| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * in kernel monitor support: allows rv to control in-kernel monitors. |
| 4 | * |
| 5 | * Copyright (C) 2022 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org> |
| 6 | */ |
| 7 | #include <getopt.h> |
| 8 | #include <stdlib.h> |
| 9 | #include <string.h> |
| 10 | #include <errno.h> |
| 11 | #include <unistd.h> |
| 12 | |
| 13 | #include <trace.h> |
| 14 | #include <utils.h> |
| 15 | #include <rv.h> |
| 16 | |
| 17 | static int config_has_id; |
| 18 | static int config_my_pid; |
| 19 | static int config_trace; |
| 20 | |
| 21 | static char *config_initial_reactor; |
| 22 | static char *config_reactor; |
| 23 | |
| 24 | /* |
| 25 | * __ikm_read_enable - reads monitor's enable status |
| 26 | * |
| 27 | * __does not log errors. |
| 28 | * |
| 29 | * Returns the current status, or -1 if the monitor does not exist, |
| 30 | * __hence not logging errors. |
| 31 | */ |
| 32 | static int __ikm_read_enable(char *monitor_name) |
| 33 | { |
| 34 | char path[MAX_PATH]; |
| 35 | long long enabled; |
| 36 | int retval; |
| 37 | |
| 38 | snprintf(path, MAX_PATH, "rv/monitors/%s/enable", monitor_name); |
| 39 | |
| 40 | retval = tracefs_instance_file_read_number(NULL, path, &enabled); |
| 41 | if (retval < 0) |
| 42 | return -1; |
| 43 | |
| 44 | return enabled; |
| 45 | } |
| 46 | |
| 47 | /* |
| 48 | * ikm_read_enable - reads monitor's enable status |
| 49 | * |
| 50 | * Returns the current status, or -1 on error. |
| 51 | */ |
| 52 | static int ikm_read_enable(char *monitor_name) |
| 53 | { |
| 54 | int enabled; |
| 55 | |
| 56 | enabled = __ikm_read_enable(monitor_name); |
| 57 | if (enabled < 0) { |
| 58 | err_msg("ikm: fail read enabled: %d\n", enabled); |
| 59 | return -1; |
| 60 | } |
| 61 | |
| 62 | debug_msg("ikm: read enabled: %d\n", enabled); |
| 63 | |
| 64 | return enabled; |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * ikm_write_enable - write to the monitor's enable file |
| 69 | * |
| 70 | * Return the number of bytes written, -1 on error. |
| 71 | */ |
| 72 | static int ikm_write_enable(char *monitor_name, char *enable_disable) |
| 73 | { |
| 74 | char path[MAX_PATH]; |
| 75 | int retval; |
| 76 | |
| 77 | debug_msg("ikm: writing enabled: %s\n", enable_disable); |
| 78 | |
| 79 | snprintf(path, MAX_PATH, "rv/monitors/%s/enable", monitor_name); |
| 80 | retval = tracefs_instance_file_write(NULL, path, enable_disable); |
| 81 | if (retval < strlen(enable_disable)) { |
| 82 | err_msg("ikm: writing enabled: %s\n", enable_disable); |
| 83 | return -1; |
| 84 | } |
| 85 | |
| 86 | return retval; |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * ikm_enable - enable a monitor |
| 91 | * |
| 92 | * Returns -1 on failure. Success otherwise. |
| 93 | */ |
| 94 | static int ikm_enable(char *monitor_name) |
| 95 | { |
| 96 | return ikm_write_enable(monitor_name, "1"); |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * ikm_disable - disable a monitor |
| 101 | * |
| 102 | * Returns -1 on failure. Success otherwise. |
| 103 | */ |
| 104 | static int ikm_disable(char *monitor_name) |
| 105 | { |
| 106 | return ikm_write_enable(monitor_name, "0"); |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * ikm_read_desc - read monitors' description |
| 111 | * |
| 112 | * Return a dynamically allocated string with the monitor's |
| 113 | * description, NULL otherwise. |
| 114 | */ |
| 115 | static char *ikm_read_desc(char *monitor_name) |
| 116 | { |
| 117 | char path[MAX_PATH]; |
| 118 | char *desc; |
| 119 | |
| 120 | snprintf(path, MAX_PATH, "rv/monitors/%s/desc", monitor_name); |
| 121 | desc = tracefs_instance_file_read(NULL, path, NULL); |
| 122 | if (!desc) { |
| 123 | err_msg("ikm: error reading monitor %s desc\n", monitor_name); |
| 124 | return NULL; |
| 125 | } |
| 126 | |
| 127 | *strstr(desc, "\n") = '\0'; |
| 128 | |
| 129 | return desc; |
| 130 | } |
| 131 | |
| 132 | /* |
| 133 | * ikm_fill_monitor_definition - fill monitor's definition |
| 134 | * |
| 135 | * Returns -1 on error, 0 otherwise. |
| 136 | */ |
| 137 | static int ikm_fill_monitor_definition(char *name, struct monitor *ikm) |
| 138 | { |
| 139 | int enabled; |
| 140 | char *desc; |
| 141 | |
| 142 | enabled = ikm_read_enable(name); |
| 143 | if (enabled < 0) { |
| 144 | err_msg("ikm: monitor %s fail to read enable file, bug?\n", name); |
| 145 | return -1; |
| 146 | } |
| 147 | |
| 148 | desc = ikm_read_desc(name); |
| 149 | if (!desc) { |
| 150 | err_msg("ikm: monitor %s does not have desc file, bug?\n", name); |
| 151 | return -1; |
| 152 | } |
| 153 | |
| 154 | strncpy(ikm->name, name, MAX_DA_NAME_LEN); |
| 155 | ikm->enabled = enabled; |
| 156 | strncpy(ikm->desc, desc, MAX_DESCRIPTION); |
| 157 | |
| 158 | free(desc); |
| 159 | |
| 160 | return 0; |
| 161 | } |
| 162 | |
| 163 | /* |
| 164 | * ikm_write_reactor - switch the reactor to *reactor |
| 165 | * |
| 166 | * Return the number or characters written, -1 on error. |
| 167 | */ |
| 168 | static int ikm_write_reactor(char *monitor_name, char *reactor) |
| 169 | { |
| 170 | char path[MAX_PATH]; |
| 171 | int retval; |
| 172 | |
| 173 | snprintf(path, MAX_PATH, "rv/monitors/%s/reactors", monitor_name); |
| 174 | retval = tracefs_instance_file_write(NULL, path, reactor); |
| 175 | debug_msg("ikm: write \"%s\" reactors: %d\n", reactor, retval); |
| 176 | |
| 177 | return retval; |
| 178 | } |
| 179 | |
| 180 | /* |
| 181 | * ikm_read_reactor - read the reactors file |
| 182 | * |
| 183 | * Returns a dynamically allocated string with monitor's |
| 184 | * available reactors, or NULL on error. |
| 185 | */ |
| 186 | static char *ikm_read_reactor(char *monitor_name) |
| 187 | { |
| 188 | char path[MAX_PATH]; |
| 189 | char *reactors; |
| 190 | |
| 191 | snprintf(path, MAX_PATH, "rv/monitors/%s/reactors", monitor_name); |
| 192 | reactors = tracefs_instance_file_read(NULL, path, NULL); |
| 193 | if (!reactors) { |
| 194 | err_msg("ikm: fail reading monitor's %s reactors file\n", monitor_name); |
| 195 | return NULL; |
| 196 | } |
| 197 | |
| 198 | return reactors; |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * ikm_get_current_reactor - get the current enabled reactor |
