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>
This commit is contained in:
Eric W. Biederman 2014-04-01 12:20:24 -07:00 committed by David S. Miller
parent f91ca783f1
commit 574f7194f6

View file

@ -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;