Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933373AbaLDXsW (ORCPT ); Thu, 4 Dec 2014 18:48:22 -0500 Received: from cantor2.suse.de ([195.135.220.15]:35029 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754730AbaLDXsV (ORCPT ); Thu, 4 Dec 2014 18:48:21 -0500 From: Alexander Graf To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Catalin Marinas , olof@lixom.net, lauraa@codeaurora.org Subject: [PATCH v2] arm64: Enable CONFIG_COMPAT also for 64k page size Date: Fri, 5 Dec 2014 00:48:19 +0100 Message-Id: <1417736899-115619-1-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.7.12.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- v1 -> v2: - add comment in KConfig explaining that segments need to be 64k aligned - conditionalize the option on EXPERT --- arch/arm64/Kconfig | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9532f8d..7fc0ad6 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -409,7 +409,7 @@ source "fs/Kconfig.binfmt" config COMPAT bool "Kernel support for 32-bit EL0" - depends on !ARM64_64K_PAGES + depends on !ARM64_64K_PAGES || EXPERT select COMPAT_BINFMT_ELF select HAVE_UID16 select OLD_SIGSUSPEND3 @@ -420,6 +420,10 @@ config COMPAT the user helper functions, VFP support and the ptrace interface are handled appropriately by the kernel. + If you also enabled CONFIG_ARM64_64K_PAGES, please be aware that you + will only be able to execute AArch32 binaries that were compiled with + 64k aligned segments. + If you want to execute 32-bit userspace applications, say Y. config SYSVIPC_COMPAT -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/