Re: [PATCH] net: bridge: Fix jump_label config

[Kefeng Wang]

On 2021/2/27 4:19, Cong Wang wrote:
> On Thu, Feb 25, 2021 at 5:39 PM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
> > On 2021/2/26 5:22, Cong Wang wrote:
> > > On Wed, Feb 24, 2021 at 8:03 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
> > > > HAVE_JUMP_LABLE is removed by commit e9666d10a567 ("jump_label: move
> > > > 'asm goto' support test to Kconfig"), use CONFIG_JUMP_LABLE instead
> > > > of HAVE_JUMP_LABLE.
> > > >
> > > > Fixes: 971502d77faa ("bridge: netfilter: unroll NF_HOOK helper in bridge input path")
> > > > Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> > > Hmm, why do we have to use a macro here? static_key_false() is defined
> > > in both cases, CONFIG_JUMP_LABEL=y or CONFIG_JUMP_LABEL=n.
> > It seems that all nf_hooks_needed related are using the macro,
> >
> > see net/netfilter/core.c and include/linux/netfilter.h,
> >
> >     #ifdef CONFIG_JUMP_LABEL
> >     struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
> > EXPORT_SYMBOL(nf_hooks_needed);
> > #endif
> >
> >     nf_static_key_inc()/nf_static_key_dec()
> Same question: why? Clearly struct static_key is defined in both cases:

Hi Cong,  the nf_hooks_needed is wrapped up by this macro, so this place 
should use it,

or we will meet the build issue,  thanks.

../net/bridge/br_input.c: In function ‘nf_hook_bridge_pre’:
../net/bridge/br_input.c:211:25: error: ‘nf_hooks_needed’ undeclared 
(first use in this function)
  211 |  if 
(!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))


> #else
> struct static_key {
>          atomic_t enabled;
> };
> #endif  /* CONFIG_JUMP_LABEL */
>
> Thanks.