1 /* AddressSanitizer, a fast memory error detector. 2 Copyright (C) 2011-2018 Free Software Foundation, Inc. 3 Contributed by Kostya Serebryany <kcc@google.com> 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #ifndef TREE_ASAN 22 #define TREE_ASAN 23 24 extern void asan_function_start (void); 25 extern void asan_finish_file (void); 26 extern rtx_insn *asan_emit_stack_protection (rtx, rtx, unsigned int, 27 HOST_WIDE_INT *, tree *, int); 28 extern rtx_insn *asan_emit_allocas_unpoison (rtx, rtx, rtx_insn *); 29 extern bool asan_protect_global (tree, bool ignore_decl_rtl_set_p = false); 30 extern void initialize_sanitizer_builtins (void); 31 extern tree asan_dynamic_init_call (bool); 32 extern bool asan_expand_check_ifn (gimple_stmt_iterator *, bool); 33 extern bool asan_expand_mark_ifn (gimple_stmt_iterator *); 34 extern bool asan_expand_poison_ifn (gimple_stmt_iterator *, bool *, 35 hash_map<tree, tree> &); 36 37 extern gimple_stmt_iterator create_cond_insert_point 38 (gimple_stmt_iterator *, bool, bool, bool, basic_block *, basic_block *); 39 40 /* Alias set for accessing the shadow memory. */ 41 extern alias_set_type asan_shadow_set; 42 43 /* Hash set of labels that are either used in a goto, or their address 44 has been taken. */ 45 extern hash_set <tree> *asan_used_labels; 46 47 /* Shadow memory is found at 48 (address >> ASAN_SHADOW_SHIFT) + asan_shadow_offset (). */ 49 #define ASAN_SHADOW_SHIFT 3 50 #define ASAN_SHADOW_GRANULARITY (1UL << ASAN_SHADOW_SHIFT) 51 52 /* Red zone size, stack and global variables are padded by ASAN_RED_ZONE_SIZE 53 up to 2 * ASAN_RED_ZONE_SIZE - 1 bytes. */ 54 #define ASAN_RED_ZONE_SIZE 32 55 56 /* Shadow memory values for stack protection. Left is below protected vars, 57 the first pointer in stack corresponding to that offset contains 58 ASAN_STACK_FRAME_MAGIC word, the second pointer to a string describing 59 the frame. Middle is for padding in between variables, right is 60 above the last protected variable and partial immediately after variables 61 up to ASAN_RED_ZONE_SIZE alignment. */ 62 #define ASAN_STACK_MAGIC_LEFT 0xf1 63 #define ASAN_STACK_MAGIC_MIDDLE 0xf2 64 #define ASAN_STACK_MAGIC_RIGHT 0xf3 65 #define ASAN_STACK_MAGIC_USE_AFTER_RET 0xf5 66 #define ASAN_STACK_MAGIC_USE_AFTER_SCOPE 0xf8 67 68 #define ASAN_STACK_FRAME_MAGIC 0x41b58ab3 69 #define ASAN_STACK_RETIRED_MAGIC 0x45e0360e 70 71 #define ASAN_USE_AFTER_SCOPE_ATTRIBUTE "use after scope memory" 72 73 /* Various flags for Asan builtins. */ 74 enum asan_check_flags 75 { 76 ASAN_CHECK_STORE = 1 << 0, 77 ASAN_CHECK_SCALAR_ACCESS = 1 << 1, 78 ASAN_CHECK_NON_ZERO_LEN = 1 << 2, 79 ASAN_CHECK_LAST = 1 << 3 80 }; 81 82 /* Flags for Asan check builtins. */ 83 #define IFN_ASAN_MARK_FLAGS DEF(POISON), DEF(UNPOISON) 84 85 enum asan_mark_flags 86 { 87 #define DEF(X) ASAN_MARK_##X 88 IFN_ASAN_MARK_FLAGS 89 #undef DEF 90 }; 91 92 /* Return true if STMT is ASAN_MARK with FLAG as first argument. */ 93 extern bool asan_mark_p (gimple *stmt, enum asan_mark_flags flag); 94 95 /* Return the size of padding needed to insert after a protected 96 decl of SIZE. */ 97 98 static inline unsigned int 99 asan_red_zone_size (unsigned int size) 100 { 101 unsigned int c = size & (ASAN_RED_ZONE_SIZE - 1); 102 return c ? 2 * ASAN_RED_ZONE_SIZE - c : ASAN_RED_ZONE_SIZE; 103 } 104 105 extern bool set_asan_shadow_offset (const char *); 106 107 extern void set_sanitized_sections (const char *); 108 109 extern bool asan_sanitize_stack_p (void); 110 111 extern bool asan_sanitize_allocas_p (void); 112 113 extern hash_set<tree> *asan_handled_variables; 114 115 /* Return TRUE if builtin with given FCODE will be intercepted by 116 libasan. */ 117 118 static inline bool 119 asan_intercepted_p (enum built_in_function fcode) 120 { 121 return fcode == BUILT_IN_INDEX 122 || fcode == BUILT_IN_MEMCHR 123 || fcode == BUILT_IN_MEMCMP 124 || fcode == BUILT_IN_MEMCPY 125 || fcode == BUILT_IN_MEMMOVE 126 || fcode == BUILT_IN_MEMSET 127 || fcode == BUILT_IN_STRCASECMP 128 || fcode == BUILT_IN_STRCAT 129 || fcode == BUILT_IN_STRCHR 130 || fcode == BUILT_IN_STRCMP 131 || fcode == BUILT_IN_STRCPY 132 || fcode == BUILT_IN_STRDUP 133 || fcode == BUILT_IN_STRLEN 134 || fcode == BUILT_IN_STRNCASECMP 135 || fcode == BUILT_IN_STRNCAT 136 || fcode == BUILT_IN_STRNCMP 137 || fcode == BUILT_IN_STRCSPN 138 || fcode == BUILT_IN_STRPBRK 139 || fcode == BUILT_IN_STRSPN 140 || fcode == BUILT_IN_STRSTR 141 || fcode == BUILT_IN_STRNCPY; 142 } 143 144 /* Return TRUE if we should instrument for use-after-scope sanity checking. */ 145 146 static inline bool 147 asan_sanitize_use_after_scope (void) 148 { 149 return (flag_sanitize_address_use_after_scope && asan_sanitize_stack_p ()); 150 } 151 152 /* Return true if DECL should be guarded on the stack. */ 153 154 static inline bool 155 asan_protect_stack_decl (tree decl) 156 { 157 return DECL_P (decl) 158 && (!DECL_ARTIFICIAL (decl) 159 || (asan_sanitize_use_after_scope () && TREE_ADDRESSABLE (decl))); 160 } 161 162 /* Return true when flag_sanitize & FLAG is non-zero. If FN is non-null, 163 remove all flags mentioned in "no_sanitize" of DECL_ATTRIBUTES. */ 164 165 static inline bool 166 sanitize_flags_p (unsigned int flag, const_tree fn = current_function_decl) 167 { 168 unsigned int result_flags = flag_sanitize & flag; 169 if (result_flags == 0) 170 return false; 171 172 if (fn != NULL_TREE) 173 { 174 tree value = lookup_attribute ("no_sanitize", DECL_ATTRIBUTES (fn)); 175 if (value) 176 result_flags &= ~tree_to_uhwi (TREE_VALUE (value)); 177 } 178 179 return result_flags; 180 } 181 182 #endif /* TREE_ASAN */ 183