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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 */
38 static 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. */
parse_probe_event(const char * str)53 static int parse_probe_event(const char *str)
54 {
55 	struct perf_probe_event *pev = &params.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 
params_add_filter(const char * str)81 static 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 
set_target(const char * ptr)103 static 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 
parse_probe_event_argv(int argc,const char ** argv)132 static 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 
opt_set_target(const struct option * opt,const char * str,int unset __maybe_unused)167 static 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 
opt_set_target_ns(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)202 static 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
opt_show_lines(const struct option * opt,const char * str,int unset __maybe_unused)233 static 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, &params.line_range);
249 
250 	return ret;
251 }
252 
opt_show_vars(const struct option * opt,const char * str,int unset __maybe_unused)253 static int opt_show_vars(const struct option *opt,
254 			 const char *str, int unset __maybe_unused)
255 {
256 	struct perf_probe_event *pev = &params.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
opt_add_probe_event(const struct option * opt,const char * str,int unset __maybe_unused)275 static 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 
opt_set_filter_with_command(const struct option * opt,const char * str,int unset)286 static 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 
opt_set_filter(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)298 static 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 
init_params(void)307 static int init_params(void)
308 {
309 	return line_range__init(&params.line_range);
310 }
311 
cleanup_params(void)312 static 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(&params.line_range);
319 	free(params.target);
320 	strfilter__delete(params.filter);
321 	nsinfo__put(params.nsi);
322 	memset(&params, 0, sizeof(params));
323 }
324 
pr_err_with_code(const char * msg,int err)325 static 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 
perf_add_probe_events(struct perf_probe_event * pevs,int npevs)335 static 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 
385 out_cleanup:
386 	cleanup_perf_probe_events(pevs, npevs);
387 	exit_probe_symbol_maps();
388 	return ret;
389 }
390 
del_perf_probe_caches(struct strfilter * filter)391 static 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 
perf_del_probe_events(struct strfilter * filter)417 static 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 
469 error:
470 	if (kfd >= 0)
471 		close(kfd);
472 	if (ufd >= 0)
473 		close(ufd);
474 out:
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 
490 static int
__cmd_probe(int argc,const char ** argv)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", &params.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(&params.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 
cmd_probe(int argc,const char ** argv)722 int 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 }
734