608
609 ret = probe_cache__open(pcache, target, nsi);
610 if (ret < 0) {
611 pr_debug("Cache open error: %d\n", ret);
612 goto out_err;
613 }
614
615 ret = probe_cache__load(pcache);
616 if (ret < 0) {
617 pr_debug("Cache read error: %d\n", ret);
618 goto out_err;
619 }
620
621 return pcache;
622
623 out_err:
624 probe_cache__delete(pcache);
625 return NULL;
626 }
627
628 static bool streql(const char *a, const char *b)
629 {
630 if (a == b)
631 return true;
632
633 if (!a || !b)
634 return false;
635
636 return !strcmp(a, b);
637 }
638
639 struct probe_cache_entry *
640 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
641 {
642 struct probe_cache_entry *entry = NULL;
643 char *cmd = synthesize_perf_probe_command(pev);
644
645 if (!cmd)
646 return NULL;
647
648 for_each_probe_cache_entry(entry, pcache) {
649 if (pev->sdt) {
650 if (entry->pev.event &&
651 streql(entry->pev.event, pev->event) &&
652 (!pev->group ||
653 streql(entry->pev.group, pev->group)))
654 goto found;
655
656 continue;
657 }
658 /* Hit if same event name or same command-string */
659 if ((pev->event &&
660 (streql(entry->pev.group, pev->group) &&
661 streql(entry->pev.event, pev->event))) ||
662 (!strcmp(entry->spev, cmd)))
663 goto found;
664 }
665 entry = NULL;
666
667 found:
668 free(cmd);
669 return entry;
670 }
671
672 struct probe_cache_entry *
673 probe_cache__find_by_name(struct probe_cache *pcache,
674 const char *group, const char *event)
675 {
676 struct probe_cache_entry *entry = NULL;
677
678 for_each_probe_cache_entry(entry, pcache) {
679 /* Hit if same event name or same command-string */
680 if (streql(entry->pev.group, group) &&
681 streql(entry->pev.event, event))
682 goto found;
683 }
684 entry = NULL;
685
686 found:
687 return entry;
688 }
689
690 int probe_cache__add_entry(struct probe_cache *pcache,
691 struct perf_probe_event *pev,
692 struct probe_trace_event *tevs, int ntevs)
693 {
694 struct probe_cache_entry *entry = NULL;
695 char *command;
696 int i, ret = 0;
697
698 if (!pcache || !pev || !tevs || ntevs <= 0) {
699 ret = -EINVAL;
700 goto out_err;
701 }
702
703 /* Remove old cache entry */
704 entry = probe_cache__find(pcache, pev);
705 if (entry) {
706 list_del_init(&entry->node);
707 probe_cache_entry__delete(entry);
708 }
709
710 ret = -ENOMEM;
711 entry = probe_cache_entry__new(pev);
712 if (!entry)
713 goto out_err;
714
715 for (i = 0; i < ntevs; i++) {
716 if (!tevs[i].point.symbol)
717 continue;
718
719 command = synthesize_probe_trace_command(&tevs[i]);
720 if (!command)
721 goto out_err;
722 ret = strlist__add(entry->tevlist, command);
723 if (ret == -ENOMEM) {
724 pr_err("strlist__add failed with -ENOMEM\n");
725 goto out_err;
726 }
727
728 free(command);
729 }
730 list_add_tail(&entry->node, &pcache->entries);
731 pr_debug("Added probe cache: %d\n", ntevs);
732 return 0;
733
734 out_err:
735 pr_debug("Failed to add probe caches\n");
736 probe_cache_entry__delete(entry);
737 return ret;
738 }
739
740 #ifdef HAVE_GELF_GETNOTE_SUPPORT
741 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
742 {
743 return note->bit32 ?
744 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
745 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
746 }
747
748 static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
749 {
750 return note->bit32 ?
