Re: [PATCH] mm: don't allow empty relative nodemask in mpol_relative_nodemask()

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

Hi Yury,

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/Yury-Norov/mm-don-t-allow-empty-relative-nodemask-in-mpol_relative_nodemask/20260529-030835
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20260528190337.878027-1-ynorov%40nvidia.com
patch subject: [PATCH] mm: don't allow empty relative nodemask in mpol_relative_nodemask()
config: x86_64-buildonly-randconfig-003-20260529 (https://download.01.org/0day-ci/archive/20260529/202605291631.6MATSv6v-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260529/202605291631.6MATSv6v-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/202605291631.6MATSv6v-lkp@intel.com/

All errors (new ones prefixed by >>):

   mm/mempolicy.c: In function 'mpol_relative_nodemask':
>> mm/mempolicy.c:377:24: error: 'return' with a value, in function returning void [-Wreturn-mismatch]
     377 |                 return -EINVAL;
         |                        ^
   mm/mempolicy.c:370:13: note: declared here
     370 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
         |             ^~~~~~~~~~~~~~~~~~~~~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for MFD_STMFX
   Depends on [n]: HAS_IOMEM [=y] && I2C [=y] && OF [=n]
   Selected by [y]:
   - PINCTRL_STMFX [=y] && PINCTRL [=y] && I2C [=y] && HAS_IOMEM [=y]


vim +/return +377 mm/mempolicy.c

   369	
   370	static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
   371					   const nodemask_t *rel)
   372	{
   373		unsigned int w = nodes_weight(*rel);
   374		nodemask_t tmp;
   375	
   376		if (w == 0)
 > 377			return -EINVAL;
   378	
   379		nodes_fold(tmp, *orig, w);
   380		nodes_onto(*ret, tmp, *rel);
   381	}
   382	

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