Re: [PATCH 4.14.y] s390/uaccess: add missing earlyclobber annotations to __clear_user()

[Greg KH <greg@kroah.com>]

On Mon, Apr 03, 2023 at 11:43:36AM +0200, Heiko Carstens wrote:
> commit 89aba4c26fae4e459f755a18912845c348ee48f3 upstream.
> 
> Add missing earlyclobber annotation to size, to, and tmp2 operands of the
> __clear_user() inline assembly since they are modified or written to before
> the last usage of all input operands. This can lead to incorrect register
> allocation for the inline assembly.
> 
> Fixes: 6c2a9e6df604 ("[S390] Use alternative user-copy operations for new hardware.")
> Reported-by: Mark Rutland <mark.rutland@arm.com>
> Link: https://lore.kernel.org/all/20230321122514.1743889-3-mark.rutland@arm.com/
> Cc: stable@vger.kernel.org
> Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
> ---
>  arch/s390/lib/uaccess.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
> index 802903c50de1..b11ebcb3d33b 100644
> --- a/arch/s390/lib/uaccess.c
> +++ b/arch/s390/lib/uaccess.c
> @@ -272,7 +272,7 @@ static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size
>  		"4: slgr  %0,%0\n"
>  		"5:\n"
>  		EX_TABLE(0b,2b) EX_TABLE(3b,5b)
> -		: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
> +		: "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
>  		: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
>  	return size;
>  }
> -- 
> 2.37.2
> 

All now queued up, thanks!

greg k-h