Pileus Git - ~andy/linux/blob - kernel/trace/trace_functions_graph.c

   1 /*
   2  *
   3  * Function graph tracer.
   4  * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
   5  * Mostly borrowed from function tracer which
   6  * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
   7  *
   8  */
   9 #include <linux/debugfs.h>
  10 #include <linux/uaccess.h>
  11 #include <linux/ftrace.h>
  12 #include <linux/slab.h>
  13 #include <linux/fs.h>
  14
  15 #include "trace.h"
  16 #include "trace_output.h"
  17
  18 /* When set, irq functions will be ignored */
  19 static int ftrace_graph_skip_irqs;
  20
  21 struct fgraph_cpu_data {
  22         pid_t           last_pid;
  23         int             depth;
  24         int             depth_irq;
  25         int             ignore;
  26         unsigned long   enter_funcs[FTRACE_RETFUNC_DEPTH];
  27 };
  28
  29 struct fgraph_data {
  30         struct fgraph_cpu_data __percpu *cpu_data;
  31
  32         /* Place to preserve last processed entry. */
  33         struct ftrace_graph_ent_entry   ent;
  34         struct ftrace_graph_ret_entry   ret;
  35         int                             failed;
  36         int                             cpu;
  37 };
  38
  39 #define TRACE_GRAPH_INDENT      2
  40
  41 /* Flag options */
  42 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
  43 #define TRACE_GRAPH_PRINT_CPU           0x2
  44 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
  45 #define TRACE_GRAPH_PRINT_PROC          0x8
  46 #define TRACE_GRAPH_PRINT_DURATION      0x10
  47 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
  48 #define TRACE_GRAPH_PRINT_IRQS          0x40
  49
  50 static struct tracer_opt trace_opts[] = {
  51         /* Display overruns? (for self-debug purpose) */
  52         { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
  53         /* Display CPU ? */
  54         { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
  55         /* Display Overhead ? */
  56         { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
  57         /* Display proc name/pid */
  58         { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
  59         /* Display duration of execution */
  60         { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
  61         /* Display absolute time of an entry */
  62         { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
  63         /* Display interrupts */
  64         { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
  65         { } /* Empty entry */
  66 };
  67
  68 static struct tracer_flags tracer_flags = {
  69         /* Don't display overruns and proc by default */
  70         .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
  71                TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS,
  72         .opts = trace_opts
  73 };
  74
  75 static struct trace_array *graph_array;
  76
  77
  78 /* Add a function return address to the trace stack on thread info.*/
  79 int
  80 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
  81                          unsigned long frame_pointer)
  82 {
  83         unsigned long long calltime;
  84         int index;
  85
  86         if (!current->ret_stack)
  87                 return -EBUSY;
  88
  89         /*
  90          * We must make sure the ret_stack is tested before we read
  91          * anything else.
  92          */
  93         smp_rmb();
  94
  95         /* The return trace stack is full */
  96         if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
  97                 atomic_inc(&current->trace_overrun);
  98                 return -EBUSY;
  99         }
 100
 101         calltime = trace_clock_local();
 102
 103         index = ++current->curr_ret_stack;
 104         barrier();
 105         current->ret_stack[index].ret = ret;
 106         current->ret_stack[index].func = func;
 107         current->ret_stack[index].calltime = calltime;
 108         current->ret_stack[index].subtime = 0;
 109         current->ret_stack[index].fp = frame_pointer;
 110         *depth = index;
 111
 112         return 0;
 113 }
 114
 115 /* Retrieve a function return address to the trace stack on thread info.*/
 116 static void
 117 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
 118                         unsigned long frame_pointer)
 119 {
 120         int index;
 121
 122         index = current->curr_ret_stack;
 123
 124         if (unlikely(index < 0)) {
 125                 ftrace_graph_stop();
 126                 WARN_ON(1);
 127                 /* Might as well panic, otherwise we have no where to go */
 128                 *ret = (unsigned long)panic;
 129                 return;
 130         }
 131
 132 #ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
 133         /*
 134          * The arch may choose to record the frame pointer used
 135          * and check it here to make sure that it is what we expect it
 136          * to be. If gcc does not set the place holder of the return
 137          * address in the frame pointer, and does a copy instead, then
 138          * the function graph trace will fail. This test detects this
 139          * case.
 140          *
 141          * Currently, x86_32 with optimize for size (-Os) makes the latest
 142          * gcc do the above.
 143          */
 144         if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
 145                 ftrace_graph_stop();
 146                 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
 147                      "  from func %ps return to %lx\n",
 148                      current->ret_stack[index].fp,
 149                      frame_pointer,
 150                      (void *)current->ret_stack[index].func,
 151                      current->ret_stack[index].ret);
 152                 *ret = (unsigned long)panic;
 153                 return;
 154         }
 155 #endif
 156
 157         *ret = current->ret_stack[index].ret;
 158         trace->func = current->ret_stack[index].func;
 159         trace->calltime = current->ret_stack[index].calltime;
 160         trace->overrun = atomic_read(&current->trace_overrun);
 161         trace->depth = index;
 162 }
 163
 164 /*
 165  * Send the trace to the ring-buffer.
 166  * @return the original return address.
 167  */
 168 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 169 {
 170         struct ftrace_graph_ret trace;
 171         unsigned long ret;
 172
 173         ftrace_pop_return_trace(&trace, &ret, frame_pointer);
 174         trace.rettime = trace_clock_local();
 175         ftrace_graph_return(&trace);
 176         barrier();
 177         current->curr_ret_stack--;
 178
 179         if (unlikely(!ret)) {
 180                 ftrace_graph_stop();
 181                 WARN_ON(1);
 182                 /* Might as well panic. What else to do? */
 183                 ret = (unsigned long)panic;
 184         }
 185
 186         return ret;
 187 }
 188
 189 int __trace_graph_entry(struct trace_array *tr,
 190                                 struct ftrace_graph_ent *trace,
 191                                 unsigned long flags,
 192                                 int pc)
 193 {
 194         struct ftrace_event_call *call = &event_funcgraph_entry;
 195         struct ring_buffer_event *event;
 196         struct ring_buffer *buffer = tr->buffer;
 197         struct ftrace_graph_ent_entry *entry;
 198
 199         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
 200                 return 0;
 201
 202         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
 203                                           sizeof(*entry), flags, pc);
 204         if (!event)
 205                 return 0;
 206         entry   = ring_buffer_event_data(event);
 207         entry->graph_ent                        = *trace;
 208         if (!filter_current_check_discard(buffer, call, entry, event))
 209                 ring_buffer_unlock_commit(buffer, event);
 210
 211         return 1;
 212 }
 213
 214 static inline int ftrace_graph_ignore_irqs(void)
 215 {
 216         if (!ftrace_graph_skip_irqs)
 217                 return 0;
 218
 219         return in_irq();
 220 }
 221
 222 int trace_graph_entry(struct ftrace_graph_ent *trace)
 223 {
 224         struct trace_array *tr = graph_array;
 225         struct trace_array_cpu *data;
 226         unsigned long flags;
 227         long disabled;
 228         int ret;
 229         int cpu;
 230         int pc;
 231
 232         if (!ftrace_trace_task(current))
 233                 return 0;
 234
 235         /* trace it when it is-nested-in or is a function enabled. */
 236         if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
 237               ftrace_graph_ignore_irqs())
 238                 return 0;
 239
 240         local_irq_save(flags);
 241         cpu = raw_smp_processor_id();
 242         data = tr->data[cpu];
 243         disabled = atomic_inc_return(&data->disabled);
 244         if (likely(disabled == 1)) {
 245                 pc = preempt_count();
 246                 ret = __trace_graph_entry(tr, trace, flags, pc);
 247         } else {
 248                 ret = 0;
 249         }
 250
 251         atomic_dec(&data->disabled);
 252         local_irq_restore(flags);
 253
 254         return ret;
 255 }
 256
 257 int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
 258 {
 259         if (tracing_thresh)
 260                 return 1;
 261         else
 262                 return trace_graph_entry(trace);
 263 }
 264
 265 void __trace_graph_return(struct trace_array *tr,
 266                                 struct ftrace_graph_ret *trace,
 267                                 unsigned long flags,
 268                                 int pc)
 269 {
 270         struct ftrace_event_call *call = &event_funcgraph_exit;
 271         struct ring_buffer_event *event;
 272         struct ring_buffer *buffer = tr->buffer;
 273         struct ftrace_graph_ret_entry *entry;
 274
 275         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
 276                 return;
 277
 278         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
 279                                           sizeof(*entry), flags, pc);
 280         if (!event)
 281                 return;
 282         entry   = ring_buffer_event_data(event);
 283         entry->ret                              = *trace;
 284         if (!filter_current_check_discard(buffer, call, entry, event))
 285                 ring_buffer_unlock_commit(buffer, event);
 286 }
 287
 288 void trace_graph_return(struct ftrace_graph_ret *trace)
 289 {
 290         struct trace_array *tr = graph_array;
 291         struct trace_array_cpu *data;
 292         unsigned long flags;
 293         long disabled;
 294         int cpu;
 295         int pc;
 296
 297         local_irq_save(flags);
 298         cpu = raw_smp_processor_id();
 299         data = tr->data[cpu];
 300         disabled = atomic_inc_return(&data->disabled);
 301         if (likely(disabled == 1)) {
 302                 pc = preempt_count();
 303                 __trace_graph_return(tr, trace, flags, pc);
 304         }
 305         atomic_dec(&data->disabled);
 306         local_irq_restore(flags);
 307 }
 308
 309 void set_graph_array(struct trace_array *tr)
 310 {
 311         graph_array = tr;
 312
 313         /* Make graph_array visible before we start tracing */
 314
 315         smp_mb();
 316 }
 317
 318 void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
 319 {
 320         if (tracing_thresh &&
 321             (trace->rettime - trace->calltime < tracing_thresh))
 322                 return;
 323         else
 324                 trace_graph_return(trace);
 325 }
 326
 327 static int graph_trace_init(struct trace_array *tr)
 328 {
 329         int ret;
 330
 331         set_graph_array(tr);
 332         if (tracing_thresh)
 333                 ret = register_ftrace_graph(&trace_graph_thresh_return,
 334                                             &trace_graph_thresh_entry);
 335         else
 336                 ret = register_ftrace_graph(&trace_graph_return,
 337                                             &trace_graph_entry);
 338         if (ret)
 339                 return ret;
 340         tracing_start_cmdline_record();
 341
 342         return 0;
 343 }
 344
 345 static void graph_trace_reset(struct trace_array *tr)
 346 {
 347         tracing_stop_cmdline_record();
 348         unregister_ftrace_graph();
 349 }
 350
 351 static int max_bytes_for_cpu;
 352
 353 static enum print_line_t
 354 print_graph_cpu(struct trace_seq *s, int cpu)
 355 {
 356         int ret;
 357
 358         /*
 359          * Start with a space character - to make it stand out
 360          * to the right a bit when trace output is pasted into
 361          * email:
 362          */
 363         ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
 364         if (!ret)
 365                 return TRACE_TYPE_PARTIAL_LINE;
 366
 367         return TRACE_TYPE_HANDLED;
 368 }
 369
 370 #define TRACE_GRAPH_PROCINFO_LENGTH     14
 371
 372 static enum print_line_t
 373 print_graph_proc(struct trace_seq *s, pid_t pid)
 374 {
 375         char comm[TASK_COMM_LEN];
 376         /* sign + log10(MAX_INT) + '\0' */
 377         char pid_str[11];
 378         int spaces = 0;
 379         int ret;
 380         int len;
 381         int i;
 382
 383         trace_find_cmdline(pid, comm);
 384         comm[7] = '\0';
 385         sprintf(pid_str, "%d", pid);
 386
 387         /* 1 stands for the "-" character */
 388         len = strlen(comm) + strlen(pid_str) + 1;
 389
 390         if (len < TRACE_GRAPH_PROCINFO_LENGTH)
 391                 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
 392
 393         /* First spaces to align center */
 394         for (i = 0; i < spaces / 2; i++) {
 395                 ret = trace_seq_printf(s, " ");
 396                 if (!ret)
 397                         return TRACE_TYPE_PARTIAL_LINE;
 398         }
 399
 400         ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
 401         if (!ret)
 402                 return TRACE_TYPE_PARTIAL_LINE;
 403
 404         /* Last spaces to align center */
 405         for (i = 0; i < spaces - (spaces / 2); i++) {
 406                 ret = trace_seq_printf(s, " ");
 407                 if (!ret)
 408                         return TRACE_TYPE_PARTIAL_LINE;
 409         }
 410         return TRACE_TYPE_HANDLED;
 411 }
 412
 413
 414 static enum print_line_t
 415 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 416 {
 417         if (!trace_seq_putc(s, ' '))
 418                 return 0;
 419
 420         return trace_print_lat_fmt(s, entry);
 421 }
 422
 423 /* If the pid changed since the last trace, output this event */
 424 static enum print_line_t
 425 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
 426 {
 427         pid_t prev_pid;
 428         pid_t *last_pid;
 429         int ret;
 430
 431         if (!data)
 432                 return TRACE_TYPE_HANDLED;
 433
 434         last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
 435
 436         if (*last_pid == pid)
 437                 return TRACE_TYPE_HANDLED;
 438
 439         prev_pid = *last_pid;
 440         *last_pid = pid;
 441
 442         if (prev_pid == -1)
 443                 return TRACE_TYPE_HANDLED;
 444 /*
 445  * Context-switch trace line:
 446
 447  ------------------------------------------
 448  | 1)  migration/0--1  =>  sshd-1755
 449  ------------------------------------------
 450
 451  */
 452         ret = trace_seq_printf(s,
 453                 " ------------------------------------------\n");
 454         if (!ret)
 455                 return TRACE_TYPE_PARTIAL_LINE;
 456
 457         ret = print_graph_cpu(s, cpu);
 458         if (ret == TRACE_TYPE_PARTIAL_LINE)
 459                 return TRACE_TYPE_PARTIAL_LINE;
 460
 461         ret = print_graph_proc(s, prev_pid);
 462         if (ret == TRACE_TYPE_PARTIAL_LINE)
 463                 return TRACE_TYPE_PARTIAL_LINE;
 464
 465         ret = trace_seq_printf(s, " => ");
 466         if (!ret)
 467                 return TRACE_TYPE_PARTIAL_LINE;
 468
 469         ret = print_graph_proc(s, pid);
 470         if (ret == TRACE_TYPE_PARTIAL_LINE)
 471                 return TRACE_TYPE_PARTIAL_LINE;
 472
 473         ret = trace_seq_printf(s,
 474                 "\n ------------------------------------------\n\n");
 475         if (!ret)
 476                 return TRACE_TYPE_PARTIAL_LINE;
 477
 478         return TRACE_TYPE_HANDLED;
 479 }
 480
 481 static struct ftrace_graph_ret_entry *
 482 get_return_for_leaf(struct trace_iterator *iter,
 483                 struct ftrace_graph_ent_entry *curr)
 484 {
 485         struct fgraph_data *data = iter->private;
 486         struct ring_buffer_iter *ring_iter = NULL;
 487         struct ring_buffer_event *event;
 488         struct ftrace_graph_ret_entry *next;
 489
 490         /*
 491          * If the previous output failed to write to the seq buffer,
 492          * then we just reuse the data from before.
 493          */
 494         if (data && data->failed) {
 495                 curr = &data->ent;
 496                 next = &data->ret;
 497         } else {
 498
 499                 ring_iter = iter->buffer_iter[iter->cpu];
 500
 501                 /* First peek to compare current entry and the next one */
 502                 if (ring_iter)
 503                         event = ring_buffer_iter_peek(ring_iter, NULL);
 504                 else {
 505                         /*
 506                          * We need to consume the current entry to see
 507                          * the next one.
 508                          */
 509                         ring_buffer_consume(iter->tr->buffer, iter->cpu,
 510                                             NULL, NULL);
 511                         event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
 512                                                  NULL, NULL);
 513                 }
 514
 515                 if (!event)
 516                         return NULL;
 517
 518                 next = ring_buffer_event_data(event);
 519
 520                 if (data) {
 521                         /*
 522                          * Save current and next entries for later reference
 523                          * if the output fails.
 524                          */
 525                         data->ent = *curr;
 526                         /*
 527                          * If the next event is not a return type, then
 528                          * we only care about what type it is. Otherwise we can
 529                          * safely copy the entire event.
