tty: fix race in tty_fasync
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / tools / perf / builtin-probe.c
blobc1e6774fd3ed316171118cb6598ac8e2dbf7a36c
1 /*
2 * builtin-probe.c
4 * Builtin probe command: Set up probe events by C expression
6 * Written by Masami Hiramatsu <mhiramat@redhat.com>
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.
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.
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.
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>
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/debugfs.h"
42 #include "util/symbol.h"
43 #include "util/thread.h"
44 #include "util/session.h"
45 #include "util/parse-options.h"
46 #include "util/parse-events.h" /* For debugfs_path */
47 #include "util/probe-finder.h"
48 #include "util/probe-event.h"
50 #define MAX_PATH_LEN 256
51 #define MAX_PROBES 128
53 /* Session management structure */
54 static struct {
55 bool need_dwarf;
56 bool list_events;
57 bool force_add;
58 int nr_probe;
59 struct probe_point probes[MAX_PROBES];
60 struct strlist *dellist;
61 struct perf_session *psession;
62 struct map *kmap;
63 } session;
66 /* Parse an event definition. Note that any error must die. */
67 static void parse_probe_event(const char *str)
69 struct probe_point *pp = &session.probes[session.nr_probe];
71 pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
72 if (++session.nr_probe == MAX_PROBES)
73 die("Too many probes (> %d) are specified.", MAX_PROBES);
75 /* Parse perf-probe event into probe_point */
76 parse_perf_probe_event(str, pp, &session.need_dwarf);
78 pr_debug("%d arguments\n", pp->nr_args);
81 static void parse_probe_event_argv(int argc, const char **argv)
83 int i, len;
84 char *buf;
86 /* Bind up rest arguments */
87 len = 0;
88 for (i = 0; i < argc; i++)
89 len += strlen(argv[i]) + 1;
90 buf = zalloc(len + 1);
91 if (!buf)
92 die("Failed to allocate memory for binding arguments.");
93 len = 0;
94 for (i = 0; i < argc; i++)
95 len += sprintf(&buf[len], "%s ", argv[i]);
96 parse_probe_event(buf);
97 free(buf);
100 static int opt_add_probe_event(const struct option *opt __used,
101 const char *str, int unset __used)
103 if (str)
104 parse_probe_event(str);
105 return 0;
108 static int opt_del_probe_event(const struct option *opt __used,
109 const char *str, int unset __used)
111 if (str) {
112 if (!session.dellist)
113 session.dellist = strlist__new(true, NULL);
114 strlist__add(session.dellist, str);
116 return 0;
119 /* Currently just checking function name from symbol map */
120 static void evaluate_probe_point(struct probe_point *pp)
122 struct symbol *sym;
123 sym = map__find_symbol_by_name(session.kmap, pp->function,
124 session.psession, NULL);
125 if (!sym)
126 die("Kernel symbol \'%s\' not found - probe not added.",
127 pp->function);
130 #ifndef NO_LIBDWARF
131 static int open_vmlinux(void)
133 if (map__load(session.kmap, session.psession, NULL) < 0) {
134 pr_debug("Failed to load kernel map.\n");
135 return -EINVAL;
137 pr_debug("Try to open %s\n", session.kmap->dso->long_name);
138 return open(session.kmap->dso->long_name, O_RDONLY);
140 #endif
142 static const char * const probe_usage[] = {
143 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
144 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
145 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
146 "perf probe --list",
147 NULL
150 static const struct option options[] = {
151 OPT_BOOLEAN('v', "verbose", &verbose,
152 "be more verbose (show parsed arguments, etc)"),
153 #ifndef NO_LIBDWARF
154 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
155 "file", "vmlinux pathname"),
156 #endif
157 OPT_BOOLEAN('l', "list", &session.list_events,
158 "list up current probe events"),
159 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
160 opt_del_probe_event),
161 OPT_CALLBACK('a', "add", NULL,
162 #ifdef NO_LIBDWARF
163 "[EVENT=]FUNC[+OFFS|%return] [ARG ...]",
164 #else
165 "[EVENT=]FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
