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 "sanitizer_common/sanitizer_allocator.h"
17 #include "sanitizer_common/sanitizer_allocator_checks.h"
18 #include "sanitizer_common/sanitizer_allocator_interface.h"
19 #include "sanitizer_common/sanitizer_allocator_report.h"
20 #include "sanitizer_common/sanitizer_common.h"
21 #include "sanitizer_common/sanitizer_ring_buffer.h"
22 #include "hwasan_poisoning.h"
23 
24 #if !defined(__aarch64__) && !defined(__x86_64__)
25 #error Unsupported platform
26 #endif
27 
28 namespace __hwasan {
29 
30 struct Metadata {
31   u32 requested_size : 31;  // sizes are < 2G.
32   u32 right_aligned  : 1;
33   u32 alloc_context_id;
34 };
35 
36 struct HwasanMapUnmapCallback {
37   void OnMap(uptr p, uptr size) const { UpdateMemoryUsage(); }
38   void OnUnmap(uptr p, uptr size) const {
39     // We are about to unmap a chunk of user memory.
40     // It can return as user-requested mmap() or another thread stack.
41     // Make it accessible with zero-tagged pointer.
42     TagMemory(p, size, 0);
43   }
44 };
45 
46 static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
47 
48 struct AP64 {
49   static const uptr kSpaceBeg = ~0ULL;
50   static const uptr kSpaceSize = 0x2000000000ULL;
51   static const uptr kMetadataSize = sizeof(Metadata);
52   typedef __sanitizer::VeryDenseSizeClassMap SizeClassMap;
53   using AddressSpaceView = LocalAddressSpaceView;
54   typedef HwasanMapUnmapCallback MapUnmapCallback;
55   static const uptr kFlags = 0;
56 };
57 typedef SizeClassAllocator64<AP64> PrimaryAllocator;
58 typedef CombinedAllocator<PrimaryAllocator> Allocator;
59 typedef Allocator::AllocatorCache AllocatorCache;
60 
61 void AllocatorSwallowThreadLocalCache(AllocatorCache *cache);
62 
63 class HwasanChunkView {
64  public:
65   HwasanChunkView() : block_(0), metadata_(nullptr) {}
66   HwasanChunkView(uptr block, Metadata *metadata)
67       : block_(block), metadata_(metadata) {}
68   bool IsAllocated() const;    // Checks if the memory is currently allocated
69   uptr Beg() const;            // First byte of user memory
70   uptr End() const;            // Last byte of user memory
71   uptr UsedSize() const;       // Size requested by the user
72   uptr ActualSize() const;     // Size allocated by the allocator.
73   u32 GetAllocStackId() const;
74   bool FromSmallHeap() const;
75  private:
76   uptr block_;
77   Metadata *const metadata_;
78 };
79 
80 HwasanChunkView FindHeapChunkByAddress(uptr address);
81 
82 // Information about one (de)allocation that happened in the past.
83 // These are recorded in a thread-local ring buffer.
84 // TODO: this is currently 24 bytes (20 bytes + alignment).
85 // Compress it to 16 bytes or extend it to be more useful.
86 struct HeapAllocationRecord {
87   uptr tagged_addr;
88   u32  alloc_context_id;
89   u32  free_context_id;
90   u32  requested_size;
91 };
92 
93 typedef RingBuffer<HeapAllocationRecord> HeapAllocationsRingBuffer;
94 
95 void GetAllocatorStats(AllocatorStatCounters s);
96 
97 } // namespace __hwasan
98 
99 #endif // HWASAN_ALLOCATOR_H
100