 530                          */
 531                         if (next->ent.type == TRACE_GRAPH_RET)
 532                                 data->ret = *next;
 533                         else
 534                                 data->ret.ent.type = next->ent.type;
 535                 }
 536         }
 537
 538         if (next->ent.type != TRACE_GRAPH_RET)
 539                 return NULL;
 540
 541         if (curr->ent.pid != next->ent.pid ||
 542                         curr->graph_ent.func != next->ret.func)
 543                 return NULL;
 544
 545         /* this is a leaf, now advance the iterator */
 546         if (ring_iter)
 547                 ring_buffer_read(ring_iter, NULL);
 548
 549         return next;
 550 }
 551
 552 /* Signal a overhead of time execution to the output */
 553 static int
 554 print_graph_overhead(unsigned long long duration, struct trace_seq *s,
 555                      u32 flags)
 556 {
 557         /* If duration disappear, we don't need anything */
 558         if (!(flags & TRACE_GRAPH_PRINT_DURATION))
 559                 return 1;
 560
 561         /* Non nested entry or return */
 562         if (duration == -1)
 563                 return trace_seq_printf(s, "  ");
 564
 565         if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
 566                 /* Duration exceeded 100 msecs */
 567                 if (duration > 100000ULL)
 568                         return trace_seq_printf(s, "! ");
 569
 570                 /* Duration exceeded 10 msecs */
 571                 if (duration > 10000ULL)
 572                         return trace_seq_printf(s, "+ ");
 573         }
 574
 575         return trace_seq_printf(s, "  ");
 576 }
 577
 578 static int print_graph_abs_time(u64 t, struct trace_seq *s)
 579 {
 580         unsigned long usecs_rem;
 581
 582         usecs_rem = do_div(t, NSEC_PER_SEC);
 583         usecs_rem /= 1000;
 584
 585         return trace_seq_printf(s, "%5lu.%06lu |  ",
 586                         (unsigned long)t, usecs_rem);
 587 }
 588
 589 static enum print_line_t
 590 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 591                 enum trace_type type, int cpu, pid_t pid, u32 flags)
 592 {
 593         int ret;
 594         struct trace_seq *s = &iter->seq;
 595
 596         if (addr < (unsigned long)__irqentry_text_start ||
 597                 addr >= (unsigned long)__irqentry_text_end)
 598                 return TRACE_TYPE_UNHANDLED;
 599
 600         /* Absolute time */
 601         if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
 602                 ret = print_graph_abs_time(iter->ts, s);
 603                 if (!ret)
 604                         return TRACE_TYPE_PARTIAL_LINE;
 605         }
 606
 607         /* Cpu */
 608         if (flags & TRACE_GRAPH_PRINT_CPU) {
 609                 ret = print_graph_cpu(s, cpu);
 610                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 611                         return TRACE_TYPE_PARTIAL_LINE;
 612         }
 613
 614         /* Proc */
 615         if (flags & TRACE_GRAPH_PRINT_PROC) {
 616                 ret = print_graph_proc(s, pid);
 617                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 618                         return TRACE_TYPE_PARTIAL_LINE;
 619                 ret = trace_seq_printf(s, " | ");
 620                 if (!ret)
 621                         return TRACE_TYPE_PARTIAL_LINE;
 622         }
 623
 624         /* No overhead */
 625         ret = print_graph_overhead(-1, s, flags);
 626         if (!ret)
 627                 return TRACE_TYPE_PARTIAL_LINE;
 628
 629         if (type == TRACE_GRAPH_ENT)
 630                 ret = trace_seq_printf(s, "==========>");
 631         else
 632                 ret = trace_seq_printf(s, "<==========");
 633
 634         if (!ret)
 635                 return TRACE_TYPE_PARTIAL_LINE;
 636
 637         /* Don't close the duration column if haven't one */
 638         if (flags & TRACE_GRAPH_PRINT_DURATION)
 639                 trace_seq_printf(s, " |");
 640         ret = trace_seq_printf(s, "\n");
 641
 642         if (!ret)
 643                 return TRACE_TYPE_PARTIAL_LINE;
 644         return TRACE_TYPE_HANDLED;
 645 }
 646
 647 enum print_line_t
 648 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 649 {
 650         unsigned long nsecs_rem = do_div(duration, 1000);
 651         /* log10(ULONG_MAX) + '\0' */
 652         char msecs_str[21];
 653         char nsecs_str[5];
 654         int ret, len;
 655         int i;
 656
 657         sprintf(msecs_str, "%lu", (unsigned long) duration);
 658
 659         /* Print msecs */
 660         ret = trace_seq_printf(s, "%s", msecs_str);
 661         if (!ret)
 662                 return TRACE_TYPE_PARTIAL_LINE;
 663
 664         len = strlen(msecs_str);
 665
 666         /* Print nsecs (we don't want to exceed 7 numbers) */
 667         if (len < 7) {
 668                 snprintf(nsecs_str, min(sizeof(nsecs_str), 8UL - len), "%03lu",
 669                          nsecs_rem);
 670                 ret = trace_seq_printf(s, ".%s", nsecs_str);
 671                 if (!ret)
 672                         return TRACE_TYPE_PARTIAL_LINE;
 673                 len += strlen(nsecs_str);
 674         }
 675
 676         ret = trace_seq_printf(s, " us ");
 677         if (!ret)
 678                 return TRACE_TYPE_PARTIAL_LINE;
 679
 680         /* Print remaining spaces to fit the row's width */
 681         for (i = len; i < 7; i++) {
 682                 ret = trace_seq_printf(s, " ");
 683                 if (!ret)
 684                         return TRACE_TYPE_PARTIAL_LINE;
 685         }
 686         return TRACE_TYPE_HANDLED;
 687 }
 688
 689 static enum print_line_t
 690 print_graph_duration(unsigned long long duration, struct trace_seq *s)
 691 {
 692         int ret;
 693
 694         ret = trace_print_graph_duration(duration, s);
 695         if (ret != TRACE_TYPE_HANDLED)
 696                 return ret;
 697
 698         ret = trace_seq_printf(s, "|  ");
 699         if (!ret)
 700                 return TRACE_TYPE_PARTIAL_LINE;
 701
 702         return TRACE_TYPE_HANDLED;
 703 }
 704
 705 /* Case of a leaf function on its call entry */
 706 static enum print_line_t
 707 print_graph_entry_leaf(struct trace_iterator *iter,
 708                 struct ftrace_graph_ent_entry *entry,
 709                 struct ftrace_graph_ret_entry *ret_entry,
 710                 struct trace_seq *s, u32 flags)
 711 {
 712         struct fgraph_data *data = iter->private;
 713         struct ftrace_graph_ret *graph_ret;
 714         struct ftrace_graph_ent *call;
 715         unsigned long long duration;
 716         int ret;
 717         int i;
 718
 719         graph_ret = &ret_entry->ret;
 720         call = &entry->graph_ent;
 721         duration = graph_ret->rettime - graph_ret->calltime;
 722
 723         if (data) {
 724                 struct fgraph_cpu_data *cpu_data;
 725                 int cpu = iter->cpu;
 726
 727                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
 728
 729                 /*
 730                  * Comments display at + 1 to depth. Since
 731                  * this is a leaf function, keep the comments
 732                  * equal to this depth.
 733                  */
 734                 cpu_data->depth = call->depth - 1;
 735
 736                 /* No need to keep this function around for this depth */
 737                 if (call->depth < FTRACE_RETFUNC_DEPTH)
 738                         cpu_data->enter_funcs[call->depth] = 0;
 739         }
 740
 741         /* Overhead */
 742         ret = print_graph_overhead(duration, s, flags);
 743         if (!ret)
 744                 return TRACE_TYPE_PARTIAL_LINE;
 745
 746         /* Duration */
 747         if (flags & TRACE_GRAPH_PRINT_DURATION) {
 748                 ret = print_graph_duration(duration, s);
 749                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 750                         return TRACE_TYPE_PARTIAL_LINE;
 751         }
 752
 753         /* Function */
 754         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 755                 ret = trace_seq_printf(s, " ");
 756                 if (!ret)
 757                         return TRACE_TYPE_PARTIAL_LINE;
 758         }
 759
 760         ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
 761         if (!ret)
 762                 return TRACE_TYPE_PARTIAL_LINE;
 763
 764         return TRACE_TYPE_HANDLED;
 765 }
 766
 767 static enum print_line_t
 768 print_graph_entry_nested(struct trace_iterator *iter,
 769                          struct ftrace_graph_ent_entry *entry,
 770                          struct trace_seq *s, int cpu, u32 flags)
 771 {
 772         struct ftrace_graph_ent *call = &entry->graph_ent;
 773         struct fgraph_data *data = iter->private;
 774         int ret;
 775         int i;
 776
 777         if (data) {
 778                 struct fgraph_cpu_data *cpu_data;
 779                 int cpu = iter->cpu;
 780
 781                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
 782                 cpu_data->depth = call->depth;
 783
 784                 /* Save this function pointer to see if the exit matches */
 785                 if (call->depth < FTRACE_RETFUNC_DEPTH)
 786                         cpu_data->enter_funcs[call->depth] = call->func;
 787         }
 788
 789         /* No overhead */
 790         ret = print_graph_overhead(-1, s, flags);
 791         if (!ret)
 792                 return TRACE_TYPE_PARTIAL_LINE;
 793
 794         /* No time */
 795         if (flags & TRACE_GRAPH_PRINT_DURATION) {
 796                 ret = trace_seq_printf(s, "            |  ");
 797                 if (!ret)
 798                         return TRACE_TYPE_PARTIAL_LINE;
 799         }
 800
 801         /* Function */
 802         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 803                 ret = trace_seq_printf(s, " ");
 804                 if (!ret)
 805                         return TRACE_TYPE_PARTIAL_LINE;
 806         }
 807
 808         ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
 809         if (!ret)
 810                 return TRACE_TYPE_PARTIAL_LINE;
 811
 812         /*
 813          * we already consumed the current entry to check the next one
 814          * and see if this is a leaf.
 815          */
 816         return TRACE_TYPE_NO_CONSUME;
 817 }
 818
 819 static enum print_line_t
 820 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
 821                      int type, unsigned long addr, u32 flags)
 822 {
 823         struct fgraph_data *data = iter->private;
 824         struct trace_entry *ent = iter->ent;
 825         int cpu = iter->cpu;
 826         int ret;
 827
 828         /* Pid */
 829         if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
 830                 return TRACE_TYPE_PARTIAL_LINE;
 831
 832         if (type) {
 833                 /* Interrupt */
 834                 ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
 835                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 836                         return TRACE_TYPE_PARTIAL_LINE;
 837         }
 838
 839         /* Absolute time */
 840         if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
 841                 ret = print_graph_abs_time(iter->ts, s);
 842                 if (!ret)
 843                         return TRACE_TYPE_PARTIAL_LINE;
 844         }
 845
 846         /* Cpu */
 847         if (flags & TRACE_GRAPH_PRINT_CPU) {
 848                 ret = print_graph_cpu(s, cpu);
 849                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 850                         return TRACE_TYPE_PARTIAL_LINE;
 851         }
 852
 853         /* Proc */
 854         if (flags & TRACE_GRAPH_PRINT_PROC) {
 855                 ret = print_graph_proc(s, ent->pid);
 856                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 857                         return TRACE_TYPE_PARTIAL_LINE;
 858
 859                 ret = trace_seq_printf(s, " | ");
 860                 if (!ret)
 861                         return TRACE_TYPE_PARTIAL_LINE;
 862         }
 863
 864         /* Latency format */
 865         if (trace_flags & TRACE_ITER_LATENCY_FMT) {
 866                 ret = print_graph_lat_fmt(s, ent);
 867                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 868                         return TRACE_TYPE_PARTIAL_LINE;
 869         }
 870
 871         return 0;
 872 }
 873
 874 /*
 875  * Entry check for irq code
 876  *
 877  * returns 1 if
 878  *  - we are inside irq code
 879  *  - we just extered irq code
 880  *
 881  * retunns 0 if
 882  *  - funcgraph-interrupts option is set
 883  *  - we are not inside irq code
 884  */
 885 static int
 886 check_irq_entry(struct trace_iterator *iter, u32 flags,
 887                 unsigned long addr, int depth)
 888 {
 889         int cpu = iter->cpu;
 890         struct fgraph_data *data = iter->private;
 891         int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
 892
 893         if (flags & TRACE_GRAPH_PRINT_IRQS)
 894                 return 0;
 895
 896         /*
 897          * We are inside the irq code
 898          */
 899         if (*depth_irq >= 0)
 900                 return 1;
 901
 902         if ((addr < (unsigned long)__irqentry_text_start) ||
 903             (addr >= (unsigned long)__irqentry_text_end))
 904                 return 0;
 905
 906         /*
 907          * We are entering irq code.
 908          */
 909         *depth_irq = depth;
 910         return 1;
 911 }
 912
 913 /*
 914  * Return check for irq code
 915  *
 916  * returns 1 if
 917  *  - we are inside irq code
 918  *  - we just left irq code
 919  *
 920  * returns 0 if
 921  *  - funcgraph-interrupts option is set
 922  *  - we are not inside irq code
 923  */
 924 static int
 925 check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
 926 {
 927         int cpu = iter->cpu;
 928         struct fgraph_data *data = iter->private;
 929         int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
 930
 931         if (flags & TRACE_GRAPH_PRINT_IRQS)
 932                 return 0;
 933
 934         /*
 935          * We are not inside the irq code.
 936          */
 937         if (*depth_irq == -1)
 938                 return 0;
 939
 940         /*
 941          * We are inside the irq code, and this is returning entry.
 942          * Let's not trace it and clear the entry depth, since
 943          * we are out of irq code.
 944          *
 945          * This condition ensures that we 'leave the irq code' once
 946          * we are out of the entry depth. Thus protecting us from
 947          * the RETURN entry loss.
 948          */
 949         if (*depth_irq >= depth) {
 950                 *depth_irq = -1;
 951                 return 1;
 952         }
 953
 954         /*
 955          * We are inside the irq code, and this is not the entry.
 956          */
 957         return 1;
 958 }
 959
 960 static enum print_line_t
 961 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 962                         struct trace_iterator *iter, u32 flags)
 963 {
 964         struct fgraph_data *data = iter->private;
 965         struct ftrace_graph_ent *call = &field->graph_ent;
 966         struct ftrace_graph_ret_entry *leaf_ret;
 967         static enum print_line_t ret;
 968         int cpu = iter->cpu;
 969
 970         if (check_irq_entry(iter, flags, call->func, call->depth))
 971                 return TRACE_TYPE_HANDLED;
 972
 973         if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
 974                 return TRACE_TYPE_PARTIAL_LINE;
 975
 976         leaf_ret = get_return_for_leaf(iter, field);
 977         if (leaf_ret)
 978                 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
 979         else
 980                 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
 981
 982         if (data) {
 983                 /*
 984                  * If we failed to write our output, then we need to make
 985                  * note of it. Because we already consumed our entry.
 986                  */
 987                 if (s->full) {
 988                         data->failed = 1;
 989                         data->cpu = cpu;
 990                 } else
 991                         data->failed = 0;
 992         }
 993
 994         return ret;
 995 }
 996
 997 static enum print_line_t
 998 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 999                    struct trace_entry *ent, struct trace_iterator *iter,
1000                    u32 flags)
1001 {
1002         unsigned long long duration = trace->rettime - trace->calltime;
1003         struct fgraph_data *data = iter->private;
1004         pid_t pid = ent->pid;
1005         int cpu = iter->cpu;
1006         int func_match = 1;
1007         int ret;
1008         int i;
1009
1010         if (check_irq_return(iter, flags, trace->depth))
1011                 return TRACE_TYPE_HANDLED;
1012
1013         if (data) {
1014                 struct fgraph_cpu_data *cpu_data;
1015                 int cpu = iter->cpu;
1016
1017                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1018
1019                 /*
1020                  * Comments display at + 1 to depth. This is the
1021                  * return from a function, we now want the comments
1022                  * to display at the same level of the bracket.
1023                  */
1024                 cpu_data->depth = trace->depth - 1;
1025
1026                 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
1027                         if (cpu_data->enter_funcs[trace->depth] != trace->func)
1028                                 func_match = 0;
1029                         cpu_data->enter_funcs[trace->depth] = 0;
1030                 }
1031         }
1032
1033         if (print_graph_prologue(iter, s, 0, 0, flags))
1034                 return TRACE_TYPE_PARTIAL_LINE;
1035
1036         /* Overhead */
1037         ret = print_graph_overhead(duration, s, flags);
1038         if (!ret)
1039                 return TRACE_TYPE_PARTIAL_LINE;
1040
1041         /* Duration */
1042         if (flags & TRACE_GRAPH_PRINT_DURATION) {
1043                 ret = print_graph_duration(duration, s);
1044                 if (ret == TRACE_TYPE_PARTIAL_LINE)
1045                         return TRACE_TYPE_PARTIAL_LINE;
1046         }
1047
1048         /* Closing brace */
1049         for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
1050                 ret = trace_seq_printf(s, " ");
1051                 if (!ret)
1052                         return TRACE_TYPE_PARTIAL_LINE;
1053         }
1054
1055         /*
1056          * If the return function does not have a matching entry,
1057          * then the entry was lost. Instead of just printing
1058          * the '}' and letting the user guess what function this
1059          * belongs to, write out the function name.
1060          */
1061         if (func_match) {
1062                 ret = trace_seq_printf(s, "}\n");
1063                 if (!ret)
1064                         return TRACE_TYPE_PARTIAL_LINE;
1065         } else {
1066                 ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1067                 if (!ret)
1068                         return TRACE_TYPE_PARTIAL_LINE;
1069         }
1070
1071         /* Overrun */
1072         if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1073                 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
1074                                         trace->overrun);
1075                 if (!ret)
1076                         return TRACE_TYPE_PARTIAL_LINE;
1077         }
1078
1079         ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1080                               cpu, pid, flags);
1081         if (ret == TRACE_TYPE_PARTIAL_LINE)
1082                 return TRACE_TYPE_PARTIAL_LINE;
1083
1084         return TRACE_TYPE_HANDLED;
1085 }
1086
1087 static enum print_line_t
1088 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1089                     struct trace_iterator *iter, u32 flags)
1090 {
1091         unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1092         struct fgraph_data *data = iter->private;
1093         struct trace_event *event;
1094         int depth = 0;
1095         int ret;
1096         int i;
1097
1098         if (data)
1099                 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1100
1101         if (print_graph_prologue(iter, s, 0, 0, flags))
1102                 return TRACE_TYPE_PARTIAL_LINE;
1103
1104         /* No overhead */
1105         ret = print_graph_overhead(-1, s, flags);
1106         if (!ret)
1107                 return TRACE_TYPE_PARTIAL_LINE;
1108
1109         /* No time */
1110         if (flags & TRACE_GRAPH_PRINT_DURATION) {
1111                 ret = trace_seq_printf(s, "            |  ");
1112                 if (!ret)
1113                         return TRACE_TYPE_PARTIAL_LINE;
1114         }
1115
1116         /* Indentation */
1117         if (depth > 0)
1118                 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1119                         ret = trace_seq_printf(s, " ");
1120                         if (!ret)
1121                                 return TRACE_TYPE_PARTIAL_LINE;
1122                 }
1123
1124         /* The comment */
1125         ret = trace_seq_printf(s, "/* ");
1126         if (!ret)
1127                 return TRACE_TYPE_PARTIAL_LINE;
1128
1129         switch (iter->ent->type) {
1130         case TRACE_BPRINT:
1131                 ret = trace_print_bprintk_msg_only(iter);
1132                 if (ret != TRACE_TYPE_HANDLED)
1133                         return ret;
1134                 break;
1135         case TRACE_PRINT:
1136                 ret = trace_print_printk_msg_only(iter);
1137                 if (ret != TRACE_TYPE_HANDLED)
1138                         return ret;
1139                 break;
1140         default:
1141                 event = ftrace_find_event(ent->type);
1142                 if (!event)
1143                         return TRACE_TYPE_UNHANDLED;
1144
1145                 ret = event->funcs->trace(iter, sym_flags, event);
1146                 if (ret != TRACE_TYPE_HANDLED)
1147                         return ret;
1148         }
1149
1150         /* Strip ending newline */
1151         if (s->buffer[s->len - 1] == '\n') {
1152                 s->buffer[s->len - 1] = '\0';
1153                 s->len--;
1154         }
1155
1156         ret = trace_seq_printf(s, " */\n");
1157         if (!ret)
1158                 return TRACE_TYPE_PARTIAL_LINE;
1159
1160         return TRACE_TYPE_HANDLED;
1161 }
1162
1163
1164 enum print_line_t
1165 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1166 {
1167         struct ftrace_graph_ent_entry *field;
1168         struct fgraph_data *data = iter->private;
1169         struct trace_entry *entry = iter->ent;
1170         struct trace_seq *s = &iter->seq;
1171         int cpu = iter->cpu;
1172         int ret;
1173
1174         if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1175                 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1176                 return TRACE_TYPE_HANDLED;
1177         }
1178
1179         /*
1180          * If the last output failed, there's a possibility we need
1181          * to print out the missing entry which would never go out.
1182          */
1183         if (data && data->failed) {
1184                 field = &data->ent;
1185                 iter->cpu = data->cpu;
1186                 ret = print_graph_entry(field, s, iter, flags);
1187                 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1188                         per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1189                         ret = TRACE_TYPE_NO_CONSUME;
1190                 }
1191                 iter->cpu = cpu;
1192                 return ret;
1193         }
1194
1195         switch (entry->type) {
1196         case TRACE_GRAPH_ENT: {
1197                 /*
1198                  * print_graph_entry() may consume the current event,
1199                  * thus @field may become invalid, so we need to save it.
1200                  * sizeof(struct ftrace_graph_ent_entry) is very small,
1201                  * it can be safely saved at the stack.
1202                  */
1203                 struct ftrace_graph_ent_entry saved;
1204                 trace_assign_type(field, entry);
1205                 saved = *field;
1206                 return print_graph_entry(&saved, s, iter, flags);
1207         }
1208         case TRACE_GRAPH_RET: {
1209                 struct ftrace_graph_ret_entry *field;
1210                 trace_assign_type(field, entry);
1211                 return print_graph_return(&field->ret, s, entry, iter, flags);
1212         }
1213         case TRACE_STACK:
1214         case TRACE_FN:
1215                 /* dont trace stack and functions as comments */
1216                 return TRACE_TYPE_UNHANDLED;
1217
1218         default:
1219                 return print_graph_comment(s, entry, iter, flags);
1220         }
1221
1222         return TRACE_TYPE_HANDLED;
1223 }
1224
1225 static enum print_line_t
1226 print_graph_function(struct trace_iterator *iter)
1227 {
1228         return print_graph_function_flags(iter, tracer_flags.val);
1229 }
1230
1231 static enum print_line_t
1232 print_graph_function_event(struct trace_iterator *iter, int flags,
1233                            struct trace_event *event)
1234 {
1235         return print_graph_function(iter);
1236 }
1237
1238 static void print_lat_header(struct seq_file *s, u32 flags)
1239 {
1240         static const char spaces[] = "                " /* 16 spaces */
1241                 "    "                                  /* 4 spaces */
1242                 "                 ";                    /* 17 spaces */
1243         int size = 0;
1244
1245         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1246                 size += 16;
1247         if (flags & TRACE_GRAPH_PRINT_CPU)
1248                 size += 4;
1249         if (flags & TRACE_GRAPH_PRINT_PROC)
1250                 size += 17;
1251
1252         seq_printf(s, "#%.*s  _-----=> irqs-off        \n", size, spaces);
1253         seq_printf(s, "#%.*s / _----=> need-resched    \n", size, spaces);
1254         seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1255         seq_printf(s, "#%.*s|| / _--=> preempt-depth   \n", size, spaces);
1256         seq_printf(s, "#%.*s||| / _-=> lock-depth      \n", size, spaces);
1257         seq_printf(s, "#%.*s|||| /                     \n", size, spaces);
1258 }
1259
1260 void print_graph_headers_flags(struct seq_file *s, u32 flags)
1261 {
1262         int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1263
1264         if (lat)
1265                 print_lat_header(s, flags);
1266
1267         /* 1st line */
1268         seq_printf(s, "#");
1269         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1270                 seq_printf(s, "     TIME       ");
1271         if (flags & TRACE_GRAPH_PRINT_CPU)
1272                 seq_printf(s, " CPU");
1273         if (flags & TRACE_GRAPH_PRINT_PROC)
1274                 seq_printf(s, "  TASK/PID       ");
1275         if (lat)
1276                 seq_printf(s, "|||||");
1277         if (flags & TRACE_GRAPH_PRINT_DURATION)
1278                 seq_printf(s, "  DURATION   ");
1279         seq_printf(s, "               FUNCTION CALLS\n");
1280
1281         /* 2nd line */
1282         seq_printf(s, "#");
1283         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1284                 seq_printf(s, "      |         ");
1285         if (flags & TRACE_GRAPH_PRINT_CPU)
1286                 seq_printf(s, " |  ");
1287         if (flags & TRACE_GRAPH_PRINT_PROC)
1288                 seq_printf(s, "   |    |        ");
1289         if (lat)
1290                 seq_printf(s, "|||||");
1291         if (flags & TRACE_GRAPH_PRINT_DURATION)
1292                 seq_printf(s, "   |   |      ");
1293         seq_printf(s, "               |   |   |   |\n");
1294 }
1295
1296 void print_graph_headers(struct seq_file *s)
1297 {
1298         print_graph_headers_flags(s, tracer_flags.val);
1299 }
1300
1301 void graph_trace_open(struct trace_iterator *iter)
1302 {
1303         /* pid and depth on the last trace processed */
1304         struct fgraph_data *data;
1305         int cpu;
1306
1307         iter->private = NULL;
1308
1309         data = kzalloc(sizeof(*data), GFP_KERNEL);
1310         if (!data)
1311                 goto out_err;
1312
1313         data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1314         if (!data->cpu_data)
1315                 goto out_err_free;
1316
1317         for_each_possible_cpu(cpu) {
1318                 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1319                 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1320                 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1321                 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1322
1323                 *pid = -1;
1324                 *depth = 0;
1325                 *ignore = 0;
1326                 *depth_irq = -1;
1327         }
1328
1329         iter->private = data;
1330
1331         return;
1332
1333  out_err_free:
1334         kfree(data);
1335  out_err:
1336         pr_warning("function graph tracer: not enough memory\n");
1337 }
1338
1339 void graph_trace_close(struct trace_iterator *iter)
1340 {
1341         struct fgraph_data *data = iter->private;
1342
1343         if (data) {
1344                 free_percpu(data->cpu_data);
1345                 kfree(data);
1346         }
1347 }
1348
1349 static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
1350 {
1351         if (bit == TRACE_GRAPH_PRINT_IRQS)
1352                 ftrace_graph_skip_irqs = !set;
1353
1354         return 0;
1355 }
1356
1357 static struct trace_event_functions graph_functions = {
1358         .trace          = print_graph_function_event,
1359 };
1360
1361 static struct trace_event graph_trace_entry_event = {
1362         .type           = TRACE_GRAPH_ENT,
1363         .funcs          = &graph_functions,
1364 };
1365
1366 static struct trace_event graph_trace_ret_event = {
1367         .type           = TRACE_GRAPH_RET,
1368         .funcs          = &graph_functions
1369 };
1370
1371 static struct tracer graph_trace __read_mostly = {
1372         .name           = "function_graph",
1373         .open           = graph_trace_open,
1374         .pipe_open      = graph_trace_open,
1375         .close          = graph_trace_close,
1376         .pipe_close     = graph_trace_close,
1377         .wait_pipe      = poll_wait_pipe,
1378         .init           = graph_trace_init,
1379         .reset          = graph_trace_reset,
1380         .print_line     = print_graph_function,
1381         .print_header   = print_graph_headers,
1382         .flags          = &tracer_flags,
1383         .set_flag       = func_graph_set_flag,
1384 #ifdef CONFIG_FTRACE_SELFTEST
1385         .selftest       = trace_selftest_startup_function_graph,
1386 #endif
1387 };
1388
1389 static __init int init_graph_trace(void)
1390 {
1391         max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1392
1393         if (!register_ftrace_event(&graph_trace_entry_event)) {
1394                 pr_warning("Warning: could not register graph trace events\n");
1395                 return 1;
1396         }
1397
1398         if (!register_ftrace_event(&graph_trace_ret_event)) {
1399                 pr_warning("Warning: could not register graph trace events\n");
1400                 return 1;
1401         }
1402
1403         return register_tracer(&graph_trace);
1404 }
1405
1406 device_initcall(init_graph_trace);