Linux Audio

Check our new training course

Loading...
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
// SPDX-License-Identifier: GPL-2.0
#include <inttypes.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/zalloc.h>

#include <api/io.h>

#include "util/dso.h"
#include "util/debug.h"
#include "util/callchain.h"
#include "util/symbol_conf.h"
#include "srcline.h"
#include "string2.h"
#include "symbol.h"
#include "subcmd/run-command.h"

/* If addr2line doesn't return data for 1 second then timeout. */
int addr2line_timeout_ms = 1 * 1000;
bool srcline_full_filename;

char *srcline__unknown = (char *)"??:0";

static const char *dso__name(struct dso *dso)
{
	const char *dso_name;

	if (dso->symsrc_filename)
		dso_name = dso->symsrc_filename;
	else
		dso_name = dso->long_name;

	if (dso_name[0] == '[')
		return NULL;

	if (!strncmp(dso_name, "/tmp/perf-", 10))
		return NULL;

	return dso_name;
}

static int inline_list__append(struct symbol *symbol, char *srcline,
			       struct inline_node *node)
{
	struct inline_list *ilist;

	ilist = zalloc(sizeof(*ilist));
	if (ilist == NULL)
		return -1;

	ilist->symbol = symbol;
	ilist->srcline = srcline;

	if (callchain_param.order == ORDER_CALLEE)
		list_add_tail(&ilist->list, &node->val);
	else
		list_add(&ilist->list, &node->val);

	return 0;
}

/* basename version that takes a const input string */
static const char *gnu_basename(const char *path)
{
	const char *base = strrchr(path, '/');

	return base ? base + 1 : path;
}

static char *srcline_from_fileline(const char *file, unsigned int line)
{
	char *srcline;

	if (!file)
		return NULL;

	if (!srcline_full_filename)
		file = gnu_basename(file);

	if (asprintf(&srcline, "%s:%u", file, line) < 0)
		return NULL;

	return srcline;
}

static struct symbol *new_inline_sym(struct dso *dso,
				     struct symbol *base_sym,
				     const char *funcname)
{
	struct symbol *inline_sym;
	char *demangled = NULL;

	if (!funcname)
		funcname = "??";

	if (dso) {
		demangled = dso__demangle_sym(dso, 0, funcname);
		if (demangled)
			funcname = demangled;
	}

	if (base_sym && strcmp(funcname, base_sym->name) == 0) {
		/* reuse the real, existing symbol */
		inline_sym = base_sym;
		/* ensure that we don't alias an inlined symbol, which could
		 * lead to double frees in inline_node__delete
		 */
		assert(!base_sym->inlined);
	} else {
		/* create a fake symbol for the inline frame */
		inline_sym = symbol__new(base_sym ? base_sym->start : 0,
					 base_sym ? (base_sym->end - base_sym->start) : 0,
					 base_sym ? base_sym->binding : 0,
					 base_sym ? base_sym->type : 0,
					 funcname);
		if (inline_sym)
			inline_sym->inlined = 1;
	}

	free(demangled);

	return inline_sym;
}

#define MAX_INLINE_NEST 1024

#ifdef HAVE_LIBBFD_SUPPORT

/*
 * Implement addr2line using libbfd.
 */
#define PACKAGE "perf"
#include <bfd.h>

struct a2l_data {
	const char 	*input;
	u64	 	addr;

	bool 		found;
	const char 	*filename;
	const char 	*funcname;
	unsigned 	line;

	bfd 		*abfd;
	asymbol 	**syms;
};

static int bfd_error(const char *string)
{
	const char *errmsg;

	errmsg = bfd_errmsg(bfd_get_error());
	fflush(stdout);

	if (string)
		pr_debug("%s: %s\n", string, errmsg);
	else
		pr_debug("%s\n", errmsg);

	return -1;
}

static int slurp_symtab(bfd *abfd, struct a2l_data *a2l)
{
	long storage;
	long symcount;
	asymbol **syms;
	bfd_boolean dynamic = FALSE;

