From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932453AbcHNR6t (ORCPT ); Sun, 14 Aug 2016 13:58:49 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54917 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932332AbcHNR6q (ORCPT ); Sun, 14 Aug 2016 13:58:46 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Simon Marchi" , "Will Deacon" , "Russell King" Date: Sat, 13 Aug 2016 18:42:58 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 39/94] ARM: fix PTRACE_SETVFPREGS on SMP systems In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 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 3.2.82-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit e2dfb4b880146bfd4b6aa8e138c0205407cebbaf upstream. PTRACE_SETVFPREGS fails to properly mark the VFP register set to be reloaded, because it undoes one of the effects of vfp_flush_hwstate(). Specifically vfp_flush_hwstate() sets thread->vfpstate.hard.cpu to an invalid CPU number, but vfp_set() overwrites this with the original CPU number, thereby rendering the hardware state as apparently "valid", even though the software state is more recent. Fix this by reverting the previous change. Fixes: 8130b9d7b9d8 ("ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers") Acked-by: Will Deacon Tested-by: Simon Marchi Signed-off-by: Russell King Signed-off-by: Ben Hutchings --- arch/arm/kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -726,8 +726,8 @@ static int vfp_set(struct task_struct *t if (ret) return ret; - vfp_flush_hwstate(thread); thread->vfpstate.hard = new_vfp; + vfp_flush_hwstate(thread); return 0; }