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Subject: Re: [PATCH] net: bridge: Fix jump_label config
To:     Cong Wang <xiyou.wangcong@gmail.com>
CC:     Roopa Prabhu <roopa@nvidia.com>,
        Nikolay Aleksandrov <nikolay@nvidia.com>,
        "David S. Miller" <davem@davemloft.net>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
References: <20210224153803.91194-1-wangkefeng.wang@huawei.com>
 <CAM_iQpV0NCoJF-qS1KPB+VE3FSMfGBH_SL-OxhMO-k0pGUEhwA@mail.gmail.com>
 <1cf51ae7-3bce-3b9f-f6aa-c20499eedf7a@huawei.com>
 <CAM_iQpWArF_At1XAcviDnyXdth4cMeUSQh7RBW-JNCDUPYfA2A@mail.gmail.com>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
Message-ID: <2a9d5d65-bf6c-7c41-113c-6297e3826b91@huawei.com>
Date:   Tue, 16 Mar 2021 23:48:18 +0800
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On 2021/2/27 4:19, Cong Wang wrote:
> On Thu, Feb 25, 2021 at 5:39 PM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>>
>> On 2021/2/26 5:22, Cong Wang wrote:
>>> On Wed, Feb 24, 2021 at 8:03 AM Kefeng Wang <wangkefeng.wang@huawei.com> 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@huawei.com>
>>> 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.
>