1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * event tracer 4 * 5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> 6 * 7 * - Added format output of fields of the trace point. 8 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>. 9 * 10 */ 11 12 #define pr_fmt(fmt) fmt 13 14 #include <linux/workqueue.h> 15 #include <linux/security.h> 16 #include <linux/spinlock.h> 17 #include <linux/kthread.h> 18 #include <linux/tracefs.h> 19 #include <linux/uaccess.h> 20 #include <linux/module.h> 21 #include <linux/ctype.h> 22 #include <linux/sort.h> 23 #include <linux/slab.h> 24 #include <linux/delay.h> 25 26 #include <trace/events/sched.h> 27 #include <trace/syscall.h> 28 29 #include <asm/setup.h> 30 31 #include "trace_output.h" 32 33 #undef TRACE_SYSTEM 34 #define TRACE_SYSTEM "TRACE_SYSTEM" 35 36 DEFINE_MUTEX(event_mutex); 37 38 LIST_HEAD(ftrace_events); 39 static LIST_HEAD(ftrace_generic_fields); 40 static LIST_HEAD(ftrace_common_fields); 41 static bool eventdir_initialized; 42 43 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO) 44 45 static struct kmem_cache *field_cachep; 46 static struct kmem_cache *file_cachep; 47 48 static inline int system_refcount(struct event_subsystem *system) 49 { 50 return system->ref_count; 51 } 52 53 static int system_refcount_inc(struct event_subsystem *system) 54 { 55 return system->ref_count++; 56 } 57 58 static int system_refcount_dec(struct event_subsystem *system) 59 { 60 return --system->ref_count; 61 } 62 63 /* Double loops, do not use break, only goto's work */ 64 #define do_for_each_event_file(tr, file) \ 65 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ 66 list_for_each_entry(file, &tr->events, list) 67 68 #define do_for_each_event_file_safe(tr, file) \ 69 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ 70 struct trace_event_file *___n; \ 71 list_for_each_entry_safe(file, ___n, &tr->events, list) 72 73 #define while_for_each_event_file() \ 74 } 75 76 static struct ftrace_event_field * 77 __find_event_field(struct list_head *head, char *name) 78 { 79 struct ftrace_event_field *field; 80 81 list_for_each_entry(field, head, link) { 82 if (!strcmp(field->name, name)) 83 return field; 84 } 85 86 return NULL; 87 } 88 89 struct ftrace_event_field * 90 trace_find_event_field(struct trace_event_call *call, char *name) 91 { 92 struct ftrace_event_field *field; 93 struct list_head *head; 94 95 head = trace_get_fields(call); 96 field = __find_event_field(head, name); 97 if (field) 98 return field; 99 100 field = __find_event_field(&ftrace_generic_fields, name); 101 if (field) 102 return field; 103 104 return __find_event_field(&ftrace_common_fields, name); 105 } 106 107 static int __trace_define_field(struct list_head *head, const char *type, 108 const char *name, int offset, int size, 109 int is_signed, int filter_type) 110 { 111 struct ftrace_event_field *field; 112 113 field = kmem_cache_alloc(field_cachep, GFP_TRACE); 114 if (!field) 115 return -ENOMEM; 116 117 field->name = name; 118 field->type = type; 119 120 if (filter_type == FILTER_OTHER) 121 field->filter_type = filter_assign_type(type); 122 else 123 field->filter_type = filter_type; 124 125 field->offset = offset; 126 field->size = size; 127 field->is_signed = is_signed; 128 129 list_add(&field->link, head); 130 131 return 0; 132 } 133 134 int trace_define_field(struct trace_event_call *call, const char *type, 135 const char *name, int offset, int size, int is_signed, 136 int filter_type) 137 { 138 struct list_head *head; 139 140 if (WARN_ON(!call->class)) 141 return 0; 142 143 head = trace_get_fields(call); 144 return __trace_define_field(head, type, name, offset, size, 145 is_signed, filter_type); 146 } 147 EXPORT_SYMBOL_GPL(trace_define_field); 148 149 #define __generic_field(type, item, filter_type) \ 150 ret = __trace_define_field(&ftrace_generic_fields, #type, \ 151 #item, 0, 0, is_signed_type(type), \ 152 filter_type); \ 153 if (ret) \ 154 return ret; 155 156 #define __common_field(type, item) \ 157 ret = __trace_define_field(&ftrace_common_fields, #type, \ 158 "common_" #item, \ 159 offsetof(typeof(ent), item), \ 160 sizeof(ent.item), \ 161 is_signed_type(type), FILTER_OTHER); \ 162 if (ret) \ 163 return ret; 164 165 static int trace_define_generic_fields(void) 166 { 167 int ret; 168 169 __generic_field(int, CPU, FILTER_CPU); 170 __generic_field(int, cpu, FILTER_CPU); 171 __generic_field(char *, COMM, FILTER_COMM); 172 __generic_field(char *, comm, FILTER_COMM); 173 174 return ret; 175 } 176 177 static int trace_define_common_fields(void) 178 { 179 int ret; 180 struct trace_entry ent; 181 182 __common_field(unsigned short, type); 183 __common_field(unsigned char, flags); 184 /* Holds both preempt_count and migrate_disable */ 185 __common_field(unsigned char, preempt_count); 186 __common_field(int, pid); 187 188 return ret; 189 } 190 191 static void trace_destroy_fields(struct trace_event_call *call) 192 { 193 struct ftrace_event_field *field, *next; 194 struct list_head *head; 195 196 head = trace_get_fields(call); 197 list_for_each_entry_safe(field, next, head, link) { 198 list_del(&field->link); 199 kmem_cache_free(field_cachep, field); 200 } 201 } 202 203 /* 204 * run-time version of trace_event_get_offsets_<call>() that returns the last 205 * accessible offset of trace fields excluding __dynamic_array bytes 206 */ 207 int trace_event_get_offsets(struct trace_event_call *call) 208 { 209 struct ftrace_event_field *tail; 210 struct list_head *head; 211 212 head = trace_get_fields(call); 213 /* 214 * head->next points to the last field with the largest offset, 215 * since it was added last by trace_define_field() 216 */ 217 tail = list_first_entry(head, struct ftrace_event_field, link); 218 return tail->offset + tail->size; 219 } 220 221 /* 222 * Check if the referenced field is an array and return true, 223 * as arrays are OK to dereference. 224 */ 225 static bool test_field(const char *fmt, struct trace_event_call *call) 226 { 227 struct trace_event_fields *field = call->class->fields_array; 228 const char *array_descriptor; 229 const char *p = fmt; 230 int len; 231 232 if (!(len = str_has_prefix(fmt, "REC->"))) 233 return false; 234 fmt += len; 235 for (p = fmt; *p; p++) { 236 if (!isalnum(*p) && *p != '_') 237 break; 238 } 239 len = p - fmt; 240 241 for (; field->type; field++) { 242 if (strncmp(field->name, fmt, len) || 243 field->name[len]) 244 continue; 245 array_descriptor = strchr(field->type, '['); 246 /* This is an array and is OK to dereference. */ 247 return array_descriptor != NULL; 248 } 249 return false; 250 } 251 252 /* 253 * Examine the print fmt of the event looking for unsafe dereference 254 * pointers using %p* that could be recorded in the trace event and 255 * much later referenced after the pointer was freed. Dereferencing 256 * pointers are OK, if it is dereferenced into the event itself. 257 */ 258 static void test_event_printk(struct trace_event_call *call) 259 { 260 u64 dereference_flags = 0; 261 bool first = true; 262 const char *fmt, *c, *r, *a; 263 int parens = 0; 264 char in_quote = 0; 265 int start_arg = 0; 266 int arg = 0; 267 int i; 268 269 fmt = call->print_fmt; 270 271 if (!fmt) 272 return; 273 274 for (i = 0; fmt[i]; i++) { 275 switch (fmt[i]) { 276 case '\\': 277 i++; 278 if (!fmt[i]) 279 return; 280 continue; 281 case '"': 282 case '\'': 283 /* 284 * The print fmt starts with a string that 285 * is processed first to find %p* usage, 286 * then after the first string, the print fmt 287 * contains arguments that are used to check 288 * if the dereferenced %p* usage is safe. 289 */ 290 if (first) { 291 if (fmt[i] == '\'') 292 continue; 293 if (in_quote) { 294 arg = 0; 295 first = false; 296 /* 297 * If there was no %p* uses 298 * the fmt is OK. 299 */ 300 if (!dereference_flags) 301 return; 302 } 303 } 304 if (in_quote) { 305 if (in_quote == fmt[i]) 306 in_quote = 0; 307 } else { 308 in_quote = fmt[i]; 309 } 310 continue; 311 case '%': 312 if (!first || !in_quote) 313 continue; 314 i++; 315 if (!fmt[i]) 316 return; 317 switch (fmt[i]) { 318 case '%': 319 continue; 320 case 'p': 321 /* Find dereferencing fields */ 322 switch (fmt[i + 1]) { 323 case 'B': case 'R': case 'r': 324 case 'b': case 'M': case 'm': 325 case 'I': case 'i': case 'E': 326 case 'U': case 'V': case 'N': 327 case 'a': case 'd': case 'D': 328 case 'g': case 't': case 'C': 329 case 'O': case 'f': 330 if (WARN_ONCE(arg == 63, 331 "Too many args for event: %s", 332 trace_event_name(call))) 333 return; 334 dereference_flags |= 1ULL << arg; 335 } 336 break; 337 default: 338 { 339 bool star = false; 340 int j; 341 342 /* Increment arg if %*s exists. */ 343 for (j = 0; fmt[i + j]; j++) { 344 if (isdigit(fmt[i + j]) || 345 fmt[i + j] == '.') 346 continue; 347 if (fmt[i + j] == '*') { 348 star = true; 349 continue; 350 } 351 if ((fmt[i + j] == 's') && star) 352 arg++; 353 break; 354 } 355 break; 356 } /* default */ 357 358 } /* switch */ 359 arg++; 360 continue; 361 case '(': 362 if (in_quote) 363 continue; 364 parens++; 365 continue; 366 case ')': 367 if (in_quote) 368 continue; 369 parens--; 370 if (WARN_ONCE(parens < 0, 371 "Paren mismatch for event: %s\narg='%s'\n%*s", 372 trace_event_name(call), 373 fmt + start_arg, 374 (i - start_arg) + 5, "^")) 375 return; 376 continue; 377 case ',': 378 if (in_quote || parens) 379 continue; 380 i++; 381 while (isspace(fmt[i])) 382 i++; 383 start_arg = i; 384 if (!(dereference_flags & (1ULL << arg))) 385 goto next_arg; 386 387 /* Find the REC-> in the argument */ 388 c = strchr(fmt + i, ','); 389 r = strstr(fmt + i, "REC->"); 390 if (r && (!c || r < c)) { 391 /* 392 * Addresses of events on the buffer, 393 * or an array on the buffer is 394 * OK to dereference. 395 * There's ways to fool this, but 396 * this is to catch common mistakes, 397 * not malicious code. 398 */ 399 a = strchr(fmt + i, '&'); 400 if ((a && (a < r)) || test_field(r, call)) 401 dereference_flags &= ~(1ULL << arg); 402 } 403 next_arg: 404 i--; 405 arg++; 406 } 407 } 408 409 /* 410 * If you triggered the below warning, the trace event reported 411 * uses an unsafe dereference pointer %p*. As the data stored 412 * at the trace event time may no longer exist when the trace 413 * event is printed, dereferencing to the original source is 414 * unsafe. The source of the dereference must be copied into the 415 * event itself, and the dereference must access the copy instead. 416 */ 417 if (WARN_ON_ONCE(dereference_flags)) { 418 arg = 1; 419 while (!(dereference_flags & 1)) { 420 dereference_flags >>= 1; 421 arg++; 422 } 423 pr_warn("event %s has unsafe dereference of argument %d\n", 424 trace_event_name(call), arg); 425 pr_warn("print_fmt: %s\n", fmt); 426 } 427 } 428 429 int trace_event_raw_init(struct trace_event_call *call) 430 { 431 int id; 432 433 id = register_trace_event(&call->event); 434 if (!id) 435 return -ENODEV; 436 437 test_event_printk(call); 438 439 return 0; 440 } 441 EXPORT_SYMBOL_GPL(trace_event_raw_init); 442 443 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file) 444 { 445 struct trace_array *tr = trace_file->tr; 446 struct trace_array_cpu *data; 447 struct trace_pid_list *no_pid_list; 448 struct trace_pid_list *pid_list; 449 450 pid_list = rcu_dereference_raw(tr->filtered_pids); 451 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids); 452 453 if (!pid_list && !no_pid_list) 454 return false; 455 456 data = this_cpu_ptr(tr->array_buffer.data); 457 458 return data->ignore_pid; 459 } 460 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid); 461 462 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, 463 struct trace_event_file *trace_file, 464 unsigned long len) 465 { 466 struct trace_event_call *event_call = trace_file->event_call; 467 468 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) && 469 trace_event_ignore_this_pid(trace_file)) 470 return NULL; 471 472 /* 473 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables 474 * preemption (adding one to the preempt_count). Since we are 475 * interested in the preempt_count at the time the tracepoint was 476 * hit, we need to subtract one to offset the increment. 477 */ 478 fbuffer->trace_ctx = tracing_gen_ctx_dec(); 479 fbuffer->trace_file = trace_file; 480 481 fbuffer->event = 482 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file, 483 event_call->event.type, len, 484 fbuffer->trace_ctx); 485 if (!fbuffer->event) 486 return NULL; 487 488 fbuffer->regs = NULL; 489 fbuffer->entry = ring_buffer_event_data(fbuffer->event); 490 return fbuffer->entry; 491 } 492 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve); 493 494 int trace_event_reg(struct trace_event_call *call, 495 enum trace_reg type, void *data) 496 { 497 struct trace_event_file *file = data; 498 499 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT)); 500 switch (type) { 501 case TRACE_REG_REGISTER: 502 return tracepoint_probe_register(call->tp, 503 call->class->probe, 504 file); 505 case TRACE_REG_UNREGISTER: 506 tracepoint_probe_unregister(call->tp, 507 call->class->probe, 508 file); 509 return 0; 510 511 #ifdef CONFIG_PERF_EVENTS 512 case TRACE_REG_PERF_REGISTER: 513 return tracepoint_probe_register(call->tp, 514 call->class->perf_probe, 515 call); 516 case TRACE_REG_PERF_UNREGISTER: 517 tracepoint_probe_unregister(call->tp, 518 call->class->perf_probe, 519 call); 520 return 0; 521 case TRACE_REG_PERF_OPEN: 522 case TRACE_REG_PERF_CLOSE: 523 case TRACE_REG_PERF_ADD: 524 case TRACE_REG_PERF_DEL: 525 return 0; 526 #endif 527 } 528 return 0; 529 } 530 EXPORT_SYMBOL_GPL(trace_event_reg); 531 532 void trace_event_enable_cmd_record(bool enable) 533 { 534 struct trace_event_file *file; 535 struct trace_array *tr; 536 537 lockdep_assert_held(&event_mutex); 538 539 do_for_each_event_file(tr, file) { 540 541 if (!