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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
35static 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
48static 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
74static 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
89static 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
109int 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
128static int open_kprobe_events(bool readwrite)
129{
130 return open_trace_file("kprobe_events", readwrite);
131}
132
133static int open_uprobe_events(bool readwrite)
134{
135 return open_trace_file("uprobe_events", readwrite);
136}
137
138int 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
152int 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 */
168struct 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
209out_close_fp:
210 fclose(fp);
211 goto out_free_sl;
212out_close_fddup:
213 close(fddup);
214out_free_sl:
215 strlist__delete(sl);
216 return NULL;
217}
218
219static 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 */
260struct strlist *probe_file__get_namelist(int fd)
261{
262 return __probe_file__get_namelist(fd, false);
263}
264
265int 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
289static 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;
317error:
318 pr_warning("Failed to delete event: %s\n",
319 str_error_r(-ret, buf, sizeof(buf)));
320 return ret;
321}
322
323int 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 }
350out:
351 strlist__delete(namelist);
352
353 return ret;
354}
355
356int 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/* Caller must ensure to remove this entry from list */
370static void probe_cache_entry__delete(struct probe_cache_entry *entry)
371{
372 if (entry) {
373 BUG_ON(!list_empty(&entry->node));
374
375 strlist__delete(entry->tevlist);
376 clear_perf_probe_event(&entry->pev);
377 zfree(&entry->spev);
378 free(entry);
379 }
380}
381
382static struct probe_cache_entry *
383probe_cache_entry__new(struct perf_probe_event *pev)
384{
385 struct probe_cache_entry *entry = zalloc(sizeof(*entry));
386
387 if (entry) {
388 INIT_LIST_HEAD(&entry->node);
389 entry->tevlist = strlist__new(NULL, NULL);
390 if (!entry->tevlist)
391 zfree(&entry);
392 else if (pev) {
393 entry->spev = synthesize_perf_probe_command(pev);
394 if (!entry->spev ||
395 perf_probe_event__copy(&entry->pev, pev) < 0) {
396 probe_cache_entry__delete(entry);
397 return NULL;
398 }
399 }
400 }
401
402 return entry;
403}
404
405int probe_cache_entry__get_event(struct probe_cache_entry *entry,
406 struct probe_trace_event **tevs)
407{
408 struct probe_trace_event *tev;
409 struct str_node *node;
410 int ret, i;
411
412 ret = strlist__nr_entries(entry->tevlist);
413 if (ret > probe_conf.max_probes)
414 return -E2BIG;
415
416 *tevs = zalloc(ret * sizeof(*tev));
417 if (!*tevs)
418 return -ENOMEM;
419
420 i = 0;
421 strlist__for_each_entry(node, entry->tevlist) {
422 tev = &(*tevs)[i++];
423 ret = parse_probe_trace_command(node->s, tev);
424 if (ret < 0)
425 break;
426 }
427 return i;
428}
429
430/* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
431static int probe_cache__open(struct probe_cache *pcache, const char *target,
432 struct nsinfo *nsi)
433{
434 char cpath[PATH_MAX];
435 char sbuildid[SBUILD_ID_SIZE];
436 char *dir_name = NULL;
437 bool is_kallsyms = false;
438 int ret, fd;
