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ceph: use i_size_{read,write} to get/set i_size
[linux/fpc-iii.git] / tools / perf / util / probe-finder.c
blob05012bb178d7a8d75ebf4879438fbc0d6f774926
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 dwfl_report_begin(dbg->dwfl);
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 dwfl_report_end(dbg->dwfl, NULL, NULL);
83
84 return 0;
85 error:
86 if (dbg->dwfl)
87 dwfl_end(dbg->dwfl);
88 else
89 close(fd);
90 memset(dbg, 0, sizeof(*dbg));
91
92 return -ENOENT;
93 }
94
95 static struct debuginfo *__debuginfo__new(const char *path)
96 {
97 struct debuginfo *dbg = zalloc(sizeof(*dbg));
98 if (!dbg)
99 return NULL;
100
101 if (debuginfo__init_offline_dwarf(dbg, path) < 0)
102 zfree(&dbg);
103 if (dbg)
104 pr_debug("Open Debuginfo file: %s\n", path);
105 return dbg;
106 }
107
108 enum dso_binary_type distro_dwarf_types[] = {
109 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
110 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
111 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
112 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
113 DSO_BINARY_TYPE__NOT_FOUND,
114 };
115
116 struct debuginfo *debuginfo__new(const char *path)
117 {
118 enum dso_binary_type *type;
119 char buf[PATH_MAX], nil = '\0';
120 struct dso *dso;
121 struct debuginfo *dinfo = NULL;
122
123 /* Try to open distro debuginfo files */
124 dso = dso__new(path);
125 if (!dso)
126 goto out;
127
128 for (type = distro_dwarf_types;
129 !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
130 type++) {
131 if (dso__read_binary_type_filename(dso, *type, &nil,
132 buf, PATH_MAX) < 0)
133 continue;
134 dinfo = __debuginfo__new(buf);
135 }
136 dso__put(dso);
137
138 out:
139 /* if failed to open all distro debuginfo, open given binary */
140 return dinfo ? : __debuginfo__new(path);
141 }
142
143 void debuginfo__delete(struct debuginfo *dbg)
144 {
145 if (dbg) {
146 if (dbg->dwfl)
147 dwfl_end(dbg->dwfl);
148 free(dbg);
149 }
150 }
151
152 /*
153 * Probe finder related functions
154 */
155
156 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
157 {
158 struct probe_trace_arg_ref *ref;
159 ref = zalloc(sizeof(struct probe_trace_arg_ref));
160 if (ref != NULL)
161 ref->offset = offs;
162 return ref;
163 }
164
165 /*
166 * Convert a location into trace_arg.
167 * If tvar == NULL, this just checks variable can be converted.
168 * If fentry == true and vr_die is a parameter, do huristic search
169 * for the location fuzzed by function entry mcount.
170 */
171 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
172 Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
173 struct probe_trace_arg *tvar)
174 {
175 Dwarf_Attribute attr;
176 Dwarf_Addr tmp = 0;
177 Dwarf_Op *op;
178 size_t nops;
179 unsigned int regn;
180 Dwarf_Word offs = 0;
181 bool ref = false;
182 const char *regs;
183 int ret, ret2 = 0;
184
185 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
186 goto static_var;
187
188 /* TODO: handle more than 1 exprs */
189 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
190 return -EINVAL; /* Broken DIE ? */
191 if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
192 ret = dwarf_entrypc(sp_die, &tmp);
193 if (ret)
194 return -ENOENT;
195
196 if (probe_conf.show_location_range &&
197 (dwarf_tag(vr_die) == DW_TAG_variable)) {
198 ret2 = -ERANGE;
199 } else if (addr != tmp ||
200 dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
201 return -ENOENT;
202 }
203
204 ret = dwarf_highpc(sp_die, &tmp);
205 if (ret)
206 return -ENOENT;
207 /*
208 * This is fuzzed by fentry mcount. We try to find the
209 * parameter location at the earliest address.
210 */
211 for (addr += 1; addr <= tmp; addr++) {
212 if (dwarf_getlocation_addr(&attr, addr, &op,
213 &nops, 1) > 0)
214 goto found;
215 }
216 return -ENOENT;
217 }
218 found:
219 if (nops == 0)
220 /* TODO: Support const_value */
221 return -ENOENT;
222
223 if (op->atom == DW_OP_addr) {
224 static_var:
225 if (!tvar)
226 return ret2;
227 /* Static variables on memory (not stack), make @varname */
228 ret = strlen(dwarf_diename(vr_die));
229 tvar->value = zalloc(ret + 2);
230 if (tvar->value == NULL)
231 return -ENOMEM;
232 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
233 tvar->ref = alloc_trace_arg_ref((long)offs);
234 if (tvar->ref == NULL)
235 return -ENOMEM;
236 return ret2;
237 }
238
239 /* If this is based on frame buffer, set the offset */
240 if (op->atom == DW_OP_fbreg) {
241 if (fb_ops == NULL)
242 return -ENOTSUP;
243 ref = true;
244 offs = op->number;
245 op = &fb_ops[0];
246 }
247
248 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
249 regn = op->atom - DW_OP_breg0;
250 offs += op->number;
251 ref = true;
252 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
253 regn = op->atom - DW_OP_reg0;
254 } else if (op->atom == DW_OP_bregx) {
255 regn = op->number;
256 offs += op->number2;
257 ref = true;
258 } else if (op->atom == DW_OP_regx) {
259 regn = op->number;
260 } else {
261 pr_debug("DW_OP %x is not supported.\n", op->atom);
262 return -ENOTSUP;
263 }
264
265 if (!tvar)
266 return ret2;
267
268 regs = get_arch_regstr(regn);
269 if (!regs) {
270 /* This should be a bug in DWARF or this tool */
271 pr_warning("Mapping for the register number %u "
272 "missing on this architecture.\n", regn);
273 return -ENOTSUP;
274 }
275
276 tvar->value = strdup(regs);
277 if (tvar->value == NULL)
278 return -ENOMEM;
279
280 if (ref) {
281 tvar->ref = alloc_trace_arg_ref((long)offs);
282 if (tvar->ref == NULL)
283 return -ENOMEM;
284 }
285 return ret2;
286 }
287
288 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
289
290 static int convert_variable_type(Dwarf_Die *vr_die,
291 struct probe_trace_arg *tvar,
292 const char *cast)
293 {
294 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
295 Dwarf_Die type;
296 char buf[16];
297 char sbuf[STRERR_BUFSIZE];
298 int bsize, boffs, total;
299 int ret;
300
301 /* TODO: check all types */
302 if (cast && strcmp(cast, "string") != 0) {
303 /* Non string type is OK */
304 tvar->type = strdup(cast);
305 return (tvar->type == NULL) ? -ENOMEM : 0;
306 }
307
308 bsize = dwarf_bitsize(vr_die);
309 if (bsize > 0) {
310 /* This is a bitfield */
311 boffs = dwarf_bitoffset(vr_die);
312 total = dwarf_bytesize(vr_die);
313 if (boffs < 0 || total < 0)
314 return -ENOENT;
315 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
316 BYTES_TO_BITS(total));
317 goto formatted;
318 }
319
320 if (die_get_real_type(vr_die, &type) == NULL) {
321 pr_warning("Failed to get a type information of %s.\n",
322 dwarf_diename(vr_die));
323 return -ENOENT;
324 }
325
326 pr_debug("%s type is %s.\n",
327 dwarf_diename(vr_die), dwarf_diename(&type));
328
329 if (cast && strcmp(cast, "string") == 0) { /* String type */
330 ret = dwarf_tag(&type);
331 if (ret != DW_TAG_pointer_type &&
332 ret != DW_TAG_array_type) {
333 pr_warning("Failed to cast into string: "
334 "%s(%s) is not a pointer nor array.\n",
335 dwarf_diename(vr_die), dwarf_diename(&type));
336 return -EINVAL;
337 }
338 if (die_get_real_type(&type, &type) == NULL) {
339 pr_warning("Failed to get a type"
340 " information.\n");
341 return -ENOENT;
342 }
343 if (ret == DW_TAG_pointer_type) {
344 while (*ref_ptr)
345 ref_ptr = &(*ref_ptr)->next;
346 /* Add new reference with offset +0 */
347 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
348 if (*ref_ptr == NULL) {
349 pr_warning("Out of memory error\n");
350 return -ENOMEM;
351 }
352 }
353 if (!die_compare_name(&type, "char") &&
354 !die_compare_name(&type, "unsigned char")) {
355 pr_warning("Failed to cast into string: "
356 "%s is not (unsigned) char *.\n",
357 dwarf_diename(vr_die));
358 return -EINVAL;
359 }
360 tvar->type = strdup(cast);
361 return (tvar->type == NULL) ? -ENOMEM : 0;
362 }
363
364 ret = dwarf_bytesize(&type);
365 if (ret <= 0)
366 /* No size ... try to use default type */
367 return 0;
368 ret = BYTES_TO_BITS(ret);
369
370 /* Check the bitwidth */
371 if (ret > MAX_BASIC_TYPE_BITS) {
372 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
373 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
374 ret = MAX_BASIC_TYPE_BITS;
375 }
376 ret = snprintf(buf, 16, "%c%d",
377 die_is_signed_type(&type) ? 's' : 'u', ret);
378
379 formatted:
380 if (ret < 0 || ret >= 16) {
381 if (ret >= 16)
382 ret = -E2BIG;
383 pr_warning("Failed to convert variable type: %s\n",
384 strerror_r(-ret, sbuf, sizeof(sbuf)));
385 return ret;
386 }
387 tvar->type = strdup(buf);
388 if (tvar->type == NULL)
389 return -ENOMEM;
390 return 0;
391 }
392
393 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
394 struct perf_probe_arg_field *field,
395 struct probe_trace_arg_ref **ref_ptr,
396 Dwarf_Die *die_mem)
397 {
398 struct probe_trace_arg_ref *ref = *ref_ptr;
399 Dwarf_Die type;
400 Dwarf_Word offs;
401 int ret, tag;
402
403 pr_debug("converting %s in %s\n", field->name, varname);
404 if (die_get_real_type(vr_die, &type) == NULL) {
405 pr_warning("Failed to get the type of %s.\n", varname);
406 return -ENOENT;
407 }
408 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
409 tag = dwarf_tag(&type);
410
411 if (field->name[0] == '[' &&
412 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
413 if (field->next)
414 /* Save original type for next field */
415 memcpy(die_mem, &type, sizeof(*die_mem));
416 /* Get the type of this array */
417 if (die_get_real_type(&type, &type) == NULL) {
418 pr_warning("Failed to get the type of %s.\n", varname);
419 return -ENOENT;
420 }
421 pr_debug2("Array real type: (%x)\n",
422 (unsigned)dwarf_dieoffset(&type));
423 if (tag == DW_TAG_pointer_type) {
424 ref = zalloc(sizeof(struct probe_trace_arg_ref));
425 if (ref == NULL)
426 return -ENOMEM;
427 if (*ref_ptr)
428 (*ref_ptr)->next = ref;
429 else
430 *ref_ptr = ref;
431 }
432 ref->offset += dwarf_bytesize(&type) * field->index;
433 if (!field->next)
434 /* Save vr_die for converting types */
435 memcpy(die_mem, vr_die, sizeof(*die_mem));
436 goto next;
437 } else if (tag == DW_TAG_pointer_type) {
438 /* Check the pointer and dereference */
439 if (!field->ref) {
440 pr_err("Semantic error: %s must be referred by '->'\n",
441 field->name);
442 return -EINVAL;
443 }
444 /* Get the type pointed by this pointer */
445 if (die_get_real_type(&type, &type) == NULL) {
446 pr_warning("Failed to get the type of %s.\n", varname);
447 return -ENOENT;
448 }
449 /* Verify it is a data structure */
450 tag = dwarf_tag(&type);
451 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
452 pr_warning("%s is not a data structure nor an union.\n",
453 varname);
454 return -EINVAL;
455 }
456
457 ref = zalloc(sizeof(struct probe_trace_arg_ref));
458 if (ref == NULL)
459 return -ENOMEM;
460 if (*ref_ptr)
461 (*ref_ptr)->next = ref;
462 else
463 *ref_ptr = ref;
464 } else {
465 /* Verify it is a data structure */
466 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
467 pr_warning("%s is not a data structure nor an union.\n",
468 varname);
469 return -EINVAL;
470 }
471 if (field->name[0] == '[') {
472 pr_err("Semantic error: %s is not a pointer"
473 " nor array.\n", varname);
474 return -EINVAL;
475 }
476 /* While prcessing unnamed field, we don't care about this */
477 if (field->ref && dwarf_diename(vr_die)) {
478 pr_err("Semantic error: %s must be referred by '.'\n",
479 field->name);
480 return -EINVAL;
481 }
482 if (!ref) {
483 pr_warning("Structure on a register is not "
484 "supported yet.\n");
485 return -ENOTSUP;
486 }
487 }
488
489 if (die_find_member(&type, field->name, die_mem) == NULL) {
490 pr_warning("%s(type:%s) has no member %s.\n", varname,
491 dwarf_diename(&type), field->name);
492 return -EINVAL;
493 }
494
495 /* Get the offset of the field */
496 if (tag == DW_TAG_union_type) {
497 offs = 0;
498 } else {
499 ret = die_get_data_member_location(die_mem, &offs);
500 if (ret < 0) {
501 pr_warning("Failed to get the offset of %s.\n",
502 field->name);
503 return ret;
504 }
505 }
506 ref->offset += (long)offs;
507
508 /* If this member is unnamed, we need to reuse this field */
509 if (!dwarf_diename(die_mem))
510 return convert_variable_fields(die_mem, varname, field,
511 &ref, die_mem);
512
513 next:
514 /* Converting next field */
515 if (field->next)
516 return convert_variable_fields(die_mem, field->name,
517 field->next, &ref, die_mem);
518 else
519 return 0;
520 }
521
522 /* Show a variables in kprobe event format */
523 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
524 {
525 Dwarf_Die die_mem;
526 int ret;
527
528 pr_debug("Converting variable %s into trace event.\n",
529 dwarf_diename(vr_die));
530
531 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
532 &pf->sp_die, pf->tvar);
533 if (ret == -ENOENT || ret == -EINVAL) {
534 pr_err("Failed to find the location of the '%s' variable at this address.\n"
535 " Perhaps it has been optimized out.\n"
536 " Use -V with the --range option to show '%s' location range.\n",
537 pf->pvar->var, pf->pvar->var);
538 } else if (ret == -ENOTSUP)
539 pr_err("Sorry, we don't support this variable location yet.\n");
540 else if (ret == 0 && pf->pvar->field) {
541 ret = convert_variable_fields(vr_die, pf->pvar->var,
542 pf->pvar->field, &pf->tvar->ref,
543 &die_mem);
544 vr_die = &die_mem;
545 }
546 if (ret == 0)
547 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
548 /* *expr will be cached in libdw. Don't free it. */
549 return ret;
550 }
551
552 /* Find a variable in a scope DIE */
553 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
554 {
555 Dwarf_Die vr_die;
556 char buf[32], *ptr;
557 int ret = 0;
558
559 /* Copy raw parameters */
560 if (!is_c_varname(pf->pvar->var))
561 return copy_to_probe_trace_arg(pf->tvar, pf->pvar);
562
563 if (pf->pvar->name)
564 pf->tvar->name = strdup(pf->pvar->name);
565 else {
566 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
567 if (ret < 0)
568 return ret;
569 ptr = strchr(buf, ':'); /* Change type separator to _ */
570 if (ptr)
571 *ptr = '_';
572 pf->tvar->name = strdup(buf);
573 }
574 if (pf->tvar->name == NULL)
575 return -ENOMEM;
576
577 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
578 /* Search child die for local variables and parameters. */
579 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
580 /* Search again in global variables */
581 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var,
582 0, &vr_die)) {
583 pr_warning("Failed to find '%s' in this function.\n",
584 pf->pvar->var);
585 ret = -ENOENT;
586 }
587 }
588 if (ret >= 0)
589 ret = convert_variable(&vr_die, pf);
590
591 return ret;
592 }
593
594 /* Convert subprogram DIE to trace point */
595 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
596 Dwarf_Addr paddr, bool retprobe,
597 const char *function,
598 struct probe_trace_point *tp)
599 {
600 Dwarf_Addr eaddr, highaddr;
601 GElf_Sym sym;
602 const char *symbol;
603
604 /* Verify the address is correct */
605 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
606 pr_warning("Failed to get entry address of %s\n",
607 dwarf_diename(sp_die));
608 return -ENOENT;
609 }
610 if (dwarf_highpc(sp_die, &highaddr) != 0) {
611 pr_warning("Failed to get end address of %s\n",
612 dwarf_diename(sp_die));
613 return -ENOENT;
614 }
615 if (paddr > highaddr) {
616 pr_warning("Offset specified is greater than size of %s\n",
617 dwarf_diename(sp_die));
618 return -EINVAL;
619 }
620
621 symbol = dwarf_diename(sp_die);
622 if (!symbol) {
623 /* Try to get the symbol name from symtab */
624 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
625 if (!symbol) {
626 pr_warning("Failed to find symbol at 0x%lx\n",
627 (unsigned long)paddr);
628 return -ENOENT;
629 }
630 eaddr = sym.st_value;
631 }
632 tp->offset = (unsigned long)(paddr - eaddr);
633 tp->address = (unsigned long)paddr;
634 tp->symbol = strdup(symbol);
635 if (!tp->symbol)
636 return -ENOMEM;
637
638 /* Return probe must be on the head of a subprogram */
639 if (retprobe) {
640 if (eaddr != paddr) {
641 pr_warning("Failed to find \"%s%%return\",\n"
642 " because %s is an inlined function and"
643 " has no return point.\n", function,
644 function);
645 return -EINVAL;
646 }
647 tp->retprobe = true;
648 }
649
650 return 0;
651 }
652
653 /* Call probe_finder callback with scope DIE */
654 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
655 {
656 Dwarf_Attribute fb_attr;
657 size_t nops;
658 int ret;
659
660 if (!sc_die) {
661 pr_err("Caller must pass a scope DIE. Program error.\n");
662 return -EINVAL;
663 }
664
665 /* If not a real subprogram, find a real one */
666 if (!die_is_func_def(sc_die)) {
667 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
668 if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
669 pr_warning("Ignoring tail call from %s\n",
670 dwarf_diename(&pf->sp_die));
671 return 0;
672 } else {
673 pr_warning("Failed to find probe point in any "
674 "functions.\n");
675 return -ENOENT;
676 }
677 }
678 } else
679 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
680
681 /* Get the frame base attribute/ops from subprogram */
682 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
683 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
684 if (ret <= 0 || nops == 0) {
685 pf->fb_ops = NULL;
686 #if _ELFUTILS_PREREQ(0, 142)
687 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
688 pf->cfi != NULL) {
689 Dwarf_Frame *frame;
690 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
691 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
692 pr_warning("Failed to get call frame on 0x%jx\n",
693 (uintmax_t)pf->addr);
694 return -ENOENT;
695 }
696 #endif
697 }
698
699 /* Call finder's callback handler */
700 ret = pf->callback(sc_die, pf);
701
702 /* *pf->fb_ops will be cached in libdw. Don't free it. */
703 pf->fb_ops = NULL;
704
705 return ret;
706 }
707
708 struct find_scope_param {
709 const char *function;
