kernel/trace/ftrace.c

   1 /*
   2  * Infrastructure for profiling code inserted by 'gcc -pg'.
   3  *
   4  * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
   5  * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
   6  *
   7  * Originally ported from the -rt patch by:
   8  *   Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
   9  *
  10  * Based on code in the latency_tracer, that is:
  11  *
  12  *  Copyright (C) 2004-2006 Ingo Molnar
  13  *  Copyright (C) 2004 William Lee Irwin III
  14  */
  15
  16 #include <linux/stop_machine.h>
  17 #include <linux/clocksource.h>
  18 #include <linux/kallsyms.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/suspend.h>
  21 #include <linux/debugfs.h>
  22 #include <linux/hardirq.h>
  23 #include <linux/kthread.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/module.h>
  26 #include <linux/ftrace.h>
  27 #include <linux/sysctl.h>
  28 #include <linux/slab.h>
  29 #include <linux/ctype.h>
  30 #include <linux/list.h>
  31 #include <linux/hash.h>
  32 #include <linux/rcupdate.h>
  33
  34 #include <trace/events/sched.h>
  35
  36 #include <asm/setup.h>
  37
  38 #include "trace_output.h"
  39 #include "trace_stat.h"
  40
  41 #define FTRACE_WARN_ON(cond)                    \
  42         ({                                      \
  43                 int ___r = cond;                \
  44                 if (WARN_ON(___r))              \
  45                         ftrace_kill();          \
  46                 ___r;                           \
  47         })
  48
  49 #define FTRACE_WARN_ON_ONCE(cond)               \
  50         ({                                      \
  51                 int ___r = cond;                \
  52                 if (WARN_ON_ONCE(___r))         \
  53                         ftrace_kill();          \
  54                 ___r;                           \
  55         })
  56
  57 /* hash bits for specific function selection */
  58 #define FTRACE_HASH_BITS 7
  59 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
  60 #define FTRACE_HASH_DEFAULT_BITS 10
  61 #define FTRACE_HASH_MAX_BITS 12
  62
  63 /* ftrace_enabled is a method to turn ftrace on or off */
  64 int ftrace_enabled __read_mostly;
  65 static int last_ftrace_enabled;
  66
  67 /* Quick disabling of function tracer. */
  68 int function_trace_stop;
  69
  70 /* List for set_ftrace_pid's pids. */
  71 LIST_HEAD(ftrace_pids);
  72 struct ftrace_pid {
  73         struct list_head list;
  74         struct pid *pid;
  75 };
  76
  77 /*
  78  * ftrace_disabled is set when an anomaly is discovered.
  79  * ftrace_disabled is much stronger than ftrace_enabled.
  80  */
  81 static int ftrace_disabled __read_mostly;
  82
  83 static DEFINE_MUTEX(ftrace_lock);
  84
  85 static struct ftrace_ops ftrace_list_end __read_mostly = {
  86         .func           = ftrace_stub,
  87 };
  88
  89 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
  90 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
  91 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
  92 static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
  93 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
  94 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
  95 static struct ftrace_ops global_ops;
  96
  97 static void
  98 ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
  99
 100 /*
 101  * Traverse the ftrace_global_list, invoking all entries.  The reason that we
 102  * can use rcu_dereference_raw() is that elements removed from this list
 103  * are simply leaked, so there is no need to interact with a grace-period
 104  * mechanism.  The rcu_dereference_raw() calls are needed to handle
 105  * concurrent insertions into the ftrace_global_list.
 106  *
 107  * Silly Alpha and silly pointer-speculation compiler optimizations!
 108  */
 109 static void ftrace_global_list_func(unsigned long ip,
 110                                     unsigned long parent_ip)
 111 {
 112         struct ftrace_ops *op;
 113
 114         if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
 115                 return;
 116
 117         trace_recursion_set(TRACE_GLOBAL_BIT);
 118         op = rcu_dereference_raw(ftrace_global_list); /*see above*/
 119         while (op != &ftrace_list_end) {
 120                 op->func(ip, parent_ip);
 121                 op = rcu_dereference_raw(op->next); /*see above*/
 122         };
 123         trace_recursion_clear(TRACE_GLOBAL_BIT);
 124 }
 125
 126 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
 127 {
 128         if (!test_tsk_trace_trace(current))
 129                 return;
 130
 131         ftrace_pid_function(ip, parent_ip);
 132 }
 133
 134 static void set_ftrace_pid_function(ftrace_func_t func)
 135 {
 136         /* do not set ftrace_pid_function to itself! */
 137         if (func != ftrace_pid_func)
 138                 ftrace_pid_function = func;
 139 }
 140
 141 /**
 142  * clear_ftrace_function - reset the ftrace function
 143  *
 144  * This NULLs the ftrace function and in essence stops
 145  * tracing.  There may be lag
 146  */
 147 void clear_ftrace_function(void)
 148 {
 149         ftrace_trace_function = ftrace_stub;
 150         __ftrace_trace_function = ftrace_stub;
 151         __ftrace_trace_function_delay = ftrace_stub;
 152         ftrace_pid_function = ftrace_stub;
 153 }
 154
 155 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 156 /*
 157  * For those archs that do not test ftrace_trace_stop in their
 158  * mcount call site, we need to do it from C.
 159  */
 160 static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
 161 {
 162         if (function_trace_stop)
 163                 return;
 164
 165         __ftrace_trace_function(ip, parent_ip);
 166 }
 167 #endif
 168
 169 static void update_global_ops(void)
 170 {
 171         ftrace_func_t func;
 172
 173         /*
 174          * If there's only one function registered, then call that
 175          * function directly. Otherwise, we need to iterate over the
 176          * registered callers.
 177          */
 178         if (ftrace_global_list == &ftrace_list_end ||
 179             ftrace_global_list->next == &ftrace_list_end)
 180                 func = ftrace_global_list->func;
 181         else
 182                 func = ftrace_global_list_func;
 183
 184         /* If we filter on pids, update to use the pid function */
 185         if (!list_empty(&ftrace_pids)) {
 186                 set_ftrace_pid_function(func);
 187                 func = ftrace_pid_func;
 188         }
 189
 190         global_ops.func = func;
 191 }
 192
 193 static void update_ftrace_function(void)
 194 {
 195         ftrace_func_t func;
 196
 197         update_global_ops();
 198
 199         /*
 200          * If we are at the end of the list and this ops is
 201          * not dynamic, then have the mcount trampoline call
 202          * the function directly
 203          */
 204         if (ftrace_ops_list == &ftrace_list_end ||
 205             (ftrace_ops_list->next == &ftrace_list_end &&
 206              !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
 207                 func = ftrace_ops_list->func;
 208         else
 209                 func = ftrace_ops_list_func;
 210
 211 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 212         ftrace_trace_function = func;
 213 #else
 214 #ifdef CONFIG_DYNAMIC_FTRACE
 215         /* do not update till all functions have been modified */
 216         __ftrace_trace_function_delay = func;
 217 #else
 218         __ftrace_trace_function = func;
 219 #endif
 220         ftrace_trace_function = ftrace_test_stop_func;
 221 #endif
 222 }
 223
 224 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
 225 {
 226         ops->next = *list;
 227         /*
 228          * We are entering ops into the list but another
 229          * CPU might be walking that list. We need to make sure
 230          * the ops->next pointer is valid before another CPU sees
 231          * the ops pointer included into the list.
 232          */
 233         rcu_assign_pointer(*list, ops);
 234 }
 235
 236 static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
 237 {
 238         struct ftrace_ops **p;
 239
 240         /*
 241          * If we are removing the last function, then simply point
 242          * to the ftrace_stub.
 243          */
 244         if (*list == ops && ops->next == &ftrace_list_end) {
 245                 *list = &ftrace_list_end;
 246                 return 0;
 247         }
 248
 249         for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
 250                 if (*p == ops)
 251                         break;
 252
 253         if (*p != ops)
 254                 return -1;
 255
 256         *p = (*p)->next;
 257         return 0;
 258 }
 259
 260 static int __register_ftrace_function(struct ftrace_ops *ops)
 261 {
 262         if (ftrace_disabled)
 263                 return -ENODEV;
 264
 265         if (FTRACE_WARN_ON(ops == &global_ops))
 266                 return -EINVAL;
 267
 268         if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
 269                 return -EBUSY;
 270
 271         if (!core_kernel_data((unsigned long)ops))
 272                 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
 273
 274         if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
 275                 int first = ftrace_global_list == &ftrace_list_end;
 276                 add_ftrace_ops(&ftrace_global_list, ops);
 277                 ops->flags |= FTRACE_OPS_FL_ENABLED;
 278                 if (first)
 279                         add_ftrace_ops(&ftrace_ops_list, &global_ops);
 280         } else
 281                 add_ftrace_ops(&ftrace_ops_list, ops);
 282
 283         if (ftrace_enabled)
 284                 update_ftrace_function();
 285
 286         return 0;
 287 }
 288
 289 static int __unregister_ftrace_function(struct ftrace_ops *ops)
 290 {
 291         int ret;
 292
 293         if (ftrace_disabled)
 294                 return -ENODEV;
 295
 296         if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
 297                 return -EBUSY;
 298
 299         if (FTRACE_WARN_ON(ops == &global_ops))
 300                 return -EINVAL;
 301
 302         if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
 303                 ret = remove_ftrace_ops(&ftrace_global_list, ops);
 304                 if (!ret && ftrace_global_list == &ftrace_list_end)
 305                         ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops);
 306                 if (!ret)
 307                         ops->flags &= ~FTRACE_OPS_FL_ENABLED;
 308         } else
 309                 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
 310
 311         if (ret < 0)
 312                 return ret;
 313
 314         if (ftrace_enabled)
 315                 update_ftrace_function();
 316
 317         /*
 318          * Dynamic ops may be freed, we must make sure that all
 319          * callers are done before leaving this function.
 320          */
 321         if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
 322                 synchronize_sched();
 323
 324         return 0;
 325 }
 326
 327 static void ftrace_update_pid_func(void)
 328 {
 329         /* Only do something if we are tracing something */
 330         if (ftrace_trace_function == ftrace_stub)
 331                 return;
 332
 333         update_ftrace_function();
 334 }
 335
 336 #ifdef CONFIG_FUNCTION_PROFILER
 337 struct ftrace_profile {
 338         struct hlist_node               node;
 339         unsigned long                   ip;
 340         unsigned long                   counter;
 341 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 342         unsigned long long              time;
 343         unsigned long long              time_squared;
 344 #endif
 345 };
 346
 347 struct ftrace_profile_page {
 348         struct ftrace_profile_page      *next;
 349         unsigned long                   index;
 350         struct ftrace_profile           records[];
 351 };
 352
 353 struct ftrace_profile_stat {
 354         atomic_t                        disabled;
 355         struct hlist_head               *hash;
 356         struct ftrace_profile_page      *pages;
 357         struct ftrace_profile_page      *start;
 358         struct tracer_stat              stat;
 359 };
 360
 361 #define PROFILE_RECORDS_SIZE                                            \
 362         (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
 363
 364 #define PROFILES_PER_PAGE                                       \
 365         (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
 366
 367 static int ftrace_profile_bits __read_mostly;
 368 static int ftrace_profile_enabled __read_mostly;
 369
 370 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
 371 static DEFINE_MUTEX(ftrace_profile_lock);
 372
 373 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
 374
 375 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
 376
 377 static void *
 378 function_stat_next(void *v, int idx)
 379 {
 380         struct ftrace_profile *rec = v;
 381         struct ftrace_profile_page *pg;
 382
 383         pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
 384
 385  again:
 386         if (idx != 0)
 387                 rec++;
 388
 389         if ((void *)rec >= (void *)&pg->records[pg->index]) {
 390                 pg = pg->next;
 391                 if (!pg)
 392                         return NULL;
 393                 rec = &pg->records[0];
 394                 if (!rec->counter)
 395                         goto again;
 396         }
 397
 398         return rec;
 399 }
 400
 401 static void *function_stat_start(struct tracer_stat *trace)
 402 {
 403         struct ftrace_profile_stat *stat =
 404                 container_of(trace, struct ftrace_profile_stat, stat);
 405
 406         if (!stat || !stat->start)
 407                 return NULL;
 408
 409         return function_stat_next(&stat->start->records[0], 0);
 410 }
 411
 412 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 413 /* function graph compares on total time */
 414 static int function_stat_cmp(void *p1, void *p2)
 415 {
 416         struct ftrace_profile *a = p1;
 417         struct ftrace_profile *b = p2;
 418
 419         if (a->time < b->time)
 420                 return -1;
 421         if (a->time > b->time)
 422                 return 1;
 423         else
 424                 return 0;
 425 }
 426 #else
 427 /* not function graph compares against hits */
 428 static int function_stat_cmp(void *p1, void *p2)
 429 {
 430         struct ftrace_profile *a = p1;
 431         struct ftrace_profile *b = p2;
 432
 433         if (a->counter < b->counter)
 434                 return -1;
 435         if (a->counter > b->counter)
 436                 return 1;
 437         else
 438                 return 0;
 439 }
 440 #endif
 441
 442 static int function_stat_headers(struct seq_file *m)
 443 {
 444 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 445         seq_printf(m, "  Function                               "
 446                    "Hit    Time            Avg             s^2\n"
 447                       "  --------                               "
 448                    "---    ----            ---             ---\n");
 449 #else
 450         seq_printf(m, "  Function                               Hit\n"
 451                       "  --------                               ---\n");
 452 #endif
 453         return 0;
 454 }
 455
 456 static int function_stat_show(struct seq_file *m, void *v)
 457 {
 458         struct ftrace_profile *rec = v;
 459         char str[KSYM_SYMBOL_LEN];
 460         int ret = 0;
 461 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 462         static struct trace_seq s;
 463         unsigned long long avg;
 464         unsigned long long stddev;
 465 #endif
 466         mutex_lock(&ftrace_profile_lock);
 467
 468         /* we raced with function_profile_reset() */
 469         if (unlikely(rec->counter == 0)) {
 470                 ret = -EBUSY;
 471                 goto out;
 472         }
 473
 474         kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
 475         seq_printf(m, "  %-30.30s  %10lu", str, rec->counter);
 476
 477 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 478         seq_printf(m, "    ");
 479         avg = rec->time;
 480         do_div(avg, rec->counter);
 481
 482         /* Sample standard deviation (s^2) */
 483         if (rec->counter <= 1)
 484                 stddev = 0;
 485         else {
 486                 stddev = rec->time_squared - rec->counter * avg * avg;
 487                 /*
 488                  * Divide only 1000 for ns^2 -> us^2 conversion.
 489                  * trace_print_graph_duration will divide 1000 again.
 490                  */
 491                 do_div(stddev, (rec->counter - 1) * 1000);
 492         }
 493
 494         trace_seq_init(&s);
 495         trace_print_graph_duration(rec->time, &s);
 496         trace_seq_puts(&s, "    ");
 497         trace_print_graph_duration(avg, &s);
 498         trace_seq_puts(&s, "    ");
 499         trace_print_graph_duration(stddev, &s);
 500         trace_print_seq(m, &s);
 501 #endif
 502         seq_putc(m, '\n');
 503 out:
 504         mutex_unlock(&ftrace_profile_lock);
 505
 506         return ret;
 507 }
 508
 509 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
 510 {
 511         struct ftrace_profile_page *pg;
 512
 513         pg = stat->pages = stat->start;
 514
 515         while (pg) {
 516                 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
 517                 pg->index = 0;
 518                 pg = pg->next;
 519         }
 520
 521         memset(stat->hash, 0,
 522                FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
 523 }
 524
 525 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
 526 {
 527         struct ftrace_profile_page *pg;
 528         int functions;
 529         int pages;
 530         int i;
 531
 532         /* If we already allocated, do nothing */
 533         if (stat->pages)
 534                 return 0;
 535
 536         stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
 537         if (!stat->pages)
 538                 return -ENOMEM;
 539
 540 #ifdef CONFIG_DYNAMIC_FTRACE
 541         functions = ftrace_update_tot_cnt;
 542 #else
 543         /*
 544          * We do not know the number of functions that exist because
 545          * dynamic tracing is what counts them. With past experience
 546          * we have around 20K functions. That should be more than enough.
 547          * It is highly unlikely we will execute every function in
 548          * the kernel.
 549          */
 550         functions = 20000;
 551 #endif
 552
 553         pg = stat->start = stat->pages;
 554
 555         pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
 556
 557         for (i = 0; i < pages; i++) {
 558                 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
 559                 if (!pg->next)
 560                         goto out_free;
 561                 pg = pg->next;
 562         }
 563
 564         return 0;
 565
 566  out_free:
 567         pg = stat->start;
 568         while (pg) {
 569                 unsigned long tmp = (unsigned long)pg;
 570
 571                 pg = pg->next;
 572                 free_page(tmp);
 573         }
 574
 575         free_page((unsigned long)stat->pages);
 576         stat->pages = NULL;
 577         stat->start = NULL;
 578
 579         return -ENOMEM;
 580 }
 581
 582 static int ftrace_profile_init_cpu(int cpu)
 583 {
 584         struct ftrace_profile_stat *stat;
 585         int size;
 586
 587         stat = &per_cpu(ftrace_profile_stats, cpu);
 588
 589         if (stat->hash) {
 590                 /* If the profile is already created, simply reset it */
 591                 ftrace_profile_reset(stat);
 592                 return 0;
 593         }
 594
 595         /*
 596          * We are profiling all functions, but usually only a few thousand
 597          * functions are hit. We'll make a hash of 1024 items.
 598          */
 599         size = FTRACE_PROFILE_HASH_SIZE;
 600
 601         stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
 602
 603         if (!stat->hash)
 604                 return -ENOMEM;
 605
 606         if (!ftrace_profile_bits) {
 607                 size--;
 608
 609                 for (; size; size >>= 1)
 610                         ftrace_profile_bits++;
 611         }
 612
 613         /* Preallocate the function profiling pages */
 614         if (ftrace_profile_pages_init(stat) < 0) {
 615                 kfree(stat->hash);
 616                 stat->hash = NULL;
 617                 return -ENOMEM;
 618         }
 619
 620         return 0;
 621 }
 622
 623 static int ftrace_profile_init(void)
 624 {
 625         int cpu;
 626         int ret = 0;
 627
 628         for_each_online_cpu(cpu) {
 629                 ret = ftrace_profile_init_cpu(cpu);
 630                 if (ret)
 631                         break;
 632         }
 633
 634         return ret;
 635 }
 636
 637 /* interrupts must be disabled */
 638 static struct ftrace_profile *
 639 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
 640 {
 641         struct ftrace_profile *rec;
 642         struct hlist_head *hhd;
 643         struct hlist_node *n;
 644         unsigned long key;
 645
 646         key = hash_long(ip, ftrace_profile_bits);
 647         hhd = &stat->hash[key];
 648
 649         if (hlist_empty(hhd))
 650                 return NULL;
 651
 652         hlist_for_each_entry_rcu(rec, n, hhd, node) {
 653                 if (rec->ip == ip)
 654                         return rec;
 655         }
 656
 657         return NULL;
 658 }
 659
 660 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
 661                                struct ftrace_profile *rec)
 662 {
 663         unsigned long key;
 664
 665         key = hash_long(rec->ip, ftrace_profile_bits);
 666         hlist_add_head_rcu(&rec->node, &stat->hash[key]);
 667 }
 668
 669 /*
 670  * The memory is already allocated, this simply finds a new record to use.
 671  */
 672 static struct ftrace_profile *
 673 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
 674 {
 675         struct ftrace_profile *rec = NULL;
 676
 677         /* prevent recursion (from NMIs) */
 678         if (atomic_inc_return(&stat->disabled) != 1)
 679                 goto out;
 680
 681         /*
 682          * Try to find the function again since an NMI
 683          * could have added it
 684          */
 685         rec = ftrace_find_profiled_func(stat, ip);
 686         if (rec)
 687                 goto out;
 688
 689         if (stat->pages->index == PROFILES_PER_PAGE) {
 690                 if (!stat->pages->next)
 691                         goto out;
 692                 stat->pages = stat->pages->next;
 693         }
 694
 695         rec = &stat->pages->records[stat->pages->index++];
 696         rec->ip = ip;
 697         ftrace_add_profile(stat, rec);
 698
 699  out:
 700         atomic_dec(&stat->disabled);
 701
 702         return rec;
 703 }
 704
 705 static void
 706 function_profile_call(unsigned long ip, unsigned long parent_ip)
 707 {
 708         struct ftrace_profile_stat *stat;
 709         struct ftrace_profile *rec;
 710         unsigned long flags;
 711
 712         if (!ftrace_profile_enabled)
 713                 return;
 714
 715         local_irq_save(flags);
 716
 717         stat = &__get_cpu_var(ftrace_profile_stats);
 718         if (!stat->hash || !ftrace_profile_enabled)
 719                 goto out;
 720
 721         rec = ftrace_find_profiled_func(stat, ip);
 722         if (!rec) {
 723                 rec = ftrace_profile_alloc(stat, ip);
 724                 if (!rec)
 725                         goto out;
 726         }
 727
 728         rec->counter++;
 729  out:
 730         local_irq_restore(flags);
 731 }
 732
 733 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 734 static int profile_graph_entry(struct ftrace_graph_ent *trace)
 735 {
 736         function_profile_call(trace->func, 0);
 737         return 1;
 738 }
 739
 740 static void profile_graph_return(struct ftrace_graph_ret *trace)
 741 {
 742         struct ftrace_profile_stat *stat;
 743         unsigned long long calltime;
 744         struct ftrace_profile *rec;
 745         unsigned long flags;
 746
 747         local_irq_save(flags);
 748         stat = &__get_cpu_var(ftrace_profile_stats);
 749         if (!stat->hash || !ftrace_profile_enabled)
 750                 goto out;
 751
 752         /* If the calltime was zero'd ignore it */
 753         if (!trace->calltime)
 754                 goto out;
 755
 756         calltime = trace->rettime - trace->calltime;
 757
 758         if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
 759                 int index;
 760
 761                 index = trace->depth;
 762
 763                 /* Append this call time to the parent time to subtract */
 764                 if (index)
 765                         current->ret_stack[index - 1].subtime += calltime;
 766
 767                 if (current->ret_stack[index].subtime < calltime)
 768                         calltime -= current->ret_stack[index].subtime;
 769                 else
 770                         calltime = 0;
 771         }
 772
 773         rec = ftrace_find_profiled_func(stat, trace->func);
 774         if (rec) {
 775                 rec->time += calltime;
 776                 rec->time_squared += calltime * calltime;
 777         }
 778
 779  out:
 780         local_irq_restore(flags);
 781 }
 782
 783 static int register_ftrace_profiler(void)
 784 {
 785         return register_ftrace_graph(&profile_graph_return,
 786                                      &profile_graph_entry);
 787 }
 788
 789 static void unregister_ftrace_profiler(void)
 790 {
 791         unregister_ftrace_graph();
 792 }
 793 #else
 794 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
 795         .func           = function_profile_call,
 796 };
 797
 798 static int register_ftrace_profiler(void)
 799 {
 800         return register_ftrace_function(&ftrace_profile_ops);
 801 }
 802
 803 static void unregister_ftrace_profiler(void)
 804 {
 805         unregister_ftrace_function(&ftrace_profile_ops);
 806 }
 807 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 808
 809 static ssize_t
 810 ftrace_profile_write(struct file *filp, const char __user *ubuf,
 811                      size_t cnt, loff_t *ppos)
 812 {
 813         unsigned long val;
 814         int ret;
 815
 816         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 817         if (ret)
 818                 return ret;
 819
 820         val = !!val;
 821
 822         mutex_lock(&ftrace_profile_lock);
 823         if (ftrace_profile_enabled ^ val) {
 824                 if (val) {
 825                         ret = ftrace_profile_init();
 826                         if (ret < 0) {
 827                                 cnt = ret;
 828                                 goto out;
 829                         }
 830
 831                         ret = register_ftrace_profiler();
 832                         if (ret < 0) {
 833                                 cnt = ret;
 834                                 goto out;
 835                         }
 836                         ftrace_profile_enabled = 1;
 837                 } else {
 838                         ftrace_profile_enabled = 0;
 839                         /*
 840                          * unregister_ftrace_profiler calls stop_machine
 841                          * so this acts like an synchronize_sched.
 842                          */
 843                         unregister_ftrace_profiler();
 844                 }
 845         }
 846  out:
 847         mutex_unlock(&ftrace_profile_lock);
 848
 849         *ppos += cnt;
 850
 851         return cnt;
 852 }
 853
 854 static ssize_t
 855 ftrace_profile_read(struct file *filp, char __user *ubuf,
 856                      size_t cnt, loff_t *ppos)
 857 {
 858         char buf[64];           /* big enough to hold a number */
 859         int r;
 860
 861         r = sprintf(buf, "%u\n", ftrace_profile_enabled);
 862         return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 863 }
 864
 865 static const struct file_operations ftrace_profile_fops = {
 866         .open           = tracing_open_generic,
 867         .read           = ftrace_profile_read,
 868         .write          = ftrace_profile_write,
 869         .llseek         = default_llseek,
 870 };
 871
 872 /* used to initialize the real stat files */
 873 static struct tracer_stat function_stats __initdata = {
 874         .name           = "functions",
 875         .stat_start     = function_stat_start,
 876         .stat_next      = function_stat_next,
 877         .stat_cmp       = function_stat_cmp,
 878         .stat_headers   = function_stat_headers,
 879         .stat_show      = function_stat_show
 880 };
 881
 882 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
 883 {
 884         struct ftrace_profile_stat *stat;
 885         struct dentry *entry;
 886         char *name;
 887         int ret;
 888         int cpu;
 889
 890         for_each_possible_cpu(cpu) {
 891                 stat = &per_cpu(ftrace_profile_stats, cpu);
 892
 893                 /* allocate enough for function name + cpu number */
 894                 name = kmalloc(32, GFP_KERNEL);
 895                 if (!name) {
 896                         /*
 897                          * The files created are permanent, if something happens
 898                          * we still do not free memory.
 899                          */
 900                         WARN(1,
 901                              "Could not allocate stat file for cpu %d\n",
 902                              cpu);
 903                         return;
 904                 }
 905                 stat->stat = function_stats;
 906                 snprintf(name, 32, "function%d", cpu);
 907                 stat->stat.name = name;
 908                 ret = register_stat_tracer(&stat->stat);
 909                 if (ret) {
 910                         WARN(1,
 911                              "Could not register function stat for cpu %d\n",
 912                              cpu);
 913                         kfree(name);
 914                         return;
 915                 }
 916         }
 917
 918         entry = debugfs_create_file("function_profile_enabled", 0644,
 919                                     d_tracer, NULL, &ftrace_profile_fops);
 920         if (!entry)
 921                 pr_warning("Could not create debugfs "
 922                            "'function_profile_enabled' entry\n");
 923 }
 924
 925 #else /* CONFIG_FUNCTION_PROFILER */
 926 static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
 927 {
 928 }
 929 #endif /* CONFIG_FUNCTION_PROFILER */
 930
 931 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
 932
 933 #ifdef CONFIG_DYNAMIC_FTRACE
 934
 935 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
 936 # error Dynamic ftrace depends on MCOUNT_RECORD
 937 #endif
 938
 939 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
 940
 941 struct ftrace_func_probe {
 942         struct hlist_node       node;
 943         struct ftrace_probe_ops *ops;
 944         unsigned long           flags;
 945         unsigned long           ip;
 946         void                    *data;
 947         struct rcu_head         rcu;
 948 };
 949
 950 enum {
 951         FTRACE_ENABLE_CALLS             = (1 << 0),
 952         FTRACE_DISABLE_CALLS            = (1 << 1),
 953         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 954         FTRACE_START_FUNC_RET           = (1 << 3),
 955         FTRACE_STOP_FUNC_RET            = (1 << 4),
 956 };
 957 struct ftrace_func_entry {
 958         struct hlist_node hlist;
 959         unsigned long ip;
 960 };
 961
 962 struct ftrace_hash {
 963         unsigned long           size_bits;
 964         struct hlist_head       *buckets;
 965         unsigned long           count;
 966         struct rcu_head         rcu;
 967 };
 968
 969 /*
 970  * We make these constant because no one should touch them,
 971  * but they are used as the default "empty hash", to avoid allocating
 972  * it all the time. These are in a read only section such that if
 973  * anyone does try to modify it, it will cause an exception.
