From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733283AbgGaMWM (ORCPT ); Fri, 31 Jul 2020 08:22:12 -0400 From: Christoph Hellwig Subject: improve compat handling for the i386 u64 alignment quirk v2 Date: Fri, 31 Jul 2020 14:21:59 +0200 Message-ID: <20200731122202.213333-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: x86@kernel.org, Jan Kara Cc: linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org Message-ID: <20200731122159.YVur810whtOnSdMhNkkdLk9JJ148UNXV1c4cQfDULgs@z> Hi all, the i386 ABI is a little special in that it uses less than natural alignment for 64-bit integer types (u64 and s64), and a significant amount of our compat handlers deals with just that. Unfortunately there is no good way to check for this specific quirk at runtime, similar how in_compat_syscall() checks for a compat syscall. This series adds such a check, and then uses the quota code as an example of how this improves the compat handling. I have a few other places in mind where this will also be useful going forward. Changes since v1: - use asm-generic/compat.h instead of linux/compat.h for compat_u64 and compat_s64 - fix a typo Diffstat: b/arch/arm64/include/asm/compat.h | 2 b/arch/mips/include/asm/compat.h | 2 b/arch/parisc/include/asm/compat.h | 2 b/arch/powerpc/include/asm/compat.h | 2 b/arch/s390/include/asm/compat.h | 2 b/arch/sparc/include/asm/compat.h | 3 b/arch/x86/entry/syscalls/syscall_32.tbl | 2 b/arch/x86/include/asm/compat.h | 3 b/fs/quota/Kconfig | 5 - b/fs/quota/Makefile | 1 b/fs/quota/compat.h | 34 ++++++++ b/fs/quota/quota.c | 73 +++++++++++++++--- b/include/asm-generic/compat.h | 8 ++ b/include/linux/compat.h | 9 ++ b/include/linux/quotaops.h | 3 b/kernel/sys_ni.c | 1 fs/quota/compat.c | 120 ------------------------------- 17 files changed, 113 insertions(+), 159 deletions(-)