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Merge tag 'davinci-fixes-for-v3.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel...
[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 "dso.h"
38 #include "debug.h"
39 #include "intlist.h"
40 #include "util.h"
41 #include "symbol.h"
42 #include "probe-finder.h"
43
44 /* Kprobe tracer basic type is up to u64 */
45 #define MAX_BASIC_TYPE_BITS 64
46
47 /* Dwarf FL wrappers */
48 static char *debuginfo_path; /* Currently dummy */
49
50 static const Dwfl_Callbacks offline_callbacks = {
51 .find_debuginfo = dwfl_standard_find_debuginfo,
52 .debuginfo_path = &debuginfo_path,
53
54 .section_address = dwfl_offline_section_address,
55
56 /* We use this table for core files too. */
57 .find_elf = dwfl_build_id_find_elf,
58 };
59
60 /* Get a Dwarf from offline image */
61 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
62 const char *path)
63 {
64 int fd;
65
66 fd = open(path, O_RDONLY);
67 if (fd < 0)
68 return fd;
69
70 dbg->dwfl = dwfl_begin(&offline_callbacks);
71 if (!dbg->dwfl)
72 goto error;
73
74 dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
75 if (!dbg->mod)
76 goto error;
77
78 dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
79 if (!dbg->dbg)
80 goto error;
81
82 return 0;
83 error:
84 if (dbg->dwfl)
85 dwfl_end(dbg->dwfl);
86 else
87 close(fd);
88 memset(dbg, 0, sizeof(*dbg));
89
90 return -ENOENT;
91 }
92
93 static struct debuginfo *__debuginfo__new(const char *path)
94 {
95 struct debuginfo *dbg = zalloc(sizeof(*dbg));
96 if (!dbg)
97 return NULL;
98
99 if (debuginfo__init_offline_dwarf(dbg, path) < 0)
100 zfree(&dbg);
101 if (dbg)
102 pr_debug("Open Debuginfo file: %s\n", path);
103 return dbg;
104 }
105
106 enum dso_binary_type distro_dwarf_types[] = {
107 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
108 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
109 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
110 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
111 DSO_BINARY_TYPE__NOT_FOUND,
112 };
113
114 struct debuginfo *debuginfo__new(const char *path)
115 {
116 enum dso_binary_type *type;
117 char buf[PATH_MAX], nil = '\0';
118 struct dso *dso;
119 struct debuginfo *dinfo = NULL;
120
121 /* Try to open distro debuginfo files */
122 dso = dso__new(path);
123 if (!dso)
124 goto out;
125
126 for (type = distro_dwarf_types;
127 !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
128 type++) {
129 if (dso__read_binary_type_filename(dso, *type, &nil,
130 buf, PATH_MAX) < 0)
131 continue;
132 dinfo = __debuginfo__new(buf);
133 }
134 dso__delete(dso);
135
136 out:
137 /* if failed to open all distro debuginfo, open given binary */
138 return dinfo ? : __debuginfo__new(path);
139 }
140
141 void debuginfo__delete(struct debuginfo *dbg)
142 {
143 if (dbg) {
144 if (dbg->dwfl)
145 dwfl_end(dbg->dwfl);
146 free(dbg);
147 }
148 }
149
150 /*
151 * Probe finder related functions
152 */
153
154 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
155 {
156 struct probe_trace_arg_ref *ref;
157 ref = zalloc(sizeof(struct probe_trace_arg_ref));
158 if (ref != NULL)
159 ref->offset = offs;
160 return ref;
161 }
162
163 /*
164 * Convert a location into trace_arg.
165 * If tvar == NULL, this just checks variable can be converted.
166 * If fentry == true and vr_die is a parameter, do huristic search
167 * for the location fuzzed by function entry mcount.
168 */
169 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
170 Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
171 struct probe_trace_arg *tvar)
172 {
173 Dwarf_Attribute attr;
174 Dwarf_Addr tmp = 0;
175 Dwarf_Op *op;
176 size_t nops;
177 unsigned int regn;
178 Dwarf_Word offs = 0;
179 bool ref = false;
180 const char *regs;
181 int ret;
182
183 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
184 goto static_var;
185
186 /* TODO: handle more than 1 exprs */
187 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
188 return -EINVAL; /* Broken DIE ? */
189 if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
190 ret = dwarf_entrypc(sp_die, &tmp);
191 if (ret || addr != tmp ||
192 dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
193 dwarf_highpc(sp_die, &tmp))
194 return -ENOENT;
195 /*
196 * This is fuzzed by fentry mcount. We try to find the
197 * parameter location at the earliest address.