 974  */
 975 static const struct hlist_head empty_buckets[1];
 976 static const struct ftrace_hash empty_hash = {
 977         .buckets = (struct hlist_head *)empty_buckets,
 978 };
 979 #define EMPTY_HASH      ((struct ftrace_hash *)&empty_hash)
 980
 981 static struct ftrace_ops global_ops = {
 982         .func                   = ftrace_stub,
 983         .notrace_hash           = EMPTY_HASH,
 984         .filter_hash            = EMPTY_HASH,
 985 };
 986
 987 static struct dyn_ftrace *ftrace_new_addrs;
 988
 989 static DEFINE_MUTEX(ftrace_regex_lock);
 990
 991 struct ftrace_page {
 992         struct ftrace_page      *next;
 993         int                     index;
 994         struct dyn_ftrace       records[];
 995 };
 996
 997 #define ENTRIES_PER_PAGE \
 998   ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
 999
1000 /* estimate from running different kernels */
1001 #define NR_TO_INIT              10000
1002
1003 static struct ftrace_page       *ftrace_pages_start;
1004 static struct ftrace_page       *ftrace_pages;
1005
1006 static struct dyn_ftrace *ftrace_free_records;
1007
1008 static struct ftrace_func_entry *
1009 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1010 {
1011         unsigned long key;
1012         struct ftrace_func_entry *entry;
1013         struct hlist_head *hhd;
1014         struct hlist_node *n;
1015
1016         if (!hash->count)
1017                 return NULL;
1018
1019         if (hash->size_bits > 0)
1020                 key = hash_long(ip, hash->size_bits);
1021         else
1022                 key = 0;
1023
1024         hhd = &hash->buckets[key];
1025
1026         hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1027                 if (entry->ip == ip)
1028                         return entry;
1029         }
1030         return NULL;
1031 }
1032
1033 static void __add_hash_entry(struct ftrace_hash *hash,
1034                              struct ftrace_func_entry *entry)
1035 {
1036         struct hlist_head *hhd;
1037         unsigned long key;
1038
1039         if (hash->size_bits)
1040                 key = hash_long(entry->ip, hash->size_bits);
1041         else
1042                 key = 0;
1043
1044         hhd = &hash->buckets[key];
1045         hlist_add_head(&entry->hlist, hhd);
1046         hash->count++;
1047 }
1048
1049 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1050 {
1051         struct ftrace_func_entry *entry;
1052
1053         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1054         if (!entry)
1055                 return -ENOMEM;
1056
1057         entry->ip = ip;
1058         __add_hash_entry(hash, entry);
1059
1060         return 0;
1061 }
1062
1063 static void
1064 free_hash_entry(struct ftrace_hash *hash,
1065                   struct ftrace_func_entry *entry)
1066 {
1067         hlist_del(&entry->hlist);
1068         kfree(entry);
1069         hash->count--;
1070 }
1071
1072 static void
1073 remove_hash_entry(struct ftrace_hash *hash,
1074                   struct ftrace_func_entry *entry)
1075 {
1076         hlist_del(&entry->hlist);
1077         hash->count--;
1078 }
1079
1080 static void ftrace_hash_clear(struct ftrace_hash *hash)
1081 {
1082         struct hlist_head *hhd;
1083         struct hlist_node *tp, *tn;
1084         struct ftrace_func_entry *entry;
1085         int size = 1 << hash->size_bits;
1086         int i;
1087
1088         if (!hash->count)
1089                 return;
1090
1091         for (i = 0; i < size; i++) {
1092                 hhd = &hash->buckets[i];
1093                 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
1094                         free_hash_entry(hash, entry);
1095         }
1096         FTRACE_WARN_ON(hash->count);
1097 }
1098
1099 static void free_ftrace_hash(struct ftrace_hash *hash)
1100 {
1101         if (!hash || hash == EMPTY_HASH)
1102                 return;
1103         ftrace_hash_clear(hash);
1104         kfree(hash->buckets);
1105         kfree(hash);
1106 }
1107
1108 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1109 {
1110         struct ftrace_hash *hash;
1111
1112         hash = container_of(rcu, struct ftrace_hash, rcu);
1113         free_ftrace_hash(hash);
1114 }
1115
1116 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1117 {
1118         if (!hash || hash == EMPTY_HASH)
1119                 return;
1120         call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1121 }
1122
1123 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1124 {
1125         struct ftrace_hash *hash;
1126         int size;
1127
1128         hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1129         if (!hash)
1130                 return NULL;
1131
1132         size = 1 << size_bits;
1133         hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL);
1134
1135         if (!hash->buckets) {
1136                 kfree(hash);
1137                 return NULL;
1138         }
1139
1140         hash->size_bits = size_bits;
1141
1142         return hash;
1143 }
1144
1145 static struct ftrace_hash *
1146 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1147 {
1148         struct ftrace_func_entry *entry;
1149         struct ftrace_hash *new_hash;
1150         struct hlist_node *tp;
1151         int size;
1152         int ret;
1153         int i;
1154
1155         new_hash = alloc_ftrace_hash(size_bits);
1156         if (!new_hash)
1157                 return NULL;
1158
1159         /* Empty hash? */
1160         if (!hash || !hash->count)
1161                 return new_hash;
1162
1163         size = 1 << hash->size_bits;
1164         for (i = 0; i < size; i++) {
1165                 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1166                         ret = add_hash_entry(new_hash, entry->ip);
1167                         if (ret < 0)
1168                                 goto free_hash;
1169                 }
1170         }
1171
1172         FTRACE_WARN_ON(new_hash->count != hash->count);
1173
1174         return new_hash;
1175
1176  free_hash:
1177         free_ftrace_hash(new_hash);
1178         return NULL;
1179 }
1180
1181 static void
1182 ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1183 static void
1184 ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1185
1186 static int
1187 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1188                  struct ftrace_hash **dst, struct ftrace_hash *src)
1189 {
1190         struct ftrace_func_entry *entry;
1191         struct hlist_node *tp, *tn;
1192         struct hlist_head *hhd;
1193         struct ftrace_hash *old_hash;
1194         struct ftrace_hash *new_hash;
1195         unsigned long key;
1196         int size = src->count;
1197         int bits = 0;
1198         int ret;
1199         int i;
1200
1201         /*
1202          * Remove the current set, update the hash and add
1203          * them back.
1204          */
1205         ftrace_hash_rec_disable(ops, enable);
1206
1207         /*
1208          * If the new source is empty, just free dst and assign it
1209          * the empty_hash.
1210          */
1211         if (!src->count) {
1212                 free_ftrace_hash_rcu(*dst);
1213                 rcu_assign_pointer(*dst, EMPTY_HASH);
1214                 /* still need to update the function records */
1215                 ret = 0;
1216                 goto out;
1217         }
1218
1219         /*
1220          * Make the hash size about 1/2 the # found
1221          */
1222         for (size /= 2; size; size >>= 1)
1223                 bits++;
1224
1225         /* Don't allocate too much */
1226         if (bits > FTRACE_HASH_MAX_BITS)
1227                 bits = FTRACE_HASH_MAX_BITS;
1228
1229         ret = -ENOMEM;
1230         new_hash = alloc_ftrace_hash(bits);
1231         if (!new_hash)
1232                 goto out;
1233
1234         size = 1 << src->size_bits;
1235         for (i = 0; i < size; i++) {
1236                 hhd = &src->buckets[i];
1237                 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1238                         if (bits > 0)
1239                                 key = hash_long(entry->ip, bits);
1240                         else
1241                                 key = 0;
1242                         remove_hash_entry(src, entry);
1243                         __add_hash_entry(new_hash, entry);
1244                 }
1245         }
1246
1247         old_hash = *dst;
1248         rcu_assign_pointer(*dst, new_hash);
1249         free_ftrace_hash_rcu(old_hash);
1250
1251         ret = 0;
1252  out:
1253         /*
1254          * Enable regardless of ret:
1255          *  On success, we enable the new hash.
1256          *  On failure, we re-enable the original hash.
1257          */
1258         ftrace_hash_rec_enable(ops, enable);
1259
1260         return ret;
1261 }
1262
1263 /*
1264  * Test the hashes for this ops to see if we want to call
1265  * the ops->func or not.
1266  *
1267  * It's a match if the ip is in the ops->filter_hash or
1268  * the filter_hash does not exist or is empty,
1269  *  AND
1270  * the ip is not in the ops->notrace_hash.
1271  *
1272  * This needs to be called with preemption disabled as
1273  * the hashes are freed with call_rcu_sched().
1274  */
1275 static int
1276 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1277 {
1278         struct ftrace_hash *filter_hash;
1279         struct ftrace_hash *notrace_hash;
1280         int ret;
1281
1282         filter_hash = rcu_dereference_raw(ops->filter_hash);
1283         notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1284
1285         if ((!filter_hash || !filter_hash->count ||
1286              ftrace_lookup_ip(filter_hash, ip)) &&
1287             (!notrace_hash || !notrace_hash->count ||
1288              !ftrace_lookup_ip(notrace_hash, ip)))
1289                 ret = 1;
1290         else
1291                 ret = 0;
1292
1293         return ret;
1294 }
1295
1296 /*
1297  * This is a double for. Do not use 'break' to break out of the loop,
1298  * you must use a goto.
1299  */
1300 #define do_for_each_ftrace_rec(pg, rec)                                 \
1301         for (pg = ftrace_pages_start; pg; pg = pg->next) {              \
1302                 int _____i;                                             \
1303                 for (_____i = 0; _____i < pg->index; _____i++) {        \
1304                         rec = &pg->records[_____i];
1305
1306 #define while_for_each_ftrace_rec()             \
1307                 }                               \
1308         }
1309
1310 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1311                                      int filter_hash,
1312                                      bool inc)
1313 {
1314         struct ftrace_hash *hash;
1315         struct ftrace_hash *other_hash;
1316         struct ftrace_page *pg;
1317         struct dyn_ftrace *rec;
1318         int count = 0;
1319         int all = 0;
1320
1321         /* Only update if the ops has been registered */
1322         if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1323                 return;
1324
1325         /*
1326          * In the filter_hash case:
1327          *   If the count is zero, we update all records.
1328          *   Otherwise we just update the items in the hash.
1329          *
1330          * In the notrace_hash case:
1331          *   We enable the update in the hash.
1332          *   As disabling notrace means enabling the tracing,
1333          *   and enabling notrace means disabling, the inc variable
1334          *   gets inversed.
1335          */
1336         if (filter_hash) {
1337                 hash = ops->filter_hash;
1338                 other_hash = ops->notrace_hash;
1339                 if (!hash || !hash->count)
1340                         all = 1;
1341         } else {
1342                 inc = !inc;
1343                 hash = ops->notrace_hash;
1344                 other_hash = ops->filter_hash;
1345                 /*
1346                  * If the notrace hash has no items,
1347                  * then there's nothing to do.
1348                  */
1349                 if (hash && !hash->count)
1350                         return;
1351         }
1352
1353         do_for_each_ftrace_rec(pg, rec) {
1354                 int in_other_hash = 0;
1355                 int in_hash = 0;
1356                 int match = 0;
1357
1358                 if (all) {
1359                         /*
1360                          * Only the filter_hash affects all records.
1361                          * Update if the record is not in the notrace hash.
1362                          */
1363                         if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1364                                 match = 1;
1365                 } else {
1366                         in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip);
1367                         in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip);
1368
1369                         /*
1370                          *
1371                          */
1372                         if (filter_hash && in_hash && !in_other_hash)
1373                                 match = 1;
1374                         else if (!filter_hash && in_hash &&
1375                                  (in_other_hash || !other_hash->count))
1376                                 match = 1;
1377                 }
1378                 if (!match)
1379                         continue;
1380
1381                 if (inc) {
1382                         rec->flags++;
1383                         if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1384                                 return;
1385                 } else {
1386                         if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1387                                 return;
1388                         rec->flags--;
1389                 }
1390                 count++;
1391                 /* Shortcut, if we handled all records, we are done. */
1392                 if (!all && count == hash->count)
1393                         return;
1394         } while_for_each_ftrace_rec();
1395 }
1396
1397 static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1398                                     int filter_hash)
1399 {
1400         __ftrace_hash_rec_update(ops, filter_hash, 0);
1401 }
1402
1403 static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1404                                    int filter_hash)
1405 {
1406         __ftrace_hash_rec_update(ops, filter_hash, 1);
1407 }
1408
1409 static void ftrace_free_rec(struct dyn_ftrace *rec)
1410 {
1411         rec->freelist = ftrace_free_records;
1412         ftrace_free_records = rec;
1413         rec->flags |= FTRACE_FL_FREE;
1414 }
1415
1416 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
1417 {
1418         struct dyn_ftrace *rec;
1419
1420         /* First check for freed records */
1421         if (ftrace_free_records) {
1422                 rec = ftrace_free_records;
1423
1424                 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
1425                         FTRACE_WARN_ON_ONCE(1);
1426                         ftrace_free_records = NULL;
1427                         return NULL;
1428                 }
1429
1430                 ftrace_free_records = rec->freelist;
1431                 memset(rec, 0, sizeof(*rec));
1432                 return rec;
1433         }
1434
1435         if (ftrace_pages->index == ENTRIES_PER_PAGE) {
1436                 if (!ftrace_pages->next) {
1437                         /* allocate another page */
1438                         ftrace_pages->next =
1439                                 (void *)get_zeroed_page(GFP_KERNEL);
1440                         if (!ftrace_pages->next)
1441                                 return NULL;
1442                 }
1443                 ftrace_pages = ftrace_pages->next;
1444         }
1445
1446         return &ftrace_pages->records[ftrace_pages->index++];
1447 }
1448
1449 static struct dyn_ftrace *
1450 ftrace_record_ip(unsigned long ip)
1451 {
1452         struct dyn_ftrace *rec;
1453
1454         if (ftrace_disabled)
1455                 return NULL;
1456
1457         rec = ftrace_alloc_dyn_node(ip);
1458         if (!rec)
1459                 return NULL;
1460
1461         rec->ip = ip;
1462         rec->newlist = ftrace_new_addrs;
1463         ftrace_new_addrs = rec;
1464
1465         return rec;
1466 }
1467
1468 static void print_ip_ins(const char *fmt, unsigned char *p)
1469 {
1470         int i;
1471
1472         printk(KERN_CONT "%s", fmt);
1473
1474         for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1475                 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1476 }
1477
1478 static void ftrace_bug(int failed, unsigned long ip)
1479 {
1480         switch (failed) {
1481         case -EFAULT:
1482                 FTRACE_WARN_ON_ONCE(1);
1483                 pr_info("ftrace faulted on modifying ");
1484                 print_ip_sym(ip);
1485                 break;
1486         case -EINVAL:
1487                 FTRACE_WARN_ON_ONCE(1);
1488                 pr_info("ftrace failed to modify ");
1489                 print_ip_sym(ip);
1490                 print_ip_ins(" actual: ", (unsigned char *)ip);
1491                 printk(KERN_CONT "\n");
1492                 break;
1493         case -EPERM:
1494                 FTRACE_WARN_ON_ONCE(1);
1495                 pr_info("ftrace faulted on writing ");
1496                 print_ip_sym(ip);
1497                 break;
1498         default:
1499                 FTRACE_WARN_ON_ONCE(1);
1500                 pr_info("ftrace faulted on unknown error ");
1501                 print_ip_sym(ip);
1502         }
1503 }
1504
1505
1506 /* Return 1 if the address range is reserved for ftrace */
1507 int ftrace_text_reserved(void *start, void *end)
1508 {
1509         struct dyn_ftrace *rec;
1510         struct ftrace_page *pg;
1511
1512         do_for_each_ftrace_rec(pg, rec) {
1513                 if (rec->ip <= (unsigned long)end &&
1514                     rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
1515                         return 1;
1516         } while_for_each_ftrace_rec();
1517         return 0;
1518 }
1519
1520
1521 static int
1522 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1523 {
1524         unsigned long ftrace_addr;
1525         unsigned long flag = 0UL;
1526
1527         ftrace_addr = (unsigned long)FTRACE_ADDR;
1528
1529         /*
1530          * If we are enabling tracing:
1531          *
1532          *   If the record has a ref count, then we need to enable it
1533          *   because someone is using it.
1534          *
1535          *   Otherwise we make sure its disabled.
1536          *
1537          * If we are disabling tracing, then disable all records that
1538          * are enabled.
1539          */
1540         if (enable && (rec->flags & ~FTRACE_FL_MASK))
1541                 flag = FTRACE_FL_ENABLED;
1542
1543         /* If the state of this record hasn't changed, then do nothing */
1544         if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1545                 return 0;
1546
1547         if (flag) {
1548                 rec->flags |= FTRACE_FL_ENABLED;
1549                 return ftrace_make_call(rec, ftrace_addr);
1550         }
1551
1552         rec->flags &= ~FTRACE_FL_ENABLED;
1553         return ftrace_make_nop(NULL, rec, ftrace_addr);
1554 }
1555
1556 static void ftrace_replace_code(int enable)
1557 {
1558         struct dyn_ftrace *rec;
1559         struct ftrace_page *pg;
1560         int failed;
1561
1562         if (unlikely(ftrace_disabled))
1563                 return;
1564
1565         do_for_each_ftrace_rec(pg, rec) {
1566                 /* Skip over free records */
1567                 if (rec->flags & FTRACE_FL_FREE)
1568                         continue;
1569
1570                 failed = __ftrace_replace_code(rec, enable);
1571                 if (failed) {
1572                         ftrace_bug(failed, rec->ip);
1573                         /* Stop processing */
1574                         return;
1575                 }
1576         } while_for_each_ftrace_rec();
1577 }
1578
1579 static int
1580 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1581 {
1582         unsigned long ip;
1583         int ret;
1584
1585         ip = rec->ip;
1586
1587         if (unlikely(ftrace_disabled))
1588                 return 0;
1589
1590         ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1591         if (ret) {
1592                 ftrace_bug(ret, ip);
1593                 return 0;
1594         }
1595         return 1;
1596 }
1597
1598 /*
1599  * archs can override this function if they must do something
1600  * before the modifying code is performed.
