From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752601AbaAOCpJ (ORCPT ); Tue, 14 Jan 2014 21:45:09 -0500 Received: from ozlabs.org ([203.10.76.45]:51149 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752086AbaAOCmR (ORCPT ); Tue, 14 Jan 2014 21:42:17 -0500 From: Rusty Russell To: linux-kernel@vger.kernel.org Cc: Heinz Graalfs , Rusty Russell Subject: [PATCH 5/6] virtio: fail adding buffer on broken queues. Date: Wed, 15 Jan 2014 13:06:10 +1030 Message-Id: <1389753371-26469-5-git-send-email-rusty@rustcorp.com.au> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1389753371-26469-1-git-send-email-rusty@rustcorp.com.au> References: <1389753371-26469-1-git-send-email-rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Heinz points out that adding buffers to a broken virtqueue (which should "never happen") still works. Failing allows drivers to detect and complain about broken devices. Now drivers are robust, we can add this extra check. Reported-by: Heinz Graalfs Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 28b5338fff71..b74033dca384 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -203,6 +203,11 @@ static inline int virtqueue_add(struct virtqueue *_vq, BUG_ON(data == NULL); + if (unlikely(vq->broken)) { + END_USE(vq); + return -EIO; + } + #ifdef DEBUG { ktime_t now = ktime_get(); @@ -309,7 +314,7 @@ add_head: * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). * - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). */ int virtqueue_add_sgs(struct virtqueue *_vq, struct scatterlist *sgs[], @@ -347,7 +352,7 @@ EXPORT_SYMBOL_GPL(virtqueue_add_sgs); * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). * - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). */ int virtqueue_add_outbuf(struct virtqueue *vq, struct scatterlist sg[], unsigned int num, @@ -369,7 +374,7 @@ EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). * - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). */ int virtqueue_add_inbuf(struct virtqueue *vq, struct scatterlist sg[], unsigned int num, -- 1.8.3.2