[IPV4]: Fix BUG() in 2.6.x, udp_poll(), fragments + CONFIG_HIGHMEM
Steven Hand <Steven.Hand@cl.cam.ac.uk> wrote:
>
> Reconstructed forward trace:
>
> net/ipv4/udp.c:1334 spin_lock_irq()
> net/ipv4/udp.c:1336 udp_checksum_complete()
> net/core/skbuff.c:1069 skb_shinfo(skb)->nr_frags > 1
> net/core/skbuff.c:1086 kunmap_skb_frag()
> net/core/skbuff.h:1087 local_bh_enable()
> kernel/softirq.c:0140 WARN_ON(irqs_disabled());
The receive queue lock is never taken in IRQs (and should never be) so
we can simply substitute bh for irq.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 4a6952e..7c24e64 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -738,7 +738,7 @@
unsigned long amount;
amount = 0;
- spin_lock_irq(&sk->sk_receive_queue.lock);
+ spin_lock_bh(&sk->sk_receive_queue.lock);
skb = skb_peek(&sk->sk_receive_queue);
if (skb != NULL) {
/*
@@ -748,7 +748,7 @@
*/
amount = skb->len - sizeof(struct udphdr);
}
- spin_unlock_irq(&sk->sk_receive_queue.lock);
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
return put_user(amount, (int __user *)arg);
}
@@ -848,12 +848,12 @@
/* Clear queue. */
if (flags&MSG_PEEK) {
int clear = 0;
- spin_lock_irq(&sk->sk_receive_queue.lock);
+ spin_lock_bh(&sk->sk_receive_queue.lock);
if (skb == skb_peek(&sk->sk_receive_queue)) {
__skb_unlink(skb, &sk->sk_receive_queue);
clear = 1;
}
- spin_unlock_irq(&sk->sk_receive_queue.lock);
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
if (clear)
kfree_skb(skb);
}
@@ -1334,7 +1334,7 @@
struct sk_buff_head *rcvq = &sk->sk_receive_queue;
struct sk_buff *skb;
- spin_lock_irq(&rcvq->lock);
+ spin_lock_bh(&rcvq->lock);
while ((skb = skb_peek(rcvq)) != NULL) {
if (udp_checksum_complete(skb)) {
UDP_INC_STATS_BH(UDP_MIB_INERRORS);
@@ -1345,7 +1345,7 @@
break;
}
}
- spin_unlock_irq(&rcvq->lock);
+ spin_unlock_bh(&rcvq->lock);
/* nothing to see, move along */
if (skb == NULL)