710 const char *file;
711 int line;
712 int diff;
713 Dwarf_Die *die_mem;
714 bool found;
715 };
716
717 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
718 {
719 struct find_scope_param *fsp = data;
720 const char *file;
721 int lno;
722
723 /* Skip if declared file name does not match */
724 if (fsp->file) {
725 file = dwarf_decl_file(fn_die);
726 if (!file || strcmp(fsp->file, file) != 0)
727 return 0;
728 }
729 /* If the function name is given, that's what user expects */
730 if (fsp->function) {
731 if (die_match_name(fn_die, fsp->function)) {
732 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
733 fsp->found = true;
734 return 1;
735 }
736 } else {
737 /* With the line number, find the nearest declared DIE */
738 dwarf_decl_line(fn_die, &lno);
739 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
740 /* Keep a candidate and continue */
741 fsp->diff = fsp->line - lno;
742 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
743 fsp->found = true;
744 }
745 }
746 return 0;
747 }
748
749 /* Find an appropriate scope fits to given conditions */
750 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
751 {
752 struct find_scope_param fsp = {
753 .function = pf->pev->point.function,
754 .file = pf->fname,
755 .line = pf->lno,
756 .diff = INT_MAX,
757 .die_mem = die_mem,
758 .found = false,
759 };
760
761 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
762
763 return fsp.found ? die_mem : NULL;
764 }
765
766 static int probe_point_line_walker(const char *fname, int lineno,
767 Dwarf_Addr addr, void *data)
768 {
769 struct probe_finder *pf = data;
770 Dwarf_Die *sc_die, die_mem;
771 int ret;
772
773 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
774 return 0;
775
776 pf->addr = addr;
777 sc_die = find_best_scope(pf, &die_mem);
778 if (!sc_die) {
779 pr_warning("Failed to find scope of probe point.\n");
780 return -ENOENT;
781 }
782
783 ret = call_probe_finder(sc_die, pf);
784
785 /* Continue if no error, because the line will be in inline function */
786 return ret < 0 ? ret : 0;
787 }
788
789 /* Find probe point from its line number */
790 static int find_probe_point_by_line(struct probe_finder *pf)
791 {
792 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
793 }
794
795 /* Find lines which match lazy pattern */
796 static int find_lazy_match_lines(struct intlist *list,
797 const char *fname, const char *pat)
798 {
799 FILE *fp;
800 char *line = NULL;
801 size_t line_len;
802 ssize_t len;
803 int count = 0, linenum = 1;
804 char sbuf[STRERR_BUFSIZE];
805
806 fp = fopen(fname, "r");
807 if (!fp) {
808 pr_warning("Failed to open %s: %s\n", fname,
809 strerror_r(errno, sbuf, sizeof(sbuf)));
810 return -errno;
811 }
812
813 while ((len = getline(&line, &line_len, fp)) > 0) {
814
815 if (line[len - 1] == '\n')
816 line[len - 1] = '\0';
817
818 if (strlazymatch(line, pat)) {
819 intlist__add(list, linenum);
820 count++;
821 }
822 linenum++;
823 }
824
825 if (ferror(fp))
826 count = -errno;
827 free(line);
828 fclose(fp);
829
830 if (count == 0)
831 pr_debug("No matched lines found in %s.\n", fname);
832 return count;
833 }
834
835 static int probe_point_lazy_walker(const char *fname, int lineno,
836 Dwarf_Addr addr, void *data)
837 {
838 struct probe_finder *pf = data;
839 Dwarf_Die *sc_die, die_mem;
840 int ret;
841
842 if (!intlist__has_entry(pf->lcache, lineno) ||
843 strtailcmp(fname, pf->fname) != 0)
844 return 0;
845
846 pr_debug("Probe line found: line:%d addr:0x%llx\n",
847 lineno, (unsigned long long)addr);
848 pf->addr = addr;
849 pf->lno = lineno;
850 sc_die = find_best_scope(pf, &die_mem);
851 if (!sc_die) {
852 pr_warning("Failed to find scope of probe point.\n");
853 return -ENOENT;
854 }
855
856 ret = call_probe_finder(sc_die, pf);
857
858 /*
859 * Continue if no error, because the lazy pattern will match
860 * to other lines
861 */
862 return ret < 0 ? ret : 0;
863 }
864
865 /* Find probe points from lazy pattern */
866 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
867 {
868 int ret = 0;
869 char *fpath;
870
871 if (intlist__empty(pf->lcache)) {
872 const char *comp_dir;
873
874 comp_dir = cu_get_comp_dir(&pf->cu_die);
875 ret = get_real_path(pf->fname, comp_dir, &fpath);
876 if (ret < 0) {
877 pr_warning("Failed to find source file path.\n");
878 return ret;
879 }
880
881 /* Matching lazy line pattern */
882 ret = find_lazy_match_lines(pf->lcache, fpath,
883 pf->pev->point.lazy_line);
884 free(fpath);
885 if (ret <= 0)
886 return ret;
887 }
888
889 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
890 }
891
892 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
893 {
894 struct probe_finder *pf = data;
895 struct perf_probe_point *pp = &pf->pev->point;
896 Dwarf_Addr addr;
897 int ret;
898
899 if (pp->lazy_line)
900 ret = find_probe_point_lazy(in_die, pf);
901 else {
902 /* Get probe address */
903 if (dwarf_entrypc(in_die, &addr) != 0) {
904 pr_warning("Failed to get entry address of %s.\n",
905 dwarf_diename(in_die));
906 return -ENOENT;
907 }
908 pf->addr = addr;
909 pf->addr += pp->offset;
910 pr_debug("found inline addr: 0x%jx\n",
911 (uintmax_t)pf->addr);
912
913 ret = call_probe_finder(in_die, pf);
914 }
915
916 return ret;
917 }
918
919 /* Callback parameter with return value for libdw */
920 struct dwarf_callback_param {
921 void *data;
922 int retval;
923 };
924
925 /* Search function from function name */
926 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
927 {
928 struct dwarf_callback_param *param = data;
929 struct probe_finder *pf = param->data;
930 struct perf_probe_point *pp = &pf->pev->point;
931
932 /* Check tag and diename */
933 if (!die_is_func_def(sp_die) ||
934 !die_match_name(sp_die, pp->function))
935 return DWARF_CB_OK;
936
937 /* Check declared file */
938 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
939 return DWARF_CB_OK;
940
941 pr_debug("Matched function: %s\n", dwarf_diename(sp_die));
942 pf->fname = dwarf_decl_file(sp_die);
943 if (pp->line) { /* Function relative line */
944 dwarf_decl_line(sp_die, &pf->lno);
945 pf->lno += pp->line;
946 param->retval = find_probe_point_by_line(pf);
947 } else if (die_is_func_instance(sp_die)) {
948 /* Instances always have the entry address */
949 dwarf_entrypc(sp_die, &pf->addr);
950 /* Real function */
951 if (pp->lazy_line)
952 param->retval = find_probe_point_lazy(sp_die, pf);
953 else {
954 pf->addr += pp->offset;
955 /* TODO: Check the address in this function */
956 param->retval = call_probe_finder(sp_die, pf);
957 }
958 } else if (!probe_conf.no_inlines) {
959 /* Inlined function: search instances */
960 param->retval = die_walk_instances(sp_die,
961 probe_point_inline_cb, (void *)pf);
962 /* This could be a non-existed inline definition */
963 if (param->retval == -ENOENT && strisglob(pp->function))
964 param->retval = 0;
965 }
966
967 /* We need to find other candidates */
968 if (strisglob(pp->function) && param->retval >= 0) {
969 param->retval = 0; /* We have to clear the result */
970 return DWARF_CB_OK;
971 }
972
973 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
974 }
975
976 static int find_probe_point_by_func(struct probe_finder *pf)
977 {
978 struct dwarf_callback_param _param = {.data = (void *)pf,
979 .retval = 0};
980 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
981 return _param.retval;
982 }
983
984 struct pubname_callback_param {
985 char *function;
986 char *file;
987 Dwarf_Die *cu_die;
988 Dwarf_Die *sp_die;
989 int found;
990 };
991
992 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
993 {
994 struct pubname_callback_param *param = data;
995
996 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
997 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
998 return DWARF_CB_OK;
999
1000 if (die_match_name(param->sp_die, param->function)) {
1001 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1002 return DWARF_CB_OK;
1003
1004 if (param->file &&
1005 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1006 return DWARF_CB_OK;
1007
1008 param->found = 1;
1009 return DWARF_CB_ABORT;
1010 }
1011 }
1012
1013 return DWARF_CB_OK;
1014 }
1015
1016 /* Find probe points from debuginfo */
1017 static int debuginfo__find_probes(struct debuginfo *dbg,
1018 struct probe_finder *pf)
1019 {
1020 struct perf_probe_point *pp = &pf->pev->point;
1021 Dwarf_Off off, noff;
1022 size_t cuhl;
1023 Dwarf_Die *diep;
1024 int ret = 0;
1025
1026 #if _ELFUTILS_PREREQ(0, 142)
1027 Elf *elf;
1028 GElf_Ehdr ehdr;
1029 GElf_Shdr shdr;
1030
1031 /* Get the call frame information from this dwarf */
1032 elf = dwarf_getelf(dbg->dbg);
1033 if (elf == NULL)
1034 return -EINVAL;
1035
1036 if (gelf_getehdr(elf, &ehdr) == NULL)
1037 return -EINVAL;
1038
1039 if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
1040 shdr.sh_type == SHT_PROGBITS) {
1041 pf->cfi = dwarf_getcfi_elf(elf);
1042 } else {
1043 pf->cfi = dwarf_getcfi(dbg->dbg);
1044 }
1045 #endif
1046
1047 off = 0;
1048 pf->lcache = intlist__new(NULL);
1049 if (!pf->lcache)
1050 return -ENOMEM;
1051
1052 /* Fastpath: lookup by function name from .debug_pubnames section */
1053 if (pp->function && !strisglob(pp->function)) {
1054 struct pubname_callback_param pubname_param = {
1055 .function = pp->function,
1056 .file = pp->file,
1057 .cu_die = &pf->cu_die,
1058 .sp_die = &pf->sp_die,
1059 .found = 0,
1060 };
1061 struct dwarf_callback_param probe_param = {
1062 .data = pf,
1063 };
1064
1065 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1066 &pubname_param, 0);
1067 if (pubname_param.found) {
1068 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1069 if (ret)
1070 goto found;
1071 }
1072 }
1073
1074 /* Loop on CUs (Compilation Unit) */
1075 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1076 /* Get the DIE(Debugging Information Entry) of this CU */
1077 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1078 if (!diep)
1079 continue;
1080
1081 /* Check if target file is included. */
1082 if (pp->file)
1083 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1084 else
1085 pf->fname = NULL;
1086
1087 if (!pp->file || pf->fname) {
1088 if (pp->function)
1089 ret = find_probe_point_by_func(pf);
1090 else if (pp->lazy_line)
1091 ret = find_probe_point_lazy(&pf->cu_die, pf);
1092 else {
1093 pf->lno = pp->line;
1094 ret = find_probe_point_by_line(pf);
1095 }
1096 if (ret < 0)
1097 break;
1098 }
1099 off = noff;
1100 }
1101
1102 found:
1103 intlist__delete(pf->lcache);
1104 pf->lcache = NULL;
1105
1106 return ret;
1107 }
1108
1109 struct local_vars_finder {
1110 struct probe_finder *pf;
1111 struct perf_probe_arg *args;
1112 bool vars;
1113 int max_args;
1114 int nargs;
1115 int ret;
1116 };
1117
1118 /* Collect available variables in this scope */
1119 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1120 {
1121 struct local_vars_finder *vf = data;
1122 struct probe_finder *pf = vf->pf;
1123 int tag;
1124
1125 tag = dwarf_tag(die_mem);
1126 if (tag == DW_TAG_formal_parameter ||
1127 (tag == DW_TAG_variable && vf->vars)) {
1128 if (convert_variable_location(die_mem, vf->pf->addr,
1129 vf->pf->fb_ops, &pf->sp_die,
1130 NULL) == 0) {
1131 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1132 if (vf->args[vf->nargs].var == NULL) {
1133 vf->ret = -ENOMEM;
1134 return DIE_FIND_CB_END;
1135 }
1136 pr_debug(" %s", vf->args[vf->nargs].var);
1137 vf->nargs++;
1138 }
1139 }
1140
1141 if (dwarf_haspc(die_mem, vf->pf->addr))
1142 return DIE_FIND_CB_CONTINUE;
1143 else
1144 return DIE_FIND_CB_SIBLING;
1145 }
1146
1147 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1148 struct perf_probe_arg *args)
1149 {
1150 Dwarf_Die die_mem;
1151 int i;
1152 int n = 0;
1153 struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
1154 .max_args = MAX_PROBE_ARGS, .ret = 0};
1155
1156 for (i = 0; i < pf->pev->nargs; i++) {
1157 /* var never be NULL */
1158 if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
1159 vf.vars = true;
1160 else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
1161 /* Copy normal argument */
1162 args[n] = pf->pev->args[i];
1163 n++;
1164 continue;
1165 }
1166 pr_debug("Expanding %s into:", pf->pev->args[i].var);
1167 vf.nargs = n;
1168 /* Special local variables */
1169 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1170 &die_mem);
1171 pr_debug(" (%d)\n", vf.nargs - n);
1172 if (vf.ret < 0)
1173 return vf.ret;
1174 n = vf.nargs;
1175 }
1176 return n;
1177 }
1178
1179 /* Add a found probe point into trace event list */
1180 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1181 {
1182 struct trace_event_finder *tf =
1183 container_of(pf, struct trace_event_finder, pf);
1184 struct perf_probe_point *pp = &pf->pev->point;
1185 struct probe_trace_event *tev;
1186 struct perf_probe_arg *args = NULL;
1187 int ret, i;
1188
1189 /* Check number of tevs */
1190 if (tf->ntevs == tf->max_tevs) {
1191 pr_warning("Too many( > %d) probe point found.\n",
1192 tf->max_tevs);
1193 return -ERANGE;
1194 }
1195 tev = &tf->tevs[tf->ntevs++];
1196
1197 /* Trace point should be converted from subprogram DIE */
1198 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1199 pp->retprobe, pp->function, &tev->point);
1200 if (ret < 0)
1201 goto end;
1202
1203 tev->point.realname = strdup(dwarf_diename(sc_die));
1204 if (!tev->point.realname) {
1205 ret = -ENOMEM;
1206 goto end;
1207 }
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 ret = -ENOMEM;
1216 goto end;
1217 }
1218
1219 ret = expand_probe_args(sc_die, pf, args);
1220 if (ret < 0)
1221 goto end;
1222
1223 tev->nargs = ret;
1224 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1225 if (tev->args == NULL) {
1226 ret = -ENOMEM;
1227 goto end;
1228 }
1229
1230 /* Find each argument */
1231 for (i = 0; i < tev->nargs; i++) {
1232 pf->pvar = &args[i];
1233 pf->tvar = &tev->args[i];
1234 /* Variable should be found from scope DIE */
1235 ret = find_variable(sc_die, pf);
1236 if (ret != 0)
1237 break;
1238 }
1239
1240 end:
1241 if (ret) {
1242 clear_probe_trace_event(tev);
1243 tf->ntevs--;
1244 }
1245 free(args);
1246 return ret;
1247 }
1248
1249 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1250 int debuginfo__find_trace_events(struct debuginfo *dbg,
1251 struct perf_probe_event *pev,
1252 struct probe_trace_event **tevs)
1253 {
1254 struct trace_event_finder tf = {
1255 .pf = {.pev = pev, .callback = add_probe_trace_event},
1256 .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
1257 int ret, i;
1258
1259 /* Allocate result tevs array */
1260 *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
1261 if (*tevs == NULL)
1262 return -ENOMEM;
1263
1264 tf.tevs = *tevs;
1265 tf.ntevs = 0;
1266
1267 ret = debuginfo__find_probes(dbg, &tf.pf);
1268 if (ret < 0) {
1269 for (i = 0; i < tf.ntevs; i++)
1270 clear_probe_trace_event(&tf.tevs[i]);
1271 zfree(tevs);
1272 return ret;
1273 }
1274
1275 return (ret < 0) ? ret : tf.ntevs;
1276 }
1277
1278 /* Collect available variables in this scope */
1279 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1280 {
1281 struct available_var_finder *af = data;
1282 struct variable_list *vl;
1283 int tag, ret;
1284
1285 vl = &af->vls[af->nvls - 1];
1286
1287 tag = dwarf_tag(die_mem);
1288 if (tag == DW_TAG_formal_parameter ||
1289 tag == DW_TAG_variable) {
1290 ret = convert_variable_location(die_mem, af->pf.addr,
1291 af->pf.fb_ops, &af->pf.sp_die,
1292 NULL);
1293 if (ret == 0 || ret == -ERANGE) {
1294 int ret2;
1295 bool externs = !af->child;
1296 struct strbuf buf;
1297
1298 strbuf_init(&buf, 64);
1299
1300 if (probe_conf.show_location_range) {
1301 if (!externs) {
1302 if (ret)
1303 strbuf_addf(&buf, "[INV]\t");
1304 else
1305 strbuf_addf(&buf, "[VAL]\t");
1306 } else
1307 strbuf_addf(&buf, "[EXT]\t");
1308 }
1309
1310 ret2 = die_get_varname(die_mem, &buf);
1311
1312 if (!ret2 && probe_conf.show_location_range &&
1313 !externs) {
1314 strbuf_addf(&buf, "\t");
1315 ret2 = die_get_var_range(&af->pf.sp_die,
1316 die_mem, &buf);
1317 }
1318
1319 pr_debug("Add new var: %s\n", buf.buf);
1320 if (ret2 == 0) {
1321 strlist__add(vl->vars,
1322 strbuf_detach(&buf, NULL));
1323 }
1324 strbuf_release(&buf);
1325 }
1326 }
1327
1328 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1329 return DIE_FIND_CB_CONTINUE;
1330 else
1331 return DIE_FIND_CB_SIBLING;
1332 }
1333
1334 /* Add a found vars into available variables list */
1335 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1336 {
1337 struct available_var_finder *af =
1338 container_of(pf, struct available_var_finder, pf);
1339 struct perf_probe_point *pp = &pf->pev->point;
1340 struct variable_list *vl;
1341 Dwarf_Die die_mem;
1342 int ret;
1343
1344 /* Check number of tevs */
1345 if (af->nvls == af->max_vls) {
1346 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1347 return -ERANGE;
1348 }
1349 vl = &af->vls[af->nvls++];
1350
1351 /* Trace point should be converted from subprogram DIE */
1352 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1353 pp->retprobe, pp->function, &vl->point);
1354 if (ret < 0)
1355 return ret;
1356
1357 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1358 vl->point.offset);
1359
1360 /* Find local variables */
1361 vl->vars = strlist__new(NULL, NULL);
1362 if (vl->vars == NULL)
1363 return -ENOMEM;
1364 af->child = true;
1365 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1366
1367 /* Find external variables */
1368 if (!probe_conf.show_ext_vars)
1369 goto out;
1370 /* Don't need to search child DIE for external vars. */
1371 af->child = false;
1372 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1373
1374 out:
1375 if (strlist__empty(vl->vars)) {
1376 strlist__delete(vl->vars);
1377 vl->vars = NULL;
1378 }
1379
1380 return ret;
1381 }
1382
1383 /*
1384 * Find available variables at given probe point
1385 * Return the number of found probe points. Return 0 if there is no
1386 * matched probe point. Return <0 if an error occurs.
1387 */
1388 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1389 struct perf_probe_event *pev,
1390 struct variable_list **vls)
1391 {
1392 struct available_var_finder af = {
1393 .pf = {.pev = pev, .callback = add_available_vars},
1394 .mod = dbg->mod,
1395 .max_vls = probe_conf.max_probes};
1396 int ret;
1397
1398 /* Allocate result vls array */
1399 *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
1400 if (*vls == NULL)
1401 return -ENOMEM;
1402
1403 af.vls = *vls;
1404 af.nvls = 0;
1405
1406 ret = debuginfo__find_probes(dbg, &af.pf);
1407 if (ret < 0) {
1408 /* Free vlist for error */
1409 while (af.nvls--) {
1410 zfree(&af.vls[af.nvls].point.symbol);
1411 strlist__delete(af.vls[af.nvls].vars);
1412 }
1413 zfree(vls);
1414 return ret;
1415 }
1416
1417 return (ret < 0) ? ret : af.nvls;
1418 }
1419
1420 /* For the kernel module, we need a special code to get a DIE */
1421 static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs)
1422 {
1423 int n, i;
1424 Elf32_Word shndx;
1425 Elf_Scn *scn;
1426 Elf *elf;
1427 GElf_Shdr mem, *shdr;
1428 const char *p;
1429
1430 elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
1431 if (!elf)
1432 return -EINVAL;
1433
1434 /* Get the number of relocations */
1435 n = dwfl_module_relocations(dbg->mod);
1436 if (n < 0)
1437 return -ENOENT;
1438 /* Search the relocation related .text section */
1439 for (i = 0; i < n; i++) {
1440 p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
1441 if (strcmp(p, ".text") == 0) {
1442 /* OK, get the section header */
1443 scn = elf_getscn(elf, shndx);
1444 if (!scn)
1445 return -ENOENT;
1446 shdr = gelf_getshdr(scn, &mem);
1447 if (!shdr)
1448 return -ENOENT;
1449 *offs = shdr->sh_addr;
1450 }
1451 }
1452 return 0;
1453 }
1454
1455 /* Reverse search */
1456 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1457 struct perf_probe_point *ppt)
1458 {
1459 Dwarf_Die cudie, spdie, indie;
1460 Dwarf_Addr _addr = 0, baseaddr = 0;
1461 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1462 int baseline = 0, lineno = 0, ret = 0;
1463 bool reloc = false;
1464
1465 retry:
1466 /* Find cu die */
1467 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
1468 if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) {
1469 addr += baseaddr;
1470 reloc = true;
1471 goto retry;
1472 }
1473 pr_warning("Failed to find debug information for address %lx\n",
1474 addr);
1475 ret = -EINVAL;
1476 goto end;
1477 }
1478
1479 /* Find a corresponding line (filename and lineno) */
1480 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1481 /* Don't care whether it failed or not */
1482
1483 /* Find a corresponding function (name, baseline and baseaddr) */
1484 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1485 /* Get function entry information */
1486 func = basefunc = dwarf_diename(&spdie);
1487 if (!func ||
1488 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1489 dwarf_decl_line(&spdie, &baseline) != 0) {
1490 lineno = 0;
1491 goto post;
1492 }
1493
1494 fname = dwarf_decl_file(&spdie);
1495 if (addr == (unsigned long)baseaddr) {
1496 /* Function entry - Relative line number is 0 */
1497 lineno = baseline;
1498 goto post;
1499 }
1500
1501 /* Track down the inline functions step by step */
1502 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1503 &indie)) {
1504 /* There is an inline function */
1505 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1506 _addr == addr) {
1507 /*
1508 * addr is at an inline function entry.
1509 * In this case, lineno should be the call-site
1510 * line number. (overwrite lineinfo)
1511 */
1512 lineno = die_get_call_lineno(&indie);
1513 fname = die_get_call_file(&indie);
1514 break;
1515 } else {
1516 /*
1517 * addr is in an inline function body.
1518 * Since lineno points one of the lines
1519 * of the inline function, baseline should
1520 * be the entry line of the inline function.
1521 */
1522 tmp = dwarf_diename(&indie);
1523 if (!tmp ||
1524 dwarf_decl_line(&indie, &baseline) != 0)
1525 break;
1526 func = tmp;
1527 spdie = indie;
1528 }
1529 }
1530 /* Verify the lineno and baseline are in a same file */
1531 tmp = dwarf_decl_file(&spdie);
1532 if (!tmp || strcmp(tmp, fname) != 0)
1533 lineno = 0;
1534 }
1535
1536 post:
1537 /* Make a relative line number or an offset */
1538 if (lineno)
1539 ppt->line = lineno - baseline;
1540 else if (basefunc) {
1541 ppt->offset = addr - (unsigned long)baseaddr;
1542 func = basefunc;
1543 }
1544
1545 /* Duplicate strings */
1546 if (func) {
1547 ppt->function = strdup(func);
1548 if (ppt->function == NULL) {
1549 ret = -ENOMEM;
1550 goto end;
1551 }
1552 }
1553 if (fname) {
1554 ppt->file = strdup(fname);
1555 if (ppt->file == NULL) {
1556 zfree(&ppt->function);
1557 ret = -ENOMEM;
1558 goto end;
1559 }
1560 }
1561 end:
1562 if (ret == 0 && (fname || func))
1563 ret = 1; /* Found a point */
1564 return ret;
1565 }
1566
1567 /* Add a line and store the src path */
1568 static int line_range_add_line(const char *src, unsigned int lineno,
1569 struct line_range *lr)
1570 {
1571 /* Copy source path */
1572 if (!lr->path) {
1573 lr->path = strdup(src);
1574 if (lr->path == NULL)
1575 return -ENOMEM;
1576 }
1577 return intlist__add(lr->line_list, lineno);
1578 }
1579
1580 static int line_range_walk_cb(const char *fname, int lineno,
1581 Dwarf_Addr addr __maybe_unused,
1582 void *data)
1583 {
1584 struct line_finder *lf = data;
1585 int err;
1586
1587 if ((strtailcmp(fname, lf->fname) != 0) ||
1588 (lf->lno_s > lineno || lf->lno_e < lineno))
1589 return 0;
1590
1591 err = line_range_add_line(fname, lineno, lf->lr);
1592 if (err < 0 && err != -EEXIST)
1593 return err;
1594
1595 return 0;
1596 }
1597
1598 /* Find line range from its line number */
1599 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1600 {
1601 int ret;
1602
1603 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1604
1605 /* Update status */
1606 if (ret >= 0)
1607 if (!intlist__empty(lf->lr->line_list))
1608 ret = lf->found = 1;
1609 else
1610 ret = 0; /* Lines are not found */
1611 else {
1612 zfree(&lf->lr->path);
1613 }
1614 return ret;
1615 }
1616
1617 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1618 {
1619 int ret = find_line_range_by_line(in_die, data);
1620
1621 /*
1622 * We have to check all instances of inlined function, because
1623 * some execution paths can be optimized out depends on the
1624 * function argument of instances. However, if an error occurs,
1625 * it should be handled by the caller.
