| Message ID | 20241209031251.515903-1-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/execmem: Make ARCH_WANTS_EXECMEM_LATE depend on EXECMEM | expand |
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]
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.
On Mon, Dec 09, 2024 at 07:43:32PM +0530, Anshuman Khandual wrote: > On 12/9/24 18:06, kernel test robot wrote: > > 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 This is wrong. What ARCH_WANTS_EXECMEM_LATE means is that, _if_ EXECMEM is enabled, the arch code require its late initialisation. Currently for arm64 EXECMEM is selected by KPROBES, BPF_JIT and MODULES. So if you don't have any of these on, you don't need EXECMEM either, no point in selecting it above just because arm64 wants a specific behaviour (late initialisation) for EXECMEM. If you do want a patch for this, I think for arm64 we simply need to select ARCH_WANTS_EXECMEM_LATE unconditionally. Not much use in having any dependencies really, it just adds to the clutter. And don't change the core Kconfig either.
On 12/9/24 22:39, Catalin Marinas wrote: > On Mon, Dec 09, 2024 at 07:43:32PM +0530, Anshuman Khandual wrote: >> On 12/9/24 18:06, kernel test robot wrote: >>> 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 > > This is wrong. What ARCH_WANTS_EXECMEM_LATE means is that, _if_ EXECMEM > is enabled, the arch code require its late initialisation. Currently for Which implies that even if ARCH_WANTS_EXECMEM_LATE is only applicable when EXECMEM is enabled, there is no real dependence on the later for platforms that need a certain init behaviour. > arm64 EXECMEM is selected by KPROBES, BPF_JIT and MODULES. So if you EXECMEM gets enabled from the above, not via ARCH_WANTS_EXECMEM_LATE as I had anticipated earlier. > don't have any of these on, you don't need EXECMEM either, no point in > selecting it above just because arm64 wants a specific behaviour (late > initialisation) for EXECMEM. Right, specific behaviour preference for a function on a platform should not necessarily pull in that function itself. > > If you do want a patch for this, I think for arm64 we simply need to > select ARCH_WANTS_EXECMEM_LATE unconditionally. Not much use in having > any dependencies really, it just adds to the clutter. And don't change > the core Kconfig either. Sure, will do.
diff --git a/arch/Kconfig b/arch/Kconfig index 6682b2a53e34..17716f32dc44 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1058,6 +1058,7 @@ config ARCH_WANTS_MODULES_DATA_IN_VMALLOC config ARCH_WANTS_EXECMEM_LATE bool + depends on EXECMEM help For architectures that do not allocate executable memory early on boot, but rather require its initialization late when there is diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b5479c8b454c..b146372bc365 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -113,7 +113,7 @@ config ARM64 select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) select ARCH_WANT_LD_ORPHAN_WARN - select ARCH_WANTS_EXECMEM_LATE if EXECMEM + select ARCH_WANTS_EXECMEM_LATE select ARCH_WANTS_NO_INSTR select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES select ARCH_HAS_UBSAN
Late initialisation of EXECMEM inherently requires EXEMEM itself, and hence this dependency should not be left with the subscribing platforms. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <kees@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- This patch applies on v6.13-rc1 arch/Kconfig | 1 + arch/arm64/Kconfig | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-)