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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 "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}
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}