| 1 | /* |
| 2 | * event tracer |
| 3 | * |
| 4 | * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> |
| 5 | * |
| 6 | * - Added format output of fields of the trace point. |
| 7 | * This was based off of work by Tom Zanussi <tzanussi@gmail.com>. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/workqueue.h> |
| 12 | #include <linux/spinlock.h> |
| 13 | #include <linux/kthread.h> |
| 14 | #include <linux/debugfs.h> |
| 15 | #include <linux/uaccess.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/ctype.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/delay.h> |
| 20 | |
| 21 | #include <asm/setup.h> |
| 22 | |
| 23 | #include "trace_output.h" |
| 24 | |
| 25 | #undef TRACE_SYSTEM |
| 26 | #define TRACE_SYSTEM "TRACE_SYSTEM" |
| 27 | |
| 28 | DEFINE_MUTEX(event_mutex); |
| 29 | |
| 30 | LIST_HEAD(ftrace_events); |
| 31 | |
| 32 | struct list_head * |
| 33 | trace_get_fields(struct ftrace_event_call *event_call) |
| 34 | { |
| 35 | if (!event_call->class->get_fields) |
| 36 | return &event_call->class->fields; |
| 37 | return event_call->class->get_fields(event_call); |
| 38 | } |
| 39 | |
| 40 | int trace_define_field(struct ftrace_event_call *call, const char *type, |
| 41 | const char *name, int offset, int size, int is_signed, |
| 42 | int filter_type) |
| 43 | { |
| 44 | struct ftrace_event_field *field; |
| 45 | struct list_head *head; |
| 46 | |
| 47 | if (WARN_ON(!call->class)) |
| 48 | return 0; |
| 49 | |
| 50 | field = kzalloc(sizeof(*field), GFP_KERNEL); |
| 51 | if (!field) |
| 52 | goto err; |
| 53 | |
| 54 | field->name = kstrdup(name, GFP_KERNEL); |
| 55 | if (!field->name) |
| 56 | goto err; |
| 57 | |
| 58 | field->type = kstrdup(type, GFP_KERNEL); |
| 59 | if (!field->type) |
| 60 | goto err; |
| 61 | |
| 62 | if (filter_type == FILTER_OTHER) |
| 63 | field->filter_type = filter_assign_type(type); |
| 64 | else |
| 65 | field->filter_type = filter_type; |
| 66 | |
| 67 | field->offset = offset; |
| 68 | field->size = size; |
| 69 | field->is_signed = is_signed; |
| 70 | |
| 71 | head = trace_get_fields(call); |
| 72 | list_add(&field->link, head); |
| 73 | |
| 74 | return 0; |
| 75 | |
| 76 | err: |
| 77 | if (field) |
| 78 | kfree(field->name); |
| 79 | kfree(field); |
| 80 | |
| 81 | return -ENOMEM; |
| 82 | } |
| 83 | EXPORT_SYMBOL_GPL(trace_define_field); |
| 84 | |
| 85 | #define __common_field(type, item) \ |
| 86 | ret = trace_define_field(call, #type, "common_" #item, \ |
| 87 | offsetof(typeof(ent), item), \ |
| 88 | sizeof(ent.item), \ |
| 89 | is_signed_type(type), FILTER_OTHER); \ |
| 90 | if (ret) \ |
| 91 | return ret; |
| 92 | |
| 93 | static int trace_define_common_fields(struct ftrace_event_call *call) |
| 94 | { |
| 95 | int ret; |
| 96 | struct trace_entry ent; |
| 97 | |
| 98 | __common_field(unsigned short, type); |
| 99 | __common_field(unsigned char, flags); |
| 100 | __common_field(unsigned char, preempt_count); |
| 101 | __common_field(int, pid); |
| 102 | __common_field(int, lock_depth); |
| 103 | |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | void trace_destroy_fields(struct ftrace_event_call *call) |
| 108 | { |
| 109 | struct ftrace_event_field *field, *next; |
| 110 | struct list_head *head; |
| 111 | |
| 112 | head = trace_get_fields(call); |
| 113 | list_for_each_entry_safe(field, next, head, link) { |
| 114 | list_del(&field->link); |
| 115 | kfree(field->type); |
| 116 | kfree(field->name); |
| 117 | kfree(field); |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | int trace_event_raw_init(struct ftrace_event_call *call) |
| 122 | { |
| 123 | int id; |
| 124 | |
| 125 | id = register_ftrace_event(&call->event); |
| 126 | if (!id) |
| 127 | return -ENODEV; |
| 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | EXPORT_SYMBOL_GPL(trace_event_raw_init); |
| 132 | |
| 133 | static int ftrace_event_enable_disable(struct ftrace_event_call *call, |
| 134 | int enable) |
| 135 | { |
| 136 | int ret = 0; |
| 137 | |
| 138 | switch (enable) { |
| 139 | case 0: |
| 140 | if (call->flags & TRACE_EVENT_FL_ENABLED) { |
| 141 | call->flags &= ~TRACE_EVENT_FL_ENABLED; |
| 142 | tracing_stop_cmdline_record(); |
| 143 | if (call->class->reg) |
| 144 | call->class->reg(call, TRACE_REG_UNREGISTER); |
| 145 | else |
| 146 | tracepoint_probe_unregister(call->name, |
| 147 | call->class->probe, |
| 148 | call); |
| 149 | } |
| 150 | break; |
| 151 | case 1: |
| 152 | if (!(call->flags & TRACE_EVENT_FL_ENABLED)) { |
| 153 | tracing_start_cmdline_record(); |
| 154 | if (call->class->reg) |
| 155 | ret = call->class->reg(call, TRACE_REG_REGISTER); |
| 156 | else |
| 157 | ret = tracepoint_probe_register(call->name, |
| 158 | call->class->probe, |
| 159 | call); |
| 160 | if (ret) { |
| 161 | tracing_stop_cmdline_record(); |
| 162 | pr_info("event trace: Could not enable event " |
| 163 | "%s\n", call->name); |
| 164 | break; |
| 165 | } |
| 166 | call->flags |= TRACE_EVENT_FL_ENABLED; |
| 167 | } |
| 168 | break; |
| 169 | } |
| 170 | |
| 171 | return ret; |
| 172 | } |
| 173 | |
| 174 | static void ftrace_clear_events(void) |
| 175 | { |
| 176 | struct ftrace_event_call *call; |
| 177 | |
| 178 | mutex_lock(&event_mutex); |
| 179 | list_for_each_entry(call, &ftrace_events, list) { |
| 180 | ftrace_event_enable_disable(call, 0); |
| 181 | } |
| 182 | mutex_unlock(&event_mutex); |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. |
| 187 | */ |
| 188 | static int __ftrace_set_clr_event(const char *match, const char *sub, |
| 189 | const char *event, int set) |
| 190 | { |
| 191 | struct ftrace_event_call *call; |
| 192 | int ret = -EINVAL; |
| 193 | |
| 194 | mutex_lock(&event_mutex); |
| 195 | list_for_each_entry(call, &ftrace_events, list) { |
| 196 | |
| 197 | if (!call->name || !call->class || |
| 198 | (!call->class->probe && !call->class->reg)) |
| 199 | continue; |
| 200 | |
| 201 | if (match && |
| 202 | strcmp(match, call->name) != 0 && |
| 203 | strcmp(match, call->class->system) != 0) |
| 204 | continue; |
| 205 | |
