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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 026E3C3A5A2 for ; Tue, 10 Sep 2019 11:12:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE93E2082C for ; Tue, 10 Sep 2019 11:12:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568113976; bh=PD9H6wLyS/xRG838kVHNjqCpnvHomor6bbn+BhwaSnk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=QLS8v7UND0wKN3k1dYmToSkZsrehqO+wylGn9GA1x6ssdTbB02mujrROjk5G8teLK GeyB7o8MT4Dcd1YHmEU/FefkBOUD8yJZEMZ6YSTadoeneMqvlp2PHXx8lsm89enTgp M3bHkAduA7+BMt0lstQwc2Kq4f7FVcWpGFMK7M2I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732396AbfIJLM4 (ORCPT ); Tue, 10 Sep 2019 07:12:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:51946 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729270AbfIJLMz (ORCPT ); Tue, 10 Sep 2019 07:12:55 -0400 Received: from localhost (110.8.30.213.rev.vodafone.pt [213.30.8.110]) (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 74CA1207FC; Tue, 10 Sep 2019 11:12:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568113975; bh=PD9H6wLyS/xRG838kVHNjqCpnvHomor6bbn+BhwaSnk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oz3PQejY4fHlFE7NNmUuqi02wtM30x68VrstR+jB50Y6No3lozKwy9x2b6C7iQQ1P 7MyfGeVyn1I5qyr6PEz1BAg0fsFy55sBQiKNz14d+DVXIkVSNakpNUkUtBJtJVV9hQ KD+acilLF9FKFjD+T4qVlZX1gXjnxqAiIOjwnPN0= Date: Tue, 10 Sep 2019 12:12:52 +0100 From: Greg KH To: Michal Hocko Cc: Yunsheng Lin , 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: <20190910111252.GA8970@kroah.com> 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> <20190910110451.GP2063@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190910110451.GP2063@dhcp22.suse.cz> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 10, 2019 at 01:04:51PM +0200, Michal Hocko wrote: > 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. That seems reasonable to me, and much more "obvious" as to what is going on. thanks, greg k-h