Re: [RFC][PATCH 05/24] x86/entry: Implement ret_from_fork body with C code

From: kernel test robot <lkp@intel.com>
To: kbuild-all@lists.01.org
Subject: Re: [RFC][PATCH 05/24] x86/entry: Implement ret_from_fork body with C code
Date: Mon, 16 Nov 2020 05:34:45 +0800	[thread overview]
Message-ID: <202011160534.nNeHXROL-lkp@intel.com> (raw)
In-Reply-To: <20201109144425.270789-6-alexandre.chartre@oracle.com>

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Hi Alexandre,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on tip/x86/mm]
[also build test WARNING on v5.10-rc3 next-20201113]
[cannot apply to tip/x86/core tip/x86/asm]
[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/Alexandre-Chartre/x86-pti-Defer-CR3-switch-to-C-code/20201109-225007
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 1fcd009102ee02e217f2e7635ab65517d785da8e
config: i386-randconfig-r014-20201109 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/63533707f1058d9d8eccb278eb735d9f88fdd222
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Alexandre-Chartre/x86-pti-Defer-CR3-switch-to-C-code/20201109-225007
        git checkout 63533707f1058d9d8eccb278eb735d9f88fdd222
        # 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@intel.com>

All warnings (new ones prefixed by >>):

>> arch/x86/entry/common.c:38:24: warning: no previous prototype for 'return_from_fork' [-Wmissing-prototypes]
      38 | __visible noinstr void return_from_fork(struct pt_regs *regs,
         |                        ^~~~~~~~~~~~~~~~
   arch/x86/entry/common.c:112:24: warning: no previous prototype for 'do_int80_syscall_32' [-Wmissing-prototypes]
     112 | __visible noinstr void do_int80_syscall_32(struct pt_regs *regs)
         |                        ^~~~~~~~~~~~~~~~~~~
   arch/x86/entry/common.c:171:24: warning: no previous prototype for 'do_fast_syscall_32' [-Wmissing-prototypes]
     171 | __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
         |                        ^~~~~~~~~~~~~~~~~~
   arch/x86/entry/common.c:223:24: warning: no previous prototype for 'do_SYSENTER_32' [-Wmissing-prototypes]
     223 | __visible noinstr long do_SYSENTER_32(struct pt_regs *regs)
         |                        ^~~~~~~~~~~~~~

vim +/return_from_fork +38 arch/x86/entry/common.c

    37	
  > 38	__visible noinstr void return_from_fork(struct pt_regs *regs,
    39						struct task_struct *prev,
    40						void (*kfunc)(void *), void *kargs)
    41	{
    42		schedule_tail(prev);
    43		if (kfunc) {
    44			/* kernel thread */
    45			kfunc(kargs);
    46			/*
    47			 * A kernel thread is allowed to return here after
    48			 * successfully calling kernel_execve(). Exit to
    49			 * userspace to complete the execve() syscall.
    50			 */
    51			regs->ax = 0;
    52		}
    53		syscall_exit_to_user_mode(regs);
    54	}
    55	

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

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