1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * probe-finder.c : C expression to kprobe event converter
5 * Written by Masami Hiramatsu <mhiramat@redhat.com>
9 #include <sys/utsname.h>
10 #include <sys/types.h>
19 #include <dwarf-regs.h>
21 #include <linux/bitops.h>
22 #include <linux/zalloc.h>
30 #include "probe-finder.h"
31 #include "probe-file.h"
34 /* Kprobe tracer basic type is up to u64 */
35 #define MAX_BASIC_TYPE_BITS 64
37 /* Dwarf FL wrappers */
38 static char *debuginfo_path; /* Currently dummy */
40 static const Dwfl_Callbacks offline_callbacks = {
41 .find_debuginfo = dwfl_standard_find_debuginfo,
42 .debuginfo_path = &debuginfo_path,
44 .section_address = dwfl_offline_section_address,
46 /* We use this table for core files too. */
47 .find_elf = dwfl_build_id_find_elf,
50 /* Get a Dwarf from offline image */
51 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
56 fd = open(path, O_RDONLY);
60 dbg->dwfl = dwfl_begin(&offline_callbacks);
64 dwfl_report_begin(dbg->dwfl);
65 dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
69 dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
73 dwfl_report_end(dbg->dwfl, NULL, NULL);
81 memset(dbg, 0, sizeof(*dbg));
86 static struct debuginfo *__debuginfo__new(const char *path)
88 struct debuginfo *dbg = zalloc(sizeof(*dbg));
92 if (debuginfo__init_offline_dwarf(dbg, path) < 0)
95 pr_debug("Open Debuginfo file: %s\n", path);
99 enum dso_binary_type distro_dwarf_types[] = {
100 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
101 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
102 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
103 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
104 DSO_BINARY_TYPE__NOT_FOUND,
107 struct debuginfo *debuginfo__new(const char *path)
109 enum dso_binary_type *type;
110 char buf[PATH_MAX], nil = '\0';
112 struct debuginfo *dinfo = NULL;
114 /* Try to open distro debuginfo files */
115 dso = dso__new(path);
119 for (type = distro_dwarf_types;
120 !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
122 if (dso__read_binary_type_filename(dso, *type, &nil,
125 dinfo = __debuginfo__new(buf);
130 /* if failed to open all distro debuginfo, open given binary */
131 return dinfo ? : __debuginfo__new(path);
134 void debuginfo__delete(struct debuginfo *dbg)
144 * Probe finder related functions
147 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
149 struct probe_trace_arg_ref *ref;
150 ref = zalloc(sizeof(struct probe_trace_arg_ref));
157 * Convert a location into trace_arg.
158 * If tvar == NULL, this just checks variable can be converted.
159 * If fentry == true and vr_die is a parameter, do huristic search
160 * for the location fuzzed by function entry mcount.
162 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
163 Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
164 unsigned int machine,
165 struct probe_trace_arg *tvar)
167 Dwarf_Attribute attr;
177 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
181 if (dwarf_attr(vr_die, DW_AT_const_value, &attr) &&
182 immediate_value_is_supported()) {
185 dwarf_formsdata(&attr, &snum);
186 ret = asprintf(&tvar->value, "\\%ld", (long)snum);
188 return ret < 0 ? -ENOMEM : 0;
191 /* TODO: handle more than 1 exprs */
192 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
193 return -EINVAL; /* Broken DIE ? */
194 if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
195 ret = dwarf_entrypc(sp_die, &tmp);
199 if (probe_conf.show_location_range &&
200 (dwarf_tag(vr_die) == DW_TAG_variable)) {
202 } else if (addr != tmp ||
203 dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
207 ret = dwarf_highpc(sp_die, &tmp);
211 * This is fuzzed by fentry mcount. We try to find the
212 * parameter location at the earliest address.
214 for (addr += 1; addr <= tmp; addr++) {
215 if (dwarf_getlocation_addr(&attr, addr, &op,
223 /* TODO: Support const_value */
226 if (op->atom == DW_OP_addr) {
230 /* Static variables on memory (not stack), make @varname */
231 ret = strlen(dwarf_diename(vr_die));
232 tvar->value = zalloc(ret + 2);
233 if (tvar->value == NULL)
235 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
236 tvar->ref = alloc_trace_arg_ref((long)offs);
237 if (tvar->ref == NULL)
242 /* If this is based on frame buffer, set the offset */
243 if (op->atom == DW_OP_fbreg) {
251 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
252 regn = op->atom - DW_OP_breg0;
255 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
256 regn = op->atom - DW_OP_reg0;
257 } else if (op->atom == DW_OP_bregx) {
261 } else if (op->atom == DW_OP_regx) {
264 pr_debug("DW_OP %x is not supported.\n", op->atom);
271 regs = get_dwarf_regstr(regn, machine);
273 /* This should be a bug in DWARF or this tool */
274 pr_warning("Mapping for the register number %u "
275 "missing on this architecture.\n", regn);
279 tvar->value = strdup(regs);
280 if (tvar->value == NULL)
284 tvar->ref = alloc_trace_arg_ref((long)offs);
285 if (tvar->ref == NULL)
291 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
293 static int convert_variable_type(Dwarf_Die *vr_die,
294 struct probe_trace_arg *tvar,
295 const char *cast, bool user_access)
297 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
300 char sbuf[STRERR_BUFSIZE];
301 int bsize, boffs, total;
305 /* TODO: check all types */