| 203 | * |
| 204 | * Reads the reactors file and find the currently enabled |
| 205 | * [reactor]. |
| 206 | * |
| 207 | * Returns a dynamically allocated memory with the current |
| 208 | * reactor. NULL otherwise. |
| 209 | */ |
| 210 | static char *ikm_get_current_reactor(char *monitor_name) |
| 211 | { |
| 212 | char *reactors = ikm_read_reactor(monitor_name); |
| 213 | char *curr_reactor = NULL; |
| 214 | char *start; |
| 215 | char *end; |
| 216 | |
| 217 | if (!reactors) |
| 218 | return NULL; |
| 219 | |
| 220 | start = strstr(reactors, "["); |
| 221 | if (!start) |
| 222 | goto out_free; |
| 223 | |
| 224 | start++; |
| 225 | |
| 226 | end = strstr(start, "]"); |
| 227 | if (!end) |
| 228 | goto out_free; |
| 229 | |
| 230 | *end = '\0'; |
| 231 | |
| 232 | curr_reactor = calloc(strlen(start) + 1, sizeof(char)); |
| 233 | if (!curr_reactor) |
| 234 | goto out_free; |
| 235 | |
| 236 | strncpy(curr_reactor, start, strlen(start)); |
| 237 | debug_msg("ikm: read current reactor %s\n", curr_reactor); |
| 238 | |
| 239 | out_free: |
| 240 | free(reactors); |
| 241 | |
| 242 | return curr_reactor; |
| 243 | } |
| 244 | |
| 245 | static int ikm_has_id(char *monitor_name) |
| 246 | { |
| 247 | char path[MAX_PATH]; |
| 248 | char *format; |
| 249 | int has_id; |
| 250 | |
| 251 | snprintf(path, MAX_PATH, "events/rv/event_%s/format", monitor_name); |
| 252 | format = tracefs_instance_file_read(NULL, path, NULL); |
| 253 | if (!format) { |
| 254 | err_msg("ikm: fail reading monitor's %s format event file\n", monitor_name); |
| 255 | return -1; |
| 256 | } |
| 257 | |
| 258 | /* print fmt: "%d: %s x %s -> %s %s", REC->id, ... */ |
| 259 | has_id = !!strstr(format, "REC->id"); |
| 260 | |
| 261 | debug_msg("ikm: monitor %s has id: %s\n", monitor_name, has_id ? "yes" : "no"); |
| 262 | |
| 263 | free(format); |
| 264 | |
| 265 | return has_id; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * ikm_list_monitors - list all available monitors |
| 270 | * |
| 271 | * Returns 0 on success, -1 otherwise. |
| 272 | */ |
| 273 | int ikm_list_monitors(void) |
| 274 | { |
| 275 | char *available_monitors; |
| 276 | struct monitor ikm; |
| 277 | char *curr, *next; |
| 278 | int retval; |
| 279 | |
| 280 | available_monitors = tracefs_instance_file_read(NULL, "rv/available_monitors", NULL); |
| 281 | |
| 282 | if (!available_monitors) { |
| 283 | err_msg("ikm: available monitors is not available, is CONFIG_RV enabled?\n"); |
| 284 | return -1; |
| 285 | } |
| 286 | |
| 287 | curr = available_monitors; |
| 288 | do { |
| 289 | next = strstr(curr, "\n"); |
| 290 | *next = '\0'; |
| 291 | |
| 292 | retval = ikm_fill_monitor_definition(curr, &ikm); |
| 293 | if (retval) |
| 294 | err_msg("ikm: error reading %d in kernel monitor, skipping\n", curr); |
| 295 | |
| 296 | printf("%-24s %s %s\n", ikm.name, ikm.desc, ikm.enabled ? "[ON]" : "[OFF]"); |
| 297 | curr = ++next; |
| 298 | |
| 299 | } while (strlen(curr)); |
| 300 | |
| 301 | free(available_monitors); |
| 302 | |
| 303 | return 0; |
| 304 | } |
| 305 | |
| 306 | static void ikm_print_header(struct trace_seq *s) |
| 307 | { |
| 308 | trace_seq_printf(s, "%16s-%-8s %5s %5s ", "<TASK>", "PID", "[CPU]", "TYPE"); |
| 309 | if (config_has_id) |
| 310 | trace_seq_printf(s, "%8s ", "ID"); |
| 311 | |
| 312 | trace_seq_printf(s, "%24s x %-24s -> %-24s %s\n", |
| 313 | "STATE", |
| 314 | "EVENT", |
| 315 | "NEXT_STATE", |
| 316 | "FINAL"); |
| 317 | |
| 318 | trace_seq_printf(s, "%16s %-8s %5s %5s ", " | ", " | ", " | ", " | "); |
| 319 | |
| 320 | if (config_has_id) |
| 321 | trace_seq_printf(s, "%8s ", " | "); |
| 322 | |
| 323 | trace_seq_printf(s, "%24s %-24s %-24s %s\n", |
| 324 | " | ", |
| 325 | " | ", |
| 326 | " | ", |
| 327 | "|"); |
| 328 | |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * ikm_event_handler - callback to handle event events |
| 333 | * |
| 334 | * Called any time a rv:"monitor"_event events is generated. |
| 335 | * It parses and print event. |
| 336 | */ |
| 337 | static int |
| 338 | ikm_event_handler(struct trace_seq *s, struct tep_record *record, |
| 339 | struct tep_event *trace_event, void *context) |
| 340 | { |
| 341 | /* if needed: struct trace_instance *inst = context; */ |
| 342 | char *state, *event, *next_state; |
| 343 | unsigned long long final_state; |
| 344 | unsigned long long pid; |
| 345 | unsigned long long id; |
| 346 | int cpu = record->cpu; |
| 347 | int val; |
| 348 | |
| 349 | if (config_has_id) |
| 350 | tep_get_field_val(s, trace_event, "id", record, &id, 1); |
| 351 | |
| 352 | tep_get_common_field_val(s, trace_event, "common_pid", record, &pid, 1); |
| 353 | |
| 354 | if (config_has_id && (config_my_pid == id)) |
| 355 | return 0; |
| 356 | else if (config_my_pid && (config_my_pid == pid)) |
| 357 | return 0; |
| 358 | |
| 359 | tep_print_event(trace_event->tep, s, record, "%16s-%-8d ", TEP_PRINT_COMM, TEP_PRINT_PID); |
| 360 | |
| 361 | trace_seq_printf(s, "[%.3d] event ", cpu); |
| 362 | |
| 363 | if (config_has_id) |
| 364 | trace_seq_printf(s, "%8llu ", id); |
| 365 | |
| 366 | state = tep_get_field_raw(s, trace_event, "state", record, &val, 0); |
| 367 | event = tep_get_field_raw(s, trace_event, "event", record, &val, 0); |
| 368 | next_state = tep_get_field_raw(s, trace_event, "next_state", record, &val, 0); |
| 369 | tep_get_field_val(s, trace_event, "final_state", record, &final_state, 1); |
| 370 | |
| 371 | trace_seq_printf(s, "%24s x %-24s -> %-24s %s\n", |
| 372 | state, |
| 373 | event, |
| 374 | next_state, |
| 375 | final_state ? "Y" : "N"); |
| 376 | |
| 377 | trace_seq_do_printf(s); |
| 378 | trace_seq_reset(s); |
| 379 | |
| 380 | return 0; |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * ikm_error_handler - callback to handle error events |
| 385 | * |
| 386 | * Called any time a rv:"monitor"_errors events is generated. |
| 387 | * It parses and print event. |
| 388 | */ |
| 389 | static int |
| 390 | ikm_error_handler(struct trace_seq *s, struct tep_record *record, |
| 391 | struct tep_event *trace_event, void *context) |
| 392 | { |
| 393 | unsigned long long pid, id; |
