1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * trace irqs off critical timings 4 * 5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> 6 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> 7 * 8 * From code in the latency_tracer, that is: 9 * 10 * Copyright (C) 2004-2006 Ingo Molnar 11 * Copyright (C) 2004 Nadia Yvette Chambers 12 */ 13 #include <linux/kallsyms.h> 14 #include <linux/uaccess.h> 15 #include <linux/module.h> 16 #include <linux/ftrace.h> 17 #include <linux/kprobes.h> 18 19 #include "trace.h" 20 21 #include <trace/events/preemptirq.h> 22 23 #if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER) 24 static struct trace_array *irqsoff_trace __read_mostly; 25 static int tracer_enabled __read_mostly; 26 27 static DEFINE_PER_CPU(int, tracing_cpu); 28 29 static DEFINE_RAW_SPINLOCK(max_trace_lock); 30 31 enum { 32 TRACER_IRQS_OFF = (1 << 1), 33 TRACER_PREEMPT_OFF = (1 << 2), 34 }; 35 36 static int trace_type __read_mostly; 37 38 static int save_flags; 39 40 static void stop_irqsoff_tracer(struct trace_array *tr, int graph); 41 static int start_irqsoff_tracer(struct trace_array *tr, int graph); 42 43 #ifdef CONFIG_PREEMPT_TRACER 44 static inline int 45 preempt_trace(int pc) 46 { 47 return ((trace_type & TRACER_PREEMPT_OFF) && pc); 48 } 49 #else 50 # define preempt_trace(pc) (0) 51 #endif 52 53 #ifdef CONFIG_IRQSOFF_TRACER 54 static inline int 55 irq_trace(void) 56 { 57 return ((trace_type & TRACER_IRQS_OFF) && 58 irqs_disabled()); 59 } 60 #else 61 # define irq_trace() (0) 62 #endif 63 64 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 65 static int irqsoff_display_graph(struct trace_array *tr, int set); 66 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) 67 #else 68 static inline int irqsoff_display_graph(struct trace_array *tr, int set) 69 { 70 return -EINVAL; 71 } 72 # define is_graph(tr) false 73 #endif 74 75 /* 76 * Sequence count - we record it when starting a measurement and 77 * skip the latency if the sequence has changed - some other section 78 * did a maximum and could disturb our measurement with serial console 79 * printouts, etc. Truly coinciding maximum latencies should be rare 80 * and what happens together happens separately as well, so this doesn't 81 * decrease the validity of the maximum found: 82 */ 83 static __cacheline_aligned_in_smp unsigned long max_sequence; 84 85 #ifdef CONFIG_FUNCTION_TRACER 86 /* 87 * Prologue for the preempt and irqs off function tracers. 88 * 89 * Returns 1 if it is OK to continue, and data->disabled is 90 * incremented. 91 * 0 if the trace is to be ignored, and data->disabled 92 * is kept the same. 93 * 94 * Note, this function is also used outside this ifdef but 95 * inside the #ifdef of the function graph tracer below. 96 * This is OK, since the function graph tracer is 97 * dependent on the function tracer. 98 */ 99 static int func_prolog_dec(struct trace_array *tr, 100 struct trace_array_cpu **data, 101 unsigned long *flags) 102 { 103 long disabled; 104 int cpu; 105 106 /* 107 * Does not matter if we preempt. We test the flags 108 * afterward, to see if irqs are disabled or not. 109 * If we preempt and get a false positive, the flags 110 * test will fail. 111 */ 112 cpu = raw_smp_processor_id(); 113 if (likely(!per_cpu(tracing_cpu, cpu))) 114 return 0; 115 116 local_save_flags(*flags); 117 /* 118 * Slight chance to get a false positive on tracing_cpu, 119 * although I'm starting to think there isn't a chance. 