	if ((bfd_get_file_flags(abfd) & HAS_SYMS) == 0)
		return bfd_error(bfd_get_filename(abfd));

	storage = bfd_get_symtab_upper_bound(abfd);
	if (storage == 0L) {
		storage = bfd_get_dynamic_symtab_upper_bound(abfd);
		dynamic = TRUE;
	}
	if (storage < 0L)
		return bfd_error(bfd_get_filename(abfd));

	syms = malloc(storage);
	if (dynamic)
		symcount = bfd_canonicalize_dynamic_symtab(abfd, syms);
	else
		symcount = bfd_canonicalize_symtab(abfd, syms);

	if (symcount < 0) {
		free(syms);
		return bfd_error(bfd_get_filename(abfd));
	}

	a2l->syms = syms;
	return 0;
}

static void find_address_in_section(bfd *abfd, asection *section, void *data)
{
	bfd_vma pc, vma;
	bfd_size_type size;
	struct a2l_data *a2l = data;
	flagword flags;

	if (a2l->found)
		return;

#ifdef bfd_get_section_flags
	flags = bfd_get_section_flags(abfd, section);
#else
	flags = bfd_section_flags(section);
#endif
	if ((flags & SEC_ALLOC) == 0)
		return;

	pc = a2l->addr;
#ifdef bfd_get_section_vma
	vma = bfd_get_section_vma(abfd, section);
#else
	vma = bfd_section_vma(section);
#endif
#ifdef bfd_get_section_size
	size = bfd_get_section_size(section);
#else
	size = bfd_section_size(section);
#endif

	if (pc < vma || pc >= vma + size)
		return;

	a2l->found = bfd_find_nearest_line(abfd, section, a2l->syms, pc - vma,
					   &a2l->filename, &a2l->funcname,
					   &a2l->line);

	if (a2l->filename && !strlen(a2l->filename))
		a2l->filename = NULL;
}

static struct a2l_data *addr2line_init(const char *path)
{
	bfd *abfd;
	struct a2l_data *a2l = NULL;

	abfd = bfd_openr(path, NULL);
	if (abfd == NULL)
		return NULL;

	if (!bfd_check_format(abfd, bfd_object))
		goto out;

	a2l = zalloc(sizeof(*a2l));
	if (a2l == NULL)
		goto out;

	a2l->abfd = abfd;
	a2l->input = strdup(path);
	if (a2l->input == NULL)
		goto out;

	if (slurp_symtab(abfd, a2l))
		goto out;

	return a2l;

out:
	if (a2l) {
		zfree((char **)&a2l->input);
		free(a2l);
	}
	bfd_close(abfd);
	return NULL;
}

static void addr2line_cleanup(struct a2l_data *a2l)
{
	if (a2l->abfd)
		bfd_close(a2l->abfd);
	zfree((char **)&a2l->input);
	zfree(&a2l->syms);
	free(a2l);
}

static int inline_list__append_dso_a2l(struct dso *dso,
				       struct inline_node *node,
				       struct symbol *sym)
{
	struct a2l_data *a2l = dso->a2l;
	struct symbol *inline_sym = new_inline_sym(dso, sym, a2l->funcname);
	char *srcline = NULL;

	if (a2l->filename)
		srcline = srcline_from_fileline(a2l->filename, a2l->line);

	return inline_list__append(inline_sym, srcline, node);
}

static int addr2line(const char *dso_name, u64 addr,
		     char **file, unsigned int *line, struct dso *dso,
		     bool unwind_inlines, struct inline_node *node,
		     struct symbol *sym)
{
	int ret = 0;
	struct a2l_data *a2l = dso->a2l;

	if (!a2l) {
		dso->a2l = addr2line_init(dso_name);
		a2l = dso->a2l;
	}

	if (a2l == NULL) {
		if (!symbol_conf.disable_add2line_warn)
			pr_warning("addr2line_init failed for %s\n", dso_name);
		return 0;
	}

