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<title>[200749] branches/safari-601.1.46-branch/Source/WebCore</title>
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<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/200749">200749</a></dd>
<dt>Author</dt> <dd>matthew_hanson@apple.com</dd>
<dt>Date</dt> <dd>2016-05-12 02:11:54 -0700 (Thu, 12 May 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>Merge <a href="http://trac.webkit.org/projects/webkit/changeset/194290">r194290</a>. rdar://problem/26228866</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#branchessafari601146branchSourceWebCoreChangeLog">branches/safari-601.1.46-branch/Source/WebCore/ChangeLog</a></li>
<li><a href="#branchessafari601146branchSourceWebCorehtmlHTMLCanvasElementcpp">branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.cpp</a></li>
<li><a href="#branchessafari601146branchSourceWebCorehtmlHTMLCanvasElementh">branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.h</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="branchessafari601146branchSourceWebCoreChangeLog"></a>
<div class="modfile"><h4>Modified: branches/safari-601.1.46-branch/Source/WebCore/ChangeLog (200748 => 200749)</h4>
<pre class="diff"><span>
<span class="info">--- branches/safari-601.1.46-branch/Source/WebCore/ChangeLog 2016-05-12 09:11:50 UTC (rev 200748)
+++ branches/safari-601.1.46-branch/Source/WebCore/ChangeLog 2016-05-12 09:11:54 UTC (rev 200749)
</span><span class="lines">@@ -1,5 +1,34 @@
</span><span class="cx"> 2016-05-12 Matthew Hanson <matthew_hanson@apple.com>
</span><span class="cx">
</span><ins>+ Merge r194290. rdar://problem/26228866
+
+ 2015-12-18 Brent Fulgham <bfulgham@apple.com>
+
+ Place an upper bound on canvas pixel count
+ https://bugs.webkit.org/show_bug.cgi?id=151825
+ <rdar://problem/23324916>
+
+ Reviewed by Simon Fraser (Relanded by Brent Fulgham)
+
+ Malformed JavaScript can attempt to create lots of canvas contexts. Limit the amount of memory
+ we will use for this purpose to some percentage of system RAM.
+
+ * html/HTMLCanvasElement.cpp:
+ (WebCore::removeFromActivePixelMemory): Added helper function
+ (WebCore::HTMLCanvasElement::~HTMLCanvasElement): Call new 'releaseImageBufferAndContext' method
+ to ensure ImageBuffer and graphics context state are properly cleaned up.
+ (WebCore::maxActivePixels): Use one quarter of the system RAM, or 2 GB (whichever is more) as
+ an upper bound on active pixel memory.
+ (WebCore::HTMLCanvasElement::getContext): If we are attempting to create a context that will cause
+ us to exceed the allowed active pixel count, fail.
+ (WebCore::HTMLCanvasElement::releaseImageBufferAndContext): Added helper function
+ (WebCore::HTMLCanvasElement::setSurfaceSize): Use the new 'releaseImageBufferAndContext' method
+ to handle active pixel memory counts.
+ (WebCore::HTMLCanvasElement::createImageBuffer): Refuse to create a backing buffer if it will
+ exceed our available pixel memory.
