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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC5BEC433F5 for ; Thu, 27 Jan 2022 23:58:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344004AbiA0X6D (ORCPT ); Thu, 27 Jan 2022 18:58:03 -0500 Received: from mga07.intel.com ([134.134.136.100]:60126 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229658AbiA0X6D (ORCPT ); Thu, 27 Jan 2022 18:58:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643327883; x=1674863883; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=fpwF/2DVAAP8AAH04cnzwc4Y7K3i/YIceEmdmUOEQmE=; b=RQtr5/yo6A2CHhhaCPEDG5V/nHZgEBIT3iW+hN60CneUNHb0ITnihxO7 GB2NKHpTY3zGofpLHlLEai4lKN/aAtWhDxtIfkMuLF9ZtbwRnSjZHtj1w IOPMarpwJjAfSYPo1TQ7e6DOETlHGoeABbU0FhdkIyZtEAlms6Ml9B7Cc wuE/ov7Hu7oaDCVl7CyRWXB5MyEHvPTkprhIZfKSA4H7SO+HBvCjExJqa rl1OeTzs6n8oioE9gb63bGBlbI8EQPXGYqwXLHvomshvD319dyHgBhQaG 7NgGgv2GMXr+bCqP2DDcW0KES/dao8Vg9KlsbSY/xqN2INZWZ/gQ0Mqu8 Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10239"; a="310311526" X-IronPort-AV: E=Sophos;i="5.88,321,1635231600"; d="scan'208";a="310311526" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2022 15:58:03 -0800 X-IronPort-AV: E=Sophos;i="5.88,321,1635231600"; d="scan'208";a="535896348" Received: from rlward-mobl1.amr.corp.intel.com (HELO vcostago-mobl3) ([10.212.255.84]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2022 15:58:02 -0800 From: Vinicius Costa Gomes To: Miroslav Lichvar , netdev@vger.kernel.org Cc: Miroslav Lichvar , Yangbo Lu , Yang Yingliang , Richard Cochran Subject: Re: [PATCH net-next 1/5] ptp: unregister virtual clocks when unregistering physical clock. In-Reply-To: <20220127114536.1121765-2-mlichvar@redhat.com> References: <20220127114536.1121765-1-mlichvar@redhat.com> <20220127114536.1121765-2-mlichvar@redhat.com> Date: Thu, 27 Jan 2022 15:58:02 -0800 Message-ID: <87czkcn33p.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Miroslav Lichvar writes: > When unregistering a physical clock which has some virtual clocks, > unregister the virtual clocks with it. > > This fixes the following oops, which can be triggered by unloading > a driver providing a PTP clock when it has enabled virtual clocks: > > BUG: unable to handle page fault for address: ffffffffc04fc4d8 > Oops: 0000 [#1] PREEMPT SMP NOPTI > RIP: 0010:ptp_vclock_read+0x31/0xb0 > Call Trace: > timecounter_read+0xf/0x50 > ptp_vclock_refresh+0x2c/0x50 > ? ptp_clock_release+0x40/0x40 > ptp_aux_kworker+0x17/0x30 > kthread_worker_fn+0x9b/0x240 > ? kthread_should_park+0x30/0x30 > kthread+0xe2/0x110 > ? kthread_complete_and_exit+0x20/0x20 > ret_from_fork+0x22/0x30 > > Fixes: 73f37068d540 ("ptp: support ptp physical/virtual clocks conversion") > Signed-off-by: Miroslav Lichvar > Cc: Yangbo Lu > Cc: Yang Yingliang > Cc: Richard Cochran > --- I am not against this change, but I think this problem was discussed before and the suggestions were to fix it differently: https://lore.kernel.org/all/20210807144332.szyazdfl42abwzmd@skbuf/ Cheers, -- Vinicius