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 #define _GNU_SOURCE
24 #include <sys/utsname.h>
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <stdio.h>
30 #include <unistd.h>
31 #include <stdlib.h>
32 #include <string.h>
33
34 #undef _GNU_SOURCE
35 #include "perf.h"
36 #include "builtin.h"
37 #include "util/util.h"
38 #include "util/strlist.h"
39 #include "util/strfilter.h"
40 #include "util/symbol.h"
41 #include "util/debug.h"
42 #include "util/debugfs.h"
43 #include "util/parse-options.h"
44 #include "util/probe-finder.h"
45 #include "util/probe-event.h"
46
47 #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
48 #define DEFAULT_FUNC_FILTER "!_*"
49 #define MAX_PATH_LEN 256
50
51 /* Session management structure */
52 static struct {
53 bool list_events;
54 bool force_add;
55 bool show_lines;
56 bool show_vars;
57 bool show_ext_vars;
58 bool show_funcs;
59 bool mod_events;
60 int nevents;
61 struct perf_probe_event events[MAX_PROBES];
62 struct strlist *dellist;
63 struct line_range line_range;
64 const char *target_module;
65 int max_probe_points;
66 struct strfilter *filter;
67 } params;
68
69 /* Parse an event definition. Note that any error must die. */
parse_probe_event(const char * str)70 static int parse_probe_event(const char *str)
71 {
72 struct perf_probe_event *pev = ¶ms.events[params.nevents];
73 int ret;
74
75 pr_debug("probe-definition(%d): %s\n", params.nevents, str);
76 if (++params.nevents == MAX_PROBES) {
77 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
78 return -1;
79 }
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
parse_probe_event_argv(int argc,const char ** argv)88 static int parse_probe_event_argv(int argc, const char **argv)
89 {
90 int i, len, ret;
91 char *buf;
92
93 /* Bind up rest arguments */
94 len = 0;
95 for (i = 0; i < argc; i++)
96 len += strlen(argv[i]) + 1;
97 buf = zalloc(len + 1);
98 if (buf == NULL)
99 return -ENOMEM;
100 len = 0;
101 for (i = 0; i < argc; i++)
102 len += sprintf(&buf[len], "%s ", argv[i]);
103 params.mod_events = true;
104 ret = parse_probe_event(buf);
105 free(buf);
106 return ret;
107 }
108
opt_add_probe_event(const struct option * opt __used,const char * str,int unset __used)109 static int opt_add_probe_event(const struct option *opt __used,
110 const char *str, int unset __used)
111 {
112 if (str) {
113 params.mod_events = true;
114 return parse_probe_event(str);
115 } else
116 return 0;
117 }
118
opt_del_probe_event(const struct option * opt __used,const char * str,int unset __used)119 static int opt_del_probe_event(const struct option *opt __used,
120 const char *str, int unset __used)
121 {
122 if (str) {
123 params.mod_events = true;
124 if (!params.dellist)
125 params.dellist = strlist__new(true, NULL);
126 strlist__add(params.dellist, str);
127 }
128 return 0;
129 }
130
131 #ifdef DWARF_SUPPORT
opt_show_lines(const struct option * opt __used,const char * str,int unset __used)132 static int opt_show_lines(const struct option *opt __used,
133 const char *str, int unset __used)
134 {
135 int ret = 0;
136
137 if (str)
138 ret = parse_line_range_desc(str, ¶ms.line_range);
139 INIT_LIST_HEAD(¶ms.line_range.line_list);
140 params.show_lines = true;
141
142 return ret;
143 }
144
opt_show_vars(const struct option * opt __used,const char * str,int unset __used)145 static int opt_show_vars(const struct option *opt __used,
146 const char *str, int unset __used)
147 {
148 struct perf_probe_event *pev = ¶ms.events[params.nevents];
149 int ret;
150
151 if (!str)
152 return 0;
153
154 ret = parse_probe_event(str);
155 if (!ret && pev->nargs != 0) {
156 pr_err(" Error: '--vars' doesn't accept arguments.\n");
157 return -EINVAL;
158 }
159 params.show_vars = true;
160
161 return ret;
162 }
163 #endif
164
opt_set_filter(const struct option * opt __used,const char * str,int unset __used)165 static int opt_set_filter(const struct option *opt __used,
166 const char *str, int unset __used)
167 {
168 const char *err;
169
170 if (str) {
171 pr_debug2("Set filter: %s\n", str);
172 if (params.filter)
173 strfilter__delete(params.filter);
