Commit 574f7194 authored Apr 01, 2014 by Eric W. Biederman Committed by David S. Miller Apr 01, 2014

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" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent f91ca783

include/linux/skbuff.h

+13 −0

Original line number	Diff line number	Diff line
		@@ -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;

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