306 if (cast && strcmp(cast, "string") != 0 && strcmp(cast, "ustring") &&
307 strcmp(cast, "x") != 0 &&
308 strcmp(cast, "s") != 0 && strcmp(cast, "u") != 0) {
309 /* Non string type is OK */
310 /* and respect signedness/hexadecimal cast */
311 tvar->type = strdup(cast);
312 return (tvar->type == NULL) ? -ENOMEM : 0;
315 bsize = dwarf_bitsize(vr_die);
317 /* This is a bitfield */
318 boffs = dwarf_bitoffset(vr_die);
319 total = dwarf_bytesize(vr_die);
320 if (boffs < 0 || total < 0)
322 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
323 BYTES_TO_BITS(total));
327 if (die_get_real_type(vr_die, &type) == NULL) {
328 pr_warning("Failed to get a type information of %s.\n",
329 dwarf_diename(vr_die));
333 pr_debug("%s type is %s.\n",
334 dwarf_diename(vr_die), dwarf_diename(&type));
336 if (cast && (!strcmp(cast, "string") || !strcmp(cast, "ustring"))) {
338 ret = dwarf_tag(&type);
339 if (ret != DW_TAG_pointer_type &&
340 ret != DW_TAG_array_type) {
341 pr_warning("Failed to cast into string: "
342 "%s(%s) is not a pointer nor array.\n",
343 dwarf_diename(vr_die), dwarf_diename(&type));
346 if (die_get_real_type(&type, &type) == NULL) {
347 pr_warning("Failed to get a type"
351 if (ret == DW_TAG_pointer_type) {
353 ref_ptr = &(*ref_ptr)->next;
354 /* Add new reference with offset +0 */
355 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
356 if (*ref_ptr == NULL) {
357 pr_warning("Out of memory error\n");
360 (*ref_ptr)->user_access = user_access;
362 if (!die_compare_name(&type, "char") &&
363 !die_compare_name(&type, "unsigned char")) {
364 pr_warning("Failed to cast into string: "
365 "%s is not (unsigned) char *.\n",
366 dwarf_diename(vr_die));
369 tvar->type = strdup(cast);
370 return (tvar->type == NULL) ? -ENOMEM : 0;
373 if (cast && (strcmp(cast, "u") == 0))
375 else if (cast && (strcmp(cast, "s") == 0))
377 else if (cast && (strcmp(cast, "x") == 0) &&
378 probe_type_is_available(PROBE_TYPE_X))
381 prefix = die_is_signed_type(&type) ? 's' :
382 probe_type_is_available(PROBE_TYPE_X) ? 'x' : 'u';
384 ret = dwarf_bytesize(&type);
386 /* No size ... try to use default type */
388 ret = BYTES_TO_BITS(ret);
390 /* Check the bitwidth */
391 if (ret > MAX_BASIC_TYPE_BITS) {
392 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
393 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
394 ret = MAX_BASIC_TYPE_BITS;
396 ret = snprintf(buf, 16, "%c%d", prefix, ret);
399 if (ret < 0 || ret >= 16) {
402 pr_warning("Failed to convert variable type: %s\n",
403 str_error_r(-ret, sbuf, sizeof(sbuf)));
406 tvar->type = strdup(buf);
407 if (tvar->type == NULL)
412 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
413 struct perf_probe_arg_field *field,
414 struct probe_trace_arg_ref **ref_ptr,
415 Dwarf_Die *die_mem, bool user_access)
417 struct probe_trace_arg_ref *ref = *ref_ptr;
422 pr_debug("converting %s in %s\n", field->name, varname);
423 if (die_get_real_type(vr_die, &type) == NULL) {
424 pr_warning("Failed to get the type of %s.\n", varname);
427 pr_debug2("Var real type: %s (%x)\n", dwarf_diename(&type),
428 (unsigned)dwarf_dieoffset(&type));
429 tag = dwarf_tag(&type);
431 if (field->name[0] == '[' &&
432 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
433 /* Save original type for next field or type */
434 memcpy(die_mem, &type, sizeof(*die_mem));
435 /* Get the type of this array */
436 if (die_get_real_type(&type, &type) == NULL) {
437 pr_warning("Failed to get the type of %s.\n", varname);
440 pr_debug2("Array real type: %s (%x)\n", dwarf_diename(&type),
441 (unsigned)dwarf_dieoffset(&type));
442 if (tag == DW_TAG_pointer_type) {
443 ref = zalloc(sizeof(struct probe_trace_arg_ref));
447 (*ref_ptr)->next = ref;
451 ref->offset += dwarf_bytesize(&type) * field->index;
452 ref->user_access = user_access;
454 } else if (tag == DW_TAG_pointer_type) {
455 /* Check the pointer and dereference */
457 pr_err("Semantic error: %s must be referred by '->'\n",
461 /* Get the type pointed by this pointer */
462 if (die_get_real_type(&type, &type) == NULL) {
463 pr_warning("Failed to get the type of %s.\n", varname);
466 /* Verify it is a data structure */
467 tag = dwarf_tag(&type);
468 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
469 pr_warning("%s is not a data structure nor a union.\n",
474 ref = zalloc(sizeof(struct probe_trace_arg_ref));
478 (*ref_ptr)->next = ref;
482 /* Verify it is a data structure */
483 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
484 pr_warning("%s is not a data structure nor a union.\n",
488 if (field->name[0] == '[') {
489 pr_err("Semantic error: %s is not a pointer"
490 " nor array.\n", varname);
493 /* While prcessing unnamed field, we don't care about this */
494 if (field->ref && dwarf_diename(vr_die)) {
495 pr_err("Semantic error: %s must be referred by '.'\n",
500 pr_warning("Structure on a register is not "
506 if (die_find_member(&type, field->name, die_mem) == NULL) {
507 pr_warning("%s(type:%s) has no member %s.\n", varname,
508 dwarf_diename(&type), field->name);
512 /* Get the offset of the field */
513 if (tag == DW_TAG_union_type) {
516 ret = die_get_data_member_location(die_mem, &offs);
518 pr_warning("Failed to get the offset of %s.\n",
523 ref->offset += (long)offs;
524 ref->user_access = user_access;
526 /* If this member is unnamed, we need to reuse this field */
527 if (!dwarf_diename(die_mem))
