2 * probe-finder.c : C expression to kprobe event converter
4 * Written by Masami Hiramatsu <mhiramat@redhat.com>
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.
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.
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.
22 #include <sys/utsname.h>
23 #include <sys/types.h>
34 #include <dwarf-regs.h>
36 #include <linux/bitops.h>
41 #include "probe-finder.h"
43 /* Kprobe tracer basic type is up to u64 */
44 #define MAX_BASIC_TYPE_BITS 64
46 /* Line number list operations */
48 /* Add a line to line number list */
49 static int line_list__add_line(struct list_head *head, int line)
54 /* Reverse search, because new line will be the last one */
55 list_for_each_entry_reverse(ln, head, list) {
56 if (ln->line < line) {
59 } else if (ln->line == line) /* Already exist */
62 /* List is empty, or the smallest entry */
65 pr_debug("line list: add a line %u\n", line);
66 ln = zalloc(sizeof(struct line_node));
70 INIT_LIST_HEAD(&ln->list);
71 list_add(&ln->list, p);
75 /* Check if the line in line number list */
76 static int line_list__has_line(struct list_head *head, int line)
80 /* Reverse search, because new line will be the last one */
81 list_for_each_entry(ln, head, list)
88 /* Init line number list */
89 static void line_list__init(struct list_head *head)
94 /* Free line number list */
95 static void line_list__free(struct list_head *head)
98 while (!list_empty(head)) {
99 ln = list_first_entry(head, struct line_node, list);
105 /* Dwarf FL wrappers */
106 static char *debuginfo_path; /* Currently dummy */
108 static const Dwfl_Callbacks offline_callbacks = {
109 .find_debuginfo = dwfl_standard_find_debuginfo,
110 .debuginfo_path = &debuginfo_path,
112 .section_address = dwfl_offline_section_address,
114 /* We use this table for core files too. */
115 .find_elf = dwfl_build_id_find_elf,
118 /* Get a Dwarf from offline image */
119 static int debuginfo__init_offline_dwarf(struct debuginfo *self,
125 fd = open(path, O_RDONLY);
129 self->dwfl = dwfl_begin(&offline_callbacks);
133 mod = dwfl_report_offline(self->dwfl, "", "", fd);
137 self->dbg = dwfl_module_getdwarf(mod, &self->bias);
144 dwfl_end(self->dwfl);
147 memset(self, 0, sizeof(*self));
152 #if _ELFUTILS_PREREQ(0, 148)
153 /* This method is buggy if elfutils is older than 0.148 */
154 static int __linux_kernel_find_elf(Dwfl_Module *mod,
156 const char *module_name,
158 char **file_name, Elf **elfp)
161 const char *path = kernel_get_module_path(module_name);
163 pr_debug2("Use file %s for %s\n", path, module_name);
165 fd = open(path, O_RDONLY);
167 *file_name = strdup(path);
171 /* If failed, try to call standard method */
172 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
176 static const Dwfl_Callbacks kernel_callbacks = {
177 .find_debuginfo = dwfl_standard_find_debuginfo,
178 .debuginfo_path = &debuginfo_path,
180 .find_elf = __linux_kernel_find_elf,
181 .section_address = dwfl_linux_kernel_module_section_address,
184 /* Get a Dwarf from live kernel image */
185 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
188 self->dwfl = dwfl_begin(&kernel_callbacks);
192 /* Load the kernel dwarves: Don't care the result here */
193 dwfl_linux_kernel_report_kernel(self->dwfl);
194 dwfl_linux_kernel_report_modules(self->dwfl);
196 self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
197 /* Here, check whether we could get a real dwarf */
199 pr_debug("Failed to find kernel dwarf at %lx\n",
200 (unsigned long)addr);
201 dwfl_end(self->dwfl);
202 memset(self, 0, sizeof(*self));
209 /* With older elfutils, this just support kernel module... */
210 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
211 Dwarf_Addr addr __used)
213 const char *path = kernel_get_module_path("kernel");
216 pr_err("Failed to find vmlinux path\n");
220 pr_debug2("Use file %s for debuginfo\n", path);
221 return debuginfo__init_offline_dwarf(self, path);
225 struct debuginfo *debuginfo__new(const char *path)
227 struct debuginfo *self = zalloc(sizeof(struct debuginfo));
231 if (debuginfo__init_offline_dwarf(self, path) < 0) {
239 struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
241 struct debuginfo *self = zalloc(sizeof(struct debuginfo));
245 if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) {
253 void debuginfo__delete(struct debuginfo *self)
257 dwfl_end(self->dwfl);
263 * Probe finder related functions
266 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
268 struct probe_trace_arg_ref *ref;
269 ref = zalloc(sizeof(struct probe_trace_arg_ref));
276 * Convert a location into trace_arg.
277 * If tvar == NULL, this just checks variable can be converted.
279 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
281 struct probe_trace_arg *tvar)
283 Dwarf_Attribute attr;
292 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
295 /* TODO: handle more than 1 exprs */
296 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
297 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
299 /* TODO: Support const_value */
303 if (op->atom == DW_OP_addr) {
307 /* Static variables on memory (not stack), make @varname */
308 ret = strlen(dwarf_diename(vr_die));
309 tvar->value = zalloc(ret + 2);
310 if (tvar->value == NULL)
312 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
313 tvar->ref = alloc_trace_arg_ref((long)offs);
314 if (tvar->ref == NULL)
319 /* If this is based on frame buffer, set the offset */
320 if (op->atom == DW_OP_fbreg) {
328 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
329 regn = op->atom - DW_OP_breg0;
332 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
333 regn = op->atom - DW_OP_reg0;
334 } else if (op->atom == DW_OP_bregx) {
338 } else if (op->atom == DW_OP_regx) {
341 pr_debug("DW_OP %x is not supported.\n", op->atom);
348 regs = get_arch_regstr(regn);
350 /* This should be a bug in DWARF or this tool */
351 pr_warning("Mapping for the register number %u "
352 "missing on this architecture.\n", regn);
356 tvar->value = strdup(regs);
357 if (tvar->value == NULL)
361 tvar->ref = alloc_trace_arg_ref((long)offs);
362 if (tvar->ref == NULL)
368 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
370 static int convert_variable_type(Dwarf_Die *vr_die,
371 struct probe_trace_arg *tvar,
374 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
377 int bsize, boffs, total;
380 /* TODO: check all types */
381 if (cast && strcmp(cast, "string") != 0) {
382 /* Non string type is OK */
383 tvar->type = strdup(cast);
384 return (tvar->type == NULL) ? -ENOMEM : 0;
387 bsize = dwarf_bitsize(vr_die);
389 /* This is a bitfield */
390 boffs = dwarf_bitoffset(vr_die);
391 total = dwarf_bytesize(vr_die);
392 if (boffs < 0 || total < 0)
394 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
395 BYTES_TO_BITS(total));
399 if (die_get_real_type(vr_die, &type) == NULL) {
400 pr_warning("Failed to get a type information of %s.\n",
401 dwarf_diename(vr_die));
405 pr_debug("%s type is %s.\n",
406 dwarf_diename(vr_die), dwarf_diename(&type));
408 if (cast && strcmp(cast, "string") == 0) { /* String type */
409 ret = dwarf_tag(&type);
410 if (ret != DW_TAG_pointer_type &&
411 ret != DW_TAG_array_type) {
412 pr_warning("Failed to cast into string: "
413 "%s(%s) is not a pointer nor array.\n",
414 dwarf_diename(vr_die), dwarf_diename(&type));
417 if (ret == DW_TAG_pointer_type) {
418 if (die_get_real_type(&type, &type) == NULL) {
419 pr_warning("Failed to get a type"
424 ref_ptr = &(*ref_ptr)->next;
425 /* Add new reference with offset +0 */
426 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
427 if (*ref_ptr == NULL) {
428 pr_warning("Out of memory error\n");
432 if (!die_compare_name(&type, "char") &&
433 !die_compare_name(&type, "unsigned char")) {
434 pr_warning("Failed to cast into string: "
435 "%s is not (unsigned) char *.\n",
436 dwarf_diename(vr_die));
439 tvar->type = strdup(cast);
440 return (tvar->type == NULL) ? -ENOMEM : 0;
443 ret = dwarf_bytesize(&type);
445 /* No size ... try to use default type */
447 ret = BYTES_TO_BITS(ret);
449 /* Check the bitwidth */
450 if (ret > MAX_BASIC_TYPE_BITS) {
451 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
452 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
453 ret = MAX_BASIC_TYPE_BITS;
455 ret = snprintf(buf, 16, "%c%d",
456 die_is_signed_type(&type) ? 's' : 'u', ret);
459 if (ret < 0 || ret >= 16) {
462 pr_warning("Failed to convert variable type: %s\n",
466 tvar->type = strdup(buf);
467 if (tvar->type == NULL)
472 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
473 struct perf_probe_arg_field *field,
474 struct probe_trace_arg_ref **ref_ptr,
477 struct probe_trace_arg_ref *ref = *ref_ptr;
482 pr_debug("converting %s in %s\n", field->name, varname);
483 if (die_get_real_type(vr_die, &type) == NULL) {
484 pr_warning("Failed to get the type of %s.\n", varname);
487 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
488 tag = dwarf_tag(&type);
490 if (field->name[0] == '[' &&
491 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
493 /* Save original type for next field */
494 memcpy(die_mem, &type, sizeof(*die_mem));
495 /* Get the type of this array */
496 if (die_get_real_type(&type, &type) == NULL) {
497 pr_warning("Failed to get the type of %s.\n", varname);
500 pr_debug2("Array real type: (%x)\n",
501 (unsigned)dwarf_dieoffset(&type));
502 if (tag == DW_TAG_pointer_type) {
503 ref = zalloc(sizeof(struct probe_trace_arg_ref));
507 (*ref_ptr)->next = ref;
511 ref->offset += dwarf_bytesize(&type) * field->index;
513 /* Save vr_die for converting types */
514 memcpy(die_mem, vr_die, sizeof(*die_mem));
516 } else if (tag == DW_TAG_pointer_type) {
517 /* Check the pointer and dereference */
519 pr_err("Semantic error: %s must be referred by '->'\n",
523 /* Get the type pointed by this pointer */
524 if (die_get_real_type(&type, &type) == NULL) {
525 pr_warning("Failed to get the type of %s.\n", varname);
528 /* Verify it is a data structure */
529 if (dwarf_tag(&type) != DW_TAG_structure_type) {
530 pr_warning("%s is not a data structure.\n", varname);
534 ref = zalloc(sizeof(struct probe_trace_arg_ref));
538 (*ref_ptr)->next = ref;
542 /* Verify it is a data structure */
543 if (tag != DW_TAG_structure_type) {
544 pr_warning("%s is not a data structure.\n", varname);
547 if (field->name[0] == '[') {
548 pr_err("Semantic error: %s is not a pointor"
549 " nor array.\n", varname);
553 pr_err("Semantic error: %s must be referred by '.'\n",
558 pr_warning("Structure on a register is not "
564 if (die_find_member(&type, field->name, die_mem) == NULL) {
565 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
566 dwarf_diename(&type), field->name);
570 /* Get the offset of the field */
571 ret = die_get_data_member_location(die_mem, &offs);
573 pr_warning("Failed to get the offset of %s.\n", field->name);
576 ref->offset += (long)offs;
579 /* Converting next field */
581 return convert_variable_fields(die_mem, field->name,
582 field->next, &ref, die_mem);
587 /* Show a variables in kprobe event format */
588 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
593 pr_debug("Converting variable %s into trace event.\n",
594 dwarf_diename(vr_die));
596 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
599 pr_err("Failed to find the location of %s at this address.\n"
600 " Perhaps, it has been optimized out.\n", pf->pvar->var);
601 else if (ret == -ENOTSUP)
602 pr_err("Sorry, we don't support this variable location yet.\n");
603 else if (pf->pvar->field) {
604 ret = convert_variable_fields(vr_die, pf->pvar->var,
605 pf->pvar->field, &pf->tvar->ref,
610 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
611 /* *expr will be cached in libdw. Don't free it. */
615 /* Find a variable in a subprogram die */
616 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
618 Dwarf_Die vr_die, *scopes;
622 if (!is_c_varname(pf->pvar->var)) {
623 /* Copy raw parameters */
624 pf->tvar->value = strdup(pf->pvar->var);
625 if (pf->tvar->value == NULL)
627 if (pf->pvar->type) {
628 pf->tvar->type = strdup(pf->pvar->type);
629 if (pf->tvar->type == NULL)
632 if (pf->pvar->name) {
633 pf->tvar->name = strdup(pf->pvar->name);
634 if (pf->tvar->name == NULL)
637 pf->tvar->name = NULL;
642 pf->tvar->name = strdup(pf->pvar->name);
644 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
647 ptr = strchr(buf, ':'); /* Change type separator to _ */
650 pf->tvar->name = strdup(buf);
652 if (pf->tvar->name == NULL)
655 pr_debug("Searching '%s' variable in context.\n",
657 /* Search child die for local variables and parameters. */
658 if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
659 ret = convert_variable(&vr_die, pf);
661 /* Search upper class */
662 nscopes = dwarf_getscopes_die(sp_die, &scopes);
663 while (nscopes-- > 1) {
664 pr_debug("Searching variables in %s\n",
665 dwarf_diename(&scopes[nscopes]));
666 /* We should check this scope, so give dummy address */
667 if (die_find_variable_at(&scopes[nscopes],
670 ret = convert_variable(&vr_die, pf);
680 pr_warning("Failed to find '%s' in this function.\n",
685 /* Convert subprogram DIE to trace point */
686 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
687 bool retprobe, struct probe_trace_point *tp)
692 /* Copy the name of probe point */
693 name = dwarf_diename(sp_die);
695 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
696 pr_warning("Failed to get entry address of %s\n",
697 dwarf_diename(sp_die));
700 tp->symbol = strdup(name);
701 if (tp->symbol == NULL)
703 tp->offset = (unsigned long)(paddr - eaddr);
705 /* This function has no name. */
706 tp->offset = (unsigned long)paddr;
708 /* Return probe must be on the head of a subprogram */
710 if (eaddr != paddr) {
711 pr_warning("Return probe must be on the head of"
712 " a real function.\n");
721 /* Call probe_finder callback with real subprogram DIE */
722 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
725 Dwarf_Attribute fb_attr;
729 /* If no real subprogram, find a real one */
730 if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
731 sp_die = die_find_realfunc(&pf->cu_die, pf->addr, &die_mem);
733 pr_warning("Failed to find probe point in any "
739 /* Get the frame base attribute/ops */
740 dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
741 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
742 if (ret <= 0 || nops == 0) {
744 #if _ELFUTILS_PREREQ(0, 142)
745 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
748 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
749 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
750 pr_warning("Failed to get call frame on 0x%jx\n",
751 (uintmax_t)pf->addr);
757 /* Call finder's callback handler */
758 ret = pf->callback(sp_die, pf);
760 /* *pf->fb_ops will be cached in libdw. Don't free it. */
766 static int probe_point_line_walker(const char *fname, int lineno,
767 Dwarf_Addr addr, void *data)
769 struct probe_finder *pf = data;
772 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
776 ret = call_probe_finder(NULL, pf);
778 /* Continue if no error, because the line will be in inline function */
779 return ret < 0 ? ret : 0;
782 /* Find probe point from its line number */
783 static int find_probe_point_by_line(struct probe_finder *pf)
785 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
788 /* Find lines which match lazy pattern */
789 static int find_lazy_match_lines(struct list_head *head,
790 const char *fname, const char *pat)
796 int count = 0, linenum = 1;
798 fp = fopen(fname, "r");
800 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
804 while ((len = getline(&line, &line_len, fp)) > 0) {
806 if (line[len - 1] == '\n')
807 line[len - 1] = '\0';
809 if (strlazymatch(line, pat)) {
810 line_list__add_line(head, linenum);
822 pr_debug("No matched lines found in %s.\n", fname);
826 static int probe_point_lazy_walker(const char *fname, int lineno,
827 Dwarf_Addr addr, void *data)
829 struct probe_finder *pf = data;
832 if (!line_list__has_line(&pf->lcache, lineno) ||
833 strtailcmp(fname, pf->fname) != 0)
836 pr_debug("Probe line found: line:%d addr:0x%llx\n",
837 lineno, (unsigned long long)addr);
839 ret = call_probe_finder(NULL, pf);
842 * Continue if no error, because the lazy pattern will match
845 return ret < 0 ? ret : 0;
848 /* Find probe points from lazy pattern */
849 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
853 if (list_empty(&pf->lcache)) {
854 /* Matching lazy line pattern */
855 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
856 pf->pev->point.lazy_line);
861 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
864 /* Callback parameter with return value */
865 struct dwarf_callback_param {
870 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
872 struct dwarf_callback_param *param = data;
873 struct probe_finder *pf = param->data;
874 struct perf_probe_point *pp = &pf->pev->point;
878 param->retval = find_probe_point_lazy(in_die, pf);
880 /* Get probe address */
881 if (dwarf_entrypc(in_die, &addr) != 0) {
882 pr_warning("Failed to get entry address of %s.\n",
883 dwarf_diename(in_die));
884 param->retval = -ENOENT;
885 return DWARF_CB_ABORT;
888 pf->addr += pp->offset;
889 pr_debug("found inline addr: 0x%jx\n",
890 (uintmax_t)pf->addr);
892 param->retval = call_probe_finder(in_die, pf);
893 if (param->retval < 0)
894 return DWARF_CB_ABORT;
900 /* Search function from function name */
901 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
903 struct dwarf_callback_param *param = data;
904 struct probe_finder *pf = param->data;
905 struct perf_probe_point *pp = &pf->pev->point;
907 /* Check tag and diename */
908 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
909 !die_compare_name(sp_die, pp->function))
912 /* Check declared file */
913 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
916 pf->fname = dwarf_decl_file(sp_die);
917 if (pp->line) { /* Function relative line */
918 dwarf_decl_line(sp_die, &pf->lno);
920 param->retval = find_probe_point_by_line(pf);
921 } else if (!dwarf_func_inline(sp_die)) {
924 param->retval = find_probe_point_lazy(sp_die, pf);
926 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
927 pr_warning("Failed to get entry address of "
928 "%s.\n", dwarf_diename(sp_die));
929 param->retval = -ENOENT;
930 return DWARF_CB_ABORT;
932 pf->addr += pp->offset;
933 /* TODO: Check the address in this function */
934 param->retval = call_probe_finder(sp_die, pf);
937 struct dwarf_callback_param _param = {.data = (void *)pf,
939 /* Inlined function: search instances */
940 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
942 param->retval = _param.retval;
945 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
948 static int find_probe_point_by_func(struct probe_finder *pf)
950 struct dwarf_callback_param _param = {.data = (void *)pf,
952 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
953 return _param.retval;
956 struct pubname_callback_param {
964 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
966 struct pubname_callback_param *param = data;
968 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
969 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
972 if (die_compare_name(param->sp_die, param->function)) {
973 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
977 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
981 return DWARF_CB_ABORT;
988 /* Find probe points from debuginfo */
989 static int debuginfo__find_probes(struct debuginfo *self,
990 struct probe_finder *pf)
992 struct perf_probe_point *pp = &pf->pev->point;
998 #if _ELFUTILS_PREREQ(0, 142)
999 /* Get the call frame information from this dwarf */
1000 pf->cfi = dwarf_getcfi(self->dbg);
1004 line_list__init(&pf->lcache);
1006 /* Fastpath: lookup by function name from .debug_pubnames section */
1008 struct pubname_callback_param pubname_param = {
1009 .function = pp->function,
1011 .cu_die = &pf->cu_die,
1012 .sp_die = &pf->sp_die,
1015 struct dwarf_callback_param probe_param = {
1019 dwarf_getpubnames(self->dbg, pubname_search_cb,
1021 if (pubname_param.found) {
1022 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1028 /* Loop on CUs (Compilation Unit) */
1029 while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1030 /* Get the DIE(Debugging Information Entry) of this CU */
1031 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1035 /* Check if target file is included. */
1037 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1041 if (!pp->file || pf->fname) {
1043 ret = find_probe_point_by_func(pf);
1044 else if (pp->lazy_line)
1045 ret = find_probe_point_lazy(NULL, pf);
1048 ret = find_probe_point_by_line(pf);
1057 line_list__free(&pf->lcache);
1062 /* Add a found probe point into trace event list */
1063 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1065 struct trace_event_finder *tf =
1066 container_of(pf, struct trace_event_finder, pf);
1067 struct probe_trace_event *tev;
1070 /* Check number of tevs */
1071 if (tf->ntevs == tf->max_tevs) {
1072 pr_warning("Too many( > %d) probe point found.\n",
1076 tev = &tf->tevs[tf->ntevs++];
1078 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1083 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1086 /* Find each argument */
1087 tev->nargs = pf->pev->nargs;
1088 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1089 if (tev->args == NULL)
1091 for (i = 0; i < pf->pev->nargs; i++) {
1092 pf->pvar = &pf->pev->args[i];
1093 pf->tvar = &tev->args[i];
1094 ret = find_variable(sp_die, pf);
1102 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1103 int debuginfo__find_trace_events(struct debuginfo *self,
1104 struct perf_probe_event *pev,
1105 struct probe_trace_event **tevs, int max_tevs)
1107 struct trace_event_finder tf = {
1108 .pf = {.pev = pev, .callback = add_probe_trace_event},
1109 .max_tevs = max_tevs};
1112 /* Allocate result tevs array */
1113 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1120 ret = debuginfo__find_probes(self, &tf.pf);
1127 return (ret < 0) ? ret : tf.ntevs;
1130 #define MAX_VAR_LEN 64
1132 /* Collect available variables in this scope */
1133 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1135 struct available_var_finder *af = data;
1136 struct variable_list *vl;
1137 char buf[MAX_VAR_LEN];
1140 vl = &af->vls[af->nvls - 1];
1142 tag = dwarf_tag(die_mem);
1143 if (tag == DW_TAG_formal_parameter ||
1144 tag == DW_TAG_variable) {
1145 ret = convert_variable_location(die_mem, af->pf.addr,
1146 af->pf.fb_ops, NULL);
1148 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1149 pr_debug2("Add new var: %s\n", buf);
1151 strlist__add(vl->vars, buf);
1155 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1156 return DIE_FIND_CB_CONTINUE;
1158 return DIE_FIND_CB_SIBLING;
1161 /* Add a found vars into available variables list */
1162 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1164 struct available_var_finder *af =
1165 container_of(pf, struct available_var_finder, pf);
1166 struct variable_list *vl;
1167 Dwarf_Die die_mem, *scopes = NULL;
1170 /* Check number of tevs */
1171 if (af->nvls == af->max_vls) {
1172 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1175 vl = &af->vls[af->nvls++];
1177 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1182 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1185 /* Find local variables */
1186 vl->vars = strlist__new(true, NULL);
1187 if (vl->vars == NULL)
1190 die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1192 /* Find external variables */
1195 /* Don't need to search child DIE for externs. */
1197 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1198 while (nscopes-- > 1)
1199 die_find_child(&scopes[nscopes], collect_variables_cb,
1200 (void *)af, &die_mem);
1205 if (strlist__empty(vl->vars)) {
1206 strlist__delete(vl->vars);
1213 /* Find available variables at given probe point */
1214 int debuginfo__find_available_vars_at(struct debuginfo *self,
1215 struct perf_probe_event *pev,
1216 struct variable_list **vls,
1217 int max_vls, bool externs)
1219 struct available_var_finder af = {
1220 .pf = {.pev = pev, .callback = add_available_vars},
1221 .max_vls = max_vls, .externs = externs};
1224 /* Allocate result vls array */
1225 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1232 ret = debuginfo__find_probes(self, &af.pf);
1234 /* Free vlist for error */
1236 if (af.vls[af.nvls].point.symbol)
1237 free(af.vls[af.nvls].point.symbol);
1238 if (af.vls[af.nvls].vars)
1239 strlist__delete(af.vls[af.nvls].vars);
1246 return (ret < 0) ? ret : af.nvls;
1249 /* Reverse search */
1250 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1251 struct perf_probe_point *ppt)
1253 Dwarf_Die cudie, spdie, indie;
1254 Dwarf_Addr _addr, baseaddr;
1255 const char *fname = NULL, *func = NULL, *tmp;
1256 int baseline = 0, lineno = 0, ret = 0;
1258 /* Adjust address with bias */
1262 if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1263 pr_warning("Failed to find debug information for address %lx\n",
1269 /* Find a corresponding line (filename and lineno) */
1270 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1271 /* Don't care whether it failed or not */
1273 /* Find a corresponding function (name, baseline and baseaddr) */
1274 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1275 /* Get function entry information */
1276 tmp = dwarf_diename(&spdie);
1278 dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1279 dwarf_decl_line(&spdie, &baseline) != 0)
1283 if (addr == (unsigned long)baseaddr)
1284 /* Function entry - Relative line number is 0 */
1286 else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1288 if (dwarf_entrypc(&indie, &_addr) == 0 &&
1291 * addr is at an inline function entry.
1292 * In this case, lineno should be the call-site
1295 lineno = die_get_call_lineno(&indie);
1298 * addr is in an inline function body.
1299 * Since lineno points one of the lines
1300 * of the inline function, baseline should
1301 * be the entry line of the inline function.
