1 //===-- tsan_sync.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 ThreadSanitizer (TSan), a race detector. 10 // 11 //===----------------------------------------------------------------------===// 12 #ifndef TSAN_SYNC_H 13 #define TSAN_SYNC_H 14 15 #include "sanitizer_common/sanitizer_atomic.h" 16 #include "sanitizer_common/sanitizer_common.h" 17 #include "sanitizer_common/sanitizer_deadlock_detector_interface.h" 18 #include "tsan_defs.h" 19 #include "tsan_clock.h" 20 #include "tsan_dense_alloc.h" 21 22 namespace __tsan { 23 24 // These need to match __tsan_mutex_* flags defined in tsan_interface.h. 25 // See documentation there as well. 26 enum MutexFlags { 27 MutexFlagLinkerInit = 1 << 0, // __tsan_mutex_linker_init 28 MutexFlagWriteReentrant = 1 << 1, // __tsan_mutex_write_reentrant 29 MutexFlagReadReentrant = 1 << 2, // __tsan_mutex_read_reentrant 30 MutexFlagReadLock = 1 << 3, // __tsan_mutex_read_lock 31 MutexFlagTryLock = 1 << 4, // __tsan_mutex_try_lock 32 MutexFlagTryLockFailed = 1 << 5, // __tsan_mutex_try_lock_failed 33 MutexFlagRecursiveLock = 1 << 6, // __tsan_mutex_recursive_lock 34 MutexFlagRecursiveUnlock = 1 << 7, // __tsan_mutex_recursive_unlock 35 MutexFlagNotStatic = 1 << 8, // __tsan_mutex_not_static 36 37 // The following flags are runtime private. 38 // Mutex API misuse was detected, so don't report any more. 39 MutexFlagBroken = 1 << 30, 40 // We did not intercept pre lock event, so handle it on post lock. 41 MutexFlagDoPreLockOnPostLock = 1 << 29, 42 // Must list all mutex creation flags. 43 MutexCreationFlagMask = MutexFlagLinkerInit | 44 MutexFlagWriteReentrant | 45 MutexFlagReadReentrant | 46 MutexFlagNotStatic, 47 }; 48 49 struct SyncVar { 50 SyncVar(); 51 52 uptr addr; // overwritten by DenseSlabAlloc freelist 53 Mutex mtx; 54 u64 uid; // Globally unique id. 55 u32 creation_stack_id; 56 u32 owner_tid; // Set only by exclusive owners. 57 u64 last_lock; 58 int recursion; 59 atomic_uint32_t flags; 60 u32 next; // in MetaMap 61 DDMutex dd; 62 SyncClock read_clock; // Used for rw mutexes only. 63 // The clock is placed last, so that it is situated on a different cache line 64 // with the mtx. This reduces contention for hot sync objects. 65 SyncClock clock; 66 67 void Init(ThreadState *thr, uptr pc, uptr addr, u64 uid); 68 void Reset(Processor *proc); 69 70 u64 GetId() const { 71 // 48 lsb is addr, then 14 bits is low part of uid, then 2 zero bits. 72 return GetLsb((u64)addr | (uid << 48), 60); 73 } 74 bool CheckId(u64 uid) const { 75 CHECK_EQ(uid, GetLsb(uid, 14)); 76 return GetLsb(this->uid, 14) == uid; 77 } 78 static uptr SplitId(u64 id, u64 *uid) { 79 *uid = id >> 48; 80 return (uptr)GetLsb(id, 48); 81 } 82 83 bool IsFlagSet(u32 f) const { 84 return atomic_load_relaxed(&flags) & f; 85 } 86 87 void SetFlags(u32 f) { 88 atomic_store_relaxed(&flags, atomic_load_relaxed(&flags) | f); 89 } 90 91 void UpdateFlags(u32 flagz) { 92 // Filter out operation flags. 93 if (!(flagz & MutexCreationFlagMask)) 94 return; 95 u32 current = atomic_load_relaxed(&flags); 96 if (current & MutexCreationFlagMask) 97 return; 98 // Note: this can be called from MutexPostReadLock which holds only read 99 // lock on the SyncVar. 100 atomic_store_relaxed(&flags, current | (flagz & MutexCreationFlagMask)); 101 } 102 }; 103 104 /* MetaMap allows to map arbitrary user pointers onto various descriptors. 105 Currently it maps pointers to heap block descriptors and sync var descs. 106 It uses 1/2 direct shadow, see tsan_platform.h. 107 */ 108 class MetaMap { 109 public: 110 MetaMap(); 111 112 void AllocBlock(ThreadState *thr, uptr pc, uptr p, uptr sz); 113 uptr FreeBlock(Processor *proc, uptr p); 114 bool FreeRange(Processor *proc, uptr p, uptr sz); 115 void ResetRange(Processor *proc, uptr p, uptr sz); 116 MBlock* GetBlock(uptr p); 117 118 SyncVar* GetOrCreateAndLock(ThreadState *thr, uptr pc, 119 uptr addr, bool write_lock); 120 SyncVar* GetIfExistsAndLock(uptr addr, bool write_lock); 121 122 void MoveMemory(uptr src, uptr dst, uptr sz); 123 124 void OnProcIdle(Processor *proc); 125 126 private: 127 static const u32 kFlagMask = 3u << 30; 128 static const u32 kFlagBlock = 1u << 30; 129 static const u32 kFlagSync = 2u << 30; 130 typedef DenseSlabAlloc<MBlock, 1 << 18, 1 << 12, kFlagMask> BlockAlloc; 131 typedef DenseSlabAlloc<SyncVar, 1 << 20, 1 << 10, kFlagMask> SyncAlloc; 132 BlockAlloc block_alloc_; 133 SyncAlloc sync_alloc_; 134 atomic_uint64_t uid_gen_; 135 136 SyncVar* GetAndLock(ThreadState *thr, uptr pc, uptr addr, bool write_lock, 137 bool create); 138 }; 139 140 } // namespace __tsan 141 142 #endif // TSAN_SYNC_H 143