From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932795AbbAYTLr (ORCPT ); Sun, 25 Jan 2015 14:11:47 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:57212 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755264AbbAYSJU (ORCPT ); Sun, 25 Jan 2015 13:09:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "H. Peter Anvin" , Andrew Morton , Daniel Borkmann , Richard Weinberger Subject: [PATCH 3.14 80/98] x86, um: actually mark system call tables readonly Date: Sun, 25 Jan 2015 10:07:38 -0800 Message-Id: <20150125180716.353030879@linuxfoundation.org> X-Mailer: git-send-email 2.2.2 In-Reply-To: <20150125180712.859646324@linuxfoundation.org> References: <20150125180712.859646324@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann commit b485342bd79af363c77ef1a421c4a0aef2de9812 upstream. Commit a074335a370e ("x86, um: Mark system call tables readonly") was supposed to mark the sys_call_table in UML as RO by adding the const, but it doesn't have the desired effect as it's nevertheless being placed into the data section since __cacheline_aligned enforces sys_call_table being placed into .data..cacheline_aligned instead. We need to use the ____cacheline_aligned version instead to fix this issue. Before: $ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table" U sys_writev 0000000000000000 D sys_call_table 0000000000000000 D syscall_table_size After: $ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table" U sys_writev 0000000000000000 R sys_call_table 0000000000000000 D syscall_table_size Fixes: a074335a370e ("x86, um: Mark system call tables readonly") Cc: H. Peter Anvin Cc: Andrew Morton Signed-off-by: Daniel Borkmann Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- arch/x86/um/sys_call_table_32.c | 2 +- arch/x86/um/sys_call_table_64.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/um/sys_call_table_32.c +++ b/arch/x86/um/sys_call_table_32.c @@ -34,7 +34,7 @@ typedef asmlinkage void (*sys_call_ptr_t extern asmlinkage void sys_ni_syscall(void); -const sys_call_ptr_t sys_call_table[] __cacheline_aligned = { +const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = { /* * Smells like a compiler bug -- it doesn't work * when the & below is removed. --- a/arch/x86/um/sys_call_table_64.c +++ b/arch/x86/um/sys_call_table_64.c @@ -46,7 +46,7 @@ typedef void (*sys_call_ptr_t)(void); extern void sys_ni_syscall(void); -const sys_call_ptr_t sys_call_table[] __cacheline_aligned = { +const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = { /* * Smells like a compiler bug -- it doesn't work * when the & below is removed.