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v6.2
  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 = &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
 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, &params.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 = &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
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(&params.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(&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
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		if (probe_conf.bootconfig)
351			ret = show_bootconfig_events(pevs, npevs);
352		else
353			ret = show_probe_trace_events(pevs, npevs);
354		goto out_cleanup;
355	}
356
357	ret = apply_perf_probe_events(pevs, npevs);
358	if (ret < 0)
359		goto out_cleanup;
360
361	for (i = k = 0; i < npevs; i++)
362		k += pevs[i].ntevs;
363
364	pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
365	for (i = 0; i < npevs; i++) {
366		struct perf_probe_event *pev = &pevs[i];
367
368		for (k = 0; k < pev->ntevs; k++) {
369			struct probe_trace_event *tev = &pev->tevs[k];
370			/* Skipped events have no event name */
371			if (!tev->event)
372				continue;
373
374			/* We use tev's name for showing new events */
375			show_perf_probe_event(tev->group, tev->event, pev,
376					      tev->point.module, false);
377
378			/* Save the last valid name */
379			event = tev->event;
380			group = tev->group;
381		}
382	}
383
384	/* Note that it is possible to skip all events because of blacklist */
385	if (event) {
386		/* Show how to use the event. */
387		pr_info("\nYou can now use it in all perf tools, such as:\n\n");
388		pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
389	}
390
391out_cleanup:
392	cleanup_perf_probe_events(pevs, npevs);
393	exit_probe_symbol_maps();
394	return ret;
395}
396
397static int del_perf_probe_caches(struct strfilter *filter)
398{
399	struct probe_cache *cache;
400	struct strlist *bidlist;
401	struct str_node *nd;
402	int ret;
403
404	bidlist = build_id_cache__list_all(false);
405	if (!bidlist) {
406		ret = -errno;
407		pr_debug("Failed to get buildids: %d\n", ret);
408		return ret ?: -ENOMEM;
409	}
410
411	strlist__for_each_entry(nd, bidlist) {
412		cache = probe_cache__new(nd->s, NULL);
413		if (!cache)
414			continue;
415		if (probe_cache__filter_purge(cache, filter) < 0 ||
416		    probe_cache__commit(cache) < 0)
417			pr_warning("Failed to remove entries for %s\n", nd->s);
418		probe_cache__delete(cache);
419	}
420	return 0;
421}
422
423static int perf_del_probe_events(struct strfilter *filter)
424{
425	int ret, ret2, ufd = -1, kfd = -1;
426	char *str = strfilter__string(filter);
427	struct strlist *klist = NULL, *ulist = NULL;
428	struct str_node *ent;
429
430	if (!str)
431		return -EINVAL;
432
433	pr_debug("Delete filter: \'%s\'\n", str);
434
435	if (probe_conf.cache)
436		return del_perf_probe_caches(filter);
437
438	/* Get current event names */
439	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
440	if (ret < 0)
441		goto out;
442
443	klist = strlist__new(NULL, NULL);
444	ulist = strlist__new(NULL, NULL);
445	if (!klist || !ulist) {
446		ret = -ENOMEM;
447		goto out;
448	}
449
450	ret = probe_file__get_events(kfd, filter, klist);
451	if (ret == 0) {
452		strlist__for_each_entry(ent, klist)
453			pr_info("Removed event: %s\n", ent->s);
454
455		ret = probe_file__del_strlist(kfd, klist);
456		if (ret < 0)
457			goto error;
458	} else if (ret == -ENOMEM)
459		goto error;
460
461	ret2 = probe_file__get_events(ufd, filter, ulist);
462	if (ret2 == 0) {
463		strlist__for_each_entry(ent, ulist)
464			pr_info("Removed event: %s\n", ent->s);
465
466		ret2 = probe_file__del_strlist(ufd, ulist);
467		if (ret2 < 0)
468			goto error;
469	} else if (ret2 == -ENOMEM)
470		goto error;
471
472	if (ret == -ENOENT && ret2 == -ENOENT)
473		pr_warning("\"%s\" does not hit any event.\n", str);
474	else
475		ret = 0;
476
477error:
478	if (kfd >= 0)
479		close(kfd);
480	if (ufd >= 0)
481		close(ufd);
482out:
483	strlist__delete(klist);
484	strlist__delete(ulist);
485	free(str);
486
487	return ret;
488}
489
490#ifdef HAVE_DWARF_SUPPORT
491#define PROBEDEF_STR	\
492	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
493#else
494#define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
495#endif
496
497
498static int
499__cmd_probe(int argc, const char **argv)
500{
501	const char * const probe_usage[] = {
502		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
503		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
504		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
505		"perf probe --list [GROUP:]EVENT ...",
506#ifdef HAVE_DWARF_SUPPORT
507		"perf probe [<options>] --line 'LINEDESC'",
508		"perf probe [<options>] --vars 'PROBEPOINT'",
509#endif
510		"perf probe [<options>] --funcs",
511		NULL
512	};
513	struct option options[] = {
514	OPT_INCR('v', "verbose", &verbose,
515		    "be more verbose (show parsed arguments, etc)"),
516	OPT_BOOLEAN('q', "quiet", &quiet,
517		    "be quiet (do not show any warnings or messages)"),
518	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
519			     "list up probe events",
520			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
521	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
522		     opt_set_filter_with_command),
523	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
 
 
 
 
 
 
524		"probe point definition, where\n"
525		"\t\tGROUP:\tGroup name (optional)\n"
526		"\t\tEVENT:\tEvent name\n"
527		"\t\tFUNC:\tFunction name\n"
528		"\t\tOFF:\tOffset from function entry (in byte)\n"
529		"\t\t%return:\tPut the probe at function return\n"
530#ifdef HAVE_DWARF_SUPPORT
531		"\t\tSRC:\tSource code path\n"
532		"\t\tRL:\tRelative line number from function entry.\n"
533		"\t\tAL:\tAbsolute line number in file.\n"
534		"\t\tPT:\tLazy expression of line code.\n"
535		"\t\tARG:\tProbe argument (local variable name or\n"
536		"\t\t\tkprobe-tracer argument format.)\n",
537#else
538		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
539#endif
540		opt_add_probe_event),
541	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
542		"Show trace event definition of given traceevent for k/uprobe_events.",
543		opt_add_probe_event),
544	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
545		    " with existing name"),
 
546	OPT_CALLBACK('L', "line", NULL,
547		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
548		     "Show source code lines.", opt_show_lines),
549	OPT_CALLBACK('V', "vars", NULL,
550		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
551		     "Show accessible variables on PROBEDEF", opt_show_vars),
552	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
553		    "Show external variables too (with --vars only)"),
554	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
555		"Show variables location range in scope (with --vars only)"),
556	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
557		   "file", "vmlinux pathname"),
558	OPT_STRING('s', "source", &symbol_conf.source_prefix,
559		   "directory", "path to kernel source"),
560	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
561		"Don't search inlined functions"),
 
 
562	OPT__DRY_RUN(&probe_event_dry_run),
563	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
564		 "Set how many probe points can be found for a probe."),
565	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
566			     "Show potential probe-able functions.",
567			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
568	OPT_CALLBACK('\0', "filter", NULL,
569		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
570		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
571		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
572		     opt_set_filter),
573	OPT_CALLBACK('x', "exec", NULL, "executable|path",
574			"target executable name or path", opt_set_target),
575	OPT_CALLBACK('m', "module", NULL, "modname|path",
576		"target module name (for online) or path (for offline)",
577		opt_set_target),
578	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
579		    "Enable symbol demangling"),
580	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
581		    "Enable kernel symbol demangling"),
582	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
583	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
584		   "Look for files with symbols relative to this directory"),
585	OPT_CALLBACK(0, "target-ns", NULL, "pid",
586		     "target pid for namespace contexts", opt_set_target_ns),
587	OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,
588		    "Output probe definition with bootconfig format"),
589	OPT_END()
590	};
591	int ret;
592
593	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
594	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
595	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
596	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
597#ifdef HAVE_DWARF_SUPPORT
598	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
599	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
600#else
601# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
602	set_nobuild('L', "line", false);
603	set_nobuild('V', "vars", false);
604	set_nobuild('\0', "externs", false);
605	set_nobuild('\0', "range", false);
606	set_nobuild('k', "vmlinux", true);
607	set_nobuild('s', "source", true);
608	set_nobuild('\0', "no-inlines", true);
609# undef set_nobuild
610#endif
611	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
612
613	argc = parse_options(argc, argv, options, probe_usage,
614			     PARSE_OPT_STOP_AT_NON_OPTION);
615
616	if (quiet) {
617		if (verbose != 0) {
618			pr_err("  Error: -v and -q are exclusive.\n");
619			return -EINVAL;
620		}
621		verbose = -1;
622	}
623
624	if (argc > 0) {
625		if (strcmp(argv[0], "-") == 0) {
626			usage_with_options_msg(probe_usage, options,
627				"'-' is not supported.\n");
628		}
629		if (params.command && params.command != 'a') {
630			usage_with_options_msg(probe_usage, options,
631				"another command except --add is set.\n");
632		}
633		ret = parse_probe_event_argv(argc, argv);
634		if (ret < 0) {
635			pr_err_with_code("  Error: Command Parse Error.", ret);
636			return ret;
637		}
638		params.command = 'a';
639	}
640
641	ret = symbol__validate_sym_arguments();
642	if (ret)
643		return ret;
644
645	if (probe_conf.max_probes == 0)
646		probe_conf.max_probes = MAX_PROBES;
 
