projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
m68knommu: fix user a5 register being overwritten
[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 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 str_error_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, *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 buf = synthesize_perf_probe_arg(pf->pvar);
567 if (!buf)
568 return -ENOMEM;
569 ptr = strchr(buf, ':'); /* Change type separator to _ */
570 if (ptr)
571 *ptr = '_';
572 pf->tvar->name = 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 Dwarf_Frame *frame = NULL;
658 size_t nops;
659 int ret;
660
661 if (!sc_die) {
662 pr_err("Caller must pass a scope DIE. Program error.\n");
663 return -EINVAL;
664 }
665
666 /* If not a real subprogram, find a real one */
667 if (!die_is_func_def(sc_die)) {
668 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
669 if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
670 pr_warning("Ignoring tail call from %s\n",
671 dwarf_diename(&pf->sp_die));
672 return 0;
673 } else {
674 pr_warning("Failed to find probe point in any "
675 "functions.\n");
676 return -ENOENT;
677 }
678 }
679 } else
680 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
681
682 /* Get the frame base attribute/ops from subprogram */
683 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
684 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
685 if (ret <= 0 || nops == 0) {
686 pf->fb_ops = NULL;
687 #if _ELFUTILS_PREREQ(0, 142)
688 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
689 (pf->cfi_eh != NULL || pf->cfi_dbg != NULL)) {
690 if ((dwarf_cfi_addrframe(pf->cfi_eh, pf->addr, &frame) != 0 &&
691 (dwarf_cfi_addrframe(pf->cfi_dbg, pf->addr, &frame) != 0)) ||
692 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
693 pr_warning("Failed to get call frame on 0x%jx\n",
694 (uintmax_t)pf->addr);
695 free(frame);
696 return -ENOENT;
697 }
698 #endif
699 }
700
701 /* Call finder's callback handler */
702 ret = pf->callback(sc_die, pf);
703
704 /* Since *pf->fb_ops can be a part of frame. we should free it here. */
705 free(frame);
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 str_error_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 static int debuginfo__find_probe_location(struct debuginfo *dbg,
1020 struct probe_finder *pf)
1021 {
1022 struct perf_probe_point *pp = &pf->pev->point;
1023 Dwarf_Off off, noff;
1024 size_t cuhl;
1025 Dwarf_Die *diep;
1026 int ret = 0;
1027
1028 off = 0;
1029 pf->lcache = intlist__new(NULL);
1030 if (!pf->lcache)
1031 return -ENOMEM;
1032
1033 /* Fastpath: lookup by function name from .debug_pubnames section */
1034 if (pp->function && !strisglob(pp->function)) {
1035 struct pubname_callback_param pubname_param = {
1036 .function = pp->function,
1037 .file = pp->file,
1038 .cu_die = &pf->cu_die,
1039 .sp_die = &pf->sp_die,
1040 .found = 0,
1041 };
1042 struct dwarf_callback_param probe_param = {
1043 .data = pf,
1044 };
1045
1046 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1047 &pubname_param, 0);
1048 if (pubname_param.found) {
1049 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1050 if (ret)
1051 goto found;
1052 }
1053 }
1054
1055 /* Loop on CUs (Compilation Unit) */
1056 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1057 /* Get the DIE(Debugging Information Entry) of this CU */
1058 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1059 if (!diep)
1060 continue;
1061
1062 /* Check if target file is included. */
1063 if (pp->file)
1064 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1065 else
1066 pf->fname = NULL;
1067
1068 if (!pp->file || pf->fname) {
1069 if (pp->function)
1070 ret = find_probe_point_by_func(pf);
1071 else if (pp->lazy_line)
1072 ret = find_probe_point_lazy(&pf->cu_die, pf);
1073 else {
1074 pf->lno = pp->line;
1075 ret = find_probe_point_by_line(pf);
1076 }
1077 if (ret < 0)
1078 break;
1079 }
1080 off = noff;
1081 }
1082
1083 found:
1084 intlist__delete(pf->lcache);
1085 pf->lcache = NULL;
1086
1087 return ret;
1088 }
1089
1090 /* Find probe points from debuginfo */
1091 static int debuginfo__find_probes(struct debuginfo *dbg,
1092 struct probe_finder *pf)
1093 {
1094 int ret = 0;
1095
1096 #if _ELFUTILS_PREREQ(0, 142)
1097 Elf *elf;
1098 GElf_Ehdr ehdr;
1099 GElf_Shdr shdr;
1100
1101 if (pf->cfi_eh || pf->cfi_dbg)
1102 return debuginfo__find_probe_location(dbg, pf);
1103
1104 /* Get the call frame information from this dwarf */
1105 elf = dwarf_getelf(dbg->dbg);
1106 if (elf == NULL)
1107 return -EINVAL;
1108
1109 if (gelf_getehdr(elf, &ehdr) == NULL)
1110 return -EINVAL;
1111
1112 if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
1113 shdr.sh_type == SHT_PROGBITS)
1114 pf->cfi_eh = dwarf_getcfi_elf(elf);
1115
1116 pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
1117 #endif
1118
1119 ret = debuginfo__find_probe_location(dbg, pf);
1120 return ret;
1121 }
1122
1123 struct local_vars_finder {
1124 struct probe_finder *pf;
1125 struct perf_probe_arg *args;
1126 bool vars;
1127 int max_args;
1128 int nargs;
1129 int ret;
1130 };
1131
1132 /* Collect available variables in this scope */
1133 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1134 {
1135 struct local_vars_finder *vf = data;
1136 struct probe_finder *pf = vf->pf;
1137 int tag;
1138
1139 tag = dwarf_tag(die_mem);
1140 if (tag == DW_TAG_formal_parameter ||
1141 (tag == DW_TAG_variable && vf->vars)) {
1142 if (convert_variable_location(die_mem, vf->pf->addr,
1143 vf->pf->fb_ops, &pf->sp_die,
1144 NULL) == 0) {
1145 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1146 if (vf->args[vf->nargs].var == NULL) {
1147 vf->ret = -ENOMEM;
1148 return DIE_FIND_CB_END;
1149 }
1150 pr_debug(" %s", vf->args[vf->nargs].var);
1151 vf->nargs++;
1152 }
1153 }
1154
1155 if (dwarf_haspc(die_mem, vf->pf->addr))
1156 return DIE_FIND_CB_CONTINUE;
1157 else
1158 return DIE_FIND_CB_SIBLING;
1159 }
1160
1161 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1162 struct perf_probe_arg *args)
1163 {
1164 Dwarf_Die die_mem;
1165 int i;
1166 int n = 0;
1167 struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
1168 .max_args = MAX_PROBE_ARGS, .ret = 0};
1169
1170 for (i = 0; i < pf->pev->nargs; i++) {
1171 /* var never be NULL */
1172 if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
1173 vf.vars = true;
1174 else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
1175 /* Copy normal argument */
1176 args[n] = pf->pev->args[i];
1177 n++;
1178 continue;
1179 }
1180 pr_debug("Expanding %s into:", pf->pev->args[i].var);
1181 vf.nargs = n;
1182 /* Special local variables */
1183 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1184 &die_mem);
1185 pr_debug(" (%d)\n", vf.nargs - n);
1186 if (vf.ret < 0)
1187 return vf.ret;
1188 n = vf.nargs;
1189 }
1190 return n;
1191 }
1192
1193 /* Add a found probe point into trace event list */
1194 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1195 {
1196 struct trace_event_finder *tf =
1197 container_of(pf, struct trace_event_finder, pf);
1198 struct perf_probe_point *pp = &pf->pev->point;
1199 struct probe_trace_event *tev;
1200 struct perf_probe_arg *args = NULL;
1201 int ret, i;
1202
1203 /* Check number of tevs */
1204 if (tf->ntevs == tf->max_tevs) {
1205 pr_warning("Too many( > %d) probe point found.\n",
1206 tf->max_tevs);
1207 return -ERANGE;
1208 }
1209 tev = &tf->tevs[tf->ntevs++];
1210
1211 /* Trace point should be converted from subprogram DIE */
1212 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1213 pp->retprobe, pp->function, &tev->point);
1214 if (ret < 0)
1215 goto end;
1216
1217 tev->point.realname = strdup(dwarf_diename(sc_die));
1218 if (!tev->point.realname) {
1219 ret = -ENOMEM;
1220 goto end;
1221 }
1222
1223 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1224 tev->point.offset);
1225
1226 /* Expand special probe argument if exist */
1227 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1228 if (args == NULL) {
1229 ret = -ENOMEM;
1230 goto end;
1231 }
1232
1233 ret = expand_probe_args(sc_die, pf, args);
1234 if (ret < 0)
1235 goto end;
1236
1237 tev->nargs = ret;
1238 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1239 if (tev->args == NULL) {
1240 ret = -ENOMEM;
1241 goto end;
1242 }
1243
1244 /* Find each argument */
1245 for (i = 0; i < tev->nargs; i++) {
1246 pf->pvar = &args[i];
1247 pf->tvar = &tev->args[i];
1248 /* Variable should be found from scope DIE */
1249 ret = find_variable(sc_die, pf);
1250 if (ret != 0)
1251 break;
1252 }
1253
1254 end:
1255 if (ret) {
1256 clear_probe_trace_event(tev);
1257 tf->ntevs--;
1258 }
1259 free(args);
1260 return ret;
1261 }
1262
1263 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1264 int debuginfo__find_trace_events(struct debuginfo *dbg,
1265 struct perf_probe_event *pev,
1266 struct probe_trace_event **tevs)
1267 {
1268 struct trace_event_finder tf = {
1269 .pf = {.pev = pev, .callback = add_probe_trace_event},
1270 .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
1271 int ret, i;
1272
1273 /* Allocate result tevs array */
1274 *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
1275 if (*tevs == NULL)
1276 return -ENOMEM;
1277
1278 tf.tevs = *tevs;
1279 tf.ntevs = 0;
1280
1281 ret = debuginfo__find_probes(dbg, &tf.pf);
1282 if (ret < 0) {
1283 for (i = 0; i < tf.ntevs; i++)
1284 clear_probe_trace_event(&tf.tevs[i]);
1285 zfree(tevs);
1286 return ret;
1287 }
1288
1289 return (ret < 0) ? ret : tf.ntevs;
1290 }
1291
1292 /* Collect available variables in this scope */
1293 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1294 {
1295 struct available_var_finder *af = data;
1296 struct variable_list *vl;
1297 struct strbuf buf = STRBUF_INIT;
1298 int tag, ret;
1299
1300 vl = &af->vls[af->nvls - 1];
1301
1302 tag = dwarf_tag(die_mem);
1303 if (tag == DW_TAG_formal_parameter ||
1304 tag == DW_TAG_variable) {
1305 ret = convert_variable_location(die_mem, af->pf.addr,
1306 af->pf.fb_ops, &af->pf.sp_die,
1307 NULL);
1308 if (ret == 0 || ret == -ERANGE) {
1309 int ret2;
1310 bool externs = !af->child;
1311
1312 if (strbuf_init(&buf, 64) < 0)
1313 goto error;
1314
1315 if (probe_conf.show_location_range) {
1316 if (!externs)
1317 ret2 = strbuf_add(&buf,
1318 ret ? "[INV]\t" : "[VAL]\t", 6);
1319 else
1320 ret2 = strbuf_add(&buf, "[EXT]\t", 6);
1321 if (ret2)
1322 goto error;
1323 }
1324
1325 ret2 = die_get_varname(die_mem, &buf);
1326
1327 if (!ret2 && probe_conf.show_location_range &&
1328 !externs) {
1329 if (strbuf_addch(&buf, '\t') < 0)
1330 goto error;
1331 ret2 = die_get_var_range(&af->pf.sp_die,
1332 die_mem, &buf);
1333 }
1334
1335 pr_debug("Add new var: %s\n", buf.buf);
1336 if (ret2 == 0) {
1337 strlist__add(vl->vars,
1338 strbuf_detach(&buf, NULL));
1339 }
1340 strbuf_release(&buf);
1341 }
1342 }
1343
1344 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1345 return DIE_FIND_CB_CONTINUE;
1346 else
1347 return DIE_FIND_CB_SIBLING;
1348 error:
1349 strbuf_release(&buf);
1350 pr_debug("Error in strbuf\n");
1351 return DIE_FIND_CB_END;
1352 }
1353
1354 /* Add a found vars into available variables list */
1355 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1356 {
1357 struct available_var_finder *af =
1358 container_of(pf, struct available_var_finder, pf);
1359 struct perf_probe_point *pp = &pf->pev->point;
1360 struct variable_list *vl;
1361 Dwarf_Die die_mem;
1362 int ret;
1363
1364 /* Check number of tevs */
1365 if (af->nvls == af->max_vls) {
1366 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1367 return -ERANGE;
1368 }
1369 vl = &af->vls[af->nvls++];
1370
1371 /* Trace point should be converted from subprogram DIE */
1372 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1373 pp->retprobe, pp->function, &vl->point);
1374 if (ret < 0)
1375 return ret;
1376
1377 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1378 vl->point.offset);
1379
1380 /* Find local variables */
1381 vl->vars = strlist__new(NULL, NULL);
1382 if (vl->vars == NULL)
1383 return -ENOMEM;
1384 af->child = true;
1385 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1386
1387 /* Find external variables */
1388 if (!probe_conf.show_ext_vars)
1389 goto out;
1390 /* Don't need to search child DIE for external vars. */
1391 af->child = false;
1392 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1393
1394 out:
1395 if (strlist__empty(vl->vars)) {
1396 strlist__delete(vl->vars);
1397 vl->vars = NULL;
1398 }
1399
1400 return ret;
1401 }
1402
1403 /*
1404 * Find available variables at given probe point
1405 * Return the number of found probe points. Return 0 if there is no
1406 * matched probe point. Return <0 if an error occurs.
