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  * DURATION column is being also used to display IRQ signs,
  79  * following values are used by print_graph_irq and others
  80  * to fill in space into DURATION column.
  81  */
  82 enum {
  83         DURATION_FILL_FULL  = -1,
  84         DURATION_FILL_START = -2,
  85         DURATION_FILL_END   = -3,
  86 };
  87
  88 static enum print_line_t
  89 print_graph_duration(unsigned long long duration, struct trace_seq *s,
  90                      u32 flags);
  91
  92 /* Add a function return address to the trace stack on thread info.*/
  93 int
  94 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
  95                          unsigned long frame_pointer)
  96 {
  97         unsigned long long calltime;
  98         int index;
  99
 100         if (!current->ret_stack)
 101                 return -EBUSY;
 102
 103         /*
 104          * We must make sure the ret_stack is tested before we read
 105          * anything else.
 106          */
 107         smp_rmb();
 108
 109         /* The return trace stack is full */
 110         if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
 111                 atomic_inc(&current->trace_overrun);
 112                 return -EBUSY;
 113         }
 114
 115         calltime = trace_clock_local();
 116
 117         index = ++current->curr_ret_stack;
 118         barrier();
 119         current->ret_stack[index].ret = ret;
 120         current->ret_stack[index].func = func;
 121         current->ret_stack[index].calltime = calltime;
 122         current->ret_stack[index].subtime = 0;
 123         current->ret_stack[index].fp = frame_pointer;
 124         *depth = index;
 125
 126         return 0;
 127 }
 128
 129 /* Retrieve a function return address to the trace stack on thread info.*/
 130 static void
 131 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
 132                         unsigned long frame_pointer)
 133 {
 134         int index;
 135
 136         index = current->curr_ret_stack;
 137
 138         if (unlikely(index < 0)) {
 139                 ftrace_graph_stop();
 140                 WARN_ON(1);
 141                 /* Might as well panic, otherwise we have no where to go */
 142                 *ret = (unsigned long)panic;
 143                 return;
 144         }
 145
 146 #if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
 147         /*
 148          * The arch may choose to record the frame pointer used
 149          * and check it here to make sure that it is what we expect it
 150          * to be. If gcc does not set the place holder of the return
 151          * address in the frame pointer, and does a copy instead, then
 152          * the function graph trace will fail. This test detects this
 153          * case.
 154          *
 155          * Currently, x86_32 with optimize for size (-Os) makes the latest
 156          * gcc do the above.
 157          *
 158          * Note, -mfentry does not use frame pointers, and this test
 159          *  is not needed if CC_USING_FENTRY is set.
 160          */
 161         if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
 162                 ftrace_graph_stop();
 163                 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
 164                      "  from func %ps return to %lx\n",
 165                      current->ret_stack[index].fp,
 166                      frame_pointer,
 167                      (void *)current->ret_stack[index].func,
 168                      current->ret_stack[index].ret);
 169                 *ret = (unsigned long)panic;
 170                 return;
 171         }
 172 #endif
 173
 174         *ret = current->ret_stack[index].ret;
 175         trace->func = current->ret_stack[index].func;
 176         trace->calltime = current->ret_stack[index].calltime;
 177         trace->overrun = atomic_read(&current->trace_overrun);
 178         trace->depth = index;
 179 }
 180
 181 /*
 182  * Send the trace to the ring-buffer.
 183  * @return the original return address.
 184  */
 185 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 186 {
 187         struct ftrace_graph_ret trace;
 188         unsigned long ret;
 189
 190         ftrace_pop_return_trace(&trace, &ret, frame_pointer);
 191         trace.rettime = trace_clock_local();
 192         ftrace_graph_return(&trace);
 193         barrier();
 194         current->curr_ret_stack--;
 195
 196         if (unlikely(!ret)) {
 197                 ftrace_graph_stop();
 198                 WARN_ON(1);
 199                 /* Might as well panic. What else to do? */
 200                 ret = (unsigned long)panic;
 201         }
 202
 203         return ret;
 204 }
 205
 206 int __trace_graph_entry(struct trace_array *tr,
 207                                 struct ftrace_graph_ent *trace,
 208                                 unsigned long flags,
 209                                 int pc)
 210 {
 211         struct ftrace_event_call *call = &event_funcgraph_entry;
 212         struct ring_buffer_event *event;
 213         struct ring_buffer *buffer = tr->buffer;
 214         struct ftrace_graph_ent_entry *entry;
 215
 216         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
 217                 return 0;
 218
 219         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
 220                                           sizeof(*entry), flags, pc);
 221         if (!event)
 222                 return 0;
 223         entry   = ring_buffer_event_data(event);
 224         entry->graph_ent                        = *trace;
 225         if (!filter_current_check_discard(buffer, call, entry, event))
 226                 __buffer_unlock_commit(buffer, event);
 227
 228         return 1;
 229 }
 230
 231 static inline int ftrace_graph_ignore_irqs(void)
