Re: video_usercopy() enforces change of VideoText IOCTLs since2.6.8

[Andrew Morton]

Gerd Knorr <kraxel@xxxxxxxxxxx> wrote:
>
> Yes, that change is wrong.  It breaks all ioctls which use arg to pass
> a integer value directly (i.e. not a pointer to a integer).
> 
> The patch below reverses it.  Please apply,
> 
>   Gerd
> 
> Index: linux-2.6.8/drivers/media/video/videodev.c
> ===================================================================
> --- linux-2.6.8.orig/drivers/media/video/videodev.c	2004-10-08 11:55:08.000000000 +0200
> +++ linux-2.6.8/drivers/media/video/videodev.c	2004-10-08 12:46:12.571630864 +0200
> @@ -183,7 +183,7 @@ video_usercopy(struct inode *inode, stru
>  	/*  Copy arguments into temp kernel buffer  */
>  	switch (_IOC_DIR(cmd)) {
>  	case _IOC_NONE:
> -		parg = NULL;
> +		parg = (void*)arg;
>  		break;

(the typecast is unneeded)

Seems that with this change we are now sometimes passing a user pointer
into (*func)().  And we're sometimes passing a kernel pointer, yes?

Are all the implementations of (*func)() handling that correctly?

It all looks fishy.
-
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