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->trace_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 pt_regs *pt_regs)
 142 {
 143         struct trace_array *tr = irqsoff_trace;
 144         struct trace_array_cpu *data;
 145         unsigned long flags;
 146
 147         if (!func_prolog_dec(tr, &data, &flags))
 148                 return;
 149
 150         trace_function(tr, ip, parent_ip, flags, preempt_count());
 151
 152         atomic_dec(&data->disabled);
 153 }
 154 #endif /* CONFIG_FUNCTION_TRACER */
 155
 156 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 157 static int irqsoff_display_graph(struct trace_array *tr, int set)
 158 {
 159         int cpu;
 160
 161         if (!(is_graph(tr) ^ set))
 162                 return 0;
 163
 164         stop_irqsoff_tracer(irqsoff_trace, !set);
 165
 166         for_each_possible_cpu(cpu)
 167                 per_cpu(tracing_cpu, cpu) = 0;
 168
 169         tr->max_latency = 0;
 170         tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
 171
 172         return start_irqsoff_tracer(irqsoff_trace, set);
 173 }
 174
 175 static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
 176 {
 177         struct trace_array *tr = irqsoff_trace;
 178         struct trace_array_cpu *data;
 179         unsigned long flags;
 180         int ret;
 181         int pc;
 182
 183         if (ftrace_graph_ignore_func(trace))
 184                 return 0;
 185         /*
 186          * Do not trace a function if it's filtered by set_graph_notrace.
 187          * Make the index of ret stack negative to indicate that it should
 188          * ignore further functions.  But it needs its own ret stack entry
 189          * to recover the original index in order to continue tracing after
 190          * returning from the function.
 191          */
 192         if (ftrace_graph_notrace_addr(trace->func))
 193                 return 1;
 194
 195         if (!func_prolog_dec(tr, &data, &flags))
 196                 return 0;
 197
 198         pc = preempt_count();
 199         ret = __trace_graph_entry(tr, trace, flags, pc);
 200         atomic_dec(&data->disabled);
 201
 202         return ret;
 203 }
 204
 205 static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
 206 {
 207         struct trace_array *tr = irqsoff_trace;
 208         struct trace_array_cpu *data;
 209         unsigned long flags;
 210         int pc;
 211
 212         ftrace_graph_addr_finish(trace);
 213
 214         if (!func_prolog_dec(tr, &data, &flags))
 215                 return;
 216
 217         pc = preempt_count();
 218         __trace_graph_return(tr, trace, flags, pc);
 219         atomic_dec(&data->disabled);
 220 }
 221
 222 static struct fgraph_ops fgraph_ops = {
 223         .entryfunc              = &irqsoff_graph_entry,
 224         .retfunc                = &irqsoff_graph_return,
 225 };
 226
 227 static void irqsoff_trace_open(struct trace_iterator *iter)
 228 {
 229         if (is_graph(iter->tr))
 230                 graph_trace_open(iter);
 231         else
 232                 iter->private = NULL;
 233 }
 234
 235 static void irqsoff_trace_close(struct trace_iterator *iter)
 236 {
 237         if (iter->private)
 238                 graph_trace_close(iter);
 239 }
 240
 241 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
 242                             TRACE_GRAPH_PRINT_PROC | \
 243                             TRACE_GRAPH_PRINT_REL_TIME | \
 244                             TRACE_GRAPH_PRINT_DURATION)
 245
 246 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 247 {
 248         /*
 249          * In graph mode call the graph tracer output function,
 250          * otherwise go with the TRACE_FN event handler
 251          */
 252         if (is_graph(iter->tr))
 253                 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
 254
 255         return TRACE_TYPE_UNHANDLED;
 256 }
 257
 258 static void irqsoff_print_header(struct seq_file *s)
 259 {
 260         struct trace_array *tr = irqsoff_trace;
 261
 262         if (is_graph(tr))
 263                 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
 264         else
 265                 trace_default_header(s);
 266 }
 267
 268 static void
 269 __trace_function(struct trace_array *tr,
 270                  unsigned long ip, unsigned long parent_ip,
 271                  unsigned long flags, int pc)
 272 {
 273         if (is_graph(tr))
 274                 trace_graph_function(tr, ip, parent_ip, flags, pc);
 275         else
 276                 trace_function(tr, ip, parent_ip, flags, pc);
 277 }
 278
 279 #else
 280 #define __trace_function trace_function
 281
 282 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 283 {
 284         return TRACE_TYPE_UNHANDLED;
 285 }
 286
 287 static void irqsoff_trace_open(struct trace_iterator *iter) { }
 288 static void irqsoff_trace_close(struct trace_iterator *iter) { }
 289
 290 #ifdef CONFIG_FUNCTION_TRACER
 291 static void irqsoff_print_header(struct seq_file *s)
 292 {
 293         trace_default_header(s);
 294 }
 295 #else
 296 static void irqsoff_print_header(struct seq_file *s)
 297 {
 298         trace_latency_header(s);
 299 }
 300 #endif /* CONFIG_FUNCTION_TRACER */
 301 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 302
 303 /*
 304  * Should this new latency be reported/recorded?
