[PATCH] Device init: Don't crash when CreateGC fails.

[Jeremy Huddleston]

Thanks Jamey!

Reviewed-by: Jeremy Huddleston <jeremyhu at apple.com>

On May 14, 2010, at 11:37, Jamey Sharp wrote:

> ActivateDevice was ignoring errors from DeviceCursorInitialize, so
> cursor-related calls failed later. Jeremy Huddleston saw that crash in
> miPointerConstrainCursor, while with Xvfb I saw it in
> miSpriteRealizeCursor.
> 
> miDCDeviceCleanup frees any non-NULL GCs. miDCDeviceInitialize calls
> Cleanup on any failure, but if it failed early then some of the pointers
> in the miDCBufferPtr were garbage. Switch from malloc to calloc to
> ensure everything's initialized safely first.
> 
> With these two fixes, if CreateGC fails then the server gracefully fails
> in FatalError instead of segfaulting.
> 
> Signed-off-by: Jamey Sharp <jamey at minilop.net>
> Cc: Peter Hutterer <peter.hutterer at who-t.net>
> ---
> dix/devices.c  |    3 ++-
> mi/midispcur.c |    2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/dix/devices.c b/dix/devices.c
> index de72c88..5bffcac 100644
> --- a/dix/devices.c
> +++ b/dix/devices.c
> @@ -467,7 +467,8 @@ ActivateDevice(DeviceIntPtr dev, BOOL sendevent)
> 
>     /* Initialize memory for sprites. */
>     if (IsMaster(dev) && dev->spriteInfo->spriteOwner)
> -        pScreen->DeviceCursorInitialize(dev, pScreen);
> +        if (!pScreen->DeviceCursorInitialize(dev, pScreen))
> +	    return BadImplementation;
> 
>     SendDevicePresenceEvent(dev->id, DeviceAdded);
>     if (sendevent)
> diff --git a/mi/midispcur.c b/mi/midispcur.c
> index 1acc469..4de37d7 100644
> --- a/mi/midispcur.c
> +++ b/mi/midispcur.c
> @@ -780,7 +780,7 @@ miDCDeviceInitialize(DeviceIntPtr pDev, ScreenPtr pScreen)
>     {
>         pScreen = screenInfo.screens[i];
> 
> -        pBuffer = malloc(sizeof(miDCBufferRec));
> +        pBuffer = calloc(1, sizeof(miDCBufferRec));
>         if (!pBuffer)
>             goto failure;
> 
> -- 
> 1.7.0
> 
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