| 206 | if (sub && strcmp(sub, call->class->system) != 0) |
| 207 | continue; |
| 208 | |
| 209 | if (event && strcmp(event, call->name) != 0) |
| 210 | continue; |
| 211 | |
| 212 | ftrace_event_enable_disable(call, set); |
| 213 | |
| 214 | ret = 0; |
| 215 | } |
| 216 | mutex_unlock(&event_mutex); |
| 217 | |
| 218 | return ret; |
| 219 | } |
| 220 | |
| 221 | static int ftrace_set_clr_event(char *buf, int set) |
| 222 | { |
| 223 | char *event = NULL, *sub = NULL, *match; |
| 224 | |
| 225 | /* |
| 226 | * The buf format can be <subsystem>:<event-name> |
| 227 | * *:<event-name> means any event by that name. |
| 228 | * :<event-name> is the same. |
| 229 | * |
| 230 | * <subsystem>:* means all events in that subsystem |
| 231 | * <subsystem>: means the same. |
| 232 | * |
| 233 | * <name> (no ':') means all events in a subsystem with |
| 234 | * the name <name> or any event that matches <name> |
| 235 | */ |
| 236 | |
| 237 | match = strsep(&buf, ":"); |
| 238 | if (buf) { |
| 239 | sub = match; |
| 240 | event = buf; |
| 241 | match = NULL; |
| 242 | |
| 243 | if (!strlen(sub) || strcmp(sub, "*") == 0) |
| 244 | sub = NULL; |
| 245 | if (!strlen(event) || strcmp(event, "*") == 0) |
| 246 | event = NULL; |
| 247 | } |
| 248 | |
| 249 | return __ftrace_set_clr_event(match, sub, event, set); |
| 250 | } |
| 251 | |
| 252 | /** |
| 253 | * trace_set_clr_event - enable or disable an event |
| 254 | * @system: system name to match (NULL for any system) |
| 255 | * @event: event name to match (NULL for all events, within system) |
| 256 | * @set: 1 to enable, 0 to disable |
| 257 | * |
| 258 | * This is a way for other parts of the kernel to enable or disable |
| 259 | * event recording. |
| 260 | * |
| 261 | * Returns 0 on success, -EINVAL if the parameters do not match any |
| 262 | * registered events. |
| 263 | */ |
| 264 | int trace_set_clr_event(const char *system, const char *event, int set) |
| 265 | { |
| 266 | return __ftrace_set_clr_event(NULL, system, event, set); |
| 267 | } |
| 268 | |
| 269 | /* 128 should be much more than enough */ |
| 270 | #define EVENT_BUF_SIZE 127 |
| 271 | |
| 272 | static ssize_t |
| 273 | ftrace_event_write(struct file *file, const char __user *ubuf, |
| 274 | size_t cnt, loff_t *ppos) |
| 275 | { |
| 276 | struct trace_parser parser; |
| 277 | ssize_t read, ret; |
| 278 | |
| 279 | if (!cnt) |
| 280 | return 0; |
| 281 | |
| 282 | ret = tracing_update_buffers(); |
| 283 | if (ret < 0) |
| 284 | return ret; |
| 285 | |
| 286 | if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) |
| 287 | return -ENOMEM; |
| 288 | |
| 289 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
| 290 | |
| 291 | if (read >= 0 && trace_parser_loaded((&parser))) { |
| 292 | int set = 1; |
| 293 | |
| 294 | if (*parser.buffer == '!') |
| 295 | set = 0; |
| 296 | |
| 297 | parser.buffer[parser.idx] = 0; |
| 298 | |
| 299 | ret = ftrace_set_clr_event(parser.buffer + !set, set); |
| 300 | if (ret) |
| 301 | goto out_put; |
| 302 | } |
| 303 | |
| 304 | ret = read; |
| 305 | |
| 306 | out_put: |
| 307 | trace_parser_put(&parser); |
| 308 | |
| 309 | return ret; |
| 310 | } |
| 311 | |
| 312 | static void * |
| 313 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 314 | { |
| 315 | struct ftrace_event_call *call = v; |
| 316 | |
| 317 | (*pos)++; |
| 318 | |
| 319 | list_for_each_entry_continue(call, &ftrace_events, list) { |
| 320 | /* |
| 321 | * The ftrace subsystem is for showing formats only. |
| 322 | * They can not be enabled or disabled via the event files. |
| 323 | */ |
| 324 | if (call->class && (call->class->probe || call->class->reg)) |
| 325 | return call; |
| 326 | } |
| 327 | |
| 328 | return NULL; |
| 329 | } |
| 330 | |
| 331 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 332 | { |
| 333 | struct ftrace_event_call *call; |
| 334 | loff_t l; |
| 335 | |
| 336 | mutex_lock(&event_mutex); |
| 337 | |
| 338 | call = list_entry(&ftrace_events, struct ftrace_event_call, list); |
| 339 | for (l = 0; l <= *pos; ) { |
| 340 | call = t_next(m, call, &l); |
| 341 | if (!call) |
| 342 | break; |
| 343 | } |
| 344 | return call; |
| 345 | } |
| 346 | |
| 347 | static void * |
| 348 | s_next(struct seq_file *m, void *v, loff_t *pos) |
| 349 | { |
| 350 | struct ftrace_event_call *call = v; |
| 351 | |
| 352 | (*pos)++; |
| 353 | |
| 354 | list_for_each_entry_continue(call, &ftrace_events, list) { |
| 355 | if (call->flags & TRACE_EVENT_FL_ENABLED) |
| 356 | return call; |
| 357 | } |
| 358 | |
| 359 | return NULL; |
| 360 | } |
| 361 | |
| 362 | static void *s_start(struct seq_file *m, loff_t *pos) |
| 363 | { |
| 364 | struct ftrace_event_call *call; |
| 365 | loff_t l; |
| 366 | |
| 367 | mutex_lock(&event_mutex); |
| 368 | |
| 369 | call = list_entry(&ftrace_events, struct ftrace_event_call, list); |
| 370 | for (l = 0; l <= *pos; ) { |
| 371 | call = s_next(m, call, &l); |
| 372 | if (!call) |
| 373 | break; |
| 374 | } |
| 375 | return call; |
| 376 | } |
| 377 | |
| 378 | static int t_show(struct seq_file *m, void *v) |
| 379 | { |
| 380 | struct ftrace_event_call *call = v; |
| 381 | |
| 382 | if (strcmp(call->class->system, TRACE_SYSTEM) != 0) |
| 383 | seq_printf(m, "%s:", call->class->system); |
| 384 | seq_printf(m, "%s\n", call->name); |
| 385 | |
| 386 | return 0; |
| 387 | } |
| 388 | |
| 389 | static void t_stop(struct seq_file *m, void *p) |
| 390 | { |
| 391 | mutex_unlock(&event_mutex); |
| 392 | } |
| 393 | |
| 394 | static int |
| 395 | ftrace_event_seq_open(struct inode *inode, struct file *file) |
| 396 | { |
| 397 | const struct seq_operations *seq_ops; |
| 398 | |
| 399 | if ((file->f_mode & FMODE_WRITE) && |
| 400 | (file->f_flags & O_TRUNC)) |
| 401 | ftrace_clear_events(); |
| 402 | |
| 403 | seq_ops = inode->i_private; |
| 404 | return seq_open(file, seq_ops); |
| 405 | } |
| 406 | |
| 407 | static ssize_t |
| 408 | event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, |
| 409 | loff_t *ppos) |
| 410 | { |
| 411 | struct ftrace_event_call *call = filp->private_data; |
