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 && *fname) ? *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()
319  * die_is_signed_type - Check whether a type DIE is signed or not
337  * die_is_func_def - Ensure that this DIE is a subprogram and definition
368  * die_entrypc - Returns entry PC (the lowest address) of a DIE
382 		return -EINVAL;  in die_entrypc()
392 		return -ENOENT;  in die_entrypc()
394 	return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;  in die_entrypc()
398  * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
421  * die_get_data_member_location - Get the data-member offset
436 		return -ENOENT;  in die_get_data_member_location()
442 			return -ENOENT;  in die_get_data_member_location()
447 			return -ENOTSUP;  in die_get_data_member_location()
462 		return -ENOENT;  in die_get_call_fileno()
473 		return -ENOENT;  in die_get_decl_fileno()
476 /* Return the file name by index */
492  * die_get_call_file - Get callsite file name of inlined function instance
495  * Get call-site file name of @in_die. This means from which file the inline
504  * die_get_decl_file - Find the declared file name of this DIE
507  * Get declared file name of @dw_die.
518  * die_find_child - Generic DIE search function in DIE tree
571 	    addr == ad->addr) {  in __die_search_func_tail_cb()
572 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_tail_cb()
579  * die_find_tailfunc - Search for a non-inlined function with tail call at
585  * Search for a non-inlined function DIE with tail call at @addr. Stores the
601 /* die_find callback for non-inlined function search */
611 	    dwarf_haspc(fn_die, ad->addr)) {  in __die_search_func_cb()
612 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_cb()
619  * die_find_realfunc - Search a non-inlined function at given address
624  * Search a non-inlined function DIE which includes @addr. Stores the
653  * die_find_top_inlinefunc - Search the top inlined function at given address
670  * die_find_inlinefunc - Search an inlined function at given address
723 	if (origin == NULL || origin->addr != iwp->addr)  in __die_walk_instances_cb()
736 	iwp->retval = iwp->callback(inst, iwp->data);  in __die_walk_instances_cb()
738 	return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;  in __die_walk_instances_cb()
742  * die_walk_instances - Walk on instances of given DIE
749  * non-zero value, or -ENOENT if there is no instance.
757 		.addr = or_die->addr,  in die_walk_instances()
760 		.retval = -ENOENT,  in die_walk_instances()
764 		return -ENOENT;  in die_walk_instances()
771 /* Line walker internal parameters */
790 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
791 			if (lw->retval != 0)  in __die_walk_funclines_cb()
794 		if (!lw->recursive)  in __die_walk_funclines_cb()
801 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
802 			if (lw->retval != 0)  in __die_walk_funclines_cb()
807 	/* Continue to search nested inlined function call-sites */  in __die_walk_funclines_cb()
826 	/* Handle function declaration line */  in __die_walk_funclines()
847 	lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);  in __die_walk_culines_cb()
848 	if (lw->retval != 0)  in __die_walk_culines_cb()
855  * die_walk_lines - Walk on lines inside given DIE
860  * Walk on all lines inside given @rt_die and call @callback on each line.
863  * Note that this walks not only dwarf line list, but also function entries
864  * and inline call-site.
869 	Dwarf_Line *line;  in die_walk_lines()  local
884 			pr_debug2("Failed to get the declared file name of %s\n",  in die_walk_lines()
886 			return -EINVAL;  in die_walk_lines()
892 		return -EINVAL;  in die_walk_lines()
898 		return -ENOENT;  in die_walk_lines()
904 		line = dwarf_onesrcline(lines, i);  in die_walk_lines()
905 		if (line == NULL ||  in die_walk_lines()
906 		    dwarf_lineno(line, &lineno) != 0 ||  in die_walk_lines()
907 		    dwarf_lineaddr(line, &addr) != 0) {  in die_walk_lines()
908 			pr_debug2("Failed to get line info. "  in die_walk_lines()
912 		/* Skip end-of-sequence */  in die_walk_lines()
913 		if (dwarf_lineendsequence(line, &flag) != 0 || flag)  in die_walk_lines()
915 		/* Skip Non statement line-info */  in die_walk_lines()
916 		if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)  in die_walk_lines()
922 			 * The line is included in given function, and  in die_walk_lines()
929 				/* Call-site check */  in die_walk_lines()
942 		/* Get source line */  in die_walk_lines()
943 		fname = dwarf_linesrc(line, NULL, NULL);  in die_walk_lines()
975 	const char *name;  member
988 	    die_compare_name(die_mem, fvp->name) &&  in __die_find_variable_cb()
997 	if (dwarf_haspc(die_mem, fvp->addr))  in __die_find_variable_cb()
1004  * die_find_variable_at - Find a given name variable at given address
1006  * @name: variable name
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,  in die_find_variable_at()  argument
1015 	struct __find_variable_param fvp = { .name = name, .addr = addr};  in die_find_variable_at()
1023 	const char *name = data;  in __die_find_member_cb()  local
1026 		if (die_compare_name(die_mem, name))  in __die_find_member_cb()
1031 			    die_find_member(&type_die, name, &tmp_die))  in __die_find_member_cb()
1039  * die_find_member - Find a given name member in a data structure
1041  * @name: member name
1044  * Find a member DIE called @name in @st_die.
1046 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,  in die_find_member()  argument
1049 	return die_find_child(st_die, __die_find_member_cb, (void *)name,  in die_find_member()
1054  * die_get_typename_from_type - Get the name of given 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
1075 		const char *name = dwarf_diename(type_die);  in die_get_typename_from_type()  local
1083 		else if (name == NULL)  in die_get_typename_from_type()
1084 			return -ENOENT;  in die_get_typename_from_type()
1085 		/* Write a base name */  in die_get_typename_from_type()
1086 		return strbuf_addf(buf, "%s%s", tmp, name ?: "");  in die_get_typename_from_type()
1091 		if (tag == DW_TAG_pointer_type && ret == -ENOENT)  in die_get_typename_from_type()
1100  * die_get_typename - Get the name of given 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
1114 		return -ENOENT;  in die_get_typename()
1120  * die_get_varname - Get the name and type of given 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".
1141  * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1147  * "@<function_name+[NN-NN,NN-NN]>".
1160 	const char *name;  in die_get_var_innermost_scope()  local
1166 	name = dwarf_diename(sp_die);  in die_get_var_innermost_scope()
1167 	if (!name)  in die_get_var_innermost_scope()
1168 		return -ENOENT;  in die_get_var_innermost_scope()
1174 		ret = -EINVAL;  in die_get_var_innermost_scope()
1180 		start -= entry;  in die_get_var_innermost_scope()
1181 		end -= entry;  in die_get_var_innermost_scope()
1184 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1185 					  name, start, end);  in die_get_var_innermost_scope()
1188 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1204  * die_get_var_range - Get byte offset range of given variable DIE
1207  * @buf: a strbuf for type and variable name and byte offset range
1210  * "@<function_name+[NN-NN,NN-NN]>".
1223 	const char *name;  in die_get_var_range()  local
1229 	name = dwarf_diename(sp_die);  in die_get_var_range()
1230 	if (!name)  in die_get_var_range()
1231 		return -ENOENT;  in die_get_var_range()
1234 		return -EINVAL;  in die_get_var_range()
1245 		start -= entry;  in die_get_var_range()
1246 		end -= entry;  in die_get_var_range()
1248 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1249 					  name, start, end);  in die_get_var_range()
1252 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1299 		if (end < data->pc)  in __die_find_var_reg_cb()
1301 		if (start > data->pc)  in __die_find_var_reg_cb()
1305 		if (data->reg < DWARF_OP_DIRECT_REGS) {  in __die_find_var_reg_cb()
1306 			if (ops->atom == (DW_OP_reg0 + data->reg) && nops == 1)  in __die_find_var_reg_cb()
1309 			if (ops->atom == DW_OP_regx && ops->number == data->reg &&  in __die_find_var_reg_cb()
1318  * die_find_variable_by_reg - Find a variable saved in a register
1356 		if (ops->atom != DW_OP_addr)  in __die_find_var_addr_cb()
1359 		if (data->addr < ops->number)  in __die_find_var_addr_cb()
1362 		if (data->addr == ops->number) {  in __die_find_var_addr_cb()
1364 			data->offset = 0;  in __die_find_var_addr_cb()
1374 		if (data->addr >= ops->number + size)  in __die_find_var_addr_cb()
1378 		data->offset = data->addr - ops->number;  in __die_find_var_addr_cb()
1385  * die_find_variable_by_addr - Find variable located at given address
1392  * Find the variable DIE located at the given address (in PC-relative mode).
1413  * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1430  * die_is_optimized_target - Check if target program is compiled with
1457  * die_search_idx - Search index of given line address
1458  * @lines: Line records of single CU
1464  * matches, set index of that line in @idx. Note that single source
1465  * line can have multiple line records. i.e. single source line can
1487  * die_get_postprologue_addr - Search next address after function prologue
1489  * @lines: Line records of single CU
1494  * Look for prologue-end marker. If there is no explicit marker, return
1495  * address of next line record or next source line.
1505 	Dwarf_Line *line;  in die_get_postprologue_addr()  local
1509 	/* entrypc_lno is actual source line number */  in die_get_postprologue_addr()
1510 	line = dwarf_onesrcline(lines, entrypc_idx);  in die_get_postprologue_addr()
1511 	if (dwarf_lineno(line, &entrypc_lno))  in die_get_postprologue_addr()
1515 		line = dwarf_onesrcline(lines, i);  in die_get_postprologue_addr()
1517 		if (dwarf_lineaddr(line, &addr) ||  in die_get_postprologue_addr()
1518 		    dwarf_lineno(line, &lno)    ||  in die_get_postprologue_addr()
1519 		    dwarf_lineprologueend(line, &p_end))  in die_get_postprologue_addr()
1526 		/* clang supports prologue-end marker */  in die_get_postprologue_addr()
1530 		/* Actual next line in source */  in die_get_postprologue_addr()
1535 		 * Single source line can have multiple line records.  in die_get_postprologue_addr()
1538 		 * contains two line records. One points to declaration and  in die_get_postprologue_addr()
1539 		 * other points to printf() line. Variable 'lno' won't get  in die_get_postprologue_addr()
1546 	dwarf_lineaddr(line, postprologue_addr);  in die_get_postprologue_addr()
1548 		dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),  in die_get_postprologue_addr()
1555  * die_skip_prologue - Use next address after prologue as probe location
1605 	if (dwarf_haspc(die_mem, data->pc)) {  in __die_find_scope_cb()
1608 		tmp = realloc(data->scopes, (data->nr + 1) * sizeof(*tmp));  in __die_find_scope_cb()
1612 		memcpy(tmp + data->nr, die_mem, sizeof(*die_mem));  in __die_find_scope_cb()
1613 		data->scopes = tmp;  in __die_find_scope_cb()
1614 		data->nr++;  in __die_find_scope_cb()
1621  * die_get_scopes - Return a list of scopes including the address