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 
20 namespace __hwasan {
21 
22 typedef __sanitizer::CompactRingBuffer<uptr> StackAllocationsRingBuffer;
23 
24 class 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() { return stack_top_; }
45   uptr stack_bottom() { return stack_bottom_; }
46   uptr stack_size() { return stack_top() - stack_bottom(); }
47   uptr tls_begin() { return tls_begin_; }
48   uptr tls_end() { return tls_end_; }
49   bool IsMainThread() { return unique_id_ == 0; }
50 
51   bool AddrIsInStack(uptr addr) {
52     return addr >= stack_bottom_ && addr < stack_top_;
53   }
54 
55   AllocatorCache *allocator_cache() { return &allocator_cache_; }
56   HeapAllocationsRingBuffer *heap_allocations() { return heap_allocations_; }
57   StackAllocationsRingBuffer *stack_allocations() { return stack_allocations_; }
58 
59   tag_t GenerateRandomTag(uptr num_bits = kTagBits);
60 
61   void DisableTagging() { tagging_disabled_++; }
62   void EnableTagging() { tagging_disabled_--; }
63 
64   u64 unique_id() const { return unique_id_; }
65   void Announce() {
66     if (announced_) return;
67     announced_ = true;
68     Print("Thread: ");
69   }
70 
71   uptr &vfork_spill() { return vfork_spill_; }
72 
73  private:
74   // NOTE: There is no Thread constructor. It is allocated
75   // via mmap() and *must* be valid in zero-initialized state.
76   void ClearShadowForThreadStackAndTLS();
77   void Print(const char *prefix);
78   void InitRandomState();
79   uptr vfork_spill_;
80   uptr stack_top_;
81   uptr stack_bottom_;
82   uptr tls_begin_;
83   uptr tls_end_;
84 
85   u32 random_state_;
86   u32 random_buffer_;
87 
88   AllocatorCache allocator_cache_;
89   HeapAllocationsRingBuffer *heap_allocations_;
90   StackAllocationsRingBuffer *stack_allocations_;
91 
92   u64 unique_id_;  // counting from zero.
93 
94   u32 tagging_disabled_;  // if non-zero, malloc uses zero tag in this thread.
95 
96   bool announced_;
97 
98   bool random_state_inited_;  // Whether InitRandomState() has been called.
99 
100   friend struct ThreadListHead;
101 };
102 
103 Thread *GetCurrentThread();
104 uptr *GetCurrentThreadLongPtr();
105 
106 struct ScopedTaggingDisabler {
107   ScopedTaggingDisabler() { GetCurrentThread()->DisableTagging(); }
108   ~ScopedTaggingDisabler() { GetCurrentThread()->EnableTagging(); }
109 };
110 
111 } // namespace __hwasan
112 
113 #endif // HWASAN_THREAD_H
114