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perf tests: Fix map_groups refcount test
[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 <stdlib.h>
30 #include <string.h>
31 #include <stdarg.h>
32 #include <dwarf-regs.h>
33
34 #include <linux/bitops.h>
35 #include "event.h"
36 #include "dso.h"
37 #include "debug.h"
38 #include "intlist.h"
39 #include "util.h"
40 #include "symbol.h"
41 #include "probe-finder.h"
42
43 /* Kprobe tracer basic type is up to u64 */
44 #define MAX_BASIC_TYPE_BITS 64
45
46 /* Dwarf FL wrappers */
47 static char *debuginfo_path; /* Currently dummy */
48
49 static const Dwfl_Callbacks offline_callbacks = {
50 .find_debuginfo = dwfl_standard_find_debuginfo,
51 .debuginfo_path = &debuginfo_path,
52
53 .section_address = dwfl_offline_section_address,
54
55 /* We use this table for core files too. */
56 .find_elf = dwfl_build_id_find_elf,
57 };
58
59 /* Get a Dwarf from offline image */
60 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
61 const char *path)
62 {
63 int fd;
64
65 fd = open(path, O_RDONLY);
66 if (fd < 0)
67 return fd;
68
69 dbg->dwfl = dwfl_begin(&offline_callbacks);
70 if (!dbg->dwfl)
71 goto error;
72
73 dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
74 if (!dbg->mod)
75 goto error;
76
77 dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
78 if (!dbg->dbg)
79 goto error;
80
81 return 0;
82 error:
83 if (dbg->dwfl)
84 dwfl_end(dbg->dwfl);
85 else
86 close(fd);
87 memset(dbg, 0, sizeof(*dbg));
88
89 return -ENOENT;
90 }
91
92 static struct debuginfo *__debuginfo__new(const char *path)
93 {
94 struct debuginfo *dbg = zalloc(sizeof(*dbg));
95 if (!dbg)
96 return NULL;
97
98 if (debuginfo__init_offline_dwarf(dbg, path) < 0)
99 zfree(&dbg);
100 if (dbg)
101 pr_debug("Open Debuginfo file: %s\n", path);
102 return dbg;
103 }
104
105 enum dso_binary_type distro_dwarf_types[] = {
106 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
107 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
108 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
109 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
110 DSO_BINARY_TYPE__NOT_FOUND,
111 };
112
113 struct debuginfo *debuginfo__new(const char *path)
114 {
115 enum dso_binary_type *type;
116 char buf[PATH_MAX], nil = '\0';
117 struct dso *dso;
118 struct debuginfo *dinfo = NULL;
119
120 /* Try to open distro debuginfo files */
121 dso = dso__new(path);
122 if (!dso)
123 goto out;
124
125 for (type = distro_dwarf_types;
126 !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
127 type++) {
128 if (dso__read_binary_type_filename(dso, *type, &nil,
129 buf, PATH_MAX) < 0)
130 continue;
131 dinfo = __debuginfo__new(buf);
132 }
133 dso__delete(dso);
134
135 out:
136 /* if failed to open all distro debuginfo, open given binary */
137 return dinfo ? : __debuginfo__new(path);
138 }
139
140 void debuginfo__delete(struct debuginfo *dbg)
141 {
142 if (dbg) {
143 if (dbg->dwfl)
144 dwfl_end(dbg->dwfl);
145 free(dbg);
146 }
147 }
148
149 /*
150 * Probe finder related functions
151 */
152
153 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
154 {
155 struct probe_trace_arg_ref *ref;
156 ref = zalloc(sizeof(struct probe_trace_arg_ref));
157 if (ref != NULL)
158 ref->offset = offs;
159 return ref;
160 }
161
162 /*
163 * Convert a location into trace_arg.
164 * If tvar == NULL, this just checks variable can be converted.
165 * If fentry == true and vr_die is a parameter, do huristic search
166 * for the location fuzzed by function entry mcount.
167 */
168 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
169 Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
170 struct probe_trace_arg *tvar)
171 {
172 Dwarf_Attribute attr;
173 Dwarf_Addr tmp = 0;
174 Dwarf_Op *op;
175 size_t nops;
176 unsigned int regn;
177 Dwarf_Word offs = 0;
178 bool ref = false;
179 const char *regs;
180 int ret, ret2 = 0;
181
182 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
183 goto static_var;
184
185 /* TODO: handle more than 1 exprs */
186 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
187 return -EINVAL; /* Broken DIE ? */
188 if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
189 ret = dwarf_entrypc(sp_die, &tmp);
190 if (ret)
191 return -ENOENT;
192
193 if (probe_conf.show_location_range &&
194 (dwarf_tag(vr_die) == DW_TAG_variable)) {
195 ret2 = -ERANGE;
196 } else if (addr != tmp ||
197 dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
198 return -ENOENT;
199 }
200
201 ret = dwarf_highpc(sp_die, &tmp);
202 if (ret)
203 return -ENOENT;
204 /*
205 * This is fuzzed by fentry mcount. We try to find the
206 * parameter location at the earliest address.
