Re: [PATCH v6 3/3] mm/gup: disallow FOLL_LONGTERM GUP-fast writing to file-backed mappings

[kernel test robot]

Hi Lorenzo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes/mm-mmap-separate-writenotify-and-dirty-tracking-logic/20230502-071520
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/dee4f4ad6532b0f94d073da263526de334d5d7e0.1682981880.git.lstoakes%40gmail.com
patch subject: [PATCH v6 3/3] mm/gup: disallow FOLL_LONGTERM GUP-fast writing to file-backed mappings
config: arm-randconfig-r013-20230502 (https://download.01.org/0day-ci/archive/20230502/202305021142.vBYXxxEh-lkp@xxxxxxxxx/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project b1465cd49efcbc114a75220b153f5a055ce7911f)
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 arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/intel-lab-lkp/linux/commit/602bb9fab888bd9176b8eeb80a0da68499c343ed
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Lorenzo-Stoakes/mm-mmap-separate-writenotify-and-dirty-tracking-logic/20230502-071520
        git checkout 602bb9fab888bd9176b8eeb80a0da68499c343ed
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202305021142.vBYXxxEh-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> mm/gup.c:114:49: warning: omitting the parameter name in a function definition is a C2x extension [-Wc2x-extensions]
   static bool stabilise_mapping_rcu(struct folio *)
                                                   ^
   1 warning generated.


vim +114 mm/gup.c

   108	
   109	static void unlock_rcu(void)
   110	{
   111		rcu_read_unlock();
   112	}
   113	#else
 > 114	static bool stabilise_mapping_rcu(struct folio *)
   115	{
   116		return true;
   117	}
   118	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests