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 <api/fs/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 bool uprobes; 58 int nevents; 59 struct perf_probe_event events[MAX_PROBES]; 60 struct strlist *dellist; 61 struct line_range line_range; 62 char *target; 63 int max_probe_points; 64 struct strfilter *filter; 65 } params; 66 67 /* Parse an event definition. Note that any error must die. */ 68 static int parse_probe_event(const char *str) 69 { 70 struct perf_probe_event *pev = ¶ms.events[params.nevents]; 71 int ret; 72 73 pr_debug("probe-definition(%d): %s\n", params.nevents, str); 74 if (++params.nevents == MAX_PROBES) { 75 pr_err("Too many probes (> %d) were specified.", MAX_PROBES); 76 return -1; 77 } 78 79 pev->uprobes = params.uprobes; 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 set_target(const char *ptr) 89 { 90 int found = 0; 91 const char *buf; 92 93 /* 94 * The first argument after options can be an absolute path 95 * to an executable / library or kernel module. 96 * 97 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH, 98 * short module name. 99 */ 100 if (!params.target && ptr && *ptr == '/') { 101 params.target = strdup(ptr); 102 if (!params.target) 103 return -ENOMEM; 104 105 found = 1; 106 buf = ptr + (strlen(ptr) - 3); 107 108 if (strcmp(buf, ".ko")) 109 params.uprobes = true; 110 111 } 112 113 return found; 114 } 115 116 static int parse_probe_event_argv(int argc, const char **argv) 117 { 118 int i, len, ret, found_target; 119 char *buf; 120 121 found_target = set_target(argv[0]); 122 if (found_target < 0) 123 return found_target; 124 125 if (found_target && argc == 1) 126 return 0; 127 128 /* Bind up rest arguments */ 129 len = 0; 130 for (i = 0; i < argc; i++) { 131 if (i == 0 && found_target) 132 continue; 133 134 len += strlen(argv[i]) + 1; 135 } 136 buf = zalloc(len + 1); 137 if (buf == NULL) 138 return -ENOMEM; 139 len = 0; 140 for (i = 0; i < argc; i++) { 141 if (i == 0 && found_target) 142 continue; 143 144 len += sprintf(&buf[len], "%s ", argv[i]); 145 } 146 params.mod_events = true; 147 ret = parse_probe_event(buf); 148 free(buf); 149 return ret; 150 } 151 152 static int opt_add_probe_event(const struct option *opt __maybe_unused, 153 const char *str, int unset __maybe_unused) 154 { 155 if (str) { 156 params.mod_events = true; 157 return parse_probe_event(str); 158 } else 159 return 0; 160 } 161 162 static int opt_del_probe_event(const struct option *opt __maybe_unused, 163 const char *str, int unset __maybe_unused) 164 { 165 if (str) { 166 params.mod_events = true; 167 if (!params.dellist) 168 params.dellist = strlist__new(true, NULL); 169 strlist__add(params.dellist, str); 170 } 171 return 0; 172 } 173 174 static int opt_set_target(const struct option *opt, const char *str, 175 int unset __maybe_unused) 176 { 177 int ret = -ENOENT; 178 char *tmp; 179 180 if (str && !params.target) { 181 if (!strcmp(opt->long_name, "exec")) 182 params.uprobes = true; 183 #ifdef HAVE_DWARF_SUPPORT 184 else if (!strcmp(opt->long_name, "module")) 185 params.uprobes = false; 186 #endif 187 else 188 return ret; 189 190 /* Expand given path to absolute path, except for modulename */ 191 if (params.uprobes || strchr(str, '/')) { 192 tmp = realpath(str, NULL); 193 if (!tmp) { 194 pr_warning("Failed to get the absolute path of %s: %m\n", str); 195 return ret; 196 } 197 } else { 198 tmp = strdup(str); 199 if (!tmp) 200 return -ENOMEM; 201 } 202 params.target = tmp; 203 ret = 0; 204 } 205 206 return ret; 207 } 208 209 #ifdef HAVE_DWARF_SUPPORT 210 static int opt_show_lines(const struct option *opt __maybe_unused, 211 const char *str, int unset __maybe_unused) 212 { 213 int ret = 0; 214 215 if (!str) 216 return 0; 217 218 if (params.show_lines) { 219 pr_warning("Warning: more than one --line options are" 220 " detected. Only the first one is valid.\n"); 221 return 0; 222 } 223 224 params.show_lines = true; 225 ret = parse_line_range_desc(str, ¶ms.line_range); 226 227 return ret; 228 } 229 230 static int opt_show_vars(const struct option *opt __maybe_unused, 231 const char *str, int unset __maybe_unused) 232 { 233 struct perf_probe_event *pev = ¶ms.events[params.nevents]; 234 int ret; 235 236 if (!str) 237 return 0; 238 239 ret = parse_probe_event(str); 240 if (!ret && pev->nargs != 0) { 241 pr_err(" Error: '--vars' doesn't accept arguments.\n"); 242 return -EINVAL; 243 } 244 params.show_vars = true; 245 246 return ret; 247 } 248 #endif 249 250 static int opt_set_filter(const struct option *opt __maybe_unused, 251 const char *str, int unset __maybe_unused) 252 { 253 const char *err; 254 255 if (str) { 256 pr_debug2("Set filter: %s\n", str); 257 if (params.filter) 258 strfilter__delete(params.filter); 259 params.filter = strfilter__new(str, &err); 260 if (!params.filter) { 261 pr_err("Filter parse error at %td.\n", err - str + 1); 262 pr_err("Source: \"%s\"\n", str); 263 pr_err(" %*c\n", (int)(err - str + 1), '^'); 264 return -EINVAL; 265 } 266 } 267 268 return 0; 269 } 270 271 static int init_params(void) 272 { 273 return line_range__init(¶ms.line_range); 274 } 275 276 static void cleanup_params(void) 277 { 278 int i; 279 280 for (i = 0; i < params.nevents; i++) 281 clear_perf_probe_event(params.events + i); 282 if (params.dellist) 283 strlist__delete(params.dellist); 284 line_range__clear(¶ms.line_range); 285 free(params.target); 286 if (params.filter) 287 strfilter__delete(params.filter); 288 memset(¶ms, 0, sizeof(params)); 289 } 290 291 static int 292 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) 293 { 294 const char * const probe_usage[] = { 295 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]", 296 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]", 297 "perf probe [<options>] --del '[GROUP:]EVENT' ...", 298 "perf probe --list", 299 #ifdef HAVE_DWARF_SUPPORT 300 "perf probe [<options>] --line 'LINEDESC'", 301 "perf probe [<options>] --vars 'PROBEPOINT'", 302 #endif 303 NULL 304 }; 305 const struct option options[] = { 306 OPT_INCR('v', "verbose", &verbose, 307 "be more verbose (show parsed arguments, etc)"), 308 OPT_BOOLEAN('l', "list", ¶ms.list_events, 309 "list up current probe events"), 310 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.", 311 opt_del_probe_event), 312 OPT_CALLBACK('a', "add", NULL, 313 #ifdef HAVE_DWARF_SUPPORT 314 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT" 315 " [[NAME=]ARG ...]", 316 #else 317 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]", 318 #endif 319 "probe point definition, where\n" 320 "\t\tGROUP:\tGroup name (optional)\n" 321 "\t\tEVENT:\tEvent name\n" 322 "\t\tFUNC:\tFunction name\n" 323 "\t\tOFF:\tOffset from function entry (in byte)\n" 324 "\t\t%return:\tPut the probe at function return\n" 325 #ifdef HAVE_DWARF_SUPPORT 326 "\t\tSRC:\tSource code path\n" 327 "\t\tRL:\tRelative line number from function entry.\n" 328 "\t\tAL:\tAbsolute line number in file.\n" 329 "\t\tPT:\tLazy expression of line code.\n" 330 "\t\tARG:\tProbe argument (local variable name or\n" 331 "\t\t\tkprobe-tracer argument format.)\n", 332 #else 333 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n", 334 #endif 335 opt_add_probe_event), 336 OPT_BOOLEAN('f', "force", ¶ms.force_add, "forcibly add events" 337 " with existing name"), 338 #ifdef HAVE_DWARF_SUPPORT 339 OPT_CALLBACK('L', "line", NULL, 340 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]", 341 "Show source code lines.", opt_show_lines), 342 OPT_CALLBACK('V', "vars", NULL, 343 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT", 344 "Show accessible variables on PROBEDEF", opt_show_vars), 345 OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars, 346 "Show external variables too (with --vars only)"), 347 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name, 348 "file", "vmlinux pathname"), 349 OPT_STRING('s', "source", &symbol_conf.source_prefix, 350 "directory", "path to kernel source"), 351 OPT_CALLBACK('m', "module", NULL, "modname|path", 352 "target module name (for online) or path (for offline)", 353 opt_set_target), 354 #endif 355 OPT__DRY_RUN(&probe_event_dry_run), 356 OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points, 357 "Set how many probe points can be found for a probe."), 358 OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs, 359 "Show potential probe-able functions."), 360 OPT_CALLBACK('\0', "filter", NULL, 361 "[!]FILTER", "Set a filter (with --vars/funcs only)\n" 362 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n" 363 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)", 364 opt_set_filter), 365 OPT_CALLBACK('x', "exec", NULL, "executable|path", 366 "target executable name or path", opt_set_target), 367 OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle, 368 "Disable symbol demangling"), 369 OPT_END() 370 }; 371 int ret; 372 373 argc = parse_options(argc, argv, options, probe_usage, 374 PARSE_OPT_STOP_AT_NON_OPTION); 375 if (argc > 0) { 376 if (strcmp(argv[0], "-") == 0) { 377 pr_warning(" Error: '-' is not supported.\n"); 378 usage_with_options(probe_usage, options); 379 } 380 ret = parse_probe_event_argv(argc, argv); 381 if (ret < 0) { 382 pr_err(" Error: Parse Error. (%d)\n", ret); 383 return ret; 384 } 385 } 386 387 if (params.max_probe_points == 0) 388 params.max_probe_points = MAX_PROBES; 389 390 if ((!params.nevents && !params.dellist && !params.list_events && 391 !params.show_lines && !params.show_funcs)) 392 usage_with_options(probe_usage, options); 393 394 /* 395 * Only consider the user's kernel image path if given. 396 */ 397 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL); 398 399 if (params.list_events) { 400 if (params.mod_events) { 401 pr_err(" Error: Don't use --list with --add/--del.\n"); 402 usage_with_options(probe_usage, options); 403 } 404 if (params.show_lines) { 405 pr_err(" Error: Don't use --list with --line.\n"); 406 usage_with_options(probe_usage, options); 407 } 408 if (params.show_vars) { 409 pr_err(" Error: Don't use --list with --vars.\n"); 410 usage_with_options(probe_usage, options); 411 } 412 if (params.show_funcs) { 413 pr_err(" Error: Don't use --list with --funcs.\n"); 414 usage_with_options(probe_usage, options); 415 } 416 if (params.uprobes) { 417 pr_warning(" Error: Don't use --list with --exec.\n"); 418 usage_with_options(probe_usage, options); 419 } 420 ret = show_perf_probe_events(); 421 if (ret < 0) 422 pr_err(" Error: Failed to show event list. (%d)\n", 423 ret); 424 return ret; 425 } 426 if (params.show_funcs) { 427 if (params.nevents != 0 || params.dellist) { 428 pr_err(" Error: Don't use --funcs with" 429 " --add/--del.\n"); 430 usage_with_options(probe_usage, options); 431 } 432 if (params.show_lines) { 433 pr_err(" Error: Don't use --funcs with --line.\n"); 434 usage_with_options(probe_usage, options); 435 } 436 if (params.show_vars) { 437 pr_err(" Error: Don't use --funcs with --vars.\n"); 438 usage_with_options(probe_usage, options); 439 } 440 if (!params.filter) 441 params.filter = strfilter__new(DEFAULT_FUNC_FILTER, 442 NULL); 443 ret = show_available_funcs(params.target, params.filter, 444 params.uprobes); 445 strfilter__delete(params.filter); 446 params.filter = NULL; 447 if (ret < 0) 448 pr_err(" Error: Failed to show functions." 449 " (%d)\n", ret); 450 return ret; 451 } 452 453 #ifdef HAVE_DWARF_SUPPORT 454 if (params.show_lines) { 455 if (params.mod_events) { 456 pr_err(" Error: Don't use --line with" 457 " --add/--del.\n"); 458 usage_with_options(probe_usage, options); 459 } 460 if (params.show_vars) { 461 pr_err(" Error: Don't use --line with --vars.\n"); 462 usage_with_options(probe_usage, options); 463 } 464 465 ret = show_line_range(¶ms.line_range, params.target); 466 if (ret < 0) 467 pr_err(" Error: Failed to show lines. (%d)\n", ret); 468 return ret; 469 } 470 if (params.show_vars) { 471 if (params.mod_events) { 472 pr_err(" Error: Don't use --vars with" 473 " --add/--del.\n"); 474 usage_with_options(probe_usage, options); 475 } 476 if (!params.filter) 477 params.filter = strfilter__new(DEFAULT_VAR_FILTER, 478 NULL); 479 480 ret = show_available_vars(params.events, params.nevents, 481 params.max_probe_points, 482 params.target, 483 params.filter, 484 params.show_ext_vars); 485 strfilter__delete(params.filter); 486 params.filter = NULL; 487 if (ret < 0) 488 pr_err(" Error: Failed to show vars. (%d)\n", ret); 489 return ret; 490 } 491 #endif 492 493 if (params.dellist) { 494 ret = del_perf_probe_events(params.dellist); 495 if (ret < 0) { 496 pr_err(" Error: Failed to delete events. (%d)\n", ret); 497 return ret; 498 } 499 } 500 501 if (params.nevents) { 502 ret = add_perf_probe_events(params.events, params.nevents, 503 params.max_probe_points, 504 params.target, 505 params.force_add); 506 if (ret < 0) { 507 pr_err(" Error: Failed to add events. (%d)\n", ret); 508 return ret; 509 } 510 } 511 return 0; 512 } 513 514 int cmd_probe(int argc, const char **argv, const char *prefix) 515 { 516 int ret; 517 518 ret = init_params(); 519 if (!ret) { 520 ret = __cmd_probe(argc, argv, prefix); 521 cleanup_params(); 522 } 523 524 return ret; 525 } 526