Re: [PATCH 5/5] mm/treewide: Drop pXd_large()

Re: [PATCH 5/5] mm/treewide: Drop pXd_large()

[kernel test robot]

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/peterx-redhat-com/mm-ppc-Define-pXd_large-with-pXd_leaf/20240228-170049
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20240228085350.520953-6-peterx%40redhat.com
patch subject: [PATCH 5/5] mm/treewide: Drop pXd_large()
config: i386-buildonly-randconfig-001-20240228 (https://download.01.org/0day-ci/archive/20240229/202402291233.CVhChP2c-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240229/202402291233.CVhChP2c-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/202402291233.CVhChP2c-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/x86/kernel/asm-offsets.c:14:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:9:
   In file included from include/linux/sched/task.h:13:
   In file included from include/linux/uaccess.h:11:
   In file included from arch/x86/include/asm/uaccess.h:17:
   In file included from arch/x86/include/asm/tlbflush.h:16:
>> arch/x86/include/asm/pgtable.h:1099:19: error: redefinition of 'pud_leaf'
    1099 | static inline int pud_leaf(pud_t pud)
         |                   ^
   include/asm-generic/pgtable-nopmd.h:34:19: note: previous definition is here
      34 | static inline int pud_leaf(pud_t pud)           { return 0; }
         |                   ^
   1 error generated.
   make[3]: *** [scripts/Makefile.build:116: arch/x86/kernel/asm-offsets.s] Error 1 shuffle=298844285
   make[3]: Target 'prepare' not remade because of errors.
   make[2]: *** [Makefile:1191: prepare0] Error 2 shuffle=298844285
   make[2]: Target 'prepare' not remade because of errors.
   make[1]: *** [Makefile:240: __sub-make] Error 2 shuffle=298844285
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:240: __sub-make] Error 2 shuffle=298844285
   make: Target 'prepare' not remade because of errors.


vim +/pud_leaf +1099 arch/x86/include/asm/pgtable.h

  1093	
  1094	static inline int pud_bad(pud_t pud)
  1095	{
  1096		return (pud_flags(pud) & ~(_KERNPG_TABLE | _PAGE_USER)) != 0;
  1097	}
  1098	#else
> 1099	static inline int pud_leaf(pud_t pud)
  1100	{
  1101		return 0;
  1102	}
  1103	#endif	/* CONFIG_PGTABLE_LEVELS > 2 */
  1104	#define pud_leaf pud_leaf
  1105	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 5/5] mm/treewide: Drop pXd_large()

[Peter Xu]

On Thu, Feb 29, 2024 at 01:17:36PM +0800, kernel test robot wrote:
> >> arch/x86/include/asm/pgtable.h:1099:19: error: redefinition of 'pud_leaf'
>     1099 | static inline int pud_leaf(pud_t pud)
>          |                   ^
>    include/asm-generic/pgtable-nopmd.h:34:19: note: previous definition is here
>       34 | static inline int pud_leaf(pud_t pud)           { return 0; }
>          |                   ^

This is CONFIG_PGTABLE_LEVELS=2.  IIUC patch 5 didn't do anything wrong,
but when renaming pud_large() it caused this confliction, while in the past
it was a silent confliction between the old pud_leaf() macro and pud_leaf()
defintion, the macro could have silently overwrote the function.

IIUC such pud_leaf() is not needed as we have a global fallback.  I'll add
a pre-requisite patch to remove such pXd_leaf() definitions.

-- 
Peter Xu