Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753401AbaKLBWF (ORCPT ); Tue, 11 Nov 2014 20:22:05 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:58535 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753383AbaKLBWC (ORCPT ); Tue, 11 Nov 2014 20:22:02 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleg Nesterov , Suresh Siddha , "H. Peter Anvin" Subject: [PATCH 3.17 052/319] x86, fpu: __restore_xstate_sig()->math_state_restore() needs preempt_disable() Date: Wed, 12 Nov 2014 10:13:10 +0900 Message-Id: <20141112011001.250148655@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141112010952.553519040@linuxfoundation.org> References: <20141112010952.553519040@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 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit df24fb859a4e200d9324e2974229fbb7adf00aef upstream. 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 Reviewed-by: Suresh Siddha Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/xsave.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -402,8 +402,11 @@ int __restore_xstate_sig(void __user *bu set_used_math(); } - if (use_eager_fpu()) + if (use_eager_fpu()) { + preempt_disable(); math_state_restore(); + preempt_enable(); + } return err; } else { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/