174 params.filter = strfilter__new(str, &err);
175 if (!params.filter) {
176 pr_err("Filter parse error at %td.\n", err - str + 1);
177 pr_err("Source: \"%s\"\n", str);
178 pr_err(" %*c\n", (int)(err - str + 1), '^');
179 return -EINVAL;
180 }
181 }
182
183 return 0;
184 }
185
186 static const char * const probe_usage[] = {
187 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
188 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
189 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
190 "perf probe --list",
191 #ifdef DWARF_SUPPORT
192 "perf probe [<options>] --line 'LINEDESC'",
193 "perf probe [<options>] --vars 'PROBEPOINT'",
194 #endif
195 NULL
196 };
197
198 static const struct option options[] = {
199 OPT_INCR('v', "verbose", &verbose,
200 "be more verbose (show parsed arguments, etc)"),
201 OPT_BOOLEAN('l', "list", ¶ms.list_events,
202 "list up current probe events"),
203 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
204 opt_del_probe_event),
205 OPT_CALLBACK('a', "add", NULL,
206 #ifdef DWARF_SUPPORT
207 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
208 " [[NAME=]ARG ...]",
209 #else
210 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
211 #endif
212 "probe point definition, where\n"
213 "\t\tGROUP:\tGroup name (optional)\n"
214 "\t\tEVENT:\tEvent name\n"
215 "\t\tFUNC:\tFunction name\n"
216 "\t\tOFF:\tOffset from function entry (in byte)\n"
217 "\t\t%return:\tPut the probe at function return\n"
218 #ifdef DWARF_SUPPORT
219 "\t\tSRC:\tSource code path\n"
220 "\t\tRL:\tRelative line number from function entry.\n"
221 "\t\tAL:\tAbsolute line number in file.\n"
222 "\t\tPT:\tLazy expression of line code.\n"
223 "\t\tARG:\tProbe argument (local variable name or\n"
224 "\t\t\tkprobe-tracer argument format.)\n",
225 #else
226 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
227 #endif
228 opt_add_probe_event),
229 OPT_BOOLEAN('f', "force", ¶ms.force_add, "forcibly add events"
230 " with existing name"),
231 #ifdef DWARF_SUPPORT
232 OPT_CALLBACK('L', "line", NULL,
233 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
234 "Show source code lines.", opt_show_lines),
235 OPT_CALLBACK('V', "vars", NULL,
236 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
237 "Show accessible variables on PROBEDEF", opt_show_vars),
238 OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars,
239 "Show external variables too (with --vars only)"),
240 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
241 "file", "vmlinux pathname"),
242 OPT_STRING('s', "source", &symbol_conf.source_prefix,
243 "directory", "path to kernel source"),
244 OPT_STRING('m', "module", ¶ms.target_module,
245 "modname", "target module name"),
246 #endif
247 OPT__DRY_RUN(&probe_event_dry_run),
248 OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points,
249 "Set how many probe points can be found for a probe."),
250 OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs,
251 "Show potential probe-able functions."),
252 OPT_CALLBACK('\0', "filter", NULL,
253 "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
254 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
255 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
256 opt_set_filter),
257 OPT_END()
258 };
259
cmd_probe(int argc,const char ** argv,const char * prefix __used)260 int cmd_probe(int argc, const char **argv, const char *prefix __used)
261 {
262 int ret;
263
264 argc = parse_options(argc, argv, options, probe_usage,
265 PARSE_OPT_STOP_AT_NON_OPTION);
266 if (argc > 0) {
267 if (strcmp(argv[0], "-") == 0) {
268 pr_warning(" Error: '-' is not supported.\n");
269 usage_with_options(probe_usage, options);
270 }
271 ret = parse_probe_event_argv(argc, argv);
272 if (ret < 0) {
273 pr_err(" Error: Parse Error. (%d)\n", ret);
274 return ret;
275 }
276 }
277
278 if (params.max_probe_points == 0)
279 params.max_probe_points = MAX_PROBES;
280
281 if ((!params.nevents && !params.dellist && !params.list_events &&
282 !params.show_lines && !params.show_funcs))
283 usage_with_options(probe_usage, options);
284
285 /*
286 * Only consider the user's kernel image path if given.
287 */
288 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
289
290 if (params.list_events) {
291 if (params.mod_events) {
292 pr_err(" Error: Don't use --list with --add/--del.\n");
293 usage_with_options(probe_usage, options);
294 }
295 if (params.show_lines) {
296 pr_err(" Error: Don't use --list with --line.\n");
297 usage_with_options(probe_usage, options);
298 }
299 if (params.show_vars) {
300 pr_err(" Error: Don't use --list with --vars.\n");
301 usage_with_options(probe_usage, options);
302 }
303 if (params.show_funcs) {
304 pr_err(" Error: Don't use --list with --funcs.\n");
305 usage_with_options(probe_usage, options);
306 }
307 ret = show_perf_probe_events();
308 if (ret < 0)
309 pr_err(" Error: Failed to show event list. (%d)\n",
310 ret);
311 return ret;
312 }
313 if (params.show_funcs) {
314 if (params.nevents != 0 || params.dellist) {
315 pr_err(" Error: Don't use --funcs with"
316 " --add/--del.\n");
317 usage_with_options(probe_usage, options);
318 }
319 if (params.show_lines) {
320 pr_err(" Error: Don't use --funcs with --line.\n");
321 usage_with_options(probe_usage, options);
322 }
323 if (params.show_vars) {
324 pr_err(" Error: Don't use --funcs with --vars.\n");
325 usage_with_options(probe_usage, options);
326 }
327 if (!params.filter)
328 params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
329 NULL);
330 ret = show_available_funcs(params.target_module,
331 params.filter);
332 strfilter__delete(params.filter);
333 if (ret < 0)
334 pr_err(" Error: Failed to show functions."
335 " (%d)\n", ret);
336 return ret;
337 }
338
339 #ifdef DWARF_SUPPORT
340 if (params.show_lines) {
341 if (params.mod_events) {
342 pr_err(" Error: Don't use --line with"
343 " --add/--del.\n");
344 usage_with_options(probe_usage, options);
345 }
346 if (params.show_vars) {
347 pr_err(" Error: Don't use --line with --vars.\n");
348 usage_with_options(probe_usage, options);
349 }
350
351 ret = show_line_range(¶ms.line_range, params.target_module);
352 if (ret < 0)
353 pr_err(" Error: Failed to show lines. (%d)\n", ret);
354 return ret;
355 }
356 if (params.show_vars) {
357 if (params.mod_events) {
358 pr_err(" Error: Don't use --vars with"
359 " --add/--del.\n");
360 usage_with_options(probe_usage, options);
361 }
362 if (!params.filter)
363 params.filter = strfilter__new(DEFAULT_VAR_FILTER,
364 NULL);
365
366 ret = show_available_vars(params.events, params.nevents,
367 params.max_probe_points,
368 params.target_module,
369 params.filter,
370 params.show_ext_vars);
371 strfilter__delete(params.filter);
372 if (ret < 0)
373 pr_err(" Error: Failed to show vars. (%d)\n", ret);
374 return ret;
375 }
376 #endif
377
378 if (params.dellist) {
379 ret = del_perf_probe_events(params.dellist);
380 strlist__delete(params.dellist);
381 if (ret < 0) {
382 pr_err(" Error: Failed to delete events. (%d)\n", ret);
383 return ret;
384 }
385 }
386
387 if (params.nevents) {
388 ret = add_perf_probe_events(params.events, params.nevents,
389 params.max_probe_points,
390 params.target_module,
391 params.force_add);
392 if (ret < 0) {
393 pr_err(" Error: Failed to add events. (%d)\n", ret);
394 return ret;
395 }
396 }
397 return 0;
398 }
399