Re: [PATCH] netfilter: turn NF_HOOK into an inline function

Arnd Bergmann [off-list ref] writes:

On Friday 09 October 2015 21:03:57 kbuild test robot wrote:

quoted

^1da177e Linus Torvalds    2005-04-16  818      cb->rt_flags &= ~DN_RT_F_IE;
^1da177e Linus Torvalds    2005-04-16  819      if (rt->rt_flags & RTCF_DOREDIRECT)
^1da177e Linus Torvalds    2005-04-16  820              cb->rt_flags |= DN_RT_F_IE;
^1da177e Linus Torvalds    2005-04-16  821  
29a26a56 Eric W. Biederman 2015-09-15  822      return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
29a26a56 Eric W. Biederman 2015-09-15 @823                     &init_net, NULL, skb, dev, skb->dev,
8f40b161 David S. Miller   2011-07-17  824                     dn_to_neigh_output);
^1da177e Linus Torvalds    2005-04-16  825  
^1da177e Linus Torvalds    2005-04-16  826  drop:

Ah, right. The 'dev' variable here is declared as

#ifdef CONFIG_NETFILTER
        struct net_device *dev = skb->dev;
#endif

Apparently because the code produced the same warning as the ipv6 code.

Removing the #ifdef here would make that code nicer and let us use
my patch. Alternatively we could put the same #ifdef into IPV6 and
not use the inline function.

Compilers are good at removing unused variabes (SSA should guarantee
this will always happen), and #ifdefs sucks.  I vote for your inline.
Especially as the case that is actively used and tested
(CONFIG_NETFILTER) has these two functions as inline functions.

Eric