From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030490Ab2HGWdZ (ORCPT ); Tue, 7 Aug 2012 18:33:25 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:54583 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030482Ab2HGWdN (ORCPT ); Tue, 7 Aug 2012 18:33:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Andreas Schwab , Thorsten Glaser , Geert Uytterhoeven Subject: [ 119/122] m68k: Make sys_atomic_cmpxchg_32 work on classic m68k Date: Tue, 7 Aug 2012 15:26:47 -0700 Message-Id: <20120807222000.933320441@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120807221948.220495155@linuxfoundation.org> References: <20120807221948.220495155@linuxfoundation.org> User-Agent: quilt/0.60-20.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andreas Schwab commit 9e2760d18b3cf179534bbc27692c84879c61b97c upstream. User space access must always go through uaccess accessors, since on classic m68k user space and kernel space are completely separate. Signed-off-by: Andreas Schwab Tested-by: Thorsten Glaser Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- arch/m68k/kernel/sys_m68k.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/arch/m68k/kernel/sys_m68k.c +++ b/arch/m68k/kernel/sys_m68k.c @@ -479,9 +479,13 @@ sys_atomic_cmpxchg_32(unsigned long newv goto bad_access; } - mem_value = *mem; + /* + * No need to check for EFAULT; we know that the page is + * present and writable. + */ + __get_user(mem_value, mem); if (mem_value == oldval) - *mem = newval; + __put_user(newval, mem); pte_unmap_unlock(pte, ptl); up_read(&mm->mmap_sem);