Re: [PATCH bpf-next 3/5] net/smc: bpf: Introduce generic hook for handshake flow

[kernel test robot <lkp@intel.com>]

Hi Wythe,

kernel test robot noticed the following build warnings:

[auto build test WARNING on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/D-Wythe/bpf-export-necessary-sympols-for-modules-with-struct_ops/20250731-164431
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20250731084240.86550-4-alibuda%40linux.alibaba.com
patch subject: [PATCH bpf-next 3/5] net/smc: bpf: Introduce generic hook for handshake flow
config: arm-randconfig-003-20250801 (https://download.01.org/0day-ci/archive/20250801/202508010316.wuSPjSOr-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 10.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250801/202508010316.wuSPjSOr-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508010316.wuSPjSOr-lkp@intel.com/

All warnings (new ones prefixed by >>):

   net/ipv4/tcp_output.c: In function 'smc_set_option':
>> net/ipv4/tcp_output.c:773:15: warning: unused variable 'sk' [-Wunused-variable]
     773 |  struct sock *sk = &tp->inet_conn.icsk_inet.sk;
         |               ^~
   net/ipv4/tcp_output.c: In function 'smc_set_option_cond':
   net/ipv4/tcp_output.c:794:21: warning: unused variable 'sk' [-Wunused-variable]
     794 |  const struct sock *sk = &tp->inet_conn.icsk_inet.sk;
         |                     ^~


vim +/sk +773 net/ipv4/tcp_output.c

   767	
   768	static void smc_set_option(struct tcp_sock *tp,
   769				   struct tcp_out_options *opts,
   770				   unsigned int *remaining)
   771	{
   772	#if IS_ENABLED(CONFIG_SMC)
 > 773		struct sock *sk = &tp->inet_conn.icsk_inet.sk;
   774		if (static_branch_unlikely(&tcp_have_smc)) {
   775			if (tp->syn_smc) {
   776				tp->syn_smc = !!smc_call_hsbpf(1, sk, syn_option, tp);
   777				/* re-check syn_smc */
   778				if (tp->syn_smc &&
   779				    *remaining >= TCPOLEN_EXP_SMC_BASE_ALIGNED) {
   780					opts->options |= OPTION_SMC;
   781					*remaining -= TCPOLEN_EXP_SMC_BASE_ALIGNED;
   782				}
   783			}
   784		}
   785	#endif
   786	}
   787	

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