207 */
208 for (addr += 1; addr <= tmp; addr++) {
209 if (dwarf_getlocation_addr(&attr, addr, &op,
210 &nops, 1) > 0)
211 goto found;
212 }
213 return -ENOENT;
214 }
215 found:
216 if (nops == 0)
217 /* TODO: Support const_value */
218 return -ENOENT;
219
220 if (op->atom == DW_OP_addr) {
221 static_var:
222 if (!tvar)
223 return ret2;
224 /* Static variables on memory (not stack), make @varname */
225 ret = strlen(dwarf_diename(vr_die));
226 tvar->value = zalloc(ret + 2);
227 if (tvar->value == NULL)
228 return -ENOMEM;
229 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
230 tvar->ref = alloc_trace_arg_ref((long)offs);
231 if (tvar->ref == NULL)
232 return -ENOMEM;
233 return ret2;
234 }
235
236 /* If this is based on frame buffer, set the offset */
237 if (op->atom == DW_OP_fbreg) {
238 if (fb_ops == NULL)
239 return -ENOTSUP;
240 ref = true;
241 offs = op->number;
242 op = &fb_ops[0];
243 }
244
245 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
246 regn = op->atom - DW_OP_breg0;
247 offs += op->number;
248 ref = true;
249 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
250 regn = op->atom - DW_OP_reg0;
251 } else if (op->atom == DW_OP_bregx) {
252 regn = op->number;
253 offs += op->number2;
254 ref = true;
255 } else if (op->atom == DW_OP_regx) {
256 regn = op->number;
257 } else {
258 pr_debug("DW_OP %x is not supported.\n", op->atom);
259 return -ENOTSUP;
260 }
261
262 if (!tvar)
263 return ret2;
264
265 regs = get_arch_regstr(regn);
266 if (!regs) {
267 /* This should be a bug in DWARF or this tool */
268 pr_warning("Mapping for the register number %u "
269 "missing on this architecture.\n", regn);
270 return -ENOTSUP;
271 }
272
273 tvar->value = strdup(regs);
274 if (tvar->value == NULL)
275 return -ENOMEM;
276
277 if (ref) {
278 tvar->ref = alloc_trace_arg_ref((long)offs);
279 if (tvar->ref == NULL)
280 return -ENOMEM;
281 }
282 return ret2;
283 }
284
285 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
286
287 static int convert_variable_type(Dwarf_Die *vr_die,
288 struct probe_trace_arg *tvar,
289 const char *cast)
290 {
291 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
292 Dwarf_Die type;
293 char buf[16];
294 char sbuf[STRERR_BUFSIZE];
295 int bsize, boffs, total;
296 int ret;
297
298 /* TODO: check all types */
299 if (cast && strcmp(cast, "string") != 0) {
300 /* Non string type is OK */
301 tvar->type = strdup(cast);
302 return (tvar->type == NULL) ? -ENOMEM : 0;
303 }
304
305 bsize = dwarf_bitsize(vr_die);
306 if (bsize > 0) {
307 /* This is a bitfield */
308 boffs = dwarf_bitoffset(vr_die);
309 total = dwarf_bytesize(vr_die);
310 if (boffs < 0 || total < 0)
311 return -ENOENT;
312 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
313 BYTES_TO_BITS(total));
314 goto formatted;
315 }
316
317 if (die_get_real_type(vr_die, &type) == NULL) {
318 pr_warning("Failed to get a type information of %s.\n",
319 dwarf_diename(vr_die));
320 return -ENOENT;
321 }
322
323 pr_debug("%s type is %s.\n",
324 dwarf_diename(vr_die), dwarf_diename(&type));
325
326 if (cast && strcmp(cast, "string") == 0) { /* String type */
327 ret = dwarf_tag(&type);
328 if (ret != DW_TAG_pointer_type &&
329 ret != DW_TAG_array_type) {
330 pr_warning("Failed to cast into string: "
331 "%s(%s) is not a pointer nor array.\n",
332 dwarf_diename(vr_die), dwarf_diename(&type));
333 return -EINVAL;
334 }
335 if (die_get_real_type(&type, &type) == NULL) {
336 pr_warning("Failed to get a type"
337 " information.\n");
338 return -ENOENT;
339 }
340 if (ret == DW_TAG_pointer_type) {
341 while (*ref_ptr)
342 ref_ptr = &(*ref_ptr)->next;
343 /* Add new reference with offset +0 */
344 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
345 if (*ref_ptr == NULL) {
346 pr_warning("Out of memory error\n");
347 return -ENOMEM;
348 }
349 }
350 if (!die_compare_name(&type, "char") &&
351 !die_compare_name(&type, "unsigned char")) {
352 pr_warning("Failed to cast into string: "
353 "%s is not (unsigned) char *.\n",
354 dwarf_diename(vr_die));
355 return -EINVAL;
356 }
357 tvar->type = strdup(cast);
358 return (tvar->type == NULL) ? -ENOMEM : 0;
359 }
360
361 ret = dwarf_bytesize(&type);
362 if (ret <= 0)
363 /* No size ... try to use default type */
364 return 0;
365 ret = BYTES_TO_BITS(ret);
366
367 /* Check the bitwidth */
368 if (ret > MAX_BASIC_TYPE_BITS) {
369 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
370 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
371 ret = MAX_BASIC_TYPE_BITS;
372 }
373 ret = snprintf(buf, 16, "%c%d",
374 die_is_signed_type(&type) ? 's' : 'u', ret);
375
376 formatted:
377 if (ret < 0 || ret >= 16) {
378 if (ret >= 16)
379 ret = -E2BIG;
380 pr_warning("Failed to convert variable type: %s\n",
381 strerror_r(-ret, sbuf, sizeof(sbuf)));
382 return ret;
383 }
384 tvar->type = strdup(buf);
385 if (tvar->type == NULL)
386 return -ENOMEM;
387 return 0;
388 }
389
390 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
391 struct perf_probe_arg_field *field,
392 struct probe_trace_arg_ref **ref_ptr,
393 Dwarf_Die *die_mem)
394 {
395 struct probe_trace_arg_ref *ref = *ref_ptr;
396 Dwarf_Die type;
397 Dwarf_Word offs;
398 int ret, tag;
399
400 pr_debug("converting %s in %s\n", field->name, varname);
401 if (die_get_real_type(vr_die, &type) == NULL) {
402 pr_warning("Failed to get the type of %s.\n", varname);
403 return -ENOENT;
404 }
405 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
406 tag = dwarf_tag(&type);
407
408 if (field->name[0] == '[' &&
409 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
410 if (field->next)
411 /* Save original type for next field */
412 memcpy(die_mem, &type, sizeof(*die_mem));
413 /* Get the type of this array */
414 if (die_get_real_type(&type, &type) == NULL) {
415 pr_warning("Failed to get the type of %s.\n", varname);
416 return -ENOENT;
417 }
418 pr_debug2("Array real type: (%x)\n",
419 (unsigned)dwarf_dieoffset(&type));
420 if (tag == DW_TAG_pointer_type) {
421 ref = zalloc(sizeof(struct probe_trace_arg_ref));
422 if (ref == NULL)
423 return -ENOMEM;
424 if (*ref_ptr)
425 (*ref_ptr)->next = ref;
426 else
427 *ref_ptr = ref;
428 }
429 ref->offset += dwarf_bytesize(&type) * field->index;
430 if (!field->next)
431 /* Save vr_die for converting types */
432 memcpy(die_mem, vr_die, sizeof(*die_mem));
433 goto next;
434 } else if (tag == DW_TAG_pointer_type) {
435 /* Check the pointer and dereference */
436 if (!field->ref) {
437 pr_err("Semantic error: %s must be referred by '->'\n",
438 field->name);
439 return -EINVAL;
440 }
441 /* Get the type pointed by this pointer */
442 if (die_get_real_type(&type, &type) == NULL) {
443 pr_warning("Failed to get the type of %s.\n", varname);
444 return -ENOENT;
445 }
446 /* Verify it is a data structure */
447 tag = dwarf_tag(&type);
448 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
449 pr_warning("%s is not a data structure nor an union.\n",
450 varname);
451 return -EINVAL;
452 }
453
454 ref = zalloc(sizeof(struct probe_trace_arg_ref));
455 if (ref == NULL)
456 return -ENOMEM;
457 if (*ref_ptr)
458 (*ref_ptr)->next = ref;
459 else
460 *ref_ptr = ref;
461 } else {
462 /* Verify it is a data structure */
463 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
464 pr_warning("%s is not a data structure nor an union.\n",
465 varname);
466 return -EINVAL;
467 }
468 if (field->name[0] == '[') {
469 pr_err("Semantic error: %s is not a pointer"
470 " nor array.\n", varname);
471 return -EINVAL;
472 }
473 /* While prcessing unnamed field, we don't care about this */
474 if (field->ref && dwarf_diename(vr_die)) {
475 pr_err("Semantic error: %s must be referred by '.'\n",
476 field->name);
477 return -EINVAL;
478 }
479 if (!ref) {
480 pr_warning("Structure on a register is not "
481 "supported yet.\n");
482 return -ENOTSUP;
483 }
484 }
485
486 if (die_find_member(&type, field->name, die_mem) == NULL) {
487 pr_warning("%s(type:%s) has no member %s.\n", varname,
488 dwarf_diename(&type), field->name);
489 return -EINVAL;
490 }
491
492 /* Get the offset of the field */
493 if (tag == DW_TAG_union_type) {
494 offs = 0;
495 } else {
496 ret = die_get_data_member_location(die_mem, &offs);
497 if (ret < 0) {
498 pr_warning("Failed to get the offset of %s.\n",
499 field->name);
500 return ret;
501 }
502 }
503 ref->offset += (long)offs;
504
505 /* If this member is unnamed, we need to reuse this field */
506 if (!dwarf_diename(die_mem))
507 return convert_variable_fields(die_mem, varname, field,
508 &ref, die_mem);
509
510 next:
511 /* Converting next field */
512 if (field->next)
513 return convert_variable_fields(die_mem, field->name,
514 field->next, &ref, die_mem);
515 else
516 return 0;
517 }
518
519 /* Show a variables in kprobe event format */
520 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
521 {
522 Dwarf_Die die_mem;
523 int ret;
524
525 pr_debug("Converting variable %s into trace event.\n",
526 dwarf_diename(vr_die));
527
528 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
529 &pf->sp_die, pf->tvar);
530 if (ret == -ENOENT || ret == -EINVAL) {
531 pr_err("Failed to find the location of the '%s' variable at this address.\n"
532 " Perhaps it has been optimized out.\n"
533 " Use -V with the --range option to show '%s' location range.\n",
534 pf->pvar->var, pf->pvar->var);
535 } else if (ret == -ENOTSUP)
536 pr_err("Sorry, we don't support this variable location yet.\n");
537 else if (ret == 0 && pf->pvar->field) {
538 ret = convert_variable_fields(vr_die, pf->pvar->var,
539 pf->pvar->field, &pf->tvar->ref,
540 &die_mem);
541 vr_die = &die_mem;
542 }
543 if (ret == 0)
544 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
545 /* *expr will be cached in libdw. Don't free it. */
546 return ret;
547 }
548
549 /* Find a variable in a scope DIE */
550 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
551 {
552 Dwarf_Die vr_die;
553 char buf[32], *ptr;
554 int ret = 0;
555
556 if (!is_c_varname(pf->pvar->var)) {
557 /* Copy raw parameters */
558 pf->tvar->value = strdup(pf->pvar->var);
559 if (pf->tvar->value == NULL)
560 return -ENOMEM;
561 if (pf->pvar->type) {
562 pf->tvar->type = strdup(pf->pvar->type);
563 if (pf->tvar->type == NULL)
564 return -ENOMEM;
565 }
566 if (pf->pvar->name) {
567 pf->tvar->name = strdup(pf->pvar->name);
568 if (pf->tvar->name == NULL)
569 return -ENOMEM;
570 } else
571 pf->tvar->name = NULL;
572 return 0;
573 }
574
575 if (pf->pvar->name)
576 pf->tvar->name = strdup(pf->pvar->name);
577 else {
578 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
579 if (ret < 0)
580 return ret;
581 ptr = strchr(buf, ':'); /* Change type separator to _ */
582 if (ptr)
583 *ptr = '_';
584 pf->tvar->name = strdup(buf);
585 }
586 if (pf->tvar->name == NULL)
587 return -ENOMEM;
588
589 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
590 /* Search child die for local variables and parameters. */
591 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
592 /* Search again in global variables */
593 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var,
594 0, &vr_die)) {
595 pr_warning("Failed to find '%s' in this function.\n",
596 pf->pvar->var);
597 ret = -ENOENT;
598 }
599 }
600 if (ret >= 0)
601 ret = convert_variable(&vr_die, pf);
602
603 return ret;
604 }
605
606 /* Convert subprogram DIE to trace point */
607 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
608 Dwarf_Addr paddr, bool retprobe,
609 struct probe_trace_point *tp)
610 {
611 Dwarf_Addr eaddr, highaddr;
612 GElf_Sym sym;
613 const char *symbol;
614
615 /* Verify the address is correct */
616 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
617 pr_warning("Failed to get entry address of %s\n",
618 dwarf_diename(sp_die));
619 return -ENOENT;
620 }
621 if (dwarf_highpc(sp_die, &highaddr) != 0) {
622 pr_warning("Failed to get end address of %s\n",
623 dwarf_diename(sp_die));
624 return -ENOENT;
625 }
626 if (paddr > highaddr) {
627 pr_warning("Offset specified is greater than size of %s\n",
628 dwarf_diename(sp_die));
629 return -EINVAL;
630 }
631
632 symbol = dwarf_diename(sp_die);
633 if (!symbol) {
634 /* Try to get the symbol name from symtab */
635 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
636 if (!symbol) {
637 pr_warning("Failed to find symbol at 0x%lx\n",
638 (unsigned long)paddr);
639 return -ENOENT;
640 }
641 eaddr = sym.st_value;
642 }
643 tp->offset = (unsigned long)(paddr - eaddr);
644 tp->address = (unsigned long)paddr;
645 tp->symbol = strdup(symbol);
646 if (!tp->symbol)
647 return -ENOMEM;
648
649 /* Return probe must be on the head of a subprogram */
650 if (retprobe) {
651 if (eaddr != paddr) {
652 pr_warning("Return probe must be on the head of"
653 " a real function.\n");
654 return -EINVAL;
655 }
656 tp->retprobe = true;
657 }
658
659 return 0;
660 }
661
662 /* Call probe_finder callback with scope DIE */
663 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
664 {
665 Dwarf_Attribute fb_attr;
666 size_t nops;
667 int ret;
668
669 if (!sc_die) {
670 pr_err("Caller must pass a scope DIE. Program error.\n");
671 return -EINVAL;
672 }
673
674 /* If not a real subprogram, find a real one */
675 if (!die_is_func_def(sc_die)) {
676 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
677 pr_warning("Failed to find probe point in any "
678 "functions.\n");
679 return -ENOENT;
680 }
681 } else
682 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
683
684 /* Get the frame base attribute/ops from subprogram */
685 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
686 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
687 if (ret <= 0 || nops == 0) {
688 pf->fb_ops = NULL;
689 #if _ELFUTILS_PREREQ(0, 142)
690 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
691 pf->cfi != NULL) {
692 Dwarf_Frame *frame;
693 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
694 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
695 pr_warning("Failed to get call frame on 0x%jx\n",
696 (uintmax_t)pf->addr);
697 return -ENOENT;
698 }
699 #endif
700 }
701
702 /* Call finder's callback handler */
703 ret = pf->callback(sc_die, pf);
704
705 /* *pf->fb_ops will be cached in libdw. Don't free it. */
706 pf->fb_ops = NULL;
707
708 return ret;
709 }
710
711 struct find_scope_param {
712 const char *function;
713 const char *file;
714 int line;
715 int diff;
716 Dwarf_Die *die_mem;
717 bool found;
718 };
719
720 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
721 {
722 struct find_scope_param *fsp = data;
723 const char *file;
724 int lno;
725
726 /* Skip if declared file name does not match */
727 if (fsp->file) {
728 file = dwarf_decl_file(fn_die);
729 if (!file || strcmp(fsp->file, file) != 0)
730 return 0;
731 }
732 /* If the function name is given, that's what user expects */
733 if (fsp->function) {
734 if (die_match_name(fn_die, fsp->function)) {
735 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
736 fsp->found = true;
737 return 1;
738 }
739 } else {
740 /* With the line number, find the nearest declared DIE */
741 dwarf_decl_line(fn_die, &lno);
742 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
743 /* Keep a candidate and continue */
744 fsp->diff = fsp->line - lno;
745 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
746 fsp->found = true;
747 }
748 }
749 return 0;
750 }
751
752 /* Find an appropriate scope fits to given conditions */
753 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
754 {
755 struct find_scope_param fsp = {
756 .function = pf->pev->point.function,
757 .file = pf->fname,
758 .line = pf->lno,
759 .diff = INT_MAX,
760 .die_mem = die_mem,
761 .found = false,
762 };
763
764 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
765
766 return fsp.found ? die_mem : NULL;
767 }
768
769 static int probe_point_line_walker(const char *fname, int lineno,
770 Dwarf_Addr addr, void *data)
771 {
772 struct probe_finder *pf = data;
773 Dwarf_Die *sc_die, die_mem;
774 int ret;
775
776 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
777 return 0;
778
779 pf->addr = addr;
780 sc_die = find_best_scope(pf, &die_mem);
781 if (!sc_die) {
782 pr_warning("Failed to find scope of probe point.\n");
783 return -ENOENT;
784 }
785
786 ret = call_probe_finder(sc_die, pf);
787
788 /* Continue if no error, because the line will be in inline function */
789 return ret < 0 ? ret : 0;
790 }
791
792 /* Find probe point from its line number */
793 static int find_probe_point_by_line(struct probe_finder *pf)
794 {
795 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
796 }
797
798 /* Find lines which match lazy pattern */
799 static int find_lazy_match_lines(struct intlist *list,
800 const char *fname, const char *pat)
801 {
802 FILE *fp;
803 char *line = NULL;
804 size_t line_len;
805 ssize_t len;
806 int count = 0, linenum = 1;
807 char sbuf[STRERR_BUFSIZE];
808
809 fp = fopen(fname, "r");
810 if (!fp) {
811 pr_warning("Failed to open %s: %s\n", fname,
812 strerror_r(errno, sbuf, sizeof(sbuf)));
813 return -errno;
814 }
815
816 while ((len = getline(&line, &line_len, fp)) > 0) {
817
818 if (line[len - 1] == '\n')
819 line[len - 1] = '\0';
820
821 if (strlazymatch(line, pat)) {
822 intlist__add(list, linenum);
823 count++;
824 }
825 linenum++;
826 }
827
828 if (ferror(fp))
829 count = -errno;
830 free(line);
831 fclose(fp);
832
833 if (count == 0)
834 pr_debug("No matched lines found in %s.\n", fname);
835 return count;
836 }
837
838 static int probe_point_lazy_walker(const char *fname, int lineno,
839 Dwarf_Addr addr, void *data)
840 {
841 struct probe_finder *pf = data;
842 Dwarf_Die *sc_die, die_mem;
843 int ret;
844
845 if (!intlist__has_entry(pf->lcache, lineno) ||
846 strtailcmp(fname, pf->fname) != 0)
847 return 0;
848
849 pr_debug("Probe line found: line:%d addr:0x%llx\n",
850 lineno, (unsigned long long)addr);
851 pf->addr = addr;
852 pf->lno = lineno;
853 sc_die = find_best_scope(pf, &die_mem);
854 if (!sc_die) {
855 pr_warning("Failed to find scope of probe point.\n");
856 return -ENOENT;
857 }
858
859 ret = call_probe_finder(sc_die, pf);
860
861 /*
862 * Continue if no error, because the lazy pattern will match
863 * to other lines
864 */
865 return ret < 0 ? ret : 0;
866 }
867
868 /* Find probe points from lazy pattern */
869 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
870 {
871 int ret = 0;
872 char *fpath;
873
874 if (intlist__empty(pf->lcache)) {
875 const char *comp_dir;
876
877 comp_dir = cu_get_comp_dir(&pf->cu_die);
878 ret = get_real_path(pf->fname, comp_dir, &fpath);
879 if (ret < 0) {
880 pr_warning("Failed to find source file path.\n");
881 return ret;
882 }
883
884 /* Matching lazy line pattern */
885 ret = find_lazy_match_lines(pf->lcache, fpath,
886 pf->pev->point.lazy_line);
887 free(fpath);
888 if (ret <= 0)
889 return ret;
890 }
891
892 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
893 }
894
895 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
896 {
897 struct probe_finder *pf = data;
898 struct perf_probe_point *pp = &pf->pev->point;
899 Dwarf_Addr addr;
900 int ret;
901
902 if (pp->lazy_line)
903 ret = find_probe_point_lazy(in_die, pf);
904 else {
905 /* Get probe address */
906 if (dwarf_entrypc(in_die, &addr) != 0) {
