1 /* 2 * builtin-probe.c 3 * 4 * Builtin probe command: Set up probe events by C expression 5 * 6 * Written by Masami Hiramatsu <mhiramat (at) 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 ret = parse_line_range_desc(str, ¶ms.line_range); 139 INIT_LIST_HEAD(¶ms.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 = ¶ms.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", ¶ms.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", ¶ms.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", ¶ms.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", ¶ms.target_module, 245 "modname", "target module name"), 246 #endif 247 OPT__DRY_RUN(&probe_event_dry_run), 248 OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points, 249 "Set how many probe points can be found for a probe."), 250 OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs, 251 "Show potential probe-able functions."), 252 OPT_CALLBACK('\0', "filter", NULL, 253 "[!]FILTER", "Set a filter (with --vars/funcs only)\n" 254 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n" 255 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)", 256 opt_set_filter), 257 OPT_END() 258 }; 259 260 int cmd_probe(int argc, const char **argv, const char *prefix __used) 261 { 262 int ret; 263 264 argc = parse_options(argc, argv, options, probe_usage, 265 PARSE_OPT_STOP_AT_NON_OPTION); 266 if (argc > 0) { 267 if (strcmp(argv[0], "-") == 0) { 268 pr_warning(" Error: '-' is not supported.\n"); 269 usage_with_options(probe_usage, options); 270 } 271 ret = parse_probe_event_argv(argc, argv); 272 if (ret < 0) { 273 pr_err(" Error: Parse Error. (%d)\n", ret); 274 return ret; 275 } 276 } 277 278 if (params.max_probe_points == 0) 279 params.max_probe_points = MAX_PROBES; 280 281 if ((!params.nevents && !params.dellist && !params.list_events && 282 !params.show_lines && !params.show_funcs)) 283 usage_with_options(probe_usage, options); 284 285 /* 286 * Only consider the user's kernel image path if given. 287 */ 288 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL); 289 290 if (params.list_events) { 291 if (params.mod_events) { 292 pr_err(" Error: Don't use --list with --add/--del.\n"); 293 usage_with_options(probe_usage, options); 294 } 295 if (params.show_lines) { 296 pr_err(" Error: Don't use --list with --line.\n"); 297 usage_with_options(probe_usage, options); 298 } 299 if (params.show_vars) { 300 pr_err(" Error: Don't use --list with --vars.\n"); 301 usage_with_options(probe_usage, options); 302 } 303 if (params.show_funcs) { 304 pr_err(" Error: Don't use --list with --funcs.\n"); 305 usage_with_options(probe_usage, options); 306 } 307 ret = show_perf_probe_events(); 308 if (ret < 0) 309 pr_err(" Error: Failed to show event list. (%d)\n", 310 ret); 311 return ret; 312 } 313 if (params.show_funcs) { 314 if (params.nevents != 0 || params.dellist) { 315 pr_err(" Error: Don't use --funcs with" 316 " --add/--del.\n"); 317 usage_with_options(probe_usage, options); 318 } 319 if (params.show_lines) { 320 pr_err(" Error: Don't use --funcs with --line.\n"); 321 usage_with_options(probe_usage, options); 322 } 323 if (params.show_vars) { 324 pr_err(" Error: Don't use --funcs with --vars.\n"); 325 usage_with_options(probe_usage, options); 326 } 327 if (!params.filter) 328 params.filter = strfilter__new(DEFAULT_FUNC_FILTER, 329 NULL); 330 ret = show_available_funcs(params.target_module, 331 params.filter); 332 strfilter__delete(params.filter); 333 if (ret < 0) 334 pr_err(" Error: Failed to show functions." 335 " (%d)\n", ret); 336 return ret; 337 } 338 339 #ifdef DWARF_SUPPORT 340 if (params.show_lines) { 341 if (params.mod_events) { 342 pr_err(" Error: Don't use --line with" 343 " --add/--del.\n"); 344 usage_with_options(probe_usage, options); 345 } 346 if (params.show_vars) { 347 pr_err(" Error: Don't use --line with --vars.\n"); 348 usage_with_options(probe_usage, options); 349 } 350 351 ret = show_line_range(¶ms.line_range, params.target_module); 352 if (ret < 0) 353 pr_err(" Error: Failed to show lines. (%d)\n", ret); 354 return ret; 355 } 356 if (params.show_vars) { 357 if (params.mod_events) { 358 pr_err(" Error: Don't use --vars with" 359 " --add/--del.\n"); 360 usage_with_options(probe_usage, options); 361 } 362 if (!params.filter) 363 params.filter = strfilter__new(DEFAULT_VAR_FILTER, 364 NULL); 365 366 ret = show_available_vars(params.events, params.nevents, 367 params.max_probe_points, 368 params.target_module, 369 params.filter, 370 params.show_ext_vars); 371 strfilter__delete(params.filter); 372 if (ret < 0) 373 pr_err(" Error: Failed to show vars. (%d)\n", ret); 374 return ret; 375 } 376 #endif 377 378 if (params.dellist) { 379 ret = del_perf_probe_events(params.dellist); 380 strlist__delete(params.dellist); 381 if (ret < 0) { 382 pr_err(" Error: Failed to delete events. (%d)\n", ret); 383 return ret; 384 } 385 } 386 387 if (params.nevents) { 388 ret = add_perf_probe_events(params.events, params.nevents, 389 params.max_probe_points, 390 params.target_module, 391 params.force_add); 392 if (ret < 0) { 393 pr_err(" Error: Failed to add events. (%d)\n", ret); 394 return ret; 395 } 396 } 397 return 0; 398 } 399
