From 574f7194f693cd80de96a39f0c43dbb346c38a15 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 1 Apr 2014 12:20:24 -0700 Subject: [PATCH] net: Add a test to see if a skb is freeable in irq context Currently netpoll and skb_release_head_state assume that a skb is freeable in hard irq context except when skb->destructor is set. The reality is far from this. So add a function skb_irq_freeable to compute the full test and in the process be the living documentation of what the requirements are of actually freeing a skb in hard irq context. Signed-off-by: "Eric W. Biederman" Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/skbuff.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 31edf63937a1..350eebe770d9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2831,6 +2831,19 @@ static inline void skb_init_secmark(struct sk_buff *skb) { } #endif +static inline bool skb_irq_freeable(const struct sk_buff *skb) +{ + return !skb->destructor && +#if IS_ENABLED(CONFIG_XFRM) + !skb->sp && +#endif +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + !skb->nfct && +#endif + !skb->_skb_refdst && + !skb_has_frag_list(skb); +} + static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) { skb->queue_mapping = queue_mapping; -- 2.20.1