1303 tmp = dwarf_diename(&indie);
1305 dwarf_decl_line(&spdie, &baseline) == 0)
1312 /* Make a relative line number or an offset */
1314 ppt->line = lineno - baseline;
1316 ppt->offset = addr - (unsigned long)baseaddr;
1318 /* Duplicate strings */
1320 ppt->function = strdup(func);
1321 if (ppt->function == NULL) {
1327 ppt->file = strdup(fname);
1328 if (ppt->file == NULL) {
1329 if (ppt->function) {
1330 free(ppt->function);
1331 ppt->function = NULL;
1338 if (ret == 0 && (fname || func))
1339 ret = 1; /* Found a point */
1343 /* Add a line and store the src path */
1344 static int line_range_add_line(const char *src, unsigned int lineno,
1345 struct line_range *lr)
1347 /* Copy source path */
1349 lr->path = strdup(src);
1350 if (lr->path == NULL)
1353 return line_list__add_line(&lr->line_list, lineno);
1356 static int line_range_walk_cb(const char *fname, int lineno,
1357 Dwarf_Addr addr __used,
1360 struct line_finder *lf = data;
1362 if ((strtailcmp(fname, lf->fname) != 0) ||
1363 (lf->lno_s > lineno || lf->lno_e < lineno))
1366 if (line_range_add_line(fname, lineno, lf->lr) < 0)
1372 /* Find line range from its line number */
1373 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1377 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1381 if (!list_empty(&lf->lr->line_list))
1382 ret = lf->found = 1;
1384 ret = 0; /* Lines are not found */
1387 lf->lr->path = NULL;
1392 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1394 struct dwarf_callback_param *param = data;
1396 param->retval = find_line_range_by_line(in_die, param->data);
1397 return DWARF_CB_ABORT; /* No need to find other instances */
1400 /* Search function from function name */
1401 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1403 struct dwarf_callback_param *param = data;
1404 struct line_finder *lf = param->data;
1405 struct line_range *lr = lf->lr;
1407 /* Check declared file */
1408 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1411 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1412 die_compare_name(sp_die, lr->function)) {
1413 lf->fname = dwarf_decl_file(sp_die);
1414 dwarf_decl_line(sp_die, &lr->offset);
1415 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1416 lf->lno_s = lr->offset + lr->start;
1417 if (lf->lno_s < 0) /* Overflow */
1418 lf->lno_s = INT_MAX;
1419 lf->lno_e = lr->offset + lr->end;
1420 if (lf->lno_e < 0) /* Overflow */
1421 lf->lno_e = INT_MAX;
1422 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1423 lr->start = lf->lno_s;
1424 lr->end = lf->lno_e;
1425 if (dwarf_func_inline(sp_die)) {
1426 struct dwarf_callback_param _param;
1427 _param.data = (void *)lf;
1429 dwarf_func_inline_instances(sp_die,
1430 line_range_inline_cb,
1432 param->retval = _param.retval;
1434 param->retval = find_line_range_by_line(sp_die, lf);
1435 return DWARF_CB_ABORT;
1440 static int find_line_range_by_func(struct line_finder *lf)
1442 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1443 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0);
1444 return param.retval;
1447 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1449 struct line_finder lf = {.lr = lr, .found = 0};
1451 Dwarf_Off off = 0, noff;
1454 const char *comp_dir;
1456 /* Fastpath: lookup by function name from .debug_pubnames section */
1458 struct pubname_callback_param pubname_param = {
1459 .function = lr->function, .file = lr->file,
1460 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1461 struct dwarf_callback_param line_range_param = {
1462 .data = (void *)&lf, .retval = 0};
1464 dwarf_getpubnames(self->dbg, pubname_search_cb,
1466 if (pubname_param.found) {
1467 line_range_search_cb(&lf.sp_die, &line_range_param);
1473 /* Loop on CUs (Compilation Unit) */
1474 while (!lf.found && ret >= 0) {
1475 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1476 NULL, NULL, NULL) != 0)
1479 /* Get the DIE(Debugging Information Entry) of this CU */
1480 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1484 /* Check if target file is included. */
1486 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1490 if (!lr->file || lf.fname) {
1492 ret = find_line_range_by_func(&lf);
1494 lf.lno_s = lr->start;
1496 ret = find_line_range_by_line(NULL, &lf);
1503 /* Store comp_dir */
1505 comp_dir = cu_get_comp_dir(&lf.cu_die);
1507 lr->comp_dir = strdup(comp_dir);
1513 pr_debug("path: %s\n", lr->path);
1514 return (ret < 0) ? ret : lf.found;