--- gcc/asan.c.jj 2012-12-05 17:00:56.000000000 +0100 +++ gcc/asan.c 2012-12-05 19:12:53.384240629 +0100 @@ -212,6 +212,21 @@ alias_set_type asan_shadow_set = -1; alias set is used for all shadow memory accesses. */ static GTY(()) tree shadow_ptr_types[2]; +/* Initialize shadow_ptr_types array. */ + +static void +asan_init_shadow_ptr_types (void) +{ + asan_shadow_set = new_alias_set (); + shadow_ptr_types[0] = build_distinct_type_copy (signed_char_type_node); + TYPE_ALIAS_SET (shadow_ptr_types[0]) = asan_shadow_set; + shadow_ptr_types[0] = build_pointer_type (shadow_ptr_types[0]); + shadow_ptr_types[1] = build_distinct_type_copy (short_integer_type_node); + TYPE_ALIAS_SET (shadow_ptr_types[1]) = asan_shadow_set; + shadow_ptr_types[1] = build_pointer_type (shadow_ptr_types[1]); + initialize_sanitizer_builtins (); +} + /* Asan pretty-printer, used for buidling of the description STRING_CSTs. */ static pretty_printer asan_pp; static bool asan_pp_initialized; @@ -234,10 +249,11 @@ asan_pp_string (void) size_t len = strlen (buf); tree ret = build_string (len + 1, buf); TREE_TYPE (ret) - = build_array_type (char_type_node, build_index_type (size_int (len))); + = build_array_type (TREE_TYPE (shadow_ptr_types[0]), + build_index_type (size_int (len))); TREE_READONLY (ret) = 1; TREE_STATIC (ret) = 1; - return build1 (ADDR_EXPR, build_pointer_type (char_type_node), ret); + return build1 (ADDR_EXPR, shadow_ptr_types[0], ret); } /* Return a CONST_INT representing 4 subsequent shadow memory bytes. */ @@ -276,6 +292,9 @@ asan_emit_stack_protection (rtx base, HO unsigned char cur_shadow_byte = ASAN_STACK_MAGIC_LEFT; tree str_cst; + if (shadow_ptr_types[0] == NULL_TREE) + asan_init_shadow_ptr_types (); + /* First of all, prepare the description string. */ if (!asan_pp_initialized) asan_pp_initialize (); @@ -429,6 +448,16 @@ asan_protect_global (tree decl) { rtx rtl, symbol; + if (TREE_CODE (decl) == STRING_CST) + { + /* Instrument all STRING_CSTs except those created + by asan_pp_string here. */ + if (shadow_ptr_types[0] != NULL_TREE + && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE + && TREE_TYPE (TREE_TYPE (decl)) == TREE_TYPE (shadow_ptr_types[0])) + return false; + return true; + } if (TREE_CODE (decl) != VAR_DECL /* TLS vars aren't statically protectable. */ || DECL_THREAD_LOCAL_P (decl) @@ -1596,6 +1625,50 @@ initialize_sanitizer_builtins (void) #undef DEF_SANITIZER_BUILTIN } +/* Called via htab_traverse. Count number of emitted + STRING_CSTs in the constant hash table. */ + +static int +count_string_csts (void **slot, void *data) +{ + struct constant_descriptor_tree *desc + = (struct constant_descriptor_tree *) *slot; + if (TREE_CODE (desc->value) == STRING_CST + && TREE_ASM_WRITTEN (desc->value) + && asan_protect_global (desc->value)) + ++*((unsigned HOST_WIDE_INT *) data); + return 1; +} + +/* Helper structure to pass two parameters to + add_string_csts. */ + +struct asan_add_string_csts_data +{ + tree type; + vec *v; +}; + +/* Called via htab_traverse. Call asan_add_global + on emitted STRING_CSTs from the constant hash table. */ + +static int +add_string_csts (void **slot, void *data) +{ + struct constant_descriptor_tree *desc + = (struct constant_descriptor_tree *) *slot; + if (TREE_CODE (desc->value) == STRING_CST + && TREE_ASM_WRITTEN (desc->value) + && asan_protect_global (desc->value)) + { + struct asan_add_string_csts_data *aascd + = (struct asan_add_string_csts_data *) data; + asan_add_global (SYMBOL_REF_DECL (XEXP (desc->rtl, 0)), + aascd->type, aascd->v); + } + return 1; +} + /* Needs to be GTY(()), because cgraph_build_static_cdtor may invoke ggc_collect. */ static GTY(()) tree asan_ctor_statements; @@ -1611,13 +1684,20 @@ asan_finish_file (void) struct varpool_node *vnode; unsigned HOST_WIDE_INT gcount = 0; - initialize_sanitizer_builtins (); + if (shadow_ptr_types[0] == NULL_TREE) + asan_init_shadow_ptr_types (); + /* Avoid instrumenting code in the asan ctors/dtors. + We don't need to insert padding after the description strings, + nor after .LASAN* array. */ + flag_asan = 0; tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT); append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements); FOR_EACH_DEFINED_VARIABLE (vnode) if (asan_protect_global (vnode->symbol.decl)) ++gcount; + htab_t const_desc_htab = constant_pool_htab (); + htab_traverse (const_desc_htab, count_string_csts, &gcount); if (gcount) { tree type = asan_global_struct (), var, ctor; @@ -1638,6 +1718,10 @@ asan_finish_file (void) FOR_EACH_DEFINED_VARIABLE (vnode) if (asan_protect_global (vnode->symbol.decl)) asan_add_global (vnode->symbol.decl, TREE_TYPE (type), v); + struct asan_add_string_csts_data aascd; + aascd.type = TREE_TYPE (type); + aascd.v = v; + htab_traverse (const_desc_htab, add_string_csts, &aascd); ctor = build_constructor (type, v); TREE_CONSTANT (ctor) = 1; TREE_STATIC (ctor) = 1; @@ -1660,20 +1744,7 @@ asan_finish_file (void) } cgraph_build_static_cdtor ('I', asan_ctor_statements, MAX_RESERVED_INIT_PRIORITY - 1); -} - -/* Initialize shadow_ptr_types array. */ - -static void -asan_init_shadow_ptr_types (void) -{ - asan_shadow_set = new_alias_set (); - shadow_ptr_types[0] = build_distinct_type_copy (signed_char_type_node); - TYPE_ALIAS_SET (shadow_ptr_types[0]) = asan_shadow_set; - shadow_ptr_types[0] = build_pointer_type (shadow_ptr_types[0]); - shadow_ptr_types[1] = build_distinct_type_copy (short_integer_type_node); - TYPE_ALIAS_SET (shadow_ptr_types[1]) = asan_shadow_set; - shadow_ptr_types[1] = build_pointer_type (shadow_ptr_types[1]); + flag_asan = 1; } /* Instrument the current function. */ @@ -1682,10 +1753,7 @@ static unsigned int asan_instrument (void) { if (shadow_ptr_types[0] == NULL_TREE) - { - asan_init_shadow_ptr_types (); - initialize_sanitizer_builtins (); - } + asan_init_shadow_ptr_types (); transform_statements (); return 0; } --- gcc/varasm.c.jj 2012-12-05 08:24:59.000000000 +0100 +++ gcc/varasm.c 2012-12-05 18:37:04.704418938 +0100 @@ -3250,11 +3250,23 @@ output_constant_def_contents (rtx symbol place_block_symbol (symbol); else { + bool asan_protected = false; align = DECL_ALIGN (decl); switch_to_section (get_constant_section (exp, align)); + if (flag_asan && TREE_CODE (exp) == STRING_CST + && asan_protect_global (exp)) + { + asan_protected = true; + align = MAX (align, ASAN_RED_ZONE_SIZE * BITS_PER_UNIT); + } if (align > BITS_PER_UNIT) ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); assemble_constant_contents (exp, XSTR (symbol, 0), align); + if (asan_protected) + { + HOST_WIDE_INT size = get_constant_size (exp); + assemble_zeros (asan_red_zone_size (size)); + } } if (flag_mudflap) mudflap_enqueue_constant (exp); @@ -6158,7 +6170,9 @@ categorize_decl_for_section (const_tree return SECCAT_TEXT; else if (TREE_CODE (decl) == STRING_CST) { - if (flag_mudflap) /* or !flag_merge_constants */ + if (flag_mudflap + || (flag_asan && asan_protect_global (CONST_CAST_TREE (decl)))) + /* or !flag_merge_constants */ return SECCAT_RODATA; else return SECCAT_RODATA_MERGE_STR; @@ -6182,7 +6196,8 @@ categorize_decl_for_section (const_tree } else if (reloc & targetm.asm_out.reloc_rw_mask ()) ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO; - else if (reloc || flag_merge_constants < 2) + else if (reloc || flag_merge_constants < 2 || flag_mudflap + || (flag_asan && asan_protect_global (CONST_CAST_TREE (decl)))) /* C and C++ don't allow different variables to share the same location. -fmerge-all-constants allows even that (at the expense of not conforming). */