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 <[email protected]>
   6  * Copyright (C) 2008 Ingo Molnar <[email protected]>
   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         else
 235                 iter->private = NULL;
 236 }
 237
 238 static void irqsoff_trace_close(struct trace_iterator *iter)
 239 {
 240         if (iter->private)
 241                 graph_trace_close(iter);
 242 }
 243
 244 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
 245                             TRACE_GRAPH_PRINT_PROC | \
 246                             TRACE_GRAPH_PRINT_REL_TIME | \
 247                             TRACE_GRAPH_PRINT_DURATION)
 248
 249 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 250 {
 251         /*
 252          * In graph mode call the graph tracer output function,
 253          * otherwise go with the TRACE_FN event handler
 254          */
 255         if (is_graph(iter->tr))
 256                 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
 257
 258         return TRACE_TYPE_UNHANDLED;
 259 }
 260
 261 static void irqsoff_print_header(struct seq_file *s)
 262 {
 263         struct trace_array *tr = irqsoff_trace;
 264
 265         if (is_graph(tr))
 266                 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
 267         else
 268                 trace_default_header(s);
 269 }
 270
 271 static void
 272 __trace_function(struct trace_array *tr,
 273                  unsigned long ip, unsigned long parent_ip,
 274                  unsigned int trace_ctx)
 275 {
 276         if (is_graph(tr))
 277                 trace_graph_function(tr, ip, parent_ip, trace_ctx);
 278         else
 279                 trace_function(tr, ip, parent_ip, trace_ctx);
 280 }
 281
 282 #else
 283 #define __trace_function trace_function
 284
 285 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 286 {
 287         return TRACE_TYPE_UNHANDLED;
 288 }
 289
 290 static void irqsoff_trace_open(struct trace_iterator *iter) { }
 291 static void irqsoff_trace_close(struct trace_iterator *iter) { }
 292
 293 #ifdef CONFIG_FUNCTION_TRACER
 294 static void irqsoff_print_header(struct seq_file *s)
 295 {
 296         trace_default_header(s);
 297 }
 298 #else
 299 static void irqsoff_print_header(struct seq_file *s)
 300 {
 301         trace_latency_header(s);
 302 }
 303 #endif /* CONFIG_FUNCTION_TRACER */
 304 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 305
 306 /*
 307  * Should this new latency be reported/recorded?
 308  */
 309 static bool report_latency(struct trace_array *tr, u64 delta)
 310 {
 311         if (tracing_thresh) {
 312                 if (delta < tracing_thresh)
 313                         return false;
 314         } else {
 315                 if (delta <= tr->max_latency)
 316                         return false;
 317         }
 318         return true;
 319 }
 320
 321 static void
 322 check_critical_timing(struct trace_array *tr,
 323                       struct trace_array_cpu *data,
 324                       unsigned long parent_ip,
 325                       int cpu)
 326 {
 327         u64 T0, T1, delta;
 328         unsigned long flags;
 329         unsigned int trace_ctx;
 330
 331         T0 = data->preempt_timestamp;
 332         T1 = ftrace_now(cpu);
 333         delta = T1-T0;
 334
 335         trace_ctx = tracing_gen_ctx();
 336
 337         if (!report_latency(tr, delta))
 338                 goto out;
 339
 340         raw_spin_lock_irqsave(&max_trace_lock, flags);
 341
 342         /* check if we are still the max latency */
 343         if (!report_latency(tr, delta))
 344                 goto out_unlock;
 345
 346         __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
 347         /* Skip 5 functions to get to the irq/preempt enable function */
 348         __trace_stack(tr, trace_ctx, 5);
 349
 350         if (data->critical_sequence != max_sequence)
 351                 goto out_unlock;
 352
 353         data->critical_end = parent_ip;
 354
 355         if (likely(!is_tracing_stopped())) {
 356                 tr->max_latency = delta;
 357                 update_max_tr_single(tr, current, cpu);
