Re: [PATCH] kprobes/x86: Fixes NMI context check on x86

[kernel test robot <lkp@intel.com>]

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Hi Masami,

I love your patch! Perhaps something to improve:

[auto build test WARNING on tip/x86/core]
[also build test WARNING on tip/auto-latest linux/master linus/master v5.9-rc2 next-20200825]
[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/Masami-Hiramatsu/kprobes-x86-Fixes-NMI-context-check-on-x86/20200825-141829
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ef2ff0f5d6008d325c9a068e20981c0d0acc4d6b
config: x86_64-randconfig-a015-20200825 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 77e5a195f818b9ace91f7b12ab948b21d7918238)
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
        # 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 >>):

>> arch/x86/kernel/kprobes/core.c:573:6: warning: no previous prototype for function 'arch_kprobe_in_nmi' [-Wmissing-prototypes]
   bool arch_kprobe_in_nmi(void)
        ^
   arch/x86/kernel/kprobes/core.c:573:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   bool arch_kprobe_in_nmi(void)
   ^
   static 
   arch/x86/kernel/kprobes/core.c:776:24: warning: no previous prototype for function 'trampoline_handler' [-Wmissing-prototypes]
   __used __visible void *trampoline_handler(struct pt_regs *regs)
                          ^
   arch/x86/kernel/kprobes/core.c:776:18: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __used __visible void *trampoline_handler(struct pt_regs *regs)
                    ^
                    static 
   2 warnings generated.

# https://github.com/0day-ci/linux/commit/2c75bf59d2f4fcecab1f1099a04ed17049df8e0a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Masami-Hiramatsu/kprobes-x86-Fixes-NMI-context-check-on-x86/20200825-141829
git checkout 2c75bf59d2f4fcecab1f1099a04ed17049df8e0a
vim +/arch_kprobe_in_nmi +573 arch/x86/kernel/kprobes/core.c

   572	
 > 573	bool arch_kprobe_in_nmi(void)
   574	{
   575		struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
   576	
   577		if (kcb->in_int3) {
   578			/*
   579			 * Since the int3 is one of NMI, we have to check in_nmi() is
   580			 * bigger than 1 << NMI_SHIFT instead of !0.
   581			 */
   582			return in_nmi() > (1 << NMI_SHIFT);
   583		} else
   584			return in_nmi();
   585	}
   586	

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

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