| 412 | char *buf; |
| 413 | |
| 414 | if (call->flags & TRACE_EVENT_FL_ENABLED) |
| 415 | buf = "1\n"; |
| 416 | else |
| 417 | buf = "0\n"; |
| 418 | |
| 419 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); |
| 420 | } |
| 421 | |
| 422 | static ssize_t |
| 423 | event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, |
| 424 | loff_t *ppos) |
| 425 | { |
| 426 | struct ftrace_event_call *call = filp->private_data; |
| 427 | char buf[64]; |
| 428 | unsigned long val; |
| 429 | int ret; |
| 430 | |
| 431 | if (cnt >= sizeof(buf)) |
| 432 | return -EINVAL; |
| 433 | |
| 434 | if (copy_from_user(&buf, ubuf, cnt)) |
| 435 | return -EFAULT; |
| 436 | |
| 437 | buf[cnt] = 0; |
| 438 | |
| 439 | ret = strict_strtoul(buf, 10, &val); |
| 440 | if (ret < 0) |
| 441 | return ret; |
| 442 | |
| 443 | ret = tracing_update_buffers(); |
| 444 | if (ret < 0) |
| 445 | return ret; |
| 446 | |
| 447 | switch (val) { |
| 448 | case 0: |
| 449 | case 1: |
| 450 | mutex_lock(&event_mutex); |
| 451 | ret = ftrace_event_enable_disable(call, val); |
| 452 | mutex_unlock(&event_mutex); |
| 453 | break; |
| 454 | |
| 455 | default: |
| 456 | return -EINVAL; |
| 457 | } |
| 458 | |
| 459 | *ppos += cnt; |
| 460 | |
| 461 | return ret ? ret : cnt; |
| 462 | } |
| 463 | |
| 464 | static ssize_t |
| 465 | system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, |
| 466 | loff_t *ppos) |
| 467 | { |
| 468 | const char set_to_char[4] = { '?', '0', '1', 'X' }; |
| 469 | const char *system = filp->private_data; |
| 470 | struct ftrace_event_call *call; |
| 471 | char buf[2]; |
| 472 | int set = 0; |
| 473 | int ret; |
| 474 | |
| 475 | mutex_lock(&event_mutex); |
| 476 | list_for_each_entry(call, &ftrace_events, list) { |
| 477 | if (!call->name || !call->class || |
| 478 | (!call->class->probe && !call->class->reg)) |
| 479 | continue; |
| 480 | |
| 481 | if (system && strcmp(call->class->system, system) != 0) |
| 482 | continue; |
| 483 | |
| 484 | /* |
| 485 | * We need to find out if all the events are set |
| 486 | * or if all events or cleared, or if we have |
| 487 | * a mixture. |
| 488 | */ |
| 489 | set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED)); |
| 490 | |
| 491 | /* |
| 492 | * If we have a mixture, no need to look further. |
| 493 | */ |
| 494 | if (set == 3) |
| 495 | break; |
| 496 | } |
| 497 | mutex_unlock(&event_mutex); |
| 498 | |
| 499 | buf[0] = set_to_char[set]; |
| 500 | buf[1] = '\n'; |
| 501 | |
| 502 | ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); |
| 503 | |
| 504 | return ret; |
| 505 | } |
| 506 | |
| 507 | static ssize_t |
| 508 | system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, |
| 509 | loff_t *ppos) |
| 510 | { |
| 511 | const char *system = filp->private_data; |
| 512 | unsigned long val; |
| 513 | char buf[64]; |
| 514 | ssize_t ret; |
| 515 | |
| 516 | if (cnt >= sizeof(buf)) |
| 517 | return -EINVAL; |
| 518 | |
| 519 | if (copy_from_user(&buf, ubuf, cnt)) |
| 520 | return -EFAULT; |
| 521 | |
| 522 | buf[cnt] = 0; |
| 523 | |
| 524 | ret = strict_strtoul(buf, 10, &val); |
| 525 | if (ret < 0) |
| 526 | return ret; |
| 527 | |
| 528 | ret = tracing_update_buffers(); |
| 529 | if (ret < 0) |
| 530 | return ret; |
| 531 | |
| 532 | if (val != 0 && val != 1) |
| 533 | return -EINVAL; |
| 534 | |
| 535 | ret = __ftrace_set_clr_event(NULL, system, NULL, val); |
| 536 | if (ret) |
| 537 | goto out; |
| 538 | |
| 539 | ret = cnt; |
| 540 | |
| 541 | out: |
| 542 | *ppos += cnt; |
| 543 | |
| 544 | return ret; |
| 545 | } |
| 546 | |
| 547 | static ssize_t |
| 548 | event_format_read(struct file *filp, char __user *ubuf, size_t cnt, |
| 549 | loff_t *ppos) |
| 550 | { |
| 551 | struct ftrace_event_call *call = filp->private_data; |
| 552 | struct ftrace_event_field *field; |
| 553 | struct list_head *head; |
| 554 | struct trace_seq *s; |
| 555 | int common_field_count = 5; |
| 556 | char *buf; |
| 557 | int r = 0; |
| 558 | |
| 559 | if (*ppos) |
| 560 | return 0; |
| 561 | |
| 562 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 563 | if (!s) |
| 564 | return -ENOMEM; |
| 565 | |
| 566 | trace_seq_init(s); |
| 567 | |
| 568 | trace_seq_printf(s, "name: %s\n", call->name); |
| 569 | trace_seq_printf(s, "ID: %d\n", call->event.type); |
| 570 | trace_seq_printf(s, "format:\n"); |
| 571 | |
| 572 | head = trace_get_fields(call); |
| 573 | list_for_each_entry_reverse(field, head, link) { |
| 574 | /* |
| 575 | * Smartly shows the array type(except dynamic array). |
| 576 | * Normal: |
| 577 | * field:TYPE VAR |
| 578 | * If TYPE := TYPE[LEN], it is shown: |
| 579 | * field:TYPE VAR[LEN] |
| 580 | */ |
| 581 | const char *array_descriptor = strchr(field->type, '['); |
| 582 | |
| 583 | if (!strncmp(field->type, "__data_loc", 10)) |
| 584 | array_descriptor = NULL; |
| 585 | |
| 586 | if (!array_descriptor) { |
| 587 | r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;" |
| 588 | "\tsize:%u;\tsigned:%d;\n", |
| 589 | field->type, field->name, field->offset, |
| 590 | field->size, !!field->is_signed); |
| 591 | } else { |
| 592 | r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;" |
| 593 | "\tsize:%u;\tsigned:%d;\n", |
| 594 | (int)(array_descriptor - field->type), |
| 595 | field->type, field->name, |
| 596 | array_descriptor, field->offset, |
| 597 | field->size, !!field->is_signed); |
| 598 | } |
| 599 | |
| 600 | if (--common_field_count == 0) |
| 601 | r = trace_seq_printf(s, "\n"); |
| 602 | |
| 603 | if (!r) |
| 604 | break; |
| 605 | } |
| 606 | |
| 607 | if (r) |
| 608 | r = trace_seq_printf(s, "\nprint fmt: %s\n", |
| 609 | call->print_fmt); |
| 610 | |
| 611 | if (!r) { |
| 612 | /* |
| 613 | * ug! The format output is bigger than a PAGE!! |
| 614 | */ |
| 615 | buf = "FORMAT TOO BIG\n"; |
| 616 | r = simple_read_from_buffer(ubuf, cnt, ppos, |
| 617 | buf, strlen(buf)); |
| 618 | goto out; |
| 619 | } |
| 620 | |
| 621 | r = simple_read_from_buffer(ubuf, cnt, ppos, |
| 622 | s->buffer, s->len); |
| 623 | out: |
| 624 | kfree(s); |