1407 */
1408 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1409 struct perf_probe_event *pev,
1410 struct variable_list **vls)
1411 {
1412 struct available_var_finder af = {
1413 .pf = {.pev = pev, .callback = add_available_vars},
1414 .mod = dbg->mod,
1415 .max_vls = probe_conf.max_probes};
1416 int ret;
1417
1418 /* Allocate result vls array */
1419 *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
1420 if (*vls == NULL)
1421 return -ENOMEM;
1422
1423 af.vls = *vls;
1424 af.nvls = 0;
1425
1426 ret = debuginfo__find_probes(dbg, &af.pf);
1427 if (ret < 0) {
1428 /* Free vlist for error */
1429 while (af.nvls--) {
1430 zfree(&af.vls[af.nvls].point.symbol);
1431 strlist__delete(af.vls[af.nvls].vars);
1432 }
1433 zfree(vls);
1434 return ret;
1435 }
1436
1437 return (ret < 0) ? ret : af.nvls;
1438 }
1439
1440 /* For the kernel module, we need a special code to get a DIE */
1441 static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs)
1442 {
1443 int n, i;
1444 Elf32_Word shndx;
1445 Elf_Scn *scn;
1446 Elf *elf;
1447 GElf_Shdr mem, *shdr;
1448 const char *p;
1449
1450 elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
1451 if (!elf)
1452 return -EINVAL;
1453
1454 /* Get the number of relocations */
1455 n = dwfl_module_relocations(dbg->mod);
1456 if (n < 0)
1457 return -ENOENT;
1458 /* Search the relocation related .text section */
1459 for (i = 0; i < n; i++) {
1460 p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
1461 if (strcmp(p, ".text") == 0) {
1462 /* OK, get the section header */
1463 scn = elf_getscn(elf, shndx);
1464 if (!scn)
1465 return -ENOENT;
1466 shdr = gelf_getshdr(scn, &mem);
1467 if (!shdr)
1468 return -ENOENT;
1469 *offs = shdr->sh_addr;
1470 }
1471 }
1472 return 0;
1473 }
1474
1475 /* Reverse search */
1476 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1477 struct perf_probe_point *ppt)
1478 {
1479 Dwarf_Die cudie, spdie, indie;
1480 Dwarf_Addr _addr = 0, baseaddr = 0;
1481 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1482 int baseline = 0, lineno = 0, ret = 0;
1483 bool reloc = false;
1484
1485 retry:
1486 /* Find cu die */
1487 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
1488 if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) {
1489 addr += baseaddr;
1490 reloc = true;
1491 goto retry;
1492 }
1493 pr_warning("Failed to find debug information for address %lx\n",
1494 addr);
1495 ret = -EINVAL;
1496 goto end;
1497 }
1498
1499 /* Find a corresponding line (filename and lineno) */
1500 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1501 /* Don't care whether it failed or not */
1502
1503 /* Find a corresponding function (name, baseline and baseaddr) */
1504 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1505 /* Get function entry information */
1506 func = basefunc = dwarf_diename(&spdie);
1507 if (!func ||
1508 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1509 dwarf_decl_line(&spdie, &baseline) != 0) {
1510 lineno = 0;
1511 goto post;
1512 }
1513
1514 fname = dwarf_decl_file(&spdie);
1515 if (addr == (unsigned long)baseaddr) {
1516 /* Function entry - Relative line number is 0 */
1517 lineno = baseline;
1518 goto post;
1519 }
1520
1521 /* Track down the inline functions step by step */
1522 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1523 &indie)) {
1524 /* There is an inline function */
1525 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1526 _addr == addr) {
1527 /*
1528 * addr is at an inline function entry.
