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

On 2021/2/27 4:19, Cong Wang wrote:

On Thu, Feb 25, 2021 at 5:39 PM Kefeng Wang [off-list ref] wrote:

quoted

On 2021/2/26 5:22, Cong Wang wrote:

quoted

On Wed, Feb 24, 2021 at 8:03 AM Kefeng Wang [off-list ref] wrote:

quoted

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 <redacted>

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.