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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * builtin-probe.c
4 *
5 * Builtin probe command: Set up probe events by C expression
6 *
7 * Written by Masami Hiramatsu <mhiramat@redhat.com>
8 */
9#include <sys/utsname.h>
10#include <sys/types.h>
11#include <sys/stat.h>
12#include <fcntl.h>
13#include <errno.h>
14#include <stdio.h>
15#include <unistd.h>
16#include <stdlib.h>
17#include <string.h>
18
19#include "builtin.h"
20#include "namespaces.h"
21#include "util/build-id.h"
22#include "util/strlist.h"
23#include "util/strfilter.h"
24#include "util/symbol_conf.h"
25#include "util/debug.h"
26#include <subcmd/parse-options.h>
27#include "util/probe-finder.h"
28#include "util/probe-event.h"
29#include "util/probe-file.h"
30#include <linux/string.h>
31#include <linux/zalloc.h>
32
33#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
34#define DEFAULT_FUNC_FILTER "!_*"
35#define DEFAULT_LIST_FILTER "*"
36
37/* Session management structure */
38static struct {
39 int command; /* Command short_name */
40 bool list_events;
41 bool uprobes;
42 bool quiet;
43 bool target_used;
44 int nevents;
45 struct perf_probe_event events[MAX_PROBES];
46 struct line_range line_range;
47 char *target;
48 struct strfilter *filter;
49 struct nsinfo *nsi;
50} params;
51
52/* Parse an event definition. Note that any error must die. */
53static int parse_probe_event(const char *str)
54{
55 struct perf_probe_event *pev = ¶ms.events[params.nevents];
56 int ret;
57
58 pr_debug("probe-definition(%d): %s\n", params.nevents, str);
59 if (++params.nevents == MAX_PROBES) {
60 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
61 return -1;
62 }
63
64 pev->uprobes = params.uprobes;
65 if (params.target) {
66 pev->target = strdup(params.target);
67 if (!pev->target)
68 return -ENOMEM;
69 params.target_used = true;
70 }
71
72 pev->nsi = nsinfo__get(params.nsi);
73
74 /* Parse a perf-probe command into event */
75 ret = parse_perf_probe_command(str, pev);
76 pr_debug("%d arguments\n", pev->nargs);
77
78 return ret;
79}
80
81static int params_add_filter(const char *str)
82{
83 const char *err = NULL;
84 int ret = 0;
85
86 pr_debug2("Add filter: %s\n", str);
87 if (!params.filter) {
88 params.filter = strfilter__new(str, &err);
89 if (!params.filter)
90 ret = err ? -EINVAL : -ENOMEM;
91 } else
92 ret = strfilter__or(params.filter, str, &err);
93
94 if (ret == -EINVAL) {
95 pr_err("Filter parse error at %td.\n", err - str + 1);
96 pr_err("Source: \"%s\"\n", str);
97 pr_err(" %*c\n", (int)(err - str + 1), '^');
98 }
99
100 return ret;
101}
102
103static int set_target(const char *ptr)
104{
105 int found = 0;
106 const char *buf;
107
108 /*
109 * The first argument after options can be an absolute path
110 * to an executable / library or kernel module.
111 *
112 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
113 * short module name.
114 */
115 if (!params.target && ptr && *ptr == '/') {
116 params.target = strdup(ptr);
117 if (!params.target)
118 return -ENOMEM;
119 params.target_used = false;
120
121 found = 1;
122 buf = ptr + (strlen(ptr) - 3);
123
124 if (strcmp(buf, ".ko"))
125 params.uprobes = true;
126
127 }
128
129 return found;
130}
131
132static int parse_probe_event_argv(int argc, const char **argv)
133{
134 int i, len, ret, found_target;
135 char *buf;
136
137 found_target = set_target(argv[0]);
138 if (found_target < 0)
139 return found_target;
140
141 if (found_target && argc == 1)
142 return 0;
143
144 /* Bind up rest arguments */
145 len = 0;
146 for (i = 0; i < argc; i++) {
147 if (i == 0 && found_target)
148 continue;
149
150 len += strlen(argv[i]) + 1;
151 }
152 buf = zalloc(len + 1);
153 if (buf == NULL)
154 return -ENOMEM;
155 len = 0;
156 for (i = 0; i < argc; i++) {
157 if (i == 0 && found_target)
158 continue;
159
160 len += sprintf(&buf[len], "%s ", argv[i]);
161 }
162 ret = parse_probe_event(buf);
163 free(buf);
164 return ret;
165}
166
167static int opt_set_target(const struct option *opt, const char *str,
168 int unset __maybe_unused)
169{
170 int ret = -ENOENT;
171 char *tmp;
172
173 if (str) {
174 if (!strcmp(opt->long_name, "exec"))
175 params.uprobes = true;
176 else if (!strcmp(opt->long_name, "module"))
177 params.uprobes = false;
178 else
179 return ret;
180
181 /* Expand given path to absolute path, except for modulename */
182 if (params.uprobes || strchr(str, '/')) {
183 tmp = nsinfo__realpath(str, params.nsi);
184 if (!tmp) {
185 pr_warning("Failed to get the absolute path of %s: %m\n", str);
186 return ret;
187 }
188 } else {
189 tmp = strdup(str);
190 if (!tmp)
191 return -ENOMEM;
192 }
193 free(params.target);
194 params.target = tmp;
195 params.target_used = false;
196 ret = 0;
197 }
198
199 return ret;
200}
201
202static int opt_set_target_ns(const struct option *opt __maybe_unused,
203 const char *str, int unset __maybe_unused)
204{
205 int ret = -ENOENT;
206 pid_t ns_pid;
207 struct nsinfo *nsip;
208
209 if (str) {
210 errno = 0;
211 ns_pid = (pid_t)strtol(str, NULL, 10);
212 if (errno != 0) {
213 ret = -errno;
214 pr_warning("Failed to parse %s as a pid: %s\n", str,
215 strerror(errno));
216 return ret;
217 }
218 nsip = nsinfo__new(ns_pid);
219 if (nsip && nsip->need_setns)
220 params.nsi = nsinfo__get(nsip);
221 nsinfo__put(nsip);
222
223 ret = 0;
224 }
225
226 return ret;
227}
228
229
230/* Command option callbacks */
231
232#ifdef HAVE_DWARF_SUPPORT
233static int opt_show_lines(const struct option *opt,
234 const char *str, int unset __maybe_unused)
235{
236 int ret = 0;
237
238 if (!str)
239 return 0;
240
241 if (params.command == 'L') {
242 pr_warning("Warning: more than one --line options are"
243 " detected. Only the first one is valid.\n");
244 return 0;
245 }
246
247 params.command = opt->short_name;
248 ret = parse_line_range_desc(str, ¶ms.line_range);
249
250 return ret;
251}
252
253static int opt_show_vars(const struct option *opt,
254 const char *str, int unset __maybe_unused)
255{
256 struct perf_probe_event *pev = ¶ms.events[params.nevents];
257 int ret;
258
259 if (!str)
260 return 0;
261
262 ret = parse_probe_event(str);
263 if (!ret && pev->nargs != 0) {
264 pr_err(" Error: '--vars' doesn't accept arguments.\n");
265 return -EINVAL;
266 }
267 params.command = opt->short_name;
268
269 return ret;
270}
271#else
272# define opt_show_lines NULL
273# define opt_show_vars NULL
274#endif
275static int opt_add_probe_event(const struct option *opt,
276 const char *str, int unset __maybe_unused)
277{
278 if (str) {
279 params.command = opt->short_name;
280 return parse_probe_event(str);
281 }
282
283 return 0;
284}
285
286static int opt_set_filter_with_command(const struct option *opt,
287 const char *str, int unset)
288{
289 if (!unset)
290 params.command = opt->short_name;
291
292 if (str)
293 return params_add_filter(str);
294
295 return 0;
296}
297
298static int opt_set_filter(const struct option *opt __maybe_unused,
299 const char *str, int unset __maybe_unused)
300{
301 if (str)
302 return params_add_filter(str);
303
304 return 0;
305}
306
307static int init_params(void)
308{
309 return line_range__init(¶ms.line_range);
310}
311
312static void cleanup_params(void)
313{
314 int i;
315
316 for (i = 0; i < params.nevents; i++)
317 clear_perf_probe_event(params.events + i);
318 line_range__clear(¶ms.line_range);
319 free(params.target);
320 strfilter__delete(params.filter);
321 nsinfo__put(params.nsi);
322 memset(¶ms, 0, sizeof(params));
323}
324
325static void pr_err_with_code(const char *msg, int err)
326{
327 char sbuf[STRERR_BUFSIZE];
328
329 pr_err("%s", msg);
330 pr_debug(" Reason: %s (Code: %d)",
331 str_error_r(-err, sbuf, sizeof(sbuf)), err);
332 pr_err("\n");
333}
334
335static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
336{
337 int ret;
338 int i, k;
339 const char *event = NULL, *group = NULL;
340
341 ret = init_probe_symbol_maps(pevs->uprobes);
342 if (ret < 0)
343 return ret;
344
345 ret = convert_perf_probe_events(pevs, npevs);
346 if (ret < 0)
347 goto out_cleanup;
348
349 if (params.command == 'D') { /* it shows definition */
350 ret = show_probe_trace_events(pevs, npevs);
351 goto out_cleanup;
352 }
353
354 ret = apply_perf_probe_events(pevs, npevs);
355 if (ret < 0)
356 goto out_cleanup;
357
358 for (i = k = 0; i < npevs; i++)
359 k += pevs[i].ntevs;
360
361 pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
362 for (i = 0; i < npevs; i++) {
363 struct perf_probe_event *pev = &pevs[i];
364
365 for (k = 0; k < pev->ntevs; k++) {
366 struct probe_trace_event *tev = &pev->tevs[k];
367
368 /* We use tev's name for showing new events */
369 show_perf_probe_event(tev->group, tev->event, pev,
370 tev->point.module, false);
371
372 /* Save the last valid name */
373 event = tev->event;
374 group = tev->group;
375 }
376 }
377
378 /* Note that it is possible to skip all events because of blacklist */
379 if (event) {
380 /* Show how to use the event. */
381 pr_info("\nYou can now use it in all perf tools, such as:\n\n");
382 pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
383 }
384
385out_cleanup:
386 cleanup_perf_probe_events(pevs, npevs);
387 exit_probe_symbol_maps();
388 return ret;
389}
390
391static int del_perf_probe_caches(struct strfilter *filter)
392{
393 struct probe_cache *cache;
394 struct strlist *bidlist;
395 struct str_node *nd;
396 int ret;
397
398 bidlist = build_id_cache__list_all(false);
399 if (!bidlist) {
400 ret = -errno;
401 pr_debug("Failed to get buildids: %d\n", ret);
402 return ret ?: -ENOMEM;
403 }
404
405 strlist__for_each_entry(nd, bidlist) {
406 cache = probe_cache__new(nd->s, NULL);
407 if (!cache)
408 continue;
409 if (probe_cache__filter_purge(cache, filter) < 0 ||
410 probe_cache__commit(cache) < 0)
411 pr_warning("Failed to remove entries for %s\n", nd->s);
412 probe_cache__delete(cache);
413 }
414 return 0;
415}
416
417static int perf_del_probe_events(struct strfilter *filter)
418{
419 int ret, ret2, ufd = -1, kfd = -1;
420 char *str = strfilter__string(filter);
421 struct strlist *klist = NULL, *ulist = NULL;
422 struct str_node *ent;
423
424 if (!str)
425 return -EINVAL;
426
427 pr_debug("Delete filter: \'%s\'\n", str);
428
429 if (probe_conf.cache)
430 return del_perf_probe_caches(filter);
431
432 /* Get current event names */
433 ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
434 if (ret < 0)
435 goto out;
436
437 klist = strlist__new(NULL, NULL);
438 ulist = strlist__new(NULL, NULL);
439 if (!klist || !ulist) {
440 ret = -ENOMEM;
441 goto out;
442 }
443
444 ret = probe_file__get_events(kfd, filter, klist);
445 if (ret == 0) {
446 strlist__for_each_entry(ent, klist)
447 pr_info("Removed event: %s\n", ent->s);
448
449 ret = probe_file__del_strlist(kfd, klist);
450 if (ret < 0)
451 goto error;
452 }
453
454 ret2 = probe_file__get_events(ufd, filter, ulist);
455 if (ret2 == 0) {
456 strlist__for_each_entry(ent, ulist)
457 pr_info("Removed event: %s\n", ent->s);
458
459 ret2 = probe_file__del_strlist(ufd, ulist);
460 if (ret2 < 0)
461 goto error;
462 }
463
464 if (ret == -ENOENT && ret2 == -ENOENT)
465 pr_warning("\"%s\" does not hit any event.\n", str);
466 else
467 ret = 0;
468
469error:
470 if (kfd >= 0)
471 close(kfd);
472 if (ufd >= 0)
473 close(ufd);
474out:
475 strlist__delete(klist);
476 strlist__delete(ulist);
477 free(str);
478
479 return ret;
480}
481
482#ifdef HAVE_DWARF_SUPPORT
483#define PROBEDEF_STR \
484 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
485#else
486#define PROBEDEF_STR "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
487#endif
488
489
490static int
491__cmd_probe(int argc, const char **argv)
492{
493 const char * const probe_usage[] = {
494 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
495 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
496 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
497 "perf probe --list [GROUP:]EVENT ...",
498#ifdef HAVE_DWARF_SUPPORT
499 "perf probe [<options>] --line 'LINEDESC'",
500 "perf probe [<options>] --vars 'PROBEPOINT'",
501#endif
502 "perf probe [<options>] --funcs",
503 NULL
504 };
505 struct option options[] = {
506 OPT_INCR('v', "verbose", &verbose,
507 "be more verbose (show parsed arguments, etc)"),
508 OPT_BOOLEAN('q', "quiet", ¶ms.quiet,
509 "be quiet (do not show any messages)"),
510 OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
511 "list up probe events",
512 opt_set_filter_with_command, DEFAULT_LIST_FILTER),
513 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
514 opt_set_filter_with_command),
515 OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
516 "probe point definition, where\n"
517 "\t\tGROUP:\tGroup name (optional)\n"
518 "\t\tEVENT:\tEvent name\n"
519 "\t\tFUNC:\tFunction name\n"
520 "\t\tOFF:\tOffset from function entry (in byte)\n"
521 "\t\t%return:\tPut the probe at function return\n"
522#ifdef HAVE_DWARF_SUPPORT
523 "\t\tSRC:\tSource code path\n"
524 "\t\tRL:\tRelative line number from function entry.\n"
525 "\t\tAL:\tAbsolute line number in file.\n"
526 "\t\tPT:\tLazy expression of line code.\n"
527 "\t\tARG:\tProbe argument (local variable name or\n"
528 "\t\t\tkprobe-tracer argument format.)\n",
529#else
530 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
531#endif
532 opt_add_probe_event),
533 OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
534 "Show trace event definition of given traceevent for k/uprobe_events.",
535 opt_add_probe_event),
536 OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
537 " with existing name"),
538 OPT_CALLBACK('L', "line", NULL,
539 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
540 "Show source code lines.", opt_show_lines),
541 OPT_CALLBACK('V', "vars", NULL,
542 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
543 "Show accessible variables on PROBEDEF", opt_show_vars),
544 OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
545 "Show external variables too (with --vars only)"),
546 OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
547 "Show variables location range in scope (with --vars only)"),
548 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
549 "file", "vmlinux pathname"),
550 OPT_STRING('s', "source", &symbol_conf.source_prefix,
551 "directory", "path to kernel source"),
552 OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
553 "Don't search inlined functions"),
554 OPT__DRY_RUN(&probe_event_dry_run),
555 OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
556 "Set how many probe points can be found for a probe."),
557 OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
558 "Show potential probe-able functions.",
559 opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
560 OPT_CALLBACK('\0', "filter", NULL,
561 "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
562 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
563 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
564 opt_set_filter),
565 OPT_CALLBACK('x', "exec", NULL, "executable|path",
566 "target executable name or path", opt_set_target),
567 OPT_CALLBACK('m', "module", NULL, "modname|path",
568 "target module name (for online) or path (for offline)",
569 opt_set_target),
570 OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
571 "Enable symbol demangling"),
572 OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
573 "Enable kernel symbol demangling"),
574 OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
575 OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
576 "Look for files with symbols relative to this directory"),
577 OPT_CALLBACK(0, "target-ns", NULL, "pid",
578 "target pid for namespace contexts", opt_set_target_ns),
579 OPT_END()
580 };
581 int ret;
582
583 set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
584 set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
585 set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
586 set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
587#ifdef HAVE_DWARF_SUPPORT
588 set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
589 set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
590#else
591# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
592 set_nobuild('L', "line", false);
593 set_nobuild('V', "vars", false);
594 set_nobuild('\0', "externs", false);
595 set_nobuild('\0', "range", false);
596 set_nobuild('k', "vmlinux", true);
597 set_nobuild('s', "source", true);
598 set_nobuild('\0', "no-inlines", true);
599# undef set_nobuild
600#endif
601 set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
602
603 argc = parse_options(argc, argv, options, probe_usage,
604 PARSE_OPT_STOP_AT_NON_OPTION);
605 if (argc > 0) {
606 if (strcmp(argv[0], "-") == 0) {
607 usage_with_options_msg(probe_usage, options,
608 "'-' is not supported.\n");
609 }
610 if (params.command && params.command != 'a') {
611 usage_with_options_msg(probe_usage, options,
612 "another command except --add is set.\n");
613 }
614 ret = parse_probe_event_argv(argc, argv);
615 if (ret < 0) {
616 pr_err_with_code(" Error: Command Parse Error.", ret);
617 return ret;
618 }
619 params.command = 'a';
620 }
621
622 if (params.quiet) {
623 if (verbose != 0) {
624 pr_err(" Error: -v and -q are exclusive.\n");
625 return -EINVAL;
626 }
627 verbose = -1;
628 }
629
630 if (probe_conf.max_probes == 0)
631 probe_conf.max_probes = MAX_PROBES;
632
633 /*
634 * Only consider the user's kernel image path if given.
635 */
636 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
637
638 /*
639 * Except for --list, --del and --add, other command doesn't depend
640 * nor change running kernel. So if user gives offline vmlinux,
641 * ignore its buildid.
642 */
643 if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
644 symbol_conf.ignore_vmlinux_buildid = true;
645
646 switch (params.command) {
647 case 'l':
648 if (params.uprobes) {
649 pr_err(" Error: Don't use --list with --exec.\n");
650 parse_options_usage(probe_usage, options, "l", true);
651 parse_options_usage(NULL, options, "x", true);
652 return -EINVAL;
653 }
654 ret = show_perf_probe_events(params.filter);
655 if (ret < 0)
656 pr_err_with_code(" Error: Failed to show event list.", ret);
657 return ret;
658 case 'F':
659 ret = show_available_funcs(params.target, params.nsi,
660 params.filter, params.uprobes);
661 if (ret < 0)
662 pr_err_with_code(" Error: Failed to show functions.", ret);
663 return ret;
664#ifdef HAVE_DWARF_SUPPORT
665 case 'L':
666 ret = show_line_range(¶ms.line_range, params.target,
667 params.nsi, params.uprobes);
668 if (ret < 0)
669 pr_err_with_code(" Error: Failed to show lines.", ret);
670 return ret;
671 case 'V':
672 if (!params.filter)
673 params.filter = strfilter__new(DEFAULT_VAR_FILTER,
674 NULL);
675
676 ret = show_available_vars(params.events, params.nevents,
677 params.filter);
678 if (ret < 0)
679 pr_err_with_code(" Error: Failed to show vars.", ret);
680 return ret;
681#endif
682 case 'd':
683 ret = perf_del_probe_events(params.filter);
684 if (ret < 0) {
685 pr_err_with_code(" Error: Failed to delete events.", ret);
686 return ret;
687 }
688 break;
689 case 'D':
690 case 'a':
691
692 /* Ensure the last given target is used */
693 if (params.target && !params.target_used) {
694 pr_err(" Error: -x/-m must follow the probe definitions.\n");
695 parse_options_usage(probe_usage, options, "m", true);
696 parse_options_usage(NULL, options, "x", true);
697 return -EINVAL;
698 }
699
700 ret = perf_add_probe_events(params.events, params.nevents);
701 if (ret < 0) {
702
703 /*
704 * When perf_add_probe_events() fails it calls
705 * cleanup_perf_probe_events(pevs, npevs), i.e.
706 * cleanup_perf_probe_events(params.events, params.nevents), which
707 * will call clear_perf_probe_event(), so set nevents to zero
708 * to avoid cleanup_params() to call clear_perf_probe_event() again
709 * on the same pevs.
710 */
711 params.nevents = 0;
712 pr_err_with_code(" Error: Failed to add events.", ret);
713 return ret;
714 }
715 break;
716 default:
717 usage_with_options(probe_usage, options);
718 }
719 return 0;
720}
721
722int cmd_probe(int argc, const char **argv)
723{
724 int ret;
725
726 ret = init_params();
727 if (!ret) {
728 ret = __cmd_probe(argc, argv);
729 cleanup_params();
730 }
731
732 return ret < 0 ? ret : 0;
733}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * builtin-probe.c
4 *
5 * Builtin probe command: Set up probe events by C expression
6 *
7 * Written by Masami Hiramatsu <mhiramat@redhat.com>
8 */
9#include <sys/utsname.h>
10#include <sys/types.h>
11#include <sys/stat.h>
12#include <fcntl.h>
13#include <errno.h>
14#include <stdio.h>
15#include <unistd.h>
16#include <stdlib.h>
17#include <string.h>
18
19#include "builtin.h"
20#include "namespaces.h"
21#include "util/build-id.h"
22#include "util/strlist.h"
23#include "util/strfilter.h"
24#include "util/symbol.h"
25#include "util/symbol_conf.h"
26#include "util/debug.h"
27#include <subcmd/parse-options.h>
28#include "util/probe-finder.h"
29#include "util/probe-event.h"
30#include "util/probe-file.h"
31#include <linux/string.h>
32#include <linux/zalloc.h>
33
34#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
35#define DEFAULT_FUNC_FILTER "!_* & !*@plt"
36#define DEFAULT_LIST_FILTER "*"
37
38/* Session management structure */
39static struct {
40 int command; /* Command short_name */
41 bool list_events;
42 bool uprobes;
43 bool target_used;
44 int nevents;
45 struct perf_probe_event events[MAX_PROBES];
46 struct line_range line_range;
47 char *target;
48 struct strfilter *filter;
49 struct nsinfo *nsi;
50} *params;
51
52/* Parse an event definition. Note that any error must die. */
53static int parse_probe_event(const char *str)
54{
55 struct perf_probe_event *pev = ¶ms->events[params->nevents];
56 int ret;
57
58 pr_debug("probe-definition(%d): %s\n", params->nevents, str);
59 if (++params->nevents == MAX_PROBES) {
60 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
61 return -1;
62 }
63
64 pev->uprobes = params->uprobes;
65 if (params->target) {
66 pev->target = strdup(params->target);
67 if (!pev->target)
68 return -ENOMEM;
69 params->target_used = true;
70 }
71
72 pev->nsi = nsinfo__get(params->nsi);
73
74 /* Parse a perf-probe command into event */
75 ret = parse_perf_probe_command(str, pev);
76 pr_debug("%d arguments\n", pev->nargs);
77
78 return ret;
79}
80
81static int params_add_filter(const char *str)
82{
83 const char *err = NULL;
84 int ret = 0;
85
86 pr_debug2("Add filter: %s\n", str);
87 if (!params->filter) {
88 params->filter = strfilter__new(str, &err);
89 if (!params->filter)
90 ret = err ? -EINVAL : -ENOMEM;
91 } else
92 ret = strfilter__or(params->filter, str, &err);
93
94 if (ret == -EINVAL) {
95 pr_err("Filter parse error at %td.\n", err - str + 1);
96 pr_err("Source: \"%s\"\n", str);
97 pr_err(" %*c\n", (int)(err - str + 1), '^');
98 }
99
100 return ret;
101}
102
103static int set_target(const char *ptr)
104{
105 int found = 0;
106 const char *buf;
107
108 /*
109 * The first argument after options can be an absolute path
110 * to an executable / library or kernel module.
111 *
112 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
113 * short module name.
114 */
115 if (!params->target && ptr && *ptr == '/') {
116 params->target = strdup(ptr);
117 if (!params->target)
118 return -ENOMEM;
119 params->target_used = false;
120
121 found = 1;
122 buf = ptr + (strlen(ptr) - 3);
123
124 if (strcmp(buf, ".ko"))
125 params->uprobes = true;
126
127 }
128
129 return found;
130}
131
132static int parse_probe_event_argv(int argc, const char **argv)
133{
134 int i, len, ret, found_target;
135 char *buf;
136
137 found_target = set_target(argv[0]);
138 if (found_target < 0)
139 return found_target;
140
141 if (found_target && argc == 1)
142 return 0;
143
144 /* Bind up rest arguments */
145 len = 0;
146 for (i = 0; i < argc; i++) {
147 if (i == 0 && found_target)
148 continue;
149
150 len += strlen(argv[i]) + 1;
151 }
152 buf = zalloc(len + 1);
153 if (buf == NULL)
154 return -ENOMEM;
155 len = 0;
156 for (i = 0; i < argc; i++) {
157 if (i == 0 && found_target)
158 continue;
159
160 len += sprintf(&buf[len], "%s ", argv[i]);
161 }
162 ret = parse_probe_event(buf);
163 free(buf);
164 return ret;
165}
166
167static int opt_set_target(const struct option *opt, const char *str,
168 int unset __maybe_unused)
169{
170 int ret = -ENOENT;
171 char *tmp;
172
173 if (str) {
174 if (!strcmp(opt->long_name, "exec"))
175 params->uprobes = true;
176 else if (!strcmp(opt->long_name, "module"))
177 params->uprobes = false;
178 else
179 return ret;
180
181 /* Expand given path to absolute path, except for modulename */
182 if (params->uprobes || strchr(str, '/')) {
183 tmp = nsinfo__realpath(str, params->nsi);
184 if (!tmp) {
185 pr_warning("Failed to get the absolute path of %s: %m\n", str);
186 return ret;
187 }
188 } else {
189 tmp = strdup(str);
190 if (!tmp)
191 return -ENOMEM;
192 }
193 free(params->target);
194 params->target = tmp;
195 params->target_used = false;
196 ret = 0;
197 }
198
199 return ret;
200}
201
202static int opt_set_target_ns(const struct option *opt __maybe_unused,
203 const char *str, int unset __maybe_unused)
204{
205 int ret = -ENOENT;
206 pid_t ns_pid;
207 struct nsinfo *nsip;
208
209 if (str) {
210 errno = 0;
211 ns_pid = (pid_t)strtol(str, NULL, 10);