120 * Leave this for now just to be paranoid. 121 */ 122 if (!irqs_disabled_flags(*flags) && !preempt_count()) 123 return 0; 124 125 *data = per_cpu_ptr(tr->array_buffer.data, cpu); 126 disabled = atomic_inc_return(&(*data)->disabled); 127 128 if (likely(disabled == 1)) 129 return 1; 130 131 atomic_dec(&(*data)->disabled); 132 133 return 0; 134 } 135 136 /* 137 * irqsoff uses its own tracer function to keep the overhead down: 138 */ 139 static void 140 irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, 141 struct ftrace_ops *op, struct ftrace_regs *fregs) 142 { 143 struct trace_array *tr = irqsoff_trace; 144 struct trace_array_cpu *data; 145 unsigned long flags; 146 unsigned int trace_ctx; 147 148 if (!func_prolog_dec(tr, &data, &flags)) 149 return; 150 151 trace_ctx = tracing_gen_ctx_flags(flags); 152 153 trace_function(tr, ip, parent_ip, trace_ctx); 154 155 atomic_dec(&data->disabled); 156 } 157 #endif /* CONFIG_FUNCTION_TRACER */ 158 159 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 160 static int irqsoff_display_graph(struct trace_array *tr, int set) 161 { 162 int cpu; 163 164 if (!(is_graph(tr) ^ set)) 165 return 0; 166 167 stop_irqsoff_tracer(irqsoff_trace, !set); 168 169 for_each_possible_cpu(cpu) 170 per_cpu(tracing_cpu, cpu) = 0; 171 172 tr->max_latency = 0; 173 tracing_reset_online_cpus(&irqsoff_trace->array_buffer); 174 175 return start_irqsoff_tracer(irqsoff_trace, set); 176 } 177 178 static int irqsoff_graph_entry(struct ftrace_graph_ent *trace, 179 struct fgraph_ops *gops) 180 { 181 struct trace_array *tr = irqsoff_trace; 182 struct trace_array_cpu *data; 183 unsigned long flags; 184 unsigned int trace_ctx; 185 u64 *calltime; 186 int ret; 187 188 if (ftrace_graph_ignore_func(gops, trace)) 189 return 0; 190 /* 191 * Do not trace a function if it's filtered by set_graph_notrace. 192 * Make the index of ret stack negative to indicate that it should 193 * ignore further functions. But it needs its own ret stack entry 194 * to recover the original index in order to continue tracing after 195 * returning from the function. 196 */ 197 if (ftrace_graph_notrace_addr(trace->func)) 198 return 1; 199 200 if (!func_prolog_dec(tr, &data, &flags)) 201 return 0; 202 203 calltime = fgraph_reserve_data(gops->idx, sizeof(*calltime)); 204 if (!calltime) 205 return 0; 206 207 *calltime = trace_clock_local(); 208 209 trace_ctx = tracing_gen_ctx_flags(flags); 210 ret = __trace_graph_entry(tr, trace, trace_ctx); 211 atomic_dec(&data->disabled); 212 213 return ret; 214 } 215 216 static void irqsoff_graph_return(struct ftrace_graph_ret *trace, 217 struct fgraph_ops *gops) 218 { 219 struct trace_array *tr = irqsoff_trace; 220 struct trace_array_cpu *data; 221 unsigned long flags; 222 unsigned int trace_ctx; 223 u64 *calltime; 224 int size; 225 226 ftrace_graph_addr_finish(gops, trace); 227 228 if (!func_prolog_dec(tr, &data, &flags)) 229 return; 230 231 calltime = fgraph_retrieve_data(gops->idx, &size); 232 if (!calltime) 233 return; 234 trace->calltime = *calltime; 235 236 trace_ctx = tracing_gen_ctx_flags(flags); 237 __trace_graph_return(tr, trace, trace_ctx); 238 atomic_dec(&data->disabled); 239 } 240 241 static struct fgraph_ops fgraph_ops = { 242 .entryfunc = &irqsoff_graph_entry, 243 .retfunc = &irqsoff_graph_return, 244 }; 245 246 static void irqsoff_trace_open(struct trace_iterator *iter) 247 { 248 if (is_graph(iter->tr)) 249 graph_trace_open(iter); 250 