From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757368Ab2HGDif (ORCPT ); Mon, 6 Aug 2012 23:38:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59712 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757336Ab2HGDi3 (ORCPT ); Mon, 6 Aug 2012 23:38:29 -0400 Message-Id: <20120807032804.958167326@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Tue, 07 Aug 2012 04:28:56 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Andreas Schwab , Thorsten Glaser , Geert Uytterhoeven Subject: [ 61/70] m68k: Make sys_atomic_cmpxchg_32 work on classic m68k In-Reply-To: <20120807032755.803571133@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-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: Ben Hutchings --- arch/m68k/kernel/sys_m68k.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c index 8623f8d..9a5932e 100644 --- a/arch/m68k/kernel/sys_m68k.c +++ b/arch/m68k/kernel/sys_m68k.c @@ -479,9 +479,13 @@ sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5, 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);