xref: /linux/tools/perf/builtin-probe.c (revision b3b77c8caef1750ebeea1054e39e358550ea9f55)
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/symbol.h"
40 #include "util/debug.h"
41 #include "util/debugfs.h"
42 #include "util/parse-options.h"
43 #include "util/probe-finder.h"
44 #include "util/probe-event.h"
45 
46 #define MAX_PATH_LEN 256
47 
48 /* Session management structure */
49 static struct {
50 	bool list_events;
51 	bool force_add;
52 	bool show_lines;
53 	int nevents;
54 	struct perf_probe_event events[MAX_PROBES];
55 	struct strlist *dellist;
56 	struct line_range line_range;
57 	int max_probe_points;
58 } params;
59 
60 
61 /* Parse an event definition. Note that any error must die. */
62 static int parse_probe_event(const char *str)
63 {
64 	struct perf_probe_event *pev = &params.events[params.nevents];
65 	int ret;
66 
67 	pr_debug("probe-definition(%d): %s\n", params.nevents, str);
68 	if (++params.nevents == MAX_PROBES)
69 		die("Too many probes (> %d) are specified.", MAX_PROBES);
70 
71 	/* Parse a perf-probe command into event */
72 	ret = parse_perf_probe_command(str, pev);
73 	pr_debug("%d arguments\n", pev->nargs);
74 
75 	return ret;
76 }
77 
78 static int parse_probe_event_argv(int argc, const char **argv)
79 {
80 	int i, len, ret;
81 	char *buf;
82 
83 	/* Bind up rest arguments */
84 	len = 0;
85 	for (i = 0; i < argc; i++)
86 		len += strlen(argv[i]) + 1;
87 	buf = xzalloc(len + 1);
88 	len = 0;
89 	for (i = 0; i < argc; i++)
90 		len += sprintf(&buf[len], "%s ", argv[i]);
91 	ret = parse_probe_event(buf);
92 	free(buf);
93 	return ret;
94 }
95 
96 static int opt_add_probe_event(const struct option *opt __used,
97 			      const char *str, int unset __used)
98 {
99 	if (str)
100 		return parse_probe_event(str);
101 	else
102 		return 0;
103 }
104 
105 static int opt_del_probe_event(const struct option *opt __used,
106 			       const char *str, int unset __used)
107 {
108 	if (str) {
109 		if (!params.dellist)
110 			params.dellist = strlist__new(true, NULL);
111 		strlist__add(params.dellist, str);
112 	}
113 	return 0;
114 }
115 
116 #ifdef DWARF_SUPPORT
117 static int opt_show_lines(const struct option *opt __used,
118 			  const char *str, int unset __used)
119 {
120 	int ret = 0;
121 
122 	if (str)
123 		ret = parse_line_range_desc(str, &params.line_range);
124 	INIT_LIST_HEAD(&params.line_range.line_list);
125 	params.show_lines = true;
126 
127 	return ret;
128 }
129 #endif
130 
131 static const char * const probe_usage[] = {
132 	"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
133 	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
134 	"perf probe [<options>] --del '[GROUP:]EVENT' ...",
135 	"perf probe --list",
136 #ifdef DWARF_SUPPORT
137 	"perf probe --line 'LINEDESC'",
138 #endif
139 	NULL
140 };
141 
142 static const struct option options[] = {
143 	OPT_INCR('v', "verbose", &verbose,
144 		    "be more verbose (show parsed arguments, etc)"),
145 	OPT_BOOLEAN('l', "list", &params.list_events,
146 		    "list up current probe events"),
147 	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
148 		opt_del_probe_event),
149 	OPT_CALLBACK('a', "add", NULL,
150 #ifdef DWARF_SUPPORT
151 		"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
152 		" [[NAME=]ARG ...]",
153 #else
154 		"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
155 #endif
156 		"probe point definition, where\n"
157 		"\t\tGROUP:\tGroup name (optional)\n"
158 		"\t\tEVENT:\tEvent name\n"
159 		"\t\tFUNC:\tFunction name\n"
160 		"\t\tOFF:\tOffset from function entry (in byte)\n"
161 		"\t\t%return:\tPut the probe at function return\n"
162 #ifdef DWARF_SUPPORT
163 		"\t\tSRC:\tSource code path\n"
164 		"\t\tRL:\tRelative line number from function entry.\n"
165 		"\t\tAL:\tAbsolute line number in file.\n"
166 		"\t\tPT:\tLazy expression of line code.\n"
167 		"\t\tARG:\tProbe argument (local variable name or\n"
168 		"\t\t\tkprobe-tracer argument format.)\n",
169 #else
170 		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
171 #endif
172 		opt_add_probe_event),
173 	OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
174 		    " with existing name"),
175 #ifdef DWARF_SUPPORT
176 	OPT_CALLBACK('L', "line", NULL,
177 		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
178 		     "Show source code lines.", opt_show_lines),
179 	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
180 		   "file", "vmlinux pathname"),
181 #endif
182 	OPT__DRY_RUN(&probe_event_dry_run),
183 	OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
184 		 "Set how many probe points can be found for a probe."),
185 	OPT_END()
186 };
187 
188 int cmd_probe(int argc, const char **argv, const char *prefix __used)
189 {
190 	int ret;
191 
192 	argc = parse_options(argc, argv, options, probe_usage,
193 			     PARSE_OPT_STOP_AT_NON_OPTION);
194 	if (argc > 0) {
195 		if (strcmp(argv[0], "-") == 0) {
196 			pr_warning("  Error: '-' is not supported.\n");
197 			usage_with_options(probe_usage, options);
198 		}
199 		ret = parse_probe_event_argv(argc, argv);
200 		if (ret < 0) {
201 			pr_err("  Error: Parse Error.  (%d)\n", ret);
202 			return ret;
203 		}
204 	}
205 
206 	if (params.max_probe_points == 0)
207 		params.max_probe_points = MAX_PROBES;
208 
209 	if ((!params.nevents && !params.dellist && !params.list_events &&
210 	     !params.show_lines))
211 		usage_with_options(probe_usage, options);
212 
213 	if (params.list_events) {
214 		if (params.nevents != 0 || params.dellist) {
215 			pr_err("  Error: Don't use --list with --add/--del.\n");
216 			usage_with_options(probe_usage, options);
217 		}
218 		if (params.show_lines) {
219 			pr_err("  Error: Don't use --list with --line.\n");
220 			usage_with_options(probe_usage, options);
221 		}
222 		ret = show_perf_probe_events();
223 		if (ret < 0)
224 			pr_err("  Error: Failed to show event list. (%d)\n",
225 			       ret);
226 		return ret;
227 	}
228 
229 #ifdef DWARF_SUPPORT
230 	if (params.show_lines) {
231 		if (params.nevents != 0 || params.dellist) {
232 			pr_warning("  Error: Don't use --line with"
233 				   " --add/--del.\n");
234 			usage_with_options(probe_usage, options);
235 		}
236 
237 		ret = show_line_range(&params.line_range);
238 		if (ret < 0)
239 			pr_err("  Error: Failed to show lines. (%d)\n", ret);
240 		return ret;
241 	}
242 #endif
243 
244 	if (params.dellist) {
245 		ret = del_perf_probe_events(params.dellist);
246 		strlist__delete(params.dellist);
247 		if (ret < 0) {
248 			pr_err("  Error: Failed to delete events. (%d)\n", ret);
249 			return ret;
250 		}
251 	}
252 
253 	if (params.nevents) {
254 		ret = add_perf_probe_events(params.events, params.nevents,
255 					    params.force_add,
256 					    params.max_probe_points);
257 		if (ret < 0) {
258 			pr_err("  Error: Failed to add events. (%d)\n", ret);
259 			return ret;
260 		}
261 	}
262 	return 0;
263 }
264 
265