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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 378ECC433B4 for ; Thu, 20 May 2021 10:01:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CAD1161CE5 for ; Thu, 20 May 2021 10:01:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CAD1161CE5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 32D5D6B00AA; Thu, 20 May 2021 06:01:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2DD206B00AB; Thu, 20 May 2021 06:01:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 17E006B00AC; Thu, 20 May 2021 06:01:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0050.hostedemail.com [216.40.44.50]) by kanga.kvack.org (Postfix) with ESMTP id DD71B6B00AA for ; Thu, 20 May 2021 06:01:23 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 7D73D82068BB for ; Thu, 20 May 2021 10:01:23 +0000 (UTC) X-FDA: 78161166846.02.9B6341E Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf27.hostedemail.com (Postfix) with ESMTP id 4A826801912D for ; Thu, 20 May 2021 10:01:21 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 8B5D9ADCE; Thu, 20 May 2021 10:01:21 +0000 (UTC) To: Stephen Boyd , Andrew Morton Cc: linux-kernel@vger.kernel.org, Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, Timur Tabi , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Kees Cook , Marco Elver , Linus Torvalds References: <20210520013539.3733631-1-swboyd@chromium.org> From: Vlastimil Babka Subject: Re: [PATCH 0/3] slub: Print non-hashed pointers in slub debugging Message-ID: Date: Thu, 20 May 2021 12:01:20 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210520013539.3733631-1-swboyd@chromium.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Authentication-Results: imf27.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf27.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.15 as permitted sender) smtp.mailfrom=vbabka@suse.cz X-Stat-Signature: 49yrxjuapfbm6kw3qehfesnjom7h953b X-Rspamd-Queue-Id: 4A826801912D X-Rspamd-Server: rspam02 X-HE-Tag: 1621504881-644119 Content-Transfer-Encoding: quoted-printable 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: +CC folks from the no_hash_pointers debate Full thread with patches here: https://lore.kernel.org/linux-mm/20210520013539.3733631-1-swboyd@chromium= .org/ On 5/20/21 3:35 AM, Stephen Boyd wrote: > I was doing some debugging recently and noticed that my pointers were > being hashed while slub_debug was on the kernel commandline. Let's make > the prints in here meaningful in that case by pushing %px throughout. But we actually added no_hash_pointers exactly so that we don't push %px = in hexdump and others. So I don't think this will be accepted. > Alternatively, we could force on no_hash_pointers if slub_debug is on > the commandline. Maybe that would be better? That would certainly be more acceptable, but maybe still too much, dunno.= I'm neutral on this approach, let's see what others think. > The final patch is just something else I noticed while looking at the > code. The message argument is never used so the debugging messages are > not as clear as they could be. >=20 > Stephen Boyd (3): > lib/hexdump: Add a raw pointer printing format for slub debugging > slub: Print raw pointer addresses when debugging > slub: Actually use 'message' in restore_bytes() >=20 > include/linux/printk.h | 1 + > lib/hexdump.c | 12 ++++++++++-- > mm/slub.c | 24 ++++++++++++------------ > 3 files changed, 23 insertions(+), 14 deletions(-) >=20 >=20 > base-commit: 6efb943b8616ec53a5e444193dccf1af9ad627b5 >=20