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 {
 180         struct trace_array *tr = irqsoff_trace;
 181         struct trace_array_cpu *data;
 182         unsigned long flags;
 183         unsigned int trace_ctx;
 184         int ret;
 185
 186         if (ftrace_graph_ignore_func(trace))
 187                 return 0;
 188         /*
 189          * Do not trace a function if it's filtered by set_graph_notrace.
 190          * Make the index of ret stack negative to indicate that it should
 191          * ignore further functions.  But it needs its own ret stack entry
 192          * to recover the original index in order to continue tracing after
 193          * returning from the function.
 194          */
 195         if (ftrace_graph_notrace_addr(trace->func))
 196                 return 1;
 197
 198         if (!func_prolog_dec(tr, &data, &flags))
 199                 return 0;
 200
 201         trace_ctx = tracing_gen_ctx_flags(flags);
 202         ret = __trace_graph_entry(tr, trace, trace_ctx);
 203         atomic_dec(&data->disabled);
 204
 205         return ret;
 206 }
 207
 208 static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
 209 {
 210         struct trace_array *tr = irqsoff_trace;
 211         struct trace_array_cpu *data;
 212         unsigned long flags;
 213         unsigned int trace_ctx;
 214
 215         ftrace_graph_addr_finish(trace);
 216
 217         if (!func_prolog_dec(tr, &data, &flags))
 218                 return;
 219
 220         trace_ctx = tracing_gen_ctx_flags(flags);
 221         __trace_graph_return(tr, trace, trace_ctx);
 222         atomic_dec(&data->disabled);
 223 }
 224
 225 static struct fgraph_ops fgraph_ops = {
 226         .entryfunc              = &irqsoff_graph_entry,
 227         .retfunc                = &irqsoff_graph_return,
 228 };
 229
 230 static void irqsoff_trace_open(struct trace_iterator *iter)
 231 {
 232         if (is_graph(iter->tr))
 233                 graph_trace_open(iter);
 234
 235 }
 236
 237 static void irqsoff_trace_close(struct trace_iterator *iter)
 238 {
 239         if (iter->private)
 240                 graph_trace_close(iter);
 241 }
 242
 243 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
 244                             TRACE_GRAPH_PRINT_PROC | \
 245                             TRACE_GRAPH_PRINT_REL_TIME | \
 246                             TRACE_GRAPH_PRINT_DURATION)
 247
 248 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 249 {
 250         /*
 251          * In graph mode call the graph tracer output function,
 252          * otherwise go with the TRACE_FN event handler
 253          */
 254         if (is_graph(iter->tr))
 255                 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
 256
 257         return TRACE_TYPE_UNHANDLED;
 258 }
 259
 260 static void irqsoff_print_header(struct seq_file *s)
 261 {
 262         struct trace_array *tr = irqsoff_trace;
 263
 264         if (is_graph(tr))
 265                 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
 266         else
 267                 trace_default_header(s);
 268 }
 269
 270 static void
 271 __trace_function(struct trace_array *tr,
 272                  unsigned long ip, unsigned long parent_ip,
 273                  unsigned int trace_ctx)
 274 {
 275         if (is_graph(tr))
 276                 trace_graph_function(tr, ip, parent_ip, trace_ctx);
 277         else
 278                 trace_function(tr, ip, parent_ip, trace_ctx);
 279 }
 280
 281 #else
 282 #define __trace_function trace_function
 283
 284 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 285 {
 286         return TRACE_TYPE_UNHANDLED;
 287 }
 288
 289 static void irqsoff_trace_open(struct trace_iterator *iter) { }
 290 static void irqsoff_trace_close(struct trace_iterator *iter) { }
 291
 292 #ifdef CONFIG_FUNCTION_TRACER
 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         unsigned int trace_ctx;
 329
 330         T0 = data->preempt_timestamp;
 331         T1 = ftrace_now(cpu);
 332         delta = T1-T0;
 333
 334         trace_ctx = tracing_gen_ctx();
 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, trace_ctx);
 346         /* Skip 5 functions to get to the irq/preempt enable function */
 347         __trace_stack(tr, trace_ctx, 5);
 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, trace_ctx);
 368 }
 369
 370 static nokprobe_inline void
 371 start_critical_timing(unsigned long ip, unsigned long parent_ip)
 372 {
 373         int cpu;
 374         struct trace_array *tr = irqsoff_trace;
 375         struct trace_array_cpu *data;
 376
 377         if (!tracer_enabled || !tracing_is_enabled())
 378                 return;
 379
 380         cpu = raw_smp_processor_id();
 381
 382         if (per_cpu(tracing_cpu, cpu))
 383                 return;
 384
 385         data = per_cpu_ptr(tr->array_buffer.data, cpu);
 386
 387         if (unlikely(!data) || atomic_read(&data->disabled))
 388                 return;
 389
 390         atomic_inc(&data->disabled);
 391
 392         data->critical_sequence = max_sequence;
 393         data->preempt_timestamp = ftrace_now(cpu);
 394         data->critical_start = parent_ip ? : ip;
 395
 396         __trace_function(tr, ip, parent_ip, tracing_gen_ctx());
 397
 398         per_cpu(tracing_cpu, cpu) = 1;
 399
 400         atomic_dec(&data->disabled);
 401 }
 402
 403 static nokprobe_inline void
 404 stop_critical_timing(unsigned long ip, unsigned long parent_ip)
 405 {
 406         int cpu;
 407         struct trace_array *tr = irqsoff_trace;
 408         struct trace_array_cpu *data;
 409         unsigned int trace_ctx;
 410
 411         cpu = raw_smp_processor_id();
 412         /* Always clear the tracing cpu on stopping the trace */
 413         if (unlikely(per_cpu(tracing_cpu, cpu)))
 414                 per_cpu(tracing_cpu, cpu) = 0;
 415         else
 416                 return;
 417
 418         if (!tracer_enabled || !tracing_is_enabled())
 419                 return;
 420
 421         data = per_cpu_ptr(tr->array_buffer.data, cpu);
 422
 423         if (unlikely(!data) ||
 424             !data->critical_start || atomic_read(&data->disabled))
 425                 return;
 426
 427         atomic_inc(&data->disabled);
 428
 429         trace_ctx = tracing_gen_ctx();
 430         __trace_function(tr, ip, parent_ip, trace_ctx);
 431         check_critical_timing(tr, data, parent_ip ? : ip, cpu);
 432         data->critical_start = 0;
 433         atomic_dec(&data->disabled);
 434 }
 435
 436 /* start and stop critical timings used to for stoppage (in idle) */
 437 void start_critical_timings(void)
 438 {
 439         if (preempt_trace(preempt_count()) || irq_trace())
 440                 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 441 }
 442 EXPORT_SYMBOL_GPL(start_critical_timings);
 443 NOKPROBE_SYMBOL(start_critical_timings);
 444
 445 void stop_critical_timings(void)
 446 {
 447         if (preempt_trace(preempt_count()) || irq_trace())
 448                 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 449 }
 450 EXPORT_SYMBOL_GPL(stop_critical_timings);
 451 NOKPROBE_SYMBOL(stop_critical_timings);
 452
 453 #ifdef CONFIG_FUNCTION_TRACER
 454 static bool function_enabled;
 455
 456 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 457 {
 458         int ret;
 459
 460         /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
 461         if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
 462                 return 0;
 463
 464         if (graph)
 465                 ret = register_ftrace_graph(&fgraph_ops);
 466         else
 467                 ret = register_ftrace_function(tr->ops);
 468
 469         if (!ret)
 470                 function_enabled = true;
 471
 472         return ret;
 473 }
 474
 475 static void unregister_irqsoff_function(struct trace_array *tr, int graph)
 476 {
 477         if (!function_enabled)
 478                 return;
 479
 480         if (graph)
 481                 unregister_ftrace_graph(&fgraph_ops);
 482         else
 483                 unregister_ftrace_function(tr->ops);
 484
 485         function_enabled = false;
 486 }
 487
 488 static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 489 {
 490         if (!(mask & TRACE_ITER_FUNCTION))
 491                 return 0;
 492
 493         if (set)
 494                 register_irqsoff_function(tr, is_graph(tr), 1);
 495         else
 496                 unregister_irqsoff_function(tr, is_graph(tr));
