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authorPatrick McHardy <kaber@trash.net>2013-04-17 06:47:00 +0000
committerDavid S. Miller <davem@davemloft.net>2013-04-19 14:57:57 -0400
commitcf0a018ac669955c10e4fca24fa55dde58434e9a (patch)
treeb2c087fe536127cf30639a773a8da78452994041 /net/netlink
parent1298ca4671acb10310baa550ed044c553e3a3387 (diff)
downloadlinux-cf0a018ac669955c10e4fca24fa55dde58434e9a.tar.gz
netlink: add netlink_skb_set_owner_r()
For mmap'ed I/O a netlink specific skb destructor needs to be invoked after the final kfree_skb() to clean up state. This doesn't work currently since the skb's ownership is transfered to the receiving socket using skb_set_owner_r(), which orphans the skb, thereby invoking the destructor prematurely. Since netlink doesn't account skbs to the originating socket, there's no need to orphan the skb. Add a netlink specific skb_set_owner_r() variant that does not orphan the skb and use a netlink specific destructor to call sock_rfree(). Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
-rw-r--r--net/netlink/af_netlink.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 26779c24b1d..58b9025978f 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -119,6 +119,20 @@ static void netlink_consume_callback(struct netlink_callback *cb)
kfree(cb);
}
+static void netlink_skb_destructor(struct sk_buff *skb)
+{
+ sock_rfree(skb);
+}
+
+static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
+{
+ WARN_ON(skb->sk != NULL);
+ skb->sk = sk;
+ skb->destructor = netlink_skb_destructor;
+ atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+ sk_mem_charge(sk, skb->truesize);
+}
+
static void netlink_sock_destruct(struct sock *sk)
{
struct netlink_sock *nlk = nlk_sk(sk);
@@ -820,7 +834,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
}
return 1;
}
- skb_set_owner_r(skb, sk);
+ netlink_skb_set_owner_r(skb, sk);
return 0;
}
@@ -890,7 +904,7 @@ static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
ret = -ECONNREFUSED;
if (nlk->netlink_rcv != NULL) {
ret = skb->len;
- skb_set_owner_r(skb, sk);
+ netlink_skb_set_owner_r(skb, sk);
NETLINK_CB(skb).sk = ssk;
nlk->netlink_rcv(skb);
consume_skb(skb);
@@ -962,7 +976,7 @@ static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
!test_bit(NETLINK_CONGESTED, &nlk->state)) {
- skb_set_owner_r(skb, sk);
+ netlink_skb_set_owner_r(skb, sk);
__netlink_sendskb(sk, skb);
return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
}