RandomizedVirtualAlloc should check for isolate presence instead of using Isolate::Current()

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 819 matching lines @@
   if (allocate_alignment == 0) {
     SYSTEM_INFO info;
     GetSystemInfo(&info);
     allocate_alignment = info.dwAllocationGranularity;
   }
   return allocate_alignment;
 }
 
 
 static void* GetRandomAddr() {
-  // 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
+  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;
+    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;
+    static const intptr_t kAllocationRandomAddressMin = 0x04000000;
+    static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000;
 #endif
-  uintptr_t address = (V8::RandomPrivate(Isolate::Current()) << kPageSizeBits)
-      | kAllocationRandomAddressMin;
-  address &= kAllocationRandomAddressMax;
-  return reinterpret_cast<void *>(address);
+    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);
@@ skipping 1185 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal