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
47  * cu_get_comp_dir - Get the path of compilation directory
62 /* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */
67 	Dwarf_Line *line;  in cu_getsrc_die()  local
76 	l = 0; u = nlines - 1;  in cu_getsrc_die()
78 		n = u - (u - l) / 2;  in cu_getsrc_die()
79 		line = dwarf_onesrcline(lines, n);  in cu_getsrc_die()
80 		if (!line || dwarf_lineaddr(line, &laddr) != 0)  in cu_getsrc_die()
83 			u = n - 1;  in cu_getsrc_die()
87 	/* Going backward to find the lowest line */  in cu_getsrc_die()
89 		line = dwarf_onesrcline(lines, --l);  in cu_getsrc_die()
90 		if (!line || dwarf_lineaddr(line, &laddr) != 0)  in cu_getsrc_die()
94 	/* Going forward to find the statement line */  in cu_getsrc_die()
96 		line = dwarf_onesrcline(lines, l++);  in cu_getsrc_die()
97 		if (!line || dwarf_lineaddr(line, &laddr) != 0 ||  in cu_getsrc_die()
98 		    dwarf_linebeginstatement(line, &flag) != 0)  in cu_getsrc_die()
104 	return line;  in cu_getsrc_die()
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.
119 	Dwarf_Line *line;  in cu_find_lineinfo()  local
131 	line = cu_getsrc_die(cu_die, addr);  in cu_find_lineinfo()
132 	if (line && dwarf_lineno(line, lineno) == 0) {  in cu_find_lineinfo()
133 		*fname = dwarf_linesrc(line, NULL, NULL);  in cu_find_lineinfo()
135 			/* line number is useless without filename */  in cu_find_lineinfo()
140 	return *lineno ?: -ENOENT;  in cu_find_lineinfo()
146  * cu_walk_functions_at - Walk on function DIEs at given address
153  * should be subprogram or inlined-subroutines.
160 	int ret = -ENOENT;  in cu_walk_functions_at()
177  * die_get_linkage_name - Get the linkage name 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.
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.
201 	const char *name;  in die_compare_name()  local
203 	name = dwarf_diename(dw_die);  in die_compare_name()
204 	return name ? (strcmp(tname, name) == 0) : false;  in die_compare_name()
208  * die_match_name - Match diename/linkage name and glob
212  * Glob matching the name of @dw_die and @glob. Return false if matching fail.
213  * This also match linkage name.
217 	const char *name;  in die_match_name()  local
219 	name = dwarf_diename(dw_die);  in die_match_name()
220 	if (name && strglobmatch(name, glob))  in die_match_name()
222 	/* fall back to check linkage name */  in die_match_name()
223 	name = die_get_linkage_name(dw_die);  in die_match_name()
224 	if (name && strglobmatch(name, glob))  in die_match_name()
231  * die_get_call_lineno - Get callsite line number of inline-function instance
234  * Get call-site line number of @in_die. This means from where the inline
243 		return -ENOENT;  in die_get_call_lineno()
250  * die_get_type - Get type DIE
287  * die_get_real_type - Get a type die, but skip qualifiers and typedef
313 		return -ENOENT;  in die_get_attr_udata()
326 		return -ENOENT;  in die_get_attr_sdata()
332  * die_is_signed_type - Check whether a type DIE is signed or not
350  * die_is_func_def - Ensure that this DIE is a subprogram and definition
381  * die_entrypc - Returns entry PC (the lowest address) of a DIE
395 		return -EINVAL;  in die_entrypc()
405 		return -ENOENT;  in die_entrypc()
407 	return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;  in die_entrypc()
411  * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
434  * die_get_data_member_location - Get the data-member offset
449 		return -ENOENT;  in die_get_data_member_location()
455 			return -ENOENT;  in die_get_data_member_location()
460 			return -ENOTSUP;  in die_get_data_member_location()
475 		return -ENOENT;  in die_get_call_fileno()
486 		return -ENOENT;  in die_get_decl_fileno()
490  * die_get_call_file - Get callsite file name of inlined function instance
493  * Get call-site file name of @in_die. This means from which file the inline
512  * die_find_child - Generic DIE search function in DIE tree
565 	    addr == ad->addr) {  in __die_search_func_tail_cb()
566 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_tail_cb()
573  * die_find_tailfunc - Search for a non-inlined function with tail call at
579  * Search for a non-inlined function DIE with tail call at @addr. Stores the
595 /* die_find callback for non-inlined function search */
605 	    dwarf_haspc(fn_die, ad->addr)) {  in __die_search_func_cb()
606 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_cb()
613  * die_find_realfunc - Search a non-inlined function at given address
618  * Search a non-inlined function DIE which includes @addr. Stores the
647  * die_find_top_inlinefunc - Search the top inlined function at given address
664  * die_find_inlinefunc - Search an inlined function at given address
717 	if (origin == NULL || origin->addr != iwp->addr)  in __die_walk_instances_cb()
730 	iwp->retval = iwp->callback(inst, iwp->data);  in __die_walk_instances_cb()
732 	return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;  in __die_walk_instances_cb()
736  * die_walk_instances - Walk on instances of given DIE
743  * non-zero value, or -ENOENT if there is no instance.