+
+2016-05-12 Matthew Hanson <matthew_hanson@apple.com>
+
</ins><span class="cx"> Merge r190820. rdar://problem/26228881
</span><span class="cx">
</span><span class="cx"> 2015-10-09 Simon Fraser <simon.fraser@apple.com>
</span></span></pre></div>
<a id="branchessafari601146branchSourceWebCorehtmlHTMLCanvasElementcpp"></a>
<div class="modfile"><h4>Modified: branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.cpp (200748 => 200749)</h4>
<pre class="diff"><span>
<span class="info">--- branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.cpp 2016-05-12 09:11:50 UTC (rev 200748)
+++ branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.cpp 2016-05-12 09:11:54 UTC (rev 200749)
</span><span class="lines">@@ -47,6 +47,7 @@
</span><span class="cx"> #include "ScriptController.h"
</span><span class="cx"> #include "Settings.h"
</span><span class="cx"> #include <math.h>
</span><ins>+#include <wtf/RAMSize.h>
</ins><span class="cx">
</span><span class="cx"> #include <runtime/JSCInlines.h>
</span><span class="cx"> #include <runtime/JSLock.h>
</span><span class="lines">@@ -75,6 +76,8 @@
</span><span class="cx"> static const unsigned MaxCanvasArea = 16384 * 16384;
</span><span class="cx"> #endif
</span><span class="cx">
</span><ins>+static size_t activePixelMemory = 0;
+
</ins><span class="cx"> HTMLCanvasElement::HTMLCanvasElement(const QualifiedName& tagName, Document& document)
</span><span class="cx"> : HTMLElement(tagName, document)
</span><span class="cx"> , m_size(DefaultWidth, DefaultHeight)
</span><span class="lines">@@ -97,12 +100,25 @@
</span><span class="cx"> return adoptRef(*new HTMLCanvasElement(tagName, document));
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+static void removeFromActivePixelMemory(size_t pixelsReleased)
+{
+ if (!pixelsReleased)
+ return;
+
+ if (pixelsReleased < activePixelMemory)
+ activePixelMemory -= pixelsReleased;
+ else
+ activePixelMemory = 0;
+}
+
</ins><span class="cx"> HTMLCanvasElement::~HTMLCanvasElement()
</span><span class="cx"> {
</span><span class="cx"> for (auto it = m_observers.begin(), end = m_observers.end(); it != end; ++it)
</span><span class="cx"> (*it)->canvasDestroyed(*this);
</span><span class="cx">
</span><span class="cx"> m_context = nullptr; // Ensure this goes away before the ImageBuffer.
</span><ins>+
+ releaseImageBufferAndContext();
</ins><span class="cx"> }
</span><span class="cx">
</span><span class="cx"> void HTMLCanvasElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
</span><span class="lines">@@ -179,6 +195,16 @@
</span><span class="cx"> }
</span><span class="cx"> #endif
</span><span class="cx">
</span><ins>+static inline size_t maxActivePixelMemory()
+{
+ static size_t maxPixelMemory;
+ static std::once_flag onceFlag;
+ std::call_once(onceFlag, [] {
+ maxPixelMemory = std::max(ramSize() / 4, 2151 * MB);
+ });
+ return maxPixelMemory;
+}
+
</ins><span class="cx"> CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type, CanvasContextAttributes* attrs)
</span><span class="cx"> {
</span><span class="cx"> // A Canvas can either be "2D" or "webgl" but never both. If you request a 2D canvas and the existing
</span><span class="lines">@@ -198,6 +224,18 @@
</span><span class="cx"> if (Settings* settings = document().settings())
</span><span class="cx"> usesDashbardCompatibilityMode = settings->usesDashboardBackwardCompatibilityMode();
</span><span class="cx"> #endif
</span><ins>+
+ // Make sure we don't use more pixel memory than the system can support.
+ size_t requestedPixelMemory = 4 * width() * height();
+ if (activePixelMemory + requestedPixelMemory > maxActivePixelMemory()) {
+ StringBuilder stringBuilder;
+ stringBuilder.appendLiteral("Total canvas memory use exceeds the maximum limit (");
+ stringBuilder.appendNumber(maxActivePixelMemory() / 1024 / 1024);
+ stringBuilder.appendLiteral(" MB).");
+ document().addConsoleMessage(MessageSource::JS, MessageLevel::Warning, stringBuilder.toString());
+ return nullptr;
+ }
+
</ins><span class="cx"> m_context = std::make_unique<CanvasRenderingContext2D>(this, document().inQuirksMode(), usesDashbardCompatibilityMode);
</span><span class="cx"> #if USE(IOSURFACE_CANVAS_BACKING_STORE) || ENABLE(ACCELERATED_2D_CANVAS)
</span><span class="cx"> // Need to make sure a RenderLayer and compositing layer get created for the Canvas
</span><span class="lines">@@ -426,12 +464,17 @@
</span><span class="cx"> m_presentedImage = nullptr;
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+void HTMLCanvasElement::releaseImageBufferAndContext()
+{
+ m_contextStateSaver = nullptr;
+ setImageBuffer(nullptr);
+}
+
</ins><span class="cx"> void HTMLCanvasElement::setSurfaceSize(const IntSize& size)
</span><span class="cx"> {
</span><span class="cx"> m_size = size;
</span><span class="cx"> m_hasCreatedImageBuffer = false;
</span><del>- m_contextStateSaver = nullptr;
- m_imageBuffer.reset();
</del><ins>+ releaseImageBufferAndContext();
</ins><span class="cx"> clearCopiedImage();
</span><span class="cx"> }
</span><span class="cx">
</span><span class="lines">@@ -571,13 +614,24 @@
</span><span class="cx"> document().addConsoleMessage(MessageSource::JS, MessageLevel::Warning, stringBuilder.toString());
</span><span class="cx"> return;
</span><span class="cx"> }
</span><ins>+
+ // Make sure we don't use more pixel memory than the system can support.
+ size_t requestedPixelMemory = 4 * width() * height();
+ if (activePixelMemory + requestedPixelMemory > maxActivePixelMemory()) {
+ StringBuilder stringBuilder;
+ stringBuilder.appendLiteral("Total canvas memory use exceeds the maximum limit (");
+ stringBuilder.appendNumber(maxActivePixelMemory() / 1024 / 1024);
+ stringBuilder.appendLiteral(" MB).");
+ document().addConsoleMessage(MessageSource::JS, MessageLevel::Warning, stringBuilder.toString());
+ return;
+ }
</ins><span class="cx">
</span><span class="cx"> IntSize bufferSize(deviceSize.width(), deviceSize.height());
</span><span class="cx"> if (!bufferSize.width() || !bufferSize.height())
</span><span class="cx"> return;
</span><span class="cx">
</span><span class="cx"> RenderingMode renderingMode = shouldAccelerate(bufferSize) ? Accelerated : Unaccelerated;
</span><del>- m_imageBuffer = ImageBuffer::create(size(), 1, ColorSpaceDeviceRGB, renderingMode);
</del><ins>+ setImageBuffer(ImageBuffer::create(size(), 1, ColorSpaceDeviceRGB, renderingMode));
</ins><span class="cx"> if (!m_imageBuffer)
</span><span class="cx"> return;
</span><span class="cx"> m_imageBuffer->context()->setShadowsIgnoreTransforms(true);
</span><span class="lines">@@ -597,6 +651,15 @@
</span><span class="cx"> #endif
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+void HTMLCanvasElement::setImageBuffer(std::unique_ptr<ImageBuffer> buffer) const
+{
+ removeFromActivePixelMemory(memoryCost());
+
+ m_imageBuffer = WTF::move(buffer);
+
+ activePixelMemory += memoryCost();
+}
+
</ins><span class="cx"> GraphicsContext* HTMLCanvasElement::drawingContext() const
</span><span class="cx"> {
</span><span class="cx"> return buffer() ? m_imageBuffer->context() : nullptr;
</span></span></pre></div>
<a id="branchessafari601146branchSourceWebCorehtmlHTMLCanvasElementh"></a>
<div class="modfile"><h4>Modified: branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.h (200748 => 200749)</h4>
<pre class="diff"><span>
<span class="info">--- branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.h 2016-05-12 09:11:50 UTC (rev 200748)
+++ branches/safari-601.1.46-branch/Source/WebCore/html/HTMLCanvasElement.h 2016-05-12 09:11:54 UTC (rev 200749)
</span><span class="lines">@@ -152,6 +152,8 @@
</span><span class="cx"> void clearImageBuffer() const;
</span><span class="cx">
</span><span class="cx"> void setSurfaceSize(const IntSize&);
</span><ins>+ void setImageBuffer(std::unique_ptr<ImageBuffer>) const;
+ void releaseImageBufferAndContext();
</ins><span class="cx">
</span><span class="cx"> bool paintsIntoCanvasBuffer() const;
</span><span class="cx">
</span></span></pre>
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