kernel/trace/trace_irqsoff.c

   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         int ret;
 186
 187         if (ftrace_graph_ignore_func(gops, trace))
 188                 return 0;
 189         /*
 190          * Do not trace a function if it's filtered by set_graph_notrace.
 191          * Make the index of ret stack negative to indicate that it should
 192          * ignore further functions.  But it needs its own ret stack entry
 193          * to recover the original index in order to continue tracing after
 194          * returning from the function.
 195          */
 196         if (ftrace_graph_notrace_addr(trace->func))
 197                 return 1;
 198
 199         if (!func_prolog_dec(tr, &data, &flags))
 200                 return 0;
 201
 202         trace_ctx = tracing_gen_ctx_flags(flags);
 203         ret = __trace_graph_entry(tr, trace, trace_ctx);
 204         atomic_dec(&data->disabled);
 205
 206         return ret;
 207 }
 208
 209 static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
 210                                  struct fgraph_ops *gops)
 211 {
 212         struct trace_array *tr = irqsoff_trace;
 213         struct trace_array_cpu *data;
 214         unsigned long flags;
 215         unsigned int trace_ctx;
 216
 217         ftrace_graph_addr_finish(gops, trace);
 218
 219         if (!func_prolog_dec(tr, &data, &flags))
 220                 return;
 221
 222         trace_ctx = tracing_gen_ctx_flags(flags);
 223         __trace_graph_return(tr, trace, trace_ctx);
 224         atomic_dec(&data->disabled);
 225 }
 226
 227 static struct fgraph_ops fgraph_ops = {
 228         .entryfunc              = &irqsoff_graph_entry,
 229         .retfunc                = &irqsoff_graph_return,
 230 };
 231
 232 static void irqsoff_trace_open(struct trace_iterator *iter)
 233 {
 234         if (is_graph(iter->tr))
 235                 graph_trace_open(iter);
 236         else
 237                 iter->private = NULL;
 238 }
 239
 240 static void irqsoff_trace_close(struct trace_iterator *iter)
 241 {
 242         if (iter->private)
 243                 graph_trace_close(iter);
 244 }
 245
 246 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
 247                             TRACE_GRAPH_PRINT_PROC | \
 248                             TRACE_GRAPH_PRINT_REL_TIME | \
 249                             TRACE_GRAPH_PRINT_DURATION)
 250
 251 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 252 {
 253         /*
 254          * In graph mode call the graph tracer output function,
 255          * otherwise go with the TRACE_FN event handler
 256          */
 257         if (is_graph(iter->tr))
 258                 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
 259
 260         return TRACE_TYPE_UNHANDLED;
 261 }
 262
 263 static void irqsoff_print_header(struct seq_file *s)
 264 {
 265         struct trace_array *tr = irqsoff_trace;
 266
 267         if (is_graph(tr))
 268                 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
 269         else
 270                 trace_default_header(s);
 271 }
 272
 273 static void
 274 __trace_function(struct trace_array *tr,
 275                  unsigned long ip, unsigned long parent_ip,
 276                  unsigned int trace_ctx)
 277 {
 278         if (is_graph(tr))
 279                 trace_graph_function(tr, ip, parent_ip, trace_ctx);
 280         else
 281                 trace_function(tr, ip, parent_ip, trace_ctx);
 282 }
 283
 284 #else
 285 #define __trace_function trace_function
 286
 287 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 288 {
 289         return TRACE_TYPE_UNHANDLED;
 290 }
 291
 292 static void irqsoff_trace_open(struct trace_iterator *iter) { }
 293 static void irqsoff_trace_close(struct trace_iterator *iter) { }
 294
 295 #ifdef CONFIG_FUNCTION_TRACER
 296 static void irqsoff_print_header(struct seq_file *s)
 297 {
 298         trace_default_header(s);
 299 }
 300 #else
 301 static void irqsoff_print_header(struct seq_file *s)
 302 {
 303         trace_latency_header(s);
 304 }
 305 #endif /* CONFIG_FUNCTION_TRACER */
 306 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 307
 308 /*
 309  * Should this new latency be reported/recorded?
 310  */
 311 static bool report_latency(struct trace_array *tr, u64 delta)
 312 {
 313         if (tracing_thresh) {
 314                 if (delta < tracing_thresh)
 315                         return false;
 316         } else {
 317                 if (delta <= tr->max_latency)
 318                         return false;
 319         }
 320         return true;
 321 }
 322
 323 static void
 324 check_critical_timing(struct trace_array *tr,
 325                       struct trace_array_cpu *data,
 326                       unsigned long parent_ip,
 327                       int cpu)
 328 {
 329         u64 T0, T1, delta;
 330         unsigned long flags;
 331         unsigned int trace_ctx;
 332
 333         T0 = data->preempt_timestamp;
 334         T1 = ftrace_now(cpu);
 335         delta = T1-T0;
 336
 337         trace_ctx = tracing_gen_ctx();
 338
 339         if (!report_latency(tr, delta))
 340                 goto out;
 341
 342         raw_spin_lock_irqsave(&max_trace_lock, flags);
 343
 344         /* check if we are still the max latency */
 345         if (!report_latency(tr, delta))
 346                 goto out_unlock;
 347
 348         __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
 349         /* Skip 5 functions to get to the irq/preempt enable function */
 350         __trace_stack(tr, trace_ctx, 5);
 351
 352         if (data->critical_sequence != max_sequence)
 353                 goto out_unlock;
 354
 355         data->critical_end = parent_ip;
 356
 357         if (likely(!is_tracing_stopped())) {
 358                 tr->max_latency = delta;
 359                 update_max_tr_single(tr, current, cpu);
 360         }
 361
 362         max_sequence++;
 363
 364 out_unlock:
 365         raw_spin_unlock_irqrestore(&max_trace_lock, flags);
 366
 367 out:
 368         data->critical_sequence = max_sequence;
 369         data->preempt_timestamp = ftrace_now(cpu);
 370         __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
 371 }
 372
 373 static nokprobe_inline void
 374 start_critical_timing(unsigned long ip, unsigned long parent_ip)
 375 {
 376         int cpu;
 377         struct trace_array *tr = irqsoff_trace;
 378         struct trace_array_cpu *data;
 379
 380         if (!tracer_enabled || !tracing_is_enabled())
 381                 return;
 382
 383         cpu = raw_smp_processor_id();
 384
 385         if (per_cpu(tracing_cpu, cpu))
 386                 return;
 387
 388         data = per_cpu_ptr(tr->array_buffer.data, cpu);
 389
 390         if (unlikely(!data) || atomic_read(&data->disabled))
 391                 return;
 392
 393         atomic_inc(&data->disabled);
 394
 395         data->critical_sequence = max_sequence;
 396         data->preempt_timestamp = ftrace_now(cpu);
 397         data->critical_start = parent_ip ? : ip;
 398
 399         __trace_function(tr, ip, parent_ip, tracing_gen_ctx());
 400
 401         per_cpu(tracing_cpu, cpu) = 1;
 402
 403         atomic_dec(&data->disabled);
 404 }
 405
 406 static nokprobe_inline void
 407 stop_critical_timing(unsigned long ip, unsigned long parent_ip)
 408 {
 409         int cpu;
 410         struct trace_array *tr = irqsoff_trace;
 411         struct trace_array_cpu *data;
 412         unsigned int trace_ctx;
 413
 414         cpu = raw_smp_processor_id();
 415         /* Always clear the tracing cpu on stopping the trace */
 416         if (unlikely(per_cpu(tracing_cpu, cpu)))
 417                 per_cpu(tracing_cpu, cpu) = 0;
 418         else
 419                 return;
 420
 421         if (!tracer_enabled || !tracing_is_enabled())
 422                 return;
 423
 424         data = per_cpu_ptr(tr->array_buffer.data, cpu);
 425
 426         if (unlikely(!data) ||
 427             !data->critical_start || atomic_read(&data->disabled))
 428                 return;
 429
 430         atomic_inc(&data->disabled);
 431
 432         trace_ctx = tracing_gen_ctx();
 433         __trace_function(tr, ip, parent_ip, trace_ctx);
 434         check_critical_timing(tr, data, parent_ip ? : ip, cpu);
 435         data->critical_start = 0;
 436         atomic_dec(&data->disabled);
 437 }
 438
 439 /* start and stop critical timings used to for stoppage (in idle) */
 440 void start_critical_timings(void)
 441 {
 442         if (preempt_trace(preempt_count()) || irq_trace())
 443                 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 444 }
 445 EXPORT_SYMBOL_GPL(start_critical_timings);
 446 NOKPROBE_SYMBOL(start_critical_timings);
 447
 448 void stop_critical_timings(void)
 449 {
 450         if (preempt_trace(preempt_count()) || irq_trace())
 451                 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 452 }
 453 EXPORT_SYMBOL_GPL(stop_critical_timings);
 454 NOKPROBE_SYMBOL(stop_critical_timings);
 455
 456 #ifdef CONFIG_FUNCTION_TRACER
 457 static bool function_enabled;
