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>
40 #include "probe-finder.h"
42 /* Kprobe tracer basic type is up to u64 */
43 #define MAX_BASIC_TYPE_BITS 64
46 * Compare the tail of two strings.
47 * Return 0 if whole of either string is same as another's tail part.
49 static int strtailcmp(const char *s1, const char *s2)
53 while (--i1 >= 0 && --i2 >= 0) {
55 return s1[i1] - s2[i2];
60 /* Line number list operations */
62 /* Add a line to line number list */
63 static int line_list__add_line(struct list_head *head, int line)
68 /* Reverse search, because new line will be the last one */
69 list_for_each_entry_reverse(ln, head, list) {
70 if (ln->line < line) {
73 } else if (ln->line == line) /* Already exist */
76 /* List is empty, or the smallest entry */
79 pr_debug("line list: add a line %u\n", line);
80 ln = zalloc(sizeof(struct line_node));
84 INIT_LIST_HEAD(&ln->list);
85 list_add(&ln->list, p);
89 /* Check if the line in line number list */
90 static int line_list__has_line(struct list_head *head, int line)
94 /* Reverse search, because new line will be the last one */
95 list_for_each_entry(ln, head, list)
102 /* Init line number list */
103 static void line_list__init(struct list_head *head)
105 INIT_LIST_HEAD(head);
108 /* Free line number list */
109 static void line_list__free(struct list_head *head)
111 struct line_node *ln;
112 while (!list_empty(head)) {
113 ln = list_first_entry(head, struct line_node, list);
121 /* Find the realpath of the target file. */
122 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
126 const char *src = NULL;
132 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
136 for (i = 0; i < nfiles; i++) {
137 src = dwarf_filesrc(files, i, NULL, NULL);
138 if (strtailcmp(src, fname) == 0)
146 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
147 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
149 Dwarf_Attribute attr;
150 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
152 return dwarf_formstring(&attr);
155 /* Compare diename and tname */
156 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
159 name = dwarf_diename(dw_die);
160 return name ? (strcmp(tname, name) == 0) : false;
163 /* Get type die, but skip qualifiers and typedef */
164 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
166 Dwarf_Attribute attr;
170 if (dwarf_attr(vr_die, DW_AT_type, &attr) == NULL ||
171 dwarf_formref_die(&attr, die_mem) == NULL)
174 tag = dwarf_tag(die_mem);
176 } while (tag == DW_TAG_const_type ||
177 tag == DW_TAG_restrict_type ||
178 tag == DW_TAG_volatile_type ||
179 tag == DW_TAG_shared_type ||
180 tag == DW_TAG_typedef);
185 static bool die_is_signed_type(Dwarf_Die *tp_die)
187 Dwarf_Attribute attr;
190 if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
191 dwarf_formudata(&attr, &ret) != 0)
194 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
195 ret == DW_ATE_signed_fixed);
198 static int die_get_byte_size(Dwarf_Die *tp_die)
200 Dwarf_Attribute attr;
203 if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
204 dwarf_formudata(&attr, &ret) != 0)
210 /* Get data_member_location offset */
211 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
213 Dwarf_Attribute attr;
218 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
221 if (dwarf_formudata(&attr, offs) != 0) {
222 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
223 ret = dwarf_getlocation(&attr, &expr, &nexpr);
224 if (ret < 0 || nexpr == 0)
227 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
228 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
229 expr[0].atom, nexpr);
232 *offs = (Dwarf_Word)expr[0].number;
237 /* Return values for die_find callbacks */
239 DIE_FIND_CB_FOUND = 0, /* End of Search */
240 DIE_FIND_CB_CHILD = 1, /* Search only children */
241 DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
242 DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
245 /* Search a child die */
246 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
247 int (*callback)(Dwarf_Die *, void *),
248 void *data, Dwarf_Die *die_mem)
253 ret = dwarf_child(rt_die, die_mem);
258 ret = callback(die_mem, data);
259 if (ret == DIE_FIND_CB_FOUND)
262 if ((ret & DIE_FIND_CB_CHILD) &&
263 die_find_child(die_mem, callback, data, &child_die)) {
264 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
267 } while ((ret & DIE_FIND_CB_SIBLING) &&
268 dwarf_siblingof(die_mem, die_mem) == 0);
273 struct __addr_die_search_param {
278 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
280 struct __addr_die_search_param *ad = data;
282 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
283 dwarf_haspc(fn_die, ad->addr)) {
284 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
285 return DWARF_CB_ABORT;
290 /* Search a real subprogram including this line, */
291 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
294 struct __addr_die_search_param ad;
