libsanitizer/tsan/tsan_mman.cc

   1 //===-- tsan_mman.cc ------------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of ThreadSanitizer (TSan), a race detector.
   9 //
  10 //===----------------------------------------------------------------------===//
  11 #include "sanitizer_common/sanitizer_common.h"
  12 #include "sanitizer_common/sanitizer_placement_new.h"
  13 #include "tsan_mman.h"
  14 #include "tsan_rtl.h"
  15 #include "tsan_report.h"
  16 #include "tsan_flags.h"
  17
  18 // May be overriden by front-end.
  19 extern "C" void WEAK __tsan_malloc_hook(void *ptr, uptr size) {
  20   (void)ptr;
  21   (void)size;
  22 }
  23
  24 extern "C" void WEAK __tsan_free_hook(void *ptr) {
  25   (void)ptr;
  26 }
  27
  28 namespace __tsan {
  29
  30 COMPILER_CHECK(sizeof(MBlock) == 16);
  31
  32 void MBlock::Lock() {
  33   atomic_uintptr_t *a = reinterpret_cast<atomic_uintptr_t*>(this);
  34   uptr v = atomic_load(a, memory_order_relaxed);
  35   for (int iter = 0;; iter++) {
  36     if (v & 1) {
  37       if (iter < 10)
  38         proc_yield(20);
  39       else
  40         internal_sched_yield();
  41       v = atomic_load(a, memory_order_relaxed);
  42       continue;
  43     }
  44     if (atomic_compare_exchange_weak(a, &v, v | 1, memory_order_acquire))
  45       break;
  46   }
  47 }
  48
  49 void MBlock::Unlock() {
  50   atomic_uintptr_t *a = reinterpret_cast<atomic_uintptr_t*>(this);
  51   uptr v = atomic_load(a, memory_order_relaxed);
  52   DCHECK(v & 1);
  53   atomic_store(a, v & ~1, memory_order_relaxed);
  54 }
  55
  56 struct MapUnmapCallback {
  57   void OnMap(uptr p, uptr size) const { }
  58   void OnUnmap(uptr p, uptr size) const {
  59     // We are about to unmap a chunk of user memory.
  60     // Mark the corresponding shadow memory as not needed.
  61     DontNeedShadowFor(p, size);
  62   }
  63 };
  64
  65 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
  66 Allocator *allocator() {
  67   return reinterpret_cast<Allocator*>(&allocator_placeholder);
  68 }
  69
  70 void InitializeAllocator() {
  71   allocator()->Init();
  72 }
  73
  74 void AllocatorThreadStart(ThreadState *thr) {
  75   allocator()->InitCache(&thr->alloc_cache);
  76   internal_allocator()->InitCache(&thr->internal_alloc_cache);
  77 }
  78
  79 void AllocatorThreadFinish(ThreadState *thr) {
  80   allocator()->DestroyCache(&thr->alloc_cache);
  81   internal_allocator()->DestroyCache(&thr->internal_alloc_cache);
  82 }
  83
  84 void AllocatorPrintStats() {
  85   allocator()->PrintStats();
  86 }
  87
  88 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
  89   if (!thr->in_signal_handler || !flags()->report_signal_unsafe)
  90     return;
  91   Context *ctx = CTX();
  92   StackTrace stack;
  93   stack.ObtainCurrent(thr, pc);
  94   ThreadRegistryLock l(ctx->thread_registry);
  95   ScopedReport rep(ReportTypeSignalUnsafe);
  96   if (!IsFiredSuppression(ctx, rep, stack)) {
  97     rep.AddStack(&stack);
  98     OutputReport(ctx, rep, rep.GetReport()->stacks[0]);
  99   }
 100 }
 101
 102 void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align) {
 103   CHECK_GT(thr->in_rtl, 0);
 104   if ((sz >= (1ull << 40)) || (align >= (1ull << 40)))
 105     return AllocatorReturnNull();
 106   void *p = allocator()->Allocate(&thr->alloc_cache, sz, align);
 107   if (p == 0)
 108     return 0;
 109   MBlock *b = new(allocator()->GetMetaData(p)) MBlock;
 110   b->Init(sz, thr->tid, CurrentStackId(thr, pc));
 111   if (CTX() && CTX()->initialized) {
 112     if (thr->ignore_reads_and_writes == 0)
 113       MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
 114     else
 115       MemoryResetRange(thr, pc, (uptr)p, sz);
 116   }
 117   DPrintf("#%d: alloc(%zu) = %p\n", thr->tid, sz, p);
 118   SignalUnsafeCall(thr, pc);
 119   return p;
 120 }
 121
 122 void user_free(ThreadState *thr, uptr pc, void *p) {
 123   CHECK_GT(thr->in_rtl, 0);
 124   CHECK_NE(p, (void*)0);
 125   DPrintf("#%d: free(%p)\n", thr->tid, p);
 126   MBlock *b = (MBlock*)allocator()->GetMetaData(p);
 127   if (b->ListHead()) {
 128     MBlock::ScopedLock l(b);
 129     for (SyncVar *s = b->ListHead(); s;) {
 130       SyncVar *res = s;
 131       s = s->next;
 132       StatInc(thr, StatSyncDestroyed);
 133       res->mtx.Lock();
 134       res->mtx.Unlock();
 135       DestroyAndFree(res);
 136     }
 137     b->ListReset();
 138   }
 139   if (CTX() && CTX()->initialized && thr->in_rtl == 1) {
 140     if (thr->ignore_reads_and_writes == 0)
 141       MemoryRangeFreed(thr, pc, (uptr)p, b->Size());
 142   }
 143   allocator()->Deallocate(&thr->alloc_cache, p);
 144   SignalUnsafeCall(thr, pc);
 145 }
 146
 147 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
 148   CHECK_GT(thr->in_rtl, 0);
 149   void *p2 = 0;
 150   // FIXME: Handle "shrinking" more efficiently,
 151   // it seems that some software actually does this.
