[llvm] r254964 - Support: Teach Asan about BumpPtrAllocator

[Justin Bogner via llvm-commits]

Author: bogner
Date: Mon Dec  7 17:12:26 2015
New Revision: 254964

URL: http://llvm.org/viewvc/llvm-project?rev=254964&view=rev
Log:
Support: Teach Asan about BumpPtrAllocator

Based on patch by Pete Cooper.

Modified:
    llvm/trunk/include/llvm/Support/Allocator.h
    llvm/trunk/include/llvm/Support/Compiler.h

Modified: llvm/trunk/include/llvm/Support/Allocator.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Allocator.h?rev=254964&r1=254963&r2=254964&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Allocator.h (original)
+++ llvm/trunk/include/llvm/Support/Allocator.h Mon Dec  7 17:12:26 2015
@@ -222,6 +222,8 @@ public:
       // Without this, MemorySanitizer messages for values originated from here
       // will point to the allocation of the entire slab.
       __msan_allocated_memory(AlignedPtr, Size);
+      // Similarly, tell ASan about this space.
+      __asan_unpoison_memory_region(AlignedPtr, Size);
       return AlignedPtr;
     }
 
@@ -229,12 +231,16 @@ public:
     size_t PaddedSize = Size + Alignment - 1;
     if (PaddedSize > SizeThreshold) {
       void *NewSlab = Allocator.Allocate(PaddedSize, 0);
+      // We own the new slab and don't want anyone reading anyting other than
+      // pieces returned from this method.  So poison the whole slab.
+      __asan_poison_memory_region(NewSlab, PaddedSize);
       CustomSizedSlabs.push_back(std::make_pair(NewSlab, PaddedSize));
 
       uintptr_t AlignedAddr = alignAddr(NewSlab, Alignment);
       assert(AlignedAddr + Size <= (uintptr_t)NewSlab + PaddedSize);
       char *AlignedPtr = (char*)AlignedAddr;
       __msan_allocated_memory(AlignedPtr, Size);
+      __asan_unpoison_memory_region(AlignedPtr, Size);
       return AlignedPtr;
     }
 
@@ -246,13 +252,16 @@ public:
     char *AlignedPtr = (char*)AlignedAddr;
     CurPtr = AlignedPtr + Size;
     __msan_allocated_memory(AlignedPtr, Size);
+    __asan_unpoison_memory_region(AlignedPtr, Size);
     return AlignedPtr;
   }
 
   // Pull in base class overloads.
   using AllocatorBase<BumpPtrAllocatorImpl>::Allocate;
 
-  void Deallocate(const void * /*Ptr*/, size_t /*Size*/) {}
+  void Deallocate(const void *Ptr, size_t Size) {
+    __asan_poison_memory_region(Ptr, Size);
+  }
 
   // Pull in base class overloads.
   using AllocatorBase<BumpPtrAllocatorImpl>::Deallocate;
@@ -310,6 +319,10 @@ private:
     size_t AllocatedSlabSize = computeSlabSize(Slabs.size());
 
     void *NewSlab = Allocator.Allocate(AllocatedSlabSize, 0);
+    // We own the new slab and don't want anyone reading anything other than
+    // pieces returned from this method.  So poison the whole slab.
+    __asan_poison_memory_region(NewSlab, AllocatedSlabSize);
+
     Slabs.push_back(NewSlab);
     CurPtr = (char *)(NewSlab);
     End = ((char *)NewSlab) + AllocatedSlabSize;

Modified: llvm/trunk/include/llvm/Support/Compiler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Compiler.h?rev=254964&r1=254963&r2=254964&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Compiler.h (original)
+++ llvm/trunk/include/llvm/Support/Compiler.h Mon Dec  7 17:12:26 2015
@@ -361,8 +361,11 @@
 /// \brief Whether LLVM itself is built with AddressSanitizer instrumentation.
 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
 # define LLVM_ADDRESS_SANITIZER_BUILD 1
+# include <sanitizer/asan_interface.h>
 #else
 # define LLVM_ADDRESS_SANITIZER_BUILD 0
+# define __asan_poison_memory_region(p, size)
+# define __asan_unpoison_memory_region(p, size)
 #endif
 
 /// \macro LLVM_THREAD_SANITIZER_BUILD