296 ad.die_mem = die_mem;
297 /* dwarf_getscopes can't find subprogram. */
298 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
304 /* die_find callback for inline function search */
305 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
307 Dwarf_Addr *addr = data;
309 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
310 dwarf_haspc(die_mem, *addr))
311 return DIE_FIND_CB_FOUND;
313 return DIE_FIND_CB_CONTINUE;
316 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
317 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
320 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
323 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
325 const char *name = data;
328 tag = dwarf_tag(die_mem);
329 if ((tag == DW_TAG_formal_parameter ||
330 tag == DW_TAG_variable) &&
331 die_compare_name(die_mem, name))
332 return DIE_FIND_CB_FOUND;
334 return DIE_FIND_CB_CONTINUE;
337 /* Find a variable called 'name' */
338 static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
341 return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
345 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
347 const char *name = data;
349 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
350 die_compare_name(die_mem, name))
351 return DIE_FIND_CB_FOUND;
353 return DIE_FIND_CB_SIBLING;
356 /* Find a member called 'name' */
357 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
360 return die_find_child(st_die, __die_find_member_cb, (void *)name,
365 * Probe finder related functions
368 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
370 struct probe_trace_arg_ref *ref;
371 ref = zalloc(sizeof(struct probe_trace_arg_ref));
377 /* Show a location */
378 static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
380 Dwarf_Attribute attr;
387 struct probe_trace_arg *tvar = pf->tvar;
390 /* TODO: handle more than 1 exprs */
391 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
392 dwarf_getlocation_addr(&attr, pf->addr, &op, &nops, 1) <= 0 ||
394 /* TODO: Support const_value */
395 pr_err("Failed to find the location of %s at this address.\n"
396 " Perhaps, it has been optimized out.\n", pf->pvar->var);
400 if (op->atom == DW_OP_addr) {
401 /* Static variables on memory (not stack), make @varname */
402 ret = strlen(dwarf_diename(vr_die));
403 tvar->value = zalloc(ret + 2);
404 if (tvar->value == NULL)
406 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
407 tvar->ref = alloc_trace_arg_ref((long)offs);
408 if (tvar->ref == NULL)
413 /* If this is based on frame buffer, set the offset */
414 if (op->atom == DW_OP_fbreg) {
415 if (pf->fb_ops == NULL) {
416 pr_warning("The attribute of frame base is not "
425 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
426 regn = op->atom - DW_OP_breg0;
429 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
430 regn = op->atom - DW_OP_reg0;
431 } else if (op->atom == DW_OP_bregx) {
435 } else if (op->atom == DW_OP_regx) {
438 pr_warning("DW_OP %x is not supported.\n", op->atom);
442 regs = get_arch_regstr(regn);
444 pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
448 tvar->value = strdup(regs);
449 if (tvar->value == NULL)
453 tvar->ref = alloc_trace_arg_ref((long)offs);
454 if (tvar->ref == NULL)
460 static int convert_variable_type(Dwarf_Die *vr_die,
461 struct probe_trace_arg *tvar,
464 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
469 /* TODO: check all types */
470 if (cast && strcmp(cast, "string") != 0) {
471 /* Non string type is OK */
472 tvar->type = strdup(cast);
473 return (tvar->type == NULL) ? -ENOMEM : 0;
476 if (die_get_real_type(vr_die, &type) == NULL) {
477 pr_warning("Failed to get a type information of %s.\n",
478 dwarf_diename(vr_die));
482 pr_debug("%s type is %s.\n",
483 dwarf_diename(vr_die), dwarf_diename(&type));
485 if (cast && strcmp(cast, "string") == 0) { /* String type */
486 ret = dwarf_tag(&type);
487 if (ret != DW_TAG_pointer_type &&
488 ret != DW_TAG_array_type) {
489 pr_warning("Failed to cast into string: "
490 "%s(%s) is not a pointer nor array.",
491 dwarf_diename(vr_die), dwarf_diename(&type));
494 if (ret == DW_TAG_pointer_type) {
495 if (die_get_real_type(&type, &type) == NULL) {
496 pr_warning("Failed to get a type information.");
500 ref_ptr = &(*ref_ptr)->next;
501 /* Add new reference with offset +0 */
502 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
503 if (*ref_ptr == NULL) {
504 pr_warning("Out of memory error\n");
508 if (!die_compare_name(&type, "char") &&
509 !die_compare_name(&type, "unsigned char")) {
510 pr_warning("Failed to cast into string: "
511 "%s is not (unsigned) char *.",
512 dwarf_diename(vr_die));
515 tvar->type = strdup(cast);
516 return (tvar->type == NULL) ? -ENOMEM : 0;
519 ret = die_get_byte_size(&type) * 8;
521 /* Check the bitwidth */
522 if (ret > MAX_BASIC_TYPE_BITS) {
523 pr_info("%s exceeds max-bitwidth."
524 " Cut down to %d bits.\n",
525 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
526 ret = MAX_BASIC_TYPE_BITS;
529 ret = snprintf(buf, 16, "%c%d",
530 die_is_signed_type(&type) ? 's' : 'u', ret);
531 if (ret < 0 || ret >= 16) {
534 pr_warning("Failed to convert variable type: %s\n",
538 tvar->type = strdup(buf);
539 if (tvar->type == NULL)
545 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
546 struct perf_probe_arg_field *field,
547 struct probe_trace_arg_ref **ref_ptr,
550 struct probe_trace_arg_ref *ref = *ref_ptr;
555 pr_debug("converting %s in %s\n", field->name, varname);
556 if (die_get_real_type(vr_die, &type) == NULL) {
557 pr_warning("Failed to get the type of %s.\n", varname);
560 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
561 tag = dwarf_tag(&type);
563 if (field->name[0] == '[' &&
564 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
566 /* Save original type for next field */
567 memcpy(die_mem, &type, sizeof(*die_mem));
568 /* Get the type of this array */
569 if (die_get_real_type(&type, &type) == NULL) {
570 pr_warning("Failed to get the type of %s.\n", varname);
573 pr_debug2("Array real type: (%x)\n",
574 (unsigned)dwarf_dieoffset(&type));
575 if (tag == DW_TAG_pointer_type) {
576 ref = zalloc(sizeof(struct probe_trace_arg_ref));
580 (*ref_ptr)->next = ref;
584 ref->offset += die_get_byte_size(&type) * field->index;
586 /* Save vr_die for converting types */
587 memcpy(die_mem, vr_die, sizeof(*die_mem));
589 } else if (tag == DW_TAG_pointer_type) {
590 /* Check the pointer and dereference */
592 pr_err("Semantic error: %s must be referred by '->'\n",
596 /* Get the type pointed by this pointer */
597 if (die_get_real_type(&type, &type) == NULL) {
598 pr_warning("Failed to get the type of %s.\n", varname);
601 /* Verify it is a data structure */
602 if (dwarf_tag(&type) != DW_TAG_structure_type) {
603 pr_warning("%s is not a data structure.\n", varname);
607 ref = zalloc(sizeof(struct probe_trace_arg_ref));
611 (*ref_ptr)->next = ref;
615 /* Verify it is a data structure */
616 if (tag != DW_TAG_structure_type) {
617 pr_warning("%s is not a data structure.\n", varname);
620 if (field->name[0] == '[') {
621 pr_err("Semantic error: %s is not a pointor nor array.",
626 pr_err("Semantic error: %s must be referred by '.'\n",
631 pr_warning("Structure on a register is not "
637 if (die_find_member(&type, field->name, die_mem) == NULL) {
638 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
639 dwarf_diename(&type), field->name);
643 /* Get the offset of the field */
644 ret = die_get_data_member_location(die_mem, &offs);
646 pr_warning("Failed to get the offset of %s.\n", field->name);
649 ref->offset += (long)offs;
652 /* Converting next field */
654 return convert_variable_fields(die_mem, field->name,
655 field->next, &ref, die_mem);
660 /* Show a variables in kprobe event format */
661 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
666 pr_debug("Converting variable %s into trace event.\n",
667 dwarf_diename(vr_die));
669 ret = convert_variable_location(vr_die, pf);
670 if (ret == 0 && pf->pvar->field) {
671 ret = convert_variable_fields(vr_die, pf->pvar->var,
672 pf->pvar->field, &pf->tvar->ref,
677 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
678 /* *expr will be cached in libdw. Don't free it. */
682 /* Find a variable in a subprogram die */
683 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
685 Dwarf_Die vr_die, *scopes;
690 pf->tvar->name = strdup(pf->pvar->name);
692 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
695 ptr = strchr(buf, ':'); /* Change type separator to _ */
698 pf->tvar->name = strdup(buf);
700 if (pf->tvar->name == NULL)
703 if (!is_c_varname(pf->pvar->var)) {
704 /* Copy raw parameters */
705 pf->tvar->value = strdup(pf->pvar->var);
706 if (pf->tvar->value == NULL)
708 if (pf->pvar->type) {
709 pf->tvar->type = strdup(pf->pvar->type);
710 if (pf->tvar->type == NULL)
716 pr_debug("Searching '%s' variable in context.\n",
718 /* Search child die for local variables and parameters. */
719 if (die_find_variable(sp_die, pf->pvar->var, &vr_die))
720 ret = convert_variable(&vr_die, pf);
722 /* Search upper class */
723 nscopes = dwarf_getscopes_die(sp_die, &scopes);
725 ret = dwarf_getscopevar(scopes, nscopes, pf->pvar->var,
726 0, NULL, 0, 0, &vr_die);
728 ret = convert_variable(&vr_die, pf);
736 pr_warning("Failed to find '%s' in this function.\n",
741 /* Show a probe point to output buffer */
742 static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
744 struct probe_trace_event *tev;
749 Dwarf_Attribute fb_attr;
752 if (pf->ntevs == pf->max_tevs) {
753 pr_warning("Too many( > %d) probe point found.\n",
757 tev = &pf->tevs[pf->ntevs++];
759 /* If no real subprogram, find a real one */
760 if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
761 sp_die = die_find_real_subprogram(&pf->cu_die,
764 pr_warning("Failed to find probe point in any "
770 /* Copy the name of probe point */
771 name = dwarf_diename(sp_die);
773 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
774 pr_warning("Failed to get entry pc of %s\n",
775 dwarf_diename(sp_die));
778 tev->point.symbol = strdup(name);
779 if (tev->point.symbol == NULL)
781 tev->point.offset = (unsigned long)(pf->addr - eaddr);
783 /* This function has no name. */
784 tev->point.offset = (unsigned long)pf->addr;
786 /* Return probe must be on the head of a subprogram */
787 if (pf->pev->point.retprobe) {
788 if (tev->point.offset != 0) {
789 pr_warning("Return probe must be on the head of"
790 " a real function\n");
793 tev->point.retprobe = true;
796 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
799 /* Get the frame base attribute/ops */
800 dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
801 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
802 if (ret <= 0 || nops == 0) {
804 #if _ELFUTILS_PREREQ(0, 142)
805 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
808 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
809 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
810 pr_warning("Failed to get CFA on 0x%jx\n",
811 (uintmax_t)pf->addr);
817 /* Find each argument */
818 tev->nargs = pf->pev->nargs;
819 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
820 if (tev->args == NULL)
822 for (i = 0; i < pf->pev->nargs; i++) {
823 pf->pvar = &pf->pev->args[i];
824 pf->tvar = &tev->args[i];
825 ret = find_variable(sp_die, pf);
830 /* *pf->fb_ops will be cached in libdw. Don't free it. */
835 /* Find probe point from its line number */
836 static int find_probe_point_by_line(struct probe_finder *pf)
845 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
846 pr_warning("No source lines found in this CU.\n");
850 for (i = 0; i < nlines && ret == 0; i++) {
851 line = dwarf_onesrcline(lines, i);
852 if (dwarf_lineno(line, &lineno) != 0 ||
856 /* TODO: Get fileno from line, but how? */
857 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
860 if (dwarf_lineaddr(line, &addr) != 0) {
861 pr_warning("Failed to get the address of the line.\n");
864 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
865 (int)i, lineno, (uintmax_t)addr);
868 ret = convert_probe_point(NULL, pf);
869 /* Continuing, because target line might be inlined. */
874 /* Find lines which match lazy pattern */
875 static int find_lazy_match_lines(struct list_head *head,
876 const char *fname, const char *pat)
878 char *fbuf, *p1, *p2;
879 int fd, line, nlines = -1;
882 fd = open(fname, O_RDONLY);
884 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
888 if (fstat(fd, &st) < 0) {
889 pr_warning("Failed to get the size of %s: %s\n",
890 fname, strerror(errno));
896 fbuf = malloc(st.st_size + 2);
899 if (read(fd, fbuf, st.st_size) < 0) {
900 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
904 fbuf[st.st_size] = '\n'; /* Dummy line */
905 fbuf[st.st_size + 1] = '\0';
909 while ((p2 = strchr(p1, '\n')) != NULL) {
911 if (strlazymatch(p1, pat)) {
912 line_list__add_line(head, line);
925 /* Find probe points from lazy pattern */
926 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
936 if (list_empty(&pf->lcache)) {
