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