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   void Init(uptr stack_buffer_start, uptr stack_buffer_size);  // Must be called from the thread itself.
27   void InitRandomState();
28   void Destroy();
29 
30   uptr stack_top() { return stack_top_; }
31   uptr stack_bottom() { return stack_bottom_; }
32   uptr stack_size() { return stack_top() - stack_bottom(); }
33   uptr tls_begin() { return tls_begin_; }
34   uptr tls_end() { return tls_end_; }
35   bool IsMainThread() { return unique_id_ == 0; }
36 
37   bool AddrIsInStack(uptr addr) {
38     return addr >= stack_bottom_ && addr < stack_top_;
39   }
40 
41   AllocatorCache *allocator_cache() { return &allocator_cache_; }
42   HeapAllocationsRingBuffer *heap_allocations() { return heap_allocations_; }
43   StackAllocationsRingBuffer *stack_allocations() { return stack_allocations_; }
44 
45   tag_t GenerateRandomTag();
46 
47   void DisableTagging() { tagging_disabled_++; }
48   void EnableTagging() { tagging_disabled_--; }
49 
50   u64 unique_id() const { return unique_id_; }
51   void Announce() {
52     if (announced_) return;
53     announced_ = true;
54     Print("Thread: ");
55   }
56 
57   uptr &vfork_spill() { return vfork_spill_; }
58 
59  private:
60   // NOTE: There is no Thread constructor. It is allocated
61   // via mmap() and *must* be valid in zero-initialized state.
62   void ClearShadowForThreadStackAndTLS();
63   void Print(const char *prefix);
64   uptr vfork_spill_;
65   uptr stack_top_;
66   uptr stack_bottom_;
67   uptr tls_begin_;
68   uptr tls_end_;
69 
70   u32 random_state_;
71   u32 random_buffer_;
72 
73   AllocatorCache allocator_cache_;
74   HeapAllocationsRingBuffer *heap_allocations_;
75   StackAllocationsRingBuffer *stack_allocations_;
76 
77   Thread *next_;  // All live threads form a linked list.
78 
79   u64 unique_id_;  // counting from zero.
80 
81   u32 tagging_disabled_;  // if non-zero, malloc uses zero tag in this thread.
82 
83   bool announced_;
84 
85   friend struct ThreadListHead;
86 };
87 
88 Thread *GetCurrentThread();
89 uptr *GetCurrentThreadLongPtr();
90 
91 struct ScopedTaggingDisabler {
92   ScopedTaggingDisabler() { GetCurrentThread()->DisableTagging(); }
93   ~ScopedTaggingDisabler() { GetCurrentThread()->EnableTagging(); }
94 };
95 
96 } // namespace __hwasan
97 
98 #endif // HWASAN_THREAD_H
99