else 251 iter->private = NULL; 252 } 253 254 static void irqsoff_trace_close(struct trace_iterator *iter) 255 { 256 if (iter->private) 257 graph_trace_close(iter); 258 } 259 260 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ 261 TRACE_GRAPH_PRINT_PROC | \ 262 TRACE_GRAPH_PRINT_REL_TIME | \ 263 TRACE_GRAPH_PRINT_DURATION) 264 265 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) 266 { 267 /* 268 * In graph mode call the graph tracer output function, 269 * otherwise go with the TRACE_FN event handler 270 */ 271 if (is_graph(iter->tr)) 272 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 273 274 return TRACE_TYPE_UNHANDLED; 275 } 276 277 static void irqsoff_print_header(struct seq_file *s) 278 { 279 struct trace_array *tr = irqsoff_trace; 280 281 if (is_graph(tr)) 282 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 283 else 284 trace_default_header(s); 285 } 286 287 static void 288 __trace_function(struct trace_array *tr, 289 unsigned long ip, unsigned long parent_ip, 290 unsigned int trace_ctx) 291 { 292 if (is_graph(tr)) 293 trace_graph_function(tr, ip, parent_ip, trace_ctx); 294 else 295 trace_function(tr, ip, parent_ip, trace_ctx); 296 } 297 298 #else 299 #define __trace_function trace_function 300 301 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) 302 { 303 return TRACE_TYPE_UNHANDLED; 304 } 305 306 static void irqsoff_trace_open(struct trace_iterator *iter) { } 307 static void irqsoff_trace_close(struct trace_iterator *iter) { } 308 309 #ifdef CONFIG_FUNCTION_TRACER 310 static void irqsoff_print_header(struct seq_file *s) 311 { 312 trace_default_header(s); 313 } 314 #else 315 static void irqsoff_print_header(struct seq_file *s) 316 { 317 trace_latency_header(s); 318 } 319 #endif /* CONFIG_FUNCTION_TRACER */ 320 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 321 322 /* 323 * Should this new latency be reported/recorded? 324 */ 325 static bool report_latency(struct trace_array *tr, u64 delta) 326 { 327 if (tracing_thresh) { 328 if (delta < tracing_thresh) 329 return false; 330 } else { 331 if (delta <= tr->max_latency) 332 return false; 333 } 334 return true; 335 } 336 337 static void 338 check_critical_timing(struct trace_array *tr, 339 struct trace_array_cpu *data, 340 unsigned long parent_ip, 341 int cpu) 342 { 343 u64 T0, T1, delta; 344 unsigned long flags; 345 unsigned int trace_ctx; 346 347 T0 = data->preempt_timestamp; 348 T1 = ftrace_now(cpu); 349 delta = T1-T0; 350 351 trace_ctx = tracing_gen_ctx(); 352 353 if (!report_latency(tr, delta)) 354 goto out; 355 356 raw_spin_lock_irqsave(&max_trace_lock, flags); 357 358 /* check if we are still the max latency */ 359 if (!report_latency(tr, delta)) 360 goto out_unlock; 361 362 __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx); 363 /* Skip 5 functions to get to the irq/preempt enable function */ 364 __trace_stack(tr, trace_ctx, 5); 365 366 if (data->critical_sequence != max_sequence) 367 goto out_unlock; 368 369 data->critical_end = parent_ip; 370 371 if (likely(!is_tracing_stopped())) { 372 tr->max_latency = delta; 373 update_max_tr_single(tr, current, cpu); 374 } 375 376 max_sequence++; 377 378 out_unlock: 379 raw_spin_unlock_irqrestore(&max_trace_lock, flags); 380 381 out: 382 data->critical_sequence = max_sequence; 383 data->preempt_timestamp = ftrace_now(cpu); 384 __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx); 385 } 386 387 static nokprobe_inline void 388 