751 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
752 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
753 }
754
755 static const char * const type_to_suffix[] = {
756 ":s64", "", "", "", ":s32", "", ":s16", ":s8",
757 "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
758 };
759
760 /*
761 * Isolate the string number and convert it into a decimal value;
762 * this will be an index to get suffix of the uprobe name (defining
763 * the type)
764 */
765 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
766 {
767 long type_idx;
768
769 type_idx = strtol(n_ptr, NULL, 10);
770 if (type_idx < -8 || type_idx > 8) {
771 pr_debug4("Failed to get a valid sdt type\n");
772 return -1;
773 }
774
775 *suffix = type_to_suffix[type_idx + 8];
776 return 0;
777 }
778
779 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
780 {
781 char *op, *desc = strdup(arg), *new_op = NULL;
782 const char *suffix = "";
783 int ret = -1;
784
785 if (desc == NULL) {
786 pr_debug4("Allocation error\n");
787 return ret;
788 }
789
790 /*
791 * Argument is in N@OP format. N is size of the argument and OP is
792 * the actual assembly operand. N can be omitted; in that case
793 * argument is just OP(without @).
794 */
795 op = strchr(desc, '@');
796 if (op) {
797 op[0] = '\0';
798 op++;
799
800 if (sdt_arg_parse_size(desc, &suffix))
801 goto error;
802 } else {
803 op = desc;
804 }
805
806 ret = arch_sdt_arg_parse_op(op, &new_op);
807
808 if (ret < 0)
809 goto error;
810
811 if (ret == SDT_ARG_VALID) {
812 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
813 if (ret < 0)
814 goto error;
815 }
816
817 ret = 0;
818 error:
819 free(desc);
820 free(new_op);
821 return ret;
822 }
823
824 static char *synthesize_sdt_probe_command(struct sdt_note *note,
825 const char *pathname,
826 const char *sdtgrp)
827 {
828 struct strbuf buf;
829 char *ret = NULL;
830 int i, args_count, err;
831 unsigned long long ref_ctr_offset;
832 char *arg;
833 int arg_idx = 0;
834
835 if (strbuf_init(&buf, 32) < 0)
836 return NULL;
837
838 err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
839 sdtgrp, note->name, pathname,
840 sdt_note__get_addr(note));
841
842 ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
843 if (ref_ctr_offset && err >= 0)
844 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
845
846 if (err < 0)
847 goto error;
848
849 if (!note->args)
850 goto out;
851
852 if (note->args) {
853 char **args = argv_split(note->args, &args_count);
854
855 if (args == NULL)
856 goto error;
857
858 for (i = 0; i < args_count; ) {
859 /*
860 * FIXUP: Arm64 ELF section '.note.stapsdt' uses string
861 * format "-4@[sp, NUM]" if a probe is to access data in
862 * the stack, e.g. below is an example for the SDT
863 * Arguments:
864 *
865 * Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4]
866 *
867 * Since the string introduces an extra space character
868 * in the middle of square brackets, the argument is
869 * divided into two items. Fixup for this case, if an
870 * item contains sub string "[sp,", need to concatenate
871 * the two items.
