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Merge tag 'v3.3.7' into 3.3/master
[zen-stable.git] / tools / perf / util / probe-finder.c
blob74bd2e63c4b4a7458989a08cc731c15edfb99c98
1 /*
2 * probe-finder.c : C expression to kprobe event converter
3 *
4 * Written by Masami Hiramatsu <mhiramat@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 *
20 */
21
22 #include <sys/utsname.h>
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <fcntl.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <unistd.h>
29 #include <getopt.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <stdarg.h>
33 #include <ctype.h>
34 #include <dwarf-regs.h>
35
36 #include <linux/bitops.h>
37 #include "event.h"
38 #include "debug.h"
39 #include "util.h"
40 #include "symbol.h"
41 #include "probe-finder.h"
42
43 /* Kprobe tracer basic type is up to u64 */
44 #define MAX_BASIC_TYPE_BITS 64
45
46 /* Line number list operations */
47
48 /* Add a line to line number list */
49 static int line_list__add_line(struct list_head *head, int line)
50 {
51 struct line_node *ln;
52 struct list_head *p;
53
54 /* Reverse search, because new line will be the last one */
55 list_for_each_entry_reverse(ln, head, list) {
56 if (ln->line < line) {
57 p = &ln->list;
58 goto found;
59 } else if (ln->line == line) /* Already exist */
60 return 1;
61 }
62 /* List is empty, or the smallest entry */
63 p = head;
64 found:
65 pr_debug("line list: add a line %u\n", line);
66 ln = zalloc(sizeof(struct line_node));
67 if (ln == NULL)
68 return -ENOMEM;
69 ln->line = line;
70 INIT_LIST_HEAD(&ln->list);
71 list_add(&ln->list, p);
72 return 0;
73 }
74
75 /* Check if the line in line number list */
76 static int line_list__has_line(struct list_head *head, int line)
77 {
78 struct line_node *ln;
79
80 /* Reverse search, because new line will be the last one */
81 list_for_each_entry(ln, head, list)
82 if (ln->line == line)
83 return 1;
84
85 return 0;
86 }
87
88 /* Init line number list */
89 static void line_list__init(struct list_head *head)
90 {
91 INIT_LIST_HEAD(head);
92 }
93
94 /* Free line number list */
95 static void line_list__free(struct list_head *head)
96 {
97 struct line_node *ln;
98 while (!list_empty(head)) {
99 ln = list_first_entry(head, struct line_node, list);
100 list_del(&ln->list);
101 free(ln);
102 }
103 }
104
105 /* Dwarf FL wrappers */
106 static char *debuginfo_path; /* Currently dummy */
107
108 static const Dwfl_Callbacks offline_callbacks = {
109 .find_debuginfo = dwfl_standard_find_debuginfo,
110 .debuginfo_path = &debuginfo_path,
111
112 .section_address = dwfl_offline_section_address,
113
114 /* We use this table for core files too. */
115 .find_elf = dwfl_build_id_find_elf,
116 };
117
118 /* Get a Dwarf from offline image */
119 static int debuginfo__init_offline_dwarf(struct debuginfo *self,
120 const char *path)
121 {
122 Dwfl_Module *mod;
123 int fd;
124
125 fd = open(path, O_RDONLY);
126 if (fd < 0)
127 return fd;
128
129 self->dwfl = dwfl_begin(&offline_callbacks);
130 if (!self->dwfl)
131 goto error;
132
133 mod = dwfl_report_offline(self->dwfl, "", "", fd);
134 if (!mod)
135 goto error;
136
137 self->dbg = dwfl_module_getdwarf(mod, &self->bias);
138 if (!self->dbg)
139 goto error;
140
141 return 0;
142 error:
143 if (self->dwfl)
144 dwfl_end(self->dwfl);
145 else
146 close(fd);
147 memset(self, 0, sizeof(*self));
148
149 return -ENOENT;
150 }
151
152 #if _ELFUTILS_PREREQ(0, 148)
153 /* This method is buggy if elfutils is older than 0.148 */
154 static int __linux_kernel_find_elf(Dwfl_Module *mod,
155 void **userdata,
156 const char *module_name,
157 Dwarf_Addr base,
158 char **file_name, Elf **elfp)
159 {
160 int fd;
161 const char *path = kernel_get_module_path(module_name);
162
163 pr_debug2("Use file %s for %s\n", path, module_name);
164 if (path) {
165 fd = open(path, O_RDONLY);
166 if (fd >= 0) {
167 *file_name = strdup(path);
168 return fd;
169 }
170 }
171 /* If failed, try to call standard method */
172 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
173 file_name, elfp);
174 }
175
176 static const Dwfl_Callbacks kernel_callbacks = {
177 .find_debuginfo = dwfl_standard_find_debuginfo,
178 .debuginfo_path = &debuginfo_path,
179
180 .find_elf = __linux_kernel_find_elf,
181 .section_address = dwfl_linux_kernel_module_section_address,
182 };
183
184 /* Get a Dwarf from live kernel image */
185 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
186 Dwarf_Addr addr)
187 {
188 self->dwfl = dwfl_begin(&kernel_callbacks);
189 if (!self->dwfl)
190 return -EINVAL;
191
192 /* Load the kernel dwarves: Don't care the result here */
193 dwfl_linux_kernel_report_kernel(self->dwfl);
194 dwfl_linux_kernel_report_modules(self->dwfl);
195
196 self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
197 /* Here, check whether we could get a real dwarf */
198 if (!self->dbg) {
199 pr_debug("Failed to find kernel dwarf at %lx\n",
200 (unsigned long)addr);
201 dwfl_end(self->dwfl);
202 memset(self, 0, sizeof(*self));
203 return -ENOENT;
204 }
205
206 return 0;
207 }
208 #else
209 /* With older elfutils, this just support kernel module... */
210 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
211 Dwarf_Addr addr __used)
212 {
213 const char *path = kernel_get_module_path("kernel");
214
215 if (!path) {
216 pr_err("Failed to find vmlinux path\n");
217 return -ENOENT;
218 }
219
220 pr_debug2("Use file %s for debuginfo\n", path);
221 return debuginfo__init_offline_dwarf(self, path);
222 }
223 #endif
224
225 struct debuginfo *debuginfo__new(const char *path)
226 {
227 struct debuginfo *self = zalloc(sizeof(struct debuginfo));
228 if (!self)
229 return NULL;
230
231 if (debuginfo__init_offline_dwarf(self, path) < 0) {
232 free(self);
233 self = NULL;
234 }
235
236 return self;
237 }
238
239 struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
240 {
241 struct debuginfo *self = zalloc(sizeof(struct debuginfo));
242 if (!self)
243 return NULL;
244
245 if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) {
246 free(self);
247 self = NULL;
248 }
249
250 return self;
251 }
252
253 void debuginfo__delete(struct debuginfo *self)
254 {
255 if (self) {
256 if (self->dwfl)
257 dwfl_end(self->dwfl);
258 free(self);
259 }
260 }
261
262 /*
263 * Probe finder related functions
264 */
265
266 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
267 {
268 struct probe_trace_arg_ref *ref;
269 ref = zalloc(sizeof(struct probe_trace_arg_ref));
270 if (ref != NULL)
271 ref->offset = offs;
272 return ref;
273 }
274
275 /*
276 * Convert a location into trace_arg.
277 * If tvar == NULL, this just checks variable can be converted.
278 */
279 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
280 Dwarf_Op *fb_ops,
281 struct probe_trace_arg *tvar)
282 {
283 Dwarf_Attribute attr;
284 Dwarf_Op *op;
285 size_t nops;
286 unsigned int regn;
287 Dwarf_Word offs = 0;
288 bool ref = false;
289 const char *regs;
290 int ret;
291
292 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
293 goto static_var;
294
295 /* TODO: handle more than 1 exprs */
296 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
297 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
298 nops == 0) {
299 /* TODO: Support const_value */
300 return -ENOENT;
301 }
302
303 if (op->atom == DW_OP_addr) {
304 static_var:
305 if (!tvar)
306 return 0;
307 /* Static variables on memory (not stack), make @varname */
308 ret = strlen(dwarf_diename(vr_die));
309 tvar->value = zalloc(ret + 2);
310 if (tvar->value == NULL)
311 return -ENOMEM;
312 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
313 tvar->ref = alloc_trace_arg_ref((long)offs);
314 if (tvar->ref == NULL)
315 return -ENOMEM;
316 return 0;
317 }
318
319 /* If this is based on frame buffer, set the offset */
320 if (op->atom == DW_OP_fbreg) {
321 if (fb_ops == NULL)
322 return -ENOTSUP;
323 ref = true;
324 offs = op->number;
325 op = &fb_ops[0];
326 }
327
328 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
329 regn = op->atom - DW_OP_breg0;
330 offs += op->number;
331 ref = true;
332 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
333 regn = op->atom - DW_OP_reg0;
334 } else if (op->atom == DW_OP_bregx) {
335 regn = op->number;
336 offs += op->number2;
337 ref = true;
338 } else if (op->atom == DW_OP_regx) {
339 regn = op->number;
340 } else {
341 pr_debug("DW_OP %x is not supported.\n", op->atom);
342 return -ENOTSUP;
343 }
344
345 if (!tvar)
346 return 0;
347
348 regs = get_arch_regstr(regn);
349 if (!regs) {
350 /* This should be a bug in DWARF or this tool */
351 pr_warning("Mapping for the register number %u "
352 "missing on this architecture.\n", regn);
353 return -ERANGE;
354 }
355
356 tvar->value = strdup(regs);
357 if (tvar->value == NULL)
358 return -ENOMEM;
359
360 if (ref) {
361 tvar->ref = alloc_trace_arg_ref((long)offs);
362 if (tvar->ref == NULL)
363 return -ENOMEM;
364 }
365 return 0;
366 }
367
368 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
369
370 static int convert_variable_type(Dwarf_Die *vr_die,
371 struct probe_trace_arg *tvar,
372 const char *cast)
373 {
374 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
375 Dwarf_Die type;
376 char buf[16];
377 int bsize, boffs, total;
378 int ret;
379
380 /* TODO: check all types */
381 if (cast && strcmp(cast, "string") != 0) {
382 /* Non string type is OK */
383 tvar->type = strdup(cast);
384 return (tvar->type == NULL) ? -ENOMEM : 0;
385 }
386
387 bsize = dwarf_bitsize(vr_die);
388 if (bsize > 0) {
389 /* This is a bitfield */
390 boffs = dwarf_bitoffset(vr_die);
391 total = dwarf_bytesize(vr_die);
392 if (boffs < 0 || total < 0)
393 return -ENOENT;
394 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
395 BYTES_TO_BITS(total));
396 goto formatted;
397 }
398
399 if (die_get_real_type(vr_die, &type) == NULL) {
400 pr_warning("Failed to get a type information of %s.\n",
401 dwarf_diename(vr_die));
402 return -ENOENT;
403 }
404
405 pr_debug("%s type is %s.\n",
406 dwarf_diename(vr_die), dwarf_diename(&type));
407
408 if (cast && strcmp(cast, "string") == 0) { /* String type */
409 ret = dwarf_tag(&type);
410 if (ret != DW_TAG_pointer_type &&
411 ret != DW_TAG_array_type) {
412 pr_warning("Failed to cast into string: "
413 "%s(%s) is not a pointer nor array.\n",
414 dwarf_diename(vr_die), dwarf_diename(&type));
415 return -EINVAL;
416 }
417 if (ret == DW_TAG_pointer_type) {
418 if (die_get_real_type(&type, &type) == NULL) {
419 pr_warning("Failed to get a type"
420 " information.\n");
421 return -ENOENT;
422 }
423 while (*ref_ptr)
424 ref_ptr = &(*ref_ptr)->next;
425 /* Add new reference with offset +0 */
426 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
427 if (*ref_ptr == NULL) {
428 pr_warning("Out of memory error\n");
429 return -ENOMEM;
430 }
431 }
432 if (!die_compare_name(&type, "char") &&
433 !die_compare_name(&type, "unsigned char")) {
434 pr_warning("Failed to cast into string: "
435 "%s is not (unsigned) char *.\n",
436 dwarf_diename(vr_die));
437 return -EINVAL;
438 }
439 tvar->type = strdup(cast);
440 return (tvar->type == NULL) ? -ENOMEM : 0;
441 }
442
443 ret = dwarf_bytesize(&type);
444 if (ret <= 0)
445 /* No size ... try to use default type */
446 return 0;
447 ret = BYTES_TO_BITS(ret);
448
449 /* Check the bitwidth */
450 if (ret > MAX_BASIC_TYPE_BITS) {
451 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
452 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
453 ret = MAX_BASIC_TYPE_BITS;
454 }
455 ret = snprintf(buf, 16, "%c%d",
456 die_is_signed_type(&type) ? 's' : 'u', ret);
457
458 formatted:
459 if (ret < 0 || ret >= 16) {
460 if (ret >= 16)
461 ret = -E2BIG;
462 pr_warning("Failed to convert variable type: %s\n",
463 strerror(-ret));
464 return ret;
465 }
466 tvar->type = strdup(buf);
467 if (tvar->type == NULL)
468 return -ENOMEM;
469 return 0;
470 }
471
472 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
473 struct perf_probe_arg_field *field,
474 struct probe_trace_arg_ref **ref_ptr,
475 Dwarf_Die *die_mem)
476 {
477 struct probe_trace_arg_ref *ref = *ref_ptr;
478 Dwarf_Die type;
479 Dwarf_Word offs;
480 int ret, tag;
481
482 pr_debug("converting %s in %s\n", field->name, varname);
483 if (die_get_real_type(vr_die, &type) == NULL) {
484 pr_warning("Failed to get the type of %s.\n", varname);
485 return -ENOENT;
486 }
487 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
488 tag = dwarf_tag(&type);
489
490 if (field->name[0] == '[' &&
491 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
492 if (field->next)
493 /* Save original type for next field */
494 memcpy(die_mem, &type, sizeof(*die_mem));
495 /* Get the type of this array */
496 if (die_get_real_type(&type, &type) == NULL) {
497 pr_warning("Failed to get the type of %s.\n", varname);
498 return -ENOENT;
499 }
500 pr_debug2("Array real type: (%x)\n",
501 (unsigned)dwarf_dieoffset(&type));
502 if (tag == DW_TAG_pointer_type) {
503 ref = zalloc(sizeof(struct probe_trace_arg_ref));
504 if (ref == NULL)
505 return -ENOMEM;
506 if (*ref_ptr)
507 (*ref_ptr)->next = ref;
508 else
509 *ref_ptr = ref;
510 }
511 ref->offset += dwarf_bytesize(&type) * field->index;
512 if (!field->next)
513 /* Save vr_die for converting types */
514 memcpy(die_mem, vr_die, sizeof(*die_mem));
515 goto next;
516 } else if (tag == DW_TAG_pointer_type) {
517 /* Check the pointer and dereference */
518 if (!field->ref) {
519 pr_err("Semantic error: %s must be referred by '->'\n",
520 field->name);
521 return -EINVAL;
522 }
523 /* Get the type pointed by this pointer */
524 if (die_get_real_type(&type, &type) == NULL) {
525 pr_warning("Failed to get the type of %s.\n", varname);
526 return -ENOENT;
527 }
528 /* Verify it is a data structure */
529 if (dwarf_tag(&type) != DW_TAG_structure_type) {
530 pr_warning("%s is not a data structure.\n", varname);
531 return -EINVAL;
532 }
533
534 ref = zalloc(sizeof(struct probe_trace_arg_ref));
535 if (ref == NULL)
536 return -ENOMEM;
537 if (*ref_ptr)
538 (*ref_ptr)->next = ref;
539 else
540 *ref_ptr = ref;
541 } else {
542 /* Verify it is a data structure */
543 if (tag != DW_TAG_structure_type) {
544 pr_warning("%s is not a data structure.\n", varname);
545 return -EINVAL;
546 }
547 if (field->name[0] == '[') {
548 pr_err("Semantic error: %s is not a pointor"
549 " nor array.\n", varname);
550 return -EINVAL;
551 }
552 if (field->ref) {
553 pr_err("Semantic error: %s must be referred by '.'\n",
554 field->name);
555 return -EINVAL;
556 }
557 if (!ref) {
558 pr_warning("Structure on a register is not "
559 "supported yet.\n");
560 return -ENOTSUP;
561 }
562 }
563
564 if (die_find_member(&type, field->name, die_mem) == NULL) {
565 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
566 dwarf_diename(&type), field->name);
567 return -EINVAL;
568 }
569
570 /* Get the offset of the field */
571 ret = die_get_data_member_location(die_mem, &offs);
572 if (ret < 0) {
573 pr_warning("Failed to get the offset of %s.\n", field->name);
574 return ret;
575 }
576 ref->offset += (long)offs;
577
578 next:
579 /* Converting next field */
580 if (field->next)
581 return convert_variable_fields(die_mem, field->name,
582 field->next, &ref, die_mem);
583 else
584 return 0;
585 }
586
587 /* Show a variables in kprobe event format */
588 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
589 {
590 Dwarf_Die die_mem;
591 int ret;
592
593 pr_debug("Converting variable %s into trace event.\n",
594 dwarf_diename(vr_die));
595
596 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
597 pf->tvar);
598 if (ret == -ENOENT)
599 pr_err("Failed to find the location of %s at this address.\n"
600 " Perhaps, it has been optimized out.\n", pf->pvar->var);
601 else if (ret == -ENOTSUP)
602 pr_err("Sorry, we don't support this variable location yet.\n");
603 else if (pf->pvar->field) {
604 ret = convert_variable_fields(vr_die, pf->pvar->var,
605 pf->pvar->field, &pf->tvar->ref,
606 &die_mem);
607 vr_die = &die_mem;
608 }
609 if (ret == 0)
610 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
611 /* *expr will be cached in libdw. Don't free it. */
612 return ret;
613 }
614
615 /* Find a variable in a scope DIE */
616 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
617 {
618 Dwarf_Die vr_die;
619 char buf[32], *ptr;
620 int ret = 0;
621
622 if (!is_c_varname(pf->pvar->var)) {
623 /* Copy raw parameters */
624 pf->tvar->value = strdup(pf->pvar->var);
625 if (pf->tvar->value == NULL)
626 return -ENOMEM;
627 if (pf->pvar->type) {
628 pf->tvar->type = strdup(pf->pvar->type);
629 if (pf->tvar->type == NULL)
630 return -ENOMEM;
631 }
632 if (pf->pvar->name) {
633 pf->tvar->name = strdup(pf->pvar->name);