| 625 | return r; |
| 626 | } |
| 627 | |
| 628 | static ssize_t |
| 629 | event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) |
| 630 | { |
| 631 | struct ftrace_event_call *call = filp->private_data; |
| 632 | struct trace_seq *s; |
| 633 | int r; |
| 634 | |
| 635 | if (*ppos) |
| 636 | return 0; |
| 637 | |
| 638 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 639 | if (!s) |
| 640 | return -ENOMEM; |
| 641 | |
| 642 | trace_seq_init(s); |
| 643 | trace_seq_printf(s, "%d\n", call->event.type); |
| 644 | |
| 645 | r = simple_read_from_buffer(ubuf, cnt, ppos, |
| 646 | s->buffer, s->len); |
| 647 | kfree(s); |
| 648 | return r; |
| 649 | } |
| 650 | |
| 651 | static ssize_t |
| 652 | event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, |
| 653 | loff_t *ppos) |
| 654 | { |
| 655 | struct ftrace_event_call *call = filp->private_data; |
| 656 | struct trace_seq *s; |
| 657 | int r; |
| 658 | |
| 659 | if (*ppos) |
| 660 | return 0; |
| 661 | |
| 662 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 663 | if (!s) |
| 664 | return -ENOMEM; |
| 665 | |
| 666 | trace_seq_init(s); |
| 667 | |
| 668 | print_event_filter(call, s); |
| 669 | r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); |
| 670 | |
| 671 | kfree(s); |
| 672 | |
| 673 | return r; |
| 674 | } |
| 675 | |
| 676 | static ssize_t |
| 677 | event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, |
| 678 | loff_t *ppos) |
| 679 | { |
| 680 | struct ftrace_event_call *call = filp->private_data; |
| 681 | char *buf; |
| 682 | int err; |
| 683 | |
| 684 | if (cnt >= PAGE_SIZE) |
| 685 | return -EINVAL; |
| 686 | |
| 687 | buf = (char *)__get_free_page(GFP_TEMPORARY); |
| 688 | if (!buf) |
| 689 | return -ENOMEM; |
| 690 | |
| 691 | if (copy_from_user(buf, ubuf, cnt)) { |
| 692 | free_page((unsigned long) buf); |
| 693 | return -EFAULT; |
| 694 | } |
| 695 | buf[cnt] = '\0'; |
| 696 | |
| 697 | err = apply_event_filter(call, buf); |
| 698 | free_page((unsigned long) buf); |
| 699 | if (err < 0) |
| 700 | return err; |
| 701 | |
| 702 | *ppos += cnt; |
| 703 | |
| 704 | return cnt; |
| 705 | } |
| 706 | |
| 707 | static ssize_t |
| 708 | subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, |
| 709 | loff_t *ppos) |
| 710 | { |
| 711 | struct event_subsystem *system = filp->private_data; |
| 712 | struct trace_seq *s; |
| 713 | int r; |
| 714 | |
| 715 | if (*ppos) |
| 716 | return 0; |
| 717 | |
| 718 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 719 | if (!s) |
| 720 | return -ENOMEM; |
| 721 | |
| 722 | trace_seq_init(s); |
| 723 | |
| 724 | print_subsystem_event_filter(system, s); |
| 725 | r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); |
| 726 | |
| 727 | kfree(s); |
| 728 | |
| 729 | return r; |
| 730 | } |
| 731 | |
| 732 | static ssize_t |
| 733 | subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, |
| 734 | loff_t *ppos) |
| 735 | { |
| 736 | struct event_subsystem *system = filp->private_data; |
| 737 | char *buf; |
| 738 | int err; |
| 739 | |
| 740 | if (cnt >= PAGE_SIZE) |
| 741 | return -EINVAL; |
| 742 | |
| 743 | buf = (char *)__get_free_page(GFP_TEMPORARY); |
| 744 | if (!buf) |
| 745 | return -ENOMEM; |
| 746 | |
| 747 | if (copy_from_user(buf, ubuf, cnt)) { |
| 748 | free_page((unsigned long) buf); |
| 749 | return -EFAULT; |
| 750 | } |
| 751 | buf[cnt] = '\0'; |
| 752 | |
| 753 | err = apply_subsystem_event_filter(system, buf); |
| 754 | free_page((unsigned long) buf); |
| 755 | if (err < 0) |
| 756 | return err; |
| 757 | |
| 758 | *ppos += cnt; |
| 759 | |
| 760 | return cnt; |
| 761 | } |
| 762 | |
| 763 | static ssize_t |
| 764 | show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) |
| 765 | { |
| 766 | int (*func)(struct trace_seq *s) = filp->private_data; |
| 767 | struct trace_seq *s; |
| 768 | int r; |
| 769 | |
| 770 | if (*ppos) |
| 771 | return 0; |
| 772 | |
| 773 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 774 | if (!s) |
| 775 | return -ENOMEM; |
| 776 | |
| 777 | trace_seq_init(s); |
| 778 | |
| 779 | func(s); |
| 780 | r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); |
| 781 | |
| 782 | kfree(s); |
| 783 | |
| 784 | return r; |
| 785 | } |
| 786 | |
| 787 | static const struct seq_operations show_event_seq_ops = { |
| 788 | .start = t_start, |
| 789 | .next = t_next, |
| 790 | .show = t_show, |
| 791 | .stop = t_stop, |
| 792 | }; |
| 793 | |
| 794 | static const struct seq_operations show_set_event_seq_ops = { |
| 795 | .start = s_start, |
| 796 | .next = s_next, |
| 797 | .show = t_show, |
| 798 | .stop = t_stop, |
| 799 | }; |
| 800 | |
| 801 | static const struct file_operations ftrace_avail_fops = { |
| 802 | .open = ftrace_event_seq_open, |
| 803 | .read = seq_read, |
| 804 | .llseek = seq_lseek, |
| 805 | .release = seq_release, |
| 806 | }; |
| 807 | |
| 808 | static const struct file_operations ftrace_set_event_fops = { |
| 809 | .open = ftrace_event_seq_open, |
| 810 | .read = seq_read, |
| 811 | .write = ftrace_event_write, |
| 812 | .llseek = seq_lseek, |
| 813 | .release = seq_release, |
| 814 | }; |
| 815 | |
| 816 | static const struct file_operations ftrace_enable_fops = { |
| 817 | .open = tracing_open_generic, |
| 818 | .read = event_enable_read, |
| 819 | .write = event_enable_write, |
| 820 | }; |
| 821 | |
| 822 | static const struct file_operations ftrace_event_format_fops = { |
| 823 | .open = tracing_open_generic, |
| 824 | .read = event_format_read, |
| 825 | }; |
| 826 | |
| 827 | static const struct file_operations ftrace_event_id_fops = { |
| 828 | .open = tracing_open_generic, |
| 829 | .read = event_id_read, |
| 830 | }; |
| 831 | |
| 832 | static const struct file_operations ftrace_event_filter_fops = { |
| 833 | .open = tracing_open_generic, |
| 834 | .read = event_filter_read, |
| 835 | .write = event_filter_write, |
| 836 | }; |
| 837 | |
| 838 | static const struct file_operations ftrace_subsystem_filter_fops = { |
| 839 | .open = tracing_open_generic, |
| 840 | .read = subsystem_filter_read, |
