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