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=-2.3 required=3.0 tests=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 83751C2D0B1 for ; Tue, 4 Feb 2020 14:19:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59BB72084E for ; Tue, 4 Feb 2020 14:19:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="R3YSkdAC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727299AbgBDOTt (ORCPT ); Tue, 4 Feb 2020 09:19:49 -0500 Received: from mail-il1-f196.google.com ([209.85.166.196]:38587 "EHLO mail-il1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727218AbgBDOTt (ORCPT ); Tue, 4 Feb 2020 09:19:49 -0500 Received: by mail-il1-f196.google.com with SMTP id f5so15992187ilq.5 for ; Tue, 04 Feb 2020 06:19:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=4NlxEaC0CdDvRmfmIJOSEJmWKwzQJ80B9aXkZjJVyL8=; b=R3YSkdACMblNudrIIr49OI3al1MMBN9pmhJpPWyJwaetdve9dKaEu4pAHACB4+u2DF 8Re7w8S0G+/W+SkBaa9pXdjLEJgZqKWQ8s9eCl/DKXsZWeLk9hHmOdPgOxqLuTCXvXyk yJRQaS5WB/Irw4AlkCK5j79caBjeqEiCu6e+ltXtI1P2/VvDKBPrk5jI5npLthe2pl+a nTQKvvmGHkeckVgcdRdGQPIKUsViJqgnocZDU+l36nuGwDK226cjTK9FOJu3VhK1iTvc k7xzCvUqwAdTduymjTDHAuc7mlfsxytXEsCZRHITH6bb+AxexBTsa7Ee6DRQnwyM7ls5 MJyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=4NlxEaC0CdDvRmfmIJOSEJmWKwzQJ80B9aXkZjJVyL8=; b=aq1TzIEAn22j0xwB0Ui70b20o4Le7YWnZ0/op3nAWd2MwZN5O8FjeicPzohpfs4lNH F60TpgrqDBDCVjXcto069QuH5Ip+7W5529gOXJpYTCy6PnkcdMmFQ4zBdB4U5CKL6blH V17v609H9zUFkHjo6jEd0MjYuqUc2Tj1jUmlY9GVQPOcHSJ+AWsMgkI0uk5Fjfq6SgUu 34kk7Plhso5V3YzvJ7HP1SG9pBLAPd/bxiIxht7UtNFr4B5MRu+aXwmnJnkxn31pk8Tn FDKCLPxB2EIHtbdhYwcEqTip3/lHOLHNFPrd9fDBRF5UDyWxoFxLHzABwn7FN6Fy5pFA OEew== X-Gm-Message-State: APjAAAWOt38bgZEv+NnWRdNUMRJ8neNzAWgZuKgdwPGhgolYb9oRfcA9 rigyl+/isMjrRuogolu/5ocrnw== X-Google-Smtp-Source: APXvYqyxorWrGAGoWeM+23k80onJrm+gVqtgsoo6CxIXcvEAH60ecFJYPhSM/N/ICQ4LGxIScoIUBA== X-Received: by 2002:a92:2904:: with SMTP id l4mr28325026ilg.166.1580825987128; Tue, 04 Feb 2020 06:19:47 -0800 (PST) Received: from [192.168.1.159] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id d17sm8838522ild.11.2020.02.04.06.19.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 Feb 2020 06:19:46 -0800 (PST) Subject: Re: [PATCH V6] brd: check and limit max_part par To: Zhiqiang Liu , Ming Lei Cc: linux-block@vger.kernel.org, "linux-kernel@vger.kernel.org" , Mingfangsen , Yanxiaodan , Guiyao , "wubo (T)" References: From: Jens Axboe Message-ID: <14b08288-7f0d-1033-302d-41549bfa5b67@kernel.dk> Date: Tue, 4 Feb 2020 07:19:45 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/4/20 4:30 AM, Zhiqiang Liu wrote: > In brd_init func, rd_nr num of brd_device are firstly allocated > and add in brd_devices, then brd_devices are traversed to add each > brd_device by calling add_disk func. When allocating brd_device, > the disk->first_minor is set to i * max_part, if rd_nr * max_part > is larger than MINORMASK, two different brd_device may have the same > devt, then only one of them can be successfully added. > when rmmod brd.ko, it will cause oops when calling brd_exit. > > Follow those steps: > # modprobe brd rd_nr=3 rd_size=102400 max_part=1048576 > # rmmod brd > then, the oops will appear. > > Oops log: > [ 726.613722] Call trace: > [ 726.614175] kernfs_find_ns+0x24/0x130 > [ 726.614852] kernfs_find_and_get_ns+0x44/0x68 > [ 726.615749] sysfs_remove_group+0x38/0xb0 > [ 726.616520] blk_trace_remove_sysfs+0x1c/0x28 > [ 726.617320] blk_unregister_queue+0x98/0x100 > [ 726.618105] del_gendisk+0x144/0x2b8 > [ 726.618759] brd_exit+0x68/0x560 [brd] > [ 726.619501] __arm64_sys_delete_module+0x19c/0x2a0 > [ 726.620384] el0_svc_common+0x78/0x130 > [ 726.621057] el0_svc_handler+0x38/0x78 > [ 726.621738] el0_svc+0x8/0xc > [ 726.622259] Code: aa0203f6 aa0103f7 aa1e03e0 d503201f (7940e260) > > Here, we add brd_check_and_reset_par func to check and limit max_part par. Applied, thanks. -- Jens Axboe