 458
 459 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 460 {
 461         int ret;
 462
 463         /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
 464         if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
 465                 return 0;
 466
 467         if (graph)
 468                 ret = register_ftrace_graph(&fgraph_ops);
 469         else
 470                 ret = register_ftrace_function(tr->ops);
 471
 472         if (!ret)
 473                 function_enabled = true;
 474
 475         return ret;
 476 }
 477
 478 static void unregister_irqsoff_function(struct trace_array *tr, int graph)
 479 {
 480         if (!function_enabled)
 481                 return;
 482
 483         if (graph)
 484                 unregister_ftrace_graph(&fgraph_ops);
 485         else
 486                 unregister_ftrace_function(tr->ops);
 487
 488         function_enabled = false;
 489 }
 490
 491 static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 492 {
 493         if (!(mask & TRACE_ITER_FUNCTION))
 494                 return 0;
 495
 496         if (set)
 497                 register_irqsoff_function(tr, is_graph(tr), 1);
 498         else
 499                 unregister_irqsoff_function(tr, is_graph(tr));
 500         return 1;
 501 }
 502 #else
 503 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 504 {
 505         return 0;
 506 }
 507 static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
 508 static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 509 {
 510         return 0;
 511 }
 512 #endif /* CONFIG_FUNCTION_TRACER */
 513
 514 static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
 515 {
 516         struct tracer *tracer = tr->current_trace;
 517
 518         if (irqsoff_function_set(tr, mask, set))
 519                 return 0;
 520
 521 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 522         if (mask & TRACE_ITER_DISPLAY_GRAPH)
 523                 return irqsoff_display_graph(tr, set);
 524 #endif
 525
 526         return trace_keep_overwrite(tracer, mask, set);
 527 }
 528
 529 static int start_irqsoff_tracer(struct trace_array *tr, int graph)
 530 {
 531         int ret;
 532
 533         ret = register_irqsoff_function(tr, graph, 0);
 534
 535         if (!ret && tracing_is_enabled())
 536                 tracer_enabled = 1;
 537         else
 538                 tracer_enabled = 0;
 539
 540         return ret;
 541 }
 542
 543 static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
 544 {
 545         tracer_enabled = 0;
 546
 547         unregister_irqsoff_function(tr, graph);
 548 }
 549
 550 static bool irqsoff_busy;
 551
 552 static int __irqsoff_tracer_init(struct trace_array *tr)
 553 {
 554         if (irqsoff_busy)
 555                 return -EBUSY;
 556
 557         save_flags = tr->trace_flags;
 558
 559         /* non overwrite screws up the latency tracers */
 560         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 561         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 562         /* without pause, we will produce garbage if another latency occurs */
 563         set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1);
 564
 565         tr->max_latency = 0;
 566         irqsoff_trace = tr;
 567         /* make sure that the tracer is visible */
 568         smp_wmb();
 569
 570         ftrace_init_array_ops(tr, irqsoff_tracer_call);
 571
 572         /* Only toplevel instance supports graph tracing */
 573         if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
 574                                       is_graph(tr))))
 575                 printk(KERN_ERR "failed to start irqsoff tracer\n");
 576
 577         irqsoff_busy = true;
 578         return 0;
 579 }
 580
 581 static void __irqsoff_tracer_reset(struct trace_array *tr)
 582 {
 583         int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
 584         int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
 585         int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE;
 586
 587         stop_irqsoff_tracer(tr, is_graph(tr));
 588
 589         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
 590         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
 591         set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag);
 592         ftrace_reset_array_ops(tr);
 593
 594         irqsoff_busy = false;
 595 }
 596
 597 static void irqsoff_tracer_start(struct trace_array *tr)
 598 {
 599         tracer_enabled = 1;
 600 }
 601
 602 static void irqsoff_tracer_stop(struct trace_array *tr)
 603 {
 604         tracer_enabled = 0;
 605 }
 606
 607 #ifdef CONFIG_IRQSOFF_TRACER
 608 /*
 609  * We are only interested in hardirq on/off events:
 610  */
 611 void tracer_hardirqs_on(unsigned long a0, unsigned long a1)
 612 {
 613         if (!preempt_trace(preempt_count()) && irq_trace())