872 */
873 if (strstr(args[i], "[sp,") && (i+1) < args_count) {
874 err = asprintf(&arg, "%s %s", args[i], args[i+1]);
875 i += 2;
876 } else {
877 err = asprintf(&arg, "%s", args[i]);
878 i += 1;
879 }
880
881 /* Failed to allocate memory */
882 if (err < 0) {
883 argv_free(args);
884 goto error;
885 }
886
887 if (synthesize_sdt_probe_arg(&buf, arg_idx, arg) < 0) {
888 free(arg);
889 argv_free(args);
890 goto error;
891 }
892
893 free(arg);
894 arg_idx++;
895 }
896
897 argv_free(args);
898 }
899
900 out:
901 ret = strbuf_detach(&buf, NULL);
902 error:
903 strbuf_release(&buf);
904 return ret;
905 }
906
907 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
908 {
909 struct probe_cache_entry *entry = NULL;
910 struct list_head sdtlist;
911 struct sdt_note *note;
912 char *buf;
913 char sdtgrp[64];
914 int ret;
915
916 INIT_LIST_HEAD(&sdtlist);
917 ret = get_sdt_note_list(&sdtlist, pathname);
918 if (ret < 0) {
919 pr_debug4("Failed to get sdt note: %d\n", ret);
920 return ret;
921 }
922 list_for_each_entry(note, &sdtlist, note_list) {
923 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
924 if (ret < 0)
925 break;
926 /* Try to find same-name entry */
927 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
928 if (!entry) {
929 entry = probe_cache_entry__new(NULL);
930 if (!entry) {
931 ret = -ENOMEM;
932 break;
933 }
934 entry->sdt = true;
935 ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
936 note->name, note->name);
937 if (ret < 0)
938 break;
939 entry->pev.event = strdup(note->name);
940 entry->pev.group = strdup(sdtgrp);
941 list_add_tail(&entry->node, &pcache->entries);
942 }
943 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
944 if (!buf) {
945 ret = -ENOMEM;
946 break;
947 }
948
949 ret = strlist__add(entry->tevlist, buf);
950
951 free(buf);
952 entry = NULL;
953
954 if (ret == -ENOMEM) {
955 pr_err("strlist__add failed with -ENOMEM\n");
956 break;
957 }
958 }
959 if (entry) {
960 list_del_init(&entry->node);
961 probe_cache_entry__delete(entry);
962 }
963 cleanup_sdt_note_list(&sdtlist);
964 return ret;
965 }
966 #endif
967
968 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
969 {
970 struct str_node *snode;
971 struct stat st;
972 struct iovec iov[3];
973 const char *prefix = entry->sdt ? "%" : "#";
974 int ret;
975 /* Save stat for rollback */
976 ret = fstat(fd, &st);
977 if (ret < 0)
978 return ret;
979
980 pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
981 iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
982 iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
983 iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
984 ret = writev(fd, iov, 3);
985 if (ret < (int)iov[1].iov_len + 2)
986 goto rollback;
987
988 strlist__for_each_entry(snode, entry->tevlist) {
989 iov[0].iov_base = (void *)snode->s;
990 iov[0].iov_len = strlen(snode->s);
991 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
992 ret = writev(fd, iov, 2);
993 if (ret < (int)iov[0].iov_len + 1)
994 goto rollback;
995 }
996 return 0;
997
998 rollback:
999 /* Rollback to avoid cache file corruption */
1000 if (ret > 0)
1001 ret = -1;
1002 if (ftruncate(fd, st.st_size) < 0)
1003 ret = -2;
1004
1005 return ret;
1006 }
1007
1008 int probe_cache__commit(struct probe_cache *pcache)
1009 {
1010 struct probe_cache_entry *entry;
1011 int ret = 0;
1012
1013 /* TBD: if we do not update existing entries, skip it */
1014 ret = lseek(pcache->fd, 0, SEEK_SET);
1015 if (ret < 0)
1016 goto out;
1017
1018 ret = ftruncate(pcache->fd, 0);
1019 if (ret < 0)
1020 goto out;
1021
1022 for_each_probe_cache_entry(entry, pcache) {
1023 ret = probe_cache_entry__write(entry, pcache->fd);
1024 pr_debug("Cache committed: %d\n", ret);
1025 if (ret < 0)
1026 break;
1027 }
1028 out:
1029 return ret;
1030 }
1031
1032 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
1033 struct strfilter *filter)
1034 {
1035 char buf[128], *ptr = entry->spev;
1036
1037 if (entry->pev.event) {
1038 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
1039 ptr = buf;
1040 }
1041 return strfilter__compare(filter, ptr);
1042 }
1043
1044 int probe_cache__filter_purge(struct probe_cache *pcache,
1045 struct strfilter *filter)
