Re: [Qemu-devel] [PATCH] Correct use of ! and &

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Sat, Aug 21, 2010 at 09:42:51AM +0000, Blue Swirl wrote:
> Combining bitwise AND and logical NOT is suspicious.
> 
> Fixed by this Coccinelle script:
> // From http://article.gmane.org/gmane.linux.kernel/646367
> @@ expression E1,E2; @@
> (
>   !E1 & !E2
> |
> - !E1 & E2
> + !(E1 & E2)
> )
> 
> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
> ---
> 
> Maybe the middle hunk should be fixed this way instead:
> -            } else if ((rw == 1) & !matching->d) {
> +            } else if ((rw == 1) && !matching->d) {
> 
> ---
>  hw/etraxfs_eth.c    |    2 +-
>  target-sh4/helper.c |    4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/etraxfs_eth.c b/hw/etraxfs_eth.c
> index b897c9c..ade96f1 100644
> --- a/hw/etraxfs_eth.c
> +++ b/hw/etraxfs_eth.c
> @@ -464,7 +464,7 @@ static int eth_match_groupaddr(struct fs_eth *eth,
> const unsigned char *sa)
> 
>  	/* First bit on the wire of a MAC address signals multicast or
>  	   physical address.  */
> -	if (!m_individual && !sa[0] & 1)
> +	if (!m_individual && !(sa[0] & 1))
>  		return 0;


Yep, the etrax part is a bug and your patch looks OK to me.

Thanks

Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>