1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * dwarf-aux.c : libdw auxiliary interfaces
11 #include "dwarf-aux.h"
16 * cu_find_realpath - Find the realpath of the target file
17 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
18 * @fname: The tail filename of the target file
20 * Find the real(long) path of @fname in @cu_die.
22 const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
26 const char *src = NULL;
32 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
36 for (i = 0; i < nfiles; i++) {
37 src = dwarf_filesrc(files, i, NULL, NULL);
38 if (strtailcmp(src, fname) == 0)
47 * cu_get_comp_dir - Get the path of compilation directory
50 * Get the path of compilation directory of given @cu_die.
51 * Since this depends on DW_AT_comp_dir, older gcc will not
52 * embedded it. In that case, this returns NULL.
54 const char *cu_get_comp_dir(Dwarf_Die *cu_die)
57 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
59 return dwarf_formstring(&attr);
62 /* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */
63 static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr)
68 size_t nlines, l, u, n;
71 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0 ||
75 /* Lines are sorted by address, use binary search */
76 l = 0; u = nlines - 1;
79 line = dwarf_onesrcline(lines, n);
80 if (!line || dwarf_lineaddr(line, &laddr) != 0)
87 /* Going backward to find the lowest line */
89 line = dwarf_onesrcline(lines, --l);
90 if (!line || dwarf_lineaddr(line, &laddr) != 0)
92 } while (laddr == addr);
94 /* Going forward to find the statement line */
96 line = dwarf_onesrcline(lines, l++);
97 if (!line || dwarf_lineaddr(line, &laddr) != 0 ||
98 dwarf_linebeginstatement(line, &flag) != 0)
108 * cu_find_lineinfo - Get a line number and file name for given address
111 * @fname: a pointer which returns the file name string
112 * @lineno: a pointer which returns the line number
114 * Find a line number and file name for @addr in @cu_die.
116 int cu_find_lineinfo(Dwarf_Die *cu_die, Dwarf_Addr addr,
117 const char **fname, int *lineno)
123 if (die_find_realfunc(cu_die, addr, &die_mem)
124 && die_entrypc(&die_mem, &faddr) == 0 &&
126 *fname = die_get_decl_file(&die_mem);
127 dwarf_decl_line(&die_mem, lineno);
131 line = cu_getsrc_die(cu_die, addr);
132 if (line && dwarf_lineno(line, lineno) == 0) {
133 *fname = dwarf_linesrc(line, NULL, NULL);
135 /* line number is useless without filename */
140 return (*lineno && *fname) ? *lineno : -ENOENT;
143 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
146 * cu_walk_functions_at - Walk on function DIEs at given address
149 * @callback: A callback which called with found DIEs
152 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
153 * should be subprogram or inlined-subroutines.
155 int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
156 int (*callback)(Dwarf_Die *, void *), void *data)
162 /* Inlined function could be recursive. Trace it until fail */
163 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
165 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
167 ret = callback(sc_die, data);
177 * die_get_linkage_name - Get the linkage name of the object
178 * @dw_die: A DIE of the object
180 * Get the linkage name attribute of given @dw_die.
181 * For C++ binary, the linkage name will be the mangled symbol.
183 const char *die_get_linkage_name(Dwarf_Die *dw_die)
185 Dwarf_Attribute attr;
187 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
189 return dwarf_formstring(&attr);
193 * die_compare_name - Compare diename and tname
195 * @tname: a string of target name
197 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
199 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
203 name = dwarf_diename(dw_die);
204 return name ? (strcmp(tname, name) == 0) : false;
208 * die_match_name - Match diename/linkage name and glob
210 * @glob: a string of target glob pattern
212 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
213 * This also match linkage name.
215 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
219 name = dwarf_diename(dw_die);
220 if (name && strglobmatch(name, glob))
222 /* fall back to check linkage name */
223 name = die_get_linkage_name(dw_die);
224 if (name && strglobmatch(name, glob))
231 * die_get_call_lineno - Get callsite line number of inline-function instance
232 * @in_die: a DIE of an inlined function instance
234 * Get call-site line number of @in_die. This means from where the inline
235 * function is called.
237 int die_get_call_lineno(Dwarf_Die *in_die)
239 Dwarf_Attribute attr;
242 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
245 dwarf_formudata(&attr, &ret);
250 * die_get_type - Get type DIE
251 * @vr_die: a DIE of a variable
252 * @die_mem: where to store a type DIE
254 * Get a DIE of the type of given variable (@vr_die), and store
255 * it to die_mem. Return NULL if fails to get a type DIE.
257 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
259 Dwarf_Attribute attr;
261 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
262 dwarf_formref_die(&attr, die_mem))
268 /* Get a type die, but skip qualifiers */
269 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
274 vr_die = die_get_type(vr_die, die_mem);
277 tag = dwarf_tag(vr_die);
278 } while (tag == DW_TAG_const_type ||
279 tag == DW_TAG_restrict_type ||
280 tag == DW_TAG_volatile_type ||
281 tag == DW_TAG_shared_type);
287 * die_get_real_type - Get a type die, but skip qualifiers and typedef
288 * @vr_die: a DIE of a variable
289 * @die_mem: where to store a type DIE
291 * Get a DIE of the type of given variable (@vr_die), and store
292 * it to die_mem. Return NULL if fails to get a type DIE.
293 * If the type is qualifiers (e.g. const) or typedef, this skips it
294 * and tries to find real type (structure or basic types, e.g. int).
296 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
299 vr_die = __die_get_real_type(vr_die, die_mem);
300 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
305 /* Get attribute and translate it as a udata */
306 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
309 Dwarf_Attribute attr;
311 if (dwarf_attr_integrate(tp_die, attr_name, &attr) == NULL ||
312 dwarf_formudata(&attr, result) != 0)
319 * die_is_signed_type - Check whether a type DIE is signed or not
320 * @tp_die: a DIE of a type
322 * Get the encoding of @tp_die and return true if the encoding
325 bool die_is_signed_type(Dwarf_Die *tp_die)
329 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
332 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
333 ret == DW_ATE_signed_fixed);
337 * die_is_func_def - Ensure that this DIE is a subprogram and definition
340 * Ensure that this DIE is a subprogram and NOT a declaration. This
341 * returns true if @dw_die is a function definition.
343 bool die_is_func_def(Dwarf_Die *dw_die)
345 Dwarf_Attribute attr;
348 if (dwarf_tag(dw_die) != DW_TAG_subprogram)
351 if (dwarf_attr(dw_die, DW_AT_declaration, &attr))
355 * DW_AT_declaration can be lost from function declaration
356 * by gcc's bug #97060.
357 * So we need to check this subprogram DIE has DW_AT_inline
358 * or an entry address.
360 if (!dwarf_attr(dw_die, DW_AT_inline, &attr) &&
361 die_entrypc(dw_die, &addr) < 0)
368 * die_entrypc - Returns entry PC (the lowest address) of a DIE
370 * @addr: where to store entry PC
372 * Since dwarf_entrypc() does not return entry PC if the DIE has only address
373 * range, we have to use this to retrieve the lowest address from the address
376 int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr)
378 Dwarf_Addr base, end;
379 Dwarf_Attribute attr;
384 if (dwarf_entrypc(dw_die, addr) == 0)
388 * Since the dwarf_ranges() will return 0 if there is no
389 * DW_AT_ranges attribute, we should check it first.
391 if (!dwarf_attr(dw_die, DW_AT_ranges, &attr))
394 return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;
398 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
401 * Ensure that this DIE is an instance (which has an entry address).
402 * This returns true if @dw_die is a function instance. If not, the @dw_die
403 * must be a prototype. You can use die_walk_instances() to find actual
406 bool die_is_func_instance(Dwarf_Die *dw_die)
409 Dwarf_Attribute attr_mem;
410 int tag = dwarf_tag(dw_die);
412 if (tag != DW_TAG_subprogram &&
413 tag != DW_TAG_inlined_subroutine)
416 return dwarf_entrypc(dw_die, &tmp) == 0 ||
417 dwarf_attr(dw_die, DW_AT_ranges, &attr_mem) != NULL;
421 * die_get_data_member_location - Get the data-member offset
422 * @mb_die: a DIE of a member of a data structure
423 * @offs: The offset of the member in the data structure
425 * Get the offset of @mb_die in the data structure including @mb_die, and
426 * stores result offset to @offs. If any error occurs this returns errno.
428 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
430 Dwarf_Attribute attr;
435 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
438 if (dwarf_formudata(&attr, offs) != 0) {
439 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
440 ret = dwarf_getlocation(&attr, &expr, &nexpr);
441 if (ret < 0 || nexpr == 0)
444 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
445 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
446 expr[0].atom, nexpr);
449 *offs = (Dwarf_Word)expr[0].number;
454 /* Get the call file index number in CU DIE */
455 static int die_get_call_fileno(Dwarf_Die *in_die)
459 if (die_get_attr_udata(in_die, DW_AT_call_file, &idx) == 0)
465 /* Get the declared file index number in CU DIE */
466 static int die_get_decl_fileno(Dwarf_Die *pdie)
470 if (die_get_attr_udata(pdie, DW_AT_decl_file, &idx) == 0)
476 /* Return the file name by index */
477 static const char *die_get_file_name(Dwarf_Die *dw_die, int idx)
481 Dwarf_Attribute attr_mem;
483 if (idx < 0 || !dwarf_attr_integrate(dw_die, DW_AT_decl_file, &attr_mem) ||
484 !dwarf_cu_die(attr_mem.cu, &cu_die, NULL, NULL, NULL, NULL, NULL, NULL) ||
485 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
488 return dwarf_filesrc(files, idx, NULL, NULL);
492 * die_get_call_file - Get callsite file name of inlined function instance
493 * @in_die: a DIE of an inlined function instance
495 * Get call-site file name of @in_die. This means from which file the inline
496 * function is called.
498 const char *die_get_call_file(Dwarf_Die *in_die)
500 return die_get_file_name(in_die, die_get_call_fileno(in_die));
504 * die_get_decl_file - Find the declared file name of this DIE
505 * @dw_die: a DIE for something declared.
507 * Get declared file name of @dw_die.
508 * NOTE: Since some version of clang DWARF5 implementation incorrectly uses
509 * file index 0 for DW_AT_decl_file, die_get_decl_file() will return NULL for
510 * such cases. Use this function instead.
512 const char *die_get_decl_file(Dwarf_Die *dw_die)
514 return die_get_file_name(dw_die, die_get_decl_fileno(dw_die));
518 * die_find_child - Generic DIE search function in DIE tree
519 * @rt_die: a root DIE
520 * @callback: a callback function
521 * @data: a user data passed to the callback function
522 * @die_mem: a buffer for result DIE
524 * Trace DIE tree from @rt_die and call @callback for each child DIE.
525 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
526 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
527 * this continues to trace the tree. Optionally, @callback can return
528 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
529 * the children and trace only the siblings respectively.
530 * Returns NULL if @callback can't find any appropriate DIE.
532 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
533 int (*callback)(Dwarf_Die *, void *),
534 void *data, Dwarf_Die *die_mem)
539 ret = dwarf_child(rt_die, die_mem);
544 ret = callback(die_mem, data);
545 if (ret == DIE_FIND_CB_END)
548 if ((ret & DIE_FIND_CB_CHILD) &&
549 die_find_child(die_mem, callback, data, &child_die)) {
550 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
553 } while ((ret & DIE_FIND_CB_SIBLING) &&
554 dwarf_siblingof(die_mem, die_mem) == 0);
559 struct __addr_die_search_param {
564 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
566 struct __addr_die_search_param *ad = data;
569 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
570 !dwarf_highpc(fn_die, &addr) &&
572 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
573 return DWARF_CB_ABORT;
579 * die_find_tailfunc - Search for a non-inlined function with tail call at
581 * @cu_die: a CU DIE which including @addr
582 * @addr: target address
583 * @die_mem: a buffer for result DIE
585 * Search for a non-inlined function DIE with tail call at @addr. Stores the
586 * DIE to @die_mem and returns it if found. Returns NULL if failed.
588 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
591 struct __addr_die_search_param ad;
593 ad.die_mem = die_mem;
594 /* dwarf_getscopes can't find subprogram. */
595 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
601 /* die_find callback for non-inlined function search */
602 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
604 struct __addr_die_search_param *ad = data;
607 * Since a declaration entry doesn't has given pc, this always returns
608 * function definition entry.
610 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
611 dwarf_haspc(fn_die, ad->addr)) {
612 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
613 return DWARF_CB_ABORT;
619 * die_find_realfunc - Search a non-inlined function at given address
620 * @cu_die: a CU DIE which including @addr
621 * @addr: target address
622 * @die_mem: a buffer for result DIE
624 * Search a non-inlined function DIE which includes @addr. Stores the
625 * DIE to @die_mem and returns it if found. Returns NULL if failed.
627 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
630 struct __addr_die_search_param ad;
632 ad.die_mem = die_mem;
633 /* dwarf_getscopes can't find subprogram. */
634 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
640 /* die_find callback for inline function search */
641 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
643 Dwarf_Addr *addr = data;
645 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
646 dwarf_haspc(die_mem, *addr))
647 return DIE_FIND_CB_END;
649 return DIE_FIND_CB_CONTINUE;
653 * die_find_top_inlinefunc - Search the top inlined function at given address
654 * @sp_die: a subprogram DIE which including @addr
655 * @addr: target address
656 * @die_mem: a buffer for result DIE
658 * Search an inlined function DIE which includes @addr. Stores the
659 * DIE to @die_mem and returns it if found. Returns NULL if failed.
660 * Even if several inlined functions are expanded recursively, this
661 * doesn't trace it down, and returns the topmost one.
663 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
666 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
670 * die_find_inlinefunc - Search an inlined function at given address
671 * @sp_die: a subprogram DIE which including @addr
672 * @addr: target address
673 * @die_mem: a buffer for result DIE
675 * Search an inlined function DIE which includes @addr. Stores the
676 * DIE to @die_mem and returns it if found. Returns NULL if failed.
677 * If several inlined functions are expanded recursively, this trace
678 * it down and returns deepest one.
