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