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perf probe: Add union member access support
[deliverable/linux.git] / tools / perf / util / probe-finder.c
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 <dwarf-regs.h>
34
35 #include <linux/bitops.h>
36 #include "event.h"
37 #include "debug.h"
38 #include "util.h"
39 #include "symbol.h"
40 #include "probe-finder.h"
41
42 /* Kprobe tracer basic type is up to u64 */
43 #define MAX_BASIC_TYPE_BITS 64
44
45 /* Line number list operations */
46
47 /* Add a line to line number list */
48 static int line_list__add_line(struct list_head *head, int line)
49 {
50 struct line_node *ln;
51 struct list_head *p;
52
53 /* Reverse search, because new line will be the last one */
54 list_for_each_entry_reverse(ln, head, list) {
55 if (ln->line < line) {
56 p = &ln->list;
57 goto found;
58 } else if (ln->line == line) /* Already exist */
59 return 1;
60 }
61 /* List is empty, or the smallest entry */
62 p = head;
63 found:
64 pr_debug("line list: add a line %u\n", line);
65 ln = zalloc(sizeof(struct line_node));
66 if (ln == NULL)
67 return -ENOMEM;
68 ln->line = line;
69 INIT_LIST_HEAD(&ln->list);
70 list_add(&ln->list, p);
71 return 0;
72 }
73
74 /* Check if the line in line number list */
75 static int line_list__has_line(struct list_head *head, int line)
76 {
77 struct line_node *ln;
78
79 /* Reverse search, because new line will be the last one */
80 list_for_each_entry(ln, head, list)
81 if (ln->line == line)
82 return 1;
83
84 return 0;
85 }
86
87 /* Init line number list */
88 static void line_list__init(struct list_head *head)
89 {
90 INIT_LIST_HEAD(head);
91 }
92
93 /* Free line number list */
94 static void line_list__free(struct list_head *head)
95 {
96 struct line_node *ln;
97 while (!list_empty(head)) {
98 ln = list_first_entry(head, struct line_node, list);
99 list_del(&ln->list);
100 free(ln);
101 }
102 }
103
104 /* Dwarf FL wrappers */
105 static char *debuginfo_path; /* Currently dummy */
106
107 static const Dwfl_Callbacks offline_callbacks = {
108 .find_debuginfo = dwfl_standard_find_debuginfo,
109 .debuginfo_path = &debuginfo_path,
110
111 .section_address = dwfl_offline_section_address,
112
113 /* We use this table for core files too. */
114 .find_elf = dwfl_build_id_find_elf,
115 };
116
117 /* Get a Dwarf from offline image */
118 static int debuginfo__init_offline_dwarf(struct debuginfo *self,
119 const char *path)
120 {
121 Dwfl_Module *mod;
122 int fd;
123
124 fd = open(path, O_RDONLY);
125 if (fd < 0)
126 return fd;
127
128 self->dwfl = dwfl_begin(&offline_callbacks);
129 if (!self->dwfl)
130 goto error;
131
132 mod = dwfl_report_offline(self->dwfl, "", "", fd);
133 if (!mod)
134 goto error;
135
136 self->dbg = dwfl_module_getdwarf(mod, &self->bias);
137 if (!self->dbg)
138 goto error;
139
140 return 0;
141 error:
142 if (self->dwfl)
143 dwfl_end(self->dwfl);
144 else
145 close(fd);
146 memset(self, 0, sizeof(*self));
147
148 return -ENOENT;
149 }
150
151 #if _ELFUTILS_PREREQ(0, 148)
152 /* This method is buggy if elfutils is older than 0.148 */
153 static int __linux_kernel_find_elf(Dwfl_Module *mod,
154 void **userdata,
155 const char *module_name,
156 Dwarf_Addr base,
157 char **file_name, Elf **elfp)
158 {
159 int fd;
160 const char *path = kernel_get_module_path(module_name);
161
162 pr_debug2("Use file %s for %s\n", path, module_name);
163 if (path) {
164 fd = open(path, O_RDONLY);
165 if (fd >= 0) {
166 *file_name = strdup(path);
167 return fd;
168 }
169 }
170 /* If failed, try to call standard method */
171 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
172 file_name, elfp);
173 }
174
175 static const Dwfl_Callbacks kernel_callbacks = {
176 .find_debuginfo = dwfl_standard_find_debuginfo,
177 .debuginfo_path = &debuginfo_path,
178
179 .find_elf = __linux_kernel_find_elf,
180 .section_address = dwfl_linux_kernel_module_section_address,
181 };
182
183 /* Get a Dwarf from live kernel image */
184 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
185 Dwarf_Addr addr)
186 {
187 self->dwfl = dwfl_begin(&kernel_callbacks);
188 if (!self->dwfl)
189 return -EINVAL;
190
191 /* Load the kernel dwarves: Don't care the result here */
192 dwfl_linux_kernel_report_kernel(self->dwfl);
193 dwfl_linux_kernel_report_modules(self->dwfl);
194
195 self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
196 /* Here, check whether we could get a real dwarf */
197 if (!self->dbg) {
198 pr_debug("Failed to find kernel dwarf at %lx\n",
199 (unsigned long)addr);
200 dwfl_end(self->dwfl);
201 memset(self, 0, sizeof(*self));
202 return -ENOENT;
203 }
204
205 return 0;
206 }
207 #else
208 /* With older elfutils, this just support kernel module... */
209 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
210 Dwarf_Addr addr __maybe_unused)
211 {
212 const char *path = kernel_get_module_path("kernel");
213
214 if (!path) {
215 pr_err("Failed to find vmlinux path\n");
216 return -ENOENT;
217 }
218
219 pr_debug2("Use file %s for debuginfo\n", path);
220 return debuginfo__init_offline_dwarf(self, path);
221 }
222 #endif
223
224 struct debuginfo *debuginfo__new(const char *path)
225 {
226 struct debuginfo *self = zalloc(sizeof(struct debuginfo));
227 if (!self)
228 return NULL;
229
230 if (debuginfo__init_offline_dwarf(self, path) < 0) {
231 free(self);
232 self = NULL;
233 }
234
235 return self;
236 }
237
238 struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
239 {
240 struct debuginfo *self = zalloc(sizeof(struct debuginfo));
241 if (!self)
242 return NULL;
243
244 if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) {
245 free(self);
246 self = NULL;
247 }
248
249 return self;
250 }
251
252 void debuginfo__delete(struct debuginfo *self)
253 {
254 if (self) {
255 if (self->dwfl)
256 dwfl_end(self->dwfl);
257 free(self);
258 }
259 }
260
261 /*
262 * Probe finder related functions
263 */
264
265 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
266 {
267 struct probe_trace_arg_ref *ref;
268 ref = zalloc(sizeof(struct probe_trace_arg_ref));
269 if (ref != NULL)
270 ref->offset = offs;
271 return ref;
272 }
273
274 /*
275 * Convert a location into trace_arg.