| 394 | int cpu = record->cpu; |
| 395 | char *state, *event; |
| 396 | int val; |
| 397 | |
| 398 | if (config_has_id) |
| 399 | tep_get_field_val(s, trace_event, "id", record, &id, 1); |
| 400 | |
| 401 | tep_get_common_field_val(s, trace_event, "common_pid", record, &pid, 1); |
| 402 | |
| 403 | if (config_has_id && config_my_pid == id) |
| 404 | return 0; |
| 405 | else if (config_my_pid == pid) |
| 406 | return 0; |
| 407 | |
| 408 | trace_seq_printf(s, "%8lld [%03d] error ", pid, cpu); |
| 409 | |
| 410 | if (config_has_id) |
| 411 | trace_seq_printf(s, "%8llu ", id); |
| 412 | |
| 413 | state = tep_get_field_raw(s, trace_event, "state", record, &val, 0); |
| 414 | event = tep_get_field_raw(s, trace_event, "event", record, &val, 0); |
| 415 | |
| 416 | trace_seq_printf(s, "%24s x %s\n", state, event); |
| 417 | |
| 418 | trace_seq_do_printf(s); |
| 419 | trace_seq_reset(s); |
| 420 | |
| 421 | return 0; |
| 422 | } |
| 423 | |
| 424 | /* |
| 425 | * ikm_setup_trace_instance - set up a tracing instance to collect data |
| 426 | * |
| 427 | * Create a trace instance, enable rv: events and enable the trace. |
| 428 | * |
| 429 | * Returns the trace_instance * with all set, NULL otherwise. |
| 430 | */ |
| 431 | static struct trace_instance *ikm_setup_trace_instance(char *monitor_name) |
| 432 | { |
| 433 | char event[MAX_DA_NAME_LEN + 7]; /* max(error_,event_) + '0' = 7 */ |
| 434 | struct trace_instance *inst; |
| 435 | int retval; |
| 436 | |
| 437 | if (!config_trace) |
| 438 | return NULL; |
| 439 | |
| 440 | config_has_id = ikm_has_id(monitor_name); |
| 441 | if (config_has_id < 0) { |
| 442 | err_msg("ikm: failed to read monitor %s event format\n", monitor_name); |
| 443 | goto out_err; |
| 444 | } |
| 445 | |
| 446 | /* alloc data */ |
| 447 | inst = calloc(1, sizeof(*inst)); |
| 448 | if (!inst) { |
| 449 | err_msg("ikm: failed to allocate trace instance"); |
| 450 | goto out_err; |
| 451 | } |
| 452 | |
| 453 | retval = trace_instance_init(inst, monitor_name); |
| 454 | if (retval) |
| 455 | goto out_free; |
| 456 | |
| 457 | /* enable events */ |
| 458 | snprintf(event, sizeof(event), "event_%s", monitor_name); |
| 459 | retval = tracefs_event_enable(inst->inst, "rv", event); |
| 460 | if (retval) |
| 461 | goto out_inst; |
| 462 | |
| 463 | tep_register_event_handler(inst->tep, -1, "rv", event, |
| 464 | ikm_event_handler, NULL); |
| 465 | |
| 466 | snprintf(event, sizeof(event), "error_%s", monitor_name); |
| 467 | retval = tracefs_event_enable(inst->inst, "rv", event); |
| 468 | if (retval) |
| 469 | goto out_inst; |
| 470 | |
| 471 | tep_register_event_handler(inst->tep, -1, "rv", event, |
| 472 | ikm_error_handler, NULL); |
| 473 | |
| 474 | /* ready to enable */ |
| 475 | tracefs_trace_on(inst->inst); |
| 476 | |
| 477 | return inst; |
| 478 | |
| 479 | out_inst: |
| 480 | trace_instance_destroy(inst); |
| 481 | out_free: |
| 482 | free(inst); |
| 483 | out_err: |
| 484 | return NULL; |
| 485 | } |
| 486 | |
| 487 | /** |
| 488 | * ikm_destroy_trace_instance - destroy a previously created instance |
| 489 | */ |
| 490 | static void ikm_destroy_trace_instance(struct trace_instance *inst) |
| 491 | { |
| 492 | if (!inst) |
| 493 | return; |
| 494 | |
| 495 | trace_instance_destroy(inst); |
| 496 | free(inst); |
| 497 | } |
| 498 | |
| 499 | /* |
| 500 | * ikm_usage_print_reactors - print all available reactors, one per line. |
| 501 | */ |
| 502 | static void ikm_usage_print_reactors(void) |
| 503 | { |
| 504 | char *reactors = tracefs_instance_file_read(NULL, "rv/available_reactors", NULL); |
| 505 | char *start, *end; |
| 506 | |
| 507 | if (!reactors) |
| 508 | return; |
| 509 | |
| 510 | fprintf(stderr, " available reactors:"); |
| 511 | |
| 512 | start = reactors; |
| 513 | end = strstr(start, "\n"); |
| 514 | |
| 515 | while (end) { |
| 516 | *end = '\0'; |
| 517 | |
| 518 | fprintf(stderr, " %s", start); |
| 519 | |
| 520 | start = ++end; |
| 521 | end = strstr(start, "\n"); |
| 522 | } |
| 523 | |
| 524 | fprintf(stderr, "\n"); |
| 525 | } |
| 526 | /* |
| 527 | * ikm_usage - print usage |
| 528 | */ |
| 529 | static void ikm_usage(int exit_val, char *monitor_name, const char *fmt, ...) |
| 530 | { |
| 531 | |
| 532 | char message[1024]; |
| 533 | va_list ap; |
| 534 | int i; |
| 535 | |
| 536 | static const char *const usage[] = { |
| 537 | "", |
| 538 | " -h/--help: print this menu and the reactor list", |
| 539 | " -r/--reactor 'reactor': enables the 'reactor'", |
| 540 | " -s/--self: when tracing (-t), also trace rv command", |
| 541 | " -t/--trace: trace monitor's event", |
| 542 | " -v/--verbose: print debug messages", |
| 543 | "", |
| 544 | NULL, |
| 545 | }; |
| 546 | |
| 547 | va_start(ap, fmt); |
| 548 | vsnprintf(message, sizeof(message), fmt, ap); |
| 549 | va_end(ap); |
| 550 | |
| 551 | fprintf(stderr, " %s\n", message); |
| 552 | |
| 553 | fprintf(stderr, "\n usage: rv mon %s [-h] [-q] [-r reactor] [-s] [-v]", monitor_name); |
| 554 | |
| 555 | for (i = 0; usage[i]; i++) |
| 556 | fprintf(stderr, "%s\n", usage[i]); |
| 557 | |
| 558 | ikm_usage_print_reactors(); |
| 559 | exit(exit_val); |
| 560 | } |
| 561 | |
| 562 | /* |
| 563 | * parse_arguments - parse arguments and set config |
| 564 | */ |
| 565 | static int parse_arguments(char *monitor_name, int argc, char **argv) |
| 566 | { |
| 567 | int c, retval; |
| 568 | |
| 569 | config_my_pid = getpid(); |
| 570 | |
| 571 | while (1) { |
| 572 | static struct option long_options[] = { |
| 573 | {"help", no_argument, 0, 'h'}, |
| 574 | {"reactor", required_argument, 0, 'r'}, |
| 575 | {"self", no_argument, 0, 's'}, |
| 576 | {"trace", no_argument, 0, 't'}, |
| 577 | {"verbose", no_argument, 0, 'v'}, |
| 578 | {0, 0, 0, 0} |
| 579 | }; |
| 580 | |
| 581 | /* getopt_long stores the option index here. */ |
| 582 | int option_index = 0; |
| 583 | |
| 584 | c = getopt_long(argc, argv, "hr:stv", long_options, &option_index); |
| 585 | |
| 586 | /* detect the end of the options. */ |
| 587 | if (c == -1) |
| 588 | break; |
| 589 | |
| 590 | switch (c) { |
| 591 | case 'h': |
| 592 | ikm_usage(0, monitor_name, "help:"); |
| 593 | break; |
| 594 | case 'r': |
| 595 | config_reactor = optarg; |
| 596 | break; |
| 597 | case 's': |
| 598 | config_my_pid = 0; |
| 599 | break; |
| 600 | case 't': |
| 601 | config_trace = 1; |
| 602 | break; |
| 603 | case 'v': |
| 604 | config_debug = 1; |
| 605 | break; |
| 606 | } |
| 607 | } |
| 608 | |
| 609 | if (config_reactor) { |
| 610 | config_initial_reactor = ikm_get_current_reactor(monitor_name); |
| 611 | if (!config_initial_reactor) |
| 612 | ikm_usage(1, monitor_name, |
| 613 | "ikm: failed to read current reactor, are reactors enabled?"); |
| 614 | |
| 615 | retval = ikm_write_reactor(monitor_name, config_reactor); |
| 616 | if (retval <= 0) |
| 617 | ikm_usage(1, monitor_name, |
| 618 | "ikm: failed to set %s reactor, is it available?", |
| 619 | config_reactor); |
| 620 | } |
| 621 | |
| 622 | debug_msg("ikm: my pid is %d\n", config_my_pid); |
| 623 | |
| 624 | return 0; |
| 625 | } |
| 626 | |
| 627 | /** |
| 628 | * ikm_run_monitor - apply configs and run the monitor |
| 629 | * |
| 630 | * Returns 1 if a monitor was found an executed, 0 if no |
| 631 | * monitors were found, or -1 on error. |
| 632 | */ |
| 633 | int ikm_run_monitor(char *monitor_name, int argc, char **argv) |
| 634 | { |
| 635 | struct trace_instance *inst = NULL; |
| 636 | int retval; |
| 637 | |
| 638 | /* |
| 639 | * Check if monitor exists by seeing it is enabled. |
| 640 | */ |
| 641 | retval = __ikm_read_enable(monitor_name); |
| 642 | if (retval < 0) |
| 643 | return 0; |
| 644 | |
| 645 | if (retval) { |
| 646 | err_msg("ikm: monitor %s (in-kernel) is already enabled\n", monitor_name); |
| 647 | return -1; |
| 648 | } |
| 649 | |
| 650 | /* we should be good to go */ |
| 651 | retval = parse_arguments(monitor_name, argc, argv); |
| 652 | if (retval) |
| 653 | ikm_usage(1, monitor_name, "ikm: failed parsing arguments"); |
| 654 | |
| 655 | if (config_trace) { |
| 656 | inst = ikm_setup_trace_instance(monitor_name); |
| 657 | if (!inst) |
| 658 | return -1; |
| 659 | } |
| 660 | |
| 661 | retval = ikm_enable(monitor_name); |
| 662 | if (retval < 0) |
| 663 | goto out_free_instance; |
| 664 | |
| 665 | if (config_trace) |
| 666 | ikm_print_header(inst->seq); |
| 667 | |
| 668 | while (!should_stop()) { |
| 669 | if (config_trace) { |
| 670 | retval = tracefs_iterate_raw_events(inst->tep, |
| 671 | inst->inst, |
| 672 | NULL, |
| 673 | 0, |
| 674 | collect_registered_events, |
| 675 | inst); |
| 676 | if (retval) { |
| 677 | err_msg("ikm: error reading trace buffer\n"); |
| 678 | break; |
| 679 | } |
| 680 | } |
| 681 | |
| 682 | sleep(1); |
| 683 | } |
| 684 | |
| 685 | ikm_disable(monitor_name); |
| 686 | ikm_destroy_trace_instance(inst); |
| 687 | |
| 688 | if (config_reactor && config_initial_reactor) |
| 689 | ikm_write_reactor(monitor_name, config_initial_reactor); |
| 690 | |
| 691 | return 1; |
| 692 | |
| 693 | out_free_instance: |
| 694 | ikm_destroy_trace_instance(inst); |
| 695 | if (config_reactor && config_initial_reactor) |
| 696 | ikm_write_reactor(monitor_name, config_initial_reactor); |
| 697 | return -1; |
| 698 | } |