1//===-- asan_interceptors_memintrinsics.h -----------------------*- C++ -*-===//
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-private header for asan_interceptors_memintrinsics.cpp
12//===---------------------------------------------------------------------===//
13#ifndef ASAN_MEMINTRIN_H
14#define ASAN_MEMINTRIN_H
15
16#include "asan_interface_internal.h"
17#include "asan_internal.h"
18#include "asan_mapping.h"
19#include "interception/interception.h"
20
21DECLARE_REAL(void *, memcpy, void *to, const void *from, SIZE_T size)
22DECLARE_REAL(void *, memset, void *block, int c, SIZE_T size)
23
24namespace __asan {
25
26// Return true if we can quickly decide that the region is unpoisoned.
27// We assume that a redzone is at least 16 bytes.
28static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
29 if (UNLIKELY(size == 0 || size > sizeof(uptr) * ASAN_SHADOW_GRANULARITY))
30 return !size;
31
32 uptr last = beg + size - 1;
33 uptr shadow_first = MEM_TO_SHADOW(beg);
34 uptr shadow_last = MEM_TO_SHADOW(last);
35 uptr uptr_first = RoundDownTo(x: shadow_first, boundary: sizeof(uptr));
36 uptr uptr_last = RoundDownTo(x: shadow_last, boundary: sizeof(uptr));
37 if (LIKELY(((*reinterpret_cast<const uptr *>(uptr_first) |
38 *reinterpret_cast<const uptr *>(uptr_last)) == 0)))
39 return true;
40 u8 shadow = AddressIsPoisoned(a: last);
41 for (; shadow_first < shadow_last; ++shadow_first)
42 shadow |= *((u8 *)shadow_first);
43 return !shadow;
44}
45
46struct AsanInterceptorContext {
47 const char *interceptor_name;
48};
49
50// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
51// and ASAN_WRITE_RANGE as macro instead of function so
52// that no extra frames are created, and stack trace contains
53// relevant information only.
54// We check all shadow bytes.
55#define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) \
56 do { \
57 uptr __offset = (uptr)(offset); \
58 uptr __size = (uptr)(size); \
59 uptr __bad = 0; \
60 if (UNLIKELY(__offset > __offset + __size)) { \
61 GET_STACK_TRACE_FATAL_HERE; \
62 ReportStringFunctionSizeOverflow(__offset, __size, &stack); \
63 } \
64 if (UNLIKELY(!QuickCheckForUnpoisonedRegion(__offset, __size)) && \
65 (__bad = __asan_region_is_poisoned(__offset, __size))) { \
66 AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx; \
67 bool suppressed = false; \
68 if (_ctx) { \
69 suppressed = IsInterceptorSuppressed(_ctx->interceptor_name); \
70 if (!suppressed && HaveStackTraceBasedSuppressions()) { \
71 GET_STACK_TRACE_FATAL_HERE; \
72 suppressed = IsStackTraceSuppressed(&stack); \
73 } \
74 } \
75 if (!suppressed) { \
76 GET_CURRENT_PC_BP_SP; \
77 ReportGenericError(pc, bp, sp, __bad, isWrite, __size, 0, false); \
78 } \
79 } \
80 } while (0)
81
82#define ASAN_READ_RANGE(ctx, offset, size) \
83 ACCESS_MEMORY_RANGE(ctx, offset, size, false)
84#define ASAN_WRITE_RANGE(ctx, offset, size) \
85 ACCESS_MEMORY_RANGE(ctx, offset, size, true)
86
87// Behavior of functions like "memcpy" or "strcpy" is undefined
88// if memory intervals overlap. We report error in this case.
89// Macro is used to avoid creation of new frames.
90static inline bool RangesOverlap(const char *offset1, uptr length1,
91 const char *offset2, uptr length2) {
92 return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
93}
94#define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) \
95 do { \
96 const char *offset1 = (const char *)_offset1; \
97 const char *offset2 = (const char *)_offset2; \
98 if (UNLIKELY(RangesOverlap(offset1, length1, offset2, length2))) { \
99 GET_STACK_TRACE_FATAL_HERE; \
100 bool suppressed = IsInterceptorSuppressed(name); \
101 if (!suppressed && HaveStackTraceBasedSuppressions()) { \
102 suppressed = IsStackTraceSuppressed(&stack); \
103 } \
104 if (!suppressed) { \
105 ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
106 offset2, length2, &stack); \
107 } \
108 } \
109 } while (0)
110
111} // namespace __asan
112
113#endif // ASAN_MEMINTRIN_H
114