From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755596AbaIBWTG (ORCPT ); Tue, 2 Sep 2014 18:19:06 -0400 Received: from terminus.zytor.com ([198.137.202.10]:40514 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751326AbaIBWTC (ORCPT ); Tue, 2 Sep 2014 18:19:02 -0400 Date: Tue, 2 Sep 2014 15:18:47 -0700 From: tip-bot for Oleg Nesterov Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, sbsiddha@gmail.com, oleg@redhat.com, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, sbsiddha@gmail.com, tglx@linutronix.de, oleg@redhat.com, hpa@linux.intel.com In-Reply-To: <20140902175717.GA21649@redhat.com> References: <20140902175717.GA21649@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/fpu] x86, fpu: __restore_xstate_sig()-> math_state_restore() needs preempt_disable() Git-Commit-ID: df24fb859a4e200d9324e2974229fbb7adf00aef X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: df24fb859a4e200d9324e2974229fbb7adf00aef Gitweb: http://git.kernel.org/tip/df24fb859a4e200d9324e2974229fbb7adf00aef Author: Oleg Nesterov AuthorDate: Tue, 2 Sep 2014 19:57:17 +0200 Committer: H. Peter Anvin CommitDate: Tue, 2 Sep 2014 14:51:15 -0700 x86, fpu: __restore_xstate_sig()->math_state_restore() needs preempt_disable() Add preempt_disable() + preempt_enable() around math_state_restore() in __restore_xstate_sig(). Otherwise __switch_to() after __thread_fpu_begin() can overwrite fpu->state we are going to restore. Signed-off-by: Oleg Nesterov Link: http://lkml.kernel.org/r/20140902175717.GA21649@redhat.com Cc: # v3.7+ Reviewed-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/kernel/xsave.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index cf0b830..4c540c4 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -400,8 +400,11 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) set_used_math(); } - if (use_eager_fpu()) + if (use_eager_fpu()) { + preempt_disable(); math_state_restore(); + preempt_enable(); + } return err; } else {