 305  */
 306 static bool report_latency(struct trace_array *tr, u64 delta)
 307 {
 308         if (tracing_thresh) {
 309                 if (delta < tracing_thresh)
 310                         return false;
 311         } else {
 312                 if (delta <= tr->max_latency)
 313                         return false;
 314         }
 315         return true;
 316 }
 317
 318 static void
 319 check_critical_timing(struct trace_array *tr,
 320                       struct trace_array_cpu *data,
 321                       unsigned long parent_ip,
 322                       int cpu)
 323 {
 324         u64 T0, T1, delta;
 325         unsigned long flags;
 326         int pc;
 327
 328         T0 = data->preempt_timestamp;
 329         T1 = ftrace_now(cpu);
 330         delta = T1-T0;
 331
 332         local_save_flags(flags);
 333
 334         pc = preempt_count();
 335
 336         if (!report_latency(tr, delta))
 337                 goto out;
 338
 339         raw_spin_lock_irqsave(&max_trace_lock, flags);
 340
 341         /* check if we are still the max latency */
 342         if (!report_latency(tr, delta))
 343                 goto out_unlock;
 344
 345         __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
 346         /* Skip 5 functions to get to the irq/preempt enable function */
 347         __trace_stack(tr, flags, 5, pc);
 348
 349         if (data->critical_sequence != max_sequence)
 350                 goto out_unlock;
 351
 352         data->critical_end = parent_ip;
 353
 354         if (likely(!is_tracing_stopped())) {
 355                 tr->max_latency = delta;
 356                 update_max_tr_single(tr, current, cpu);
 357         }
 358
 359         max_sequence++;
 360
 361 out_unlock:
 362         raw_spin_unlock_irqrestore(&max_trace_lock, flags);
 363
 364 out:
 365         data->critical_sequence = max_sequence;
 366         data->preempt_timestamp = ftrace_now(cpu);
 367         __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
 368 }
 369
 370 static nokprobe_inline void
 371 start_critical_timing(unsigned long ip, unsigned long parent_ip, int pc)
 372 {
 373         int cpu;
 374         struct trace_array *tr = irqsoff_trace;
 375         struct trace_array_cpu *data;
 376         unsigned long flags;
 377
 378         if (!tracer_enabled || !tracing_is_enabled())
 379                 return;
 380
 381         cpu = raw_smp_processor_id();
 382
 383         if (per_cpu(tracing_cpu, cpu))
 384                 return;
 385
 386         data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 387
 388         if (unlikely(!data) || atomic_read(&data->disabled))
 389                 return;
 390
 391         atomic_inc(&data->disabled);
 392
 393         data->critical_sequence = max_sequence;
 394         data->preempt_timestamp = ftrace_now(cpu);
 395         data->critical_start = parent_ip ? : ip;
 396
 397         local_save_flags(flags);
 398
 399         __trace_function(tr, ip, parent_ip, flags, pc);
 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, int pc)
 408 {
 409         int cpu;
 410         struct trace_array *tr = irqsoff_trace;
 411         struct trace_array_cpu *data;
 412         unsigned long flags;
 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->trace_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         local_save_flags(flags);
 433         __trace_function(tr, ip, parent_ip, flags, pc);
 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         int pc = preempt_count();
 443
 444         if (preempt_trace(pc) || irq_trace())
 445                 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1, pc);
 446 }
 447 EXPORT_SYMBOL_GPL(start_critical_timings);
 448 NOKPROBE_SYMBOL(start_critical_timings);
 449
 450 void stop_critical_timings(void)
 451 {
 452         int pc = preempt_count();
 453
 454         if (preempt_trace(pc) || irq_trace())
 455                 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1, pc);
 456 }
 457 EXPORT_SYMBOL_GPL(stop_critical_timings);
 458 NOKPROBE_SYMBOL(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(&fgraph_ops);
 473         else
 474                 ret = register_ftrace_function(tr->ops);
 475
 476         if (!ret)
 477                 function_enabled = true;
 478
 479         return ret;
 480 }
 481
 482 static void unregister_irqsoff_function(struct trace_array *tr, int graph)
 483 {
 484         if (!function_enabled)
 485                 return;
 486
 487         if (graph)
 488                 unregister_ftrace_graph(&fgraph_ops);
 489         else
 490                 unregister_ftrace_function(tr->ops);
 491
 492         function_enabled = false;
 493 }
 494
 495 static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 496 {
 497         if (!(mask & TRACE_ITER_FUNCTION))
 498                 return 0;
 499
 500         if (set)
 501                 register_irqsoff_function(tr, is_graph(tr), 1);
 502         else
 503                 unregister_irqsoff_function(tr, is_graph(tr));
 504         return 1;
 505 }
 506 #else
 507 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 508 {
 509         return 0;
 510 }
 511 static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
 512 static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 513 {
 514         return 0;
 515 }
 516 #endif /* CONFIG_FUNCTION_TRACER */
 517
 518 static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
 519 {
 520         struct tracer *tracer = tr->current_trace;
 521
 522         if (irqsoff_function_set(tr, mask, set))
 523                 return 0;
 524
 525 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 526         if (mask & TRACE_ITER_DISPLAY_GRAPH)
 527                 return irqsoff_display_graph(tr, set);
 528 #endif
 529
 530         return trace_keep_overwrite(tracer, mask, set);
 531 }
 532
 533 static int start_irqsoff_tracer(struct trace_array *tr, int graph)
 534 {
 535         int ret;
 536
 537         ret = register_irqsoff_function(tr, graph, 0);
 538
 539         if (!ret && tracing_is_enabled())
 540                 tracer_enabled = 1;
 541         else
 542                 tracer_enabled = 0;
 543
 544         return ret;
 545 }
 546
 547 static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
 548 {
 549         tracer_enabled = 0;
 550
 551         unregister_irqsoff_function(tr, graph);
 552 }
 553
 554 static bool irqsoff_busy;
 555
 556 static int __irqsoff_tracer_init(struct trace_array *tr)
 557 {
 558         if (irqsoff_busy)
 559                 return -EBUSY;
 560
 561         save_flags = tr->trace_flags;
 562
 563         /* non overwrite screws up the latency tracers */
 564         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 565         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 566
 567         tr->max_latency = 0;
 568         irqsoff_trace = tr;
 569         /* make sure that the tracer is visible */
 570         smp_wmb();
 571
 572         ftrace_init_array_ops(tr, irqsoff_tracer_call);
 573
 574         /* Only toplevel instance supports graph tracing */
 575         if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
 576                                       is_graph(tr))))
 577                 printk(KERN_ERR "failed to start irqsoff tracer\n");
 578
 579         irqsoff_busy = true;
 580         return 0;
 581 }
 582
 583 static void __irqsoff_tracer_reset(struct trace_array *tr)
 584 {
 585         int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
 586         int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
 587
 588         stop_irqsoff_tracer(tr, is_graph(tr));
 589
 590         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
 591         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_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         unsigned int pc = preempt_count();
 614
 615         if (!preempt_trace(pc) && irq_trace())
 616                 stop_critical_timing(a0, a1, pc);
 617 }
 618 NOKPROBE_SYMBOL(tracer_hardirqs_on);
 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 NOKPROBE_SYMBOL(tracer_hardirqs_off);
 628
 629 static int irqsoff_tracer_init(struct trace_array *tr)
 630 {
 631         trace_type = TRACER_IRQS_OFF;
 632
 633         return __irqsoff_tracer_init(tr);
 634 }
 635
 636 static void irqsoff_tracer_reset(struct trace_array *tr)
 637 {
 638         __irqsoff_tracer_reset(tr);
 639 }
 640
 641 static struct tracer irqsoff_tracer __read_mostly =
 642 {
 643         .name           = "irqsoff",
 644         .init           = irqsoff_tracer_init,
 645         .reset          = irqsoff_tracer_reset,
 646         .start          = irqsoff_tracer_start,
 647         .stop           = irqsoff_tracer_stop,
 648         .print_max      = true,
 649         .print_header   = irqsoff_print_header,
 650         .print_line     = irqsoff_print_line,
 651         .flag_changed   = irqsoff_flag_changed,
 652 #ifdef CONFIG_FTRACE_SELFTEST
 653         .selftest    = trace_selftest_startup_irqsoff,
 654 #endif
 655         .open           = irqsoff_trace_open,
 656         .close          = irqsoff_trace_close,
 657         .allow_instances = true,
 658         .use_max_tr     = true,
 659 };
 660 #endif /*  CONFIG_IRQSOFF_TRACER */
 661
 662 #ifdef CONFIG_PREEMPT_TRACER
 663 void tracer_preempt_on(unsigned long a0, unsigned long a1)
 664 {
 665         int pc = preempt_count();
 666
 667         if (preempt_trace(pc) && !irq_trace())
 668                 stop_critical_timing(a0, a1, pc);
 669 }
 670
 671 void tracer_preempt_off(unsigned long a0, unsigned long a1)
 672 {
 673         int pc = preempt_count();
 674
 675         if (preempt_trace(pc) && !irq_trace())
 676                 start_critical_timing(a0, a1, pc);
 677 }
 678
 679 static int preemptoff_tracer_init(struct trace_array *tr)
 680 {
 681         trace_type = TRACER_PREEMPT_OFF;
 682
 683         return __irqsoff_tracer_init(tr);
 684 }
 685
 686 static void preemptoff_tracer_reset(struct trace_array *tr)
 687 {
 688         __irqsoff_tracer_reset(tr);
 689 }
 690
 691 static struct tracer preemptoff_tracer __read_mostly =
 692 {
 693         .name           = "preemptoff",
 694         .init           = preemptoff_tracer_init,
 695         .reset          = preemptoff_tracer_reset,
 696         .start          = irqsoff_tracer_start,
 697         .stop           = irqsoff_tracer_stop,
 698         .print_max      = true,
 699         .print_header   = irqsoff_print_header,
 700         .print_line     = irqsoff_print_line,
 701         .flag_changed   = irqsoff_flag_changed,
 702 #ifdef CONFIG_FTRACE_SELFTEST
 703         .selftest    = trace_selftest_startup_preemptoff,
 704 #endif
 705         .open           = irqsoff_trace_open,
 706         .close          = irqsoff_trace_close,
 707         .allow_instances = true,
 708         .use_max_tr     = true,
 709 };
 710 #endif /* CONFIG_PREEMPT_TRACER */
 711
 712 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 713
 714 static int preemptirqsoff_tracer_init(struct trace_array *tr)
 715 {
 716         trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
 717
 718         return __irqsoff_tracer_init(tr);
 719 }
 720
 721 static void preemptirqsoff_tracer_reset(struct trace_array *tr)
 722 {
 723         __irqsoff_tracer_reset(tr);
 724 }
 725
 726 static struct tracer preemptirqsoff_tracer __read_mostly =
 727 {
 728         .name           = "preemptirqsoff",
 729         .init           = preemptirqsoff_tracer_init,
 730         .reset          = preemptirqsoff_tracer_reset,
 731         .start          = irqsoff_tracer_start,
 732         .stop           = irqsoff_tracer_stop,
 733         .print_max      = true,
 734         .print_header   = irqsoff_print_header,
 735         .print_line     = irqsoff_print_line,
 736         .flag_changed   = irqsoff_flag_changed,
 737 #ifdef CONFIG_FTRACE_SELFTEST
 738         .selftest    = trace_selftest_startup_preemptirqsoff,
 739 #endif
 740         .open           = irqsoff_trace_open,
 741         .close          = irqsoff_trace_close,
 742         .allow_instances = true,
 743         .use_max_tr     = true,
 744 };
 745 #endif
 746
 747 __init static int init_irqsoff_tracer(void)
 748 {
 749 #ifdef CONFIG_IRQSOFF_TRACER
 750         register_tracer(&irqsoff_tracer);
 751 #endif
 752 #ifdef CONFIG_PREEMPT_TRACER
 753         register_tracer(&preemptoff_tracer);
 754 #endif
 755 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 756         register_tracer(&preemptirqsoff_tracer);
 757 #endif
 758
 759         return 0;
 760 }
 761 core_initcall(init_irqsoff_tracer);
 762 #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */