1 //===-- asan_interceptors_memintrinsics.cpp -------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===---------------------------------------------------------------------===//
8 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // ASan versions of memcpy, memmove, and memset.
12 //===---------------------------------------------------------------------===//
13 
14 #define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
15 
16 #include "asan_interceptors_memintrinsics.h"
17 
18 #include "asan_interceptors.h"
19 #include "asan_report.h"
20 #include "asan_stack.h"
21 #include "asan_suppressions.h"
22 
23 using namespace __asan;
24 
25 // memcpy is called during __asan_init() from the internals of printf(...).
26 // We do not treat memcpy with to==from as a bug.
27 // See http://llvm.org/bugs/show_bug.cgi?id=11763.
28 #define ASAN_MEMCPY_IMPL(ctx, to, from, size)                 \
29   do {                                                        \
30     if (LIKELY(replace_intrin_cached)) {                      \
31       if (LIKELY(to != from)) {                               \
32         CHECK_RANGES_OVERLAP("memcpy", to, size, from, size); \
33       }                                                       \
34       ASAN_READ_RANGE(ctx, from, size);                       \
35       ASAN_WRITE_RANGE(ctx, to, size);                        \
36     } else if (UNLIKELY(!asan_inited)) {                      \
37       return internal_memcpy(to, from, size);                 \
38     }                                                         \
39     return REAL(memcpy)(to, from, size);                      \
40   } while (0)
41 
42 // memset is called inside Printf.
43 #define ASAN_MEMSET_IMPL(ctx, block, c, size) \
44   do {                                        \
45     if (LIKELY(replace_intrin_cached)) {      \
46       ASAN_WRITE_RANGE(ctx, block, size);     \
47     } else if (UNLIKELY(!asan_inited)) {      \
48       return internal_memset(block, c, size); \
49     }                                         \
50     return REAL(memset)(block, c, size);      \
51   } while (0)
52 
53 #define ASAN_MEMMOVE_IMPL(ctx, to, from, size) \
54   do {                                         \
55     if (LIKELY(replace_intrin_cached)) {       \
56       ASAN_READ_RANGE(ctx, from, size);        \
57       ASAN_WRITE_RANGE(ctx, to, size);         \
58     }                                          \
59     return internal_memmove(to, from, size);   \
60   } while (0)
61 
62 void *__asan_memcpy(void *to, const void *from, uptr size) {
63   ASAN_MEMCPY_IMPL(nullptr, to, from, size);
64 }
65 
66 void *__asan_memset(void *block, int c, uptr size) {
67   ASAN_MEMSET_IMPL(nullptr, block, c, size);
68 }
69 
70 void *__asan_memmove(void *to, const void *from, uptr size) {
71   ASAN_MEMMOVE_IMPL(nullptr, to, from, size);
72 }
73 
74 #if SANITIZER_FUCHSIA
75 
76 // Fuchsia doesn't use sanitizer_common_interceptors.inc, but
77 // the only things there it wants are these three.  Just define them
78 // as aliases here rather than repeating the contents.
79 
80 extern "C" decltype(__asan_memcpy) memcpy[[gnu::alias("__asan_memcpy")]];
81 extern "C" decltype(__asan_memmove) memmove[[gnu::alias("__asan_memmove")]];
82 extern "C" decltype(__asan_memset) memset[[gnu::alias("__asan_memset")]];
83 
84 #else  // SANITIZER_FUCHSIA
85 
86 #define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size) \
87   do {                                                       \
88     ASAN_INTERCEPTOR_ENTER(ctx, memmove);                    \
89     ASAN_MEMMOVE_IMPL(ctx, to, from, size);                  \
90   } while (false)
91 
92 #define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size) \
93   do {                                                      \
94     ASAN_INTERCEPTOR_ENTER(ctx, memcpy);                    \
95     ASAN_MEMCPY_IMPL(ctx, to, from, size);                  \
96   } while (false)
97 
98 #define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size) \
99   do {                                                      \
100     ASAN_INTERCEPTOR_ENTER(ctx, memset);                    \
101     ASAN_MEMSET_IMPL(ctx, block, c, size);                  \
102   } while (false)
103 
104 #include "sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc"
105 
106 #endif  // SANITIZER_FUCHSIA
107