276 * If tvar == NULL, this just checks variable can be converted.
277 */
278 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
279 Dwarf_Op *fb_ops,
280 struct probe_trace_arg *tvar)
281 {
282 Dwarf_Attribute attr;
283 Dwarf_Op *op;
284 size_t nops;
285 unsigned int regn;
286 Dwarf_Word offs = 0;
287 bool ref = false;
288 const char *regs;
289 int ret;
290
291 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
292 goto static_var;
293
294 /* TODO: handle more than 1 exprs */
295 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
296 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
297 nops == 0) {
298 /* TODO: Support const_value */
299 return -ENOENT;
300 }
301
302 if (op->atom == DW_OP_addr) {
303 static_var:
304 if (!tvar)
305 return 0;
306 /* Static variables on memory (not stack), make @varname */
307 ret = strlen(dwarf_diename(vr_die));
308 tvar->value = zalloc(ret + 2);
309 if (tvar->value == NULL)
310 return -ENOMEM;
311 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
312 tvar->ref = alloc_trace_arg_ref((long)offs);
313 if (tvar->ref == NULL)
314 return -ENOMEM;
315 return 0;
316 }
317
318 /* If this is based on frame buffer, set the offset */
319 if (op->atom == DW_OP_fbreg) {
320 if (fb_ops == NULL)
321 return -ENOTSUP;
322 ref = true;
323 offs = op->number;
324 op = &fb_ops[0];
325 }
326
327 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
328 regn = op->atom - DW_OP_breg0;
329 offs += op->number;
330 ref = true;
331 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
332 regn = op->atom - DW_OP_reg0;
333 } else if (op->atom == DW_OP_bregx) {
334 regn = op->number;
335 offs += op->number2;
336 ref = true;
337 } else if (op->atom == DW_OP_regx) {
338 regn = op->number;
339 } else {
340 pr_debug("DW_OP %x is not supported.\n", op->atom);
341 return -ENOTSUP;
342 }
343
344 if (!tvar)
345 return 0;
346
347 regs = get_arch_regstr(regn);
348 if (!regs) {
349 /* This should be a bug in DWARF or this tool */
350 pr_warning("Mapping for the register number %u "
351 "missing on this architecture.\n", regn);
352 return -ERANGE;
353 }
354
355 tvar->value = strdup(regs);
356 if (tvar->value == NULL)
357 return -ENOMEM;
358
359 if (ref) {
360 tvar->ref = alloc_trace_arg_ref((long)offs);
361 if (tvar->ref == NULL)
362 return -ENOMEM;
363 }
364 return 0;
365 }
366
367 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
368
369 static int convert_variable_type(Dwarf_Die *vr_die,
370 struct probe_trace_arg *tvar,
371 const char *cast)
372 {
373 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
374 Dwarf_Die type;
375 char buf[16];
376 int bsize, boffs, total;
377 int ret;
378
379 /* TODO: check all types */
380 if (cast && strcmp(cast, "string") != 0) {
381 /* Non string type is OK */
382 tvar->type = strdup(cast);
383 return (tvar->type == NULL) ? -ENOMEM : 0;
384 }
385
386 bsize = dwarf_bitsize(vr_die);
387 if (bsize > 0) {
388 /* This is a bitfield */
389 boffs = dwarf_bitoffset(vr_die);
390 total = dwarf_bytesize(vr_die);
391 if (boffs < 0 || total < 0)
392 return -ENOENT;
393 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
394 BYTES_TO_BITS(total));
395 goto formatted;
396 }
397
398 if (die_get_real_type(vr_die, &type) == NULL) {
399 pr_warning("Failed to get a type information of %s.\n",
400 dwarf_diename(vr_die));
401 return -ENOENT;
402 }
403
404 pr_debug("%s type is %s.\n",
405 dwarf_diename(vr_die), dwarf_diename(&type));
406
407 if (cast && strcmp(cast, "string") == 0) { /* String type */
408 ret = dwarf_tag(&type);
409 if (ret != DW_TAG_pointer_type &&
410 ret != DW_TAG_array_type) {
411 pr_warning("Failed to cast into string: "
412 "%s(%s) is not a pointer nor array.\n",
413 dwarf_diename(vr_die), dwarf_diename(&type));
414 return -EINVAL;
415 }
416 if (ret == DW_TAG_pointer_type) {
417 if (die_get_real_type(&type, &type) == NULL) {
418 pr_warning("Failed to get a type"
419 " information.\n");
420 return -ENOENT;
421 }
422 while (*ref_ptr)
423 ref_ptr = &(*ref_ptr)->next;
424 /* Add new reference with offset +0 */
425 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
426 if (*ref_ptr == NULL) {
427 pr_warning("Out of memory error\n");
428 return -ENOMEM;
429 }
430 }
431 if (!die_compare_name(&type, "char") &&
432 !die_compare_name(&type, "unsigned char")) {
433 pr_warning("Failed to cast into string: "
434 "%s is not (unsigned) char *.\n",
435 dwarf_diename(vr_die));
436 return -EINVAL;
437 }
438 tvar->type = strdup(cast);
439 return (tvar->type == NULL) ? -ENOMEM : 0;
440 }
441
442 ret = dwarf_bytesize(&type);
443 if (ret <= 0)
444 /* No size ... try to use default type */
445 return 0;
446 ret = BYTES_TO_BITS(ret);
447
448 /* Check the bitwidth */
449 if (ret > MAX_BASIC_TYPE_BITS) {
450 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
451 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
452 ret = MAX_BASIC_TYPE_BITS;
453 }
454 ret = snprintf(buf, 16, "%c%d",
455 die_is_signed_type(&type) ? 's' : 'u', ret);
456
457 formatted:
458 if (ret < 0 || ret >= 16) {
459 if (ret >= 16)
460 ret = -E2BIG;