166 #endif
167 "probe point definition, where\n"
168 "\t\tGROUP:\tGroup name (optional)\n"
169 "\t\tEVENT:\tEvent name\n"
170 "\t\tFUNC:\tFunction name\n"
171 "\t\tOFFS:\tOffset from function entry (in byte)\n"
172 "\t\t%return:\tPut the probe at function return\n"
173 #ifdef NO_LIBDWARF
174 "\t\tARG:\tProbe argument (only \n"
175 #else
176 "\t\tSRC:\tSource code path\n"
177 "\t\tRLN:\tRelative line number from function entry.\n"
178 "\t\tALN:\tAbsolute line number in file.\n"
179 "\t\tARG:\tProbe argument (local variable name or\n"
180 #endif
181 "\t\t\tkprobe-tracer argument format.)\n",
182 opt_add_probe_event),
183 OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
184 " with existing name"),
185 OPT_END()
188 int cmd_probe(int argc, const char **argv, const char *prefix __used)
190 int i, ret;
191 #ifndef NO_LIBDWARF
192 int fd;
193 #endif
194 struct probe_point *pp;
196 argc = parse_options(argc, argv, options, probe_usage,
197 PARSE_OPT_STOP_AT_NON_OPTION);
198 if (argc > 0) {
199 if (strcmp(argv[0], "-") == 0) {
200 pr_warning(" Error: '-' is not supported.\n");
201 usage_with_options(probe_usage, options);
203 parse_probe_event_argv(argc, argv);
206 if ((!session.nr_probe && !session.dellist && !session.list_events))
207 usage_with_options(probe_usage, options);
209 if (debugfs_valid_mountpoint(debugfs_path) < 0)
210 die("Failed to find debugfs path.");
212 if (session.list_events) {
213 if (session.nr_probe != 0 || session.dellist) {
214 pr_warning(" Error: Don't use --list with"
215 " --add/--del.\n");
216 usage_with_options(probe_usage, options);
218 show_perf_probe_events();
219 return 0;
222 if (session.dellist) {
223 del_trace_kprobe_events(session.dellist);
224 strlist__delete(session.dellist);
225 if (session.nr_probe == 0)
226 return 0;
229 /* Initialize symbol maps for vmlinux */
230 symbol_conf.sort_by_name = true;
231 if (symbol_conf.vmlinux_name == NULL)
232 symbol_conf.try_vmlinux_path = true;
233 if (symbol__init() < 0)
234 die("Failed to init symbol map.");
235 session.psession = perf_session__new(NULL, O_WRONLY, false);
236 if (session.psession == NULL)
237 die("Failed to init perf_session.");
238 session.kmap = map_groups__find_by_name(&session.psession->kmaps,
239 MAP__FUNCTION,
240 "[kernel.kallsyms]");
241 if (!session.kmap)
242 die("Could not find kernel map.\n");
244 if (session.need_dwarf)
245 #ifdef NO_LIBDWARF
246 die("Debuginfo-analysis is not supported");
247 #else /* !NO_LIBDWARF */
248 pr_debug("Some probes require debuginfo.\n");
250 fd = open_vmlinux();
251 if (fd < 0) {
252 if (session.need_dwarf)
253 die("Could not open debuginfo file.");
255 pr_debug("Could not open vmlinux/module file."
256 " Try to use symbols.\n");
257 goto end_dwarf;
260 /* Searching probe points */
261 for (i = 0; i < session.nr_probe; i++) {
262 pp = &session.probes[i];
263 if (pp->found)
264 continue;
266 lseek(fd, SEEK_SET, 0);
267 ret = find_probepoint(fd, pp);
268 if (ret > 0)
269 continue;
270 if (ret == 0) { /* No error but failed to find probe point. */
271 synthesize_perf_probe_point(pp);
272 die("Probe point '%s' not found. - probe not added.",
273 pp->probes[0]);
275 /* Error path */
276 if (session.need_dwarf) {
277 if (ret == -ENOENT)
278 pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
279 die("Could not analyze debuginfo.");
281 pr_debug("An error occurred in debuginfo analysis."
282 " Try to use symbols.\n");
283 break;
285 close(fd);
287 end_dwarf:
288 #endif /* !NO_LIBDWARF */
290 /* Synthesize probes without dwarf */
291 for (i = 0; i < session.nr_probe; i++) {
292 pp = &session.probes[i];
293 if (pp->found) /* This probe is already found. */
294 continue;
296 evaluate_probe_point(pp);
297 ret = synthesize_trace_kprobe_event(pp);
298 if (ret == -E2BIG)
299 die("probe point definition becomes too long.");
300 else if (ret < 0)
301 die("Failed to synthesize a probe point.");
304 /* Settng up probe points */
305 add_trace_kprobe_events(session.probes, session.nr_probe,
306 session.force_add);
307 return 0;