tools/perf/builtin-probe.c

   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         bool show_vars;
  54         bool show_ext_vars;
  55         bool mod_events;
  56         int nevents;
  57         struct perf_probe_event events[MAX_PROBES];
  58         struct strlist *dellist;
  59         struct line_range line_range;
  60         const char *target_module;
  61         int max_probe_points;
  62 } params;
  63
  64 /* Parse an event definition. Note that any error must die. */
  65 static int parse_probe_event(const char *str)
  66 {
  67         struct perf_probe_event *pev = &params.events[params.nevents];
  68         int ret;
  69
  70         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  71         if (++params.nevents == MAX_PROBES) {
  72                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  73                 return -1;
  74         }
  75
  76         /* Parse a perf-probe command into event */
  77         ret = parse_perf_probe_command(str, pev);
  78         pr_debug("%d arguments\n", pev->nargs);
  79
  80         return ret;
  81 }
  82
  83 static int parse_probe_event_argv(int argc, const char **argv)
  84 {
  85         int i, len, ret;
  86         char *buf;
  87
  88         /* Bind up rest arguments */
  89         len = 0;
  90         for (i = 0; i < argc; i++)
  91                 len += strlen(argv[i]) + 1;
  92         buf = zalloc(len + 1);
  93         if (buf == NULL)
  94                 return -ENOMEM;
  95         len = 0;
  96         for (i = 0; i < argc; i++)
  97                 len += sprintf(&buf[len], "%s ", argv[i]);
  98         params.mod_events = true;
  99         ret = parse_probe_event(buf);
 100         free(buf);
 101         return ret;
 102 }
 103
 104 static int opt_add_probe_event(const struct option *opt __used,
 105                               const char *str, int unset __used)
 106 {
 107         if (str) {
 108                 params.mod_events = true;
 109                 return parse_probe_event(str);
 110         } else
 111                 return 0;
 112 }
 113
 114 static int opt_del_probe_event(const struct option *opt __used,
 115                                const char *str, int unset __used)
 116 {
 117         if (str) {
 118                 params.mod_events = true;
 119                 if (!params.dellist)
 120                         params.dellist = strlist__new(true, NULL);
 121                 strlist__add(params.dellist, str);
 122         }
 123         return 0;
 124 }
 125
 126 #ifdef DWARF_SUPPORT
 127 static int opt_show_lines(const struct option *opt __used,
 128                           const char *str, int unset __used)
 129 {
 130         int ret = 0;
 131
 132         if (str)
 133                 ret = parse_line_range_desc(str, &params.line_range);
 134         INIT_LIST_HEAD(&params.line_range.line_list);
 135         params.show_lines = true;
 136
 137         return ret;
 138 }
 139
 140 static int opt_show_vars(const struct option *opt __used,
 141                          const char *str, int unset __used)
 142 {
 143         struct perf_probe_event *pev = &params.events[params.nevents];
 144         int ret;
 145
 146         if (!str)
 147                 return 0;
 148
 149         ret = parse_probe_event(str);
 150         if (!ret && pev->nargs != 0) {
 151                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 152                 return -EINVAL;
 153         }
 154         params.show_vars = true;
 155
 156         return ret;
 157 }
 158 #endif
 159
 160 static const char * const probe_usage[] = {
 161         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 162         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 163         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 164         "perf probe --list",
 165 #ifdef DWARF_SUPPORT
 166         "perf probe [<options>] --line 'LINEDESC'",
 167         "perf probe [<options>] --vars 'PROBEPOINT'",
 168 #endif
 169         NULL
 170 };
 171
 172 static const struct option options[] = {
 173         OPT_INCR('v', "verbose", &verbose,
 174                     "be more verbose (show parsed arguments, etc)"),
 175         OPT_BOOLEAN('l', "list", &params.list_events,
 176                     "list up current probe events"),
 177         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 178                 opt_del_probe_event),
 179         OPT_CALLBACK('a', "add", NULL,
 180 #ifdef DWARF_SUPPORT
 181                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 182                 " [[NAME=]ARG ...]",
 183 #else
 184                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 185 #endif
 186                 "probe point definition, where\n"
 187                 "\t\tGROUP:\tGroup name (optional)\n"
 188                 "\t\tEVENT:\tEvent name\n"
 189                 "\t\tFUNC:\tFunction name\n"
 190                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 191                 "\t\t%return:\tPut the probe at function return\n"
 192 #ifdef DWARF_SUPPORT
 193                 "\t\tSRC:\tSource code path\n"
 194                 "\t\tRL:\tRelative line number from function entry.\n"
 195                 "\t\tAL:\tAbsolute line number in file.\n"
 196                 "\t\tPT:\tLazy expression of line code.\n"
 197                 "\t\tARG:\tProbe argument (local variable name or\n"
 198                 "\t\t\tkprobe-tracer argument format.)\n",
 199 #else
 200                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 201 #endif
 202                 opt_add_probe_event),
 203         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 204                     " with existing name"),
 205 #ifdef DWARF_SUPPORT
