arch/x86/entry/common.c:736:24: warning: no previous prototype for function 'xen_pv_evtchn_do_upcall'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   754e0b0e35608ed5206d6a67a791563c631cec07
commit: 2f6474e4636bcc68af6c44abb2703f12d7f083da x86/entry: Switch XEN/PV hypercall entry to IDTENTRY
date:   1 year, 8 months ago
config: x86_64-randconfig-a006-20220214 (https://download.01.org/0day-ci/archive/20220214/202202141812.bb7YTaL8-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project ea071884b0cc7210b3cc5fe858f0e892a779a23b)
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f6474e4636bcc68af6c44abb2703f12d7f083da
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 2f6474e4636bcc68af6c44abb2703f12d7f083da
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/entry/

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

All warnings (new ones prefixed by >>):

   arch/x86/entry/common.c:59:24: warning: no previous prototype for function 'enter_from_user_mode' [-Wmissing-prototypes]
   __visible noinstr void enter_from_user_mode(void)
                          ^
   arch/x86/entry/common.c:59:19: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __visible noinstr void enter_from_user_mode(void)
                     ^
                     static 
   arch/x86/entry/common.c:274:24: warning: no previous prototype for function 'prepare_exit_to_usermode' [-Wmissing-prototypes]
   __visible noinstr void prepare_exit_to_usermode(struct pt_regs *regs)
                          ^
   arch/x86/entry/common.c:274:19: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __visible noinstr void prepare_exit_to_usermode(struct pt_regs *regs)
                     ^
                     static 
   arch/x86/entry/common.c:336:24: warning: no previous prototype for function 'syscall_return_slowpath' [-Wmissing-prototypes]
   __visible noinstr void syscall_return_slowpath(struct pt_regs *regs)
                          ^
   arch/x86/entry/common.c:336:19: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __visible noinstr void syscall_return_slowpath(struct pt_regs *regs)
                     ^
                     static 
>> arch/x86/entry/common.c:736:24: warning: no previous prototype for function 'xen_pv_evtchn_do_upcall' [-Wmissing-prototypes]
   __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
                          ^
   arch/x86/entry/common.c:736:19: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
                     ^
                     static 
   4 warnings generated.


vim +/xen_pv_evtchn_do_upcall +736 arch/x86/entry/common.c

   735	
 > 736	__visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)

---
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