1 //===-- hwasan_allocator.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 HWAddressSanitizer.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef HWASAN_ALLOCATOR_H
14 #define HWASAN_ALLOCATOR_H
15 
16 #include "hwasan.h"
17 #include "hwasan_interface_internal.h"
18 #include "hwasan_mapping.h"
19 #include "hwasan_poisoning.h"
20 #include "lsan/lsan_common.h"
21 #include "sanitizer_common/sanitizer_allocator.h"
22 #include "sanitizer_common/sanitizer_allocator_checks.h"
23 #include "sanitizer_common/sanitizer_allocator_interface.h"
24 #include "sanitizer_common/sanitizer_allocator_report.h"
25 #include "sanitizer_common/sanitizer_common.h"
26 #include "sanitizer_common/sanitizer_ring_buffer.h"
27 
28 #if !defined(__aarch64__) && !defined(__x86_64__) && !(SANITIZER_RISCV64)
29 #  error Unsupported platform
30 #endif
31 
32 namespace __hwasan {
33 
34 struct Metadata {
35  private:
36   atomic_uint64_t alloc_context_id;
37   u32 requested_size_low;
38   u16 requested_size_high;
39   atomic_uint8_t chunk_state;
40   u8 lsan_tag;
41 
42  public:
43   inline void SetAllocated(u32 stack, u64 size);
44   inline void SetUnallocated();
45 
46   inline bool IsAllocated() const;
47   inline u64 GetRequestedSize() const;
48   inline u32 GetAllocStackId() const;
49   inline void SetLsanTag(__lsan::ChunkTag tag);
50   inline __lsan::ChunkTag GetLsanTag() const;
51 };
52 static_assert(sizeof(Metadata) == 16);
53 
54 struct HwasanMapUnmapCallback {
55   void OnMap(uptr p, uptr size) const { UpdateMemoryUsage(); }
56   void OnUnmap(uptr p, uptr size) const {
57     // We are about to unmap a chunk of user memory.
58     // It can return as user-requested mmap() or another thread stack.
59     // Make it accessible with zero-tagged pointer.
60     TagMemory(p, size, 0);
61   }
62 };
63 
64 static const uptr kMaxAllowedMallocSize = 1UL << 40;  // 1T
65 
66 struct AP64 {
67   static const uptr kSpaceBeg = ~0ULL;
68 
69 #if defined(HWASAN_ALIASING_MODE)
70   static const uptr kSpaceSize = 1ULL << kAddressTagShift;
71 #else
72   static const uptr kSpaceSize = 0x2000000000ULL;
73 #endif
74   static const uptr kMetadataSize = sizeof(Metadata);
75   typedef __sanitizer::VeryDenseSizeClassMap SizeClassMap;
76   using AddressSpaceView = LocalAddressSpaceView;
77   typedef HwasanMapUnmapCallback MapUnmapCallback;
78   static const uptr kFlags = 0;
79 };
80 typedef SizeClassAllocator64<AP64> PrimaryAllocator;
81 typedef CombinedAllocator<PrimaryAllocator> Allocator;
82 typedef Allocator::AllocatorCache AllocatorCache;
83 
84 void AllocatorSwallowThreadLocalCache(AllocatorCache *cache);
85 
86 class HwasanChunkView {
87  public:
88   HwasanChunkView() : block_(0), metadata_(nullptr) {}
89   HwasanChunkView(uptr block, Metadata *metadata)
90       : block_(block), metadata_(metadata) {}
91   bool IsAllocated() const;    // Checks if the memory is currently allocated
92   uptr Beg() const;            // First byte of user memory
93   uptr End() const;            // Last byte of user memory
94   uptr UsedSize() const;       // Size requested by the user
95   uptr ActualSize() const;     // Size allocated by the allocator.
96   u32 GetAllocStackId() const;
97   bool FromSmallHeap() const;
98   bool AddrIsInside(uptr addr) const;
99 
100  private:
101   friend class __lsan::LsanMetadata;
102   uptr block_;
103   Metadata *const metadata_;
104 };
105 
106 HwasanChunkView FindHeapChunkByAddress(uptr address);
107 
108 // Information about one (de)allocation that happened in the past.
109 // These are recorded in a thread-local ring buffer.
110 // TODO: this is currently 24 bytes (20 bytes + alignment).
111 // Compress it to 16 bytes or extend it to be more useful.
112 struct HeapAllocationRecord {
113   uptr tagged_addr;
114   u32  alloc_context_id;
115   u32  free_context_id;
116   u32  requested_size;
117 };
118 
119 typedef RingBuffer<HeapAllocationRecord> HeapAllocationsRingBuffer;
120 
121 void GetAllocatorStats(AllocatorStatCounters s);
122 
123 inline bool InTaggableRegion(uptr addr) {
124 #if defined(HWASAN_ALIASING_MODE)
125   // Aliases are mapped next to shadow so that the upper bits match the shadow
126   // base.
127   return (addr >> kTaggableRegionCheckShift) ==
128          (GetShadowOffset() >> kTaggableRegionCheckShift);
129 #endif
130   return true;
131 }
132 
133 } // namespace __hwasan
134 
135 #endif // HWASAN_ALLOCATOR_H
136