tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   f11901ed723d1351843771c3a84b03a253bbf8b2
commit: ad723674d6758478829ee766e3f1a2a24d56236f x86/efi: move common keyring handler functions to new file
date:   12 months ago
config: x86_64-randconfig-a005-20201024 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 77cbf2595331b11018c2cffb76eb5b8db69f4577)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad723674d6758478829ee766e3f1a2a24d56236f
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout ad723674d6758478829ee766e3f1a2a24d56236f
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> security/integrity/platform_certs/keyring_handler.c:62:30: warning: no previous prototype for function 'get_handler_for_db' [-Wmissing-prototypes]
   __init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
                                ^
   security/integrity/platform_certs/keyring_handler.c:62:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
          ^
          static 
>> security/integrity/platform_certs/keyring_handler.c:73:30: warning: no previous prototype for function 'get_handler_for_dbx' [-Wmissing-prototypes]
   __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
                                ^
   security/integrity/platform_certs/keyring_handler.c:73:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
          ^
          static 
   2 warnings generated.

vim +/get_handler_for_db +62 security/integrity/platform_certs/keyring_handler.c

    57	
    58	/*
    59	 * Return the appropriate handler for particular signature list types found in
    60	 * the UEFI db and MokListRT tables.
    61	 */
  > 62	__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
    63	{
    64		if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
    65			return add_to_platform_keyring;
    66		return 0;
    67	}
    68	
    69	/*
    70	 * Return the appropriate handler for particular signature list types found in
    71	 * the UEFI dbx and MokListXRT tables.
    72	 */
  > 73	__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org