680 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
685 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
689 /* Inlined function could be recursive. Trace it until fail */
691 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
692 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
699 struct __instance_walk_param {
701 int (*callback)(Dwarf_Die *, void *);
706 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
708 struct __instance_walk_param *iwp = data;
709 Dwarf_Attribute attr_mem;
710 Dwarf_Die origin_mem;
711 Dwarf_Attribute *attr;
715 if (!die_is_func_instance(inst))
716 return DIE_FIND_CB_CONTINUE;
718 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
720 return DIE_FIND_CB_CONTINUE;
722 origin = dwarf_formref_die(attr, &origin_mem);
723 if (origin == NULL || origin->addr != iwp->addr)
724 return DIE_FIND_CB_CONTINUE;
726 /* Ignore redundant instances */
727 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
728 dwarf_decl_line(origin, &tmp);
729 if (die_get_call_lineno(inst) == tmp) {
730 tmp = die_get_decl_fileno(origin);
731 if (die_get_call_fileno(inst) == tmp)
732 return DIE_FIND_CB_CONTINUE;
736 iwp->retval = iwp->callback(inst, iwp->data);
738 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
742 * die_walk_instances - Walk on instances of given DIE
743 * @or_die: an abstract original DIE
744 * @callback: a callback function which is called with instance DIE
747 * Walk on the instances of give @in_die. @in_die must be an inlined function
748 * declaration. This returns the return value of @callback if it returns
749 * non-zero value, or -ENOENT if there is no instance.
751 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
756 struct __instance_walk_param iwp = {
757 .addr = or_die->addr,
758 .callback = callback,
763 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
766 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
771 /* Line walker internal parameters */
772 struct __line_walk_param {
774 line_walk_callback_t callback;
779 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
781 struct __line_walk_param *lw = data;
786 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
787 fname = die_get_call_file(in_die);
788 lineno = die_get_call_lineno(in_die);
789 if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) {
790 lw->retval = lw->callback(fname, lineno, addr, lw->data);
792 return DIE_FIND_CB_END;
795 return DIE_FIND_CB_SIBLING;
799 fname = die_get_decl_file(in_die);
800 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
801 lw->retval = lw->callback(fname, lineno, addr, lw->data);
803 return DIE_FIND_CB_END;
807 /* Continue to search nested inlined function call-sites */
808 return DIE_FIND_CB_CONTINUE;
811 /* Walk on lines of blocks included in given DIE */
812 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
813 line_walk_callback_t callback, void *data)
815 struct __line_walk_param lw = {
816 .recursive = recursive,
817 .callback = callback,
826 /* Handle function declaration line */
827 fname = die_get_decl_file(sp_die);
828 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
829 die_entrypc(sp_die, &addr) == 0) {
830 lw.retval = callback(fname, lineno, addr, data);
834 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
839 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
841 struct __line_walk_param *lw = data;
844 * Since inlined function can include another inlined function in
845 * the same file, we need to walk in it recursively.
847 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
849 return DWARF_CB_ABORT;
855 * die_walk_lines - Walk on lines inside given DIE
856 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
857 * @callback: callback routine
860 * Walk on all lines inside given @rt_die and call @callback on each line.
861 * If the @rt_die is a function, walk only on the lines inside the function,
862 * otherwise @rt_die must be a CU DIE.
863 * Note that this walks not only dwarf line list, but also function entries
864 * and inline call-site.
866 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
871 const char *fname, *decf = NULL, *inf = NULL;
874 Dwarf_Die die_mem, *cu_die;
879 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
880 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
881 dwarf_decl_line(rt_die, &decl);
882 decf = die_get_decl_file(rt_die);
884 pr_debug2("Failed to get the declared file name of %s\n",
885 dwarf_diename(rt_die));
891 pr_debug2("Failed to get CU from given DIE.\n");
895 /* Get lines list in the CU */
896 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
897 pr_debug2("Failed to get source lines on this CU.\n");
900 pr_debug2("Get %zd lines from this CU\n", nlines);
902 /* Walk on the lines on lines list */
903 for (i = 0; i < nlines; i++) {
904 line = dwarf_onesrcline(lines, i);
906 dwarf_lineno(line, &lineno) != 0 ||
907 dwarf_lineaddr(line, &addr) != 0) {
908 pr_debug2("Failed to get line info. "
909 "Possible error in debuginfo.\n");
912 /* Skip end-of-sequence */
913 if (dwarf_lineendsequence(line, &flag) != 0 || flag)
915 /* Skip Non statement line-info */
916 if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)
918 /* Filter lines based on address */
919 if (rt_die != cu_die) {
922 * The line is included in given function, and
923 * no inline block includes it.
