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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 40B4EC3A5A2 for ; Tue, 10 Sep 2019 11:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DA9020692 for ; Tue, 10 Sep 2019 11:04:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568113495; bh=vxm3z6UWbuS96zxG4ftNwH5crEzyY8v+vNsrZHxvMZc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=wc2sTD05Betf7/Sa7aucfeuLHc2OM0gePD90BOCcTR5TrSPPvRD83JabBxyfjBlDs TQOdOyaCzBnG9SeNPGS+Tfh/BrxrMLJUWEZMQRKS1rb4LCbgib14oxT+81mMa13t/M Dqq/dSFhQvq4iRTPBT+o/SB/3U9oYTlYtUPhcKic= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731274AbfIJLEy (ORCPT ); Tue, 10 Sep 2019 07:04:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:51846 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726406AbfIJLEx (ORCPT ); Tue, 10 Sep 2019 07:04:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6A4B6AC10; Tue, 10 Sep 2019 11:04:52 +0000 (UTC) Date: Tue, 10 Sep 2019 13:04:51 +0200 From: Michal Hocko To: Yunsheng Lin Cc: Greg KH , rafael@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, linuxarm@huawei.com Subject: Re: [PATCH] driver core: ensure a device has valid node id in device_add() Message-ID: <20190910110451.GP2063@dhcp22.suse.cz> References: <1568009063-77714-1-git-send-email-linyunsheng@huawei.com> <20190909095347.GB6314@kroah.com> <9598b359-ab96-7d61-687a-917bee7a5cd9@huawei.com> <20190910093114.GA19821@kroah.com> <34feca56-c95e-41a6-e09f-8fc2d2fd2bce@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <34feca56-c95e-41a6-e09f-8fc2d2fd2bce@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 10-09-19 18:58:05, Yunsheng Lin wrote: > On 2019/9/10 17:31, Greg KH wrote: > > On Tue, Sep 10, 2019 at 02:43:32PM +0800, Yunsheng Lin wrote: > >> On 2019/9/9 17:53, Greg KH wrote: > >>> On Mon, Sep 09, 2019 at 02:04:23PM +0800, Yunsheng Lin wrote: > >>>> Currently a device does not belong to any of the numa nodes > >>>> (dev->numa_node is NUMA_NO_NODE) when the node id is neither > >>>> specified by fw nor by virtual device layer and the device has > >>>> no parent device. > >>> > >>> Is this really a problem? > >> > >> Not really. > >> Someone need to guess the node id when it is not specified, right? > > > > No, why? Guessing guarantees you will get it wrong on some systems. > > > > Are you seeing real problems because the id is not being set? What > > problem is this fixing that you can actually observe? > > When passing the return value of dev_to_node() to cpumask_of_node() > without checking the node id if the node id is not valid, there is > global-out-of-bounds detected by KASAN as below: OK, I seem to remember this being brought up already. And now when I think about it, we really want to make cpumask_of_node NUMA_NO_NODE aware. That means using the same trick the allocator does for this special case. -- Michal Hocko SUSE Labs