From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
To: "Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: yuanxzhang@fudan.edu.cn, Xiyu Yang <xiyuyang19@fudan.edu.cn>,
Xin Tan <tanxin.ctf@gmail.com>
Subject: [PATCH] vhost_net: Convert from atomic_t to refcount_t on vhost_net_ubuf_ref->refcount
Date: Sat, 17 Jul 2021 18:20:30 +0800 [thread overview]
Message-ID: <1626517230-42920-1-git-send-email-xiyuyang19@fudan.edu.cn> (raw)
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
drivers/vhost/net.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 6414bd5741b8..e23150ca7d4c 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -5,6 +5,7 @@
* virtio-net server in host kernel.
*/
+#include <linux/refcount.h>
#include <linux/compat.h>
#include <linux/eventfd.h>
#include <linux/vhost.h>
@@ -92,7 +93,7 @@ struct vhost_net_ubuf_ref {
* 1: no outstanding ubufs
* >1: outstanding ubufs
*/
- atomic_t refcount;
+ refcount_t refcount;
wait_queue_head_t wait;
struct vhost_virtqueue *vq;
};
@@ -240,7 +241,7 @@ vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
if (!ubufs)
return ERR_PTR(-ENOMEM);
- atomic_set(&ubufs->refcount, 1);
+ refcount_set(&ubufs->refcount, 1);
init_waitqueue_head(&ubufs->wait);
ubufs->vq = vq;
return ubufs;
@@ -248,7 +249,8 @@ vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
{
- int r = atomic_sub_return(1, &ubufs->refcount);
+ refcount_dec(&ubufs->refcount);
+ int r = refcount_read(&ubufs->refcount);
if (unlikely(!r))
wake_up(&ubufs->wait);
return r;
@@ -257,7 +259,7 @@ static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
{
vhost_net_ubuf_put(ubufs);
- wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
+ wait_event(ubufs->wait, !refcount_read(&ubufs->refcount));
}
static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
@@ -909,7 +911,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
ctl.ptr = ubuf;
msg.msg_controllen = sizeof(ctl);
ubufs = nvq->ubufs;
- atomic_inc(&ubufs->refcount);
+ refcount_inc(&ubufs->refcount);
nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
} else {
msg.msg_control = NULL;
@@ -1384,7 +1386,7 @@ static void vhost_net_flush(struct vhost_net *n)
vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
n->tx_flush = false;
- atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
+ refcount_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
}
}
--
2.7.4
next reply other threads:[~2021-07-17 10:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-17 10:20 Xiyu Yang [this message]
2021-07-18 20:20 ` [PATCH] vhost_net: Convert from atomic_t to refcount_t on vhost_net_ubuf_ref->refcount kernel test robot
2021-07-18 22:38 ` kernel test robot
2021-09-05 16:17 ` Michael S. Tsirkin
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