925 if (!dwarf_haspc(rt_die, addr))
928 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
929 /* Call-site check */
930 inf = die_get_call_file(&die_mem);
931 if ((inf && !strcmp(inf, decf)) &&
932 die_get_call_lineno(&die_mem) == lineno)
935 dwarf_decl_line(&die_mem, &inl);
937 decf != die_get_decl_file(&die_mem))
942 /* Get source line */
943 fname = dwarf_linesrc(line, NULL, NULL);
945 ret = callback(fname, lineno, addr, data);
951 * Dwarf lines doesn't include function declarations and inlined
952 * subroutines. We have to check functions list or given function.
954 if (rt_die != cu_die)
956 * Don't need walk inlined functions recursively, because
957 * inner inlined functions don't have the lines of the
958 * specified function.
960 ret = __die_walk_funclines(rt_die, false, callback, data);
962 struct __line_walk_param param = {
963 .callback = callback,
967 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
974 struct __find_variable_param {
979 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
981 struct __find_variable_param *fvp = data;
982 Dwarf_Attribute attr;
985 tag = dwarf_tag(die_mem);
986 if ((tag == DW_TAG_formal_parameter ||
987 tag == DW_TAG_variable) &&
988 die_compare_name(die_mem, fvp->name) &&
990 * Does the DIE have location information or const value
991 * or external instance?
993 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
994 dwarf_attr(die_mem, DW_AT_location, &attr) ||
995 dwarf_attr(die_mem, DW_AT_const_value, &attr)))
996 return DIE_FIND_CB_END;
997 if (dwarf_haspc(die_mem, fvp->addr))
998 return DIE_FIND_CB_CONTINUE;
1000 return DIE_FIND_CB_SIBLING;
1004 * die_find_variable_at - Find a given name variable at given address
1005 * @sp_die: a function DIE
1006 * @name: variable name
1008 * @die_mem: a buffer for result DIE
1010 * Find a variable DIE called @name at @addr in @sp_die.
1012 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
1013 Dwarf_Addr addr, Dwarf_Die *die_mem)
1015 struct __find_variable_param fvp = { .name = name, .addr = addr};
1017 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
1021 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
1023 const char *name = data;
1025 if (dwarf_tag(die_mem) == DW_TAG_member) {
1026 if (die_compare_name(die_mem, name))
1027 return DIE_FIND_CB_END;
1028 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
1029 Dwarf_Die type_die, tmp_die;
1030 if (die_get_type(die_mem, &type_die) &&
1031 die_find_member(&type_die, name, &tmp_die))
1032 return DIE_FIND_CB_END;
1035 return DIE_FIND_CB_SIBLING;
1039 * die_find_member - Find a given name member in a data structure
1040 * @st_die: a data structure type DIE
1041 * @name: member name
1042 * @die_mem: a buffer for result DIE
1044 * Find a member DIE called @name in @st_die.
1046 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
1049 return die_find_child(st_die, __die_find_member_cb, (void *)name,
1054 * die_get_typename_from_type - Get the name of given type DIE
1055 * @type_die: a type DIE
1056 * @buf: a strbuf for result type name
1058 * Get the name of @type_die and stores it to @buf. Return 0 if succeeded.
1059 * and Return -ENOENT if failed to find type name.
1060 * Note that the result will stores typedef name if possible, and stores
1061 * "*(function_type)" if the type is a function pointer.
1063 int die_get_typename_from_type(Dwarf_Die *type_die, struct strbuf *buf)
1066 const char *tmp = "";
1068 tag = dwarf_tag(type_die);
1069 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
1071 else if (tag == DW_TAG_subroutine_type) {
1072 /* Function pointer */
1073 return strbuf_add(buf, "(function_type)", 15);
1075 const char *name = dwarf_diename(type_die);
1077 if (tag == DW_TAG_union_type)
1079 else if (tag == DW_TAG_structure_type)
1081 else if (tag == DW_TAG_enumeration_type)
1083 else if (name == NULL)
1085 /* Write a base name */
1086 return strbuf_addf(buf, "%s%s", tmp, name ?: "");
1088 ret = die_get_typename(type_die, buf);
1090 /* void pointer has no type attribute */
1091 if (tag == DW_TAG_pointer_type && ret == -ENOENT)
1092 return strbuf_addf(buf, "void*");
1096 return strbuf_addstr(buf, tmp);
1100 * die_get_typename - Get the name of given variable DIE
1101 * @vr_die: a variable DIE
1102 * @buf: a strbuf for result type name
1104 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
1105 * and Return -ENOENT if failed to find type name.
1106 * Note that the result will stores typedef name if possible, and stores
1107 * "*(function_type)" if the type is a function pointer.
1109 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
1113 if (__die_get_real_type(vr_die, &type) == NULL)
1116 return die_get_typename_from_type(&type, buf);
1120 * die_get_varname - Get the name and type of given variable DIE
1121 * @vr_die: a variable DIE
1122 * @buf: a strbuf for type and variable name
1124 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1126 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
1130 ret = die_get_typename(vr_die, buf);
1132 pr_debug("Failed to get type, make it unknown.\n");
1133 ret = strbuf_add(buf, "(unknown_type)", 14);
1136 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
1139 #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
1141 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1142 * @sp_die: a subprogram DIE
1143 * @vr_die: a variable DIE
1144 * @buf: a strbuf for variable byte offset range
1146 * Get the innermost scope range of @vr_die and stores it in @buf as
1147 * "@<function_name+[NN-NN,NN-NN]>".
1149 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
1156 Dwarf_Addr start, end;
1162 ret = die_entrypc(sp_die, &entry);
1166 name = dwarf_diename(sp_die);
1170 count = dwarf_getscopes_die(vr_die, &scopes);
1172 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1178 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1179 &start, &end)) > 0) {
1184 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1188 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1196 ret = strbuf_add(buf, "]>", 2);
1204 * die_get_var_range - Get byte offset range of given variable DIE
1205 * @sp_die: a subprogram DIE
1206 * @vr_die: a variable DIE
1207 * @buf: a strbuf for type and variable name and byte offset range
1209 * Get the byte offset range of @vr_die and stores it in @buf as
1210 * "@<function_name+[NN-NN,NN-NN]>".
1212 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1216 Dwarf_Addr start, end;
1221 Dwarf_Attribute attr;
1225 ret = die_entrypc(sp_die, &entry);
1229 name = dwarf_diename(sp_die);
1233 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1236 while ((offset = dwarf_getlocations(&attr, offset, &base,
1237 &start, &end, &op, &nops)) > 0) {
1239 /* Single Location Descriptions */
1240 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1244 /* Location Lists */
1248 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1252 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1260 ret = strbuf_add(buf, "]>", 2);
1265 /* Interval parameters for __die_find_var_reg_cb() */
1266 struct find_var_data {
1267 /* Target instruction address */
1269 /* Target memory address (for global data) */
1271 /* Target register */
1273 /* Access offset, set for global data */
1275 /* True if the current register is the frame base */
1279 /* Max number of registers DW_OP_regN supports */
1280 #define DWARF_OP_DIRECT_REGS 32
1282 static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data,
1283 u64 addr_offset, u64 addr_type)
1288 if (addr_offset == addr_type) {
1289 /* Update offset relative to the start of the variable */
1294 if (die_get_real_type(die_mem, &type_die) == NULL)
1297 if (dwarf_aggregate_size(&type_die, &size) < 0)
1300 if (addr_offset >= addr_type + size)
1303 /* Update offset relative to the start of the variable */
1304 data->offset = addr_offset - addr_type;
1308 static bool check_allowed_ops(Dwarf_Op *ops, size_t nops)
1310 /* The first op is checked separately */
1315 * It needs to make sure if the location expression matches to the given
1316 * register and offset exactly. Thus it rejects any complex expressions
1317 * and only allows a few of selected operators that doesn't change the
1321 switch (ops->atom) {
1322 case DW_OP_stack_value:
1323 case DW_OP_deref_size:
1336 /* Only checks direct child DIEs in the given scope. */
1337 static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg)
1339 struct find_var_data *data = arg;
1340 int tag = dwarf_tag(die_mem);
1342 Dwarf_Attribute attr;
1343 Dwarf_Addr base, start, end;
1347 if (tag != DW_TAG_variable && tag != DW_TAG_formal_parameter)
1348 return DIE_FIND_CB_SIBLING;
1350 if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)
1351 return DIE_FIND_CB_SIBLING;
1353 while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) {
1354 /* Assuming the location list is sorted by address */
1357 if (start > data->pc)
1360 /* Local variables accessed using frame base register */
1361 if (data->is_fbreg && ops->atom == DW_OP_fbreg &&
1362 data->offset >= (int)ops->number &&
1363 check_allowed_ops(ops, nops) &&
1364 match_var_offset(die_mem, data, data->offset, ops->number))
1365 return DIE_FIND_CB_END;
1367 /* Only match with a simple case */
1368 if (data->reg < DWARF_OP_DIRECT_REGS) {
1369 /* pointer variables saved in a register 0 to 31 */
1370 if (ops->atom == (DW_OP_reg0 + data->reg) &&
1371 check_allowed_ops(ops, nops))
1372 return DIE_FIND_CB_END;
1374 /* Local variables accessed by a register + offset */
1375 if (ops->atom == (DW_OP_breg0 + data->reg) &&
1376 check_allowed_ops(ops, nops) &&
1377 match_var_offset(die_mem, data, data->offset, ops->number))
1378 return DIE_FIND_CB_END;
1380 /* pointer variables saved in a register 32 or above */
1381 if (ops->atom == DW_OP_regx && ops->number == data->reg &&
1382 check_allowed_ops(ops, nops))
1383 return DIE_FIND_CB_END;
1385 /* Local variables accessed by a register + offset */
1386 if (ops->atom == DW_OP_bregx && data->reg == ops->number &&
1387 check_allowed_ops(ops, nops) &&
1388 match_var_offset(die_mem, data, data->offset, ops->number2))
1389 return DIE_FIND_CB_END;
1392 return DIE_FIND_CB_SIBLING;
1396 * die_find_variable_by_reg - Find a variable saved in a register
1397 * @sc_die: a scope DIE
1398 * @pc: the program address to find
1399 * @reg: the register number to find
1400 * @poffset: pointer to offset, will be updated for fbreg case
1401 * @is_fbreg: boolean value if the current register is the frame base
1402 * @die_mem: a buffer to save the resulting DIE
1404 * Find the variable DIE accessed by the given register. It'll update the @offset
1405 * when the variable is in the stack.
1407 Dwarf_Die *die_find_variable_by_reg(Dwarf_Die *sc_die, Dwarf_Addr pc, int reg,
1408 int *poffset, bool is_fbreg,
1411 struct find_var_data data = {
1415 .is_fbreg = is_fbreg,
1419 result = die_find_child(sc_die, __die_find_var_reg_cb, &data, die_mem);
1421 *poffset = data.offset;
1425 /* Only checks direct child DIEs in the given scope */
1426 static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg)
1428 struct find_var_data *data = arg;
1429 int tag = dwarf_tag(die_mem);
1431 Dwarf_Attribute attr;
1432 Dwarf_Addr base, start, end;
1436 if (tag != DW_TAG_variable)
1437 return DIE_FIND_CB_SIBLING;
1439 if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)
1440 return DIE_FIND_CB_SIBLING;
1442 while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) {
1443 if (ops->atom != DW_OP_addr)
1446 if (data->addr < ops->number)
1449 if (check_allowed_ops(ops, nops) &&
1450 match_var_offset(die_mem, data, data->addr, ops->number))
1451 return DIE_FIND_CB_END;
1453 return DIE_FIND_CB_SIBLING;
1457 * die_find_variable_by_addr - Find variable located at given address
1458 * @sc_die: a scope DIE
1459 * @pc: the program address to find
1460 * @addr: the data address to find
1461 * @die_mem: a buffer to save the resulting DIE
1462 * @offset: the offset in the resulting type
1464 * Find the variable DIE located at the given address (in PC-relative mode).
1465 * This is usually for global variables.
1467 Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc,
1468 Dwarf_Addr addr, Dwarf_Die *die_mem,
1471 struct find_var_data data = {
1477 result = die_find_child(sc_die, __die_find_var_addr_cb, &data, die_mem);
1479 *offset = data.offset;
1482 #endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
1484 #ifdef HAVE_DWARF_CFI_SUPPORT
1485 static int reg_from_dwarf_op(Dwarf_Op *op)
1488 case DW_OP_reg0 ... DW_OP_reg31:
1489 return op->atom - DW_OP_reg0;
1490 case DW_OP_breg0 ... DW_OP_breg31:
1491 return op->atom - DW_OP_breg0;
1501 static int offset_from_dwarf_op(Dwarf_Op *op)
1504 case DW_OP_reg0 ... DW_OP_reg31:
1507 case DW_OP_breg0 ... DW_OP_breg31:
1518 * die_get_cfa - Get frame base information
1519 * @dwarf: a Dwarf info
1520 * @pc: program address
1521 * @preg: pointer for saved register
1522 * @poffset: pointer for saved offset
1524 * This function gets register and offset for CFA (Canonical Frame Address)
1525 * by searching the CIE/FDE info. The CFA usually points to the start address
1526 * of the current stack frame and local variables can be located using an offset
1527 * from the CFA. The @preg and @poffset will be updated if it returns 0.
1529 int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset)
1532 Dwarf_Frame *frame = NULL;
1533 Dwarf_Op *ops = NULL;
1536 cfi = dwarf_getcfi(dwarf);
1540 if (!dwarf_cfi_addrframe(cfi, pc, &frame) &&
1541 !dwarf_frame_cfa(frame, &ops, &nops) &&
1542 check_allowed_ops(ops, nops)) {
1543 *preg = reg_from_dwarf_op(ops);
1544 *poffset = offset_from_dwarf_op(ops);
1549 #endif /* HAVE_DWARF_CFI_SUPPORT */
1552 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1553 * @vr_die: a variable DIE
1555 static bool die_has_loclist(Dwarf_Die *vr_die)
1557 Dwarf_Attribute loc;
1558 int tag = dwarf_tag(vr_die);
1560 if (tag != DW_TAG_formal_parameter &&
1561 tag != DW_TAG_variable)
1564 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1565 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1569 * die_is_optimized_target - Check if target program is compiled with
1573 * For any object in given CU whose DW_AT_location is a location list,
1574 * target program is compiled with optimization. This is applicable to
1577 bool die_is_optimized_target(Dwarf_Die *cu_die)
1581 if (die_has_loclist(cu_die))
1584 if (!dwarf_child(cu_die, &tmp_die) &&
1585 die_is_optimized_target(&tmp_die))
1588 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1589 die_is_optimized_target(&tmp_die))
1596 * die_search_idx - Search index of given line address
1597 * @lines: Line records of single CU
1598 * @nr_lines: Number of @lines
1599 * @addr: address we are looking for
1600 * @idx: index to be set by this function (return value)
1602 * Search for @addr by looping over every lines of CU. If address
1603 * matches, set index of that line in @idx. Note that single source
1604 * line can have multiple line records. i.e. single source line can
1605 * have multiple index.
1607 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1608 Dwarf_Addr addr, unsigned long *idx)
1613 for (i = 0; i < nr_lines; i++) {
1614 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1626 * die_get_postprologue_addr - Search next address after function prologue
1627 * @entrypc_idx: entrypc index
1628 * @lines: Line records of single CU
1629 * @nr_lines: Number of @lines
1630 * @hignpc: high PC address of function
1631 * @postprologue_addr: Next address after function prologue (return value)
1633 * Look for prologue-end marker. If there is no explicit marker, return
1634 * address of next line record or next source line.
1636 static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1638 unsigned long nr_lines,
1640 Dwarf_Addr *postprologue_addr)
1643 int entrypc_lno, lno;
1648 /* entrypc_lno is actual source line number */
1649 line = dwarf_onesrcline(lines, entrypc_idx);
1650 if (dwarf_lineno(line, &entrypc_lno))
1653 for (i = entrypc_idx; i < nr_lines; i++) {
1654 line = dwarf_onesrcline(lines, i);
1656 if (dwarf_lineaddr(line, &addr) ||
1657 dwarf_lineno(line, &lno) ||
1658 dwarf_lineprologueend(line, &p_end))
1661 /* highpc is exclusive. [entrypc,highpc) */
1665 /* clang supports prologue-end marker */
1669 /* Actual next line in source */
1670 if (lno != entrypc_lno)
1674 * Single source line can have multiple line records.
1676 * void foo() { printf("hello\n"); }
1677 * contains two line records. One points to declaration and
1678 * other points to printf() line. Variable 'lno' won't get
1679 * incremented in this case but 'i' will.
1681 if (i != entrypc_idx)
1685 dwarf_lineaddr(line, postprologue_addr);
1686 if (*postprologue_addr >= highpc)
1687 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1694 * die_skip_prologue - Use next address after prologue as probe location
1695 * @sp_die: a subprogram DIE
1697 * @entrypc: entrypc of the function
1699 * Function prologue prepares stack and registers before executing function
1700 * logic. When target program is compiled without optimization, function
1701 * parameter information is only valid after prologue. When we probe entrypc
1702 * of the function, and try to record function parameter, it contains
1705 void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1706 Dwarf_Addr *entrypc)
1708 size_t nr_lines = 0;
1709 unsigned long entrypc_idx = 0;
1710 Dwarf_Lines *lines = NULL;
1711 Dwarf_Addr postprologue_addr;
1714 if (dwarf_highpc(sp_die, &highpc))
1717 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1720 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1723 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1724 highpc, &postprologue_addr))
1727 *entrypc = postprologue_addr;
1730 /* Internal parameters for __die_find_scope_cb() */
1731 struct find_scope_data {
1732 /* Target instruction address */
1734 /* Number of scopes found [output] */
1736 /* Array of scopes found, 0 for the outermost one. [output] */
1740 static int __die_find_scope_cb(Dwarf_Die *die_mem, void *arg)
1742 struct find_scope_data *data = arg;
1744 if (dwarf_haspc(die_mem, data->pc)) {
1747 tmp = realloc(data->scopes, (data->nr + 1) * sizeof(*tmp));
1749 return DIE_FIND_CB_END;
1751 memcpy(tmp + data->nr, die_mem, sizeof(*die_mem));
1754 return DIE_FIND_CB_CHILD;
1756 return DIE_FIND_CB_SIBLING;
1760 * die_get_scopes - Return a list of scopes including the address
1761 * @cu_die: a compile unit DIE
1762 * @pc: the address to find
1763 * @scopes: the array of DIEs for scopes (result)
1765 * This function does the same as the dwarf_getscopes() but doesn't follow
1766 * the origins of inlined functions. It returns the number of scopes saved
1767 * in the @scopes argument. The outer scope will be saved first (index 0) and
1768 * the last one is the innermost scope at the @pc.
1770 int die_get_scopes(Dwarf_Die *cu_die, Dwarf_Addr pc, Dwarf_Die **scopes)
1772 struct find_scope_data data = {
1777 die_find_child(cu_die, __die_find_scope_cb, &data, &die_mem);
1779 *scopes = data.scopes;