461 pr_warning("Failed to convert variable type: %s\n",
462 strerror(-ret));
463 return ret;
464 }
465 tvar->type = strdup(buf);
466 if (tvar->type == NULL)
467 return -ENOMEM;
468 return 0;
469 }
470
471 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
472 struct perf_probe_arg_field *field,
473 struct probe_trace_arg_ref **ref_ptr,
474 Dwarf_Die *die_mem)
475 {
476 struct probe_trace_arg_ref *ref = *ref_ptr;
477 Dwarf_Die type;
478 Dwarf_Word offs;
479 int ret, tag;
480
481 pr_debug("converting %s in %s\n", field->name, varname);
482 if (die_get_real_type(vr_die, &type) == NULL) {
483 pr_warning("Failed to get the type of %s.\n", varname);
484 return -ENOENT;
485 }
486 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
487 tag = dwarf_tag(&type);
488
489 if (field->name[0] == '[' &&
490 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
491 if (field->next)
492 /* Save original type for next field */
493 memcpy(die_mem, &type, sizeof(*die_mem));
494 /* Get the type of this array */
495 if (die_get_real_type(&type, &type) == NULL) {
496 pr_warning("Failed to get the type of %s.\n", varname);
497 return -ENOENT;
498 }
499 pr_debug2("Array real type: (%x)\n",
500 (unsigned)dwarf_dieoffset(&type));
501 if (tag == DW_TAG_pointer_type) {
502 ref = zalloc(sizeof(struct probe_trace_arg_ref));
503 if (ref == NULL)
504 return -ENOMEM;
505 if (*ref_ptr)
506 (*ref_ptr)->next = ref;
507 else
508 *ref_ptr = ref;
509 }
510 ref->offset += dwarf_bytesize(&type) * field->index;
511 if (!field->next)
512 /* Save vr_die for converting types */
513 memcpy(die_mem, vr_die, sizeof(*die_mem));
514 goto next;
515 } else if (tag == DW_TAG_pointer_type) {
516 /* Check the pointer and dereference */
517 if (!field->ref) {
518 pr_err("Semantic error: %s must be referred by '->'\n",
519 field->name);
520 return -EINVAL;
521 }
522 /* Get the type pointed by this pointer */
523 if (die_get_real_type(&type, &type) == NULL) {
524 pr_warning("Failed to get the type of %s.\n", varname);
525 return -ENOENT;
526 }
527 /* Verify it is a data structure */
528 tag = dwarf_tag(&type);
529 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
530 pr_warning("%s is not a data structure nor an union.\n",
531 varname);
532 return -EINVAL;
533 }
534
535 ref = zalloc(sizeof(struct probe_trace_arg_ref));
536 if (ref == NULL)
537 return -ENOMEM;
538 if (*ref_ptr)
539 (*ref_ptr)->next = ref;
540 else
541 *ref_ptr = ref;
542 } else {
543 /* Verify it is a data structure */
544 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
545 pr_warning("%s is not a data structure nor an union.\n",
546 varname);
547 return -EINVAL;
548 }
549 if (field->name[0] == '[') {
550 pr_err("Semantic error: %s is not a pointor"
551 " nor array.\n", varname);
552 return -EINVAL;
553 }
554 if (field->ref) {
555 pr_err("Semantic error: %s must be referred by '.'\n",
556 field->name);
557 return -EINVAL;
558 }
559 if (!ref) {
560 pr_warning("Structure on a register is not "
561 "supported yet.\n");
562 return -ENOTSUP;
563 }
564 }
565
566 if (die_find_member(&type, field->name, die_mem) == NULL) {
567 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
568 dwarf_diename(&type), field->name);
569 return -EINVAL;
570 }
571
572 /* Get the offset of the field */
573 if (tag == DW_TAG_union_type) {
574 offs = 0;
575 } else {
576 ret = die_get_data_member_location(die_mem, &offs);
577 if (ret < 0) {
578 pr_warning("Failed to get the offset of %s.\n",
579 field->name);
580 return ret;
581 }
582 }
583 ref->offset += (long)offs;
584
585 next:
586 /* Converting next field */
587 if (field->next)
588 return convert_variable_fields(die_mem, field->name,
589 field->next, &ref, die_mem);
590 else
591 return 0;
592 }
593
594 /* Show a variables in kprobe event format */
595 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
596 {
597 Dwarf_Die die_mem;
598 int ret;
599
600 pr_debug("Converting variable %s into trace event.\n",
601 dwarf_diename(vr_die));
602
603 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
604 pf->tvar);
605 if (ret == -ENOENT)
606 pr_err("Failed to find the location of %s at this address.\n"
607 " Perhaps, it has been optimized out.\n", pf->pvar->var);
608 else if (ret == -ENOTSUP)
609 pr_err("Sorry, we don't support this variable location yet.\n");
610 else if (pf->pvar->field) {
611 ret = convert_variable_fields(vr_die, pf->pvar->var,
612 pf->pvar->field, &pf->tvar->ref,
613 &die_mem);
614 vr_die = &die_mem;
615 }
616 if (ret == 0)
617 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
618 /* *expr will be cached in libdw. Don't free it. */
619 return ret;
620 }
621
622 /* Find a variable in a scope DIE */
623 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
624 {
625 Dwarf_Die vr_die;
626 char buf[32], *ptr;
627 int ret = 0;
628
629 if (!is_c_varname(pf->pvar->var)) {
630 /* Copy raw parameters */
631 pf->tvar->value = strdup(pf->pvar->var);
632 if (pf->tvar->value == NULL)
633 return -ENOMEM;
634 if (pf->pvar->type) {
635 pf->tvar->type = strdup(pf->pvar->type);
636 if (pf->tvar->type == NULL)