647
648	/*
649	 * Only consider the user's kernel image path if given.
650	 */
651	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
652
653	/*
654	 * Except for --list, --del and --add, other command doesn't depend
655	 * nor change running kernel. So if user gives offline vmlinux,
656	 * ignore its buildid.
657	 */
658	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
659		symbol_conf.ignore_vmlinux_buildid = true;
660
661	switch (params.command) {
662	case 'l':
 
 
 
 
 
 
 
663		if (params.uprobes) {
664			pr_err("  Error: Don't use --list with --exec.\n");
665			parse_options_usage(probe_usage, options, "l", true);
666			parse_options_usage(NULL, options, "x", true);
667			return -EINVAL;
668		}
669		ret = show_perf_probe_events(params.filter);
670		if (ret < 0)
671			pr_err_with_code("  Error: Failed to show event list.", ret);
 
672		return ret;
673	case 'F':
674		ret = show_available_funcs(params.target, params.nsi,
675					   params.filter, params.uprobes);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
676		if (ret < 0)
677			pr_err_with_code("  Error: Failed to show functions.", ret);
 
678		return ret;
 
 
679#ifdef HAVE_DWARF_SUPPORT
680	case 'L':
681		ret = show_line_range(&params.line_range, params.target,
682				      params.nsi, params.uprobes);
 
 
 
 
 
 
 
 
 
683		if (ret < 0)
684			pr_err_with_code("  Error: Failed to show lines.", ret);
685		return ret;
686	case 'V':
 
 
 
 
 
 
687		if (!params.filter)
688			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
689						       NULL);
690
691		ret = show_available_vars(params.events, params.nevents,
692					  params.filter);
 
 
 
 
 
693		if (ret < 0)
694			pr_err_with_code("  Error: Failed to show vars.", ret);
695		return ret;
 
696#endif
697	case 'd':
698		ret = perf_del_probe_events(params.filter);
 
699		if (ret < 0) {
700			pr_err_with_code("  Error: Failed to delete events.", ret);
701			return ret;
702		}
703		break;
704	case 'D':
705		if (probe_conf.bootconfig && params.uprobes) {
706			pr_err("  Error: --bootconfig doesn't support uprobes.\n");
707			return -EINVAL;
708		}
709		__fallthrough;
710	case 'a':
711
712		/* Ensure the last given target is used */
713		if (params.target && !params.target_used) {
714			pr_err("  Error: -x/-m must follow the probe definitions.\n");
715			parse_options_usage(probe_usage, options, "m", true);
716			parse_options_usage(NULL, options, "x", true);
717			return -EINVAL;
718		}
719
720		ret = perf_add_probe_events(params.events, params.nevents);
 
 
 
