| //===-- sanitizer_stack_store.h ---------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SANITIZER_STACK_STORE_H |
| #define SANITIZER_STACK_STORE_H |
| |
| #include "sanitizer_atomic.h" |
| #include "sanitizer_common.h" |
| #include "sanitizer_internal_defs.h" |
| #include "sanitizer_mutex.h" |
| #include "sanitizer_stacktrace.h" |
| |
| namespace __sanitizer { |
| |
| class StackStore { |
| static constexpr uptr kBlockSizeFrames = 0x100000; |
| static constexpr uptr kBlockCount = 0x1000; |
| static constexpr uptr kBlockSizeBytes = kBlockSizeFrames * sizeof(uptr); |
| |
| public: |
| enum class Compression : u8 { |
| None = 0, |
| Test, |
| }; |
| |
| constexpr StackStore() = default; |
| |
| using Id = u32; // Enough for 2^32 * sizeof(uptr) bytes of traces. |
| static_assert(u64(kBlockCount) * kBlockSizeFrames == 1ull << (sizeof(Id) * 8), |
| ""); |
| |
| Id Store(const StackTrace &trace, |
| uptr *pack /* number of blocks completed by this call */); |
| StackTrace Load(Id id); |
| uptr Allocated() const; |
| |
| // Packs all blocks which don't expect any more writes. A block is going to be |
| // packed once. As soon trace from that block was requested, it will unpack |
| // and stay unpacked after that. |
| // Returns the number of released bytes. |
| uptr Pack(Compression type); |
| |
| void TestOnlyUnmap(); |
| |
| private: |
| friend class StackStoreTest; |
| static constexpr uptr GetBlockIdx(uptr frame_idx) { |
| return frame_idx / kBlockSizeFrames; |
| } |
| |
| static constexpr uptr GetInBlockIdx(uptr frame_idx) { |
| return frame_idx % kBlockSizeFrames; |
| } |
| |
| static constexpr uptr IdToOffset(Id id) { |
| CHECK_NE(id, 0); |
| return id - 1; // Avoid zero as id. |
| } |
| |
| static constexpr uptr OffsetToId(Id id) { |
| // This makes UINT32_MAX to 0 and it will be retrived as and empty stack. |
| // But this is not a problem as we will not be able to store anything after |
| // that anyway. |
| return id + 1; // Avoid zero as id. |
| } |
| |
| uptr *Alloc(uptr count, uptr *idx, uptr *pack); |
| |
| // Total number of allocated frames. |
| atomic_uintptr_t total_frames_ = {}; |
| |
| // Each block will hold pointer to exactly kBlockSizeFrames. |
| class BlockInfo { |
| atomic_uintptr_t data_; |
| // Counter to track store progress to know when we can Pack() the block. |
| atomic_uint32_t stored_; |
| // Protects alloc of new blocks. |
| mutable StaticSpinMutex mtx_; |
| |
| enum class State : u8 { |
| Storing = 0, |
| Packed, |
| Unpacked, |
| }; |
| State state GUARDED_BY(mtx_); |
| |
| uptr *Create(); |
| |
| public: |
| uptr *Get() const; |
| uptr *GetOrCreate(); |
| uptr *GetOrUnpack(); |
| uptr Pack(Compression type); |
| uptr Allocated() const; |
| void TestOnlyUnmap(); |
| bool Stored(uptr n); |
| bool IsPacked() const; |
| }; |
| |
| BlockInfo blocks_[kBlockCount] = {}; |
| }; |
| |
| } // namespace __sanitizer |
| |
| #endif // SANITIZER_STACK_STORE_H |