	a2l->addr = addr;
	a2l->found = false;

	bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);

	if (!a2l->found)
		return 0;

	if (unwind_inlines) {
		int cnt = 0;

		if (node && inline_list__append_dso_a2l(dso, node, sym))
			return 0;

		while (bfd_find_inliner_info(a2l->abfd, &a2l->filename,
					     &a2l->funcname, &a2l->line) &&
		       cnt++ < MAX_INLINE_NEST) {

			if (a2l->filename && !strlen(a2l->filename))
				a2l->filename = NULL;

			if (node != NULL) {
				if (inline_list__append_dso_a2l(dso, node, sym))
					return 0;
				// found at least one inline frame
				ret = 1;
			}
		}
	}

	if (file) {
		*file = a2l->filename ? strdup(a2l->filename) : NULL;
		ret = *file ? 1 : 0;
	}

	if (line)
		*line = a2l->line;

	return ret;
}

void dso__free_a2l(struct dso *dso)
{
	struct a2l_data *a2l = dso->a2l;

	if (!a2l)
		return;

	addr2line_cleanup(a2l);

	dso->a2l = NULL;
}

#else /* HAVE_LIBBFD_SUPPORT */

static int filename_split(char *filename, unsigned int *line_nr)
{
	char *sep;

	sep = strchr(filename, '\n');
	if (sep)
		*sep = '\0';

	if (!strcmp(filename, "??:0"))
		return 0;

	sep = strchr(filename, ':');
	if (sep) {
		*sep++ = '\0';
		*line_nr = strtoul(sep, NULL, 0);
		return 1;
	}
	pr_debug("addr2line missing ':' in filename split\n");
	return 0;
}

static void addr2line_subprocess_cleanup(struct child_process *a2l)
{
	if (a2l->pid != -1) {
		kill(a2l->pid, SIGKILL);
		finish_command(a2l); /* ignore result, we don't care */
		a2l->pid = -1;
		close(a2l->in);
		close(a2l->out);
	}

	free(a2l);
}

static struct child_process *addr2line_subprocess_init(const char *addr2line_path,
							const char *binary_path)
{
	const char *argv[] = {
		addr2line_path ?: "addr2line",
		"-e", binary_path,
		"-a", "-i", "-f", NULL
	};
	struct child_process *a2l = zalloc(sizeof(*a2l));
	int start_command_status = 0;

	if (a2l == NULL) {
		pr_err("Failed to allocate memory for addr2line");
		return NULL;
	}

	a2l->pid = -1;
	a2l->in = -1;
	a2l->out = -1;
	a2l->no_stderr = 1;

	a2l->argv = argv;
	start_command_status = start_command(a2l);
	a2l->argv = NULL; /* it's not used after start_command; avoid dangling pointers */

	if (start_command_status != 0) {
		pr_warning("could not start addr2line (%s) for %s: start_command return code %d\n",
			addr2line_path, binary_path, start_command_status);
		addr2line_subprocess_cleanup(a2l);
		return NULL;
	}

	return a2l;
}

enum a2l_style {
	BROKEN,
	GNU_BINUTILS,
	LLVM,
};

static enum a2l_style addr2line_configure(struct child_process *a2l, const char *dso_name)
{
	static bool cached;
	static enum a2l_style style;

	if (!cached) {
		char buf[128];
		struct io io;
		int ch;
		int lines;

		if (write(a2l->in, ",\n", 2) != 2)
			return BROKEN;

		io__init(&io, a2l->out, buf, sizeof(buf));
		ch = io__get_char(&io);
		if (ch == ',') {
			style = LLVM;
			cached = true;
			lines = 1;
			pr_debug("Detected LLVM addr2line style\n");
		} else if (ch == '0') {
			style = GNU_BINUTILS;
			cached = true;
			lines = 3;
			pr_debug("Detected binutils addr2line style\n");
		} else {
			if (!symbol_conf.disable_add2line_warn) {
				char *output = NULL;
				size_t output_len;