 358         }
 359
 360         max_sequence++;
 361
 362 out_unlock:
 363         raw_spin_unlock_irqrestore(&max_trace_lock, flags);
 364
 365 out:
 366         data->critical_sequence = max_sequence;
 367         data->preempt_timestamp = ftrace_now(cpu);
 368         __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
 369 }
 370
 371 static nokprobe_inline void
 372 start_critical_timing(unsigned long ip, unsigned long parent_ip)
 373 {
 374         int cpu;
 375         struct trace_array *tr = irqsoff_trace;
 376         struct trace_array_cpu *data;
 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->array_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         __trace_function(tr, ip, parent_ip, tracing_gen_ctx());
 398
 399         per_cpu(tracing_cpu, cpu) = 1;
 400
 401         atomic_dec(&data->disabled);
 402 }
 403
 404 static nokprobe_inline void
 405 stop_critical_timing(unsigned long ip, unsigned long parent_ip)
 406 {
 407         int cpu;
 408         struct trace_array *tr = irqsoff_trace;
 409         struct trace_array_cpu *data;
 410         unsigned int trace_ctx;
 411
 412         cpu = raw_smp_processor_id();
 413         /* Always clear the tracing cpu on stopping the trace */
 414         if (unlikely(per_cpu(tracing_cpu, cpu)))
 415                 per_cpu(tracing_cpu, cpu) = 0;
 416         else
 417                 return;
 418
 419         if (!tracer_enabled || !tracing_is_enabled())
 420                 return;
 421
 422         data = per_cpu_ptr(tr->array_buffer.data, cpu);
 423
 424         if (unlikely(!data) ||
 425             !data->critical_start || atomic_read(&data->disabled))
 426                 return;
 427
 428         atomic_inc(&data->disabled);
 429
 430         trace_ctx = tracing_gen_ctx();
 431         __trace_function(tr, ip, parent_ip, trace_ctx);
 432         check_critical_timing(tr, data, parent_ip ? : ip, cpu);
 433         data->critical_start = 0;
 434         atomic_dec(&data->disabled);
 435 }
 436
 437 /* start and stop critical timings used to for stoppage (in idle) */
 438 void start_critical_timings(void)
 439 {
 440         if (preempt_trace(preempt_count()) || irq_trace())
 441                 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 442 }
 443 EXPORT_SYMBOL_GPL(start_critical_timings);
 444 NOKPROBE_SYMBOL(start_critical_timings);
 445
 446 void stop_critical_timings(void)
 447 {
 448         if (preempt_trace(preempt_count()) || irq_trace())
 449                 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 450 }
 451 EXPORT_SYMBOL_GPL(stop_critical_timings);
 452 NOKPROBE_SYMBOL(stop_critical_timings);
 453
 454 #ifdef CONFIG_FUNCTION_TRACER
 455 static bool function_enabled;
 456
 457 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 458 {
 459         int ret;
 460
 461         /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
 462         if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
 463                 return 0;
 464
 465         if (graph)
 466                 ret = register_ftrace_graph(&fgraph_ops);
 467         else
 468                 ret = register_ftrace_function(tr->ops);
 469
 470         if (!ret)
 471                 function_enabled = true;
 472
 473         return ret;
 474 }
 475
 476 static void unregister_irqsoff_function(struct trace_array *tr, int graph)
 477 {
 478         if (!function_enabled)
 479                 return;
 480
 481         if (graph)
 482                 unregister_ftrace_graph(&fgraph_ops);
 483         else
 484                 unregister_ftrace_function(tr->ops);
 485
 486         function_enabled = false;
 487 }
 488
 489 static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 490 {
 491         if (!(mask & TRACE_ITER_FUNCTION))
 492                 return 0;
 493
 494         if (set)
 495                 register_irqsoff_function(tr, is_graph(tr), 1);
 496         else
 497                 unregister_irqsoff_function(tr, is_graph(tr));
 498         return 1;
 499 }
 500 #else
 501 static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
 502 {
 503         return 0;
 504 }
