Merge r10797 from the bleeding_edge to the 3.8 branch.

src/platform-win32.cc

 // Copyright 2012 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 813 matching lines @@
   static size_t allocate_alignment = 0;
   if (allocate_alignment == 0) {
     SYSTEM_INFO info;
     GetSystemInfo(&info);
     allocate_alignment = info.dwAllocationGranularity;
   }
   return allocate_alignment;
 }
 
 
+static void* GetRandomAddr() {
+  Isolate* isolate = Isolate::UncheckedCurrent();
+  // Note that the current isolate isn't set up in a call path via
+  // CpuFeatures::Probe. We don't care about randomization in this case because
+  // the code page is immediately freed.
+  if (isolate != NULL) {
+    // The address range used to randomize RWX allocations in OS::Allocate
+    // Try not to map pages into the default range that windows loads DLLs
+    // Use a multiple of 64k to prevent committing unused memory.
+    // Note: This does not guarantee RWX regions will be within the
+    // range kAllocationRandomAddressMin to kAllocationRandomAddressMax
+#ifdef V8_HOST_ARCH_64_BIT
+    static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000;
+    static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000;
+#else
+    static const intptr_t kAllocationRandomAddressMin = 0x04000000;
+    static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000;
+#endif
+    uintptr_t address = (V8::RandomPrivate(isolate) << kPageSizeBits)
+        | kAllocationRandomAddressMin;
+    address &= kAllocationRandomAddressMax;
+    return reinterpret_cast<void *>(address);
+  }
+  return NULL;
+}
+
+
+static void* RandomizedVirtualAlloc(size_t size, int action, int protection) {
+  LPVOID base = NULL;
+
+  if (protection == PAGE_EXECUTE_READWRITE || protection == PAGE_NOACCESS) {
+    // For exectutable pages try and randomize the allocation address
+    for (size_t attempts = 0; base == NULL && attempts < 3; ++attempts) {
+      base = VirtualAlloc(GetRandomAddr(), size, action, protection);
+    }
+  }
+
+  // After three attempts give up and let the OS find an address to use.
+  if (base == NULL) base = VirtualAlloc(NULL, size, action, protection);
+
+  return base;
+}
+
+
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,
                    bool is_executable) {
-  // The address range used to randomize RWX allocations in OS::Allocate
-  // Try not to map pages into the default range that windows loads DLLs
-  // Use a multiple of 64k to prevent committing unused memory.
-  // Note: This does not guarantee RWX regions will be within the
-  // range kAllocationRandomAddressMin to kAllocationRandomAddressMax
-#ifdef V8_HOST_ARCH_64_BIT
-  static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000;
-  static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000;
-#else
-  static const intptr_t kAllocationRandomAddressMin = 0x04000000;
-  static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000;
-#endif
-
   // VirtualAlloc rounds allocated size to page size automatically.
   size_t msize = RoundUp(requested, static_cast<int>(GetPageSize()));
-  intptr_t address = 0;
 
   // Windows XP SP2 allows Data Excution Prevention (DEP).
   int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
 
-  // For exectutable pages try and randomize the allocation address
-  if (prot == PAGE_EXECUTE_READWRITE &&
-      msize >= static_cast<size_t>(Page::kPageSize)) {
-    address = (V8::RandomPrivate(Isolate::Current()) << kPageSizeBits)
-      | kAllocationRandomAddressMin;
-    address &= kAllocationRandomAddressMax;
-  }
-
-  LPVOID mbase = VirtualAlloc(reinterpret_cast<void *>(address),
-                              msize,
-                              MEM_COMMIT | MEM_RESERVE,
-                              prot);
-  if (mbase == NULL && address != 0)
-    mbase = VirtualAlloc(NULL, msize, MEM_COMMIT | MEM_RESERVE, prot);
+  LPVOID mbase = RandomizedVirtualAlloc(msize,
+                                        MEM_COMMIT | MEM_RESERVE,
+                                        prot);
 
   if (mbase == NULL) {
     LOG(ISOLATE, StringEvent("OS::Allocate", "VirtualAlloc failed"));
     return NULL;
   }
 
   ASSERT(IsAligned(reinterpret_cast<size_t>(mbase), OS::AllocateAlignment()));
 
   *allocated = msize;
   UpdateAllocatedSpaceLimits(mbase, static_cast<int>(msize));
@@ skipping 583 matching lines @@
 }
 
 
 bool VirtualMemory::Uncommit(void* address, size_t size) {
   ASSERT(IsReserved());
   return UncommitRegion(address, size);
 }
 
 
 void* VirtualMemory::ReserveRegion(size_t size) {
-  return VirtualAlloc(NULL, size, MEM_RESERVE, PAGE_NOACCESS);
+  return RandomizedVirtualAlloc(size, MEM_RESERVE, PAGE_NOACCESS);
 }
 
 
 bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
   int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
   if (NULL == VirtualAlloc(base, size, MEM_COMMIT, prot)) {
     return false;
   }
 
   UpdateAllocatedSpaceLimits(base, static_cast<int>(size));
@@ skipping 15 matching lines @@
 bool VirtualMemory::UncommitRegion(void* base, size_t size) {
   return VirtualFree(base, size, MEM_DECOMMIT) != 0;
 }
 
 
 bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
   return VirtualFree(base, 0, MEM_RELEASE) != 0;
 }
 
 
-
 // ----------------------------------------------------------------------------
 // Win32 thread support.
 
 // Definition of invalid thread handle and id.
 static const HANDLE kNoThread = INVALID_HANDLE_VALUE;
 
 // Entry point for threads. The supplied argument is a pointer to the thread
 // object. The entry function dispatches to the run method in the thread
 // object. It is important that this function has __stdcall calling
 // convention.
@@ skipping 524 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal