linux-kernel - [PATCH] virtio: document ENOSPC

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-next>] [day] [month] [year] [list]

Message-ID: <2e6ec46b8d5e6755be291cec8e2ec57ef286e97b.1748356035.git.mst@redhat.com>
Date: Tue, 27 May 2025 10:27:19 -0400
From: "Michael S. Tsirkin" <mst@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: Parav Pandit <parav@...dia.com>, Jason Wang <jasowang@...hat.com>,
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
	Eugenio Pérez <eperezma@...hat.com>,
	virtualization@...ts.linux.dev
Subject: [PATCH] virtio: document ENOSPC

drivers handle ENOSPC specially since it's an error one can
get from a working VQ. Document the semantics.

Reported-by: Parav Pandit <parav@...dia.com>
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
---
 drivers/virtio/virtio_ring.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b784aab66867..97ab0cce527d 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2296,6 +2296,10 @@ static inline int virtqueue_add(struct virtqueue *_vq,
  * at the same time (except where noted).
  *
  * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
+ *
+ * NB: ENOSPC is a special code that is only returned on an attempt to add a
+ * buffer to a full VQ. It indicates that some buffers are outstanding and that
+ * the operation can be retried after some buffers have been used.
  */
 int virtqueue_add_sgs(struct virtqueue *_vq,
 		      struct scatterlist *sgs[],
-- 
MST