528 return convert_variable_fields(die_mem, varname, field,
529 &ref, die_mem, user_access);
532 /* Converting next field */
534 return convert_variable_fields(die_mem, field->name,
535 field->next, &ref, die_mem, user_access);
540 static void print_var_not_found(const char *varname)
542 pr_err("Failed to find the location of the '%s' variable at this address.\n"
543 " Perhaps it has been optimized out.\n"
544 " Use -V with the --range option to show '%s' location range.\n",
548 /* Show a variables in kprobe event format */
549 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
554 pr_debug("Converting variable %s into trace event.\n",
555 dwarf_diename(vr_die));
557 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
558 &pf->sp_die, pf->machine, pf->tvar);
559 if (ret == -ENOENT && pf->skip_empty_arg)
560 /* This can be found in other place. skip it */
562 if (ret == -ENOENT || ret == -EINVAL) {
563 print_var_not_found(pf->pvar->var);
564 } else if (ret == -ENOTSUP)
565 pr_err("Sorry, we don't support this variable location yet.\n");
566 else if (ret == 0 && pf->pvar->field) {
567 ret = convert_variable_fields(vr_die, pf->pvar->var,
568 pf->pvar->field, &pf->tvar->ref,
569 &die_mem, pf->pvar->user_access);
573 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type,
574 pf->pvar->user_access);
575 /* *expr will be cached in libdw. Don't free it. */
579 /* Find a variable in a scope DIE */
580 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
586 /* Copy raw parameters */
587 if (!is_c_varname(pf->pvar->var))
588 return copy_to_probe_trace_arg(pf->tvar, pf->pvar);
591 pf->tvar->name = strdup(pf->pvar->name);
593 buf = synthesize_perf_probe_arg(pf->pvar);
596 ptr = strchr(buf, ':'); /* Change type separator to _ */
599 pf->tvar->name = buf;
601 if (pf->tvar->name == NULL)
604 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
605 /* Search child die for local variables and parameters. */
606 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
607 /* Search again in global variables */
608 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var,
610 if (pf->skip_empty_arg)
612 pr_warning("Failed to find '%s' in this function.\n",
618 ret = convert_variable(&vr_die, pf);
623 /* Convert subprogram DIE to trace point */
624 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
625 Dwarf_Addr paddr, bool retprobe,
626 const char *function,
627 struct probe_trace_point *tp)
633 /* Verify the address is correct */
634 if (!dwarf_haspc(sp_die, paddr)) {
635 pr_warning("Specified offset is out of %s\n",
636 dwarf_diename(sp_die));
640 if (dwarf_entrypc(sp_die, &eaddr) == 0) {
641 /* If the DIE has entrypc, use it. */
642 symbol = dwarf_diename(sp_die);
644 /* Try to get actual symbol name and address from symtab */
645 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
646 eaddr = sym.st_value;
649 pr_warning("Failed to find symbol at 0x%lx\n",
650 (unsigned long)paddr);
654 tp->offset = (unsigned long)(paddr - eaddr);
655 tp->address = (unsigned long)paddr;
656 tp->symbol = strdup(symbol);
660 /* Return probe must be on the head of a subprogram */
662 if (eaddr != paddr) {
663 pr_warning("Failed to find \"%s%%return\",\n"
664 " because %s is an inlined function and"
665 " has no return point.\n", function,
675 /* Call probe_finder callback with scope DIE */
676 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
678 Dwarf_Attribute fb_attr;
679 Dwarf_Frame *frame = NULL;
684 pr_err("Caller must pass a scope DIE. Program error.\n");
688 /* If not a real subprogram, find a real one */
689 if (!die_is_func_def(sc_die)) {
690 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
691 if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
692 pr_warning("Ignoring tail call from %s\n",
693 dwarf_diename(&pf->sp_die));
696 pr_warning("Failed to find probe point in any "
702 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
704 /* Get the frame base attribute/ops from subprogram */
705 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
706 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
707 if (ret <= 0 || nops == 0) {
709 #if _ELFUTILS_PREREQ(0, 142)
710 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
711 (pf->cfi_eh != NULL || pf->cfi_dbg != NULL)) {
712 if ((dwarf_cfi_addrframe(pf->cfi_eh, pf->addr, &frame) != 0 &&
713 (dwarf_cfi_addrframe(pf->cfi_dbg, pf->addr, &frame) != 0)) ||
714 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
715 pr_warning("Failed to get call frame on 0x%jx\n",
716 (uintmax_t)pf->addr);
723 /* Call finder's callback handler */
724 ret = pf->callback(sc_die, pf);
726 /* Since *pf->fb_ops can be a part of frame. we should free it here. */
733 struct find_scope_param {
734 const char *function;
742 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
744 struct find_scope_param *fsp = data;
748 /* Skip if declared file name does not match */
750 file = dwarf_decl_file(fn_die);
751 if (!file || strcmp(fsp->file, file) != 0)
754 /* If the function name is given, that's what user expects */
756 if (die_match_name(fn_die, fsp->function)) {
757 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
762 /* With the line number, find the nearest declared DIE */
763 dwarf_decl_line(fn_die, &lno);
764 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
765 /* Keep a candidate and continue */
766 fsp->diff = fsp->line - lno;
767 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
774 /* Return innermost DIE */
775 static int find_inner_scope_cb(Dwarf_Die *fn_die, void *data)
777 struct find_scope_param *fsp = data;
779 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
784 /* Find an appropriate scope fits to given conditions */
785 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
787 struct find_scope_param fsp = {
788 .function = pf->pev->point.function,
797 ret = cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb,
799 if (!ret && !fsp.found)
800 cu_walk_functions_at(&pf->cu_die, pf->addr,
801 find_inner_scope_cb, &fsp);
803 return fsp.found ? die_mem : NULL;
806 static int verify_representive_line(struct probe_finder *pf, const char *fname,
807 int lineno, Dwarf_Addr addr)
809 const char *__fname, *__func = NULL;
813 /* Verify line number and address by reverse search */
814 if (cu_find_lineinfo(&pf->cu_die, addr, &__fname, &__lineno) < 0)
817 pr_debug2("Reversed line: %s:%d\n", __fname, __lineno);
818 if (strcmp(fname, __fname) || lineno == __lineno)
821 pr_warning("This line is sharing the address with other lines.\n");
823 if (pf->pev->point.function) {
824 /* Find best match function name and lines */
826 if (find_best_scope(pf, &die_mem)
827 && die_match_name(&die_mem, pf->pev->point.function)
828 && dwarf_decl_line(&die_mem, &lineno) == 0) {
829 __func = dwarf_diename(&die_mem);
833 pr_warning("Please try to probe at %s:%d instead.\n",
834 __func ? : __fname, __lineno);
839 static int probe_point_line_walker(const char *fname, int lineno,
840 Dwarf_Addr addr, void *data)
842 struct probe_finder *pf = data;
843 Dwarf_Die *sc_die, die_mem;
846 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
849 if (verify_representive_line(pf, fname, lineno, addr))
853 sc_die = find_best_scope(pf, &die_mem);
855 pr_warning("Failed to find scope of probe point.\n");
859 ret = call_probe_finder(sc_die, pf);
861 /* Continue if no error, because the line will be in inline function */
862 return ret < 0 ? ret : 0;
865 /* Find probe point from its line number */
866 static int find_probe_point_by_line(struct probe_finder *pf)
868 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
871 /* Find lines which match lazy pattern */
872 static int find_lazy_match_lines(struct intlist *list,
873 const char *fname, const char *pat)
879 int count = 0, linenum = 1;
880 char sbuf[STRERR_BUFSIZE];
882 fp = fopen(fname, "r");
884 pr_warning("Failed to open %s: %s\n", fname,
885 str_error_r(errno, sbuf, sizeof(sbuf)));
889 while ((len = getline(&line, &line_len, fp)) > 0) {
891 if (line[len - 1] == '\n')
892 line[len - 1] = '\0';
894 if (strlazymatch(line, pat)) {
895 intlist__add(list, linenum);
907 pr_debug("No matched lines found in %s.\n", fname);
911 static int probe_point_lazy_walker(const char *fname, int lineno,
912 Dwarf_Addr addr, void *data)
914 struct probe_finder *pf = data;
915 Dwarf_Die *sc_die, die_mem;
918 if (!intlist__has_entry(pf->lcache, lineno) ||
919 strtailcmp(fname, pf->fname) != 0)
922 pr_debug("Probe line found: line:%d addr:0x%llx\n",
923 lineno, (unsigned long long)addr);
926 sc_die = find_best_scope(pf, &die_mem);
928 pr_warning("Failed to find scope of probe point.\n");
932 ret = call_probe_finder(sc_die, pf);
935 * Continue if no error, because the lazy pattern will match
938 return ret < 0 ? ret : 0;
941 /* Find probe points from lazy pattern */
942 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
947 if (intlist__empty(pf->lcache)) {
948 const char *comp_dir;
950 comp_dir = cu_get_comp_dir(&pf->cu_die);
951 ret = get_real_path(pf->fname, comp_dir, &fpath);
953 pr_warning("Failed to find source file path.\n");
957 /* Matching lazy line pattern */
958 ret = find_lazy_match_lines(pf->lcache, fpath,
959 pf->pev->point.lazy_line);
965 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
968 static void skip_prologue(Dwarf_Die *sp_die, struct probe_finder *pf)
970 struct perf_probe_point *pp = &pf->pev->point;
973 if (!pf->pev->uprobes)
976 /* Compiled with optimization? */
977 if (die_is_optimized_target(&pf->cu_die))
980 /* Don't know entrypc? */
984 /* Only FUNC and FUNC@SRC are eligible. */
985 if (!pp->function || pp->line || pp->retprobe || pp->lazy_line ||
986 pp->offset || pp->abs_address)
989 /* Not interested in func parameter? */
990 if (!perf_probe_with_var(pf->pev))
993 pr_info("Target program is compiled without optimization. Skipping prologue.\n"
994 "Probe on address 0x%" PRIx64 " to force probing at the function entry.\n\n",
997 die_skip_prologue(sp_die, &pf->cu_die, &pf->addr);
1000 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1002 struct probe_finder *pf = data;
1003 struct perf_probe_point *pp = &pf->pev->point;
1008 ret = find_probe_point_lazy(in_die, pf);
1010 /* Get probe address */
1011 if (die_entrypc(in_die, &addr) != 0) {
1012 pr_warning("Failed to get entry address of %s.\n",
1013 dwarf_diename(in_die));
1017 pr_debug("%s has no valid entry address. skipped.\n",
1018 dwarf_diename(in_die));
1022 pf->addr += pp->offset;
1023 pr_debug("found inline addr: 0x%jx\n",
1024 (uintmax_t)pf->addr);
1026 ret = call_probe_finder(in_die, pf);
1032 /* Callback parameter with return value for libdw */
1033 struct dwarf_callback_param {
1038 /* Search function from function name */
1039 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1041 struct dwarf_callback_param *param = data;
1042 struct probe_finder *pf = param->data;
1043 struct perf_probe_point *pp = &pf->pev->point;
1045 /* Check tag and diename */
1046 if (!die_is_func_def(sp_die) ||
1047 !die_match_name(sp_die, pp->function))
1050 /* Check declared file */
1051 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
1054 pr_debug("Matched function: %s [%lx]\n", dwarf_diename(sp_die),
1055 (unsigned long)dwarf_dieoffset(sp_die));
1056 pf->fname = dwarf_decl_file(sp_die);
1057 if (pp->line) { /* Function relative line */
1058 dwarf_decl_line(sp_die, &pf->lno);
1059 pf->lno += pp->line;
1060 param->retval = find_probe_point_by_line(pf);
1061 } else if (die_is_func_instance(sp_die)) {
1062 /* Instances always have the entry address */
1063 die_entrypc(sp_die, &pf->addr);
1064 /* But in some case the entry address is 0 */
1065 if (pf->addr == 0) {
1066 pr_debug("%s has no entry PC. Skipped\n",
1067 dwarf_diename(sp_die));
1070 } else if (pp->lazy_line)
1071 param->retval = find_probe_point_lazy(sp_die, pf);
1073 skip_prologue(sp_die, pf);
1074 pf->addr += pp->offset;
1075 /* TODO: Check the address in this function */
1076 param->retval = call_probe_finder(sp_die, pf);
1078 } else if (!probe_conf.no_inlines) {
1079 /* Inlined function: search instances */
1080 param->retval = die_walk_instances(sp_die,
1081 probe_point_inline_cb, (void *)pf);
1082 /* This could be a non-existed inline definition */
1083 if (param->retval == -ENOENT)
1087 /* We need to find other candidates */
1088 if (strisglob(pp->function) && param->retval >= 0) {
1089 param->retval = 0; /* We have to clear the result */
1093 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1096 static int find_probe_point_by_func(struct probe_finder *pf)
1098 struct dwarf_callback_param _param = {.data = (void *)pf,
1100 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1101 return _param.retval;
1104 struct pubname_callback_param {
1112 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1114 struct pubname_callback_param *param = data;
1116 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1117 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1120 if (die_match_name(param->sp_die, param->function)) {
1121 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1125 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1129 return DWARF_CB_ABORT;
1136 static int debuginfo__find_probe_location(struct debuginfo *dbg,
1137 struct probe_finder *pf)
1139 struct perf_probe_point *pp = &pf->pev->point;
1140 Dwarf_Off off, noff;
1146 pf->lcache = intlist__new(NULL);
1150 /* Fastpath: lookup by function name from .debug_pubnames section */
1151 if (pp->function && !strisglob(pp->function)) {
1152 struct pubname_callback_param pubname_param = {
1153 .function = pp->function,
1155 .cu_die = &pf->cu_die,
1156 .sp_die = &pf->sp_die,
1159 struct dwarf_callback_param probe_param = {
1163 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1165 if (pubname_param.found) {
1166 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1172 /* Loop on CUs (Compilation Unit) */
1173 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1174 /* Get the DIE(Debugging Information Entry) of this CU */
1175 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1179 /* Check if target file is included. */
1181 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1185 if (!pp->file || pf->fname) {
1187 ret = find_probe_point_by_func(pf);
1188 else if (pp->lazy_line)
1189 ret = find_probe_point_lazy(&pf->cu_die, pf);
1192 ret = find_probe_point_by_line(pf);
1201 intlist__delete(pf->lcache);
1207 /* Find probe points from debuginfo */
1208 static int debuginfo__find_probes(struct debuginfo *dbg,
1209 struct probe_finder *pf)
1215 if (pf->cfi_eh || pf->cfi_dbg)
1216 return debuginfo__find_probe_location(dbg, pf);
1218 /* Get the call frame information from this dwarf */
1219 elf = dwarf_getelf(dbg->dbg);
1223 if (gelf_getehdr(elf, &ehdr) == NULL)
1226 pf->machine = ehdr.e_machine;
1228 #if _ELFUTILS_PREREQ(0, 142)
1232 if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
1233 shdr.sh_type == SHT_PROGBITS)
1234 pf->cfi_eh = dwarf_getcfi_elf(elf);
1236 pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
1240 ret = debuginfo__find_probe_location(dbg, pf);
1244 struct local_vars_finder {
1245 struct probe_finder *pf;
1246 struct perf_probe_arg *args;
1253 /* Collect available variables in this scope */
1254 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1256 struct local_vars_finder *vf = data;
1257 struct probe_finder *pf = vf->pf;
1260 tag = dwarf_tag(die_mem);
1261 if (tag == DW_TAG_formal_parameter ||
1262 (tag == DW_TAG_variable && vf->vars)) {
1263 if (convert_variable_location(die_mem, vf->pf->addr,
1264 vf->pf->fb_ops, &pf->sp_die,
1265 pf->machine, NULL) == 0) {
1266 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1267 if (vf->args[vf->nargs].var == NULL) {
1269 return DIE_FIND_CB_END;
1271 pr_debug(" %s", vf->args[vf->nargs].var);
1276 if (dwarf_haspc(die_mem, vf->pf->addr))
1277 return DIE_FIND_CB_CONTINUE;
1279 return DIE_FIND_CB_SIBLING;
1282 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1283 struct perf_probe_arg *args)
1288 struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
1289 .max_args = MAX_PROBE_ARGS, .ret = 0};
1291 for (i = 0; i < pf->pev->nargs; i++) {
1292 /* var never be NULL */
1293 if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
1295 else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
1296 /* Copy normal argument */
1297 args[n] = pf->pev->args[i];
1301 pr_debug("Expanding %s into:", pf->pev->args[i].var);
1303 /* Special local variables */
1304 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1306 pr_debug(" (%d)\n", vf.nargs - n);
1314 static bool trace_event_finder_overlap(struct trace_event_finder *tf)
1318 for (i = 0; i < tf->ntevs; i++) {
1319 if (tf->pf.addr == tf->tevs[i].point.address)
1325 /* Add a found probe point into trace event list */
1326 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1328 struct trace_event_finder *tf =
1329 container_of(pf, struct trace_event_finder, pf);
1330 struct perf_probe_point *pp = &pf->pev->point;
1331 struct probe_trace_event *tev;
1332 struct perf_probe_arg *args = NULL;
1336 * For some reason (e.g. different column assigned to same address)
1337 * This callback can be called with the address which already passed.
1340 if (trace_event_finder_overlap(tf))
1343 /* Check number of tevs */
1344 if (tf->ntevs == tf->max_tevs) {
1345 pr_warning("Too many( > %d) probe point found.\n",
1349 tev = &tf->tevs[tf->ntevs++];
1351 /* Trace point should be converted from subprogram DIE */
1352 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1353 pp->retprobe, pp->function, &tev->point);
1357 tev->point.realname = strdup(dwarf_diename(sc_die));
1358 if (!tev->point.realname) {
1363 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1366 /* Expand special probe argument if exist */
1367 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1373 ret = expand_probe_args(sc_die, pf, args);
1378 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1379 if (tev->args == NULL) {
1384 /* Find each argument */
1385 for (i = 0; i < tev->nargs; i++) {
1386 pf->pvar = &args[i];
1387 pf->tvar = &tev->args[i];
1388 /* Variable should be found from scope DIE */
1389 ret = find_variable(sc_die, pf);
1396 clear_probe_trace_event(tev);
1403 static int fill_empty_trace_arg(struct perf_probe_event *pev,
1404 struct probe_trace_event *tevs, int ntevs)
1410 for (i = 0; i < pev->nargs; i++) {
1412 for (j = 0; j < ntevs; j++) {
1413 if (tevs[j].args[i].value) {
1414 type = tevs[j].args[i].type;
1419 print_var_not_found(pev->args[i].var);
1422 for (j = 0; j < ntevs; j++) {
1423 valp = &tevs[j].args[i].value;
1427 ret = asprintf(valp, "\\%lx", probe_conf.magic_num);
1430 /* Note that type can be NULL */
1432 tevs[j].args[i].type = strdup(type);
1433 if (!tevs[j].args[i].type)
1441 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1442 int debuginfo__find_trace_events(struct debuginfo *dbg,
1443 struct perf_probe_event *pev,
1444 struct probe_trace_event **tevs)
1446 struct trace_event_finder tf = {
1447 .pf = {.pev = pev, .callback = add_probe_trace_event},
1448 .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
1451 /* Allocate result tevs array */
1452 *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
1459 if (pev->nargs != 0 && immediate_value_is_supported())
1460 tf.pf.skip_empty_arg = true;
1462 ret = debuginfo__find_probes(dbg, &tf.pf);
1463 if (ret >= 0 && tf.pf.skip_empty_arg)
1464 ret = fill_empty_trace_arg(pev, tf.tevs, tf.ntevs);
1467 for (i = 0; i < tf.ntevs; i++)
1468 clear_probe_trace_event(&tf.tevs[i]);
1473 return (ret < 0) ? ret : tf.ntevs;
1476 /* Collect available variables in this scope */
1477 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1479 struct available_var_finder *af = data;
1480 struct variable_list *vl;
1481 struct strbuf buf = STRBUF_INIT;
1484 vl = &af->vls[af->nvls - 1];
1486 tag = dwarf_tag(die_mem);
1487 if (tag == DW_TAG_formal_parameter ||
1488 tag == DW_TAG_variable) {
1489 ret = convert_variable_location(die_mem, af->pf.addr,
1490 af->pf.fb_ops, &af->pf.sp_die,
1491 af->pf.machine, NULL);
1492 if (ret == 0 || ret == -ERANGE) {
1494 bool externs = !af->child;
1496 if (strbuf_init(&buf, 64) < 0)
1499 if (probe_conf.show_location_range) {
1501 ret2 = strbuf_add(&buf,
1502 ret ? "[INV]\t" : "[VAL]\t", 6);
1504 ret2 = strbuf_add(&buf, "[EXT]\t", 6);
1509 ret2 = die_get_varname(die_mem, &buf);
1511 if (!ret2 && probe_conf.show_location_range &&
1513 if (strbuf_addch(&buf, '\t') < 0)
1515 ret2 = die_get_var_range(&af->pf.sp_die,
1519 pr_debug("Add new var: %s\n", buf.buf);
1521 strlist__add(vl->vars,
1522 strbuf_detach(&buf, NULL));
1524 strbuf_release(&buf);
1528 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1529 return DIE_FIND_CB_CONTINUE;
1531 return DIE_FIND_CB_SIBLING;
1533 strbuf_release(&buf);
1534 pr_debug("Error in strbuf\n");
1535 return DIE_FIND_CB_END;
1538 static bool available_var_finder_overlap(struct available_var_finder *af)
1542 for (i = 0; i < af->nvls; i++) {
1543 if (af->pf.addr == af->vls[i].point.address)
1550 /* Add a found vars into available variables list */
1551 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1553 struct available_var_finder *af =
1554 container_of(pf, struct available_var_finder, pf);
1555 struct perf_probe_point *pp = &pf->pev->point;
1556 struct variable_list *vl;
1561 * For some reason (e.g. different column assigned to same address),
1562 * this callback can be called with the address which already passed.
1565 if (available_var_finder_overlap(af))
1568 /* Check number of tevs */
1569 if (af->nvls == af->max_vls) {
1570 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1573 vl = &af->vls[af->nvls++];
1575 /* Trace point should be converted from subprogram DIE */
1576 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1577 pp->retprobe, pp->function, &vl->point);
1581 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1584 /* Find local variables */
1585 vl->vars = strlist__new(NULL, NULL);
1586 if (vl->vars == NULL)
1589 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1591 /* Find external variables */
1592 if (!probe_conf.show_ext_vars)
1594 /* Don't need to search child DIE for external vars. */
1596 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1599 if (strlist__empty(vl->vars)) {
1600 strlist__delete(vl->vars);
1608 * Find available variables at given probe point
1609 * Return the number of found probe points. Return 0 if there is no
1610 * matched probe point. Return <0 if an error occurs.
1612 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1613 struct perf_probe_event *pev,
1614 struct variable_list **vls)
1616 struct available_var_finder af = {
1617 .pf = {.pev = pev, .callback = add_available_vars},
1619 .max_vls = probe_conf.max_probes};
1622 /* Allocate result vls array */
1623 *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
1630 ret = debuginfo__find_probes(dbg, &af.pf);
1632 /* Free vlist for error */
1634 zfree(&af.vls[af.nvls].point.symbol);
1635 strlist__delete(af.vls[af.nvls].vars);
1641 return (ret < 0) ? ret : af.nvls;
1644 /* For the kernel module, we need a special code to get a DIE */
1645 int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
1652 GElf_Shdr mem, *shdr;
1655 elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
1659 /* Get the number of relocations */
1660 n = dwfl_module_relocations(dbg->mod);
1663 /* Search the relocation related .text section */
1664 for (i = 0; i < n; i++) {
1665 p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
1666 if (strcmp(p, ".text") == 0) {
1667 /* OK, get the section header */
1668 scn = elf_getscn(elf, shndx);
1671 shdr = gelf_getshdr(scn, &mem);
1674 *offs = shdr->sh_addr;
1676 *offs -= shdr->sh_offset;
1682 /* Reverse search */
1683 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1684 struct perf_probe_point *ppt)
1686 Dwarf_Die cudie, spdie, indie;
1687 Dwarf_Addr _addr = 0, baseaddr = 0;
1688 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1689 int baseline = 0, lineno = 0, ret = 0;
1691 /* We always need to relocate the address for aranges */
1692 if (debuginfo__get_text_offset(dbg, &baseaddr, false) == 0)
1695 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
1696 pr_warning("Failed to find debug information for address %lx\n",
1702 /* Find a corresponding line (filename and lineno) */
1703 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1704 /* Don't care whether it failed or not */
1706 /* Find a corresponding function (name, baseline and baseaddr) */
1707 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1708 /* Get function entry information */
1709 func = basefunc = dwarf_diename(&spdie);
1711 die_entrypc(&spdie, &baseaddr) != 0 ||
1712 dwarf_decl_line(&spdie, &baseline) != 0) {
1717 fname = dwarf_decl_file(&spdie);
1718 if (addr == (unsigned long)baseaddr) {
1719 /* Function entry - Relative line number is 0 */
1724 /* Track down the inline functions step by step */
1725 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1727 /* There is an inline function */
1728 if (die_entrypc(&indie, &_addr) == 0 &&
1731 * addr is at an inline function entry.
1732 * In this case, lineno should be the call-site
1733 * line number. (overwrite lineinfo)
1735 lineno = die_get_call_lineno(&indie);
1736 fname = die_get_call_file(&indie);
1740 * addr is in an inline function body.
1741 * Since lineno points one of the lines
1742 * of the inline function, baseline should
1743 * be the entry line of the inline function.
