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
67 	Dwarf_Lines *lines;  in cu_getsrc_die()  local
72 	if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0 ||  in cu_getsrc_die()
76 	/* Lines are sorted by address, use binary search */  in cu_getsrc_die()
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()
84 			u = n - 1;  in cu_getsrc_die()
90 		line = dwarf_onesrcline(lines, --l);  in cu_getsrc_die()
97 		line = dwarf_onesrcline(lines, l++);  in cu_getsrc_die()
109  * cu_find_lineinfo - Get a line number and file name for given address
141 	return (*lineno && *fname) ? *lineno : -ENOENT;  in cu_find_lineinfo()
144 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
147  * cu_walk_functions_at - Walk on function DIEs at given address
151  * @data: A user data
154  * should be subprogram or inlined-subroutines.
157 		    int (*callback)(Dwarf_Die *, void *), void *data)  in cu_walk_functions_at()  argument
161 	int ret = -ENOENT;  in cu_walk_functions_at()
168 		ret = callback(sc_die, data);  in cu_walk_functions_at()
178  * die_get_linkage_name - Get the linkage name of the object
194  * die_compare_name - Compare diename and tname
209  * die_match_name - Match diename/linkage name and glob
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
423  * @mb_die: a DIE of a member of a data structure
424  * @offs: The offset of the member in the data structure
426  * Get the offset of @mb_die in the data structure including @mb_die, and
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()
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
519  * die_find_child - Generic DIE search function in DIE tree
522  * @data: a user data passed to the callback function
535 			  void *data, Dwarf_Die *die_mem)  in die_find_child()  argument
545 		ret = callback(die_mem, data);  in die_find_child()
550 		    die_find_child(die_mem, callback, data, &child_die)) {  in die_find_child()
565 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)  in __die_search_func_tail_cb()  argument
567 	struct __addr_die_search_param *ad = data;  in __die_search_func_tail_cb()
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 */
603 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)  in __die_search_func_cb()  argument
605 	struct __addr_die_search_param *ad = data;  in __die_search_func_cb()
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
642 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)  in __die_find_inline_cb()  argument
644 	Dwarf_Addr *addr = data;  in __die_find_inline_cb()
654  * die_find_top_inlinefunc - Search the top inlined function at given address
671  * die_find_inlinefunc - Search an inlined function at given address
700 static int __die_find_func_rettype_cb(Dwarf_Die *die_mem, void *data)  in __die_find_func_rettype_cb()  argument
708 	if (func_name && !strcmp(func_name, data))  in __die_find_func_rettype_cb()
715  * die_find_func_rettype - Search a return type of function
720  * Search a non-inlined function which matches to @name and stores the
746 	void    *data;  member
750 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)  in __die_walk_instances_cb()  argument
752 	struct __instance_walk_param *iwp = data;  in __die_walk_instances_cb()
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
789  * @data: user data
793  * non-zero value, or -ENOENT if there is no instance.
796 		       void *data)  in die_walk_instances()  argument
801 		.addr = or_die->addr,  in die_walk_instances()
803 		.data = data,  in die_walk_instances()
804 		.retval = -ENOENT,  in die_walk_instances()
808 		return -ENOENT;  in die_walk_instances()
819 	void *data;  member
823 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)  in __die_walk_funclines_cb()  argument
825 	struct __line_walk_param *lw = data;  in __die_walk_funclines_cb()
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()
855 /* Walk on lines of blocks included in given DIE */
857 				line_walk_callback_t callback, void *data)  in __die_walk_funclines()  argument
862 		.data = data,  in __die_walk_funclines()
874 		lw.retval = callback(fname, lineno, addr, data);  in __die_walk_funclines()
883 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)  in __die_walk_culines_cb()  argument
885 	struct __line_walk_param *lw = data;  in __die_walk_culines_cb()
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
902  * @data: user data
904  * Walk on all lines inside given @rt_die and call @callback on each line.
905  * If the @rt_die is a function, walk only on the lines inside the function,
908  * and inline call-site.
910 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)  in die_walk_lines()  argument
912 	Dwarf_Lines *lines;  in die_walk_lines()  local
930 			return -EINVAL;  in die_walk_lines()
936 		return -EINVAL;  in die_walk_lines()
939 	/* Get lines list in the CU */  in die_walk_lines()
940 	if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {  in die_walk_lines()
941 		pr_debug2("Failed to get source lines on this CU.\n");  in die_walk_lines()
942 		return -ENOENT;  in die_walk_lines()
944 	pr_debug2("Get %zd lines from this CU\n", nlines);  in die_walk_lines()
946 	/* Walk on the lines on lines list */  in die_walk_lines()
948 		line = dwarf_onesrcline(lines, i);  in die_walk_lines()
956 		/* Skip end-of-sequence */  in die_walk_lines()
959 		/* Skip Non statement line-info */  in die_walk_lines()
962 		/* Filter lines based on address */  in die_walk_lines()
973 				/* Call-site check */  in die_walk_lines()
989 		ret = callback(fname, lineno, addr, data);  in die_walk_lines()
995 	 * Dwarf lines doesn't include function declarations and inlined  in die_walk_lines()
1001 		 * inner inlined functions don't have the lines of the  in die_walk_lines()
1004 		ret = __die_walk_funclines(rt_die, false, callback, data);  in die_walk_lines()
1008 			.data = data,  in die_walk_lines()
1023 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)  in __die_find_variable_cb()  argument
1025 	struct __find_variable_param *fvp = data;  in __die_find_variable_cb()
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
1065 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)  in __die_find_member_cb()  argument
1067 	const char *name = data;  in __die_find_member_cb()
1083  * die_find_member - Find a given name member in a data structure
1084  * @st_die: a data structure type DIE
1098  * die_get_typename_from_type - Get the name of given type DIE
1103  * and Return -ENOENT if failed to find type name.
1130 			return -ENOENT;  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
1151  * and Return -ENOENT if failed to find type name.
1160 		return -ENOENT;  in die_get_typename()
1166  * die_get_varname - Get the name and type of given variable DIE
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]>".
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()
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
1321  * "@<function_name+[NN-NN,NN-NN]>".
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()
1363 			ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,  in die_get_var_range()
1380 	/* Target memory address (for global data) */
1384 	/* Access offset, set for global data */
1393 static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data,  in match_var_offset()  argument
1401 		data->offset = 0;  in match_var_offset()
1424 	data->offset = addr_offset - addr_type;  in match_var_offset()
1431 	struct find_var_data *data = arg;  in __die_find_var_reg_cb()  local
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
1509 	struct find_var_data data = {  in die_find_variable_by_reg()  local
1517 	result = die_find_child(sc_die, __die_find_var_reg_cb, &data, die_mem);  in die_find_variable_by_reg()
1519 		*poffset = data.offset;  in die_find_variable_by_reg()
1526 	struct find_var_data *data = arg;  in __die_find_var_addr_cb()  local
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
1555  * @addr: the data address to find
1559  * Find the variable DIE located at the given address (in PC-relative mode).
1565 	struct find_var_data data = {  in die_find_variable_by_addr()  local
1570 	result = die_find_child(sc_die, __die_find_var_addr_cb, &data, die_mem);  in die_find_variable_by_addr()
1572 		*offset = data.offset;  in die_find_variable_by_addr()
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
1784  * @nr_lines: Number of @lines
1788  * Search for @addr by looping over every lines of CU. If address
1793 static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,  in die_search_idx()  argument
1800 		if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))  in die_search_idx()
1812  * die_get_postprologue_addr - Search next address after function prologue
1814  * @lines: Line records of single CU
1815  * @nr_lines: Number of @lines
1819  * Look for prologue-end marker. If there is no explicit marker, return
1823 				      Dwarf_Lines *lines,  in die_get_postprologue_addr()  argument
1835 	line = dwarf_onesrcline(lines, entrypc_idx);  in die_get_postprologue_addr()
1840 		line = dwarf_onesrcline(lines, i);  in die_get_postprologue_addr()
1851 		/* clang supports prologue-end marker */  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
1896 	Dwarf_Lines *lines = NULL;  in die_skip_prologue()  local
1903 	if (dwarf_getsrclines(cu_die, &lines, &nr_lines))  in die_skip_prologue()
1906 	if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))  in die_skip_prologue()
1909 	if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,  in die_skip_prologue()
1928 	struct find_scope_data *data = arg;  in __die_find_scope_cb()  local
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
1958 	struct find_scope_data data = {  in die_get_scopes()  local
1963 	die_find_child(cu_die, __die_find_scope_cb, &data, &die_mem);  in die_get_scopes()
1965 	*scopes = data.scopes;  in die_get_scopes()
1966 	return data.nr;  in die_get_scopes()
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