 232 {
 233         if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
 234                 return 0;
 235
 236         return in_irq();
 237 }
 238
 239 int trace_graph_entry(struct ftrace_graph_ent *trace)
 240 {
 241         struct trace_array *tr = graph_array;
 242         struct trace_array_cpu *data;
 243         unsigned long flags;
 244         long disabled;
 245         int ret;
 246         int cpu;
 247         int pc;
 248
 249         if (!ftrace_trace_task(current))
 250                 return 0;
 251
 252         /* trace it when it is-nested-in or is a function enabled. */
 253         if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
 254               ftrace_graph_ignore_irqs())
 255                 return 0;
 256
 257         local_irq_save(flags);
 258         cpu = raw_smp_processor_id();
 259         data = tr->data[cpu];
 260         disabled = atomic_inc_return(&data->disabled);
 261         if (likely(disabled == 1)) {
 262                 pc = preempt_count();
 263                 ret = __trace_graph_entry(tr, trace, flags, pc);
 264         } else {
 265                 ret = 0;
 266         }
 267
 268         atomic_dec(&data->disabled);
 269         local_irq_restore(flags);
 270
 271         return ret;
 272 }
 273
 274 int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
 275 {
 276         if (tracing_thresh)
 277                 return 1;
 278         else
 279                 return trace_graph_entry(trace);
 280 }
 281
 282 static void
 283 __trace_graph_function(struct trace_array *tr,
 284                 unsigned long ip, unsigned long flags, int pc)
 285 {
 286         u64 time = trace_clock_local();
 287         struct ftrace_graph_ent ent = {
 288                 .func  = ip,
 289                 .depth = 0,
 290         };
 291         struct ftrace_graph_ret ret = {
 292                 .func     = ip,
 293                 .depth    = 0,
 294                 .calltime = time,
 295                 .rettime  = time,
 296         };
 297
 298         __trace_graph_entry(tr, &ent, flags, pc);
 299         __trace_graph_return(tr, &ret, flags, pc);
 300 }
 301
 302 void
 303 trace_graph_function(struct trace_array *tr,
 304                 unsigned long ip, unsigned long parent_ip,
 305                 unsigned long flags, int pc)
 306 {
 307         __trace_graph_function(tr, ip, flags, pc);
 308 }
 309
 310 void __trace_graph_return(struct trace_array *tr,
 311                                 struct ftrace_graph_ret *trace,
 312                                 unsigned long flags,
 313                                 int pc)
 314 {
 315         struct ftrace_event_call *call = &event_funcgraph_exit;
 316         struct ring_buffer_event *event;
 317         struct ring_buffer *buffer = tr->buffer;
 318         struct ftrace_graph_ret_entry *entry;
 319
 320         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
 321                 return;
 322
 323         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
 324                                           sizeof(*entry), flags, pc);
 325         if (!event)
 326                 return;
 327         entry   = ring_buffer_event_data(event);
 328         entry->ret                              = *trace;
 329         if (!filter_current_check_discard(buffer, call, entry, event))
 330                 __buffer_unlock_commit(buffer, event);
 331 }
 332
 333 void trace_graph_return(struct ftrace_graph_ret *trace)
 334 {
 335         struct trace_array *tr = graph_array;
 336         struct trace_array_cpu *data;
 337         unsigned long flags;
 338         long disabled;
 339         int cpu;
 340         int pc;
 341
 342         local_irq_save(flags);
 343         cpu = raw_smp_processor_id();
 344         data = tr->data[cpu];
 345         disabled = atomic_inc_return(&data->disabled);
 346         if (likely(disabled == 1)) {
 347                 pc = preempt_count();
 348                 __trace_graph_return(tr, trace, flags, pc);
 349         }
 350         atomic_dec(&data->disabled);
 351         local_irq_restore(flags);
 352 }
 353
 354 void set_graph_array(struct trace_array *tr)
 355 {
 356         graph_array = tr;
 357
 358         /* Make graph_array visible before we start tracing */
 359
 360         smp_mb();
 361 }
 362
 363 void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
 364 {
 365         if (tracing_thresh &&
 366             (trace->rettime - trace->calltime < tracing_thresh))
 367                 return;
 368         else
 369                 trace_graph_return(trace);
 370 }
 371
 372 static int graph_trace_init(struct trace_array *tr)
 373 {
 374         int ret;
 375
 376         set_graph_array(tr);
 377         if (tracing_thresh)
 378                 ret = register_ftrace_graph(&trace_graph_thresh_return,
 379                                             &trace_graph_thresh_entry);
 380         else
 381                 ret = register_ftrace_graph(&trace_graph_return,
 382                                             &trace_graph_entry);
 383         if (ret)
 384                 return ret;
 385         tracing_start_cmdline_record();
 386
 387         return 0;
 388 }
 389
 390 static void graph_trace_reset(struct trace_array *tr)
 391 {
 392         tracing_stop_cmdline_record();
 393         unregister_ftrace_graph();
 394 }
 395
 396 static int max_bytes_for_cpu;
 397
 398 static enum print_line_t
 399 print_graph_cpu(struct trace_seq *s, int cpu)
 400 {
 401         int ret;
 402
 403         /*
 404          * Start with a space character - to make it stand out
 405          * to the right a bit when trace output is pasted into
 406          * email:
 407          */
 408         ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
 409         if (!ret)
 410                 return TRACE_TYPE_PARTIAL_LINE;
 411
 412         return TRACE_TYPE_HANDLED;
 413 }
 414
 415 #define TRACE_GRAPH_PROCINFO_LENGTH     14
 416
 417 static enum print_line_t
 418 print_graph_proc(struct trace_seq *s, pid_t pid)
 419 {
 420         char comm[TASK_COMM_LEN];
 421         /* sign + log10(MAX_INT) + '\0' */
 422         char pid_str[11];
 423         int spaces = 0;
 424         int ret;
 425         int len;
 426         int i;
 427
 428         trace_find_cmdline(pid, comm);
 429         comm[7] = '\0';
 430         sprintf(pid_str, "%d", pid);
 431
 432         /* 1 stands for the "-" character */
 433         len = strlen(comm) + strlen(pid_str) + 1;
 434
 435         if (len < TRACE_GRAPH_PROCINFO_LENGTH)
 436                 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
 437
 438         /* First spaces to align center */
 439         for (i = 0; i < spaces / 2; i++) {
 440                 ret = trace_seq_printf(s, " ");
 441                 if (!ret)
 442                         return TRACE_TYPE_PARTIAL_LINE;
 443         }
 444
 445         ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
 446         if (!ret)
 447                 return TRACE_TYPE_PARTIAL_LINE;
 448
 449         /* Last spaces to align center */
 450         for (i = 0; i < spaces - (spaces / 2); i++) {
 451                 ret = trace_seq_printf(s, " ");
 452                 if (!ret)
 453                         return TRACE_TYPE_PARTIAL_LINE;
 454         }
 455         return TRACE_TYPE_HANDLED;
 456 }
 457
 458
 459 static enum print_line_t
 460 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 461 {
 462         if (!trace_seq_putc(s, ' '))
 463                 return 0;
 464
 465         return trace_print_lat_fmt(s, entry);
 466 }
 467
 468 /* If the pid changed since the last trace, output this event */
 469 static enum print_line_t
 470 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
 471 {
 472         pid_t prev_pid;
 473         pid_t *last_pid;
 474         int ret;
 475
 476         if (!data)
 477                 return TRACE_TYPE_HANDLED;
 478
 479         last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
 480
 481         if (*last_pid == pid)
 482                 return TRACE_TYPE_HANDLED;
 483
 484         prev_pid = *last_pid;
 485         *last_pid = pid;
 486
 487         if (prev_pid == -1)
 488                 return TRACE_TYPE_HANDLED;
 489 /*
 490  * Context-switch trace line:
 491
 492  ------------------------------------------
 493  | 1)  migration/0--1  =>  sshd-1755
 494  ------------------------------------------
 495
 496  */
 497         ret = trace_seq_printf(s,
 498                 " ------------------------------------------\n");
 499         if (!ret)
 500                 return TRACE_TYPE_PARTIAL_LINE;
 501
 502         ret = print_graph_cpu(s, cpu);
 503         if (ret == TRACE_TYPE_PARTIAL_LINE)
 504                 return TRACE_TYPE_PARTIAL_LINE;
 505
 506         ret = print_graph_proc(s, prev_pid);
 507         if (ret == TRACE_TYPE_PARTIAL_LINE)
 508                 return TRACE_TYPE_PARTIAL_LINE;
 509
 510         ret = trace_seq_printf(s, " => ");
 511         if (!ret)
 512                 return TRACE_TYPE_PARTIAL_LINE;
 513
 514         ret = print_graph_proc(s, pid);
 515         if (ret == TRACE_TYPE_PARTIAL_LINE)
 516                 return TRACE_TYPE_PARTIAL_LINE;
 517
 518         ret = trace_seq_printf(s,
 519                 "\n ------------------------------------------\n\n");
 520         if (!ret)
 521                 return TRACE_TYPE_PARTIAL_LINE;
 522
 523         return TRACE_TYPE_HANDLED;
 524 }
 525
 526 static struct ftrace_graph_ret_entry *
 527 get_return_for_leaf(struct trace_iterator *iter,
 528                 struct ftrace_graph_ent_entry *curr)
 529 {
 530         struct fgraph_data *data = iter->private;
 531         struct ring_buffer_iter *ring_iter = NULL;
 532         struct ring_buffer_event *event;
 533         struct ftrace_graph_ret_entry *next;
 534
 535         /*
 536          * If the previous output failed to write to the seq buffer,
 537          * then we just reuse the data from before.
 538          */
 539         if (data && data->failed) {
 540                 curr = &data->ent;
 541                 next = &data->ret;
 542         } else {
 543
 544                 ring_iter = trace_buffer_iter(iter, iter->cpu);
 545
 546                 /* First peek to compare current entry and the next one */
 547                 if (ring_iter)
 548                         event = ring_buffer_iter_peek(ring_iter, NULL);
 549                 else {
 550                         /*
 551                          * We need to consume the current entry to see
 552                          * the next one.
 553                          */
 554                         ring_buffer_consume(iter->tr->buffer, iter->cpu,
 555                                             NULL, NULL);
 556                         event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
 557                                                  NULL, NULL);
 558                 }
 559
 560                 if (!event)
 561                         return NULL;
 562
 563                 next = ring_buffer_event_data(event);
 564
 565                 if (data) {
 566                         /*
 567                          * Save current and next entries for later reference
 568                          * if the output fails.
 569                          */
 570                         data->ent = *curr;
 571                         /*
 572                          * If the next event is not a return type, then
 573                          * we only care about what type it is. Otherwise we can
 574                          * safely copy the entire event.
 575                          */
 576                         if (next->ent.type == TRACE_GRAPH_RET)
 577                                 data->ret = *next;
 578                         else
 579                                 data->ret.ent.type = next->ent.type;
 580                 }
 581         }
 582
 583         if (next->ent.type != TRACE_GRAPH_RET)
 584                 return NULL;
 585
 586         if (curr->ent.pid != next->ent.pid ||
 587                         curr->graph_ent.func != next->ret.func)
 588                 return NULL;
 589
 590         /* this is a leaf, now advance the iterator */
 591         if (ring_iter)
 592                 ring_buffer_read(ring_iter, NULL);
 593
 594         return next;
 595 }
 596
 597 static int print_graph_abs_time(u64 t, struct trace_seq *s)
 598 {
 599         unsigned long usecs_rem;
 600
 601         usecs_rem = do_div(t, NSEC_PER_SEC);
 602         usecs_rem /= 1000;
 603
 604         return trace_seq_printf(s, "%5lu.%06lu |  ",
 605                         (unsigned long)t, usecs_rem);
 606 }
 607
 608 static enum print_line_t
 609 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 610                 enum trace_type type, int cpu, pid_t pid, u32 flags)
 611 {
 612         int ret;
 613         struct trace_seq *s = &iter->seq;
 614
 615         if (addr < (unsigned long)__irqentry_text_start ||
 616                 addr >= (unsigned long)__irqentry_text_end)
 617                 return TRACE_TYPE_UNHANDLED;
 618
 619         if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
 620                 /* Absolute time */
 621                 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
 622                         ret = print_graph_abs_time(iter->ts, s);
 623                         if (!ret)
 624                                 return TRACE_TYPE_PARTIAL_LINE;
 625                 }
 626
 627                 /* Cpu */
 628                 if (flags & TRACE_GRAPH_PRINT_CPU) {
 629                         ret = print_graph_cpu(s, cpu);
 630                         if (ret == TRACE_TYPE_PARTIAL_LINE)
 631                                 return TRACE_TYPE_PARTIAL_LINE;
 632                 }
 633
 634                 /* Proc */
 635                 if (flags & TRACE_GRAPH_PRINT_PROC) {
 636                         ret = print_graph_proc(s, pid);
 637                         if (ret == TRACE_TYPE_PARTIAL_LINE)
 638                                 return TRACE_TYPE_PARTIAL_LINE;
 639                         ret = trace_seq_printf(s, " | ");
 640                         if (!ret)
 641                                 return TRACE_TYPE_PARTIAL_LINE;
 642                 }
 643         }
 644
 645         /* No overhead */
 646         ret = print_graph_duration(DURATION_FILL_START, s, flags);
 647         if (ret != TRACE_TYPE_HANDLED)
 648                 return ret;
 649
 650         if (type == TRACE_GRAPH_ENT)
 651                 ret = trace_seq_printf(s, "==========>");
 652         else
 653                 ret = trace_seq_printf(s, "<==========");
 654
 655         if (!ret)
 656                 return TRACE_TYPE_PARTIAL_LINE;
 657
 658         ret = print_graph_duration(DURATION_FILL_END, s, flags);
 659         if (ret != TRACE_TYPE_HANDLED)
 660                 return ret;
 661
 662         ret = trace_seq_printf(s, "\n");
 663
 664         if (!ret)
 665                 return TRACE_TYPE_PARTIAL_LINE;
 666         return TRACE_TYPE_HANDLED;
 667 }
 668
 669 enum print_line_t
 670 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 671 {
 672         unsigned long nsecs_rem = do_div(duration, 1000);
 673         /* log10(ULONG_MAX) + '\0' */
 674         char msecs_str[21];
 675         char nsecs_str[5];
 676         int ret, len;
 677         int i;
 678
 679         sprintf(msecs_str, "%lu", (unsigned long) duration);
 680
 681         /* Print msecs */
 682         ret = trace_seq_printf(s, "%s", msecs_str);
 683         if (!ret)
 684                 return TRACE_TYPE_PARTIAL_LINE;
 685
 686         len = strlen(msecs_str);
 687
 688         /* Print nsecs (we don't want to exceed 7 numbers) */
 689         if (len < 7) {
 690                 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
 691
 692                 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
 693                 ret = trace_seq_printf(s, ".%s", nsecs_str);
 694                 if (!ret)
 695                         return TRACE_TYPE_PARTIAL_LINE;
 696                 len += strlen(nsecs_str);
 697         }
 698
 699         ret = trace_seq_printf(s, " us ");
 700         if (!ret)
 701                 return TRACE_TYPE_PARTIAL_LINE;
 702
 703         /* Print remaining spaces to fit the row's width */
 704         for (i = len; i < 7; i++) {
 705                 ret = trace_seq_printf(s, " ");
 706                 if (!ret)
 707                         return TRACE_TYPE_PARTIAL_LINE;
 708         }
 709         return TRACE_TYPE_HANDLED;
 710 }
 711
 712 static enum print_line_t
 713 print_graph_duration(unsigned long long duration, struct trace_seq *s,
 714                      u32 flags)
 715 {
 716         int ret = -1;
 717
 718         if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
 719             !(trace_flags & TRACE_ITER_CONTEXT_INFO))
 720                         return TRACE_TYPE_HANDLED;
 721
 722         /* No real adata, just filling the column with spaces */
 723         switch (duration) {
 724         case DURATION_FILL_FULL:
 725                 ret = trace_seq_printf(s, "              |  ");
 726                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
 727         case DURATION_FILL_START:
 728                 ret = trace_seq_printf(s, "  ");
 729                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
 730         case DURATION_FILL_END:
 731                 ret = trace_seq_printf(s, " |");
 732                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
 733         }
 734
 735         /* Signal a overhead of time execution to the output */
 736         if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
 737                 /* Duration exceeded 100 msecs */
 738                 if (duration > 100000ULL)
 739                         ret = trace_seq_printf(s, "! ");
 740                 /* Duration exceeded 10 msecs */
 741                 else if (duration > 10000ULL)
 742                         ret = trace_seq_printf(s, "+ ");
 743         }
 744
 745         /*
 746          * The -1 means we either did not exceed the duration tresholds
 747          * or we dont want to print out the overhead. Either way we need
 748          * to fill out the space.
 749          */
 750         if (ret == -1)
 751                 ret = trace_seq_printf(s, "  ");
 752
 753         /* Catching here any failure happenned above */
 754         if (!ret)
 755                 return TRACE_TYPE_PARTIAL_LINE;
 756
 757         ret = trace_print_graph_duration(duration, s);
 758         if (ret != TRACE_TYPE_HANDLED)
 759                 return ret;
 760
 761         ret = trace_seq_printf(s, "|  ");
 762         if (!ret)
 763                 return TRACE_TYPE_PARTIAL_LINE;
 764
 765         return TRACE_TYPE_HANDLED;
 766 }
 767
 768 /* Case of a leaf function on its call entry */
 769 static enum print_line_t
 770 print_graph_entry_leaf(struct trace_iterator *iter,
 771                 struct ftrace_graph_ent_entry *entry,
 772                 struct ftrace_graph_ret_entry *ret_entry,
 773                 struct trace_seq *s, u32 flags)
 774 {
 775         struct fgraph_data *data = iter->private;
 776         struct ftrace_graph_ret *graph_ret;
 777         struct ftrace_graph_ent *call;
 778         unsigned long long duration;
 779         int ret;
 780         int i;
 781
 782         graph_ret = &ret_entry->ret;
 783         call = &entry->graph_ent;
 784         duration = graph_ret->rettime - graph_ret->calltime;
 785
 786         if (data) {
 787                 struct fgraph_cpu_data *cpu_data;
 788                 int cpu = iter->cpu;
 789
 790                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
 791
 792                 /*
 793                  * Comments display at + 1 to depth. Since
 794                  * this is a leaf function, keep the comments
 795                  * equal to this depth.
 796                  */
 797                 cpu_data->depth = call->depth - 1;
 798
 799                 /* No need to keep this function around for this depth */
 800                 if (call->depth < FTRACE_RETFUNC_DEPTH)
 801                         cpu_data->enter_funcs[call->depth] = 0;
 802         }
 803
 804         /* Overhead and duration */
 805         ret = print_graph_duration(duration, s, flags);
 806         if (ret == TRACE_TYPE_PARTIAL_LINE)
 807                 return TRACE_TYPE_PARTIAL_LINE;
 808
 809         /* Function */
 810         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 811                 ret = trace_seq_printf(s, " ");
 812                 if (!ret)
 813                         return TRACE_TYPE_PARTIAL_LINE;
 814         }
 815
 816         ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
 817         if (!ret)
 818                 return TRACE_TYPE_PARTIAL_LINE;
 819
 820         return TRACE_TYPE_HANDLED;
 821 }
 822
 823 static enum print_line_t
 824 print_graph_entry_nested(struct trace_iterator *iter,
 825                          struct ftrace_graph_ent_entry *entry,
 826                          struct trace_seq *s, int cpu, u32 flags)
 827 {
 828         struct ftrace_graph_ent *call = &entry->graph_ent;
 829         struct fgraph_data *data = iter->private;
 830         int ret;
 831         int i;
 832
 833         if (data) {
 834                 struct fgraph_cpu_data *cpu_data;
 835                 int cpu = iter->cpu;
 836
 837                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
 838                 cpu_data->depth = call->depth;
 839
 840                 /* Save this function pointer to see if the exit matches */
 841                 if (call->depth < FTRACE_RETFUNC_DEPTH)
 842                         cpu_data->enter_funcs[call->depth] = call->func;
 843         }
 844
 845         /* No time */
 846         ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
 847         if (ret != TRACE_TYPE_HANDLED)
 848                 return ret;
 849
 850         /* Function */
 851         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 852                 ret = trace_seq_printf(s, " ");
 853                 if (!ret)
 854                         return TRACE_TYPE_PARTIAL_LINE;
 855         }
 856
 857         ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
 858         if (!ret)
 859                 return TRACE_TYPE_PARTIAL_LINE;
 860
 861         /*
 862          * we already consumed the current entry to check the next one
 863          * and see if this is a leaf.
 864          */
 865         return TRACE_TYPE_NO_CONSUME;
 866 }
 867
 868 static enum print_line_t
 869 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
 870                      int type, unsigned long addr, u32 flags)
 871 {
 872         struct fgraph_data *data = iter->private;
 873         struct trace_entry *ent = iter->ent;
 874         int cpu = iter->cpu;
 875         int ret;
 876
 877         /* Pid */
 878         if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
 879                 return TRACE_TYPE_PARTIAL_LINE;
 880
 881         if (type) {
 882                 /* Interrupt */
 883                 ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
 884                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 885                         return TRACE_TYPE_PARTIAL_LINE;
 886         }
 887
 888         if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
 889                 return 0;
 890
 891         /* Absolute time */
 892         if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
 893                 ret = print_graph_abs_time(iter->ts, s);
 894                 if (!ret)
 895                         return TRACE_TYPE_PARTIAL_LINE;
 896         }
 897
 898         /* Cpu */
 899         if (flags & TRACE_GRAPH_PRINT_CPU) {
 900                 ret = print_graph_cpu(s, cpu);
 901                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 902                         return TRACE_TYPE_PARTIAL_LINE;
 903         }
 904
 905         /* Proc */
 906         if (flags & TRACE_GRAPH_PRINT_PROC) {
 907                 ret = print_graph_proc(s, ent->pid);
 908                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 909                         return TRACE_TYPE_PARTIAL_LINE;
 910
 911                 ret = trace_seq_printf(s, " | ");
 912                 if (!ret)
 913                         return TRACE_TYPE_PARTIAL_LINE;
 914         }
 915
 916         /* Latency format */
 917         if (trace_flags & TRACE_ITER_LATENCY_FMT) {
 918                 ret = print_graph_lat_fmt(s, ent);
 919                 if (ret == TRACE_TYPE_PARTIAL_LINE)
 920                         return TRACE_TYPE_PARTIAL_LINE;
 921         }
 922
 923         return 0;
 924 }
 925
 926 /*
 927  * Entry check for irq code
 928  *
 929  * returns 1 if
 930  *  - we are inside irq code
 931  *  - we just entered irq code
 932  *
 933  * retunns 0 if
 934  *  - funcgraph-interrupts option is set
 935  *  - we are not inside irq code
 936  */
 937 static int
 938 check_irq_entry(struct trace_iterator *iter, u32 flags,
 939                 unsigned long addr, int depth)
 940 {
 941         int cpu = iter->cpu;
 942         int *depth_irq;
 943         struct fgraph_data *data = iter->private;
 944
 945         /*
 946          * If we are either displaying irqs, or we got called as
 947          * a graph event and private data does not exist,
 948          * then we bypass the irq check.
 949          */
 950         if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
 951             (!data))
 952                 return 0;
 953
 954         depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
 955
 956         /*
 957          * We are inside the irq code
 958          */
 959         if (*depth_irq >= 0)
 960                 return 1;
 961
 962         if ((addr < (unsigned long)__irqentry_text_start) ||
 963             (addr >= (unsigned long)__irqentry_text_end))
 964                 return 0;
 965
 966         /*
 967          * We are entering irq code.
 968          */
 969         *depth_irq = depth;
 970         return 1;
 971 }
 972
 973 /*
 974  * Return check for irq code
 975  *
 976  * returns 1 if
 977  *  - we are inside irq code
 978  *  - we just left irq code
 979  *
 980  * returns 0 if
 981  *  - funcgraph-interrupts option is set
 982  *  - we are not inside irq code
 983  */
 984 static int
 985 check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
 986 {
 987         int cpu = iter->cpu;
 988         int *depth_irq;
 989         struct fgraph_data *data = iter->private;
 990
 991         /*
 992          * If we are either displaying irqs, or we got called as
 993          * a graph event and private data does not exist,
 994          * then we bypass the irq check.
 995          */
 996         if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
 997             (!data))
 998                 return 0;
 999
1000         depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1001
1002         /*
1003          * We are not inside the irq code.
1004          */
1005         if (*depth_irq == -1)
1006                 return 0;
1007
1008         /*
1009          * We are inside the irq code, and this is returning entry.
1010          * Let's not trace it and clear the entry depth, since
1011          * we are out of irq code.
1012          *
1013          * This condition ensures that we 'leave the irq code' once
1014          * we are out of the entry depth. Thus protecting us from
1015          * the RETURN entry loss.
1016          */
1017         if (*depth_irq >= depth) {
1018                 *depth_irq = -1;
1019                 return 1;
1020         }
1021
1022         /*
1023          * We are inside the irq code, and this is not the entry.
1024          */
1025         return 1;
1026 }
1027
1028 static enum print_line_t
1029 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1030                         struct trace_iterator *iter, u32 flags)
1031 {
1032         struct fgraph_data *data = iter->private;
1033         struct ftrace_graph_ent *call = &field->graph_ent;
1034         struct ftrace_graph_ret_entry *leaf_ret;
1035         static enum print_line_t ret;
1036         int cpu = iter->cpu;
1037
1038         if (check_irq_entry(iter, flags, call->func, call->depth))
1039                 return TRACE_TYPE_HANDLED;
1040
1041         if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
1042                 return TRACE_TYPE_PARTIAL_LINE;
1043
1044         leaf_ret = get_return_for_leaf(iter, field);
1045         if (leaf_ret)
1046                 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1047         else
1048                 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1049
1050         if (data) {
1051                 /*
1052                  * If we failed to write our output, then we need to make
1053                  * note of it. Because we already consumed our entry.
1054                  */
1055                 if (s->full) {
1056                         data->failed = 1;
1057                         data->cpu = cpu;
1058                 } else
1059                         data->failed = 0;
1060         }
1061
1062         return ret;
1063 }
1064
1065 static enum print_line_t
1066 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1067                    struct trace_entry *ent, struct trace_iterator *iter,
1068                    u32 flags)
1069 {
1070         unsigned long long duration = trace->rettime - trace->calltime;
1071         struct fgraph_data *data = iter->private;
1072         pid_t pid = ent->pid;
1073         int cpu = iter->cpu;
1074         int func_match = 1;
1075         int ret;
1076         int i;
1077
1078         if (check_irq_return(iter, flags, trace->depth))
1079                 return TRACE_TYPE_HANDLED;
1080
1081         if (data) {
1082                 struct fgraph_cpu_data *cpu_data;
1083                 int cpu = iter->cpu;
1084
1085                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1086
1087                 /*
1088                  * Comments display at + 1 to depth. This is the
1089                  * return from a function, we now want the comments
1090                  * to display at the same level of the bracket.
1091                  */
1092                 cpu_data->depth = trace->depth - 1;
1093
1094                 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
1095                         if (cpu_data->enter_funcs[trace->depth] != trace->func)
1096                                 func_match = 0;
1097                         cpu_data->enter_funcs[trace->depth] = 0;
1098                 }
1099         }
1100
1101         if (print_graph_prologue(iter, s, 0, 0, flags))
1102                 return TRACE_TYPE_PARTIAL_LINE;
1103
1104         /* Overhead and duration */
1105         ret = print_graph_duration(duration, s, flags);
1106         if (ret == TRACE_TYPE_PARTIAL_LINE)
1107                 return TRACE_TYPE_PARTIAL_LINE;
1108
1109         /* Closing brace */
1110         for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
1111                 ret = trace_seq_printf(s, " ");
1112                 if (!ret)
1113                         return TRACE_TYPE_PARTIAL_LINE;
1114         }
1115
1116         /*
1117          * If the return function does not have a matching entry,
1118          * then the entry was lost. Instead of just printing
1119          * the '}' and letting the user guess what function this
1120          * belongs to, write out the function name.
1121          */
1122         if (func_match) {
1123                 ret = trace_seq_printf(s, "}\n");
1124                 if (!ret)
1125                         return TRACE_TYPE_PARTIAL_LINE;
1126         } else {
1127                 ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1128                 if (!ret)
1129                         return TRACE_TYPE_PARTIAL_LINE;
1130         }
1131
1132         /* Overrun */
1133         if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1134                 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
1135                                         trace->overrun);
1136                 if (!ret)
1137                         return TRACE_TYPE_PARTIAL_LINE;
1138         }
1139
1140         ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1141                               cpu, pid, flags);
1142         if (ret == TRACE_TYPE_PARTIAL_LINE)
1143                 return TRACE_TYPE_PARTIAL_LINE;
1144
1145         return TRACE_TYPE_HANDLED;
1146 }
1147
1148 static enum print_line_t
1149 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1150                     struct trace_iterator *iter, u32 flags)
1151 {
1152         unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1153         struct fgraph_data *data = iter->private;
1154         struct trace_event *event;
1155         int depth = 0;
1156         int ret;
1157         int i;
1158
1159         if (data)
1160                 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1161
1162         if (print_graph_prologue(iter, s, 0, 0, flags))
1163                 return TRACE_TYPE_PARTIAL_LINE;
1164
1165         /* No time */
1166         ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
1167         if (ret != TRACE_TYPE_HANDLED)
1168                 return ret;
1169
1170         /* Indentation */
1171         if (depth > 0)
1172                 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1173                         ret = trace_seq_printf(s, " ");
1174                         if (!ret)
1175                                 return TRACE_TYPE_PARTIAL_LINE;
1176                 }
1177
1178         /* The comment */
1179         ret = trace_seq_printf(s, "/* ");
1180         if (!ret)
1181                 return TRACE_TYPE_PARTIAL_LINE;
1182
1183         switch (iter->ent->type) {
1184         case TRACE_BPRINT:
1185                 ret = trace_print_bprintk_msg_only(iter);
1186                 if (ret != TRACE_TYPE_HANDLED)
1187                         return ret;
1188                 break;
1189         case TRACE_PRINT:
1190                 ret = trace_print_printk_msg_only(iter);
1191                 if (ret != TRACE_TYPE_HANDLED)
1192                         return ret;
1193                 break;
1194         default:
1195                 event = ftrace_find_event(ent->type);
1196                 if (!event)
1197                         return TRACE_TYPE_UNHANDLED;
1198
1199                 ret = event->funcs->trace(iter, sym_flags, event);
1200                 if (ret != TRACE_TYPE_HANDLED)
1201                         return ret;
1202         }
1203
1204         /* Strip ending newline */
1205         if (s->buffer[s->len - 1] == '\n') {
1206                 s->buffer[s->len - 1] = '\0';
1207                 s->len--;
1208         }
1209
1210         ret = trace_seq_printf(s, " */\n");
1211         if (!ret)
1212                 return TRACE_TYPE_PARTIAL_LINE;
1213
1214         return TRACE_TYPE_HANDLED;
1215 }
1216
1217
1218 enum print_line_t
1219 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1220 {
1221         struct ftrace_graph_ent_entry *field;
1222         struct fgraph_data *data = iter->private;
1223         struct trace_entry *entry = iter->ent;
1224         struct trace_seq *s = &iter->seq;
1225         int cpu = iter->cpu;
1226         int ret;
1227
1228         if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1229                 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1230                 return TRACE_TYPE_HANDLED;
1231         }
1232
1233         /*
1234          * If the last output failed, there's a possibility we need
1235          * to print out the missing entry which would never go out.
1236          */
1237         if (data && data->failed) {
1238                 field = &data->ent;
1239                 iter->cpu = data->cpu;
1240                 ret = print_graph_entry(field, s, iter, flags);
1241                 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1242                         per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1243                         ret = TRACE_TYPE_NO_CONSUME;
1244                 }
1245                 iter->cpu = cpu;
1246                 return ret;
1247         }
1248
1249         switch (entry->type) {
1250         case TRACE_GRAPH_ENT: {
1251                 /*
1252                  * print_graph_entry() may consume the current event,
1253                  * thus @field may become invalid, so we need to save it.
1254                  * sizeof(struct ftrace_graph_ent_entry) is very small,
1255                  * it can be safely saved at the stack.
1256                  */
1257                 struct ftrace_graph_ent_entry saved;
1258                 trace_assign_type(field, entry);
1259                 saved = *field;
1260                 return print_graph_entry(&saved, s, iter, flags);
1261         }
1262         case TRACE_GRAPH_RET: {
1263                 struct ftrace_graph_ret_entry *field;
1264                 trace_assign_type(field, entry);
1265                 return print_graph_return(&field->ret, s, entry, iter, flags);
1266         }
1267         case TRACE_STACK:
1268         case TRACE_FN:
1269                 /* dont trace stack and functions as comments */
1270                 return TRACE_TYPE_UNHANDLED;
1271
1272         default:
1273                 return print_graph_comment(s, entry, iter, flags);
1274         }
1275
1276         return TRACE_TYPE_HANDLED;
1277 }
1278
1279 static enum print_line_t
1280 print_graph_function(struct trace_iterator *iter)
1281 {
1282         return print_graph_function_flags(iter, tracer_flags.val);
1283 }
1284
1285 static enum print_line_t
1286 print_graph_function_event(struct trace_iterator *iter, int flags,
1287                            struct trace_event *event)
1288 {
1289         return print_graph_function(iter);
1290 }
1291
1292 static void print_lat_header(struct seq_file *s, u32 flags)
1293 {
1294         static const char spaces[] = "                " /* 16 spaces */
1295                 "    "                                  /* 4 spaces */
1296                 "                 ";                    /* 17 spaces */
1297         int size = 0;
1298
1299         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1300                 size += 16;
1301         if (flags & TRACE_GRAPH_PRINT_CPU)
1302                 size += 4;
1303         if (flags & TRACE_GRAPH_PRINT_PROC)
1304                 size += 17;
1305
1306         seq_printf(s, "#%.*s  _-----=> irqs-off        \n", size, spaces);
1307         seq_printf(s, "#%.*s / _----=> need-resched    \n", size, spaces);
1308         seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1309         seq_printf(s, "#%.*s|| / _--=> preempt-depth   \n", size, spaces);
1310         seq_printf(s, "#%.*s||| /                      \n", size, spaces);
1311 }
1312
1313 static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
1314 {
1315         int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1316
1317         if (lat)
1318                 print_lat_header(s, flags);
1319
1320         /* 1st line */
1321         seq_printf(s, "#");
1322         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1323                 seq_printf(s, "     TIME       ");
1324         if (flags & TRACE_GRAPH_PRINT_CPU)
1325                 seq_printf(s, " CPU");
1326         if (flags & TRACE_GRAPH_PRINT_PROC)
1327                 seq_printf(s, "  TASK/PID       ");
1328         if (lat)
1329                 seq_printf(s, "||||");
1330         if (flags & TRACE_GRAPH_PRINT_DURATION)
1331                 seq_printf(s, "  DURATION   ");
1332         seq_printf(s, "               FUNCTION CALLS\n");
1333
1334         /* 2nd line */
1335         seq_printf(s, "#");
1336         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1337                 seq_printf(s, "      |         ");
1338         if (flags & TRACE_GRAPH_PRINT_CPU)
1339                 seq_printf(s, " |  ");
1340         if (flags & TRACE_GRAPH_PRINT_PROC)
1341                 seq_printf(s, "   |    |        ");
1342         if (lat)
1343                 seq_printf(s, "||||");
1344         if (flags & TRACE_GRAPH_PRINT_DURATION)
1345                 seq_printf(s, "   |   |      ");
1346         seq_printf(s, "               |   |   |   |\n");
1347 }
1348
1349 void print_graph_headers(struct seq_file *s)
1350 {
1351         print_graph_headers_flags(s, tracer_flags.val);
1352 }
1353
1354 void print_graph_headers_flags(struct seq_file *s, u32 flags)
1355 {
1356         struct trace_iterator *iter = s->private;
1357
1358         if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
1359                 return;
1360
1361         if (trace_flags & TRACE_ITER_LATENCY_FMT) {
1362                 /* print nothing if the buffers are empty */
1363                 if (trace_empty(iter))
1364                         return;
1365
1366                 print_trace_header(s, iter);
1367         }
1368
1369         __print_graph_headers_flags(s, flags);
1370 }
1371
1372 void graph_trace_open(struct trace_iterator *iter)
1373 {
1374         /* pid and depth on the last trace processed */
1375         struct fgraph_data *data;
1376         int cpu;
1377
1378         iter->private = NULL;
1379
1380         data = kzalloc(sizeof(*data), GFP_KERNEL);
1381         if (!data)
1382                 goto out_err;
1383
1384         data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1385         if (!data->cpu_data)
1386                 goto out_err_free;
1387
1388         for_each_possible_cpu(cpu) {
1389                 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1390                 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1391                 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1392                 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1393
1394                 *pid = -1;
1395                 *depth = 0;
1396                 *ignore = 0;
1397                 *depth_irq = -1;
1398         }
1399
1400         iter->private = data;
1401
1402         return;
1403
1404  out_err_free:
1405         kfree(data);
1406  out_err:
1407         pr_warning("function graph tracer: not enough memory\n");
1408 }
1409
1410 void graph_trace_close(struct trace_iterator *iter)
1411 {
1412         struct fgraph_data *data = iter->private;
1413
1414         if (data) {
1415                 free_percpu(data->cpu_data);
1416                 kfree(data);
1417         }
1418 }
1419
1420 static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
1421 {
1422         if (bit == TRACE_GRAPH_PRINT_IRQS)
1423                 ftrace_graph_skip_irqs = !set;
1424
1425         return 0;
1426 }
1427
1428 static struct trace_event_functions graph_functions = {
1429         .trace          = print_graph_function_event,
1430 };
1431
1432 static struct trace_event graph_trace_entry_event = {
1433         .type           = TRACE_GRAPH_ENT,
1434         .funcs          = &graph_functions,
1435 };
1436
1437 static struct trace_event graph_trace_ret_event = {
1438         .type           = TRACE_GRAPH_RET,
1439         .funcs          = &graph_functions
1440 };
1441
1442 static struct tracer graph_trace __read_mostly = {
1443         .name           = "function_graph",
1444         .open           = graph_trace_open,
1445         .pipe_open      = graph_trace_open,
1446         .close          = graph_trace_close,
1447         .pipe_close     = graph_trace_close,
1448         .wait_pipe      = poll_wait_pipe,
1449         .init           = graph_trace_init,
1450         .reset          = graph_trace_reset,
1451         .print_line     = print_graph_function,
1452         .print_header   = print_graph_headers,
1453         .flags          = &tracer_flags,
1454         .set_flag       = func_graph_set_flag,
1455 #ifdef CONFIG_FTRACE_SELFTEST
1456         .selftest       = trace_selftest_startup_function_graph,
1457 #endif
1458 };
1459
1460 static __init int init_graph_trace(void)
1461 {
1462         max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1463
1464         if (!register_ftrace_event(&graph_trace_entry_event)) {
1465                 pr_warning("Warning: could not register graph trace events\n");
1466                 return 1;
1467         }
1468
1469         if (!register_ftrace_event(&graph_trace_ret_event)) {
1470                 pr_warning("Warning: could not register graph trace events\n");
1471                 return 1;
1472         }
1473
1474         return register_tracer(&graph_trace);
1475 }
1476
1477 core_initcall(init_graph_trace);