From e84af6ddef0e447c56b256a2bb5a90af11bdac2e Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 10 Nov 2009 14:11:01 +0000 Subject: [PATCH] skbuff: Do not allow skb recycling with disabled IRQs NAPI drivers try to recycle SKBs in their polling routine, but we generally don't know the context in which the polling will be called, and the skb recycling itself may require IRQs to be enabled. This patch adds irqs_disabled() test to the skb_recycle_check() routine, so that we'll not let the drivers hit the skb recycling path with IRQs disabled. As a side effect, this patch actually disables skb recycling for some [broken] drivers. E.g. gianfar driver grabs an irqsave spinlock during TX ring processing, and then tries to recycle an skb, and that caused the following badness: nf_conntrack version 0.5.0 (1008 buckets, 4032 max) ------------[ cut here ]------------ Badness at kernel/softirq.c:143 NIP: c003e3c4 LR: c423a528 CTR: c003e344 ... NIP [c003e3c4] local_bh_enable+0x80/0xc4 LR [c423a528] destroy_conntrack+0xd4/0x13c [nf_conntrack] Call Trace: [c15d1b60] [c003e32c] local_bh_disable+0x1c/0x34 (unreliable) [c15d1b70] [c423a528] destroy_conntrack+0xd4/0x13c [nf_conntrack] [c15d1b80] [c02c6370] nf_conntrack_destroy+0x3c/0x70 Signed-off-by: David S. Miller --- net/core/skbuff.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 80a96166df39..941bac907484 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -493,6 +493,9 @@ int skb_recycle_check(struct sk_buff *skb, int skb_size) { struct skb_shared_info *shinfo; + if (irqs_disabled()) + return 0; + if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE) return 0; -- 2.20.1