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Merge 3.16-rc5 into char-misc-next
[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 || ret == -EINVAL)
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 (ret == 0 && 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 pr_warning("Failed to find '%s' in this function.\n",
577 pf->pvar->var);
578 ret = -ENOENT;
579 }
580 if (ret >= 0)
581 ret = convert_variable(&vr_die, pf);
582
583 return ret;
584 }
585
586 /* Convert subprogram DIE to trace point */
587 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
588 Dwarf_Addr paddr, bool retprobe,
589 struct probe_trace_point *tp)
590 {
591 Dwarf_Addr eaddr, highaddr;
592 GElf_Sym sym;
593 const char *symbol;
594
595 /* Verify the address is correct */
596 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
597 pr_warning("Failed to get entry address of %s\n",
598 dwarf_diename(sp_die));
599 return -ENOENT;
600 }
601 if (dwarf_highpc(sp_die, &highaddr) != 0) {
602 pr_warning("Failed to get end address of %s\n",
603 dwarf_diename(sp_die));
604 return -ENOENT;
605 }
606 if (paddr > highaddr) {
607 pr_warning("Offset specified is greater than size of %s\n",
608 dwarf_diename(sp_die));
609 return -EINVAL;
610 }
611
612 /* Get an appropriate symbol from symtab */
613 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
614 if (!symbol) {
615 pr_warning("Failed to find symbol at 0x%lx\n",
616 (unsigned long)paddr);
617 return -ENOENT;
618 }
619 tp->offset = (unsigned long)(paddr - sym.st_value);
620 tp->address = (unsigned long)paddr;
621 tp->symbol = strdup(symbol);
622 if (!tp->symbol)
623 return -ENOMEM;
624
625 /* Return probe must be on the head of a subprogram */
626 if (retprobe) {
627 if (eaddr != paddr) {
628 pr_warning("Return probe must be on the head of"
629 " a real function.\n");
630 return -EINVAL;
631 }
632 tp->retprobe = true;
633 }
634
635 return 0;
636 }
637
638 /* Call probe_finder callback with scope DIE */
639 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
640 {
641 Dwarf_Attribute fb_attr;
642 size_t nops;
643 int ret;
644
645 if (!sc_die) {
646 pr_err("Caller must pass a scope DIE. Program error.\n");
647 return -EINVAL;
648 }
649
650 /* If not a real subprogram, find a real one */
651 if (!die_is_func_def(sc_die)) {
652 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
653 pr_warning("Failed to find probe point in any "
654 "functions.\n");
655 return -ENOENT;
656 }
657 } else
658 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
659
660 /* Get the frame base attribute/ops from subprogram */
661 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
662 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
663 if (ret <= 0 || nops == 0) {
664 pf->fb_ops = NULL;
665 #if _ELFUTILS_PREREQ(0, 142)
666 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
667 pf->cfi != NULL) {
668 Dwarf_Frame *frame;
669 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
670 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
671 pr_warning("Failed to get call frame on 0x%jx\n",
672 (uintmax_t)pf->addr);
673 return -ENOENT;
674 }
675 #endif
676 }
677
678 /* Call finder's callback handler */
679 ret = pf->callback(sc_die, pf);
680
681 /* *pf->fb_ops will be cached in libdw. Don't free it. */
682 pf->fb_ops = NULL;
683
684 return ret;
685 }
686
687 struct find_scope_param {
688 const char *function;
689 const char *file;
690 int line;
691 int diff;
692 Dwarf_Die *die_mem;
693 bool found;
694 };
695
696 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
697 {
698 struct find_scope_param *fsp = data;
699 const char *file;
700 int lno;
701
702 /* Skip if declared file name does not match */
703 if (fsp->file) {
704 file = dwarf_decl_file(fn_die);
705 if (!file || strcmp(fsp->file, file) != 0)
706 return 0;
707 }
708 /* If the function name is given, that's what user expects */
709 if (fsp->function) {
710 if (die_compare_name(fn_die, fsp->function)) {
711 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
712 fsp->found = true;
713 return 1;
714 }
715 } else {
716 /* With the line number, find the nearest declared DIE */
717 dwarf_decl_line(fn_die, &lno);
718 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
719 /* Keep a candidate and continue */
720 fsp->diff = fsp->line - lno;
721 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
722 fsp->found = true;
723 }
724 }
725 return 0;
726 }
727
728 /* Find an appropriate scope fits to given conditions */
729 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
730 {
731 struct find_scope_param fsp = {
732 .function = pf->pev->point.function,
733 .file = pf->fname,
734 .line = pf->lno,
735 .diff = INT_MAX,
736 .die_mem = die_mem,
737 .found = false,
738 };
739
740 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
741
742 return fsp.found ? die_mem : NULL;
743 }
744
745 static int probe_point_line_walker(const char *fname, int lineno,
746 Dwarf_Addr addr, void *data)
747 {
748 struct probe_finder *pf = data;
749 Dwarf_Die *sc_die, die_mem;
750 int ret;
751
752 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
753 return 0;
754
755 pf->addr = addr;
756 sc_die = find_best_scope(pf, &die_mem);
757 if (!sc_die) {
758 pr_warning("Failed to find scope of probe point.\n");
759 return -ENOENT;
760 }
761
762 ret = call_probe_finder(sc_die, pf);
763
764 /* Continue if no error, because the line will be in inline function */
765 return ret < 0 ? ret : 0;
766 }
767
768 /* Find probe point from its line number */
769 static int find_probe_point_by_line(struct probe_finder *pf)
770 {
771 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
772 }
773
774 /* Find lines which match lazy pattern */
775 static int find_lazy_match_lines(struct intlist *list,
776 const char *fname, const char *pat)
777 {
778 FILE *fp;
779 char *line = NULL;
780 size_t line_len;
781 ssize_t len;
782 int count = 0, linenum = 1;
783
784 fp = fopen(fname, "r");
785 if (!fp) {
786 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
787 return -errno;
788 }
789
790 while ((len = getline(&line, &line_len, fp)) > 0) {
791
792 if (line[len - 1] == '\n')
793 line[len - 1] = '\0';
794
795 if (strlazymatch(line, pat)) {
796 intlist__add(list, linenum);
797 count++;
798 }
799 linenum++;
800 }
801
802 if (ferror(fp))
803 count = -errno;
804 free(line);
805 fclose(fp);
806
807 if (count == 0)
808 pr_debug("No matched lines found in %s.\n", fname);
809 return count;
810 }
811
812 static int probe_point_lazy_walker(const char *fname, int lineno,
813 Dwarf_Addr addr, void *data)
814 {
815 struct probe_finder *pf = data;
816 Dwarf_Die *sc_die, die_mem;
817 int ret;
818
819 if (!intlist__has_entry(pf->lcache, lineno) ||
820 strtailcmp(fname, pf->fname) != 0)
821 return 0;
822
823 pr_debug("Probe line found: line:%d addr:0x%llx\n",
824 lineno, (unsigned long long)addr);
825 pf->addr = addr;
826 pf->lno = lineno;
827 sc_die = find_best_scope(pf, &die_mem);
828 if (!sc_die) {
829 pr_warning("Failed to find scope of probe point.\n");
830 return -ENOENT;
831 }
832
833 ret = call_probe_finder(sc_die, pf);
834
835 /*
836 * Continue if no error, because the lazy pattern will match
837 * to other lines
838 */
839 return ret < 0 ? ret : 0;
840 }
841
842 /* Find probe points from lazy pattern */
843 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
844 {
845 int ret = 0;
846
847 if (intlist__empty(pf->lcache)) {
848 /* Matching lazy line pattern */
849 ret = find_lazy_match_lines(pf->lcache, pf->fname,
850 pf->pev->point.lazy_line);
851 if (ret <= 0)
852 return ret;
853 }
854
855 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
856 }
857
858 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
859 {
