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
47 * Compare the tail of two strings.
48 * Return 0 if whole of either string is same as another's tail part.
50 static int strtailcmp(const char *s1, const char *s2)
54 while (--i1 >= 0 && --i2 >= 0) {
56 return s1[i1] - s2[i2];
61 /* Line number list operations */
63 /* Add a line to line number list */
64 static int line_list__add_line(struct list_head *head, int line)
69 /* Reverse search, because new line will be the last one */
70 list_for_each_entry_reverse(ln, head, list) {
71 if (ln->line < line) {
74 } else if (ln->line == line) /* Already exist */
77 /* List is empty, or the smallest entry */
80 pr_debug("line list: add a line %u\n", line);
81 ln = zalloc(sizeof(struct line_node));
85 INIT_LIST_HEAD(&ln->list);
86 list_add(&ln->list, p);
90 /* Check if the line in line number list */
91 static int line_list__has_line(struct list_head *head, int line)
95 /* Reverse search, because new line will be the last one */
96 list_for_each_entry(ln, head, list)
103 /* Init line number list */
104 static void line_list__init(struct list_head *head)
106 INIT_LIST_HEAD(head);
109 /* Free line number list */
110 static void line_list__free(struct list_head *head)
112 struct line_node *ln;
113 while (!list_empty(head)) {
114 ln = list_first_entry(head, struct line_node, list);
120 /* Dwarf FL wrappers */
121 static char *debuginfo_path; /* Currently dummy */
123 static const Dwfl_Callbacks offline_callbacks = {
124 .find_debuginfo = dwfl_standard_find_debuginfo,
125 .debuginfo_path = &debuginfo_path,
127 .section_address = dwfl_offline_section_address,
129 /* We use this table for core files too. */
130 .find_elf = dwfl_build_id_find_elf,
133 /* Get a Dwarf from offline image */
134 static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
142 *dwflp = dwfl_begin(&offline_callbacks);
146 mod = dwfl_report_offline(*dwflp, "", "", fd);
150 dbg = dwfl_module_getdwarf(mod, bias);
159 #if _ELFUTILS_PREREQ(0, 148)
160 /* This method is buggy if elfutils is older than 0.148 */
161 static int __linux_kernel_find_elf(Dwfl_Module *mod,
163 const char *module_name,
165 char **file_name, Elf **elfp)
168 const char *path = kernel_get_module_path(module_name);
170 pr_debug2("Use file %s for %s\n", path, module_name);
172 fd = open(path, O_RDONLY);
174 *file_name = strdup(path);
178 /* If failed, try to call standard method */
179 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
183 static const Dwfl_Callbacks kernel_callbacks = {
184 .find_debuginfo = dwfl_standard_find_debuginfo,
185 .debuginfo_path = &debuginfo_path,
187 .find_elf = __linux_kernel_find_elf,
188 .section_address = dwfl_linux_kernel_module_section_address,
191 /* Get a Dwarf from live kernel image */
192 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
200 *dwflp = dwfl_begin(&kernel_callbacks);
204 /* Load the kernel dwarves: Don't care the result here */
205 dwfl_linux_kernel_report_kernel(*dwflp);
206 dwfl_linux_kernel_report_modules(*dwflp);
208 dbg = dwfl_addrdwarf(*dwflp, addr, bias);
209 /* Here, check whether we could get a real dwarf */
211 pr_debug("Failed to find kernel dwarf at %lx\n",
212 (unsigned long)addr);
219 /* With older elfutils, this just support kernel module... */
220 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp,
224 const char *path = kernel_get_module_path("kernel");
227 pr_err("Failed to find vmlinux path\n");
231 pr_debug2("Use file %s for debuginfo\n", path);
232 fd = open(path, O_RDONLY);
236 return dwfl_init_offline_dwarf(fd, dwflp, bias);
242 /* Find the realpath of the target file. */
243 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
247 const char *src = NULL;
253 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
257 for (i = 0; i < nfiles; i++) {
258 src = dwarf_filesrc(files, i, NULL, NULL);
259 if (strtailcmp(src, fname) == 0)
267 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
268 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
270 Dwarf_Attribute attr;
271 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
273 return dwarf_formstring(&attr);
276 /* Compare diename and tname */
277 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
280 name = dwarf_diename(dw_die);
281 return name ? (strcmp(tname, name) == 0) : false;
284 /* Get callsite line number of inline-function instance */
285 static int die_get_call_lineno(Dwarf_Die *in_die)
287 Dwarf_Attribute attr;
290 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
293 dwarf_formudata(&attr, &ret);
298 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
300 Dwarf_Attribute attr;
302 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
303 dwarf_formref_die(&attr, die_mem))
309 /* Get a type die, but skip qualifiers */
310 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
315 vr_die = die_get_type(vr_die, die_mem);
318 tag = dwarf_tag(vr_die);
319 } while (tag == DW_TAG_const_type ||
320 tag == DW_TAG_restrict_type ||
321 tag == DW_TAG_volatile_type ||
322 tag == DW_TAG_shared_type);
327 /* Get a type die, but skip qualifiers and typedef */
328 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
331 vr_die = __die_get_real_type(vr_die, die_mem);
332 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
337 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
340 Dwarf_Attribute attr;
342 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
343 dwarf_formudata(&attr, result) != 0)
349 static bool die_is_signed_type(Dwarf_Die *tp_die)
353 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
356 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
357 ret == DW_ATE_signed_fixed);
360 static int die_get_byte_size(Dwarf_Die *tp_die)
364 if (die_get_attr_udata(tp_die, DW_AT_byte_size, &ret))
370 static int die_get_bit_size(Dwarf_Die *tp_die)
374 if (die_get_attr_udata(tp_die, DW_AT_bit_size, &ret))
380 static int die_get_bit_offset(Dwarf_Die *tp_die)
384 if (die_get_attr_udata(tp_die, DW_AT_bit_offset, &ret))
390 /* Get data_member_location offset */
391 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
393 Dwarf_Attribute attr;
398 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
401 if (dwarf_formudata(&attr, offs) != 0) {
402 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
403 ret = dwarf_getlocation(&attr, &expr, &nexpr);
404 if (ret < 0 || nexpr == 0)
407 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
408 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
409 expr[0].atom, nexpr);
412 *offs = (Dwarf_Word)expr[0].number;
417 /* Return values for die_find callbacks */
419 DIE_FIND_CB_FOUND = 0, /* End of Search */
420 DIE_FIND_CB_CHILD = 1, /* Search only children */
421 DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
422 DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
425 /* Search a child die */
426 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
427 int (*callback)(Dwarf_Die *, void *),
428 void *data, Dwarf_Die *die_mem)
433 ret = dwarf_child(rt_die, die_mem);
438 ret = callback(die_mem, data);
439 if (ret == DIE_FIND_CB_FOUND)
442 if ((ret & DIE_FIND_CB_CHILD) &&
443 die_find_child(die_mem, callback, data, &child_die)) {
444 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
447 } while ((ret & DIE_FIND_CB_SIBLING) &&
448 dwarf_siblingof(die_mem, die_mem) == 0);
453 struct __addr_die_search_param {
458 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
460 struct __addr_die_search_param *ad = data;
462 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
463 dwarf_haspc(fn_die, ad->addr)) {
464 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
465 return DWARF_CB_ABORT;
470 /* Search a real subprogram including this line, */
471 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
474 struct __addr_die_search_param ad;
476 ad.die_mem = die_mem;
477 /* dwarf_getscopes can't find subprogram. */
478 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
484 /* die_find callback for inline function search */
485 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
487 Dwarf_Addr *addr = data;
489 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
490 dwarf_haspc(die_mem, *addr))
491 return DIE_FIND_CB_FOUND;
493 return DIE_FIND_CB_CONTINUE;
496 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
497 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
500 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
503 /* Walker on lines (Note: line number will not be sorted) */
504 typedef int (* line_walk_handler_t) (const char *fname, int lineno,
505 Dwarf_Addr addr, void *data);
507 struct __line_walk_param {
509 line_walk_handler_t handler;
514 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
516 struct __line_walk_param *lw = data;
520 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
521 lineno = die_get_call_lineno(in_die);
522 if (lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
523 lw->retval = lw->handler(lw->fname, lineno, addr,
526 return DIE_FIND_CB_FOUND;
529 return DIE_FIND_CB_SIBLING;
532 /* Walk on lines of blocks included in given DIE */
533 static int __die_walk_funclines(Dwarf_Die *sp_die,
534 line_walk_handler_t handler, void *data)
536 struct __line_walk_param lw = {
545 /* Handle function declaration line */
546 lw.fname = dwarf_decl_file(sp_die);
547 if (lw.fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
548 dwarf_entrypc(sp_die, &addr) == 0) {
549 lw.retval = handler(lw.fname, lineno, addr, data);
553 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
558 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
560 struct __line_walk_param *lw = data;
562 lw->retval = __die_walk_funclines(sp_die, lw->handler, lw->data);
564 return DWARF_CB_ABORT;
570 * Walk on lines inside given PDIE. If the PDIE is subprogram, walk only on
571 * the lines inside the subprogram, otherwise PDIE must be a CU DIE.
573 static int die_walk_lines(Dwarf_Die *pdie, line_walk_handler_t handler,
581 Dwarf_Die die_mem, *cu_die;
585 if (dwarf_tag(pdie) == DW_TAG_subprogram)
586 cu_die = dwarf_diecu(pdie, &die_mem, NULL, NULL);
590 pr_debug2("Failed to get CU from subprogram\n");
594 /* Get lines list in the CU */
595 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
596 pr_debug2("Failed to get source lines on this CU.\n");
599 pr_debug2("Get %zd lines from this CU\n", nlines);
601 /* Walk on the lines on lines list */
602 for (i = 0; i < nlines; i++) {
603 line = dwarf_onesrcline(lines, i);
605 dwarf_lineno(line, &lineno) != 0 ||
606 dwarf_lineaddr(line, &addr) != 0) {
607 pr_debug2("Failed to get line info. "
608 "Possible error in debuginfo.\n");
611 /* Filter lines based on address */
615 * The line is included in given function, and
616 * no inline block includes it.
618 if (!dwarf_haspc(pdie, addr) ||
619 die_find_inlinefunc(pdie, addr, &die_mem))
621 /* Get source line */
622 fname = dwarf_linesrc(line, NULL, NULL);
624 ret = handler(fname, lineno, addr, data);
630 * Dwarf lines doesn't include function declarations and inlined
631 * subroutines. We have to check functions list or given function.
634 ret = __die_walk_funclines(pdie, handler, data);
636 struct __line_walk_param param = {
641 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
648 struct __find_variable_param {
653 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
655 struct __find_variable_param *fvp = data;
658 tag = dwarf_tag(die_mem);
659 if ((tag == DW_TAG_formal_parameter ||
660 tag == DW_TAG_variable) &&
661 die_compare_name(die_mem, fvp->name))
662 return DIE_FIND_CB_FOUND;
664 if (dwarf_haspc(die_mem, fvp->addr))
665 return DIE_FIND_CB_CONTINUE;
667 return DIE_FIND_CB_SIBLING;
670 /* Find a variable called 'name' at given address */
671 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
672 Dwarf_Addr addr, Dwarf_Die *die_mem)
674 struct __find_variable_param fvp = { .name = name, .addr = addr};
676 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
680 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
682 const char *name = data;
684 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
685 die_compare_name(die_mem, name))
686 return DIE_FIND_CB_FOUND;
688 return DIE_FIND_CB_SIBLING;
691 /* Find a member called 'name' */
692 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
695 return die_find_child(st_die, __die_find_member_cb, (void *)name,
699 /* Get the name of given variable DIE */
700 static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
704 const char *tmp = "";
706 if (__die_get_real_type(vr_die, &type) == NULL)
709 tag = dwarf_tag(&type);
710 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
712 else if (tag == DW_TAG_subroutine_type) {
713 /* Function pointer */
714 ret = snprintf(buf, len, "(function_type)");
715 return (ret >= len) ? -E2BIG : ret;
717 if (!dwarf_diename(&type))
719 if (tag == DW_TAG_union_type)
721 else if (tag == DW_TAG_structure_type)
723 /* Write a base name */
724 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
725 return (ret >= len) ? -E2BIG : ret;
727 ret = die_get_typename(&type, buf, len);
729 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
730 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
735 /* Get the name and type of given variable DIE, stored as "type\tname" */
736 static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
740 ret = die_get_typename(vr_die, buf, len);
742 pr_debug("Failed to get type, make it unknown.\n");
743 ret = snprintf(buf, len, "(unknown_type)");
746 ret2 = snprintf(buf + ret, len - ret, "\t%s",
747 dwarf_diename(vr_die));
748 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
754 * Probe finder related functions
757 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
759 struct probe_trace_arg_ref *ref;
760 ref = zalloc(sizeof(struct probe_trace_arg_ref));
767 * Convert a location into trace_arg.
768 * If tvar == NULL, this just checks variable can be converted.
770 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
772 struct probe_trace_arg *tvar)
774 Dwarf_Attribute attr;
783 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
786 /* TODO: handle more than 1 exprs */
787 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
788 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
790 /* TODO: Support const_value */
794 if (op->atom == DW_OP_addr) {
798 /* Static variables on memory (not stack), make @varname */
799 ret = strlen(dwarf_diename(vr_die));
800 tvar->value = zalloc(ret + 2);
801 if (tvar->value == NULL)
803 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
804 tvar->ref = alloc_trace_arg_ref((long)offs);
805 if (tvar->ref == NULL)
810 /* If this is based on frame buffer, set the offset */
811 if (op->atom == DW_OP_fbreg) {
819 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
820 regn = op->atom - DW_OP_breg0;
823 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
824 regn = op->atom - DW_OP_reg0;
825 } else if (op->atom == DW_OP_bregx) {
829 } else if (op->atom == DW_OP_regx) {
832 pr_debug("DW_OP %x is not supported.\n", op->atom);
839 regs = get_arch_regstr(regn);
841 /* This should be a bug in DWARF or this tool */
842 pr_warning("Mapping for the register number %u "
843 "missing on this architecture.\n", regn);
847 tvar->value = strdup(regs);
848 if (tvar->value == NULL)
852 tvar->ref = alloc_trace_arg_ref((long)offs);
853 if (tvar->ref == NULL)
859 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
861 static int convert_variable_type(Dwarf_Die *vr_die,
862 struct probe_trace_arg *tvar,
865 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
870 /* TODO: check all types */
871 if (cast && strcmp(cast, "string") != 0) {
872 /* Non string type is OK */
873 tvar->type = strdup(cast);
874 return (tvar->type == NULL) ? -ENOMEM : 0;
877 if (die_get_bit_size(vr_die) != 0) {
878 /* This is a bitfield */
879 ret = snprintf(buf, 16, "b%d@%d/%zd", die_get_bit_size(vr_die),
880 die_get_bit_offset(vr_die),
881 BYTES_TO_BITS(die_get_byte_size(vr_die)));
885 if (die_get_real_type(vr_die, &type) == NULL) {
886 pr_warning("Failed to get a type information of %s.\n",
887 dwarf_diename(vr_die));
891 pr_debug("%s type is %s.\n",
892 dwarf_diename(vr_die), dwarf_diename(&type));
894 if (cast && strcmp(cast, "string") == 0) { /* String type */
895 ret = dwarf_tag(&type);
896 if (ret != DW_TAG_pointer_type &&
897 ret != DW_TAG_array_type) {
898 pr_warning("Failed to cast into string: "
899 "%s(%s) is not a pointer nor array.\n",
900 dwarf_diename(vr_die), dwarf_diename(&type));
903 if (ret == DW_TAG_pointer_type) {
904 if (die_get_real_type(&type, &type) == NULL) {
905 pr_warning("Failed to get a type"
910 ref_ptr = &(*ref_ptr)->next;
911 /* Add new reference with offset +0 */
912 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
913 if (*ref_ptr == NULL) {
914 pr_warning("Out of memory error\n");
918 if (!die_compare_name(&type, "char") &&
919 !die_compare_name(&type, "unsigned char")) {
920 pr_warning("Failed to cast into string: "
921 "%s is not (unsigned) char *.\n",
922 dwarf_diename(vr_die));
925 tvar->type = strdup(cast);
926 return (tvar->type == NULL) ? -ENOMEM : 0;
929 ret = BYTES_TO_BITS(die_get_byte_size(&type));
931 /* No size ... try to use default type */
934 /* Check the bitwidth */
935 if (ret > MAX_BASIC_TYPE_BITS) {
936 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
937 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
938 ret = MAX_BASIC_TYPE_BITS;
940 ret = snprintf(buf, 16, "%c%d",
941 die_is_signed_type(&type) ? 's' : 'u', ret);
944 if (ret < 0 || ret >= 16) {
947 pr_warning("Failed to convert variable type: %s\n",
951 tvar->type = strdup(buf);
952 if (tvar->type == NULL)
957 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
958 struct perf_probe_arg_field *field,
959 struct probe_trace_arg_ref **ref_ptr,
962 struct probe_trace_arg_ref *ref = *ref_ptr;
967 pr_debug("converting %s in %s\n", field->name, varname);
968 if (die_get_real_type(vr_die, &type) == NULL) {
969 pr_warning("Failed to get the type of %s.\n", varname);
972 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
973 tag = dwarf_tag(&type);
975 if (field->name[0] == '[' &&
976 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
978 /* Save original type for next field */
979 memcpy(die_mem, &type, sizeof(*die_mem));
980 /* Get the type of this array */
981 if (die_get_real_type(&type, &type) == NULL) {
982 pr_warning("Failed to get the type of %s.\n", varname);
985 pr_debug2("Array real type: (%x)\n",
986 (unsigned)dwarf_dieoffset(&type));
987 if (tag == DW_TAG_pointer_type) {
988 ref = zalloc(sizeof(struct probe_trace_arg_ref));
992 (*ref_ptr)->next = ref;
996 ref->offset += die_get_byte_size(&type) * field->index;
998 /* Save vr_die for converting types */
999 memcpy(die_mem, vr_die, sizeof(*die_mem));
1001 } else if (tag == DW_TAG_pointer_type) {
1002 /* Check the pointer and dereference */
1004 pr_err("Semantic error: %s must be referred by '->'\n",
1008 /* Get the type pointed by this pointer */
1009 if (die_get_real_type(&type, &type) == NULL) {
1010 pr_warning("Failed to get the type of %s.\n", varname);
1013 /* Verify it is a data structure */
1014 if (dwarf_tag(&type) != DW_TAG_structure_type) {
1015 pr_warning("%s is not a data structure.\n", varname);
1019 ref = zalloc(sizeof(struct probe_trace_arg_ref));
1023 (*ref_ptr)->next = ref;
1027 /* Verify it is a data structure */
1028 if (tag != DW_TAG_structure_type) {
1029 pr_warning("%s is not a data structure.\n", varname);
1032 if (field->name[0] == '[') {
1033 pr_err("Semantic error: %s is not a pointor"
1034 " nor array.\n", varname);
1038 pr_err("Semantic error: %s must be referred by '.'\n",
1043 pr_warning("Structure on a register is not "
1044 "supported yet.\n");
1049 if (die_find_member(&type, field->name, die_mem) == NULL) {
1050 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
1051 dwarf_diename(&type), field->name);
1055 /* Get the offset of the field */
1056 ret = die_get_data_member_location(die_mem, &offs);
1058 pr_warning("Failed to get the offset of %s.\n", field->name);
1061 ref->offset += (long)offs;
1064 /* Converting next field */
1066 return convert_variable_fields(die_mem, field->name,
1067 field->next, &ref, die_mem);
1072 /* Show a variables in kprobe event format */
1073 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
1078 pr_debug("Converting variable %s into trace event.\n",
1079 dwarf_diename(vr_die));
1081 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
1084 pr_err("Failed to find the location of %s at this address.\n"
1085 " Perhaps, it has been optimized out.\n", pf->pvar->var);
1086 else if (ret == -ENOTSUP)
1087 pr_err("Sorry, we don't support this variable location yet.\n");
1088 else if (pf->pvar->field) {
1089 ret = convert_variable_fields(vr_die, pf->pvar->var,
1090 pf->pvar->field, &pf->tvar->ref,
1095 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
1096 /* *expr will be cached in libdw. Don't free it. */
1100 /* Find a variable in a subprogram die */
1101 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
1103 Dwarf_Die vr_die, *scopes;
1107 if (!is_c_varname(pf->pvar->var)) {
1108 /* Copy raw parameters */
1109 pf->tvar->value = strdup(pf->pvar->var);
1110 if (pf->tvar->value == NULL)
1112 if (pf->pvar->type) {
1113 pf->tvar->type = strdup(pf->pvar->type);
1114 if (pf->tvar->type == NULL)
1117 if (pf->pvar->name) {
1118 pf->tvar->name = strdup(pf->pvar->name);
1119 if (pf->tvar->name == NULL)
1122 pf->tvar->name = NULL;
1127 pf->tvar->name = strdup(pf->pvar->name);
1129 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
1132 ptr = strchr(buf, ':'); /* Change type separator to _ */
1135 pf->tvar->name = strdup(buf);
1137 if (pf->tvar->name == NULL)
1140 pr_debug("Searching '%s' variable in context.\n",
1142 /* Search child die for local variables and parameters. */
1143 if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
1144 ret = convert_variable(&vr_die, pf);
1146 /* Search upper class */
1147 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1148 while (nscopes-- > 1) {
1149 pr_debug("Searching variables in %s\n",
1150 dwarf_diename(&scopes[nscopes]));
1151 /* We should check this scope, so give dummy address */
1152 if (die_find_variable_at(&scopes[nscopes],
1155 ret = convert_variable(&vr_die, pf);
1165 pr_warning("Failed to find '%s' in this function.\n",
1170 /* Convert subprogram DIE to trace point */
1171 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
1172 bool retprobe, struct probe_trace_point *tp)
1177 /* Copy the name of probe point */
1178 name = dwarf_diename(sp_die);
1180 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
1181 pr_warning("Failed to get entry address of %s\n",
1182 dwarf_diename(sp_die));
1185 tp->symbol = strdup(name);
1186 if (tp->symbol == NULL)
1188 tp->offset = (unsigned long)(paddr - eaddr);
1190 /* This function has no name. */
1191 tp->offset = (unsigned long)paddr;
1193 /* Return probe must be on the head of a subprogram */
1195 if (eaddr != paddr) {
1196 pr_warning("Return probe must be on the head of"
1197 " a real function.\n");
1200 tp->retprobe = true;
1206 /* Call probe_finder callback with real subprogram DIE */
1207 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
1210 Dwarf_Attribute fb_attr;
1214 /* If no real subprogram, find a real one */
1215 if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
1216 sp_die = die_find_real_subprogram(&pf->cu_die,
1217 pf->addr, &die_mem);
1219 pr_warning("Failed to find probe point in any "
1225 /* Get the frame base attribute/ops */
1226 dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1227 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1228 if (ret <= 0 || nops == 0) {
