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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Brian Norris <briannorris@chromium.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>,
	Ingo Molnar <mingo@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] debugfs: Only clobber mode/uid/gid on remount if asked
Date: Thu, 1 Sep 2022 17:58:14 +0200	[thread overview]
Message-ID: <YxDWlgulBijTzj3y@kroah.com> (raw)
In-Reply-To: <20220826174353.1.Icbd40fce59f55ad74b80e5d435ea233579348a78@changeid>

On Fri, Aug 26, 2022 at 05:44:16PM -0700, Brian Norris wrote:
> Users may have explicitly configured their debugfs permissions; we
> shouldn't overwrite those just because a second mount appeared.

What userspace mounts debugfs twice?

> Only clobber if the options were provided at mount time.
> 
>   # Don't change /sys/kernel/debug/ permissions.
>   mount -t debugfs none /mnt/foo
> 
>   # Change /sys/kernel/debug/ mode and uid, but not gid.
>   mount -t debugfs -o uid=bar,mode=0750 none /mnt/baz

So what happens today with this change?  Without it?

> 
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
> I'm open to writing an LTP test case for this, if that seems like a good
> idea.

If it's really needed, again, why would debugfs be ever mounted more
than once?

thanks,

greg k-h

  parent reply	other threads:[~2022-09-01 15:58 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-27  0:44 [PATCH 1/2] debugfs: Only clobber mode/uid/gid on remount if asked Brian Norris
2022-08-27  0:44 ` [PATCH 2/2] tracefs: " Brian Norris
2022-09-07 11:44   ` Steven Rostedt
2022-09-07 20:52     ` Brian Norris
2022-09-08  1:25       ` Steven Rostedt
2022-09-07 21:46   ` Steven Rostedt
2022-09-07 21:48     ` Steven Rostedt
2022-09-07 21:53       ` Brian Norris
2022-09-07 22:45         ` Steven Rostedt
2022-09-01 15:58 ` Greg Kroah-Hartman [this message]
2022-09-01 16:11   ` [PATCH 1/2] debugfs: " Steven Rostedt
2022-09-01 22:32   ` Brian Norris
2022-09-02  5:45     ` Greg Kroah-Hartman
2022-09-09  0:16       ` Brian Norris
2022-09-09  0:43         ` Steven Rostedt
2022-09-09  0:57           ` Brian Norris
2022-09-09  1:05             ` Steven Rostedt

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