439 struct nscookie nsc;
440
441 if (target && build_id_cache__cached(target)) {
442 /* This is a cached buildid */
443 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
444 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
445 goto found;
446 }
447
448 if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
449 target = DSO__NAME_KALLSYMS;
450 is_kallsyms = true;
451 ret = sysfs__sprintf_build_id("/", sbuildid);
452 } else {
453 nsinfo__mountns_enter(nsi, &nsc);
454 ret = filename__sprintf_build_id(target, sbuildid);
455 nsinfo__mountns_exit(&nsc);
456 }
457
458 if (ret < 0) {
459 pr_debug("Failed to get build-id from %s.\n", target);
460 return ret;
461 }
462
463 /* If we have no buildid cache, make it */
464 if (!build_id_cache__cached(sbuildid)) {
465 ret = build_id_cache__add_s(sbuildid, target, nsi,
466 is_kallsyms, NULL);
467 if (ret < 0) {
468 pr_debug("Failed to add build-id cache: %s\n", target);
469 return ret;
470 }
471 }
472
473 dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
474 false);
475found:
476 if (!dir_name) {
477 pr_debug("Failed to get cache from %s\n", target);
478 return -ENOMEM;
479 }
480
481 snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
482 fd = open(cpath, O_CREAT | O_RDWR, 0644);
483 if (fd < 0)
484 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
485 free(dir_name);
486 pcache->fd = fd;
487
488 return fd;
489}
490
491static int probe_cache__load(struct probe_cache *pcache)
492{
493 struct probe_cache_entry *entry = NULL;
494 char buf[MAX_CMDLEN], *p;
495 int ret = 0, fddup;
496 FILE *fp;
497
498 fddup = dup(pcache->fd);
499 if (fddup < 0)
500 return -errno;
501 fp = fdopen(fddup, "r");
502 if (!fp) {
503 close(fddup);
504 return -EINVAL;
505 }
506
507 while (!feof(fp)) {
508 if (!fgets(buf, MAX_CMDLEN, fp))
509 break;
510 p = strchr(buf, '\n');
511 if (p)
512 *p = '\0';
513 /* #perf_probe_event or %sdt_event */
514 if (buf[0] == '#' || buf[0] == '%') {
515 entry = probe_cache_entry__new(NULL);
516 if (!entry) {
517 ret = -ENOMEM;
518 goto out;
519 }
520 if (buf[0] == '%')
521 entry->sdt = true;
522 entry->spev = strdup(buf + 1);
523 if (entry->spev)
524 ret = parse_perf_probe_command(buf + 1,
525 &entry->pev);
526 else
527 ret = -ENOMEM;
528 if (ret < 0) {
529 probe_cache_entry__delete(entry);
530 goto out;
531 }
532 list_add_tail(&entry->node, &pcache->entries);
533 } else { /* trace_probe_event */
534 if (!entry) {
535 ret = -EINVAL;
536 goto out;
537 }
538 ret = strlist__add(entry->tevlist, buf);
539 if (ret == -ENOMEM) {
540 pr_err("strlist__add failed with -ENOMEM\n");
541 goto out;
542 }
543 }
544 }
545out:
546 fclose(fp);
547 return ret;
548}
549
550static struct probe_cache *probe_cache__alloc(void)
551{
552 struct probe_cache *pcache = zalloc(sizeof(*pcache));
553
554 if (pcache) {
555 INIT_LIST_HEAD(&pcache->entries);
556 pcache->fd = -EINVAL;
557 }
558 return pcache;
559}
560
561void probe_cache__purge(struct probe_cache *pcache)
562{
563 struct probe_cache_entry *entry, *n;
564
565 list_for_each_entry_safe(entry, n, &pcache->entries, node) {
566 list_del_init(&entry->node);
567 probe_cache_entry__delete(entry);
568 }
569}
570
571void probe_cache__delete(struct probe_cache *pcache)
572{
573 if (!pcache)
574 return;
575
576 probe_cache__purge(pcache);
577 if (pcache->fd > 0)
578 close(pcache->fd);
579 free(pcache);
580}
581
582struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
583{
584 struct probe_cache *pcache = probe_cache__alloc();
585 int ret;
586
587 if (!pcache)
588 return NULL;
589
590 ret = probe_cache__open(pcache, target, nsi);
591 if (ret < 0) {
592 pr_debug("Cache open error: %d\n", ret);
593 goto out_err;
594 }
595
596 ret = probe_cache__load(pcache);
597 if (ret < 0) {
598 pr_debug("Cache read error: %d\n", ret);
599 goto out_err;
600 }
601
602 return pcache;
603
604out_err:
605 probe_cache__delete(pcache);
606 return NULL;
607}
608
609static bool streql(const char *a, const char *b)
610{
611 if (a == b)
612 return true;
613
614 if (!a || !b)
615 return false;
616
617 return !strcmp(a, b);
618}
619
620struct probe_cache_entry *
621probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
622{
623 struct probe_cache_entry *entry = NULL;
624 char *cmd = synthesize_perf_probe_command(pev);
625
626 if (!cmd)
627 return NULL;
628
629 for_each_probe_cache_entry(entry, pcache) {
630 if (pev->sdt) {
631 if (entry->pev.event &&
632 streql(entry->pev.event, pev->event) &&
633 (!pev->group ||
634 streql(entry->pev.group, pev->group)))
635 goto found;
636
637 continue;
638 }
639 /* Hit if same event name or same command-string */
640 if ((pev->event &&
641 (streql(entry->pev.group, pev->group) &&
642 streql(entry->pev.event, pev->event))) ||
643 (!strcmp(entry->spev, cmd)))
644 goto found;
645 }
646 entry = NULL;
647
648found:
649 free(cmd);
650 return entry;
651}
652
653struct probe_cache_entry *
654probe_cache__find_by_name(struct probe_cache *pcache,
655 const char *group, const char *event)
656{
657 struct probe_cache_entry *entry = NULL;
658
659 for_each_probe_cache_entry(entry, pcache) {
660 /* Hit if same event name or same command-string */
661 if (streql(entry->pev.group, group) &&
662 streql(entry->pev.event, event))
663 goto found;
664 }
665 entry = NULL;
666
667found:
668 return entry;
669}
670
671int probe_cache__add_entry(struct probe_cache *pcache,
672 struct perf_probe_event *pev,
673 struct probe_trace_event *tevs, int ntevs)
674{
675 struct probe_cache_entry *entry = NULL;
676 char *command;
677 int i, ret = 0;
678
679 if (!pcache || !pev || !tevs || ntevs <= 0) {
680 ret = -EINVAL;
681 goto out_err;
682 }
683
684 /* Remove old cache entry */
685 entry = probe_cache__find(pcache, pev);
686 if (entry) {
687 list_del_init(&entry->node);
688 probe_cache_entry__delete(entry);
689 }
690
691 ret = -ENOMEM;
692 entry = probe_cache_entry__new(pev);
693 if (!entry)
694 goto out_err;
695
696 for (i = 0; i < ntevs; i++) {
697 if (!tevs[i].point.symbol)
698 continue;
699
700 command = synthesize_probe_trace_command(&tevs[i]);
701 if (!command)
702 goto out_err;
703 ret = strlist__add(entry->tevlist, command);
704 if (ret == -ENOMEM) {
705 pr_err("strlist__add failed with -ENOMEM\n");
706 goto out_err;
707 }
708
709 free(command);
710 }
711 list_add_tail(&entry->node, &pcache->entries);
712 pr_debug("Added probe cache: %d\n", ntevs);
713 return 0;
714
715out_err:
716 pr_debug("Failed to add probe caches\n");
717 probe_cache_entry__delete(entry);
718 return ret;
719}
720
721#ifdef HAVE_GELF_GETNOTE_SUPPORT
722static unsigned long long sdt_note__get_addr(struct sdt_note *note)
723{
724 return note->bit32 ?
725 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
726 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
727}
728
729static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
730{
731 return note->bit32 ?