 
721		if (ret < 0) {
722
723			/*
724			 * When perf_add_probe_events() fails it calls
725			 * cleanup_perf_probe_events(pevs, npevs), i.e.
726			 * cleanup_perf_probe_events(params.events, params.nevents), which
727			 * will call clear_perf_probe_event(), so set nevents to zero
728			 * to avoid cleanup_params() to call clear_perf_probe_event() again
729			 * on the same pevs.
730			 */
731			params.nevents = 0;
732			pr_err_with_code("  Error: Failed to add events.", ret);
733			return ret;
734		}
735		break;
736	default:
737		usage_with_options(probe_usage, options);
738	}
739	return 0;
740}
741
742int cmd_probe(int argc, const char **argv)
743{
744	int ret;
745
746	ret = init_params();
747	if (!ret) {
748		ret = __cmd_probe(argc, argv);
749		cleanup_params();
750	}
751
752	return ret < 0 ? ret : 0;
753}
v3.15
 
  1/*
  2 * builtin-probe.c
  3 *
  4 * Builtin probe command: Set up probe events by C expression
  5 *
  6 * Written by Masami Hiramatsu <mhiramat@redhat.com>
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License as published by
 10 * the Free Software Foundation; either version 2 of the License, or
 11 * (at your option) any later version.
 12 *
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 *
 18 * You should have received a copy of the GNU General Public License
 19 * along with this program; if not, write to the Free Software
 20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 21 *
 22 */
 23#include <sys/utsname.h>
 24#include <sys/types.h>
 25#include <sys/stat.h>
 26#include <fcntl.h>
 27#include <errno.h>
 28#include <stdio.h>
 29#include <unistd.h>
 30#include <stdlib.h>
 31#include <string.h>
 32
 33#include "perf.h"
 34#include "builtin.h"
 35#include "util/util.h"
 
 36#include "util/strlist.h"
 37#include "util/strfilter.h"
 38#include "util/symbol.h"
 
 39#include "util/debug.h"
 40#include <api/fs/debugfs.h>
 41#include "util/parse-options.h"
 42#include "util/probe-finder.h"
 43#include "util/probe-event.h"
 
 
 
 44
 45#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
 46#define DEFAULT_FUNC_FILTER "!_*"
 
 47
 48/* Session management structure */
 49static struct {
 
 50	bool list_events;
 51	bool force_add;
 52	bool show_lines;
 53	bool show_vars;
 54	bool show_ext_vars;
 55	bool show_funcs;
 56	bool mod_events;
 57	bool uprobes;
 
 58	int nevents;
 59	struct perf_probe_event events[MAX_PROBES];
 60	struct strlist *dellist;
 61	struct line_range line_range;
 62	char *target;
 63	int max_probe_points;
 64	struct strfilter *filter;
 
 65} params;
 66
 67/* Parse an event definition. Note that any error must die. */
 68static int parse_probe_event(const char *str)
 69{
 70	struct perf_probe_event *pev = &params.events[params.nevents];
 71	int ret;
 72
 73	pr_debug("probe-definition(%d): %s\n", params.nevents, str);
 74	if (++params.nevents == MAX_PROBES) {
 75		pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
 76		return -1;
 77	}
 78
 79	pev->uprobes = params.uprobes;
 
 
 
 
 
 
 
 
 80
 81	/* Parse a perf-probe command into event */
 82	ret = parse_perf_probe_command(str, pev);
 83	pr_debug("%d arguments\n", pev->nargs);
 84
 85	return ret;
 86}
 87
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 88static int set_target(const char *ptr)
 89{
 90	int found = 0;
 91	const char *buf;
 92
 93	/*
 94	 * The first argument after options can be an absolute path
 95	 * to an executable / library or kernel module.
 96	 *
 97	 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
 98	 * short module name.
 99	 */
100	if (!params.target && ptr && *ptr == '/') {
101		params.target = strdup(ptr);
102		if (!params.target)
103			return -ENOMEM;
 
