On 12/05/2014 06:14 AM, Catalin Marinas wrote: > On Thu, Dec 04, 2014 at 09:15:12PM +0000, Olof Johansson wrote: >> On Thu, Dec 4, 2014 at 7:46 AM, Alexander Graf <ag...@suse.de> wrote: >>> With binutils 2.25 the default alignment for 32bit arm sections changed to >>> have everything 64k aligned. Armv7 binaries built with this binutils version >>> run successfully on an arm64 system. >>> >>> Since effectively there is now the chance to run armv7 code on arm64 even >>> with 64k page size, it doesn't make sense to block people from enabling >>> CONFIG_COMPAT on those configurations. >>> >>> Signed-off-by: Alexander Graf <ag...@suse.de> >>> --- >>> arch/arm64/Kconfig | 1 - >>> 1 file changed, 1 deletion(-) >>> >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index 9532f8d..3cf4f238 100644 >>> --- a/arch/arm64/Kconfig >>> +++ b/arch/arm64/Kconfig >>> @@ -409,7 +409,6 @@ source "fs/Kconfig.binfmt" >>> >>> config COMPAT >>> bool "Kernel support for 32-bit EL0" >>> - depends on !ARM64_64K_PAGES >>> select COMPAT_BINFMT_ELF >>> select HAVE_UID16 >>> select OLD_SIGSUSPEND3 >> >> This is hardly "compat". Sure, it's great to have a new binutils that >> has larger alignment, but practically not a single existing binary >> will work today if someone tries to do this. >> >> So, it seems very premature to take this off. At the very least >> document it like Will requested, and make it depend on !ARM_64K_PAGES >> || EXPERT. > > That would work for me. We need to be clear that most existing 32-bit > binaries will fail.
Agreed. Btw we intend to ensure that a future Fedora mass rebuild incorporates this change in alignment on 32-bit to allow 32-bit Fedora userspace to exist inside a (32-bit personality) chroot on AArch64. This will allow us to migrate to 64-bit native builders both for 32 and 64-bit in advance of the eventual plan for KVM based build guests. Jon. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
