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
18  * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
48  * cu_get_comp_dir - Get the path of compilation directory
49  * @cu_die: a CU DIE
52  * Since this depends on DW_AT_comp_dir, older gcc will not
77 	l = 0; u = nlines - 1;  in cu_getsrc_die()
79 		n = u - (u - l) / 2;  in cu_getsrc_die()
84 			u = n - 1;  in cu_getsrc_die()
90 		line = dwarf_onesrcline(lines, --l);  in cu_getsrc_die()
109  * cu_find_lineinfo - Get a line number and file name for given address
110  * @cu_die: a CU DIE
141 	return (*lineno && *fname) ? *lineno : -ENOENT;  in cu_find_lineinfo()
147  * cu_walk_functions_at - Walk on function DIEs at given address
148  * @cu_die: A CU DIE
153  * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
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
179  * @dw_die: A DIE of the object
194  * die_compare_name - Compare diename and tname
195  * @dw_die: a DIE
209  * die_match_name - Match diename/linkage name and glob
210  * @dw_die: a DIE
232  * die_get_call_lineno - Get callsite line number of inline-function instance
233  * @in_die: a DIE of an inlined 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
252  * @vr_die: a DIE of a variable
253  * @die_mem: where to store a type DIE
255  * Get a DIE of the type of given variable (@vr_die), and store
256  * it to die_mem. Return NULL if fails to get a type DIE.
269 /* Get a type die, but skip qualifiers */
288  * die_get_real_type - Get a type die, but skip qualifiers and typedef
289  * @vr_die: a DIE of a variable
290  * @die_mem: where to store a type DIE
292  * Get a DIE of the type of given variable (@vr_die), and store
293  * it to die_mem. Return NULL if fails to get a type DIE.
314 		return -ENOENT;  in die_get_attr_udata()
320  * die_is_signed_type - Check whether a type DIE is signed or not
321  * @tp_die: a DIE of a type
338  * die_is_func_def - Ensure that this DIE is a subprogram and definition
339  * @dw_die: a DIE
341  * Ensure that this DIE is a subprogram and NOT a declaration. This
358 	 * So we need to check this subprogram DIE has DW_AT_inline  in die_is_func_def()
369  * die_entrypc - Returns entry PC (the lowest address) of a DIE
370  * @dw_die: a DIE
373  * Since dwarf_entrypc() does not return entry PC if the DIE has only address
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
400  * @dw_die: a DIE
402  * Ensure that this DIE is an instance (which has an entry address).
422  * die_get_data_member_location - Get the data-member offset
423  * @mb_die: a DIE of a member of a data structure
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()
455 /* Get the call file index number in CU DIE */
463 		return -ENOENT;  in die_get_call_fileno()
466 /* Get the declared file index number in CU DIE */
474 		return -ENOENT;  in die_get_decl_fileno()
493  * die_get_call_file - Get callsite file name of inlined function instance
494  * @in_die: a DIE of an 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
506  * @dw_die: a DIE for something declared.
519  * die_find_child - Generic DIE search function in DIE tree
520  * @rt_die: a root DIE
523  * @die_mem: a buffer for result DIE
525  * Trace DIE tree from @rt_die and call @callback for each child DIE.
526  * If @callback returns DIE_FIND_CB_END, this stores the DIE into
531  * Returns NULL if @callback can't find any appropriate DIE.
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
582  * @cu_die: a CU DIE which including @addr
584  * @die_mem: a buffer for result DIE
586  * Search for a non-inlined function DIE with tail call at @addr. Stores the
587  * DIE to @die_mem and returns it if found. Returns NULL if failed.
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
621  * @cu_die: a CU DIE which including @addr
623  * @die_mem: a buffer for result DIE
625  * Search a non-inlined function DIE which includes @addr. Stores the
626  * DIE to @die_mem and returns it if found. Returns NULL if failed.
654  * die_find_top_inlinefunc - Search the top inlined function at given address
655  * @sp_die: a subprogram DIE which including @addr
657  * @die_mem: a buffer for result DIE
659  * Search an inlined function DIE which includes @addr. Stores the
660  * DIE to @die_mem and returns it if found. Returns NULL if failed.
671  * die_find_inlinefunc - Search an inlined function at given address
672  * @sp_die: a subprogram DIE which including @addr
674  * @die_mem: a buffer for result DIE
676  * Search an inlined function DIE which includes @addr. Stores the
677  * DIE to @die_mem and returns it if found. Returns NULL if failed.
715  * die_find_func_rettype - Search a return type of function
716  * @cu_die: a CU DIE
718  * @die_mem: a buffer for result DIE
720  * Search a non-inlined function which matches to @name and stores the
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
787  * @or_die: an abstract original DIE
788  * @callback: a callback function which is called with instance DIE
791  * Walk on the instances of give @in_die. @in_die must be an inlined function
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()
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 */
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
900  * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
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,
906  * otherwise @rt_die must be a CU DIE.
908  * and inline call-site.
922 	/* Get the CU die */  in die_walk_lines()
930 			return -EINVAL;  in die_walk_lines()
935 		pr_debug2("Failed to get CU from given DIE.\n");  in die_walk_lines()
936 		return -EINVAL;  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()
946 	/* Walk on the lines on lines list */  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()
1032 	    die_compare_name(die_mem, fvp->name) &&  in __die_find_variable_cb()
1034 	 * Does the DIE have location information or const value  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
1049  * @sp_die: a function DIE
1052  * @die_mem: a buffer for result DIE
1054  * Find a variable DIE called @name at @addr in @sp_die.
1083  * die_find_member - Find a given name member in a data structure
1084  * @st_die: a data structure type DIE
1086  * @die_mem: a buffer for result DIE
1088  * Find a member DIE called @name in @st_die.
1098  * die_get_typename_from_type - Get the name of given type DIE
1099  * @type_die: a 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
1147  * @vr_die: a 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
1167  * @vr_die: a 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
1253  * @sp_die: a subprogram DIE
1254  * @vr_die: a variable DIE
1258  * "@<function_name+[NN-NN,NN-NN]>".
1279 		return -ENOENT;  in die_get_var_innermost_scope()
1283 	/* (*SCOPES)[1] is the DIE for the scope containing that scope */  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
1316  * @sp_die: a subprogram DIE
1317  * @vr_die: a 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()
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
1495  * @sc_die: a scope DIE
1500  * @die_mem: a buffer to save the resulting DIE
1502  * Find the variable DIE accessed by the given register.  It'll update the @offset
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
1554  * @sc_die: a scope DIE
1556  * @die_mem: a buffer to save the resulting DIE
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
1623  * @sc_die: a scope DIE
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
1685  * @cu_die: a CU DIE
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
1739  * @vr_die: a variable DIE
1755  * die_is_optimized_target - Check if target program is compiled with
1757  * @cu_die: a CU DIE
1782  * die_search_idx - Search index of given line address
1812  * die_get_postprologue_addr - Search next address after function prologue
1819  * Look for prologue-end marker. If there is no explicit marker, return
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
1881  * @sp_die: a subprogram DIE
1882  * @cu_die: a CU DIE
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
1947  * @cu_die: a compile unit DIE
2008  * die_get_member_type - Return type info of struct member
2009  * @type_die: a type DIE
2011  * @die_mem: a buffer to save the resulting DIE
2058 				offset -= loc;  in die_get_member_type()
2066  * die_deref_ptr_type - Return type info for pointer access
2067  * @ptr_die: a pointer type DIE
2069  * @die_mem: a buffer to save the resulting DIE