From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www.kot-begemot.co.uk (ns1.kot-begemot.co.uk [217.160.28.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BA111C07EA; Mon, 4 Nov 2024 16:54:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.160.28.25 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730739283; cv=none; b=tc4fvTeI2h97+rHMUXmUZ0bexAxTKYIJDyy6NruYTwZH1P/scWVFAt90kXwXuu4kKsaQxpukHkU34JJddMOqRkQssFPbXRopz+xrZjoIid/AzzCh6I3JqDeUAyRI5OdaYzNbvHPzc8OB9Qkj0f7LpQG6QeDHDkM9krvvdNpir9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730739283; c=relaxed/simple; bh=xsxDHFnbfImmtC2rlnjfXAj+o2HkYwfXIviVbt9W8xM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Plfm7Anq+FokeoetrF5e2k6eT5L5yF+AFRhRSBweYr0YsTBEuNhQ2Pf7UZC6lqkwuktchJj051h/9j0trJKlcgpVazcjr4SlxUkkVzUgsW66EAqYhYoOGysXWy04v14Gb+E4tUdQSH2poHe2AFMbi8VIrFK2bY7+5jwsV2BThLY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=cambridgegreys.com; spf=pass smtp.mailfrom=cambridgegreys.com; arc=none smtp.client-ip=217.160.28.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=cambridgegreys.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cambridgegreys.com Received: from [192.168.17.6] (helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1t80LU-00Dwha-O1; Mon, 04 Nov 2024 16:54:28 +0000 Received: from jain.kot-begemot.co.uk ([192.168.3.3]) by jain.kot-begemot.co.uk with esmtp (Exim 4.96) (envelope-from ) id 1t80LR-00C1Rg-2Z; Mon, 04 Nov 2024 16:54:28 +0000 Message-ID: <54288e93-c389-444c-afe4-bd099523bfab@cambridgegreys.com> Date: Mon, 4 Nov 2024 16:54:25 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/4] um: net: Do not use drvdata in release To: Tiwei Bie , richard@nod.at, johannes@sipsolutions.net Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20241104163203.435515-1-tiwei.btw@antgroup.com> <20241104163203.435515-4-tiwei.btw@antgroup.com> Content-Language: en-US From: Anton Ivanov In-Reply-To: <20241104163203.435515-4-tiwei.btw@antgroup.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -1.0 X-Spam-Score: -1.0 X-Clacks-Overhead: GNU Terry Pratchett On 04/11/2024 16:32, Tiwei Bie wrote: > The drvdata is not available in release. Let's just use container_of() > to get the uml_net instance. Otherwise, removing a network device will > result in a crash: > > RIP: 0033:net_device_release+0x10/0x6f > RSP: 00000000e20c7c40 EFLAGS: 00010206 > RAX: 000000006002e4e7 RBX: 00000000600f1baf RCX: 00000000624074e0 > RDX: 0000000062778000 RSI: 0000000060551c80 RDI: 00000000627af028 > RBP: 00000000e20c7c50 R08: 00000000603ad594 R09: 00000000e20c7b70 > R10: 000000000000135a R11: 00000000603ad422 R12: 0000000000000000 > R13: 0000000062c7af00 R14: 0000000062406d60 R15: 00000000627700b6 > Kernel panic - not syncing: Segfault with no mm > CPU: 0 UID: 0 PID: 29 Comm: kworker/0:2 Not tainted 6.12.0-rc6-g59b723cd2adb #1 > Workqueue: events mc_work_proc > Stack: > 627af028 62c7af00 e20c7c80 60276fcd > 62778000 603f5820 627af028 00000000 > e20c7cb0 603a2bcd 627af000 62770010 > Call Trace: > [<60276fcd>] device_release+0x70/0xba > [<603a2bcd>] kobject_put+0xba/0xe7 > [<60277265>] put_device+0x19/0x1c > [<60281266>] platform_device_put+0x26/0x29 > [<60281e5f>] platform_device_unregister+0x2c/0x2e > [<6002ec9c>] net_remove+0x63/0x69 > [<60031316>] ? mconsole_reply+0x0/0x50 > [<600310c8>] mconsole_remove+0x160/0x1cc > [<60087d40>] ? __remove_hrtimer+0x38/0x74 > [<60087ff8>] ? hrtimer_try_to_cancel+0x8c/0x98 > [<6006b3cf>] ? dl_server_stop+0x3f/0x48 > [<6006b390>] ? dl_server_stop+0x0/0x48 > [<600672e8>] ? dequeue_entities+0x327/0x390 > [<60038fa6>] ? um_set_signals+0x0/0x43 > [<6003070c>] mc_work_proc+0x77/0x91 > [<60057664>] process_scheduled_works+0x1b3/0x2dd > [<60055f32>] ? assign_work+0x0/0x58 > [<60057f0a>] worker_thread+0x1e9/0x293 > [<6005406f>] ? set_pf_worker+0x0/0x64 > [<6005d65d>] ? arch_local_irq_save+0x0/0x2d > [<6005d748>] ? kthread_exit+0x0/0x3a > [<60057d21>] ? worker_thread+0x0/0x293 > [<6005dbf1>] kthread+0x126/0x12b > [<600219c5>] new_thread_handler+0x85/0xb6 > > Cc: stable@vger.kernel.org > Signed-off-by: Tiwei Bie > --- > arch/um/drivers/net_kern.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c > index 77c4afb8ab90..75d04fb4994a 100644 > --- a/arch/um/drivers/net_kern.c > +++ b/arch/um/drivers/net_kern.c > @@ -336,7 +336,7 @@ static struct platform_driver uml_net_driver = { > > static void net_device_release(struct device *dev) > { > - struct uml_net *device = dev_get_drvdata(dev); > + struct uml_net *device = container_of(dev, struct uml_net, pdev.dev); > struct net_device *netdev = device->dev; > struct uml_net_private *lp = netdev_priv(netdev); > Acked-By: Anton Ivanov -- Anton R. 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