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 #include <sys/utsname.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33 #include "perf.h"
  34 #include "builtin.h"
  35 #include "util/util.h"
  36 #include "util/strlist.h"
  37 #include "util/strfilter.h"
  38 #include "util/symbol.h"
  39 #include "util/debug.h"
  40 #include "util/debugfs.h"
  41 #include "util/parse-options.h"
  42 #include "util/probe-finder.h"
  43 #include "util/probe-event.h"
  44
  45 #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
  46 #define DEFAULT_FUNC_FILTER "!_*"
  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 show_funcs;
  56         bool mod_events;
  57         int nevents;
  58         struct perf_probe_event events[MAX_PROBES];
  59         struct strlist *dellist;
  60         struct line_range line_range;
  61         const char *target_module;
  62         int max_probe_points;
  63         struct strfilter *filter;
  64 } params;
  65
  66 /* Parse an event definition. Note that any error must die. */
  67 static int parse_probe_event(const char *str)
  68 {
  69         struct perf_probe_event *pev = &params.events[params.nevents];
  70         int ret;
  71
  72         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  73         if (++params.nevents == MAX_PROBES) {
  74                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  75                 return -1;
  76         }
  77
  78         /* Parse a perf-probe command into event */
  79         ret = parse_perf_probe_command(str, pev);
  80         pr_debug("%d arguments\n", pev->nargs);
  81
  82         return ret;
  83 }
  84
  85 static int parse_probe_event_argv(int argc, const char **argv)
  86 {
  87         int i, len, ret;
  88         char *buf;
  89
  90         /* Bind up rest arguments */
  91         len = 0;
  92         for (i = 0; i < argc; i++)
  93                 len += strlen(argv[i]) + 1;
  94         buf = zalloc(len + 1);
  95         if (buf == NULL)
  96                 return -ENOMEM;
  97         len = 0;
  98         for (i = 0; i < argc; i++)
  99                 len += sprintf(&buf[len], "%s ", argv[i]);
 100         params.mod_events = true;
 101         ret = parse_probe_event(buf);
 102         free(buf);
 103         return ret;
 104 }
 105
 106 static int opt_add_probe_event(const struct option *opt __used,
 107                               const char *str, int unset __used)
 108 {
 109         if (str) {
 110                 params.mod_events = true;
 111                 return parse_probe_event(str);
 112         } else
 113                 return 0;
 114 }
 115
 116 static int opt_del_probe_event(const struct option *opt __used,
 117                                const char *str, int unset __used)
 118 {
 119         if (str) {
 120                 params.mod_events = true;
 121                 if (!params.dellist)
 122                         params.dellist = strlist__new(true, NULL);
 123                 strlist__add(params.dellist, str);
 124         }
 125         return 0;
 126 }
 127
 128 #ifdef DWARF_SUPPORT
 129 static int opt_show_lines(const struct option *opt __used,
 130                           const char *str, int unset __used)
 131 {
 132         int ret = 0;
 133
 134         if (!str)
 135                 return 0;
 136
 137         if (params.show_lines) {
 138                 pr_warning("Warning: more than one --line options are"
 139                            " detected. Only the first one is valid.\n");
 140                 return 0;
 141         }
 142
 143         params.show_lines = true;
 144         ret = parse_line_range_desc(str, &params.line_range);
 145         INIT_LIST_HEAD(&params.line_range.line_list);
 146
 147         return ret;
 148 }
 149
 150 static int opt_show_vars(const struct option *opt __used,
 151                          const char *str, int unset __used)
 152 {
 153         struct perf_probe_event *pev = &params.events[params.nevents];
 154         int ret;
 155
 156         if (!str)
 157                 return 0;
 158
 159         ret = parse_probe_event(str);
 160         if (!ret && pev->nargs != 0) {
 161                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 162                 return -EINVAL;
 163         }
 164         params.show_vars = true;
 165
 166         return ret;
 167 }
 168 #endif
 169
 170 static int opt_set_filter(const struct option *opt __used,
 171                           const char *str, int unset __used)
 172 {
 173         const char *err;
 174
 175         if (str) {
 176                 pr_debug2("Set filter: %s\n", str);
 177                 if (params.filter)
 178                         strfilter__delete(params.filter);
 179                 params.filter = strfilter__new(str, &err);
 180                 if (!params.filter) {
 181                         pr_err("Filter parse error at %td.\n", err - str + 1);
 182                         pr_err("Source: \"%s\"\n", str);
 183                         pr_err("         %*c\n", (int)(err - str + 1), '^');
 184                         return -EINVAL;
 185                 }
 186         }
 187
 188         return 0;
 189 }
 190
 191 static const char * const probe_usage[] = {
 192         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 193         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 194         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 195         "perf probe --list",
 196 #ifdef DWARF_SUPPORT
 197         "perf probe [<options>] --line 'LINEDESC'",
 198         "perf probe [<options>] --vars 'PROBEPOINT'",
 199 #endif
 200         NULL
 201 };
 202
 203 static const struct option options[] = {
 204         OPT_INCR('v', "verbose", &verbose,
 205                     "be more verbose (show parsed arguments, etc)"),
 206         OPT_BOOLEAN('l', "list", &params.list_events,
 207                     "list up current probe events"),
 208         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 209                 opt_del_probe_event),
 210         OPT_CALLBACK('a', "add", NULL,
 211 #ifdef DWARF_SUPPORT
 212                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 213                 " [[NAME=]ARG ...]",
 214 #else
 215                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 216 #endif
 217                 "probe point definition, where\n"
 218                 "\t\tGROUP:\tGroup name (optional)\n"
 219                 "\t\tEVENT:\tEvent name\n"
 220                 "\t\tFUNC:\tFunction name\n"
 221                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 222                 "\t\t%return:\tPut the probe at function return\n"
 223 #ifdef DWARF_SUPPORT
 224                 "\t\tSRC:\tSource code path\n"
 225                 "\t\tRL:\tRelative line number from function entry.\n"
 226                 "\t\tAL:\tAbsolute line number in file.\n"
 227                 "\t\tPT:\tLazy expression of line code.\n"
 228                 "\t\tARG:\tProbe argument (local variable name or\n"
 229                 "\t\t\tkprobe-tracer argument format.)\n",
 230 #else
 231                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 232 #endif
 233                 opt_add_probe_event),
 234         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 235                     " with existing name"),
 236 #ifdef DWARF_SUPPORT
 237         OPT_CALLBACK('L', "line", NULL,
 238                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 239                      "Show source code lines.", opt_show_lines),
 240         OPT_CALLBACK('V', "vars", NULL,
 241                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 242                      "Show accessible variables on PROBEDEF", opt_show_vars),
 243         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 244                     "Show external variables too (with --vars only)"),
 245         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 246                    "file", "vmlinux pathname"),
 247         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 248                    "directory", "path to kernel source"),
 249         OPT_STRING('m', "module", &params.target_module,
 250                    "modname|path",
 251                    "target module name (for online) or path (for offline)"),
 252 #endif
 253         OPT__DRY_RUN(&probe_event_dry_run),
 254         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 255                  "Set how many probe points can be found for a probe."),
 256         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 257                     "Show potential probe-able functions."),
 258         OPT_CALLBACK('\0', "filter", NULL,
 259                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 260                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 261                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 262                      opt_set_filter),
 263         OPT_END()
 264 };
 265
 266 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 267 {
 268         int ret;
 269
 270         argc = parse_options(argc, argv, options, probe_usage,
 271                              PARSE_OPT_STOP_AT_NON_OPTION);
 272         if (argc > 0) {
 273                 if (strcmp(argv[0], "-") == 0) {
 274                         pr_warning("  Error: '-' is not supported.\n");
 275                         usage_with_options(probe_usage, options);
 276                 }
 277                 ret = parse_probe_event_argv(argc, argv);
 278                 if (ret < 0) {
 279                         pr_err("  Error: Parse Error.  (%d)\n", ret);
 280                         return ret;
 281                 }
 282         }
 283
 284         if (params.max_probe_points == 0)
 285                 params.max_probe_points = MAX_PROBES;
 286
 287         if ((!params.nevents && !params.dellist && !params.list_events &&
 288              !params.show_lines && !params.show_funcs))
 289                 usage_with_options(probe_usage, options);
 290
 291         /*
 292          * Only consider the user's kernel image path if given.
 293          */
 294         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 295
 296         if (params.list_events) {
 297                 if (params.mod_events) {
 298                         pr_err("  Error: Don't use --list with --add/--del.\n");
 299                         usage_with_options(probe_usage, options);
 300                 }
 301                 if (params.show_lines) {
 302                         pr_err("  Error: Don't use --list with --line.\n");
 303                         usage_with_options(probe_usage, options);
 304                 }
 305                 if (params.show_vars) {
 306                         pr_err(" Error: Don't use --list with --vars.\n");
 307                         usage_with_options(probe_usage, options);
 308                 }
 309                 if (params.show_funcs) {
 310                         pr_err("  Error: Don't use --list with --funcs.\n");
 311                         usage_with_options(probe_usage, options);
 312                 }
 313                 ret = show_perf_probe_events();
 314                 if (ret < 0)
 315                         pr_err("  Error: Failed to show event list. (%d)\n",
 316                                ret);
 317                 return ret;
 318         }
 319         if (params.show_funcs) {
 320                 if (params.nevents != 0 || params.dellist) {
 321                         pr_err("  Error: Don't use --funcs with"
 322                                " --add/--del.\n");
 323                         usage_with_options(probe_usage, options);
 324                 }
 325                 if (params.show_lines) {
 326                         pr_err("  Error: Don't use --funcs with --line.\n");
 327                         usage_with_options(probe_usage, options);
 328                 }
 329                 if (params.show_vars) {
 330                         pr_err("  Error: Don't use --funcs with --vars.\n");
 331                         usage_with_options(probe_usage, options);
 332                 }
 333                 if (!params.filter)
 334                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 335                                                        NULL);
 336                 ret = show_available_funcs(params.target_module,
 337                                            params.filter);
 338                 strfilter__delete(params.filter);
 339                 if (ret < 0)
 340                         pr_err("  Error: Failed to show functions."
 341                                " (%d)\n", ret);
 342                 return ret;
 343         }
 344
 345 #ifdef DWARF_SUPPORT
 346         if (params.show_lines) {
 347                 if (params.mod_events) {
 348                         pr_err("  Error: Don't use --line with"
 349                                " --add/--del.\n");
 350                         usage_with_options(probe_usage, options);
 351                 }
 352                 if (params.show_vars) {
 353                         pr_err(" Error: Don't use --line with --vars.\n");
 354                         usage_with_options(probe_usage, options);
 355                 }
 356
 357                 ret = show_line_range(&params.line_range, params.target_module);
 358                 if (ret < 0)
 359                         pr_err("  Error: Failed to show lines. (%d)\n", ret);
 360                 return ret;
 361         }
 362         if (params.show_vars) {
 363                 if (params.mod_events) {
 364                         pr_err("  Error: Don't use --vars with"
 365                                " --add/--del.\n");
 366                         usage_with_options(probe_usage, options);
 367                 }
 368                 if (!params.filter)
 369                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 370                                                        NULL);
 371
 372                 ret = show_available_vars(params.events, params.nevents,
 373                                           params.max_probe_points,
 374                                           params.target_module,
 375                                           params.filter,
 376                                           params.show_ext_vars);
 377                 strfilter__delete(params.filter);
 378                 if (ret < 0)
 379                         pr_err("  Error: Failed to show vars. (%d)\n", ret);
 380                 return ret;
 381         }
 382 #endif
 383
 384         if (params.dellist) {
 385                 ret = del_perf_probe_events(params.dellist);
 386                 strlist__delete(params.dellist);
 387                 if (ret < 0) {
 388                         pr_err("  Error: Failed to delete events. (%d)\n", ret);
 389                         return ret;
 390                 }
 391         }
 392
 393         if (params.nevents) {
 394                 ret = add_perf_probe_events(params.events, params.nevents,
 395                                             params.max_probe_points,
 396                                             params.target_module,
 397                                             params.force_add);
 398                 if (ret < 0) {
 399                         pr_err("  Error: Failed to add events. (%d)\n", ret);
 400                         return ret;
 401                 }
 402         }
 403         return 0;
 404 }