On Mon, Sep 24, 2018 at 02:10:04PM +0200, Florian Westphal wrote: > Unfortunately some versions of gcc emit following warning: > $ make net/xfrm/xfrm_output.o > linux/compiler.h:252:20: warning: array subscript is above array bounds [-Warray-bounds] > hook_head = rcu_dereference(net->nf.hooks_arp[hook]); > ^~~~~~~~~~~~~~~~~~~~~ > xfrm_output_resume passes skb_dst(skb)->ops->family as its 'pf' arg so compiler > can't know that we'll never access hooks_arp[]. > (NFPROTO_IPV4 or NFPROTO_IPV6 are only possible cases). > > Avoid this by adding an explicit WARN_ON_ONCE() check. > > This patch has no effect if the family is a compile-time constant as gcc > will remove the switch() construct entirely. Applied, thanks Florian.
