aboutsummaryrefslogtreecommitdiff
path: root/tools/perf/util/probe-finder.c
blob: 0e8c8f1594ec296f7a1d76fdf9ea22c23aff55e5 (plain)
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
/*
 * probe-finder.c : C expression to kprobe event converter
 *
 * Written by Masami Hiramatsu <mhiramat@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 */

#include <sys/utsname.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>

#include "string.h"
#include "event.h"
#include "debug.h"
#include "util.h"
#include "probe-finder.h"


/*
 * Generic dwarf analysis helpers
 */

#define X86_32_MAX_REGS 8
const char *x86_32_regs_table[X86_32_MAX_REGS] = {
	"%ax",
	"%cx",
	"%dx",
	"%bx",
	"$stack",	/* Stack address instead of %sp */
	"%bp",
	"%si",
	"%di",
};

#define X86_64_MAX_REGS 16
const char *x86_64_regs_table[X86_64_MAX_REGS] = {
	"%ax",
	"%dx",
	"%cx",
	"%bx",
	"%si",
	"%di",
	"%bp",
	"%sp",
	"%r8",
	"%r9",
	"%r10",
	"%r11",
	"%r12",
	"%r13",
	"%r14",
	"%r15",
};

/* TODO: switching by dwarf address size */
#ifdef __x86_64__
#define ARCH_MAX_REGS X86_64_MAX_REGS
#define arch_regs_table x86_64_regs_table
#else
#define ARCH_MAX_REGS X86_32_MAX_REGS
#define arch_regs_table x86_32_regs_table
#endif

/* Return architecture dependent register string (for kprobe-tracer) */
static const char *get_arch_regstr(unsigned int n)
{
	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
}

/*
 * Compare the tail of two strings.
 * Return 0 if whole of either string is same as another's tail part.
 */
static int strtailcmp(const char *s1, const char *s2)
{
	int i1 = strlen(s1);
	int i2 = strlen(s2);
	while (--i1 >= 0 && --i2 >= 0) {
		if (s1[i1] != s2[i2])
			return s1[i1] - s2[i2];
	}
	return 0;
}

/* Line number list operations */

/* Add a line to line number list */
static void line_list__add_line(struct list_head *head, unsigned int line)
{
	struct line_node *ln;
	struct list_head *p;

	/* Reverse search, because new line will be the last one */
	list_for_each_entry_reverse(ln, head, list) {
		if (ln->line < line) {
			p = &ln->list;
			goto found;
		} else if (ln->line == line)	/* Already exist */
			return ;
	}
	/* List is empty, or the smallest entry */
	p = head;
found:
	pr_debug("line list: add a line %u\n", line);
	ln = zalloc(sizeof(struct line_node));
	DIE_IF(ln == NULL);
	ln->line = line;
	INIT_LIST_HEAD(&ln->list);
	list_add(&ln->list, p);
}

/* Check if the line in line number list */
static int line_list__has_line(struct list_head *head, unsigned int line)
{
	struct line_node *ln;

	/* Reverse search, because new line will be the last one */
	list_for_each_entry(ln, head, list)
		if (ln->line == line)
			return 1;

	return 0;
}

/* Init line number list */
static void line_list__init(struct list_head *head)
{
	INIT_LIST_HEAD(head);
}

/* Free line number list */
static void line_list__free(struct list_head *head)
{
	struct line_node *ln;
	while (!list_empty(head)) {
		ln = list_first_entry(head, struct line_node, list);
		list_del(&ln->list);
		free(ln);
	}
}

/* Dwarf wrappers */

/* Find the realpath of the target file. */
static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
{
	Dwarf_Files *files;
	size_t nfiles, i;
	const char *src = NULL;
	int ret;

	if (!fname)
		return NULL;

	ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
	if (ret != 0)
		return NULL;

	for (i = 0; i < nfiles; i++) {
		src = dwarf_filesrc(files, i, NULL, NULL);
		if (strtailcmp(src, fname) == 0)
			break;
	}
	return src;
}

struct __addr_die_search_param {
	Dwarf_Addr	addr;
	Dwarf_Die	*die_mem;
};

static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
{
	struct __addr_die_search_param *ad = data;

	if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
	    dwarf_haspc(fn_die, ad->addr)) {
		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
		return DWARF_CB_ABORT;
	}
	return DWARF_CB_OK;
}

/* Search a real subprogram including this line, */
static Dwarf_Die *die_get_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
					  Dwarf_Die *die_mem)
{
	struct __addr_die_search_param ad;
	ad.addr = addr;
	ad.die_mem = die_mem;
	/* dwarf_getscopes can't find subprogram. */
	if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
		return NULL;
	else
		return die_mem;
}

/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
static Dwarf_Die *die_get_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
				     Dwarf_Die *die_mem)
{
	Dwarf_Die child_die;
	int ret;

	ret = dwarf_child(sp_die, die_mem);
	if (ret != 0)
		return NULL;

	do {
		if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
		    dwarf_haspc(die_mem, addr))
			return die_mem;

		if (die_get_inlinefunc(die_mem, addr, &child_die)) {
			memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
			return die_mem;
		}
	} while (dwarf_siblingof(die_mem, die_mem) == 0);

	return NULL;
}

/* Compare diename and tname */
static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
{
	const char *name;
	name = dwarf_diename(dw_die);
	DIE_IF(name == NULL);
	return strcmp(tname, name);
}

/* Get entry pc(or low pc, 1st entry of ranges)  of the die */
static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
{
	Dwarf_Addr epc;
	int ret;

	ret = dwarf_entrypc(dw_die, &epc);
	DIE_IF(ret == -1);
	return epc;
}

/* Get a variable die */
static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
				    Dwarf_Die *die_mem)
{
	Dwarf_Die child_die;
	int tag;
	int ret;

	ret = dwarf_child(sp_die, die_mem);
	if (ret != 0)
		return NULL;

	do {
		tag = dwarf_tag(die_mem);
		if ((tag == DW_TAG_formal_parameter ||
		     tag == DW_TAG_variable) &&
		    (die_compare_name(die_mem, name) == 0))
			return die_mem;

		if (die_find_variable(die_mem, name, &child_die)) {
			memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
			return die_mem;
		}
	} while (dwarf_siblingof(die_mem, die_mem) == 0);

	return NULL;
}

/*
 * Probe finder related functions
 */

/* Show a location */
static void show_location(Dwarf_Op *op, struct probe_finder *pf)
{
	unsigned int regn;
	Dwarf_Word offs = 0;
	int deref = 0, ret;
	const char *regs;

	/* TODO: support CFA */
	/* If this is based on frame buffer, set the offset */
	if (op->atom == DW_OP_fbreg) {
		if (pf->fb_ops == NULL)
			die("The attribute of frame base is not supported.\n");
		deref = 1;
		offs = op->number;
		op = &pf->fb_ops[0];
	}

	if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
		regn = op->atom - DW_OP_breg0;
		offs += op->number;
		deref = 1;
	} else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
		regn = op->atom - DW_OP_reg0;
	} else if (op->atom == DW_OP_bregx) {
		regn = op->number;
		offs += op->number2;
		deref = 1;
	} else if (op->atom == DW_OP_regx) {
		regn = op->number;
	} else
		die("DW_OP %d is not supported.", op->atom);

	regs = get_arch_regstr(regn);
	if (!regs)
		die("%u exceeds max register number.", regn);

	if (deref)
		ret = snprintf(pf->buf, pf->len, " %s=%+jd(%s)",
			       pf->var, (intmax_t)offs, regs);
	else
		ret = snprintf(pf->buf, pf->len, " %s=%s", pf->var, regs);
	DIE_IF(ret < 0);
	DIE_IF(ret >= pf->len);
}

/* Show a variables in kprobe event format */
static void show_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
	Dwarf_Attribute attr;
	Dwarf_Op *expr;
	size_t nexpr;
	int ret;

	if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
		goto error;
	/* TODO: handle more than 1 exprs */
	ret = dwarf_getlocation_addr(&attr, (pf->addr - pf->cu_base),
				     &expr, &nexpr, 1);
	if (ret <= 0 || nexpr == 0)
		goto error;

	show_location(expr, pf);
	/* *expr will be cached in libdw. Don't free it. */
	return ;
error:
	/* TODO: Support const_value */
	die("Failed to find the location of %s at this address.\n"
	    " Perhaps, it has been optimized out.", pf->var);
}

/* Find a variable in a subprogram die */
static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
{
	int ret;
	Dwarf_Die vr_die;

	/* TODO: Support struct members and arrays */
	if (!is_c_varname(pf->var)) {
		/* Output raw parameters */
		ret = snprintf(pf->buf, pf->len, " %s", pf->var);
		DIE_IF(ret < 0);
		DIE_IF(ret >= pf->len);
		return ;
	}

	pr_debug("Searching '%s' variable in context.\n", pf->var);
	/* Search child die for local variables and parameters. */
	if (!die_find_variable(sp_die, pf->var, &vr_die))
		die("Failed to find '%s' in this function.", pf->var);

	show_variable(&vr_die, pf);
}

/* Show a probe point to output buffer */
static void show_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
{
	struct probe_point *pp = pf->pp;
	Dwarf_Addr eaddr;
	Dwarf_Die die_mem;
	const char *name;
	char tmp[MAX_PROBE_BUFFER];
	int ret, i, len;
	Dwarf_Attribute fb_attr;
	size_t nops;

	/* If no real subprogram, find a real one */
	if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
		sp_die = die_get_real_subprogram(&pf->cu_die,
						 pf->addr, &die_mem);
		if (!sp_die)
			die("Probe point is not found in subprograms.");
	}

	/* Output name of probe point */
	name = dwarf_diename(sp_die);
	if (name) {
		dwarf_entrypc(sp_die, &eaddr);
		ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%lu", name,
				(unsigned long)(pf->addr - eaddr));
		/* Copy the function name if possible */
		if (!pp->function) {
			pp->function = strdup(name);
			pp->offset = (size_t)(pf->addr - eaddr);
		}
	} else {
		/* This function has no name. */
		ret = snprintf(tmp, MAX_PROBE_BUFFER, "0x%jx",
			       (uintmax_t)pf->addr);
		if (!pp->function) {
			/* TODO: Use _stext */
			pp->function = strdup("");
			pp->offset = (size_t)pf->addr;
		}
	}
	DIE_IF(ret < 0);
	DIE_IF(ret >= MAX_PROBE_BUFFER);
	len = ret;
	pr_debug("Probe point found: %s\n", tmp);

	/* Get the frame base attribute/ops */
	dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
	ret = dwarf_getlocation_addr(&fb_attr, (pf->addr - pf->cu_base),
				     &pf->fb_ops, &nops, 1);
	if (ret <= 0 || nops == 0)
		pf->fb_ops = NULL;

	/* Find each argument */
	/* TODO: use dwarf_cfi_addrframe */
	for (i = 0; i < pp->nr_args; i++) {
		pf->var = pp->args[i];
		pf->buf = &tmp[len];
		pf->len = MAX_PROBE_BUFFER - len;
		find_variable(sp_die, pf);
		len += strlen(pf->buf);
	}

	/* *pf->fb_ops will be cached in libdw. Don't free it. */
	pf->fb_ops = NULL;

	if (pp->found == MAX_PROBES)
		die("Too many( > %d) probe point found.\n", MAX_PROBES);

	pp->probes[pp->found] = strdup(tmp);
	pp->found++;
}

/* Find probe point from its line number */
static void find_probe_point_by_line(struct probe_finder *pf)
{
	Dwarf_Lines *lines;
	Dwarf_Line *line;
	size_t nlines, i;
	Dwarf_Addr addr;
	int lineno;
	int ret;

	ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
	DIE_IF(ret != 0);

	for (i = 0; i < nlines; i++) {
		line = dwarf_onesrcline(lines, i);
		dwarf_lineno(line, &lineno);
		if (lineno != pf->lno)
			continue;

		/* TODO: Get fileno from line, but how? */
		if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
			continue;

		ret = dwarf_lineaddr(line, &addr);
		DIE_IF(ret != 0);
		pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
			 (int)i, lineno, (uintmax_t)addr);
		pf->addr = addr;

		show_probe_point(NULL, pf);
		/* Continuing, because target line might be inlined. */
	}
}

/* Find lines which match lazy pattern */
static int find_lazy_match_lines(struct list_head *head,
				 const char *fname, const char *pat)
{
	char *fbuf, *p1, *p2;
	int fd, line, nlines = 0;
	struct stat st;

	fd = open(fname, O_RDONLY);
	if (fd < 0)
		die("failed to open %s", fname);
	DIE_IF(fstat(fd, &st) < 0);
	fbuf = malloc(st.st_size + 2);
	DIE_IF(fbuf == NULL);
	DIE_IF(read(fd, fbuf, st.st_size) < 0);
	close(fd);
	fbuf[st.st_size] = '\n';	/* Dummy line */
	fbuf[st.st_size + 1] = '\0';
	p1 = fbuf;
	line = 1;
	while ((p2 = strchr(p1, '\n')) != NULL) {
		*p2 = '\0';
		if (strlazymatch(p1, pat)) {
			line_list__add_line(head, line);
			nlines++;
		}
		line++;
		p1 = p2 + 1;
	}
	free(fbuf);
	return nlines;
}

/* Find probe points from lazy pattern  */
static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
{
	Dwarf_Lines *lines;
	Dwarf_Line *line;
	size_t nlines, i;
	Dwarf_Addr addr;
	Dwarf_Die die_mem;
	int lineno;
	int ret;

	if (list_empty(&pf->lcache)) {
		/* Matching lazy line pattern */
		ret = find_lazy_match_lines(&pf->lcache, pf->fname,
					    pf->pp->lazy_line);
		if (ret <= 0)
			die("No matched lines found in %s.", pf->fname);
	}

	ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
	DIE_IF(ret != 0);
	for (i = 0; i < nlines; i++) {
		line = dwarf_onesrcline(lines, i);

		dwarf_lineno(line, &lineno);
		if (!line_list__has_line(&pf->lcache, lineno))
			continue;

		/* TODO: Get fileno from line, but how? */
		if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
			continue;

		ret = dwarf_lineaddr(line, &addr);
		DIE_IF(ret != 0);
		if (sp_die) {
			/* Address filtering 1: does sp_die include addr? */
			if (!dwarf_haspc(sp_die, addr))
				continue;
			/* Address filtering 2: No child include addr? */
			if (die_get_inlinefunc(sp_die, addr, &die_mem))
				continue;
		}

		pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
			 (int)i, lineno, (unsigned long long)addr);
		pf->addr = addr;

		show_probe_point(sp_die, pf);
		/* Continuing, because target line might be inlined. */
	}
	/* TODO: deallocate lines, but how? */
}

static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
	struct probe_finder *pf = (struct probe_finder *)data;
	struct probe_point *pp = pf->pp;

	if (pp->lazy_line)
		find_probe_point_lazy(in_die, pf);
	else {
		/* Get probe address */
		pf->addr = die_get_entrypc(in_die);
		pf->addr += pp->offset;
		pr_debug("found inline addr: 0x%jx\n",
			 (uintmax_t)pf->addr);

		show_probe_point(in_die, pf);
	}

	return DWARF_CB_OK;
}

/* Search function from function name */
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
{
	struct probe_finder *pf = (struct probe_finder *)data;
	struct probe_point *pp = pf->pp;

	/* Check tag and diename */
	if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
	    die_compare_name(sp_die, pp->function) != 0)
		return 0;

	pf->fname = dwarf_decl_file(sp_die);
	if (pp->line) { /* Function relative line */
		dwarf_decl_line(sp_die, &pf->lno);
		pf->lno += pp->line;
		find_probe_point_by_line(pf);
	} else if (!dwarf_func_inline(sp_die)) {
		/* Real function */
		if (pp->lazy_line)
			find_probe_point_lazy(sp_die, pf);
		else {
			pf->addr = die_get_entrypc(sp_die);
			pf->addr += pp->offset;
			/* TODO: Check the address in this function */
			show_probe_point(sp_die, pf);
		}
	} else
		/* Inlined function: search instances */
		dwarf_func_inline_instances(sp_die, probe_point_inline_cb, pf);

	return 1; /* Exit; no same symbol in this CU. */
}

static void find_probe_point_by_func(struct probe_finder *pf)
{
	dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, pf, 0);
}

/* Find a probe point */
int find_probe_point(int fd, struct probe_point *pp)
{
	struct probe_finder pf = {.pp = pp};
	int ret;
	Dwarf_Off off, noff;
	size_t cuhl;
	Dwarf_Die *diep;
	Dwarf *dbg;

	dbg = dwarf_begin(fd, DWARF_C_READ);
	if (!dbg)
		return -ENOENT;

	pp->found = 0;
	off = 0;
	line_list__init(&pf.lcache);
	/* Loop on CUs (Compilation Unit) */
	while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
		/* Get the DIE(Debugging Information Entry) of this CU */
		diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
		if (!diep)
			continue;