(file->flags & EVENT_FILE_FL_ENABLED)) 542 continue; 543 544 if (enable) { 545 tracing_start_cmdline_record(); 546 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 547 } else { 548 tracing_stop_cmdline_record(); 549 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 550 } 551 } while_for_each_event_file(); 552 } 553 554 void trace_event_enable_tgid_record(bool enable) 555 { 556 struct trace_event_file *file; 557 struct trace_array *tr; 558 559 lockdep_assert_held(&event_mutex); 560 561 do_for_each_event_file(tr, file) { 562 if (!(file->flags & EVENT_FILE_FL_ENABLED)) 563 continue; 564 565 if (enable) { 566 tracing_start_tgid_record(); 567 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); 568 } else { 569 tracing_stop_tgid_record(); 570 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, 571 &file->flags); 572 } 573 } while_for_each_event_file(); 574 } 575 576 static int __ftrace_event_enable_disable(struct trace_event_file *file, 577 int enable, int soft_disable) 578 { 579 struct trace_event_call *call = file->event_call; 580 struct trace_array *tr = file->tr; 581 unsigned long file_flags = file->flags; 582 int ret = 0; 583 int disable; 584 585 switch (enable) { 586 case 0: 587 /* 588 * When soft_disable is set and enable is cleared, the sm_ref 589 * reference counter is decremented. If it reaches 0, we want 590 * to clear the SOFT_DISABLED flag but leave the event in the 591 * state that it was. That is, if the event was enabled and 592 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED 593 * is set we do not want the event to be enabled before we 594 * clear the bit. 595 * 596 * When soft_disable is not set but the SOFT_MODE flag is, 597 * we do nothing. Do not disable the tracepoint, otherwise 598 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work. 599 */ 600 if (soft_disable) { 601 if (atomic_dec_return(&file->sm_ref) > 0) 602 break; 603 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED; 604 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags); 605 } else 606 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE); 607 608 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) { 609 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags); 610 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) { 611 tracing_stop_cmdline_record(); 612 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 613 } 614 615 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) { 616 tracing_stop_tgid_record(); 617 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); 618 } 619 620 call->class->reg(call, TRACE_REG_UNREGISTER, file); 621 } 622 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */ 623 if (file->flags & EVENT_FILE_FL_SOFT_MODE) 624 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 625 else 626 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 627 break; 628 case 1: 629 /* 630 * When soft_disable is set and enable is set, we want to 631 * register the tracepoint for the event, but leave the event 632 * as is. That means, if the event was already enabled, we do 633 * nothing (but set SOFT_MODE). If the event is disabled, we 634 * set SOFT_DISABLED before enabling the event tracepoint, so 635 * it still seems to be disabled. 636 */ 637 if (!soft_disable) 638 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 639 else { 640 if (atomic_inc_return(&file->sm_ref) > 1) 641 break; 642 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags); 643 } 644 645 if (!(file->flags & EVENT_FILE_FL_ENABLED)) { 646 bool cmd = false, tgid = false; 647 648 /* Keep the event disabled, when going to SOFT_MODE. */ 649 if (soft_disable) 650 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags); 651 652 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) { 653 cmd = true; 654 tracing_start_cmdline_record(); 655 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags); 656 } 657 658 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) { 659 tgid = true; 660 tracing_start_tgid_record(); 661 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); 662 } 663 664 ret = call->class->reg(call, TRACE_REG_REGISTER, file); 665 if (ret) { 666 if (cmd) 667 tracing_stop_cmdline_record(); 668 if (tgid) 669 tracing_stop_tgid_record(); 670 pr_info("event trace: Could not enable event " 671 "%s\n", trace_event_name(call)); 672 break; 673 } 674 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags); 675 676 /* WAS_ENABLED gets set but never cleared. */ 677 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags); 678 } 679 break; 680 } 681 682 /* Enable or disable use of trace_buffered_event */ 683 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) != 684 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) { 685 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED) 686 trace_buffered_event_enable(); 687 else 688 trace_buffered_event_disable(); 689 } 690 691 return ret; 692 } 693 694 int trace_event_enable_disable(struct trace_event_file *file, 695 int enable, int soft_disable) 696 { 697 return __ftrace_event_enable_disable(file, enable, soft_disable); 698 } 699 700 static int ftrace_event_enable_disable(struct trace_event_file *file, 701 int enable) 702 { 703 return __ftrace_event_enable_disable(file, enable, 0); 704 } 705 706 static void ftrace_clear_events(struct trace_array *tr) 707 { 708 struct trace_event_file *file; 709 710 mutex_lock(&event_mutex); 711 list_for_each_entry(file, &tr->events, list) { 712 ftrace_event_enable_disable(file, 0); 713 } 714 mutex_unlock(&event_mutex); 715 } 716 717 static void 718 event_filter_pid_sched_process_exit(void *data, struct task_struct *task) 719 { 720 struct trace_pid_list *pid_list; 721 struct trace_array *tr = data; 722 723 pid_list = rcu_dereference_raw(tr->filtered_pids); 724 trace_filter_add_remove_task(pid_list, NULL, task); 725 726 pid_list = rcu_dereference_raw(tr->filtered_no_pids); 727 trace_filter_add_remove_task(pid_list, NULL, task); 728 } 729 730 static void 731 event_filter_pid_sched_process_fork(void *data, 732 struct task_struct *self, 733 struct task_struct *task) 734 { 735 struct trace_pid_list *pid_list; 736 struct trace_array *tr = data; 737 738 pid_list = rcu_dereference_sched(tr->filtered_pids); 739 trace_filter_add_remove_task(pid_list, self, task); 740 741 pid_list = rcu_dereference_sched(tr->filtered_no_pids); 742 trace_filter_add_remove_task(pid_list, self, task); 743 } 744 745 void trace_event_follow_fork(struct trace_array *tr, bool enable) 746 { 747 if (enable) { 748 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork, 749 tr, INT_MIN); 750 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit, 751 tr, INT_MAX); 752 } else { 753 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork, 754 tr); 755 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit, 756 tr); 757 } 758 } 759 760 static void 761 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt, 762 struct task_struct *prev, struct task_struct *next) 763 { 764 struct trace_array *tr = data; 765 struct trace_pid_list *no_pid_list; 766 struct trace_pid_list *pid_list; 767 bool ret; 768 769 pid_list = rcu_dereference_sched(tr->filtered_pids); 770 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids); 771 772 /* 773 * Sched switch is funny, as we only want to ignore it 774 * in the notrace case if both prev and next should be ignored. 775 */ 776 ret = trace_ignore_this_task(NULL, no_pid_list, prev) && 777 trace_ignore_this_task(NULL, no_pid_list, next); 778 779 this_cpu_write(tr->array_buffer.data->ignore_pid, ret || 780 (trace_ignore_this_task(pid_list, NULL, prev) && 781 trace_ignore_this_task(pid_list, NULL, next))); 782 } 783 784 static void 785 event_filter_pid_sched_switch_probe_post(void *data, bool preempt, 786 struct task_struct *prev, struct task_struct *next) 787 { 788 struct trace_array *tr = data; 789 struct trace_pid_list *no_pid_list; 790 struct trace_pid_list *pid_list; 791 792 pid_list = rcu_dereference_sched(tr->filtered_pids); 793 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids); 794 795 this_cpu_write(tr->array_buffer.data->ignore_pid, 796 trace_ignore_this_task(pid_list, no_pid_list, next)); 797 } 798 799 static void 800 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task) 801 { 802 struct trace_array *tr = data; 803 struct trace_pid_list *no_pid_list; 804 struct trace_pid_list *pid_list; 805 806 /* Nothing to do if we are already tracing */ 807 if (!this_cpu_read(tr->array_buffer.data->ignore_pid)) 808 return; 809 810 pid_list = rcu_dereference_sched(tr->filtered_pids); 811 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids); 812 813 this_cpu_write(tr->array_buffer.data->ignore_pid, 814 trace_ignore_this_task(pid_list, no_pid_list, task)); 815 } 816 817 static void 818 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task) 819 { 820 struct trace_array *tr = data; 821 struct trace_pid_list *no_pid_list; 822 struct trace_pid_list *pid_list; 823 824 /* Nothing to do if we are not tracing */ 825 if (this_cpu_read(tr->array_buffer.data->ignore_pid)) 826 return; 827 828 pid_list = rcu_dereference_sched(tr->filtered_pids); 829 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids); 830 831 /* Set tracing if current is enabled */ 832 this_cpu_write(tr->array_buffer.data->ignore_pid, 833 trace_ignore_this_task(pid_list, no_pid_list, current)); 834 } 835 836 static void unregister_pid_events(struct trace_array *tr) 837 { 838 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr); 839 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr); 840 841 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr); 842 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr); 843 844 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr); 845 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr); 846 847 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr); 848 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr); 849 } 850 851 static void __ftrace_clear_event_pids(struct trace_array *tr, int type) 852 { 853 struct trace_pid_list *pid_list; 854 struct trace_pid_list *no_pid_list; 855 struct trace_event_file *file; 856 int cpu; 857 858 pid_list = rcu_dereference_protected(tr->filtered_pids, 859 lockdep_is_held(&event_mutex)); 860 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids, 861 lockdep_is_held(&event_mutex)); 862 863 /* Make sure there's something to do */ 864 if (!pid_type_enabled(type, pid_list, no_pid_list)) 865 return; 866 867 if (!still_need_pid_events(type, pid_list, no_pid_list)) { 868 unregister_pid_events(tr); 869 870 list_for_each_entry(file, &tr->events, list) { 871 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags); 872 } 873 874 for_each_possible_cpu(cpu) 875 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false; 876 } 877 878 if (type & TRACE_PIDS) 879 rcu_assign_pointer(tr->filtered_pids, NULL); 880 881 if (type & TRACE_NO_PIDS) 882 rcu_assign_pointer(tr->filtered_no_pids, NULL); 883 884 /* Wait till all users are no longer using pid filtering */ 885 tracepoint_synchronize_unregister(); 886 887 if ((type & TRACE_PIDS) && pid_list) 888 trace_pid_list_free(pid_list); 889 890 if ((type & TRACE_NO_PIDS) && no_pid_list) 891 trace_pid_list_free(no_pid_list); 892 } 893 894 static void ftrace_clear_event_pids(struct trace_array *tr, int type) 895 { 896 mutex_lock(&event_mutex); 897 __ftrace_clear_event_pids(tr, type); 898 mutex_unlock(&event_mutex); 899 } 900 901 static void __put_system(struct event_subsystem *system) 902 { 903 struct event_filter *filter = system->filter; 904 905 WARN_ON_ONCE(system_refcount(system) == 0); 906 if (system_refcount_dec(system)) 907 return; 908 909 list_del(&system->list); 910 911 if (filter) { 912 kfree(filter->filter_string); 913 kfree(filter); 914 } 915 kfree_const(system->name); 916 kfree(system); 917 } 918 919 static void __get_system(struct event_subsystem *system) 920 { 921 WARN_ON_ONCE(system_refcount(system) == 0); 922 system_refcount_inc(system); 923 } 924 925 static void __get_system_dir(struct trace_subsystem_dir *dir) 926 { 927 WARN_ON_ONCE(dir->ref_count == 0); 928 dir->ref_count++; 929 __get_system(dir->subsystem); 930 } 931 932 static void __put_system_dir(struct trace_subsystem_dir *dir) 933 { 934 WARN_ON_ONCE(dir->ref_count == 0); 935 /* If the subsystem is about to be freed, the dir must be too */ 936 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1); 937 938 __put_system(dir->subsystem); 939 if (!--dir->ref_count) 940 kfree(dir); 941 } 942 943 static void put_system(struct trace_subsystem_dir *dir) 944 { 945 mutex_lock(&event_mutex); 946 __put_system_dir(dir); 947 mutex_unlock(&event_mutex); 948 } 949 950 static void remove_subsystem(struct trace_subsystem_dir *dir) 951 { 952 if (!dir) 953 return; 954 955 if (!--dir->nr_events) { 956 tracefs_remove(dir->entry); 957 list_del(&dir->list); 958 __put_system_dir(dir); 959 } 960 } 961 962 static void remove_event_file_dir(struct trace_event_file *file) 963 { 964 struct dentry *dir = file->dir; 965 struct dentry *child; 966 967 if (dir) { 968 spin_lock(&dir->d_lock); /* probably unneeded */ 969 list_for_each_entry(child, &dir->d_subdirs, d_child) { 970 if (d_really_is_positive(child)) /* probably unneeded */ 971 d_inode(child)->i_private = NULL; 972 } 973 spin_unlock(&dir->d_lock); 974 975 tracefs_remove(dir); 976 } 977 978 list_del(&file->list); 979 remove_subsystem(file->system); 980 free_event_filter(file->filter); 981 kmem_cache_free(file_cachep, file); 982 } 983 984 /* 985 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. 986 */ 987 static int 988 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match, 989 const char *sub, const char *event, int set) 990 { 991 struct trace_event_file *file; 992 struct trace_event_call *call; 993 const char *name; 994 int ret = -EINVAL; 995 int eret = 0; 996 997 list_for_each_entry(file, &tr->events, list) { 998 999 call = file->event_call; 1000 name = trace_event_name(call); 1001 1002 if (!name || !call->class || !call->class->reg) 1003 continue; 1004 1005 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) 1006 continue; 1007 1008 if (match && 1009 strcmp(match, name) != 0 && 1010 strcmp(match, call->class->system) != 0) 1011 continue; 1012 1013 if (sub && strcmp(sub, call->class->system) != 0) 1014 continue; 1015 1016 if (event && strcmp(event, name) != 0) 1017 continue; 1018 1019 ret = ftrace_event_enable_disable(file, set); 1020 1021 /* 1022 * Save the first error and return that. Some events 1023 * may still have been enabled, but let the user 1024 * know that something went wrong. 1025 */ 1026 if (ret && !eret) 1027 eret = ret; 1028 1029 ret = eret; 1030 } 1031 1032 return ret; 1033 } 1034 1035 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, 1036 const char *sub, const char *event, int set) 1037 { 1038 int ret; 1039 1040 mutex_lock(&event_mutex); 1041 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set); 1042 mutex_unlock(&event_mutex); 1043 1044 return ret; 1045 } 1046 1047 int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set) 1048 { 1049 char *event = NULL, *sub = NULL, *match; 1050 int ret; 1051 1052 if (!tr) 1053 return -ENOENT; 1054 /* 1055 * The buf format can be <subsystem>:<event-name> 1056 * *:<event-name> means any event by that name. 1057 * :<event-name> is the same. 1058 * 1059 * <subsystem>:* means all events in that subsystem 1060 * <subsystem>: means the same. 1061 * 1062 * <name> (no ':') means all events in a subsystem with 1063 * the name <name> or any event that matches <name> 1064 */ 1065 1066 match = strsep(&buf, ":"); 1067 if (buf) { 1068 sub = match; 1069 event = buf; 1070 match = NULL; 1071 1072 if (!strlen(sub) || strcmp(sub, "*") == 0) 1073 sub = NULL; 1074 if (!strlen(event) || strcmp(event, "*") == 0) 1075 event = NULL; 1076 } 1077 1078 ret = __ftrace_set_clr_event(tr, match, sub, event, set); 1079 1080 /* Put back the colon to allow this to be called again */ 1081 if (buf) 1082 *(buf - 1) = ':'; 1083 1084 return ret; 1085 } 1086 1087 /** 1088 * trace_set_clr_event - enable or disable an event 1089 * @system: system name to match (NULL for any system) 1090 * @event: event name to match (NULL for all events, within system) 1091 * @set: 1 to enable, 0 to disable 1092 * 1093 * This is a way for other parts of the kernel to enable or disable 1094 * event recording. 1095 * 1096 * Returns 0 on success, -EINVAL if the parameters do not match any 1097 * registered events. 1098 */ 1099 int trace_set_clr_event(const char *system, const char *event, int set) 1100 { 1101 struct trace_array *tr = top_trace_array(); 1102 1103 if (!tr) 1104 return -ENODEV; 1105 1106 return __ftrace_set_clr_event(tr, NULL, system, event, set); 1107 } 1108 EXPORT_SYMBOL_GPL(trace_set_clr_event); 1109 1110 /** 1111 * trace_array_set_clr_event - enable or disable an event for a trace array. 1112 * @tr: concerned trace array. 1113 * @system: system name to match (NULL for any system) 1114 * @event: event name to match (NULL for all events, within system) 1115 * @enable: true to enable, false to disable 1116 * 1117 * This is a way for other parts of the kernel to enable or disable 1118 * event recording. 1119 * 1120 * Returns 0 on success, -EINVAL if the parameters do not match any 1121 * registered events. 1122 */ 1123 int trace_array_set_clr_event(struct trace_array *tr, const char *system, 1124 const char *event, bool enable) 1125 { 1126 int set; 1127 1128 if (!tr) 1129 return -ENOENT; 1130 1131 set = (enable == true) ? 1 : 0; 1132 return __ftrace_set_clr_event(tr, NULL, system, event, set); 1133 } 1134 EXPORT_SYMBOL_GPL(trace_array_set_clr_event); 1135 1136 /* 128 should be much more than enough */ 1137 #define EVENT_BUF_SIZE 127 1138 1139 static ssize_t 1140 ftrace_event_write(struct file *file, const char __user *ubuf, 1141 size_t cnt, loff_t *ppos) 1142 { 1143 struct trace_parser parser; 1144 struct seq_file *m = file->private_data; 1145 struct trace_array *tr = m->private; 1146 ssize_t read, ret; 1147 1148 if (!cnt) 1149 return 0; 1150 1151 ret = tracing_update_buffers(); 1152 if (ret < 0) 1153 return ret; 1154 1155 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) 1156 return -ENOMEM; 1157 1158 read = trace_get_user(&parser, ubuf, cnt, ppos); 1159 1160 if (read >= 0 && trace_parser_loaded((&parser))) { 1161 int set = 1; 1162 1163 if (*parser.buffer == '!') 1164 set = 0; 1165 1166 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set); 1167 if (ret) 1168 goto out_put; 1169 } 1170 1171 ret = read; 1172 1173 out_put: 1174 trace_parser_put(&parser); 1175 1176 return ret; 1177 } 1178 1179 static void * 1180 t_next(struct seq_file *m, void *v, loff_t *pos) 1181 { 1182 struct trace_event_file *file = v; 1183 struct trace_event_call *call; 1184 struct trace_array *tr = m->private; 1185 1186 (*pos)++; 1187 1188 list_for_each_entry_continue(file, &tr->events, list) { 1189 call = file->event_call; 1190 /* 1191 * The ftrace subsystem is for showing formats only. 1192 * They can not be enabled or disabled via the event files. 1193 */ 1194 if (call->class && call->class->reg && 1195 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) 1196 return file; 1197 } 1198 1199 return NULL; 1200 } 1201 1202 static void *t_start(struct seq_file *m, loff_t *pos) 1203 { 1204 struct trace_event_file *file; 1205 struct trace_array *tr = m->private; 1206 loff_t l; 1207 1208 mutex_lock(&event_mutex); 1209 1210 file = list_entry(&tr->events, struct trace_event_file, list); 1211 for (l = 0; l <= *pos; ) { 1212 file = t_next(m, file, &l); 1213 if (!file) 1214 break; 1215 } 1216 return file; 1217 } 1218 1219 static void * 1220 s_next(struct seq_file *m, void *v, loff_t *pos) 1221 { 1222 struct trace_event_file *file = v; 1223 struct trace_array *tr = m->private; 1224 1225 (*pos)++; 1226 1227 list_for_each_entry_continue(file, &tr->events, list) { 1228 if (file->flags & EVENT_FILE_FL_ENABLED) 1229 return file; 1230 } 1231 1232 return NULL; 1233 } 1234 1235 static void *s_start(struct seq_file *m, loff_t *pos) 1236 { 1237 struct trace_event_file *file; 1238 struct trace_array *tr = m->private; 1239 loff_t l; 1240 1241 mutex_lock(&event_mutex); 1242 1243 file = list_entry(&tr->events, struct trace_event_file, list); 1244 for (l = 0; l <= *pos; ) { 1245 file = s_next(m, file, &l); 1246 if (!file) 1247 break; 1248 } 1249 return file; 1250 } 1251 1252 static int t_show(struct seq_file *m, void *v) 1253 { 1254 struct trace_event_file *file = v; 1255 struct trace_event_call *call = file->event_call; 1256 1257 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) 1258 seq_printf(m, "%s:", call->class->system); 1259 seq_printf(m, "%s\n", trace_event_name(call)); 1260 1261 return 0; 1262 } 1263 1264 static void t_stop(struct seq_file *m, void *p) 1265 { 1266 mutex_unlock(&event_mutex); 1267 } 1268 1269 static void * 1270 __next(struct seq_file *m, void *v, loff_t *pos, int type) 1271 { 1272 struct trace_array *tr = m->private; 1273 struct trace_pid_list *pid_list; 1274 1275 if (type == TRACE_PIDS) 1276 pid_list = rcu_dereference_sched(tr->filtered_pids); 1277 else 1278 pid_list = rcu_dereference_sched(tr->filtered_no_pids); 1279 1280 return trace_pid_next(pid_list, v, pos); 1281 } 1282 1283 static void * 1284 p_next(struct seq_file *m, void *v, loff_t *pos) 1285 { 1286 return __next(m, v, pos, TRACE_PIDS); 1287 } 1288 1289 static void * 1290 np_next(struct seq_file *m, void *v, loff_t *pos) 1291 { 1292 return __next(m, v, pos, TRACE_NO_PIDS); 1293 } 1294 1295 static void *__start(struct seq_file *m, loff_t *pos, int type) 1296 __acquires(RCU) 1297 { 1298 struct trace_pid_list *pid_list; 1299 struct trace_array *tr = m->private; 1300 1301 /* 1302 * Grab the mutex, to keep calls to p_next() having the same 1303 * tr->filtered_pids as p_start() has. 1304 * If we just passed the tr->filtered_pids around, then RCU would 1305 * have been enough, but doing that makes things more complex. 1306 */ 1307 mutex_lock(&event_mutex); 1308 rcu_read_lock_sched(); 1309 1310 if (type == TRACE_PIDS) 1311 pid_list = rcu_dereference_sched(tr->filtered_pids); 1312 else 1313 pid_list = rcu_dereference_sched(tr->filtered_no_pids); 1314 1315 if (!pid_list) 1316 return NULL; 1317 1318 return trace_pid_start(pid_list, pos); 1319 } 1320 1321 static void *p_start(struct seq_file *m, loff_t *pos) 1322 __acquires(RCU) 1323 { 1324 return __start(m, pos, TRACE_PIDS); 1325 } 1326 1327 static void *np_start(struct seq_file *m, loff_t *pos) 1328 __acquires(RCU) 1329 { 1330 return __start(m, pos, TRACE_NO_PIDS); 1331 } 1332 1333 static void p_stop(struct seq_file *m, void *p) 1334 __releases(RCU) 1335 { 1336 rcu_read_unlock_sched(); 1337 mutex_unlock(&event_mutex); 1338 } 1339 1340 static ssize_t 1341 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, 1342 loff_t *ppos) 1343 { 1344 struct trace_event_file *file; 1345 unsigned long flags; 1346 char buf[4] = "0"; 1347 1348 mutex_lock(&event_mutex); 1349 file = event_file_data(filp); 1350 if (likely(file)) 1351 flags = file->flags; 1352 mutex_unlock(&event_mutex); 1353 1354 if (!file) 1355 return -ENODEV; 1356 1357 if (flags & EVENT_FILE_FL_ENABLED && 1358 !(flags & EVENT_FILE_FL_SOFT_DISABLED)) 1359 strcpy(buf, "1"); 1360 1361 if (flags & EVENT_FILE_FL_SOFT_DISABLED || 1362 flags & EVENT_FILE_FL_SOFT_MODE) 1363 strcat(buf, "*"); 1364 1365 strcat(buf, "\n"); 1366 1367 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf)); 1368 } 1369 1370 static ssize_t 1371 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 1372 loff_t *ppos) 1373 { 1374 struct trace_event_file *file; 1375 unsigned long val; 1376 int ret; 1377 1378 ret = kstrtoul_from_user(ubuf, cnt, 10, &val); 1379 if (ret) 1380 return ret; 1381 1382 ret = tracing_update_buffers(); 1383 if (ret < 0) 1384 return ret; 1385 1386 switch (val) { 1387 case 0: 1388 case 1: 1389 ret = -ENODEV; 1390 mutex_lock(&event_mutex); 1391 file = event_file_data(filp); 1392 if (likely(file)) 1393 ret = ftrace_event_enable_disable(file, val); 1394 mutex_unlock(&event_mutex); 1395 break; 1396 1397 default: 1398 return -EINVAL; 1399 } 1400 1401 *ppos += cnt; 1402 1403 return ret ? ret : cnt; 1404 } 1405 1406 static ssize_t 1407 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, 1408 loff_t *ppos) 1409 { 1410 const char set_to_char[4] = { '?', '0', '1', 'X' }; 1411 struct trace_subsystem_dir *dir = filp->private_data; 1412 struct event_subsystem *system = dir->subsystem; 1413 struct trace_event_call *call; 1414 struct trace_event_file *file; 1415 struct trace_array *tr = dir->tr; 1416 char buf[2]; 1417 int set = 0; 1418 int ret; 1419 1420 mutex_lock(&event_mutex); 1421 list_for_each_entry(file, &tr->events, list) { 1422 call = file->event_call; 1423 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) || 1424 !trace_event_name(call) || !call->class || !call->class->reg) 1425 continue; 1426 1427 if (system && strcmp(call->class->system, system->name) != 0) 1428 continue; 1429 1430 /* 1431 * We need to find out if all the events are set 1432 * or if all events or cleared, or if we have 1433 * a mixture. 1434 */ 1435 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED)); 1436 1437 /* 1438 * If we have a mixture, no need to look further. 