1//===-- hwasan_thread.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_THREAD_H
14#define HWASAN_THREAD_H
15
16#include "hwasan_allocator.h"
17#include "sanitizer_common/sanitizer_common.h"
18#include "sanitizer_common/sanitizer_ring_buffer.h"
19
20namespace __hwasan {
21
22typedef __sanitizer::CompactRingBuffer<uptr> StackAllocationsRingBuffer;
23
24class Thread {
25 public:
26 // These are optional parameters that can be passed to Init.
27 struct InitState;
28
29 void Init(uptr stack_buffer_start, uptr stack_buffer_size,
30 const InitState *state = nullptr);
31
32 void InitStackAndTls(const InitState *state = nullptr);
33
34 // Must be called from the thread itself.
35 void InitStackRingBuffer(uptr stack_buffer_start, uptr stack_buffer_size);
36
37 inline void EnsureRandomStateInited() {
38 if (UNLIKELY(!random_state_inited_))
39 InitRandomState();
40 }
41
42 void Destroy();
43
44 uptr stack_top();
45 uptr stack_bottom();
46 uptr stack_size();
47 uptr tls_begin() { return tls_begin_; }
48 uptr tls_end() { return tls_end_; }
49 DTLS *dtls() { return dtls_; }
50 bool IsMainThread() { return unique_id_ == 0; }
51
52 bool AddrIsInStack(uptr addr) {
53 return addr >= stack_bottom_ && addr < stack_top_;
54 }
55
56 void StartSwitchFiber(uptr bottom, uptr size);
57 void FinishSwitchFiber(uptr *bottom_old, uptr *size_old);
58
59 AllocatorCache *allocator_cache() { return &allocator_cache_; }
60 HeapAllocationsRingBuffer *heap_allocations() { return heap_allocations_; }
61 StackAllocationsRingBuffer *stack_allocations() { return stack_allocations_; }
62
63 tag_t GenerateRandomTag(uptr num_bits = kTagBits);
64
65 void DisableTagging() { tagging_disabled_++; }
66 void EnableTagging() { tagging_disabled_--; }
67
68 u32 unique_id() const { return unique_id_; }
69 void Announce() {
70 if (announced_) return;
71 announced_ = true;
72 Print(prefix: "Thread: ");
73 }
74
75 ThreadID os_id() const { return os_id_; }
76 void set_os_id(ThreadID os_id) { os_id_ = os_id; }
77
78 uptr &vfork_spill() { return vfork_spill_; }
79
80 private:
81 // NOTE: There is no Thread constructor. It is allocated
82 // via mmap() and *must* be valid in zero-initialized state.
83 void ClearShadowForThreadStackAndTLS();
84 void Print(const char *prefix);
85 void InitRandomState();
86
87 struct StackBounds {
88 uptr bottom;
89 uptr top;
90 };
91 StackBounds GetStackBounds() const;
92
93 uptr vfork_spill_;
94 uptr stack_top_;
95 uptr stack_bottom_;
96 // these variables are used when the thread is about to switch stack
97 uptr next_stack_top_;
98 uptr next_stack_bottom_;
99 // true if switching is in progress
100 atomic_uint8_t stack_switching_;
101
102 uptr tls_begin_;
103 uptr tls_end_;
104 DTLS *dtls_;
105
106 u32 random_state_;
107 u32 random_buffer_;
108
109 AllocatorCache allocator_cache_;
110 HeapAllocationsRingBuffer *heap_allocations_;
111 StackAllocationsRingBuffer *stack_allocations_;
112
113 u32 unique_id_; // counting from zero.
114
115 ThreadID os_id_;
116
117 u32 tagging_disabled_; // if non-zero, malloc uses zero tag in this thread.
118
119 bool announced_;
120
121 bool random_state_inited_; // Whether InitRandomState() has been called.
122
123 friend struct ThreadListHead;
124};
125
126Thread *GetCurrentThread();
127uptr *GetCurrentThreadLongPtr();
128
129// Used to handle fork().
130void EnsureMainThreadIDIsCorrect();
131
132struct ScopedTaggingDisabler {
133 ScopedTaggingDisabler() { GetCurrentThread()->DisableTagging(); }
134 ~ScopedTaggingDisabler() { GetCurrentThread()->EnableTagging(); }
135};
136
137} // namespace __hwasan
138
139#endif // HWASAN_THREAD_H
140