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v3.15
   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_sem);
  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_bputs_msg_only(struct trace_iterator *iter)
  41{
  42	struct trace_seq *s = &iter->seq;
  43	struct trace_entry *entry = iter->ent;
  44	struct bputs_entry *field;
  45	int ret;
  46
  47	trace_assign_type(field, entry);
  48
  49	ret = trace_seq_puts(s, field->str);
  50	if (!ret)
  51		return TRACE_TYPE_PARTIAL_LINE;
  52
  53	return TRACE_TYPE_HANDLED;
  54}
  55
  56enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  57{
  58	struct trace_seq *s = &iter->seq;
  59	struct trace_entry *entry = iter->ent;
  60	struct bprint_entry *field;
  61	int ret;
  62
  63	trace_assign_type(field, entry);
  64
  65	ret = trace_seq_bprintf(s, field->fmt, field->buf);
  66	if (!ret)
  67		return TRACE_TYPE_PARTIAL_LINE;
  68
  69	return TRACE_TYPE_HANDLED;
  70}
  71
  72enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  73{
  74	struct trace_seq *s = &iter->seq;
  75	struct trace_entry *entry = iter->ent;
  76	struct print_entry *field;
  77	int ret;
  78
  79	trace_assign_type(field, entry);
  80
  81	ret = trace_seq_puts(s, field->buf);
  82	if (!ret)
  83		return TRACE_TYPE_PARTIAL_LINE;
  84
  85	return TRACE_TYPE_HANDLED;
  86}
  87
  88/**
  89 * trace_seq_printf - sequence printing of trace information
  90 * @s: trace sequence descriptor
  91 * @fmt: printf format string
  92 *
  93 * It returns 0 if the trace oversizes the buffer's free
  94 * space, 1 otherwise.
  95 *
  96 * The tracer may use either sequence operations or its own
  97 * copy to user routines. To simplify formating of a trace
  98 * trace_seq_printf is used to store strings into a special
  99 * buffer (@s). Then the output may be either used by
 100 * the sequencer or pulled into another buffer.
 101 */
 102int
 103trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
 104{
 105	int len = (PAGE_SIZE - 1) - s->len;
 106	va_list ap;
 107	int ret;
 108
 109	if (s->full || !len)
 110		return 0;
 111
 112	va_start(ap, fmt);
 113	ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
 114	va_end(ap);
 115
 116	/* If we can't write it all, don't bother writing anything */
 117	if (ret >= len) {
 118		s->full = 1;
 119		return 0;
 120	}
 121
 122	s->len += ret;
 123
 124	return 1;
 125}
 126EXPORT_SYMBOL_GPL(trace_seq_printf);
 127
 128/**
 129 * trace_seq_vprintf - sequence printing of trace information
 130 * @s: trace sequence descriptor
 131 * @fmt: printf format string
 132 *
 133 * The tracer may use either sequence operations or its own
 134 * copy to user routines. To simplify formating of a trace
 135 * trace_seq_printf is used to store strings into a special
 136 * buffer (@s). Then the output may be either used by
 137 * the sequencer or pulled into another buffer.
 138 */
 139int
 140trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
 141{
 142	int len = (PAGE_SIZE - 1) - s->len;
 143	int ret;
 144
 145	if (s->full || !len)
 146		return 0;
 147
 148	ret = vsnprintf(s->buffer + s->len, len, fmt, args);
 149
 150	/* If we can't write it all, don't bother writing anything */
 151	if (ret >= len) {
 152		s->full = 1;
 153		return 0;
 154	}
 155
 156	s->len += ret;
 157
 158	return len;
 159}
 160EXPORT_SYMBOL_GPL(trace_seq_vprintf);
 161
 162int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
 163{
 164	int len = (PAGE_SIZE - 1) - s->len;
 165	int ret;
 166
 167	if (s->full || !len)
 168		return 0;
 169
 170	ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
 171
 172	/* If we can't write it all, don't bother writing anything */
 173	if (ret >= len) {
 174		s->full = 1;
 175		return 0;
 176	}
 177
 178	s->len += ret;
 179
 180	return len;
 181}
 182
 183/**
 184 * trace_seq_puts - trace sequence printing of simple string
 185 * @s: trace sequence descriptor
 186 * @str: simple string to record
 187 *
 188 * The tracer may use either the sequence operations or its own
 189 * copy to user routines. This function records a simple string
 190 * into a special buffer (@s) for later retrieval by a sequencer
 191 * or other mechanism.
