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 #define MAX_PATH_LEN 256
  50
  51 /* Session management structure */
  52 static 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. */
  70 static 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
  88 static 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
 109 static 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
 119 static 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
 132 static 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
 145 static 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
 165 static 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
 186 static 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
 198 static 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|path",
 246                    "target module name (for online) or path (for offline)"),
 247 #endif
 248         OPT__DRY_RUN(&probe_event_dry_run),
 249         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 250                  "Set how many probe points can be found for a probe."),
 251         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 252                     "Show potential probe-able functions."),
 253         OPT_CALLBACK('\0', "filter", NULL,
 254                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 255                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 256                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 257                      opt_set_filter),
 258         OPT_END()
 259 };
 260
 261 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 262 {
 263         int ret;
 264
 265         argc = parse_options(argc, argv, options, probe_usage,
 266                              PARSE_OPT_STOP_AT_NON_OPTION);
 267         if (argc > 0) {
 268                 if (strcmp(argv[0], "-") == 0) {
 269                         pr_warning("  Error: '-' is not supported.\n");
 270                         usage_with_options(probe_usage, options);
 271                 }
 272                 ret = parse_probe_event_argv(argc, argv);
 273                 if (ret < 0) {
 274                         pr_err("  Error: Parse Error.  (%d)\n", ret);
 275                         return ret;
 276                 }
 277         }
 278
 279         if (params.max_probe_points == 0)
 280                 params.max_probe_points = MAX_PROBES;
 281
 282         if ((!params.nevents && !params.dellist && !params.list_events &&
 283              !params.show_lines && !params.show_funcs))
 284                 usage_with_options(probe_usage, options);
 285
 286         /*
 287          * Only consider the user's kernel image path if given.
 288          */
 289         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 290
 291         if (params.list_events) {
 292                 if (params.mod_events) {
 293                         pr_err("  Error: Don't use --list with --add/--del.\n");
 294                         usage_with_options(probe_usage, options);
 295                 }
 296                 if (params.show_lines) {
 297                         pr_err("  Error: Don't use --list with --line.\n");
 298                         usage_with_options(probe_usage, options);
 299                 }
 300                 if (params.show_vars) {
 301                         pr_err(" Error: Don't use --list with --vars.\n");
 302                         usage_with_options(probe_usage, options);
 303                 }
 304                 if (params.show_funcs) {
 305                         pr_err("  Error: Don't use --list with --funcs.\n");
 306                         usage_with_options(probe_usage, options);
 307                 }
 308                 ret = show_perf_probe_events();
 309                 if (ret < 0)
 310                         pr_err("  Error: Failed to show event list. (%d)\n",
 311                                ret);
 312                 return ret;
 313         }
 314         if (params.show_funcs) {
 315                 if (params.nevents != 0 || params.dellist) {
 316                         pr_err("  Error: Don't use --funcs with"
 317                                " --add/--del.\n");
 318                         usage_with_options(probe_usage, options);
 319                 }
 320                 if (params.show_lines) {
 321                         pr_err("  Error: Don't use --funcs with --line.\n");
 322                         usage_with_options(probe_usage, options);
 323                 }
 324                 if (params.show_vars) {
 325                         pr_err("  Error: Don't use --funcs with --vars.\n");
 326                         usage_with_options(probe_usage, options);
 327                 }
 328                 if (!params.filter)
 329                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 330                                                        NULL);
 331                 ret = show_available_funcs(params.target_module,
 332                                            params.filter);
 333                 strfilter__delete(params.filter);
 334                 if (ret < 0)
 335                         pr_err("  Error: Failed to show functions."
 336                                " (%d)\n", ret);
 337                 return ret;
 338         }
 339
 340 #ifdef DWARF_SUPPORT
 341         if (params.show_lines) {
 342                 if (params.mod_events) {
 343                         pr_err("  Error: Don't use --line with"
 344                                " --add/--del.\n");
 345                         usage_with_options(probe_usage, options);
 346                 }
 347                 if (params.show_vars) {
 348                         pr_err(" Error: Don't use --line with --vars.\n");
 349                         usage_with_options(probe_usage, options);
 350                 }
 351
 352                 ret = show_line_range(&params.line_range, params.target_module);
 353                 if (ret < 0)
 354                         pr_err("  Error: Failed to show lines. (%d)\n", ret);
 355                 return ret;
 356         }
 357         if (params.show_vars) {
 358                 if (params.mod_events) {
 359                         pr_err("  Error: Don't use --vars with"
 360                                " --add/--del.\n");
 361                         usage_with_options(probe_usage, options);
 362                 }
 363                 if (!params.filter)
 364                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 365                                                        NULL);
 366
 367                 ret = show_available_vars(params.events, params.nevents,
 368                                           params.max_probe_points,
 369                                           params.target_module,
 370                                           params.filter,
 371                                           params.show_ext_vars);
 372                 strfilter__delete(params.filter);
 373                 if (ret < 0)
 374                         pr_err("  Error: Failed to show vars. (%d)\n", ret);
 375                 return ret;
 376         }
 377 #endif
 378
 379         if (params.dellist) {
 380                 ret = del_perf_probe_events(params.dellist);
 381                 strlist__delete(params.dellist);
 382                 if (ret < 0) {
 383                         pr_err("  Error: Failed to delete events. (%d)\n", ret);
 384                         return ret;
 385                 }
 386         }
 387
 388         if (params.nevents) {
 389                 ret = add_perf_probe_events(params.events, params.nevents,
 390                                             params.max_probe_points,
 391                                             params.target_module,
 392                                             params.force_add);
 393                 if (ret < 0) {
 394                         pr_err("  Error: Failed to add events. (%d)\n", ret);
 395                         return ret;
 396                 }
 397         }
 398         return 0;
 399 }