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 int opt_add_probe_event(const struct option *opt __used,
83 const char *str, int unset __used)
86 parse_probe_event(str);
91 static int open_default_vmlinux(void)
94 char fname[MAX_PATH_LEN];
99 pr_debug("uname() failed.\n");
102 session.release = uts.release;
103 for (i = 0; i < NR_SEARCH_PATH; i++) {
104 ret = snprintf(fname, MAX_PATH_LEN,
105 default_search_path[i], session.release);
106 if (ret >= MAX_PATH_LEN || ret < 0) {
107 pr_debug("Filename(%d,%s) is too long.\n", i,
112 pr_debug("try to open %s\n", fname);
113 fd = open(fname, O_RDONLY);
121 static const char * const probe_usage[] = {
122 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
123 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
128 static const struct option options[] = {
129 OPT_BOOLEAN('v', "verbose", &verbose,
130 "be more verbose (show parsed arguments, etc)"),
132 OPT_STRING('k', "vmlinux", &session.vmlinux, "file",
133 "vmlinux/module pathname"),
135 OPT_BOOLEAN('l', "list", &listing, "list up current probes"),
136 OPT_CALLBACK('a', "add", NULL,
138 "FUNC[+OFFS|%return] [ARG ...]",
140 "FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
142 "probe point definition, where\n"
143 "\t\tGRP:\tGroup name (optional)\n"
144 "\t\tNAME:\tEvent name\n"
145 "\t\tFUNC:\tFunction name\n"
146 "\t\tOFFS:\tOffset from function entry (in byte)\n"
147 "\t\t%return:\tPut the probe at function return\n"
149 "\t\tARG:\tProbe argument (only \n"
151 "\t\tSRC:\tSource code path\n"
152 "\t\tRLN:\tRelative line number from function entry.\n"
153 "\t\tALN:\tAbsolute line number in file.\n"
154 "\t\tARG:\tProbe argument (local variable name or\n"
156 "\t\t\tkprobe-tracer argument format.)\n",
157 opt_add_probe_event),
161 int cmd_probe(int argc, const char **argv, const char *prefix __used)
167 struct probe_point *pp;
169 argc = parse_options(argc, argv, options, probe_usage,
170 PARSE_OPT_STOP_AT_NON_OPTION);
171 for (i = 0; i < argc; i++)
172 parse_probe_event(argv[i]);
174 if ((session.nr_probe == 0 && !listing) ||
175 (session.nr_probe != 0 && listing))
176 usage_with_options(probe_usage, options);
179 show_perf_probe_events();
183 if (session.need_dwarf)
185 die("Debuginfo-analysis is not supported");
186 #else /* !NO_LIBDWARF */
187 pr_debug("Some probes require debuginfo.\n");
190 fd = open(session.vmlinux, O_RDONLY);
192 fd = open_default_vmlinux();
194 if (session.need_dwarf)
195 die("Could not open vmlinux/module file.");
197 pr_warning("Could not open vmlinux/module file."
198 " Try to use symbols.\n");
202 /* Searching probe points */
203 for (j = 0; j < session.nr_probe; j++) {
204 pp = &session.probes[j];
208 lseek(fd, SEEK_SET, 0);
209 ret = find_probepoint(fd, pp);
211 if (session.need_dwarf)
212 die("Could not analyze debuginfo.");
214 pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n");
217 if (ret == 0) /* No error but failed to find probe point. */
218 die("No probe point found.");
223 #endif /* !NO_LIBDWARF */
225 /* Synthesize probes without dwarf */
226 for (j = 0; j < session.nr_probe; j++) {
227 pp = &session.probes[j];
228 if (pp->found) /* This probe is already found. */
231 ret = synthesize_trace_kprobe_event(pp);
233 die("probe point definition becomes too long.");
235 die("Failed to synthesize a probe point.");
238 /* Settng up probe points */
239 add_trace_kprobe_events(session.probes, session.nr_probe);