1439 */ 1440 if (set == 3) 1441 break; 1442 } 1443 mutex_unlock(&event_mutex); 1444 1445 buf[0] = set_to_char[set]; 1446 buf[1] = '\n'; 1447 1448 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); 1449 1450 return ret; 1451 } 1452 1453 static ssize_t 1454 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 1455 loff_t *ppos) 1456 { 1457 struct trace_subsystem_dir *dir = filp->private_data; 1458 struct event_subsystem *system = dir->subsystem; 1459 const char *name = NULL; 1460 unsigned long val; 1461 ssize_t ret; 1462 1463 ret = kstrtoul_from_user(ubuf, cnt, 10, &val); 1464 if (ret) 1465 return ret; 1466 1467 ret = tracing_update_buffers(); 1468 if (ret < 0) 1469 return ret; 1470 1471 if (val != 0 && val != 1) 1472 return -EINVAL; 1473 1474 /* 1475 * Opening of "enable" adds a ref count to system, 1476 * so the name is safe to use. 1477 */ 1478 if (system) 1479 name = system->name; 1480 1481 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val); 1482 if (ret) 1483 goto out; 1484 1485 ret = cnt; 1486 1487 out: 1488 *ppos += cnt; 1489 1490 return ret; 1491 } 1492 1493 enum { 1494 FORMAT_HEADER = 1, 1495 FORMAT_FIELD_SEPERATOR = 2, 1496 FORMAT_PRINTFMT = 3, 1497 }; 1498 1499 static void *f_next(struct seq_file *m, void *v, loff_t *pos) 1500 { 1501 struct trace_event_call *call = event_file_data(m->private); 1502 struct list_head *common_head = &ftrace_common_fields; 1503 struct list_head *head = trace_get_fields(call); 1504 struct list_head *node = v; 1505 1506 (*pos)++; 1507 1508 switch ((unsigned long)v) { 1509 case FORMAT_HEADER: 1510 node = common_head; 1511 break; 1512 1513 case FORMAT_FIELD_SEPERATOR: 1514 node = head; 1515 break; 1516 1517 case FORMAT_PRINTFMT: 1518 /* all done */ 1519 return NULL; 1520 } 1521 1522 node = node->prev; 1523 if (node == common_head) 1524 return (void *)FORMAT_FIELD_SEPERATOR; 1525 else if (node == head) 1526 return (void *)FORMAT_PRINTFMT; 1527 else 1528 return node; 1529 } 1530 1531 static int f_show(struct seq_file *m, void *v) 1532 { 1533 struct trace_event_call *call = event_file_data(m->private); 1534 struct ftrace_event_field *field; 1535 const char *array_descriptor; 1536 1537 switch ((unsigned long)v) { 1538 case FORMAT_HEADER: 1539 seq_printf(m, "name: %s\n", trace_event_name(call)); 1540 seq_printf(m, "ID: %d\n", call->event.type); 1541 seq_puts(m, "format:\n"); 1542 return 0; 1543 1544 case FORMAT_FIELD_SEPERATOR: 1545 seq_putc(m, '\n'); 1546 return 0; 1547 1548 case FORMAT_PRINTFMT: 1549 seq_printf(m, "\nprint fmt: %s\n", 1550 call->print_fmt); 1551 return 0; 1552 } 1553 1554 field = list_entry(v, struct ftrace_event_field, link); 1555 /* 1556 * Smartly shows the array type(except dynamic array). 1557 * Normal: 1558 * field:TYPE VAR 1559 * If TYPE := TYPE[LEN], it is shown: 1560 * field:TYPE VAR[LEN] 1561 */ 1562 array_descriptor = strchr(field->type, '['); 1563 1564 if (str_has_prefix(field->type, "__data_loc")) 1565 array_descriptor = NULL; 1566 1567 if (!array_descriptor) 1568 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", 1569 field->type, field->name, field->offset, 1570 field->size, !!field->is_signed); 1571 else 1572 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", 1573 (int)(array_descriptor - field->type), 1574 field->type, field->name, 1575 array_descriptor, field->offset, 1576 field->size, !!field->is_signed); 1577 1578 return 0; 1579 } 1580 1581 static void *f_start(struct seq_file *m, loff_t *pos) 1582 { 1583 void *p = (void *)FORMAT_HEADER; 1584 loff_t l = 0; 1585 1586 /* ->stop() is called even if ->start() fails */ 1587 mutex_lock(&event_mutex); 1588 if (!event_file_data(m->private)) 1589 return ERR_PTR(-ENODEV); 1590 1591 while (l < *pos && p) 1592 p = f_next(m, p, &l); 1593 1594 return p; 1595 } 1596 1597 static void f_stop(struct seq_file *m, void *p) 1598 { 1599 mutex_unlock(&event_mutex); 1600 } 1601 1602 static const struct seq_operations trace_format_seq_ops = { 1603 .start = f_start, 1604 .next = f_next, 1605 .stop = f_stop, 1606 .show = f_show, 1607 }; 1608 1609 static int trace_format_open(struct inode *inode, struct file *file) 1610 { 1611 struct seq_file *m; 1612 int ret; 1613 1614 /* Do we want to hide event format files on tracefs lockdown? */ 1615 1616 ret = seq_open(file, &trace_format_seq_ops); 1617 if (ret < 0) 1618 return ret; 1619 1620 m = file->private_data; 1621 m->private = file; 1622 1623 return 0; 1624 } 1625 1626 static ssize_t 1627 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) 1628 { 1629 int id = (long)event_file_data(filp); 1630 char buf[32]; 1631 int len; 1632 1633 if (unlikely(!id)) 1634 return -ENODEV; 1635 1636 len = sprintf(buf, "%d\n", id); 1637 1638 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len); 1639 } 1640 1641 static ssize_t 1642 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, 1643 loff_t *ppos) 1644 { 1645 struct trace_event_file *file; 1646 struct trace_seq *s; 1647 int r = -ENODEV; 1648 1649 if (*ppos) 1650 return 0; 1651 1652 s = kmalloc(sizeof(*s), GFP_KERNEL); 1653 1654 if (!s) 1655 return -ENOMEM; 1656 1657 trace_seq_init(s); 1658 1659 mutex_lock(&event_mutex); 1660 file = event_file_data(filp); 1661 if (file) 1662 print_event_filter(file, s); 1663 mutex_unlock(&event_mutex); 1664 1665 if (file) 1666 r = simple_read_from_buffer(ubuf, cnt, ppos, 1667 s->buffer, trace_seq_used(s)); 1668 1669 kfree(s); 1670 1671 return r; 1672 } 1673 1674 static ssize_t 1675 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, 1676 loff_t *ppos) 1677 { 1678 struct trace_event_file *file; 1679 char *buf; 1680 int err = -ENODEV; 1681 1682 if (cnt >= PAGE_SIZE) 1683 return -EINVAL; 1684 1685 buf = memdup_user_nul(ubuf, cnt); 1686 if (IS_ERR(buf)) 1687 return PTR_ERR(buf); 1688 1689 mutex_lock(&event_mutex); 1690 file = event_file_data(filp); 1691 if (file) 1692 err = apply_event_filter(file, buf); 1693 mutex_unlock(&event_mutex); 1694 1695 kfree(buf); 1696 if (err < 0) 1697 return err; 1698 1699 *ppos += cnt; 1700 1701 return cnt; 1702 } 1703 1704 static LIST_HEAD(event_subsystems); 1705 1706 static int subsystem_open(struct inode *inode, struct file *filp) 1707 { 1708 struct event_subsystem *system = NULL; 1709 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */ 1710 struct trace_array *tr; 1711 int ret; 1712 1713 if (tracing_is_disabled()) 1714 return -ENODEV; 1715 1716 /* Make sure the system still exists */ 1717 mutex_lock(&event_mutex); 1718 mutex_lock(&trace_types_lock); 1719 list_for_each_entry(tr, &ftrace_trace_arrays, list) { 1720 list_for_each_entry(dir, &tr->systems, list) { 1721 if (dir == inode->i_private) { 1722 /* Don't open systems with no events */ 1723 if (dir->nr_events) { 1724 __get_system_dir(dir); 1725 system = dir->subsystem; 1726 } 1727 goto exit_loop; 1728 } 1729 } 1730 } 1731 exit_loop: 1732 mutex_unlock(&trace_types_lock); 1733 mutex_unlock(&event_mutex); 1734 1735 if (!system) 1736 return -ENODEV; 1737 1738 /* Some versions of gcc think dir can be uninitialized here */ 1739 WARN_ON(!dir); 1740 1741 /* Still need to increment the ref count of the system */ 1742 if (trace_array_get(tr) < 0) { 1743 put_system(dir); 1744 return -ENODEV; 1745 } 1746 1747 ret = tracing_open_generic(inode, filp); 1748 if (ret < 0) { 1749 trace_array_put(tr); 1750 put_system(dir); 1751 } 1752 1753 return ret; 1754 } 1755 1756 static int system_tr_open(struct inode *inode, struct file *filp) 1757 { 1758 struct trace_subsystem_dir *dir; 1759 struct trace_array *tr = inode->i_private; 1760 int ret; 1761 1762 /* Make a temporary dir that has no system but points to tr */ 1763 dir = kzalloc(sizeof(*dir), GFP_KERNEL); 1764 if (!dir) 1765 return -ENOMEM; 1766 1767 ret = tracing_open_generic_tr(inode, filp); 1768 if (ret < 0) { 1769 kfree(dir); 1770 return ret; 1771 } 1772 dir->tr = tr; 1773 filp->private_data = dir; 1774 1775 return 0; 1776 } 1777 1778 static int subsystem_release(struct inode *inode, struct file *file) 1779 { 1780 struct trace_subsystem_dir *dir = file->private_data; 1781 1782 trace_array_put(dir->tr); 1783 1784 /* 1785 * If dir->subsystem is NULL, then this is a temporary 1786 * descriptor that was made for a trace_array to enable 1787 * all subsystems. 1788 */ 1789 if (dir->subsystem) 1790 put_system(dir); 1791 else 1792 kfree(dir); 1793 1794 return 0; 1795 } 1796 1797 static ssize_t 1798 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, 1799 loff_t *ppos) 1800 { 1801 struct trace_subsystem_dir *dir = filp->private_data; 1802 struct event_subsystem *system = dir->subsystem; 1803 struct trace_seq *s; 1804 int r; 1805 1806 if (*ppos) 1807 return 0; 1808 1809 s = kmalloc(sizeof(*s), GFP_KERNEL); 1810 if (!s) 1811 return -ENOMEM; 1812 1813 trace_seq_init(s); 1814 1815 print_subsystem_event_filter(system, s); 1816 r = simple_read_from_buffer(ubuf, cnt, ppos, 1817 s->buffer, trace_seq_used(s)); 1818 1819 kfree(s); 1820 1821 return r; 1822 } 1823 1824 static ssize_t 1825 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, 1826 loff_t *ppos) 1827 { 1828 struct trace_subsystem_dir *dir = filp->private_data; 1829 char *buf; 1830 int err; 1831 1832 if (cnt >= PAGE_SIZE) 1833 return -EINVAL; 1834 1835 buf = memdup_user_nul(ubuf, cnt); 1836 if (IS_ERR(buf)) 1837 return PTR_ERR(buf); 1838 1839 err = apply_subsystem_event_filter(dir, buf); 1840 kfree(buf); 1841 if (err < 0) 1842 return err; 1843 1844 *ppos += cnt; 1845 1846 return cnt; 1847 } 1848 1849 static ssize_t 1850 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) 1851 { 1852 int (*func)(struct trace_seq *s) = filp->private_data; 1853 struct trace_seq *s; 1854 int r; 1855 1856 if (*ppos) 1857 return 0; 1858 1859 s = kmalloc(sizeof(*s), GFP_KERNEL); 1860 if (!s) 1861 return -ENOMEM; 1862 1863 trace_seq_init(s); 1864 1865 func(s); 1866 r = simple_read_from_buffer(ubuf, cnt, ppos, 1867 s->buffer, trace_seq_used(s)); 1868 1869 kfree(s); 1870 1871 return r; 1872 } 1873 1874 static void ignore_task_cpu(void *data) 1875 { 1876 struct trace_array *tr = data; 1877 struct trace_pid_list *pid_list; 1878 struct trace_pid_list *no_pid_list; 1879 1880 /* 1881 * This function is called by on_each_cpu() while the 1882 * event_mutex is held. 1883 */ 1884 pid_list = rcu_dereference_protected(tr->filtered_pids, 1885 mutex_is_locked(&event_mutex)); 1886 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids, 1887 mutex_is_locked(&event_mutex)); 1888 1889 this_cpu_write(tr->array_buffer.data->ignore_pid, 1890 trace_ignore_this_task(pid_list, no_pid_list, current)); 1891 } 1892 1893 static void register_pid_events(struct trace_array *tr) 1894 { 1895 /* 1896 * Register a probe that is called before all other probes 1897 * to set ignore_pid if next or prev do not match. 1898 * Register a probe this is called after all other probes 1899 * to only keep ignore_pid set if next pid matches. 1900 */ 1901 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre, 1902 tr, INT_MAX); 1903 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post, 1904 tr, 0); 1905 1906 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, 1907 tr, INT_MAX); 1908 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, 1909 tr, 0); 1910 1911 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, 1912 tr, INT_MAX); 1913 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, 1914 tr, 0); 1915 1916 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre, 1917 tr, INT_MAX); 1918 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post, 1919 tr, 0); 1920 } 1921 1922 static ssize_t 1923 event_pid_write(struct file *filp, const char __user *ubuf, 1924 size_t cnt, loff_t *ppos, int type) 1925 { 1926 struct seq_file *m = filp->private_data; 1927 struct trace_array *tr = m->private; 1928 struct trace_pid_list *filtered_pids = NULL; 1929 struct trace_pid_list *other_pids = NULL; 1930 struct trace_pid_list *pid_list; 1931 struct trace_event_file *file; 1932 ssize_t ret; 1933 1934 if (!cnt) 1935 return 0; 1936 1937 ret = tracing_update_buffers(); 1938 if (ret < 0) 1939 return ret; 1940 1941 mutex_lock(&event_mutex); 1942 1943 if (type == TRACE_PIDS) { 1944 filtered_pids = rcu_dereference_protected(tr->filtered_pids, 1945 lockdep_is_held(&event_mutex)); 1946 other_pids = rcu_dereference_protected(tr->filtered_no_pids, 1947 lockdep_is_held(&event_mutex)); 1948 } else { 1949 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids, 1950 lockdep_is_held(&event_mutex)); 1951 other_pids = rcu_dereference_protected(tr->filtered_pids, 1952 lockdep_is_held(&event_mutex)); 1953 } 1954 1955 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); 1956 if (ret < 0) 1957 goto out; 1958 1959 if (type == TRACE_PIDS) 1960 rcu_assign_pointer(tr->filtered_pids, pid_list); 1961 else 1962 rcu_assign_pointer(tr->filtered_no_pids, pid_list); 1963 1964 list_for_each_entry(file, &tr->events, list) { 1965 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags); 1966 } 1967 1968 if (filtered_pids) { 1969 tracepoint_synchronize_unregister(); 1970 trace_pid_list_free(filtered_pids); 1971 } else if (pid_list && !other_pids) { 1972 register_pid_events(tr); 1973 } 1974 1975 /* 1976 * Ignoring of pids is done at task switch. But we have to 1977 * check for those tasks that are currently running. 1978 * Always do this in case a pid was appended or removed. 1979 */ 1980 on_each_cpu(ignore_task_cpu, tr, 1); 1981 1982 out: 1983 mutex_unlock(&event_mutex); 1984 1985 if (ret > 0) 1986 *ppos += ret; 1987 1988 return ret; 1989 } 1990 1991 static ssize_t 1992 ftrace_event_pid_write(struct file *filp, const char __user *ubuf, 1993 size_t cnt, loff_t *ppos) 1994 { 1995 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); 1996 } 1997 1998 static ssize_t 1999 ftrace_event_npid_write(struct file *filp, const char __user *ubuf, 2000 size_t cnt, loff_t *ppos) 2001 { 2002 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); 2003 } 2004 2005 static int ftrace_event_avail_open(struct inode *inode, struct file *file); 2006 static int ftrace_event_set_open(struct inode *inode, struct file *file); 2007 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file); 2008 static int ftrace_event_set_npid_open(struct inode *inode, struct file *file); 2009 static int ftrace_event_release(struct inode *inode, struct file *file); 2010 2011 static const struct seq_operations show_event_seq_ops = { 2012 .start = t_start, 2013 .next = t_next, 2014 .show = t_show, 2015 .stop = t_stop, 2016 }; 2017 2018 static const struct seq_operations show_set_event_seq_ops = { 2019 .start = s_start, 2020 .next = s_next, 2021 .show = t_show, 2022 .stop = t_stop, 2023 }; 2024 2025 static const struct seq_operations show_set_pid_seq_ops = { 2026 .start = p_start, 2027 .next = p_next, 2028 .show = trace_pid_show, 2029 .stop = p_stop, 2030 }; 2031 2032 static const struct seq_operations show_set_no_pid_seq_ops = { 2033 .start = np_start, 2034 .next = np_next, 2035 .show = trace_pid_show, 2036 .stop = p_stop, 2037 }; 2038 2039 static const struct file_operations ftrace_avail_fops = { 2040 .open = ftrace_event_avail_open, 2041 .read = seq_read, 2042 .llseek = seq_lseek, 2043 .release = seq_release, 2044 }; 2045 2046 static const struct file_operations ftrace_set_event_fops = { 2047 .open = ftrace_event_set_open, 2048 .read = seq_read, 2049 .write = ftrace_event_write, 2050 .llseek = seq_lseek, 2051 .release = ftrace_event_release, 2052 }; 2053 2054 static const struct file_operations ftrace_set_event_pid_fops = { 2055 .open = ftrace_event_set_pid_open, 2056 .read = seq_read, 2057 .write = ftrace_event_pid_write, 2058 .llseek = seq_lseek, 2059 .release = ftrace_event_release, 2060 }; 2061 2062 static const struct file_operations ftrace_set_event_notrace_pid_fops = { 2063 .open = ftrace_event_set_npid_open, 2064 .read = seq_read, 2065 .write = ftrace_event_npid_write, 2066 .llseek = seq_lseek, 2067 .release = ftrace_event_release, 2068 }; 2069 2070 static const struct file_operations ftrace_enable_fops = { 2071 .open = tracing_open_generic, 2072 .read = event_enable_read, 2073 .write = event_enable_write, 2074 .llseek = default_llseek, 2075 }; 2076 2077 static const struct file_operations ftrace_event_format_fops = { 2078 .open = trace_format_open, 2079 .read = seq_read, 2080 .llseek = seq_lseek, 2081 .release = seq_release, 2082 }; 2083 2084 static const struct file_operations ftrace_event_id_fops = { 2085 .read = event_id_read, 2086 .llseek = default_llseek, 2087 }; 2088 2089 static const struct file_operations ftrace_event_filter_fops = { 2090 .open = tracing_open_generic, 2091 .read = event_filter_read, 2092 .write = event_filter_write, 2093 .llseek = default_llseek, 2094 }; 2095 2096 static const struct file_operations ftrace_subsystem_filter_fops = { 2097 .open = subsystem_open, 2098 .read = subsystem_filter_read, 2099 .write = subsystem_filter_write, 2100 .llseek = default_llseek, 2101 .release = subsystem_release, 2102 }; 2103 2104 static const struct file_operations ftrace_system_enable_fops = { 2105 .open = subsystem_open, 2106 .read = system_enable_read, 2107 .write = system_enable_write, 2108 .llseek = default_llseek, 2109 .release = subsystem_release, 2110 }; 2111 2112 static const struct file_operations ftrace_tr_enable_fops = { 2113 .open = system_tr_open, 2114 .read = system_enable_read, 2115 .write = system_enable_write, 2116 .llseek = default_llseek, 2117 .release = subsystem_release, 2118 }; 2119 2120 static const struct file_operations ftrace_show_header_fops = { 2121 .open = tracing_open_generic, 2122 .read = show_header, 2123 .llseek = default_llseek, 2124 }; 2125 2126 static int 2127 ftrace_event_open(struct inode *inode, struct file *file, 2128 const struct seq_operations *seq_ops) 2129 { 2130 struct seq_file *m; 2131 int ret; 2132 2133 ret = security_locked_down(LOCKDOWN_TRACEFS); 2134 if (ret) 2135 return ret; 2136 2137 ret = seq_open(file, seq_ops); 2138 if (ret < 0) 2139 return ret; 2140 m = file->private_data; 2141 /* copy tr over to seq ops */ 2142 m->private = inode->i_private; 2143 2144 return ret; 2145 } 2146 2147 static int ftrace_event_release(struct inode *inode, struct file *file) 2148 { 2149 struct trace_array *tr = inode->i_private; 2150 2151 trace_array_put(tr); 2152 2153 return seq_release(inode, file); 2154 } 2155 2156 static int 2157 ftrace_event_avail_open(struct inode *inode, struct file *file) 2158 { 2159 const struct seq_operations *seq_ops = &show_event_seq_ops; 2160 2161 /* Checks for tracefs lockdown */ 2162 return ftrace_event_open(inode, file, seq_ops); 2163 } 2164 2165 static int 2166 ftrace_event_set_open(struct inode *inode, struct file *file) 2167 { 2168 const struct seq_operations *seq_ops = &show_set_event_seq_ops; 2169 struct trace_array *tr = inode->i_private; 2170 int ret; 2171 2172 ret = tracing_check_open_get_tr(tr); 2173 if (ret) 2174 return ret; 2175 2176 if ((file->f_mode & FMODE_WRITE) && 2177 (file->f_flags & O_TRUNC)) 2178 ftrace_clear_events(tr); 2179 2180 ret = ftrace_event_open(inode, file, seq_ops); 2181 if (ret < 0) 2182 trace_array_put(tr); 2183 return ret; 2184 } 2185 2186 static int 2187 ftrace_event_set_pid_open(struct inode *inode, struct file *file) 2188 { 2189 const struct seq_operations *seq_ops = &show_set_pid_seq_ops; 2190 struct trace_array *tr = inode->i_private; 2191 int ret; 2192 2193 ret = tracing_check_open_get_tr(tr); 2194 if (ret) 2195 return ret; 2196 2197 if ((file->f_mode & FMODE_WRITE) && 2198 (file->f_flags & O_TRUNC)) 2199 ftrace_clear_event_pids(tr, TRACE_PIDS); 2200 2201 ret = ftrace_event_open(inode, file, seq_ops); 2202 if (ret < 0) 2203 trace_array_put(tr); 2204 return ret; 2205 } 2206 2207 static int 2208 ftrace_event_set_npid_open(struct inode *inode, struct file *file) 2209 { 2210 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops; 2211 struct trace_array *tr = inode->i_private; 2212 int ret; 2213 2214 ret = tracing_check_open_get_tr(tr); 2215 if (ret) 2216 return ret; 2217 2218 if ((file->f_mode & FMODE_WRITE) && 2219 (file->f_flags & O_TRUNC)) 2220 ftrace_clear_event_pids(tr, TRACE_NO_PIDS); 2221 2222 ret = ftrace_event_open(inode, file, seq_ops); 2223 if (ret < 0) 2224 trace_array_put(tr); 2225 return ret; 2226 } 2227 2228 static struct event_subsystem * 2229 create_new_subsystem(const char *name) 2230 { 2231 struct event_subsystem *system; 2232 2233 /* need to create new entry */ 2234 system = kmalloc(sizeof(*system), GFP_KERNEL); 2235 if (!system) 2236 return NULL; 2237 2238 system->ref_count = 1; 2239 2240 /* Only allocate if dynamic (kprobes and modules) */ 2241 system->name = kstrdup_const(name, GFP_KERNEL); 2242 if (!system->name) 2243 goto out_free; 2244 2245 system->filter = NULL; 2246 2247 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); 2248 if (!system->filter) 2249 goto out_free; 2250 2251 list_add(&system->list, &event_subsystems); 2252 2253 return system; 2254 2255 out_free: 2256 kfree_const(system->name); 2257 kfree(system); 2258 return NULL; 2259 } 2260 2261 static struct dentry * 2262 event_subsystem_dir(struct trace_array *tr, const char *name, 2263 struct trace_event_file *file, struct dentry *parent) 2264 { 2265 struct trace_subsystem_dir *dir; 2266 struct event_subsystem *system; 2267 struct dentry *entry; 2268 2269 /* First see if we did not already create this dir */ 2270 list_for_each_entry(dir, &tr->systems, list) { 2271 system = dir->subsystem; 2272 if (strcmp(system->name, name) == 0) { 2273 dir->nr_events++; 2274 file->system = dir; 2275 return dir->entry; 2276 } 2277 } 2278 2279 /* Now see if the system itself exists. */ 2280 list_for_each_entry(system, &event_subsystems, list) { 2281 if (strcmp(system->name, name) == 0) 2282 break; 2283 } 2284 /* Reset system variable when not found */ 2285 if (&system->list == &event_subsystems) 2286 system = NULL; 2287 2288 dir = kmalloc(sizeof(*dir), GFP_KERNEL); 2289 if (!dir) 2290 goto out_fail; 2291 2292 if (!system) { 2293 system = create_new_subsystem(name); 2294 if (!system) 2295 goto out_free; 2296 } else 2297 __get_system(system); 2298 2299 dir->entry = tracefs_create_dir(name, parent); 2300 if (!dir->entry) { 2301 pr_warn("Failed to create system directory %s\n", name); 2302 __put_system(system); 2303 goto out_free; 2304 } 2305 2306 dir->tr = tr; 2307 dir->ref_count = 1; 2308 dir->nr_events = 1; 2309 dir->subsystem = system; 2310 file->system = dir; 2311 2312 /* the ftrace system is special, do not create enable or filter files */ 2313 if (strcmp(name, "ftrace") != 0) { 2314 2315 entry = tracefs_create_file("filter", TRACE_MODE_WRITE, 2316 dir->entry, dir, 2317 &ftrace_subsystem_filter_fops); 2318 if (!entry) { 2319 kfree(system->filter); 2320 system->filter = NULL; 2321 pr_warn("Could not create tracefs '%s/filter' entry\n", name); 2322 } 2323 2324 trace_create_file("enable", TRACE_MODE_WRITE, dir->entry, dir, 2325 &ftrace_system_enable_fops); 2326 } 2327 2328 list_add(&dir->list, &tr->systems); 2329 2330 return dir->entry; 2331 2332 out_free: 2333 kfree(dir); 2334 out_fail: 2335 /* Only print this message if failed on memory allocation */ 2336 if (!dir || !system) 2337 pr_warn("No memory to create event subsystem %s\n", name); 2338 return NULL; 2339 } 2340 2341 static int 2342 event_define_fields(struct trace_event_call *call) 2343 { 2344 struct list_head *head; 2345 int ret = 0; 2346 2347 /* 2348 * Other events may have the same class. Only update 2349 * the fields if they are not already defined. 2350 */ 2351 head = trace_get_fields(call); 2352 if (list_empty(head)) { 2353 struct trace_event_fields *field = call->class->fields_array; 2354 unsigned int offset = sizeof(struct trace_entry); 2355 2356 for (; field->type; field++) { 2357 if (field->type == TRACE_FUNCTION_TYPE) { 2358 field->define_fields(call); 2359 break; 2360 } 2361 2362 offset = ALIGN(offset, field->align); 2363 ret = trace_define_field(call, field->type, field->name, 2364 offset, field->size, 2365 field->is_signed, field->filter_type); 2366 if (WARN_ON_ONCE(ret)) { 2367 pr_err("error code is %d\n", ret); 2368 break; 2369 } 2370 2371 offset += field->size; 2372 } 2373 } 2374 2375 return ret; 2376 } 2377 2378 static int 2379 event_create_dir(struct dentry *parent, struct trace_event_file *file) 2380 { 2381 struct trace_event_call *call = file->event_call; 2382 struct trace_array *tr = file->tr; 2383 struct dentry *d_events; 2384 const char *name; 2385 int ret; 2386 2387 /* 2388 * If the trace point header did not define TRACE_SYSTEM 2389 * then the system would be called "TRACE_SYSTEM". 2390 */ 2391 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) { 2392 d_events = event_subsystem_dir(tr, call->class->system, file, parent); 2393 if (!d_events) 2394 return -ENOMEM; 2395 } else 2396 d_events = parent; 2397 2398 name = trace_event_name(call); 2399 file->dir = tracefs_create_dir(name, d_events); 2400 if (!file->dir) { 2401 pr_warn("Could not create tracefs '%s' directory\n", name); 2402 return -1; 2403 } 2404 2405 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) 2406 trace_create_file("enable", TRACE_MODE_WRITE, file->dir, file, 2407 &ftrace_enable_fops); 2408 2409 #ifdef CONFIG_PERF_EVENTS 2410 if (call->event.type && call->class->reg) 2411 trace_create_file("id", TRACE_MODE_READ, file->dir, 2412 (void *)(long)call->event.type, 2413 &ftrace_event_id_fops); 2414 #endif 2415 2416 ret = event_define_fields(call); 2417 if (ret < 0) { 2418 pr_warn("Could not initialize trace point events/%s\n", name); 2419 return ret; 2420 } 2421 2422 /* 2423 * Only event directories that can be enabled should have 2424 * triggers or filters. 2425 */ 2426 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) { 2427 trace_create_file("filter", TRACE_MODE_WRITE, file->dir, 2428 file, &ftrace_event_filter_fops); 2429 2430 trace_create_file("trigger", TRACE_MODE_WRITE, file->dir, 2431 file, &event_trigger_fops); 2432 } 2433 2434 #ifdef CONFIG_HIST_TRIGGERS 2435 trace_create_file("hist", TRACE_MODE_READ, file->dir, file, 2436 &event_hist_fops); 2437 #endif 2438 #ifdef CONFIG_HIST_TRIGGERS_DEBUG 2439 trace_create_file("hist_debug", TRACE_MODE_READ, file->dir, file, 2440 &event_hist_debug_fops); 2441 #endif 2442 trace_create_file("format", TRACE_MODE_READ, file->dir, call, 2443 &ftrace_event_format_fops); 2444 2445 #ifdef CONFIG_TRACE_EVENT_INJECT 2446 if (call->event.type && call->class->reg) 2447 trace_create_file("inject", 0200, file->dir, file, 2448 &event_inject_fops); 2449 #endif 2450 2451 return 0; 2452 } 2453 2454 static void remove_event_from_tracers(struct trace_event_call *call) 2455 { 2456 struct trace_event_file *file; 2457 struct trace_array *tr; 2458 2459 do_for_each_event_file_safe(tr, file) { 2460 if (file->event_call != call) 2461 continue; 2462 2463 remove_event_file_dir(file); 2464 /* 2465 * The do_for_each_event_file_safe() is 2466 * a double loop. After finding the call for this 2467 * trace_array, we use break to jump to the next 2468 * trace_array. 2469 */ 2470 break; 2471 } while_for_each_event_file(); 2472 } 2473 2474 static void event_remove(struct trace_event_call *call) 2475 { 2476 struct trace_array *tr; 2477 struct trace_event_file *file; 2478 2479 do_for_each_event_file(tr, file) { 2480 if (file->event_call != call) 2481 continue; 2482 2483 if (file->flags & EVENT_FILE_FL_WAS_ENABLED) 2484 tr->clear_trace = true; 2485 2486 ftrace_event_enable_disable(file, 0); 2487 /* 2488 * The do_for_each_event_file() is 2489 * a double loop. After finding the call for this 2490 * trace_array, we use break to jump to the next 2491 * trace_array. 2492 */ 2493 break; 2494 } while_for_each_event_file(); 2495 2496 if (call->event.funcs) 2497 __unregister_trace_event(&call->event); 2498 remove_event_from_tracers(call); 2499 list_del(&call->list); 2500 } 2501 2502 static int event_init(struct trace_event_call *call) 2503 { 2504 int ret = 0; 2505 const char *name; 2506 2507 name = trace_event_name(call); 2508 if (WARN_ON(!name)) 2509 return -EINVAL; 2510 2511 if (call->class->raw_init) { 2512 ret = call->class->raw_init(call); 2513 if (ret < 0 && ret != -ENOSYS) 2514 pr_warn("Could not initialize trace events/%s\n", name); 2515 } 2516 2517 return ret; 2518 } 2519 2520 static int 2521 __register_event(struct trace_event_call *call, struct module *mod) 2522 { 2523 int ret; 2524 2525 ret = event_init(call); 2526 if (ret < 0) 2527 return ret; 2528 2529 list_add(&call->list, &ftrace_events); 2530 if (call->flags & TRACE_EVENT_FL_DYNAMIC) 2531 atomic_set(&call->refcnt, 0); 2532 else 2533 call->module = mod; 2534 2535 return 0; 2536 } 2537 2538 static char *eval_replace(char *ptr, struct trace_eval_map *map, int len) 2539 { 2540 int rlen; 2541 int elen; 2542 2543 /* Find the length of the eval value as a string */ 2544 elen = snprintf(ptr, 0, "%ld", map->eval_value); 2545 /* Make sure there's enough room to replace the string with the value */ 2546 if (len < elen) 2547 return NULL; 2548 2549 snprintf(ptr, elen + 1, "%ld", map->eval_value); 2550 2551 /* Get the rest of the string of ptr */ 2552 rlen = strlen(ptr + len); 2553 memmove(ptr + elen, ptr + len, rlen); 2554 /* Make sure we end the new string */ 2555 ptr[elen + rlen] = 0; 2556 2557 return ptr + elen; 2558 } 2559 2560 static void update_event_printk(struct trace_event_call *call, 2561 struct trace_eval_map *map) 2562 { 2563 char *ptr; 2564 int quote = 0; 2565 int len = strlen(map->eval_string); 2566 2567 for (ptr = call->print_fmt; *ptr; ptr++) { 2568 if (*ptr == '\\') { 2569 ptr++; 2570 /* paranoid */ 2571 if (!*ptr) 2572 break; 2573 continue; 2574 } 2575 if (*ptr == '"') { 2576 quote ^= 1; 2577 continue; 2578 } 2579 if (quote) 2580 continue; 2581 if (isdigit(*ptr)) { 2582 /* skip numbers */ 2583 do { 2584 ptr++; 2585 /* Check for alpha chars like ULL */ 2586 } while (isalnum(*ptr)); 2587 if (!*ptr) 2588 break; 2589 /* 2590 * A number must have some kind of delimiter after 2591 * it, and we can ignore that too. 2592 */ 2593 continue; 2594 } 2595 if (isalpha(*ptr) || *ptr == '_') { 2596 if (strncmp(map->eval_string, ptr, len) == 0 && 2597 !isalnum(ptr[len]) && ptr[len] != '_') { 2598 ptr = eval_replace(ptr, map, len); 2599 /* enum/sizeof string smaller than value */ 2600 if (WARN_ON_ONCE(!ptr)) 2601 return; 2602 /* 2603 * No need to decrement here, as eval_replace() 2604 * returns the pointer to the character passed 2605 * the eval, and two evals can not be placed 2606 * back to back without something in between. 2607 * We can skip that something in between. 2608 */ 2609 continue; 2610 } 2611 skip_more: 2612 do { 2613 ptr++; 2614 } while (isalnum(*ptr) || *ptr == '_'); 2615 if (!*ptr) 2616 break; 2617 /* 2618 * If what comes after this variable is a '.' or 2619 * '->' then we can continue to ignore that string. 2620 */ 2621 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) { 2622 ptr += *ptr == '.' ? 1 : 2; 2623 if (!*ptr) 2624 break; 2625 goto skip_more; 2626 } 2627 /* 2628 * Once again, we can skip the delimiter that came 2629 * after the string. 2630 */ 2631 continue; 2632 } 2633 } 2634 } 2635 2636 void trace_event_eval_update(struct trace_eval_map **map, int len) 2637 { 2638 struct trace_event_call *call, *p; 2639 const char *last_system = NULL; 2640 bool first = false; 2641 int last_i; 2642 int i; 2643 2644 down_write(&trace_event_sem); 2645 list_for_each_entry_safe(call, p, &ftrace_events, list) { 2646 /* events are usually grouped together with systems */ 2647 if (!last_system || call->class->system != last_system) { 2648 first = true; 2649 last_i = 0; 2650 last_system = call->class->system; 2651 } 2652 2653 /* 2654 * Since calls are grouped by systems, the likelihood that the 2655 * next call in the iteration belongs to the same system as the 2656 * previous call is high. As an optimization, we skip searching 2657 * for a map[] that matches the call's system if the last call 2658 * was from the same system. That's what last_i is for. If the 2659 * call has the same system as the previous call, then last_i 2660 * will be the index of the first map[] that has a matching 2661 * system. 2662 */ 2663 for (i = last_i; i < len; i++) { 2664 if (call->class->system == map[i]->system) { 2665 /* Save the first system if need be */ 2666 if (first) { 2667 last_i = i; 2668 first = false; 2669 } 2670 update_event_printk(call, map[i]); 2671 } 2672 } 2673 } 2674 up_write(&trace_event_sem); 2675 } 2676 2677 static struct trace_event_file * 2678 trace_create_new_event(struct trace_event_call *call, 2679 struct trace_array *tr) 2680 { 2681 struct trace_event_file *file; 2682 2683 file = kmem_cache_alloc(file_cachep, GFP_TRACE); 2684 if (!file) 2685 return NULL; 2686 2687 file->event_call = call; 2688 file->tr = tr; 2689 atomic_set(&file->sm_ref, 0); 2690 atomic_set(&file->tm_ref, 0); 2691 INIT_LIST_HEAD(&file->triggers); 2692 list_add(&file->list, &tr->events); 2693 2694 return file; 2695 } 2696 2697 /* Add an event to a trace directory */ 2698 static int 2699 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr) 2700 { 2701 struct trace_event_file *file; 2702 2703 file = trace_create_new_event(call, tr); 2704 if (!file) 2705 return -ENOMEM; 2706 2707 if (eventdir_initialized) 2708 return event_create_dir(tr->event_dir, file); 2709 else 2710 return event_define_fields(call); 2711 } 2712 2713 /* 2714 * Just create a descriptor for early init. A descriptor is required 2715 * for enabling events at boot. We want to enable events before 2716 * the filesystem is initialized. 2717 */ 2718 static int 2719 __trace_early_add_new_event(struct trace_event_call *call, 2720 struct trace_array *tr) 2721 { 2722 struct trace_event_file *file; 2723 2724 file = trace_create_new_event(call, tr); 2725 if (!file) 2726 return -ENOMEM; 2727 2728 return event_define_fields(call); 2729 } 2730 2731 struct ftrace_module_file_ops; 2732 static void __add_event_to_tracers(struct trace_event_call *call); 2733 2734 /* Add an additional event_call dynamically */ 2735 int trace_add_event_call(struct trace_event_call *call) 2736 { 2737 int ret; 2738 lockdep_assert_held(&event_mutex); 2739 2740 mutex_lock(&trace_types_lock); 2741 2742 ret = __register_event(call, NULL); 2743 if (ret >= 0) 2744 __add_event_to_tracers(call); 2745 2746 mutex_unlock(&trace_types_lock); 2747 return ret; 2748 } 2749 2750 /* 2751 * Must be called under locking of trace_types_lock, event_mutex and 2752 * trace_event_sem. 2753 */ 2754 static void __trace_remove_event_call(struct trace_event_call *call) 2755 { 2756 event_remove(call); 2757 trace_destroy_fields(call); 2758 free_event_filter(call->filter); 2759 call->filter = NULL; 2760 } 2761 2762 static int probe_remove_event_call(struct trace_event_call *call) 2763 { 2764 struct trace_array *tr; 2765 struct trace_event_file *file; 2766 2767 #ifdef CONFIG_PERF_EVENTS 2768 if (call->perf_refcount) 2769 return -EBUSY; 2770 #endif 2771 do_for_each_event_file(tr, file) { 2772 if (file->event_call != call) 2773 continue; 2774 /* 2775 * We can't rely on ftrace_event_enable_disable(enable => 0) 2776 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress 2777 * TRACE_REG_UNREGISTER. 2778 */ 2779 if (file->flags & EVENT_FILE_FL_ENABLED) 2780 return -EBUSY; 2781 /* 2782 * The do_for_each_event_file_safe() is 2783 * a double loop. After finding the call for this 2784 * trace_array, we use break to jump to the next 2785 * trace_array. 2786 */ 2787 break; 2788 } while_for_each_event_file(); 2789 2790 __trace_remove_event_call(call); 2791 2792 return 0; 2793 } 2794 2795 /* Remove an event_call */ 2796 int trace_remove_event_call(struct trace_event_call *call) 2797 { 2798 int ret; 2799 2800 lockdep_assert_held(&event_mutex); 2801 2802 mutex_lock(&trace_types_lock); 2803 down_write(&trace_event_sem); 2804 ret = probe_remove_event_call(call); 2805 up_write(&trace_event_sem); 2806 mutex_unlock(&trace_types_lock); 2807 2808 return ret; 2809 } 2810 2811 #define for_each_event(event, start, end) \ 2812 for (event = start; \ 2813 (unsigned long)event < (unsigned long)end; \ 2814 event++) 2815 2816 #ifdef CONFIG_MODULES 2817 2818 static void trace_module_add_events(struct module *mod) 2819 { 2820 struct trace_event_call **call, **start, **end; 2821 2822 if (!mod->num_trace_events) 2823 return; 2824 2825 /* Don't add infrastructure for mods without tracepoints */ 2826 if (trace_module_has_bad_taint(mod)) { 2827 pr_err("%s: module has bad taint, not creating trace events\n", 2828 mod->name); 2829 return; 2830 } 2831 2832 start = mod->trace_events; 2833 end = mod->trace_events + mod->num_trace_events; 2834 2835 for_each_event(call, start, end) { 2836 __register_event(*call, mod); 2837 __add_event_to_tracers(*call); 2838 } 2839 } 2840 2841 static void trace_module_remove_events(struct module *mod) 2842 { 2843 struct trace_event_call *call, *p; 2844 2845 down_write(&trace_event_sem); 2846 list_for_each_entry_safe(call, p, &ftrace_events, list) { 2847 if ((call->flags & TRACE_EVENT_FL_DYNAMIC) || !call->module) 2848 continue; 2849 if (call->module == mod) 2850 __trace_remove_event_call(call); 2851 } 2852 up_write(&trace_event_sem); 2853 2854 /* 2855 * It is safest to reset the ring buffer if the module being unloaded 2856 * registered any events that were used. The only worry is if 2857 * a new module gets loaded, and takes on the same id as the events 2858 * of this module. When printing out the buffer, traced events left 2859 * over from this module may be passed to the new module events and 2860 * unexpected results may occur. 2861 */ 2862 tracing_reset_all_online_cpus(); 2863 } 2864 2865 static int trace_module_notify(struct notifier_block *self, 2866 unsigned long val, void *data) 2867 { 2868 struct module *mod = data; 2869 2870 mutex_lock(&event_mutex); 2871 mutex_lock(&trace_types_lock); 2872 switch (val) { 2873 case MODULE_STATE_COMING: 2874 trace_module_add_events(mod); 2875 break; 2876 case MODULE_STATE_GOING: 2877 trace_module_remove_events(mod); 2878 break; 2879 } 2880 mutex_unlock(&trace_types_lock); 2881 mutex_unlock(&event_mutex); 2882 2883 return NOTIFY_OK; 2884 } 2885 2886 static struct notifier_block trace_module_nb = { 2887 .notifier_call = trace_module_notify, 2888 .priority = 1, /* higher than trace.c module notify */ 2889 }; 2890 #endif /* CONFIG_MODULES */ 2891 2892 /* Create a new event directory structure for a trace directory. */ 2893 static void 2894 __trace_add_event_dirs(struct trace_array *tr) 2895 { 2896 struct trace_event_call *call; 2897 int ret; 2898 2899 list_for_each_entry(call, &ftrace_events, list) { 2900 ret = __trace_add_new_event(call, tr); 2901 if (ret < 0) 2902 pr_warn("Could not create directory for event %s\n", 2903 trace_event_name(call)); 2904 } 2905 } 2906 2907 /* Returns any file that matches the system and event */ 2908 struct trace_event_file * 2909 __find_event_file(struct trace_array *tr, const char *system, const char *event) 2910 { 2911 struct trace_event_file *file; 2912 struct trace_event_call *call; 2913 const char *name; 2914 2915 list_for_each_entry(file, &tr->events, list) { 2916 2917 call = file->event_call; 2918 name = trace_event_name(call); 2919 2920 if (!name || !call->class) 2921 continue; 2922 2923 if (strcmp(event, name) == 0 && 2924 strcmp(system, call->class->system) == 0) 2925 return file; 2926 } 2927 return NULL; 2928 } 2929 2930 /* Returns valid trace event files that match system and event */ 2931 struct trace_event_file * 2932 find_event_file(struct trace_array *tr, const char *system, const char *event) 2933 { 2934 struct trace_event_file *file; 2935 2936 file = __find_event_file(tr, system, event); 2937 if (!file || !file->event_call->class->reg || 2938 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) 2939 return NULL; 2940 2941 return file; 2942 } 2943 2944 /** 2945 * trace_get_event_file - Find and return a trace event file 2946 * @instance: The name of the trace instance containing the event 2947 * @system: The name of the system containing the event 2948 * @event: The name of the event 2949 * 2950 * Return a trace event file given the trace instance name, trace 2951 * system, and trace event name. If the instance name is NULL, it 2952 * refers to the top-level trace array. 2953 * 2954 * This function will look it up and return it if found, after calling 2955 * trace_array_get() to prevent the instance from going away, and 2956 * increment the event's module refcount to prevent it from being 2957 * removed. 2958 * 2959 * To release the file, call trace_put_event_file(), which will call 2960 * trace_array_put() and decrement the event's module refcount. 2961 * 2962 * Return: The trace event on success, ERR_PTR otherwise. 2963 */ 2964 struct trace_event_file *trace_get_event_file(const char *instance, 2965 const char *system, 2966 const char *event) 2967 { 2968 struct trace_array *tr = top_trace_array(); 2969 struct trace_event_file *file = NULL; 2970 int ret = -EINVAL; 2971 2972 if (instance) { 2973 tr = trace_array_find_get(instance); 2974 if (!tr) 2975 return ERR_PTR(-ENOENT); 2976 } else { 2977 ret = trace_array_get(tr); 2978 if (ret) 2979 return ERR_PTR(ret); 2980 } 2981 2982 mutex_lock(&event_mutex); 2983 2984 file = find_event_file(tr, system, event); 2985 if (!file) { 2986 trace_array_put(tr); 2987 ret = -EINVAL; 2988 goto out; 2989 } 2990 2991 /* Don't let event modules unload while in use */ 2992 ret = trace_event_try_get_ref(file->event_call); 2993 if (!ret) { 2994 trace_array_put(tr); 2995 ret = -EBUSY; 2996 goto out; 2997 } 2998 2999 ret = 0; 3000 out: 3001 mutex_unlock(&event_mutex); 3002 3003 if (ret) 3004 file = ERR_PTR(ret); 3005 3006 return file; 3007 } 3008 EXPORT_SYMBOL_GPL(trace_get_event_file); 3009 3010 /** 3011 * trace_put_event_file - Release a file from trace_get_event_file() 3012 * @file: The trace event file 3013 * 3014 * If a file was retrieved using trace_get_event_file(), this should 3015 * be called when it's no longer needed. It will cancel the previous 3016 * trace_array_get() called by that function, and decrement the 3017 * event's module refcount. 3018 */ 3019 void trace_put_event_file(struct trace_event_file *file) 3020 { 3021 mutex_lock(&event_mutex); 3022 trace_event_put_ref(file->event_call); 3023 mutex_unlock(&event_mutex); 3024 3025 trace_array_put(file->tr); 3026 } 3027 EXPORT_SYMBOL_GPL(trace_put_event_file); 3028 3029 #ifdef CONFIG_DYNAMIC_FTRACE 3030 3031 /* Avoid typos */ 3032 #define ENABLE_EVENT_STR "enable_event" 3033 #define DISABLE_EVENT_STR "disable_event" 3034 3035 struct event_probe_data { 3036 struct trace_event_file *file; 3037 unsigned long count; 3038 int ref; 3039 bool enable; 3040 }; 3041 3042 static void update_event_probe(struct event_probe_data *data) 3043 { 3044 if (data->enable) 3045 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags); 3046 else 3047 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags); 3048 } 3049 3050 static void 3051 event_enable_probe(unsigned long ip, unsigned long parent_ip, 3052 struct trace_array *tr, struct ftrace_probe_ops *ops, 3053 void *data) 3054 { 3055 struct ftrace_func_mapper *mapper = data; 3056 struct event_probe_data *edata; 3057 void **pdata; 3058 3059 pdata = ftrace_func_mapper_find_ip(mapper, ip); 3060 if (!pdata || !*pdata) 3061 return; 3062 3063 edata = *pdata; 3064 update_event_probe(edata); 3065 } 3066 3067 static void 3068 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, 3069 struct trace_array *tr, struct ftrace_probe_ops *ops, 3070 void *data) 3071 { 3072 struct ftrace_func_mapper *mapper = data; 3073 struct event_probe_data *edata; 3074 void **pdata; 3075 3076 pdata = ftrace_func_mapper_find_ip(mapper, ip); 3077 if (!pdata || !*pdata) 3078 return; 3079 3080 edata = *pdata; 3081 3082 if (!edata->count) 3083 return; 3084 3085 /* Skip if the event is in a state we want to switch to */ 3086 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED)) 3087 return; 3088 3089 if (edata->count != -1) 3090 (edata->count)--; 3091 3092 update_event_probe(edata); 3093 } 3094 3095 static int 3096 event_enable_print(struct seq_file *m, unsigned long ip, 3097 struct ftrace_probe_ops *ops, void *data) 3098 { 3099 struct ftrace_func_mapper *mapper = data; 3100 struct event_probe_data *edata; 3101 void **pdata; 3102 3103 pdata = ftrace_func_mapper_find_ip(mapper, ip); 3104 3105 if (WARN_ON_ONCE(!pdata || !*pdata)) 3106 return 0; 3107 3108 edata = *pdata; 3109 3110 seq_printf(m, "%ps:", (void *)ip); 3111 3112 seq_printf(m, "%s:%s:%s", 3113 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, 3114 edata->file->event_call->class->system, 3115 trace_event_name(edata->file->event_call)); 3116 3117 if (edata->count == -1) 3118 seq_puts(m, ":unlimited\n"); 3119 else 3120 seq_printf(m, ":count=%ld\n", edata->count); 3121 3122 return 0; 3123 } 3124 3125 static int 3126 event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr, 3127 unsigned long ip, void *init_data, void **data) 3128 { 3129 struct ftrace_func_mapper *mapper = *data; 3130 struct event_probe_data *edata = init_data; 3131 int ret; 3132 3133 if (!mapper) { 3134 mapper = allocate_ftrace_func_mapper(); 3135 if (!mapper) 3136 return -ENODEV; 3137 *data = mapper; 3138 } 3139 3140 ret = ftrace_func_mapper_add_ip(mapper, ip, edata); 3141 if (ret < 0) 3142 return ret; 3143 3144 edata->ref++; 3145 3146 return 0; 3147 } 3148 3149 static int free_probe_data(void *data) 3150 { 3151 struct event_probe_data *edata = data; 3152 3153 edata->ref--; 3154 if (!edata->ref) { 3155 /* Remove the SOFT_MODE flag */ 3156 __ftrace_event_enable_disable(edata->file, 0, 1); 3157 trace_event_put_ref(edata->file->event_call); 3158 kfree(edata); 3159 } 3160 return 0; 3161 } 3162 3163 static void 3164 event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr, 3165 unsigned long ip, void *data) 3166 { 3167 struct ftrace_func_mapper *mapper = data; 3168 struct event_probe_data *edata; 3169 3170 if (!ip) { 3171 if (!mapper) 3172 return; 3173 free_ftrace_func_mapper(mapper, free_probe_data); 3174 return; 3175 } 3176 3177 edata = ftrace_func_mapper_remove_ip(mapper, ip); 3178 3179 if (WARN_ON_ONCE(!edata)) 3180 return; 3181 3182 if (WARN_ON_ONCE(edata->ref <= 0)) 3183 return; 3184 3185 free_probe_data(edata); 3186 } 3187 3188 static struct ftrace_probe_ops event_enable_probe_ops = { 3189 .func = event_enable_probe, 3190 .print = event_enable_print, 3191 .init = event_enable_init, 3192 .free = event_enable_free, 3193 }; 3194 3195 static struct ftrace_probe_ops event_enable_count_probe_ops = { 3196 .func = event_enable_count_probe, 3197 .print = event_enable_print, 3198 .init = event_enable_init, 3199 .free = event_enable_free, 3200 }; 3201 3202 static struct ftrace_probe_ops event_disable_probe_ops = { 3203 .func = event_enable_probe, 3204 .print = event_enable_print, 3205 .init = event_enable_init, 3206 .free = event_enable_free, 3207 }; 3208 3209 static struct ftrace_probe_ops event_disable_count_probe_ops = { 3210 .func = event_enable_count_probe, 3211 .print = event_enable_print, 3212 .init = event_enable_init, 3213 .free = event_enable_free, 3214 }; 3215 3216 static int 3217 event_enable_func(struct trace_array *tr, struct ftrace_hash *hash, 3218 char *glob, char *cmd, char *param, int enabled) 3219 { 3220 struct trace_event_file *file; 3221 struct ftrace_probe_ops *ops; 3222 struct event_probe_data *data; 3223 const char *system; 3224 const char *event; 3225 char *number; 3226 bool enable; 3227 int ret; 3228 3229 if (!tr) 3230 return -ENODEV; 3231 3232 /* hash funcs only work with set_ftrace_filter */ 3233 if (!enabled || !param) 3234 return -EINVAL; 3235 3236 system = strsep(¶m, ":"); 3237 if (!param) 3238 return -EINVAL; 3239 3240 event = strsep(¶m, ":"); 3241 3242 mutex_lock(&event_mutex); 3243 3244 ret = -EINVAL; 3245 file = find_event_file(tr, system, event); 3246 if (!file) 3247 goto out; 3248 3249 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; 3250 3251 if (enable) 3252 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops; 3253 else 3254 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops; 3255 3256 if (glob[0] == '!') { 3257 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops); 3258 goto out; 3259 } 3260 3261 ret = -ENOMEM; 3262 3263 data = kzalloc(sizeof(*data), GFP_KERNEL); 3264 if (!data) 3265 goto out; 3266 3267 data->enable = enable; 3268 data->count = -1; 3269 data->file = file; 3270 3271 if (!param) 3272 goto out_reg; 3273 3274 number = strsep(¶m, ":"); 3275 3276 ret = -EINVAL; 3277 if (!strlen(number)) 3278 goto out_free; 3279 3280 /* 3281 * We use the callback data field (which is a pointer) 3282 * as our counter. 3283 */ 3284 ret = kstrtoul(number, 0, &data->count); 3285 if (ret) 3286 goto out_free; 3287 3288 out_reg: 3289 /* Don't let event modules unload while probe registered */ 3290 ret = trace_event_try_get_ref(file->event_call); 3291 if (!ret) { 3292 ret = -EBUSY; 3293 goto out_free; 3294 } 3295 3296 ret = __ftrace_event_enable_disable(file, 1, 1); 3297 if (ret < 0) 3298 goto out_put; 3299 3300 ret = register_ftrace_function_probe(glob, tr, ops, data); 3301 /* 3302 * The above returns on success the # of functions enabled, 3303 * but if it didn't find any functions it returns zero. 3304 * Consider no functions a failure too. 3305 */ 3306 if (!ret) { 3307 ret = -ENOENT; 3308 goto out_disable; 3309 } else if (ret < 0) 3310 goto out_disable; 3311 /* Just return zero, not the number of enabled functions */ 3312 ret = 0; 3313 out: 3314 mutex_unlock(&event_mutex); 3315 return ret; 3316 3317 out_disable: 3318 __ftrace_event_enable_disable(file, 0, 1); 3319 out_put: 3320 trace_event_put_ref(file->event_call); 3321 out_free: 3322 kfree(data); 3323 goto out; 3324 } 3325 3326 static struct ftrace_func_command event_enable_cmd = { 3327 .name = ENABLE_EVENT_STR, 3328 .func = event_enable_func, 3329 }; 3330 3331 static struct ftrace_func_command event_disable_cmd = { 3332 .name = DISABLE_EVENT_STR, 3333 .func = event_enable_func, 3334 }; 3335 3336 static __init int register_event_cmds(void) 3337 { 3338 int ret; 3339 3340 ret = register_ftrace_command(&event_enable_cmd); 3341 if (WARN_ON(ret < 0)) 3342 return ret; 3343 ret = register_ftrace_command(&event_disable_cmd); 3344 if (WARN_ON(ret < 0)) 3345 unregister_ftrace_command(&event_enable_cmd); 3346 return ret; 3347 } 3348 #else 3349 static inline int register_event_cmds(void) { return 0; } 3350 #endif /* CONFIG_DYNAMIC_FTRACE */ 3351 3352 /* 3353 * The top level array and trace arrays created by boot-time tracing 3354 * have already had its trace_event_file descriptors created in order 3355 * to allow for early events to be recorded. 3356 * This function is called after the tracefs has been initialized, 3357 * and we now have to create the files associated to the events. 3358 */ 3359 static void __trace_early_add_event_dirs(struct trace_array *tr) 3360 { 3361 struct trace_event_file *file; 3362 int ret; 3363 3364 3365 list_for_each_entry(file, &tr->events, list) { 3366 ret = event_create_dir(tr->event_dir, file); 3367 if (ret < 0) 3368 pr_warn("Could not create directory for event %s\n", 3369 trace_event_name(file->event_call)); 3370 } 3371 } 3372 3373 /* 3374 * For early boot up, the top trace array and the trace arrays created 3375 * by boot-time tracing require to have a list of events that can be 3376 * enabled. This must be done before the filesystem is set up in order 3377 * to allow events to be traced early. 3378 */ 3379 void __trace_early_add_events(struct trace_array *tr) 3380 { 3381 struct trace_event_call *call; 3382 int ret; 3383 3384 list_for_each_entry(call, &ftrace_events, list) { 3385 /* Early boot up should not have any modules loaded */ 3386 if (!(call->flags & TRACE_EVENT_FL_DYNAMIC) && 3387 WARN_ON_ONCE(call->module)) 3388 continue; 3389 3390 ret = __trace_early_add_new_event(call, tr); 3391 if (ret < 0) 3392 pr_warn("Could not create early event %s\n", 3393 trace_event_name(call)); 3394 } 3395 } 3396 3397 /* Remove the event directory structure for a trace directory. */ 3398 static void 3399 __trace_remove_event_dirs(struct trace_array *tr) 3400 { 3401 struct trace_event_file *file, *next; 3402 3403 list_for_each_entry_safe(file, next, &tr->events, list) 3404 remove_event_file_dir(file); 3405 } 3406 3407 static void __add_event_to_tracers(struct trace_event_call *call) 3408 { 3409 struct trace_array *tr; 3410 3411 list_for_each_entry(tr, &ftrace_trace_arrays, list) 3412 __trace_add_new_event(call, tr); 3413 } 3414 3415 extern struct trace_event_call *__start_ftrace_events[]; 3416 extern struct trace_event_call *__stop_ftrace_events[]; 3417 3418 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; 3419 3420 static __init int setup_trace_event(char *str) 3421 { 3422 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE); 3423 ring_buffer_expanded = true; 3424 disable_tracing_selftest("running event tracing"); 3425 3426 return 1; 3427 } 3428 __setup("trace_event=", setup_trace_event); 3429 3430 /* Expects to have event_mutex held when called */ 3431 static int 3432 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) 3433 { 3434 struct dentry *d_events; 3435 struct dentry *entry; 3436 3437 entry = tracefs_create_file("set_event", TRACE_MODE_WRITE, parent, 3438 tr, &ftrace_set_event_fops); 3439 if (!entry) { 3440 pr_warn("Could not create tracefs 'set_event' entry\n"); 3441 return -ENOMEM; 3442 } 3443 3444 d_events = tracefs_create_dir("events", parent); 3445 if (!d_events) { 3446 pr_warn("Could not create tracefs 'events' directory\n"); 3447 return -ENOMEM; 3448 } 3449 3450 entry = trace_create_file("enable", TRACE_MODE_WRITE, d_events, 3451 tr, &ftrace_tr_enable_fops); 3452 if (!entry) { 3453 pr_warn("Could not create tracefs 'enable' entry\n"); 3454 return -ENOMEM; 3455 } 3456 3457 /* There are not as crucial, just warn if they are not created */ 3458 3459 entry = tracefs_create_file("set_event_pid", TRACE_MODE_WRITE, parent, 3460 tr, &ftrace_set_event_pid_fops); 3461 if (!entry) 3462 pr_warn("Could not create tracefs 'set_event_pid' entry\n"); 3463 3464 entry = tracefs_create_file("set_event_notrace_pid", 3465 TRACE_MODE_WRITE, parent, tr, 3466 &ftrace_set_event_notrace_pid_fops); 3467 if (!entry) 3468 pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n"); 3469 3470 /* ring buffer internal formats */ 3471 entry = trace_create_file("header_page", TRACE_MODE_READ, d_events, 3472 ring_buffer_print_page_header, 3473 &ftrace_show_header_fops); 3474 if (!entry) 3475 pr_warn("Could not create tracefs 'header_page' entry\n"); 3476 3477 entry = trace_create_file("header_event", TRACE_MODE_READ, d_events, 3478 ring_buffer_print_entry_header, 3479 &ftrace_show_header_fops); 3480 if (!entry) 3481 pr_warn("Could not create tracefs 'header_event' entry\n"); 3482 3483 tr->event_dir = d_events; 3484 3485 return 0; 3486 } 3487 3488 /** 3489 * event_trace_add_tracer - add a instance of a trace_array to events 3490 * @parent: The parent dentry to place the files/directories for events in 3491 * @tr: The trace array associated with these events 3492 * 3493 * When a new instance is created, it needs to set up its events 3494 * directory, as well as other files associated with events. It also 3495 * creates the event hierarchy in the @parent/events directory. 