104
105		found = 1;
106		buf = ptr + (strlen(ptr) - 3);
107
108		if (strcmp(buf, ".ko"))
109			params.uprobes = true;
110
111	}
112
113	return found;
114}
115
116static int parse_probe_event_argv(int argc, const char **argv)
117{
118	int i, len, ret, found_target;
119	char *buf;
120
121	found_target = set_target(argv[0]);
122	if (found_target < 0)
123		return found_target;
124
125	if (found_target && argc == 1)
126		return 0;
127
128	/* Bind up rest arguments */
129	len = 0;
130	for (i = 0; i < argc; i++) {
131		if (i == 0 && found_target)
132			continue;
133
134		len += strlen(argv[i]) + 1;
135	}
136	buf = zalloc(len + 1);
137	if (buf == NULL)
138		return -ENOMEM;
139	len = 0;
140	for (i = 0; i < argc; i++) {
141		if (i == 0 && found_target)
142			continue;
143
144		len += sprintf(&buf[len], "%s ", argv[i]);
145	}
146	params.mod_events = true;
147	ret = parse_probe_event(buf);
148	free(buf);
149	return ret;
150}
151
152static int opt_add_probe_event(const struct option *opt __maybe_unused,
153			      const char *str, int unset __maybe_unused)
154{
155	if (str) {
156		params.mod_events = true;
157		return parse_probe_event(str);
158	} else
159		return 0;
160}
161
162static int opt_del_probe_event(const struct option *opt __maybe_unused,
163			       const char *str, int unset __maybe_unused)
164{
165	if (str) {
166		params.mod_events = true;
167		if (!params.dellist)
168			params.dellist = strlist__new(true, NULL);
169		strlist__add(params.dellist, str);
170	}
171	return 0;
172}
173
174static int opt_set_target(const struct option *opt, const char *str,
175			int unset __maybe_unused)
176{
177	int ret = -ENOENT;
178	char *tmp;
179
180	if  (str && !params.target) {
181		if (!strcmp(opt->long_name, "exec"))
182			params.uprobes = true;
183#ifdef HAVE_DWARF_SUPPORT
184		else if (!strcmp(opt->long_name, "module"))
185			params.uprobes = false;
186#endif
187		else
188			return ret;
189
190		/* Expand given path to absolute path, except for modulename */
191		if (params.uprobes || strchr(str, '/')) {
192			tmp = realpath(str, NULL);
193			if (!tmp) {
194				pr_warning("Failed to get the absolute path of %s: %m\n", str);
195				return ret;
196			}
197		} else {
198			tmp = strdup(str);
199			if (!tmp)
200				return -ENOMEM;
201		}
 
202		params.target = tmp;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
203		ret = 0;
204	}
205
206	return ret;
207}
208
 
 
 
209#ifdef HAVE_DWARF_SUPPORT
210static int opt_show_lines(const struct option *opt __maybe_unused,
211			  const char *str, int unset __maybe_unused)
212{
213	int ret = 0;
214
215	if (!str)
216		return 0;
217
218	if (params.show_lines) {
219		pr_warning("Warning: more than one --line options are"
220			   " detected. Only the first one is valid.\n");
221		return 0;
222	}
223
224	params.show_lines = true;
225	ret = parse_line_range_desc(str, &params.line_range);
226
227	return ret;
228}
229
230static int opt_show_vars(const struct option *opt __maybe_unused,
231			 const char *str, int unset __maybe_unused)
232{
233	struct perf_probe_event *pev = &params.events[params.nevents];
234	int ret;
235
236	if (!str)
237		return 0;
238
239	ret = parse_probe_event(str);
240	if (!ret && pev->nargs != 0) {
241		pr_err("  Error: '--vars' doesn't accept arguments.\n");
242		return -EINVAL;
243	}
244	params.show_vars = true;
245
246	return ret;
247}
 
 
 
248#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
249
250static int opt_set_filter(const struct option *opt __maybe_unused,
251			  const char *str, int unset __maybe_unused)
252{
253	const char *err;
254
255	if (str) {
256		pr_debug2("Set filter: %s\n", str);
257		if (params.filter)
258			strfilter__delete(params.filter);
259		params.filter = strfilter__new(str, &err);
260		if (!params.filter) {
261			pr_err("Filter parse error at %td.\n", err - str + 1);
262			pr_err("Source: \"%s\"\n", str);
263			pr_err("         %*c\n", (int)(err - str + 1), '^');
264			return -EINVAL;
265		}
266	}
267
268	return 0;
269}
270
271static int init_params(void)
272{
273	return line_range__init(&params.line_range);
274}
275
276static void cleanup_params(void)
277{
278	int i;
279
280	for (i = 0; i < params.nevents; i++)
281		clear_perf_probe_event(params.events + i);
282	if (params.dellist)
283		strlist__delete(params.dellist);
284	line_range__clear(&params.line_range);
285	free(params.target);
286	if (params.filter)
287		strfilter__delete(params.filter);
288	memset(&params, 0, sizeof(params));
289}
290
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
291static int
292__cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
293{
294	const char * const probe_usage[] = {
295		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
296		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
297		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
298		"perf probe --list",
299#ifdef HAVE_DWARF_SUPPORT
300		"perf probe [<options>] --line 'LINEDESC'",
301		"perf probe [<options>] --vars 'PROBEPOINT'",
302#endif
 
303		NULL
304};
305	const struct option options[] = {
306	OPT_INCR('v', "verbose", &verbose,
307		    "be more verbose (show parsed arguments, etc)"),
308	OPT_BOOLEAN('l', "list", &params.list_events,
309		    "list up current probe events"),
 
 
 
310	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
311		opt_del_probe_event),
312	OPT_CALLBACK('a', "add", NULL,
313#ifdef HAVE_DWARF_SUPPORT
314		"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
315		" [[NAME=]ARG ...]",
316#else
317		"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
318#endif
319		"probe point definition, where\n"
320		"\t\tGROUP:\tGroup name (optional)\n"
321		"\t\tEVENT:\tEvent name\n"
322		"\t\tFUNC:\tFunction name\n"
323		"\t\tOFF:\tOffset from function entry (in byte)\n"
324		"\t\t%return:\tPut the probe at function return\n"
325#ifdef HAVE_DWARF_SUPPORT
326		"\t\tSRC:\tSource code path\n"
327		"\t\tRL:\tRelative line number from function entry.\n"
328		"\t\tAL:\tAbsolute line number in file.\n"
329		"\t\tPT:\tLazy expression of line code.\n"
330		"\t\tARG:\tProbe argument (local variable name or\n"
331		"\t\t\tkprobe-tracer argument format.)\n",
332#else
333		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
334#endif
335		opt_add_probe_event),
336	OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 
 
 
337		    " with existing name"),
338#ifdef HAVE_DWARF_SUPPORT
339	OPT_CALLBACK('L', "line", NULL,
340		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
341		     "Show source code lines.", opt_show_lines),
342	OPT_CALLBACK('V', "vars", NULL,
343		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
344		     "Show accessible variables on PROBEDEF", opt_show_vars),
345	OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
346		    "Show external variables too (with --vars only)"),
 
 
347	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
348		   "file", "vmlinux pathname"),
349	OPT_STRING('s', "source", &symbol_conf.source_prefix,
350		   "directory", "path to kernel source"),
351	OPT_CALLBACK('m', "module", NULL, "modname|path",
352		"target module name (for online) or path (for offline)",
353		opt_set_target),
354#endif
355	OPT__DRY_RUN(&probe_event_dry_run),
356	OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
357		 "Set how many probe points can be found for a probe."),
358	OPT_BOOLEAN('F', "funcs", &params.show_funcs,
359		    "Show potential probe-able functions."),
 
360	OPT_CALLBACK('\0', "filter", NULL,
361		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
362		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
363		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
364		     opt_set_filter),
365	OPT_CALLBACK('x', "exec", NULL, "executable|path",
366			"target executable name or path", opt_set_target),
 
 
 
367	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
368		    "Disable symbol demangling"),
 
 
 
 
 
 
 
 
 
369	OPT_END()
370	};
371	int ret;
372
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
373	argc = parse_options(argc, argv, options, probe_usage,
374			     PARSE_OPT_STOP_AT_NON_OPTION);
 
 
 
 
 
 
 
 
 
375	if (argc > 0) {
376		if (strcmp(argv[0], "-") == 0) {
377			pr_warning("  Error: '-' is not supported.\n");
378			usage_with_options(probe_usage, options);
 
 
 
 
379		}
380		ret = parse_probe_event_argv(argc, argv);
381		if (ret < 0) {
382			pr_err("  Error: Parse Error.  (%d)\n", ret);
383			return ret;
384		}
 
385	}
386
387	if (params.max_probe_points == 0)
388		params.max_probe_points = MAX_PROBES;
 