198 */
199 for (addr += 1; addr <= tmp; addr++) {
200 if (dwarf_getlocation_addr(&attr, addr, &op,
201 &nops, 1) > 0)
202 goto found;
203 }
204 return -ENOENT;
205 }
206 found:
207 if (nops == 0)
208 /* TODO: Support const_value */
209 return -ENOENT;
210
211 if (op->atom == DW_OP_addr) {
212 static_var:
213 if (!tvar)
214 return 0;
215 /* Static variables on memory (not stack), make @varname */
216 ret = strlen(dwarf_diename(vr_die));
217 tvar->value = zalloc(ret + 2);
218 if (tvar->value == NULL)
219 return -ENOMEM;
220 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
221 tvar->ref = alloc_trace_arg_ref((long)offs);
222 if (tvar->ref == NULL)
223 return -ENOMEM;
224 return 0;
225 }
226
227 /* If this is based on frame buffer, set the offset */
228 if (op->atom == DW_OP_fbreg) {
229 if (fb_ops == NULL)
230 return -ENOTSUP;
231 ref = true;
232 offs = op->number;
233 op = &fb_ops[0];
234 }
235
236 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
237 regn = op->atom - DW_OP_breg0;
238 offs += op->number;
239 ref = true;
240 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
241 regn = op->atom - DW_OP_reg0;
242 } else if (op->atom == DW_OP_bregx) {
243 regn = op->number;
244 offs += op->number2;
245 ref = true;
246 } else if (op->atom == DW_OP_regx) {
247 regn = op->number;
248 } else {
249 pr_debug("DW_OP %x is not supported.\n", op->atom);
250 return -ENOTSUP;
251 }
252
253 if (!tvar)
254 return 0;
255
256 regs = get_arch_regstr(regn);
257 if (!regs) {
258 /* This should be a bug in DWARF or this tool */
259 pr_warning("Mapping for the register number %u "
260 "missing on this architecture.\n", regn);
261 return -ERANGE;
262 }
263
264 tvar->value = strdup(regs);
265 if (tvar->value == NULL)
266 return -ENOMEM;
267
268 if (ref) {
269 tvar->ref = alloc_trace_arg_ref((long)offs);
270 if (tvar->ref == NULL)
271 return -ENOMEM;
272 }
273 return 0;
274 }
275
276 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
277
278 static int convert_variable_type(Dwarf_Die *vr_die,
279 struct probe_trace_arg *tvar,
280 const char *cast)
281 {
282 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
283 Dwarf_Die type;
284 char buf[16];
285 int bsize, boffs, total;
286 int ret;
287
288 /* TODO: check all types */
289 if (cast && strcmp(cast, "string") != 0) {
290 /* Non string type is OK */
291 tvar->type = strdup(cast);
292 return (tvar->type == NULL) ? -ENOMEM : 0;
293 }
294
295 bsize = dwarf_bitsize(vr_die);
296 if (bsize > 0) {
297 /* This is a bitfield */
298 boffs = dwarf_bitoffset(vr_die);
299 total = dwarf_bytesize(vr_die);
300 if (boffs < 0 || total < 0)
301 return -ENOENT;
302 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
303 BYTES_TO_BITS(total));
304 goto formatted;
305 }
306
307 if (die_get_real_type(vr_die, &type) == NULL) {
308 pr_warning("Failed to get a type information of %s.\n",
309 dwarf_diename(vr_die));
310 return -ENOENT;
311 }
312
313 pr_debug("%s type is %s.\n",
314 dwarf_diename(vr_die), dwarf_diename(&type));
315
316 if (cast && strcmp(cast, "string") == 0) { /* String type */
317 ret = dwarf_tag(&type);
318 if (ret != DW_TAG_pointer_type &&
319 ret != DW_TAG_array_type) {
320 pr_warning("Failed to cast into string: "
321 "%s(%s) is not a pointer nor array.\n",
322 dwarf_diename(vr_die), dwarf_diename(&type));
323 return -EINVAL;
324 }
325 if (die_get_real_type(&type, &type) == NULL) {
326 pr_warning("Failed to get a type"
327 " information.\n");
328 return -ENOENT;
329 }
330 if (ret == DW_TAG_pointer_type) {
331 while (*ref_ptr)
332 ref_ptr = &(*ref_ptr)->next;
333 /* Add new reference with offset +0 */
334 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
335 if (*ref_ptr == NULL) {
336 pr_warning("Out of memory error\n");
337 return -ENOMEM;
338 }
339 }
340 if (!die_compare_name(&type, "char") &&
341 !die_compare_name(&type, "unsigned char")) {
342 pr_warning("Failed to cast into string: "
343 "%s is not (unsigned) char *.\n",
344 dwarf_diename(vr_die));
345 return -EINVAL;
346 }
347 tvar->type = strdup(cast);
348 return (tvar->type == NULL) ? -ENOMEM : 0;
349 }
350
351 ret = dwarf_bytesize(&type);
352 if (ret <= 0)
353 /* No size ... try to use default type */
354 return 0;
355 ret = BYTES_TO_BITS(ret);
356
357 /* Check the bitwidth */
358 if (ret > MAX_BASIC_TYPE_BITS) {
359 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
360 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
361 ret = MAX_BASIC_TYPE_BITS;
362 }
363 ret = snprintf(buf, 16, "%c%d",
364 die_is_signed_type(&type) ? 's' : 'u', ret);
365
366 formatted:
367 if (ret < 0 || ret >= 16) {
368 if (ret >= 16)
369 ret = -E2BIG;
370 pr_warning("Failed to convert variable type: %s\n",
371 strerror(-ret));
372 return ret;
373 }
374 tvar->type = strdup(buf);
375 if (tvar->type == NULL)
376 return -ENOMEM;
377 return 0;
378 }
379
380 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
381 struct perf_probe_arg_field *field,
382 struct probe_trace_arg_ref **ref_ptr,
383 Dwarf_Die *die_mem)
384 {
385 struct probe_trace_arg_ref *ref = *ref_ptr;
386 Dwarf_Die type;
387 Dwarf_Word offs;
388 int ret, tag;
389
390 pr_debug("converting %s in %s\n", field->name, varname);
391 if (die_get_real_type(vr_die, &type) == NULL) {
392 pr_warning("Failed to get the type of %s.\n", varname);
393 return -ENOENT;
394 }
395 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
396 tag = dwarf_tag(&type);
397
398 if (field->name[0] == '[' &&
399 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
400 if (field->next)
401 /* Save original type for next field */
402 memcpy(die_mem, &type, sizeof(*die_mem));
403 /* Get the type of this array */
404 if (die_get_real_type(&type, &type) == NULL) {
405 pr_warning("Failed to get the type of %s.\n", varname);
406 return -ENOENT;
407 }
408 pr_debug2("Array real type: (%x)\n",
409 (unsigned)dwarf_dieoffset(&type));
410 if (tag == DW_TAG_pointer_type) {
411 ref = zalloc(sizeof(struct probe_trace_arg_ref));
412 if (ref == NULL)
413 return -ENOMEM;
414 if (*ref_ptr)
415 (*ref_ptr)->next = ref;
416 else
417 *ref_ptr = ref;
418 }
419 ref->offset += dwarf_bytesize(&type) * field->index;
420 if (!field->next)
421 /* Save vr_die for converting types */
422 memcpy(die_mem, vr_die, sizeof(*die_mem));
423 goto next;
424 } else if (tag == DW_TAG_pointer_type) {
425 /* Check the pointer and dereference */
426 if (!field->ref) {
427 pr_err("Semantic error: %s must be referred by '->'\n",
428 field->name);
429 return -EINVAL;
430 }
431 /* Get the type pointed by this pointer */
432 if (die_get_real_type(&type, &type) == NULL) {
433 pr_warning("Failed to get the type of %s.\n", varname);
434 return -ENOENT;
435 }
436 /* Verify it is a data structure */
437 tag = dwarf_tag(&type);
438 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
439 pr_warning("%s is not a data structure nor an union.\n",
440 varname);
441 return -EINVAL;
442 }
443
444 ref = zalloc(sizeof(struct probe_trace_arg_ref));
445 if (ref == NULL)
446 return -ENOMEM;
447 if (*ref_ptr)
448 (*ref_ptr)->next = ref;
449 else
450 *ref_ptr = ref;
451 } else {
452 /* Verify it is a data structure */
453 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
454 pr_warning("%s is not a data structure nor an union.\n",
455 varname);
456 return -EINVAL;
457 }
458 if (field->name[0] == '[') {
459 pr_err("Semantic error: %s is not a pointor"
460 " nor array.\n", varname);
461 return -EINVAL;
462 }
463 if (field->ref) {
464 pr_err("Semantic error: %s must be referred by '.'\n",
465 field->name);
466 return -EINVAL;
467 }
468 if (!ref) {
469 pr_warning("Structure on a register is not "
470 "supported yet.\n");
471 return -ENOTSUP;
472 }
473 }
474
475 if (die_find_member(&type, field->name, die_mem) == NULL) {
476 pr_warning("%s(type:%s) has no member %s.\n", varname,
477 dwarf_diename(&type), field->name);
478 return -EINVAL;
479 }
480
481 /* Get the offset of the field */
482 if (tag == DW_TAG_union_type) {
483 offs = 0;
484 } else {
485 ret = die_get_data_member_location(die_mem, &offs);
486 if (ret < 0) {
487 pr_warning("Failed to get the offset of %s.\n",
488 field->name);
489 return ret;
490 }
491 }
492 ref->offset += (long)offs;
493
494 next:
495 /* Converting next field */
496 if (field->next)
497 return convert_variable_fields(die_mem, field->name,
498 field->next, &ref, die_mem);
499 else
500 return 0;
501 }
502
503 /* Show a variables in kprobe event format */
504 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
505 {
506 Dwarf_Die die_mem;
507 int ret;
508
509 pr_debug("Converting variable %s into trace event.\n",
510 dwarf_diename(vr_die));
511
512 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
513 &pf->sp_die, pf->tvar);
514 if (ret == -ENOENT)
515 pr_err("Failed to find the location of %s at this address.\n"
516 " Perhaps, it has been optimized out.\n", pf->pvar->var);
517 else if (ret == -ENOTSUP)
518 pr_err("Sorry, we don't support this variable location yet.\n");
519 else if (pf->pvar->field) {
520 ret = convert_variable_fields(vr_die, pf->pvar->var,
521 pf->pvar->field, &pf->tvar->ref,
522 &die_mem);
523 vr_die = &die_mem;
524 }
525 if (ret == 0)
526 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
527 /* *expr will be cached in libdw. Don't free it. */
528 return ret;
529 }
530
531 /* Find a variable in a scope DIE */
532 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
533 {
534 Dwarf_Die vr_die;
535 char buf[32], *ptr;
536 int ret = 0;
537
538 if (!is_c_varname(pf->pvar->var)) {
539 /* Copy raw parameters */
540 pf->tvar->value = strdup(pf->pvar->var);
541 if (pf->tvar->value == NULL)
542 return -ENOMEM;
543 if (pf->pvar->type) {
544 pf->tvar->type = strdup(pf->pvar->type);
545 if (pf->tvar->type == NULL)
546 return -ENOMEM;
547 }
548 if (pf->pvar->name) {
549 pf->tvar->name = strdup(pf->pvar->name);
550 if (pf->tvar->name == NULL)
551 return -ENOMEM;
552 } else
553 pf->tvar->name = NULL;
554 return 0;
555 }
556
557 if (pf->pvar->name)
558 pf->tvar->name = strdup(pf->pvar->name);
559 else {
560 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
561 if (ret < 0)
562 return ret;
563 ptr = strchr(buf, ':'); /* Change type separator to _ */
564 if (ptr)
565 *ptr = '_';
566 pf->tvar->name = strdup(buf);
567 }
568 if (pf->tvar->name == NULL)
569 return -ENOMEM;
570
571 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
572 /* Search child die for local variables and parameters. */
573 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
574 /* Search again in global variables */
575 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
576 ret = -ENOENT;
577 }
578 if (ret >= 0)
579 ret = convert_variable(&vr_die, pf);
580
581 if (ret < 0)
582 pr_warning("Failed to find '%s' in this function.\n",
583 pf->pvar->var);
584 return ret;
585 }
586