637 return -ENOMEM;
638 }
639 if (pf->pvar->name) {
640 pf->tvar->name = strdup(pf->pvar->name);
641 if (pf->tvar->name == NULL)
642 return -ENOMEM;
643 } else
644 pf->tvar->name = NULL;
645 return 0;
646 }
647
648 if (pf->pvar->name)
649 pf->tvar->name = strdup(pf->pvar->name);
650 else {
651 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
652 if (ret < 0)
653 return ret;
654 ptr = strchr(buf, ':'); /* Change type separator to _ */
655 if (ptr)
656 *ptr = '_';
657 pf->tvar->name = strdup(buf);
658 }
659 if (pf->tvar->name == NULL)
660 return -ENOMEM;
661
662 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
663 /* Search child die for local variables and parameters. */
664 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
665 /* Search again in global variables */
666 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
667 ret = -ENOENT;
668 }
669 if (ret >= 0)
670 ret = convert_variable(&vr_die, pf);
671
672 if (ret < 0)
673 pr_warning("Failed to find '%s' in this function.\n",
674 pf->pvar->var);
675 return ret;
676 }
677
678 /* Convert subprogram DIE to trace point */
679 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
680 bool retprobe, struct probe_trace_point *tp)
681 {
682 Dwarf_Addr eaddr, highaddr;
683 const char *name;
684
685 /* Copy the name of probe point */
686 name = dwarf_diename(sp_die);
687 if (name) {
688 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
689 pr_warning("Failed to get entry address of %s\n",
690 dwarf_diename(sp_die));
691 return -ENOENT;
692 }
693 if (dwarf_highpc(sp_die, &highaddr) != 0) {
694 pr_warning("Failed to get end address of %s\n",
695 dwarf_diename(sp_die));
696 return -ENOENT;
697 }
698 if (paddr > highaddr) {
699 pr_warning("Offset specified is greater than size of %s\n",
700 dwarf_diename(sp_die));
701 return -EINVAL;
702 }
703 tp->symbol = strdup(name);
704 if (tp->symbol == NULL)
705 return -ENOMEM;
706 tp->offset = (unsigned long)(paddr - eaddr);
707 } else
708 /* This function has no name. */
709 tp->offset = (unsigned long)paddr;
710
711 /* Return probe must be on the head of a subprogram */
712 if (retprobe) {
713 if (eaddr != paddr) {
714 pr_warning("Return probe must be on the head of"
715 " a real function.\n");
716 return -EINVAL;
717 }
718 tp->retprobe = true;
719 }
720
721 return 0;
722 }
723
724 /* Call probe_finder callback with scope DIE */
725 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
726 {
727 Dwarf_Attribute fb_attr;
728 size_t nops;
729 int ret;
730
731 if (!sc_die) {
732 pr_err("Caller must pass a scope DIE. Program error.\n");
733 return -EINVAL;
734 }
735
736 /* If not a real subprogram, find a real one */
737 if (dwarf_tag(sc_die) != DW_TAG_subprogram) {
738 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
739 pr_warning("Failed to find probe point in any "
740 "functions.\n");
741 return -ENOENT;
742 }
743 } else
744 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
745
746 /* Get the frame base attribute/ops from subprogram */
747 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
748 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
749 if (ret <= 0 || nops == 0) {
750 pf->fb_ops = NULL;
751 #if _ELFUTILS_PREREQ(0, 142)
752 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
753 pf->cfi != NULL) {
754 Dwarf_Frame *frame;
755 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
756 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
757 pr_warning("Failed to get call frame on 0x%jx\n",
758 (uintmax_t)pf->addr);
759 return -ENOENT;
760 }
761 #endif
762 }
763
764 /* Call finder's callback handler */
765 ret = pf->callback(sc_die, pf);
766
767 /* *pf->fb_ops will be cached in libdw. Don't free it. */
768 pf->fb_ops = NULL;
769
770 return ret;
771 }
772
773 struct find_scope_param {
774 const char *function;
775 const char *file;
776 int line;
777 int diff;
778 Dwarf_Die *die_mem;
779 bool found;
780 };
781
782 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
783 {
784 struct find_scope_param *fsp = data;
785 const char *file;
786 int lno;
787
788 /* Skip if declared file name does not match */
789 if (fsp->file) {
790 file = dwarf_decl_file(fn_die);
791 if (!file || strcmp(fsp->file, file) != 0)
792 return 0;
793 }
794 /* If the function name is given, that's what user expects */
795 if (fsp->function) {
796 if (die_compare_name(fn_die, fsp->function)) {
797 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
798 fsp->found = true;
799 return 1;
800 }
801 } else {
802 /* With the line number, find the nearest declared DIE */
803 dwarf_decl_line(fn_die, &lno);
804 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
805 /* Keep a candidate and continue */
806 fsp->diff = fsp->line - lno;
807 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
808 fsp->found = true;
809 }
810 }
811 return 0;
812 }
813
814 /* Find an appropriate scope fits to given conditions */
815 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
816 {
817 struct find_scope_param fsp = {
818 .function = pf->pev->point.function,
819 .file = pf->fname,
