linux-kernel - [PATCH] drm/vmwgfx: Zero initialize handle in vmw_execbuf

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Message-Id: <20190307222611.18100-1-natechancellor@gmail.com>
Date:   Thu,  7 Mar 2019 15:26:11 -0700
From:   Nathan Chancellor <natechancellor@...il.com>
To:     VMware Graphics <linux-graphics-maintainer@...are.com>,
        Thomas Hellstrom <thellstrom@...are.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        clang-built-linux@...glegroups.com,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Nathan Chancellor <natechancellor@...il.com>
Subject: [PATCH] drm/vmwgfx: Zero initialize handle in vmw_execbuf_process

When building with -Wsometimes-uninitialized, Clang warns:

drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c:3964:7: warning: variable
'handle' is used uninitialized whenever '?:' condition is false
[-Wsometimes-uninitialized]

It's not wrong; however, in practice, this is never an issue because
the value of handle isn't used when user_fence_rep is NULL because
vmw_execbuf_copy_fence_user returns immediately when that is the case.
Just zero initialize this variable so that Clang no longer warns.

Link: https://github.com/ClangBuiltLinux/linux/issues/397
Signed-off-by: Nathan Chancellor <natechancellor@...il.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 88b8178d4687..4ba06c2828a1 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -3829,7 +3829,7 @@ int vmw_execbuf_process(struct drm_file *file_priv,
 	struct vmw_sw_context *sw_context = &dev_priv->ctx;
 	struct vmw_fence_obj *fence = NULL;
 	struct vmw_cmdbuf_header *header;
-	uint32_t handle;
+	uint32_t handle = 0;
 	int ret;
 	int32_t out_fence_fd = -1;
 	struct sync_file *sync_file = NULL;
-- 
2.21.0