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/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
  50 /* Session management structure */
  51 static struct {
  52         bool list_events;
  53         bool force_add;
  54         bool show_lines;
  55         bool show_vars;
  56         bool show_ext_vars;
  57         bool show_funcs;
  58         bool mod_events;
  59         int nevents;
  60         struct perf_probe_event events[MAX_PROBES];
  61         struct strlist *dellist;
  62         struct line_range line_range;
  63         const char *target_module;
  64         int max_probe_points;
  65         struct strfilter *filter;
  66 } params;
  67
  68 /* Parse an event definition. Note that any error must die. */
  69 static int parse_probe_event(const char *str)
  70 {
  71         struct perf_probe_event *pev = &params.events[params.nevents];
  72         int ret;
  73
  74         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  75         if (++params.nevents == MAX_PROBES) {
  76                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  77                 return -1;
  78         }
  79
  80         /* Parse a perf-probe command into event */
  81         ret = parse_perf_probe_command(str, pev);
  82         pr_debug("%d arguments\n", pev->nargs);
  83
  84         return ret;
  85 }
  86
  87 static int parse_probe_event_argv(int argc, const char **argv)
  88 {
  89         int i, len, ret;
  90         char *buf;
  91
  92         /* Bind up rest arguments */
  93         len = 0;
  94         for (i = 0; i < argc; i++)
  95                 len += strlen(argv[i]) + 1;
  96         buf = zalloc(len + 1);
  97         if (buf == NULL)
  98                 return -ENOMEM;
  99         len = 0;
 100         for (i = 0; i < argc; i++)
 101                 len += sprintf(&buf[len], "%s ", argv[i]);
 102         params.mod_events = true;
 103         ret = parse_probe_event(buf);
 104         free(buf);
 105         return ret;
 106 }
 107
 108 static int opt_add_probe_event(const struct option *opt __used,
 109                               const char *str, int unset __used)
 110 {
 111         if (str) {
 112                 params.mod_events = true;
 113                 return parse_probe_event(str);
 114         } else
 115                 return 0;
 116 }
 117
 118 static int opt_del_probe_event(const struct option *opt __used,
 119                                const char *str, int unset __used)
 120 {
 121         if (str) {
 122                 params.mod_events = true;
 123                 if (!params.dellist)
 124                         params.dellist = strlist__new(true, NULL);
 125                 strlist__add(params.dellist, str);
 126         }
 127         return 0;
 128 }
 129
 130 #ifdef DWARF_SUPPORT
 131 static int opt_show_lines(const struct option *opt __used,
 132                           const char *str, int unset __used)
 133 {
 134         int ret = 0;
 135
 136         if (!str)
 137                 return 0;
 138
 139         if (params.show_lines) {
 140                 pr_warning("Warning: more than one --line options are"
 141                            " detected. Only the first one is valid.\n");
 142                 return 0;
 143         }
 144
 145         params.show_lines = true;
 146         ret = parse_line_range_desc(str, &params.line_range);
 147         INIT_LIST_HEAD(&params.line_range.line_list);
 148
 149         return ret;
 150 }
 151
 152 static int opt_show_vars(const struct option *opt __used,
 153                          const char *str, int unset __used)
 154 {
 155         struct perf_probe_event *pev = &params.events[params.nevents];
 156         int ret;
 157
 158         if (!str)
 159                 return 0;
 160
 161         ret = parse_probe_event(str);
 162         if (!ret && pev->nargs != 0) {
 163                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 164                 return -EINVAL;
 165         }
 166         params.show_vars = true;
 167
 168         return ret;
 169 }
 170 #endif
 171
 172 static int opt_set_filter(const struct option *opt __used,
 173                           const char *str, int unset __used)
 174 {
 175         const char *err;
 176
 177         if (str) {
 178                 pr_debug2("Set filter: %s\n", str);
 179                 if (params.filter)
 180                         strfilter__delete(params.filter);
 181                 params.filter = strfilter__new(str, &err);
 182                 if (!params.filter) {
 183                         pr_err("Filter parse error at %td.\n", err - str + 1);
 184                         pr_err("Source: \"%s\"\n", str);
 185                         pr_err("         %*c\n", (int)(err - str + 1), '^');
 186                         return -EINVAL;
 187                 }
 188         }
 189
 190         return 0;
 191 }
 192
 193 static const char * const probe_usage[] = {
 194         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 195         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 196         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 197         "perf probe --list",
 198 #ifdef DWARF_SUPPORT
 199         "perf probe [<options>] --line 'LINEDESC'",
 200         "perf probe [<options>] --vars 'PROBEPOINT'",
 201 #endif
 202         NULL
 203 };
 204
 205 static const struct option options[] = {
 206         OPT_INCR('v', "verbose", &verbose,
 207                     "be more verbose (show parsed arguments, etc)"),
 208         OPT_BOOLEAN('l', "list", &params.list_events,
 209                     "list up current probe events"),
 210         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 211                 opt_del_probe_event),
 212         OPT_CALLBACK('a', "add", NULL,
 213 #ifdef DWARF_SUPPORT
 214                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 215                 " [[NAME=]ARG ...]",
 216 #else
 217                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 218 #endif
 219                 "probe point definition, where\n"
 220                 "\t\tGROUP:\tGroup name (optional)\n"
 221                 "\t\tEVENT:\tEvent name\n"
 222                 "\t\tFUNC:\tFunction name\n"
 223                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 224                 "\t\t%return:\tPut the probe at function return\n"
 225 #ifdef DWARF_SUPPORT
 226                 "\t\tSRC:\tSource code path\n"
 227                 "\t\tRL:\tRelative line number from function entry.\n"
 228                 "\t\tAL:\tAbsolute line number in file.\n"
 229                 "\t\tPT:\tLazy expression of line code.\n"
 230                 "\t\tARG:\tProbe argument (local variable name or\n"
 231                 "\t\t\tkprobe-tracer argument format.)\n",
 232 #else
 233                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 234 #endif
 235                 opt_add_probe_event),
 236         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 237                     " with existing name"),
 238 #ifdef DWARF_SUPPORT
 239         OPT_CALLBACK('L', "line", NULL,
 240                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 241                      "Show source code lines.", opt_show_lines),
 242         OPT_CALLBACK('V', "vars", NULL,
 243                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 244                      "Show accessible variables on PROBEDEF", opt_show_vars),
 245         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 246                     "Show external variables too (with --vars only)"),
 247         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 248                    "file", "vmlinux pathname"),
 249         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 250                    "directory", "path to kernel source"),
 251         OPT_STRING('m', "module", &params.target_module,
 252                    "modname|path",
 253                    "target module name (for online) or path (for offline)"),
 254 #endif
 255         OPT__DRY_RUN(&probe_event_dry_run),
 256         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 257                  "Set how many probe points can be found for a probe."),
 258         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 259                     "Show potential probe-able functions."),
 260         OPT_CALLBACK('\0', "filter", NULL,
 261                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 262                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 263                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 264                      opt_set_filter),
 265         OPT_END()
 266 };
 267
 268 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 269 {
 270         int ret;
 271
 272         argc = parse_options(argc, argv, options, probe_usage,
 273                              PARSE_OPT_STOP_AT_NON_OPTION);
 274         if (argc > 0) {
 275                 if (strcmp(argv[0], "-") == 0) {
 276                         pr_warning("  Error: '-' is not supported.\n");
 277                         usage_with_options(probe_usage, options);
 278                 }
 279                 ret = parse_probe_event_argv(argc, argv);
 280                 if (ret < 0) {
 281                         pr_err("  Error: Parse Error.  (%d)\n", ret);
 282                         return ret;
 283                 }
 284         }
 285
 286         if (params.max_probe_points == 0)
 287                 params.max_probe_points = MAX_PROBES;
 288
 289         if ((!params.nevents && !params.dellist && !params.list_events &&
 290              !params.show_lines && !params.show_funcs))
 291                 usage_with_options(probe_usage, options);
 292
 293         /*
 294          * Only consider the user's kernel image path if given.
 295          */
 296         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 297
 298         if (params.list_events) {
 299                 if (params.mod_events) {
 300                         pr_err("  Error: Don't use --list with --add/--del.\n");
 301                         usage_with_options(probe_usage, options);
 302                 }
 303                 if (params.show_lines) {
 304                         pr_err("  Error: Don't use --list with --line.\n");
 305                         usage_with_options(probe_usage, options);
 306                 }
 307                 if (params.show_vars) {
 308                         pr_err(" Error: Don't use --list with --vars.\n");
 309                         usage_with_options(probe_usage, options);
 310                 }
 311                 if (params.show_funcs) {
 312                         pr_err("  Error: Don't use --list with --funcs.\n");
 313                         usage_with_options(probe_usage, options);
 314                 }
 315                 ret = show_perf_probe_events();
 316                 if (ret < 0)
 317                         pr_err("  Error: Failed to show event list. (%d)\n",
 318                                ret);
 319                 return ret;
 320         }
 321         if (params.show_funcs) {
 322                 if (params.nevents != 0 || params.dellist) {
 323                         pr_err("  Error: Don't use --funcs with"
 324                                " --add/--del.\n");
 325                         usage_with_options(probe_usage, options);
 326                 }
 327                 if (params.show_lines) {
 328                         pr_err("  Error: Don't use --funcs with --line.\n");
 329                         usage_with_options(probe_usage, options);
 330                 }
 331                 if (params.show_vars) {
 332                         pr_err("  Error: Don't use --funcs with --vars.\n");
 333                         usage_with_options(probe_usage, options);
 334                 }
 335                 if (!params.filter)
 336                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 337                                                        NULL);
 338                 ret = show_available_funcs(params.target_module,
 339                                            params.filter);
 340                 strfilter__delete(params.filter);
 341                 if (ret < 0)
 342                         pr_err("  Error: Failed to show functions."
 343                                " (%d)\n", ret);
 344                 return ret;
 345         }
 346
 347 #ifdef DWARF_SUPPORT
 348         if (params.show_lines) {
 349                 if (params.mod_events) {
 350                         pr_err("  Error: Don't use --line with"
 351                                " --add/--del.\n");
 352                         usage_with_options(probe_usage, options);
 353                 }
 354                 if (params.show_vars) {
 355                         pr_err(" Error: Don't use --line with --vars.\n");
 356                         usage_with_options(probe_usage, options);
 357                 }
 358
 359                 ret = show_line_range(&params.line_range, params.target_module);
 360                 if (ret < 0)
 361                         pr_err("  Error: Failed to show lines. (%d)\n", ret);
 362                 return ret;
 363         }
 364         if (params.show_vars) {
 365                 if (params.mod_events) {
 366                         pr_err("  Error: Don't use --vars with"
 367                                " --add/--del.\n");
 368                         usage_with_options(probe_usage, options);
 369                 }
 370                 if (!params.filter)
 371                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 372                                                        NULL);
 373
 374                 ret = show_available_vars(params.events, params.nevents,
 375                                           params.max_probe_points,
 376                                           params.target_module,
 377                                           params.filter,
 378                                           params.show_ext_vars);
 379                 strfilter__delete(params.filter);
 380                 if (ret < 0)
 381                         pr_err("  Error: Failed to show vars. (%d)\n", ret);
 382                 return ret;
 383         }
 384 #endif
 385
 386         if (params.dellist) {
 387                 ret = del_perf_probe_events(params.dellist);
 388                 strlist__delete(params.dellist);
 389                 if (ret < 0) {
 390                         pr_err("  Error: Failed to delete events. (%d)\n", ret);
 391                         return ret;
 392                 }
 393         }
 394
 395         if (params.nevents) {
 396                 ret = add_perf_probe_events(params.events, params.nevents,
 397                                             params.max_probe_points,
 398                                             params.target_module,
 399                                             params.force_add);
 400                 if (ret < 0) {
 401                         pr_err("  Error: Failed to add events. (%d)\n", ret);
 402                         return ret;
 403                 }
 404         }
 405         return 0;
 406 }