 206         OPT_CALLBACK('L', "line", NULL,
 207                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 208                      "Show source code lines.", opt_show_lines),
 209         OPT_CALLBACK('V', "vars", NULL,
 210                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 211                      "Show accessible variables on PROBEDEF", opt_show_vars),
 212         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 213                     "Show external variables too (with --vars only)"),
 214         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 215                    "file", "vmlinux pathname"),
 216         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 217                    "directory", "path to kernel source"),
 218         OPT_STRING('m', "module", &params.target_module,
 219                    "modname", "target module name"),
 220 #endif
 221         OPT__DRY_RUN(&probe_event_dry_run),
 222         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 223                  "Set how many probe points can be found for a probe."),
 224         OPT_END()
 225 };
 226
 227 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 228 {
 229         int ret;
 230
 231         argc = parse_options(argc, argv, options, probe_usage,
 232                              PARSE_OPT_STOP_AT_NON_OPTION);
 233         if (argc > 0) {
 234                 if (strcmp(argv[0], "-") == 0) {
 235                         pr_warning("  Error: '-' is not supported.\n");
 236                         usage_with_options(probe_usage, options);
 237                 }
 238                 ret = parse_probe_event_argv(argc, argv);
 239                 if (ret < 0) {
 240                         pr_err("  Error: Parse Error.  (%d)\n", ret);
 241                         return ret;
 242                 }
 243         }
 244
 245         if (params.max_probe_points == 0)
 246                 params.max_probe_points = MAX_PROBES;
 247
 248         if ((!params.nevents && !params.dellist && !params.list_events &&
 249              !params.show_lines))
 250                 usage_with_options(probe_usage, options);
 251
 252         /*
 253          * Only consider the user's kernel image path if given.
 254          */
 255         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 256
 257         if (params.list_events) {
 258                 if (params.mod_events) {
 259                         pr_err("  Error: Don't use --list with --add/--del.\n");
 260                         usage_with_options(probe_usage, options);
 261                 }
 262                 if (params.show_lines) {
 263                         pr_err("  Error: Don't use --list with --line.\n");
 264                         usage_with_options(probe_usage, options);
 265                 }
 266                 if (params.show_vars) {
 267                         pr_err(" Error: Don't use --list with --vars.\n");
 268                         usage_with_options(probe_usage, options);
 269                 }
 270                 ret = show_perf_probe_events();
 271                 if (ret < 0)
 272                         pr_err("  Error: Failed to show event list. (%d)\n",
 273                                ret);
 274                 return ret;
 275         }
 276
 277 #ifdef DWARF_SUPPORT
 278         if (params.show_lines) {
 279                 if (params.mod_events) {
 280                         pr_err("  Error: Don't use --line with"
 281                                " --add/--del.\n");
 282                         usage_with_options(probe_usage, options);
 283                 }
 284                 if (params.show_vars) {
 285                         pr_err(" Error: Don't use --line with --vars.\n");
 286                         usage_with_options(probe_usage, options);
 287                 }
 288
 289                 ret = show_line_range(&params.line_range, params.target_module);
 290                 if (ret < 0)
 291                         pr_err("  Error: Failed to show lines. (%d)\n", ret);
 292                 return ret;
 293         }
 294         if (params.show_vars) {
 295                 if (params.mod_events) {
 296                         pr_err("  Error: Don't use --vars with"
 297                                " --add/--del.\n");
 298                         usage_with_options(probe_usage, options);
 299                 }
 300                 ret = show_available_vars(params.events, params.nevents,
 301                                           params.max_probe_points,
 302                                           params.target_module,
 303                                           params.show_ext_vars);
 304                 if (ret < 0)
 305                         pr_err("  Error: Failed to show vars. (%d)\n", ret);
 306                 return ret;
 307         }
 308 #endif
 309
 310         if (params.dellist) {
 311                 ret = del_perf_probe_events(params.dellist);
 312                 strlist__delete(params.dellist);
 313                 if (ret < 0) {
 314                         pr_err("  Error: Failed to delete events. (%d)\n", ret);
 315                         return ret;
 316                 }
 317         }
 318
 319         if (params.nevents) {
 320                 ret = add_perf_probe_events(params.events, params.nevents,
 321                                             params.max_probe_points,
 322                                             params.target_module,
 323                                             params.force_add);
 324                 if (ret < 0) {
 325                         pr_err("  Error: Failed to add events. (%d)\n", ret);
 326                         return ret;
 327                 }
 328         }
 329         return 0;
 330 }