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_mutex.h" 21 #include "tsan_dense_alloc.h" 22 23 namespace __tsan { 24 25 // These need to match __tsan_mutex_* flags defined in tsan_interface.h. 26 // See documentation there as well. 27 enum MutexFlags { 28 MutexFlagLinkerInit = 1 << 0, // __tsan_mutex_linker_init 29 MutexFlagWriteReentrant = 1 << 1, // __tsan_mutex_write_reentrant 30 MutexFlagReadReentrant = 1 << 2, // __tsan_mutex_read_reentrant 31 MutexFlagReadLock = 1 << 3, // __tsan_mutex_read_lock 32 MutexFlagTryLock = 1 << 4, // __tsan_mutex_try_lock 33 MutexFlagTryLockFailed = 1 << 5, // __tsan_mutex_try_lock_failed 34 MutexFlagRecursiveLock = 1 << 6, // __tsan_mutex_recursive_lock 35 MutexFlagRecursiveUnlock = 1 << 7, // __tsan_mutex_recursive_unlock 36 MutexFlagNotStatic = 1 << 8, // __tsan_mutex_not_static 37 38 // The following flags are runtime private. 39 // Mutex API misuse was detected, so don't report any more. 40 MutexFlagBroken = 1 << 30, 41 // We did not intercept pre lock event, so handle it on post lock. 42 MutexFlagDoPreLockOnPostLock = 1 << 29, 43 // Must list all mutex creation flags. 44 MutexCreationFlagMask = MutexFlagLinkerInit | 45 MutexFlagWriteReentrant | 46 MutexFlagReadReentrant | 47 MutexFlagNotStatic, 48 }; 49 50 struct SyncVar { 51 SyncVar(); 52 53 static const int kInvalidTid = -1; 54 55 uptr addr; // overwritten by DenseSlabAlloc freelist 56 Mutex mtx; 57 u64 uid; // Globally unique id. 58 u32 creation_stack_id; 59 int owner_tid; // Set only by exclusive owners. 60 u64 last_lock; 61 int recursion; 62 atomic_uint32_t flags; 63 u32 next; // in MetaMap 64 DDMutex dd; 65 SyncClock read_clock; // Used for rw mutexes only. 66 // The clock is placed last, so that it is situated on a different cache line 67 // with the mtx. This reduces contention for hot sync objects. 68 SyncClock clock; 69 70 void Init(ThreadState *thr, uptr pc, uptr addr, u64 uid); 71 void Reset(Processor *proc); 72 GetIdSyncVar73 u64 GetId() const { 74 // 48 lsb is addr, then 14 bits is low part of uid, then 2 zero bits. 75 return GetLsb((u64)addr | (uid << 48), 60); 76 } CheckIdSyncVar77 bool CheckId(u64 uid) const { 78 CHECK_EQ(uid, GetLsb(uid, 14)); 79 return GetLsb(this->uid, 14) == uid; 80 } SplitIdSyncVar81 static uptr SplitId(u64 id, u64 *uid) { 82 *uid = id >> 48; 83 return (uptr)GetLsb(id, 48); 84 } 85 IsFlagSetSyncVar86 bool IsFlagSet(u32 f) const { 87 return atomic_load_relaxed(&flags) & f; 88 } 89 SetFlagsSyncVar90 void SetFlags(u32 f) { 91 atomic_store_relaxed(&flags, atomic_load_relaxed(&flags) | f); 92 } 93 UpdateFlagsSyncVar94 void UpdateFlags(u32 flagz) { 95 // Filter out operation flags. 96 if (!(flagz & MutexCreationFlagMask)) 97 return; 98 u32 current = atomic_load_relaxed(&flags); 99 if (current & MutexCreationFlagMask) 100 return; 101 // Note: this can be called from MutexPostReadLock which holds only read 102 // lock on the SyncVar. 103 atomic_store_relaxed(&flags, current | (flagz & MutexCreationFlagMask)); 104 } 105 }; 106 107 /* MetaMap allows to map arbitrary user pointers onto various descriptors. 108 Currently it maps pointers to heap block descriptors and sync var descs. 109 It uses 1/2 direct shadow, see tsan_platform.h. 110 */ 111 class MetaMap { 112 public: 113 MetaMap(); 114 115 void AllocBlock(ThreadState *thr, uptr pc, uptr p, uptr sz); 116 uptr FreeBlock(Processor *proc, uptr p); 117 bool FreeRange(Processor *proc, uptr p, uptr sz); 118 void ResetRange(Processor *proc, uptr p, uptr sz); 119 MBlock* GetBlock(uptr p); 120 121 SyncVar* GetOrCreateAndLock(ThreadState *thr, uptr pc, 122 uptr addr, bool write_lock); 123 SyncVar* GetIfExistsAndLock(uptr addr, bool write_lock); 124 125 void MoveMemory(uptr src, uptr dst, uptr sz); 126 127 void OnProcIdle(Processor *proc); 128 129 private: 130 static const u32 kFlagMask = 3u << 30; 131 static const u32 kFlagBlock = 1u << 30; 132 static const u32 kFlagSync = 2u << 30; 133 typedef DenseSlabAlloc<MBlock, 1<<16, 1<<12> BlockAlloc; 134 typedef DenseSlabAlloc<SyncVar, 1<<16, 1<<10> SyncAlloc; 135 BlockAlloc block_alloc_; 136 SyncAlloc sync_alloc_; 137 atomic_uint64_t uid_gen_; 138 139 SyncVar* GetAndLock(ThreadState *thr, uptr pc, uptr addr, bool write_lock, 140 bool create); 141 }; 142 143 } // namespace __tsan 144 145 #endif // TSAN_SYNC_H 146