860 struct probe_finder *pf = data;
861 struct perf_probe_point *pp = &pf->pev->point;
862 Dwarf_Addr addr;
863 int ret;
864
865 if (pp->lazy_line)
866 ret = find_probe_point_lazy(in_die, pf);
867 else {
868 /* Get probe address */
869 if (dwarf_entrypc(in_die, &addr) != 0) {
870 pr_warning("Failed to get entry address of %s.\n",
871 dwarf_diename(in_die));
872 return -ENOENT;
873 }
874 pf->addr = addr;
875 pf->addr += pp->offset;
876 pr_debug("found inline addr: 0x%jx\n",
877 (uintmax_t)pf->addr);
878
879 ret = call_probe_finder(in_die, pf);
880 }
881
882 return ret;
883 }
884
885 /* Callback parameter with return value for libdw */
886 struct dwarf_callback_param {
887 void *data;
888 int retval;
889 };
890
891 /* Search function from function name */
892 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
893 {
894 struct dwarf_callback_param *param = data;
895 struct probe_finder *pf = param->data;
896 struct perf_probe_point *pp = &pf->pev->point;
897
898 /* Check tag and diename */
899 if (!die_is_func_def(sp_die) ||
900 !die_compare_name(sp_die, pp->function))
901 return DWARF_CB_OK;
902
903 /* Check declared file */
904 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
905 return DWARF_CB_OK;
906
907 pf->fname = dwarf_decl_file(sp_die);
908 if (pp->line) { /* Function relative line */
909 dwarf_decl_line(sp_die, &pf->lno);
910 pf->lno += pp->line;
911 param->retval = find_probe_point_by_line(pf);
912 } else if (!dwarf_func_inline(sp_die)) {
913 /* Real function */
914 if (pp->lazy_line)
915 param->retval = find_probe_point_lazy(sp_die, pf);
916 else {
917 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
918 pr_warning("Failed to get entry address of "
919 "%s.\n", dwarf_diename(sp_die));
920 param->retval = -ENOENT;
921 return DWARF_CB_ABORT;
922 }
923 pf->addr += pp->offset;
924 /* TODO: Check the address in this function */
925 param->retval = call_probe_finder(sp_die, pf);
926 }
927 } else
928 /* Inlined function: search instances */
929 param->retval = die_walk_instances(sp_die,
930 probe_point_inline_cb, (void *)pf);
931
932 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
933 }
934
935 static int find_probe_point_by_func(struct probe_finder *pf)
936 {
937 struct dwarf_callback_param _param = {.data = (void *)pf,
938 .retval = 0};
939 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
940 return _param.retval;
941 }
942
943 struct pubname_callback_param {
944 char *function;
945 char *file;
946 Dwarf_Die *cu_die;
947 Dwarf_Die *sp_die;
948 int found;
949 };
950
951 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
952 {
953 struct pubname_callback_param *param = data;
954
955 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
956 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
957 return DWARF_CB_OK;
958
959 if (die_compare_name(param->sp_die, param->function)) {
960 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
961 return DWARF_CB_OK;
962
963 if (param->file &&
964 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
965 return DWARF_CB_OK;
966
967 param->found = 1;
968 return DWARF_CB_ABORT;
969 }
970 }
971
972 return DWARF_CB_OK;
973 }
974
975 /* Find probe points from debuginfo */
976 static int debuginfo__find_probes(struct debuginfo *dbg,
977 struct probe_finder *pf)
978 {
979 struct perf_probe_point *pp = &pf->pev->point;
980 Dwarf_Off off, noff;
981 size_t cuhl;
982 Dwarf_Die *diep;
983 int ret = 0;
984
985 #if _ELFUTILS_PREREQ(0, 142)
986 /* Get the call frame information from this dwarf */
987 pf->cfi = dwarf_getcfi_elf(dwarf_getelf(dbg->dbg));
988 #endif
989
990 off = 0;
991 pf->lcache = intlist__new(NULL);
992 if (!pf->lcache)
993 return -ENOMEM;
994
995 /* Fastpath: lookup by function name from .debug_pubnames section */
996 if (pp->function) {
997 struct pubname_callback_param pubname_param = {
998 .function = pp->function,
999 .file = pp->file,
1000 .cu_die = &pf->cu_die,
1001 .sp_die = &pf->sp_die,
1002 .found = 0,
1003 };
1004 struct dwarf_callback_param probe_param = {
1005 .data = pf,
1006 };
1007
1008 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1009 &pubname_param, 0);
1010 if (pubname_param.found) {
1011 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1012 if (ret)
1013 goto found;
1014 }
1015 }
1016
1017 /* Loop on CUs (Compilation Unit) */
1018 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1019 /* Get the DIE(Debugging Information Entry) of this CU */
1020 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1021 if (!diep)
1022 continue;
1023
1024 /* Check if target file is included. */
1025 if (pp->file)
1026 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1027 else
1028 pf->fname = NULL;
1029
1030 if (!pp->file || pf->fname) {
1031 if (pp->function)
1032 ret = find_probe_point_by_func(pf);
1033 else if (pp->lazy_line)
1034 ret = find_probe_point_lazy(NULL, pf);
1035 else {
1036 pf->lno = pp->line;
1037 ret = find_probe_point_by_line(pf);
1038 }
1039 if (ret < 0)
1040 break;
1041 }
1042 off = noff;
1043 }
1044
1045 found:
1046 intlist__delete(pf->lcache);
1047 pf->lcache = NULL;
1048
1049 return ret;
1050 }
1051
1052 struct local_vars_finder {
1053 struct probe_finder *pf;
1054 struct perf_probe_arg *args;
1055 int max_args;
1056 int nargs;
1057 int ret;
1058 };
1059
1060 /* Collect available variables in this scope */
1061 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1062 {
1063 struct local_vars_finder *vf = data;
1064 struct probe_finder *pf = vf->pf;
1065 int tag;
1066
1067 tag = dwarf_tag(die_mem);
1068 if (tag == DW_TAG_formal_parameter ||
1069 tag == DW_TAG_variable) {
1070 if (convert_variable_location(die_mem, vf->pf->addr,
1071 vf->pf->fb_ops, &pf->sp_die,
1072 NULL) == 0) {
1073 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1074 if (vf->args[vf->nargs].var == NULL) {
1075 vf->ret = -ENOMEM;
1076 return DIE_FIND_CB_END;
1077 }
1078 pr_debug(" %s", vf->args[vf->nargs].var);
1079 vf->nargs++;
1080 }
1081 }
1082
1083 if (dwarf_haspc(die_mem, vf->pf->addr))
1084 return DIE_FIND_CB_CONTINUE;
1085 else
1086 return DIE_FIND_CB_SIBLING;
1087 }
1088
1089 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1090 struct perf_probe_arg *args)
1091 {
1092 Dwarf_Die die_mem;
1093 int i;
1094 int n = 0;
1095 struct local_vars_finder vf = {.pf = pf, .args = args,
1096 .max_args = MAX_PROBE_ARGS, .ret = 0};
1097
1098 for (i = 0; i < pf->pev->nargs; i++) {
1099 /* var never be NULL */
1100 if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
1101 pr_debug("Expanding $vars into:");
1102 vf.nargs = n;
1103 /* Special local variables */
1104 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1105 &die_mem);
1106 pr_debug(" (%d)\n", vf.nargs - n);
1107 if (vf.ret < 0)
1108 return vf.ret;
1109 n = vf.nargs;
1110 } else {
1111 /* Copy normal argument */
1112 args[n] = pf->pev->args[i];
1113 n++;
1114 }
1115 }
1116 return n;
1117 }
1118
1119 /* Add a found probe point into trace event list */
1120 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1121 {
1122 struct trace_event_finder *tf =
1123 container_of(pf, struct trace_event_finder, pf);
1124 struct probe_trace_event *tev;
1125 struct perf_probe_arg *args;
1126 int ret, i;
1127
1128 /* Check number of tevs */
1129 if (tf->ntevs == tf->max_tevs) {
1130 pr_warning("Too many( > %d) probe point found.\n",
1131 tf->max_tevs);
1132 return -ERANGE;
1133 }
1134 tev = &tf->tevs[tf->ntevs++];
1135
1136 /* Trace point should be converted from subprogram DIE */
1137 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1138 pf->pev->point.retprobe, &tev->point);
1139 if (ret < 0)
1140 return ret;
1141
1142 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1143 tev->point.offset);
1144
1145 /* Expand special probe argument if exist */
1146 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1147 if (args == NULL)
1148 return -ENOMEM;
1149
1150 ret = expand_probe_args(sc_die, pf, args);
1151 if (ret < 0)
1152 goto end;
1153
1154 tev->nargs = ret;
1155 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1156 if (tev->args == NULL) {
1157 ret = -ENOMEM;
1158 goto end;
1159 }
1160
1161 /* Find each argument */
1162 for (i = 0; i < tev->nargs; i++) {
1163 pf->pvar = &args[i];
1164 pf->tvar = &tev->args[i];
1165 /* Variable should be found from scope DIE */
1166 ret = find_variable(sc_die, pf);
1167 if (ret != 0)
1168 break;
1169 }
1170
1171 end:
1172 free(args);
1173 return ret;
1174 }
1175
1176 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1177 int debuginfo__find_trace_events(struct debuginfo *dbg,
1178 struct perf_probe_event *pev,
1179 struct probe_trace_event **tevs, int max_tevs)
1180 {
1181 struct trace_event_finder tf = {
1182 .pf = {.pev = pev, .callback = add_probe_trace_event},
1183 .mod = dbg->mod, .max_tevs = max_tevs};
1184 int ret;
1185
1186 /* Allocate result tevs array */
1187 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1188 if (*tevs == NULL)
1189 return -ENOMEM;
1190
1191 tf.tevs = *tevs;
1192 tf.ntevs = 0;
1193
1194 ret = debuginfo__find_probes(dbg, &tf.pf);
1195 if (ret < 0) {
1196 zfree(tevs);
1197 return ret;
1198 }
1199
1200 return (ret < 0) ? ret : tf.ntevs;
1201 }
1202
1203 #define MAX_VAR_LEN 64
1204
1205 /* Collect available variables in this scope */
1206 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1207 {
1208 struct available_var_finder *af = data;
1209 struct variable_list *vl;
1210 char buf[MAX_VAR_LEN];
1211 int tag, ret;
1212
1213 vl = &af->vls[af->nvls - 1];
1214
1215 tag = dwarf_tag(die_mem);
1216 if (tag == DW_TAG_formal_parameter ||
1217 tag == DW_TAG_variable) {
1218 ret = convert_variable_location(die_mem, af->pf.addr,
1219 af->pf.fb_ops, &af->pf.sp_die,
1220 NULL);
1221 if (ret == 0) {
1222 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1223 pr_debug2("Add new var: %s\n", buf);
1224 if (ret > 0)
1225 strlist__add(vl->vars, buf);
1226 }
1227 }
1228
1229 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1230 return DIE_FIND_CB_CONTINUE;
1231 else
1232 return DIE_FIND_CB_SIBLING;
1233 }
1234
1235 /* Add a found vars into available variables list */
1236 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1237 {
1238 struct available_var_finder *af =
1239 container_of(pf, struct available_var_finder, pf);
1240 struct variable_list *vl;
1241 Dwarf_Die die_mem;
1242 int ret;
1243
1244 /* Check number of tevs */
1245 if (af->nvls == af->max_vls) {
1246 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1247 return -ERANGE;
1248 }
1249 vl = &af->vls[af->nvls++];
1250
1251 /* Trace point should be converted from subprogram DIE */
1252 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1253 pf->pev->point.retprobe, &vl->point);
1254 if (ret < 0)
1255 return ret;
1256
1257 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1258 vl->point.offset);
1259
1260 /* Find local variables */
1261 vl->vars = strlist__new(true, NULL);
1262 if (vl->vars == NULL)
1263 return -ENOMEM;
1264 af->child = true;
1265 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1266
1267 /* Find external variables */
1268 if (!af->externs)
1269 goto out;
1270 /* Don't need to search child DIE for externs. */
1271 af->child = false;
1272 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1273
1274 out:
1275 if (strlist__empty(vl->vars)) {
1276 strlist__delete(vl->vars);
1277 vl->vars = NULL;
1278 }
1279
1280 return ret;
1281 }
1282
1283 /*
1284 * Find available variables at given probe point
1285 * Return the number of found probe points. Return 0 if there is no
1286 * matched probe point. Return <0 if an error occurs.
1287 */
1288 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1289 struct perf_probe_event *pev,
1290 struct variable_list **vls,
1291 int max_vls, bool externs)
1292 {
1293 struct available_var_finder af = {
1294 .pf = {.pev = pev, .callback = add_available_vars},
1295 .mod = dbg->mod,
1296 .max_vls = max_vls, .externs = externs};
1297 int ret;
1298
1299 /* Allocate result vls array */
1300 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1301 if (*vls == NULL)
1302 return -ENOMEM;
1303
1304 af.vls = *vls;
1305 af.nvls = 0;
1306
1307 ret = debuginfo__find_probes(dbg, &af.pf);
1308 if (ret < 0) {
1309 /* Free vlist for error */
1310 while (af.nvls--) {
1311 zfree(&af.vls[af.nvls].point.symbol);
1312 strlist__delete(af.vls[af.nvls].vars);
1313 }
1314 zfree(vls);
1315 return ret;
1316 }
1317
1318 return (ret < 0) ? ret : af.nvls;
1319 }
1320
1321 /* Reverse search */
1322 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1323 struct perf_probe_point *ppt)
1324 {
1325 Dwarf_Die cudie, spdie, indie;
1326 Dwarf_Addr _addr = 0, baseaddr = 0;
1327 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1328 int baseline = 0, lineno = 0, ret = 0;
1329
1330 /* Adjust address with bias */
1331 addr += dbg->bias;
1332
1333 /* Find cu die */
1334 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
1335 pr_warning("Failed to find debug information for address %lx\n",
1336 addr);
1337 ret = -EINVAL;
1338 goto end;
1339 }
1340
1341 /* Find a corresponding line (filename and lineno) */
1342 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1343 /* Don't care whether it failed or not */
1344
1345 /* Find a corresponding function (name, baseline and baseaddr) */
1346 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1347 /* Get function entry information */
1348 func = basefunc = dwarf_diename(&spdie);
1349 if (!func ||
1350 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1351 dwarf_decl_line(&spdie, &baseline) != 0) {
1352 lineno = 0;
1353 goto post;
1354 }
1355
1356 fname = dwarf_decl_file(&spdie);
1357 if (addr == (unsigned long)baseaddr) {
1358 /* Function entry - Relative line number is 0 */
1359 lineno = baseline;
1360 goto post;
1361 }
1362
1363 /* Track down the inline functions step by step */
1364 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1365 &indie)) {
1366 /* There is an inline function */
1367 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1368 _addr == addr) {
1369 /*
1370 * addr is at an inline function entry.
1371 * In this case, lineno should be the call-site
1372 * line number. (overwrite lineinfo)
1373 */
1374 lineno = die_get_call_lineno(&indie);
1375 fname = die_get_call_file(&indie);
1376 break;
1377 } else {
1378 /*
1379 * addr is in an inline function body.
1380 * Since lineno points one of the lines
1381 * of the inline function, baseline should
1382 * be the entry line of the inline function.
1383 */
1384 tmp = dwarf_diename(&indie);
1385 if (!tmp ||
1386 dwarf_decl_line(&indie, &baseline) != 0)
1387 break;
1388 func = tmp;
1389 spdie = indie;
1390 }
1391 }
1392 /* Verify the lineno and baseline are in a same file */
1393 tmp = dwarf_decl_file(&spdie);
1394 if (!tmp || strcmp(tmp, fname) != 0)
1395 lineno = 0;
1396 }
1397
1398 post:
1399 /* Make a relative line number or an offset */
1400 if (lineno)
1401 ppt->line = lineno - baseline;
1402 else if (basefunc) {
1403 ppt->offset = addr - (unsigned long)baseaddr;
1404 func = basefunc;
1405 }
1406
1407 /* Duplicate strings */
1408 if (func) {
1409 ppt->function = strdup(func);
1410 if (ppt->function == NULL) {
1411 ret = -ENOMEM;
1412 goto end;
1413 }
1414 }
1415 if (fname) {
1416 ppt->file = strdup(fname);
1417 if (ppt->file == NULL) {
1418 zfree(&ppt->function);
1419 ret = -ENOMEM;
1420 goto end;
1421 }
1422 }
1423 end:
1424 if (ret == 0 && (fname || func))
1425 ret = 1; /* Found a point */
1426 return ret;
1427 }
1428
1429 /* Add a line and store the src path */
1430 static int line_range_add_line(const char *src, unsigned int lineno,
1431 struct line_range *lr)
1432 {
1433 /* Copy source path */
1434 if (!lr->path) {
1435 lr->path = strdup(src);
1436 if (lr->path == NULL)
1437 return -ENOMEM;
1438 }
1439 return intlist__add(lr->line_list, lineno);
1440 }
1441
1442 static int line_range_walk_cb(const char *fname, int lineno,
1443 Dwarf_Addr addr __maybe_unused,
1444 void *data)
1445 {
1446 struct line_finder *lf = data;
1447 int err;
1448
1449 if ((strtailcmp(fname, lf->fname) != 0) ||
1450 (lf->lno_s > lineno || lf->lno_e < lineno))
1451 return 0;
1452
1453 err = line_range_add_line(fname, lineno, lf->lr);
1454 if (err < 0 && err != -EEXIST)
1455 return err;
1456
1457 return 0;
1458 }
1459
1460 /* Find line range from its line number */
1461 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1462 {
1463 int ret;
1464
1465 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1466
1467 /* Update status */
1468 if (ret >= 0)
1469 if (!intlist__empty(lf->lr->line_list))
1470 ret = lf->found = 1;
1471 else
1472 ret = 0; /* Lines are not found */
1473 else {
1474 zfree(&lf->lr->path);
1475 }
1476 return ret;
1477 }
1478
1479 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1480 {
1481 int ret = find_line_range_by_line(in_die, data);
1482
1483 /*
1484 * We have to check all instances of inlined function, because
1485 * some execution paths can be optimized out depends on the
1486 * function argument of instances. However, if an error occurs,
1487 * it should be handled by the caller.
1488 */
1489 return ret < 0 ? ret : 0;
1490 }
1491
1492 /* Search function definition from function name */
1493 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1494 {
1495 struct dwarf_callback_param *param = data;
1496 struct line_finder *lf = param->data;
1497 struct line_range *lr = lf->lr;
1498
1499 /* Check declared file */
1500 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1501 return DWARF_CB_OK;
1502
1503 if (die_is_func_def(sp_die) &&
1504 die_compare_name(sp_die, lr->function)) {
1505 lf->fname = dwarf_decl_file(sp_die);
1506 dwarf_decl_line(sp_die, &lr->offset);
1507 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1508 lf->lno_s = lr->offset + lr->start;
1509 if (lf->lno_s < 0) /* Overflow */
1510 lf->lno_s = INT_MAX;
1511 lf->lno_e = lr->offset + lr->end;
1512 if (lf->lno_e < 0) /* Overflow */
1513 lf->lno_e = INT_MAX;
1514 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1515 lr->start = lf->lno_s;
1516 lr->end = lf->lno_e;
1517 if (dwarf_func_inline(sp_die))
1518 param->retval = die_walk_instances(sp_die,
1519 line_range_inline_cb, lf);
1520 else
1521 param->retval = find_line_range_by_line(sp_die, lf);
1522 return DWARF_CB_ABORT;
1523 }
1524 return DWARF_CB_OK;
1525 }
1526
1527 static int find_line_range_by_func(struct line_finder *lf)
1528 {
1529 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1530 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1531 return param.retval;
1532 }
1533
1534 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1535 {
1536 struct line_finder lf = {.lr = lr, .found = 0};
1537 int ret = 0;
1538 Dwarf_Off off = 0, noff;
1539 size_t cuhl;
1540 Dwarf_Die *diep;
1541 const char *comp_dir;
1542
1543 /* Fastpath: lookup by function name from .debug_pubnames section */
1544 if (lr->function) {
1545 struct pubname_callback_param pubname_param = {
1546 .function = lr->function, .file = lr->file,
1547 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1548 struct dwarf_callback_param line_range_param = {
1549 .data = (void *)&lf, .retval = 0};
1550
1551 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1552 &pubname_param, 0);
1553 if (pubname_param.found) {
1554 line_range_search_cb(&lf.sp_die, &line_range_param);
1555 if (lf.found)
1556 goto found;
1557 }
1558 }
1559
1560 /* Loop on CUs (Compilation Unit) */
1561 while (!lf.found && ret >= 0) {
1562 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1563 NULL, NULL, NULL) != 0)
1564 break;
1565
1566 /* Get the DIE(Debugging Information Entry) of this CU */
1567 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1568 if (!diep)
1569 continue;
1570
1571 /* Check if target file is included. */
1572 if (lr->file)
1573 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1574 else
1575 lf.fname = 0;
1576
1577 if (!lr->file || lf.fname) {
1578 if (lr->function)
1579 ret = find_line_range_by_func(&lf);
1580 else {
1581 lf.lno_s = lr->start;
1582 lf.lno_e = lr->end;
1583 ret = find_line_range_by_line(NULL, &lf);
1584 }
1585 }
1586 off = noff;
1587 }
1588
1589 found:
1590 /* Store comp_dir */
1591 if (lf.found) {
1592 comp_dir = cu_get_comp_dir(&lf.cu_die);
1593 if (comp_dir) {
1594 lr->comp_dir = strdup(comp_dir);
1595 if (!lr->comp_dir)
1596 ret = -ENOMEM;
1597 }
1598 }
1599
1600 pr_debug("path: %s\n", lr->path);
1601 return (ret < 0) ? ret : lf.found;
1602 }
1603
Linux kernel - Deliverables
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