code for encrypting sensitive tcmalloc metadata

third_party/tcmalloc/chromium/src/metadata_encode.h

Index: third_party/tcmalloc/chromium/src/metadata_encode.h
diff --git a/third_party/tcmalloc/chromium/src/static_vars.cc b/third_party/tcmalloc/chromium/src/metadata_encode.h
similarity index 53%
copy from third_party/tcmalloc/chromium/src/static_vars.cc
copy to third_party/tcmalloc/chromium/src/metadata_encode.h
index 2ca132e46eab49da5e2c91fa2544d282ad260a0c..dc0ec9eb37c52cd173feabb7e9c64b10a7ec7b12 100644
--- a/third_party/tcmalloc/chromium/src/static_vars.cc
+++ b/third_party/tcmalloc/chromium/src/metadata_encode.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2008, Google Inc.
+// Copyright (c) 2011, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -28,41 +28,47 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // ---
-// Author: Ken Ashcraft <opensource@google.com>
+// Author: Rebecca Shapiro
+//
+// Here lies code that aids in encoding allocator metadata.  Because
+// some, but not all operating systems provide metadata encoding
+// facilities, this header file is used to determine which encoding
+// implementation gets included in the build.
+
+
+#ifndef TCMALLOC_METADATA_ENCODE_H_
+#define TCMALLOC_METADATA_ENCODE_H_
+
+#include "config.h"
+#ifdef HAVE_STDINT_H
+#include <stdint.h>                     // for uintptr_t
+#endif
 
-#include "static_vars.h"
-#include <stddef.h>                     // for NULL
-#include <new>                          // for operator new
-#include "internal_logging.h"  // for CHECK_CONDITION
-#include "sampler.h"           // for Sampler
+#include "config_hardening.h"
+#ifndef TCMALLOC_SPAN_ENCODE
+#include "metadata_encode_disabled.h"
+#else
+#ifdef OS_WIN
+#include "metadata_encode_disabled.h"
+#else // TCMALLOC_SPAN_ENCODE and not OS_WIN.
+#include "metadata_encode_posix.h"
+#endif // OS_WIN
+#endif // TCMALLOC_SPAN_ENCODE
 
 namespace tcmalloc {
 
-SpinLock Static::pageheap_lock_(SpinLock::LINKER_INITIALIZED);
-SizeMap Static::sizemap_;
-CentralFreeListPadded Static::central_cache_[kNumClasses];
-PageHeapAllocator<Span> Static::span_allocator_;
-PageHeapAllocator<StackTrace> Static::stacktrace_allocator_;
-Span Static::sampled_objects_;
-PageHeapAllocator<StackTraceTable::Bucket> Static::bucket_allocator_;
-StackTrace* Static::growth_stacks_ = NULL;
-char Static::pageheap_memory_[sizeof(PageHeap)];
+template <typename T>
+inline T EncodePtr(T ptr){
+  return reinterpret_cast<T>(
+      EncodeUintptr(reinterpret_cast<uintptr_t>(ptr)));
+}
+
+template <typename T>
+inline T DecodePtr(T ptr){
+  return reinterpret_cast<T>(
+      DecodeUintptr(reinterpret_cast<uintptr_t>(ptr)));
+}
 
-void Static::InitStaticVars() {
-  sizemap_.Init();
-  span_allocator_.Init();
-  span_allocator_.New(); // Reduce cache conflicts
-  span_allocator_.New(); // Reduce cache conflicts
-  stacktrace_allocator_.Init();
-  bucket_allocator_.Init();
-  // Do a bit of sanitizing: make sure central_cache is aligned properly
-  CHECK_CONDITION((sizeof(central_cache_[0]) % 64) == 0);
-  for (int i = 0; i < kNumClasses; ++i) {
-    central_cache_[i].Init(i);
-  }
-  new ((void*)pageheap_memory_) PageHeap;
-  DLL_Init(&sampled_objects_);
-  Sampler::InitStatics();
 }
 
-}  // namespace tcmalloc
+#endif // TCMALLOC_METADATA_ENCODE_H_