212 if (errno != 0) {
213 ret = -errno;
214 pr_warning("Failed to parse %s as a pid: %s\n", str,
215 strerror(errno));
216 return ret;
217 }
218 nsip = nsinfo__new(ns_pid);
219 if (nsip && nsinfo__need_setns(nsip))
220 params->nsi = nsinfo__get(nsip);
221 nsinfo__put(nsip);
222
223 ret = 0;
224 }
225
226 return ret;
227}
228
229
230/* Command option callbacks */
231
232#ifdef HAVE_DWARF_SUPPORT
233static int opt_show_lines(const struct option *opt,
234 const char *str, int unset __maybe_unused)
235{
236 int ret = 0;
237
238 if (!str)
239 return 0;
240
241 if (params->command == 'L') {
242 pr_warning("Warning: more than one --line options are"
243 " detected. Only the first one is valid.\n");
244 return 0;
245 }
246
247 params->command = opt->short_name;
248 ret = parse_line_range_desc(str, ¶ms->line_range);
249
250 return ret;
251}
252
253static int opt_show_vars(const struct option *opt,
254 const char *str, int unset __maybe_unused)
255{
256 struct perf_probe_event *pev = ¶ms->events[params->nevents];
257 int ret;
258
259 if (!str)
260 return 0;
261
262 ret = parse_probe_event(str);
263 if (!ret && pev->nargs != 0) {
264 pr_err(" Error: '--vars' doesn't accept arguments.\n");
265 return -EINVAL;
266 }
267 params->command = opt->short_name;
268
269 return ret;
270}
271#else
272# define opt_show_lines NULL
273# define opt_show_vars NULL
274#endif
275static int opt_add_probe_event(const struct option *opt,
276 const char *str, int unset __maybe_unused)
277{
278 if (str) {
279 params->command = opt->short_name;
280 return parse_probe_event(str);
281 }
282
283 return 0;
284}
285
286static int opt_set_filter_with_command(const struct option *opt,
287 const char *str, int unset)
288{
289 if (!unset)
290 params->command = opt->short_name;
291
292 if (str)
293 return params_add_filter(str);
294
295 return 0;
296}
297
298static int opt_set_filter(const struct option *opt __maybe_unused,
299 const char *str, int unset __maybe_unused)
300{
301 if (str)
302 return params_add_filter(str);
303
304 return 0;
305}
306
307static int init_params(void)
308{
309 int ret;
310
311 params = calloc(1, sizeof(*params));
312 if (!params)
313 return -ENOMEM;
314
315 ret = line_range__init(¶ms->line_range);
316 if (ret)
317 zfree(¶ms);
318 return ret;
319}
320
321static void cleanup_params(void)
322{
323 int i;
324
325 for (i = 0; i < params->nevents; i++)
326 clear_perf_probe_event(params->events + i);
327 line_range__clear(¶ms->line_range);
328 free(params->target);
329 strfilter__delete(params->filter);
330 nsinfo__put(params->nsi);
331 zfree(¶ms);
332}
333
334static void pr_err_with_code(const char *msg, int err)
335{
336 char sbuf[STRERR_BUFSIZE];
337
338 pr_err("%s", msg);
339 pr_debug(" Reason: %s (Code: %d)",
340 str_error_r(-err, sbuf, sizeof(sbuf)), err);
341 pr_err("\n");
342}
343
344static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
345{
346 int ret;
347 int i, k;
348 const char *event = NULL, *group = NULL;
349
350 ret = init_probe_symbol_maps(pevs->uprobes);
351 if (ret < 0)
352 return ret;
353
354 ret = convert_perf_probe_events(pevs, npevs);
355 if (ret < 0)
356 goto out_cleanup;
357
358 if (params->command == 'D') { /* it shows definition */
359 if (probe_conf.bootconfig)
360 ret = show_bootconfig_events(pevs, npevs);
361 else
362 ret = show_probe_trace_events(pevs, npevs);
363 goto out_cleanup;
364 }
365
366 ret = apply_perf_probe_events(pevs, npevs);
367 if (ret < 0)
368 goto out_cleanup;
369
370 for (i = k = 0; i < npevs; i++)
371 k += pevs[i].ntevs;
372
373 pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
374 for (i = 0; i < npevs; i++) {
375 struct perf_probe_event *pev = &pevs[i];
376
377 for (k = 0; k < pev->ntevs; k++) {
378 struct probe_trace_event *tev = &pev->tevs[k];
379 /* Skipped events have no event name */
380 if (!tev->event)
381 continue;
382
383 /* We use tev's name for showing new events */
384 show_perf_probe_event(tev->group, tev->event, pev,
385 tev->point.module, false);
386
387 /* Save the last valid name */
388 event = tev->event;
389 group = tev->group;
390 }
391 }
392
393 /* Note that it is possible to skip all events because of blacklist */
394 if (event) {
395#ifndef HAVE_LIBTRACEEVENT
396 pr_info("\nperf is not linked with libtraceevent, to use the new probe you can use tracefs:\n\n");
397 pr_info("\tcd /sys/kernel/tracing/\n");
398 pr_info("\techo 1 > events/%s/%s/enable\n", group, event);
399 pr_info("\techo 1 > tracing_on\n");
400 pr_info("\tcat trace_pipe\n");
401 pr_info("\tBefore removing the probe, echo 0 > events/%s/%s/enable\n", group, event);
402#else
403 /* Show how to use the event. */
404 pr_info("\nYou can now use it in all perf tools, such as:\n\n");
405 pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
406#endif
407 }
408
409out_cleanup:
410 cleanup_perf_probe_events(pevs, npevs);
411 exit_probe_symbol_maps();
412 return ret;
413}
414
415static int del_perf_probe_caches(struct strfilter *filter)
416{
417 struct probe_cache *cache;
418 struct strlist *bidlist;
419 struct str_node *nd;
420 int ret;
421
422 bidlist = build_id_cache__list_all(false);
423 if (!bidlist) {
424 ret = -errno;
425 pr_debug("Failed to get buildids: %d\n", ret);
426 return ret ?: -ENOMEM;
427 }
428
429 strlist__for_each_entry(nd, bidlist) {
430 cache = probe_cache__new(nd->s, NULL);
431 if (!cache)
432 continue;
433 if (probe_cache__filter_purge(cache, filter) < 0 ||
434 probe_cache__commit(cache) < 0)
435 pr_warning("Failed to remove entries for %s\n", nd->s);
436 probe_cache__delete(cache);
437 }
438 return 0;
439}
440
441static int perf_del_probe_events(struct strfilter *filter)
442{
443 int ret, ret2, ufd = -1, kfd = -1;
444 char *str = strfilter__string(filter);
445 struct strlist *klist = NULL, *ulist = NULL;
446 struct str_node *ent;
447
448 if (!str)
449 return -EINVAL;
450
451 pr_debug("Delete filter: \'%s\'\n", str);
452
453 if (probe_conf.cache)
454 return del_perf_probe_caches(filter);
455
456 /* Get current event names */
457 ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
458 if (ret < 0)
459 goto out;
460
461 klist = strlist__new(NULL, NULL);
462 ulist = strlist__new(NULL, NULL);
463 if (!klist || !ulist) {
464 ret = -ENOMEM;
465 goto out;
466 }
467
468 ret = probe_file__get_events(kfd, filter, klist);
469 if (ret == 0) {
470 strlist__for_each_entry(ent, klist)
471 pr_info("Removed event: %s\n", ent->s);
472
473 ret = probe_file__del_strlist(kfd, klist);
474 if (ret < 0)
475 goto error;
476 } else if (ret == -ENOMEM)
477 goto error;
478
479 ret2 = probe_file__get_events(ufd, filter, ulist);
480 if (ret2 == 0) {
481 strlist__for_each_entry(ent, ulist)
482 pr_info("Removed event: %s\n", ent->s);
483
484 ret2 = probe_file__del_strlist(ufd, ulist);
485 if (ret2 < 0)
486 goto error;
487 } else if (ret2 == -ENOMEM)
488 goto error;
489
490 if (ret == -ENOENT && ret2 == -ENOENT)
491 pr_warning("\"%s\" does not hit any event.\n", str);
492 else
493 ret = 0;
494
495error:
496 if (kfd >= 0)
497 close(kfd);
498 if (ufd >= 0)
499 close(ufd);
500out:
501 strlist__delete(klist);
502 strlist__delete(ulist);
503 free(str);
504
505 return ret;
506}
507
508#ifdef HAVE_DWARF_SUPPORT
509#define PROBEDEF_STR \
510 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
511#else
512#define PROBEDEF_STR "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
513#endif
514
515
516static int
517__cmd_probe(int argc, const char **argv)
518{
519 const char * const probe_usage[] = {
520 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
521 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
522 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
523 "perf probe --list [GROUP:]EVENT ...",
524#ifdef HAVE_DWARF_SUPPORT
525 "perf probe [<options>] --line 'LINEDESC'",
526 "perf probe [<options>] --vars 'PROBEPOINT'",
527#endif
528 "perf probe [<options>] --funcs",
529 NULL
530 };
531 struct option options[] = {
532 OPT_INCR('v', "verbose", &verbose,
533 "be more verbose (show parsed arguments, etc)"),
534 OPT_BOOLEAN('q', "quiet", &quiet,
535 "be quiet (do not show any warnings or messages)"),
536 OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
537 "list up probe events",
538 opt_set_filter_with_command, DEFAULT_LIST_FILTER),
539 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
540 opt_set_filter_with_command),
541 OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
542 "probe point definition, where\n"
543 "\t\tGROUP:\tGroup name (optional)\n"
544 "\t\tEVENT:\tEvent name\n"
545 "\t\tFUNC:\tFunction name\n"
546 "\t\tOFF:\tOffset from function entry (in byte)\n"
547 "\t\t%return:\tPut the probe at function return\n"
548#ifdef HAVE_DWARF_SUPPORT
549 "\t\tSRC:\tSource code path\n"
550 "\t\tRL:\tRelative line number from function entry.\n"
551 "\t\tAL:\tAbsolute line number in file.\n"
552 "\t\tPT:\tLazy expression of line code.\n"
553 "\t\tARG:\tProbe argument (local variable name or\n"
554 "\t\t\tkprobe-tracer argument format.)\n",
555#else
556 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
557#endif
558 opt_add_probe_event),
559 OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
560 "Show trace event definition of given traceevent for k/uprobe_events.",
561 opt_add_probe_event),
562 OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
563 " with existing name"),
564 OPT_CALLBACK('L', "line", NULL,
565 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
566 "Show source code lines.", opt_show_lines),
567 OPT_CALLBACK('V', "vars", NULL,
568 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
569 "Show accessible variables on PROBEDEF", opt_show_vars),
570 OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
571 "Show external variables too (with --vars only)"),
572 OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
573 "Show variables location range in scope (with --vars only)"),
574 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
575 "file", "vmlinux pathname"),
576 OPT_STRING('s', "source", &symbol_conf.source_prefix,
577 "directory", "path to kernel source"),
578 OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
579 "Don't search inlined functions"),
580 OPT__DRY_RUN(&probe_event_dry_run),
581 OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
582 "Set how many probe points can be found for a probe."),
583 OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
584 "Show potential probe-able functions.",
585 opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
586 OPT_CALLBACK('\0', "filter", NULL,
587 "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
588 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
589 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
590 opt_set_filter),
591 OPT_CALLBACK('x', "exec", NULL, "executable|path",
592 "target executable name or path", opt_set_target),
593 OPT_CALLBACK('m', "module", NULL, "modname|path",
594 "target module name (for online) or path (for offline)",
595 opt_set_target),
596 OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
597 "Enable symbol demangling"),
598 OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
599 "Enable kernel symbol demangling"),
600 OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
601 OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
602 "Look for files with symbols relative to this directory"),
603 OPT_CALLBACK(0, "target-ns", NULL, "pid",
604 "target pid for namespace contexts", opt_set_target_ns),
605 OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,
606 "Output probe definition with bootconfig format"),
607 OPT_END()
608 };
609 int ret;
610
611 set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
612 set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
613 set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
614 set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
615#ifdef HAVE_DWARF_SUPPORT
616 set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
617 set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
618#else
619# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
620 set_nobuild('L', "line", false);
621 set_nobuild('V', "vars", false);
622 set_nobuild('\0', "externs", false);
623 set_nobuild('\0', "range", false);
624 set_nobuild('k', "vmlinux", true);
625 set_nobuild('s', "source", true);
626 set_nobuild('\0', "no-inlines", true);
627# undef set_nobuild
628#endif
629 set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
630
631 argc = parse_options(argc, argv, options, probe_usage,
632 PARSE_OPT_STOP_AT_NON_OPTION);
633
634 if (quiet) {
635 if (verbose != 0) {
636 pr_err(" Error: -v and -q are exclusive.\n");
637 return -EINVAL;
638 }
639 verbose = -1;
640 }
641
642 if (argc > 0) {
643 if (strcmp(argv[0], "-") == 0) {
644 usage_with_options_msg(probe_usage, options,
645 "'-' is not supported.\n");
646 }
647 if (params->command && params->command != 'a') {
648 usage_with_options_msg(probe_usage, options,
649 "another command except --add is set.\n");
650 }
651 ret = parse_probe_event_argv(argc, argv);
652 if (ret < 0) {
653 pr_err_with_code(" Error: Command Parse Error.", ret);
654 return ret;
655 }
656 params->command = 'a';
657 }
658
659 ret = symbol__validate_sym_arguments();
660 if (ret)
661 return ret;
662
663 if (probe_conf.max_probes == 0)
664 probe_conf.max_probes = MAX_PROBES;
665
666 /*
667 * Only consider the user's kernel image path if given.
668 */
669 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
670
671 /*
672 * Except for --list, --del and --add, other command doesn't depend
673 * nor change running kernel. So if user gives offline vmlinux,
674 * ignore its buildid.
675 */
676 if (!strchr("lda", params->command) && symbol_conf.vmlinux_name)
677 symbol_conf.ignore_vmlinux_buildid = true;
678
679 switch (params->command) {
680 case 'l':
681 if (params->uprobes) {
682 pr_err(" Error: Don't use --list with --exec.\n");
683 parse_options_usage(probe_usage, options, "l", true);
684 parse_options_usage(NULL, options, "x", true);
685 return -EINVAL;
686 }
687 ret = show_perf_probe_events(params->filter);
688 if (ret < 0)
689 pr_err_with_code(" Error: Failed to show event list.", ret);
690 return ret;
691 case 'F':
692 ret = show_available_funcs(params->target, params->nsi,
693 params->filter, params->uprobes);
694 if (ret < 0)
695 pr_err_with_code(" Error: Failed to show functions.", ret);
696 return ret;
697#ifdef HAVE_DWARF_SUPPORT
698 case 'L':
699 ret = show_line_range(¶ms->line_range, params->target,
700 params->nsi, params->uprobes);
701 if (ret < 0)
702 pr_err_with_code(" Error: Failed to show lines.", ret);
703 return ret;
704 case 'V':
705 if (!params->filter)
706 params->filter = strfilter__new(DEFAULT_VAR_FILTER,
707 NULL);
708
709 ret = show_available_vars(params->events, params->nevents,
710 params->filter);
711 if (ret < 0)
712 pr_err_with_code(" Error: Failed to show vars.", ret);
713 return ret;
714#endif
715 case 'd':
716 ret = perf_del_probe_events(params->filter);
717 if (ret < 0) {
718 pr_err_with_code(" Error: Failed to delete events.", ret);
719 return ret;
720 }
721 break;
722 case 'D':
723 if (probe_conf.bootconfig && params->uprobes) {
724 pr_err(" Error: --bootconfig doesn't support uprobes.\n");
725 return -EINVAL;
726 }
727 fallthrough;
728 case 'a':
729
730 /* Ensure the last given target is used */
731 if (params->target && !params->target_used) {
732 pr_err(" Error: -x/-m must follow the probe definitions.\n");
733 parse_options_usage(probe_usage, options, "m", true);
734 parse_options_usage(NULL, options, "x", true);
735 return -EINVAL;
736 }
737
738 ret = perf_add_probe_events(params->events, params->nevents);
739 if (ret < 0) {
740
741 /*
742 * When perf_add_probe_events() fails it calls
743 * cleanup_perf_probe_events(pevs, npevs), i.e.
744 * cleanup_perf_probe_events(params->events, params->nevents), which
745 * will call clear_perf_probe_event(), so set nevents to zero
746 * to avoid cleanup_params() to call clear_perf_probe_event() again
747 * on the same pevs.
748 */
749 params->nevents = 0;
750 pr_err_with_code(" Error: Failed to add events.", ret);
751 return ret;
752 }
753 break;
754 default:
755 usage_with_options(probe_usage, options);
756 }
757 return 0;
758}
759
760int cmd_probe(int argc, const char **argv)
761{
762 int ret;
763
764 ret = init_params();
765 if (!ret) {
766 ret = __cmd_probe(argc, argv);
767 cleanup_params();
768 }
769
770 return ret < 0 ? ret : 0;
771}