2011-09-15 Chris Marrin <cmarrin@apple.com>

        Crash can occur when doing a PlatformCAAnimation::copy() with no valueFunction
        https://bugs.webkit.org/show_bug.cgi?id=67510

        Reviewed by Adam Roben.

        Another fix to take care of one last crash when running pause-crash.html.
        CACF can't deal with null valueFunctions, so avoid setting it when it doesn't
        exist.

        This also adds logic to the Windows Hook in LayerChangesFlusher to prevent it
        from catching the null pointer exception generated by the pause-crash.html test
        before this bug was fixed. Windows was ignoring the exception, so the testcase
        would appear to succeed, even though it should have crashed.

        * WebCore.vcproj/WebCore.vcproj:
        * platform/graphics/ca/win/LayerChangesFlusher.cpp:
        (WebCore::LayerChangesFlusher::hookCallback):
        * platform/graphics/ca/win/PlatformCAAnimationWin.cpp:
        (PlatformCAAnimation::copy):
        * platform\win\StructuredExceptionHandlerSupressor.h: New file to encapsulate the exception handling supression.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@95243 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 4cb1a5d..9d763da 100644 (file)
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,26 @@
+2011-09-15  Chris Marrin  <cmarrin@apple.com>
+
+        Crash can occur when doing a PlatformCAAnimation::copy() with no valueFunction
+        https://bugs.webkit.org/show_bug.cgi?id=67510
+
+        Reviewed by Adam Roben.
+        
+        Another fix to take care of one last crash when running pause-crash.html.
+        CACF can't deal with null valueFunctions, so avoid setting it when it doesn't 
+        exist.
+        
+        This also adds logic to the Windows Hook in LayerChangesFlusher to prevent it
+        from catching the null pointer exception generated by the pause-crash.html test
+        before this bug was fixed. Windows was ignoring the exception, so the testcase
+        would appear to succeed, even though it should have crashed.
+
+        * WebCore.vcproj/WebCore.vcproj:
+        * platform/graphics/ca/win/LayerChangesFlusher.cpp:
+        (WebCore::LayerChangesFlusher::hookCallback):
+        * platform/graphics/ca/win/PlatformCAAnimationWin.cpp:
+        (PlatformCAAnimation::copy):
+        * platform\win\StructuredExceptionHandlerSupressor.h: New file to encapsulate the exception handling supression.
+
 2011-09-15  David Hyatt  <hyatt@apple.com>
 
         https://bugs.webkit.org/show_bug.cgi?id=27579

diff --git a/Source/WebCore/WebCore.vcproj/WebCore.vcproj b/Source/WebCore/WebCore.vcproj/WebCore.vcproj
index dfa3b9f..c54772a 100755 (executable)
--- a/Source/WebCore/WebCore.vcproj/WebCore.vcproj
+++ b/Source/WebCore/WebCore.vcproj/WebCore.vcproj
@@ -27324,6 +27324,10 @@
                                        RelativePath="..\platform\win\SoundWin.cpp"
                                        >
                                </File>
+                <File
+                RelativePath="..\platform\win\StructuredExceptionHandlerSupressor.h"
+                >
+                </File>
                                <File
                                        RelativePath="..\platform\win\SystemInfo.cpp"
                                        >
@@ -30174,6 +30178,14 @@
                                                        RelativePath="..\platform\graphics\ca\win\LayerChangesFlusher.cpp"
                                                        >
                                                        <FileConfiguration
+                            Name="Debug|Win32"
+                            >
+                            <Tool
+                            Name="VCCLCompilerTool"
+                            DisableSpecificWarnings="4733"
+                            />
+                                                       </FileConfiguration>
+                                                       <FileConfiguration
                                                                Name="Debug_Cairo_CFLite|Win32"
                                                                ExcludedFromBuild="true"
                                                                >

diff --git a/Source/WebCore/platform/graphics/ca/win/LayerChangesFlusher.cpp b/Source/WebCore/platform/graphics/ca/win/LayerChangesFlusher.cpp
index ec2a9ff..f347c24 100644 (file)
--- a/Source/WebCore/platform/graphics/ca/win/LayerChangesFlusher.cpp
+++ b/Source/WebCore/platform/graphics/ca/win/LayerChangesFlusher.cpp
@@ -29,6 +29,7 @@
 #if USE(ACCELERATED_COMPOSITING)
 
 #include "AbstractCACFLayerTreeHost.h"
+#include "StructuredExceptionHandlerSupressor.h"
 #include <wtf/StdLibExtras.h>
 #include <wtf/Vector.h>
 
@@ -71,6 +72,10 @@ void LayerChangesFlusher::cancelPendingFlush(AbstractCACFLayerTreeHost* host)
 
 LRESULT LayerChangesFlusher::hookCallback(int code, WPARAM wParam, LPARAM lParam)
 {
+    // Supress the exception handler Windows puts around all hook calls so we can
+    // crash for debugging purposes if an exception is hit.
+    StructuredExceptionHandlerSupressor supressor;
+
     return shared().hookFired(code, wParam, lParam);
 }
 

diff --git a/Source/WebCore/platform/graphics/ca/win/PlatformCAAnimationWin.cpp b/Source/WebCore/platform/graphics/ca/win/PlatformCAAnimationWin.cpp
index 4cb49e0..683d703 100644 (file)
--- a/Source/WebCore/platform/graphics/ca/win/PlatformCAAnimationWin.cpp
+++ b/Source/WebCore/platform/graphics/ca/win/PlatformCAAnimationWin.cpp
@@ -183,7 +183,8 @@ PassRefPtr<PlatformCAAnimation> PlatformCAAnimation::copy() const
     animation->setRemovedOnCompletion(isRemovedOnCompletion());
     animation->setAdditive(isAdditive());
     animation->copyTimingFunctionFrom(this);
-    animation->setValueFunction(valueFunction());
+    if (valueFunction())
+        animation->setValueFunction(valueFunction());
     
     // Copy the specific Basic or Keyframe values
     if (animationType() == Keyframe) {

diff --git a/Source/WebCore/platform/win/StructuredExceptionHandlerSupressor.h b/Source/WebCore/platform/win/StructuredExceptionHandlerSupressor.h
new file mode 100644 (file)
index 0000000..8da97f1
--- /dev/null
+++ b/Source/WebCore/platform/win/StructuredExceptionHandlerSupressor.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2011 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. AND ITS CONTRIBUTORS ``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 ITS 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.
+ */
+
+#ifndef StructuredExceptionHandlerSupressor_h
+#define StructuredExceptionHandlerSupressor_h
+
+namespace WebCore {
+
+class StructuredExceptionHandlerSupressor {
+    WTF_MAKE_NONCOPYABLE(StructuredExceptionHandlerSupressor);
+public:
+    StructuredExceptionHandlerSupressor()
+    {
+        // Windows puts an __try/__except block around some calls, such as hooks.
+        // The exception handler then ignores system exceptions like invalid addresses
+        // and null pointers. This class can be used to remove this block and prevent
+        // it from catching the exception. Typically this will cause the exception to crash 
+        // which is often desirable to allow crashlogs to be recorded for debugging purposed.
+        // While this class is in scope we replace the Windows exception handler with 0xffffffff, 
+        // which indicates that the exception should not be handled.
+
+        // Windows doesn't like assigning to member variables, so we need to get the value into
+        // a local variable and store it afterwards.
+        void* registration;
+
+        __asm mov eax, FS:[0]
+        __asm mov [registration], eax
+        __asm mov eax, 0xffffffff
+        __asm mov FS:[0], eax
+
+        m_savedExceptionRegistration = registration;
+    }
+
+    ~StructuredExceptionHandlerSupressor()
+    {
+        // Restore the exception handler
+        __asm mov eax, [m_savedExceptionRegistration]
+        __asm mov FS:[0], eax
+    }
+
+private:
+    void* m_savedExceptionRegistration;
+};
+
+} // namespace WebCore
+
+#endif // StructuredExceptionHandlerSupressor_h