net/socket.c:1676:21: error: no previous declaration for 'update_socket_protocol'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   d90b0276af8f25a0b8ae081a30d1b2a61263393b
commit: 0dd061a6a115f25132989cbd591a25afb2dee086 bpf: Add update_socket_protocol hook
date:   5 weeks ago
config: x86_64-sof-customedconfig-avs-defconfig (https://download.01.org/0day-ci/archive/20230923/202309231748.AETjbleh-lkp@xxxxxxxxx/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230923/202309231748.AETjbleh-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309231748.AETjbleh-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

>> net/socket.c:1676:21: error: no previous declaration for 'update_socket_protocol' [-Werror=missing-declarations]
    __weak noinline int update_socket_protocol(int family, int type, int protocol)
                        ^~~~~~~~~~~~~~~~~~~~~~
   cc1: all warnings being treated as errors


vim +/update_socket_protocol +1676 net/socket.c

  1659	
  1660	/*	A hook for bpf progs to attach to and update socket protocol.
  1661	 *
  1662	 *	A static noinline declaration here could cause the compiler to
  1663	 *	optimize away the function. A global noinline declaration will
  1664	 *	keep the definition, but may optimize away the callsite.
  1665	 *	Therefore, __weak is needed to ensure that the call is still
  1666	 *	emitted, by telling the compiler that we don't know what the
  1667	 *	function might eventually be.
  1668	 *
  1669	 *	__diag_* below are needed to dismiss the missing prototype warning.
  1670	 */
  1671	
  1672	__diag_push();
  1673	__diag_ignore_all("-Wmissing-prototypes",
  1674			  "A fmod_ret entry point for BPF programs");
  1675	
> 1676	__weak noinline int update_socket_protocol(int family, int type, int protocol)
  1677	{
  1678		return protocol;
  1679	}
  1680	

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