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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 12:52:25 +0200
Message-ID: <20190815105225.GA16395@kroah.com> (raw)
In-Reply-To: <9629068a41a160de0145a18dd22924bce70f37fe.camel@oracle.com>

On Thu, Aug 15, 2019 at 12:35:26PM +0200, Knut Omang wrote:
> On Thu, 2019-08-15 at 10:49 +0200, Greg Kroah-Hartman wrote:
> > > 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.
> 
> Ok, will remove it :-)
> 
> I tried in vain to find the commit from Al Viro that made the code safe,
> to identify which kernels that are safe from this issue,
> but he has a **lot** of commits, do you have a clue for what/where to look?
> 
> It will be good to have a mention/comment on this for future reference, 
> like the earliest kernel version where this is safe.

Always use a "newer" kernel to be "safe" and you will be fine :)

> Maybe we can even get rid of some more of the remaining of these too..
> (I notice there's 65 cases of 'if (!try_module_get(THIS_MODULE))'
> right now)

Something to put on a TODO list somewhere...

thanks,

greg k-h

  reply index

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
2019-08-15 10:35         ` Knut Omang
2019-08-15 10:52           ` Greg Kroah-Hartman [this message]
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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