				io__getline(&io, &output, &output_len);
				pr_warning("%s %s: addr2line configuration failed\n",
					   __func__, dso_name);
				pr_warning("\t%c%s", ch, output);
			}
			pr_debug("Unknown/broken addr2line style\n");
			return BROKEN;
		}
		while (lines) {
			ch = io__get_char(&io);
			if (ch <= 0)
				break;
			if (ch == '\n')
				lines--;
		}
		/* Ignore SIGPIPE in the event addr2line exits. */
		signal(SIGPIPE, SIG_IGN);
	}
	return style;
}

static int read_addr2line_record(struct io *io,
				 enum a2l_style style,
				 const char *dso_name,
				 u64 addr,
				 bool first,
				 char **function,
				 char **filename,
				 unsigned int *line_nr)
{
	/*
	 * Returns:
	 * -1 ==> error
	 * 0 ==> sentinel (or other ill-formed) record read
	 * 1 ==> a genuine record read
	 */
	char *line = NULL;
	size_t line_len = 0;
	unsigned int dummy_line_nr = 0;
	int ret = -1;

	if (function != NULL)
		zfree(function);

	if (filename != NULL)
		zfree(filename);

	if (line_nr != NULL)
		*line_nr = 0;

	/*
	 * Read the first line. Without an error this will be:
	 * - for the first line an address like 0x1234,
	 * - the binutils sentinel 0x0000000000000000,
	 * - the llvm-addr2line the sentinel ',' character,
	 * - the function name line for an inlined function.
	 */
	if (io__getline(io, &line, &line_len) < 0 || !line_len)
		goto error;

	pr_debug("%s %s: addr2line read address for sentinel: %s", __func__, dso_name, line);
	if (style == LLVM && line_len == 2 && line[0] == ',') {
		/* Found the llvm-addr2line sentinel character. */
		zfree(&line);
		return 0;
	} else if (style == GNU_BINUTILS && (!first || addr != 0)) {
		int zero_count = 0, non_zero_count = 0;
		/*
		 * Check for binutils sentinel ignoring it for the case the
		 * requested address is 0.
		 */

		/* A given address should always start 0x. */
		if (line_len >= 2 || line[0] != '0' || line[1] != 'x') {
			for (size_t i = 2; i < line_len; i++) {
				if (line[i] == '0')
					zero_count++;
				else if (line[i] != '\n')
					non_zero_count++;
			}
			if (!non_zero_count) {
				int ch;

				if (first && !zero_count) {
					/* Line was erroneous just '0x'. */
					goto error;
				}
				/*
				 * Line was 0x0..0, the sentinel for binutils. Remove
				 * the function and filename lines.
				 */
				zfree(&line);
				do {
					ch = io__get_char(io);
				} while (ch > 0 && ch != '\n');
				do {
					ch = io__get_char(io);
				} while (ch > 0 && ch != '\n');
				return 0;
			}
		}
	}
	/* Read the second function name line (if inline data then this is the first line). */
	if (first && (io__getline(io, &line, &line_len) < 0 || !line_len))
		goto error;

	pr_debug("%s %s: addr2line read line: %s", __func__, dso_name, line);
	if (function != NULL)
		*function = strdup(strim(line));

	zfree(&line);
	line_len = 0;

	/* Read the third filename and line number line. */
	if (io__getline(io, &line, &line_len) < 0 || !line_len)
		goto error;

	pr_debug("%s %s: addr2line filename:number : %s", __func__, dso_name, line);
	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0 &&
	    style == GNU_BINUTILS) {
		ret = 0;
		goto error;
	}

	if (filename != NULL)
		*filename = strdup(line);

	zfree(&line);
	line_len = 0;

	return 1;

error:
	free(line);
	if (function != NULL)
		zfree(function);
	if (filename != NULL)
		zfree(filename);
	return ret;
}

static int inline_list__append_record(struct dso *dso,
				      struct inline_node *node,
				      struct symbol *sym,
				      const char *function,
				      const char *filename,
				      unsigned int line_nr)
{
	struct symbol *inline_sym = new_inline_sym(dso, sym, function);

	return inline_list__append(inline_sym, srcline_from_fileline(filename, line_nr), node);
}

static int addr2line(const char *dso_name, u64 addr,
		     char **file, unsigned int *line_nr,
		     struct dso *dso,
		     bool unwind_inlines,
		     struct inline_node *node,
		     struct symbol *sym __maybe_unused)
{
	struct child_process *a2l = dso->a2l;
	char *record_function = NULL;
	char *record_filename = NULL;
	unsigned int record_line_nr = 0;
	int record_status = -1;
	int ret = 0;
	size_t inline_count = 0;
	int len;
	char buf[128];
	ssize_t written;
	struct io io = { .eof = false };
	enum a2l_style a2l_style;

	if (!a2l) {
		if (!filename__has_section(dso_name, ".debug_line"))
			goto out;

		dso->a2l = addr2line_subprocess_init(symbol_conf.addr2line_path, dso_name);
		a2l = dso->a2l;
	}

	if (a2l == NULL) {
		if (!symbol_conf.disable_add2line_warn)
			pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name);
		goto out;
	}
	a2l_style = addr2line_configure(a2l, dso_name);
	if (a2l_style == BROKEN)
		goto out;

	/*
	 * Send our request and then *deliberately* send something that can't be
	 * interpreted as a valid address to ask addr2line about (namely,
	 * ","). This causes addr2line to first write out the answer to our
	 * request, in an unbounded/unknown number of records, and then to write
	 * out the lines "0x0...0", "??" and "??:0", for GNU binutils, or ","
	 * for llvm-addr2line, so that we can detect when it has finished giving
	 * us anything useful.
	 */
	len = snprintf(buf, sizeof(buf), "%016"PRIx64"\n,\n", addr);
	written = len > 0 ? write(a2l->in, buf, len) : -1;
	if (written != len) {
		if (!symbol_conf.disable_add2line_warn)
			pr_warning("%s %s: could not send request\n", __func__, dso_name);
		goto out;
	}
	io__init(&io, a2l->out, buf, sizeof(buf));
	io.timeout_ms = addr2line_timeout_ms;
	switch (read_addr2line_record(&io, a2l_style, dso_name, addr, /*first=*/true,
				      &record_function, &record_filename, &record_line_nr)) {
	case -1:
		if (!symbol_conf.disable_add2line_warn)
			pr_warning("%s %s: could not read first record\n", __func__, dso_name);
		goto out;
	case 0:
		/*
		 * The first record was invalid, so return failure, but first
		 * read another record, since we sent a sentinel ',' for the
		 * sake of detected the last inlined function. Treat this as the
		 * first of a record as the ',' generates a new start with GNU
		 * binutils, also force a non-zero address as we're no longer
		 * reading that record.
		 */
		switch (read_addr2line_record(&io, a2l_style, dso_name,
					      /*addr=*/1, /*first=*/true,
					      NULL, NULL, NULL)) {
		case -1:
			if (!symbol_conf.disable_add2line_warn)
				pr_warning("%s %s: could not read sentinel record\n",
					   __func__, dso_name);
			break;
		case 0:
			/* The sentinel as expected. */
			break;
		default:
			if (!symbol_conf.disable_add2line_warn)
				pr_warning("%s %s: unexpected record instead of sentinel",
					   __func__, dso_name);
			break;
		}
		goto out;
	default:
		/* First record as expected. */
		break;
	}

	if (file) {
		*file = strdup(record_filename);
		ret = 1;
	}
	if (line_nr)
		*line_nr = record_line_nr;

	if (unwind_inlines) {
		if (node && inline_list__append_record(dso, node, sym,
						       record_function,
						       record_filename,
						       record_line_nr)) {
			ret = 0;
			goto out;
		}
	}

	/*
	 * We have to read the records even if we don't care about the inline
	 * info. This isn't the first record and force the address to non-zero
	 * as we're reading records beyond the first.
	 */
	while ((record_status = read_addr2line_record(&io,
						      a2l_style,
						      dso_name,
						      /*addr=*/1,
						      /*first=*/false,
						      &record_function,
						      &record_filename,
						      &record_line_nr)) == 1) {
		if (unwind_inlines && node && inline_count++ < MAX_INLINE_NEST) {
			if (inline_list__append_record(dso, node, sym,
						       record_function,
						       record_filename,
						       record_line_nr)) {
				ret = 0;
				goto out;
			}
			ret = 1; /* found at least one inline frame */
		}
	}

out:
	free(record_function);
	free(record_filename);
	if (io.eof) {
		dso->a2l = NULL;
		addr2line_subprocess_cleanup(a2l);
	}
	return ret;
}

void dso__free_a2l(struct dso *dso)
{
	struct child_process *a2l = dso->a2l;

	if (!a2l)
		return;

	addr2line_subprocess_cleanup(a2l);

	dso->a2l = NULL;
}

#endif /* HAVE_LIBBFD_SUPPORT */

static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
					struct dso *dso, struct symbol *sym)
{
	struct inline_node *node;

	node = zalloc(sizeof(*node));
	if (node == NULL) {
		perror("not enough memory for the inline node");
		return NULL;
	}

	INIT_LIST_HEAD(&node->val);
	node->addr = addr;

	addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym);
	return node;
}

/*
 * Number of addr2line failures (without success) before disabling it for that
 * dso.
 */
#define A2L_FAIL_LIMIT 123

char *__get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
		  bool show_sym, bool show_addr, bool unwind_inlines,
		  u64 ip)
{
	char *file = NULL;
	unsigned line = 0;
	char *srcline;
	const char *dso_name;

	if (!dso->has_srcline)
		goto out;

	dso_name = dso__name(dso);
	if (dso_name == NULL)
		goto out;

	if (!addr2line(dso_name, addr, &file, &line, dso,
		       unwind_inlines, NULL, sym))
		goto out;

	srcline = srcline_from_fileline(file, line);
	free(file);

	if (!srcline)
		goto out;

	dso->a2l_fails = 0;

	return srcline;

out:
	if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
		dso->has_srcline = 0;
		dso__free_a2l(dso);
	}

	if (!show_addr)
		return (show_sym && sym) ?
			    strndup(sym->name, sym->namelen) : SRCLINE_UNKNOWN;

	if (sym) {
		if (asprintf(&srcline, "%s+%" PRIu64, show_sym ? sym->name : "",
					ip - sym->start) < 0)
			return SRCLINE_UNKNOWN;
	} else if (asprintf(&srcline, "%s[%" PRIx64 "]", dso->short_name, addr) < 0)
		return SRCLINE_UNKNOWN;
	return srcline;
}

/* Returns filename and fills in line number in line */
char *get_srcline_split(struct dso *dso, u64 addr, unsigned *line)
{
	char *file = NULL;
	const char *dso_name;

	if (!dso->has_srcline)
		goto out;

	dso_name = dso__name(dso);
	if (dso_name == NULL)
		goto out;

	if (!addr2line(dso_name, addr, &file, line, dso, true, NULL, NULL))
		goto out;

	dso->a2l_fails = 0;
	return file;

out:
	if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
		dso->has_srcline = 0;
		dso__free_a2l(dso);
	}

	return NULL;
}

void zfree_srcline(char **srcline)
{
	if (*srcline == NULL)
		return;

	if (*srcline != SRCLINE_UNKNOWN)
		free(*srcline);

