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