820 .line = pf->lno,
821 .diff = INT_MAX,
822 .die_mem = die_mem,
823 .found = false,
824 };
825
826 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
827
828 return fsp.found ? die_mem : NULL;
829 }
830
831 static int probe_point_line_walker(const char *fname, int lineno,
832 Dwarf_Addr addr, void *data)
833 {
834 struct probe_finder *pf = data;
835 Dwarf_Die *sc_die, die_mem;
836 int ret;
837
838 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
839 return 0;
840
841 pf->addr = addr;
842 sc_die = find_best_scope(pf, &die_mem);
843 if (!sc_die) {
844 pr_warning("Failed to find scope of probe point.\n");
845 return -ENOENT;
846 }
847
848 ret = call_probe_finder(sc_die, pf);
849
850 /* Continue if no error, because the line will be in inline function */
851 return ret < 0 ? ret : 0;
852 }
853
854 /* Find probe point from its line number */
855 static int find_probe_point_by_line(struct probe_finder *pf)
856 {
857 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
858 }
859
860 /* Find lines which match lazy pattern */
861 static int find_lazy_match_lines(struct list_head *head,
862 const char *fname, const char *pat)
863 {
864 FILE *fp;
865 char *line = NULL;
866 size_t line_len;
867 ssize_t len;
868 int count = 0, linenum = 1;
869
870 fp = fopen(fname, "r");
871 if (!fp) {
872 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
873 return -errno;
874 }
875
876 while ((len = getline(&line, &line_len, fp)) > 0) {
877
878 if (line[len - 1] == '\n')
879 line[len - 1] = '\0';
880
881 if (strlazymatch(line, pat)) {
882 line_list__add_line(head, linenum);
883 count++;
884 }
885 linenum++;
886 }
887
888 if (ferror(fp))
889 count = -errno;
890 free(line);
891 fclose(fp);
892
893 if (count == 0)
894 pr_debug("No matched lines found in %s.\n", fname);
895 return count;
896 }
897
898 static int probe_point_lazy_walker(const char *fname, int lineno,
899 Dwarf_Addr addr, void *data)
900 {
901 struct probe_finder *pf = data;
902 Dwarf_Die *sc_die, die_mem;
903 int ret;
904
905 if (!line_list__has_line(&pf->lcache, lineno) ||
906 strtailcmp(fname, pf->fname) != 0)
907 return 0;
908
909 pr_debug("Probe line found: line:%d addr:0x%llx\n",
910 lineno, (unsigned long long)addr);
911 pf->addr = addr;
912 pf->lno = lineno;
913 sc_die = find_best_scope(pf, &die_mem);
914 if (!sc_die) {
915 pr_warning("Failed to find scope of probe point.\n");
916 return -ENOENT;
917 }
918
919 ret = call_probe_finder(sc_die, pf);
920
921 /*
922 * Continue if no error, because the lazy pattern will match
923 * to other lines
924 */
925 return ret < 0 ? ret : 0;
926 }
927
928 /* Find probe points from lazy pattern */
929 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
930 {
931 int ret = 0;
932
933 if (list_empty(&pf->lcache)) {
934 /* Matching lazy line pattern */
935 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
936 pf->pev->point.lazy_line);
937 if (ret <= 0)
938 return ret;
939 }
940
941 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
942 }
943
944 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
945 {
946 struct probe_finder *pf = data;
947 struct perf_probe_point *pp = &pf->pev->point;
948 Dwarf_Addr addr;
949 int ret;
950
951 if (pp->lazy_line)
952 ret = find_probe_point_lazy(in_die, pf);
953 else {
954 /* Get probe address */
955 if (dwarf_entrypc(in_die, &addr) != 0) {
956 pr_warning("Failed to get entry address of %s.\n",
957 dwarf_diename(in_die));
958 return -ENOENT;
959 }
960 pf->addr = addr;
961 pf->addr += pp->offset;
962 pr_debug("found inline addr: 0x%jx\n",
963 (uintmax_t)pf->addr);
964
965 ret = call_probe_finder(in_die, pf);
966 }
967
968 return ret;
969 }
970
971 /* Callback parameter with return value for libdw */
972 struct dwarf_callback_param {
973 void *data;
974 int retval;
975 };
976
977 /* Search function from function name */
978 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
979 {
980 struct dwarf_callback_param *param = data;
981 struct probe_finder *pf = param->data;
982 struct perf_probe_point *pp = &pf->pev->point;
983 Dwarf_Attribute attr;
984
985 /* Check tag and diename */
986 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
987 !die_compare_name(sp_die, pp->function) ||
988 dwarf_attr(sp_die, DW_AT_declaration, &attr))
989 return DWARF_CB_OK;
990
991 /* Check declared file */
992 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
993 return DWARF_CB_OK;
994
995 pf->fname = dwarf_decl_file(sp_die);
996 if (pp->line) { /* Function relative line */
997 dwarf_decl_line(sp_die, &pf->lno);
998 pf->lno += pp->line;
999 param->retval = find_probe_point_by_line(pf);
1000 } else if (!dwarf_func_inline(sp_die)) {
1001 /* Real function */
1002 if (pp->lazy_line)
1003 param->retval = find_probe_point_lazy(sp_die, pf);
1004 else {
1005 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1006 pr_warning("Failed to get entry address of "
1007 "%s.\n", dwarf_diename(sp_die));
1008 param->retval = -ENOENT;
1009 return DWARF_CB_ABORT;
1010 }
1011 pf->addr += pp->offset;
1012 /* TODO: Check the address in this function */
