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=-12.6 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,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 3C05FC433F2 for ; Sun, 26 Jul 2020 16:04:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0EC832070B for ; Sun, 26 Jul 2020 16:04:26 +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="kohjCkwv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727809AbgGZQEQ (ORCPT ); Sun, 26 Jul 2020 12:04:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727852AbgGZQEO (ORCPT ); Sun, 26 Jul 2020 12:04:14 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51AC9C0619D2; Sun, 26 Jul 2020 09:04:14 -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=Qgxj/loCE+O6wxKk/eqjrsxG348MHNKY89kEnscKvrM=; b=kohjCkwvuA7bxnRm6vGl5H2oKA GzAu5e2DedmqSrCUCxMa2wVzikiqeFhOAl7DopN5IIIPZlxSBnMNN1s+aIJdy4r4w128g5qlQktZ5 YtdAxg07ilyloUoEIvwAATlsMwEJ2nW7RmE7UbmspjS0dD6kmdr2r9RVAXNyFcrA+yeLf7HHn7MeA oabw8e8mNooy7RXCnSFXymIHpGIym1zjyeQwgy9bn5uUfiWozo8sO8UGDSnNOxX8JYvlai4HlPcaf 0UXci6cy2qYk0tiaI2aLMi1nEhYIefNc0mTYxWPPIcsAX+lmWN71eVWE26/hBWamIXrO4SA/W1fnc 8i9ErYBw==; Received: from [2001:4bb8:18c:2acc:2375:88ff:9f84:118d] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jzj8E-0000Zf-1n; Sun, 26 Jul 2020 16:04:10 +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 3/4] compat: add a compat_need_64bit_alignment_fixup() helper Date: Sun, 26 Jul 2020 18:04:00 +0200 Message-Id: <20200726160401.311569-4-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200726160401.311569-1-hch@lst.de> References: <20200726160401.311569-1-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 c22a7f1d253b87..afdd44ba3a8869 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -945,6 +945,15 @@ 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