634 if (pf->tvar->name == NULL)
635 return -ENOMEM;
636 } else
637 pf->tvar->name = NULL;
638 return 0;
639 }
640
641 if (pf->pvar->name)
642 pf->tvar->name = strdup(pf->pvar->name);
643 else {
644 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
645 if (ret < 0)
646 return ret;
647 ptr = strchr(buf, ':'); /* Change type separator to _ */
648 if (ptr)
649 *ptr = '_';
650 pf->tvar->name = strdup(buf);
651 }
652 if (pf->tvar->name == NULL)
653 return -ENOMEM;
654
655 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
656 /* Search child die for local variables and parameters. */
657 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
658 /* Search again in global variables */
659 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
660 ret = -ENOENT;
661 }
662 if (ret >= 0)
663 ret = convert_variable(&vr_die, pf);
664
665 if (ret < 0)
666 pr_warning("Failed to find '%s' in this function.\n",
667 pf->pvar->var);
668 return ret;
669 }
670
671 /* Convert subprogram DIE to trace point */
672 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
673 bool retprobe, struct probe_trace_point *tp)
674 {
675 Dwarf_Addr eaddr, highaddr;
676 const char *name;
677
678 /* Copy the name of probe point */
679 name = dwarf_diename(sp_die);
680 if (name) {
681 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
682 pr_warning("Failed to get entry address of %s\n",
683 dwarf_diename(sp_die));
684 return -ENOENT;
685 }
686 if (dwarf_highpc(sp_die, &highaddr) != 0) {
687 pr_warning("Failed to get end address of %s\n",
688 dwarf_diename(sp_die));
689 return -ENOENT;
690 }
691 if (paddr > highaddr) {
692 pr_warning("Offset specified is greater than size of %s\n",
693 dwarf_diename(sp_die));
694 return -EINVAL;
695 }
696 tp->symbol = strdup(name);
697 if (tp->symbol == NULL)
698 return -ENOMEM;
699 tp->offset = (unsigned long)(paddr - eaddr);
700 } else
701 /* This function has no name. */
702 tp->offset = (unsigned long)paddr;
703
704 /* Return probe must be on the head of a subprogram */
705 if (retprobe) {
706 if (eaddr != paddr) {
707 pr_warning("Return probe must be on the head of"
708 " a real function.\n");
709 return -EINVAL;
710 }
711 tp->retprobe = true;
712 }
713
714 return 0;
715 }
716
717 /* Call probe_finder callback with scope DIE */
718 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
719 {
720 Dwarf_Attribute fb_attr;
721 size_t nops;
722 int ret;
723
724 if (!sc_die) {
725 pr_err("Caller must pass a scope DIE. Program error.\n");
726 return -EINVAL;
727 }
728
729 /* If not a real subprogram, find a real one */
730 if (dwarf_tag(sc_die) != DW_TAG_subprogram) {
731 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
732 pr_warning("Failed to find probe point in any "
733 "functions.\n");
734 return -ENOENT;
735 }
736 } else
737 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
738
739 /* Get the frame base attribute/ops from subprogram */
740 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
741 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
742 if (ret <= 0 || nops == 0) {
743 pf->fb_ops = NULL;
744 #if _ELFUTILS_PREREQ(0, 142)
745 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
746 pf->cfi != NULL) {
747 Dwarf_Frame *frame;
748 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
749 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
750 pr_warning("Failed to get call frame on 0x%jx\n",
751 (uintmax_t)pf->addr);
752 return -ENOENT;
753 }
754 #endif
755 }
756
757 /* Call finder's callback handler */
758 ret = pf->callback(sc_die, pf);
759
760 /* *pf->fb_ops will be cached in libdw. Don't free it. */
761 pf->fb_ops = NULL;
762
763 return ret;
764 }
765
766 struct find_scope_param {
767 const char *function;
768 const char *file;
769 int line;
770 int diff;
771 Dwarf_Die *die_mem;
772 bool found;
773 };
774
775 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
776 {
777 struct find_scope_param *fsp = data;
778 const char *file;
779 int lno;
780
781 /* Skip if declared file name does not match */
782 if (fsp->file) {
783 file = dwarf_decl_file(fn_die);
784 if (!file || strcmp(fsp->file, file) != 0)
785 return 0;
786 }
787 /* If the function name is given, that's what user expects */
788 if (fsp->function) {
789 if (die_compare_name(fn_die, fsp->function)) {
790 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
791 fsp->found = true;
792 return 1;
793 }
794 } else {
795 /* With the line number, find the nearest declared DIE */
796 dwarf_decl_line(fn_die, &lno);
797 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
798 /* Keep a candidate and continue */
799 fsp->diff = fsp->line - lno;
800 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
801 fsp->found = true;
802 }
803 }
804 return 0;
805 }
806
807 /* Find an appropriate scope fits to given conditions */
808 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
809 {
810 struct find_scope_param fsp = {
811 .function = pf->pev->point.function,
812 .file = pf->fname,
813 .line = pf->lno,
814 .diff = INT_MAX,
815 .die_mem = die_mem,
816 .found = false,
817 };
818
819 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
820
821 return fsp.found ? die_mem : NULL;
822 }
823
824 static int probe_point_line_walker(const char *fname, int lineno,
825 Dwarf_Addr addr, void *data)
826 {
827 struct probe_finder *pf = data;
828 Dwarf_Die *sc_die, die_mem;
829 int ret;
830
831 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
832 return 0;
833
834 pf->addr = addr;
835 sc_die = find_best_scope(pf, &die_mem);
836 if (!sc_die) {
837 pr_warning("Failed to find scope of probe point.\n");
838 return -ENOENT;
839 }
840
841 ret = call_probe_finder(sc_die, pf);
842
843 /* Continue if no error, because the line will be in inline function */
844 return ret < 0 ? ret : 0;
845 }
846
847 /* Find probe point from its line number */
848 static int find_probe_point_by_line(struct probe_finder *pf)
849 {
850 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
851 }
852
853 /* Find lines which match lazy pattern */
854 static int find_lazy_match_lines(struct list_head *head,
855 const char *fname, const char *pat)
856 {
857 FILE *fp;
858 char *line = NULL;
859 size_t line_len;
860 ssize_t len;
861 int count = 0, linenum = 1;
862
863 fp = fopen(fname, "r");
864 if (!fp) {
865 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
866 return -errno;
867 }
868
869 while ((len = getline(&line, &line_len, fp)) > 0) {
870
871 if (line[len - 1] == '\n')
872 line[len - 1] = '\0';
873
874 if (strlazymatch(line, pat)) {
875 line_list__add_line(head, linenum);
876 count++;
877 }
878 linenum++;
879 }
880
881 if (ferror(fp))
882 count = -errno;
883 free(line);
884 fclose(fp);
885
886 if (count == 0)
887 pr_debug("No matched lines found in %s.\n", fname);
888 return count;
889 }
890
891 static int probe_point_lazy_walker(const char *fname, int lineno,
892 Dwarf_Addr addr, void *data)
893 {
894 struct probe_finder *pf = data;
895 Dwarf_Die *sc_die, die_mem;
896 int ret;
897
898 if (!line_list__has_line(&pf->lcache, lineno) ||
899 strtailcmp(fname, pf->fname) != 0)
900 return 0;
901
902 pr_debug("Probe line found: line:%d addr:0x%llx\n",
903 lineno, (unsigned long long)addr);
904 pf->addr = addr;
905 pf->lno = lineno;
906 sc_die = find_best_scope(pf, &die_mem);
907 if (!sc_die) {
908 pr_warning("Failed to find scope of probe point.\n");
909 return -ENOENT;
910 }
911
912 ret = call_probe_finder(sc_die, pf);
913
914 /*
915 * Continue if no error, because the lazy pattern will match
916 * to other lines
917 */
918 return ret < 0 ? ret : 0;
919 }
920
921 /* Find probe points from lazy pattern */
922 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
923 {
924 int ret = 0;
925
926 if (list_empty(&pf->lcache)) {
927 /* Matching lazy line pattern */
928 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
929 pf->pev->point.lazy_line);
930 if (ret <= 0)
931 return ret;
932 }
933
934 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
935 }
936
937 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
938 {
939 struct probe_finder *pf = data;
940 struct perf_probe_point *pp = &pf->pev->point;
941 Dwarf_Addr addr;
942 int ret;
943
944 if (pp->lazy_line)
945 ret = find_probe_point_lazy(in_die, pf);
946 else {
947 /* Get probe address */
948 if (dwarf_entrypc(in_die, &addr) != 0) {
949 pr_warning("Failed to get entry address of %s.\n",
950 dwarf_diename(in_die));
951 return -ENOENT;
952 }
953 pf->addr = addr;
954 pf->addr += pp->offset;
955 pr_debug("found inline addr: 0x%jx\n",
956 (uintmax_t)pf->addr);
957
958 ret = call_probe_finder(in_die, pf);
959 }
960
961 return ret;
962 }
963
964 /* Callback parameter with return value for libdw */
965 struct dwarf_callback_param {
966 void *data;
967 int retval;
968 };
969
970 /* Search function from function name */
971 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
972 {
973 struct dwarf_callback_param *param = data;
974 struct probe_finder *pf = param->data;
975 struct perf_probe_point *pp = &pf->pev->point;
976
977 /* Check tag and diename */
978 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
979 !die_compare_name(sp_die, pp->function))
980 return DWARF_CB_OK;
981
982 /* Check declared file */
983 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
984 return DWARF_CB_OK;
985
986 pf->fname = dwarf_decl_file(sp_die);
987 if (pp->line) { /* Function relative line */
988 dwarf_decl_line(sp_die, &pf->lno);
989 pf->lno += pp->line;
990 param->retval = find_probe_point_by_line(pf);
991 } else if (!dwarf_func_inline(sp_die)) {
992 /* Real function */
993 if (pp->lazy_line)
994 param->retval = find_probe_point_lazy(sp_die, pf);
995 else {
996 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
997 pr_warning("Failed to get entry address of "
998 "%s.\n", dwarf_diename(sp_die));
999 param->retval = -ENOENT;
1000 return DWARF_CB_ABORT;
1001 }
1002 pf->addr += pp->offset;
1003 /* TODO: Check the address in this function */
1004 param->retval = call_probe_finder(sp_die, pf);
1005 }
1006 } else
1007 /* Inlined function: search instances */
1008 param->retval = die_walk_instances(sp_die,
1009 probe_point_inline_cb, (void *)pf);
1010
1011 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1012 }
1013
1014 static int find_probe_point_by_func(struct probe_finder *pf)
1015 {
1016 struct dwarf_callback_param _param = {.data = (void *)pf,
1017 .retval = 0};
1018 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1019 return _param.retval;
1020 }
1021
1022 struct pubname_callback_param {
1023 char *function;
1024 char *file;
1025 Dwarf_Die *cu_die;
1026 Dwarf_Die *sp_die;
1027 int found;
1028 };
1029
1030 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1031 {
1032 struct pubname_callback_param *param = data;
1033
1034 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1035 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1036 return DWARF_CB_OK;
1037
1038 if (die_compare_name(param->sp_die, param->function)) {
1039 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1040 return DWARF_CB_OK;
1041
1042 if (param->file &&
1043 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1044 return DWARF_CB_OK;
1045
1046 param->found = 1;
1047 return DWARF_CB_ABORT;
1048 }
1049 }
1050
1051 return DWARF_CB_OK;
1052 }
1053
1054 /* Find probe points from debuginfo */
1055 static int debuginfo__find_probes(struct debuginfo *self,
1056 struct probe_finder *pf)
1057 {
1058 struct perf_probe_point *pp = &pf->pev->point;
1059 Dwarf_Off off, noff;
1060 size_t cuhl;
1061 Dwarf_Die *diep;
1062 int ret = 0;
1063
1064 #if _ELFUTILS_PREREQ(0, 142)
1065 /* Get the call frame information from this dwarf */
1066 pf->cfi = dwarf_getcfi(self->dbg);
1067 #endif
1068
1069 off = 0;
1070 line_list__init(&pf->lcache);
1071
1072 /* Fastpath: lookup by function name from .debug_pubnames section */
1073 if (pp->function) {
1074 struct pubname_callback_param pubname_param = {
1075 .function = pp->function,
1076 .file = pp->file,
1077 .cu_die = &pf->cu_die,
1078 .sp_die = &pf->sp_die,
1079 .found = 0,
1080 };
1081 struct dwarf_callback_param probe_param = {
1082 .data = pf,
1083 };
1084
1085 dwarf_getpubnames(self->dbg, pubname_search_cb,
1086 &pubname_param, 0);
1087 if (pubname_param.found) {
1088 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1089 if (ret)
1090 goto found;
1091 }
1092 }
1093
1094 /* Loop on CUs (Compilation Unit) */
1095 while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1096 /* Get the DIE(Debugging Information Entry) of this CU */
1097 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1098 if (!diep)
1099 continue;
1100
1101 /* Check if target file is included. */
1102 if (pp->file)
1103 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1104 else
1105 pf->fname = NULL;
1106
1107 if (!pp->file || pf->fname) {
1108 if (pp->function)
1109 ret = find_probe_point_by_func(pf);
1110 else if (pp->lazy_line)
1111 ret = find_probe_point_lazy(NULL, pf);
1112 else {
1113 pf->lno = pp->line;
1114 ret = find_probe_point_by_line(pf);
1115 }
1116 if (ret < 0)
1117 break;
1118 }
1119 off = noff;
1120 }
1121
1122 found:
1123 line_list__free(&pf->lcache);
1124
1125 return ret;
1126 }
1127
1128 /* Add a found probe point into trace event list */
1129 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1130 {
1131 struct trace_event_finder *tf =
1132 container_of(pf, struct trace_event_finder, pf);
1133 struct probe_trace_event *tev;
1134 int ret, i;
1135
1136 /* Check number of tevs */
1137 if (tf->ntevs == tf->max_tevs) {
1138 pr_warning("Too many( > %d) probe point found.\n",
1139 tf->max_tevs);
1140 return -ERANGE;
1141 }
1142 tev = &tf->tevs[tf->ntevs++];
1143
1144 /* Trace point should be converted from subprogram DIE */
1145 ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1146 pf->pev->point.retprobe, &tev->point);
1147 if (ret < 0)
1148 return ret;
1149
1150 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1151 tev->point.offset);
1152
1153 /* Find each argument */
1154 tev->nargs = pf->pev->nargs;
1155 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1156 if (tev->args == NULL)
1157 return -ENOMEM;
1158 for (i = 0; i < pf->pev->nargs; i++) {
1159 pf->pvar = &pf->pev->args[i];
1160 pf->tvar = &tev->args[i];
1161 /* Variable should be found from scope DIE */
1162 ret = find_variable(sc_die, pf);
1163 if (ret != 0)
1164 return ret;
1165 }
1166
1167 return 0;
1168 }
1169
1170 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1171 int debuginfo__find_trace_events(struct debuginfo *self,
1172 struct perf_probe_event *pev,
1173 struct probe_trace_event **tevs, int max_tevs)
1174 {
1175 struct trace_event_finder tf = {
1176 .pf = {.pev = pev, .callback = add_probe_trace_event},
1177 .max_tevs = max_tevs};
1178 int ret;
1179
1180 /* Allocate result tevs array */
1181 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1182 if (*tevs == NULL)
1183 return -ENOMEM;
1184
1185 tf.tevs = *tevs;
1186 tf.ntevs = 0;
1187
1188 ret = debuginfo__find_probes(self, &tf.pf);
1189 if (ret < 0) {
1190 free(*tevs);
1191 *tevs = NULL;
