From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87CBBC433E0 for ; Fri, 31 Jul 2020 12:22:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EDA32087C for ; Fri, 31 Jul 2020 12:22:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="V3I6U4u4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733290AbgGaMWP (ORCPT ); Fri, 31 Jul 2020 08:22:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733285AbgGaMWM (ORCPT ); Fri, 31 Jul 2020 08:22:12 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F4F1C06174A; Fri, 31 Jul 2020 05:22:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=XJVkNSbm3rNjn+7yYFiPCzhlPnNgnxohOidDxm683oU=; b=V3I6U4u4zECJMCSr8grbvFcJW0 aINEZxdcBI9e7BwM0h4uMMjXa+LOmh/up37cfjbD7lt7ha3RNhBay4PTAXSZqF/WqwnIIYuVr2L0l lOftc3sWjQ6xHTJkcF/BeJt6wZ+wA/CvquyoxxaTj5orCMU7NMeeHDWTuHQno0nTfy2jM9RaXrqHN PirBX1OuYkgji2N3NuMSPBK8w7MUuRSgZeuf5rnI+tYB1gmKIIlXTlimivbRY2Em67o1sOwbHumtw Shr3vd9WOEG4+5byb2wNJwqPzImknwD0aY8ZhRpmGXWt7g9Nt0oyE48qn2443p41PSH0+70Nn8THf b7gYCGlQ==; Received: from 138.57.168.109.cust.ip.kpnqwest.it ([109.168.57.138] helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k1U37-000269-7W; Fri, 31 Jul 2020 12:22:09 +0000 From: Christoph Hellwig 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 Subject: [PATCH 2/3] compat: add a compat_need_64bit_alignment_fixup() helper Date: Fri, 31 Jul 2020 14:22:01 +0200 Message-Id: <20200731122202.213333-3-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200731122202.213333-1-hch@lst.de> References: <20200731122202.213333-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org Add a helper to check if the calling syscall needs a fixup for non-natural 64-bit type alignment in the compat ABI. This will only return true for i386 syscalls on x86_64. Signed-off-by: Christoph Hellwig --- arch/x86/include/asm/compat.h | 1 + include/linux/compat.h | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index bf547701f41f87..0e327a01f50fbb 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -209,6 +209,7 @@ static inline bool in_compat_syscall(void) return in_32bit_syscall(); } #define in_compat_syscall in_compat_syscall /* override the generic impl */ +#define compat_need_64bit_alignment_fixup in_ia32_syscall #endif struct compat_siginfo; diff --git a/include/linux/compat.h b/include/linux/compat.h index e90100c0de72e4..a195f90f156cf6 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -937,6 +937,15 @@ static inline bool in_compat_syscall(void) { return false; } #endif /* CONFIG_COMPAT */ +/* + * Some legacy ABIs like the i386 one use less than natural alignment for 64-bit + * types, and will need special compat treatment for that. Most architectures + * don't need that special handling even for compat syscalls. + */ +#ifndef compat_need_64bit_alignment_fixup +#define compat_need_64bit_alignment_fixup() false +#endif + /* * A pointer passed in from user mode. This should not * be used for syscall parameters, just declare them -- 2.27.0