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

[kernel test robot]

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: i386-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

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/kernel/kprobes/core.c:573:6: warning: no previous prototype for 'arch_kprobe_in_nmi' [-Wmissing-prototypes]
     573 | bool arch_kprobe_in_nmi(void)
         |      ^~~~~~~~~~~~~~~~~~
   arch/x86/kernel/kprobes/core.c:776:24: warning: no previous prototype for 'trampoline_handler' [-Wmissing-prototypes]
     776 | __used __visible void *trampoline_handler(struct pt_regs *regs)
         |                        ^~~~~~~~~~~~~~~~~~

# 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@xxxxxxxxxxxx

Attachment: .config.gz
Description: application/gzip