1745 tmp = dwarf_diename(&indie);
1747 dwarf_decl_line(&indie, &baseline) != 0)
1753 /* Verify the lineno and baseline are in a same file */
1754 tmp = dwarf_decl_file(&spdie);
1755 if (!tmp || strcmp(tmp, fname) != 0)
1760 /* Make a relative line number or an offset */
1762 ppt->line = lineno - baseline;
1763 else if (basefunc) {
1764 ppt->offset = addr - (unsigned long)baseaddr;
1768 /* Duplicate strings */
1770 ppt->function = strdup(func);
1771 if (ppt->function == NULL) {
1777 ppt->file = strdup(fname);
1778 if (ppt->file == NULL) {
1779 zfree(&ppt->function);
1785 if (ret == 0 && (fname || func))
1786 ret = 1; /* Found a point */
1790 /* Add a line and store the src path */
1791 static int line_range_add_line(const char *src, unsigned int lineno,
1792 struct line_range *lr)
1794 /* Copy source path */
1796 lr->path = strdup(src);
1797 if (lr->path == NULL)
1800 return intlist__add(lr->line_list, lineno);
1803 static int line_range_walk_cb(const char *fname, int lineno,
1804 Dwarf_Addr addr __maybe_unused,
1807 struct line_finder *lf = data;
1808 const char *__fname;
1812 if ((strtailcmp(fname, lf->fname) != 0) ||
1813 (lf->lno_s > lineno || lf->lno_e < lineno))
1816 /* Make sure this line can be reversable */
1817 if (cu_find_lineinfo(&lf->cu_die, addr, &__fname, &__lineno) > 0
1818 && (lineno != __lineno || strcmp(fname, __fname)))
1821 err = line_range_add_line(fname, lineno, lf->lr);
1822 if (err < 0 && err != -EEXIST)
1828 /* Find line range from its line number */
1829 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1833 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1837 if (!intlist__empty(lf->lr->line_list))
1838 ret = lf->found = 1;
1840 ret = 0; /* Lines are not found */
1842 zfree(&lf->lr->path);
1847 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1849 int ret = find_line_range_by_line(in_die, data);
1852 * We have to check all instances of inlined function, because
1853 * some execution paths can be optimized out depends on the
1854 * function argument of instances. However, if an error occurs,
1855 * it should be handled by the caller.
1857 return ret < 0 ? ret : 0;
1860 /* Search function definition from function name */
1861 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1863 struct dwarf_callback_param *param = data;
1864 struct line_finder *lf = param->data;
1865 struct line_range *lr = lf->lr;
1867 /* Check declared file */
1868 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1871 if (die_is_func_def(sp_die) &&
1872 die_match_name(sp_die, lr->function)) {
1873 lf->fname = dwarf_decl_file(sp_die);
1874 dwarf_decl_line(sp_die, &lr->offset);
1875 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1876 lf->lno_s = lr->offset + lr->start;
1877 if (lf->lno_s < 0) /* Overflow */
1878 lf->lno_s = INT_MAX;
1879 lf->lno_e = lr->offset + lr->end;
1880 if (lf->lno_e < 0) /* Overflow */
1881 lf->lno_e = INT_MAX;
1882 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1883 lr->start = lf->lno_s;
1884 lr->end = lf->lno_e;
1885 if (!die_is_func_instance(sp_die))
1886 param->retval = die_walk_instances(sp_die,
1887 line_range_inline_cb, lf);
1889 param->retval = find_line_range_by_line(sp_die, lf);
1890 return DWARF_CB_ABORT;
1895 static int find_line_range_by_func(struct line_finder *lf)
1897 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1898 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0);
1899 return param.retval;
1902 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1904 struct line_finder lf = {.lr = lr, .found = 0};
1906 Dwarf_Off off = 0, noff;
1909 const char *comp_dir;
1911 /* Fastpath: lookup by function name from .debug_pubnames section */
1913 struct pubname_callback_param pubname_param = {
1914 .function = lr->function, .file = lr->file,
1915 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1916 struct dwarf_callback_param line_range_param = {
1917 .data = (void *)&lf, .retval = 0};
1919 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1921 if (pubname_param.found) {
1922 line_range_search_cb(&lf.sp_die, &line_range_param);
1928 /* Loop on CUs (Compilation Unit) */
1929 while (!lf.found && ret >= 0) {
1930 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1931 NULL, NULL, NULL) != 0)
1934 /* Get the DIE(Debugging Information Entry) of this CU */
1935 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1939 /* Check if target file is included. */
1941 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1945 if (!lr->file || lf.fname) {
1947 ret = find_line_range_by_func(&lf);
1949 lf.lno_s = lr->start;
1951 ret = find_line_range_by_line(NULL, &lf);
1958 /* Store comp_dir */
1960 comp_dir = cu_get_comp_dir(&lf.cu_die);
1962 lr->comp_dir = strdup(comp_dir);
1968 pr_debug("path: %s\n", lr->path);
1969 return (ret < 0) ? ret : lf.found;
1973 * Find a src file from a DWARF tag path. Prepend optional source path prefix
1974 * and chop off leading directories that do not exist. Result is passed back as
1975 * a newly allocated path on success.
1976 * Return 0 if file was found and readable, -errno otherwise.
1978 int get_real_path(const char *raw_path, const char *comp_dir,
1981 const char *prefix = symbol_conf.source_prefix;
1984 if (raw_path[0] != '/' && comp_dir)
1985 /* If not an absolute path, try to use comp_dir */
1988 if (access(raw_path, R_OK) == 0) {
1989 *new_path = strdup(raw_path);
1990 return *new_path ? 0 : -ENOMEM;
1996 *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
2001 sprintf(*new_path, "%s/%s", prefix, raw_path);
2003 if (access(*new_path, R_OK) == 0)
2006 if (!symbol_conf.source_prefix) {
2007 /* In case of searching comp_dir, don't retry */
2017 raw_path = strchr(++raw_path, '/');