1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * dwarf-aux.c : libdw auxiliary interfaces
11 #include "dwarf-aux.h"
12 #include "dwarf-regs.h"
17  * cu_find_realpath - Find the realpath of the target file
48  * cu_get_comp_dir - Get the path of compilation directory
63 /* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */
68 	Dwarf_Line *line;  in cu_getsrc_die()  local
77 	l = 0; u = nlines - 1;  in cu_getsrc_die()
79 		n = u - (u - l) / 2;  in cu_getsrc_die()
80 		line = dwarf_onesrcline(lines, n);  in cu_getsrc_die()
81 		if (!line || dwarf_lineaddr(line, &laddr) != 0)  in cu_getsrc_die()
84 			u = n - 1;  in cu_getsrc_die()
88 	/* Going backward to find the lowest line */  in cu_getsrc_die()
90 		line = dwarf_onesrcline(lines, --l);  in cu_getsrc_die()
91 		if (!line || dwarf_lineaddr(line, &laddr) != 0)  in cu_getsrc_die()
95 	/* Going forward to find the statement line */  in cu_getsrc_die()
97 		line = dwarf_onesrcline(lines, l++);  in cu_getsrc_die()
98 		if (!line || dwarf_lineaddr(line, &laddr) != 0 ||  in cu_getsrc_die()
99 		    dwarf_linebeginstatement(line, &flag) != 0)  in cu_getsrc_die()
105 	return line;  in cu_getsrc_die()
109  * cu_find_lineinfo - Get a line number and file name for given address
112  * @fname: a pointer which returns the file name string
113  * @lineno: a pointer which returns the line number
115  * Find a line number and file name for @addr in @cu_die.
120 	Dwarf_Line *line;  in cu_find_lineinfo()  local
132 	line = cu_getsrc_die(cu_die, addr);  in cu_find_lineinfo()
133 	if (line && dwarf_lineno(line, lineno) == 0) {  in cu_find_lineinfo()
134 		*fname = dwarf_linesrc(line, NULL, NULL);  in cu_find_lineinfo()
136 			/* line number is useless without filename */  in cu_find_lineinfo()
141 	return (*lineno && *fname) ? *lineno : -ENOENT;  in cu_find_lineinfo()
147  * cu_walk_functions_at - Walk on function DIEs at given address
154  * should be subprogram or inlined-subroutines.
161 	int ret = -ENOENT;  in cu_walk_functions_at()
178  * die_get_linkage_name - Get the linkage name of the object
181  * Get the linkage name attribute of given @dw_die.
182  * For C++ binary, the linkage name will be the mangled symbol.
194  * die_compare_name - Compare diename and tname
196  * @tname: a string of target name
198  * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
202 	const char *name;  in die_compare_name()  local
204 	name = dwarf_diename(dw_die);  in die_compare_name()
205 	return name ? (strcmp(tname, name) == 0) : false;  in die_compare_name()
209  * die_match_name - Match diename/linkage name and glob
213  * Glob matching the name of @dw_die and @glob. Return false if matching fail.
214  * This also match linkage name.
218 	const char *name;  in die_match_name()  local
220 	name = dwarf_diename(dw_die);  in die_match_name()
221 	if (name && strglobmatch(name, glob))  in die_match_name()
223 	/* fall back to check linkage name */  in die_match_name()
224 	name = die_get_linkage_name(dw_die);  in die_match_name()
225 	if (name && strglobmatch(name, glob))  in die_match_name()
232  * die_get_call_lineno - Get callsite line number of inline-function instance
235  * Get call-site line number of @in_die. This means from where the inline
244 		return -ENOENT;  in die_get_call_lineno()
251  * die_get_type - Get type DIE
288  * die_get_real_type - Get a type die, but skip qualifiers and typedef
314 		return -ENOENT;  in die_get_attr_udata()
320  * die_is_signed_type - Check whether a type DIE is signed or not
338  * die_is_func_def - Ensure that this DIE is a subprogram and definition
369  * die_entrypc - Returns entry PC (the lowest address) of a DIE
383 		return -EINVAL;  in die_entrypc()
393 		return -ENOENT;  in die_entrypc()
395 	return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;  in die_entrypc()
399  * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
422  * die_get_data_member_location - Get the data-member offset
437 		return -ENOENT;  in die_get_data_member_location()
443 			return -ENOENT;  in die_get_data_member_location()
448 			return -ENOTSUP;  in die_get_data_member_location()
463 		return -ENOENT;  in die_get_call_fileno()
474 		return -ENOENT;  in die_get_decl_fileno()
477 /* Return the file name by index */
493  * die_get_call_file - Get callsite file name of inlined function instance
496  * Get call-site file name of @in_die. This means from which file the inline
505  * die_get_decl_file - Find the declared file name of this DIE
508  * Get declared file name of @dw_die.
519  * die_find_child - Generic DIE search function in DIE tree
572 	    addr == ad->addr) {  in __die_search_func_tail_cb()
573 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_tail_cb()
580  * die_find_tailfunc - Search for a non-inlined function with tail call at
586  * Search for a non-inlined function DIE with tail call at @addr. Stores the
602 /* die_find callback for non-inlined function search */
612 	    dwarf_haspc(fn_die, ad->addr)) {  in __die_search_func_cb()
613 		memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));  in __die_search_func_cb()
620  * die_find_realfunc - Search a non-inlined function at given address
625  * Search a non-inlined function DIE which includes @addr. Stores the
654  * die_find_top_inlinefunc - Search the top inlined function at given address
671  * die_find_inlinefunc - Search an inlined function at given address
715  * die_find_func_rettype - Search a return type of function
717  * @name: target function name
720  * Search a non-inlined function which matches to @name and stores the
727 Dwarf_Die *die_find_func_rettype(Dwarf_Die *cu_die, const char *name,  in die_find_func_rettype()  argument
733 				(void *)name, &tmp_die);  in die_find_func_rettype()
767 	if (origin == NULL || origin->addr != iwp->addr)  in __die_walk_instances_cb()
780 	iwp->retval = iwp->callback(inst, iwp->data);  in __die_walk_instances_cb()
782 	return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;  in __die_walk_instances_cb()
786  * die_walk_instances - Walk on instances of given DIE
793  * non-zero value, or -ENOENT if there is no instance.
801 		.addr = or_die->addr,  in die_walk_instances()
804 		.retval = -ENOENT,  in die_walk_instances()
808 		return -ENOENT;  in die_walk_instances()
815 /* Line walker internal parameters */
834 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
835 			if (lw->retval != 0)  in __die_walk_funclines_cb()
838 		if (!lw->recursive)  in __die_walk_funclines_cb()
845 			lw->retval = lw->callback(fname, lineno, addr, lw->data);  in __die_walk_funclines_cb()
846 			if (lw->retval != 0)  in __die_walk_funclines_cb()
851 	/* Continue to search nested inlined function call-sites */  in __die_walk_funclines_cb()
870 	/* Handle function declaration line */  in __die_walk_funclines()
891 	lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);  in __die_walk_culines_cb()
892 	if (lw->retval != 0)  in __die_walk_culines_cb()
899  * die_walk_lines - Walk on lines inside given DIE
904  * Walk on all lines inside given @rt_die and call @callback on each line.
907  * Note that this walks not only dwarf line list, but also function entries
908  * and inline call-site.
913 	Dwarf_Line *line;  in die_walk_lines()  local
928 			pr_debug2("Failed to get the declared file name of %s\n",  in die_walk_lines()
930 			return -EINVAL;  in die_walk_lines()
936 		return -EINVAL;  in die_walk_lines()
942 		return -ENOENT;  in die_walk_lines()
948 		line = dwarf_onesrcline(lines, i);  in die_walk_lines()
949 		if (line == NULL ||  in die_walk_lines()
950 		    dwarf_lineno(line, &lineno) != 0 ||  in die_walk_lines()
951 		    dwarf_lineaddr(line, &addr) != 0) {  in die_walk_lines()
952 			pr_debug2("Failed to get line info. "  in die_walk_lines()
956 		/* Skip end-of-sequence */  in die_walk_lines()
957 		if (dwarf_lineendsequence(line, &flag) != 0 || flag)  in die_walk_lines()
959 		/* Skip Non statement line-info */  in die_walk_lines()
960 		if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)  in die_walk_lines()
966 			 * The line is included in given function, and  in die_walk_lines()
973 				/* Call-site check */  in die_walk_lines()
986 		/* Get source line */  in die_walk_lines()
987 		fname = dwarf_linesrc(line, NULL, NULL);  in die_walk_lines()
1019 	const char *name;  member
1032 	    die_compare_name(die_mem, fvp->name) &&  in __die_find_variable_cb()
1041 	if (dwarf_haspc(die_mem, fvp->addr))  in __die_find_variable_cb()
1048  * die_find_variable_at - Find a given name variable at given address
1050  * @name: variable name
1054  * Find a variable DIE called @name at @addr in @sp_die.
1056 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,  in die_find_variable_at()  argument
1059 	struct __find_variable_param fvp = { .name = name, .addr = addr};  in die_find_variable_at()
1067 	const char *name = data;  in __die_find_member_cb()  local
1070 		if (die_compare_name(die_mem, name))  in __die_find_member_cb()
1075 			    die_find_member(&type_die, name, &tmp_die))  in __die_find_member_cb()
1083  * die_find_member - Find a given name member in a data structure
1085  * @name: member name
1088  * Find a member DIE called @name in @st_die.
1090 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,  in die_find_member()  argument
1093 	return die_find_child(st_die, __die_find_member_cb, (void *)name,  in die_find_member()
1098  * die_get_typename_from_type - Get the name of given type DIE
1100  * @buf: a strbuf for result type name
1102  * Get the name of @type_die and stores it to @buf. Return 0 if succeeded.
1103  * and Return -ENOENT if failed to find type name.
1104  * Note that the result will stores typedef name if possible, and stores
1121 		const char *name = dwarf_diename(type_die);  in die_get_typename_from_type()  local
1129 		else if (name == NULL)  in die_get_typename_from_type()
1130 			return -ENOENT;  in die_get_typename_from_type()
1131 		/* Write a base name */  in die_get_typename_from_type()
1132 		return strbuf_addf(buf, "%s%s", tmp, name ?: "");  in die_get_typename_from_type()
1137 		if (tag == DW_TAG_pointer_type && ret == -ENOENT)  in die_get_typename_from_type()
1146  * die_get_typename - Get the name of given variable DIE
1148  * @buf: a strbuf for result type name
1150  * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
1151  * and Return -ENOENT if failed to find type name.
1152  * Note that the result will stores typedef name if possible, and stores
1160 		return -ENOENT;  in die_get_typename()
1166  * die_get_varname - Get the name and type of given variable DIE
1168  * @buf: a strbuf for type and variable name
1170  * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1188 	switch (op->atom) {  in reg_from_dwarf_op()
1190 		return op->atom - DW_OP_reg0;  in reg_from_dwarf_op()
1192 		return op->atom - DW_OP_breg0;  in reg_from_dwarf_op()
1195 		return op->number;  in reg_from_dwarf_op()
1201 	return -1;  in reg_from_dwarf_op()
1206 	switch (op->atom) {  in offset_from_dwarf_op()
1212 		return op->number;  in offset_from_dwarf_op()
1214 		return op->number2;  in offset_from_dwarf_op()
1218 	return -1;  in offset_from_dwarf_op()
1225 	nops--;  in check_allowed_ops()
1234 		switch (ops->atom) {  in check_allowed_ops()
1244 		nops--;  in check_allowed_ops()
1252  * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1258  * "@<function_name+[NN-NN,NN-NN]>".
1271 	const char *name;  in die_get_var_innermost_scope()  local
1277 	name = dwarf_diename(sp_die);  in die_get_var_innermost_scope()
1278 	if (!name)  in die_get_var_innermost_scope()
1279 		return -ENOENT;  in die_get_var_innermost_scope()
1285 		ret = -EINVAL;  in die_get_var_innermost_scope()
1291 		start -= entry;  in die_get_var_innermost_scope()
1292 		end -= entry;  in die_get_var_innermost_scope()
1295 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1296 					  name, start, end);  in die_get_var_innermost_scope()
1299 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_innermost_scope()
1315  * die_get_var_range - Get byte offset range of given variable DIE
1318  * @buf: a strbuf for type and variable name and byte offset range
1321  * "@<function_name+[NN-NN,NN-NN]>".
1334 	const char *name;  in die_get_var_range()  local
1340 	name = dwarf_diename(sp_die);  in die_get_var_range()
1341 	if (!name)  in die_get_var_range()
1342 		return -ENOENT;  in die_get_var_range()
1345 		return -EINVAL;  in die_get_var_range()
1356 		start -= entry;  in die_get_var_range()
1357 		end -= entry;  in die_get_var_range()
1359 			ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1360 					  name, start, end);  in die_get_var_range()
1363 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1401 		data->offset = 0;  in match_var_offset()
1424 	data->offset = addr_offset - addr_type;  in match_var_offset()
1447 		if (end <= data->pc)  in __die_find_var_reg_cb()
1449 		if (start > data->pc)  in __die_find_var_reg_cb()
1453 		if (data->is_fbreg && ops->atom == DW_OP_fbreg &&  in __die_find_var_reg_cb()
1455 		    match_var_offset(die_mem, data, data->offset, ops->number,  in __die_find_var_reg_cb()
1460 		if (data->reg < DWARF_OP_DIRECT_REGS) {  in __die_find_var_reg_cb()
1462 			if (ops->atom == (DW_OP_reg0 + data->reg) &&  in __die_find_var_reg_cb()
1464 			    match_var_offset(die_mem, data, data->offset, 0,  in __die_find_var_reg_cb()
1469 			if (ops->atom == (DW_OP_breg0 + data->reg) &&  in __die_find_var_reg_cb()
1471 			    match_var_offset(die_mem, data, data->offset, ops->number,  in __die_find_var_reg_cb()
1476 			if (ops->atom == DW_OP_regx && ops->number == data->reg &&  in __die_find_var_reg_cb()
1478 			    match_var_offset(die_mem, data, data->offset, 0,  in __die_find_var_reg_cb()
1483 			if (ops->atom == DW_OP_bregx && data->reg == ops->number &&  in __die_find_var_reg_cb()
1485 			    match_var_offset(die_mem, data, data->offset, ops->number2,  in __die_find_var_reg_cb()
1494  * die_find_variable_by_reg - Find a variable saved in a register
1541 		if (ops->atom != DW_OP_addr)  in __die_find_var_addr_cb()
1545 		    match_var_offset(die_mem, data, data->addr, ops->number,  in __die_find_var_addr_cb()
1553  * die_find_variable_by_addr - Find variable located at given address
1559  * Find the variable DIE located at the given address (in PC-relative mode).
1611 	vt->die_off = dwarf_dieoffset(&type_die);  in __die_collect_vars_cb()
1612 	vt->addr = start;  in __die_collect_vars_cb()
1613 	vt->reg = reg_from_dwarf_op(ops);  in __die_collect_vars_cb()
1614 	vt->offset = offset_from_dwarf_op(ops);  in __die_collect_vars_cb()
1615 	vt->next = *var_types;  in __die_collect_vars_cb()
1622  * die_collect_vars - Save all variables and parameters
1627  * The @var_types is a singly-linked list containing type and location info.
1660 	if (ops->atom != DW_OP_addr)  in __die_collect_global_vars_cb()
1673 	vt->die_off = dwarf_dieoffset(&type_die);  in __die_collect_global_vars_cb()
1674 	vt->addr = ops->number;  in __die_collect_global_vars_cb()
1675 	vt->reg = -1;  in __die_collect_global_vars_cb()
1676 	vt->offset = 0;  in __die_collect_global_vars_cb()
1677 	vt->next = *var_types;  in __die_collect_global_vars_cb()
1684  * die_collect_global_vars - Save all global variables
1689  * The @var_types is a singly-linked list containing type and location info.
1704  * die_get_cfa - Get frame base information
1724 		return -1;  in die_get_cfa()
1733 	return -1;  in die_get_cfa()
1738  * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1755  * die_is_optimized_target - Check if target program is compiled with
1782  * die_search_idx - Search index of given line address
1783  * @lines: Line records of single CU
1789  * matches, set index of that line in @idx. Note that single source
1790  * line can have multiple line records. i.e. single source line can
1812  * die_get_postprologue_addr - Search next address after function prologue
1814  * @lines: Line records of single CU
1819  * Look for prologue-end marker. If there is no explicit marker, return
1820  * address of next line record or next source line.
1830 	Dwarf_Line *line;  in die_get_postprologue_addr()  local
1834 	/* entrypc_lno is actual source line number */  in die_get_postprologue_addr()
1835 	line = dwarf_onesrcline(lines, entrypc_idx);  in die_get_postprologue_addr()
1836 	if (dwarf_lineno(line, &entrypc_lno))  in die_get_postprologue_addr()
1840 		line = dwarf_onesrcline(lines, i);  in die_get_postprologue_addr()
1842 		if (dwarf_lineaddr(line, &addr) ||  in die_get_postprologue_addr()
1843 		    dwarf_lineno(line, &lno)    ||  in die_get_postprologue_addr()
1844 		    dwarf_lineprologueend(line, &p_end))  in die_get_postprologue_addr()
1851 		/* clang supports prologue-end marker */  in die_get_postprologue_addr()
1855 		/* Actual next line in source */  in die_get_postprologue_addr()
1860 		 * Single source line can have multiple line records.  in die_get_postprologue_addr()
1863 		 * contains two line records. One points to declaration and  in die_get_postprologue_addr()
1864 		 * other points to printf() line. Variable 'lno' won't get  in die_get_postprologue_addr()
1871 	dwarf_lineaddr(line, postprologue_addr);  in die_get_postprologue_addr()
1873 		dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),  in die_get_postprologue_addr()
1880  * die_skip_prologue - Use next address after prologue as probe location
1930 	if (dwarf_haspc(die_mem, data->pc)) {  in __die_find_scope_cb()
1933 		tmp = realloc(data->scopes, (data->nr + 1) * sizeof(*tmp));  in __die_find_scope_cb()
1937 		memcpy(tmp + data->nr, die_mem, sizeof(*die_mem));  in __die_find_scope_cb()
1938 		data->scopes = tmp;  in __die_find_scope_cb()
1939 		data->nr++;  in __die_find_scope_cb()
1946  * die_get_scopes - Return a list of scopes including the address
2008  * die_get_member_type - Return type info of struct member
2058 				offset -= loc;  in die_get_member_type()
2066  * die_deref_ptr_type - Return type info for pointer access