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_allocator_interface.h"
  12 #include "sanitizer_common/sanitizer_common.h"
  13 #include "sanitizer_common/sanitizer_placement_new.h"
  14 #include "tsan_mman.h"
  15 #include "tsan_rtl.h"
  16 #include "tsan_report.h"
  17 #include "tsan_flags.h"
  18
  19 // May be overriden by front-end.
  20 SANITIZER_WEAK_DEFAULT_IMPL
  21 void __sanitizer_malloc_hook(void *ptr, uptr size) {
  22   (void)ptr;
  23   (void)size;
  24 }
  25
  26 SANITIZER_WEAK_DEFAULT_IMPL
  27 void __sanitizer_free_hook(void *ptr) {
  28   (void)ptr;
  29 }
  30
  31 namespace __tsan {
  32
  33 struct MapUnmapCallback {
  34   void OnMap(uptr p, uptr size) const { }
  35   void OnUnmap(uptr p, uptr size) const {
  36     // We are about to unmap a chunk of user memory.
  37     // Mark the corresponding shadow memory as not needed.
  38     DontNeedShadowFor(p, size);
  39     // Mark the corresponding meta shadow memory as not needed.
  40     // Note the block does not contain any meta info at this point
  41     // (this happens after free).
  42     const uptr kMetaRatio = kMetaShadowCell / kMetaShadowSize;
  43     const uptr kPageSize = GetPageSizeCached() * kMetaRatio;
  44     // Block came from LargeMmapAllocator, so must be large.
  45     // We rely on this in the calculations below.
  46     CHECK_GE(size, 2 * kPageSize);
  47     uptr diff = RoundUp(p, kPageSize) - p;
  48     if (diff != 0) {
  49       p += diff;
  50       size -= diff;
  51     }
  52     diff = p + size - RoundDown(p + size, kPageSize);
  53     if (diff != 0)
  54       size -= diff;
  55     ReleaseMemoryToOS((uptr)MemToMeta(p), size / kMetaRatio);
  56   }
  57 };
  58
  59 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
  60 Allocator *allocator() {
  61   return reinterpret_cast<Allocator*>(&allocator_placeholder);
  62 }
  63
  64 struct GlobalProc {
  65   Mutex mtx;
  66   Processor *proc;
  67
  68   GlobalProc()
  69       : mtx(MutexTypeGlobalProc, StatMtxGlobalProc)
  70       , proc(ProcCreate()) {
  71   }
  72 };
  73
  74 static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
  75 GlobalProc *global_proc() {
  76   return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
  77 }
  78
  79 ScopedGlobalProcessor::ScopedGlobalProcessor() {
  80   GlobalProc *gp = global_proc();
  81   ThreadState *thr = cur_thread();
  82   if (thr->proc())
  83     return;
  84   // If we don't have a proc, use the global one.
  85   // There are currently only two known case where this path is triggered:
  86   //   __interceptor_free
  87   //   __nptl_deallocate_tsd
  88   //   start_thread
  89   //   clone
  90   // and:
  91   //   ResetRange
  92   //   __interceptor_munmap
  93   //   __deallocate_stack
  94   //   start_thread
  95   //   clone
  96   // Ideally, we destroy thread state (and unwire proc) when a thread actually
  97   // exits (i.e. when we join/wait it). Then we would not need the global proc
  98   gp->mtx.Lock();
  99   ProcWire(gp->proc, thr);
 100 }
 101
 102 ScopedGlobalProcessor::~ScopedGlobalProcessor() {
 103   GlobalProc *gp = global_proc();
 104   ThreadState *thr = cur_thread();
 105   if (thr->proc() != gp->proc)
 106     return;
 107   ProcUnwire(gp->proc, thr);
 108   gp->mtx.Unlock();
 109 }
 110
 111 void InitializeAllocator() {
 112   allocator()->Init(common_flags()->allocator_may_return_null);
 113 }
 114
 115 void InitializeAllocatorLate() {
 116   new(global_proc()) GlobalProc();
 117 }
 118
 119 void AllocatorProcStart(Processor *proc) {
 120   allocator()->InitCache(&proc->alloc_cache);
 121   internal_allocator()->InitCache(&proc->internal_alloc_cache);
 122 }
 123
 124 void AllocatorProcFinish(Processor *proc) {
 125   allocator()->DestroyCache(&proc->alloc_cache);
 126   internal_allocator()->DestroyCache(&proc->internal_alloc_cache);
 127 }
 128
 129 void AllocatorPrintStats() {
 130   allocator()->PrintStats();
 131 }
 132
 133 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
 134   if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
 135       !flags()->report_signal_unsafe)
 136     return;
 137   VarSizeStackTrace stack;
 138   ObtainCurrentStack(thr, pc, &stack);
 139   if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
 140     return;
 141   ThreadRegistryLock l(ctx->thread_registry);
 142   ScopedReport rep(ReportTypeSignalUnsafe);
 143   rep.AddStack(stack, true);
 144   OutputReport(thr, rep);
 145 }
 146
 147 void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align, bool signal) {
 148   if ((sz >= (1ull << 40)) || (align >= (1ull << 40)))
 149     return allocator()->ReturnNullOrDieOnBadRequest();
 150   void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
 151   if (p == 0)
 152     return 0;
 153   if (ctx && ctx->initialized)
 154     OnUserAlloc(thr, pc, (uptr)p, sz, true);
 155   if (signal)
 156     SignalUnsafeCall(thr, pc);
 157   return p;
 158 }
 159
 160 void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
 161   if (CallocShouldReturnNullDueToOverflow(size, n))
 162     return allocator()->ReturnNullOrDieOnBadRequest();
 163   void *p = user_alloc(thr, pc, n * size);
 164   if (p)
 165     internal_memset(p, 0, n * size);
 166   return p;
 167 }
 168
 169 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
 170   ScopedGlobalProcessor sgp;
 171   if (ctx && ctx->initialized)
 172     OnUserFree(thr, pc, (uptr)p, true);
 173   allocator()->Deallocate(&thr->proc()->alloc_cache, p);
 174   if (signal)
 175     SignalUnsafeCall(thr, pc);
 176 }
 177
 178 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
 179   DPrintf("#%d: alloc(%zu) = %p\n", thr->tid, sz, p);
 180   ctx->metamap.AllocBlock(thr, pc, p, sz);
 181   if (write && thr->ignore_reads_and_writes == 0)
 182     MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
 183   else
 184     MemoryResetRange(thr, pc, (uptr)p, sz);
 185 }
 186
 187 void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
 188   CHECK_NE(p, (void*)0);
 189   uptr sz = ctx->metamap.FreeBlock(thr->proc(), p);
 190   DPrintf("#%d: free(%p, %zu)\n", thr->tid, p, sz);
 191   if (write && thr->ignore_reads_and_writes == 0)
 192     MemoryRangeFreed(thr, pc, (uptr)p, sz);
 193 }
 194
 195 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
 196   // FIXME: Handle "shrinking" more efficiently,
 197   // it seems that some software actually does this.
 198   void *p2 = user_alloc(thr, pc, sz);
 199   if (p2 == 0)
 200     return 0;
 201   if (p) {
 202     uptr oldsz = user_alloc_usable_size(p);
 203     internal_memcpy(p2, p, min(oldsz, sz));
 204     user_free(thr, pc, p);
 205   }
 206   return p2;
 207 }
 208
 209 uptr user_alloc_usable_size(const void *p) {
 210   if (p == 0)
 211     return 0;
 212   MBlock *b = ctx->metamap.GetBlock((uptr)p);
 213   if (!b)
 214     return 0;  // Not a valid pointer.
 215   if (b->siz == 0)
 216     return 1;  // Zero-sized allocations are actually 1 byte.
 217   return b->siz;
 218 }
 219
 220 void invoke_malloc_hook(void *ptr, uptr size) {
 221   ThreadState *thr = cur_thread();
 222   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 223     return;
 224   __sanitizer_malloc_hook(ptr, size);
 225   RunMallocHooks(ptr, size);
 226 }
 227
 228 void invoke_free_hook(void *ptr) {
 229   ThreadState *thr = cur_thread();
 230   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 231     return;
 232   __sanitizer_free_hook(ptr);
 233   RunFreeHooks(ptr);
 234 }
 235
 236 void *internal_alloc(MBlockType typ, uptr sz) {
 237   ThreadState *thr = cur_thread();
 238   if (thr->nomalloc) {
 239     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 240     CHECK(0);
 241   }
 242   return InternalAlloc(sz, &thr->proc()->internal_alloc_cache);
 243 }
 244
 245 void internal_free(void *p) {
 246   ThreadState *thr = cur_thread();
 247   if (thr->nomalloc) {
 248     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 249     CHECK(0);
 250   }
 251   InternalFree(p, &thr->proc()->internal_alloc_cache);
 252 }
 253
 254 }  // namespace __tsan
 255
 256 using namespace __tsan;
 257
 258 extern "C" {
 259 uptr __sanitizer_get_current_allocated_bytes() {
 260   uptr stats[AllocatorStatCount];
 261   allocator()->GetStats(stats);
 262   return stats[AllocatorStatAllocated];
 263 }
 264
 265 uptr __sanitizer_get_heap_size() {
 266   uptr stats[AllocatorStatCount];
 267   allocator()->GetStats(stats);
 268   return stats[AllocatorStatMapped];
 269 }
 270
 271 uptr __sanitizer_get_free_bytes() {
 272   return 1;
 273 }
 274
 275 uptr __sanitizer_get_unmapped_bytes() {
 276   return 1;
 277 }
 278
 279 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
 280   return size;
 281 }
 282
 283 int __sanitizer_get_ownership(const void *p) {
 284   return allocator()->GetBlockBegin(p) != 0;
 285 }
 286
 287 uptr __sanitizer_get_allocated_size(const void *p) {
 288   return user_alloc_usable_size(p);
 289 }
 290
 291 void __tsan_on_thread_idle() {
 292   ThreadState *thr = cur_thread();
 293   allocator()->SwallowCache(&thr->proc()->alloc_cache);
 294   internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
 295   ctx->metamap.OnProcIdle(thr->proc());
 296 }
 297 }  // extern "C"