		/* Check if target file is included. */
		if (pp->file)
			pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
		else
			pf.fname = NULL;

		if (!pp->file || pf.fname) {
			/* Save CU base address (for frame_base) */
			ret = dwarf_lowpc(&pf.cu_die, &pf.cu_base);
			if (ret != 0)
				pf.cu_base = 0;
			if (pp->function)
				find_probe_point_by_func(&pf);
			else if (pp->lazy_line)
				find_probe_point_lazy(NULL, &pf);
			else {
				pf.lno = pp->line;
				find_probe_point_by_line(&pf);
			}
		}
		off = noff;
	}
	line_list__free(&pf.lcache);
	dwarf_end(dbg);

	return pp->found;
}

/* Find line range from its line number */
static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
{
	Dwarf_Lines *lines;
	Dwarf_Line *line;
	size_t nlines, i;
	Dwarf_Addr addr;
	int lineno;
	int ret;
	const char *src;
	Dwarf_Die die_mem;

	line_list__init(&lf->lr->line_list);
	ret = dwarf_getsrclines(&lf->cu_die, &lines, &nlines);
	DIE_IF(ret != 0);

	for (i = 0; i < nlines; i++) {
		line = dwarf_onesrcline(lines, i);
		ret = dwarf_lineno(line, &lineno);
		DIE_IF(ret != 0);
		if (lf->lno_s > lineno || lf->lno_e < lineno)
			continue;

		if (sp_die) {
			/* Address filtering 1: does sp_die include addr? */
			ret = dwarf_lineaddr(line, &addr);
			DIE_IF(ret != 0);
			if (!dwarf_haspc(sp_die, addr))
				continue;

			/* Address filtering 2: No child include addr? */
			if (die_get_inlinefunc(sp_die, addr, &die_mem))
				continue;
		}

		/* TODO: Get fileno from line, but how? */
		src = dwarf_linesrc(line, NULL, NULL);
		if (strtailcmp(src, lf->fname) != 0)
			continue;

		/* Copy real path */
		if (!lf->lr->path)
			lf->lr->path = strdup(src);
		line_list__add_line(&lf->lr->line_list, (unsigned int)lineno);
	}
	/* Update status */
	if (!list_empty(&lf->lr->line_list))
		lf->found = 1;
	else {
		free(lf->lr->path);
		lf->lr->path = NULL;
	}
}

static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
{
	find_line_range_by_line(in_die, (struct line_finder *)data);
	return DWARF_CB_ABORT;	/* No need to find other instances */
}

/* Search function from function name */
static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
{
	struct line_finder *lf = (struct line_finder *)data;
	struct line_range *lr = lf->lr;

	if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
	    die_compare_name(sp_die, lr->function) == 0) {
		lf->fname = dwarf_decl_file(sp_die);
		dwarf_decl_line(sp_die, &lr->offset);
		pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
		lf->lno_s = lr->offset + lr->start;
		if (!lr->end)
			lf->lno_e = INT_MAX;
		else
			lf->lno_e = lr->offset + lr->end;
		lr->start = lf->lno_s;
		lr->end = lf->lno_e;
		if (dwarf_func_inline(sp_die))
			dwarf_func_inline_instances(sp_die,
						    line_range_inline_cb, lf);
		else
			find_line_range_by_line(sp_die, lf);
		return 1;
	}
	return 0;
}

static void find_line_range_by_func(struct line_finder *lf)
{
	dwarf_getfuncs(&lf->cu_die, line_range_search_cb, lf, 0);
}

int find_line_range(int fd, struct line_range *lr)
{
	struct line_finder lf = {.lr = lr, .found = 0};
	int ret;
	Dwarf_Off off = 0, noff;
	size_t cuhl;
	Dwarf_Die *diep;
	Dwarf *dbg;

	dbg = dwarf_begin(fd, DWARF_C_READ);
	if (!dbg)
		return -ENOENT;

	/* Loop on CUs (Compilation Unit) */
	while (!lf.found) {
		ret = dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL);
		if (ret != 0)
			break;

		/* Get the DIE(Debugging Information Entry) of this CU */
		diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
		if (!diep)
			continue;

		/* Check if target file is included. */
		if (lr->file)
			lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
		else
			lf.fname = 0;

		if (!lr->file || lf.fname) {
			if (lr->function)
				find_line_range_by_func(&lf);
			else {
				lf.lno_s = lr->start;
				if (!lr->end)
					lf.lno_e = INT_MAX;
				else
					lf.lno_e = lr->end;
				find_line_range_by_line(NULL, &lf);
			}
		}
		off = noff;
	}
	pr_debug("path: %lx\n", (unsigned long)lr->path);
	dwarf_end(dbg);
	return lf.found;
}