From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754837AbZEWWnY (ORCPT ); Sat, 23 May 2009 18:43:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752399AbZEWWnQ (ORCPT ); Sat, 23 May 2009 18:43:16 -0400 Received: from mx2.redhat.com ([66.187.237.31]:38195 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752200AbZEWWnP (ORCPT ); Sat, 23 May 2009 18:43:15 -0400 Message-ID: <4A187BDE.5070601@redhat.com> Date: Sat, 23 May 2009 18:42:38 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: Ingo Molnar CC: "Larry H." , linux-kernel@vger.kernel.org, Linus Torvalds , linux-mm@kvack.org, Ingo Molnar , Alan Cox , pageexec@freemail.hu Subject: Re: [patch 0/5] Support for sanitization flag in low-level page allocator References: <20090520183045.GB10547@oblivion.subreption.com> <4A15A8C7.2030505@redhat.com> <20090522073436.GA3612@elte.hu> <20090522113809.GB13971@oblivion.subreption.com> <20090523124944.GA23042@elte.hu> In-Reply-To: <20090523124944.GA23042@elte.hu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > What you are missing is that your patch makes _no technical sense_ > if you allow the same information to leak over the kernel stack. > Kernel stacks can be freed and reused, swapped out and thus > 'exposed'. Kernel stacks may be freed and reused, but Larry's latest patch takes care of that by clearing them at page free time. As for being swapped out - I do not believe that kernel stacks can ever be swapped out in Linux. -- All rights reversed. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 8B5E76B0055 for ; Sat, 23 May 2009 18:42:24 -0400 (EDT) Message-ID: <4A187BDE.5070601@redhat.com> Date: Sat, 23 May 2009 18:42:38 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [patch 0/5] Support for sanitization flag in low-level page allocator References: <20090520183045.GB10547@oblivion.subreption.com> <4A15A8C7.2030505@redhat.com> <20090522073436.GA3612@elte.hu> <20090522113809.GB13971@oblivion.subreption.com> <20090523124944.GA23042@elte.hu> In-Reply-To: <20090523124944.GA23042@elte.hu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Ingo Molnar Cc: "Larry H." , linux-kernel@vger.kernel.org, Linus Torvalds , linux-mm@kvack.org, Ingo Molnar , Alan Cox , pageexec@freemail.hu List-ID: Ingo Molnar wrote: > What you are missing is that your patch makes _no technical sense_ > if you allow the same information to leak over the kernel stack. > Kernel stacks can be freed and reused, swapped out and thus > 'exposed'. Kernel stacks may be freed and reused, but Larry's latest patch takes care of that by clearing them at page free time. As for being swapped out - I do not believe that kernel stacks can ever be swapped out in Linux. -- All rights reversed. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org