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   void InitRandomState();
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   void Destroy();
38 
39   uptr stack_top() { return stack_top_; }
40   uptr stack_bottom() { return stack_bottom_; }
41   uptr stack_size() { return stack_top() - stack_bottom(); }
42   uptr tls_begin() { return tls_begin_; }
43   uptr tls_end() { return tls_end_; }
44   bool IsMainThread() { return unique_id_ == 0; }
45 
46   bool AddrIsInStack(uptr addr) {
47     return addr >= stack_bottom_ && addr < stack_top_;
48   }
49 
50   AllocatorCache *allocator_cache() { return &allocator_cache_; }
51   HeapAllocationsRingBuffer *heap_allocations() { return heap_allocations_; }
52   StackAllocationsRingBuffer *stack_allocations() { return stack_allocations_; }
53 
54   tag_t GenerateRandomTag(uptr num_bits = kTagBits);
55 
56   void DisableTagging() { tagging_disabled_++; }
57   void EnableTagging() { tagging_disabled_--; }
58 
59   u64 unique_id() const { return unique_id_; }
60   void Announce() {
61     if (announced_) return;
62     announced_ = true;
63     Print("Thread: ");
64   }
65 
66   uptr &vfork_spill() { return vfork_spill_; }
67 
68  private:
69   // NOTE: There is no Thread constructor. It is allocated
70   // via mmap() and *must* be valid in zero-initialized state.
71   void ClearShadowForThreadStackAndTLS();
72   void Print(const char *prefix);
73   uptr vfork_spill_;
74   uptr stack_top_;
75   uptr stack_bottom_;
76   uptr tls_begin_;
77   uptr tls_end_;
78 
79   u32 random_state_;
80   u32 random_buffer_;
81 
82   AllocatorCache allocator_cache_;
83   HeapAllocationsRingBuffer *heap_allocations_;
84   StackAllocationsRingBuffer *stack_allocations_;
85 
86   u64 unique_id_;  // counting from zero.
87 
88   u32 tagging_disabled_;  // if non-zero, malloc uses zero tag in this thread.
89 
90   bool announced_;
91 
92   friend struct ThreadListHead;
93 };
94 
95 Thread *GetCurrentThread();
96 uptr *GetCurrentThreadLongPtr();
97 
98 struct ScopedTaggingDisabler {
99   ScopedTaggingDisabler() { GetCurrentThread()->DisableTagging(); }
100   ~ScopedTaggingDisabler() { GetCurrentThread()->EnableTagging(); }
101 };
102 
103 } // namespace __hwasan
104 
105 #endif // HWASAN_THREAD_H
106