732 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
733 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
734}
735
736static const char * const type_to_suffix[] = {
737 ":s64", "", "", "", ":s32", "", ":s16", ":s8",
738 "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
739};
740
741/*
742 * Isolate the string number and convert it into a decimal value;
743 * this will be an index to get suffix of the uprobe name (defining
744 * the type)
745 */
746static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
747{
748 long type_idx;
749
750 type_idx = strtol(n_ptr, NULL, 10);
751 if (type_idx < -8 || type_idx > 8) {
752 pr_debug4("Failed to get a valid sdt type\n");
753 return -1;
754 }
755
756 *suffix = type_to_suffix[type_idx + 8];
757 return 0;
758}
759
760static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
761{
762 char *op, *desc = strdup(arg), *new_op = NULL;
763 const char *suffix = "";
764 int ret = -1;
765
766 if (desc == NULL) {
767 pr_debug4("Allocation error\n");
768 return ret;
769 }
770
771 /*
772 * Argument is in N@OP format. N is size of the argument and OP is
773 * the actual assembly operand. N can be omitted; in that case
774 * argument is just OP(without @).
775 */
776 op = strchr(desc, '@');
777 if (op) {
778 op[0] = '\0';
779 op++;
780
781 if (sdt_arg_parse_size(desc, &suffix))
782 goto error;
783 } else {
784 op = desc;
785 }
786
787 ret = arch_sdt_arg_parse_op(op, &new_op);
788
789 if (ret < 0)
790 goto error;
791
792 if (ret == SDT_ARG_VALID) {
793 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
794 if (ret < 0)
795 goto error;
796 }
797
798 ret = 0;
799error:
800 free(desc);
801 free(new_op);
802 return ret;
803}
804
805static char *synthesize_sdt_probe_command(struct sdt_note *note,
806 const char *pathname,
807 const char *sdtgrp)
808{
809 struct strbuf buf;
810 char *ret = NULL;
811 int i, args_count, err;
812 unsigned long long ref_ctr_offset;
813 char *arg;
814 int arg_idx = 0;
815
816 if (strbuf_init(&buf, 32) < 0)
817 return NULL;
818
819 err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
820 sdtgrp, note->name, pathname,
821 sdt_note__get_addr(note));
822
823 ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
824 if (ref_ctr_offset && err >= 0)
825 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
826
827 if (err < 0)
828 goto error;
829
830 if (!note->args)
831 goto out;
832
833 if (note->args) {
834 char **args = argv_split(note->args, &args_count);
835
836 if (args == NULL)
837 goto error;
838
839 for (i = 0; i < args_count; ) {
840 /*
841 * FIXUP: Arm64 ELF section '.note.stapsdt' uses string
842 * format "-4@[sp, NUM]" if a probe is to access data in
843 * the stack, e.g. below is an example for the SDT
844 * Arguments:
845 *
846 * Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4]
847 *
848 * Since the string introduces an extra space character
849 * in the middle of square brackets, the argument is
850 * divided into two items. Fixup for this case, if an
851 * item contains sub string "[sp,", need to concatenate
852 * the two items.
853 */
854 if (strstr(args[i], "[sp,") && (i+1) < args_count) {
855 err = asprintf(&arg, "%s %s", args[i], args[i+1]);
856 i += 2;
857 } else {
858 err = asprintf(&arg, "%s", args[i]);
859 i += 1;
860 }
861
862 /* Failed to allocate memory */
863 if (err < 0) {
864 argv_free(args);
865 goto error;
866 }
867
868 if (synthesize_sdt_probe_arg(&buf, arg_idx, arg) < 0) {
869 free(arg);
870 argv_free(args);
871 goto error;
872 }
873
874 free(arg);
875 arg_idx++;
876 }
877
878 argv_free(args);
879 }
880
881out:
882 ret = strbuf_detach(&buf, NULL);
883error:
884 strbuf_release(&buf);
885 return ret;
886}
887
888int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
889{
