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authorAndrey Vagin <avagin@openvz.org>2017-05-17 21:39:05 +0300
committerDavid S. Miller <davem@davemloft.net>2017-05-18 17:32:58 +0300
commitde321ed38471257ee45eac145bfd539254d13954 (patch)
tree9ad79c96c56f8380b39b4ef81514a6aa5dbb798b
parent667271455f883d23e6418ef3376eb1214da9d066 (diff)
downloadlinux-de321ed38471257ee45eac145bfd539254d13954.tar.xz
net: fix __skb_try_recv_from_queue to return the old behavior
This function has to return NULL on a error case, because there is a separate error variable. The offset has to be changed only if skb is returned v2: fix udp code to not use an extra variable Cc: Paolo Abeni <pabeni@redhat.com> Cc: Eric Dumazet <edumazet@google.com> Cc: David S. Miller <davem@davemloft.net> Fixes: 65101aeca522 ("net/sock: factor out dequeue/peek with offset cod") Signed-off-by: Andrei Vagin <avagin@openvz.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/datagram.c14
-rw-r--r--net/ipv4/udp.c12
2 files changed, 11 insertions, 15 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c
index a4592b43b40d..bc46118486fe 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -170,20 +170,21 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
struct sk_buff **last)
{
struct sk_buff *skb;
+ int _off = *off;
*last = queue->prev;
skb_queue_walk(queue, skb) {
if (flags & MSG_PEEK) {
- if (*off >= skb->len && (skb->len || *off ||
+ if (_off >= skb->len && (skb->len || _off ||
skb->peeked)) {
- *off -= skb->len;
+ _off -= skb->len;
continue;
}
if (!skb->len) {
skb = skb_set_peeked(skb);
if (unlikely(IS_ERR(skb))) {
*err = PTR_ERR(skb);
- return skb;
+ return NULL;
}
}
*peeked = 1;
@@ -193,6 +194,7 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
if (destructor)
destructor(sk, skb);
}
+ *off = _off;
return skb;
}
return NULL;
@@ -253,8 +255,6 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned int flags,
*peeked = 0;
do {
- int _off = *off;
-
/* Again only user level code calls this function, so nothing
* interrupt level will suddenly eat the receive_queue.
*
@@ -263,8 +263,10 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned int flags,
*/
spin_lock_irqsave(&queue->lock, cpu_flags);
skb = __skb_try_recv_from_queue(sk, queue, flags, destructor,
- peeked, &_off, err, last);
+ peeked, off, &error, last);
spin_unlock_irqrestore(&queue->lock, cpu_flags);
+ if (error)
+ goto no_packet;
if (skb)
return skb;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 922a62d45714..e7b6cfcca627 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1465,16 +1465,13 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
error = -EAGAIN;
*peeked = 0;
do {
- int _off = *off;
-
spin_lock_bh(&queue->lock);
skb = __skb_try_recv_from_queue(sk, queue, flags,
udp_skb_destructor,
- peeked, &_off, err,
+ peeked, off, err,
&last);
if (skb) {
spin_unlock_bh(&queue->lock);
- *off = _off;
return skb;
}
@@ -1488,20 +1485,17 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
* the sk_receive_queue lock if fwd memory scheduling
* is needed.
*/
- _off = *off;
spin_lock(&sk_queue->lock);
skb_queue_splice_tail_init(sk_queue, queue);
skb = __skb_try_recv_from_queue(sk, queue, flags,
udp_skb_dtor_locked,
- peeked, &_off, err,
+ peeked, off, err,
&last);
spin_unlock(&sk_queue->lock);
spin_unlock_bh(&queue->lock);
- if (skb) {
- *off = _off;
+ if (skb)
return skb;
- }
busy_check:
if (!sk_can_busy_loop(sk))