1013 param->retval = call_probe_finder(sp_die, pf);
1014 }
1015 } else
1016 /* Inlined function: search instances */
1017 param->retval = die_walk_instances(sp_die,
1018 probe_point_inline_cb, (void *)pf);
1019
1020 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1021 }
1022
1023 static int find_probe_point_by_func(struct probe_finder *pf)
1024 {
1025 struct dwarf_callback_param _param = {.data = (void *)pf,
1026 .retval = 0};
1027 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1028 return _param.retval;
1029 }
1030
1031 struct pubname_callback_param {
1032 char *function;
1033 char *file;
1034 Dwarf_Die *cu_die;
1035 Dwarf_Die *sp_die;
1036 int found;
1037 };
1038
1039 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1040 {
1041 struct pubname_callback_param *param = data;
1042
1043 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1044 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1045 return DWARF_CB_OK;
1046
1047 if (die_compare_name(param->sp_die, param->function)) {
1048 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1049 return DWARF_CB_OK;
1050
1051 if (param->file &&
1052 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1053 return DWARF_CB_OK;
1054
1055 param->found = 1;
1056 return DWARF_CB_ABORT;
1057 }
1058 }
1059
1060 return DWARF_CB_OK;
1061 }
1062
1063 /* Find probe points from debuginfo */
1064 static int debuginfo__find_probes(struct debuginfo *self,
1065 struct probe_finder *pf)
1066 {
1067 struct perf_probe_point *pp = &pf->pev->point;
1068 Dwarf_Off off, noff;
1069 size_t cuhl;
1070 Dwarf_Die *diep;
1071 int ret = 0;
1072
1073 #if _ELFUTILS_PREREQ(0, 142)
1074 /* Get the call frame information from this dwarf */
1075 pf->cfi = dwarf_getcfi(self->dbg);
1076 #endif
1077
1078 off = 0;
1079 line_list__init(&pf->lcache);
1080
1081 /* Fastpath: lookup by function name from .debug_pubnames section */
1082 if (pp->function) {
1083 struct pubname_callback_param pubname_param = {
1084 .function = pp->function,
1085 .file = pp->file,
1086 .cu_die = &pf->cu_die,
1087 .sp_die = &pf->sp_die,
1088 .found = 0,
1089 };
1090 struct dwarf_callback_param probe_param = {
1091 .data = pf,
1092 };
1093
1094 dwarf_getpubnames(self->dbg, pubname_search_cb,
1095 &pubname_param, 0);
1096 if (pubname_param.found) {
1097 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1098 if (ret)
1099 goto found;
1100 }
1101 }
1102
1103 /* Loop on CUs (Compilation Unit) */
1104 while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1105 /* Get the DIE(Debugging Information Entry) of this CU */
1106 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1107 if (!diep)
1108 continue;
1109
1110 /* Check if target file is included. */
1111 if (pp->file)
1112 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1113 else
1114 pf->fname = NULL;
1115
1116 if (!pp->file || pf->fname) {
1117 if (pp->function)
1118 ret = find_probe_point_by_func(pf);
1119 else if (pp->lazy_line)
1120 ret = find_probe_point_lazy(NULL, pf);
1121 else {
1122 pf->lno = pp->line;
1123 ret = find_probe_point_by_line(pf);
1124 }
1125 if (ret < 0)
1126 break;
1127 }
1128 off = noff;
1129 }
1130
1131 found:
1132 line_list__free(&pf->lcache);
1133
1134 return ret;
1135 }
1136
1137 /* Add a found probe point into trace event list */
1138 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1139 {
1140 struct trace_event_finder *tf =
1141 container_of(pf, struct trace_event_finder, pf);
1142 struct probe_trace_event *tev;
1143 int ret, i;
1144
1145 /* Check number of tevs */
1146 if (tf->ntevs == tf->max_tevs) {
1147 pr_warning("Too many( > %d) probe point found.\n",
1148 tf->max_tevs);
1149 return -ERANGE;
1150 }
1151 tev = &tf->tevs[tf->ntevs++];
1152
1153 /* Trace point should be converted from subprogram DIE */
1154 ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1155 pf->pev->point.retprobe, &tev->point);
1156 if (ret < 0)
1157 return ret;
1158
1159 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1160 tev->point.offset);
1161
1162 /* Find each argument */
1163 tev->nargs = pf->pev->nargs;
1164 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1165 if (tev->args == NULL)
1166 return -ENOMEM;
1167 for (i = 0; i < pf->pev->nargs; i++) {
1168 pf->pvar = &pf->pev->args[i];
1169 pf->tvar = &tev->args[i];
1170 /* Variable should be found from scope DIE */
1171 ret = find_variable(sc_die, pf);
1172 if (ret != 0)
1173 return ret;
1174 }
1175
1176 return 0;
1177 }
1178
1179 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1180 int debuginfo__find_trace_events(struct debuginfo *self,
1181 struct perf_probe_event *pev,
1182 struct probe_trace_event **tevs, int max_tevs)
1183 {
1184 struct trace_event_finder tf = {
1185 .pf = {.pev = pev, .callback = add_probe_trace_event},
1186 .max_tevs = max_tevs};
1187 int ret;
1188
1189 /* Allocate result tevs array */
1190 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1191 if (*tevs == NULL)
1192 return -ENOMEM;
1193
1194 tf.tevs = *tevs;
1195 tf.ntevs = 0;
1196
1197 ret = debuginfo__find_probes(self, &tf.pf);
1198 if (ret < 0) {
