Re: [PATCH 2/7] mm/gup: check if both GUP_GET and GUP_PIN are set in __get_user_pages() earlier

[Baoquan He <bhe@redhat.com>]

On 03/30/25 at 09:49pm, kernel test robot wrote:
> Hi Baoquan,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on akpm-mm/mm-everything]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Baoquan-He/mm-gup-fix-wrongly-calculated-returned-value-in-fault_in_safe_writeable/20250330-201949
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/20250330121718.175815-3-bhe%40redhat.com
> patch subject: [PATCH 2/7] mm/gup: check if both GUP_GET and GUP_PIN are set in __get_user_pages() earlier
> config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20250330/202503302151.MdrisJhx-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250330/202503302151.MdrisJhx-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202503302151.MdrisJhx-lkp@intel.com/

Thanks for testing this patchset and reporting this error.

> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from arch/x86/include/asm/bug.h:110,
>                     from include/linux/bug.h:5,
>                     from include/linux/thread_info.h:13,
>                     from include/linux/spinlock.h:60,
>                     from mm/gup.c:5:
>    mm/gup.c: In function '__get_user_pages':
>    mm/gup.c:1433:27: error: 'flags' undeclared (first use in this function)
>     1433 |         if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
>          |                           ^~~~~

It's a copy-and-paste error, below change can fix it. It's weird my
building didn't figure it out. I will re-run a building on the patchset,
then send v2 for patch 2.

diff --git a/mm/gup.c b/mm/gup.c
index 3d2c57f59b4d..1ae41c1b2649 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1430,7 +1430,7 @@ static long __get_user_pages(struct mm_struct *mm,
 	VM_BUG_ON(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN)));
 
 	/* FOLL_GET and FOLL_PIN are mutually exclusive. */
-	if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
+	if (WARN_ON_ONCE((gup_flags & (FOLL_PIN | FOLL_GET)) ==
 			 (FOLL_PIN | FOLL_GET)))
 		return ERR_PTR(-EINVAL);