 152   if (sz) {
 153     p2 = user_alloc(thr, pc, sz);
 154     if (p2 == 0)
 155       return 0;
 156     if (p) {
 157       MBlock *b = user_mblock(thr, p);
 158       CHECK_NE(b, 0);
 159       internal_memcpy(p2, p, min(b->Size(), sz));
 160     }
 161   }
 162   if (p)
 163     user_free(thr, pc, p);
 164   return p2;
 165 }
 166
 167 uptr user_alloc_usable_size(ThreadState *thr, uptr pc, void *p) {
 168   CHECK_GT(thr->in_rtl, 0);
 169   if (p == 0)
 170     return 0;
 171   MBlock *b = (MBlock*)allocator()->GetMetaData(p);
 172   return b ? b->Size() : 0;
 173 }
 174
 175 MBlock *user_mblock(ThreadState *thr, void *p) {
 176   CHECK_NE(p, 0);
 177   Allocator *a = allocator();
 178   void *b = a->GetBlockBegin(p);
 179   if (b == 0)
 180     return 0;
 181   return (MBlock*)a->GetMetaData(b);
 182 }
 183
 184 void invoke_malloc_hook(void *ptr, uptr size) {
 185   Context *ctx = CTX();
 186   ThreadState *thr = cur_thread();
 187   if (ctx == 0 || !ctx->initialized || thr->in_rtl)
 188     return;
 189   __tsan_malloc_hook(ptr, size);
 190 }
 191
 192 void invoke_free_hook(void *ptr) {
 193   Context *ctx = CTX();
 194   ThreadState *thr = cur_thread();
 195   if (ctx == 0 || !ctx->initialized || thr->in_rtl)
 196     return;
 197   __tsan_free_hook(ptr);
 198 }
 199
 200 void *internal_alloc(MBlockType typ, uptr sz) {
 201   ThreadState *thr = cur_thread();
 202   CHECK_GT(thr->in_rtl, 0);
 203   CHECK_LE(sz, InternalSizeClassMap::kMaxSize);
 204   if (thr->nomalloc) {
 205     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 206     CHECK(0);
 207   }
 208   return InternalAlloc(sz, &thr->internal_alloc_cache);
 209 }
 210
 211 void internal_free(void *p) {
 212   ThreadState *thr = cur_thread();
 213   CHECK_GT(thr->in_rtl, 0);
 214   if (thr->nomalloc) {
 215     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 216     CHECK(0);
 217   }
 218   InternalFree(p, &thr->internal_alloc_cache);
 219 }
 220
 221 }  // namespace __tsan
 222
 223 using namespace __tsan;
 224
 225 extern "C" {
 226 uptr __tsan_get_current_allocated_bytes() {
 227   u64 stats[AllocatorStatCount];
 228   allocator()->GetStats(stats);
 229   u64 m = stats[AllocatorStatMalloced];
 230   u64 f = stats[AllocatorStatFreed];
 231   return m >= f ? m - f : 1;
 232 }
 233
 234 uptr __tsan_get_heap_size() {
 235   u64 stats[AllocatorStatCount];
 236   allocator()->GetStats(stats);
 237   u64 m = stats[AllocatorStatMmapped];
 238   u64 f = stats[AllocatorStatUnmapped];
 239   return m >= f ? m - f : 1;
 240 }
 241
 242 uptr __tsan_get_free_bytes() {
 243   return 1;
 244 }
 245
 246 uptr __tsan_get_unmapped_bytes() {
 247   return 1;
 248 }
 249
 250 uptr __tsan_get_estimated_allocated_size(uptr size) {
 251   return size;
 252 }
 253
 254 bool __tsan_get_ownership(void *p) {
 255   return allocator()->GetBlockBegin(p) != 0;
 256 }
 257
 258 uptr __tsan_get_allocated_size(void *p) {
 259   if (p == 0)
 260     return 0;
 261   p = allocator()->GetBlockBegin(p);
 262   if (p == 0)
 263     return 0;
 264   MBlock *b = (MBlock*)allocator()->GetMetaData(p);
 265   return b->Size();
 266 }
 267
 268 void __tsan_on_thread_idle() {
 269   ThreadState *thr = cur_thread();
 270   allocator()->SwallowCache(&thr->alloc_cache);
 271   internal_allocator()->SwallowCache(&thr->internal_alloc_cache);
 272 }
 273 }  // extern "C"