389
390	if ((!params.nevents && !params.dellist && !params.list_events &&
391	     !params.show_lines && !params.show_funcs))
392		usage_with_options(probe_usage, options);
393
394	/*
395	 * Only consider the user's kernel image path if given.
396	 */
397	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
398
399	if (params.list_events) {
400		if (params.mod_events) {
401			pr_err("  Error: Don't use --list with --add/--del.\n");
402			usage_with_options(probe_usage, options);
403		}
404		if (params.show_lines) {
405			pr_err("  Error: Don't use --list with --line.\n");
406			usage_with_options(probe_usage, options);
407		}
408		if (params.show_vars) {
409			pr_err(" Error: Don't use --list with --vars.\n");
410			usage_with_options(probe_usage, options);
411		}
412		if (params.show_funcs) {
413			pr_err("  Error: Don't use --list with --funcs.\n");
414			usage_with_options(probe_usage, options);
415		}
416		if (params.uprobes) {
417			pr_warning("  Error: Don't use --list with --exec.\n");
418			usage_with_options(probe_usage, options);
 
 
419		}
420		ret = show_perf_probe_events();
421		if (ret < 0)
422			pr_err("  Error: Failed to show event list. (%d)\n",
423			       ret);
424		return ret;
425	}
426	if (params.show_funcs) {
427		if (params.nevents != 0 || params.dellist) {
428			pr_err("  Error: Don't use --funcs with"
429			       " --add/--del.\n");
430			usage_with_options(probe_usage, options);
431		}
432		if (params.show_lines) {
433			pr_err("  Error: Don't use --funcs with --line.\n");
434			usage_with_options(probe_usage, options);
435		}
436		if (params.show_vars) {
437			pr_err("  Error: Don't use --funcs with --vars.\n");
438			usage_with_options(probe_usage, options);
439		}
440		if (!params.filter)
441			params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
442						       NULL);
443		ret = show_available_funcs(params.target, params.filter,
444					params.uprobes);
445		strfilter__delete(params.filter);
446		params.filter = NULL;
447		if (ret < 0)
448			pr_err("  Error: Failed to show functions."
449			       " (%d)\n", ret);
450		return ret;
451	}
452
453#ifdef HAVE_DWARF_SUPPORT
454	if (params.show_lines) {
455		if (params.mod_events) {
456			pr_err("  Error: Don't use --line with"
457			       " --add/--del.\n");
458			usage_with_options(probe_usage, options);
459		}
460		if (params.show_vars) {
461			pr_err(" Error: Don't use --line with --vars.\n");
462			usage_with_options(probe_usage, options);
463		}
464
465		ret = show_line_range(&params.line_range, params.target);
466		if (ret < 0)
467			pr_err("  Error: Failed to show lines. (%d)\n", ret);
468		return ret;
469	}
470	if (params.show_vars) {
471		if (params.mod_events) {
472			pr_err("  Error: Don't use --vars with"
473			       " --add/--del.\n");
474			usage_with_options(probe_usage, options);
475		}
476		if (!params.filter)
477			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
478						       NULL);
479
480		ret = show_available_vars(params.events, params.nevents,
481					  params.max_probe_points,
482					  params.target,
483					  params.filter,
484					  params.show_ext_vars);
485		strfilter__delete(params.filter);
486		params.filter = NULL;
487		if (ret < 0)
488			pr_err("  Error: Failed to show vars. (%d)\n", ret);
489		return ret;
490	}
491#endif
492
493	if (params.dellist) {
494		ret = del_perf_probe_events(params.dellist);
495		if (ret < 0) {
496			pr_err("  Error: Failed to delete events. (%d)\n", ret);
497			return ret;
498		}
499	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
500
501	if (params.nevents) {
502		ret = add_perf_probe_events(params.events, params.nevents,
503					    params.max_probe_points,
504					    params.target,
505					    params.force_add);
506		if (ret < 0) {
507			pr_err("  Error: Failed to add events. (%d)\n", ret);
 
 
 
 
 
 
 
 
 
 
508			return ret;
509		}
 
 
 
510	}
511	return 0;
512}
513
514int cmd_probe(int argc, const char **argv, const char *prefix)
515{
516	int ret;
517
518	ret = init_params();
519	if (!ret) {
520		ret = __cmd_probe(argc, argv, prefix);
521		cleanup_params();
522	}
523
524	return ret;
525}