1601  */
1602 int __weak ftrace_arch_code_modify_prepare(void)
1603 {
1604         return 0;
1605 }
1606
1607 /*
1608  * archs can override this function if they must do something
1609  * after the modifying code is performed.
1610  */
1611 int __weak ftrace_arch_code_modify_post_process(void)
1612 {
1613         return 0;
1614 }
1615
1616 static int __ftrace_modify_code(void *data)
1617 {
1618         int *command = data;
1619
1620         /*
1621          * Do not call function tracer while we update the code.
1622          * We are in stop machine, no worrying about races.
1623          */
1624         function_trace_stop++;
1625
1626         if (*command & FTRACE_ENABLE_CALLS)
1627                 ftrace_replace_code(1);
1628         else if (*command & FTRACE_DISABLE_CALLS)
1629                 ftrace_replace_code(0);
1630
1631         if (*command & FTRACE_UPDATE_TRACE_FUNC)
1632                 ftrace_update_ftrace_func(ftrace_trace_function);
1633
1634         if (*command & FTRACE_START_FUNC_RET)
1635                 ftrace_enable_ftrace_graph_caller();
1636         else if (*command & FTRACE_STOP_FUNC_RET)
1637                 ftrace_disable_ftrace_graph_caller();
1638
1639 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
1640         /*
1641          * For archs that call ftrace_test_stop_func(), we must
1642          * wait till after we update all the function callers
1643          * before we update the callback. This keeps different
1644          * ops that record different functions from corrupting
1645          * each other.
1646          */
1647         __ftrace_trace_function = __ftrace_trace_function_delay;
1648 #endif
1649         function_trace_stop--;
1650
1651         return 0;
1652 }
1653
1654 static void ftrace_run_update_code(int command)
1655 {
1656         int ret;
1657
1658         ret = ftrace_arch_code_modify_prepare();
1659         FTRACE_WARN_ON(ret);
1660         if (ret)
1661                 return;
1662
1663         stop_machine(__ftrace_modify_code, &command, NULL);
1664
1665         ret = ftrace_arch_code_modify_post_process();
1666         FTRACE_WARN_ON(ret);
1667 }
1668
1669 static ftrace_func_t saved_ftrace_func;
1670 static int ftrace_start_up;
1671 static int global_start_up;
1672
1673 static void ftrace_startup_enable(int command)
1674 {
1675         if (saved_ftrace_func != ftrace_trace_function) {
1676                 saved_ftrace_func = ftrace_trace_function;
1677                 command |= FTRACE_UPDATE_TRACE_FUNC;
1678         }
1679
1680         if (!command || !ftrace_enabled)
1681                 return;
1682
1683         ftrace_run_update_code(command);
1684 }
1685
1686 static int ftrace_startup(struct ftrace_ops *ops, int command)
1687 {
1688         bool hash_enable = true;
1689
1690         if (unlikely(ftrace_disabled))
1691                 return -ENODEV;
1692
1693         ftrace_start_up++;
1694         command |= FTRACE_ENABLE_CALLS;
1695
1696         /* ops marked global share the filter hashes */
1697         if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1698                 ops = &global_ops;
1699                 /* Don't update hash if global is already set */
1700                 if (global_start_up)
1701                         hash_enable = false;
1702                 global_start_up++;
1703         }
1704
1705         ops->flags |= FTRACE_OPS_FL_ENABLED;
1706         if (hash_enable)
1707                 ftrace_hash_rec_enable(ops, 1);
1708
1709         ftrace_startup_enable(command);
1710
1711         return 0;
1712 }
1713
1714 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
1715 {
1716         bool hash_disable = true;
1717
1718         if (unlikely(ftrace_disabled))
1719                 return;
1720
1721         ftrace_start_up--;
1722         /*
1723          * Just warn in case of unbalance, no need to kill ftrace, it's not
1724          * critical but the ftrace_call callers may be never nopped again after
1725          * further ftrace uses.
1726          */
1727         WARN_ON_ONCE(ftrace_start_up < 0);
1728
1729         if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1730                 ops = &global_ops;
1731                 global_start_up--;
1732                 WARN_ON_ONCE(global_start_up < 0);
1733                 /* Don't update hash if global still has users */
1734                 if (global_start_up) {
1735                         WARN_ON_ONCE(!ftrace_start_up);
1736                         hash_disable = false;
1737                 }
1738         }
1739
1740         if (hash_disable)
1741                 ftrace_hash_rec_disable(ops, 1);
1742
1743         if (ops != &global_ops || !global_start_up)
1744                 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
1745
1746         if (!ftrace_start_up)
1747                 command |= FTRACE_DISABLE_CALLS;
1748
1749         if (saved_ftrace_func != ftrace_trace_function) {
1750                 saved_ftrace_func = ftrace_trace_function;
1751                 command |= FTRACE_UPDATE_TRACE_FUNC;
1752         }
1753
1754         if (!command || !ftrace_enabled)
1755                 return;
1756
1757         ftrace_run_update_code(command);
1758 }
1759
1760 static void ftrace_startup_sysctl(void)
1761 {
1762         if (unlikely(ftrace_disabled))
1763                 return;
1764
1765         /* Force update next time */
1766         saved_ftrace_func = NULL;
1767         /* ftrace_start_up is true if we want ftrace running */
1768         if (ftrace_start_up)
1769                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
1770 }
1771
1772 static void ftrace_shutdown_sysctl(void)
1773 {
1774         if (unlikely(ftrace_disabled))
1775                 return;
1776
1777         /* ftrace_start_up is true if ftrace is running */
1778         if (ftrace_start_up)
1779                 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
1780 }
1781
1782 static cycle_t          ftrace_update_time;
1783 static unsigned long    ftrace_update_cnt;
1784 unsigned long           ftrace_update_tot_cnt;
1785
1786 static int ops_traces_mod(struct ftrace_ops *ops)
1787 {
1788         struct ftrace_hash *hash;
1789
1790         hash = ops->filter_hash;
1791         return !!(!hash || !hash->count);
1792 }
1793
1794 static int ftrace_update_code(struct module *mod)
1795 {
1796         struct dyn_ftrace *p;
1797         cycle_t start, stop;
1798         unsigned long ref = 0;
1799
1800         /*
1801          * When adding a module, we need to check if tracers are
1802          * currently enabled and if they are set to trace all functions.
1803          * If they are, we need to enable the module functions as well
1804          * as update the reference counts for those function records.
1805          */
1806         if (mod) {
1807                 struct ftrace_ops *ops;
1808
1809                 for (ops = ftrace_ops_list;
1810                      ops != &ftrace_list_end; ops = ops->next) {
1811                         if (ops->flags & FTRACE_OPS_FL_ENABLED &&
1812                             ops_traces_mod(ops))
1813                                 ref++;
1814                 }
1815         }
1816
1817         start = ftrace_now(raw_smp_processor_id());
1818         ftrace_update_cnt = 0;
1819
1820         while (ftrace_new_addrs) {
1821
1822                 /* If something went wrong, bail without enabling anything */
1823                 if (unlikely(ftrace_disabled))
1824                         return -1;
1825
1826                 p = ftrace_new_addrs;
1827                 ftrace_new_addrs = p->newlist;
1828                 p->flags = ref;
1829
1830                 /*
1831                  * Do the initial record conversion from mcount jump
1832                  * to the NOP instructions.
1833                  */
1834                 if (!ftrace_code_disable(mod, p)) {
1835                         ftrace_free_rec(p);
1836                         /* Game over */
1837                         break;
1838                 }
1839
1840                 ftrace_update_cnt++;
1841
1842                 /*
1843                  * If the tracing is enabled, go ahead and enable the record.
1844                  *
1845                  * The reason not to enable the record immediatelly is the
1846                  * inherent check of ftrace_make_nop/ftrace_make_call for
1847                  * correct previous instructions.  Making first the NOP
1848                  * conversion puts the module to the correct state, thus
1849                  * passing the ftrace_make_call check.
1850                  */
1851                 if (ftrace_start_up && ref) {
1852                         int failed = __ftrace_replace_code(p, 1);
1853                         if (failed) {
1854                                 ftrace_bug(failed, p->ip);
1855                                 ftrace_free_rec(p);
1856                         }
1857                 }
1858         }
1859
1860         stop = ftrace_now(raw_smp_processor_id());
1861         ftrace_update_time = stop - start;
1862         ftrace_update_tot_cnt += ftrace_update_cnt;
1863
1864         return 0;
1865 }
1866
1867 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
1868 {
1869         struct ftrace_page *pg;
1870         int cnt;
1871         int i;
1872
1873         /* allocate a few pages */
1874         ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
1875         if (!ftrace_pages_start)
1876                 return -1;
1877
1878         /*
1879          * Allocate a few more pages.
1880          *
1881          * TODO: have some parser search vmlinux before
1882          *   final linking to find all calls to ftrace.
1883          *   Then we can:
1884          *    a) know how many pages to allocate.
1885          *     and/or
1886          *    b) set up the table then.
1887          *
1888          *  The dynamic code is still necessary for
1889          *  modules.
1890          */
1891
1892         pg = ftrace_pages = ftrace_pages_start;
1893
1894         cnt = num_to_init / ENTRIES_PER_PAGE;
1895         pr_info("ftrace: allocating %ld entries in %d pages\n",
1896                 num_to_init, cnt + 1);
1897
1898         for (i = 0; i < cnt; i++) {
1899                 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
1900
1901                 /* If we fail, we'll try later anyway */
1902                 if (!pg->next)
1903                         break;
1904
1905                 pg = pg->next;
1906         }
1907
1908         return 0;
1909 }
1910
1911 enum {
1912         FTRACE_ITER_FILTER      = (1 << 0),
1913         FTRACE_ITER_NOTRACE     = (1 << 1),
1914         FTRACE_ITER_PRINTALL    = (1 << 2),
1915         FTRACE_ITER_HASH        = (1 << 3),
1916         FTRACE_ITER_ENABLED     = (1 << 4),
1917 };
1918
1919 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1920
1921 struct ftrace_iterator {
1922         loff_t                          pos;
1923         loff_t                          func_pos;
1924         struct ftrace_page              *pg;
1925         struct dyn_ftrace               *func;
1926         struct ftrace_func_probe        *probe;
1927         struct trace_parser             parser;
1928         struct ftrace_hash              *hash;
1929         struct ftrace_ops               *ops;
1930         int                             hidx;
1931         int                             idx;
1932         unsigned                        flags;
1933 };
1934
1935 static void *
1936 t_hash_next(struct seq_file *m, loff_t *pos)
1937 {
1938         struct ftrace_iterator *iter = m->private;
1939         struct hlist_node *hnd = NULL;
1940         struct hlist_head *hhd;
1941
1942         (*pos)++;
1943         iter->pos = *pos;
1944
1945         if (iter->probe)
1946                 hnd = &iter->probe->node;
1947  retry:
1948         if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
1949                 return NULL;
1950
1951         hhd = &ftrace_func_hash[iter->hidx];
1952
1953         if (hlist_empty(hhd)) {
1954                 iter->hidx++;
1955                 hnd = NULL;
1956                 goto retry;
1957         }
1958
1959         if (!hnd)
1960                 hnd = hhd->first;
1961         else {
1962                 hnd = hnd->next;
1963                 if (!hnd) {
1964                         iter->hidx++;
1965                         goto retry;
1966                 }
1967         }
1968
1969         if (WARN_ON_ONCE(!hnd))
1970                 return NULL;
1971
1972         iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
1973
1974         return iter;
1975 }
1976
1977 static void *t_hash_start(struct seq_file *m, loff_t *pos)
1978 {
1979         struct ftrace_iterator *iter = m->private;
1980         void *p = NULL;
1981         loff_t l;
1982
1983         if (iter->func_pos > *pos)
1984                 return NULL;
1985
1986         iter->hidx = 0;
1987         for (l = 0; l <= (*pos - iter->func_pos); ) {
1988                 p = t_hash_next(m, &l);
1989                 if (!p)
1990                         break;
1991         }
1992         if (!p)
1993                 return NULL;
1994
1995         /* Only set this if we have an item */
1996         iter->flags |= FTRACE_ITER_HASH;
1997
1998         return iter;
1999 }
2000
2001 static int
2002 t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2003 {
2004         struct ftrace_func_probe *rec;
2005
2006         rec = iter->probe;
2007         if (WARN_ON_ONCE(!rec))
2008                 return -EIO;
2009
2010         if (rec->ops->print)
2011                 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2012
2013         seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2014
2015         if (rec->data)
2016                 seq_printf(m, ":%p", rec->data);
2017         seq_putc(m, '\n');
2018
2019         return 0;
2020 }
2021
2022 static void *
2023 t_next(struct seq_file *m, void *v, loff_t *pos)
2024 {
2025         struct ftrace_iterator *iter = m->private;
2026         struct ftrace_ops *ops = &global_ops;
2027         struct dyn_ftrace *rec = NULL;
2028
2029         if (unlikely(ftrace_disabled))
2030                 return NULL;
2031
2032         if (iter->flags & FTRACE_ITER_HASH)
2033                 return t_hash_next(m, pos);
2034
2035         (*pos)++;
2036         iter->pos = iter->func_pos = *pos;
2037
2038         if (iter->flags & FTRACE_ITER_PRINTALL)
2039                 return t_hash_start(m, pos);
2040
2041  retry:
2042         if (iter->idx >= iter->pg->index) {
2043                 if (iter->pg->next) {
2044                         iter->pg = iter->pg->next;
2045                         iter->idx = 0;
2046                         goto retry;
2047                 }
2048         } else {
2049                 rec = &iter->pg->records[iter->idx++];
2050                 if ((rec->flags & FTRACE_FL_FREE) ||
2051
2052                     ((iter->flags & FTRACE_ITER_FILTER) &&
2053                      !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
2054
2055                     ((iter->flags & FTRACE_ITER_NOTRACE) &&
2056                      !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2057
2058                     ((iter->flags & FTRACE_ITER_ENABLED) &&
2059                      !(rec->flags & ~FTRACE_FL_MASK))) {
2060
2061                         rec = NULL;
2062                         goto retry;
2063                 }
2064         }
2065
2066         if (!rec)
2067                 return t_hash_start(m, pos);
2068
2069         iter->func = rec;
2070
2071         return iter;
2072 }
2073
2074 static void reset_iter_read(struct ftrace_iterator *iter)
2075 {
2076         iter->pos = 0;
2077         iter->func_pos = 0;
2078         iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
2079 }
2080
2081 static void *t_start(struct seq_file *m, loff_t *pos)
2082 {
2083         struct ftrace_iterator *iter = m->private;
2084         struct ftrace_ops *ops = &global_ops;
2085         void *p = NULL;
2086         loff_t l;
2087
2088         mutex_lock(&ftrace_lock);
2089
2090         if (unlikely(ftrace_disabled))
2091                 return NULL;
2092
2093         /*
2094          * If an lseek was done, then reset and start from beginning.
2095          */
2096         if (*pos < iter->pos)
2097                 reset_iter_read(iter);
2098
2099         /*
2100          * For set_ftrace_filter reading, if we have the filter
2101          * off, we can short cut and just print out that all
2102          * functions are enabled.
2103          */
2104         if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) {
2105                 if (*pos > 0)
2106                         return t_hash_start(m, pos);
2107                 iter->flags |= FTRACE_ITER_PRINTALL;
2108                 /* reset in case of seek/pread */
2109                 iter->flags &= ~FTRACE_ITER_HASH;
2110                 return iter;
2111         }
2112
2113         if (iter->flags & FTRACE_ITER_HASH)
2114                 return t_hash_start(m, pos);
2115
2116         /*
2117          * Unfortunately, we need to restart at ftrace_pages_start
2118          * every time we let go of the ftrace_mutex. This is because
2119          * those pointers can change without the lock.
2120          */
2121         iter->pg = ftrace_pages_start;
2122         iter->idx = 0;
2123         for (l = 0; l <= *pos; ) {
2124                 p = t_next(m, p, &l);
2125                 if (!p)
2126                         break;
2127         }
2128
2129         if (!p) {
2130                 if (iter->flags & FTRACE_ITER_FILTER)
2131                         return t_hash_start(m, pos);
2132
2133                 return NULL;
2134         }
2135
2136         return iter;
2137 }
2138
2139 static void t_stop(struct seq_file *m, void *p)
2140 {
2141         mutex_unlock(&ftrace_lock);
2142 }
2143
2144 static int t_show(struct seq_file *m, void *v)
2145 {
2146         struct ftrace_iterator *iter = m->private;
2147         struct dyn_ftrace *rec;
2148
2149         if (iter->flags & FTRACE_ITER_HASH)
2150                 return t_hash_show(m, iter);
2151
2152         if (iter->flags & FTRACE_ITER_PRINTALL) {
2153                 seq_printf(m, "#### all functions enabled ####\n");
2154                 return 0;
2155         }
2156
2157         rec = iter->func;
2158
2159         if (!rec)
2160                 return 0;
2161
2162         seq_printf(m, "%ps", (void *)rec->ip);
2163         if (iter->flags & FTRACE_ITER_ENABLED)
2164                 seq_printf(m, " (%ld)",
2165                            rec->flags & ~FTRACE_FL_MASK);
2166         seq_printf(m, "\n");
2167
2168         return 0;
2169 }
2170
2171 static const struct seq_operations show_ftrace_seq_ops = {
2172         .start = t_start,
2173         .next = t_next,
2174         .stop = t_stop,
2175         .show = t_show,
2176 };
2177
2178 static int
2179 ftrace_avail_open(struct inode *inode, struct file *file)
2180 {
2181         struct ftrace_iterator *iter;
2182         int ret;
2183
2184         if (unlikely(ftrace_disabled))
2185                 return -ENODEV;
2186
2187         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2188         if (!iter)
2189                 return -ENOMEM;
2190
2191         iter->pg = ftrace_pages_start;
2192
2193         ret = seq_open(file, &show_ftrace_seq_ops);
2194         if (!ret) {
2195                 struct seq_file *m = file->private_data;
2196
2197                 m->private = iter;
2198         } else {
2199                 kfree(iter);
2200         }
2201
2202         return ret;
2203 }
2204
2205 static int
2206 ftrace_enabled_open(struct inode *inode, struct file *file)
2207 {
2208         struct ftrace_iterator *iter;
2209         int ret;
2210
2211         if (unlikely(ftrace_disabled))
2212                 return -ENODEV;
2213
2214         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2215         if (!iter)
2216                 return -ENOMEM;
2217
2218         iter->pg = ftrace_pages_start;
2219         iter->flags = FTRACE_ITER_ENABLED;
2220
2221         ret = seq_open(file, &show_ftrace_seq_ops);
2222         if (!ret) {
2223                 struct seq_file *m = file->private_data;
2224
2225                 m->private = iter;
2226         } else {
2227                 kfree(iter);
2228         }
2229
2230         return ret;
2231 }
2232
2233 static void ftrace_filter_reset(struct ftrace_hash *hash)
2234 {
2235         mutex_lock(&ftrace_lock);
2236         ftrace_hash_clear(hash);
2237         mutex_unlock(&ftrace_lock);
2238 }
2239
2240 static int
2241 ftrace_regex_open(struct ftrace_ops *ops, int flag,
2242                   struct inode *inode, struct file *file)
2243 {
2244         struct ftrace_iterator *iter;
2245         struct ftrace_hash *hash;
2246         int ret = 0;
2247
2248         if (unlikely(ftrace_disabled))
2249                 return -ENODEV;
2250
2251         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2252         if (!iter)
2253                 return -ENOMEM;
2254
2255         if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2256                 kfree(iter);
2257                 return -ENOMEM;
2258         }
2259
2260         if (flag & FTRACE_ITER_NOTRACE)
2261                 hash = ops->notrace_hash;
2262         else
2263                 hash = ops->filter_hash;
2264
2265         iter->ops = ops;
2266         iter->flags = flag;
2267
2268         if (file->f_mode & FMODE_WRITE) {
2269                 mutex_lock(&ftrace_lock);
2270                 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2271                 mutex_unlock(&ftrace_lock);
2272
2273                 if (!iter->hash) {
2274                         trace_parser_put(&iter->parser);
2275                         kfree(iter);
2276                         return -ENOMEM;
2277                 }
2278         }
2279
2280         mutex_lock(&ftrace_regex_lock);
2281
2282         if ((file->f_mode & FMODE_WRITE) &&
2283             (file->f_flags & O_TRUNC))
2284                 ftrace_filter_reset(iter->hash);
2285
2286         if (file->f_mode & FMODE_READ) {
2287                 iter->pg = ftrace_pages_start;
2288
2289                 ret = seq_open(file, &show_ftrace_seq_ops);
2290                 if (!ret) {
2291                         struct seq_file *m = file->private_data;
2292                         m->private = iter;
2293                 } else {
2294                         /* Failed */
2295                         free_ftrace_hash(iter->hash);
2296                         trace_parser_put(&iter->parser);
2297                         kfree(iter);
2298                 }
2299         } else
2300                 file->private_data = iter;
2301         mutex_unlock(&ftrace_regex_lock);
2302
2303         return ret;
2304 }
2305
2306 static int
2307 ftrace_filter_open(struct inode *inode, struct file *file)
2308 {
2309         return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER,
2310                                  inode, file);
2311 }
2312
2313 static int
2314 ftrace_notrace_open(struct inode *inode, struct file *file)
2315 {
2316         return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2317                                  inode, file);
2318 }
2319
2320 static loff_t
2321 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
2322 {
2323         loff_t ret;
2324
2325         if (file->f_mode & FMODE_READ)
2326                 ret = seq_lseek(file, offset, origin);
2327         else
2328                 file->f_pos = ret = 1;
2329
2330         return ret;
2331 }
2332
2333 static int ftrace_match(char *str, char *regex, int len, int type)
2334 {
2335         int matched = 0;
2336         int slen;
2337
2338         switch (type) {
2339         case MATCH_FULL:
2340                 if (strcmp(str, regex) == 0)
2341                         matched = 1;
2342                 break;
2343         case MATCH_FRONT_ONLY:
2344                 if (strncmp(str, regex, len) == 0)
2345                         matched = 1;
2346                 break;
2347         case MATCH_MIDDLE_ONLY:
2348                 if (strstr(str, regex))
2349                         matched = 1;
2350                 break;
2351         case MATCH_END_ONLY:
2352                 slen = strlen(str);
2353                 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2354                         matched = 1;
2355                 break;
2356         }
2357
2358         return matched;
2359 }
2360
2361 static int
2362 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2363 {
2364         struct ftrace_func_entry *entry;
2365         int ret = 0;
2366
2367         entry = ftrace_lookup_ip(hash, rec->ip);
2368         if (not) {
2369                 /* Do nothing if it doesn't exist */
2370                 if (!entry)
2371                         return 0;
2372
2373                 free_hash_entry(hash, entry);
2374         } else {
2375                 /* Do nothing if it exists */
2376                 if (entry)
2377                         return 0;
2378
2379                 ret = add_hash_entry(hash, rec->ip);
2380         }
2381         return ret;
2382 }
2383
2384 static int
2385 ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2386                     char *regex, int len, int type)
2387 {
2388         char str[KSYM_SYMBOL_LEN];
2389         char *modname;
2390
2391         kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2392
2393         if (mod) {
2394                 /* module lookup requires matching the module */
2395                 if (!modname || strcmp(modname, mod))
2396                         return 0;
2397
2398                 /* blank search means to match all funcs in the mod */
2399                 if (!len)
2400                         return 1;
2401         }
2402
2403         return ftrace_match(str, regex, len, type);
2404 }
2405
2406 static int
2407 match_records(struct ftrace_hash *hash, char *buff,
2408               int len, char *mod, int not)
2409 {
2410         unsigned search_len = 0;
2411         struct ftrace_page *pg;
2412         struct dyn_ftrace *rec;
2413         int type = MATCH_FULL;
2414         char *search = buff;
2415         int found = 0;
2416         int ret;
2417
2418         if (len) {
2419                 type = filter_parse_regex(buff, len, &search, &not);
2420                 search_len = strlen(search);
2421         }
2422
2423         mutex_lock(&ftrace_lock);
2424
2425         if (unlikely(ftrace_disabled))
2426                 goto out_unlock;
2427
2428         do_for_each_ftrace_rec(pg, rec) {
2429
2430                 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2431                         ret = enter_record(hash, rec, not);
2432                         if (ret < 0) {
2433                                 found = ret;
2434                                 goto out_unlock;
2435                         }
2436                         found = 1;
2437                 }
2438         } while_for_each_ftrace_rec();
2439  out_unlock:
2440         mutex_unlock(&ftrace_lock);
2441
2442         return found;
2443 }
2444
2445 static int
2446 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2447 {
2448         return match_records(hash, buff, len, NULL, 0);
2449 }
2450
2451 static int
2452 ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2453 {
2454         int not = 0;
2455
2456         /* blank or '*' mean the same */
2457         if (strcmp(buff, "*") == 0)
2458                 buff[0] = 0;
2459
2460         /* handle the case of 'dont filter this module' */
2461         if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2462                 buff[0] = 0;
2463                 not = 1;
2464         }
2465
2466         return match_records(hash, buff, strlen(buff), mod, not);
2467 }
2468
2469 /*
2470  * We register the module command as a template to show others how
2471  * to register the a command as well.
2472  */
2473
2474 static int
2475 ftrace_mod_callback(struct ftrace_hash *hash,
2476                     char *func, char *cmd, char *param, int enable)
2477 {
2478         char *mod;
2479         int ret = -EINVAL;
2480
2481         /*
2482          * cmd == 'mod' because we only registered this func
2483          * for the 'mod' ftrace_func_command.
2484          * But if you register one func with multiple commands,
2485          * you can tell which command was used by the cmd
2486          * parameter.
2487          */
2488
2489         /* we must have a module name */
2490         if (!param)
2491                 return ret;
2492
2493         mod = strsep(&param, ":");
2494         if (!strlen(mod))
2495                 return ret;
2496
2497         ret = ftrace_match_module_records(hash, func, mod);
2498         if (!ret)
2499                 ret = -EINVAL;
2500         if (ret < 0)
2501                 return ret;
2502
2503         return 0;
2504 }
2505
2506 static struct ftrace_func_command ftrace_mod_cmd = {
2507         .name                   = "mod",
2508         .func                   = ftrace_mod_callback,
2509 };
2510
2511 static int __init ftrace_mod_cmd_init(void)
2512 {
2513         return register_ftrace_command(&ftrace_mod_cmd);
2514 }
2515 device_initcall(ftrace_mod_cmd_init);
2516
2517 static void
2518 function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
2519 {
2520         struct ftrace_func_probe *entry;
2521         struct hlist_head *hhd;
2522         struct hlist_node *n;
2523         unsigned long key;
2524
2525         key = hash_long(ip, FTRACE_HASH_BITS);
2526
2527         hhd = &ftrace_func_hash[key];
2528
2529         if (hlist_empty(hhd))
2530                 return;
2531
2532         /*
2533          * Disable preemption for these calls to prevent a RCU grace
2534          * period. This syncs the hash iteration and freeing of items
2535          * on the hash. rcu_read_lock is too dangerous here.
2536          */
2537         preempt_disable_notrace();
2538         hlist_for_each_entry_rcu(entry, n, hhd, node) {
2539                 if (entry->ip == ip)
2540                         entry->ops->func(ip, parent_ip, &entry->data);
2541         }
2542         preempt_enable_notrace();
2543 }
2544
2545 static struct ftrace_ops trace_probe_ops __read_mostly =
2546 {
2547         .func           = function_trace_probe_call,
2548 };
2549
2550 static int ftrace_probe_registered;
2551
2552 static void __enable_ftrace_function_probe(void)
2553 {
2554         int ret;
2555         int i;
2556
2557         if (ftrace_probe_registered)
2558                 return;
2559
2560         for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2561                 struct hlist_head *hhd = &ftrace_func_hash[i];
2562                 if (hhd->first)
2563                         break;
2564         }
2565         /* Nothing registered? */
2566         if (i == FTRACE_FUNC_HASHSIZE)
2567                 return;
2568
2569         ret = __register_ftrace_function(&trace_probe_ops);
2570         if (!ret)
2571                 ret = ftrace_startup(&trace_probe_ops, 0);
2572
2573         ftrace_probe_registered = 1;
2574 }
2575
2576 static void __disable_ftrace_function_probe(void)
2577 {
2578         int ret;
2579         int i;
2580
2581         if (!ftrace_probe_registered)
2582                 return;
2583
2584         for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2585                 struct hlist_head *hhd = &ftrace_func_hash[i];
2586                 if (hhd->first)
2587                         return;
2588         }
2589
2590         /* no more funcs left */
2591         ret = __unregister_ftrace_function(&trace_probe_ops);
2592         if (!ret)
2593                 ftrace_shutdown(&trace_probe_ops, 0);
2594
2595         ftrace_probe_registered = 0;
2596 }
2597
2598
2599 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2600 {
2601         struct ftrace_func_probe *entry =
2602                 container_of(rhp, struct ftrace_func_probe, rcu);
2603
2604         if (entry->ops->free)
2605                 entry->ops->free(&entry->data);
2606         kfree(entry);
2607 }
2608
2609
2610 int
2611 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2612                               void *data)
2613 {
2614         struct ftrace_func_probe *entry;
2615         struct ftrace_page *pg;
2616         struct dyn_ftrace *rec;
2617         int type, len, not;
2618         unsigned long key;
2619         int count = 0;
2620         char *search;
2621
2622         type = filter_parse_regex(glob, strlen(glob), &search, &not);
2623         len = strlen(search);
2624
2625         /* we do not support '!' for function probes */
2626         if (WARN_ON(not))
2627                 return -EINVAL;
2628
2629         mutex_lock(&ftrace_lock);
2630
2631         if (unlikely(ftrace_disabled))
2632                 goto out_unlock;
2633
2634         do_for_each_ftrace_rec(pg, rec) {
2635
2636                 if (!ftrace_match_record(rec, NULL, search, len, type))
2637                         continue;
2638
2639                 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2640                 if (!entry) {
2641                         /* If we did not process any, then return error */
2642                         if (!count)
2643                                 count = -ENOMEM;
2644                         goto out_unlock;
2645                 }
2646
2647                 count++;
2648
2649                 entry->data = data;
2650
2651                 /*
2652                  * The caller might want to do something special
2653                  * for each function we find. We call the callback
2654                  * to give the caller an opportunity to do so.