 497         return 1;
 498 }
 499 #else
 500 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 501 {
 502         return 0;
 503 }
 504 static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
 505 static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 506 {
 507         return 0;
 508 }
 509 #endif /* CONFIG_FUNCTION_TRACER */
 510
 511 static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
 512 {
 513         struct tracer *tracer = tr->current_trace;
 514
 515         if (irqsoff_function_set(tr, mask, set))
 516                 return 0;
 517
 518 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 519         if (mask & TRACE_ITER_DISPLAY_GRAPH)
 520                 return irqsoff_display_graph(tr, set);
 521 #endif
 522
 523         return trace_keep_overwrite(tracer, mask, set);
 524 }
 525
 526 static int start_irqsoff_tracer(struct trace_array *tr, int graph)
 527 {
 528         int ret;
 529
 530         ret = register_irqsoff_function(tr, graph, 0);
 531
 532         if (!ret && tracing_is_enabled())
 533                 tracer_enabled = 1;
 534         else
 535                 tracer_enabled = 0;
 536
 537         return ret;
 538 }
 539
 540 static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
 541 {
 542         tracer_enabled = 0;
 543
 544         unregister_irqsoff_function(tr, graph);
 545 }
 546
 547 static bool irqsoff_busy;
 548
 549 static int __irqsoff_tracer_init(struct trace_array *tr)
 550 {
 551         if (irqsoff_busy)
 552                 return -EBUSY;
 553
 554         save_flags = tr->trace_flags;
 555
 556         /* non overwrite screws up the latency tracers */
 557         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 558         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 559         /* without pause, we will produce garbage if another latency occurs */
 560         set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1);
 561
 562         tr->max_latency = 0;
 563         irqsoff_trace = tr;
 564         /* make sure that the tracer is visible */
 565         smp_wmb();
 566
 567         ftrace_init_array_ops(tr, irqsoff_tracer_call);
 568
 569         /* Only toplevel instance supports graph tracing */
 570         if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
 571                                       is_graph(tr))))
 572                 printk(KERN_ERR "failed to start irqsoff tracer\n");
 573
 574         irqsoff_busy = true;
 575         return 0;
 576 }
 577
 578 static void __irqsoff_tracer_reset(struct trace_array *tr)
 579 {
 580         int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
 581         int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
 582         int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE;
 583
 584         stop_irqsoff_tracer(tr, is_graph(tr));
 585
 586         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
 587         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
 588         set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag);
 589         ftrace_reset_array_ops(tr);
 590
 591         irqsoff_busy = false;
 592 }
 593
 594 static void irqsoff_tracer_start(struct trace_array *tr)
 595 {
 596         tracer_enabled = 1;
 597 }
 598
 599 static void irqsoff_tracer_stop(struct trace_array *tr)
 600 {
 601         tracer_enabled = 0;
 602 }
 603
 604 #ifdef CONFIG_IRQSOFF_TRACER
 605 /*
 606  * We are only interested in hardirq on/off events:
 607  */
 608 void tracer_hardirqs_on(unsigned long a0, unsigned long a1)
 609 {
 610         if (!preempt_trace(preempt_count()) && irq_trace())
 611                 stop_critical_timing(a0, a1);
 612 }
 613 NOKPROBE_SYMBOL(tracer_hardirqs_on);
 614
 615 void tracer_hardirqs_off(unsigned long a0, unsigned long a1)
 616 {
 617         if (!preempt_trace(preempt_count()) && irq_trace())
 618                 start_critical_timing(a0, a1);
 619 }
 620 NOKPROBE_SYMBOL(tracer_hardirqs_off);
 621
 622 static int irqsoff_tracer_init(struct trace_array *tr)
 623 {
 624         trace_type = TRACER_IRQS_OFF;
 625
 626         return __irqsoff_tracer_init(tr);
 627 }
 628
 629 static void irqsoff_tracer_reset(struct trace_array *tr)
 630 {
 631         __irqsoff_tracer_reset(tr);
 632 }
 633
 634 static struct tracer irqsoff_tracer __read_mostly =
 635 {
 636         .name           = "irqsoff",
 637         .init           = irqsoff_tracer_init,
 638         .reset          = irqsoff_tracer_reset,
 639         .start          = irqsoff_tracer_start,
 640         .stop           = irqsoff_tracer_stop,
 641         .print_max      = true,
 642         .print_header   = irqsoff_print_header,
 643         .print_line     = irqsoff_print_line,
 644         .flag_changed   = irqsoff_flag_changed,
 645 #ifdef CONFIG_FTRACE_SELFTEST
 646         .selftest    = trace_selftest_startup_irqsoff,
 647 #endif
 648         .open           = irqsoff_trace_open,
 649         .close          = irqsoff_trace_close,
 650         .allow_instances = true,
 651         .use_max_tr     = true,
 652 };
 653 #endif /*  CONFIG_IRQSOFF_TRACER */
 654
 655 #ifdef CONFIG_PREEMPT_TRACER
 656 void tracer_preempt_on(unsigned long a0, unsigned long a1)
 657 {
 658         if (preempt_trace(preempt_count()) && !irq_trace())
 659                 stop_critical_timing(a0, a1);
 660 }
 661
 662 void tracer_preempt_off(unsigned long a0, unsigned long a1)
 663 {
 664         if (preempt_trace(preempt_count()) && !irq_trace())
 665                 start_critical_timing(a0, a1);
 666 }
 667
 668 static int preemptoff_tracer_init(struct trace_array *tr)
 669 {
 670         trace_type = TRACER_PREEMPT_OFF;
 671
 672         return __irqsoff_tracer_init(tr);
 673 }
 674
 675 static void preemptoff_tracer_reset(struct trace_array *tr)
 676 {
 677         __irqsoff_tracer_reset(tr);
 678 }
 679
 680 static struct tracer preemptoff_tracer __read_mostly =
 681 {
 682         .name           = "preemptoff",
 683         .init           = preemptoff_tracer_init,
 684         .reset          = preemptoff_tracer_reset,
 685         .start          = irqsoff_tracer_start,
 686         .stop           = irqsoff_tracer_stop,
 687         .print_max      = true,
 688         .print_header   = irqsoff_print_header,
 689         .print_line     = irqsoff_print_line,
 690         .flag_changed   = irqsoff_flag_changed,
 691 #ifdef CONFIG_FTRACE_SELFTEST
 692         .selftest    = trace_selftest_startup_preemptoff,
 693 #endif
 694         .open           = irqsoff_trace_open,
 695         .close          = irqsoff_trace_close,
 696         .allow_instances = true,
 697         .use_max_tr     = true,
 698 };
 699 #endif /* CONFIG_PREEMPT_TRACER */
 700
 701 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 702
 703 static int preemptirqsoff_tracer_init(struct trace_array *tr)
 704 {
 705         trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
 706
 707         return __irqsoff_tracer_init(tr);
 708 }
 709
 710 static void preemptirqsoff_tracer_reset(struct trace_array *tr)
 711 {
 712         __irqsoff_tracer_reset(tr);
 713 }
 714
 715 static struct tracer preemptirqsoff_tracer __read_mostly =
 716 {
 717         .name           = "preemptirqsoff",
 718         .init           = preemptirqsoff_tracer_init,
 719         .reset          = preemptirqsoff_tracer_reset,
 720         .start          = irqsoff_tracer_start,
 721         .stop           = irqsoff_tracer_stop,
 722         .print_max      = true,
 723         .print_header   = irqsoff_print_header,
 724         .print_line     = irqsoff_print_line,
 725         .flag_changed   = irqsoff_flag_changed,
 726 #ifdef CONFIG_FTRACE_SELFTEST
 727         .selftest    = trace_selftest_startup_preemptirqsoff,
 728 #endif
 729         .open           = irqsoff_trace_open,
 730         .close          = irqsoff_trace_close,
 731         .allow_instances = true,
 732         .use_max_tr     = true,
 733 };
 734 #endif
 735
 736 __init static int init_irqsoff_tracer(void)
 737 {
 738 #ifdef CONFIG_IRQSOFF_TRACER
 739         register_tracer(&irqsoff_tracer);
 740 #endif
 741 #ifdef CONFIG_PREEMPT_TRACER
 742         register_tracer(&preemptoff_tracer);
 743 #endif
 744 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 745         register_tracer(&preemptirqsoff_tracer);
 746 #endif
 747
 748         return 0;
 749 }
 750 core_initcall(init_irqsoff_tracer);
 751 #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */