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authorHerbert Xu <herbert@gondor.apana.org.au>2008-09-15 11:48:46 -0700
committerDavid S. Miller <davem@davemloft.net>2008-09-15 11:48:46 -0700
commit93821778def10ec1e69aa3ac10adee975dad4ff3 (patch)
tree5cd95c0592407ac49b4f6bd9aa8ba71d93500aae /net
parentcff502a38394fd33693f6233e03fca363dfa956d (diff)
downloadlinux-93821778def10ec1e69aa3ac10adee975dad4ff3.tar.bz2
udp: Fix rcv socket locking
The previous patch in response to the recursive locking on IPsec reception is broken as it tries to drop the BH socket lock while in user context. This patch fixes it by shrinking the section protected by the socket lock to sock_queue_rcv_skb only. The only reason we added the lock is for the accounting which happens in that function. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/udp.c62
1 files changed, 33 insertions, 29 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8e42fbbd5761..57e26fa66185 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -951,6 +951,27 @@ int udp_disconnect(struct sock *sk, int flags)
return 0;
}
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ int is_udplite = IS_UDPLITE(sk);
+ int rc;
+
+ if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
+ /* Note that an ENOMEM error is charged twice */
+ if (rc == -ENOMEM)
+ UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
+ is_udplite);
+ goto drop;
+ }
+
+ return 0;
+
+drop:
+ UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+ kfree_skb(skb);
+ return -1;
+}
+
/* returns:
* -1: error
* 0: success
@@ -989,9 +1010,7 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
up->encap_rcv != NULL) {
int ret;
- bh_unlock_sock(sk);
ret = (*up->encap_rcv)(sk, skb);
- bh_lock_sock(sk);
if (ret <= 0) {
UDP_INC_STATS_BH(sock_net(sk),
UDP_MIB_INDATAGRAMS,
@@ -1044,17 +1063,16 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
goto drop;
}
- if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
- /* Note that an ENOMEM error is charged twice */
- if (rc == -ENOMEM) {
- UDP_INC_STATS_BH(sock_net(sk),
- UDP_MIB_RCVBUFERRORS, is_udplite);
- atomic_inc(&sk->sk_drops);
- }
- goto drop;
- }
+ rc = 0;
- return 0;
+ bh_lock_sock(sk);
+ if (!sock_owned_by_user(sk))
+ rc = __udp_queue_rcv_skb(sk, skb);
+ else
+ sk_add_backlog(sk, skb);
+ bh_unlock_sock(sk);
+
+ return rc;
drop:
UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
@@ -1092,15 +1110,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
skb1 = skb_clone(skb, GFP_ATOMIC);
if (skb1) {
- int ret = 0;
-
- bh_lock_sock(sk);
- if (!sock_owned_by_user(sk))
- ret = udp_queue_rcv_skb(sk, skb1);
- else
- sk_add_backlog(sk, skb1);
- bh_unlock_sock(sk);
-
+ int ret = udp_queue_rcv_skb(sk, skb1);
if (ret > 0)
/* we should probably re-process instead
* of dropping packets here. */
@@ -1195,13 +1205,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
uh->dest, inet_iif(skb), udptable);
if (sk != NULL) {
- int ret = 0;
- bh_lock_sock(sk);
- if (!sock_owned_by_user(sk))
- ret = udp_queue_rcv_skb(sk, skb);
- else
- sk_add_backlog(sk, skb);
- bh_unlock_sock(sk);
+ int ret = udp_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
@@ -1494,7 +1498,7 @@ struct proto udp_prot = {
.sendmsg = udp_sendmsg,
.recvmsg = udp_recvmsg,
.sendpage = udp_sendpage,
- .backlog_rcv = udp_queue_rcv_skb,
+ .backlog_rcv = __udp_queue_rcv_skb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v4_get_port,