2655                  */
2656                 if (ops->callback) {
2657                         if (ops->callback(rec->ip, &entry->data) < 0) {
2658                                 /* caller does not like this func */
2659                                 kfree(entry);
2660                                 continue;
2661                         }
2662                 }
2663
2664                 entry->ops = ops;
2665                 entry->ip = rec->ip;
2666
2667                 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2668                 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2669
2670         } while_for_each_ftrace_rec();
2671         __enable_ftrace_function_probe();
2672
2673  out_unlock:
2674         mutex_unlock(&ftrace_lock);
2675
2676         return count;
2677 }
2678
2679 enum {
2680         PROBE_TEST_FUNC         = 1,
2681         PROBE_TEST_DATA         = 2
2682 };
2683
2684 static void
2685 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2686                                   void *data, int flags)
2687 {
2688         struct ftrace_func_probe *entry;
2689         struct hlist_node *n, *tmp;
2690         char str[KSYM_SYMBOL_LEN];
2691         int type = MATCH_FULL;
2692         int i, len = 0;
2693         char *search;
2694
2695         if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
2696                 glob = NULL;
2697         else if (glob) {
2698                 int not;
2699
2700                 type = filter_parse_regex(glob, strlen(glob), &search, &not);
2701                 len = strlen(search);
2702
2703                 /* we do not support '!' for function probes */
2704                 if (WARN_ON(not))
2705                         return;
2706         }
2707
2708         mutex_lock(&ftrace_lock);
2709         for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2710                 struct hlist_head *hhd = &ftrace_func_hash[i];
2711
2712                 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2713
2714                         /* break up if statements for readability */
2715                         if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
2716                                 continue;
2717
2718                         if ((flags & PROBE_TEST_DATA) && entry->data != data)
2719                                 continue;
2720
2721                         /* do this last, since it is the most expensive */
2722                         if (glob) {
2723                                 kallsyms_lookup(entry->ip, NULL, NULL,
2724                                                 NULL, str);
2725                                 if (!ftrace_match(str, glob, len, type))
2726                                         continue;
2727                         }
2728
2729                         hlist_del(&entry->node);
2730                         call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2731                 }
2732         }
2733         __disable_ftrace_function_probe();
2734         mutex_unlock(&ftrace_lock);
2735 }
2736
2737 void
2738 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2739                                 void *data)
2740 {
2741         __unregister_ftrace_function_probe(glob, ops, data,
2742                                           PROBE_TEST_FUNC | PROBE_TEST_DATA);
2743 }
2744
2745 void
2746 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
2747 {
2748         __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
2749 }
2750
2751 void unregister_ftrace_function_probe_all(char *glob)
2752 {
2753         __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
2754 }
2755
2756 static LIST_HEAD(ftrace_commands);
2757 static DEFINE_MUTEX(ftrace_cmd_mutex);
2758
2759 int register_ftrace_command(struct ftrace_func_command *cmd)
2760 {
2761         struct ftrace_func_command *p;
2762         int ret = 0;
2763
2764         mutex_lock(&ftrace_cmd_mutex);
2765         list_for_each_entry(p, &ftrace_commands, list) {
2766                 if (strcmp(cmd->name, p->name) == 0) {
2767                         ret = -EBUSY;
2768                         goto out_unlock;
2769                 }
2770         }
2771         list_add(&cmd->list, &ftrace_commands);
2772  out_unlock:
2773         mutex_unlock(&ftrace_cmd_mutex);
2774
2775         return ret;
2776 }
2777
2778 int unregister_ftrace_command(struct ftrace_func_command *cmd)
2779 {
2780         struct ftrace_func_command *p, *n;
2781         int ret = -ENODEV;
2782
2783         mutex_lock(&ftrace_cmd_mutex);
2784         list_for_each_entry_safe(p, n, &ftrace_commands, list) {
2785                 if (strcmp(cmd->name, p->name) == 0) {
2786                         ret = 0;
2787                         list_del_init(&p->list);
2788                         goto out_unlock;
2789                 }
2790         }
2791  out_unlock:
2792         mutex_unlock(&ftrace_cmd_mutex);
2793
2794         return ret;
2795 }
2796
2797 static int ftrace_process_regex(struct ftrace_hash *hash,
2798                                 char *buff, int len, int enable)
2799 {
2800         char *func, *command, *next = buff;
2801         struct ftrace_func_command *p;
2802         int ret = -EINVAL;
2803
2804         func = strsep(&next, ":");
2805
2806         if (!next) {
2807                 ret = ftrace_match_records(hash, func, len);
2808                 if (!ret)
2809                         ret = -EINVAL;
2810                 if (ret < 0)
2811                         return ret;
2812                 return 0;
2813         }
2814
2815         /* command found */
2816
2817         command = strsep(&next, ":");
2818
2819         mutex_lock(&ftrace_cmd_mutex);
2820         list_for_each_entry(p, &ftrace_commands, list) {
2821                 if (strcmp(p->name, command) == 0) {
2822                         ret = p->func(hash, func, command, next, enable);
2823                         goto out_unlock;
2824                 }
2825         }
2826  out_unlock:
2827         mutex_unlock(&ftrace_cmd_mutex);
2828
2829         return ret;
2830 }
2831
2832 static ssize_t
2833 ftrace_regex_write(struct file *file, const char __user *ubuf,
2834                    size_t cnt, loff_t *ppos, int enable)
2835 {
2836         struct ftrace_iterator *iter;
2837         struct trace_parser *parser;
2838         ssize_t ret, read;
2839
2840         if (!cnt)
2841                 return 0;
2842
2843         mutex_lock(&ftrace_regex_lock);
2844
2845         ret = -ENODEV;
2846         if (unlikely(ftrace_disabled))
2847                 goto out_unlock;
2848
2849         if (file->f_mode & FMODE_READ) {
2850                 struct seq_file *m = file->private_data;
2851                 iter = m->private;
2852         } else
2853                 iter = file->private_data;
2854
2855         parser = &iter->parser;
2856         read = trace_get_user(parser, ubuf, cnt, ppos);
2857
2858         if (read >= 0 && trace_parser_loaded(parser) &&
2859             !trace_parser_cont(parser)) {
2860                 ret = ftrace_process_regex(iter->hash, parser->buffer,
2861                                            parser->idx, enable);
2862                 trace_parser_clear(parser);
2863                 if (ret)
2864                         goto out_unlock;
2865         }
2866
2867         ret = read;
2868 out_unlock:
2869         mutex_unlock(&ftrace_regex_lock);
2870
2871         return ret;
2872 }
2873
2874 static ssize_t
2875 ftrace_filter_write(struct file *file, const char __user *ubuf,
2876                     size_t cnt, loff_t *ppos)
2877 {
2878         return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
2879 }
2880
2881 static ssize_t
2882 ftrace_notrace_write(struct file *file, const char __user *ubuf,
2883                      size_t cnt, loff_t *ppos)
2884 {
2885         return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
2886 }
2887
2888 static int
2889 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
2890                  int reset, int enable)
2891 {
2892         struct ftrace_hash **orig_hash;
2893         struct ftrace_hash *hash;
2894         int ret;
2895
2896         /* All global ops uses the global ops filters */
2897         if (ops->flags & FTRACE_OPS_FL_GLOBAL)
2898                 ops = &global_ops;
2899
2900         if (unlikely(ftrace_disabled))
2901                 return -ENODEV;
2902
2903         if (enable)
2904                 orig_hash = &ops->filter_hash;
2905         else
2906                 orig_hash = &ops->notrace_hash;
2907
2908         hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
2909         if (!hash)
2910                 return -ENOMEM;
2911
2912         mutex_lock(&ftrace_regex_lock);
2913         if (reset)
2914                 ftrace_filter_reset(hash);
2915         if (buf)
2916                 ftrace_match_records(hash, buf, len);
2917
2918         mutex_lock(&ftrace_lock);
2919         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
2920         if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
2921             && ftrace_enabled)
2922                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
2923
2924         mutex_unlock(&ftrace_lock);
2925
2926         mutex_unlock(&ftrace_regex_lock);
2927
2928         free_ftrace_hash(hash);
2929         return ret;
2930 }
2931
2932 /**
2933  * ftrace_set_filter - set a function to filter on in ftrace
2934  * @ops - the ops to set the filter with
2935  * @buf - the string that holds the function filter text.
2936  * @len - the length of the string.
2937  * @reset - non zero to reset all filters before applying this filter.
2938  *
2939  * Filters denote which functions should be enabled when tracing is enabled.
2940  * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2941  */
2942 void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
2943                        int len, int reset)
2944 {
2945         ftrace_set_regex(ops, buf, len, reset, 1);
2946 }
2947 EXPORT_SYMBOL_GPL(ftrace_set_filter);
2948
2949 /**
2950  * ftrace_set_notrace - set a function to not trace in ftrace
2951  * @ops - the ops to set the notrace filter with
2952  * @buf - the string that holds the function notrace text.
2953  * @len - the length of the string.
2954  * @reset - non zero to reset all filters before applying this filter.
2955  *
2956  * Notrace Filters denote which functions should not be enabled when tracing
2957  * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2958  * for tracing.
2959  */
2960 void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
2961                         int len, int reset)
2962 {
2963         ftrace_set_regex(ops, buf, len, reset, 0);
2964 }
2965 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
2966 /**
2967  * ftrace_set_filter - set a function to filter on in ftrace
2968  * @ops - the ops to set the filter with
2969  * @buf - the string that holds the function filter text.
2970  * @len - the length of the string.
2971  * @reset - non zero to reset all filters before applying this filter.
2972  *
2973  * Filters denote which functions should be enabled when tracing is enabled.
2974  * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2975  */
2976 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
2977 {
2978         ftrace_set_regex(&global_ops, buf, len, reset, 1);
2979 }
2980 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
2981
2982 /**
2983  * ftrace_set_notrace - set a function to not trace in ftrace
2984  * @ops - the ops to set the notrace filter with
2985  * @buf - the string that holds the function notrace text.
2986  * @len - the length of the string.
2987  * @reset - non zero to reset all filters before applying this filter.
2988  *
2989  * Notrace Filters denote which functions should not be enabled when tracing
2990  * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2991  * for tracing.
2992  */
2993 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
2994 {
2995         ftrace_set_regex(&global_ops, buf, len, reset, 0);
2996 }
2997 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
2998
2999 /*
3000  * command line interface to allow users to set filters on boot up.
3001  */
3002 #define FTRACE_FILTER_SIZE              COMMAND_LINE_SIZE
3003 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3004 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3005
3006 static int __init set_ftrace_notrace(char *str)
3007 {
3008         strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3009         return 1;
3010 }
3011 __setup("ftrace_notrace=", set_ftrace_notrace);
3012
3013 static int __init set_ftrace_filter(char *str)
3014 {
3015         strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3016         return 1;
3017 }
3018 __setup("ftrace_filter=", set_ftrace_filter);
3019
3020 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3021 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3022 static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3023
3024 static int __init set_graph_function(char *str)
3025 {
3026         strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3027         return 1;
3028 }
3029 __setup("ftrace_graph_filter=", set_graph_function);
3030
3031 static void __init set_ftrace_early_graph(char *buf)
3032 {
3033         int ret;
3034         char *func;
3035
3036         while (buf) {
3037                 func = strsep(&buf, ",");
3038                 /* we allow only one expression at a time */
3039                 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3040                                       func);
3041                 if (ret)
3042                         printk(KERN_DEBUG "ftrace: function %s not "
3043                                           "traceable\n", func);
3044         }
3045 }
3046 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3047
3048 static void __init
3049 set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
3050 {
3051         char *func;
3052
3053         while (buf) {
3054                 func = strsep(&buf, ",");
3055                 ftrace_set_regex(ops, func, strlen(func), 0, enable);
3056         }
3057 }
3058
3059 static void __init set_ftrace_early_filters(void)
3060 {
3061         if (ftrace_filter_buf[0])
3062                 set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1);
3063         if (ftrace_notrace_buf[0])
3064                 set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0);
3065 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3066         if (ftrace_graph_buf[0])
3067                 set_ftrace_early_graph(ftrace_graph_buf);
3068 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3069 }
3070
3071 static int
3072 ftrace_regex_release(struct inode *inode, struct file *file)
3073 {
3074         struct seq_file *m = (struct seq_file *)file->private_data;
3075         struct ftrace_iterator *iter;
3076         struct ftrace_hash **orig_hash;
3077         struct trace_parser *parser;
3078         int filter_hash;
3079         int ret;
3080
3081         mutex_lock(&ftrace_regex_lock);
3082         if (file->f_mode & FMODE_READ) {
3083                 iter = m->private;
3084
3085                 seq_release(inode, file);
3086         } else
3087                 iter = file->private_data;
3088
3089         parser = &iter->parser;
3090         if (trace_parser_loaded(parser)) {
3091                 parser->buffer[parser->idx] = 0;
3092                 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3093         }
3094
3095         trace_parser_put(parser);
3096
3097         if (file->f_mode & FMODE_WRITE) {
3098                 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3099
3100                 if (filter_hash)
3101                         orig_hash = &iter->ops->filter_hash;
3102                 else
3103                         orig_hash = &iter->ops->notrace_hash;
3104
3105                 mutex_lock(&ftrace_lock);
3106                 ret = ftrace_hash_move(iter->ops, filter_hash,
3107                                        orig_hash, iter->hash);
3108                 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
3109                     && ftrace_enabled)
3110                         ftrace_run_update_code(FTRACE_ENABLE_CALLS);
3111
3112                 mutex_unlock(&ftrace_lock);
3113         }
3114         free_ftrace_hash(iter->hash);
3115         kfree(iter);
3116
3117         mutex_unlock(&ftrace_regex_lock);
3118         return 0;
3119 }
3120
3121 static const struct file_operations ftrace_avail_fops = {
3122         .open = ftrace_avail_open,
3123         .read = seq_read,
3124         .llseek = seq_lseek,
3125         .release = seq_release_private,
3126 };
3127
3128 static const struct file_operations ftrace_enabled_fops = {
3129         .open = ftrace_enabled_open,
3130         .read = seq_read,
3131         .llseek = seq_lseek,
3132         .release = seq_release_private,
3133 };
3134
3135 static const struct file_operations ftrace_filter_fops = {
3136         .open = ftrace_filter_open,
3137         .read = seq_read,
3138         .write = ftrace_filter_write,
3139         .llseek = ftrace_regex_lseek,
3140         .release = ftrace_regex_release,
3141 };
3142
3143 static const struct file_operations ftrace_notrace_fops = {
3144         .open = ftrace_notrace_open,
3145         .read = seq_read,
3146         .write = ftrace_notrace_write,
3147         .llseek = ftrace_regex_lseek,
3148         .release = ftrace_regex_release,
3149 };
3150
3151 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3152
3153 static DEFINE_MUTEX(graph_lock);
3154
3155 int ftrace_graph_count;
3156 int ftrace_graph_filter_enabled;
3157 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3158
3159 static void *
3160 __g_next(struct seq_file *m, loff_t *pos)
3161 {
3162         if (*pos >= ftrace_graph_count)
3163                 return NULL;
3164         return &ftrace_graph_funcs[*pos];
3165 }
3166
3167 static void *
3168 g_next(struct seq_file *m, void *v, loff_t *pos)
3169 {
3170         (*pos)++;
3171         return __g_next(m, pos);
3172 }
3173
3174 static void *g_start(struct seq_file *m, loff_t *pos)
3175 {
3176         mutex_lock(&graph_lock);
3177
3178         /* Nothing, tell g_show to print all functions are enabled */
3179         if (!ftrace_graph_filter_enabled && !*pos)
3180                 return (void *)1;
3181
3182         return __g_next(m, pos);
3183 }
3184
3185 static void g_stop(struct seq_file *m, void *p)
3186 {
3187         mutex_unlock(&graph_lock);
3188 }
3189
3190 static int g_show(struct seq_file *m, void *v)
3191 {
3192         unsigned long *ptr = v;
3193
3194         if (!ptr)
3195                 return 0;
3196
3197         if (ptr == (unsigned long *)1) {
3198                 seq_printf(m, "#### all functions enabled ####\n");
3199                 return 0;
3200         }
3201
3202         seq_printf(m, "%ps\n", (void *)*ptr);
3203
3204         return 0;
3205 }
3206
3207 static const struct seq_operations ftrace_graph_seq_ops = {
3208         .start = g_start,
3209         .next = g_next,
3210         .stop = g_stop,
3211         .show = g_show,
3212 };
3213
3214 static int
3215 ftrace_graph_open(struct inode *inode, struct file *file)
3216 {
3217         int ret = 0;
3218
3219         if (unlikely(ftrace_disabled))
3220                 return -ENODEV;
3221
3222         mutex_lock(&graph_lock);
3223         if ((file->f_mode & FMODE_WRITE) &&
3224             (file->f_flags & O_TRUNC)) {
3225                 ftrace_graph_filter_enabled = 0;
3226                 ftrace_graph_count = 0;
3227                 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3228         }
3229         mutex_unlock(&graph_lock);
3230
3231         if (file->f_mode & FMODE_READ)
3232                 ret = seq_open(file, &ftrace_graph_seq_ops);
3233
3234         return ret;
3235 }
3236
3237 static int
3238 ftrace_graph_release(struct inode *inode, struct file *file)
3239 {
3240         if (file->f_mode & FMODE_READ)
3241                 seq_release(inode, file);
3242         return 0;
3243 }
3244
3245 static int
3246 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3247 {
3248         struct dyn_ftrace *rec;
3249         struct ftrace_page *pg;
3250         int search_len;
3251         int fail = 1;
3252         int type, not;
3253         char *search;
3254         bool exists;
3255         int i;
3256
3257         /* decode regex */
3258         type = filter_parse_regex(buffer, strlen(buffer), &search, &not);
3259         if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3260                 return -EBUSY;
3261
3262         search_len = strlen(search);
3263
3264         mutex_lock(&ftrace_lock);
3265
3266         if (unlikely(ftrace_disabled)) {
3267                 mutex_unlock(&ftrace_lock);
3268                 return -ENODEV;
3269         }
3270
3271         do_for_each_ftrace_rec(pg, rec) {
3272
3273                 if (rec->flags & FTRACE_FL_FREE)
3274                         continue;
3275
3276                 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3277                         /* if it is in the array */
3278                         exists = false;
3279                         for (i = 0; i < *idx; i++) {
3280                                 if (array[i] == rec->ip) {
3281                                         exists = true;
3282                                         break;
3283                                 }
3284                         }
3285
3286                         if (!not) {
3287                                 fail = 0;
3288                                 if (!exists) {
3289                                         array[(*idx)++] = rec->ip;
3290                                         if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3291                                                 goto out;
3292                                 }
3293                         } else {
3294                                 if (exists) {
3295                                         array[i] = array[--(*idx)];
3296                                         array[*idx] = 0;
3297                                         fail = 0;
3298                                 }
3299                         }
3300                 }
3301         } while_for_each_ftrace_rec();
3302 out:
3303         mutex_unlock(&ftrace_lock);
3304
3305         if (fail)
3306                 return -EINVAL;
3307
3308         ftrace_graph_filter_enabled = 1;
3309         return 0;
3310 }
3311
3312 static ssize_t
3313 ftrace_graph_write(struct file *file, const char __user *ubuf,
3314                    size_t cnt, loff_t *ppos)
3315 {
3316         struct trace_parser parser;
3317         ssize_t read, ret;
3318
3319         if (!cnt)
3320                 return 0;
3321
3322         mutex_lock(&graph_lock);
3323
3324         if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3325                 ret = -ENOMEM;
3326                 goto out_unlock;
3327         }
3328
3329         read = trace_get_user(&parser, ubuf, cnt, ppos);
3330
3331         if (read >= 0 && trace_parser_loaded((&parser))) {
3332                 parser.buffer[parser.idx] = 0;
3333
3334                 /* we allow only one expression at a time */
3335                 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3336                                         parser.buffer);
3337                 if (ret)
3338                         goto out_free;
3339         }
3340
3341         ret = read;
3342
3343 out_free:
3344         trace_parser_put(&parser);
3345 out_unlock:
3346         mutex_unlock(&graph_lock);
3347
3348         return ret;
3349 }
3350
3351 static const struct file_operations ftrace_graph_fops = {
3352         .open           = ftrace_graph_open,
3353         .read           = seq_read,
3354         .write          = ftrace_graph_write,
3355         .release        = ftrace_graph_release,
3356         .llseek         = seq_lseek,
3357 };
3358 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3359
3360 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3361 {
3362
3363         trace_create_file("available_filter_functions", 0444,
3364                         d_tracer, NULL, &ftrace_avail_fops);
3365
3366         trace_create_file("enabled_functions", 0444,
3367                         d_tracer, NULL, &ftrace_enabled_fops);
3368
3369         trace_create_file("set_ftrace_filter", 0644, d_tracer,
3370                         NULL, &ftrace_filter_fops);
3371
3372         trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3373                                     NULL, &ftrace_notrace_fops);
3374
3375 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3376         trace_create_file("set_graph_function", 0444, d_tracer,
3377                                     NULL,
3378                                     &ftrace_graph_fops);
3379 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3380
3381         return 0;
3382 }
3383
3384 static int ftrace_process_locs(struct module *mod,
3385                                unsigned long *start,
3386                                unsigned long *end)
3387 {
3388         unsigned long *p;
3389         unsigned long addr;
3390         unsigned long flags = 0; /* Shut up gcc */
3391
3392         mutex_lock(&ftrace_lock);
3393         p = start;
3394         while (p < end) {
3395                 addr = ftrace_call_adjust(*p++);
3396                 /*
3397                  * Some architecture linkers will pad between
3398                  * the different mcount_loc sections of different
3399                  * object files to satisfy alignments.
3400                  * Skip any NULL pointers.
3401                  */
3402                 if (!addr)
3403                         continue;
3404                 ftrace_record_ip(addr);
3405         }
3406
3407         /*
3408          * We only need to disable interrupts on start up
3409          * because we are modifying code that an interrupt
3410          * may execute, and the modification is not atomic.
3411          * But for modules, nothing runs the code we modify
3412          * until we are finished with it, and there's no
3413          * reason to cause large interrupt latencies while we do it.
3414          */
3415         if (!mod)
3416                 local_irq_save(flags);
3417         ftrace_update_code(mod);
3418         if (!mod)
3419                 local_irq_restore(flags);
3420         mutex_unlock(&ftrace_lock);
3421
3422         return 0;
3423 }
3424
3425 #ifdef CONFIG_MODULES
3426 void ftrace_release_mod(struct module *mod)
3427 {
3428         struct dyn_ftrace *rec;
3429         struct ftrace_page *pg;
3430
3431         mutex_lock(&ftrace_lock);
3432
3433         if (ftrace_disabled)
3434                 goto out_unlock;
3435
3436         do_for_each_ftrace_rec(pg, rec) {
3437                 if (within_module_core(rec->ip, mod)) {
3438                         /*
3439                          * rec->ip is changed in ftrace_free_rec()
3440                          * It should not between s and e if record was freed.
3441                          */
3442                         FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
3443                         ftrace_free_rec(rec);
3444                 }
3445         } while_for_each_ftrace_rec();
3446  out_unlock:
3447         mutex_unlock(&ftrace_lock);
3448 }
3449
3450 static void ftrace_init_module(struct module *mod,
3451                                unsigned long *start, unsigned long *end)
3452 {
3453         if (ftrace_disabled || start == end)
3454                 return;
3455         ftrace_process_locs(mod, start, end);
3456 }
3457
3458 static int ftrace_module_notify(struct notifier_block *self,
3459                                 unsigned long val, void *data)
3460 {
3461         struct module *mod = data;
3462
3463         switch (val) {
3464         case MODULE_STATE_COMING:
3465                 ftrace_init_module(mod, mod->ftrace_callsites,
3466                                    mod->ftrace_callsites +
3467                                    mod->num_ftrace_callsites);
3468                 break;
3469         case MODULE_STATE_GOING:
3470                 ftrace_release_mod(mod);
3471                 break;
3472         }
3473
3474         return 0;
3475 }
3476 #else
3477 static int ftrace_module_notify(struct notifier_block *self,
3478                                 unsigned long val, void *data)
3479 {
3480         return 0;
3481 }
3482 #endif /* CONFIG_MODULES */
3483
3484 struct notifier_block ftrace_module_nb = {
3485         .notifier_call = ftrace_module_notify,
3486         .priority = 0,
3487 };
3488
3489 extern unsigned long __start_mcount_loc[];
3490 extern unsigned long __stop_mcount_loc[];
3491
3492 void __init ftrace_init(void)
3493 {
3494         unsigned long count, addr, flags;
3495         int ret;
3496
3497         /* Keep the ftrace pointer to the stub */
3498         addr = (unsigned long)ftrace_stub;
3499
3500         local_irq_save(flags);
3501         ftrace_dyn_arch_init(&addr);
3502         local_irq_restore(flags);
3503
3504         /* ftrace_dyn_arch_init places the return code in addr */
3505         if (addr)
3506                 goto failed;
3507
3508         count = __stop_mcount_loc - __start_mcount_loc;
3509
3510         ret = ftrace_dyn_table_alloc(count);
3511         if (ret)
3512                 goto failed;
3513
3514         last_ftrace_enabled = ftrace_enabled = 1;
3515
3516         ret = ftrace_process_locs(NULL,
3517                                   __start_mcount_loc,
3518                                   __stop_mcount_loc);
3519
3520         ret = register_module_notifier(&ftrace_module_nb);
3521         if (ret)
3522                 pr_warning("Failed to register trace ftrace module notifier\n");
3523
3524         set_ftrace_early_filters();
3525
3526         return;
3527  failed:
3528         ftrace_disabled = 1;
3529 }
3530
3531 #else
3532
3533 static struct ftrace_ops global_ops = {
3534         .func                   = ftrace_stub,
3535 };
3536
3537 static int __init ftrace_nodyn_init(void)
3538 {
3539         ftrace_enabled = 1;
3540         return 0;
3541 }
3542 device_initcall(ftrace_nodyn_init);
3543
3544 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
3545 static inline void ftrace_startup_enable(int command) { }
3546 /* Keep as macros so we do not need to define the commands */
3547 # define ftrace_startup(ops, command)                   \
3548         ({                                              \
3549                 (ops)->flags |= FTRACE_OPS_FL_ENABLED;  \
3550                 0;                                      \
3551         })
3552 # define ftrace_shutdown(ops, command)  do { } while (0)
3553 # define ftrace_startup_sysctl()        do { } while (0)
3554 # define ftrace_shutdown_sysctl()       do { } while (0)
3555
3556 static inline int
3557 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
3558 {
3559         return 1;
3560 }
3561
3562 #endif /* CONFIG_DYNAMIC_FTRACE */
3563
3564 static void
3565 ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
3566 {
3567         struct ftrace_ops *op;
3568
3569         if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
3570                 return;
3571
3572         trace_recursion_set(TRACE_INTERNAL_BIT);
3573         /*
3574          * Some of the ops may be dynamically allocated,
3575          * they must be freed after a synchronize_sched().
3576          */
3577         preempt_disable_notrace();
3578         op = rcu_dereference_raw(ftrace_ops_list);
3579         while (op != &ftrace_list_end) {
3580                 if (ftrace_ops_test(op, ip))
3581                         op->func(ip, parent_ip);
3582                 op = rcu_dereference_raw(op->next);
3583         };
3584         preempt_enable_notrace();
3585         trace_recursion_clear(TRACE_INTERNAL_BIT);
3586 }
3587
3588 static void clear_ftrace_swapper(void)
3589 {
3590         struct task_struct *p;
3591         int cpu;
3592
3593         get_online_cpus();
3594         for_each_online_cpu(cpu) {
3595                 p = idle_task(cpu);
3596                 clear_tsk_trace_trace(p);
3597         }
3598         put_online_cpus();
3599 }
3600
3601 static void set_ftrace_swapper(void)
3602 {
3603         struct task_struct *p;
3604         int cpu;
3605
3606         get_online_cpus();
3607         for_each_online_cpu(cpu) {
3608                 p = idle_task(cpu);
3609                 set_tsk_trace_trace(p);
3610         }
3611         put_online_cpus();
3612 }
3613
3614 static void clear_ftrace_pid(struct pid *pid)
3615 {
3616         struct task_struct *p;
3617
3618         rcu_read_lock();
3619         do_each_pid_task(pid, PIDTYPE_PID, p) {
3620                 clear_tsk_trace_trace(p);
3621         } while_each_pid_task(pid, PIDTYPE_PID, p);
3622         rcu_read_unlock();
3623
3624         put_pid(pid);
3625 }
3626
3627 static void set_ftrace_pid(struct pid *pid)
3628 {
3629         struct task_struct *p;
3630
3631         rcu_read_lock();
3632         do_each_pid_task(pid, PIDTYPE_PID, p) {
3633                 set_tsk_trace_trace(p);
3634         } while_each_pid_task(pid, PIDTYPE_PID, p);
3635         rcu_read_unlock();
3636 }
3637
3638 static void clear_ftrace_pid_task(struct pid *pid)
3639 {
3640         if (pid == ftrace_swapper_pid)
3641                 clear_ftrace_swapper();
3642         else
3643                 clear_ftrace_pid(pid);
3644 }
3645
3646 static void set_ftrace_pid_task(struct pid *pid)
3647 {
3648         if (pid == ftrace_swapper_pid)
3649                 set_ftrace_swapper();
3650         else
3651                 set_ftrace_pid(pid);
3652 }
3653
3654 static int ftrace_pid_add(int p)
3655 {
3656         struct pid *pid;
3657         struct ftrace_pid *fpid;
3658         int ret = -EINVAL;
3659
3660         mutex_lock(&ftrace_lock);
3661
3662         if (!p)
3663                 pid = ftrace_swapper_pid;
3664         else
3665                 pid = find_get_pid(p);
3666
3667         if (!pid)
3668                 goto out;
3669
3670         ret = 0;
3671
3672         list_for_each_entry(fpid, &ftrace_pids, list)
3673                 if (fpid->pid == pid)
3674                         goto out_put;
3675
3676         ret = -ENOMEM;
3677
3678         fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
3679         if (!fpid)
3680                 goto out_put;
3681
3682         list_add(&fpid->list, &ftrace_pids);
3683         fpid->pid = pid;
3684
3685         set_ftrace_pid_task(pid);
3686
3687         ftrace_update_pid_func();
3688         ftrace_startup_enable(0);
3689
3690         mutex_unlock(&ftrace_lock);
3691         return 0;
3692
3693 out_put:
3694         if (pid != ftrace_swapper_pid)
3695                 put_pid(pid);
3696
3697 out:
3698         mutex_unlock(&ftrace_lock);
3699         return ret;
3700 }
3701
3702 static void ftrace_pid_reset(void)
3703 {
3704         struct ftrace_pid *fpid, *safe;
3705
3706         mutex_lock(&ftrace_lock);
3707         list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
3708                 struct pid *pid = fpid->pid;
3709
3710                 clear_ftrace_pid_task(pid);
3711
3712                 list_del(&fpid->list);
3713                 kfree(fpid);
3714         }
3715
3716         ftrace_update_pid_func();
3717         ftrace_startup_enable(0);
3718
3719         mutex_unlock(&ftrace_lock);
3720 }
3721
3722 static void *fpid_start(struct seq_file *m, loff_t *pos)
3723 {
3724         mutex_lock(&ftrace_lock);
3725
3726         if (list_empty(&ftrace_pids) && (!*pos))
3727                 return (void *) 1;
3728
3729         return seq_list_start(&ftrace_pids, *pos);
3730 }
3731
3732 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
3733 {
3734         if (v == (void *)1)
3735                 return NULL;
3736
3737         return seq_list_next(v, &ftrace_pids, pos);
3738 }
3739
3740 static void fpid_stop(struct seq_file *m, void *p)
3741 {
3742         mutex_unlock(&ftrace_lock);
3743 }
3744
3745 static int fpid_show(struct seq_file *m, void *v)
3746 {
3747         const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
3748
3749         if (v == (void *)1) {
3750                 seq_printf(m, "no pid\n");
3751                 return 0;
3752         }
3753
3754         if (fpid->pid == ftrace_swapper_pid)
3755                 seq_printf(m, "swapper tasks\n");
3756         else
3757                 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
3758
3759         return 0;
3760 }
3761
3762 static const struct seq_operations ftrace_pid_sops = {
3763         .start = fpid_start,
3764         .next = fpid_next,
3765         .stop = fpid_stop,
3766         .show = fpid_show,
3767 };
3768
3769 static int
3770 ftrace_pid_open(struct inode *inode, struct file *file)
3771 {
3772         int ret = 0;
3773
3774         if ((file->f_mode & FMODE_WRITE) &&
3775             (file->f_flags & O_TRUNC))
3776                 ftrace_pid_reset();
3777
3778         if (file->f_mode & FMODE_READ)
3779                 ret = seq_open(file, &ftrace_pid_sops);
3780
3781         return ret;
3782 }
3783
3784 static ssize_t
3785 ftrace_pid_write(struct file *filp, const char __user *ubuf,
3786                    size_t cnt, loff_t *ppos)
3787 {
3788         char buf[64], *tmp;
3789         long val;
3790         int ret;
3791
3792         if (cnt >= sizeof(buf))
3793                 return -EINVAL;
3794
3795         if (copy_from_user(&buf, ubuf, cnt))
3796                 return -EFAULT;
3797
3798         buf[cnt] = 0;
3799
3800         /*
3801          * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
3802          * to clean the filter quietly.
3803          */
3804         tmp = strstrip(buf);
3805         if (strlen(tmp) == 0)
3806                 return 1;
3807
3808         ret = strict_strtol(tmp, 10, &val);
3809         if (ret < 0)
3810                 return ret;
3811
3812         ret = ftrace_pid_add(val);
3813
3814         return ret ? ret : cnt;
3815 }
3816
3817 static int
3818 ftrace_pid_release(struct inode *inode, struct file *file)
3819 {
3820         if (file->f_mode & FMODE_READ)
3821                 seq_release(inode, file);
3822
3823         return 0;
3824 }
3825
3826 static const struct file_operations ftrace_pid_fops = {
3827         .open           = ftrace_pid_open,
3828         .write          = ftrace_pid_write,
3829         .read           = seq_read,
3830         .llseek         = seq_lseek,
3831         .release        = ftrace_pid_release,
3832 };
3833
3834 static __init int ftrace_init_debugfs(void)
3835 {
3836         struct dentry *d_tracer;
3837
3838         d_tracer = tracing_init_dentry();
3839         if (!d_tracer)
3840                 return 0;
3841
3842         ftrace_init_dyn_debugfs(d_tracer);
3843
3844         trace_create_file("set_ftrace_pid", 0644, d_tracer,
3845                             NULL, &ftrace_pid_fops);
3846
3847         ftrace_profile_debugfs(d_tracer);
3848
3849         return 0;
3850 }
3851 fs_initcall(ftrace_init_debugfs);
3852
3853 /**
3854  * ftrace_kill - kill ftrace
3855  *
3856  * This function should be used by panic code. It stops ftrace
3857  * but in a not so nice way. If you need to simply kill ftrace
3858  * from a non-atomic section, use ftrace_kill.
3859  */
3860 void ftrace_kill(void)
3861 {
3862         ftrace_disabled = 1;
3863         ftrace_enabled = 0;
3864         clear_ftrace_function();
3865 }
3866
3867 /**
3868  * Test if ftrace is dead or not.
3869  */
3870 int ftrace_is_dead(void)
3871 {
3872         return ftrace_disabled;
3873 }
3874
3875 /**
3876  * register_ftrace_function - register a function for profiling
3877  * @ops - ops structure that holds the function for profiling.
3878  *
3879  * Register a function to be called by all functions in the
3880  * kernel.
3881  *
3882  * Note: @ops->func and all the functions it calls must be labeled
3883  *       with "notrace", otherwise it will go into a
3884  *       recursive loop.
3885  */
3886 int register_ftrace_function(struct ftrace_ops *ops)
3887 {
3888         int ret = -1;
3889
3890         mutex_lock(&ftrace_lock);
3891
3892         if (unlikely(ftrace_disabled))
3893                 goto out_unlock;
3894
3895         ret = __register_ftrace_function(ops);
3896         if (!ret)
3897                 ret = ftrace_startup(ops, 0);
3898
3899
3900  out_unlock:
3901         mutex_unlock(&ftrace_lock);
3902         return ret;
3903 }
3904 EXPORT_SYMBOL_GPL(register_ftrace_function);
3905
3906 /**
3907  * unregister_ftrace_function - unregister a function for profiling.
3908  * @ops - ops structure that holds the function to unregister
3909  *
3910  * Unregister a function that was added to be called by ftrace profiling.
3911  */
3912 int unregister_ftrace_function(struct ftrace_ops *ops)
3913 {
3914         int ret;
3915
3916         mutex_lock(&ftrace_lock);
3917         ret = __unregister_ftrace_function(ops);
3918         if (!ret)
3919                 ftrace_shutdown(ops, 0);
3920         mutex_unlock(&ftrace_lock);
3921
3922         return ret;
3923 }
3924 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
3925
3926 int
3927 ftrace_enable_sysctl(struct ctl_table *table, int write,
3928                      void __user *buffer, size_t *lenp,
3929                      loff_t *ppos)
3930 {
3931         int ret = -ENODEV;
3932
3933         mutex_lock(&ftrace_lock);
3934
3935         if (unlikely(ftrace_disabled))
3936                 goto out;
3937
3938         ret = proc_dointvec(table, write, buffer, lenp, ppos);
3939
3940         if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
3941                 goto out;
3942
3943         last_ftrace_enabled = !!ftrace_enabled;
3944
3945         if (ftrace_enabled) {
3946
3947                 ftrace_startup_sysctl();
3948
3949                 /* we are starting ftrace again */
3950                 if (ftrace_ops_list != &ftrace_list_end) {
3951                         if (ftrace_ops_list->next == &ftrace_list_end)
3952                                 ftrace_trace_function = ftrace_ops_list->func;
3953                         else
3954                                 ftrace_trace_function = ftrace_ops_list_func;
3955                 }
3956
3957         } else {
3958                 /* stopping ftrace calls (just send to ftrace_stub) */
3959                 ftrace_trace_function = ftrace_stub;
3960
3961                 ftrace_shutdown_sysctl();
3962         }
3963
3964  out:
3965         mutex_unlock(&ftrace_lock);
3966         return ret;
3967 }
3968
3969 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3970
3971 static int ftrace_graph_active;
3972 static struct notifier_block ftrace_suspend_notifier;
3973
3974 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
3975 {
3976         return 0;
3977 }
3978
3979 /* The callbacks that hook a function */
3980 trace_func_graph_ret_t ftrace_graph_return =
3981                         (trace_func_graph_ret_t)ftrace_stub;
3982 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
3983
3984 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3985 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
3986 {
3987         int i;
3988         int ret = 0;
3989         unsigned long flags;
3990         int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
3991         struct task_struct *g, *t;
3992
3993         for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
3994                 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
3995                                         * sizeof(struct ftrace_ret_stack),
3996                                         GFP_KERNEL);
3997                 if (!ret_stack_list[i]) {
3998                         start = 0;
3999                         end = i;
4000                         ret = -ENOMEM;
4001                         goto free;
4002                 }
4003         }
4004
4005         read_lock_irqsave(&tasklist_lock, flags);
4006         do_each_thread(g, t) {
4007                 if (start == end) {
4008                         ret = -EAGAIN;
4009                         goto unlock;
4010                 }
4011
4012                 if (t->ret_stack == NULL) {
4013                         atomic_set(&t->tracing_graph_pause, 0);
4014                         atomic_set(&t->trace_overrun, 0);
4015                         t->curr_ret_stack = -1;
4016                         /* Make sure the tasks see the -1 first: */
4017                         smp_wmb();
4018                         t->ret_stack = ret_stack_list[start++];
4019                 }
4020         } while_each_thread(g, t);
4021
4022 unlock:
4023         read_unlock_irqrestore(&tasklist_lock, flags);
4024 free:
4025         for (i = start; i < end; i++)
4026                 kfree(ret_stack_list[i]);
4027         return ret;
4028 }
4029
4030 static void
4031 ftrace_graph_probe_sched_switch(void *ignore,
4032                         struct task_struct *prev, struct task_struct *next)
4033 {
4034         unsigned long long timestamp;
4035         int index;
4036
4037         /*
4038          * Does the user want to count the time a function was asleep.
4039          * If so, do not update the time stamps.
4040          */
4041         if (trace_flags & TRACE_ITER_SLEEP_TIME)
4042                 return;
4043
4044         timestamp = trace_clock_local();
4045
4046         prev->ftrace_timestamp = timestamp;
4047
4048         /* only process tasks that we timestamped */
4049         if (!next->ftrace_timestamp)
4050                 return;
4051
4052         /*
4053          * Update all the counters in next to make up for the
4054          * time next was sleeping.
4055          */
4056         timestamp -= next->ftrace_timestamp;
4057
4058         for (index = next->curr_ret_stack; index >= 0; index--)
4059                 next->ret_stack[index].calltime += timestamp;
4060 }
4061
4062 /* Allocate a return stack for each task */
4063 static int start_graph_tracing(void)
4064 {
4065         struct ftrace_ret_stack **ret_stack_list;
4066         int ret, cpu;
4067
4068         ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4069                                 sizeof(struct ftrace_ret_stack *),
4070                                 GFP_KERNEL);
4071
4072         if (!ret_stack_list)
4073                 return -ENOMEM;
4074
4075         /* The cpu_boot init_task->ret_stack will never be freed */
4076         for_each_online_cpu(cpu) {
4077                 if (!idle_task(cpu)->ret_stack)
4078                         ftrace_graph_init_idle_task(idle_task(cpu), cpu);
4079         }
4080
4081         do {
4082                 ret = alloc_retstack_tasklist(ret_stack_list);
4083         } while (ret == -EAGAIN);
4084
4085         if (!ret) {
4086                 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4087                 if (ret)
4088                         pr_info("ftrace_graph: Couldn't activate tracepoint"
4089                                 " probe to kernel_sched_switch\n");
4090         }
4091
4092         kfree(ret_stack_list);
4093         return ret;
4094 }
4095
4096 /*
4097  * Hibernation protection.
4098  * The state of the current task is too much unstable during
4099  * suspend/restore to disk. We want to protect against that.
4100  */
4101 static int
4102 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4103                                                         void *unused)
4104 {
4105         switch (state) {
4106         case PM_HIBERNATION_PREPARE:
4107                 pause_graph_tracing();
4108                 break;
4109
4110         case PM_POST_HIBERNATION:
4111                 unpause_graph_tracing();
4112                 break;
4113         }
4114         return NOTIFY_DONE;
4115 }
4116
4117 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4118                         trace_func_graph_ent_t entryfunc)
4119 {
4120         int ret = 0;
4121
4122         mutex_lock(&ftrace_lock);
4123
4124         /* we currently allow only one tracer registered at a time */
4125         if (ftrace_graph_active) {
4126                 ret = -EBUSY;
4127                 goto out;
4128         }
4129
4130         ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4131         register_pm_notifier(&ftrace_suspend_notifier);
4132
4133         ftrace_graph_active++;
4134         ret = start_graph_tracing();
4135         if (ret) {
4136                 ftrace_graph_active--;
4137                 goto out;
4138         }
4139
4140         ftrace_graph_return = retfunc;
4141         ftrace_graph_entry = entryfunc;
4142
4143         ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4144
4145 out:
4146         mutex_unlock(&ftrace_lock);
4147         return ret;
4148 }
4149
4150 void unregister_ftrace_graph(void)
4151 {
4152         mutex_lock(&ftrace_lock);
4153
4154         if (unlikely(!ftrace_graph_active))
4155                 goto out;
4156
4157         ftrace_graph_active--;
4158         ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4159         ftrace_graph_entry = ftrace_graph_entry_stub;
4160         ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4161         unregister_pm_notifier(&ftrace_suspend_notifier);
4162         unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4163
4164  out:
4165         mutex_unlock(&ftrace_lock);
4166 }
4167
4168 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4169
4170 static void
4171 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4172 {
4173         atomic_set(&t->tracing_graph_pause, 0);
4174         atomic_set(&t->trace_overrun, 0);
4175         t->ftrace_timestamp = 0;
4176         /* make curr_ret_stack visible before we add the ret_stack */
4177         smp_wmb();
4178         t->ret_stack = ret_stack;
4179 }
4180
4181 /*
4182  * Allocate a return stack for the idle task. May be the first
4183  * time through, or it may be done by CPU hotplug online.
4184  */
4185 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4186 {
4187         t->curr_ret_stack = -1;
4188         /*
4189          * The idle task has no parent, it either has its own
4190          * stack or no stack at all.
4191          */
4192         if (t->ret_stack)
4193                 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4194
4195         if (ftrace_graph_active) {
4196                 struct ftrace_ret_stack *ret_stack;
4197
4198                 ret_stack = per_cpu(idle_ret_stack, cpu);
4199                 if (!ret_stack) {
4200                         ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4201                                             * sizeof(struct ftrace_ret_stack),
4202                                             GFP_KERNEL);
4203                         if (!ret_stack)
4204                                 return;
4205                         per_cpu(idle_ret_stack, cpu) = ret_stack;
4206                 }
4207                 graph_init_task(t, ret_stack);
4208         }
4209 }
4210
4211 /* Allocate a return stack for newly created task */
4212 void ftrace_graph_init_task(struct task_struct *t)
4213 {
4214         /* Make sure we do not use the parent ret_stack */
4215         t->ret_stack = NULL;
4216         t->curr_ret_stack = -1;
4217
4218         if (ftrace_graph_active) {
4219                 struct ftrace_ret_stack *ret_stack;
4220
4221                 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4222                                 * sizeof(struct ftrace_ret_stack),
4223                                 GFP_KERNEL);
4224                 if (!ret_stack)
4225                         return;
4226                 graph_init_task(t, ret_stack);
4227         }
4228 }
4229
4230 void ftrace_graph_exit_task(struct task_struct *t)
4231 {
4232         struct ftrace_ret_stack *ret_stack = t->ret_stack;
4233
4234         t->ret_stack = NULL;
4235         /* NULL must become visible to IRQs before we free it: */
4236         barrier();
4237
4238         kfree(ret_stack);
4239 }
4240
4241 void ftrace_graph_stop(void)
4242 {
4243         ftrace_stop();
4244 }
4245 #endif