587 /* Convert subprogram DIE to trace point */
588 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
589 Dwarf_Addr paddr, bool retprobe,
590 struct probe_trace_point *tp)
591 {
592 Dwarf_Addr eaddr, highaddr;
593 GElf_Sym sym;
594 const char *symbol;
595
596 /* Verify the address is correct */
597 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
598 pr_warning("Failed to get entry address of %s\n",
599 dwarf_diename(sp_die));
600 return -ENOENT;
601 }
602 if (dwarf_highpc(sp_die, &highaddr) != 0) {
603 pr_warning("Failed to get end address of %s\n",
604 dwarf_diename(sp_die));
605 return -ENOENT;
606 }
607 if (paddr > highaddr) {
608 pr_warning("Offset specified is greater than size of %s\n",
609 dwarf_diename(sp_die));
610 return -EINVAL;
611 }
612
613 /* Get an appropriate symbol from symtab */
614 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
615 if (!symbol) {
616 pr_warning("Failed to find symbol at 0x%lx\n",
617 (unsigned long)paddr);
618 return -ENOENT;
619 }
620 tp->offset = (unsigned long)(paddr - sym.st_value);
621 tp->address = (unsigned long)paddr;
622 tp->symbol = strdup(symbol);
623 if (!tp->symbol)
624 return -ENOMEM;
625
626 /* Return probe must be on the head of a subprogram */
627 if (retprobe) {
628 if (eaddr != paddr) {
629 pr_warning("Return probe must be on the head of"
630 " a real function.\n");
631 return -EINVAL;
632 }
633 tp->retprobe = true;
634 }
635
636 return 0;
637 }
638
639 /* Call probe_finder callback with scope DIE */
640 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
641 {
642 Dwarf_Attribute fb_attr;
643 size_t nops;
644 int ret;
645
646 if (!sc_die) {
647 pr_err("Caller must pass a scope DIE. Program error.\n");
648 return -EINVAL;
649 }
650
651 /* If not a real subprogram, find a real one */
652 if (!die_is_func_def(sc_die)) {
653 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
654 pr_warning("Failed to find probe point in any "
655 "functions.\n");
656 return -ENOENT;
657 }
658 } else
659 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
660
661 /* Get the frame base attribute/ops from subprogram */
662 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
663 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
664 if (ret <= 0 || nops == 0) {
665 pf->fb_ops = NULL;
666 #if _ELFUTILS_PREREQ(0, 142)
667 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
668 pf->cfi != NULL) {
669 Dwarf_Frame *frame;
670 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
671 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
672 pr_warning("Failed to get call frame on 0x%jx\n",
673 (uintmax_t)pf->addr);
674 return -ENOENT;
675 }
676 #endif
677 }
678
679 /* Call finder's callback handler */
680 ret = pf->callback(sc_die, pf);
681
682 /* *pf->fb_ops will be cached in libdw. Don't free it. */
683 pf->fb_ops = NULL;
684
685 return ret;
686 }
687
688 struct find_scope_param {
689 const char *function;
690 const char *file;
691 int line;
692 int diff;
693 Dwarf_Die *die_mem;
694 bool found;
695 };
696
697 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
698 {
699 struct find_scope_param *fsp = data;
700 const char *file;
701 int lno;
702
703 /* Skip if declared file name does not match */
704 if (fsp->file) {
705 file = dwarf_decl_file(fn_die);
706 if (!file || strcmp(fsp->file, file) != 0)
707 return 0;
708 }
709 /* If the function name is given, that's what user expects */
710 if (fsp->function) {
711 if (die_compare_name(fn_die, fsp->function)) {
712 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
713 fsp->found = true;
714 return 1;
715 }
716 } else {
717 /* With the line number, find the nearest declared DIE */
718 dwarf_decl_line(fn_die, &lno);
719 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
720 /* Keep a candidate and continue */
721 fsp->diff = fsp->line - lno;
722 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
723 fsp->found = true;
724 }
725 }
726 return 0;
727 }
728
729 /* Find an appropriate scope fits to given conditions */
730 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
731 {
732 struct find_scope_param fsp = {
733 .function = pf->pev->point.function,
734 .file = pf->fname,
735 .line = pf->lno,
736 .diff = INT_MAX,
737 .die_mem = die_mem,
738 .found = false,
739 };
740
741 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
742
743 return fsp.found ? die_mem : NULL;
744 }
745
746 static int probe_point_line_walker(const char *fname, int lineno,
747 Dwarf_Addr addr, void *data)
748 {
749 struct probe_finder *pf = data;
750 Dwarf_Die *sc_die, die_mem;
751 int ret;
752
753 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
754 return 0;
755
756 pf->addr = addr;
757 sc_die = find_best_scope(pf, &die_mem);
758 if (!sc_die) {
759 pr_warning("Failed to find scope of probe point.\n");
760 return -ENOENT;
761 }
762
763 ret = call_probe_finder(sc_die, pf);
764
765 /* Continue if no error, because the line will be in inline function */
766 return ret < 0 ? ret : 0;
767 }
768
769 /* Find probe point from its line number */
770 static int find_probe_point_by_line(struct probe_finder *pf)
771 {
772 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
773 }
774
775 /* Find lines which match lazy pattern */
776 static int find_lazy_match_lines(struct intlist *list,
777 const char *fname, const char *pat)
778 {
779 FILE *fp;
780 char *line = NULL;
781 size_t line_len;
782 ssize_t len;
783 int count = 0, linenum = 1;
784
785 fp = fopen(fname, "r");
786 if (!fp) {
787 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
788 return -errno;
789 }
790
791 while ((len = getline(&line, &line_len, fp)) > 0) {
792
793 if (line[len - 1] == '\n')
794 line[len - 1] = '\0';
795
796 if (strlazymatch(line, pat)) {
797 intlist__add(list, linenum);
798 count++;
799 }
800 linenum++;
801 }
802
803 if (ferror(fp))
804 count = -errno;
805 free(line);
806 fclose(fp);
807
808 if (count == 0)
809 pr_debug("No matched lines found in %s.\n", fname);
810 return count;
811 }
812
813 static int probe_point_lazy_walker(const char *fname, int lineno,
814 Dwarf_Addr addr, void *data)
815 {
816 struct probe_finder *pf = data;
817 Dwarf_Die *sc_die, die_mem;
818 int ret;
819
820 if (!intlist__has_entry(pf->lcache, lineno) ||
821 strtailcmp(fname, pf->fname) != 0)
822 return 0;
823
824 pr_debug("Probe line found: line:%d addr:0x%llx\n",
825 lineno, (unsigned long long)addr);
826 pf->addr = addr;
827 pf->lno = lineno;
828 sc_die = find_best_scope(pf, &die_mem);
829 if (!sc_die) {
830 pr_warning("Failed to find scope of probe point.\n");
831 return -ENOENT;
832 }
833
834 ret = call_probe_finder(sc_die, pf);
835
836 /*
837 * Continue if no error, because the lazy pattern will match
838 * to other lines
839 */
840 return ret < 0 ? ret : 0;
841 }
842
843 /* Find probe points from lazy pattern */
844 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
845 {
846 int ret = 0;
847
848 if (intlist__empty(pf->lcache)) {
849 /* Matching lazy line pattern */
850 ret = find_lazy_match_lines(pf->lcache, pf->fname,
851 pf->pev->point.lazy_line);
852 if (ret <= 0)
853 return ret;
854 }
855
856 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
857 }
858
859 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
860 {
861 struct probe_finder *pf = data;
862 struct perf_probe_point *pp = &pf->pev->point;
863 Dwarf_Addr addr;
864 int ret;
865
866 if (pp->lazy_line)
867 ret = find_probe_point_lazy(in_die, pf);
868 else {
869 /* Get probe address */
870 if (dwarf_entrypc(in_die, &addr) != 0) {
871 pr_warning("Failed to get entry address of %s.\n",
872 dwarf_diename(in_die));
873 return -ENOENT;
874 }
875 pf->addr = addr;
876 pf->addr += pp->offset;
877 pr_debug("found inline addr: 0x%jx\n",
878 (uintmax_t)pf->addr);
879
880 ret = call_probe_finder(in_die, pf);
881 }
882
883 return ret;
884 }
885
886 /* Callback parameter with return value for libdw */
887 struct dwarf_callback_param {
888 void *data;
889 int retval;
890 };
891
892 /* Search function from function name */
893 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
894 {
895 struct dwarf_callback_param *param = data;
896 struct probe_finder *pf = param->data;
897 struct perf_probe_point *pp = &pf->pev->point;
898
899 /* Check tag and diename */
900 if (!die_is_func_def(sp_die) ||
901 !die_compare_name(sp_die, pp->function))
902 return DWARF_CB_OK;
903
904 /* Check declared file */
905 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
906 return DWARF_CB_OK;
907
908 pf->fname = dwarf_decl_file(sp_die);
909 if (pp->line) { /* Function relative line */
910 dwarf_decl_line(sp_die, &pf->lno);
911 pf->lno += pp->line;
912 param->retval = find_probe_point_by_line(pf);
913 } else if (!dwarf_func_inline(sp_die)) {
914 /* Real function */
915 if (pp->lazy_line)
916 param->retval = find_probe_point_lazy(sp_die, pf);
917 else {
918 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
919 pr_warning("Failed to get entry address of "
920 "%s.\n", dwarf_diename(sp_die));
921 param->retval = -ENOENT;
922 return DWARF_CB_ABORT;
923 }
924 pf->addr += pp->offset;
925 /* TODO: Check the address in this function */
926 param->retval = call_probe_finder(sp_die, pf);
927 }
928 } else
929 /* Inlined function: search instances */
930 param->retval = die_walk_instances(sp_die,
931 probe_point_inline_cb, (void *)pf);
932
933 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
934 }
935
936 static int find_probe_point_by_func(struct probe_finder *pf)
937 {
938 struct dwarf_callback_param _param = {.data = (void *)pf,
939 .retval = 0};
940 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
941 return _param.retval;
942 }
943
944 struct pubname_callback_param {
945 char *function;
946 char *file;
947 Dwarf_Die *cu_die;
948 Dwarf_Die *sp_die;
949 int found;
950 };
951
952 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
953 {
954 struct pubname_callback_param *param = data;
955
956 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
957 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
958 return DWARF_CB_OK;
959
960 if (die_compare_name(param->sp_die, param->function)) {
961 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
962 return DWARF_CB_OK;
963
964 if (param->file &&
965 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
966 return DWARF_CB_OK;
967
968 param->found = 1;
969 return DWARF_CB_ABORT;
970 }
971 }
972
973 return DWARF_CB_OK;
974 }
975
976 /* Find probe points from debuginfo */
977 static int debuginfo__find_probes(struct debuginfo *dbg,
978 struct probe_finder *pf)
979 {
980 struct perf_probe_point *pp = &pf->pev->point;
981 Dwarf_Off off, noff;
982 size_t cuhl;
983 Dwarf_Die *diep;
984 int ret = 0;
985
986 #if _ELFUTILS_PREREQ(0, 142)
987 /* Get the call frame information from this dwarf */
988 pf->cfi = dwarf_getcfi_elf(dwarf_getelf(dbg->dbg));
989 #endif
990
991 off = 0;
992 pf->lcache = intlist__new(NULL);
993 if (!pf->lcache)
994 return -ENOMEM;
995
996 /* Fastpath: lookup by function name from .debug_pubnames section */
997 if (pp->function) {
998 struct pubname_callback_param pubname_param = {
999 .function = pp->function,
1000 .file = pp->file,
1001 .cu_die = &pf->cu_die,
1002 .sp_die = &pf->sp_die,
1003 .found = 0,
1004 };
1005 struct dwarf_callback_param probe_param = {
1006 .data = pf,
1007 };
1008
1009 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1010 &pubname_param, 0);
1011 if (pubname_param.found) {
1012 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1013 if (ret)
1014 goto found;
1015 }
1016 }
1017
1018 /* Loop on CUs (Compilation Unit) */
1019 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1020 /* Get the DIE(Debugging Information Entry) of this CU */
1021 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1022 if (!diep)
1023 continue;
1024
1025 /* Check if target file is included. */
1026 if (pp->file)
1027 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1028 else
1029 pf->fname = NULL;
1030
1031 if (!pp->file || pf->fname) {
1032 if (pp->function)
1033 ret = find_probe_point_by_func(pf);
1034 else if (pp->lazy_line)
1035 ret = find_probe_point_lazy(NULL, pf);
1036 else {
1037 pf->lno = pp->line;
1038 ret = find_probe_point_by_line(pf);
1039 }
1040 if (ret < 0)
1041 break;
1042 }
1043 off = noff;
1044 }
1045
1046 found:
1047 intlist__delete(pf->lcache);
1048 pf->lcache = NULL;
1049
1050 return ret;
1051 }
1052
1053 struct local_vars_finder {
1054 struct probe_finder *pf;
1055 struct perf_probe_arg *args;
1056 int max_args;
1057 int nargs;
1058 int ret;
1059 };
1060
1061 /* Collect available variables in this scope */
1062 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1063 {
1064 struct local_vars_finder *vf = data;
1065 struct probe_finder *pf = vf->pf;
1066 int tag;
1067
1068 tag = dwarf_tag(die_mem);
1069 if (tag == DW_TAG_formal_parameter ||
1070 tag == DW_TAG_variable) {
1071 if (convert_variable_location(die_mem, vf->pf->addr,
1072 vf->pf->fb_ops, &pf->sp_die,
1073 NULL) == 0) {
1074 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1075 if (vf->args[vf->nargs].var == NULL) {
1076 vf->ret = -ENOMEM;
1077 return DIE_FIND_CB_END;
1078 }
1079 pr_debug(" %s", vf->args[vf->nargs].var);
1080 vf->nargs++;
1081 }
1082 }
1083
1084 if (dwarf_haspc(die_mem, vf->pf->addr))
1085 return DIE_FIND_CB_CONTINUE;
1086 else
1087 return DIE_FIND_CB_SIBLING;
1088 }
1089
1090 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1091 struct perf_probe_arg *args)
1092 {
1093 Dwarf_Die die_mem;
1094 int i;
1095 int n = 0;
1096 struct local_vars_finder vf = {.pf = pf, .args = args,
1097 .max_args = MAX_PROBE_ARGS, .ret = 0};
1098
1099 for (i = 0; i < pf->pev->nargs; i++) {
1100 /* var never be NULL */
1101 if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
1102 pr_debug("Expanding $vars into:");
1103 vf.nargs = n;
1104 /* Special local variables */
1105 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1106 &die_mem);
1107 pr_debug(" (%d)\n", vf.nargs - n);
1108 if (vf.ret < 0)
1109 return vf.ret;
1110 n = vf.nargs;
1111 } else {
1112 /* Copy normal argument */
1113 args[n] = pf->pev->args[i];
1114 n++;
1115 }
1116 }
1117 return n;
1118 }
1119
1120 /* Add a found probe point into trace event list */
1121 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1122 {
1123 struct trace_event_finder *tf =
1124 container_of(pf, struct trace_event_finder, pf);
1125 struct probe_trace_event *tev;
1126 struct perf_probe_arg *args;
1127 int ret, i;
1128
1129 /* Check number of tevs */
1130 if (tf->ntevs == tf->max_tevs) {
1131 pr_warning("Too many( > %d) probe point found.\n",
1132 tf->max_tevs);
1133 return -ERANGE;
1134 }
1135 tev = &tf->tevs[tf->ntevs++];
1136
1137 /* Trace point should be converted from subprogram DIE */
1138 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1139 pf->pev->point.retprobe, &tev->point);
1140 if (ret < 0)
1141 return ret;
1142
1143 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1144 tev->point.offset);
1145
1146 /* Expand special probe argument if exist */
1147 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1148 if (args == NULL)
1149 return -ENOMEM;
1150
1151 ret = expand_probe_args(sc_die, pf, args);
1152 if (ret < 0)
1153 goto end;
1154
1155 tev->nargs = ret;
1156 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1157 if (tev->args == NULL) {
1158 ret = -ENOMEM;
1159 goto end;
1160 }
1161
1162 /* Find each argument */
1163 for (i = 0; i < tev->nargs; i++) {
1164 pf->pvar = &args[i];
1165 pf->tvar = &tev->args[i];
1166 /* Variable should be found from scope DIE */
1167 ret = find_variable(sc_die, pf);
1168 if (ret != 0)
1169 break;
1170 }
1171
1172 end:
1173 free(args);
1174 return ret;
1175 }
1176
1177 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1178 int debuginfo__find_trace_events(struct debuginfo *dbg,
1179 struct perf_probe_event *pev,
1180 struct probe_trace_event **tevs, int max_tevs)
1181 {
1182 struct trace_event_finder tf = {
1183 .pf = {.pev = pev, .callback = add_probe_trace_event},
1184 .mod = dbg->mod, .max_tevs = max_tevs};
1185 int ret;
1186
1187 /* Allocate result tevs array */
1188 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1189 if (*tevs == NULL)
1190 return -ENOMEM;
1191
1192 tf.tevs = *tevs;
1193 tf.ntevs = 0;
1194
1195 ret = debuginfo__find_probes(dbg, &tf.pf);
1196 if (ret < 0) {
1197 zfree(tevs);
1198 return ret;
1199 }
1200
1201 return (ret < 0) ? ret : tf.ntevs;
1202 }
1203
1204 #define MAX_VAR_LEN 64
1205
1206 /* Collect available variables in this scope */
1207 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1208 {
1209 struct available_var_finder *af = data;
1210 struct variable_list *vl;
1211 char buf[MAX_VAR_LEN];
1212 int tag, ret;
1213
1214 vl = &af->vls[af->nvls - 1];
1215
1216 tag = dwarf_tag(die_mem);
1217 if (tag == DW_TAG_formal_parameter ||
1218 tag == DW_TAG_variable) {
1219 ret = convert_variable_location(die_mem, af->pf.addr,
1220 af->pf.fb_ops, &af->pf.sp_die,
1221 NULL);
1222 if (ret == 0) {
1223 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1224 pr_debug2("Add new var: %s\n", buf);
1225 if (ret > 0)
1226 strlist__add(vl->vars, buf);
1227 }
1228 }
1229
1230 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1231 return DIE_FIND_CB_CONTINUE;
1232 else
1233 return DIE_FIND_CB_SIBLING;
1234 }
1235
1236 /* Add a found vars into available variables list */
1237 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1238 {
1239 struct available_var_finder *af =
1240 container_of(pf, struct available_var_finder, pf);
1241 struct variable_list *vl;
1242 Dwarf_Die die_mem;
1243 int ret;
1244
1245 /* Check number of tevs */
1246 if (af->nvls == af->max_vls) {
1247 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1248 return -ERANGE;
1249 }
1250 vl = &af->vls[af->nvls++];
1251
1252 /* Trace point should be converted from subprogram DIE */
1253 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1254 pf->pev->point.retprobe, &vl->point);
1255 if (ret < 0)
1256 return ret;
1257
1258 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1259 vl->point.offset);
1260
1261 /* Find local variables */
1262 vl->vars = strlist__new(true, NULL);
1263 if (vl->vars == NULL)
1264 return -ENOMEM;
1265 af->child = true;
1266 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1267
1268 /* Find external variables */
1269 if (!af->externs)
1270 goto out;
1271 /* Don't need to search child DIE for externs. */
1272 af->child = false;
1273 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1274
1275 out:
1276 if (strlist__empty(vl->vars)) {
1277 strlist__delete(vl->vars);
1278 vl->vars = NULL;
1279 }
1280
1281 return ret;
1282 }
1283
1284 /* Find available variables at given probe point */
1285 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1286 struct perf_probe_event *pev,
1287 struct variable_list **vls,
1288 int max_vls, bool externs)
1289 {
1290 struct available_var_finder af = {
1291 .pf = {.pev = pev, .callback = add_available_vars},
1292 .mod = dbg->mod,
1293 .max_vls = max_vls, .externs = externs};
1294 int ret;
1295
1296 /* Allocate result vls array */
1297 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1298 if (*vls == NULL)
1299 return -ENOMEM;
1300
1301 af.vls = *vls;
1302 af.nvls = 0;
1303
1304 ret = debuginfo__find_probes(dbg, &af.pf);
1305 if (ret < 0) {
1306 /* Free vlist for error */
1307 while (af.nvls--) {
1308 zfree(&af.vls[af.nvls].point.symbol);
1309 strlist__delete(af.vls[af.nvls].vars);
1310 }
1311 zfree(vls);
1312 return ret;
1313 }
1314
1315 return (ret < 0) ? ret : af.nvls;
1316 }
1317
1318 /* Reverse search */
1319 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1320 struct perf_probe_point *ppt)
1321 {
1322 Dwarf_Die cudie, spdie, indie;
1323 Dwarf_Addr _addr = 0, baseaddr = 0;
1324 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1325 int baseline = 0, lineno = 0, ret = 0;
1326
1327 /* Adjust address with bias */
1328 addr += dbg->bias;
1329
1330 /* Find cu die */
1331 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
1332 pr_warning("Failed to find debug information for address %lx\n",
1333 addr);
1334 ret = -EINVAL;
1335 goto end;
1336 }
1337
1338 /* Find a corresponding line (filename and lineno) */
1339 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1340 /* Don't care whether it failed or not */
1341
1342 /* Find a corresponding function (name, baseline and baseaddr) */
1343 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1344 /* Get function entry information */
1345 func = basefunc = dwarf_diename(&spdie);
1346 if (!func ||
1347 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1348 dwarf_decl_line(&spdie, &baseline) != 0) {
1349 lineno = 0;
1350 goto post;
1351 }
1352
1353 fname = dwarf_decl_file(&spdie);
1354 if (addr == (unsigned long)baseaddr) {
1355 /* Function entry - Relative line number is 0 */
1356 lineno = baseline;
1357 goto post;
1358 }
1359
1360 /* Track down the inline functions step by step */
1361 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1362 &indie)) {
1363 /* There is an inline function */
1364 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1365 _addr == addr) {
1366 /*
1367 * addr is at an inline function entry.
1368 * In this case, lineno should be the call-site
1369 * line number. (overwrite lineinfo)
1370 */
1371 lineno = die_get_call_lineno(&indie);
1372 fname = die_get_call_file(&indie);
1373 break;
1374 } else {
1375 /*
1376 * addr is in an inline function body.
1377 * Since lineno points one of the lines
1378 * of the inline function, baseline should
1379 * be the entry line of the inline function.