start_critical_timing(unsigned long ip, unsigned long parent_ip) 389 { 390 int cpu; 391 struct trace_array *tr = irqsoff_trace; 392 struct trace_array_cpu *data; 393 394 if (!tracer_enabled || !tracing_is_enabled()) 395 return; 396 397 cpu = raw_smp_processor_id(); 398 399 if (per_cpu(tracing_cpu, cpu)) 400 return; 401 402 data = per_cpu_ptr(tr->array_buffer.data, cpu); 403 404 if (unlikely(!data) || atomic_read(&data->disabled)) 405 return; 406 407 atomic_inc(&data->disabled); 408 409 data->critical_sequence = max_sequence; 410 data->preempt_timestamp = ftrace_now(cpu); 411 data->critical_start = parent_ip ? : ip; 412 413 __trace_function(tr, ip, parent_ip, tracing_gen_ctx()); 414 415 per_cpu(tracing_cpu, cpu) = 1; 416 417 atomic_dec(&data->disabled); 418 } 419 420 static nokprobe_inline void 421 stop_critical_timing(unsigned long ip, unsigned long parent_ip) 422 { 423 int cpu; 424 struct trace_array *tr = irqsoff_trace; 425 struct trace_array_cpu *data; 426 unsigned int trace_ctx; 427 428 cpu = raw_smp_processor_id(); 429 /* Always clear the tracing cpu on stopping the trace */ 430 if (unlikely(per_cpu(tracing_cpu, cpu))) 431 per_cpu(tracing_cpu, cpu) = 0; 432 else 433 return; 434 435 if (!tracer_enabled || !tracing_is_enabled()) 436 return; 437 438 data = per_cpu_ptr(tr->array_buffer.data, cpu); 439 440 if (unlikely(!data) || 441 !data->critical_start || atomic_read(&data->disabled)) 442 return; 443 444 atomic_inc(&data->disabled); 445 446 trace_ctx = tracing_gen_ctx(); 447 __trace_function(tr, ip, parent_ip, trace_ctx); 448 check_critical_timing(tr, data, parent_ip ? : ip, cpu); 449 data->critical_start = 0; 450 atomic_dec(&data->disabled); 451 } 452 453 /* start and stop critical timings used to for stoppage (in idle) */ 454 void start_critical_timings(void) 455 { 456 if (preempt_trace(preempt_count()) || irq_trace()) 457 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); 458 } 459 EXPORT_SYMBOL_GPL(start_critical_timings); 460 NOKPROBE_SYMBOL(start_critical_timings); 461 462 void stop_critical_timings(void) 463 { 464 if (preempt_trace(preempt_count()) || irq_trace()) 465 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); 466 } 467 EXPORT_SYMBOL_GPL(stop_critical_timings); 468 NOKPROBE_SYMBOL(stop_critical_timings); 469 470 #ifdef CONFIG_FUNCTION_TRACER 471 static bool function_enabled; 472 473 static int register_irqsoff_function(struct trace_array *tr, int graph, int set) 474 { 475 int ret; 476 477 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 478 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) 479 return 0; 480 481 if (graph) 482 ret = register_ftrace_graph(&fgraph_ops); 483 else 484 ret = register_ftrace_function(tr->ops); 485 486 if (!ret) 487 function_enabled = true; 488 489 return ret; 490 } 491 492 static void unregister_irqsoff_function(struct trace_array *tr, int graph) 493 { 494 if (!function_enabled) 495 return; 496 497 if (graph) 498 unregister_ftrace_graph(&fgraph_ops); 499 else 500 unregister_ftrace_function(tr->ops); 501 502 function_enabled = false; 503 } 504 505 static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) 506 { 507 if (!