907 pr_warning("Failed to get entry address of %s.\n",
908 dwarf_diename(in_die));
909 return -ENOENT;
910 }
911 pf->addr = addr;
912 pf->addr += pp->offset;
913 pr_debug("found inline addr: 0x%jx\n",
914 (uintmax_t)pf->addr);
915
916 ret = call_probe_finder(in_die, pf);
917 }
918
919 return ret;
920 }
921
922 /* Callback parameter with return value for libdw */
923 struct dwarf_callback_param {
924 void *data;
925 int retval;
926 };
927
928 /* Search function from function name */
929 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
930 {
931 struct dwarf_callback_param *param = data;
932 struct probe_finder *pf = param->data;
933 struct perf_probe_point *pp = &pf->pev->point;
934
935 /* Check tag and diename */
936 if (!die_is_func_def(sp_die) ||
937 !die_match_name(sp_die, pp->function))
938 return DWARF_CB_OK;
939
940 /* Check declared file */
941 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
942 return DWARF_CB_OK;
943
944 pr_debug("Matched function: %s\n", dwarf_diename(sp_die));
945 pf->fname = dwarf_decl_file(sp_die);
946 if (pp->line) { /* Function relative line */
947 dwarf_decl_line(sp_die, &pf->lno);
948 pf->lno += pp->line;
949 param->retval = find_probe_point_by_line(pf);
950 } else if (die_is_func_instance(sp_die)) {
951 /* Instances always have the entry address */
952 dwarf_entrypc(sp_die, &pf->addr);
953 /* Real function */
954 if (pp->lazy_line)
955 param->retval = find_probe_point_lazy(sp_die, pf);
956 else {
957 pf->addr += pp->offset;
958 /* TODO: Check the address in this function */
959 param->retval = call_probe_finder(sp_die, pf);
960 }
961 } else if (!probe_conf.no_inlines) {
962 /* Inlined function: search instances */
963 param->retval = die_walk_instances(sp_die,
964 probe_point_inline_cb, (void *)pf);
965 /* This could be a non-existed inline definition */
966 if (param->retval == -ENOENT && strisglob(pp->function))
967 param->retval = 0;
968 }
969
970 /* We need to find other candidates */
971 if (strisglob(pp->function) && param->retval >= 0) {
972 param->retval = 0; /* We have to clear the result */
973 return DWARF_CB_OK;
974 }
975
976 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
977 }
978
979 static int find_probe_point_by_func(struct probe_finder *pf)
980 {
981 struct dwarf_callback_param _param = {.data = (void *)pf,
982 .retval = 0};
983 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
984 return _param.retval;
985 }
986
987 struct pubname_callback_param {
988 char *function;
989 char *file;
990 Dwarf_Die *cu_die;
991 Dwarf_Die *sp_die;
992 int found;
993 };
994
995 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
996 {
997 struct pubname_callback_param *param = data;
998
999 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1000 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1001 return DWARF_CB_OK;
1002
1003 if (die_match_name(param->sp_die, param->function)) {
1004 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1005 return DWARF_CB_OK;
1006
1007 if (param->file &&
1008 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1009 return DWARF_CB_OK;
1010
1011 param->found = 1;
1012 return DWARF_CB_ABORT;
1013 }
1014 }
1015
1016 return DWARF_CB_OK;
1017 }
1018
1019 /* Find probe points from debuginfo */
1020 static int debuginfo__find_probes(struct debuginfo *dbg,
1021 struct probe_finder *pf)
1022 {
1023 struct perf_probe_point *pp = &pf->pev->point;
1024 Dwarf_Off off, noff;
1025 size_t cuhl;
1026 Dwarf_Die *diep;
1027 int ret = 0;
1028
1029 #if _ELFUTILS_PREREQ(0, 142)
1030 Elf *elf;
1031 GElf_Ehdr ehdr;
1032 GElf_Shdr shdr;
1033
1034 /* Get the call frame information from this dwarf */
1035 elf = dwarf_getelf(dbg->dbg);
1036 if (elf == NULL)
1037 return -EINVAL;
1038
1039 if (gelf_getehdr(elf, &ehdr) == NULL)
1040 return -EINVAL;
1041
1042 if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
1043 shdr.sh_type == SHT_PROGBITS) {
1044 pf->cfi = dwarf_getcfi_elf(elf);
1045 } else {
1046 pf->cfi = dwarf_getcfi(dbg->dbg);
1047 }
1048 #endif
1049
1050 off = 0;
1051 pf->lcache = intlist__new(NULL);
1052 if (!pf->lcache)
1053 return -ENOMEM;
1054
1055 /* Fastpath: lookup by function name from .debug_pubnames section */
1056 if (pp->function && !strisglob(pp->function)) {
1057 struct pubname_callback_param pubname_param = {
1058 .function = pp->function,
1059 .file = pp->file,
1060 .cu_die = &pf->cu_die,
1061 .sp_die = &pf->sp_die,
1062 .found = 0,
1063 };
1064 struct dwarf_callback_param probe_param = {
1065 .data = pf,
1066 };
1067
1068 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1069 &pubname_param, 0);
1070 if (pubname_param.found) {
1071 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1072 if (ret)
1073 goto found;
1074 }
1075 }
1076
1077 /* Loop on CUs (Compilation Unit) */
1078 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1079 /* Get the DIE(Debugging Information Entry) of this CU */
1080 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1081 if (!diep)
1082 continue;
1083
1084 /* Check if target file is included. */
1085 if (pp->file)
1086 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1087 else
1088 pf->fname = NULL;
1089
1090 if (!pp->file || pf->fname) {
1091 if (pp->function)
1092 ret = find_probe_point_by_func(pf);
1093 else if (pp->lazy_line)
1094 ret = find_probe_point_lazy(&pf->cu_die, pf);
1095 else {
1096 pf->lno = pp->line;
1097 ret = find_probe_point_by_line(pf);
1098 }
1099 if (ret < 0)
1100 break;
1101 }
1102 off = noff;
1103 }
1104
1105 found:
1106 intlist__delete(pf->lcache);
1107 pf->lcache = NULL;
1108
1109 return ret;
1110 }
1111
1112 struct local_vars_finder {
1113 struct probe_finder *pf;
1114 struct perf_probe_arg *args;
1115 bool vars;
1116 int max_args;
1117 int nargs;
1118 int ret;
1119 };
1120
1121 /* Collect available variables in this scope */
1122 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1123 {
1124 struct local_vars_finder *vf = data;
1125 struct probe_finder *pf = vf->pf;
1126 int tag;
1127
1128 tag = dwarf_tag(die_mem);
1129 if (tag == DW_TAG_formal_parameter ||
1130 (tag == DW_TAG_variable && vf->vars)) {
1131 if (convert_variable_location(die_mem, vf->pf->addr,
1132 vf->pf->fb_ops, &pf->sp_die,
1133 NULL) == 0) {
1134 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1135 if (vf->args[vf->nargs].var == NULL) {
1136 vf->ret = -ENOMEM;
1137 return DIE_FIND_CB_END;
1138 }
1139 pr_debug(" %s", vf->args[vf->nargs].var);
1140 vf->nargs++;
1141 }
1142 }
1143
1144 if (dwarf_haspc(die_mem, vf->pf->addr))
1145 return DIE_FIND_CB_CONTINUE;
1146 else
1147 return DIE_FIND_CB_SIBLING;
1148 }
1149
1150 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1151 struct perf_probe_arg *args)
1152 {
1153 Dwarf_Die die_mem;
1154 int i;
1155 int n = 0;
1156 struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
1157 .max_args = MAX_PROBE_ARGS, .ret = 0};
1158
1159 for (i = 0; i < pf->pev->nargs; i++) {
1160 /* var never be NULL */
1161 if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
1162 vf.vars = true;
1163 else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
1164 /* Copy normal argument */
1165 args[n] = pf->pev->args[i];
1166 n++;
1167 continue;
1168 }
1169 pr_debug("Expanding %s into:", pf->pev->args[i].var);
1170 vf.nargs = n;
1171 /* Special local variables */
1172 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1173 &die_mem);
1174 pr_debug(" (%d)\n", vf.nargs - n);
1175 if (vf.ret < 0)
1176 return vf.ret;
1177 n = vf.nargs;
1178 }
1179 return n;
1180 }
1181
1182 /* Add a found probe point into trace event list */
1183 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1184 {
1185 struct trace_event_finder *tf =
1186 container_of(pf, struct trace_event_finder, pf);
1187 struct probe_trace_event *tev;
1188 struct perf_probe_arg *args;
1189 int ret, i;
1190
1191 /* Check number of tevs */
1192 if (tf->ntevs == tf->max_tevs) {
1193 pr_warning("Too many( > %d) probe point found.\n",
1194 tf->max_tevs);
1195 return -ERANGE;
1196 }
1197 tev = &tf->tevs[tf->ntevs++];
1198
1199 /* Trace point should be converted from subprogram DIE */
1200 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1201 pf->pev->point.retprobe, &tev->point);
1202 if (ret < 0)
1203 return ret;
1204
1205 tev->point.realname = strdup(dwarf_diename(sc_die));
1206 if (!tev->point.realname)
1207 return -ENOMEM;
1208
1209 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1210 tev->point.offset);
1211
1212 /* Expand special probe argument if exist */
1213 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1214 if (args == NULL)
1215 return -ENOMEM;
1216
1217 ret = expand_probe_args(sc_die, pf, args);
1218 if (ret < 0)
1219 goto end;
1220
1221 tev->nargs = ret;
1222 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1223 if (tev->args == NULL) {
1224 ret = -ENOMEM;
1225 goto end;
1226 }
1227
1228 /* Find each argument */
1229 for (i = 0; i < tev->nargs; i++) {
1230 pf->pvar = &args[i];
1231 pf->tvar = &tev->args[i];
1232 /* Variable should be found from scope DIE */
1233 ret = find_variable(sc_die, pf);
1234 if (ret != 0)
1235 break;
1236 }
1237
1238 end:
1239 free(args);
1240 return ret;
1241 }
1242
1243 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1244 int debuginfo__find_trace_events(struct debuginfo *dbg,
1245 struct perf_probe_event *pev,
1246 struct probe_trace_event **tevs)
1247 {
1248 struct trace_event_finder tf = {
1249 .pf = {.pev = pev, .callback = add_probe_trace_event},
1250 .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
1251 int ret;
1252
1253 /* Allocate result tevs array */
1254 *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
1255 if (*tevs == NULL)
1256 return -ENOMEM;
1257
1258 tf.tevs = *tevs;
1259 tf.ntevs = 0;
1260
1261 ret = debuginfo__find_probes(dbg, &tf.pf);
1262 if (ret < 0) {
1263 zfree(tevs);
1264 return ret;
1265 }
1266
1267 return (ret < 0) ? ret : tf.ntevs;
1268 }
1269
1270 /* Collect available variables in this scope */
1271 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1272 {
1273 struct available_var_finder *af = data;
1274 struct variable_list *vl;
1275 int tag, ret;
1276
1277 vl = &af->vls[af->nvls - 1];
1278
1279 tag = dwarf_tag(die_mem);
1280 if (tag == DW_TAG_formal_parameter ||
1281 tag == DW_TAG_variable) {
1282 ret = convert_variable_location(die_mem, af->pf.addr,
1283 af->pf.fb_ops, &af->pf.sp_die,
1284 NULL);
1285 if (ret == 0 || ret == -ERANGE) {
1286 int ret2;
1287 bool externs = !af->child;
1288 struct strbuf buf;
1289
1290 strbuf_init(&buf, 64);
1291
1292 if (probe_conf.show_location_range) {
1293 if (!externs) {
1294 if (ret)
1295 strbuf_addf(&buf, "[INV]\t");
1296 else
1297 strbuf_addf(&buf, "[VAL]\t");
1298 } else
1299 strbuf_addf(&buf, "[EXT]\t");
1300 }
1301
1302 ret2 = die_get_varname(die_mem, &buf);
1303
1304 if (!ret2 && probe_conf.show_location_range &&
1305 !externs) {
1306 strbuf_addf(&buf, "\t");
1307 ret2 = die_get_var_range(&af->pf.sp_die,
1308 die_mem, &buf);
1309 }
1310
1311 pr_debug("Add new var: %s\n", buf.buf);
1312 if (ret2 == 0) {
1313 strlist__add(vl->vars,
1314 strbuf_detach(&buf, NULL));
1315 }
1316 strbuf_release(&buf);
1317 }
1318 }
1319
1320 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1321 return DIE_FIND_CB_CONTINUE;
1322 else
1323 return DIE_FIND_CB_SIBLING;
1324 }
1325
1326 /* Add a found vars into available variables list */
1327 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1328 {
1329 struct available_var_finder *af =
1330 container_of(pf, struct available_var_finder, pf);
1331 struct variable_list *vl;
1332 Dwarf_Die die_mem;
1333 int ret;
1334
1335 /* Check number of tevs */
1336 if (af->nvls == af->max_vls) {
1337 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1338 return -ERANGE;
1339 }
1340 vl = &af->vls[af->nvls++];
1341
1342 /* Trace point should be converted from subprogram DIE */
1343 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1344 pf->pev->point.retprobe, &vl->point);
1345 if (ret < 0)
1346 return ret;
1347
1348 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1349 vl->point.offset);
1350
1351 /* Find local variables */
1352 vl->vars = strlist__new(true, NULL);
1353 if (vl->vars == NULL)
1354 return -ENOMEM;
1355 af->child = true;
1356 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1357
1358 /* Find external variables */
1359 if (!probe_conf.show_ext_vars)
1360 goto out;
1361 /* Don't need to search child DIE for external vars. */
1362 af->child = false;
1363 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1364
1365 out:
1366 if (strlist__empty(vl->vars)) {
1367 strlist__delete(vl->vars);
1368 vl->vars = NULL;
1369 }
1370
1371 return ret;
1372 }
1373
1374 /*
1375 * Find available variables at given probe point
1376 * Return the number of found probe points. Return 0 if there is no
1377 * matched probe point. Return <0 if an error occurs.
1378 */
1379 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1380 struct perf_probe_event *pev,
1381 struct variable_list **vls)
1382 {
1383 struct available_var_finder af = {
1384 .pf = {.pev = pev, .callback = add_available_vars},
1385 .mod = dbg->mod,
1386 .max_vls = probe_conf.max_probes};
1387 int ret;
1388
1389 /* Allocate result vls array */
1390 *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
1391 if (*vls == NULL)
1392 return -ENOMEM;
1393
1394 af.vls = *vls;
1395 af.nvls = 0;
1396
1397 ret = debuginfo__find_probes(dbg, &af.pf);
1398 if (ret < 0) {
1399 /* Free vlist for error */
1400 while (af.nvls--) {
1401 zfree(&af.vls[af.nvls].point.symbol);
1402 strlist__delete(af.vls[af.nvls].vars);
1403 }
1404 zfree(vls);
1405 return ret;
1406 }
1407
1408 return (ret < 0) ? ret : af.nvls;
1409 }
1410
1411 /* Reverse search */
1412 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1413 struct perf_probe_point *ppt)
1414 {
1415 Dwarf_Die cudie, spdie, indie;
1416 Dwarf_Addr _addr = 0, baseaddr = 0;
1417 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1418 int baseline = 0, lineno = 0, ret = 0;
1419
1420 /* Find cu die */
1421 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
1422 pr_warning("Failed to find debug information for address %lx\n",
1423 addr);
1424 ret = -EINVAL;
1425 goto end;
1426 }
1427
1428 /* Find a corresponding line (filename and lineno) */
1429 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1430 /* Don't care whether it failed or not */
1431
1432 /* Find a corresponding function (name, baseline and baseaddr) */
1433 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1434 /* Get function entry information */
1435 func = basefunc = dwarf_diename(&spdie);
1436 if (!func ||
1437 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1438 dwarf_decl_line(&spdie, &baseline) != 0) {
1439 lineno = 0;
1440 goto post;
1441 }
1442
1443 fname = dwarf_decl_file(&spdie);
1444 if (addr == (unsigned long)baseaddr) {
1445 /* Function entry - Relative line number is 0 */
1446 lineno = baseline;
1447 goto post;
1448 }
1449
1450 /* Track down the inline functions step by step */
1451 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1452 &indie)) {
1453 /* There is an inline function */
1454 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1455 _addr == addr) {
1456 /*
1457 * addr is at an inline function entry.
1458 * In this case, lineno should be the call-site
1459 * line number. (overwrite lineinfo)
1460 */
1461 lineno = die_get_call_lineno(&indie);
1462 fname = die_get_call_file(&indie);
1463 break;
1464 } else {
1465 /*
1466 * addr is in an inline function body.
1467 * Since lineno points one of the lines
1468 * of the inline function, baseline should
1469 * be the entry line of the inline function.
1470 */
1471 tmp = dwarf_diename(&indie);
1472 if (!tmp ||
1473 dwarf_decl_line(&indie, &baseline) != 0)
1474 break;
1475 func = tmp;
1476 spdie = indie;
1477 }
1478 }
1479 /* Verify the lineno and baseline are in a same file */
1480 tmp = dwarf_decl_file(&spdie);
1481 if (!tmp || strcmp(tmp, fname) != 0)
1482 lineno = 0;
1483 }
1484
1485 post:
1486 /* Make a relative line number or an offset */
1487 if (lineno)
1488 ppt->line = lineno - baseline;
1489 else if (basefunc) {
1490 ppt->offset = addr - (unsigned long)baseaddr;
1491 func = basefunc;
1492 }
1493
1494 /* Duplicate strings */
1495 if (func) {
1496 ppt->function = strdup(func);
1497 if (ppt->function == NULL) {
1498 ret = -ENOMEM;
1499 goto end;
1500 }
1501 }
1502 if (fname) {
1503 ppt->file = strdup(fname);
1504 if (ppt->file == NULL) {
1505 zfree(&ppt->function);
1506 ret = -ENOMEM;
1507 goto end;
1508 }
1509 }
1510 end:
1511 if (ret == 0 && (fname || func))
1512 ret = 1; /* Found a point */
1513 return ret;
1514 }
1515
1516 /* Add a line and store the src path */
1517 static int line_range_add_line(const char *src, unsigned int lineno,
1518 struct line_range *lr)
1519 {
1520 /* Copy source path */
1521 if (!lr->path) {
1522 lr->path = strdup(src);
1523 if (lr->path == NULL)
1524 return -ENOMEM;
1525 }
1526 return intlist__add(lr->line_list, lineno);
1527 }
1528
1529 static int line_range_walk_cb(const char *fname, int lineno,
1530 Dwarf_Addr addr __maybe_unused,
1531 void *data)
1532 {
1533 struct line_finder *lf = data;
1534 int err;
1535
1536 if ((strtailcmp(fname, lf->fname) != 0) ||
1537 (lf->lno_s > lineno || lf->lno_e < lineno))
1538 return 0;
1539
1540 err = line_range_add_line(fname, lineno, lf->lr);
1541 if (err < 0 && err != -EEXIST)
1542 return err;
1543
1544 return 0;
1545 }
1546
1547 /* Find line range from its line number */
1548 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1549 {
1550 int ret;
1551
1552 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1553
1554 /* Update status */
1555 if (ret >= 0)
1556 if (!intlist__empty(lf->lr->line_list))
1557 ret = lf->found = 1;
1558 else
1559 ret = 0; /* Lines are not found */
1560 else {
1561 zfree(&lf->lr->path);
1562 }
1563 return ret;
1564 }
1565
1566 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1567 {
1568 int ret = find_line_range_by_line(in_die, data);
1569
1570 /*
1571 * We have to check all instances of inlined function, because
1572 * some execution paths can be optimized out depends on the
1573 * function argument of instances. However, if an error occurs,
1574 * it should be handled by the caller.
