From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4C44C31E40 for ; Fri, 9 Aug 2019 14:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 907A2204EC for ; Fri, 9 Aug 2019 14:26:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="JH5PlAW1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407048AbfHIO0Z (ORCPT ); Fri, 9 Aug 2019 10:26:25 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:51728 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbfHIO0Y (ORCPT ); Fri, 9 Aug 2019 10:26:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=EaBoxEWlwr4zZ1rJszejMFTUZoMex/Sf4azgLrG5t04=; b=JH5PlAW1P2xfQ+UotOi2WPcif C19dMDk6AncmpZY3SMLP16T8M5SGZUNI02MGYfsWwHSsQxhnYdPMXDE/rLpAP+7lCYOyADYpGM0z7 gtGfOgSE7pZzBwYe+vjSFFHzHmuJDIsqXYQL3ViPGaBxFATmoPqv3oK1UJBO9sAZ02mPwUw29Najp nWDEyZSTpAapVfw0ofuowNHThlH+U7ZlvyQyETUpS2WbUhnYzz9F7kwdt5498KBCoEACm6R+Y6j7q pZa5eIT2eGWi3ZBnt4MBZ2NR5uL/1SxETSyrY8IFjGvtEQ73OpE+b1AxiX4A/ilb/+hcfrlkKqrEv VYTD+LGxg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hw5qT-0007Je-Q0; Fri, 09 Aug 2019 14:26:17 +0000 Date: Fri, 9 Aug 2019 07:26:17 -0700 From: Matthew Wilcox To: Miles Chen Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com, "Tobin C . Harding" , Kees Cook Subject: Re: [RFC PATCH v2] mm: slub: print kernel addresses in slub debug messages Message-ID: <20190809142617.GO5482@bombadil.infradead.org> References: <20190809010837.24166-1-miles.chen@mediatek.com> <20190809024644.GL5482@bombadil.infradead.org> <1565359918.12824.20.camel@mtkswgap22> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1565359918.12824.20.camel@mtkswgap22> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 09, 2019 at 10:11:58PM +0800, Miles Chen wrote: > On Thu, 2019-08-08 at 19:46 -0700, Matthew Wilcox wrote: > > On Fri, Aug 09, 2019 at 09:08:37AM +0800, miles.chen@mediatek.com wrote: > > > INFO: Slab 0x(____ptrval____) objects=25 used=10 fp=0x(____ptrval____) > > > > ... you don't have any randomness on your platform? > > We have randomized base on our platforms. Look at initialize_ptr_random(). If you have randomness, then you get a siphash_1u32() of the address. With no randomness, you get this ___ptrval___ string instead.