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_dense_alloc.h"
  20 #include "tsan_shadow.h"
  21 #include "tsan_vector_clock.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 // SyncVar is a descriptor of a user synchronization object
  51 // (mutex or an atomic variable).
  52 struct SyncVar {
  53   SyncVar();
  54
  55   uptr addr;  // overwritten by DenseSlabAlloc freelist
  56   Mutex mtx;
  57   StackID creation_stack_id;
  58   Tid owner_tid;  // Set only by exclusive owners.
  59   FastState last_lock;
  60   int recursion;
  61   atomic_uint32_t flags;
  62   u32 next;  // in MetaMap
  63   DDMutex dd;
  64   VectorClock *read_clock;  // Used for rw mutexes only.
  65   VectorClock *clock;
  66
  67   void Init(ThreadState *thr, uptr pc, uptr addr, bool save_stack);
  68   void Reset();
  69
  70   bool IsFlagSet(u32 f) const {
  71     return atomic_load_relaxed(&flags) & f;
  72   }
  73
  74   void SetFlags(u32 f) {
  75     atomic_store_relaxed(&flags, atomic_load_relaxed(&flags) | f);
  76   }
  77
  78   void UpdateFlags(u32 flagz) {
  79     // Filter out operation flags.
  80     if (!(flagz & MutexCreationFlagMask))
  81       return;
  82     u32 current = atomic_load_relaxed(&flags);
  83     if (current & MutexCreationFlagMask)
  84       return;
  85     // Note: this can be called from MutexPostReadLock which holds only read
  86     // lock on the SyncVar.
  87     atomic_store_relaxed(&flags, current | (flagz & MutexCreationFlagMask));
  88   }
  89 };
  90
  91 // MetaMap maps app addresses to heap block (MBlock) and sync var (SyncVar)
  92 // descriptors. It uses 1/2 direct shadow, see tsan_platform.h for the mapping.
  93 class MetaMap {
  94  public:
  95   MetaMap();
  96
  97   void AllocBlock(ThreadState *thr, uptr pc, uptr p, uptr sz);
  98
  99   // FreeBlock resets all sync objects in the range if reset=true and must not
 100   // run concurrently with ResetClocks which resets all sync objects
 101   // w/o any synchronization (as part of DoReset).
 102   // If we don't have a thread slot (very early/late in thread lifetime or
 103   // Go/Java callbacks) or the slot is not locked, then reset must be set to
 104   // false. In such case sync object clocks will be reset later (when it's
 105   // reused or during the next ResetClocks).
 106   uptr FreeBlock(Processor *proc, uptr p, bool reset);
 107   bool FreeRange(Processor *proc, uptr p, uptr sz, bool reset);
 108   void ResetRange(Processor *proc, uptr p, uptr sz, bool reset);
 109   // Reset vector clocks of all sync objects.
 110   // Must be called when no other threads access sync objects.
 111   void ResetClocks();
 112   MBlock* GetBlock(uptr p);
 113
 114   SyncVar *GetSyncOrCreate(ThreadState *thr, uptr pc, uptr addr,
 115                            bool save_stack) {
 116     return GetSync(thr, pc, addr, true, save_stack);
 117   }
 118   SyncVar *GetSyncIfExists(uptr addr) {
 119     return GetSync(nullptr, 0, addr, false, false);
 120   }
 121
 122   void MoveMemory(uptr src, uptr dst, uptr sz);
 123
 124   void OnProcIdle(Processor *proc);
 125
 126   struct MemoryStats {
 127     uptr mem_block;
 128     uptr sync_obj;
 129   };
 130
 131   MemoryStats GetMemoryStats() const;
 132
 133  private:
 134   static const u32 kFlagMask  = 3u << 30;
 135   static const u32 kFlagBlock = 1u << 30;
 136   static const u32 kFlagSync  = 2u << 30;
 137   typedef DenseSlabAlloc<MBlock, 1 << 18, 1 << 12, kFlagMask> BlockAlloc;
 138   typedef DenseSlabAlloc<SyncVar, 1 << 20, 1 << 10, kFlagMask> SyncAlloc;
 139   BlockAlloc block_alloc_;
 140   SyncAlloc sync_alloc_;
 141
 142   SyncVar *GetSync(ThreadState *thr, uptr pc, uptr addr, bool create,
 143                    bool save_stack);
 144 };
 145
 146 }  // namespace __tsan
 147
 148 #endif  // TSAN_SYNC_H