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.
24 #include <sys/utsname.h>
25 #include <sys/types.h>
37 #include "util/util.h"
38 #include "util/event.h"
39 #include "util/debug.h"
40 #include "util/parse-options.h"
41 #include "util/parse-events.h" /* For debugfs_path */
42 #include "util/probe-finder.h"
43 #include "util/probe-event.h"
45 /* Default vmlinux search paths */
46 #define NR_SEARCH_PATH 3
47 const char *default_search_path[NR_SEARCH_PATH] = {
48 "/lib/modules/%s/build/vmlinux", /* Custom build kernel */
49 "/usr/lib/debug/lib/modules/%s/vmlinux", /* Red Hat debuginfo */
50 "/boot/vmlinux-debug-%s", /* Ubuntu */
53 #define MAX_PATH_LEN 256
54 #define MAX_PROBES 128
56 /* Session management structure */
62 struct probe_point probes[MAX_PROBES];
67 /* Parse an event definition. Note that any error must die. */
68 static void parse_probe_event(const char *str)
70 struct probe_point *pp = &session.probes[session.nr_probe];
72 pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
73 if (++session.nr_probe == MAX_PROBES)
74 die("Too many probes (> %d) are specified.", MAX_PROBES);
76 /* Parse perf-probe event into probe_point */
77 session.need_dwarf = parse_perf_probe_event(str, pp);
79 pr_debug("%d arguments\n", pp->nr_args);
82 static void parse_probe_event_argv(int argc, const char **argv)
87 /* Bind up rest arguments */
89 for (i = 0; i < argc; i++)
90 len += strlen(argv[i]) + 1;
91 buf = zalloc(len + 1);
93 die("Failed to allocate memory for binding arguments.");
95 for (i = 0; i < argc; i++)
96 len += sprintf(&buf[len], "%s ", argv[i]);
97 parse_probe_event(buf);
101 static int opt_add_probe_event(const struct option *opt __used,
102 const char *str, int unset __used)
105 parse_probe_event(str);
110 static int open_default_vmlinux(void)
113 char fname[MAX_PATH_LEN];
118 pr_debug("uname() failed.\n");
121 session.release = uts.release;
122 for (i = 0; i < NR_SEARCH_PATH; i++) {
123 ret = snprintf(fname, MAX_PATH_LEN,
124 default_search_path[i], session.release);
125 if (ret >= MAX_PATH_LEN || ret < 0) {
126 pr_debug("Filename(%d,%s) is too long.\n", i,
131 pr_debug("try to open %s\n", fname);
132 fd = open(fname, O_RDONLY);
140 static const char * const probe_usage[] = {
141 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
142 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
147 static const struct option options[] = {
148 OPT_BOOLEAN('v', "verbose", &verbose,
149 "be more verbose (show parsed arguments, etc)"),
151 OPT_STRING('k', "vmlinux", &session.vmlinux, "file",
152 "vmlinux/module pathname"),
154 OPT_BOOLEAN('l', "list", &listing, "list up current probes"),
155 OPT_CALLBACK('a', "add", NULL,
157 "FUNC[+OFFS|%return] [ARG ...]",
159 "FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
161 "probe point definition, where\n"
162 "\t\tGRP:\tGroup name (optional)\n"
163 "\t\tNAME:\tEvent name\n"
164 "\t\tFUNC:\tFunction name\n"
165 "\t\tOFFS:\tOffset from function entry (in byte)\n"
166 "\t\t%return:\tPut the probe at function return\n"
168 "\t\tARG:\tProbe argument (only \n"
170 "\t\tSRC:\tSource code path\n"
171 "\t\tRLN:\tRelative line number from function entry.\n"
172 "\t\tALN:\tAbsolute line number in file.\n"
173 "\t\tARG:\tProbe argument (local variable name or\n"
175 "\t\t\tkprobe-tracer argument format.)\n",
176 opt_add_probe_event),
180 int cmd_probe(int argc, const char **argv, const char *prefix __used)
186 struct probe_point *pp;
188 argc = parse_options(argc, argv, options, probe_usage,
189 PARSE_OPT_STOP_AT_NON_OPTION);
191 parse_probe_event_argv(argc, argv);
193 if ((session.nr_probe == 0 && !listing) ||
194 (session.nr_probe != 0 && listing))
195 usage_with_options(probe_usage, options);
198 show_perf_probe_events();
202 if (session.need_dwarf)
204 die("Debuginfo-analysis is not supported");
205 #else /* !NO_LIBDWARF */
206 pr_debug("Some probes require debuginfo.\n");
209 fd = open(session.vmlinux, O_RDONLY);
211 fd = open_default_vmlinux();
213 if (session.need_dwarf)
214 die("Could not open vmlinux/module file.");
216 pr_debug("Could not open vmlinux/module file."
217 " Try to use symbols.\n");
221 /* Searching probe points */
222 for (i = 0; i < session.nr_probe; i++) {
223 pp = &session.probes[i];
227 lseek(fd, SEEK_SET, 0);
228 ret = find_probepoint(fd, pp);
230 if (session.need_dwarf)
231 die("Could not analyze debuginfo.");
233 pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n");
236 if (ret == 0) /* No error but failed to find probe point. */
237 die("No probe point found.");
242 #endif /* !NO_LIBDWARF */
244 /* Synthesize probes without dwarf */
245 for (i = 0; i < session.nr_probe; i++) {
246 pp = &session.probes[i];
247 if (pp->found) /* This probe is already found. */
250 ret = synthesize_trace_kprobe_event(pp);
252 die("probe point definition becomes too long.");
254 die("Failed to synthesize a probe point.");
257 /* Settng up probe points */
258 add_trace_kprobe_events(session.probes, session.nr_probe);