1230 #if _ELFUTILS_PREREQ(0, 142)
1231 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1234 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1235 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1236 pr_warning("Failed to get call frame on 0x%jx\n",
1237 (uintmax_t)pf->addr);
1243 /* Call finder's callback handler */
1244 ret = pf->callback(sp_die, pf);
1246 /* *pf->fb_ops will be cached in libdw. Don't free it. */
1252 static int probe_point_line_walker(const char *fname, int lineno,
1253 Dwarf_Addr addr, void *data)
1255 struct probe_finder *pf = data;
1258 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
1262 ret = call_probe_finder(NULL, pf);
1264 /* Continue if no error, because the line will be in inline function */
1265 return ret < 0 ? ret : 0;
1268 /* Find probe point from its line number */
1269 static int find_probe_point_by_line(struct probe_finder *pf)
1271 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
1274 /* Find lines which match lazy pattern */
1275 static int find_lazy_match_lines(struct list_head *head,
1276 const char *fname, const char *pat)
1282 int count = 0, linenum = 1;
1284 fp = fopen(fname, "r");
1286 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
1290 while ((len = getline(&line, &line_len, fp)) > 0) {
1292 if (line[len - 1] == '\n')
1293 line[len - 1] = '\0';
1295 if (strlazymatch(line, pat)) {
1296 line_list__add_line(head, linenum);
1308 pr_debug("No matched lines found in %s.\n", fname);
1312 static int probe_point_lazy_walker(const char *fname, int lineno,
1313 Dwarf_Addr addr, void *data)
1315 struct probe_finder *pf = data;
1318 if (!line_list__has_line(&pf->lcache, lineno) ||
1319 strtailcmp(fname, pf->fname) != 0)
1322 pr_debug("Probe line found: line:%d addr:0x%llx\n",
1323 lineno, (unsigned long long)addr);
1325 ret = call_probe_finder(NULL, pf);
1328 * Continue if no error, because the lazy pattern will match
1331 return ret < 0 ? ret : 0;
1334 /* Find probe points from lazy pattern */
1335 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1339 if (list_empty(&pf->lcache)) {
1340 /* Matching lazy line pattern */
1341 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1342 pf->pev->point.lazy_line);
1347 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
1350 /* Callback parameter with return value */
1351 struct dwarf_callback_param {
1356 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1358 struct dwarf_callback_param *param = data;
1359 struct probe_finder *pf = param->data;
1360 struct perf_probe_point *pp = &pf->pev->point;
1364 param->retval = find_probe_point_lazy(in_die, pf);
1366 /* Get probe address */
1367 if (dwarf_entrypc(in_die, &addr) != 0) {
1368 pr_warning("Failed to get entry address of %s.\n",
1369 dwarf_diename(in_die));
1370 param->retval = -ENOENT;
1371 return DWARF_CB_ABORT;
1374 pf->addr += pp->offset;
1375 pr_debug("found inline addr: 0x%jx\n",
1376 (uintmax_t)pf->addr);
1378 param->retval = call_probe_finder(in_die, pf);
1379 if (param->retval < 0)
1380 return DWARF_CB_ABORT;
1386 /* Search function from function name */
1387 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1389 struct dwarf_callback_param *param = data;
1390 struct probe_finder *pf = param->data;
1391 struct perf_probe_point *pp = &pf->pev->point;
1393 /* Check tag and diename */
1394 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1395 !die_compare_name(sp_die, pp->function))
1398 /* Check declared file */
1399 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
1402 pf->fname = dwarf_decl_file(sp_die);
1403 if (pp->line) { /* Function relative line */
1404 dwarf_decl_line(sp_die, &pf->lno);
1405 pf->lno += pp->line;
1406 param->retval = find_probe_point_by_line(pf);
1407 } else if (!dwarf_func_inline(sp_die)) {
1410 param->retval = find_probe_point_lazy(sp_die, pf);
1412 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1413 pr_warning("Failed to get entry address of "
1414 "%s.\n", dwarf_diename(sp_die));
1415 param->retval = -ENOENT;
1416 return DWARF_CB_ABORT;
1418 pf->addr += pp->offset;
1419 /* TODO: Check the address in this function */
1420 param->retval = call_probe_finder(sp_die, pf);
1423 struct dwarf_callback_param _param = {.data = (void *)pf,
1425 /* Inlined function: search instances */
1426 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1428 param->retval = _param.retval;
1431 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1434 static int find_probe_point_by_func(struct probe_finder *pf)
1436 struct dwarf_callback_param _param = {.data = (void *)pf,
1438 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1439 return _param.retval;
1442 /* Find probe points from debuginfo */
1443 static int find_probes(int fd, struct probe_finder *pf)
1445 struct perf_probe_point *pp = &pf->pev->point;
1446 Dwarf_Off off, noff;
1451 Dwarf_Addr bias; /* Currently ignored */
1454 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1456 pr_warning("No debug information found in the vmlinux - "
1457 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1461 #if _ELFUTILS_PREREQ(0, 142)
1462 /* Get the call frame information from this dwarf */
1463 pf->cfi = dwarf_getcfi(dbg);
1467 line_list__init(&pf->lcache);
1468 /* Loop on CUs (Compilation Unit) */
1469 while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1470 /* Get the DIE(Debugging Information Entry) of this CU */
1471 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1475 /* Check if target file is included. */
1477 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1481 if (!pp->file || pf->fname) {
1483 ret = find_probe_point_by_func(pf);
1484 else if (pp->lazy_line)
1485 ret = find_probe_point_lazy(NULL, pf);
1488 ret = find_probe_point_by_line(pf);
1495 line_list__free(&pf->lcache);
1502 /* Add a found probe point into trace event list */
1503 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1505 struct trace_event_finder *tf =
1506 container_of(pf, struct trace_event_finder, pf);
1507 struct probe_trace_event *tev;
1510 /* Check number of tevs */
1511 if (tf->ntevs == tf->max_tevs) {
1512 pr_warning("Too many( > %d) probe point found.\n",
1516 tev = &tf->tevs[tf->ntevs++];
1518 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1523 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1526 /* Find each argument */
1527 tev->nargs = pf->pev->nargs;
1528 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1529 if (tev->args == NULL)
1531 for (i = 0; i < pf->pev->nargs; i++) {
1532 pf->pvar = &pf->pev->args[i];
1533 pf->tvar = &tev->args[i];
1534 ret = find_variable(sp_die, pf);
1542 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1543 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1544 struct probe_trace_event **tevs, int max_tevs)
1546 struct trace_event_finder tf = {
1547 .pf = {.pev = pev, .callback = add_probe_trace_event},
1548 .max_tevs = max_tevs};
1551 /* Allocate result tevs array */
1552 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1559 ret = find_probes(fd, &tf.pf);
1566 return (ret < 0) ? ret : tf.ntevs;
1569 #define MAX_VAR_LEN 64
1571 /* Collect available variables in this scope */
1572 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1574 struct available_var_finder *af = data;
1575 struct variable_list *vl;
1576 char buf[MAX_VAR_LEN];
1579 vl = &af->vls[af->nvls - 1];
1581 tag = dwarf_tag(die_mem);
1582 if (tag == DW_TAG_formal_parameter ||
1583 tag == DW_TAG_variable) {
1584 ret = convert_variable_location(die_mem, af->pf.addr,
1585 af->pf.fb_ops, NULL);
1587 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1588 pr_debug2("Add new var: %s\n", buf);
1590 strlist__add(vl->vars, buf);
1594 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1595 return DIE_FIND_CB_CONTINUE;
1597 return DIE_FIND_CB_SIBLING;
1600 /* Add a found vars into available variables list */
1601 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1603 struct available_var_finder *af =
1604 container_of(pf, struct available_var_finder, pf);
1605 struct variable_list *vl;
1606 Dwarf_Die die_mem, *scopes = NULL;
1609 /* Check number of tevs */
1610 if (af->nvls == af->max_vls) {
1611 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1614 vl = &af->vls[af->nvls++];
1616 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1621 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1624 /* Find local variables */
1625 vl->vars = strlist__new(true, NULL);
1626 if (vl->vars == NULL)
1629 die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1631 /* Find external variables */
1634 /* Don't need to search child DIE for externs. */
1636 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1637 while (nscopes-- > 1)
1638 die_find_child(&scopes[nscopes], collect_variables_cb,
1639 (void *)af, &die_mem);
1644 if (strlist__empty(vl->vars)) {
1645 strlist__delete(vl->vars);
1652 /* Find available variables at given probe point */
1653 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1654 struct variable_list **vls, int max_vls,
1657 struct available_var_finder af = {
1658 .pf = {.pev = pev, .callback = add_available_vars},
1659 .max_vls = max_vls, .externs = externs};
1662 /* Allocate result vls array */
1663 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1670 ret = find_probes(fd, &af.pf);
1672 /* Free vlist for error */
1674 if (af.vls[af.nvls].point.symbol)
1675 free(af.vls[af.nvls].point.symbol);
1676 if (af.vls[af.nvls].vars)
1677 strlist__delete(af.vls[af.nvls].vars);
1684 return (ret < 0) ? ret : af.nvls;
1687 /* Reverse search */
1688 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1690 Dwarf_Die cudie, spdie, indie;
1694 Dwarf_Addr laddr, eaddr, bias = 0;
1696 int lineno, ret = 0;
1699 /* Open the live linux kernel */
1700 dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1702 pr_warning("No debug information found in the vmlinux - "
1703 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1708 /* Adjust address with bias */
1711 if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1712 pr_warning("Failed to find debug information for address %lx\n",
1718 /* Find a corresponding line */
1719 line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1721 if (dwarf_lineaddr(line, &laddr) == 0 &&
1722 (Dwarf_Addr)addr == laddr &&
1723 dwarf_lineno(line, &lineno) == 0) {
1724 tmp = dwarf_linesrc(line, NULL, NULL);
1727 ppt->file = strdup(tmp);
1728 if (ppt->file == NULL) {
1737 /* Find a corresponding function */
1738 if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1739 tmp = dwarf_diename(&spdie);
1740 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1744 if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1746 /* addr in an inline function */
1747 tmp = dwarf_diename(&indie);
1750 ret = dwarf_decl_line(&indie, &lineno);
1752 if (eaddr == addr) { /* Function entry */
1756 ret = dwarf_decl_line(&spdie, &lineno);
1759 /* Make a relative line number */
1760 ppt->line -= lineno;
1764 /* We don't have a line number, let's use offset */
1765 ppt->offset = addr - (unsigned long)eaddr;
1767 ppt->function = strdup(tmp);
1768 if (ppt->function == NULL) {
1779 ret = found ? 1 : 0;
1783 /* Add a line and store the src path */
1784 static int line_range_add_line(const char *src, unsigned int lineno,
1785 struct line_range *lr)
1787 /* Copy source path */
1789 lr->path = strdup(src);
1790 if (lr->path == NULL)
1793 return line_list__add_line(&lr->line_list, lineno);
1796 static int line_range_walk_cb(const char *fname, int lineno,
1797 Dwarf_Addr addr __used,
1800 struct line_finder *lf = data;
1802 if ((strtailcmp(fname, lf->fname) != 0) ||
1803 (lf->lno_s > lineno || lf->lno_e < lineno))
1806 if (line_range_add_line(fname, lineno, lf->lr) < 0)
1812 /* Find line range from its line number */
1813 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1817 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1821 if (!list_empty(&lf->lr->line_list))
1822 ret = lf->found = 1;
1824 ret = 0; /* Lines are not found */
1827 lf->lr->path = NULL;
1832 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1834 struct dwarf_callback_param *param = data;
1836 param->retval = find_line_range_by_line(in_die, param->data);
1837 return DWARF_CB_ABORT; /* No need to find other instances */
1840 /* Search function from function name */
1841 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1843 struct dwarf_callback_param *param = data;
1844 struct line_finder *lf = param->data;
1845 struct line_range *lr = lf->lr;
1847 /* Check declared file */
1848 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1851 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1852 die_compare_name(sp_die, lr->function)) {
1853 lf->fname = dwarf_decl_file(sp_die);
1854 dwarf_decl_line(sp_die, &lr->offset);
1855 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1856 lf->lno_s = lr->offset + lr->start;
1857 if (lf->lno_s < 0) /* Overflow */
1858 lf->lno_s = INT_MAX;
1859 lf->lno_e = lr->offset + lr->end;
1860 if (lf->lno_e < 0) /* Overflow */
1861 lf->lno_e = INT_MAX;
1862 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1863 lr->start = lf->lno_s;
1864 lr->end = lf->lno_e;
1865 if (dwarf_func_inline(sp_die)) {
1866 struct dwarf_callback_param _param;
1867 _param.data = (void *)lf;
1869 dwarf_func_inline_instances(sp_die,
1870 line_range_inline_cb,
1872 param->retval = _param.retval;
1874 param->retval = find_line_range_by_line(sp_die, lf);
1875 return DWARF_CB_ABORT;
1880 static int find_line_range_by_func(struct line_finder *lf)
1882 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1883 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0);
1884 return param.retval;
1887 int find_line_range(int fd, struct line_range *lr)
1889 struct line_finder lf = {.lr = lr, .found = 0};
1891 Dwarf_Off off = 0, noff;
1896 Dwarf_Addr bias; /* Currently ignored */
1897 const char *comp_dir;
1899 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1901 pr_warning("No debug information found in the vmlinux - "
1902 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1906 /* Loop on CUs (Compilation Unit) */
1907 while (!lf.found && ret >= 0) {
1908 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1911 /* Get the DIE(Debugging Information Entry) of this CU */
1912 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1916 /* Check if target file is included. */
1918 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1922 if (!lr->file || lf.fname) {
1924 ret = find_line_range_by_func(&lf);
1926 lf.lno_s = lr->start;
1928 ret = find_line_range_by_line(NULL, &lf);
1934 /* Store comp_dir */
1936 comp_dir = cu_get_comp_dir(&lf.cu_die);
1938 lr->comp_dir = strdup(comp_dir);
1944 pr_debug("path: %s\n", lr->path);
1946 return (ret < 0) ? ret : lf.found;