1529 * In this case, lineno should be the call-site
1530 * line number. (overwrite lineinfo)
1531 */
1532 lineno = die_get_call_lineno(&indie);
1533 fname = die_get_call_file(&indie);
1534 break;
1535 } else {
1536 /*
1537 * addr is in an inline function body.
1538 * Since lineno points one of the lines
1539 * of the inline function, baseline should
1540 * be the entry line of the inline function.
1541 */
1542 tmp = dwarf_diename(&indie);
1543 if (!tmp ||
1544 dwarf_decl_line(&indie, &baseline) != 0)
1545 break;
1546 func = tmp;
1547 spdie = indie;
1548 }
1549 }
1550 /* Verify the lineno and baseline are in a same file */
1551 tmp = dwarf_decl_file(&spdie);
1552 if (!tmp || strcmp(tmp, fname) != 0)
1553 lineno = 0;
1554 }
1555
1556 post:
1557 /* Make a relative line number or an offset */
1558 if (lineno)
1559 ppt->line = lineno - baseline;
1560 else if (basefunc) {
1561 ppt->offset = addr - (unsigned long)baseaddr;
1562 func = basefunc;
1563 }
1564
1565 /* Duplicate strings */
1566 if (func) {
1567 ppt->function = strdup(func);
1568 if (ppt->function == NULL) {
1569 ret = -ENOMEM;
1570 goto end;
1571 }
1572 }
1573 if (fname) {
1574 ppt->file = strdup(fname);
1575 if (ppt->file == NULL) {
1576 zfree(&ppt->function);
1577 ret = -ENOMEM;
1578 goto end;
1579 }
1580 }
1581 end:
1582 if (ret == 0 && (fname || func))
1583 ret = 1; /* Found a point */
1584 return ret;
1585 }
1586
1587 /* Add a line and store the src path */
1588 static int line_range_add_line(const char *src, unsigned int lineno,
1589 struct line_range *lr)
1590 {
1591 /* Copy source path */
1592 if (!lr->path) {
1593 lr->path = strdup(src);
1594 if (lr->path == NULL)
1595 return -ENOMEM;
1596 }
1597 return intlist__add(lr->line_list, lineno);
1598 }
1599
1600 static int line_range_walk_cb(const char *fname, int lineno,
1601 Dwarf_Addr addr __maybe_unused,
1602 void *data)
1603 {
1604 struct line_finder *lf = data;
1605 int err;
1606
1607 if ((strtailcmp(fname, lf->fname) != 0) ||
1608 (lf->lno_s > lineno || lf->lno_e < lineno))
1609 return 0;
1610
1611 err = line_range_add_line(fname, lineno, lf->lr);
1612 if (err < 0 && err != -EEXIST)
1613 return err;
1614
1615 return 0;
1616 }
1617
1618 /* Find line range from its line number */
1619 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1620 {
1621 int ret;
1622
1623 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1624
1625 /* Update status */
1626 if (ret >= 0)
1627 if (!intlist__empty(lf->lr->line_list))
1628 ret = lf->found = 1;
1629 else
1630 ret = 0; /* Lines are not found */
1631 else {
1632 zfree(&lf->lr->path);
1633 }
1634 return ret;
1635 }
1636
1637 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1638 {
1639 int ret = find_line_range_by_line(in_die, data);
1640
1641 /*
1642 * We have to check all instances of inlined function, because
1643 * some execution paths can be optimized out depends on the
1644 * function argument of instances. However, if an error occurs,
1645 * it should be handled by the caller.
1646 */
1647 return ret < 0 ? ret : 0;
1648 }
1649
1650 /* Search function definition from function name */
1651 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1652 {
1653 struct dwarf_callback_param *param = data;
1654 struct line_finder *lf = param->data;
1655 struct line_range *lr = lf->lr;
1656
1657 /* Check declared file */
1658 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1659 return DWARF_CB_OK;
1660
1661 if (die_is_func_def(sp_die) &&
1662 die_match_name(sp_die, lr->function)) {
1663 lf->fname = dwarf_decl_file(sp_die);
1664 dwarf_decl_line(sp_die, &lr->offset);
1665 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1666 lf->lno_s = lr->offset + lr->start;
1667 if (lf->lno_s < 0) /* Overflow */
1668 lf->lno_s = INT_MAX;
1669 lf->lno_e = lr->offset + lr->end;
1670 if (lf->lno_e < 0) /* Overflow */
1671 lf->lno_e = INT_MAX;
1672 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1673 lr->start = lf->lno_s;
1674 lr->end = lf->lno_e;
1675 if (!die_is_func_instance(sp_die))
1676 param->retval = die_walk_instances(sp_die,
1677 line_range_inline_cb, lf);
1678 else
1679 param->retval = find_line_range_by_line(sp_die, lf);
1680 return DWARF_CB_ABORT;
1681 }
1682 return DWARF_CB_OK;
1683 }
1684
1685 static int find_line_range_by_func(struct line_finder *lf)
1686 {
1687 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1688 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1689 return param.retval;
1690 }
1691
1692 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1693 {
1694 struct line_finder lf = {.lr = lr, .found = 0};
1695 int ret = 0;
1696 Dwarf_Off off = 0, noff;
1697 size_t cuhl;
1698 Dwarf_Die *diep;
1699 const char *comp_dir;
1700
1701 /* Fastpath: lookup by function name from .debug_pubnames section */
1702 if (lr->function) {
1703 struct pubname_callback_param pubname_param = {
1704 .function = lr->function, .file = lr->file,
1705 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1706 struct dwarf_callback_param line_range_param = {
1707 .data = (void *)&lf, .retval = 0};
1708
1709 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1710 &pubname_param, 0);
1711 if (pubname_param.found) {
1712 line_range_search_cb(&lf.sp_die, &line_range_param);
1713 if (lf.found)
1714 goto found;
1715 }
1716 }
1717
1718 /* Loop on CUs (Compilation Unit) */
1719 while (!lf.found && ret >= 0) {
1720 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1721 NULL, NULL, NULL) != 0)
1722 break;
1723
1724 /* Get the DIE(Debugging Information Entry) of this CU */
1725 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1726 if (!diep)
1727 continue;
1728
1729 /* Check if target file is included. */
1730 if (lr->file)
1731 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1732 else
1733 lf.fname = 0;
1734
1735 if (!lr->file || lf.fname) {
1736 if (lr->function)
1737 ret = find_line_range_by_func(&lf);
1738 else {
1739 lf.lno_s = lr->start;
1740 lf.lno_e = lr->end;
1741 ret = find_line_range_by_line(NULL, &lf);
1742 }
1743 }
1744 off = noff;
1745 }
1746
1747 found:
1748 /* Store comp_dir */
1749 if (lf.found) {
1750 comp_dir = cu_get_comp_dir(&lf.cu_die);
1751 if (comp_dir) {
1752 lr->comp_dir = strdup(comp_dir);
1753 if (!lr->comp_dir)
1754 ret = -ENOMEM;
1755 }
1756 }
1757
1758 pr_debug("path: %s\n", lr->path);
1759 return (ret < 0) ? ret : lf.found;
1760 }
1761
1762 /*
1763 * Find a src file from a DWARF tag path. Prepend optional source path prefix
1764 * and chop off leading directories that do not exist. Result is passed back as
1765 * a newly allocated path on success.
1766 * Return 0 if file was found and readable, -errno otherwise.
1767 */
1768 int get_real_path(const char *raw_path, const char *comp_dir,
1769 char **new_path)
1770 {
1771 const char *prefix = symbol_conf.source_prefix;
1772
1773 if (!prefix) {
1774 if (raw_path[0] != '/' && comp_dir)
1775 /* If not an absolute path, try to use comp_dir */
1776 prefix = comp_dir;
1777 else {
1778 if (access(raw_path, R_OK) == 0) {
1779 *new_path = strdup(raw_path);
1780 return *new_path ? 0 : -ENOMEM;
1781 } else
1782 return -errno;
1783 }
1784 }
1785
1786 *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
1787 if (!*new_path)
1788 return -ENOMEM;
1789
1790 for (;;) {
1791 sprintf(*new_path, "%s/%s", prefix, raw_path);
1792
1793 if (access(*new_path, R_OK) == 0)
1794 return 0;
1795
1796 if (!symbol_conf.source_prefix) {
1797 /* In case of searching comp_dir, don't retry */
1798 zfree(new_path);
1799 return -errno;
1800 }
1801
1802 switch (errno) {
1803 case ENAMETOOLONG:
1804 case ENOENT:
1805 case EROFS:
1806 case EFAULT:
1807 raw_path = strchr(++raw_path, '/');
1808 if (!raw_path) {
1809 zfree(new_path);
1810 return -ENOENT;
1811 }
1812 continue;
1813
1814 default:
1815 zfree(new_path);
1816 return -errno;
1817 }
1818 }
1819 }
Linux kernel - Deliverables
This page took 0.070805 seconds and 5 git commands to generate.