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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 DE4D1C433E0 for ; Wed, 10 Feb 2021 16:46:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2906264DF6 for ; Wed, 10 Feb 2021 16:46:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2906264DF6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7CD486B0070; Wed, 10 Feb 2021 11:46:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 77E7A6B0072; Wed, 10 Feb 2021 11:46:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6BB5D6B0073; Wed, 10 Feb 2021 11:46:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0181.hostedemail.com [216.40.44.181]) by kanga.kvack.org (Postfix) with ESMTP id 537456B0070 for ; Wed, 10 Feb 2021 11:46:39 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1218E348D for ; Wed, 10 Feb 2021 16:46:39 +0000 (UTC) X-FDA: 77802936918.08.48BC97E Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf13.hostedemail.com (Postfix) with ESMTP id 527C2E0011C4 for ; Wed, 10 Feb 2021 16:46:38 +0000 (UTC) Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6681564DDF; Wed, 10 Feb 2021 16:46:35 +0000 (UTC) Date: Wed, 10 Feb 2021 11:46:33 -0500 From: Steven Rostedt To: Tetsuo Handa Cc: Timur Tabi , Petr Mladek , Sergey Senozhatsky , Vlastimil Babka , Andy Shevchenko , Matthew Wilcox , akpm@linux-foundation.org, Linus Torvalds , roman.fietze@magna.com, Kees Cook , John Ogness , akinobu.mita@gmail.com, glider@google.com, Andrey Konovalov , Marco Elver , Rasmus Villemoes , Pavel Machek , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/3][RESEND] add support for never printing hashed addresses Message-ID: <20210210114633.1b755f6e@gandalf.local.home> In-Reply-To: References: <20210210051814.845713-1-timur@kernel.org> <6da0be5a-7cb0-4943-e61f-7c3275e60cb6@i-love.sakura.ne.jp> <20210210111836.2468f10a@gandalf.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: jadyb94sgfiy66txy5gnnqohw84d59pu X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 527C2E0011C4 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: none/none X-HE-Tag: 1612975598-923529 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 11 Feb 2021 01:39:41 +0900 Tetsuo Handa wrote: > On 2021/02/11 1:18, Steven Rostedt wrote: > > The point of this exercise is to be able to debug the *same* kernel that > > someone is having issues with. And this is to facilitate that debugging. > > That's too difficult to use. If a problem is not reproducible, we will have > no choice but always specify "never hash pointers" command line option. If a > problem is reproducible, we can rebuild that kernel with "never hash pointers" > config option turned on. Now the question is, why do you need the unhashed pointer? Currently, the instruction pointer is what is fine right? You get the a function and its offset. If there's something that is needed, perhaps we should look at how to fix that, instead of just unhashing all pointers by default. -- Steve