From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [PATCH 4/8] netpoll: take rcu_read_lock_bh() in netpoll_rx() Date: Mon, 6 Aug 2012 22:23:28 +0800 Message-ID: <1344263012-4031-5-git-send-email-amwang@redhat.com> References: <1344263012-4031-1-git-send-email-amwang@redhat.com> Cc: Cong Wang , "David S. Miller" To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:45910 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756571Ab2HFOXz (ORCPT ); Mon, 6 Aug 2012 10:23:55 -0400 In-Reply-To: <1344263012-4031-1-git-send-email-amwang@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: In __netpoll_rx(), it dereferences ->npinfo without rcu_dereference_bh(), this patch fixes it by using the 'npinfo' passed from netpoll_rx() where it is already dereferenced with rcu_dereference_bh(). Cc: "David S. Miller" Signed-off-by: Cong Wang --- include/linux/netpoll.h | 4 ++-- net/core/netpoll.c | 3 +-- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index 907812e..5d881c3 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -52,7 +52,7 @@ void netpoll_set_trap(int trap); void __netpoll_cleanup(struct netpoll *np); void __netpoll_free_rcu(struct netpoll *np); void netpoll_cleanup(struct netpoll *np); -int __netpoll_rx(struct sk_buff *skb); +int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo); void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, struct net_device *dev); static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) @@ -77,7 +77,7 @@ static inline bool netpoll_rx(struct sk_buff *skb) spin_lock(&npinfo->rx_lock); /* check rx_flags again with the lock held */ - if (npinfo->rx_flags && __netpoll_rx(skb)) + if (npinfo->rx_flags && __netpoll_rx(skb, npinfo)) ret = true; spin_unlock(&npinfo->rx_lock); diff --git a/net/core/netpoll.c b/net/core/netpoll.c index dc17f1d..d055bb0 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -543,13 +543,12 @@ static void arp_reply(struct sk_buff *skb) spin_unlock_irqrestore(&npinfo->rx_lock, flags); } -int __netpoll_rx(struct sk_buff *skb) +int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) { int proto, len, ulen; int hits = 0; const struct iphdr *iph; struct udphdr *uh; - struct netpoll_info *npinfo = skb->dev->npinfo; struct netpoll *np, *tmp; if (list_empty(&npinfo->rx_np)) -- 1.7.7.6