Manually randomize the memory addresses for regions of JIT code in the Large ...

src/platform-win32.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 822 matching lines @@
   }
   return allocate_alignment;
 }
 
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,
                    bool is_executable) {
   // VirtualAlloc rounds allocated size to page size automatically.
   size_t msize = RoundUp(requested, static_cast<int>(GetPageSize()));
-
+  intptr_t address = NULL;
   // Windows XP SP2 allows Data Excution Prevention (DEP).
   int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
-  LPVOID mbase = VirtualAlloc(NULL, msize, MEM_COMMIT | MEM_RESERVE, prot);
+  // TODO(805): Port to Linux
+  // For exectutable pages try and randomize the allocation address
+  if (prot == PAGE_EXECUTE_READWRITE && msize >= Page::kPageSize) {
+      address = (V8::Random() << kPageSizeBits) | kAllocationRandomAddressMin;
+      address &= kAllocationRandomAddressMax;
+  }
+
+  LPVOID mbase = VirtualAlloc(reinterpret_cast<void *>(address),
+                              msize,
+                              MEM_COMMIT | MEM_RESERVE,
+                              prot);
+  if (mbase == NULL && address != NULL)
+    mbase = VirtualAlloc(NULL, msize, MEM_COMMIT | MEM_RESERVE, prot);
+
   if (mbase == NULL) {
     LOG(StringEvent("OS::Allocate", "VirtualAlloc failed"));
     return NULL;
   }
 
   ASSERT(IsAligned(reinterpret_cast<size_t>(mbase), OS::AllocateAlignment()));
 
   *allocated = msize;
   UpdateAllocatedSpaceLimits(mbase, static_cast<int>(msize));
   return mbase;
@@ skipping 1045 matching lines @@
 
   // Release the thread handles
   CloseHandle(data_->sampler_thread_);
   CloseHandle(data_->profiled_thread_);
 }
 
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal