Re: [PATCH] mm/execmem: Make ARCH_WANTS_EXECMEM_LATE depend on EXECMEM

[Anshuman Khandual <anshuman.khandual@arm.com>]

On 12/9/24 18:06, kernel test robot wrote:
> Hi Anshuman,
> 
> 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/Anshuman-Khandual/mm-execmem-Make-ARCH_WANTS_EXECMEM_LATE-depend-on-EXECMEM/20241209-111533
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/20241209031251.515903-1-anshuman.khandual%40arm.com
> patch subject: [PATCH] mm/execmem: Make ARCH_WANTS_EXECMEM_LATE depend on EXECMEM
> config: arm64-kismet-CONFIG_ARCH_WANTS_EXECMEM_LATE-CONFIG_ARM64-0-0 (https://download.01.org/0day-ci/archive/20241209/202412092048.tTzJ5szH-lkp@intel.com/config)
> reproduce: (https://download.01.org/0day-ci/archive/20241209/202412092048.tTzJ5szH-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/202412092048.tTzJ5szH-lkp@intel.com/
> 
> kismet warnings: (new ones prefixed by >>)
>>> kismet: WARNING: unmet direct dependencies detected for ARCH_WANTS_EXECMEM_LATE when selected by ARM64
>    WARNING: unmet direct dependencies detected for ARCH_WANTS_EXECMEM_LATE
>      Depends on [n]: EXECMEM [=n]
>      Selected by [y]:
>      - ARM64 [=y]

Although above mentioned config here has CONFIG_ARCH_WANTS_EXECMEM_LATE=y
and CONFIG_EXECMEM=n (actually absent), could that really happen though ?

Tried making CONFIG_EXECMEM=n (rather deselecting) but that did now allow
setting CONFIG_EXECMEM=n, it always remained set. Reverting this patch i.e
the current behaviour is also the same (CONFIG_EXECMEM always remains set).

select ARCH_WANTS_EXECMEM_LATE if EXECMEM

Above statement seems to be selecting EXECMEM as well but the intent seems
to be a dependency check instead! OR arch selection for a config brings in
all its dependencies as well.

If the selection is always, should this change be like the following ?

config ARCH_WANTS_EXECMEM_LATE
 	bool
	selects EXECMEM

Although a similar config ARCH_WANTS_EXECMEM_ROX is dependent on MMU and
!HIGHMEM at the generic memory level.