1046 {
1047 struct probe_cache_entry *entry, *tmp;
1048
1049 list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
1050 if (probe_cache_entry__compare(entry, filter)) {
1051 pr_info("Removed cached event: %s\n", entry->spev);
1052 list_del_init(&entry->node);
1053 probe_cache_entry__delete(entry);
1054 }
1055 }
1056 return 0;
1057 }
1058
1059 static int probe_cache__show_entries(struct probe_cache *pcache,
1060 struct strfilter *filter)
1061 {
1062 struct probe_cache_entry *entry;
1063
1064 for_each_probe_cache_entry(entry, pcache) {
1065 if (probe_cache_entry__compare(entry, filter))
1066 printf("%s\n", entry->spev);
1067 }
1068 return 0;
1069 }
1070
1071 /* Show all cached probes */
1072 int probe_cache__show_all_caches(struct strfilter *filter)
1073 {
1074 struct probe_cache *pcache;
1075 struct strlist *bidlist;
1076 struct str_node *nd;
1077 char *buf = strfilter__string(filter);
1078
1079 pr_debug("list cache with filter: %s\n", buf);
1080 free(buf);
1081
1082 bidlist = build_id_cache__list_all(true);
1083 if (!bidlist) {
1084 pr_debug("Failed to get buildids: %d\n", errno);
1085 return -EINVAL;
1086 }
1087 strlist__for_each_entry(nd, bidlist) {
1088 pcache = probe_cache__new(nd->s, NULL);
1089 if (!pcache)
1090 continue;
1091 if (!list_empty(&pcache->entries)) {
1092 buf = build_id_cache__origname(nd->s);
1093 printf("%s (%s):\n", buf, nd->s);
1094 free(buf);
1095 probe_cache__show_entries(pcache, filter);
1096 }
1097 probe_cache__delete(pcache);
1098 }
1099 strlist__delete(bidlist);
1100
1101 return 0;
1102 }
1103
1104 enum ftrace_readme {
1105 FTRACE_README_PROBE_TYPE_X = 0,
1106 FTRACE_README_KRETPROBE_OFFSET,
1107 FTRACE_README_UPROBE_REF_CTR,
1108 FTRACE_README_USER_ACCESS,
1109 FTRACE_README_MULTIPROBE_EVENT,
1110 FTRACE_README_IMMEDIATE_VALUE,
1111 FTRACE_README_END,
1112 };
1113
1114 static struct {
1115 const char *pattern;
1116 bool avail;
1117 } ftrace_readme_table[] = {
1118 #define DEFINE_TYPE(idx, pat) \
1119 [idx] = {.pattern = pat, .avail = false}
1120 DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1121 DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1122 DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1123 DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
1124 DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1125 DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1126 };
1127
1128 static bool scan_ftrace_readme(enum ftrace_readme type)
1129 {
1130 int fd;
1131 FILE *fp;
1132 char *buf = NULL;
1133 size_t len = 0;
1134 bool ret = false;
1135 static bool scanned = false;
1136
1137 if (scanned)
1138 goto result;
1139
1140 fd = open_trace_file("README", false);
1141 if (fd < 0)
1142 return ret;
1143
1144 fp = fdopen(fd, "r");
1145 if (!fp) {
1146 close(fd);
1147 return ret;
1148 }
1149
1150 while (getline(&buf, &len, fp) > 0)
1151 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1152 if (!ftrace_readme_table[i].avail)
1153 ftrace_readme_table[i].avail =
1154 strglobmatch(buf, ftrace_readme_table[i].pattern);
1155 scanned = true;
1156
1157 fclose(fp);
1158 free(buf);
1159
1160 result:
1161 if (type >= FTRACE_README_END)
1162 return false;
1163
1164 return ftrace_readme_table[type].avail;
1165 }
1166
1167 bool probe_type_is_available(enum probe_type type)
1168 {
1169 if (type >= PROBE_TYPE_END)
1170 return false;
1171 else if (type == PROBE_TYPE_X)
1172 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1173
1174 return true;
1175 }
1176
1177 bool kretprobe_offset_is_supported(void)
1178 {
1179 return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1180 }
1181
1182 bool uprobe_ref_ctr_is_supported(void)
1183 {
1184 return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1185 }
1186
1187 bool user_access_is_supported(void)
1188 {
1189 return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1190 }
1191
1192 bool multiprobe_event_is_supported(void)
1193 {
1194 return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1195 }
1196
1197 bool immediate_value_is_supported(void)
1198 {
1199 return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1200 }
1201
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