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Backed out changeset 209d492c3ec5 (bug 1332594) for jit-test failures on a CLOSED TREE.

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This commit is contained in:
Ryan VanderMeulen 2017-01-20 18:29:30 -05:00
parent c1a7aaaddb
commit 8ea9bfe6fc
2 changed files with 56 additions and 25 deletions
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51
js/src/ds/PageProtectingVector.h
View File

@ -8,7 +8,6 @@
#define ds_PageProtectingVector_h
#include "mozilla/Atomics.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Vector.h"
#include "ds/MemoryProtectionExceptionHandler.h"
@ -540,7 +539,10 @@ PageProtectingVector<T, N, A, P, Q, G, D, I, X>::lockSlow() const
class ProtectedReallocPolicy
{
static const uint8_t PoisonPattern = 0xe5;
/* We hardcode the page size here to minimize administrative overhead. */
static const size_t pageShift = 12;
static const size_t pageSize = 1 << pageShift;
static const size_t pageMask = pageSize - 1;
public:
template <typename T> T* maybe_pod_malloc(size_t numElems) {
@ -551,34 +553,35 @@ class ProtectedReallocPolicy
}
template <typename T> T* maybe_pod_realloc(T* oldAddr, size_t oldSize, size_t newSize) {
MOZ_ASSERT_IF(oldAddr, oldSize);
MOZ_ASSERT(gc::SystemPageSize() == pageSize);
if (MOZ_UNLIKELY(!newSize))
return nullptr;
if (MOZ_UNLIKELY(!oldAddr))
return js_pod_malloc<T>(newSize);
T* tmpAddr = js_pod_malloc<T>(newSize);
if (MOZ_UNLIKELY(!tmpAddr))
return js_pod_realloc<T>(oldAddr, oldSize, newSize);
size_t bytes = (newSize >= oldSize ? oldSize : newSize) * sizeof(T);
memcpy(tmpAddr, oldAddr, bytes);
T* newAddr = js_pod_realloc<T>(oldAddr, oldSize, newSize);
if (MOZ_UNLIKELY(!newAddr)) {
js_free(tmpAddr);
return js_pod_realloc<T>(oldAddr, oldSize, newSize);
T* newAddr = nullptr;
size_t initPage = (uintptr_t(oldAddr - 1) >> pageShift) + 1;
size_t lastPage = (uintptr_t(oldAddr + oldSize) >> pageShift) - 1;
size_t toCopy = (newSize >= oldSize ? oldSize : newSize) * sizeof(T);
if (MOZ_UNLIKELY(oldSize >= 32 * 1024 && lastPage >= initPage)) {
T* protectAddr = reinterpret_cast<T*>(initPage << pageShift);
size_t protectSize = (lastPage - initPage + 1) << pageShift;
MemoryProtectionExceptionHandler::addRegion(protectAddr, protectSize);
gc::MakePagesReadOnly(protectAddr, protectSize);
newAddr = js_pod_malloc<T>(newSize);
if (MOZ_LIKELY(newAddr))
memcpy(newAddr, oldAddr, toCopy);
gc::UnprotectPages(protectAddr, protectSize);
MemoryProtectionExceptionHandler::removeRegion(protectAddr);
if (MOZ_LIKELY(newAddr))
js_free(oldAddr);
} else {
newAddr = js_pod_malloc<T>(newSize);
if (MOZ_LIKELY(newAddr)) {
memcpy(newAddr, oldAddr, toCopy);
js_free(oldAddr);
}
}
const uint8_t* newAddrBytes = reinterpret_cast<const uint8_t*>(newAddr);
const uint8_t* tmpAddrBytes = reinterpret_cast<const uint8_t*>(tmpAddr);
if (!mozilla::PodEqual(tmpAddrBytes, newAddrBytes, bytes)) {
if (oldAddr == newAddr)
MOZ_CRASH("New buffer doesn't match the old buffer (newAddr == oldAddr)!");
else
MOZ_CRASH("New buffer doesn't match the old buffer (newAddr != oldAddr)!");
}
js_free(tmpAddr);
return newAddr;
}

30
js/src/jit/x86-shared/AssemblerBuffer-x86-shared.h
View File

@ -126,6 +126,30 @@ namespace jit {
return m_oom;
}
#ifndef RELEASE_OR_BETA
const unsigned char* acquireBuffer() const
{
MOZ_RELEASE_ASSERT(!m_oom);
return m_buffer.acquire();
}
void releaseBuffer() const { m_buffer.release(); }
unsigned char* acquireData() { return m_buffer.acquire(); }
void releaseData() const { m_buffer.release(); }
void disableProtection() { m_buffer.disableProtection(); }
void enableProtection() { m_buffer.enableProtection(); }
void setLowerBoundForProtection(size_t size)
{
m_buffer.setLowerBoundForProtection(size);
}
void unprotectRegion(unsigned char* first, size_t size)
{
m_buffer.unprotectRegion(first, size);
}
void reprotectRegion(unsigned char* first, size_t size)
{
m_buffer.reprotectRegion(first, size);
}
#else
const unsigned char* acquireBuffer() const
{
MOZ_RELEASE_ASSERT(!m_oom);
@ -139,6 +163,7 @@ namespace jit {
void setLowerBoundForProtection(size_t) {}
void unprotectRegion(unsigned char*, size_t) {}
void reprotectRegion(unsigned char*, size_t) {}
#endif
protected:
/*
@ -161,7 +186,10 @@ namespace jit {
}
#ifndef RELEASE_OR_BETA
mozilla::Vector<unsigned char, 256, ProtectedReallocPolicy> m_buffer;
PageProtectingVector<unsigned char, 256, ProtectedReallocPolicy,
/* ProtectUsed = */ false, /* ProtectUnused = */ false,
/* GuardAgainstReentrancy = */ true, /* DetectPoison = */ true,
/* InitialLowerBound = */ 32 * 1024> m_buffer;
#else
mozilla::Vector<unsigned char, 256, SystemAllocPolicy> m_buffer;
#endif