| 841 | .write = subsystem_filter_write, |
| 842 | }; |
| 843 | |
| 844 | static const struct file_operations ftrace_system_enable_fops = { |
| 845 | .open = tracing_open_generic, |
| 846 | .read = system_enable_read, |
| 847 | .write = system_enable_write, |
| 848 | }; |
| 849 | |
| 850 | static const struct file_operations ftrace_show_header_fops = { |
| 851 | .open = tracing_open_generic, |
| 852 | .read = show_header, |
| 853 | }; |
| 854 | |
| 855 | static struct dentry *event_trace_events_dir(void) |
| 856 | { |
| 857 | static struct dentry *d_tracer; |
| 858 | static struct dentry *d_events; |
| 859 | |
| 860 | if (d_events) |
| 861 | return d_events; |
| 862 | |
| 863 | d_tracer = tracing_init_dentry(); |
| 864 | if (!d_tracer) |
| 865 | return NULL; |
| 866 | |
| 867 | d_events = debugfs_create_dir("events", d_tracer); |
| 868 | if (!d_events) |
| 869 | pr_warning("Could not create debugfs " |
| 870 | "'events' directory\n"); |
| 871 | |
| 872 | return d_events; |
| 873 | } |
| 874 | |
| 875 | static LIST_HEAD(event_subsystems); |
| 876 | |
| 877 | static struct dentry * |
| 878 | event_subsystem_dir(const char *name, struct dentry *d_events) |
| 879 | { |
| 880 | struct event_subsystem *system; |
| 881 | struct dentry *entry; |
| 882 | |
| 883 | /* First see if we did not already create this dir */ |
| 884 | list_for_each_entry(system, &event_subsystems, list) { |
| 885 | if (strcmp(system->name, name) == 0) { |
| 886 | system->nr_events++; |
| 887 | return system->entry; |
| 888 | } |
| 889 | } |
| 890 | |
| 891 | /* need to create new entry */ |
| 892 | system = kmalloc(sizeof(*system), GFP_KERNEL); |
| 893 | if (!system) { |
| 894 | pr_warning("No memory to create event subsystem %s\n", |
| 895 | name); |
| 896 | return d_events; |
| 897 | } |
| 898 | |
| 899 | system->entry = debugfs_create_dir(name, d_events); |
| 900 | if (!system->entry) { |
| 901 | pr_warning("Could not create event subsystem %s\n", |
| 902 | name); |
| 903 | kfree(system); |
| 904 | return d_events; |
| 905 | } |
| 906 | |
| 907 | system->nr_events = 1; |
| 908 | system->name = kstrdup(name, GFP_KERNEL); |
| 909 | if (!system->name) { |
| 910 | debugfs_remove(system->entry); |
| 911 | kfree(system); |
| 912 | return d_events; |
| 913 | } |
| 914 | |
| 915 | list_add(&system->list, &event_subsystems); |
| 916 | |
| 917 | system->filter = NULL; |
| 918 | |
| 919 | system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); |
| 920 | if (!system->filter) { |
| 921 | pr_warning("Could not allocate filter for subsystem " |
| 922 | "'%s'\n", name); |
| 923 | return system->entry; |
| 924 | } |
| 925 | |
| 926 | entry = debugfs_create_file("filter", 0644, system->entry, system, |
| 927 | &ftrace_subsystem_filter_fops); |
| 928 | if (!entry) { |
| 929 | kfree(system->filter); |
| 930 | system->filter = NULL; |
| 931 | pr_warning("Could not create debugfs " |
| 932 | "'%s/filter' entry\n", name); |
| 933 | } |
| 934 | |
| 935 | trace_create_file("enable", 0644, system->entry, |
| 936 | (void *)system->name, |
| 937 | &ftrace_system_enable_fops); |
| 938 | |
| 939 | return system->entry; |
| 940 | } |
| 941 | |
| 942 | static int |
| 943 | event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, |
| 944 | const struct file_operations *id, |
| 945 | const struct file_operations *enable, |
| 946 | const struct file_operations *filter, |
| 947 | const struct file_operations *format) |
| 948 | { |
| 949 | struct list_head *head; |
| 950 | int ret; |
| 951 | |
| 952 | /* |
| 953 | * If the trace point header did not define TRACE_SYSTEM |
| 954 | * then the system would be called "TRACE_SYSTEM". |
| 955 | */ |
| 956 | if (strcmp(call->class->system, TRACE_SYSTEM) != 0) |
| 957 | d_events = event_subsystem_dir(call->class->system, d_events); |
| 958 | |
| 959 | call->dir = debugfs_create_dir(call->name, d_events); |
| 960 | if (!call->dir) { |
| 961 | pr_warning("Could not create debugfs " |
| 962 | "'%s' directory\n", call->name); |
| 963 | return -1; |
| 964 | } |
| 965 | |
| 966 | if (call->class->probe || call->class->reg) |
| 967 | trace_create_file("enable", 0644, call->dir, call, |
| 968 | enable); |
| 969 | |
| 970 | #ifdef CONFIG_PERF_EVENTS |
| 971 | if (call->event.type && (call->class->perf_probe || call->class->reg)) |
| 972 | trace_create_file("id", 0444, call->dir, call, |
| 973 | id); |
| 974 | #endif |
| 975 | |
| 976 | if (call->class->define_fields) { |
| 977 | /* |
| 978 | * Other events may have the same class. Only update |
| 979 | * the fields if they are not already defined. |
| 980 | */ |
| 981 | head = trace_get_fields(call); |
| 982 | if (list_empty(head)) { |
| 983 | ret = trace_define_common_fields(call); |
| 984 | if (!ret) |
| 985 | ret = call->class->define_fields(call); |
| 986 | if (ret < 0) { |
| 987 | pr_warning("Could not initialize trace point" |
| 988 | " events/%s\n", call->name); |
| 989 | return ret; |
| 990 | } |
| 991 | } |
| 992 | trace_create_file("filter", 0644, call->dir, call, |
| 993 | filter); |
| 994 | } |
| 995 | |
| 996 | trace_create_file("format", 0444, call->dir, call, |
| 997 | format); |
| 998 | |
| 999 | return 0; |
| 1000 | } |
| 1001 | |
| 1002 | static int __trace_add_event_call(struct ftrace_event_call *call) |
| 1003 | { |
| 1004 | struct dentry *d_events; |
| 1005 | int ret; |
| 1006 | |
| 1007 | if (!call->name) |
| 1008 | return -EINVAL; |
| 1009 | |
| 1010 | if (call->class->raw_init) { |
| 1011 | ret = call->class->raw_init(call); |
| 1012 | if (ret < 0) { |
| 1013 | if (ret != -ENOSYS) |
| 1014 | pr_warning("Could not initialize trace " |
| 1015 | "events/%s\n", call->name); |
| 1016 | return ret; |
| 1017 | } |
| 1018 | } |
| 1019 | |
| 1020 | d_events = event_trace_events_dir(); |
| 1021 | if (!d_events) |
| 1022 | return -ENOENT; |
| 1023 | |
| 1024 | ret = event_create_dir(call, d_events, &ftrace_event_id_fops, |
| 1025 | &ftrace_enable_fops, &ftrace_event_filter_fops, |
| 1026 | &ftrace_event_format_fops); |
| 1027 | if (!ret) |
| 1028 | list_add(&call->list, &ftrace_events); |
