Hi,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on arm64/for-next/core]
[also build test WARNING on tip/x86/core tip/x86/asm linus/master v5.8-rc7]
[cannot apply to next-20200728]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/madvenka-linux-microsoft-com/Implement-Trampoline-File-Descriptor/20200728-211419
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: m68k-allmodconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
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
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k 

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 >>):

   In file included from arch/m68k/include/asm/io_mm.h:25,
                    from arch/m68k/include/asm/io.h:8,
                    from include/linux/io.h:13,
                    from include/linux/irq.h:20,
                    from include/asm-generic/hardirq.h:13,
                    from ./arch/m68k/include/generated/asm/hardirq.h:1,
                    from include/linux/hardirq.h:10,
                    from include/linux/trace_events.h:9,
                    from include/trace/syscall.h:7,
                    from include/linux/syscalls.h:85,
                    from fs/trampfd/trampfd_syscall.c:14:
   arch/m68k/include/asm/raw_io.h: In function 'raw_rom_outsb':
   arch/m68k/include/asm/raw_io.h:83:7: warning: variable '__w' set but not used [-Wunused-but-set-variable]
      83 |  ({u8 __w, __v = (b);  u32 _addr = ((u32) (addr)); \
         |       ^~~
   arch/m68k/include/asm/raw_io.h:430:3: note: in expansion of macro 'rom_out_8'
     430 |   rom_out_8(port, *buf++);
         |   ^~~~~~~~~
   arch/m68k/include/asm/raw_io.h: In function 'raw_rom_outsw':
   arch/m68k/include/asm/raw_io.h:86:8: warning: variable '__w' set but not used [-Wunused-but-set-variable]
      86 |  ({u16 __w, __v = (w); u32 _addr = ((u32) (addr)); \
         |        ^~~
   arch/m68k/include/asm/raw_io.h:448:3: note: in expansion of macro 'rom_out_be16'
     448 |   rom_out_be16(port, *buf++);
         |   ^~~~~~~~~~~~
   arch/m68k/include/asm/raw_io.h: In function 'raw_rom_outsw_swapw':
   arch/m68k/include/asm/raw_io.h:90:8: warning: variable '__w' set but not used [-Wunused-but-set-variable]
      90 |  ({u16 __w, __v = (w); u32 _addr = ((u32) (addr)); \
         |        ^~~
   arch/m68k/include/asm/raw_io.h:466:3: note: in expansion of macro 'rom_out_le16'
     466 |   rom_out_le16(port, *buf++);
         |   ^~~~~~~~~~~~
   fs/trampfd/trampfd_syscall.c: At top level:
>> fs/trampfd/trampfd_syscall.c:81:12: warning: no previous prototype for 'trampfd_init' [-Wmissing-prototypes]
      81 | int __init trampfd_init(void)
         |            ^~~~~~~~~~~~

vim +/trampfd_init +81 fs/trampfd/trampfd_syscall.c

    80	
  > 81	int __init trampfd_init(void)

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