webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 265 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/jit/ExecutableAllocator.cpp b/Source/JavaScriptCore/jit/ExecutableAllocator.cpp
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index 000000000..d2911a319
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+++ b/Source/JavaScriptCore/jit/ExecutableAllocator.cpp
@@ -0,0 +1,265 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "ExecutableAllocator.h"
+
+#include "JSCInlines.h"
+
+#if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
+#include "CodeProfiling.h"
+#include <wtf/HashSet.h>
+#include <wtf/Lock.h>
+#include <wtf/MetaAllocator.h>
+#include <wtf/NeverDestroyed.h>
+#include <wtf/PageReservation.h>
+#include <wtf/VMTags.h>
+#endif
+
+// Uncomment to create an artificial executable memory usage limit. This limit
+// is imperfect and is primarily useful for testing the VM's ability to handle
+// out-of-executable-memory situations.
+// #define EXECUTABLE_MEMORY_LIMIT 1000000
+
+#if ENABLE(ASSEMBLER)
+
+using namespace WTF;
+
+namespace JSC {
+
+#if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
+
+class DemandExecutableAllocator : public MetaAllocator {
+public:
+    DemandExecutableAllocator()
+        : MetaAllocator(jitAllocationGranule)
+    {
+        std::lock_guard<StaticLock> lock(allocatorsMutex());
+        allocators().add(this);
+        // Don't preallocate any memory here.
+    }
+    
+    virtual ~DemandExecutableAllocator()
+    {
+        {
+            std::lock_guard<StaticLock> lock(allocatorsMutex());
+            allocators().remove(this);
+        }
+        for (unsigned i = 0; i < reservations.size(); ++i)
+            reservations.at(i).deallocate();
+    }
+
+    static size_t bytesAllocatedByAllAllocators()
+    {
+        size_t total = 0;
+        std::lock_guard<StaticLock> lock(allocatorsMutex());
+        for (HashSet<DemandExecutableAllocator*>::const_iterator allocator = allocators().begin(); allocator != allocators().end(); ++allocator)
+            total += (*allocator)->bytesAllocated();
+        return total;
+    }
+
+    static size_t bytesCommittedByAllocactors()
+    {
+        size_t total = 0;
+        std::lock_guard<StaticLock> lock(allocatorsMutex());
+        for (HashSet<DemandExecutableAllocator*>::const_iterator allocator = allocators().begin(); allocator != allocators().end(); ++allocator)
+            total += (*allocator)->bytesCommitted();
+        return total;
+    }
+
+#if ENABLE(META_ALLOCATOR_PROFILE)
+    static void dumpProfileFromAllAllocators()
+    {
+        std::lock_guard<StaticLock> lock(allocatorsMutex());
+        for (HashSet<DemandExecutableAllocator*>::const_iterator allocator = allocators().begin(); allocator != allocators().end(); ++allocator)
+            (*allocator)->dumpProfile();
+    }
+#endif
+
+protected:
+    virtual void* allocateNewSpace(size_t& numPages)
+    {
+        size_t newNumPages = (((numPages * pageSize() + JIT_ALLOCATOR_LARGE_ALLOC_SIZE - 1) / JIT_ALLOCATOR_LARGE_ALLOC_SIZE * JIT_ALLOCATOR_LARGE_ALLOC_SIZE) + pageSize() - 1) / pageSize();
+        
+        ASSERT(newNumPages >= numPages);
+        
+        numPages = newNumPages;
+        
+#ifdef EXECUTABLE_MEMORY_LIMIT
+        if (bytesAllocatedByAllAllocators() >= EXECUTABLE_MEMORY_LIMIT)
+            return 0;
+#endif
+        
+        PageReservation reservation = PageReservation::reserve(numPages * pageSize(), OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
+        RELEASE_ASSERT(reservation);
+        
+        reservations.append(reservation);
+        
+        return reservation.base();
+    }