(mask & TRACE_ITER_FUNCTION)) 508 return 0; 509 510 if (set) 511 register_irqsoff_function(tr, is_graph(tr), 1); 512 else 513 unregister_irqsoff_function(tr, is_graph(tr)); 514 return 1; 515 } 516 #else 517 static int register_irqsoff_function(struct trace_array *tr, int graph, int set) 518 { 519 return 0; 520 } 521 static void unregister_irqsoff_function(struct trace_array *tr, int graph) { } 522 static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) 523 { 524 return 0; 525 } 526 #endif /* CONFIG_FUNCTION_TRACER */ 527 528 static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) 529 { 530 struct tracer *tracer = tr->current_trace; 531 532 if (irqsoff_function_set(tr, mask, set)) 533 return 0; 534 535 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 536 if (mask & TRACE_ITER_DISPLAY_GRAPH) 537 return irqsoff_display_graph(tr, set); 538 #endif 539 540 return trace_keep_overwrite(tracer, mask, set); 541 } 542 543 static int start_irqsoff_tracer(struct trace_array *tr, int graph) 544 { 545 int ret; 546 547 ret = register_irqsoff_function(tr, graph, 0); 548 549 if (!ret && tracing_is_enabled()) 550 tracer_enabled = 1; 551 else 552 tracer_enabled = 0; 553 554 return ret; 555 } 556 557 static void stop_irqsoff_tracer(struct trace_array *tr, int graph) 558 { 559 tracer_enabled = 0; 560 561 unregister_irqsoff_function(tr, graph); 562 } 563 564 static bool irqsoff_busy; 565 566 static int __irqsoff_tracer_init(struct trace_array *tr) 567 { 568 if (irqsoff_busy) 569 return -EBUSY; 570 571 save_flags = tr->trace_flags; 572 573 /* non overwrite screws up the latency tracers */ 574 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 575 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 576 /* without pause, we will produce garbage if another latency occurs */ 577 set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1); 578 579 tr->max_latency = 0; 580 irqsoff_trace = tr; 581 /* make sure that the tracer is visible */ 582 smp_wmb(); 583 584 ftrace_init_array_ops(tr, irqsoff_tracer_call); 585 586 /* Only toplevel instance supports graph tracing */ 587 if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL && 588 is_graph(tr)))) 589 printk(KERN_ERR "failed to start irqsoff tracer\n"); 590 591 irqsoff_busy = true; 592 return 0; 593 } 594 595 static void __irqsoff_tracer_reset(struct trace_array *tr) 596 { 597 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 598 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 599 int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE; 600 601 stop_irqsoff_tracer(tr, is_graph(tr)); 602 603 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 604 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 605 set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag); 606 ftrace_reset_array_ops(tr); 607 608 irqsoff_busy = false; 609 } 610 611 static void irqsoff_tracer_start(struct trace_array *tr) 612 { 613 tracer_enabled = 1; 614 } 615 616 static void irqsoff_tracer_stop(struct trace_array *tr) 617 { 618 tracer_enabled = 0; 619 } 620 621 #ifdef CONFIG_IRQSOFF_TRACER 622 /* 623 * We are only interested in hardirq on/off events: 624 */ 625 void tracer_hardirqs_on(unsigned long a0, unsigned long a1) 626 { 627 if (!preempt_trace(preempt_count()) && irq_trace()) 628 stop_critical_timing(a0, a1); 629 } 630 NOKPROBE_SYMBOL(tracer_hardirqs_on); 631 632 void tracer_hardirqs_off(unsigned long a0, unsigned long a1) 633 { 634 if (!preempt_trace(preempt_count()) && irq_trace()) 635 start_critical_timing(a0, a1); 636 } 637 NOKPROBE_SYMBOL(tracer_hardirqs_off); 638 639 static int irqsoff_tracer_init(struct trace_array *tr) 640 { 641 trace_type = TRACER_IRQS_OFF; 642 643 return __irqsoff_tracer_init(tr); 644 } 645 646 static void irqsoff_tracer_reset(struct trace_array *tr) 647 { 648 __irqsoff_tracer_reset(tr); 649 } 650 651 static struct tracer irqsoff_tracer __read_mostly = 652 { 653 .name = "irqsoff", 654 .init = irqsoff_tracer_init, 655 .reset = irqsoff_tracer_reset, 656 .start = irqsoff_tracer_start, 657 .stop = irqsoff_tracer_stop, 658 .print_max = true, 659 .print_header = irqsoff_print_header, 660 .print_line = irqsoff_print_line, 661 .flag_changed = irqsoff_flag_changed, 662 #ifdef CONFIG_FTRACE_SELFTEST 663 .selftest = trace_selftest_startup_irqsoff, 664 #endif 665 .open = irqsoff_trace_open, 666 .close = irqsoff_trace_close, 667 .allow_instances = true, 668 .use_max_tr = true, 669 }; 670 #endif /* CONFIG_IRQSOFF_TRACER */ 671 672 #ifdef CONFIG_PREEMPT_TRACER 673 void tracer_preempt_on(unsigned long a0, unsigned long a1) 674 { 675 if (preempt_trace(preempt_count()) && !irq_trace()) 676 stop_critical_timing(a0, a1); 677 } 678 679 void tracer_preempt_off(unsigned long a0, unsigned long a1) 680 { 681 if (preempt_trace(preempt_count()) && !irq_trace()) 682 start_critical_timing(a0, a1); 683 } 684 685 static int preemptoff_tracer_init(struct trace_array *tr) 686 { 687 trace_type = TRACER_PREEMPT_OFF; 688 689 return __irqsoff_tracer_init(tr); 690 } 691 692 static void preemptoff_tracer_reset(struct trace_array *tr) 693 { 694 __irqsoff_tracer_reset(tr); 695 } 696 697 static struct tracer preemptoff_tracer __read_mostly = 698 { 699 .name = "preemptoff", 700 .init = preemptoff_tracer_init, 701 .reset = preemptoff_tracer_reset, 702 .start = irqsoff_tracer_start, 703 .stop = irqsoff_tracer_stop, 704 .print_max = true, 705 .print_header = irqsoff_print_header, 706 .print_line = irqsoff_print_line, 707 .flag_changed = irqsoff_flag_changed, 708 #ifdef CONFIG_FTRACE_SELFTEST 709 .selftest = trace_selftest_startup_preemptoff, 710 #endif 711 .open = irqsoff_trace_open, 712 .close = irqsoff_trace_close, 713 .allow_instances = true, 714 .use_max_tr = true, 715 }; 716 #endif /* CONFIG_PREEMPT_TRACER */ 717 718 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) 719 720 static int preemptirqsoff_tracer_init(struct trace_array *tr) 721 { 722 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; 723 724 return __irqsoff_tracer_init(tr); 725 } 726 727 static void preemptirqsoff_tracer_reset(struct trace_array *tr) 728 { 729 __irqsoff_tracer_reset(tr); 730 } 731 732 static struct tracer preemptirqsoff_tracer __read_mostly = 733 { 734 .name = "preemptirqsoff", 735 .init = preemptirqsoff_tracer_init, 736 .reset = preemptirqsoff_tracer_reset, 737 .start = irqsoff_tracer_start, 738 .stop = irqsoff_tracer_stop, 739 .print_max = true, 740 .print_header = irqsoff_print_header, 741 .print_line = irqsoff_print_line, 742 .flag_changed = irqsoff_flag_changed, 743 #ifdef CONFIG_FTRACE_SELFTEST 744 .selftest = trace_selftest_startup_preemptirqsoff, 745 #endif 746 .open = irqsoff_trace_open, 747 .close = irqsoff_trace_close, 748 .allow_instances = true, 749 .use_max_tr = true, 750 }; 751 #endif 752 753 __init static int init_irqsoff_tracer(void) 754 { 755 #ifdef CONFIG_IRQSOFF_TRACER 756 register_tracer(&irqsoff_tracer); 757 #endif 758 #ifdef CONFIG_PREEMPT_TRACER 759 register_tracer(&preemptoff_tracer); 760 #endif 761 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) 762 register_tracer(&preemptirqsoff_tracer); 763 #endif 764 765 return 0; 766 } 767 core_initcall(init_irqsoff_tracer); 768 #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */ 769