	*srcline = NULL;
}

char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
		  bool show_sym, bool show_addr, u64 ip)
{
	return __get_srcline(dso, addr, sym, show_sym, show_addr, false, ip);
}

struct srcline_node {
	u64			addr;
	char			*srcline;
	struct rb_node		rb_node;
};

void srcline__tree_insert(struct rb_root_cached *tree, u64 addr, char *srcline)
{
	struct rb_node **p = &tree->rb_root.rb_node;
	struct rb_node *parent = NULL;
	struct srcline_node *i, *node;
	bool leftmost = true;

	node = zalloc(sizeof(struct srcline_node));
	if (!node) {
		perror("not enough memory for the srcline node");
		return;
	}

	node->addr = addr;
	node->srcline = srcline;

	while (*p != NULL) {
		parent = *p;
		i = rb_entry(parent, struct srcline_node, rb_node);
		if (addr < i->addr)
			p = &(*p)->rb_left;
		else {
			p = &(*p)->rb_right;
			leftmost = false;
		}
	}
	rb_link_node(&node->rb_node, parent, p);
	rb_insert_color_cached(&node->rb_node, tree, leftmost);
}

char *srcline__tree_find(struct rb_root_cached *tree, u64 addr)
{
	struct rb_node *n = tree->rb_root.rb_node;

	while (n) {
		struct srcline_node *i = rb_entry(n, struct srcline_node,
						  rb_node);

		if (addr < i->addr)
			n = n->rb_left;
		else if (addr > i->addr)
			n = n->rb_right;
		else
			return i->srcline;
	}

	return NULL;
}

void srcline__tree_delete(struct rb_root_cached *tree)
{
	struct srcline_node *pos;
	struct rb_node *next = rb_first_cached(tree);

	while (next) {
		pos = rb_entry(next, struct srcline_node, rb_node);
		next = rb_next(&pos->rb_node);
		rb_erase_cached(&pos->rb_node, tree);
		zfree_srcline(&pos->srcline);
		zfree(&pos);
	}
}

struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr,
					    struct symbol *sym)
{
	const char *dso_name;

	dso_name = dso__name(dso);
	if (dso_name == NULL)
		return NULL;

	return addr2inlines(dso_name, addr, dso, sym);
}

void inline_node__delete(struct inline_node *node)
{
	struct inline_list *ilist, *tmp;

	list_for_each_entry_safe(ilist, tmp, &node->val, list) {
		list_del_init(&ilist->list);
		zfree_srcline(&ilist->srcline);
		/* only the inlined symbols are owned by the list */
		if (ilist->symbol && ilist->symbol->inlined)
			symbol__delete(ilist->symbol);
		free(ilist);
	}

	free(node);
}

void inlines__tree_insert(struct rb_root_cached *tree,
			  struct inline_node *inlines)
{
	struct rb_node **p = &tree->rb_root.rb_node;
	struct rb_node *parent = NULL;
	const u64 addr = inlines->addr;
	struct inline_node *i;
	bool leftmost = true;

	while (*p != NULL) {
		parent = *p;
		i = rb_entry(parent, struct inline_node, rb_node);
		if (addr < i->addr)
			p = &(*p)->rb_left;
		else {
			p = &(*p)->rb_right;
			leftmost = false;
		}
	}
	rb_link_node(&inlines->rb_node, parent, p);
	rb_insert_color_cached(&inlines->rb_node, tree, leftmost);
}

struct inline_node *inlines__tree_find(struct rb_root_cached *tree, u64 addr)
{
	struct rb_node *n = tree->rb_root.rb_node;

	while (n) {
		struct inline_node *i = rb_entry(n, struct inline_node,
						 rb_node);

		if (addr < i->addr)
			n = n->rb_left;
		else if (addr > i->addr)
			n = n->rb_right;
		else
			return i;
	}

	return NULL;
}

void inlines__tree_delete(struct rb_root_cached *tree)
{
	struct inline_node *pos;
	struct rb_node *next = rb_first_cached(tree);

	while (next) {
		pos = rb_entry(next, struct inline_node, rb_node);
		next = rb_next(&pos->rb_node);
		rb_erase_cached(&pos->rb_node, tree);
		inline_node__delete(pos);
	}
}