+    
+    virtual void notifyNeedPage(void* page)
+    {
+        OSAllocator::commit(page, pageSize(), EXECUTABLE_POOL_WRITABLE, true);
+    }
+    
+    virtual void notifyPageIsFree(void* page)
+    {
+        OSAllocator::decommit(page, pageSize());
+    }
+
+private:
+    Vector<PageReservation, 16> reservations;
+    static HashSet<DemandExecutableAllocator*>& allocators()
+    {
+        DEPRECATED_DEFINE_STATIC_LOCAL(HashSet<DemandExecutableAllocator*>, sAllocators, ());
+        return sAllocators;
+    }
+
+    static StaticLock& allocatorsMutex()
+    {
+        static StaticLock mutex;
+
+        return mutex;
+    }
+};
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+void ExecutableAllocator::initializeAllocator()
+{
+}
+#else
+static DemandExecutableAllocator* gAllocator;
+
+namespace {
+static inline DemandExecutableAllocator* allocator()
+{
+    return gAllocator;
+}
+}
+
+void ExecutableAllocator::initializeAllocator()
+{
+    ASSERT(!gAllocator);
+    gAllocator = new DemandExecutableAllocator();
+    CodeProfiling::notifyAllocator(gAllocator);
+}
+#endif
+
+ExecutableAllocator::ExecutableAllocator(VM&)
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+    : m_allocator(std::make_unique<DemandExecutableAllocator>())
+#endif
+{
+    ASSERT(allocator());
+}
+
+ExecutableAllocator::~ExecutableAllocator()
+{
+}
+
+bool ExecutableAllocator::isValid() const
+{
+    return true;
+}
+
+bool ExecutableAllocator::underMemoryPressure()
+{
+#ifdef EXECUTABLE_MEMORY_LIMIT
+    return DemandExecutableAllocator::bytesAllocatedByAllAllocators() > EXECUTABLE_MEMORY_LIMIT / 2;
+#else
+    return false;
+#endif
+}
+
+double ExecutableAllocator::memoryPressureMultiplier(size_t addedMemoryUsage)
+{
+    double result;
+#ifdef EXECUTABLE_MEMORY_LIMIT
+    size_t bytesAllocated = DemandExecutableAllocator::bytesAllocatedByAllAllocators() + addedMemoryUsage;
+    if (bytesAllocated >= EXECUTABLE_MEMORY_LIMIT)
+        bytesAllocated = EXECUTABLE_MEMORY_LIMIT;
+    result = static_cast<double>(EXECUTABLE_MEMORY_LIMIT) /
+        (EXECUTABLE_MEMORY_LIMIT - bytesAllocated);
+#else
+    UNUSED_PARAM(addedMemoryUsage);
+    result = 1.0;
+#endif
+    if (result < 1.0)
+        result = 1.0;
+    return result;
+
+}
+
+RefPtr<ExecutableMemoryHandle> ExecutableAllocator::allocate(VM&, size_t sizeInBytes, void* ownerUID, JITCompilationEffort effort)
+{
+    RefPtr<ExecutableMemoryHandle> result = allocator()->allocate(sizeInBytes, ownerUID);
+    RELEASE_ASSERT(result || effort != JITCompilationMustSucceed);
+    return result;
+}
+
+size_t ExecutableAllocator::committedByteCount()
+{
+    return DemandExecutableAllocator::bytesCommittedByAllocactors();
+}
+
+#if ENABLE(META_ALLOCATOR_PROFILE)
+void ExecutableAllocator::dumpProfile()
+{
+    DemandExecutableAllocator::dumpProfileFromAllAllocators();
+}
+#endif
+
+#endif // ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+
+#if OS(WINDOWS)
+#error "ASSEMBLER_WX_EXCLUSIVE not yet suported on this platform."
+#endif
+
+void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting)
+{
+    size_t pageSize = WTF::pageSize();
+
+    // Calculate the start of the page containing this region,
+    // and account for this extra memory within size.
+    intptr_t startPtr = reinterpret_cast<intptr_t>(start);
+    intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
+    void* pageStart = reinterpret_cast<void*>(pageStartPtr);
+    size += (startPtr - pageStartPtr);
+
+    // Round size up
+    size += (pageSize - 1);
+    size &= ~(pageSize - 1);
+
+    mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
+}
+
+#endif
+
+}
+
+#endif // HAVE(ASSEMBLER)