1192 return ret;
1193 }
1194
1195 return (ret < 0) ? ret : tf.ntevs;
1196 }
1197
1198 #define MAX_VAR_LEN 64
1199
1200 /* Collect available variables in this scope */
1201 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1202 {
1203 struct available_var_finder *af = data;
1204 struct variable_list *vl;
1205 char buf[MAX_VAR_LEN];
1206 int tag, ret;
1207
1208 vl = &af->vls[af->nvls - 1];
1209
1210 tag = dwarf_tag(die_mem);
1211 if (tag == DW_TAG_formal_parameter ||
1212 tag == DW_TAG_variable) {
1213 ret = convert_variable_location(die_mem, af->pf.addr,
1214 af->pf.fb_ops, NULL);
1215 if (ret == 0) {
1216 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1217 pr_debug2("Add new var: %s\n", buf);
1218 if (ret > 0)
1219 strlist__add(vl->vars, buf);
1220 }
1221 }
1222
1223 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1224 return DIE_FIND_CB_CONTINUE;
1225 else
1226 return DIE_FIND_CB_SIBLING;
1227 }
1228
1229 /* Add a found vars into available variables list */
1230 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1231 {
1232 struct available_var_finder *af =
1233 container_of(pf, struct available_var_finder, pf);
1234 struct variable_list *vl;
1235 Dwarf_Die die_mem;
1236 int ret;
1237
1238 /* Check number of tevs */
1239 if (af->nvls == af->max_vls) {
1240 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1241 return -ERANGE;
1242 }
1243 vl = &af->vls[af->nvls++];
1244
1245 /* Trace point should be converted from subprogram DIE */
1246 ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1247 pf->pev->point.retprobe, &vl->point);
1248 if (ret < 0)
1249 return ret;
1250
1251 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1252 vl->point.offset);
1253
1254 /* Find local variables */
1255 vl->vars = strlist__new(true, NULL);
1256 if (vl->vars == NULL)
1257 return -ENOMEM;
1258 af->child = true;
1259 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1260
1261 /* Find external variables */
1262 if (!af->externs)
1263 goto out;
1264 /* Don't need to search child DIE for externs. */
1265 af->child = false;
1266 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1267
1268 out:
1269 if (strlist__empty(vl->vars)) {
1270 strlist__delete(vl->vars);
1271 vl->vars = NULL;
1272 }
1273
1274 return ret;
1275 }
1276
1277 /* Find available variables at given probe point */
1278 int debuginfo__find_available_vars_at(struct debuginfo *self,
1279 struct perf_probe_event *pev,
1280 struct variable_list **vls,
1281 int max_vls, bool externs)
1282 {
1283 struct available_var_finder af = {
1284 .pf = {.pev = pev, .callback = add_available_vars},
1285 .max_vls = max_vls, .externs = externs};
1286 int ret;
1287
1288 /* Allocate result vls array */
1289 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1290 if (*vls == NULL)
1291 return -ENOMEM;
1292
1293 af.vls = *vls;
1294 af.nvls = 0;
1295
1296 ret = debuginfo__find_probes(self, &af.pf);
1297 if (ret < 0) {
1298 /* Free vlist for error */
1299 while (af.nvls--) {
1300 if (af.vls[af.nvls].point.symbol)
1301 free(af.vls[af.nvls].point.symbol);
1302 if (af.vls[af.nvls].vars)
1303 strlist__delete(af.vls[af.nvls].vars);
1304 }
1305 free(af.vls);
1306 *vls = NULL;
1307 return ret;
1308 }
1309
1310 return (ret < 0) ? ret : af.nvls;
1311 }
1312
1313 /* Reverse search */
1314 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1315 struct perf_probe_point *ppt)
1316 {
1317 Dwarf_Die cudie, spdie, indie;
1318 Dwarf_Addr _addr, baseaddr;
1319 const char *fname = NULL, *func = NULL, *tmp;
1320 int baseline = 0, lineno = 0, ret = 0;
1321
1322 /* Adjust address with bias */
1323 addr += self->bias;
1324
1325 /* Find cu die */
1326 if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1327 pr_warning("Failed to find debug information for address %lx\n",
1328 addr);
1329 ret = -EINVAL;
1330 goto end;
1331 }
1332
1333 /* Find a corresponding line (filename and lineno) */
1334 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1335 /* Don't care whether it failed or not */
1336
1337 /* Find a corresponding function (name, baseline and baseaddr) */
1338 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1339 /* Get function entry information */
1340 tmp = dwarf_diename(&spdie);
1341 if (!tmp ||
1342 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1343 dwarf_decl_line(&spdie, &baseline) != 0)
1344 goto post;
1345 func = tmp;
1346
1347 if (addr == (unsigned long)baseaddr)
1348 /* Function entry - Relative line number is 0 */
1349 lineno = baseline;
1350 else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1351 &indie)) {
1352 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1353 _addr == addr)
1354 /*
1355 * addr is at an inline function entry.
1356 * In this case, lineno should be the call-site
1357 * line number.
1358 */
1359 lineno = die_get_call_lineno(&indie);
1360 else {
1361 /*
1362 * addr is in an inline function body.
1363 * Since lineno points one of the lines
1364 * of the inline function, baseline should
1365 * be the entry line of the inline function.
