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 <lk/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 */
49 static 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 const 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. */
parse_probe_event(const char * str)68 static int parse_probe_event(const char *str)
69 {
70 struct perf_probe_event *pev = ¶ms.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
set_target(const char * ptr)88 static 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 = ptr;
102 found = 1;
103 buf = ptr + (strlen(ptr) - 3);
104
105 if (strcmp(buf, ".ko"))
106 params.uprobes = true;
107
108 }
109
110 return found;
111 }
112
parse_probe_event_argv(int argc,const char ** argv)113 static int parse_probe_event_argv(int argc, const char **argv)
114 {
115 int i, len, ret, found_target;
116 char *buf;
117
118 found_target = set_target(argv[0]);
119 if (found_target && argc == 1)
120 return 0;
121
122 /* Bind up rest arguments */
123 len = 0;
124 for (i = 0; i < argc; i++) {
125 if (i == 0 && found_target)
126 continue;
127
128 len += strlen(argv[i]) + 1;
129 }
130 buf = zalloc(len + 1);
131 if (buf == NULL)
132 return -ENOMEM;
133 len = 0;
134 for (i = 0; i < argc; i++) {
135 if (i == 0 && found_target)
136 continue;
137
138 len += sprintf(&buf[len], "%s ", argv[i]);
139 }
140 params.mod_events = true;
141 ret = parse_probe_event(buf);
142 free(buf);
143 return ret;
144 }
145
opt_add_probe_event(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)146 static int opt_add_probe_event(const struct option *opt __maybe_unused,
147 const char *str, int unset __maybe_unused)
148 {
149 if (str) {
150 params.mod_events = true;
151 return parse_probe_event(str);
152 } else
153 return 0;
154 }
155
opt_del_probe_event(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)156 static int opt_del_probe_event(const struct option *opt __maybe_unused,
157 const char *str, int unset __maybe_unused)
158 {
159 if (str) {
160 params.mod_events = true;
161 if (!params.dellist)
162 params.dellist = strlist__new(true, NULL);
163 strlist__add(params.dellist, str);
164 }
165 return 0;
166 }
167
opt_set_target(const struct option * opt,const char * str,int unset __maybe_unused)168 static int opt_set_target(const struct option *opt, const char *str,
169 int unset __maybe_unused)
170 {
171 int ret = -ENOENT;
172
173 if (str && !params.target) {
174 if (!strcmp(opt->long_name, "exec"))
175 params.uprobes = true;
176 #ifdef DWARF_SUPPORT
177 else if (!strcmp(opt->long_name, "module"))
178 params.uprobes = false;
179 #endif
180 else
181 return ret;
182
183 params.target = str;
184 ret = 0;
185 }
186
187 return ret;
188 }
189
190 #ifdef DWARF_SUPPORT
opt_show_lines(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)191 static int opt_show_lines(const struct option *opt __maybe_unused,
192 const char *str, int unset __maybe_unused)
193 {
194 int ret = 0;
195
196 if (!str)
197 return 0;
198
199 if (params.show_lines) {
200 pr_warning("Warning: more than one --line options are"
201 " detected. Only the first one is valid.\n");
202 return 0;
203 }
204
205 params.show_lines = true;
206 ret = parse_line_range_desc(str, ¶ms.line_range);
207 INIT_LIST_HEAD(¶ms.line_range.line_list);
208
209 return ret;
210 }
211
opt_show_vars(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)212 static int opt_show_vars(const struct option *opt __maybe_unused,
213 const char *str, int unset __maybe_unused)
214 {
215 struct perf_probe_event *pev = ¶ms.events[params.nevents];
216 int ret;
217
218 if (!str)
219 return 0;
220
221 ret = parse_probe_event(str);
222 if (!ret && pev->nargs != 0) {
223 pr_err(" Error: '--vars' doesn't accept arguments.\n");
224 return -EINVAL;
225 }
226 params.show_vars = true;
227
228 return ret;
229 }
230 #endif
231
opt_set_filter(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)232 static int opt_set_filter(const struct option *opt __maybe_unused,
233 const char *str, int unset __maybe_unused)
234 {
235 const char *err;
236
237 if (str) {
238 pr_debug2("Set filter: %s\n", str);
239 if (params.filter)
240 strfilter__delete(params.filter);
241 params.filter = strfilter__new(str, &err);
