linux-kernel - Re: [PATCH 5/5] staging: fsl-dpaa2/eth: Remove Rx frame size check

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 9 Jul 2018 22:28:09 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Ioana Radulescu <ruxandra.radulescu@....com>
Cc:     gregkh@...uxfoundation.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org, ioana.ciornei@....com
Subject: Re: [PATCH 5/5] staging: fsl-dpaa2/eth: Remove Rx frame size check

On Mon, Jul 09, 2018 at 10:01:11AM -0500, Ioana Radulescu wrote:
> @@ -2385,6 +2365,12 @@ static int netdev_init(struct net_device *net_dev)
>  
>  	/* Set MTU upper limit; lower limit is 68B (default value) */
>  	net_dev->max_mtu = DPAA2_ETH_MAX_MTU;
> +	err = dpni_set_max_frame_length(priv->mc_io, 0, priv->mc_token,
> +					(u16)DPAA2_ETH_MFL);

The cast was there in the original code so this is not a comment on this
particular patch (which seems fine) but there is no need to cast.

Generally it's best to avoid unnecessary casts.  As a human reader, I
find the cast confusing.  It indicates that DPAA2_ETH_MFL somehow
requires special handling.  Perhaps it's negative or we are trying to
truncate away the high bits.  But neither of those things really make
sense.

>From a static analysis perspective if DPAA2_ETH_MFL doesn't fit nicely
then we would want to generate a warning.  But the cast explicitly
disables the check.

regards,
dan carpenter