1199 free(*tevs);
1200 *tevs = NULL;
1201 return ret;
1202 }
1203
1204 return (ret < 0) ? ret : tf.ntevs;
1205 }
1206
1207 #define MAX_VAR_LEN 64
1208
1209 /* Collect available variables in this scope */
1210 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1211 {
1212 struct available_var_finder *af = data;
1213 struct variable_list *vl;
1214 char buf[MAX_VAR_LEN];
1215 int tag, ret;
1216
1217 vl = &af->vls[af->nvls - 1];
1218
1219 tag = dwarf_tag(die_mem);
1220 if (tag == DW_TAG_formal_parameter ||
1221 tag == DW_TAG_variable) {
1222 ret = convert_variable_location(die_mem, af->pf.addr,
1223 af->pf.fb_ops, NULL);
1224 if (ret == 0) {
1225 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1226 pr_debug2("Add new var: %s\n", buf);
1227 if (ret > 0)
1228 strlist__add(vl->vars, buf);
1229 }
1230 }
1231
1232 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1233 return DIE_FIND_CB_CONTINUE;
1234 else
1235 return DIE_FIND_CB_SIBLING;
1236 }
1237
1238 /* Add a found vars into available variables list */
1239 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1240 {
1241 struct available_var_finder *af =
1242 container_of(pf, struct available_var_finder, pf);
1243 struct variable_list *vl;
1244 Dwarf_Die die_mem;
1245 int ret;
1246
1247 /* Check number of tevs */
1248 if (af->nvls == af->max_vls) {
1249 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1250 return -ERANGE;
1251 }
1252 vl = &af->vls[af->nvls++];
1253
1254 /* Trace point should be converted from subprogram DIE */
1255 ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1256 pf->pev->point.retprobe, &vl->point);
1257 if (ret < 0)
1258 return ret;
1259
1260 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1261 vl->point.offset);
1262
1263 /* Find local variables */
1264 vl->vars = strlist__new(true, NULL);
1265 if (vl->vars == NULL)
1266 return -ENOMEM;
1267 af->child = true;
1268 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1269
1270 /* Find external variables */
1271 if (!af->externs)
1272 goto out;
1273 /* Don't need to search child DIE for externs. */
1274 af->child = false;
1275 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1276
1277 out:
1278 if (strlist__empty(vl->vars)) {
1279 strlist__delete(vl->vars);
1280 vl->vars = NULL;
1281 }
1282
1283 return ret;
1284 }
1285
1286 /* Find available variables at given probe point */
1287 int debuginfo__find_available_vars_at(struct debuginfo *self,
1288 struct perf_probe_event *pev,
1289 struct variable_list **vls,
1290 int max_vls, bool externs)
1291 {
1292 struct available_var_finder af = {
1293 .pf = {.pev = pev, .callback = add_available_vars},
1294 .max_vls = max_vls, .externs = externs};
1295 int ret;
1296
1297 /* Allocate result vls array */
1298 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1299 if (*vls == NULL)
1300 return -ENOMEM;
1301
1302 af.vls = *vls;
1303 af.nvls = 0;
1304
1305 ret = debuginfo__find_probes(self, &af.pf);
1306 if (ret < 0) {
1307 /* Free vlist for error */
1308 while (af.nvls--) {
1309 if (af.vls[af.nvls].point.symbol)
1310 free(af.vls[af.nvls].point.symbol);
1311 if (af.vls[af.nvls].vars)
1312 strlist__delete(af.vls[af.nvls].vars);
1313 }
1314 free(af.vls);
1315 *vls = NULL;
1316 return ret;
1317 }
1318
1319 return (ret < 0) ? ret : af.nvls;
1320 }
1321
1322 /* Reverse search */
1323 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1324 struct perf_probe_point *ppt)
1325 {
1326 Dwarf_Die cudie, spdie, indie;
1327 Dwarf_Addr _addr, baseaddr;
1328 const char *fname = NULL, *func = NULL, *tmp;
1329 int baseline = 0, lineno = 0, ret = 0;
1330
1331 /* Adjust address with bias */
1332 addr += self->bias;
1333
1334 /* Find cu die */
1335 if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1336 pr_warning("Failed to find debug information for address %lx\n",
1337 addr);
1338 ret = -EINVAL;
1339 goto end;
1340 }
1341
1342 /* Find a corresponding line (filename and lineno) */
1343 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1344 /* Don't care whether it failed or not */
1345
1346 /* Find a corresponding function (name, baseline and baseaddr) */
1347 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1348 /* Get function entry information */
1349 tmp = dwarf_diename(&spdie);
1350 if (!tmp ||
1351 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1352 dwarf_decl_line(&spdie, &baseline) != 0)
1353 goto post;
1354 func = tmp;
1355
1356 if (addr == (unsigned long)baseaddr)
1357 /* Function entry - Relative line number is 0 */
1358 lineno = baseline;
1359 else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1360 &indie)) {
1361 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1362 _addr == addr)
1363 /*
1364 * addr is at an inline function entry.
1365 * In this case, lineno should be the call-site
1366 * line number.
1367 */
1368 lineno = die_get_call_lineno(&indie);
1369 else {
1370 /*
1371 * addr is in an inline function body.
1372 * Since lineno points one of the lines
1373 * of the inline function, baseline should
1374 * be the entry line of the inline function.