3496 * 3497 * Returns 0 on success. 3498 * 3499 * Must be called with event_mutex held. 3500 */ 3501 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr) 3502 { 3503 int ret; 3504 3505 lockdep_assert_held(&event_mutex); 3506 3507 ret = create_event_toplevel_files(parent, tr); 3508 if (ret) 3509 goto out; 3510 3511 down_write(&trace_event_sem); 3512 /* If tr already has the event list, it is initialized in early boot. */ 3513 if (unlikely(!list_empty(&tr->events))) 3514 __trace_early_add_event_dirs(tr); 3515 else 3516 __trace_add_event_dirs(tr); 3517 up_write(&trace_event_sem); 3518 3519 out: 3520 return ret; 3521 } 3522 3523 /* 3524 * The top trace array already had its file descriptors created. 3525 * Now the files themselves need to be created. 3526 */ 3527 static __init int 3528 early_event_add_tracer(struct dentry *parent, struct trace_array *tr) 3529 { 3530 int ret; 3531 3532 mutex_lock(&event_mutex); 3533 3534 ret = create_event_toplevel_files(parent, tr); 3535 if (ret) 3536 goto out_unlock; 3537 3538 down_write(&trace_event_sem); 3539 __trace_early_add_event_dirs(tr); 3540 up_write(&trace_event_sem); 3541 3542 out_unlock: 3543 mutex_unlock(&event_mutex); 3544 3545 return ret; 3546 } 3547 3548 /* Must be called with event_mutex held */ 3549 int event_trace_del_tracer(struct trace_array *tr) 3550 { 3551 lockdep_assert_held(&event_mutex); 3552 3553 /* Disable any event triggers and associated soft-disabled events */ 3554 clear_event_triggers(tr); 3555 3556 /* Clear the pid list */ 3557 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); 3558 3559 /* Disable any running events */ 3560 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0); 3561 3562 /* Make sure no more events are being executed */ 3563 tracepoint_synchronize_unregister(); 3564 3565 down_write(&trace_event_sem); 3566 __trace_remove_event_dirs(tr); 3567 tracefs_remove(tr->event_dir); 3568 up_write(&trace_event_sem); 3569 3570 tr->event_dir = NULL; 3571 3572 return 0; 3573 } 3574 3575 static __init int event_trace_memsetup(void) 3576 { 3577 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC); 3578 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC); 3579 return 0; 3580 } 3581 3582 static __init void 3583 early_enable_events(struct trace_array *tr, bool disable_first) 3584 { 3585 char *buf = bootup_event_buf; 3586 char *token; 3587 int ret; 3588 3589 while (true) { 3590 token = strsep(&buf, ","); 3591 3592 if (!token) 3593 break; 3594 3595 if (*token) { 3596 /* Restarting syscalls requires that we stop them first */ 3597 if (disable_first) 3598 ftrace_set_clr_event(tr, token, 0); 3599 3600 ret = ftrace_set_clr_event(tr, token, 1); 3601 if (ret) 3602 pr_warn("Failed to enable trace event: %s\n", token); 3603 } 3604 3605 /* Put back the comma to allow this to be called again */ 3606 if (buf) 3607 *(buf - 1) = ','; 3608 } 3609 } 3610 3611 static __init int event_trace_enable(void) 3612 { 3613 struct trace_array *tr = top_trace_array(); 3614 struct trace_event_call **iter, *call; 3615 int ret; 3616 3617 if (!tr) 3618 return -ENODEV; 3619 3620 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) { 3621 3622 call = *iter; 3623 ret = event_init(call); 3624 if (!ret) 3625 list_add(&call->list, &ftrace_events); 3626 } 3627 3628 /* 3629 * We need the top trace array to have a working set of trace 3630 * points at early init, before the debug files and directories 3631 * are created. Create the file entries now, and attach them 3632 * to the actual file dentries later. 3633 */ 3634 __trace_early_add_events(tr); 3635 3636 early_enable_events(tr, false); 3637 3638 trace_printk_start_comm(); 3639 3640 register_event_cmds(); 3641 3642 register_trigger_cmds(); 3643 3644 return 0; 3645 } 3646 3647 /* 3648 * event_trace_enable() is called from trace_event_init() first to 3649 * initialize events and perhaps start any events that are on the 3650 * command line. Unfortunately, there are some events that will not 3651 * start this early, like the system call tracepoints that need 3652 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But 3653 * event_trace_enable() is called before pid 1 starts, and this flag 3654 * is never set, making the syscall tracepoint never get reached, but 3655 * the event is enabled regardless (and not doing anything). 3656 */ 3657 static __init int event_trace_enable_again(void) 3658 { 3659 struct trace_array *tr; 3660 3661 tr = top_trace_array(); 3662 if (!tr) 3663 return -ENODEV; 3664 3665 early_enable_events(tr, true); 3666 3667 return 0; 3668 } 3669 3670 early_initcall(event_trace_enable_again); 3671 3672 /* Init fields which doesn't related to the tracefs */ 3673 static __init int event_trace_init_fields(void) 3674 { 3675 if (trace_define_generic_fields()) 3676 pr_warn("tracing: Failed to allocated generic fields"); 3677 3678 if (trace_define_common_fields()) 3679 pr_warn("tracing: Failed to allocate common fields"); 3680 3681 return 0; 3682 } 3683 3684 __init int event_trace_init(void) 3685 { 3686 struct trace_array *tr; 3687 struct dentry *entry; 3688 int ret; 3689 3690 tr = top_trace_array(); 3691 if (!tr) 3692 return -ENODEV; 3693 3694 entry = tracefs_create_file("available_events", TRACE_MODE_READ, 3695 NULL, tr, &ftrace_avail_fops); 3696 if (!entry) 3697 pr_warn("Could not create tracefs 'available_events' entry\n"); 3698 3699 ret = early_event_add_tracer(NULL, tr); 3700 if (ret) 3701 return ret; 3702 3703 #ifdef CONFIG_MODULES 3704 ret = register_module_notifier(&trace_module_nb); 3705 if (ret) 3706 pr_warn("Failed to register trace events module notifier\n"); 3707 #endif 3708 3709 eventdir_initialized = true; 3710 3711 return 0; 3712 } 3713 3714 void __init trace_event_init(void) 3715 { 3716 event_trace_memsetup(); 3717 init_ftrace_syscalls(); 3718 event_trace_enable(); 3719 event_trace_init_fields(); 3720 } 3721 3722 #ifdef CONFIG_EVENT_TRACE_STARTUP_TEST 3723 3724 static DEFINE_SPINLOCK(test_spinlock); 3725 static DEFINE_SPINLOCK(test_spinlock_irq); 3726 static DEFINE_MUTEX(test_mutex); 3727 3728 static __init void test_work(struct work_struct *dummy) 3729 { 3730 spin_lock(&test_spinlock); 3731 spin_lock_irq(&test_spinlock_irq); 3732 udelay(1); 3733 spin_unlock_irq(&test_spinlock_irq); 3734 spin_unlock(&test_spinlock); 3735 3736 mutex_lock(&test_mutex); 3737 msleep(1); 3738 mutex_unlock(&test_mutex); 3739 } 3740 3741 static __init int event_test_thread(void *unused) 3742 { 3743 void *test_malloc; 3744 3745 test_malloc = kmalloc(1234, GFP_KERNEL); 3746 if (!test_malloc) 3747 pr_info("failed to kmalloc\n"); 3748 3749 schedule_on_each_cpu(test_work); 3750 3751 kfree(test_malloc); 3752 3753 set_current_state(TASK_INTERRUPTIBLE); 3754 while (!kthread_should_stop()) { 3755 schedule(); 3756 set_current_state(TASK_INTERRUPTIBLE); 3757 } 3758 __set_current_state(TASK_RUNNING); 3759 3760 return 0; 3761 } 3762 3763 /* 3764 * Do various things that may trigger events. 3765 */ 3766 static __init void event_test_stuff(void) 3767 { 3768 struct task_struct *test_thread; 3769 3770 test_thread = kthread_run(event_test_thread, NULL, "test-events"); 3771 msleep(1); 3772 kthread_stop(test_thread); 3773 } 3774 3775 /* 3776 * For every trace event defined, we will test each trace point separately, 3777 * and then by groups, and finally all trace points. 3778 */ 3779 static __init void event_trace_self_tests(void) 3780 { 3781 struct trace_subsystem_dir *dir; 3782 struct trace_event_file *file; 3783 struct trace_event_call *call; 3784 struct event_subsystem *system; 3785 struct trace_array *tr; 3786 int ret; 3787 3788 tr = top_trace_array(); 3789 if (!tr) 3790 return; 3791 3792 pr_info("Running tests on trace events:\n"); 3793 3794 list_for_each_entry(file, &tr->events, list) { 3795 3796 call = file->event_call; 3797 3798 /* Only test those that have a probe */ 3799 if (!call->class || !call->class->probe) 3800 continue; 3801 3802 /* 3803 * Testing syscall events here is pretty useless, but 3804 * we still do it if configured. But this is time consuming. 3805 * What we really need is a user thread to perform the 3806 * syscalls as we test. 3807 */ 3808 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS 3809 if (call->class->system && 3810 strcmp(call->class->system, "syscalls") == 0) 3811 continue; 3812 #endif 3813 3814 pr_info("Testing event %s: ", trace_event_name(call)); 3815 3816 /* 3817 * If an event is already enabled, someone is using 3818 * it and the self test should not be on. 3819 */ 3820 if (file->flags & EVENT_FILE_FL_ENABLED) { 3821 pr_warn("Enabled event during self test!\n"); 3822 WARN_ON_ONCE(1); 3823 continue; 3824 } 3825 3826 ftrace_event_enable_disable(file, 1); 3827 event_test_stuff(); 3828 ftrace_event_enable_disable(file, 0); 3829 3830 pr_cont("OK\n"); 3831 } 3832 3833 /* Now test at the sub system level */ 3834 3835 pr_info("Running tests on trace event systems:\n"); 3836 3837 list_for_each_entry(dir, &tr->systems, list) { 3838 3839 system = dir->subsystem; 3840 3841 /* the ftrace system is special, skip it */ 3842 if (strcmp(system->name, "ftrace") == 0) 3843 continue; 3844 3845 pr_info("Testing event system %s: ", system->name); 3846 3847 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1); 3848 if (WARN_ON_ONCE(ret)) { 3849 pr_warn("error enabling system %s\n", 3850 system->name); 3851 continue; 3852 } 3853 3854 event_test_stuff(); 3855 3856 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0); 3857 if (WARN_ON_ONCE(ret)) { 3858 pr_warn("error disabling system %s\n", 3859 system->name); 3860 continue; 3861 } 3862 3863 pr_cont("OK\n"); 3864 } 3865 3866 /* Test with all events enabled */ 3867 3868 pr_info("Running tests on all trace events:\n"); 3869 pr_info("Testing all events: "); 3870 3871 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1); 3872 if (WARN_ON_ONCE(ret)) { 3873 pr_warn("error enabling all events\n"); 3874 return; 3875 } 3876 3877 event_test_stuff(); 3878 3879 /* reset sysname */ 3880 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0); 3881 if (WARN_ON_ONCE(ret)) { 3882 pr_warn("error disabling all events\n"); 3883 return; 3884 } 3885 3886 pr_cont("OK\n"); 3887 } 3888 3889 #ifdef CONFIG_FUNCTION_TRACER 3890 3891 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); 3892 3893 static struct trace_event_file event_trace_file __initdata; 3894 3895 static void __init 3896 function_test_events_call(unsigned long ip, unsigned long parent_ip, 3897 struct ftrace_ops *op, struct ftrace_regs *regs) 3898 { 3899 struct trace_buffer *buffer; 3900 struct ring_buffer_event *event; 3901 struct ftrace_entry *entry; 3902 unsigned int trace_ctx; 3903 long disabled; 3904 int cpu; 3905 3906 trace_ctx = tracing_gen_ctx(); 3907 preempt_disable_notrace(); 3908 cpu = raw_smp_processor_id(); 3909 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu)); 3910 3911 if (disabled != 1) 3912 goto out; 3913 3914 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file, 3915 TRACE_FN, sizeof(*entry), 3916 trace_ctx); 3917 if (!event) 3918 goto out; 3919 entry = ring_buffer_event_data(event); 3920 entry->ip = ip; 3921 entry->parent_ip = parent_ip; 3922 3923 event_trigger_unlock_commit(&event_trace_file, buffer, event, 3924 entry, trace_ctx); 3925 out: 3926 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu)); 3927 preempt_enable_notrace(); 3928 } 3929 3930 static struct ftrace_ops trace_ops __initdata = 3931 { 3932 .func = function_test_events_call, 3933 }; 3934 3935 static __init void event_trace_self_test_with_function(void) 3936 { 3937 int ret; 3938 3939 event_trace_file.tr = top_trace_array(); 3940 if (WARN_ON(!event_trace_file.tr)) 3941 return; 3942 3943 ret = register_ftrace_function(&trace_ops); 3944 if (WARN_ON(ret < 0)) { 3945 pr_info("Failed to enable function tracer for event tests\n"); 3946 return; 3947 } 3948 pr_info("Running tests again, along with the function tracer\n"); 3949 event_trace_self_tests(); 3950 unregister_ftrace_function(&trace_ops); 3951 } 3952 #else 3953 static __init void event_trace_self_test_with_function(void) 3954 { 3955 } 3956 #endif 3957 3958 static __init int event_trace_self_tests_init(void) 3959 { 3960 if (!tracing_selftest_disabled) { 3961 event_trace_self_tests(); 3962 event_trace_self_test_with_function(); 3963 } 3964 3965 return 0; 3966 } 3967 3968 late_initcall(event_trace_self_tests_init); 3969 3970 #endif 3971