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 = ¶ms.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 return 0; 139 140 if (params.show_lines) { 141 pr_warning("Warning: more than one --line options are" 142 " detected. Only the first one is valid.\n"); 143 return 0; 144 } 145 146 params.show_lines = true; 147 ret = parse_line_range_desc(str, ¶ms.line_range); 148 INIT_LIST_HEAD(¶ms.line_range.line_list); 149 150 return ret; 151 } 152 153 static int opt_show_vars(const struct option *opt __used, 154 const char *str, int unset __used) 155 { 156 struct perf_probe_event *pev = ¶ms.events[params.nevents]; 157 int ret; 158 159 if (!str) 160 return 0; 161 162 ret = parse_probe_event(str); 163 if (!ret && pev->nargs != 0) { 164 pr_err(" Error: '--vars' doesn't accept arguments.\n"); 165 return -EINVAL; 166 } 167 params.show_vars = true; 168 169 return ret; 170 } 171 #endif 172 173 static int opt_set_filter(const struct option *opt __used, 174 const char *str, int unset __used) 175 { 176 const char *err; 177 178 if (str) { 179 pr_debug2("Set filter: %s\n", str); 180 if (params.filter) 181 strfilter__delete(params.filter); 182 params.filter = strfilter__new(str, &err); 183 if (!params.filter) { 184 pr_err("Filter parse error at %td.\n", err - str + 1); 185 pr_err("Source: \"%s\"\n", str); 186 pr_err(" %*c\n", (int)(err - str + 1), '^'); 187 return -EINVAL; 188 } 189 } 190 191 return 0; 192 } 193 194 static const char * const probe_usage[] = { 195 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]", 196 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]", 197 "perf probe [<options>] --del '[GROUP:]EVENT' ...", 198 "perf probe --list", 199 #ifdef DWARF_SUPPORT 200 "perf probe [<options>] --line 'LINEDESC'", 201 "perf probe [<options>] --vars 'PROBEPOINT'", 202 #endif 203 NULL 204 }; 205 206 static const struct option options[] = { 207 OPT_INCR('v', "verbose", &verbose, 208 "be more verbose (show parsed arguments, etc)"), 209 OPT_BOOLEAN('l', "list", ¶ms.list_events, 210 "list up current probe events"), 211 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.", 212 opt_del_probe_event), 213 OPT_CALLBACK('a', "add", NULL, 214 #ifdef DWARF_SUPPORT 215 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT" 216 " [[NAME=]ARG ...]", 217 #else 218 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]", 219 #endif 220 "probe point definition, where\n" 221 "\t\tGROUP:\tGroup name (optional)\n" 222 "\t\tEVENT:\tEvent name\n" 223 "\t\tFUNC:\tFunction name\n" 224 "\t\tOFF:\tOffset from function entry (in byte)\n" 225 "\t\t%return:\tPut the probe at function return\n" 226 #ifdef DWARF_SUPPORT 227 "\t\tSRC:\tSource code path\n" 228 "\t\tRL:\tRelative line number from function entry.\n" 229 "\t\tAL:\tAbsolute line number in file.\n" 230 "\t\tPT:\tLazy expression of line code.\n" 231 "\t\tARG:\tProbe argument (local variable name or\n" 232 "\t\t\tkprobe-tracer argument format.)\n", 233 #else 234 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n", 235 #endif 236 opt_add_probe_event), 237 OPT_BOOLEAN('f', "force", ¶ms.force_add, "forcibly add events" 238 " with existing name"), 239 #ifdef DWARF_SUPPORT 240 OPT_CALLBACK('L', "line", NULL, 241 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]", 242 "Show source code lines.", opt_show_lines), 243 OPT_CALLBACK('V', "vars", NULL, 244 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT", 245 "Show accessible variables on PROBEDEF", opt_show_vars), 246 OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars, 247 "Show external variables too (with --vars only)"), 248 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name, 249 "file", "vmlinux pathname"), 250 OPT_STRING('s', "source", &symbol_conf.source_prefix, 251 "directory", "path to kernel source"), 252 OPT_STRING('m', "module", ¶ms.target_module, 253 "modname|path", 254 "target module name (for online) or path (for offline)"), 255 #endif 256 OPT__DRY_RUN(&probe_event_dry_run), 257 OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points, 258 "Set how many probe points can be found for a probe."), 259 OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs, 260 "Show potential probe-able functions."), 261 OPT_CALLBACK('\0', "filter", NULL, 262 "[!]FILTER", "Set a filter (with --vars/funcs only)\n" 263 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n" 264 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)", 265 opt_set_filter), 266 OPT_END() 267 }; 268 269 int cmd_probe(int argc, const char **argv, const char *prefix __used) 270 { 271 int ret; 272 273 argc = parse_options(argc, argv, options, probe_usage, 274 PARSE_OPT_STOP_AT_NON_OPTION); 275 if (argc > 0) { 276 if (strcmp(argv[0], "-") == 0) { 277 pr_warning(" Error: '-' is not supported.