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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 3FFBDC47255 for ; Sat, 9 May 2020 00:25:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1459521655 for ; Sat, 9 May 2020 00:25:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588983952; bh=Ei2JHTi4sdU47AkE85V7sekI2RjA21qxjX5dG12CqXg=; h=From:To:Cc:Subject:Date:List-ID:From; b=TA8oCvZY8amZpE2Bon/gjmc4NwuJLWAftdCooVKZZicD2Xru2PpZFYn61lJYXutsk C67naz7hDiegqzKOca7kmU5+gfNtHvUo2M9S3slB8XK7vyYBfEad5qprQ+PeA9RAJR +D8E+EG66C1q5gqocIvwyi/EU+0fPxbth1/4/sWU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728392AbgEIAZh (ORCPT ); Fri, 8 May 2020 20:25:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:57908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727959AbgEIAZh (ORCPT ); Fri, 8 May 2020 20:25:37 -0400 Received: from localhost (c-67-180-165-146.hsd1.ca.comcast.net [67.180.165.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F137B21582; Sat, 9 May 2020 00:25:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588983937; bh=Ei2JHTi4sdU47AkE85V7sekI2RjA21qxjX5dG12CqXg=; h=From:To:Cc:Subject:Date:From; b=0MgInU9qDOkt3AK2ILhu+1PvhrX4LhiF2GDYvxjwCeYjLPfIJUZS83dQ6c0P0M+fi JxSqkeB1dc9IeRSKUSX+cLDYxYrD/+74ifmZwa0ePXvfIcETou1kdgBiZ0dJPpLqws trmdf+PlmMKacFPp8eFQBB378BeUaAaY5dvT/QEU= From: Andy Lutomirski To: X86 ML , LKML Cc: Andy Lutomirski , Thorsten Glaser , stable@kernel.org Subject: [PATCH] Revert "x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long" Date: Fri, 8 May 2020 17:25:32 -0700 Message-Id: <92e55442b744a5951fdc9cfee10badd0a5f7f828.1588983892.git.luto@kernel.org> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This reverts commit 45e29d119e9923ff14dfb840e3482bef1667bbfb and adds a comment to discourage someone else from making the same mistake again. It turns out that some user code fails to compile if __X32_SYSCALL_BIT is unsigned long. See, for example: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=954294 Reported-by: Thorsten Glaser Fixes: 45e29d119e99 ("x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long") Cc: stable@kernel.org Signed-off-by: Andy Lutomirski --- arch/x86/include/uapi/asm/unistd.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/uapi/asm/unistd.h b/arch/x86/include/uapi/asm/unistd.h index 196fdd02b8b1..be5e2e747f50 100644 --- a/arch/x86/include/uapi/asm/unistd.h +++ b/arch/x86/include/uapi/asm/unistd.h @@ -2,8 +2,15 @@ #ifndef _UAPI_ASM_X86_UNISTD_H #define _UAPI_ASM_X86_UNISTD_H -/* x32 syscall flag bit */ -#define __X32_SYSCALL_BIT 0x40000000UL +/* + * x32 syscall flag bit. Some user programs expect syscall NR macros + * and __X32_SYSCALL_BIT to have type int, even though syscall numbers + * are, for practical purposes, unsigned long. + * + * Fortunately, expressions like (nr & ~__X32_SYSCALL_BIT) do the right + * thing regardless. + */ +#define __X32_SYSCALL_BIT 0x40000000 #ifndef __KERNEL__ # ifdef __i386__ -- 2.25.4