linux/kernel/trace/trace_output.c
<<
>>
Prefs
   1/*
   2 * trace_output.c
   3 *
   4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   5 *
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/mutex.h>
  10#include <linux/ftrace.h>
  11
  12#include "trace_output.h"
  13
  14/* must be a power of 2 */
  15#define EVENT_HASHSIZE  128
  16
  17DECLARE_RWSEM(trace_event_mutex);
  18
  19static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  20
  21static int next_event_type = __TRACE_LAST_TYPE + 1;
  22
  23int trace_print_seq(struct seq_file *m, struct trace_seq *s)
  24{
  25        int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
  26        int ret;
  27
  28        ret = seq_write(m, s->buffer, len);
  29
  30        /*
  31         * Only reset this buffer if we successfully wrote to the
  32         * seq_file buffer.
  33         */
  34        if (!ret)
  35                trace_seq_init(s);
  36
  37        return ret;
  38}
  39
  40enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  41{
  42        struct trace_seq *s = &iter->seq;
  43        struct trace_entry *entry = iter->ent;
  44        struct bprint_entry *field;
  45        int ret;
  46
  47        trace_assign_type(field, entry);
  48
  49        ret = trace_seq_bprintf(s, field->fmt, field->buf);
  50        if (!ret)
  51                return TRACE_TYPE_PARTIAL_LINE;
  52
  53        return TRACE_TYPE_HANDLED;
  54}
  55
  56enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  57{
  58        struct trace_seq *s = &iter->seq;
  59        struct trace_entry *entry = iter->ent;
  60        struct print_entry *field;
  61        int ret;
  62
  63        trace_assign_type(field, entry);
  64
  65        ret = trace_seq_printf(s, "%s", field->buf);
  66        if (!ret)
  67                return TRACE_TYPE_PARTIAL_LINE;
  68
  69        return TRACE_TYPE_HANDLED;
  70}
  71
  72/**
  73 * trace_seq_printf - sequence printing of trace information
  74 * @s: trace sequence descriptor
  75 * @fmt: printf format string
  76 *
  77 * It returns 0 if the trace oversizes the buffer's free
  78 * space, 1 otherwise.
  79 *
  80 * The tracer may use either sequence operations or its own
  81 * copy to user routines. To simplify formating of a trace
  82 * trace_seq_printf is used to store strings into a special
  83 * buffer (@s). Then the output may be either used by
  84 * the sequencer or pulled into another buffer.
  85 */
  86int
  87trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
  88{
  89        int len = (PAGE_SIZE - 1) - s->len;
  90        va_list ap;
  91        int ret;
  92
  93        if (s->full || !len)
  94                return 0;
  95
  96        va_start(ap, fmt);
  97        ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
  98        va_end(ap);
  99
 100        /* If we can't write it all, don't bother writing anything */
 101        if (ret >= len) {
 102                s->full = 1;
 103                return 0;
 104        }
 105
 106        s->len += ret;
 107
 108        return 1;
 109}
 110EXPORT_SYMBOL_GPL(trace_seq_printf);
 111
 112/**
 113 * trace_seq_vprintf - sequence printing of trace information
 114 * @s: trace sequence descriptor
 115 * @fmt: printf format string
 116 *
 117 * The tracer may use either sequence operations or its own
 118 * copy to user routines. To simplify formating of a trace
 119 * trace_seq_printf is used to store strings into a special
 120 * buffer (@s). Then the output may be either used by
 121 * the sequencer or pulled into another buffer.
 122 */
 123int
 124trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
 125{
 126        int len = (PAGE_SIZE - 1) - s->len;
 127        int ret;
 128
 129        if (s->full || !len)
 130                return 0;
 131
 132        ret = vsnprintf(s->buffer + s->len, len, fmt, args);
 133
 134        /* If we can't write it all, don't bother writing anything */
 135        if (ret >= len) {
 136                s->full = 1;
 137                return 0;
 138        }
 139
 140        s->len += ret;
 141
 142        return len;
 143}
 144EXPORT_SYMBOL_GPL(trace_seq_vprintf);
 145
 146int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
 147{
 148        int len = (PAGE_SIZE - 1) - s->len;
 149        int ret;
 150
 151        if (s->full || !len)
 152                return 0;
 153
 154        ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
 155
 156        /* If we can't write it all, don't bother writing anything */
 157        if (ret >= len) {
 158                s->full = 1;
 159                return 0;
 160        }
 161
 162        s->len += ret;
 163
 164        return len;
 165}
 166
 167/**
 168 * trace_seq_puts - trace sequence printing of simple string
 169 * @s: trace sequence descriptor
 170 * @str: simple string to record
 171 *
 172 * The tracer may use either the sequence operations or its own
 173 * copy to user routines. This function records a simple string
 174 * into a special buffer (@s) for later retrieval by a sequencer
 175 * or other mechanism.
 176 */
 177int trace_seq_puts(struct trace_seq *s, const char *str)
 178{
 179        int len = strlen(str);
 180
 181        if (s->full)
 182                return 0;
 183
 184        if (len > ((PAGE_SIZE - 1) - s->len)) {
 185                s->full = 1;
 186                return 0;
 187        }
 188
 189        memcpy(s->buffer + s->len, str, len);
 190        s->len += len;
 191
 192        return len;
 193}
 194
 195int trace_seq_putc(struct trace_seq *s, unsigned char c)
 196{
 197        if (s->full)
 198                return 0;
 199
 200        if (s->len >= (PAGE_SIZE - 1)) {
 201                s->full = 1;
 202                return 0;
 203        }
 204
 205        s->buffer[s->len++] = c;
 206
 207        return 1;
 208}
 209EXPORT_SYMBOL(trace_seq_putc);
 210
 211int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
 212{
 213        if (s->full)
 214                return 0;
 215
 216        if (len > ((PAGE_SIZE - 1) - s->len)) {
 217                s->full = 1;
 218                return 0;
 219        }
 220
 221        memcpy(s->buffer + s->len, mem, len);
 222        s->len += len;
 223
 224        return len;
 225}
 226
 227int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
 228{
 229        unsigned char hex[HEX_CHARS];
 230        const unsigned char *data = mem;
 231        int i, j;
 232
 233        if (s->full)
 234                return 0;
 235
 236#ifdef __BIG_ENDIAN
 237        for (i = 0, j = 0; i < len; i++) {
 238#else
 239        for (i = len-1, j = 0; i >= 0; i--) {
 240#endif
 241                hex[j++] = hex_asc_hi(data[i]);
 242                hex[j++] = hex_asc_lo(data[i]);
 243        }
 244        hex[j++] = ' ';
 245
 246        return trace_seq_putmem(s, hex, j);
 247}
 248
 249void *trace_seq_reserve(struct trace_seq *s, size_t len)
 250{
 251        void *ret;
 252
 253        if (s->full)
 254                return NULL;
 255
 256        if (len > ((PAGE_SIZE - 1) - s->len)) {
 257                s->full = 1;
 258                return NULL;
 259        }
 260
 261        ret = s->buffer + s->len;
 262        s->len += len;
 263
 264        return ret;
 265}
 266
 267int trace_seq_path(struct trace_seq *s, struct path *path)
 268{
 269        unsigned char *p;
 270
 271        if (s->full)
 272                return 0;
 273
 274        if (s->len >= (PAGE_SIZE - 1)) {
 275                s->full = 1;
 276                return 0;
 277        }
 278
 279        p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
 280        if (!IS_ERR(p)) {
 281                p = mangle_path(s->buffer + s->len, p, "\n");
 282                if (p) {
 283                        s->len = p - s->buffer;
 284                        return 1;
 285                }
 286        } else {
 287                s->buffer[s->len++] = '?';
 288                return 1;
 289        }
 290
 291        s->full = 1;
 292        return 0;
 293}
 294
 295const char *
 296ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 297                       unsigned long flags,
 298                       const struct trace_print_flags *flag_array)
 299{
 300        unsigned long mask;
 301        const char *str;
 302        const char *ret = p->buffer + p->len;
 303        int i;
 304
 305        for (i = 0;  flag_array[i].name && flags; i++) {
 306
 307                mask = flag_array[i].mask;
 308                if ((flags & mask) != mask)
 309                        continue;
 310
 311                str = flag_array[i].name;
 312                flags &= ~mask;
 313                if (p->len && delim)
 314                        trace_seq_puts(p, delim);
 315                trace_seq_puts(p, str);
 316        }
 317
 318        /* check for left over flags */
 319        if (flags) {
 320                if (p->len && delim)
 321                        trace_seq_puts(p, delim);
 322                trace_seq_printf(p, "0x%lx", flags);
 323        }
 324
 325        trace_seq_putc(p, 0);
 326
 327        return ret;
 328}
 329EXPORT_SYMBOL(ftrace_print_flags_seq);
 330
 331const char *
 332ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 333                         const struct trace_print_flags *symbol_array)
 334{
 335        int i;
 336        const char *ret = p->buffer + p->len;
 337
 338        for (i = 0;  symbol_array[i].name; i++) {
 339
 340                if (val != symbol_array[i].mask)
 341                        continue;
 342
 343                trace_seq_puts(p, symbol_array[i].name);
 344                break;
 345        }
 346
 347        if (!p->len)
 348                trace_seq_printf(p, "0x%lx", val);
 349                
 350        trace_seq_putc(p, 0);
 351
 352        return ret;
 353}
 354EXPORT_SYMBOL(ftrace_print_symbols_seq);
 355
 356#if BITS_PER_LONG == 32
 357const char *
 358ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 359                         const struct trace_print_flags_u64 *symbol_array)
 360{
 361        int i;
 362        const char *ret = p->buffer + p->len;
 363
 364        for (i = 0;  symbol_array[i].name; i++) {
 365
 366                if (val != symbol_array[i].mask)
 367                        continue;
 368
 369                trace_seq_puts(p, symbol_array[i].name);
 370                break;
 371        }
 372
 373        if (!p->len)
 374                trace_seq_printf(p, "0x%llx", val);
 375
 376        trace_seq_putc(p, 0);
 377
 378        return ret;
 379}
 380EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
 381#endif
 382
 383const char *
 384ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 385{
 386        int i;
 387        const char *ret = p->buffer + p->len;
 388
 389        for (i = 0; i < buf_len; i++)
 390                trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 391
 392        trace_seq_putc(p, 0);
 393
 394        return ret;
 395}
 396EXPORT_SYMBOL(ftrace_print_hex_seq);
 397
 398#ifdef CONFIG_KRETPROBES
 399static inline const char *kretprobed(const char *name)
 400{
 401        static const char tramp_name[] = "kretprobe_trampoline";
 402        int size = sizeof(tramp_name);
 403
 404        if (strncmp(tramp_name, name, size) == 0)
 405                return "[unknown/kretprobe'd]";
 406        return name;
 407}
 408#else
 409static inline const char *kretprobed(const char *name)
 410{
 411        return name;
 412}
 413#endif /* CONFIG_KRETPROBES */
 414
 415static int
 416seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 417{
 418#ifdef CONFIG_KALLSYMS
 419        char str[KSYM_SYMBOL_LEN];
 420        const char *name;
 421
 422        kallsyms_lookup(address, NULL, NULL, NULL, str);
 423
 424        name = kretprobed(str);
 425
 426        return trace_seq_printf(s, fmt, name);
 427#endif
 428        return 1;
 429}
 430
 431static int
 432seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 433                     unsigned long address)
 434{
 435#ifdef CONFIG_KALLSYMS
 436        char str[KSYM_SYMBOL_LEN];
 437        const char *name;
 438
 439        sprint_symbol(str, address);
 440        name = kretprobed(str);
 441
 442        return trace_seq_printf(s, fmt, name);
 443#endif
 444        return 1;
 445}
 446
 447#ifndef CONFIG_64BIT
 448# define IP_FMT "%08lx"
 449#else
 450# define IP_FMT "%016lx"
 451#endif
 452
 453int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 454                      unsigned long ip, unsigned long sym_flags)
 455{
 456        struct file *file = NULL;
 457        unsigned long vmstart = 0;
 458        int ret = 1;
 459
 460        if (s->full)
 461                return 0;
 462
 463        if (mm) {
 464                const struct vm_area_struct *vma;
 465
 466                down_read(&mm->mmap_sem);
 467                vma = find_vma(mm, ip);
 468                if (vma) {
 469                        file = vma->vm_file;
 470                        vmstart = vma->vm_start;
 471                }
 472                if (file) {
 473                        ret = trace_seq_path(s, &file->f_path);
 474                        if (ret)
 475                                ret = trace_seq_printf(s, "[+0x%lx]",
 476                                                       ip - vmstart);
 477                }
 478                up_read(&mm->mmap_sem);
 479        }
 480        if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 481                ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 482        return ret;
 483}
 484
 485int
 486seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 487                      unsigned long sym_flags)
 488{
 489        struct mm_struct *mm = NULL;
 490        int ret = 1;
 491        unsigned int i;
 492
 493        if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 494                struct task_struct *task;
 495                /*
 496                 * we do the lookup on the thread group leader,
 497                 * since individual threads might have already quit!
 498                 */
 499                rcu_read_lock();
 500                task = find_task_by_vpid(entry->tgid);
 501                if (task)
 502                        mm = get_task_mm(task);
 503                rcu_read_unlock();
 504        }
 505
 506        for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 507                unsigned long ip = entry->caller[i];
 508
 509                if (ip == ULONG_MAX || !ret)
 510                        break;
 511                if (ret)
 512                        ret = trace_seq_puts(s, " => ");
 513                if (!ip) {
 514                        if (ret)
 515                                ret = trace_seq_puts(s, "??");
 516                        if (ret)
 517                                ret = trace_seq_puts(s, "\n");
 518                        continue;
 519                }
 520                if (!ret)
 521                        break;
 522                if (ret)
 523                        ret = seq_print_user_ip(s, mm, ip, sym_flags);
 524                ret = trace_seq_puts(s, "\n");
 525        }
 526
 527        if (mm)
 528                mmput(mm);
 529        return ret;
 530}
 531
 532int
 533seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 534{
 535        int ret;
 536
 537        if (!ip)
 538                return trace_seq_printf(s, "0");
 539
 540        if (sym_flags & TRACE_ITER_SYM_OFFSET)
 541                ret = seq_print_sym_offset(s, "%s", ip);
 542        else
 543                ret = seq_print_sym_short(s, "%s", ip);
 544
 545        if (!ret)
 546                return 0;
 547
 548        if (sym_flags & TRACE_ITER_SYM_ADDR)
 549                ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 550        return ret;
 551}
 552
 553/**
 554 * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 555 * @s: trace seq struct to write to
 556 * @entry: The trace entry field from the ring buffer
 557 *
 558 * Prints the generic fields of irqs off, in hard or softirq, preempt
 559 * count.
 560 */
 561int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 562{
 563        char hardsoft_irq;
 564        char need_resched;
 565        char irqs_off;
 566        int hardirq;
 567        int softirq;
 568        int ret;
 569
 570        hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 571        softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 572
 573        irqs_off =
 574                (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 575                (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 576                '.';
 577        need_resched =
 578                (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
 579        hardsoft_irq =
 580                (hardirq && softirq) ? 'H' :
 581                hardirq ? 'h' :
 582                softirq ? 's' :
 583                '.';
 584
 585        if (!trace_seq_printf(s, "%c%c%c",
 586                              irqs_off, need_resched, hardsoft_irq))
 587                return 0;
 588
 589        if (entry->preempt_count)
 590                ret = trace_seq_printf(s, "%x", entry->preempt_count);
 591        else
 592                ret = trace_seq_putc(s, '.');
 593
 594        return ret;
 595}
 596
 597static int
 598lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 599{
 600        char comm[TASK_COMM_LEN];
 601
 602        trace_find_cmdline(entry->pid, comm);
 603
 604        if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 605                              comm, entry->pid, cpu))
 606                return 0;
 607
 608        return trace_print_lat_fmt(s, entry);
 609}
 610
 611static unsigned long preempt_mark_thresh = 100;
 612
 613static int
 614lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 615                    unsigned long rel_usecs)
 616{
 617        return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
 618                                rel_usecs > preempt_mark_thresh ? '!' :
 619                                  rel_usecs > 1 ? '+' : ' ');
 620}
 621
 622int trace_print_context(struct trace_iterator *iter)
 623{
 624        struct trace_seq *s = &iter->seq;
 625        struct trace_entry *entry = iter->ent;
 626        unsigned long long t = ns2usecs(iter->ts);
 627        unsigned long usec_rem = do_div(t, USEC_PER_SEC);
 628        unsigned long secs = (unsigned long)t;
 629        char comm[TASK_COMM_LEN];
 630
 631        trace_find_cmdline(entry->pid, comm);
 632
 633        return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
 634                                comm, entry->pid, iter->cpu, secs, usec_rem);
 635}
 636
 637int trace_print_lat_context(struct trace_iterator *iter)
 638{
 639        u64 next_ts;
 640        int ret;
 641        struct trace_seq *s = &iter->seq;
 642        struct trace_entry *entry = iter->ent,
 643                           *next_entry = trace_find_next_entry(iter, NULL,
 644                                                               &next_ts);
 645        unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 646        unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 647        unsigned long rel_usecs;
 648
 649        if (!next_entry)
 650                next_ts = iter->ts;
 651        rel_usecs = ns2usecs(next_ts - iter->ts);
 652
 653        if (verbose) {
 654                char comm[TASK_COMM_LEN];
 655
 656                trace_find_cmdline(entry->pid, comm);
 657
 658                ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
 659                                       " %ld.%03ldms (+%ld.%03ldms): ", comm,
 660                                       entry->pid, iter->cpu, entry->flags,
 661                                       entry->preempt_count, iter->idx,
 662                                       ns2usecs(iter->ts),
 663                                       abs_usecs / USEC_PER_MSEC,
 664                                       abs_usecs % USEC_PER_MSEC,
 665                                       rel_usecs / USEC_PER_MSEC,
 666                                       rel_usecs % USEC_PER_MSEC);
 667        } else {
 668                ret = lat_print_generic(s, entry, iter->cpu);
 669                if (ret)
 670                        ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
 671        }
 672
 673        return ret;
 674}
 675
 676static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 677
 678static int task_state_char(unsigned long state)
 679{
 680        int bit = state ? __ffs(state) + 1 : 0;
 681
 682        return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 683}
 684
 685/**
 686 * ftrace_find_event - find a registered event
 687 * @type: the type of event to look for
 688 *
 689 * Returns an event of type @type otherwise NULL
 690 * Called with trace_event_read_lock() held.
 691 */
 692struct trace_event *ftrace_find_event(int type)
 693{
 694        struct trace_event *event;
 695        struct hlist_node *n;
 696        unsigned key;
 697
 698        key = type & (EVENT_HASHSIZE - 1);
 699
 700        hlist_for_each_entry(event, n, &event_hash[key], node) {
 701                if (event->type == type)
 702                        return event;
 703        }
 704
 705        return NULL;
 706}
 707
 708static LIST_HEAD(ftrace_event_list);
 709
 710static int trace_search_list(struct list_head **list)
 711{
 712        struct trace_event *e;
 713        int last = __TRACE_LAST_TYPE;
 714
 715        if (list_empty(&ftrace_event_list)) {
 716                *list = &ftrace_event_list;
 717                return last + 1;
 718        }
 719
 720        /*
 721         * We used up all possible max events,
 722         * lets see if somebody freed one.
 723         */
 724        list_for_each_entry(e, &ftrace_event_list, list) {
 725                if (e->type != last + 1)
 726                        break;
 727                last++;
 728        }
 729
 730        /* Did we used up all 65 thousand events??? */
 731        if ((last + 1) > FTRACE_MAX_EVENT)
 732                return 0;
 733
 734        *list = &e->list;
 735        return last + 1;
 736}
 737
 738void trace_event_read_lock(void)
 739{
 740        down_read(&trace_event_mutex);
 741}
 742
 743void trace_event_read_unlock(void)
 744{
 745        up_read(&trace_event_mutex);
 746}
 747
 748/**
 749 * register_ftrace_event - register output for an event type
 750 * @event: the event type to register
 751 *
 752 * Event types are stored in a hash and this hash is used to
 753 * find a way to print an event. If the @event->type is set
 754 * then it will use that type, otherwise it will assign a
 755 * type to use.
 756 *
 757 * If you assign your own type, please make sure it is added
 758 * to the trace_type enum in trace.h, to avoid collisions
 759 * with the dynamic types.
 760 *
 761 * Returns the event type number or zero on error.
 762 */
 763int register_ftrace_event(struct trace_event *event)
 764{
 765        unsigned key;
 766        int ret = 0;
 767
 768        down_write(&trace_event_mutex);
 769
 770        if (WARN_ON(!event))
 771                goto out;
 772
 773        if (WARN_ON(!event->funcs))
 774                goto out;
 775
 776        INIT_LIST_HEAD(&event->list);
 777
 778        if (!event->type) {
 779                struct list_head *list = NULL;
 780
 781                if (next_event_type > FTRACE_MAX_EVENT) {
 782
 783                        event->type = trace_search_list(&list);
 784                        if (!event->type)
 785                                goto out;
 786
 787                } else {
 788                        
 789                        event->type = next_event_type++;
 790                        list = &ftrace_event_list;
 791                }
 792
 793                if (WARN_ON(ftrace_find_event(event->type)))
 794                        goto out;
 795
 796                list_add_tail(&event->list, list);
 797
 798        } else if (event->type > __TRACE_LAST_TYPE) {
 799                printk(KERN_WARNING "Need to add type to trace.h\n");
 800                WARN_ON(1);
 801                goto out;
 802        } else {
 803                /* Is this event already used */
 804                if (ftrace_find_event(event->type))
 805                        goto out;
 806        }
 807
 808        if (event->funcs->trace == NULL)
 809                event->funcs->trace = trace_nop_print;
 810        if (event->funcs->raw == NULL)
 811                event->funcs->raw = trace_nop_print;
 812        if (event->funcs->hex == NULL)
 813                event->funcs->hex = trace_nop_print;
 814        if (event->funcs->binary == NULL)
 815                event->funcs->binary = trace_nop_print;
 816
 817        key = event->type & (EVENT_HASHSIZE - 1);
 818
 819        hlist_add_head(&event->node, &event_hash[key]);
 820
 821        ret = event->type;
 822 out:
 823        up_write(&trace_event_mutex);
 824
 825        return ret;
 826}
 827EXPORT_SYMBOL_GPL(register_ftrace_event);
 828
 829/*
 830 * Used by module code with the trace_event_mutex held for write.
 831 */
 832int __unregister_ftrace_event(struct trace_event *event)
 833{
 834        hlist_del(&event->node);
 835        list_del(&event->list);
 836        return 0;
 837}
 838
 839/**
 840 * unregister_ftrace_event - remove a no longer used event
 841 * @event: the event to remove
 842 */
 843int unregister_ftrace_event(struct trace_event *event)
 844{
 845        down_write(&trace_event_mutex);
 846        __unregister_ftrace_event(event);
 847        up_write(&trace_event_mutex);
 848
 849        return 0;
 850}
 851EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 852
 853/*
 854 * Standard events
 855 */
 856
 857enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 858                                  struct trace_event *event)
 859{
 860        if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
 861                return TRACE_TYPE_PARTIAL_LINE;
 862
 863        return TRACE_TYPE_HANDLED;
 864}
 865
 866/* TRACE_FN */
 867static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 868                                        struct trace_event *event)
 869{
 870        struct ftrace_entry *field;
 871        struct trace_seq *s = &iter->seq;
 872
 873        trace_assign_type(field, iter->ent);
 874
 875        if (!seq_print_ip_sym(s, field->ip, flags))
 876                goto partial;
 877
 878        if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 879                if (!trace_seq_printf(s, " <-"))
 880                        goto partial;
 881                if (!seq_print_ip_sym(s,
 882                                      field->parent_ip,
 883                                      flags))
 884                        goto partial;
 885        }
 886        if (!trace_seq_printf(s, "\n"))
 887                goto partial;
 888
 889        return TRACE_TYPE_HANDLED;
 890
 891 partial:
 892        return TRACE_TYPE_PARTIAL_LINE;
 893}
 894
 895static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 896                                      struct trace_event *event)
 897{
 898        struct ftrace_entry *field;
 899
 900        trace_assign_type(field, iter->ent);
 901
 902        if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 903                              field->ip,
 904                              field->parent_ip))
 905                return TRACE_TYPE_PARTIAL_LINE;
 906
 907        return TRACE_TYPE_HANDLED;
 908}
 909
 910static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 911                                      struct trace_event *event)
 912{
 913        struct ftrace_entry *field;
 914        struct trace_seq *s = &iter->seq;
 915
 916        trace_assign_type(field, iter->ent);
 917
 918        SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 919        SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 920
 921        return TRACE_TYPE_HANDLED;
 922}
 923
 924static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 925                                      struct trace_event *event)
 926{
 927        struct ftrace_entry *field;
 928        struct trace_seq *s = &iter->seq;
 929
 930        trace_assign_type(field, iter->ent);
 931
 932        SEQ_PUT_FIELD_RET(s, field->ip);
 933        SEQ_PUT_FIELD_RET(s, field->parent_ip);
 934
 935        return TRACE_TYPE_HANDLED;
 936}
 937
 938static struct trace_event_functions trace_fn_funcs = {
 939        .trace          = trace_fn_trace,
 940        .raw            = trace_fn_raw,
 941        .hex            = trace_fn_hex,
 942        .binary         = trace_fn_bin,
 943};
 944
 945static struct trace_event trace_fn_event = {
 946        .type           = TRACE_FN,
 947        .funcs          = &trace_fn_funcs,
 948};
 949
 950/* TRACE_CTX an TRACE_WAKE */
 951static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 952                                             char *delim)
 953{
 954        struct ctx_switch_entry *field;
 955        char comm[TASK_COMM_LEN];
 956        int S, T;
 957
 958
 959        trace_assign_type(field, iter->ent);
 960
 961        T = task_state_char(field->next_state);
 962        S = task_state_char(field->prev_state);
 963        trace_find_cmdline(field->next_pid, comm);
 964        if (!trace_seq_printf(&iter->seq,
 965                              " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 966                              field->prev_pid,
 967                              field->prev_prio,
 968                              S, delim,
 969                              field->next_cpu,
 970                              field->next_pid,
 971                              field->next_prio,
 972                              T, comm))
 973                return TRACE_TYPE_PARTIAL_LINE;
 974
 975        return TRACE_TYPE_HANDLED;
 976}
 977
 978static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 979                                         struct trace_event *event)
 980{
 981        return trace_ctxwake_print(iter, "==>");
 982}
 983
 984static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 985                                          int flags, struct trace_event *event)
 986{
 987        return trace_ctxwake_print(iter, "  +");
 988}
 989
 990static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 991{
 992        struct ctx_switch_entry *field;
 993        int T;
 994
 995        trace_assign_type(field, iter->ent);
 996
 997        if (!S)
 998                S = task_state_char(field->prev_state);
 999        T = task_state_char(field->next_state);
1000        if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1001                              field->prev_pid,
1002                              field->prev_prio,
1003                              S,
1004                              field->next_cpu,
1005                              field->next_pid,
1006                              field->next_prio,
1007                              T))
1008                return TRACE_TYPE_PARTIAL_LINE;
1009
1010        return TRACE_TYPE_HANDLED;
1011}
1012
1013static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1014                                       struct trace_event *event)
1015{
1016        return trace_ctxwake_raw(iter, 0);
1017}
1018
1019static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1020                                        struct trace_event *event)
1021{
1022        return trace_ctxwake_raw(iter, '+');
1023}
1024
1025
1026static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1027{
1028        struct ctx_switch_entry *field;
1029        struct trace_seq *s = &iter->seq;
1030        int T;
1031
1032        trace_assign_type(field, iter->ent);
1033
1034        if (!S)
1035                S = task_state_char(field->prev_state);
1036        T = task_state_char(field->next_state);
1037
1038        SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1039        SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1040        SEQ_PUT_HEX_FIELD_RET(s, S);
1041        SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1042        SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1043        SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1044        SEQ_PUT_HEX_FIELD_RET(s, T);
1045
1046        return TRACE_TYPE_HANDLED;
1047}
1048
1049static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1050                                       struct trace_event *event)
1051{
1052        return trace_ctxwake_hex(iter, 0);
1053}
1054
1055static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1056                                        struct trace_event *event)
1057{
1058        return trace_ctxwake_hex(iter, '+');
1059}
1060
1061static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1062                                           int flags, struct trace_event *event)
1063{
1064        struct ctx_switch_entry *field;
1065        struct trace_seq *s = &iter->seq;
1066
1067        trace_assign_type(field, iter->ent);
1068
1069        SEQ_PUT_FIELD_RET(s, field->prev_pid);
1070        SEQ_PUT_FIELD_RET(s, field->prev_prio);
1071        SEQ_PUT_FIELD_RET(s, field->prev_state);
1072        SEQ_PUT_FIELD_RET(s, field->next_pid);
1073        SEQ_PUT_FIELD_RET(s, field->next_prio);
1074        SEQ_PUT_FIELD_RET(s, field->next_state);
1075
1076        return TRACE_TYPE_HANDLED;
1077}
1078
1079static struct trace_event_functions trace_ctx_funcs = {
1080        .trace          = trace_ctx_print,
1081        .raw            = trace_ctx_raw,
1082        .hex            = trace_ctx_hex,
1083        .binary         = trace_ctxwake_bin,
1084};
1085
1086static struct trace_event trace_ctx_event = {
1087        .type           = TRACE_CTX,
1088        .funcs          = &trace_ctx_funcs,
1089};
1090
1091static struct trace_event_functions trace_wake_funcs = {
1092        .trace          = trace_wake_print,
1093        .raw            = trace_wake_raw,
1094        .hex            = trace_wake_hex,
1095        .binary         = trace_ctxwake_bin,
1096};
1097
1098static struct trace_event trace_wake_event = {
1099        .type           = TRACE_WAKE,
1100        .funcs          = &trace_wake_funcs,
1101};
1102
1103/* TRACE_STACK */
1104
1105static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1106                                           int flags, struct trace_event *event)
1107{
1108        struct stack_entry *field;
1109        struct trace_seq *s = &iter->seq;
1110        unsigned long *p;
1111        unsigned long *end;
1112
1113        trace_assign_type(field, iter->ent);
1114        end = (unsigned long *)((long)iter->ent + iter->ent_size);
1115
1116        if (!trace_seq_puts(s, "<stack trace>\n"))
1117                goto partial;
1118
1119        for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1120                if (!trace_seq_puts(s, " => "))
1121                        goto partial;
1122
1123                if (!seq_print_ip_sym(s, *p, flags))
1124                        goto partial;
1125                if (!trace_seq_puts(s, "\n"))
1126                        goto partial;
1127        }
1128
1129        return TRACE_TYPE_HANDLED;
1130
1131 partial:
1132        return TRACE_TYPE_PARTIAL_LINE;
1133}
1134
1135static struct trace_event_functions trace_stack_funcs = {
1136        .trace          = trace_stack_print,
1137};
1138
1139static struct trace_event trace_stack_event = {
1140        .type           = TRACE_STACK,
1141        .funcs          = &trace_stack_funcs,
1142};
1143
1144/* TRACE_USER_STACK */
1145static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1146                                                int flags, struct trace_event *event)
1147{
1148        struct userstack_entry *field;
1149        struct trace_seq *s = &iter->seq;
1150
1151        trace_assign_type(field, iter->ent);
1152
1153        if (!trace_seq_puts(s, "<user stack trace>\n"))
1154                goto partial;
1155
1156        if (!seq_print_userip_objs(field, s, flags))
1157                goto partial;
1158
1159        return TRACE_TYPE_HANDLED;
1160
1161 partial:
1162        return TRACE_TYPE_PARTIAL_LINE;
1163}
1164
1165static struct trace_event_functions trace_user_stack_funcs = {
1166        .trace          = trace_user_stack_print,
1167};
1168
1169static struct trace_event trace_user_stack_event = {
1170        .type           = TRACE_USER_STACK,
1171        .funcs          = &trace_user_stack_funcs,
1172};
1173
1174/* TRACE_BPRINT */
1175static enum print_line_t
1176trace_bprint_print(struct trace_iterator *iter, int flags,
1177                   struct trace_event *event)
1178{
1179        struct trace_entry *entry = iter->ent;
1180        struct trace_seq *s = &iter->seq;
1181        struct bprint_entry *field;
1182
1183        trace_assign_type(field, entry);
1184
1185        if (!seq_print_ip_sym(s, field->ip, flags))
1186                goto partial;
1187
1188        if (!trace_seq_puts(s, ": "))
1189                goto partial;
1190
1191        if (!trace_seq_bprintf(s, field->fmt, field->buf))
1192                goto partial;
1193
1194        return TRACE_TYPE_HANDLED;
1195
1196 partial:
1197        return TRACE_TYPE_PARTIAL_LINE;
1198}
1199
1200
1201static enum print_line_t
1202trace_bprint_raw(struct trace_iterator *iter, int flags,
1203                 struct trace_event *event)
1204{
1205        struct bprint_entry *field;
1206        struct trace_seq *s = &iter->seq;
1207
1208        trace_assign_type(field, iter->ent);
1209
1210        if (!trace_seq_printf(s, ": %lx : ", field->ip))
1211                goto partial;
1212
1213        if (!trace_seq_bprintf(s, field->fmt, field->buf))
1214                goto partial;
1215
1216        return TRACE_TYPE_HANDLED;
1217
1218 partial:
1219        return TRACE_TYPE_PARTIAL_LINE;
1220}
1221
1222static struct trace_event_functions trace_bprint_funcs = {
1223        .trace          = trace_bprint_print,
1224        .raw            = trace_bprint_raw,
1225};
1226
1227static struct trace_event trace_bprint_event = {
1228        .type           = TRACE_BPRINT,
1229        .funcs          = &trace_bprint_funcs,
1230};
1231
1232/* TRACE_PRINT */
1233static enum print_line_t trace_print_print(struct trace_iterator *iter,
1234                                           int flags, struct trace_event *event)
1235{
1236        struct print_entry *field;
1237        struct trace_seq *s = &iter->seq;
1238
1239        trace_assign_type(field, iter->ent);
1240
1241        if (!seq_print_ip_sym(s, field->ip, flags))
1242                goto partial;
1243
1244        if (!trace_seq_printf(s, ": %s", field->buf))
1245                goto partial;
1246
1247        return TRACE_TYPE_HANDLED;
1248
1249 partial:
1250        return TRACE_TYPE_PARTIAL_LINE;
1251}
1252
1253static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1254                                         struct trace_event *event)
1255{
1256        struct print_entry *field;
1257
1258        trace_assign_type(field, iter->ent);
1259
1260        if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1261                goto partial;
1262
1263        return TRACE_TYPE_HANDLED;
1264
1265 partial:
1266        return TRACE_TYPE_PARTIAL_LINE;
1267}
1268
1269static struct trace_event_functions trace_print_funcs = {
1270        .trace          = trace_print_print,
1271        .raw            = trace_print_raw,
1272};
1273
1274static struct trace_event trace_print_event = {
1275        .type           = TRACE_PRINT,
1276        .funcs          = &trace_print_funcs,
1277};
1278
1279
1280static struct trace_event *events[] __initdata = {
1281        &trace_fn_event,
1282        &trace_ctx_event,
1283        &trace_wake_event,
1284        &trace_stack_event,
1285        &trace_user_stack_event,
1286        &trace_bprint_event,
1287        &trace_print_event,
1288        NULL
1289};
1290
1291__init static int init_events(void)
1292{
1293        struct trace_event *event;
1294        int i, ret;
1295
1296        for (i = 0; events[i]; i++) {
1297                event = events[i];
1298
1299                ret = register_ftrace_event(event);
1300                if (!ret) {
1301                        printk(KERN_WARNING "event %d failed to register\n",
1302                               event->type);
1303                        WARN_ON_ONCE(1);
1304                }
1305        }
1306
1307        return 0;
1308}
1309device_initcall(init_events);
1310
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.