 505 static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
 506 static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
 507 {
 508         return 0;
 509 }
 510 #endif /* CONFIG_FUNCTION_TRACER */
 511
 512 static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
 513 {
 514         struct tracer *tracer = tr->current_trace;
 515
 516         if (irqsoff_function_set(tr, mask, set))
 517                 return 0;
 518
 519 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 520         if (mask & TRACE_ITER_DISPLAY_GRAPH)
 521                 return irqsoff_display_graph(tr, set);
 522 #endif
 523
 524         return trace_keep_overwrite(tracer, mask, set);
 525 }
 526
 527 static int start_irqsoff_tracer(struct trace_array *tr, int graph)
 528 {
 529         int ret;
 530
 531         ret = register_irqsoff_function(tr, graph, 0);
 532
 533         if (!ret && tracing_is_enabled())
 534                 tracer_enabled = 1;
 535         else
 536                 tracer_enabled = 0;
 537
 538         return ret;
 539 }
 540
 541 static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
 542 {
 543         tracer_enabled = 0;
 544
 545         unregister_irqsoff_function(tr, graph);
 546 }
 547
 548 static bool irqsoff_busy;
 549
 550 static int __irqsoff_tracer_init(struct trace_array *tr)
 551 {
 552         if (irqsoff_busy)
 553                 return -EBUSY;
 554
 555         save_flags = tr->trace_flags;
 556
 557         /* non overwrite screws up the latency tracers */
 558         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 559         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 560         /* without pause, we will produce garbage if another latency occurs */
 561         set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1);
 562
 563         tr->max_latency = 0;
 564         irqsoff_trace = tr;
 565         /* make sure that the tracer is visible */
 566         smp_wmb();
 567
 568         ftrace_init_array_ops(tr, irqsoff_tracer_call);
 569
 570         /* Only toplevel instance supports graph tracing */
 571         if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
 572                                       is_graph(tr))))
 573                 printk(KERN_ERR "failed to start irqsoff tracer\n");
 574
 575         irqsoff_busy = true;
 576         return 0;
 577 }
 578
 579 static void __irqsoff_tracer_reset(struct trace_array *tr)
 580 {
 581         int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
 582         int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
 583         int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE;
 584
 585         stop_irqsoff_tracer(tr, is_graph(tr));
 586
 587         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
 588         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
 589         set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag);
 590         ftrace_reset_array_ops(tr);
 591
 592         irqsoff_busy = false;
 593 }
 594
 595 static void irqsoff_tracer_start(struct trace_array *tr)
 596 {
 597         tracer_enabled = 1;
 598 }
 599
 600 static void irqsoff_tracer_stop(struct trace_array *tr)
 601 {
 602         tracer_enabled = 0;
 603 }
 604
 605 #ifdef CONFIG_IRQSOFF_TRACER
 606 /*
 607  * We are only interested in hardirq on/off events:
 608  */
 609 void tracer_hardirqs_on(unsigned long a0, unsigned long a1)
 610 {
 611         if (!preempt_trace(preempt_count()) && irq_trace())
 612                 stop_critical_timing(a0, a1);
 613 }
 614 NOKPROBE_SYMBOL(tracer_hardirqs_on);
 615
 616 void tracer_hardirqs_off(unsigned long a0, unsigned long a1)
 617 {
 618         if (!preempt_trace(preempt_count()) && irq_trace())
 619                 start_critical_timing(a0, a1);
 620 }
 621 NOKPROBE_SYMBOL(tracer_hardirqs_off);
 622
 623 static int irqsoff_tracer_init(struct trace_array *tr)
 624 {
 625         trace_type = TRACER_IRQS_OFF;
 626
 627         return __irqsoff_tracer_init(tr);
 628 }
 629
 630 static void irqsoff_tracer_reset(struct trace_array *tr)
 631 {
 632         __irqsoff_tracer_reset(tr);
 633 }
 634
 635 static struct tracer irqsoff_tracer __read_mostly =
