libsanitizer/tsan/tsan_sync.h

   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
  73   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   }
  77   bool CheckId(u64 uid) const {
  78     CHECK_EQ(uid, GetLsb(uid, 14));
  79     return GetLsb(this->uid, 14) == uid;
  80   }
  81   static uptr SplitId(u64 id, u64 *uid) {
  82     *uid = id >> 48;
  83     return (uptr)GetLsb(id, 48);
  84   }
  85
  86   bool IsFlagSet(u32 f) const {
  87     return atomic_load_relaxed(&flags) & f;
  88   }
  89
  90   void SetFlags(u32 f) {
  91     atomic_store_relaxed(&flags, atomic_load_relaxed(&flags) | f);
  92   }
  93
  94   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