242 if (!params.filter) {
243 pr_err("Filter parse error at %td.\n", err - str + 1);
244 pr_err("Source: \"%s\"\n", str);
245 pr_err(" %*c\n", (int)(err - str + 1), '^');
246 return -EINVAL;
247 }
248 }
249
250 return 0;
251 }
252
cmd_probe(int argc,const char ** argv,const char * prefix __maybe_unused)253 int cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
254 {
255 const char * const probe_usage[] = {
256 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
257 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
258 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
259 "perf probe --list",
260 #ifdef DWARF_SUPPORT
261 "perf probe [<options>] --line 'LINEDESC'",
262 "perf probe [<options>] --vars 'PROBEPOINT'",
263 #endif
264 NULL
265 };
266 const struct option options[] = {
267 OPT_INCR('v', "verbose", &verbose,
268 "be more verbose (show parsed arguments, etc)"),
269 OPT_BOOLEAN('l', "list", ¶ms.list_events,
270 "list up current probe events"),
271 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
272 opt_del_probe_event),
273 OPT_CALLBACK('a', "add", NULL,
274 #ifdef DWARF_SUPPORT
275 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
276 " [[NAME=]ARG ...]",
277 #else
278 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
279 #endif
280 "probe point definition, where\n"
281 "\t\tGROUP:\tGroup name (optional)\n"
282 "\t\tEVENT:\tEvent name\n"
283 "\t\tFUNC:\tFunction name\n"
284 "\t\tOFF:\tOffset from function entry (in byte)\n"
285 "\t\t%return:\tPut the probe at function return\n"
286 #ifdef DWARF_SUPPORT
287 "\t\tSRC:\tSource code path\n"
288 "\t\tRL:\tRelative line number from function entry.\n"
289 "\t\tAL:\tAbsolute line number in file.\n"
290 "\t\tPT:\tLazy expression of line code.\n"
291 "\t\tARG:\tProbe argument (local variable name or\n"
292 "\t\t\tkprobe-tracer argument format.)\n",
293 #else
294 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
295 #endif
296 opt_add_probe_event),
297 OPT_BOOLEAN('f', "force", ¶ms.force_add, "forcibly add events"
298 " with existing name"),
299 #ifdef DWARF_SUPPORT
300 OPT_CALLBACK('L', "line", NULL,
301 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
302 "Show source code lines.", opt_show_lines),
303 OPT_CALLBACK('V', "vars", NULL,
304 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
305 "Show accessible variables on PROBEDEF", opt_show_vars),
306 OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars,
307 "Show external variables too (with --vars only)"),
308 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
309 "file", "vmlinux pathname"),
310 OPT_STRING('s', "source", &symbol_conf.source_prefix,
311 "directory", "path to kernel source"),
312 OPT_CALLBACK('m', "module", NULL, "modname|path",
313 "target module name (for online) or path (for offline)",
314 opt_set_target),
315 #endif
316 OPT__DRY_RUN(&probe_event_dry_run),
317 OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points,
318 "Set how many probe points can be found for a probe."),
319 OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs,
320 "Show potential probe-able functions."),
321 OPT_CALLBACK('\0', "filter", NULL,
322 "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
323 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
324 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
325 opt_set_filter),
326 OPT_CALLBACK('x', "exec", NULL, "executable|path",
327 "target executable name or path", opt_set_target),
328 OPT_END()
329 };
330 int ret;
331
332 argc = parse_options(argc, argv, options, probe_usage,
333 PARSE_OPT_STOP_AT_NON_OPTION);
334 if (argc > 0) {
335 if (strcmp(argv[0], "-") == 0) {
336 pr_warning(" Error: '-' is not supported.\n");
337 usage_with_options(probe_usage, options);
338 }
339 ret = parse_probe_event_argv(argc, argv);
340 if (ret < 0) {
341 pr_err(" Error: Parse Error. (%d)\n", ret);
342 return ret;
343 }
344 }
345
346 if (params.max_probe_points == 0)
347 params.max_probe_points = MAX_PROBES;
348
349 if ((!params.nevents && !params.dellist && !params.list_events &&
350 !params.show_lines && !params.show_funcs))
351 usage_with_options(probe_usage, options);
352
353 /*
354 * Only consider the user's kernel image path if given.
355 */
356 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
357
358 if (params.list_events) {
359 if (params.mod_events) {
360 pr_err(" Error: Don't use --list with --add/--del.\n");
361 usage_with_options(probe_usage, options);
362 }
363 if (params.show_lines) {
364 pr_err(" Error: Don't use --list with --line.\n");
365 usage_with_options(probe_usage, options);
366 }
367 if (params.show_vars) {
368 pr_err(" Error: Don't use --list with --vars.\n");
369 usage_with_options(probe_usage, options);
370 }
371 if (params.show_funcs) {
372 pr_err(" Error: Don't use --list with --funcs.\n");
373 usage_with_options(probe_usage, options);
374 }
375 if (params.uprobes) {
376 pr_warning(" Error: Don't use --list with --exec.\n");
377 usage_with_options(probe_usage, options);
378 }
379 ret = show_perf_probe_events();
380 if (ret < 0)
381 pr_err(" Error: Failed to show event list. (%d)\n",
382 ret);
383 return ret;
384 }
385 if (params.show_funcs) {
386 if (params.nevents != 0 || params.dellist) {
387 pr_err(" Error: Don't use --funcs with"
388 " --add/--del.\n");
389 usage_with_options(probe_usage, options);
390 }
391 if (params.show_lines) {
392 pr_err(" Error: Don't use --funcs with --line.\n");
393 usage_with_options(probe_usage, options);
394 }
395 if (params.show_vars) {
396 pr_err(" Error: Don't use --funcs with --vars.\n");
397 usage_with_options(probe_usage, options);
398 }
399 if (!params.filter)
400 params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
401 NULL);
402 ret = show_available_funcs(params.target, params.filter,
403 params.uprobes);
404 strfilter__delete(params.filter);
405 if (ret < 0)
406 pr_err(" Error: Failed to show functions."
407 " (%d)\n", ret);
408 return ret;
409 }
410
411 #ifdef DWARF_SUPPORT
412 if (params.show_lines && !params.uprobes) {
413 if (params.mod_events) {
414 pr_err(" Error: Don't use --line with"
415 " --add/--del.\n");
416 usage_with_options(probe_usage, options);
417 }
418 if (params.show_vars) {
419 pr_err(" Error: Don't use --line with --vars.\n");
420 usage_with_options(probe_usage, options);
421 }
422
423 ret = show_line_range(¶ms.line_range, params.target);
424 if (ret < 0)
425 pr_err(" Error: Failed to show lines. (%d)\n", ret);
426 return ret;
427 }
428 if (params.show_vars) {
429 if (params.mod_events) {
430 pr_err(" Error: Don't use --vars with"
431 " --add/--del.\n");
432 usage_with_options(probe_usage, options);
433 }
434 if (!params.filter)
435 params.filter = strfilter__new(DEFAULT_VAR_FILTER,
436 NULL);
437
438 ret = show_available_vars(params.events, params.nevents,
439 params.max_probe_points,
440 params.target,
441 params.filter,
442 params.show_ext_vars);
443 strfilter__delete(params.filter);
444 if (ret < 0)
445 pr_err(" Error: Failed to show vars. (%d)\n", ret);
446 return ret;
447 }
448 #endif
449
450 if (params.dellist) {
451 ret = del_perf_probe_events(params.dellist);
452 strlist__delete(params.dellist);
453 if (ret < 0) {
454 pr_err(" Error: Failed to delete events. (%d)\n", ret);
455 return ret;
456 }
457 }
458
459 if (params.nevents) {
460 ret = add_perf_probe_events(params.events, params.nevents,
461 params.max_probe_points,
462 params.target,
463 params.force_add);
464 if (ret < 0) {
465 pr_err(" Error: Failed to add events. (%d)\n", ret);
466 return ret;
467 }
468 }
469 return 0;
470 }
471