 636 {
 637         .name           = "irqsoff",
 638         .init           = irqsoff_tracer_init,
 639         .reset          = irqsoff_tracer_reset,
 640         .start          = irqsoff_tracer_start,
 641         .stop           = irqsoff_tracer_stop,
 642         .print_max      = true,
 643         .print_header   = irqsoff_print_header,
 644         .print_line     = irqsoff_print_line,
 645         .flag_changed   = irqsoff_flag_changed,
 646 #ifdef CONFIG_FTRACE_SELFTEST
 647         .selftest    = trace_selftest_startup_irqsoff,
 648 #endif
 649         .open           = irqsoff_trace_open,
 650         .close          = irqsoff_trace_close,
 651         .allow_instances = true,
 652         .use_max_tr     = true,
 653 };
 654 #endif /*  CONFIG_IRQSOFF_TRACER */
 655
 656 #ifdef CONFIG_PREEMPT_TRACER
 657 void tracer_preempt_on(unsigned long a0, unsigned long a1)
 658 {
 659         if (preempt_trace(preempt_count()) && !irq_trace())
 660                 stop_critical_timing(a0, a1);
 661 }
 662
 663 void tracer_preempt_off(unsigned long a0, unsigned long a1)
 664 {
 665         if (preempt_trace(preempt_count()) && !irq_trace())
 666                 start_critical_timing(a0, a1);
 667 }
 668
 669 static int preemptoff_tracer_init(struct trace_array *tr)
 670 {
 671         trace_type = TRACER_PREEMPT_OFF;
 672
 673         return __irqsoff_tracer_init(tr);
 674 }
 675
 676 static void preemptoff_tracer_reset(struct trace_array *tr)
 677 {
 678         __irqsoff_tracer_reset(tr);
 679 }
 680
 681 static struct tracer preemptoff_tracer __read_mostly =
 682 {
 683         .name           = "preemptoff",
 684         .init           = preemptoff_tracer_init,
 685         .reset          = preemptoff_tracer_reset,
 686         .start          = irqsoff_tracer_start,
 687         .stop           = irqsoff_tracer_stop,
 688         .print_max      = true,
 689         .print_header   = irqsoff_print_header,
 690         .print_line     = irqsoff_print_line,
 691         .flag_changed   = irqsoff_flag_changed,
 692 #ifdef CONFIG_FTRACE_SELFTEST
 693         .selftest    = trace_selftest_startup_preemptoff,
 694 #endif
 695         .open           = irqsoff_trace_open,
 696         .close          = irqsoff_trace_close,
 697         .allow_instances = true,
 698         .use_max_tr     = true,
 699 };
 700 #endif /* CONFIG_PREEMPT_TRACER */
 701
 702 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 703
 704 static int preemptirqsoff_tracer_init(struct trace_array *tr)
 705 {
 706         trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
 707
 708         return __irqsoff_tracer_init(tr);
 709 }
 710
 711 static void preemptirqsoff_tracer_reset(struct trace_array *tr)
 712 {
 713         __irqsoff_tracer_reset(tr);
 714 }
 715
 716 static struct tracer preemptirqsoff_tracer __read_mostly =
 717 {
 718         .name           = "preemptirqsoff",
 719         .init           = preemptirqsoff_tracer_init,
 720         .reset          = preemptirqsoff_tracer_reset,
 721         .start          = irqsoff_tracer_start,
 722         .stop           = irqsoff_tracer_stop,
 723         .print_max      = true,
 724         .print_header   = irqsoff_print_header,
 725         .print_line     = irqsoff_print_line,
 726         .flag_changed   = irqsoff_flag_changed,
 727 #ifdef CONFIG_FTRACE_SELFTEST
 728         .selftest    = trace_selftest_startup_preemptirqsoff,
 729 #endif
 730         .open           = irqsoff_trace_open,
 731         .close          = irqsoff_trace_close,
 732         .allow_instances = true,
 733         .use_max_tr     = true,
 734 };
 735 #endif
 736
 737 __init static int init_irqsoff_tracer(void)
 738 {
 739 #ifdef CONFIG_IRQSOFF_TRACER
 740         register_tracer(&irqsoff_tracer);
 741 #endif
 742 #ifdef CONFIG_PREEMPT_TRACER
 743         register_tracer(&preemptoff_tracer);
 744 #endif
 745 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 746         register_tracer(&preemptirqsoff_tracer);
 747 #endif
 748
 749         return 0;
 750 }
 751 core_initcall(init_irqsoff_tracer);
 752 #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */