Re: [PATCH v6 23/30] arm64: kpkeys: Ensure the linear map can be modified

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

Hi Kevin,

kernel test robot noticed the following build errors:

[auto build test ERROR on 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f]

url:    https://github.com/intel-lab-lkp/linux/commits/Kevin-Brodsky/mm-Introduce-kpkeys/20260228-020115
base:   6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
patch link:    https://lore.kernel.org/r/20260227175518.3728055-24-kevin.brodsky%40arm.com
patch subject: [PATCH v6 23/30] arm64: kpkeys: Ensure the linear map can be modified
config: arm64-allnoconfig (https://download.01.org/0day-ci/archive/20260228/202602280415.zn69IEgu-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260228/202602280415.zn69IEgu-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/202602280415.zn69IEgu-lkp@intel.com/

All errors (new ones prefixed by >>):

   arch/arm64/mm/mmu.c: In function 'force_pte_mapping':
>> arch/arm64/mm/mmu.c:768:17: error: implicit declaration of function 'arm64_supports_kpkeys_hardened_pgtables' [-Wimplicit-function-declaration]
     768 |                 arm64_supports_kpkeys_hardened_pgtables();
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   arch/arm64/mm/pageattr.c: In function 'can_set_direct_map':
>> arch/arm64/mm/pageattr.c:100:17: error: implicit declaration of function 'arm64_supports_kpkeys_hardened_pgtables' [-Wimplicit-function-declaration]
     100 |                 arm64_supports_kpkeys_hardened_pgtables();
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/arm64_supports_kpkeys_hardened_pgtables +768 arch/arm64/mm/mmu.c

   757	
   758	static inline bool force_pte_mapping(void)
   759	{
   760		const bool bbml2 = system_capabilities_finalized() ?
   761			system_supports_bbml2_noabort() : cpu_supports_bbml2_noabort();
   762	
   763		if (debug_pagealloc_enabled())
   764			return true;
   765		if (bbml2)
   766			return false;
   767		return rodata_full || arm64_kfence_can_set_direct_map() || is_realm_world() ||
 > 768			arm64_supports_kpkeys_hardened_pgtables();
   769	}
   770	

-- 
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