1366 */
1367 tmp = dwarf_diename(&indie);
1368 if (tmp &&
1369 dwarf_decl_line(&spdie, &baseline) == 0)
1370 func = tmp;
1371 }
1372 }
1373 }
1374
1375 post:
1376 /* Make a relative line number or an offset */
1377 if (lineno)
1378 ppt->line = lineno - baseline;
1379 else if (func)
1380 ppt->offset = addr - (unsigned long)baseaddr;
1381
1382 /* Duplicate strings */
1383 if (func) {
1384 ppt->function = strdup(func);
1385 if (ppt->function == NULL) {
1386 ret = -ENOMEM;
1387 goto end;
1388 }
1389 }
1390 if (fname) {
1391 ppt->file = strdup(fname);
1392 if (ppt->file == NULL) {
1393 if (ppt->function) {
1394 free(ppt->function);
1395 ppt->function = NULL;
1396 }
1397 ret = -ENOMEM;
1398 goto end;
1399 }
1400 }
1401 end:
1402 if (ret == 0 && (fname || func))
1403 ret = 1; /* Found a point */
1404 return ret;
1405 }
1406
1407 /* Add a line and store the src path */
1408 static int line_range_add_line(const char *src, unsigned int lineno,
1409 struct line_range *lr)
1410 {
1411 /* Copy source path */
1412 if (!lr->path) {
1413 lr->path = strdup(src);
1414 if (lr->path == NULL)
1415 return -ENOMEM;
1416 }
1417 return line_list__add_line(&lr->line_list, lineno);
1418 }
1419
1420 static int line_range_walk_cb(const char *fname, int lineno,
1421 Dwarf_Addr addr __used,
1422 void *data)
1423 {
1424 struct line_finder *lf = data;
1425
1426 if ((strtailcmp(fname, lf->fname) != 0) ||
1427 (lf->lno_s > lineno || lf->lno_e < lineno))
1428 return 0;
1429
1430 if (line_range_add_line(fname, lineno, lf->lr) < 0)
1431 return -EINVAL;
1432
1433 return 0;
1434 }
1435
1436 /* Find line range from its line number */
1437 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1438 {
1439 int ret;
1440
1441 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1442
1443 /* Update status */
1444 if (ret >= 0)
1445 if (!list_empty(&lf->lr->line_list))
1446 ret = lf->found = 1;
1447 else
1448 ret = 0; /* Lines are not found */
1449 else {
1450 free(lf->lr->path);
1451 lf->lr->path = NULL;
1452 }
1453 return ret;
1454 }
1455
1456 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1457 {
1458 find_line_range_by_line(in_die, data);
1459
1460 /*
1461 * We have to check all instances of inlined function, because
1462 * some execution paths can be optimized out depends on the
1463 * function argument of instances
1464 */
1465 return 0;
1466 }
1467
1468 /* Search function from function name */
1469 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1470 {
1471 struct dwarf_callback_param *param = data;
1472 struct line_finder *lf = param->data;
1473 struct line_range *lr = lf->lr;
1474
1475 /* Check declared file */
1476 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1477 return DWARF_CB_OK;
1478
1479 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1480 die_compare_name(sp_die, lr->function)) {
1481 lf->fname = dwarf_decl_file(sp_die);
1482 dwarf_decl_line(sp_die, &lr->offset);
1483 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1484 lf->lno_s = lr->offset + lr->start;
1485 if (lf->lno_s < 0) /* Overflow */
1486 lf->lno_s = INT_MAX;
1487 lf->lno_e = lr->offset + lr->end;
1488 if (lf->lno_e < 0) /* Overflow */
1489 lf->lno_e = INT_MAX;
1490 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1491 lr->start = lf->lno_s;
1492 lr->end = lf->lno_e;
1493 if (dwarf_func_inline(sp_die))
1494 param->retval = die_walk_instances(sp_die,
1495 line_range_inline_cb, lf);
1496 else
1497 param->retval = find_line_range_by_line(sp_die, lf);
1498 return DWARF_CB_ABORT;
1499 }
1500 return DWARF_CB_OK;
1501 }
1502
1503 static int find_line_range_by_func(struct line_finder *lf)
1504 {
1505 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1506 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1507 return param.retval;
1508 }
1509
1510 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1511 {
1512 struct line_finder lf = {.lr = lr, .found = 0};
1513 int ret = 0;
1514 Dwarf_Off off = 0, noff;
1515 size_t cuhl;
1516 Dwarf_Die *diep;
1517 const char *comp_dir;
1518
1519 /* Fastpath: lookup by function name from .debug_pubnames section */
1520 if (lr->function) {
1521 struct pubname_callback_param pubname_param = {
1522 .function = lr->function, .file = lr->file,
1523 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1524 struct dwarf_callback_param line_range_param = {
1525 .data = (void *)&lf, .retval = 0};
1526
1527 dwarf_getpubnames(self->dbg, pubname_search_cb,
1528 &pubname_param, 0);
1529 if (pubname_param.found) {
1530 line_range_search_cb(&lf.sp_die, &line_range_param);
1531 if (lf.found)
1532 goto found;
1533 }
1534 }
1535
1536 /* Loop on CUs (Compilation Unit) */
1537 while (!lf.found && ret >= 0) {
1538 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1539 NULL, NULL, NULL) != 0)
1540 break;
1541
1542 /* Get the DIE(Debugging Information Entry) of this CU */
1543 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1544 if (!diep)
1545 continue;
1546
1547 /* Check if target file is included. */
1548 if (lr->file)
1549 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1550 else
1551 lf.fname = 0;
1552
1553 if (!lr->file || lf.fname) {
1554 if (lr->function)
1555 ret = find_line_range_by_func(&lf);
1556 else {
1557 lf.lno_s = lr->start;
1558 lf.lno_e = lr->end;
1559 ret = find_line_range_by_line(NULL, &lf);
1560 }
1561 }
1562 off = noff;
1563 }
1564
1565 found:
1566 /* Store comp_dir */
1567 if (lf.found) {
1568 comp_dir = cu_get_comp_dir(&lf.cu_die);
1569 if (comp_dir) {
1570 lr->comp_dir = strdup(comp_dir);
1571 if (!lr->comp_dir)
1572 ret = -ENOMEM;
1573 }
1574 }
1575
1576 pr_debug("path: %s\n", lr->path);
1577 return (ret < 0) ? ret : lf.found;
1578 }
1579