1380 */
1381 tmp = dwarf_diename(&indie);
1382 if (!tmp ||
1383 dwarf_decl_line(&indie, &baseline) != 0)
1384 break;
1385 func = tmp;
1386 spdie = indie;
1387 }
1388 }
1389 /* Verify the lineno and baseline are in a same file */
1390 tmp = dwarf_decl_file(&spdie);
1391 if (!tmp || strcmp(tmp, fname) != 0)
1392 lineno = 0;
1393 }
1394
1395 post:
1396 /* Make a relative line number or an offset */
1397 if (lineno)
1398 ppt->line = lineno - baseline;
1399 else if (basefunc) {
1400 ppt->offset = addr - (unsigned long)baseaddr;
1401 func = basefunc;
1402 }
1403
1404 /* Duplicate strings */
1405 if (func) {
1406 ppt->function = strdup(func);
1407 if (ppt->function == NULL) {
1408 ret = -ENOMEM;
1409 goto end;
1410 }
1411 }
1412 if (fname) {
1413 ppt->file = strdup(fname);
1414 if (ppt->file == NULL) {
1415 zfree(&ppt->function);
1416 ret = -ENOMEM;
1417 goto end;
1418 }
1419 }
1420 end:
1421 if (ret == 0 && (fname || func))
1422 ret = 1; /* Found a point */
1423 return ret;
1424 }
1425
1426 /* Add a line and store the src path */
1427 static int line_range_add_line(const char *src, unsigned int lineno,
1428 struct line_range *lr)
1429 {
1430 /* Copy source path */
1431 if (!lr->path) {
1432 lr->path = strdup(src);
1433 if (lr->path == NULL)
1434 return -ENOMEM;
1435 }
1436 return intlist__add(lr->line_list, lineno);
1437 }
1438
1439 static int line_range_walk_cb(const char *fname, int lineno,
1440 Dwarf_Addr addr __maybe_unused,
1441 void *data)
1442 {
1443 struct line_finder *lf = data;
1444 int err;
1445
1446 if ((strtailcmp(fname, lf->fname) != 0) ||
1447 (lf->lno_s > lineno || lf->lno_e < lineno))
1448 return 0;
1449
1450 err = line_range_add_line(fname, lineno, lf->lr);
1451 if (err < 0 && err != -EEXIST)
1452 return err;
1453
1454 return 0;
1455 }
1456
1457 /* Find line range from its line number */
1458 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1459 {
1460 int ret;
1461
1462 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1463
1464 /* Update status */
1465 if (ret >= 0)
1466 if (!intlist__empty(lf->lr->line_list))
1467 ret = lf->found = 1;
1468 else
1469 ret = 0; /* Lines are not found */
1470 else {
1471 zfree(&lf->lr->path);
1472 }
1473 return ret;
1474 }
1475
1476 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1477 {
1478 int ret = find_line_range_by_line(in_die, data);
1479
1480 /*
1481 * We have to check all instances of inlined function, because
1482 * some execution paths can be optimized out depends on the
1483 * function argument of instances. However, if an error occurs,
1484 * it should be handled by the caller.
1485 */
1486 return ret < 0 ? ret : 0;
1487 }
1488
1489 /* Search function definition from function name */
1490 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1491 {
1492 struct dwarf_callback_param *param = data;
1493 struct line_finder *lf = param->data;
1494 struct line_range *lr = lf->lr;
1495
1496 /* Check declared file */
1497 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1498 return DWARF_CB_OK;
1499
1500 if (die_is_func_def(sp_die) &&
1501 die_compare_name(sp_die, lr->function)) {
1502 lf->fname = dwarf_decl_file(sp_die);
1503 dwarf_decl_line(sp_die, &lr->offset);
1504 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1505 lf->lno_s = lr->offset + lr->start;
1506 if (lf->lno_s < 0) /* Overflow */
1507 lf->lno_s = INT_MAX;
1508 lf->lno_e = lr->offset + lr->end;
1509 if (lf->lno_e < 0) /* Overflow */
1510 lf->lno_e = INT_MAX;
1511 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1512 lr->start = lf->lno_s;
1513 lr->end = lf->lno_e;
1514 if (dwarf_func_inline(sp_die))
1515 param->retval = die_walk_instances(sp_die,
1516 line_range_inline_cb, lf);
1517 else
1518 param->retval = find_line_range_by_line(sp_die, lf);
1519 return DWARF_CB_ABORT;
1520 }
1521 return DWARF_CB_OK;
1522 }
1523
1524 static int find_line_range_by_func(struct line_finder *lf)
1525 {
1526 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1527 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1528 return param.retval;
1529 }
1530
1531 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1532 {
1533 struct line_finder lf = {.lr = lr, .found = 0};
1534 int ret = 0;
1535 Dwarf_Off off = 0, noff;
1536 size_t cuhl;
1537 Dwarf_Die *diep;
1538 const char *comp_dir;
1539
1540 /* Fastpath: lookup by function name from .debug_pubnames section */
1541 if (lr->function) {
1542 struct pubname_callback_param pubname_param = {
1543 .function = lr->function, .file = lr->file,
1544 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1545 struct dwarf_callback_param line_range_param = {
1546 .data = (void *)&lf, .retval = 0};
1547
1548 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1549 &pubname_param, 0);
1550 if (pubname_param.found) {
1551 line_range_search_cb(&lf.sp_die, &line_range_param);
1552 if (lf.found)
1553 goto found;
1554 }
1555 }
1556
1557 /* Loop on CUs (Compilation Unit) */
1558 while (!lf.found && ret >= 0) {
1559 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1560 NULL, NULL, NULL) != 0)
1561 break;
1562
1563 /* Get the DIE(Debugging Information Entry) of this CU */
1564 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1565 if (!diep)
1566 continue;
1567
1568 /* Check if target file is included. */
1569 if (lr->file)
1570 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1571 else
1572 lf.fname = 0;
1573
1574 if (!lr->file || lf.fname) {
1575 if (lr->function)
1576 ret = find_line_range_by_func(&lf);
1577 else {
1578 lf.lno_s = lr->start;
1579 lf.lno_e = lr->end;
1580 ret = find_line_range_by_line(NULL, &lf);
1581 }
1582 }
1583 off = noff;
1584 }
1585
1586 found:
1587 /* Store comp_dir */
1588 if (lf.found) {
1589 comp_dir = cu_get_comp_dir(&lf.cu_die);
1590 if (comp_dir) {
1591 lr->comp_dir = strdup(comp_dir);
1592 if (!lr->comp_dir)
1593 ret = -ENOMEM;
1594 }
1595 }
1596
1597 pr_debug("path: %s\n", lr->path);
1598 return (ret < 0) ? ret : lf.found;
1599 }
1600
Linux kernel - Deliverables
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