1 /* AddressSanitizer, a fast memory error detector.
2 Copyright (C) 2011-2017 Free Software Foundation, Inc.
3 Contributed by Kostya Serebryany <kcc@google.com>
5 This file is part of GCC.
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
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
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/>. */
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 bool asan_protect_global (tree
);
29 extern void initialize_sanitizer_builtins (void);
30 extern tree
asan_dynamic_init_call (bool);
31 extern bool asan_expand_check_ifn (gimple_stmt_iterator
*, bool);
32 extern bool asan_expand_mark_ifn (gimple_stmt_iterator
*);
33 extern bool asan_expand_poison_ifn (gimple_stmt_iterator
*, bool *,
34 hash_map
<tree
, tree
> &);
36 extern gimple_stmt_iterator create_cond_insert_point
37 (gimple_stmt_iterator
*, bool, bool, bool, basic_block
*, basic_block
*);
39 /* Alias set for accessing the shadow memory. */
40 extern alias_set_type asan_shadow_set
;
42 /* Hash set of labels that are either used in a goto, or their address
44 extern hash_set
<tree
> *asan_used_labels
;
46 /* Shadow memory is found at
47 (address >> ASAN_SHADOW_SHIFT) + asan_shadow_offset (). */
48 #define ASAN_SHADOW_SHIFT 3
49 #define ASAN_SHADOW_GRANULARITY (1UL << ASAN_SHADOW_SHIFT)
51 /* Red zone size, stack and global variables are padded by ASAN_RED_ZONE_SIZE
52 up to 2 * ASAN_RED_ZONE_SIZE - 1 bytes. */
53 #define ASAN_RED_ZONE_SIZE 32
55 /* Shadow memory values for stack protection. Left is below protected vars,
56 the first pointer in stack corresponding to that offset contains
57 ASAN_STACK_FRAME_MAGIC word, the second pointer to a string describing
58 the frame. Middle is for padding in between variables, right is
59 above the last protected variable and partial immediately after variables
60 up to ASAN_RED_ZONE_SIZE alignment. */
61 #define ASAN_STACK_MAGIC_LEFT 0xf1
62 #define ASAN_STACK_MAGIC_MIDDLE 0xf2
63 #define ASAN_STACK_MAGIC_RIGHT 0xf3
64 #define ASAN_STACK_MAGIC_USE_AFTER_RET 0xf5
65 #define ASAN_STACK_MAGIC_USE_AFTER_SCOPE 0xf8
67 #define ASAN_STACK_FRAME_MAGIC 0x41b58ab3
68 #define ASAN_STACK_RETIRED_MAGIC 0x45e0360e
70 #define ASAN_USE_AFTER_SCOPE_ATTRIBUTE "use after scope memory"
72 /* Various flags for Asan builtins. */
75 ASAN_CHECK_STORE
= 1 << 0,
76 ASAN_CHECK_SCALAR_ACCESS
= 1 << 1,
77 ASAN_CHECK_NON_ZERO_LEN
= 1 << 2,
78 ASAN_CHECK_LAST
= 1 << 3
81 /* Flags for Asan check builtins. */
82 #define IFN_ASAN_MARK_FLAGS DEF(POISON), DEF(UNPOISON)
86 #define DEF(X) ASAN_MARK_##X
91 /* Return true if STMT is ASAN_MARK with FLAG as first argument. */
92 extern bool asan_mark_p (gimple
*stmt
, enum asan_mark_flags flag
);
94 /* Return the size of padding needed to insert after a protected
97 static inline unsigned int
98 asan_red_zone_size (unsigned int size
)
100 unsigned int c
= size
& (ASAN_RED_ZONE_SIZE
- 1);
101 return c
? 2 * ASAN_RED_ZONE_SIZE
- c
: ASAN_RED_ZONE_SIZE
;
104 extern bool set_asan_shadow_offset (const char *);
106 extern void set_sanitized_sections (const char *);
108 extern bool asan_sanitize_stack_p (void);
110 /* Return TRUE if builtin with given FCODE will be intercepted by
114 asan_intercepted_p (enum built_in_function fcode
)
116 return fcode
== BUILT_IN_INDEX
117 || fcode
== BUILT_IN_MEMCHR
118 || fcode
== BUILT_IN_MEMCMP
119 || fcode
== BUILT_IN_MEMCPY
120 || fcode
== BUILT_IN_MEMMOVE
121 || fcode
== BUILT_IN_MEMSET
122 || fcode
== BUILT_IN_STRCASECMP
123 || fcode
== BUILT_IN_STRCAT
124 || fcode
== BUILT_IN_STRCHR
125 || fcode
== BUILT_IN_STRCMP
126 || fcode
== BUILT_IN_STRCPY
127 || fcode
== BUILT_IN_STRDUP
128 || fcode
== BUILT_IN_STRLEN
129 || fcode
== BUILT_IN_STRNCASECMP
130 || fcode
== BUILT_IN_STRNCAT
131 || fcode
== BUILT_IN_STRNCMP
132 || fcode
== BUILT_IN_STRCSPN
133 || fcode
== BUILT_IN_STRPBRK
134 || fcode
== BUILT_IN_STRSPN
135 || fcode
== BUILT_IN_STRSTR
136 || fcode
== BUILT_IN_STRNCPY
;
139 /* Return TRUE if we should instrument for use-after-scope sanity checking. */
142 asan_sanitize_use_after_scope (void)
144 return (flag_sanitize_address_use_after_scope
&& asan_sanitize_stack_p ());
147 /* Return true if DECL should be guarded on the stack. */
150 asan_protect_stack_decl (tree decl
)
153 && (!DECL_ARTIFICIAL (decl
)
154 || (asan_sanitize_use_after_scope () && TREE_ADDRESSABLE (decl
)));
157 /* Return true when flag_sanitize & FLAG is non-zero. If FN is non-null,
158 remove all flags mentioned in "no_sanitize" of DECL_ATTRIBUTES. */
161 sanitize_flags_p (unsigned int flag
, const_tree fn
= current_function_decl
)
163 unsigned int result_flags
= flag_sanitize
& flag
;
164 if (result_flags
== 0)
169 tree value
= lookup_attribute ("no_sanitize", DECL_ATTRIBUTES (fn
));
171 result_flags
&= ~tree_to_uhwi (TREE_VALUE (value
));
177 #endif /* TREE_ASAN */