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