1375 */
1376 tmp = dwarf_diename(&indie);
1377 if (tmp &&
1378 dwarf_decl_line(&spdie, &baseline) == 0)
1379 func = tmp;
1380 }
1381 }
1382 }
1383
1384 post:
1385 /* Make a relative line number or an offset */
1386 if (lineno)
1387 ppt->line = lineno - baseline;
1388 else if (func)
1389 ppt->offset = addr - (unsigned long)baseaddr;
1390
1391 /* Duplicate strings */
1392 if (func) {
1393 ppt->function = strdup(func);
1394 if (ppt->function == NULL) {
1395 ret = -ENOMEM;
1396 goto end;
1397 }
1398 }
1399 if (fname) {
1400 ppt->file = strdup(fname);
1401 if (ppt->file == NULL) {
1402 if (ppt->function) {
1403 free(ppt->function);
1404 ppt->function = NULL;
1405 }
1406 ret = -ENOMEM;
1407 goto end;
1408 }
1409 }
1410 end:
1411 if (ret == 0 && (fname || func))
1412 ret = 1; /* Found a point */
1413 return ret;
1414 }
1415
1416 /* Add a line and store the src path */
1417 static int line_range_add_line(const char *src, unsigned int lineno,
1418 struct line_range *lr)
1419 {
1420 /* Copy source path */
1421 if (!lr->path) {
1422 lr->path = strdup(src);
1423 if (lr->path == NULL)
1424 return -ENOMEM;
1425 }
1426 return line_list__add_line(&lr->line_list, lineno);
1427 }
1428
1429 static int line_range_walk_cb(const char *fname, int lineno,
1430 Dwarf_Addr addr __maybe_unused,
1431 void *data)
1432 {
1433 struct line_finder *lf = data;
1434
1435 if ((strtailcmp(fname, lf->fname) != 0) ||
1436 (lf->lno_s > lineno || lf->lno_e < lineno))
1437 return 0;
1438
1439 if (line_range_add_line(fname, lineno, lf->lr) < 0)
1440 return -EINVAL;
1441
1442 return 0;
1443 }
1444
1445 /* Find line range from its line number */
1446 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1447 {
1448 int ret;
1449
1450 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1451
1452 /* Update status */
1453 if (ret >= 0)
1454 if (!list_empty(&lf->lr->line_list))
1455 ret = lf->found = 1;
1456 else
1457 ret = 0; /* Lines are not found */
1458 else {
1459 free(lf->lr->path);
1460 lf->lr->path = NULL;
1461 }
1462 return ret;
1463 }
1464
1465 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1466 {
1467 find_line_range_by_line(in_die, data);
1468
1469 /*
1470 * We have to check all instances of inlined function, because
1471 * some execution paths can be optimized out depends on the
1472 * function argument of instances
1473 */
1474 return 0;
1475 }
1476
1477 /* Search function from function name */
1478 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1479 {
1480 struct dwarf_callback_param *param = data;
1481 struct line_finder *lf = param->data;
1482 struct line_range *lr = lf->lr;
1483
1484 /* Check declared file */
1485 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1486 return DWARF_CB_OK;
1487
1488 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1489 die_compare_name(sp_die, lr->function)) {
1490 lf->fname = dwarf_decl_file(sp_die);
1491 dwarf_decl_line(sp_die, &lr->offset);
1492 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1493 lf->lno_s = lr->offset + lr->start;
1494 if (lf->lno_s < 0) /* Overflow */
1495 lf->lno_s = INT_MAX;
1496 lf->lno_e = lr->offset + lr->end;
1497 if (lf->lno_e < 0) /* Overflow */
1498 lf->lno_e = INT_MAX;
1499 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1500 lr->start = lf->lno_s;
1501 lr->end = lf->lno_e;
1502 if (dwarf_func_inline(sp_die))
1503 param->retval = die_walk_instances(sp_die,
1504 line_range_inline_cb, lf);
1505 else
1506 param->retval = find_line_range_by_line(sp_die, lf);
1507 return DWARF_CB_ABORT;
1508 }
1509 return DWARF_CB_OK;
1510 }
1511
1512 static int find_line_range_by_func(struct line_finder *lf)
1513 {
1514 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1515 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1516 return param.retval;
1517 }
1518
1519 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1520 {
1521 struct line_finder lf = {.lr = lr, .found = 0};
1522 int ret = 0;
1523 Dwarf_Off off = 0, noff;
1524 size_t cuhl;
1525 Dwarf_Die *diep;
1526 const char *comp_dir;
1527
1528 /* Fastpath: lookup by function name from .debug_pubnames section */
1529 if (lr->function) {
1530 struct pubname_callback_param pubname_param = {
1531 .function = lr->function, .file = lr->file,
1532 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1533 struct dwarf_callback_param line_range_param = {
1534 .data = (void *)&lf, .retval = 0};
1535
1536 dwarf_getpubnames(self->dbg, pubname_search_cb,
1537 &pubname_param, 0);
1538 if (pubname_param.found) {
1539 line_range_search_cb(&lf.sp_die, &line_range_param);
1540 if (lf.found)
1541 goto found;
1542 }
1543 }
1544
1545 /* Loop on CUs (Compilation Unit) */
1546 while (!lf.found && ret >= 0) {
1547 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1548 NULL, NULL, NULL) != 0)
1549 break;
1550
1551 /* Get the DIE(Debugging Information Entry) of this CU */
1552 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1553 if (!diep)
1554 continue;
1555
1556 /* Check if target file is included. */
1557 if (lr->file)
1558 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1559 else
1560 lf.fname = 0;
1561
1562 if (!lr->file || lf.fname) {
1563 if (lr->function)
1564 ret = find_line_range_by_func(&lf);
1565 else {
1566 lf.lno_s = lr->start;
1567 lf.lno_e = lr->end;
1568 ret = find_line_range_by_line(NULL, &lf);
1569 }
1570 }
1571 off = noff;
1572 }
1573
1574 found:
1575 /* Store comp_dir */
1576 if (lf.found) {
1577 comp_dir = cu_get_comp_dir(&lf.cu_die);
1578 if (comp_dir) {
1579 lr->comp_dir = strdup(comp_dir);
1580 if (!lr->comp_dir)
1581 ret = -ENOMEM;
1582 }
1583 }
1584
1585 pr_debug("path: %s\n", lr->path);
1586 return (ret < 0) ? ret : lf.found;
1587 }
1588
Linux kernel - Deliverables
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