 192 */
 193int trace_seq_puts(struct trace_seq *s, const char *str)
 194{
 195	int len = strlen(str);
 196
 197	if (s->full)
 198		return 0;
 199
 200	if (len > ((PAGE_SIZE - 1) - s->len)) {
 201		s->full = 1;
 202		return 0;
 203	}
 204
 205	memcpy(s->buffer + s->len, str, len);
 206	s->len += len;
 207
 208	return len;
 209}
 210
 211int trace_seq_putc(struct trace_seq *s, unsigned char c)
 212{
 213	if (s->full)
 214		return 0;
 215
 216	if (s->len >= (PAGE_SIZE - 1)) {
 217		s->full = 1;
 218		return 0;
 219	}
 220
 221	s->buffer[s->len++] = c;
 222
 223	return 1;
 224}
 225EXPORT_SYMBOL(trace_seq_putc);
 226
 227int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
 228{
 229	if (s->full)
 230		return 0;
 231
 232	if (len > ((PAGE_SIZE - 1) - s->len)) {
 233		s->full = 1;
 234		return 0;
 235	}
 236
 237	memcpy(s->buffer + s->len, mem, len);
 238	s->len += len;
 239
 240	return len;
 241}
 242
 243int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
 244{
 245	unsigned char hex[HEX_CHARS];
 246	const unsigned char *data = mem;
 247	int i, j;
 248
 249	if (s->full)
 250		return 0;
 251
 252#ifdef __BIG_ENDIAN
 253	for (i = 0, j = 0; i < len; i++) {
 254#else
 255	for (i = len-1, j = 0; i >= 0; i--) {
 256#endif
 257		hex[j++] = hex_asc_hi(data[i]);
 258		hex[j++] = hex_asc_lo(data[i]);
 259	}
 260	hex[j++] = ' ';
 261
 262	return trace_seq_putmem(s, hex, j);
 263}
 264
 265void *trace_seq_reserve(struct trace_seq *s, size_t len)
 266{
 267	void *ret;
 268
 269	if (s->full)
 270		return NULL;
 271
 272	if (len > ((PAGE_SIZE - 1) - s->len)) {
 273		s->full = 1;
 274		return NULL;
 275	}
 276
 277	ret = s->buffer + s->len;
 278	s->len += len;
 279
 280	return ret;
 281}
 282
 283int trace_seq_path(struct trace_seq *s, const struct path *path)
 284{
 285	unsigned char *p;
 286
 287	if (s->full)
 288		return 0;
 289
 290	if (s->len >= (PAGE_SIZE - 1)) {
 291		s->full = 1;
 292		return 0;
 293	}
 294
 295	p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
 296	if (!IS_ERR(p)) {
 297		p = mangle_path(s->buffer + s->len, p, "\n");
 298		if (p) {
 299			s->len = p - s->buffer;
 300			return 1;
 301		}
 302	} else {
 303		s->buffer[s->len++] = '?';
 304		return 1;
 305	}
 306
 307	s->full = 1;
 308	return 0;
 309}
 310
 311const char *
 312ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 313		       unsigned long flags,
 314		       const struct trace_print_flags *flag_array)
 315{
 316	unsigned long mask;
 317	const char *str;
 318	const char *ret = p->buffer + p->len;
 319	int i, first = 1;
 320
 321	for (i = 0;  flag_array[i].name && flags; i++) {
 322
 323		mask = flag_array[i].mask;
 324		if ((flags & mask) != mask)
 325			continue;
 326
 327		str = flag_array[i].name;
 328		flags &= ~mask;
 329		if (!first && delim)
 330			trace_seq_puts(p, delim);
 331		else
 332			first = 0;
 333		trace_seq_puts(p, str);
 334	}
 335
 336	/* check for left over flags */
 337	if (flags) {
 338		if (!first && delim)
 339			trace_seq_puts(p, delim);
 340		trace_seq_printf(p, "0x%lx", flags);
 341	}
 342
 343	trace_seq_putc(p, 0);
 344
 345	return ret;
 346}
 347EXPORT_SYMBOL(ftrace_print_flags_seq);
 348
 349const char *
 350ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 351			 const struct trace_print_flags *symbol_array)
 352{
 353	int i;
 354	const char *ret = p->buffer + p->len;
 355
 356	for (i = 0;  symbol_array[i].name; i++) {
 357
 358		if (val != symbol_array[i].mask)
 359			continue;
 360
 361		trace_seq_puts(p, symbol_array[i].name);
 362		break;
 363	}
 364
 365	if (ret == (const char *)(p->buffer + p->len))
 366		trace_seq_printf(p, "0x%lx", val);
 367		
 368	trace_seq_putc(p, 0);
 369
 370	return ret;
 371}
 372EXPORT_SYMBOL(ftrace_print_symbols_seq);
 373
 374#if BITS_PER_LONG == 32
 375const char *
 376ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 377			 const struct trace_print_flags_u64 *symbol_array)
 378{
 379	int i;
 380	const char *ret = p->buffer + p->len;
 381
 382	for (i = 0;  symbol_array[i].name; i++) {
 383
 384		if (val != symbol_array[i].mask)
 385			continue;
 386
 387		trace_seq_puts(p, symbol_array[i].name);
 388		break;
 389	}
 390
 391	if (ret == (const char *)(p->buffer + p->len))
 392		trace_seq_printf(p, "0x%llx", val);
 393
 394	trace_seq_putc(p, 0);
 395
 396	return ret;
 397}
 398EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
 399#endif
 400
 401const char *
 402ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 403{
 404	int i;
 405	const char *ret = p->buffer + p->len;
 406
 407	for (i = 0; i < buf_len; i++)
 408		trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 409
 410	trace_seq_putc(p, 0);
 411
 412	return ret;
 413}
 414EXPORT_SYMBOL(ftrace_print_hex_seq);
 415
 416int ftrace_raw_output_prep(struct trace_iterator *iter,
 417			   struct trace_event *trace_event)
 418{
 419	struct ftrace_event_call *event;
 420	struct trace_seq *s = &iter->seq;
 421	struct trace_seq *p = &iter->tmp_seq;
 422	struct trace_entry *entry;
 423	int ret;
 424
 425	event = container_of(trace_event, struct ftrace_event_call, event);
 426	entry = iter->ent;
 427
 428	if (entry->type != event->event.type) {
 429		WARN_ON_ONCE(1);
 430		return TRACE_TYPE_UNHANDLED;
 431	}
 432
 433	trace_seq_init(p);
 434	ret = trace_seq_printf(s, "%s: ", ftrace_event_name(event));
 435	if (!ret)
 436		return TRACE_TYPE_PARTIAL_LINE;
 437
 438	return 0;
 439}
 440EXPORT_SYMBOL(ftrace_raw_output_prep);
 441
 442static int ftrace_output_raw(struct trace_iterator *iter, char *name,
 443			     char *fmt, va_list ap)
 444{
 445	struct trace_seq *s = &iter->seq;
 446	int ret;
 447
 448	ret = trace_seq_printf(s, "%s: ", name);
 449	if (!ret)
 450		return TRACE_TYPE_PARTIAL_LINE;
 451
 452	ret = trace_seq_vprintf(s, fmt, ap);
 453
 454	if (!ret)
 455		return TRACE_TYPE_PARTIAL_LINE;
 456
 457	return TRACE_TYPE_HANDLED;
 458}
 459
 460int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 461{
 462	va_list ap;
 463	int ret;
 464
 465	va_start(ap, fmt);
 466	ret = ftrace_output_raw(iter, name, fmt, ap);
 467	va_end(ap);
 468
 469	return ret;
 470}
 471EXPORT_SYMBOL_GPL(ftrace_output_call);
 472
 473#ifdef CONFIG_KRETPROBES
 474static inline const char *kretprobed(const char *name)
 475{
 476	static const char tramp_name[] = "kretprobe_trampoline";
 477	int size = sizeof(tramp_name);
 478
 479	if (strncmp(tramp_name, name, size) == 0)
 480		return "[unknown/kretprobe'd]";
 481	return name;
 482}
 483#else
 484static inline const char *kretprobed(const char *name)
 485{
 486	return name;
 487}
 488#endif /* CONFIG_KRETPROBES */
 489
 490static int
 491seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 492{
 493#ifdef CONFIG_KALLSYMS
 494	char str[KSYM_SYMBOL_LEN];
 495	const char *name;
 496
 497	kallsyms_lookup(address, NULL, NULL, NULL, str);
 498
 499	name = kretprobed(str);
 500
 501	return trace_seq_printf(s, fmt, name);
 502#endif
 503	return 1;
 504}
 505
 506static int
 507seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 508		     unsigned long address)
 509{
 510#ifdef CONFIG_KALLSYMS
 511	char str[KSYM_SYMBOL_LEN];
 512	const char *name;
 513
 514	sprint_symbol(str, address);
 515	name = kretprobed(str);
 516
 517	return trace_seq_printf(s, fmt, name);
 518#endif
 519	return 1;
 520}
 521
 522#ifndef CONFIG_64BIT
 523# define IP_FMT "%08lx"
 524#else
 525# define IP_FMT "%016lx"
 526#endif
 527
 528int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 529		      unsigned long ip, unsigned long sym_flags)
 530{
 531	struct file *file = NULL;
 532	unsigned long vmstart = 0;
 533	int ret = 1;
 534
 535	if (s->full)
 536		return 0;
 537
 538	if (mm) {
 539		const struct vm_area_struct *vma;
 540
 541		down_read(&mm->mmap_sem);
 542		vma = find_vma(mm, ip);
 543		if (vma) {
 544			file = vma->vm_file;
 545			vmstart = vma->vm_start;
 546		}
 547		if (file) {
 548			ret = trace_seq_path(s, &file->f_path);
 549			if (ret)
 550				ret = trace_seq_printf(s, "[+0x%lx]",
 551						       ip - vmstart);
 552		}
 553		up_read(&mm->mmap_sem);
 554	}
 555	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 556		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 557	return ret;
 558}
 559
 560int
 561seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 562		      unsigned long sym_flags)
 563{
 564	struct mm_struct *mm = NULL;
 565	int ret = 1;
 566	unsigned int i;
 567
 568	if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 569		struct task_struct *task;
 570		/*
 571		 * we do the lookup on the thread group leader,
 572		 * since individual threads might have already quit!
 573		 */
 574		rcu_read_lock();
 575		task = find_task_by_vpid(entry->tgid);
 576		if (task)
 577			mm = get_task_mm(task);
 578		rcu_read_unlock();
 579	}
 580
 581	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 582		unsigned long ip = entry->caller[i];
 583
 584		if (ip == ULONG_MAX || !ret)
 585			break;
 586		if (ret)
 587			ret = trace_seq_puts(s, " => ");
 588		if (!ip) {
 589			if (ret)
 590				ret = trace_seq_puts(s, "??");
 591			if (ret)
 592				ret = trace_seq_putc(s, '\n');
 593			continue;
 594		}
 595		if (!ret)
 596			break;
 597		if (ret)
 598			ret = seq_print_user_ip(s, mm, ip, sym_flags);
 599		ret = trace_seq_putc(s, '\n');
 600	}
 601
 602	if (mm)
 603		mmput(mm);
 604	return ret;
 605}
 606
 607int
 608seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 609{
 610	int ret;
 611
 612	if (!ip)
 613		return trace_seq_putc(s, '0');
 614
 615	if (sym_flags & TRACE_ITER_SYM_OFFSET)
 616		ret = seq_print_sym_offset(s, "%s", ip);
 617	else
 618		ret = seq_print_sym_short(s, "%s", ip);
 619
 620	if (!ret)
 621		return 0;
 622
 623	if (sym_flags & TRACE_ITER_SYM_ADDR)
 624		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 625	return ret;
 626}
 627
 628/**
 629 * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 630 * @s: trace seq struct to write to
 631 * @entry: The trace entry field from the ring buffer
 632 *
 633 * Prints the generic fields of irqs off, in hard or softirq, preempt
 634 * count.
 635 */
 636int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 637{
 638	char hardsoft_irq;
 639	char need_resched;
 640	char irqs_off;
 641	int hardirq;
 642	int softirq;
 643	int ret;
 644
 645	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 646	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 647
 648	irqs_off =
 649		(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 650		(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 651		'.';
 652
 653	switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 654				TRACE_FLAG_PREEMPT_RESCHED)) {
 655	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 656		need_resched = 'N';
 657		break;
 658	case TRACE_FLAG_NEED_RESCHED:
 659		need_resched = 'n';
 660		break;
 661	case TRACE_FLAG_PREEMPT_RESCHED:
 662		need_resched = 'p';
 663		break;
 664	default:
 665		need_resched = '.';
 666		break;
 667	}
 668
 669	hardsoft_irq =
 670		(hardirq && softirq) ? 'H' :
 671		hardirq ? 'h' :
 672		softirq ? 's' :
 673		'.';
 674
 675	if (!trace_seq_printf(s, "%c%c%c",
 676			      irqs_off, need_resched, hardsoft_irq))
 677		return 0;
 678
 679	if (entry->preempt_count)
 680		ret = trace_seq_printf(s, "%x", entry->preempt_count);
 681	else
 682		ret = trace_seq_putc(s, '.');
 683
 684	return ret;
 685}
 686
 687static int
 688lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 689{
 690	char comm[TASK_COMM_LEN];
 691
 692	trace_find_cmdline(entry->pid, comm);
 693
 694	if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 695			      comm, entry->pid, cpu))
 696		return 0;
 697
 698	return trace_print_lat_fmt(s, entry);
 699}
 700
 701static unsigned long preempt_mark_thresh_us = 100;
 702
 703static int
 704lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 
 705{
 706	unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
 707	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 708	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 709	unsigned long long rel_ts = next_ts - iter->ts;
 710	struct trace_seq *s = &iter->seq;
 711
 712	if (in_ns) {
 713		abs_ts = ns2usecs(abs_ts);
 714		rel_ts = ns2usecs(rel_ts);
 715	}
 716
 717	if (verbose && in_ns) {
 718		unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 719		unsigned long abs_msec = (unsigned long)abs_ts;
 720		unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 721		unsigned long rel_msec = (unsigned long)rel_ts;
 722
 723		return trace_seq_printf(
 724				s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 725				ns2usecs(iter->ts),
 726				abs_msec, abs_usec,
 727				rel_msec, rel_usec);
 728	} else if (verbose && !in_ns) {
 729		return trace_seq_printf(
 730				s, "[%016llx] %lld (+%lld): ",
 731				iter->ts, abs_ts, rel_ts);
 732	} else if (!verbose && in_ns) {
 733		return trace_seq_printf(
 734				s, " %4lldus%c: ",
 735				abs_ts,
 736				rel_ts > preempt_mark_thresh_us ? '!' :
 737				  rel_ts > 1 ? '+' : ' ');
 738	} else { /* !verbose && !in_ns */
 739		return trace_seq_printf(s, " %4lld: ", abs_ts);
 740	}
 741}
 742
 743int trace_print_context(struct trace_iterator *iter)
 744{
 745	struct trace_seq *s = &iter->seq;
 746	struct trace_entry *entry = iter->ent;
 747	unsigned long long t;
 748	unsigned long secs, usec_rem;
 
 749	char comm[TASK_COMM_LEN];
 750	int ret;
 751
 752	trace_find_cmdline(entry->pid, comm);
 753
 754	ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
 755			       comm, entry->pid, iter->cpu);
 756	if (!ret)
 757		return 0;
 758
 759	if (trace_flags & TRACE_ITER_IRQ_INFO) {
 760		ret = trace_print_lat_fmt(s, entry);
 761		if (!ret)
 762			return 0;
 763	}
 764
 765	if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 766		t = ns2usecs(iter->ts);
 767		usec_rem = do_div(t, USEC_PER_SEC);
 768		secs = (unsigned long)t;
 769		return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 770	} else
 771		return trace_seq_printf(s, " %12llu: ", iter->ts);
 772}
 773
 774int trace_print_lat_context(struct trace_iterator *iter)
 775{
 776	u64 next_ts;
 777	int ret;
 778	/* trace_find_next_entry will reset ent_size */
 779	int ent_size = iter->ent_size;
 780	struct trace_seq *s = &iter->seq;
 781	struct trace_entry *entry = iter->ent,
 782			   *next_entry = trace_find_next_entry(iter, NULL,
 783							       &next_ts);
 784	unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 785
 786	/* Restore the original ent_size */
 787	iter->ent_size = ent_size;
 788
 789	if (!next_entry)
 790		next_ts = iter->ts;
 
 791
 792	if (verbose) {
 793		char comm[TASK_COMM_LEN];
 794
 795		trace_find_cmdline(entry->pid, comm);
 796
 797		ret = trace_seq_printf(
 798				s, "%16s %5d %3d %d %08x %08lx ",
 799				comm, entry->pid, iter->cpu, entry->flags,
 800				entry->preempt_count, iter->idx);
 
 
 
 
 
 801	} else {
 802		ret = lat_print_generic(s, entry, iter->cpu);
 
 
 803	}
 804
 805	if (ret)
 806		ret = lat_print_timestamp(iter, next_ts);
 807
 808	return ret;
 809}
 810
 811static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 812
 813static int task_state_char(unsigned long state)
 814{
 815	int bit = state ? __ffs(state) + 1 : 0;
 816
 817	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 818}
 819
 820/**
 821 * ftrace_find_event - find a registered event
 822 * @type: the type of event to look for
 823 *
 824 * Returns an event of type @type otherwise NULL
 825 * Called with trace_event_read_lock() held.
 826 */
 827struct trace_event *ftrace_find_event(int type)
 828{
 829	struct trace_event *event;
 
 830	unsigned key;
 831
 832	key = type & (EVENT_HASHSIZE - 1);
 833
 834	hlist_for_each_entry(event, &event_hash[key], node) {
 835		if (event->type == type)
 836			return event;
 837	}
 838
 839	return NULL;
 840}
 841
 842static LIST_HEAD(ftrace_event_list);
 843
 844static int trace_search_list(struct list_head **list)
 845{
 846	struct trace_event *e;
 847	int last = __TRACE_LAST_TYPE;
 848
 849	if (list_empty(&ftrace_event_list)) {
 850		*list = &ftrace_event_list;
 851		return last + 1;
 852	}
 853
 854	/*
 855	 * We used up all possible max events,
 856	 * lets see if somebody freed one.
 857	 */
 858	list_for_each_entry(e, &ftrace_event_list, list) {
 859		if (e->type != last + 1)
 860			break;
 861		last++;
 862	}
 863
 864	/* Did we used up all 65 thousand events??? */
 865	if ((last + 1) > FTRACE_MAX_EVENT)
 866		return 0;
 867
 868	*list = &e->list;
 869	return last + 1;
 870}
 871
 872void trace_event_read_lock(void)
 873{
 874	down_read(&trace_event_sem);
 875}
 876
 877void trace_event_read_unlock(void)
 878{
 879	up_read(&trace_event_sem);
 880}
 881
 882/**
 883 * register_ftrace_event - register output for an event type
 884 * @event: the event type to register
 885 *
 886 * Event types are stored in a hash and this hash is used to
 887 * find a way to print an event. If the @event->type is set
 888 * then it will use that type, otherwise it will assign a
 889 * type to use.
 890 *
 891 * If you assign your own type, please make sure it is added
 892 * to the trace_type enum in trace.h, to avoid collisions
 893 * with the dynamic types.
 894 *
 895 * Returns the event type number or zero on error.
 896 */
 897int register_ftrace_event(struct trace_event *event)
 898{
 899	unsigned key;
 900	int ret = 0;
 901
 902	down_write(&trace_event_sem);
 903
 904	if (WARN_ON(!event))
 905		goto out;
 906
 907	if (WARN_ON(!event->funcs))
 908		goto out;
 909
 910	INIT_LIST_HEAD(&event->list);
 911
 912	if (!event->type) {
 913		struct list_head *list = NULL;
 914
 915		if (next_event_type > FTRACE_MAX_EVENT) {
 916
 917			event->type = trace_search_list(&list);
 918			if (!event->type)
 919				goto out;
 920
 921		} else {
 922			
 923			event->type = next_event_type++;
 924			list = &ftrace_event_list;
 925		}
 926
 927		if (WARN_ON(ftrace_find_event(event->type)))
 928			goto out;
 929
 930		list_add_tail(&event->list, list);
 931
 932	} else if (event->type > __TRACE_LAST_TYPE) {
 933		printk(KERN_WARNING "Need to add type to trace.h\n");
 934		WARN_ON(1);
 935		goto out;
 936	} else {
 937		/* Is this event already used */
 938		if (ftrace_find_event(event->type))
 939			goto out;
 940	}
 941
 942	if (event->funcs->trace == NULL)
 943		event->funcs->trace = trace_nop_print;
 944	if (event->funcs->raw == NULL)
 945		event->funcs->raw = trace_nop_print;
 946	if (event->funcs->hex == NULL)
 947		event->funcs->hex = trace_nop_print;
 948	if (event->funcs->binary == NULL)
 949		event->funcs->binary = trace_nop_print;
 950
 951	key = event->type & (EVENT_HASHSIZE - 1);
 952
 953	hlist_add_head(&event->node, &event_hash[key]);
 954
 955	ret = event->type;
 956 out:
 957	up_write(&trace_event_sem);
 958
 959	return ret;
 960}
 961EXPORT_SYMBOL_GPL(register_ftrace_event);
 962
 963/*
 964 * Used by module code with the trace_event_sem held for write.
 965 */
 966int __unregister_ftrace_event(struct trace_event *event)
 967{
 968	hlist_del(&event->node);
 969	list_del(&event->list);
 970	return 0;
 971}
 972
 973/**
 974 * unregister_ftrace_event - remove a no longer used event
 975 * @event: the event to remove
 976 */
 977int unregister_ftrace_event(struct trace_event *event)
 978{
 979	down_write(&trace_event_sem);
 980	__unregister_ftrace_event(event);
 981	up_write(&trace_event_sem);
 982
 983	return 0;
 984}
 985EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 986
 987/*
 988 * Standard events
 989 */
 990
 991enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 992				  struct trace_event *event)
 993{
 994	if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
 995		return TRACE_TYPE_PARTIAL_LINE;
 996
 997	return TRACE_TYPE_HANDLED;
 998}
 999
1000/* TRACE_FN */
1001static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
1002					struct trace_event *event)
1003{
1004	struct ftrace_entry *field;
1005	struct trace_seq *s = &iter->seq;
1006
1007	trace_assign_type(field, iter->ent);
1008
1009	if (!seq_print_ip_sym(s, field->ip, flags))
1010		goto partial;
1011
1012	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
1013		if (!trace_seq_puts(s, " <-"))
1014			goto partial;
1015		if (!seq_print_ip_sym(s,
1016				      field->parent_ip,
1017				      flags))
1018			goto partial;
1019	}
1020	if (!trace_seq_putc(s, '\n'))
1021		goto partial;
1022
1023	return TRACE_TYPE_HANDLED;
1024
1025 partial:
1026	return TRACE_TYPE_PARTIAL_LINE;
1027}
1028
1029static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
1030				      struct trace_event *event)
1031{
1032	struct ftrace_entry *field;
1033
1034	trace_assign_type(field, iter->ent);
1035
1036	if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
1037			      field->ip,
1038			      field->parent_ip))
1039		return TRACE_TYPE_PARTIAL_LINE;
1040
1041	return TRACE_TYPE_HANDLED;
1042}
1043
1044static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
1045				      struct trace_event *event)
1046{
1047	struct ftrace_entry *field;
1048	struct trace_seq *s = &iter->seq;
1049
1050	trace_assign_type(field, iter->ent);
1051
1052	SEQ_PUT_HEX_FIELD_RET(s, field->ip);
1053	SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
1054
1055	return TRACE_TYPE_HANDLED;
1056}
1057
1058static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
1059				      struct trace_event *event)
1060{
1061	struct ftrace_entry *field;
1062	struct trace_seq *s = &iter->seq;
1063
1064	trace_assign_type(field, iter->ent);
1065
1066	SEQ_PUT_FIELD_RET(s, field->ip);
1067	SEQ_PUT_FIELD_RET(s, field->parent_ip);
1068
1069	return TRACE_TYPE_HANDLED;
1070}
1071
1072static struct trace_event_functions trace_fn_funcs = {
1073	.trace		= trace_fn_trace,
1074	.raw		= trace_fn_raw,
1075	.hex		= trace_fn_hex,
1076	.binary		= trace_fn_bin,
1077};
1078
1079static struct trace_event trace_fn_event = {
1080	.type		= TRACE_FN,
1081	.funcs		= &trace_fn_funcs,
1082};
1083
1084/* TRACE_CTX an TRACE_WAKE */
1085static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
1086					     char *delim)
1087{
1088	struct ctx_switch_entry *field;
1089	char comm[TASK_COMM_LEN];
1090	int S, T;
1091
1092
1093	trace_assign_type(field, iter->ent);
1094
1095	T = task_state_char(field->next_state);
1096	S = task_state_char(field->prev_state);
1097	trace_find_cmdline(field->next_pid, comm);
1098	if (!trace_seq_printf(&iter->seq,
1099			      " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1100			      field->prev_pid,
1101			      field->prev_prio,
1102			      S, delim,
1103			      field->next_cpu,
1104			      field->next_pid,
1105			      field->next_prio,
1106			      T, comm))
1107		return TRACE_TYPE_PARTIAL_LINE;
1108
1109	return TRACE_TYPE_HANDLED;
1110}
1111
1112static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
1113					 struct trace_event *event)
1114{
1115	return trace_ctxwake_print(iter, "==>");
1116}
1117
1118static enum print_line_t trace_wake_print(struct trace_iterator *iter,
1119					  int flags, struct trace_event *event)
1120{
1121	return trace_ctxwake_print(iter, "  +");
1122}
1123
1124static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
1125{
1126	struct ctx_switch_entry *field;
1127	int T;
1128
1129	trace_assign_type(field, iter->ent);
1130
1131	if (!S)
1132		S = task_state_char(field->prev_state);
1133	T = task_state_char(field->next_state);
1134	if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1135			      field->prev_pid,
1136			      field->prev_prio,
1137			      S,
1138			      field->next_cpu,
1139			      field->next_pid,
1140			      field->next_prio,
1141			      T))
1142		return TRACE_TYPE_PARTIAL_LINE;
1143
1144	return TRACE_TYPE_HANDLED;
1145}
1146
1147static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1148				       struct trace_event *event)
1149{
1150	return trace_ctxwake_raw(iter, 0);
1151}
1152
1153static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1154					struct trace_event *event)
1155{
1156	return trace_ctxwake_raw(iter, '+');
1157}
1158
1159
1160static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1161{
1162	struct ctx_switch_entry *field;
1163	struct trace_seq *s = &iter->seq;
1164	int T;
1165
1166	trace_assign_type(field, iter->ent);
1167
1168	if (!S)
1169		S = task_state_char(field->prev_state);
1170	T = task_state_char(field->next_state);
1171
1172	SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1173	SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1174	SEQ_PUT_HEX_FIELD_RET(s, S);
1175	SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1176	SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1177	SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1178	SEQ_PUT_HEX_FIELD_RET(s, T);
1179
1180	return TRACE_TYPE_HANDLED;
1181}
1182
1183static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1184				       struct trace_event *event)
1185{
1186	return trace_ctxwake_hex(iter, 0);
1187}
1188
1189static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1190					struct trace_event *event)
1191{
1192	return trace_ctxwake_hex(iter, '+');
1193}
1194
1195static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1196					   int flags, struct trace_event *event)
1197{
1198	struct ctx_switch_entry *field;
1199	struct trace_seq *s = &iter->seq;
1200
1201	trace_assign_type(field, iter->ent);
1202
1203	SEQ_PUT_FIELD_RET(s, field->prev_pid);
1204	SEQ_PUT_FIELD_RET(s, field->prev_prio);
1205	SEQ_PUT_FIELD_RET(s, field->prev_state);
1206	SEQ_PUT_FIELD_RET(s, field->next_pid);
1207	SEQ_PUT_FIELD_RET(s, field->next_prio);
1208	SEQ_PUT_FIELD_RET(s, field->next_state);
1209
1210	return TRACE_TYPE_HANDLED;
1211}
1212
1213static struct trace_event_functions trace_ctx_funcs = {
1214	.trace		= trace_ctx_print,
1215	.raw		= trace_ctx_raw,
1216	.hex		= trace_ctx_hex,
1217	.binary		= trace_ctxwake_bin,
1218};
1219
1220static struct trace_event trace_ctx_event = {
1221	.type		= TRACE_CTX,
1222	.funcs		= &trace_ctx_funcs,
1223};
1224
1225static struct trace_event_functions trace_wake_funcs = {
1226	.trace		= trace_wake_print,
1227	.raw		= trace_wake_raw,
1228	.hex		= trace_wake_hex,
1229	.binary		= trace_ctxwake_bin,
1230};
1231
1232static struct trace_event trace_wake_event = {
1233	.type		= TRACE_WAKE,
1234	.funcs		= &trace_wake_funcs,
1235};
1236
1237/* TRACE_STACK */
1238
1239static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1240					   int flags, struct trace_event *event)
1241{
1242	struct stack_entry *field;
1243	struct trace_seq *s = &iter->seq;
1244	unsigned long *p;
1245	unsigned long *end;
1246
1247	trace_assign_type(field, iter->ent);
1248	end = (unsigned long *)((long)iter->ent + iter->ent_size);
1249
1250	if (!trace_seq_puts(s, "<stack trace>\n"))
1251		goto partial;
1252
1253	for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1254		if (!trace_seq_puts(s, " => "))
1255			goto partial;
1256
1257		if (!seq_print_ip_sym(s, *p, flags))
1258			goto partial;
1259		if (!trace_seq_putc(s, '\n'))
1260			goto partial;
1261	}
1262
1263	return TRACE_TYPE_HANDLED;
1264
1265 partial:
1266	return TRACE_TYPE_PARTIAL_LINE;
1267}
1268
1269static struct trace_event_functions trace_stack_funcs = {
1270	.trace		= trace_stack_print,
1271};
1272
1273static struct trace_event trace_stack_event = {
1274	.type		= TRACE_STACK,
1275	.funcs		= &trace_stack_funcs,
1276};
1277
1278/* TRACE_USER_STACK */
1279static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1280						int flags, struct trace_event *event)
1281{
1282	struct userstack_entry *field;
1283	struct trace_seq *s = &iter->seq;
1284
1285	trace_assign_type(field, iter->ent);
1286
1287	if (!trace_seq_puts(s, "<user stack trace>\n"))
1288		goto partial;
1289
1290	if (!seq_print_userip_objs(field, s, flags))
1291		goto partial;
1292
1293	return TRACE_TYPE_HANDLED;
1294
1295 partial:
1296	return TRACE_TYPE_PARTIAL_LINE;
1297}
1298
1299static struct trace_event_functions trace_user_stack_funcs = {
1300	.trace		= trace_user_stack_print,
1301};
1302
1303static struct trace_event trace_user_stack_event = {
1304	.type		= TRACE_USER_STACK,
1305	.funcs		= &trace_user_stack_funcs,
1306};
1307
1308/* TRACE_BPUTS */
1309static enum print_line_t
1310trace_bputs_print(struct trace_iterator *iter, int flags,
1311		   struct trace_event *event)
1312{
1313	struct trace_entry *entry = iter->ent;
1314	struct trace_seq *s = &iter->seq;
1315	struct bputs_entry *field;
1316
1317	trace_assign_type(field, entry);
1318
1319	if (!seq_print_ip_sym(s, field->ip, flags))
1320		goto partial;
1321
1322	if (!trace_seq_puts(s, ": "))
1323		goto partial;
1324
1325	if (!trace_seq_puts(s, field->str))
1326		goto partial;
1327
1328	return TRACE_TYPE_HANDLED;
1329
1330 partial:
1331	return TRACE_TYPE_PARTIAL_LINE;
1332}
1333
1334
1335static enum print_line_t
1336trace_bputs_raw(struct trace_iterator *iter, int flags,
1337		struct trace_event *event)
1338{
1339	struct bputs_entry *field;
1340	struct trace_seq *s = &iter->seq;
1341
1342	trace_assign_type(field, iter->ent);
1343
1344	if (!trace_seq_printf(s, ": %lx : ", field->ip))
1345		goto partial;
1346
1347	if (!trace_seq_puts(s, field->str))
1348		goto partial;
1349
1350	return TRACE_TYPE_HANDLED;
1351
1352 partial:
1353	return TRACE_TYPE_PARTIAL_LINE;
1354}
1355
1356static struct trace_event_functions trace_bputs_funcs = {
1357	.trace		= trace_bputs_print,
1358	.raw		= trace_bputs_raw,
1359};
1360
1361static struct trace_event trace_bputs_event = {
1362	.type		= TRACE_BPUTS,
1363	.funcs		= &trace_bputs_funcs,
1364};
1365
1366/* TRACE_BPRINT */
1367static enum print_line_t
1368trace_bprint_print(struct trace_iterator *iter, int flags,
1369		   struct trace_event *event)
1370{
1371	struct trace_entry *entry = iter->ent;
1372	struct trace_seq *s = &iter->seq;
1373	struct bprint_entry *field;
1374
1375	trace_assign_type(field, entry);
1376
1377	if (!seq_print_ip_sym(s, field->ip, flags))
1378		goto partial;
1379
1380	if (!trace_seq_puts(s, ": "))
1381		goto partial;
1382
1383	if (!trace_seq_bprintf(s, field->fmt, field->buf))
1384		goto partial;
1385
1386	return TRACE_TYPE_HANDLED;
1387
1388 partial:
1389	return TRACE_TYPE_PARTIAL_LINE;
1390}
1391
1392
1393static enum print_line_t
1394trace_bprint_raw(struct trace_iterator *iter, int flags,
1395		 struct trace_event *event)
1396{
1397	struct bprint_entry *field;
1398	struct trace_seq *s = &iter->seq;
1399
1400	trace_assign_type(field, iter->ent);
1401
1402	if (!trace_seq_printf(s, ": %lx : ", field->ip))
1403		goto partial;
1404
1405	if (!trace_seq_bprintf(s, field->fmt, field->buf))
1406		goto partial;
1407
1408	return TRACE_TYPE_HANDLED;
1409
1410 partial:
1411	return TRACE_TYPE_PARTIAL_LINE;
1412}
1413
1414static struct trace_event_functions trace_bprint_funcs = {
1415	.trace		= trace_bprint_print,
1416	.raw		= trace_bprint_raw,
1417};
1418
1419static struct trace_event trace_bprint_event = {
1420	.type		= TRACE_BPRINT,
1421	.funcs		= &trace_bprint_funcs,
1422};
1423
1424/* TRACE_PRINT */
1425static enum print_line_t trace_print_print(struct trace_iterator *iter,
1426					   int flags, struct trace_event *event)
1427{
1428	struct print_entry *field;
1429	struct trace_seq *s = &iter->seq;
1430
1431	trace_assign_type(field, iter->ent);
1432
1433	if (!seq_print_ip_sym(s, field->ip, flags))
1434		goto partial;
1435
1436	if (!trace_seq_printf(s, ": %s", field->buf))
1437		goto partial;
1438
1439	return TRACE_TYPE_HANDLED;
1440
1441 partial:
1442	return TRACE_TYPE_PARTIAL_LINE;
1443}
1444
1445static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1446					 struct trace_event *event)
1447{
1448	struct print_entry *field;
1449
1450	trace_assign_type(field, iter->ent);
1451
1452	if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1453		goto partial;
1454
1455	return TRACE_TYPE_HANDLED;
1456
1457 partial:
1458	return TRACE_TYPE_PARTIAL_LINE;
1459}
1460
1461static struct trace_event_functions trace_print_funcs = {
1462	.trace		= trace_print_print,
1463	.raw		= trace_print_raw,
1464};
1465
1466static struct trace_event trace_print_event = {
1467	.type	 	= TRACE_PRINT,
1468	.funcs		= &trace_print_funcs,
1469};
1470
1471
1472static struct trace_event *events[] __initdata = {
1473	&trace_fn_event,
1474	&trace_ctx_event,
1475	&trace_wake_event,
1476	&trace_stack_event,
1477	&trace_user_stack_event,
1478	&trace_bputs_event,
1479	&trace_bprint_event,
1480	&trace_print_event,
1481	NULL
1482};
1483
1484__init static int init_events(void)
1485{
1486	struct trace_event *event;
1487	int i, ret;
1488
1489	for (i = 0; events[i]; i++) {
1490		event = events[i];
1491
1492		ret = register_ftrace_event(event);
1493		if (!ret) {
1494			printk(KERN_WARNING "event %d failed to register\n",
1495			       event->type);
1496			WARN_ON_ONCE(1);
1497		}
1498	}
1499
1500	return 0;
1501}
1502early_initcall(init_events);
v3.1
   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);