1626 */
1627 return ret < 0 ? ret : 0;
1628 }
1629
1630 /* Search function definition from function name */
1631 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1632 {
1633 struct dwarf_callback_param *param = data;
1634 struct line_finder *lf = param->data;
1635 struct line_range *lr = lf->lr;
1636
1637 /* Check declared file */
1638 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1639 return DWARF_CB_OK;
1640
1641 if (die_is_func_def(sp_die) &&
1642 die_match_name(sp_die, lr->function)) {
1643 lf->fname = dwarf_decl_file(sp_die);
1644 dwarf_decl_line(sp_die, &lr->offset);
1645 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1646 lf->lno_s = lr->offset + lr->start;
1647 if (lf->lno_s < 0) /* Overflow */
1648 lf->lno_s = INT_MAX;
1649 lf->lno_e = lr->offset + lr->end;
1650 if (lf->lno_e < 0) /* Overflow */
1651 lf->lno_e = INT_MAX;
1652 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1653 lr->start = lf->lno_s;
1654 lr->end = lf->lno_e;
1655 if (!die_is_func_instance(sp_die))
1656 param->retval = die_walk_instances(sp_die,
1657 line_range_inline_cb, lf);
1658 else
1659 param->retval = find_line_range_by_line(sp_die, lf);
1660 return DWARF_CB_ABORT;
1661 }
1662 return DWARF_CB_OK;
1663 }
1664
1665 static int find_line_range_by_func(struct line_finder *lf)
1666 {
1667 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1668 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1669 return param.retval;
1670 }
1671
1672 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1673 {
1674 struct line_finder lf = {.lr = lr, .found = 0};
1675 int ret = 0;
1676 Dwarf_Off off = 0, noff;
1677 size_t cuhl;
1678 Dwarf_Die *diep;
1679 const char *comp_dir;
1680
1681 /* Fastpath: lookup by function name from .debug_pubnames section */
1682 if (lr->function) {
1683 struct pubname_callback_param pubname_param = {
1684 .function = lr->function, .file = lr->file,
1685 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1686 struct dwarf_callback_param line_range_param = {
1687 .data = (void *)&lf, .retval = 0};
1688
1689 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1690 &pubname_param, 0);
1691 if (pubname_param.found) {
1692 line_range_search_cb(&lf.sp_die, &line_range_param);
1693 if (lf.found)
1694 goto found;
1695 }
1696 }
1697
1698 /* Loop on CUs (Compilation Unit) */
1699 while (!lf.found && ret >= 0) {
1700 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1701 NULL, NULL, NULL) != 0)
1702 break;
1703
1704 /* Get the DIE(Debugging Information Entry) of this CU */
1705 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1706 if (!diep)
1707 continue;
1708
1709 /* Check if target file is included. */
1710 if (lr->file)
1711 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1712 else
1713 lf.fname = 0;
1714
1715 if (!lr->file || lf.fname) {
1716 if (lr->function)
1717 ret = find_line_range_by_func(&lf);
1718 else {
1719 lf.lno_s = lr->start;
1720 lf.lno_e = lr->end;
1721 ret = find_line_range_by_line(NULL, &lf);
1722 }
1723 }
1724 off = noff;
1725 }
1726
1727 found:
1728 /* Store comp_dir */
1729 if (lf.found) {
1730 comp_dir = cu_get_comp_dir(&lf.cu_die);
1731 if (comp_dir) {
1732 lr->comp_dir = strdup(comp_dir);
1733 if (!lr->comp_dir)
1734 ret = -ENOMEM;
1735 }
1736 }
1737
1738 pr_debug("path: %s\n", lr->path);
1739 return (ret < 0) ? ret : lf.found;
1740 }
1741
1742 /*
1743 * Find a src file from a DWARF tag path. Prepend optional source path prefix
1744 * and chop off leading directories that do not exist. Result is passed back as
1745 * a newly allocated path on success.
1746 * Return 0 if file was found and readable, -errno otherwise.
1747 */
1748 int get_real_path(const char *raw_path, const char *comp_dir,
1749 char **new_path)
1750 {
1751 const char *prefix = symbol_conf.source_prefix;
1752
1753 if (!prefix) {
1754 if (raw_path[0] != '/' && comp_dir)
1755 /* If not an absolute path, try to use comp_dir */
1756 prefix = comp_dir;
1757 else {
1758 if (access(raw_path, R_OK) == 0) {
1759 *new_path = strdup(raw_path);
1760 return *new_path ? 0 : -ENOMEM;
1761 } else
1762 return -errno;
1763 }
1764 }
1765
1766 *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
1767 if (!*new_path)
1768 return -ENOMEM;
1769
1770 for (;;) {
1771 sprintf(*new_path, "%s/%s", prefix, raw_path);
1772
1773 if (access(*new_path, R_OK) == 0)
1774 return 0;
1775
1776 if (!symbol_conf.source_prefix) {
1777 /* In case of searching comp_dir, don't retry */
1778 zfree(new_path);
1779 return -errno;
1780 }
1781
1782 switch (errno) {
1783 case ENAMETOOLONG:
1784 case ENOENT:
1785 case EROFS:
1786 case EFAULT:
1787 raw_path = strchr(++raw_path, '/');
1788 if (!raw_path) {
1789 zfree(new_path);
1790 return -ENOENT;
1791 }
1792 continue;
1793
1794 default:
1795 zfree(new_path);
1796 return -errno;
1797 }
1798 }
1799 }
Linux with added FPC-III support