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path: root/drivers/net/tun.c
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Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c61
1 files changed, 36 insertions, 25 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ef33950a45d9..23e9eb66197f 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -681,15 +681,6 @@ static void tun_queue_purge(struct tun_file *tfile)
skb_queue_purge(&tfile->sk.sk_error_queue);
}
-static void tun_cleanup_tx_ring(struct tun_file *tfile)
-{
- if (tfile->tx_ring.queue) {
- ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
- xdp_rxq_info_unreg(&tfile->xdp_rxq);
- memset(&tfile->tx_ring, 0, sizeof(tfile->tx_ring));
- }
-}
-
static void __tun_detach(struct tun_file *tfile, bool clean)
{
struct tun_file *ntfile;
@@ -736,7 +727,9 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
tun->dev->reg_state == NETREG_REGISTERED)
unregister_netdevice(tun->dev);
}
- tun_cleanup_tx_ring(tfile);
+ if (tun)
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
sock_put(&tfile->sk);
}
}
@@ -783,14 +776,14 @@ static void tun_detach_all(struct net_device *dev)
tun_napi_del(tun, tfile);
/* Drop read queue */
tun_queue_purge(tfile);
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
sock_put(&tfile->sk);
- tun_cleanup_tx_ring(tfile);
}
list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
tun_enable_queue(tfile);
tun_queue_purge(tfile);
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
sock_put(&tfile->sk);
- tun_cleanup_tx_ring(tfile);
}
BUG_ON(tun->numdisabled != 0);
@@ -834,7 +827,8 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
}
if (!tfile->detached &&
- ptr_ring_init(&tfile->tx_ring, dev->tx_queue_len, GFP_KERNEL)) {
+ ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
+ GFP_KERNEL, tun_ptr_free)) {
err = -ENOMEM;
goto out;
}
@@ -1429,6 +1423,13 @@ static void tun_net_init(struct net_device *dev)
dev->max_mtu = MAX_MTU - dev->hard_header_len;
}
+static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
+{
+ struct sock *sk = tfile->socket.sk;
+
+ return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
+}
+
/* Character device part */
/* Poll */
@@ -1451,10 +1452,14 @@ static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
if (!ptr_ring_empty(&tfile->tx_ring))
mask |= EPOLLIN | EPOLLRDNORM;
- if (tun->dev->flags & IFF_UP &&
- (sock_writeable(sk) ||
- (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
- sock_writeable(sk))))
+ /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
+ * guarantee EPOLLOUT to be raised by either here or
+ * tun_sock_write_space(). Then process could get notification
+ * after it writes to a down device and meets -EIO.
+ */
+ if (tun_sock_writeable(tun, tfile) ||
+ (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
+ tun_sock_writeable(tun, tfile)))
mask |= EPOLLOUT | EPOLLWRNORM;
if (tun->dev->reg_state != NETREG_REGISTERED)
@@ -1645,7 +1650,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
else
*skb_xdp = 0;
- preempt_disable();
+ local_bh_disable();
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog && !*skb_xdp) {
@@ -1670,7 +1675,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
if (err)
goto err_redirect;
rcu_read_unlock();
- preempt_enable();
+ local_bh_enable();
return NULL;
case XDP_TX:
get_page(alloc_frag->page);
@@ -1679,7 +1684,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
goto err_redirect;
tun_xdp_flush(tun->dev);
rcu_read_unlock();
- preempt_enable();
+ local_bh_enable();
return NULL;
case XDP_PASS:
delta = orig_data - xdp.data;
@@ -1698,7 +1703,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
skb = build_skb(buf, buflen);
if (!skb) {
rcu_read_unlock();
- preempt_enable();
+ local_bh_enable();
return ERR_PTR(-ENOMEM);
}
@@ -1708,7 +1713,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
alloc_frag->offset += buflen;
rcu_read_unlock();
- preempt_enable();
+ local_bh_enable();
return skb;
@@ -1716,7 +1721,7 @@ err_redirect:
put_page(alloc_frag->page);
err_xdp:
rcu_read_unlock();
- preempt_enable();
+ local_bh_enable();
this_cpu_inc(tun->pcpu_stats->rx_dropped);
return NULL;
}
@@ -1912,16 +1917,19 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
struct bpf_prog *xdp_prog;
int ret;
+ local_bh_disable();
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog) {
ret = do_xdp_generic(xdp_prog, skb);
if (ret != XDP_PASS) {
rcu_read_unlock();
+ local_bh_enable();
return total_len;
}
}
rcu_read_unlock();
+ local_bh_enable();
}
rcu_read_lock();
@@ -3219,6 +3227,11 @@ static int tun_chr_open(struct inode *inode, struct file * file)
&tun_proto, 0);
if (!tfile)
return -ENOMEM;
+ if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
+ sk_free(&tfile->sk);
+ return -ENOMEM;
+ }
+
RCU_INIT_POINTER(tfile->tun, NULL);
tfile->flags = 0;
tfile->ifindex = 0;
@@ -3239,8 +3252,6 @@ static int tun_chr_open(struct inode *inode, struct file * file)
sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
- memset(&tfile->tx_ring, 0, sizeof(tfile->tx_ring));
-
return 0;
}