937 /* Matching lazy line pattern */
938 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
939 pf->pev->point.lazy_line);
941 pr_debug("No matched lines found in %s.\n", pf->fname);
947 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
948 pr_warning("No source lines found in this CU.\n");
952 for (i = 0; i < nlines && ret >= 0; i++) {
953 line = dwarf_onesrcline(lines, i);
955 if (dwarf_lineno(line, &lineno) != 0 ||
956 !line_list__has_line(&pf->lcache, lineno))
959 /* TODO: Get fileno from line, but how? */
960 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
963 if (dwarf_lineaddr(line, &addr) != 0) {
964 pr_debug("Failed to get the address of line %d.\n",
969 /* Address filtering 1: does sp_die include addr? */
970 if (!dwarf_haspc(sp_die, addr))
972 /* Address filtering 2: No child include addr? */
973 if (die_find_inlinefunc(sp_die, addr, &die_mem))
977 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
978 (int)i, lineno, (unsigned long long)addr);
981 ret = convert_probe_point(sp_die, pf);
982 /* Continuing, because target line might be inlined. */
984 /* TODO: deallocate lines, but how? */
988 /* Callback parameter with return value */
989 struct dwarf_callback_param {
994 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
996 struct dwarf_callback_param *param = data;
997 struct probe_finder *pf = param->data;
998 struct perf_probe_point *pp = &pf->pev->point;
1002 param->retval = find_probe_point_lazy(in_die, pf);
1004 /* Get probe address */
1005 if (dwarf_entrypc(in_die, &addr) != 0) {
1006 pr_warning("Failed to get entry pc of %s.\n",
1007 dwarf_diename(in_die));
1008 param->retval = -ENOENT;
1009 return DWARF_CB_ABORT;
1012 pf->addr += pp->offset;
1013 pr_debug("found inline addr: 0x%jx\n",
1014 (uintmax_t)pf->addr);
1016 param->retval = convert_probe_point(in_die, pf);
1017 if (param->retval < 0)
1018 return DWARF_CB_ABORT;
1024 /* Search function from function name */
1025 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1027 struct dwarf_callback_param *param = data;
1028 struct probe_finder *pf = param->data;
1029 struct perf_probe_point *pp = &pf->pev->point;
1031 /* Check tag and diename */
1032 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1033 !die_compare_name(sp_die, pp->function))
1036 pf->fname = dwarf_decl_file(sp_die);
1037 if (pp->line) { /* Function relative line */
1038 dwarf_decl_line(sp_die, &pf->lno);
1039 pf->lno += pp->line;
1040 param->retval = find_probe_point_by_line(pf);
1041 } else if (!dwarf_func_inline(sp_die)) {
1044 param->retval = find_probe_point_lazy(sp_die, pf);
1046 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1047 pr_warning("Failed to get entry pc of %s.\n",
1048 dwarf_diename(sp_die));
1049 param->retval = -ENOENT;
1050 return DWARF_CB_ABORT;
1052 pf->addr += pp->offset;
1053 /* TODO: Check the address in this function */
1054 param->retval = convert_probe_point(sp_die, pf);
1057 struct dwarf_callback_param _param = {.data = (void *)pf,
1059 /* Inlined function: search instances */
1060 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1062 param->retval = _param.retval;
1065 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1068 static int find_probe_point_by_func(struct probe_finder *pf)
1070 struct dwarf_callback_param _param = {.data = (void *)pf,
1072 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1073 return _param.retval;
1076 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1077 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1078 struct probe_trace_event **tevs, int max_tevs)
1080 struct probe_finder pf = {.pev = pev, .max_tevs = max_tevs};
1081 struct perf_probe_point *pp = &pev->point;
1082 Dwarf_Off off, noff;
1088 pf.tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1089 if (pf.tevs == NULL)
1094 dbg = dwarf_begin(fd, DWARF_C_READ);
1096 pr_warning("No dwarf info found in the vmlinux - "
1097 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1103 #if _ELFUTILS_PREREQ(0, 142)
1104 /* Get the call frame information from this dwarf */
1105 pf.cfi = dwarf_getcfi(dbg);
1109 line_list__init(&pf.lcache);
1110 /* Loop on CUs (Compilation Unit) */
1111 while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1113 /* Get the DIE(Debugging Information Entry) of this CU */
1114 diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
1118 /* Check if target file is included. */
1120 pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
1124 if (!pp->file || pf.fname) {
1126 ret = find_probe_point_by_func(&pf);
1127 else if (pp->lazy_line)
1128 ret = find_probe_point_lazy(NULL, &pf);
1131 ret = find_probe_point_by_line(&pf);
1136 line_list__free(&pf.lcache);
1139 return (ret < 0) ? ret : pf.ntevs;
1142 /* Reverse search */
1143 int find_perf_probe_point(int fd, unsigned long addr,
1144 struct perf_probe_point *ppt)
1146 Dwarf_Die cudie, spdie, indie;
1149 Dwarf_Addr laddr, eaddr;
1151 int lineno, ret = 0;
1154 dbg = dwarf_begin(fd, DWARF_C_READ);
1159 if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
1164 /* Find a corresponding line */
1165 line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1167 if (dwarf_lineaddr(line, &laddr) == 0 &&
1168 (Dwarf_Addr)addr == laddr &&
1169 dwarf_lineno(line, &lineno) == 0) {
1170 tmp = dwarf_linesrc(line, NULL, NULL);
1173 ppt->file = strdup(tmp);
1174 if (ppt->file == NULL) {
1183 /* Find a corresponding function */
1184 if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1185 tmp = dwarf_diename(&spdie);
1186 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1190 if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1192 /* addr in an inline function */
1193 tmp = dwarf_diename(&indie);
1196 ret = dwarf_decl_line(&indie, &lineno);
1198 if (eaddr == addr) { /* Function entry */
1202 ret = dwarf_decl_line(&spdie, &lineno);
1205 /* Make a relative line number */
1206 ppt->line -= lineno;
1210 /* We don't have a line number, let's use offset */
1211 ppt->offset = addr - (unsigned long)eaddr;
1213 ppt->function = strdup(tmp);
1214 if (ppt->function == NULL) {
1224 ret = found ? 1 : 0;
1228 /* Add a line and store the src path */
1229 static int line_range_add_line(const char *src, unsigned int lineno,
1230 struct line_range *lr)
1232 /* Copy source path */
1234 lr->path = strdup(src);
1235 if (lr->path == NULL)
1238 return line_list__add_line(&lr->line_list, lineno);
1241 /* Search function declaration lines */
1242 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1244 struct dwarf_callback_param *param = data;
1245 struct line_finder *lf = param->data;
1249 src = dwarf_decl_file(sp_die);
1250 if (src && strtailcmp(src, lf->fname) != 0)
1253 if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1254 (lf->lno_s > lineno || lf->lno_e < lineno))
1257 param->retval = line_range_add_line(src, lineno, lf->lr);
1258 if (param->retval < 0)
1259 return DWARF_CB_ABORT;
1263 static int find_line_range_func_decl_lines(struct line_finder *lf)
1265 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1266 dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, ¶m, 0);
1267 return param.retval;
1270 /* Find line range from its line number */
1271 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1277 int lineno, ret = 0;
1281 line_list__init(&lf->lr->line_list);
1282 if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1283 pr_warning("No source lines found in this CU.\n");
1287 /* Search probable lines on lines list */
1288 for (i = 0; i < nlines; i++) {
1289 line = dwarf_onesrcline(lines, i);
1290 if (dwarf_lineno(line, &lineno) != 0 ||
1291 (lf->lno_s > lineno || lf->lno_e < lineno))
1295 /* Address filtering 1: does sp_die include addr? */
1296 if (dwarf_lineaddr(line, &addr) != 0 ||
1297 !dwarf_haspc(sp_die, addr))
1300 /* Address filtering 2: No child include addr? */
1301 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1305 /* TODO: Get fileno from line, but how? */
1306 src = dwarf_linesrc(line, NULL, NULL);
1307 if (strtailcmp(src, lf->fname) != 0)
1310 ret = line_range_add_line(src, lineno, lf->lr);
1316 * Dwarf lines doesn't include function declarations. We have to
1317 * check functions list or given function.
1320 src = dwarf_decl_file(sp_die);
1321 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1322 (lf->lno_s <= lineno && lf->lno_e >= lineno))
1323 ret = line_range_add_line(src, lineno, lf->lr);
1325 ret = find_line_range_func_decl_lines(lf);
1329 if (!list_empty(&lf->lr->line_list))
1330 ret = lf->found = 1;
1332 ret = 0; /* Lines are not found */
1335 lf->lr->path = NULL;
1340 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1342 struct dwarf_callback_param *param = data;
1344 param->retval = find_line_range_by_line(in_die, param->data);
1345 return DWARF_CB_ABORT; /* No need to find other instances */
1348 /* Search function from function name */
1349 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1351 struct dwarf_callback_param *param = data;
1352 struct line_finder *lf = param->data;
1353 struct line_range *lr = lf->lr;
1355 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1356 die_compare_name(sp_die, lr->function)) {
1357 lf->fname = dwarf_decl_file(sp_die);
1358 dwarf_decl_line(sp_die, &lr->offset);
1359 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1360 lf->lno_s = lr->offset + lr->start;
1361 if (lf->lno_s < 0) /* Overflow */
1362 lf->lno_s = INT_MAX;
1363 lf->lno_e = lr->offset + lr->end;
1364 if (lf->lno_e < 0) /* Overflow */
1365 lf->lno_e = INT_MAX;
1366 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1367 lr->start = lf->lno_s;
1368 lr->end = lf->lno_e;
1369 if (dwarf_func_inline(sp_die)) {
1370 struct dwarf_callback_param _param;
1371 _param.data = (void *)lf;
1373 dwarf_func_inline_instances(sp_die,
1374 line_range_inline_cb,
1376 param->retval = _param.retval;
1378 param->retval = find_line_range_by_line(sp_die, lf);
1379 return DWARF_CB_ABORT;
1384 static int find_line_range_by_func(struct line_finder *lf)
1386 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1387 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0);
1388 return param.retval;
1391 int find_line_range(int fd, struct line_range *lr)
1393 struct line_finder lf = {.lr = lr, .found = 0};
1395 Dwarf_Off off = 0, noff;
1399 const char *comp_dir;
1401 dbg = dwarf_begin(fd, DWARF_C_READ);
1403 pr_warning("No dwarf info found in the vmlinux - "
1404 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1408 /* Loop on CUs (Compilation Unit) */
1409 while (!lf.found && ret >= 0) {
1410 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1413 /* Get the DIE(Debugging Information Entry) of this CU */
1414 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1418 /* Check if target file is included. */
1420 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1424 if (!lr->file || lf.fname) {
1426 ret = find_line_range_by_func(&lf);
1428 lf.lno_s = lr->start;
1430 ret = find_line_range_by_line(NULL, &lf);
1436 /* Store comp_dir */
1438 comp_dir = cu_get_comp_dir(&lf.cu_die);
1440 lr->comp_dir = strdup(comp_dir);
1446 pr_debug("path: %s\n", lr->path);
1449 return (ret < 0) ? ret : lf.found;