1575 */
1576 return ret < 0 ? ret : 0;
1577 }
1578
1579 /* Search function definition from function name */
1580 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1581 {
1582 struct dwarf_callback_param *param = data;
1583 struct line_finder *lf = param->data;
1584 struct line_range *lr = lf->lr;
1585
1586 /* Check declared file */
1587 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1588 return DWARF_CB_OK;
1589
1590 if (die_is_func_def(sp_die) &&
1591 die_match_name(sp_die, lr->function)) {
1592 lf->fname = dwarf_decl_file(sp_die);
1593 dwarf_decl_line(sp_die, &lr->offset);
1594 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1595 lf->lno_s = lr->offset + lr->start;
1596 if (lf->lno_s < 0) /* Overflow */
1597 lf->lno_s = INT_MAX;
1598 lf->lno_e = lr->offset + lr->end;
1599 if (lf->lno_e < 0) /* Overflow */
1600 lf->lno_e = INT_MAX;
1601 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1602 lr->start = lf->lno_s;
1603 lr->end = lf->lno_e;
1604 if (!die_is_func_instance(sp_die))
1605 param->retval = die_walk_instances(sp_die,
1606 line_range_inline_cb, lf);
1607 else
1608 param->retval = find_line_range_by_line(sp_die, lf);
1609 return DWARF_CB_ABORT;
1610 }
1611 return DWARF_CB_OK;
1612 }
1613
1614 static int find_line_range_by_func(struct line_finder *lf)
1615 {
1616 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1617 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1618 return param.retval;
1619 }
1620
1621 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1622 {
1623 struct line_finder lf = {.lr = lr, .found = 0};
1624 int ret = 0;
1625 Dwarf_Off off = 0, noff;
1626 size_t cuhl;
1627 Dwarf_Die *diep;
1628 const char *comp_dir;
1629
1630 /* Fastpath: lookup by function name from .debug_pubnames section */
1631 if (lr->function) {
1632 struct pubname_callback_param pubname_param = {
1633 .function = lr->function, .file = lr->file,
1634 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1635 struct dwarf_callback_param line_range_param = {
1636 .data = (void *)&lf, .retval = 0};
1637
1638 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1639 &pubname_param, 0);
1640 if (pubname_param.found) {
1641 line_range_search_cb(&lf.sp_die, &line_range_param);
1642 if (lf.found)
1643 goto found;
1644 }
1645 }
1646
1647 /* Loop on CUs (Compilation Unit) */
1648 while (!lf.found && ret >= 0) {
1649 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1650 NULL, NULL, NULL) != 0)
1651 break;
1652
1653 /* Get the DIE(Debugging Information Entry) of this CU */
1654 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1655 if (!diep)
1656 continue;
1657
1658 /* Check if target file is included. */
1659 if (lr->file)
1660 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1661 else
1662 lf.fname = 0;
1663
1664 if (!lr->file || lf.fname) {
1665 if (lr->function)
1666 ret = find_line_range_by_func(&lf);
1667 else {
1668 lf.lno_s = lr->start;
1669 lf.lno_e = lr->end;
1670 ret = find_line_range_by_line(NULL, &lf);
1671 }
1672 }
1673 off = noff;
1674 }
1675
1676 found:
1677 /* Store comp_dir */
1678 if (lf.found) {
1679 comp_dir = cu_get_comp_dir(&lf.cu_die);
1680 if (comp_dir) {
1681 lr->comp_dir = strdup(comp_dir);
1682 if (!lr->comp_dir)
1683 ret = -ENOMEM;
1684 }
1685 }
1686
1687 pr_debug("path: %s\n", lr->path);
1688 return (ret < 0) ? ret : lf.found;
1689 }
1690
1691 /*
1692 * Find a src file from a DWARF tag path. Prepend optional source path prefix
1693 * and chop off leading directories that do not exist. Result is passed back as
1694 * a newly allocated path on success.
1695 * Return 0 if file was found and readable, -errno otherwise.
1696 */
1697 int get_real_path(const char *raw_path, const char *comp_dir,
1698 char **new_path)
1699 {
1700 const char *prefix = symbol_conf.source_prefix;
1701
1702 if (!prefix) {
1703 if (raw_path[0] != '/' && comp_dir)
1704 /* If not an absolute path, try to use comp_dir */
1705 prefix = comp_dir;
1706 else {
1707 if (access(raw_path, R_OK) == 0) {
1708 *new_path = strdup(raw_path);
1709 return *new_path ? 0 : -ENOMEM;
1710 } else
1711 return -errno;
1712 }
1713 }
1714
1715 *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
1716 if (!*new_path)
1717 return -ENOMEM;
1718
1719 for (;;) {
1720 sprintf(*new_path, "%s/%s", prefix, raw_path);
1721
1722 if (access(*new_path, R_OK) == 0)
1723 return 0;
1724
1725 if (!symbol_conf.source_prefix) {
1726 /* In case of searching comp_dir, don't retry */
1727 zfree(new_path);
1728 return -errno;
1729 }
1730
1731 switch (errno) {
1732 case ENAMETOOLONG:
1733 case ENOENT:
1734 case EROFS:
1735 case EFAULT:
1736 raw_path = strchr(++raw_path, '/');
1737 if (!raw_path) {
1738 zfree(new_path);
1739 return -ENOENT;
1740 }
1741 continue;
1742
1743 default:
1744 zfree(new_path);
1745 return -errno;
1746 }
1747 }
1748 }
Linux kernel - Deliverables
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