890 struct probe_cache_entry *entry = NULL;
891 struct list_head sdtlist;
892 struct sdt_note *note;
893 char *buf;
894 char sdtgrp[64];
895 int ret;
896
897 INIT_LIST_HEAD(&sdtlist);
898 ret = get_sdt_note_list(&sdtlist, pathname);
899 if (ret < 0) {
900 pr_debug4("Failed to get sdt note: %d\n", ret);
901 return ret;
902 }
903 list_for_each_entry(note, &sdtlist, note_list) {
904 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
905 if (ret < 0)
906 break;
907 /* Try to find same-name entry */
908 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
909 if (!entry) {
910 entry = probe_cache_entry__new(NULL);
911 if (!entry) {
912 ret = -ENOMEM;
913 break;
914 }
915 entry->sdt = true;
916 ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
917 note->name, note->name);
918 if (ret < 0)
919 break;
920 entry->pev.event = strdup(note->name);
921 entry->pev.group = strdup(sdtgrp);
922 list_add_tail(&entry->node, &pcache->entries);
923 }
924 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
925 if (!buf) {
926 ret = -ENOMEM;
927 break;
928 }
929
930 ret = strlist__add(entry->tevlist, buf);
931
932 free(buf);
933 entry = NULL;
934
935 if (ret == -ENOMEM) {
936 pr_err("strlist__add failed with -ENOMEM\n");
937 break;
938 }
939 }
940 if (entry) {
941 list_del_init(&entry->node);
942 probe_cache_entry__delete(entry);
943 }
944 cleanup_sdt_note_list(&sdtlist);
945 return ret;
946}
947#endif
948
949static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
950{
951 struct str_node *snode;
952 struct stat st;
953 struct iovec iov[3];
954 const char *prefix = entry->sdt ? "%" : "#";
955 int ret;
956 /* Save stat for rollback */
957 ret = fstat(fd, &st);
958 if (ret < 0)
959 return ret;
960
961 pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
962 iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
963 iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
964 iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
965 ret = writev(fd, iov, 3);
966 if (ret < (int)iov[1].iov_len + 2)
967 goto rollback;
968
969 strlist__for_each_entry(snode, entry->tevlist) {
970 iov[0].iov_base = (void *)snode->s;
971 iov[0].iov_len = strlen(snode->s);
972 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
973 ret = writev(fd, iov, 2);
974 if (ret < (int)iov[0].iov_len + 1)
975 goto rollback;
976 }
977 return 0;
978
979rollback:
980 /* Rollback to avoid cache file corruption */
981 if (ret > 0)
982 ret = -1;
983 if (ftruncate(fd, st.st_size) < 0)
984 ret = -2;
985
986 return ret;
987}
988
989int probe_cache__commit(struct probe_cache *pcache)
990{
991 struct probe_cache_entry *entry;
992 int ret = 0;
993
994 /* TBD: if we do not update existing entries, skip it */
995 ret = lseek(pcache->fd, 0, SEEK_SET);
996 if (ret < 0)
997 goto out;
998
999 ret = ftruncate(pcache->fd, 0);
1000 if (ret < 0)
1001 goto out;
1002
1003 for_each_probe_cache_entry(entry, pcache) {
1004 ret = probe_cache_entry__write(entry, pcache->fd);
1005 pr_debug("Cache committed: %d\n", ret);
1006 if (ret < 0)
1007 break;
1008 }
1009out:
1010 return ret;
1011}
1012
1013static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
1014 struct strfilter *filter)
1015{
1016 char buf[128], *ptr = entry->spev;
1017
1018 if (entry->pev.event) {
1019 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
1020 ptr = buf;
1021 }
1022 return strfilter__compare(filter, ptr);
1023}
1024
1025int probe_cache__filter_purge(struct probe_cache *pcache,
1026 struct strfilter *filter)
1027{
1028 struct probe_cache_entry *entry, *tmp;
1029
1030 list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
1031 if (probe_cache_entry__compare(entry, filter)) {
1032 pr_info("Removed cached event: %s\n", entry->spev);
1033 list_del_init(&entry->node);
1034 probe_cache_entry__delete(entry);
1035 }
1036 }
1037 return 0;
1038}
1039
1040static int probe_cache__show_entries(struct probe_cache *pcache,
1041 struct strfilter *filter)
1042{
1043 struct probe_cache_entry *entry;
1044
1045 for_each_probe_cache_entry(entry, pcache) {
1046 if (probe_cache_entry__compare(entry, filter))
1047 printf("%s\n", entry->spev);
1048 }
1049 return 0;
1050}
1051
1052/* Show all cached probes */
1053int probe_cache__show_all_caches(struct strfilter *filter)
1054{
1055 struct probe_cache *pcache;
1056 struct strlist *bidlist;
1057 struct str_node *nd;
1058 char *buf = strfilter__string(filter);
1059
1060 pr_debug("list cache with filter: %s\n", buf);
1061 free(buf);
1062
1063 bidlist = build_id_cache__list_all(true);
1064 if (!bidlist) {
1065 pr_debug("Failed to get buildids: %d\n", errno);
1066 return -EINVAL;
1067 }
1068 strlist__for_each_entry(nd, bidlist) {
1069 pcache = probe_cache__new(nd->s, NULL);
1070 if (!pcache)
1071 continue;
1072 if (!list_empty(&pcache->entries)) {
1073 buf = build_id_cache__origname(nd->s);
1074 printf("%s (%s):\n", buf, nd->s);
1075 free(buf);
1076 probe_cache__show_entries(pcache, filter);
1077 }
1078 probe_cache__delete(pcache);
1079 }
1080 strlist__delete(bidlist);
1081
1082 return 0;
1083}
1084
1085enum ftrace_readme {
1086 FTRACE_README_PROBE_TYPE_X = 0,
1087 FTRACE_README_KRETPROBE_OFFSET,
1088 FTRACE_README_UPROBE_REF_CTR,
1089 FTRACE_README_USER_ACCESS,
1090 FTRACE_README_MULTIPROBE_EVENT,
1091 FTRACE_README_IMMEDIATE_VALUE,
1092 FTRACE_README_END,
1093};
1094
1095static struct {
1096 const char *pattern;
1097 bool avail;
1098} ftrace_readme_table[] = {
1099#define DEFINE_TYPE(idx, pat) \
1100 [idx] = {.pattern = pat, .avail = false}
1101 DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1102 DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1103 DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1104 DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
1105 DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1106 DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1107};
1108
1109static bool scan_ftrace_readme(enum ftrace_readme type)
1110{
1111 int fd;
1112 FILE *fp;
1113 char *buf = NULL;
1114 size_t len = 0;
1115 bool ret = false;
1116 static bool scanned = false;
1117
1118 if (scanned)
1119 goto result;
1120
1121 fd = open_trace_file("README", false);
1122 if (fd < 0)
1123 return ret;
1124
1125 fp = fdopen(fd, "r");
1126 if (!fp) {
1127 close(fd);
1128 return ret;
1129 }
1130
1131 while (getline(&buf, &len, fp) > 0)
1132 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1133 if (!ftrace_readme_table[i].avail)
1134 ftrace_readme_table[i].avail =
1135 strglobmatch(buf, ftrace_readme_table[i].pattern);
1136 scanned = true;
1137
1138 fclose(fp);
1139 free(buf);
1140
1141result:
1142 if (type >= FTRACE_README_END)
1143 return false;
1144
1145 return ftrace_readme_table[type].avail;
1146}
1147
1148bool probe_type_is_available(enum probe_type type)
1149{
1150 if (type >= PROBE_TYPE_END)
1151 return false;
1152 else if (type == PROBE_TYPE_X)
1153 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1154
1155 return true;
1156}
1157
1158bool kretprobe_offset_is_supported(void)
1159{
1160 return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1161}
1162
1163bool uprobe_ref_ctr_is_supported(void)
1164{
1165 return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1166}
1167
1168bool user_access_is_supported(void)
1169{
1170 return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1171}
1172
1173bool multiprobe_event_is_supported(void)
1174{
1175 return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1176}
1177
1178bool immediate_value_is_supported(void)
1179{
1180 return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1181}