 614                 stop_critical_timing(a0, a1);
 615 }
 616 NOKPROBE_SYMBOL(tracer_hardirqs_on);
 617
 618 void tracer_hardirqs_off(unsigned long a0, unsigned long a1)
 619 {
 620         if (!preempt_trace(preempt_count()) && irq_trace())
 621                 start_critical_timing(a0, a1);
 622 }
 623 NOKPROBE_SYMBOL(tracer_hardirqs_off);
 624
 625 static int irqsoff_tracer_init(struct trace_array *tr)
 626 {
 627         trace_type = TRACER_IRQS_OFF;
 628
 629         return __irqsoff_tracer_init(tr);
 630 }
 631
 632 static void irqsoff_tracer_reset(struct trace_array *tr)
 633 {
 634         __irqsoff_tracer_reset(tr);
 635 }
 636
 637 static struct tracer irqsoff_tracer __read_mostly =
 638 {
 639         .name           = "irqsoff",
 640         .init           = irqsoff_tracer_init,
 641         .reset          = irqsoff_tracer_reset,
 642         .start          = irqsoff_tracer_start,
 643         .stop           = irqsoff_tracer_stop,
 644         .print_max      = true,
 645         .print_header   = irqsoff_print_header,
 646         .print_line     = irqsoff_print_line,
 647         .flag_changed   = irqsoff_flag_changed,
 648 #ifdef CONFIG_FTRACE_SELFTEST
 649         .selftest    = trace_selftest_startup_irqsoff,
 650 #endif
 651         .open           = irqsoff_trace_open,
 652         .close          = irqsoff_trace_close,
 653         .allow_instances = true,
 654         .use_max_tr     = true,
 655 };
 656 #endif /*  CONFIG_IRQSOFF_TRACER */
 657
 658 #ifdef CONFIG_PREEMPT_TRACER
 659 void tracer_preempt_on(unsigned long a0, unsigned long a1)
 660 {
 661         if (preempt_trace(preempt_count()) && !irq_trace())
 662                 stop_critical_timing(a0, a1);
 663 }
 664
 665 void tracer_preempt_off(unsigned long a0, unsigned long a1)
 666 {
 667         if (preempt_trace(preempt_count()) && !irq_trace())
 668                 start_critical_timing(a0, a1);
 669 }
 670
 671 static int preemptoff_tracer_init(struct trace_array *tr)
 672 {
 673         trace_type = TRACER_PREEMPT_OFF;
 674
 675         return __irqsoff_tracer_init(tr);
 676 }
 677
 678 static void preemptoff_tracer_reset(struct trace_array *tr)
 679 {
 680         __irqsoff_tracer_reset(tr);
 681 }
 682
 683 static struct tracer preemptoff_tracer __read_mostly =
 684 {
 685         .name           = "preemptoff",
 686         .init           = preemptoff_tracer_init,
 687         .reset          = preemptoff_tracer_reset,
 688         .start          = irqsoff_tracer_start,
 689         .stop           = irqsoff_tracer_stop,
 690         .print_max      = true,
 691         .print_header   = irqsoff_print_header,
 692         .print_line     = irqsoff_print_line,
 693         .flag_changed   = irqsoff_flag_changed,
 694 #ifdef CONFIG_FTRACE_SELFTEST
 695         .selftest    = trace_selftest_startup_preemptoff,
 696 #endif
 697         .open           = irqsoff_trace_open,
 698         .close          = irqsoff_trace_close,
 699         .allow_instances = true,
 700         .use_max_tr     = true,
 701 };
 702 #endif /* CONFIG_PREEMPT_TRACER */
 703
 704 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 705
 706 static int preemptirqsoff_tracer_init(struct trace_array *tr)
 707 {
 708         trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
 709
 710         return __irqsoff_tracer_init(tr);
 711 }
 712
 713 static void preemptirqsoff_tracer_reset(struct trace_array *tr)
 714 {
 715         __irqsoff_tracer_reset(tr);
 716 }
 717
 718 static struct tracer preemptirqsoff_tracer __read_mostly =
 719 {
 720         .name           = "preemptirqsoff",
 721         .init           = preemptirqsoff_tracer_init,
 722         .reset          = preemptirqsoff_tracer_reset,
 723         .start          = irqsoff_tracer_start,
 724         .stop           = irqsoff_tracer_stop,
 725         .print_max      = true,
 726         .print_header   = irqsoff_print_header,
 727         .print_line     = irqsoff_print_line,
 728         .flag_changed   = irqsoff_flag_changed,
 729 #ifdef CONFIG_FTRACE_SELFTEST
 730         .selftest    = trace_selftest_startup_preemptirqsoff,
 731 #endif
 732         .open           = irqsoff_trace_open,
 733         .close          = irqsoff_trace_close,
 734         .allow_instances = true,
 735         .use_max_tr     = true,
 736 };
 737 #endif
 738
 739 __init static int init_irqsoff_tracer(void)
 740 {
 741 #ifdef CONFIG_IRQSOFF_TRACER
 742         register_tracer(&irqsoff_tracer);
 743 #endif
 744 #ifdef CONFIG_PREEMPT_TRACER
 745         register_tracer(&preemptoff_tracer);
 746 #endif
 747 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 748         register_tracer(&preemptirqsoff_tracer);
 749 #endif
 750
 751         return 0;
 752 }
 753 core_initcall(init_irqsoff_tracer);
 754 #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */