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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * trace_output.c
   4 *
   5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   6 *
   7 */
 
   8#include <linux/module.h>
   9#include <linux/mutex.h>
  10#include <linux/ftrace.h>
  11#include <linux/sched/clock.h>
  12#include <linux/sched/mm.h>
  13
  14#include "trace_output.h"
  15
  16/* must be a power of 2 */
  17#define EVENT_HASHSIZE	128
  18
  19DECLARE_RWSEM(trace_event_sem);
  20
  21static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  22
  23static int next_event_type = __TRACE_LAST_TYPE + 1;
  24
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  25enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  26{
  27	struct trace_seq *s = &iter->seq;
  28	struct trace_entry *entry = iter->ent;
  29	struct bputs_entry *field;
 
  30
  31	trace_assign_type(field, entry);
  32
  33	trace_seq_puts(s, field->str);
 
 
  34
  35	return trace_handle_return(s);
  36}
  37
  38enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  39{
  40	struct trace_seq *s = &iter->seq;
  41	struct trace_entry *entry = iter->ent;
  42	struct bprint_entry *field;
 
  43
  44	trace_assign_type(field, entry);
  45
  46	trace_seq_bprintf(s, field->fmt, field->buf);
 
 
  47
  48	return trace_handle_return(s);
  49}
  50
  51enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  52{
  53	struct trace_seq *s = &iter->seq;
  54	struct trace_entry *entry = iter->ent;
  55	struct print_entry *field;
 
  56
  57	trace_assign_type(field, entry);
  58
  59	trace_seq_puts(s, field->buf);
 
 
  60
  61	return trace_handle_return(s);
  62}
  63
  64const char *
  65trace_print_flags_seq(struct trace_seq *p, const char *delim,
  66		      unsigned long flags,
  67		      const struct trace_print_flags *flag_array)
 
 
 
 
 
 
 
 
 
 
 
 
  68{
  69	unsigned long mask;
  70	const char *str;
  71	const char *ret = trace_seq_buffer_ptr(p);
  72	int i, first = 1;
  73
  74	for (i = 0;  flag_array[i].name && flags; i++) {
 
  75
  76		mask = flag_array[i].mask;
  77		if ((flags & mask) != mask)
  78			continue;
  79
  80		str = flag_array[i].name;
  81		flags &= ~mask;
  82		if (!first && delim)
  83			trace_seq_puts(p, delim);
  84		else
  85			first = 0;
  86		trace_seq_puts(p, str);
  87	}
  88
  89	/* check for left over flags */
  90	if (flags) {
  91		if (!first && delim)
  92			trace_seq_puts(p, delim);
  93		trace_seq_printf(p, "0x%lx", flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  94	}
  95
  96	trace_seq_putc(p, 0);
  97
  98	return ret;
  99}
 100EXPORT_SYMBOL(trace_print_flags_seq);
 101
 102const char *
 103trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 104			const struct trace_print_flags *symbol_array)
 105{
 106	int i;
 107	const char *ret = trace_seq_buffer_ptr(p);
 108
 109	for (i = 0;  symbol_array[i].name; i++) {
 
 110
 111		if (val != symbol_array[i].mask)
 112			continue;
 113
 114		trace_seq_puts(p, symbol_array[i].name);
 115		break;
 
 
 116	}
 117
 118	if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 119		trace_seq_printf(p, "0x%lx", val);
 120
 121	trace_seq_putc(p, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 122
 123	return ret;
 124}
 125EXPORT_SYMBOL(trace_print_symbols_seq);
 126
 127#if BITS_PER_LONG == 32
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 128const char *
 129trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 130		      unsigned long long flags,
 131		      const struct trace_print_flags_u64 *flag_array)
 132{
 133	unsigned long long mask;
 134	const char *str;
 135	const char *ret = trace_seq_buffer_ptr(p);
 136	int i, first = 1;
 137
 138	for (i = 0;  flag_array[i].name && flags; i++) {
 139
 140		mask = flag_array[i].mask;
 141		if ((flags & mask) != mask)
 142			continue;
 143
 144		str = flag_array[i].name;
 145		flags &= ~mask;
 146		if (!first && delim)
 147			trace_seq_puts(p, delim);
 148		else
 149			first = 0;
 150		trace_seq_puts(p, str);
 151	}
 152
 153	/* check for left over flags */
 154	if (flags) {
 155		if (!first && delim)
 156			trace_seq_puts(p, delim);
 157		trace_seq_printf(p, "0x%llx", flags);
 158	}
 159
 160	trace_seq_putc(p, 0);
 161
 162	return ret;
 163}
 164EXPORT_SYMBOL(trace_print_flags_seq_u64);
 165
 166const char *
 167trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 168			 const struct trace_print_flags_u64 *symbol_array)
 169{
 170	int i;
 171	const char *ret = trace_seq_buffer_ptr(p);
 172
 173	for (i = 0;  symbol_array[i].name; i++) {
 174
 175		if (val != symbol_array[i].mask)
 176			continue;
 177
 178		trace_seq_puts(p, symbol_array[i].name);
 179		break;
 180	}
 181
 182	if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 183		trace_seq_printf(p, "0x%llx", val);
 184
 185	trace_seq_putc(p, 0);
 186
 187	return ret;
 188}
 189EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 190#endif
 191
 
 192const char *
 193trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 194			unsigned int bitmask_size)
 195{
 196	const char *ret = trace_seq_buffer_ptr(p);
 
 197
 198	trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 199	trace_seq_putc(p, 0);
 200
 201	return ret;
 202}
 203EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 204
 205/**
 206 * trace_print_hex_seq - print buffer as hex sequence
 207 * @p: trace seq struct to write to
 208 * @buf: The buffer to print
 209 * @buf_len: Length of @buf in bytes
 210 * @concatenate: Print @buf as single hex string or with spacing
 211 *
 212 * Prints the passed buffer as a hex sequence either as a whole,
 213 * single hex string if @concatenate is true or with spacing after
 214 * each byte in case @concatenate is false.
 215 */
 216const char *
 217trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 218		    bool concatenate)
 219{
 220	int i;
 221	const char *ret = trace_seq_buffer_ptr(p);
 222	const char *fmt = concatenate ? "%*phN" : "%*ph";
 223
 224	for (i = 0; i < buf_len; i += 16)
 225		trace_seq_printf(p, fmt, min(buf_len - i, 16), &buf[i]);
 226	trace_seq_putc(p, 0);
 227
 228	return ret;
 229}
 230EXPORT_SYMBOL(trace_print_hex_seq);
 
 231
 232const char *
 233trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 234		      size_t el_size)
 235{
 236	const char *ret = trace_seq_buffer_ptr(p);
 237	const char *prefix = "";
 238	void *ptr = (void *)buf;
 239	size_t buf_len = count * el_size;
 240
 241	trace_seq_putc(p, '{');
 242
 243	while (ptr < buf + buf_len) {
 244		switch (el_size) {
 245		case 1:
 246			trace_seq_printf(p, "%s0x%x", prefix,
 247					 *(u8 *)ptr);
 248			break;
 249		case 2:
 250			trace_seq_printf(p, "%s0x%x", prefix,
 251					 *(u16 *)ptr);
 252			break;
 253		case 4:
 254			trace_seq_printf(p, "%s0x%x", prefix,
 255					 *(u32 *)ptr);
 256			break;
 257		case 8:
 258			trace_seq_printf(p, "%s0x%llx", prefix,
 259					 *(u64 *)ptr);
 260			break;
 261		default:
 262			trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 263					 *(u8 *)ptr);
 264			el_size = 1;
 265		}
 266		prefix = ",";
 267		ptr += el_size;
 268	}
 269
 270	trace_seq_putc(p, '}');
 271	trace_seq_putc(p, 0);
 272
 273	return ret;
 274}
 275EXPORT_SYMBOL(trace_print_array_seq);
 276
 277int trace_raw_output_prep(struct trace_iterator *iter,
 278			  struct trace_event *trace_event)
 279{
 280	struct trace_event_call *event;
 281	struct trace_seq *s = &iter->seq;
 282	struct trace_seq *p = &iter->tmp_seq;
 283	struct trace_entry *entry;
 
 284
 285	event = container_of(trace_event, struct trace_event_call, event);
 286	entry = iter->ent;
 287
 288	if (entry->type != event->event.type) {
 289		WARN_ON_ONCE(1);
 290		return TRACE_TYPE_UNHANDLED;
 291	}
 292
 293	trace_seq_init(p);
 294	trace_seq_printf(s, "%s: ", trace_event_name(event));
 
 
 295
 296	return trace_handle_return(s);
 297}
 298EXPORT_SYMBOL(trace_raw_output_prep);
 299
 300static int trace_output_raw(struct trace_iterator *iter, char *name,
 301			    char *fmt, va_list ap)
 302{
 303	struct trace_seq *s = &iter->seq;
 
 304
 305	trace_seq_printf(s, "%s: ", name);
 306	trace_seq_vprintf(s, fmt, ap);
 
 307
 308	return trace_handle_return(s);
 
 
 
 
 
 309}
 310
 311int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 312{
 313	va_list ap;
 314	int ret;
 315
 316	va_start(ap, fmt);
 317	ret = trace_output_raw(iter, name, fmt, ap);
 318	va_end(ap);
 319
 320	return ret;
 321}
 322EXPORT_SYMBOL_GPL(trace_output_call);
 323
 324#ifdef CONFIG_KRETPROBES
 325static inline const char *kretprobed(const char *name)
 326{
 327	static const char tramp_name[] = "kretprobe_trampoline";
 328	int size = sizeof(tramp_name);
 329
 330	if (strncmp(tramp_name, name, size) == 0)
 331		return "[unknown/kretprobe'd]";
 332	return name;
 333}
 334#else
 335static inline const char *kretprobed(const char *name)
 336{
 337	return name;
 338}
 339#endif /* CONFIG_KRETPROBES */
 340
 341static void
 342seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
 343{
 344#ifdef CONFIG_KALLSYMS
 345	char str[KSYM_SYMBOL_LEN];
 346	const char *name;
 347
 348	if (offset)
 349		sprint_symbol(str, address);
 350	else
 351		kallsyms_lookup(address, NULL, NULL, NULL, str);
 352	name = kretprobed(str);
 353
 354	if (name && strlen(name)) {
 355		trace_seq_puts(s, name);
 356		return;
 357	}
 358#endif
 359	trace_seq_printf(s, "0x%08lx", address);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 360}
 361
 362#ifndef CONFIG_64BIT
 363# define IP_FMT "%08lx"
 364#else
 365# define IP_FMT "%016lx"
 366#endif
 367
 368static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 369			     unsigned long ip, unsigned long sym_flags)
 370{
 371	struct file *file = NULL;
 372	unsigned long vmstart = 0;
 373	int ret = 1;
 374
 375	if (s->full)
 376		return 0;
 377
 378	if (mm) {
 379		const struct vm_area_struct *vma;
 380
 381		down_read(&mm->mmap_sem);
 382		vma = find_vma(mm, ip);
 383		if (vma) {
 384			file = vma->vm_file;
 385			vmstart = vma->vm_start;
 386		}
 387		if (file) {
 388			ret = trace_seq_path(s, &file->f_path);
 389			if (ret)
 390				trace_seq_printf(s, "[+0x%lx]",
 391						 ip - vmstart);
 392		}
 393		up_read(&mm->mmap_sem);
 394	}
 395	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 396		trace_seq_printf(s, " <" IP_FMT ">", ip);
 397	return !trace_seq_has_overflowed(s);
 398}
 399
 400int
 401seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 
 402{
 403	if (!ip) {
 404		trace_seq_putc(s, '0');
 405		goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 406	}
 407
 408	seq_print_sym(s, ip, sym_flags & TRACE_ITER_SYM_OFFSET);
 
 409
 410	if (sym_flags & TRACE_ITER_SYM_ADDR)
 411		trace_seq_printf(s, " <" IP_FMT ">", ip);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 412
 413 out:
 414	return !trace_seq_has_overflowed(s);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 415}
 416
 417/**
 418 * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 419 * @s: trace seq struct to write to
 420 * @entry: The trace entry field from the ring buffer
 421 *
 422 * Prints the generic fields of irqs off, in hard or softirq, preempt
 423 * count.
 424 */
 425int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 426{
 427	char hardsoft_irq;
 428	char need_resched;
 429	char irqs_off;
 430	int hardirq;
 431	int softirq;
 432	int nmi;
 433
 434	nmi = entry->flags & TRACE_FLAG_NMI;
 435	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 436	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 437
 438	irqs_off =
 439		(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 440		(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 441		'.';
 442
 443	switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 444				TRACE_FLAG_PREEMPT_RESCHED)) {
 445	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 446		need_resched = 'N';
 447		break;
 448	case TRACE_FLAG_NEED_RESCHED:
 449		need_resched = 'n';
 450		break;
 451	case TRACE_FLAG_PREEMPT_RESCHED:
 452		need_resched = 'p';
 453		break;
 454	default:
 455		need_resched = '.';
 456		break;
 457	}
 458
 459	hardsoft_irq =
 460		(nmi && hardirq)     ? 'Z' :
 461		nmi                  ? 'z' :
 462		(hardirq && softirq) ? 'H' :
 463		hardirq              ? 'h' :
 464		softirq              ? 's' :
 465		                       '.' ;
 466
 467	trace_seq_printf(s, "%c%c%c",
 468			 irqs_off, need_resched, hardsoft_irq);
 
 469
 470	if (entry->preempt_count)
 471		trace_seq_printf(s, "%x", entry->preempt_count);
 472	else
 473		trace_seq_putc(s, '.');
 474
 475	return !trace_seq_has_overflowed(s);
 476}
 477
 478static int
 479lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 480{
 481	char comm[TASK_COMM_LEN];
 482
 483	trace_find_cmdline(entry->pid, comm);
 484
 485	trace_seq_printf(s, "%8.8s-%-5d %3d",
 486			 comm, entry->pid, cpu);
 
 487
 488	return trace_print_lat_fmt(s, entry);
 489}
 490
 491#undef MARK
 492#define MARK(v, s) {.val = v, .sym = s}
 493/* trace overhead mark */
 494static const struct trace_mark {
 495	unsigned long long	val; /* unit: nsec */
 496	char			sym;
 497} mark[] = {
 498	MARK(1000000000ULL	, '$'), /* 1 sec */
 499	MARK(100000000ULL	, '@'), /* 100 msec */
 500	MARK(10000000ULL	, '*'), /* 10 msec */
 501	MARK(1000000ULL		, '#'), /* 1000 usecs */
 502	MARK(100000ULL		, '!'), /* 100 usecs */
 503	MARK(10000ULL		, '+'), /* 10 usecs */
 504};
 505#undef MARK
 506
 507char trace_find_mark(unsigned long long d)
 508{
 509	int i;
 510	int size = ARRAY_SIZE(mark);
 511
 512	for (i = 0; i < size; i++) {
 513		if (d > mark[i].val)
 514			break;
 515	}
 516
 517	return (i == size) ? ' ' : mark[i].sym;
 518}
 519
 520static int
 521lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 522{
 523	struct trace_array *tr = iter->tr;
 524	unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 525	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 526	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 527	unsigned long long rel_ts = next_ts - iter->ts;
 528	struct trace_seq *s = &iter->seq;
 529
 530	if (in_ns) {
 531		abs_ts = ns2usecs(abs_ts);
 532		rel_ts = ns2usecs(rel_ts);
 533	}
 534
 535	if (verbose && in_ns) {
 536		unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 537		unsigned long abs_msec = (unsigned long)abs_ts;
 538		unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 539		unsigned long rel_msec = (unsigned long)rel_ts;
 540
 541		trace_seq_printf(
 542			s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 543			ns2usecs(iter->ts),
 544			abs_msec, abs_usec,
 545			rel_msec, rel_usec);
 546
 547	} else if (verbose && !in_ns) {
 548		trace_seq_printf(
 549			s, "[%016llx] %lld (+%lld): ",
 550			iter->ts, abs_ts, rel_ts);
 551
 552	} else if (!verbose && in_ns) {
 553		trace_seq_printf(
 554			s, " %4lldus%c: ",
 555			abs_ts,
 556			trace_find_mark(rel_ts * NSEC_PER_USEC));
 557
 558	} else { /* !verbose && !in_ns */
 559		trace_seq_printf(s, " %4lld: ", abs_ts);
 560	}
 561
 562	return !trace_seq_has_overflowed(s);
 563}
 564
 565int trace_print_context(struct trace_iterator *iter)
 566{
 567	struct trace_array *tr = iter->tr;
 568	struct trace_seq *s = &iter->seq;
 569	struct trace_entry *entry = iter->ent;
 570	unsigned long long t;
 571	unsigned long secs, usec_rem;
 572	char comm[TASK_COMM_LEN];
 
 573
 574	trace_find_cmdline(entry->pid, comm);
 575
 576	trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
 577
 578	if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 579		unsigned int tgid = trace_find_tgid(entry->pid);
 580
 581		if (!tgid)
 582			trace_seq_printf(s, "(-----) ");
 583		else
 584			trace_seq_printf(s, "(%5d) ", tgid);
 585	}
 586
 587	trace_seq_printf(s, "[%03d] ", iter->cpu);
 588
 589	if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 590		trace_print_lat_fmt(s, entry);
 591
 592	if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 593		t = ns2usecs(iter->ts);
 594		usec_rem = do_div(t, USEC_PER_SEC);
 595		secs = (unsigned long)t;
 596		trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 597	} else
 598		trace_seq_printf(s, " %12llu: ", iter->ts);
 599
 600	return !trace_seq_has_overflowed(s);
 601}
 602
 603int trace_print_lat_context(struct trace_iterator *iter)
 604{
 605	struct trace_array *tr = iter->tr;
 
 606	/* trace_find_next_entry will reset ent_size */
 607	int ent_size = iter->ent_size;
 608	struct trace_seq *s = &iter->seq;
 609	u64 next_ts;
 610	struct trace_entry *entry = iter->ent,
 611			   *next_entry = trace_find_next_entry(iter, NULL,
 612							       &next_ts);
 613	unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 614
 615	/* Restore the original ent_size */
 616	iter->ent_size = ent_size;
 617
 618	if (!next_entry)
 619		next_ts = iter->ts;
 620
 621	if (verbose) {
 622		char comm[TASK_COMM_LEN];
 623
 624		trace_find_cmdline(entry->pid, comm);
 625
 626		trace_seq_printf(
 627			s, "%16s %5d %3d %d %08x %08lx ",
 628			comm, entry->pid, iter->cpu, entry->flags,
 629			entry->preempt_count, iter->idx);
 630	} else {
 631		lat_print_generic(s, entry, iter->cpu);
 632	}
 633
 634	lat_print_timestamp(iter, next_ts);
 
 
 
 
 
 
 635
 636	return !trace_seq_has_overflowed(s);
 
 
 
 
 637}
 638
 639/**
 640 * ftrace_find_event - find a registered event
 641 * @type: the type of event to look for
 642 *
 643 * Returns an event of type @type otherwise NULL
 644 * Called with trace_event_read_lock() held.
 645 */
 646struct trace_event *ftrace_find_event(int type)
 647{
 648	struct trace_event *event;
 649	unsigned key;
 650
 651	key = type & (EVENT_HASHSIZE - 1);
 652
 653	hlist_for_each_entry(event, &event_hash[key], node) {
 654		if (event->type == type)
 655			return event;
 656	}
 657
 658	return NULL;
 659}
 660
 661static LIST_HEAD(ftrace_event_list);
 662
 663static int trace_search_list(struct list_head **list)
 664{
 665	struct trace_event *e;
 666	int last = __TRACE_LAST_TYPE;
 667
 668	if (list_empty(&ftrace_event_list)) {
 669		*list = &ftrace_event_list;
 670		return last + 1;
 671	}
 672
 673	/*
 674	 * We used up all possible max events,
 675	 * lets see if somebody freed one.
 676	 */
 677	list_for_each_entry(e, &ftrace_event_list, list) {
 678		if (e->type != last + 1)
 679			break;
 680		last++;
 681	}
 682
 683	/* Did we used up all 65 thousand events??? */
 684	if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 685		return 0;
 686
 687	*list = &e->list;
 688	return last + 1;
 689}
 690
 691void trace_event_read_lock(void)
 692{
 693	down_read(&trace_event_sem);
 694}
 695
 696void trace_event_read_unlock(void)
 697{
 698	up_read(&trace_event_sem);
 699}
 700
 701/**
 702 * register_trace_event - register output for an event type
 703 * @event: the event type to register
 704 *
 705 * Event types are stored in a hash and this hash is used to
 706 * find a way to print an event. If the @event->type is set
 707 * then it will use that type, otherwise it will assign a
 708 * type to use.
 709 *
 710 * If you assign your own type, please make sure it is added
 711 * to the trace_type enum in trace.h, to avoid collisions
 712 * with the dynamic types.
 713 *
 714 * Returns the event type number or zero on error.
 715 */
 716int register_trace_event(struct trace_event *event)
 717{
 718	unsigned key;
 719	int ret = 0;
 720
 721	down_write(&trace_event_sem);
 722
 723	if (WARN_ON(!event))
 724		goto out;
 725
 726	if (WARN_ON(!event->funcs))
 727		goto out;
 728
 729	INIT_LIST_HEAD(&event->list);
 730
 731	if (!event->type) {
 732		struct list_head *list = NULL;
 733
 734		if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 735
 736			event->type = trace_search_list(&list);
 737			if (!event->type)
 738				goto out;
 739
 740		} else {
 741
 742			event->type = next_event_type++;
 743			list = &ftrace_event_list;
 744		}
 745
 746		if (WARN_ON(ftrace_find_event(event->type)))
 747			goto out;
 748
 749		list_add_tail(&event->list, list);
 750
 751	} else if (event->type > __TRACE_LAST_TYPE) {
 752		printk(KERN_WARNING "Need to add type to trace.h\n");
 753		WARN_ON(1);
 754		goto out;
 755	} else {
 756		/* Is this event already used */
 757		if (ftrace_find_event(event->type))
 758			goto out;
 759	}
 760
 761	if (event->funcs->trace == NULL)
 762		event->funcs->trace = trace_nop_print;
 763	if (event->funcs->raw == NULL)
 764		event->funcs->raw = trace_nop_print;
 765	if (event->funcs->hex == NULL)
 766		event->funcs->hex = trace_nop_print;
 767	if (event->funcs->binary == NULL)
 768		event->funcs->binary = trace_nop_print;
 769
 770	key = event->type & (EVENT_HASHSIZE - 1);
 771
 772	hlist_add_head(&event->node, &event_hash[key]);
 773
 774	ret = event->type;
 775 out:
 776	up_write(&trace_event_sem);
 777
 778	return ret;
 779}
 780EXPORT_SYMBOL_GPL(register_trace_event);
 781
 782/*
 783 * Used by module code with the trace_event_sem held for write.
 784 */
 785int __unregister_trace_event(struct trace_event *event)
 786{
 787	hlist_del(&event->node);
 788	list_del(&event->list);
 789	return 0;
 790}
 791
 792/**
 793 * unregister_trace_event - remove a no longer used event
 794 * @event: the event to remove
 795 */
 796int unregister_trace_event(struct trace_event *event)
 797{
 798	down_write(&trace_event_sem);
 799	__unregister_trace_event(event);
 800	up_write(&trace_event_sem);
 801
 802	return 0;
 803}
 804EXPORT_SYMBOL_GPL(unregister_trace_event);
 805
 806/*
 807 * Standard events
 808 */
 809
 810enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 811				  struct trace_event *event)
 812{
 813	trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 
 814
 815	return trace_handle_return(&iter->seq);
 816}
 817
 818/* TRACE_FN */
 819static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 820					struct trace_event *event)
 821{
 822	struct ftrace_entry *field;
 823	struct trace_seq *s = &iter->seq;
 824
 825	trace_assign_type(field, iter->ent);
 826
 827	seq_print_ip_sym(s, field->ip, flags);
 
 828
 829	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 830		trace_seq_puts(s, " <-");
 831		seq_print_ip_sym(s, field->parent_ip, flags);
 
 
 
 
 832	}
 
 
 833
 834	trace_seq_putc(s, '\n');
 835
 836	return trace_handle_return(s);
 
 837}
 838
 839static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 840				      struct trace_event *event)
 841{
 842	struct ftrace_entry *field;
 843
 844	trace_assign_type(field, iter->ent);
 845
 846	trace_seq_printf(&iter->seq, "%lx %lx\n",
 847			 field->ip,
 848			 field->parent_ip);
 
 849
 850	return trace_handle_return(&iter->seq);
 851}
 852
 853static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 854				      struct trace_event *event)
 855{
 856	struct ftrace_entry *field;
 857	struct trace_seq *s = &iter->seq;
 858
 859	trace_assign_type(field, iter->ent);
 860
 861	SEQ_PUT_HEX_FIELD(s, field->ip);
 862	SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 863
 864	return trace_handle_return(s);
 865}
 866
 867static enum print_line_t trace_fn_bin(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	SEQ_PUT_FIELD(s, field->ip);
 876	SEQ_PUT_FIELD(s, field->parent_ip);
 877
 878	return trace_handle_return(s);
 879}
 880
 881static struct trace_event_functions trace_fn_funcs = {
 882	.trace		= trace_fn_trace,
 883	.raw		= trace_fn_raw,
 884	.hex		= trace_fn_hex,
 885	.binary		= trace_fn_bin,
 886};
 887
 888static struct trace_event trace_fn_event = {
 889	.type		= TRACE_FN,
 890	.funcs		= &trace_fn_funcs,
 891};
 892
 893/* TRACE_CTX an TRACE_WAKE */
 894static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 895					     char *delim)
 896{
 897	struct ctx_switch_entry *field;
 898	char comm[TASK_COMM_LEN];
 899	int S, T;
 900
 901
 902	trace_assign_type(field, iter->ent);
 903
 904	T = task_index_to_char(field->next_state);
 905	S = task_index_to_char(field->prev_state);
 906	trace_find_cmdline(field->next_pid, comm);
 907	trace_seq_printf(&iter->seq,
 908			 " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 909			 field->prev_pid,
 910			 field->prev_prio,
 911			 S, delim,
 912			 field->next_cpu,
 913			 field->next_pid,
 914			 field->next_prio,
 915			 T, comm);
 
 916
 917	return trace_handle_return(&iter->seq);
 918}
 919
 920static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 921					 struct trace_event *event)
 922{
 923	return trace_ctxwake_print(iter, "==>");
 924}
 925
 926static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 927					  int flags, struct trace_event *event)
 928{
 929	return trace_ctxwake_print(iter, "  +");
 930}
 931
 932static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 933{
 934	struct ctx_switch_entry *field;
 935	int T;
 936
 937	trace_assign_type(field, iter->ent);
 938
 939	if (!S)
 940		S = task_index_to_char(field->prev_state);
 941	T = task_index_to_char(field->next_state);
 942	trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 943			 field->prev_pid,
 944			 field->prev_prio,
 945			 S,
 946			 field->next_cpu,
 947			 field->next_pid,
 948			 field->next_prio,
 949			 T);
 
 950
 951	return trace_handle_return(&iter->seq);
 952}
 953
 954static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 955				       struct trace_event *event)
 956{
 957	return trace_ctxwake_raw(iter, 0);
 958}
 959
 960static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 961					struct trace_event *event)
 962{
 963	return trace_ctxwake_raw(iter, '+');
 964}
 965
 966
 967static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 968{
 969	struct ctx_switch_entry *field;
 970	struct trace_seq *s = &iter->seq;
 971	int T;
 972
 973	trace_assign_type(field, iter->ent);
 974
 975	if (!S)
 976		S = task_index_to_char(field->prev_state);
 977	T = task_index_to_char(field->next_state);
 978
 979	SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 980	SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 981	SEQ_PUT_HEX_FIELD(s, S);
 982	SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 983	SEQ_PUT_HEX_FIELD(s, field->next_pid);
 984	SEQ_PUT_HEX_FIELD(s, field->next_prio);
 985	SEQ_PUT_HEX_FIELD(s, T);
 986
 987	return trace_handle_return(s);
 988}
 989
 990static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 991				       struct trace_event *event)
 992{
 993	return trace_ctxwake_hex(iter, 0);
 994}
 995
 996static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 997					struct trace_event *event)
 998{
 999	return trace_ctxwake_hex(iter, '+');
1000}
1001
1002static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1003					   int flags, struct trace_event *event)
1004{
1005	struct ctx_switch_entry *field;
1006	struct trace_seq *s = &iter->seq;
1007
1008	trace_assign_type(field, iter->ent);
1009
1010	SEQ_PUT_FIELD(s, field->prev_pid);
1011	SEQ_PUT_FIELD(s, field->prev_prio);
1012	SEQ_PUT_FIELD(s, field->prev_state);
1013	SEQ_PUT_FIELD(s, field->next_cpu);
1014	SEQ_PUT_FIELD(s, field->next_pid);
1015	SEQ_PUT_FIELD(s, field->next_prio);
1016	SEQ_PUT_FIELD(s, field->next_state);
1017
1018	return trace_handle_return(s);
1019}
1020
1021static struct trace_event_functions trace_ctx_funcs = {
1022	.trace		= trace_ctx_print,
1023	.raw		= trace_ctx_raw,
1024	.hex		= trace_ctx_hex,
1025	.binary		= trace_ctxwake_bin,
1026};
1027
1028static struct trace_event trace_ctx_event = {
1029	.type		= TRACE_CTX,
1030	.funcs		= &trace_ctx_funcs,
1031};
1032
1033static struct trace_event_functions trace_wake_funcs = {
1034	.trace		= trace_wake_print,
1035	.raw		= trace_wake_raw,
1036	.hex		= trace_wake_hex,
1037	.binary		= trace_ctxwake_bin,
1038};
1039
1040static struct trace_event trace_wake_event = {
1041	.type		= TRACE_WAKE,
1042	.funcs		= &trace_wake_funcs,
1043};
1044
1045/* TRACE_STACK */
1046
1047static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1048					   int flags, struct trace_event *event)
1049{
1050	struct stack_entry *field;
1051	struct trace_seq *s = &iter->seq;
1052	unsigned long *p;
1053	unsigned long *end;
1054
1055	trace_assign_type(field, iter->ent);
1056	end = (unsigned long *)((long)iter->ent + iter->ent_size);
1057
1058	trace_seq_puts(s, "<stack trace>\n");
 
1059
1060	for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {
 
 
1061
1062		if (trace_seq_has_overflowed(s))
1063			break;
1064
1065		trace_seq_puts(s, " => ");
1066		seq_print_ip_sym(s, *p, flags);
1067		trace_seq_putc(s, '\n');
1068	}
1069
1070	return trace_handle_return(s);
 
 
 
1071}
1072
1073static struct trace_event_functions trace_stack_funcs = {
1074	.trace		= trace_stack_print,
1075};
1076
1077static struct trace_event trace_stack_event = {
1078	.type		= TRACE_STACK,
1079	.funcs		= &trace_stack_funcs,
1080};
1081
1082/* TRACE_USER_STACK */
1083static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1084						int flags, struct trace_event *event)
1085{
1086	struct trace_array *tr = iter->tr;
1087	struct userstack_entry *field;
1088	struct trace_seq *s = &iter->seq;
1089	struct mm_struct *mm = NULL;
1090	unsigned int i;
1091
1092	trace_assign_type(field, iter->ent);
1093
1094	trace_seq_puts(s, "<user stack trace>\n");
 
1095
1096	if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1097		struct task_struct *task;
1098		/*
1099		 * we do the lookup on the thread group leader,
1100		 * since individual threads might have already quit!
1101		 */
1102		rcu_read_lock();
1103		task = find_task_by_vpid(field->tgid);
1104		if (task)
1105			mm = get_task_mm(task);
1106		rcu_read_unlock();
1107	}
1108
1109	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1110		unsigned long ip = field->caller[i];
1111
1112		if (!ip || trace_seq_has_overflowed(s))
1113			break;
1114
1115		trace_seq_puts(s, " => ");
1116		seq_print_user_ip(s, mm, ip, flags);
1117		trace_seq_putc(s, '\n');
1118	}
1119
1120	if (mm)
1121		mmput(mm);
1122
1123	return trace_handle_return(s);
1124}
1125
1126static struct trace_event_functions trace_user_stack_funcs = {
1127	.trace		= trace_user_stack_print,
1128};
1129
1130static struct trace_event trace_user_stack_event = {
1131	.type		= TRACE_USER_STACK,
1132	.funcs		= &trace_user_stack_funcs,
1133};
1134
1135/* TRACE_HWLAT */
1136static enum print_line_t
1137trace_hwlat_print(struct trace_iterator *iter, int flags,
1138		  struct trace_event *event)
1139{
1140	struct trace_entry *entry = iter->ent;
1141	struct trace_seq *s = &iter->seq;
1142	struct hwlat_entry *field;
1143
1144	trace_assign_type(field, entry);
1145
1146	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1147			 field->seqnum,
1148			 field->duration,
1149			 field->outer_duration,
1150			 (long long)field->timestamp.tv_sec,
1151			 field->timestamp.tv_nsec);
1152
1153	if (field->nmi_count) {
1154		/*
1155		 * The generic sched_clock() is not NMI safe, thus
1156		 * we only record the count and not the time.
1157		 */
1158		if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1159			trace_seq_printf(s, " nmi-total:%llu",
1160					 field->nmi_total_ts);
1161		trace_seq_printf(s, " nmi-count:%u",
1162				 field->nmi_count);
1163	}
1164
1165	trace_seq_putc(s, '\n');
1166
1167	return trace_handle_return(s);
1168}
1169
1170
1171static enum print_line_t
1172trace_hwlat_raw(struct trace_iterator *iter, int flags,
1173		struct trace_event *event)
1174{
1175	struct hwlat_entry *field;
1176	struct trace_seq *s = &iter->seq;
1177
1178	trace_assign_type(field, iter->ent);
1179
1180	trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1181			 field->duration,
1182			 field->outer_duration,
1183			 (long long)field->timestamp.tv_sec,
1184			 field->timestamp.tv_nsec,
1185			 field->seqnum);
1186
1187	return trace_handle_return(s);
1188}
1189
1190static struct trace_event_functions trace_hwlat_funcs = {
1191	.trace		= trace_hwlat_print,
1192	.raw		= trace_hwlat_raw,
1193};
1194
1195static struct trace_event trace_hwlat_event = {
1196	.type		= TRACE_HWLAT,
1197	.funcs		= &trace_hwlat_funcs,
1198};
1199
1200/* TRACE_BPUTS */
1201static enum print_line_t
1202trace_bputs_print(struct trace_iterator *iter, int flags,
1203		   struct trace_event *event)
1204{
1205	struct trace_entry *entry = iter->ent;
1206	struct trace_seq *s = &iter->seq;
1207	struct bputs_entry *field;
1208
1209	trace_assign_type(field, entry);
1210
1211	seq_print_ip_sym(s, field->ip, flags);
1212	trace_seq_puts(s, ": ");
1213	trace_seq_puts(s, field->str);
 
 
1214
1215	return trace_handle_return(s);
 
 
 
 
 
 
1216}
1217
1218
1219static enum print_line_t
1220trace_bputs_raw(struct trace_iterator *iter, int flags,
1221		struct trace_event *event)
1222{
1223	struct bputs_entry *field;
1224	struct trace_seq *s = &iter->seq;
1225
1226	trace_assign_type(field, iter->ent);
1227
1228	trace_seq_printf(s, ": %lx : ", field->ip);
1229	trace_seq_puts(s, field->str);
 
 
 
1230
1231	return trace_handle_return(s);
 
 
 
1232}
1233
1234static struct trace_event_functions trace_bputs_funcs = {
1235	.trace		= trace_bputs_print,
1236	.raw		= trace_bputs_raw,
1237};
1238
1239static struct trace_event trace_bputs_event = {
1240	.type		= TRACE_BPUTS,
1241	.funcs		= &trace_bputs_funcs,
1242};
1243
1244/* TRACE_BPRINT */
1245static enum print_line_t
1246trace_bprint_print(struct trace_iterator *iter, int flags,
1247		   struct trace_event *event)
1248{
1249	struct trace_entry *entry = iter->ent;
1250	struct trace_seq *s = &iter->seq;
1251	struct bprint_entry *field;
1252
1253	trace_assign_type(field, entry);
1254
1255	seq_print_ip_sym(s, field->ip, flags);
1256	trace_seq_puts(s, ": ");
1257	trace_seq_bprintf(s, field->fmt, field->buf);
 
 
1258
1259	return trace_handle_return(s);
 
 
 
 
 
 
1260}
1261
1262
1263static enum print_line_t
1264trace_bprint_raw(struct trace_iterator *iter, int flags,
1265		 struct trace_event *event)
1266{
1267	struct bprint_entry *field;
1268	struct trace_seq *s = &iter->seq;
1269
1270	trace_assign_type(field, iter->ent);
1271
1272	trace_seq_printf(s, ": %lx : ", field->ip);
1273	trace_seq_bprintf(s, field->fmt, field->buf);
 
 
 
1274
1275	return trace_handle_return(s);
 
 
 
1276}
1277
1278static struct trace_event_functions trace_bprint_funcs = {
1279	.trace		= trace_bprint_print,
1280	.raw		= trace_bprint_raw,
1281};
1282
1283static struct trace_event trace_bprint_event = {
1284	.type		= TRACE_BPRINT,
1285	.funcs		= &trace_bprint_funcs,
1286};
1287
1288/* TRACE_PRINT */
1289static enum print_line_t trace_print_print(struct trace_iterator *iter,
1290					   int flags, struct trace_event *event)
1291{
1292	struct print_entry *field;
1293	struct trace_seq *s = &iter->seq;
1294
1295	trace_assign_type(field, iter->ent);
1296
1297	seq_print_ip_sym(s, field->ip, flags);
1298	trace_seq_printf(s, ": %s", field->buf);
 
 
 
 
 
1299
1300	return trace_handle_return(s);
 
1301}
1302
1303static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1304					 struct trace_event *event)
1305{
1306	struct print_entry *field;
1307
1308	trace_assign_type(field, iter->ent);
1309
1310	trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
 
1311
1312	return trace_handle_return(&iter->seq);
 
 
 
1313}
1314
1315static struct trace_event_functions trace_print_funcs = {
1316	.trace		= trace_print_print,
1317	.raw		= trace_print_raw,
1318};
1319
1320static struct trace_event trace_print_event = {
1321	.type	 	= TRACE_PRINT,
1322	.funcs		= &trace_print_funcs,
1323};
1324
1325static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1326					 struct trace_event *event)
1327{
1328	struct raw_data_entry *field;
1329	int i;
1330
1331	trace_assign_type(field, iter->ent);
1332
1333	trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1334
1335	for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1336		trace_seq_printf(&iter->seq, " %02x",
1337				 (unsigned char)field->buf[i]);
1338
1339	trace_seq_putc(&iter->seq, '\n');
1340
1341	return trace_handle_return(&iter->seq);
1342}
1343
1344static struct trace_event_functions trace_raw_data_funcs = {
1345	.trace		= trace_raw_data,
1346	.raw		= trace_raw_data,
1347};
1348
1349static struct trace_event trace_raw_data_event = {
1350	.type	 	= TRACE_RAW_DATA,
1351	.funcs		= &trace_raw_data_funcs,
1352};
1353
1354
1355static struct trace_event *events[] __initdata = {
1356	&trace_fn_event,
1357	&trace_ctx_event,
1358	&trace_wake_event,
1359	&trace_stack_event,
1360	&trace_user_stack_event,
1361	&trace_bputs_event,
1362	&trace_bprint_event,
1363	&trace_print_event,
1364	&trace_hwlat_event,
1365	&trace_raw_data_event,
1366	NULL
1367};
1368
1369__init static int init_events(void)
1370{
1371	struct trace_event *event;
1372	int i, ret;
1373
1374	for (i = 0; events[i]; i++) {
1375		event = events[i];
1376
1377		ret = register_trace_event(event);
1378		if (!ret) {
1379			printk(KERN_WARNING "event %d failed to register\n",
1380			       event->type);
1381			WARN_ON_ONCE(1);
1382		}
1383	}
1384
1385	return 0;
1386}
1387early_initcall(init_events);
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);