1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
//===-- scudo_allocator.h ---------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// Header for scudo_allocator.cpp.
///
//===----------------------------------------------------------------------===//
#ifndef SCUDO_ALLOCATOR_H_
#define SCUDO_ALLOCATOR_H_
#include "scudo_flags.h"
#include "sanitizer_common/sanitizer_allocator.h"
#if !SANITIZER_LINUX
# error "The Scudo hardened allocator is currently only supported on Linux."
#endif
#include <atomic>
namespace __scudo {
enum AllocType : u8 {
FromMalloc = 0, // Memory block came from malloc, realloc, calloc, etc.
FromNew = 1, // Memory block came from operator new.
FromNewArray = 2, // Memory block came from operator new [].
FromMemalign = 3, // Memory block came from memalign, posix_memalign, etc.
};
enum ChunkState : u8 {
ChunkAvailable = 0,
ChunkAllocated = 1,
ChunkQuarantine = 2
};
// Our header requires 64 bits of storage. Having the offset saves us from
// using functions such as GetBlockBegin, that is fairly costly. Our first
// implementation used the MetaData as well, which offers the advantage of
// being stored away from the chunk itself, but accessing it was costly as
// well. The header will be atomically loaded and stored using the 16-byte
// primitives offered by the platform (likely requires cmpxchg16b support).
typedef u64 PackedHeader;
struct UnpackedHeader {
u64 Checksum : 16;
u64 UnusedBytes : 20; // Needed for reallocation purposes.
u64 State : 2; // available, allocated, or quarantined
u64 AllocType : 2; // malloc, new, new[], or memalign
u64 Offset : 16; // Offset from the beginning of the backend
// allocation to the beginning of the chunk itself,
// in multiples of MinAlignment. See comment about
// its maximum value and test in init().
u64 Salt : 8;
};
typedef std::atomic<PackedHeader> AtomicPackedHeader;
COMPILER_CHECK(sizeof(UnpackedHeader) == sizeof(PackedHeader));
// Minimum alignment of 8 bytes for 32-bit, 16 for 64-bit
const uptr MinAlignmentLog = FIRST_32_SECOND_64(3, 4);
const uptr MaxAlignmentLog = 24; // 16 MB
const uptr MinAlignment = 1 << MinAlignmentLog;
const uptr MaxAlignment = 1 << MaxAlignmentLog;
const uptr ChunkHeaderSize = sizeof(PackedHeader);
const uptr AlignedChunkHeaderSize =
(ChunkHeaderSize + MinAlignment - 1) & ~(MinAlignment - 1);
struct AllocatorOptions {
u32 QuarantineSizeMb;
u32 ThreadLocalQuarantineSizeKb;
bool MayReturnNull;
s32 ReleaseToOSIntervalMs;
bool DeallocationTypeMismatch;
bool DeleteSizeMismatch;
bool ZeroContents;
void setFrom(const Flags *f, const CommonFlags *cf);
void copyTo(Flags *f, CommonFlags *cf) const;
};
void initAllocator(const AllocatorOptions &options);
void drainQuarantine();
void *scudoMalloc(uptr Size, AllocType Type);
void scudoFree(void *Ptr, AllocType Type);
void scudoSizedFree(void *Ptr, uptr Size, AllocType Type);
void *scudoRealloc(void *Ptr, uptr Size);
void *scudoCalloc(uptr NMemB, uptr Size);
void *scudoMemalign(uptr Alignment, uptr Size);
void *scudoValloc(uptr Size);
void *scudoPvalloc(uptr Size);
int scudoPosixMemalign(void **MemPtr, uptr Alignment, uptr Size);
void *scudoAlignedAlloc(uptr Alignment, uptr Size);
uptr scudoMallocUsableSize(void *Ptr);
#include "scudo_allocator_secondary.h"
} // namespace __scudo
#endif // SCUDO_ALLOCATOR_H_
|