751 		.addr = or_die->addr,  in die_walk_instances()
754 		.retval = -ENOENT,  in die_walk_instances()
758 		return -ENOENT;  in die_walk_instances()
765 /* Line walker internal parameters */
784 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
785 			if (lw->retval != 0)  in __die_walk_funclines_cb()
788 		if (!lw->recursive)  in __die_walk_funclines_cb()
795 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
796 			if (lw->retval != 0)  in __die_walk_funclines_cb()
801 	/* Continue to search nested inlined function call-sites */  in __die_walk_funclines_cb()
820 	/* Handle function declaration line */  in __die_walk_funclines()
841 	lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);  in __die_walk_culines_cb()
842 	if (lw->retval != 0)  in __die_walk_culines_cb()
849  * die_walk_lines - Walk on lines inside given DIE
854  * Walk on all lines inside given @rt_die and call @callback on each line.
857  * Note that this walks not only dwarf line list, but also function entries
858  * and inline call-site.
863 	Dwarf_Line *line;  in die_walk_lines()  local
881 		return -EINVAL;  in die_walk_lines()
887 		return -ENOENT;  in die_walk_lines()
893 		line = dwarf_onesrcline(lines, i);  in die_walk_lines()
894 		if (line == NULL ||  in die_walk_lines()
895 		    dwarf_lineno(line, &lineno) != 0 ||  in die_walk_lines()
896 		    dwarf_lineaddr(line, &addr) != 0) {  in die_walk_lines()
897 			pr_debug2("Failed to get line info. "  in die_walk_lines()
901 		/* Skip end-of-sequence */  in die_walk_lines()
902 		if (dwarf_lineendsequence(line, &flag) != 0 || flag)  in die_walk_lines()
904 		/* Skip Non statement line-info */  in die_walk_lines()
905 		if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)  in die_walk_lines()
911 			 * The line is included in given function, and  in die_walk_lines()
918 				/* Call-site check */  in die_walk_lines()
931 		/* Get source line */  in die_walk_lines()
932 		fname = dwarf_linesrc(line, NULL, NULL);  in die_walk_lines()
964 	const char *name;  member
977 	    die_compare_name(die_mem, fvp->name) &&  in __die_find_variable_cb()
986 	if (dwarf_haspc(die_mem, fvp->addr))  in __die_find_variable_cb()
993  * die_find_variable_at - Find a given name variable at given address
995  * @name: variable name
999  * Find a variable DIE called @name at @addr in @sp_die.
1001 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,  in die_find_variable_at()  argument
1004 	struct __find_variable_param fvp = { .name = name, .addr = addr};  in die_find_variable_at()
1012 	const char *name = data;  in __die_find_member_cb()  local
1015 		if (die_compare_name(die_mem, name))  in __die_find_member_cb()
1020 			    die_find_member(&type_die, name, &tmp_die))  in __die_find_member_cb()
1028  * die_find_member - Find a given name member in a data structure
1030  * @name: member name
1033  * Find a member DIE called @name in @st_die.
1035 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,  in die_find_member()  argument
1038 	return die_find_child(st_die, __die_find_member_cb, (void *)name,  in die_find_member()
1043  * die_get_typename - Get the name of given variable DIE
1045  * @buf: a strbuf for result type name
1047  * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
1048  * and Return -ENOENT if failed to find type name.
1049  * Note that the result will stores typedef name if possible, and stores
1059 		return -ENOENT;  in die_get_typename()
1069 			return -ENOENT;  in die_get_typename()
1076 		/* Write a base name */  in die_get_typename()
1084  * die_get_varname - Get the name and type of given variable DIE
1086  * @buf: a strbuf for type and variable name
1088  * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1105  * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1111  * "@<function_name+[NN-NN,NN-NN]>".
1124 	const char *name;  in die_get_var_innermost_scope()  local
1130 	name = dwarf_diename(sp_die);  in die_get_var_innermost_scope()
1131 	if (!name)  in die_get_var_innermost_scope()
1132 		return -ENOENT;  in die_get_var_innermost_scope()
1138 		ret = -EINVAL;  in die_get_var_innermost_scope()
1144 		start -= entry;  in die_get_var_innermost_scope()
1145 		end -= entry;  in die_get_var_innermost_scope()
1148 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1149 					  name, start, end);  in die_get_var_innermost_scope()
1152 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1168  * die_get_var_range - Get byte offset range of given variable DIE
1171  * @buf: a strbuf for type and variable name and byte offset range
1174  * "@<function_name+[NN-NN,NN-NN]>".
1187 	const char *name;  in die_get_var_range()  local
1193 	name = dwarf_diename(sp_die);  in die_get_var_range()
1194 	if (!name)  in die_get_var_range()
1195 		return -ENOENT;  in die_get_var_range()
1198 		return -EINVAL;  in die_get_var_range()
1209 		start -= entry;  in die_get_var_range()
1210 		end -= entry;  in die_get_var_range()
1212 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1213 					  name, start, end);  in die_get_var_range()
1216 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1233 	return -ENOTSUP;  in die_get_var_range()
1238  * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1255  * die_is_optimized_target - Check if target program is compiled with
1282  * die_search_idx - Search index of given line address
1283  * @lines: Line records of single CU
1289  * matches, set index of that line in @idx. Note that single source
1290  * line can have multiple line records. i.e. single source line can
1312  * die_get_postprologue_addr - Search next address after function prologue
1314  * @lines: Line records of single CU
1319  * Look for prologue-end marker. If there is no explicit marker, return
1320  * address of next line record or next source line.
1330 	Dwarf_Line *line;  in die_get_postprologue_addr()  local
1334 	/* entrypc_lno is actual source line number */  in die_get_postprologue_addr()
1335 	line = dwarf_onesrcline(lines, entrypc_idx);  in die_get_postprologue_addr()
1336 	if (dwarf_lineno(line, &entrypc_lno))  in die_get_postprologue_addr()
1340 		line = dwarf_onesrcline(lines, i);  in die_get_postprologue_addr()
1342 		if (dwarf_lineaddr(line, &addr) ||  in die_get_postprologue_addr()
1343 		    dwarf_lineno(line, &lno)    ||  in die_get_postprologue_addr()
1344 		    dwarf_lineprologueend(line, &p_end))  in die_get_postprologue_addr()
1351 		/* clang supports prologue-end marker */  in die_get_postprologue_addr()
1355 		/* Actual next line in source */  in die_get_postprologue_addr()
1360 		 * Single source line can have multiple line records.  in die_get_postprologue_addr()
1363 		 * contains two line records. One points to declaration and  in die_get_postprologue_addr()
1364 		 * other points to printf() line. Variable 'lno' won't get  in die_get_postprologue_addr()
1371 	dwarf_lineaddr(line, postprologue_addr);  in die_get_postprologue_addr()
1373 		dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),  in die_get_postprologue_addr()
1380  * die_skip_prologue - Use next address after prologue as probe location