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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED, 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 CC282C43142 for ; Wed, 27 Jun 2018 05:45:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75D50268F1 for ; Wed, 27 Jun 2018 05:45:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="arcnDB1a" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75D50268F1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753175AbeF0Fp5 (ORCPT ); Wed, 27 Jun 2018 01:45:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:41128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751316AbeF0Fpz (ORCPT ); Wed, 27 Jun 2018 01:45:55 -0400 Received: from localhost (c-71-202-137-17.hsd1.ca.comcast.net [71.202.137.17]) (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 BE91E267FF; Wed, 27 Jun 2018 05:45:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1530078354; bh=V6ohwXtyx/0JJfI970j3QZNpDE24Mvnj4xYCGvl5A9M=; h=From:To:Cc:Subject:Date:From; b=arcnDB1a7+Bm0NOfye1Cmq5zmFU1c9AI/rDrenBurFCAo+dT2Jnh4Pv4r1h7zQ/j5 fVxoziAr2ebuBjkHsxy4IFlDdfawYEKXWmYt93unPWRV66LvVzEPDsoa1avjr+zK0N rzmKiCvcMMBDUZacMVAPSgwW5WXRJg6ztNEL9oKQ= From: Andy Lutomirski To: x86@kernel.org, LKML Cc: Borislav Petkov , zhijianx.li@intel.com, Andy Lutomirski , stable@vger.kernel.org Subject: [PATCH] x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80" Date: Tue, 26 Jun 2018 22:45:52 -0700 Message-Id: <6012b922485401bc42676e804171ded262fc2ef2.1530078306.git.luto@kernel.org> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80") was busted. My original patch had a minor conflict with some of the nospec changes. git apply is very clever and silently accepted the patch by making the same changes to a different function in the same file. There was obviously a huge offset, but git apply for some reason doesn't feel any need to say so. Move the changes to the correct function. Now the test_syscall_vdso_32 selftests passes. If anyone cares to observe the original problem, try applying the patch at https://lore.kernel.org/lkml/d4c4d9985fbe64f8c9e19291886453914b48caee.1523975710.git.luto@kernel.org/raw to the kernel at 316d097c4cd4e7f2ef50c40cff2db266593c4ec4. git am and git apply accept the patch without any complaints at all. patch -p1 at least prints out a message about the huge offset. Reported-by: zhijianx.li@intel.com Fixes: 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80") Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski --- arch/x86/entry/entry_64_compat.S | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 9de7f1e1dede..7d0df78db727 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -84,13 +84,13 @@ ENTRY(entry_SYSENTER_compat) pushq %rdx /* pt_regs->dx */ pushq %rcx /* pt_regs->cx */ pushq $-ENOSYS /* pt_regs->ax */ - pushq %r8 /* pt_regs->r8 */ + pushq $0 /* pt_regs->r8 = 0 */ xorl %r8d, %r8d /* nospec r8 */ - pushq %r9 /* pt_regs->r9 */ + pushq $0 /* pt_regs->r9 = 0 */ xorl %r9d, %r9d /* nospec r9 */ - pushq %r10 /* pt_regs->r10 */ + pushq $0 /* pt_regs->r10 = 0 */ xorl %r10d, %r10d /* nospec r10 */ - pushq %r11 /* pt_regs->r11 */ + pushq $0 /* pt_regs->r11 = 0 */ xorl %r11d, %r11d /* nospec r11 */ pushq %rbx /* pt_regs->rbx */ xorl %ebx, %ebx /* nospec rbx */ @@ -374,13 +374,13 @@ ENTRY(entry_INT80_compat) pushq %rcx /* pt_regs->cx */ xorl %ecx, %ecx /* nospec cx */ pushq $-ENOSYS /* pt_regs->ax */ - pushq $0 /* pt_regs->r8 = 0 */ + pushq %r8 /* pt_regs->r8 */ xorl %r8d, %r8d /* nospec r8 */ - pushq $0 /* pt_regs->r9 = 0 */ + pushq %r9 /* pt_regs->r9 */ xorl %r9d, %r9d /* nospec r9 */ - pushq $0 /* pt_regs->r10 = 0 */ + pushq %r10 /* pt_regs->r10*/ xorl %r10d, %r10d /* nospec r10 */ - pushq $0 /* pt_regs->r11 = 0 */ + pushq %r11 /* pt_regs->r11 */ xorl %r11d, %r11d /* nospec r11 */ pushq %rbx /* pt_regs->rbx */ xorl %ebx, %ebx /* nospec rbx */ -- 2.17.1