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Unified Diff: base/allocator/partition_allocator/address_space_randomization.cc

Issue 2518253002: Move Partition Allocator into Chromium base. (Closed)
Patch Set: Move OOM_CRASH into its own, more specific header. Fixes Windows build. Created 4 years ago
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Index: base/allocator/partition_allocator/address_space_randomization.cc
diff --git a/third_party/WebKit/Source/wtf/allocator/AddressSpaceRandomization.cpp b/base/allocator/partition_allocator/address_space_randomization.cc
similarity index 75%
rename from third_party/WebKit/Source/wtf/allocator/AddressSpaceRandomization.cpp
rename to base/allocator/partition_allocator/address_space_randomization.cc
index 4fca2678ef82e6648d6ae80a33e9fb47dc2fb4dc..fd66b1b0e14000e437a8d91e0c51390a38b715aa 100644
--- a/third_party/WebKit/Source/wtf/allocator/AddressSpaceRandomization.cpp
+++ b/base/allocator/partition_allocator/address_space_randomization.cc
@@ -2,26 +2,27 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
-#include "wtf/allocator/AddressSpaceRandomization.h"
+#include "base/allocator/partition_allocator/address_space_randomization.h"
-#include "wtf/SpinLock.h"
-#include "wtf/allocator/PageAllocator.h"
+#include "base/allocator/partition_allocator/page_allocator.h"
+#include "base/synchronization/spin_lock.h"
+#include "build/build_config.h"
-#if OS(WIN)
+#if defined(OS_WIN)
#include <windows.h>
#else
#include <sys/time.h>
#include <unistd.h>
#endif
-namespace WTF {
+namespace base {
namespace {
// This is the same PRNG as used by tcmalloc for mapping address randomness;
// see http://burtleburtle.net/bob/rand/smallprng.html
struct ranctx {
- SpinLock lock;
+ subtle::SpinLock lock;
bool initialized;
uint32_t a;
uint32_t b;
@@ -43,14 +44,14 @@ uint32_t ranvalInternal(ranctx* x) {
#undef rot
uint32_t ranval(ranctx* x) {
- SpinLock::Guard guard(x->lock);
+ subtle::SpinLock::Guard guard(x->lock);
if (UNLIKELY(!x->initialized)) {
x->initialized = true;
char c;
uint32_t seed = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(&c));
uint32_t pid;
uint32_t usec;
-#if OS(WIN)
+#if defined(OS_WIN)
pid = GetCurrentProcessId();
SYSTEMTIME st;
GetSystemTime(&st);
@@ -77,21 +78,20 @@ static struct ranctx s_ranctx;
} // namespace
-// Calculates a random preferred mapping address. In calculating an
-// address, we balance good ASLR against not fragmenting the address
-// space too badly.
+// Calculates a random preferred mapping address. In calculating an address, we
+// balance good ASLR against not fragmenting the address space too badly.
void* getRandomPageBase() {
uintptr_t random;
random = static_cast<uintptr_t>(ranval(&s_ranctx));
-#if CPU(X86_64)
+#if defined(ARCH_CPU_X86_64)
random <<= 32UL;
random |= static_cast<uintptr_t>(ranval(&s_ranctx));
-// This address mask gives a low liklihood of address space collisions.
-// We handle the situation gracefully if there is a collision.
-#if OS(WIN)
- // 64-bit Windows has a bizarrely small 8TB user address space.
- // Allocates in the 1-5TB region.
- // TODO(cevans): I think Win 8.1 has 47-bits like Linux.
+// This address mask gives a low likelihood of address space collisions. We
+// handle the situation gracefully if there is a collision.
+#if defined(OS_WIN)
+ // 64-bit Windows has a bizarrely small 8TB user address space. Allocates in
+ // the 1-5TB region. TODO(palmer): See if Windows >= 8.1 has the full 47 bits,
+ // and use it if so. crbug.com/672219
random &= 0x3ffffffffffUL;
random += 0x10000000000UL;
#elif defined(MEMORY_TOOL_REPLACES_ALLOCATOR)
@@ -102,12 +102,12 @@ void* getRandomPageBase() {
// Linux and OS X support the full 47-bit user space of x64 processors.
random &= 0x3fffffffffffUL;
#endif
-#elif CPU(ARM64)
+#elif defined(ARCH_CPU_ARM64)
// ARM64 on Linux has 39-bit user space.
random &= 0x3fffffffffUL;
random += 0x1000000000UL;
-#else // !CPU(X86_64) && !CPU(ARM64)
-#if OS(WIN)
+#else // !defined(ARCH_CPU_X86_64) && !defined(ARCH_CPU_ARM64)
+#if defined(OS_WIN)
// On win32 host systems the randomization plus huge alignment causes
// excessive fragmentation. Plus most of these systems lack ASLR, so the
// randomization isn't buying anything. In that case we just skip it.
@@ -117,14 +117,14 @@ void* getRandomPageBase() {
isWow64 = FALSE;
if (!isWow64)
return nullptr;
-#endif // OS(WIN)
+#endif // defined(OS_WIN)
// This is a good range on Windows, Linux and Mac.
// Allocates in the 0.5-1.5GB region.
random &= 0x3fffffff;
random += 0x20000000;
-#endif // CPU(X86_64)
+#endif // defined(ARCH_CPU_X86_64)
random &= kPageAllocationGranularityBaseMask;
return reinterpret_cast<void*>(random);
}
-} // namespace WTF
+} // namespace base

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