From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRZ45-004NEP-1M for linux-um@lists.infradead.org; Tue, 08 Mar 2022 12:35:47 +0000 From: Xuan Zhuo Subject: [PATCH v7 08/26] virtio_ring: extract the logic of freeing vring Date: Tue, 8 Mar 2022 20:35:00 +0800 Message-Id: <20220308123518.33800-9-xuanzhuo@linux.alibaba.com> In-Reply-To: <20220308123518.33800-1-xuanzhuo@linux.alibaba.com> References: <20220308123518.33800-1-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Cc: Jeff Dike , Richard Weinberger , Anton Ivanov , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Jakub Kicinski , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Alexander Gordeev , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Johannes Berg , Vincent Whitchurch , Xuan Zhuo , linux-um@lists.infradead.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, bpf@vger.kernel.org Introduce vring_free() to free the vring of vq. Prevent double free by setting vq->reset. Signed-off-by: Xuan Zhuo --- drivers/virtio/virtio_ring.c | 25 ++++++++++++++++++++----- include/linux/virtio.h | 8 ++++++++ 2 files changed, 28 insertions(+), 5 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index b5a9bf4f45b3..e0422c04c903 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2442,14 +2442,10 @@ struct virtqueue *vring_new_virtqueue(unsigned int index, } EXPORT_SYMBOL_GPL(vring_new_virtqueue); -void vring_del_virtqueue(struct virtqueue *_vq) +static void __vring_free(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); - spin_lock(&vq->vq.vdev->vqs_list_lock); - list_del(&_vq->list); - spin_unlock(&vq->vq.vdev->vqs_list_lock); - if (vq->we_own_ring) { if (vq->packed_ring) { vring_free_queue(vq->vq.vdev, @@ -2480,6 +2476,25 @@ void vring_del_virtqueue(struct virtqueue *_vq) kfree(vq->split.desc_state); kfree(vq->split.desc_extra); } +} + +static void vring_free(struct virtqueue *vq) +{ + __vring_free(vq); + vq->reset = VIRTIO_VQ_RESET_STEP_VRING_RELEASE; +} + +void vring_del_virtqueue(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + spin_lock(&vq->vq.vdev->vqs_list_lock); + list_del(&_vq->list); + spin_unlock(&vq->vq.vdev->vqs_list_lock); + + if (_vq->reset != VIRTIO_VQ_RESET_STEP_VRING_RELEASE) + __vring_free(_vq); + kfree(vq); } EXPORT_SYMBOL_GPL(vring_del_virtqueue); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index d59adc4be068..e3714e6db330 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -10,6 +10,13 @@ #include #include +enum virtio_vq_reset_step { + VIRTIO_VQ_RESET_STEP_NONE, + VIRTIO_VQ_RESET_STEP_DEVICE, + VIRTIO_VQ_RESET_STEP_VRING_RELEASE, + VIRTIO_VQ_RESET_STEP_VRING_ATTACH, +}; + /** * virtqueue - a queue to register buffers for sending or receiving. * @list: the chain of virtqueues for this device @@ -33,6 +40,7 @@ struct virtqueue { unsigned int num_free; unsigned int num_max; void *priv; + enum virtio_vq_reset_step reset; }; int virtqueue_add_outbuf(struct virtqueue *vq, -- 2.31.0 _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um