From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH v4 10/29] x86/die: Don't try to recover from an OOPS on a non-default stack Date: Sun, 3 Jul 2016 11:40:38 +0200 Message-ID: <20160703094038.GA1781@pd.tnic> References: <37ac7589ff0ea147e8a21cda5eb84d3af1f6cd60.1466974736.git.luto@kernel.org> <20160702172441.GA22748@pd.tnic> <20160702183451.e2nlfkfxlsuicbqd@treble> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from mail.skyhub.de ([78.46.96.112]:38238 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750955AbcGCJkr (ORCPT ); Sun, 3 Jul 2016 05:40:47 -0400 Content-Disposition: inline In-Reply-To: <20160702183451.e2nlfkfxlsuicbqd@treble> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Josh Poimboeuf Cc: Andy Lutomirski , x86@kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Jann Horn , Heiko Carstens On Sat, Jul 02, 2016 at 01:34:51PM -0500, Josh Poimboeuf wrote: > The existing 'object_is_on_stack()' can probably be used: > > if (!object_is_on_stack(current_top_of_stack())) > panic("..."); > > Though that function isn't quite accurately named. It should really > have 'task_stack' in its name, like 'object_is_on_task_stack()'. Or > even better, something more concise like 'on_task_stack()'. So I'm obviously missing something here: object_is_on_stack() uses task_stack_page(current) -> task_struct.stack while current_stack_pointer() reads %rsp directly. I'm guessing %rsp and task_struct.stack are in sync? -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.