From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Knut Omang <knut.omang@oracle.com>
Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org,
Shuah Khan <shuah@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
Shreyans Devendra Doshi <0xinfosect0r@gmail.com>,
Alan Maguire <alan.maguire@oracle.com>,
Brendan Higgins <brendanhiggins@google.com>,
Kevin Hilman <khilman@baylibre.com>,
Hidenori Yamaji <hidenori.yamaji@sony.com>,
Frank Rowand <frowand.list@gmail.com>,
Timothy Bird <Tim.Bird@sony.com>,
Luis Chamberlain <mcgrof@kernel.org>,
Theodore Ts'o <tytso@mit.edu>, Daniel Vetter <daniel@ffwll.ch>,
Stephen Boyd <sboyd@kernel.org>
Subject: Re: [RFC 06/19] ktf: A simple debugfs interface to test results
Date: Thu, 15 Aug 2019 10:49:21 +0200 [thread overview]
Message-ID: <20190815084921.GE3512@kroah.com> (raw)
In-Reply-To: <a63bea757e02656a38463cc794da7da15273dd16.camel@oracle.com>
On Wed, Aug 14, 2019 at 07:17:07PM +0200, Knut Omang wrote:
> I notice the discussion and your response here:
> http://linux-kernel.2935.n7.nabble.com/debugfs-and-module-unloading-td865175.html
> I assume that means that protection against module unload while a debugfs file
> is open is now safe.
It should be, if you set the *owner field of your file_operations
properly. Try it and see!
> On older kernels, having this code in place is far better than an unprotected
> debugfs entry/exit - I have tested it extensively in the past :-)
Yes, it seems to work, but again, it really is racy and will fail.
Please don't use it.
> I perfectly agree with you that reducing the hole for a race condition
> is generally a bad idea, but from the above mail thread
> it seems that's the only available choice for older kernels?
I have no idea, but please, do not use that pattern of code as it is
racy in all kernels, from all of time.
thanks,
greg k-h
next prev parent reply other threads:[~2019-08-15 8:49 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-13 6:09 [RFC 00/19] Integration of Kernel Test Framework (KTF) into the kernel tree Knut Omang
2019-08-13 6:09 ` [RFC 01/19] kbuild: Fixes to rules for host-cshlib and host-cxxshlib Knut Omang
2019-08-13 14:01 ` Masahiro Yamada
2019-08-13 16:19 ` Knut Omang
2019-08-14 2:02 ` Masahiro Yamada
2019-08-14 5:50 ` Knut Omang
2019-08-14 5:52 ` Knut Omang
2019-08-14 12:52 ` Knut Omang
2019-08-21 1:47 ` Masahiro Yamada
2019-08-21 4:03 ` Knut Omang
2019-08-13 6:09 ` [RFC 02/19] ktf: Introduce the main part of the kernel side of ktf Knut Omang
2019-09-09 1:23 ` Brendan Higgins
2019-09-10 6:15 ` Knut Omang
2019-08-13 6:09 ` [RFC 03/19] ktf: Introduce a generic netlink protocol for test result communication Knut Omang
2019-09-09 1:28 ` Brendan Higgins
2019-09-10 6:30 ` Knut Omang
2019-08-13 6:09 ` [RFC 04/19] ktf: An implementation of a generic associative array container Knut Omang
2019-08-13 6:09 ` [RFC 05/19] ktf: Implementation of ktf support for overriding function entry and return Knut Omang
2019-08-13 6:09 ` [RFC 06/19] ktf: A simple debugfs interface to test results Knut Omang
2019-08-13 8:21 ` Greg Kroah-Hartman
2019-08-14 17:17 ` Knut Omang
2019-08-15 8:49 ` Greg Kroah-Hartman [this message]
2019-08-15 10:35 ` Knut Omang
2019-08-15 10:52 ` Greg Kroah-Hartman
2019-08-13 6:09 ` [RFC 07/19] ktf: Simple coverage support Knut Omang
2019-08-13 6:09 ` [RFC 08/19] ktf: Configurable context support for network info setup Knut Omang
2019-08-13 6:09 ` [RFC 09/19] ktf: resolve: A helper utility to aid in exposing private kernel symbols to KTF tests Knut Omang
2019-08-13 6:09 ` [RFC 10/19] ktf: Add documentation for Kernel Test Framework (KTF) Knut Omang
2019-08-13 6:09 ` [RFC 11/19] ktf: Add a small test suite with a few tests to test KTF itself Knut Omang
2019-08-13 6:09 ` [RFC 12/19] ktf: Main part of user land library for executing tests Knut Omang
2019-08-13 6:09 ` [RFC 13/19] ktf: Integration logic for running ktf tests from googletest Knut Omang
2019-08-13 6:09 ` [RFC 14/19] ktf: Internal debugging facilities Knut Omang
2019-08-13 6:09 ` [RFC 15/19] ktf: Some simple examples Knut Omang
2019-08-13 6:09 ` [RFC 16/19] ktf: Some user applications to run tests Knut Omang
2019-08-13 6:09 ` [RFC 17/19] ktf: Toplevel ktf Makefile/makefile includes and scripts to run from kselftest Knut Omang
2019-08-13 6:09 ` [RFC 18/19] kselftests: Enable building ktf Knut Omang
2019-08-13 6:09 ` [RFC 19/19] Documentation/dev-tools: Add index entry for KTF documentation Knut Omang
2019-08-13 8:10 ` [RFC 00/19] Integration of Kernel Test Framework (KTF) into the kernel tree Brendan Higgins
2019-08-13 8:17 ` Brendan Higgins
2019-08-13 11:29 ` Knut Omang
2019-08-13 17:50 ` Brendan Higgins
2019-08-13 8:23 ` Greg Kroah-Hartman
2019-08-13 9:51 ` Knut Omang
2019-08-13 17:02 ` Brendan Higgins
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