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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham 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 8D5C2C433B4 for ; Sat, 24 Apr 2021 10:52:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65E44613DE for ; Sat, 24 Apr 2021 10:52:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231771AbhDXKww (ORCPT ); Sat, 24 Apr 2021 06:52:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:53446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231490AbhDXKwt (ORCPT ); Sat, 24 Apr 2021 06:52:49 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (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 0CB1E61396; Sat, 24 Apr 2021 10:52:09 +0000 (UTC) Date: Sat, 24 Apr 2021 11:52:50 +0100 From: Jonathan Cameron To: Tomasz Duszynski Cc: , , , Subject: Re: [PATCH v2] iio: core: fix ioctl handlers removal Message-ID: <20210424115250.14d21a71@jic23-huawei> In-Reply-To: <20210423080244.2790-1-tomasz.duszynski@octakon.com> References: <20210423080244.2790-1-tomasz.duszynski@octakon.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Fri, 23 Apr 2021 10:02:44 +0200 Tomasz Duszynski wrote: > Currently ioctl handlers are removed twice. For the first time during > iio_device_unregister() then later on inside > iio_device_unregister_eventset() and iio_buffers_free_sysfs_and_mask(). > Double free leads to kernel panic. > > Fix this by not touching ioctl handlers list directly but rather > letting code responsible for registration call the matching cleanup > routine itself. > > Fixes: 8dedcc3eee3ac ("iio: core: centralize ioctl() calls to the main chardev") > Signed-off-by: Tomasz Duszynski > Acked-by: Alexandru Ardelean There are a bunch of unused local variables as a result of this change (build warnings on my standard W=1 C=1 test). I've dropped those as well and applied this to the fixes-togreg branch of iio.git. We are a bit unfortunate on timing for this as I won't send a pull request for fixes until towards the end of the merge window. I've marked it for stable though so it should filter back fairly quickly so kernels people actually use. Thanks, Jonathan > --- > v2: > * add fixes tag and ack > > drivers/iio/industrialio-core.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index d92c58a94fe4..98944cfc7331 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -1939,9 +1939,6 @@ void iio_device_unregister(struct iio_dev *indio_dev) > > indio_dev->info = NULL; > > - list_for_each_entry_safe(h, t, &iio_dev_opaque->ioctl_handlers, entry) > - list_del(&h->entry); > - > iio_device_wakeup_eventset(indio_dev); > iio_buffer_wakeup_poll(indio_dev); > > -- > 2.31.1 >