\n"); 278 usage_with_options(probe_usage, options); 279 } 280 ret = parse_probe_event_argv(argc, argv); 281 if (ret < 0) { 282 pr_err(" Error: Parse Error. (%d)\n", ret); 283 return ret; 284 } 285 } 286 287 if (params.max_probe_points == 0) 288 params.max_probe_points = MAX_PROBES; 289 290 if ((!params.nevents && !params.dellist && !params.list_events && 291 !params.show_lines && !params.show_funcs)) 292 usage_with_options(probe_usage, options); 293 294 /* 295 * Only consider the user's kernel image path if given. 296 */ 297 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL); 298 299 if (params.list_events) { 300 if (params.mod_events) { 301 pr_err(" Error: Don't use --list with --add/--del.\n"); 302 usage_with_options(probe_usage, options); 303 } 304 if (params.show_lines) { 305 pr_err(" Error: Don't use --list with --line.\n"); 306 usage_with_options(probe_usage, options); 307 } 308 if (params.show_vars) { 309 pr_err(" Error: Don't use --list with --vars.\n"); 310 usage_with_options(probe_usage, options); 311 } 312 if (params.show_funcs) { 313 pr_err(" Error: Don't use --list with --funcs.\n"); 314 usage_with_options(probe_usage, options); 315 } 316 ret = show_perf_probe_events(); 317 if (ret < 0) 318 pr_err(" Error: Failed to show event list. (%d)\n", 319 ret); 320 return ret; 321 } 322 if (params.show_funcs) { 323 if (params.nevents != 0 || params.dellist) { 324 pr_err(" Error: Don't use --funcs with" 325 " --add/--del.\n"); 326 usage_with_options(probe_usage, options); 327 } 328 if (params.show_lines) { 329 pr_err(" Error: Don't use --funcs with --line.\n"); 330 usage_with_options(probe_usage, options); 331 } 332 if (params.show_vars) { 333 pr_err(" Error: Don't use --funcs with --vars.\n"); 334 usage_with_options(probe_usage, options); 335 } 336 if (!params.filter) 337 params.filter = strfilter__new(DEFAULT_FUNC_FILTER, 338 NULL); 339 ret = show_available_funcs(params.target_module, 340 params.filter); 341 strfilter__delete(params.filter); 342 if (ret < 0) 343 pr_err(" Error: Failed to show functions." 344 " (%d)\n", ret); 345 return ret; 346 } 347 348 #ifdef DWARF_SUPPORT 349 if (params.show_lines) { 350 if (params.mod_events) { 351 pr_err(" Error: Don't use --line with" 352 " --add/--del.\n"); 353 usage_with_options(probe_usage, options); 354 } 355 if (params.show_vars) { 356 pr_err(" Error: Don't use --line with --vars.\n"); 357 usage_with_options(probe_usage, options); 358 } 359 360 ret = show_line_range(¶ms.line_range, params.target_module); 361 if (ret < 0) 362 pr_err(" Error: Failed to show lines. (%d)\n", ret); 363 return ret; 364 } 365 if (params.show_vars) { 366 if (params.mod_events) { 367 pr_err(" Error: Don't use --vars with" 368 " --add/--del.\n"); 369 usage_with_options(probe_usage, options); 370 } 371 if (!params.filter) 372 params.filter = strfilter__new(DEFAULT_VAR_FILTER, 373 NULL); 374 375 ret = show_available_vars(params.events, params.nevents, 376 params.max_probe_points, 377 params.target_module, 378 params.filter, 379 params.show_ext_vars); 380 strfilter__delete(params.filter); 381 if (ret < 0) 382 pr_err(" Error: Failed to show vars. (%d)\n", ret); 383 return ret; 384 } 385 #endif 386 387 if (params.dellist) { 388 ret = del_perf_probe_events(params.dellist); 389 strlist__delete(params.dellist); 390 if (ret < 0) { 391 pr_err(" Error: Failed to delete events. (%d)\n", ret); 392 return ret; 393 } 394 } 395 396 if (params.nevents) { 397 ret = add_perf_probe_events(params.events, params.nevents, 398 params.max_probe_points, 399 params.target_module, 400 params.force_add); 401 if (ret < 0) { 402 pr_err(" Error: Failed to add events. (%d)\n", ret); 403 return ret; 404 } 405 } 406 return 0; 407 } 408