| 1029 | |
| 1030 | return ret; |
| 1031 | } |
| 1032 | |
| 1033 | /* Add an additional event_call dynamically */ |
| 1034 | int trace_add_event_call(struct ftrace_event_call *call) |
| 1035 | { |
| 1036 | int ret; |
| 1037 | mutex_lock(&event_mutex); |
| 1038 | ret = __trace_add_event_call(call); |
| 1039 | mutex_unlock(&event_mutex); |
| 1040 | return ret; |
| 1041 | } |
| 1042 | |
| 1043 | static void remove_subsystem_dir(const char *name) |
| 1044 | { |
| 1045 | struct event_subsystem *system; |
| 1046 | |
| 1047 | if (strcmp(name, TRACE_SYSTEM) == 0) |
| 1048 | return; |
| 1049 | |
| 1050 | list_for_each_entry(system, &event_subsystems, list) { |
| 1051 | if (strcmp(system->name, name) == 0) { |
| 1052 | if (!--system->nr_events) { |
| 1053 | struct event_filter *filter = system->filter; |
| 1054 | |
| 1055 | debugfs_remove_recursive(system->entry); |
| 1056 | list_del(&system->list); |
| 1057 | if (filter) { |
| 1058 | kfree(filter->filter_string); |
| 1059 | kfree(filter); |
| 1060 | } |
| 1061 | kfree(system->name); |
| 1062 | kfree(system); |
| 1063 | } |
| 1064 | break; |
| 1065 | } |
| 1066 | } |
| 1067 | } |
| 1068 | |
| 1069 | /* |
| 1070 | * Must be called under locking both of event_mutex and trace_event_mutex. |
| 1071 | */ |
| 1072 | static void __trace_remove_event_call(struct ftrace_event_call *call) |
| 1073 | { |
| 1074 | ftrace_event_enable_disable(call, 0); |
| 1075 | if (call->event.funcs) |
| 1076 | __unregister_ftrace_event(&call->event); |
| 1077 | debugfs_remove_recursive(call->dir); |
| 1078 | list_del(&call->list); |
| 1079 | trace_destroy_fields(call); |
| 1080 | destroy_preds(call); |
| 1081 | remove_subsystem_dir(call->class->system); |
| 1082 | } |
| 1083 | |
| 1084 | /* Remove an event_call */ |
| 1085 | void trace_remove_event_call(struct ftrace_event_call *call) |
| 1086 | { |
| 1087 | mutex_lock(&event_mutex); |
| 1088 | down_write(&trace_event_mutex); |
| 1089 | __trace_remove_event_call(call); |
| 1090 | up_write(&trace_event_mutex); |
| 1091 | mutex_unlock(&event_mutex); |
| 1092 | } |
| 1093 | |
| 1094 | #define for_each_event(event, start, end) \ |
| 1095 | for (event = start; \ |
| 1096 | (unsigned long)event < (unsigned long)end; \ |
| 1097 | event++) |
| 1098 | |
| 1099 | #ifdef CONFIG_MODULES |
| 1100 | |
| 1101 | static LIST_HEAD(ftrace_module_file_list); |
| 1102 | |
| 1103 | /* |
| 1104 | * Modules must own their file_operations to keep up with |
| 1105 | * reference counting. |
| 1106 | */ |
| 1107 | struct ftrace_module_file_ops { |
| 1108 | struct list_head list; |
| 1109 | struct module *mod; |
| 1110 | struct file_operations id; |
| 1111 | struct file_operations enable; |
| 1112 | struct file_operations format; |
| 1113 | struct file_operations filter; |
| 1114 | }; |
| 1115 | |
| 1116 | static struct ftrace_module_file_ops * |
| 1117 | trace_create_file_ops(struct module *mod) |
| 1118 | { |
| 1119 | struct ftrace_module_file_ops *file_ops; |
| 1120 | |
| 1121 | /* |
| 1122 | * This is a bit of a PITA. To allow for correct reference |
| 1123 | * counting, modules must "own" their file_operations. |
| 1124 | * To do this, we allocate the file operations that will be |
| 1125 | * used in the event directory. |
| 1126 | */ |
| 1127 | |
| 1128 | file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL); |
| 1129 | if (!file_ops) |
| 1130 | return NULL; |
| 1131 | |
| 1132 | file_ops->mod = mod; |
| 1133 | |
| 1134 | file_ops->id = ftrace_event_id_fops; |
| 1135 | file_ops->id.owner = mod; |
| 1136 | |
| 1137 | file_ops->enable = ftrace_enable_fops; |
| 1138 | file_ops->enable.owner = mod; |
| 1139 | |
| 1140 | file_ops->filter = ftrace_event_filter_fops; |
| 1141 | file_ops->filter.owner = mod; |
| 1142 | |
| 1143 | file_ops->format = ftrace_event_format_fops; |
| 1144 | file_ops->format.owner = mod; |
| 1145 | |
| 1146 | list_add(&file_ops->list, &ftrace_module_file_list); |
| 1147 | |
| 1148 | return file_ops; |
| 1149 | } |
| 1150 | |
| 1151 | static void trace_module_add_events(struct module *mod) |
| 1152 | { |
| 1153 | struct ftrace_module_file_ops *file_ops = NULL; |
| 1154 | struct ftrace_event_call *call, *start, *end; |
| 1155 | struct dentry *d_events; |
| 1156 | int ret; |
| 1157 | |
| 1158 | start = mod->trace_events; |
| 1159 | end = mod->trace_events + mod->num_trace_events; |
| 1160 | |
| 1161 | if (start == end) |
| 1162 | return; |
| 1163 | |
| 1164 | d_events = event_trace_events_dir(); |
| 1165 | if (!d_events) |
| 1166 | return; |
| 1167 | |
| 1168 | for_each_event(call, start, end) { |
| 1169 | /* The linker may leave blanks */ |
| 1170 | if (!call->name) |
| 1171 | continue; |
| 1172 | if (call->class->raw_init) { |
| 1173 | ret = call->class->raw_init(call); |
| 1174 | if (ret < 0) { |
| 1175 | if (ret != -ENOSYS) |
| 1176 | pr_warning("Could not initialize trace " |
| 1177 | "point events/%s\n", call->name); |
| 1178 | continue; |
| 1179 | } |
| 1180 | } |
| 1181 | /* |
| 1182 | * This module has events, create file ops for this module |
| 1183 | * if not already done. |
| 1184 | */ |
| 1185 | if (!file_ops) { |
| 1186 | file_ops = trace_create_file_ops(mod); |
| 1187 | if (!file_ops) |
| 1188 | return; |
| 1189 | } |
| 1190 | call->mod = mod; |
| 1191 | ret = event_create_dir(call, d_events, |
| 1192 | &file_ops->id, &file_ops->enable, |
| 1193 | &file_ops->filter, &file_ops->format); |
| 1194 | if (!ret) |
| 1195 | list_add(&call->list, &ftrace_events); |
| 1196 | } |
| 1197 | } |
| 1198 | |
| 1199 | static void trace_module_remove_events(struct module *mod) |
| 1200 | { |
| 1201 | struct ftrace_module_file_ops *file_ops; |
| 1202 | struct ftrace_event_call *call, *p; |
| 1203 | bool found = false; |
| 1204 | |
| 1205 | down_write(&trace_event_mutex); |
| 1206 | list_for_each_entry_safe(call, p, &ftrace_events, list) { |
| 1207 | if (call->mod == mod) { |
| 1208 | found = true; |
| 1209 | __trace_remove_event_call(call); |
| 1210 | } |
| 1211 | } |
| 1212 | |
| 1213 | /* Now free the file_operations */ |
