perf probe: Support event name for --add option
[linux-2.6.git] / tools / perf / builtin-probe.c
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/event.h"
40 #include "util/debug.h"
41 #include "util/parse-options.h"
42 #include "util/parse-events.h"  /* For debugfs_path */
43 #include "util/probe-finder.h"
44 #include "util/probe-event.h"
45
46 /* Default vmlinux search paths */
47 #define NR_SEARCH_PATH 4
48 const char *default_search_path[NR_SEARCH_PATH] = {
49 "/lib/modules/%s/build/vmlinux",                /* Custom build kernel */
50 "/usr/lib/debug/lib/modules/%s/vmlinux",        /* Red Hat debuginfo */
51 "/boot/vmlinux-debug-%s",                       /* Ubuntu */
52 "./vmlinux",                                    /* CWD */
53 };
54
55 #define MAX_PATH_LEN 256
56 #define MAX_PROBES 128
57
58 /* Session management structure */
59 static struct {
60         char *vmlinux;
61         char *release;
62         bool need_dwarf;
63         bool list_events;
64         int nr_probe;
65         struct probe_point probes[MAX_PROBES];
66         struct strlist *dellist;
67 } session;
68
69
70 /* Parse an event definition. Note that any error must die. */
71 static void parse_probe_event(const char *str)
72 {
73         struct probe_point *pp = &session.probes[session.nr_probe];
74
75         pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
76         if (++session.nr_probe == MAX_PROBES)
77                 die("Too many probes (> %d) are specified.", MAX_PROBES);
78
79         /* Parse perf-probe event into probe_point */
80         parse_perf_probe_event(str, pp, &session.need_dwarf);
81
82         pr_debug("%d arguments\n", pp->nr_args);
83 }
84
85 static void parse_probe_event_argv(int argc, const char **argv)
86 {
87         int i, len;
88         char *buf;
89
90         /* Bind up rest arguments */
91         len = 0;
92         for (i = 0; i < argc; i++)
93                 len += strlen(argv[i]) + 1;
94         buf = zalloc(len + 1);
95         if (!buf)
96                 die("Failed to allocate memory for binding arguments.");
97         len = 0;
98         for (i = 0; i < argc; i++)
99                 len += sprintf(&buf[len], "%s ", argv[i]);
100         parse_probe_event(buf);
101         free(buf);
102 }
103
104 static int opt_add_probe_event(const struct option *opt __used,
105                               const char *str, int unset __used)
106 {
107         if (str)
108                 parse_probe_event(str);
109         return 0;
110 }
111
112 static int opt_del_probe_event(const struct option *opt __used,
113                                const char *str, int unset __used)
114 {
115         if (str) {
116                 if (!session.dellist)
117                         session.dellist = strlist__new(true, NULL);
118                 strlist__add(session.dellist, str);
119         }
120         return 0;
121 }
122
123 #ifndef NO_LIBDWARF
124 static int open_default_vmlinux(void)
125 {
126         struct utsname uts;
127         char fname[MAX_PATH_LEN];
128         int fd, ret, i;
129
130         ret = uname(&uts);
131         if (ret) {
132                 pr_debug("uname() failed.\n");
133                 return -errno;
134         }
135         session.release = uts.release;
136         for (i = 0; i < NR_SEARCH_PATH; i++) {
137                 ret = snprintf(fname, MAX_PATH_LEN,
138                                default_search_path[i], session.release);
139                 if (ret >= MAX_PATH_LEN || ret < 0) {
140                         pr_debug("Filename(%d,%s) is too long.\n", i,
141                                 uts.release);
142                         errno = E2BIG;
143                         return -E2BIG;
144                 }
145                 pr_debug("try to open %s\n", fname);
146                 fd = open(fname, O_RDONLY);
147                 if (fd >= 0)
148                         break;
149         }
150         return fd;
151 }
152 #endif
153
154 static const char * const probe_usage[] = {
155         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
156         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
157         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
158         "perf probe --list",
159         NULL
160 };
161
162 static const struct option options[] = {
163         OPT_BOOLEAN('v', "verbose", &verbose,
164                     "be more verbose (show parsed arguments, etc)"),
165 #ifndef NO_LIBDWARF
166         OPT_STRING('k', "vmlinux", &session.vmlinux, "file",
167                 "vmlinux/module pathname"),
168 #endif
169         OPT_BOOLEAN('l', "list", &session.list_events,
170                     "list up current probe events"),
171         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
172                 opt_del_probe_event),
173         OPT_CALLBACK('a', "add", NULL,
174 #ifdef NO_LIBDWARF
175                 "[EVENT=]FUNC[+OFFS|%return] [ARG ...]",
176 #else
