commit 69ffc317eb3960f18e9d70cb8c3ade94ed4ac399
author Nicolas Capens <capn@google.com> Fri Aug 30 09:54:19 2019 -0400
committer Nicolas Capens <nicolascapens@google.com> Fri Aug 30 15:16:17 2019 +0000
tree 21aa01a4ff19f2a37ad1716887e034da408fc546
parent 680d3761065603431d6e4680900db67e7d28717d

Initialize the blend state using memset

The BlendState structure is part of the cache key used to look up pixel
routines, which must not contain any uninitialized bits. The
PixelProcessor::States structure gets zero-initialized as a whole by
the Memset<> base class, but when writing BlendState structures into it
any uninitialized bits may get copied over.

Thus BlendState must also be zero-initialized, using Memset<>.

Bug: b/140286664
Bug: b/140193782
Change-Id: I031ec1a5f3be4329ae16366bfd4c8f17e2371384
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/35768
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

src/Device/Context.cpp

diff --git a/src/Device/Context.cpp b/src/Device/Context.cpp
index af55417..f517e6b 100644
--- a/src/Device/Context.cpp
+++ b/src/Device/Context.cpp
@@ -24,19 +24,6 @@
 
 namespace sw
 {
-	void BlendState::init()
-	{
-		alphaBlendEnable = false;
-
-		sourceBlendFactor = VK_BLEND_FACTOR_ONE;
-		destBlendFactor = VK_BLEND_FACTOR_ZERO;
-		blendOperation = VK_BLEND_OP_ADD;
-
-		sourceBlendFactorAlpha = VK_BLEND_FACTOR_ONE;
-		destBlendFactorAlpha = VK_BLEND_FACTOR_ZERO;
-		blendOperationAlpha = VK_BLEND_OP_ADD;
-	}
-
 	Context::Context()
 	{
 		init();
@@ -101,9 +88,8 @@
 		for(int i = 0; i < RENDERTARGETS; ++i)
 		{
 			renderTarget[i] = nullptr;
-
-			blendState[i].init();
 		}
+
 		depthBuffer = nullptr;
 		stencilBuffer = nullptr;
 

src/Device/Context.hpp

diff --git a/src/Device/Context.hpp b/src/Device/Context.hpp
index 502eacf..c86d956 100644
--- a/src/Device/Context.hpp
+++ b/src/Device/Context.hpp
@@ -18,6 +18,7 @@
 #include "Vulkan/VkConfig.h"
 #include "Vulkan/VkDescriptorSet.hpp"
 #include "Config.hpp"
+#include "Memset.hpp"
 #include "Stream.hpp"
 #include "System/Types.hpp"
 
@@ -36,9 +37,26 @@
 		unsigned char data[vk::MAX_PUSH_CONSTANT_SIZE];
 	};
 
-	struct BlendState
+	struct BlendState : Memset<BlendState>
 	{
-		void init();
+		BlendState() : Memset(this, 0) {}
+
+		BlendState(bool alphaBlendEnable,
+		           VkBlendFactor sourceBlendFactor,
+		           VkBlendFactor destBlendFactor,
+		           VkBlendOp blendOperation,
+		           VkBlendFactor sourceBlendFactorAlpha,
+		           VkBlendFactor destBlendFactorAlpha,
+		           VkBlendOp blendOperationAlpha) :
+			Memset(this, 0),
+			alphaBlendEnable(alphaBlendEnable),
+			sourceBlendFactor(sourceBlendFactor),
+			destBlendFactor(destBlendFactor),
+			blendOperation(blendOperation),
+			sourceBlendFactorAlpha(sourceBlendFactorAlpha),
+			destBlendFactorAlpha(destBlendFactorAlpha),
+			blendOperationAlpha(blendOperationAlpha)
+		{}
 
 		bool alphaBlendEnable;
 		VkBlendFactor sourceBlendFactor;