Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 23 Jun 2021 16:09:52 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Neeraj Upadhyay <neeraju@codeaurora.org>
Cc:     jasowang@redhat.com, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] vringh: Use wiov->used to check for read/write desc order
Message-ID: <20210623160923-mutt-send-email-mst@kernel.org>
References: <1624361873-6097-1-git-send-email-neeraju@codeaurora.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1624361873-6097-1-git-send-email-neeraju@codeaurora.org>
Precedence: bulk

On Tue, Jun 22, 2021 at 05:07:53PM +0530, Neeraj Upadhyay wrote:
> As iov->used is incremented when descriptors are processed
> in __vringh_iov(), use it to check for incorrect read
> and write descriptor order.

Could the commit log be clearer? why is wiov->i incorrect here?

> Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
> ---
>  drivers/vhost/vringh.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
> index 4af8fa2..14e2043 100644
> --- a/drivers/vhost/vringh.c
> +++ b/drivers/vhost/vringh.c
> @@ -359,7 +359,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
>  			iov = wiov;
>  		else {
>  			iov = riov;
> -			if (unlikely(wiov && wiov->i)) {
> +			if (unlikely(wiov && wiov->used)) {
>  				vringh_bad("Readable desc %p after writable",
>  					   &descs[i]);
>  				err = -EINVAL;
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, 
> hosted by The Linux Foundation