177                 "[EVENT=]FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
178 #endif
179                 "probe point definition, where\n"
180                 "\t\tGROUP:\tGroup name (optional)\n"
181                 "\t\tEVENT:\tEvent name\n"
182                 "\t\tFUNC:\tFunction name\n"
183                 "\t\tOFFS:\tOffset from function entry (in byte)\n"
184                 "\t\t%return:\tPut the probe at function return\n"
185 #ifdef NO_LIBDWARF
186                 "\t\tARG:\tProbe argument (only \n"
187 #else
188                 "\t\tSRC:\tSource code path\n"
189                 "\t\tRLN:\tRelative line number from function entry.\n"
190                 "\t\tALN:\tAbsolute line number in file.\n"
191                 "\t\tARG:\tProbe argument (local variable name or\n"
192 #endif
193                 "\t\t\tkprobe-tracer argument format.)\n",
194                 opt_add_probe_event),
195         OPT_END()
196 };
197
198 int cmd_probe(int argc, const char **argv, const char *prefix __used)
199 {
200         int i, ret;
201 #ifndef NO_LIBDWARF
202         int fd;
203 #endif
204         struct probe_point *pp;
205
206         argc = parse_options(argc, argv, options, probe_usage,
207                              PARSE_OPT_STOP_AT_NON_OPTION);
208         if (argc > 0) {
209                 if (strcmp(argv[0], "-") == 0) {
210                         pr_warning("  Error: '-' is not supported.\n");
211                         usage_with_options(probe_usage, options);
212                 }
213                 parse_probe_event_argv(argc, argv);
214         }
215
216         if ((!session.nr_probe && !session.dellist && !session.list_events))
217                 usage_with_options(probe_usage, options);
218
219         if (session.list_events) {
220                 if (session.nr_probe != 0 || session.dellist) {
221                         pr_warning("  Error: Don't use --list with"
222                                    " --add/--del.\n");
223                         usage_with_options(probe_usage, options);
224                 }
225                 show_perf_probe_events();
226                 return 0;
227         }
228
229         if (session.dellist) {
230                 del_trace_kprobe_events(session.dellist);
231                 strlist__delete(session.dellist);
232                 if (session.nr_probe == 0)
233                         return 0;
234         }
235
236         if (session.need_dwarf)
237 #ifdef NO_LIBDWARF
238                 die("Debuginfo-analysis is not supported");
239 #else   /* !NO_LIBDWARF */
240                 pr_debug("Some probes require debuginfo.\n");
241
242         if (session.vmlinux) {
243                 pr_debug("Try to open %s.", session.vmlinux);
244                 fd = open(session.vmlinux, O_RDONLY);
245         } else
246                 fd = open_default_vmlinux();
247         if (fd < 0) {
248                 if (session.need_dwarf)
249                         die("Could not open debuginfo file.");
250
251                 pr_debug("Could not open vmlinux/module file."
252                          " Try to use symbols.\n");
253                 goto end_dwarf;
254         }
255
256         /* Searching probe points */
257         for (i = 0; i < session.nr_probe; i++) {
258                 pp = &session.probes[i];
259                 if (pp->found)
260                         continue;
261
262                 lseek(fd, SEEK_SET, 0);
263                 ret = find_probepoint(fd, pp);
264                 if (ret > 0)
265                         continue;
266                 if (ret == 0)   /* No error but failed to find probe point. */
267                         die("No probe point found.");
268                 /* Error path */
269                 if (session.need_dwarf) {
270                         if (ret == -ENOENT)
271                                 pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
272                         die("Could not analyze debuginfo.");
273                 }
274                 pr_debug("An error occurred in debuginfo analysis."
275                          " Try to use symbols.\n");
276                 break;
277         }
278         close(fd);
279
280 end_dwarf:
281 #endif /* !NO_LIBDWARF */
282
283         /* Synthesize probes without dwarf */
284         for (i = 0; i < session.nr_probe; i++) {
285                 pp = &session.probes[i];
286                 if (pp->found)  /* This probe is already found. */
287                         continue;
288
289                 ret = synthesize_trace_kprobe_event(pp);
290                 if (ret == -E2BIG)
291                         die("probe point definition becomes too long.");
292                 else if (ret < 0)
293                         die("Failed to synthesize a probe point.");
294         }
295
296         /* Settng up probe points */
297         add_trace_kprobe_events(session.probes, session.nr_probe);
298         return 0;
299 }
300