Root/tools/perf/builtin-probe.c

Source at commit ec7cab4cbb721bff91ec924ec691efd8daf36579 created 9 years 7 months ago.
By Maarten ter Huurne, MIPS: JZ4740: A320: Updated quickstart documentation.
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/strfilter.h"
40#include "util/symbol.h"
41#include "util/debug.h"
42#include "util/debugfs.h"
43#include "util/parse-options.h"
44#include "util/probe-finder.h"
45#include "util/probe-event.h"
46
47#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
48#define DEFAULT_FUNC_FILTER "!_*"
49#define MAX_PATH_LEN 256
50
51/* Session management structure */
52static struct {
53    bool list_events;
54    bool force_add;
55    bool show_lines;
56    bool show_vars;
57    bool show_ext_vars;
58    bool show_funcs;
59    bool mod_events;
60    int nevents;
61    struct perf_probe_event events[MAX_PROBES];
62    struct strlist *dellist;
63    struct line_range line_range;
64    const char *target_module;
65    int max_probe_points;
66    struct strfilter *filter;
67} params;
68
69/* Parse an event definition. Note that any error must die. */
70static int parse_probe_event(const char *str)
71{
72    struct perf_probe_event *pev = &params.events[params.nevents];
73    int ret;
74
75    pr_debug("probe-definition(%d): %s\n", params.nevents, str);
76    if (++params.nevents == MAX_PROBES) {
77        pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
78        return -1;
79    }
80
81    /* Parse a perf-probe command into event */
82    ret = parse_perf_probe_command(str, pev);
83    pr_debug("%d arguments\n", pev->nargs);
84
85    return ret;
86}
87
88static int parse_probe_event_argv(int argc, const char **argv)
89{
90    int i, len, ret;
91    char *buf;
92
93    /* Bind up rest arguments */
94    len = 0;
95    for (i = 0; i < argc; i++)
96        len += strlen(argv[i]) + 1;
97    buf = zalloc(len + 1);
98    if (buf == NULL)
99        return -ENOMEM;
100    len = 0;
101    for (i = 0; i < argc; i++)
102        len += sprintf(&buf[len], "%s ", argv[i]);
103    params.mod_events = true;
104    ret = parse_probe_event(buf);
105    free(buf);
106    return ret;
107}
108
109static int opt_add_probe_event(const struct option *opt __used,
110                  const char *str, int unset __used)
111{
112    if (str) {
113        params.mod_events = true;
114        return parse_probe_event(str);
115    } else
116        return 0;
117}
118
119static int opt_del_probe_event(const struct option *opt __used,
120                   const char *str, int unset __used)
121{
122    if (str) {
123        params.mod_events = true;
124        if (!params.dellist)
125            params.dellist = strlist__new(true, NULL);
126        strlist__add(params.dellist, str);
127    }
128    return 0;
129}
130
131#ifdef DWARF_SUPPORT
132static int opt_show_lines(const struct option *opt __used,
133              const char *str, int unset __used)
134{
135    int ret = 0;
136
137    if (str)
138        ret = parse_line_range_desc(str, &params.line_range);
139    INIT_LIST_HEAD(&params.line_range.line_list);
140    params.show_lines = true;
141
142    return ret;
143}
144
145static int opt_show_vars(const struct option *opt __used,
146             const char *str, int unset __used)
147{
148    struct perf_probe_event *pev = &params.events[params.nevents];
149    int ret;
150
151    if (!str)
152        return 0;
153
154    ret = parse_probe_event(str);
155    if (!ret && pev->nargs != 0) {
156        pr_err(" Error: '--vars' doesn't accept arguments.\n");
157        return -EINVAL;
158    }
159    params.show_vars = true;
160
161    return ret;
162}
163#endif
164
165static int opt_set_filter(const struct option *opt __used,
166              const char *str, int unset __used)
167{
168    const char *err;
169
170    if (str) {
171        pr_debug2("Set filter: %s\n", str);
172        if (params.filter)
173            strfilter__delete(params.filter);
174        params.filter = strfilter__new(str, &err);
175        if (!params.filter) {
176            pr_err("Filter parse error at %td.\n", err - str + 1);
177            pr_err("Source: \"%s\"\n", str);
178            pr_err(" %*c\n", (int)(err - str + 1), '^');
179            return -EINVAL;
180        }
181    }
182
183    return 0;
184}
185
186static const char * const probe_usage[] = {
187    "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
188    "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
189    "perf probe [<options>] --del '[GROUP:]EVENT' ...",
190    "perf probe --list",
191#ifdef DWARF_SUPPORT
192    "perf probe [<options>] --line 'LINEDESC'",
193    "perf probe [<options>] --vars 'PROBEPOINT'",
194#endif
195    NULL
196};
197
198static const struct option options[] = {
199    OPT_INCR('v', "verbose", &verbose,
200            "be more verbose (show parsed arguments, etc)"),
201    OPT_BOOLEAN('l', "list", &params.list_events,
202            "list up current probe events"),
203    OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
204        opt_del_probe_event),
205    OPT_CALLBACK('a', "add", NULL,
206#ifdef DWARF_SUPPORT
207        "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
208        " [[NAME=]ARG ...]",
209#else
210        "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
211#endif
212        "probe point definition, where\n"
213        "\t\tGROUP:\tGroup name (optional)\n"
214        "\t\tEVENT:\tEvent name\n"
215        "\t\tFUNC:\tFunction name\n"
216        "\t\tOFF:\tOffset from function entry (in byte)\n"
217        "\t\t%return:\tPut the probe at function return\n"
218#ifdef DWARF_SUPPORT
219        "\t\tSRC:\tSource code path\n"
220        "\t\tRL:\tRelative line number from function entry.\n"
221        "\t\tAL:\tAbsolute line number in file.\n"
222        "\t\tPT:\tLazy expression of line code.\n"
223        "\t\tARG:\tProbe argument (local variable name or\n"
224        "\t\t\tkprobe-tracer argument format.)\n",
225#else
226        "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
227#endif
228        opt_add_probe_event),
229    OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
230            " with existing name"),
231#ifdef DWARF_SUPPORT
232    OPT_CALLBACK('L', "line", NULL,
233             "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
234             "Show source code lines.", opt_show_lines),
235    OPT_CALLBACK('V', "vars", NULL,
236             "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
237             "Show accessible variables on PROBEDEF", opt_show_vars),
238    OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
239            "Show external variables too (with --vars only)"),
240    OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
241           "file", "vmlinux pathname"),
242    OPT_STRING('s', "source", &symbol_conf.source_prefix,
243           "directory", "path to kernel source"),
244    OPT_STRING('m', "module", &params.target_module,
245           "modname", "target module name"),
246#endif
247    OPT__DRY_RUN(&probe_event_dry_run),
248    OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
249         "Set how many probe points can be found for a probe."),
250    OPT_BOOLEAN('F', "funcs", &params.show_funcs,
251            "Show potential probe-able functions."),
252    OPT_CALLBACK('\0', "filter", NULL,
253             "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
254             "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
255             "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
256             opt_set_filter),
257    OPT_END()
258};
259
260int cmd_probe(int argc, const char **argv, const char *prefix __used)
261{
262    int ret;
263
264    argc = parse_options(argc, argv, options, probe_usage,
265                 PARSE_OPT_STOP_AT_NON_OPTION);
266    if (argc > 0) {
267        if (strcmp(argv[0], "-") == 0) {
268            pr_warning(" Error: '-' is not supported.\n");
269            usage_with_options(probe_usage, options);
270        }
271        ret = parse_probe_event_argv(argc, argv);
272        if (ret < 0) {
273            pr_err(" Error: Parse Error. (%d)\n", ret);
274            return ret;
275        }
276    }
277
278    if (params.max_probe_points == 0)
279        params.max_probe_points = MAX_PROBES;
280
281    if ((!params.nevents && !params.dellist && !params.list_events &&
282         !params.show_lines && !params.show_funcs))
283        usage_with_options(probe_usage, options);
284
285    /*
286     * Only consider the user's kernel image path if given.
287     */
288    symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
289
290    if (params.list_events) {
291        if (params.mod_events) {
292            pr_err(" Error: Don't use --list with --add/--del.\n");
293            usage_with_options(probe_usage, options);
294        }
295        if (params.show_lines) {
296            pr_err(" Error: Don't use --list with --line.\n");
297            usage_with_options(probe_usage, options);
298        }
299        if (params.show_vars) {
300            pr_err(" Error: Don't use --list with --vars.\n");
301            usage_with_options(probe_usage, options);
302        }
303        if (params.show_funcs) {
304            pr_err(" Error: Don't use --list with --funcs.\n");
305            usage_with_options(probe_usage, options);
306        }
307        ret = show_perf_probe_events();
308        if (ret < 0)
309            pr_err(" Error: Failed to show event list. (%d)\n",
310                   ret);
311        return ret;
312    }
313    if (params.show_funcs) {
314        if (params.nevents != 0 || params.dellist) {
315            pr_err(" Error: Don't use --funcs with"
316                   " --add/--del.\n");
317            usage_with_options(probe_usage, options);
318        }
319        if (params.show_lines) {
320            pr_err(" Error: Don't use --funcs with --line.\n");
321            usage_with_options(probe_usage, options);
322        }
323        if (params.show_vars) {
324            pr_err(" Error: Don't use --funcs with --vars.\n");
325            usage_with_options(probe_usage, options);
326        }
327        if (!params.filter)
328            params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
329                               NULL);
330        ret = show_available_funcs(params.target_module,
331                       params.filter);
332        strfilter__delete(params.filter);
333        if (ret < 0)
334            pr_err(" Error: Failed to show functions."
335                   " (%d)\n", ret);
336        return ret;
337    }
338
339#ifdef DWARF_SUPPORT
340    if (params.show_lines) {
341        if (params.mod_events) {
342            pr_err(" Error: Don't use --line with"
343                   " --add/--del.\n");
344            usage_with_options(probe_usage, options);
345        }
346        if (params.show_vars) {
347            pr_err(" Error: Don't use --line with --vars.\n");
348            usage_with_options(probe_usage, options);
349        }
350
351        ret = show_line_range(&params.line_range, params.target_module);
352        if (ret < 0)
353            pr_err(" Error: Failed to show lines. (%d)\n", ret);
354        return ret;
355    }
356    if (params.show_vars) {
357        if (params.mod_events) {
358            pr_err(" Error: Don't use --vars with"
359                   " --add/--del.\n");
360            usage_with_options(probe_usage, options);
361        }
362        if (!params.filter)
363            params.filter = strfilter__new(DEFAULT_VAR_FILTER,
364                               NULL);
365
366        ret = show_available_vars(params.events, params.nevents,
367                      params.max_probe_points,
368                      params.target_module,
369                      params.filter,
370                      params.show_ext_vars);
371        strfilter__delete(params.filter);
372        if (ret < 0)
373            pr_err(" Error: Failed to show vars. (%d)\n", ret);
374        return ret;
375    }
376#endif
377
378    if (params.dellist) {
379        ret = del_perf_probe_events(params.dellist);
380        strlist__delete(params.dellist);
381        if (ret < 0) {
382            pr_err(" Error: Failed to delete events. (%d)\n", ret);
383            return ret;
384        }
385    }
386
387    if (params.nevents) {
388        ret = add_perf_probe_events(params.events, params.nevents,
389                        params.max_probe_points,
390                        params.target_module,
391                        params.force_add);
392        if (ret < 0) {
393            pr_err(" Error: Failed to add events. (%d)\n", ret);
394            return ret;
395        }
396    }
397    return 0;
398}
399

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