| 1214 | list_for_each_entry(file_ops, &ftrace_module_file_list, list) { |
| 1215 | if (file_ops->mod == mod) |
| 1216 | break; |
| 1217 | } |
| 1218 | if (&file_ops->list != &ftrace_module_file_list) { |
| 1219 | list_del(&file_ops->list); |
| 1220 | kfree(file_ops); |
| 1221 | } |
| 1222 | |
| 1223 | /* |
| 1224 | * It is safest to reset the ring buffer if the module being unloaded |
| 1225 | * registered any events. |
| 1226 | */ |
| 1227 | if (found) |
| 1228 | tracing_reset_current_online_cpus(); |
| 1229 | up_write(&trace_event_mutex); |
| 1230 | } |
| 1231 | |
| 1232 | static int trace_module_notify(struct notifier_block *self, |
| 1233 | unsigned long val, void *data) |
| 1234 | { |
| 1235 | struct module *mod = data; |
| 1236 | |
| 1237 | mutex_lock(&event_mutex); |
| 1238 | switch (val) { |
| 1239 | case MODULE_STATE_COMING: |
| 1240 | trace_module_add_events(mod); |
| 1241 | break; |
| 1242 | case MODULE_STATE_GOING: |
| 1243 | trace_module_remove_events(mod); |
| 1244 | break; |
| 1245 | } |
| 1246 | mutex_unlock(&event_mutex); |
| 1247 | |
| 1248 | return 0; |
| 1249 | } |
| 1250 | #else |
| 1251 | static int trace_module_notify(struct notifier_block *self, |
| 1252 | unsigned long val, void *data) |
| 1253 | { |
| 1254 | return 0; |
| 1255 | } |
| 1256 | #endif /* CONFIG_MODULES */ |
| 1257 | |
| 1258 | static struct notifier_block trace_module_nb = { |
| 1259 | .notifier_call = trace_module_notify, |
| 1260 | .priority = 0, |
| 1261 | }; |
| 1262 | |
| 1263 | extern struct ftrace_event_call __start_ftrace_events[]; |
| 1264 | extern struct ftrace_event_call __stop_ftrace_events[]; |
| 1265 | |
| 1266 | static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; |
| 1267 | |
| 1268 | static __init int setup_trace_event(char *str) |
| 1269 | { |
| 1270 | strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE); |
| 1271 | ring_buffer_expanded = 1; |
| 1272 | tracing_selftest_disabled = 1; |
| 1273 | |
| 1274 | return 1; |
| 1275 | } |
| 1276 | __setup("trace_event=", setup_trace_event); |
| 1277 | |
| 1278 | static __init int event_trace_init(void) |
| 1279 | { |
| 1280 | struct ftrace_event_call *call; |
| 1281 | struct dentry *d_tracer; |
| 1282 | struct dentry *entry; |
| 1283 | struct dentry *d_events; |
| 1284 | int ret; |
| 1285 | char *buf = bootup_event_buf; |
| 1286 | char *token; |
| 1287 | |
| 1288 | d_tracer = tracing_init_dentry(); |
| 1289 | if (!d_tracer) |
| 1290 | return 0; |
| 1291 | |
| 1292 | entry = debugfs_create_file("available_events", 0444, d_tracer, |
| 1293 | (void *)&show_event_seq_ops, |
| 1294 | &ftrace_avail_fops); |
| 1295 | if (!entry) |
| 1296 | pr_warning("Could not create debugfs " |
| 1297 | "'available_events' entry\n"); |
| 1298 | |
| 1299 | entry = debugfs_create_file("set_event", 0644, d_tracer, |
| 1300 | (void *)&show_set_event_seq_ops, |
| 1301 | &ftrace_set_event_fops); |
| 1302 | if (!entry) |
| 1303 | pr_warning("Could not create debugfs " |
| 1304 | "'set_event' entry\n"); |
| 1305 | |
| 1306 | d_events = event_trace_events_dir(); |
| 1307 | if (!d_events) |
| 1308 | return 0; |
| 1309 | |
| 1310 | /* ring buffer internal formats */ |
| 1311 | trace_create_file("header_page", 0444, d_events, |
| 1312 | ring_buffer_print_page_header, |
| 1313 | &ftrace_show_header_fops); |
| 1314 | |
| 1315 | trace_create_file("header_event", 0444, d_events, |
| 1316 | ring_buffer_print_entry_header, |
| 1317 | &ftrace_show_header_fops); |
| 1318 | |
| 1319 | trace_create_file("enable", 0644, d_events, |
| 1320 | NULL, &ftrace_system_enable_fops); |
| 1321 | |
| 1322 | for_each_event(call, __start_ftrace_events, __stop_ftrace_events) { |
| 1323 | /* The linker may leave blanks */ |
| 1324 | if (!call->name) |
| 1325 | continue; |
| 1326 | if (call->class->raw_init) { |
| 1327 | ret = call->class->raw_init(call); |
| 1328 | if (ret < 0) { |
| 1329 | if (ret != -ENOSYS) |
| 1330 | pr_warning("Could not initialize trace " |
| 1331 | "point events/%s\n", call->name); |
| 1332 | continue; |
| 1333 | } |
| 1334 | } |
| 1335 | ret = event_create_dir(call, d_events, &ftrace_event_id_fops, |
| 1336 | &ftrace_enable_fops, |
| 1337 | &ftrace_event_filter_fops, |
| 1338 | &ftrace_event_format_fops); |
| 1339 | if (!ret) |
| 1340 | list_add(&call->list, &ftrace_events); |
| 1341 | } |
| 1342 | |
| 1343 | while (true) { |
| 1344 | token = strsep(&buf, ","); |
| 1345 | |
| 1346 | if (!token) |
| 1347 | break; |
| 1348 | if (!*token) |
| 1349 | continue; |
| 1350 | |
| 1351 | ret = ftrace_set_clr_event(token, 1); |
| 1352 | if (ret) |
| 1353 | pr_warning("Failed to enable trace event: %s\n", token); |
| 1354 | } |
| 1355 | |
| 1356 | ret = register_module_notifier(&trace_module_nb); |
| 1357 | if (ret) |
| 1358 | pr_warning("Failed to register trace events module notifier\n"); |
| 1359 | |
| 1360 | return 0; |
| 1361 | } |
| 1362 | fs_initcall(event_trace_init); |
| 1363 | |
| 1364 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
| 1365 | |
| 1366 | static DEFINE_SPINLOCK(test_spinlock); |
| 1367 | static DEFINE_SPINLOCK(test_spinlock_irq); |
| 1368 | static DEFINE_MUTEX(test_mutex); |
| 1369 | |
| 1370 | static __init void test_work(struct work_struct *dummy) |
| 1371 | { |
| 1372 | spin_lock(&test_spinlock); |
| 1373 | spin_lock_irq(&test_spinlock_irq); |
| 1374 | udelay(1); |
| 1375 | spin_unlock_irq(&test_spinlock_irq); |
| 1376 | spin_unlock(&test_spinlock); |
| 1377 | |
| 1378 | mutex_lock(&test_mutex); |
| 1379 | msleep(1); |
| 1380 | mutex_unlock(&test_mutex); |
| 1381 | } |
| 1382 | |
| 1383 | static __init int event_test_thread(void *unused) |
| 1384 | { |
| 1385 | void *test_malloc; |
| 1386 | |
| 1387 | test_malloc = kmalloc(1234, GFP_KERNEL); |
| 1388 | if (!test_malloc) |
| 1389 | pr_info("failed to kmalloc\n"); |
| 1390 | |
| 1391 | schedule_on_each_cpu(test_work); |
| 1392 | |
| 1393 | kfree(test_malloc); |
| 1394 | |
| 1395 | set_current_state(TASK_INTERRUPTIBLE); |
| 1396 | while (!kthread_should_stop()) |
| 1397 | schedule(); |
| 1398 | |
| 1399 | return 0; |
| 1400 | } |
| 1401 | |
| 1402 | /* |
| 1403 | * Do various things that may trigger events. |
| 1404 | */ |
| 1405 | static __init void event_test_stuff(void) |
| 1406 | { |
| 1407 | struct task_struct *test_thread; |
| 1408 | |
| 1409 | test_thread = kthread_run(event_test_thread, NULL, "test-events"); |
| 1410 | msleep(1); |
| 1411 | kthread_stop(test_thread); |
| 1412 | } |
| 1413 | |
| 1414 | /* |
| 1415 | * For every trace event defined, we will test each trace point separately, |
| 1416 | * and then by groups, and finally all trace points. |
| 1417 | */ |
| 1418 | static __init void event_trace_self_tests(void) |
| 1419 | { |
| 1420 | struct ftrace_event_call *call; |
| 1421 | struct event_subsystem *system; |
| 1422 | int ret; |
| 1423 | |
| 1424 | pr_info("Running tests on trace events:\n"); |
| 1425 | |
| 1426 | list_for_each_entry(call, &ftrace_events, list) { |
| 1427 | |
| 1428 | /* Only test those that have a probe */ |
| 1429 | if (!call->class || !call->class->probe) |
| 1430 | continue; |
| 1431 | |
| 1432 | /* |
| 1433 | * Testing syscall events here is pretty useless, but |
| 1434 | * we still do it if configured. But this is time consuming. |
| 1435 | * What we really need is a user thread to perform the |
| 1436 | * syscalls as we test. |
| 1437 | */ |
| 1438 | #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS |
| 1439 | if (call->class->system && |
| 1440 | strcmp(call->class->system, "syscalls") == 0) |
| 1441 | continue; |
| 1442 | #endif |
| 1443 | |
| 1444 | pr_info("Testing event %s: ", call->name); |
| 1445 | |
| 1446 | /* |
| 1447 | * If an event is already enabled, someone is using |
| 1448 | * it and the self test should not be on. |
| 1449 | */ |
| 1450 | if (call->flags & TRACE_EVENT_FL_ENABLED) { |
| 1451 | pr_warning("Enabled event during self test!\n"); |
| 1452 | WARN_ON_ONCE(1); |
| 1453 | continue; |
| 1454 | } |
| 1455 | |
| 1456 | ftrace_event_enable_disable(call, 1); |
| 1457 | event_test_stuff(); |
| 1458 | ftrace_event_enable_disable(call, 0); |
| 1459 | |
| 1460 | pr_cont("OK\n"); |
| 1461 | } |
| 1462 | |
| 1463 | /* Now test at the sub system level */ |
| 1464 | |
| 1465 | pr_info("Running tests on trace event systems:\n"); |
| 1466 | |
| 1467 | list_for_each_entry(system, &event_subsystems, list) { |
| 1468 | |
| 1469 | /* the ftrace system is special, skip it */ |
| 1470 | if (strcmp(system->name, "ftrace") == 0) |
| 1471 | continue; |
| 1472 | |
| 1473 | pr_info("Testing event system %s: ", system->name); |
| 1474 | |
| 1475 | ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1); |
| 1476 | if (WARN_ON_ONCE(ret)) { |
| 1477 | pr_warning("error enabling system %s\n", |
| 1478 | system->name); |
| 1479 | continue; |
| 1480 | } |
| 1481 | |
| 1482 | event_test_stuff(); |
| 1483 | |
| 1484 | ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0); |
| 1485 | if (WARN_ON_ONCE(ret)) |
| 1486 | pr_warning("error disabling system %s\n", |
| 1487 | system->name); |
| 1488 | |
| 1489 | pr_cont("OK\n"); |
| 1490 | } |
| 1491 | |
| 1492 | /* Test with all events enabled */ |
| 1493 | |
| 1494 | pr_info("Running tests on all trace events:\n"); |
| 1495 | pr_info("Testing all events: "); |
| 1496 | |
| 1497 | ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1); |
| 1498 | if (WARN_ON_ONCE(ret)) { |
| 1499 | pr_warning("error enabling all events\n"); |
| 1500 | return; |
| 1501 | } |
| 1502 | |
| 1503 | event_test_stuff(); |
| 1504 | |
| 1505 | /* reset sysname */ |
| 1506 | ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0); |
| 1507 | if (WARN_ON_ONCE(ret)) { |
| 1508 | pr_warning("error disabling all events\n"); |
| 1509 | return; |
| 1510 | } |
| 1511 | |
| 1512 | pr_cont("OK\n"); |
| 1513 | } |
| 1514 | |
| 1515 | #ifdef CONFIG_FUNCTION_TRACER |
| 1516 | |
| 1517 | static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); |
| 1518 | |
| 1519 | static void |
| 1520 | function_test_events_call(unsigned long ip, unsigned long parent_ip) |
| 1521 | { |
| 1522 | struct ring_buffer_event *event; |
| 1523 | struct ring_buffer *buffer; |
| 1524 | struct ftrace_entry *entry; |
| 1525 | unsigned long flags; |
| 1526 | long disabled; |
| 1527 | int resched; |
| 1528 | int cpu; |
| 1529 | int pc; |
| 1530 | |
| 1531 | pc = preempt_count(); |
| 1532 | resched = ftrace_preempt_disable(); |
| 1533 | cpu = raw_smp_processor_id(); |
| 1534 | disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu)); |
| 1535 | |
| 1536 | if (disabled != 1) |
| 1537 | goto out; |
| 1538 | |
| 1539 | local_save_flags(flags); |
| 1540 | |
| 1541 | event = trace_current_buffer_lock_reserve(&buffer, |
| 1542 | TRACE_FN, sizeof(*entry), |
| 1543 | flags, pc); |
| 1544 | if (!event) |
| 1545 | goto out; |
| 1546 | entry = ring_buffer_event_data(event); |
| 1547 | entry->ip = ip; |
| 1548 | entry->parent_ip = parent_ip; |
| 1549 | |
| 1550 | trace_nowake_buffer_unlock_commit(buffer, event, flags, pc); |
| 1551 | |
| 1552 | out: |
| 1553 | atomic_dec(&per_cpu(ftrace_test_event_disable, cpu)); |
| 1554 | ftrace_preempt_enable(resched); |
| 1555 | } |
| 1556 | |
| 1557 | static struct ftrace_ops trace_ops __initdata = |
| 1558 | { |
| 1559 | .func = function_test_events_call, |
| 1560 | }; |
| 1561 | |
| 1562 | static __init void event_trace_self_test_with_function(void) |
| 1563 | { |
| 1564 | register_ftrace_function(&trace_ops); |
| 1565 | pr_info("Running tests again, along with the function tracer\n"); |
| 1566 | event_trace_self_tests(); |
| 1567 | unregister_ftrace_function(&trace_ops); |
| 1568 | } |
| 1569 | #else |
| 1570 | static __init void event_trace_self_test_with_function(void) |
| 1571 | { |
| 1572 | } |
| 1573 | #endif |
| 1574 | |
| 1575 | static __init int event_trace_self_tests_init(void) |
| 1576 | { |
| 1577 | if (!tracing_selftest_disabled) { |
| 1578 | event_trace_self_tests(); |
| 1579 | event_trace_self_test_with_function(); |
| 1580 | } |
| 1581 | |
| 1582 | return 0; |
| 1583 | } |
| 1584 | |
| 1585 | late_initcall(event_trace_self_tests_init); |
| 1586 | |
| 1587 | #endif |