From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756490AbcE0SPp (ORCPT ); Fri, 27 May 2016 14:15:45 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:42204 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755576AbcE0SPm (ORCPT ); Fri, 27 May 2016 14:15:42 -0400 Date: Fri, 27 May 2016 11:15:41 -0700 From: Greg Kroah-Hartman To: Nicolai Stange Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Riley Andrews , Gustavo Padovan Subject: Re: [PATCH] staging/android: sync_debug: unproxify debugfs files' fops Message-ID: <20160527181541.GA19224@kroah.com> References: <1464372234-13431-1-git-send-email-nicstange@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464372234-13431-1-git-send-email-nicstange@gmail.com> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 27, 2016 at 08:03:54PM +0200, Nicolai Stange wrote: > Since commit 49d200deaa68 ("debugfs: prevent access to removed files' > private data"), a debugfs file's file_operations methods get proxied > through lifetime aware wrappers. > > However, only a certain subset of the file_operations members is supported > by debugfs and ->compat_ioctl isn't among them -- it appears to be NULL > from the VFS layer's perspective. > > This behaviour breaks the /sys/kernel/debug/sync/sw_sync file introduced > concurrently with commit a44eb74cd413 ("staging/android: move SW_SYNC_USER > to a debugfs file"). > > Since that file never gets removed, there is no file removal race and thus, > a lifetime checking proxy isn't needed. > > Avoid the proxying for /sys/kernel/debug/sync/sw_sync by creating it via > debugfs_create_file_unsafe() rather than debugfs_create_file(). > For consistency, do the same for /sys/kernel/debug/sync/info. > > Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private > data") > Fixes: a44eb74cd413 ("staging/android: move SW_SYNC_USER to a debugfs > file") > Signed-off-by: Nicolai Stange > --- > Applicable to linux-next-20160527. > x86_64 allmodconfig build succeeds w/o any new warnings. > > Related discussion can be found here: > http://lkml.kernel.org/g/878tz22peb.fsf@gmail.com > > drivers/staging/android/sync_debug.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) Thanks, will queue this up after 4.7-rc1 is out. greg k-h