From: Johannes Berg <johannes@sipsolutions.net>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, nstange@suse.de,
ap420073@gmail.com, David.Laight@aculab.com,
netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
rafael@kernel.org
Subject: Re: [CRAZY-RFF] debugfs: track open files and release on remove
Date: Fri, 09 Oct 2020 10:19:02 +0200 [thread overview]
Message-ID: <1ec056cf3ec0953d2d1abaa05e37e89b29c7cc63.camel@sipsolutions.net> (raw)
In-Reply-To: <20201009081624.GA401030@kroah.com>
On Fri, 2020-10-09 at 10:16 +0200, Greg KH wrote:
> On Fri, Oct 09, 2020 at 10:06:14AM +0200, Johannes Berg wrote:
> > We used to say the proxy_fops weren't needed and it wasn't an issue, and
> > then still implemented it. Dunno. I'm not really too concerned about it
> > myself, only root can hold the files open and remove modules ...
>
> proxy_fops were needed because devices can be removed from the system at
> any time, causing their debugfs files to want to also be removed. It
> wasn't because of unloading kernel code.
Indeed, that's true. Still, we lived with it for years.
Anyway, like I said, I really just did this more to see that it _could_
be done, not to suggest that it _should_ :-)
I think adding the .owner everywhere would be good, and perhaps we can
somehow put a check somewhere like
WARN_ON(is_module_address((unsigned long)fops) && !fops->owner);
to prevent the issue in the future?
johannes
next prev parent reply other threads:[~2020-10-09 8:19 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 15:48 [PATCH net 000/117] net: avoid to remove module when its debugfs is being used Taehee Yoo
2020-10-08 15:59 ` David Laight
2020-10-08 16:14 ` Johannes Berg
2020-10-08 16:37 ` Taehee Yoo
2020-10-09 5:38 ` Nicolai Stange
2020-10-09 10:07 ` Taehee Yoo
2020-10-09 5:09 ` Nicolai Stange
2020-10-09 7:45 ` Johannes Berg
2020-10-09 10:15 ` Taehee Yoo
2020-10-09 10:21 ` Johannes Berg
2020-10-09 10:41 ` [RFC] debugfs: protect against rmmod while files are open Johannes Berg
2020-10-09 10:48 ` Johannes Berg
2020-10-09 10:56 ` David Laight
2020-10-09 10:56 ` Johannes Berg
2020-10-09 11:15 ` gregkh
2020-10-09 15:33 ` [PATCH net 000/117] net: avoid to remove module when its debugfs is being used Steve deRosier
2020-10-09 7:53 ` [CRAZY-RFF] debugfs: track open files and release on remove Johannes Berg
2020-10-09 8:03 ` Greg KH
2020-10-09 8:06 ` Johannes Berg
2020-10-09 8:16 ` Greg KH
2020-10-09 8:19 ` Johannes Berg [this message]
2020-10-09 8:34 ` David Laight
2020-10-09 8:44 ` Johannes Berg
2020-10-09 9:00 ` David Laight
2020-10-09 8:47 ` Greg KH
2020-10-09 8:48 ` Johannes Berg
2020-10-10 9:38 ` Greg KH
2020-10-10 10:47 ` Johannes Berg
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1ec056cf3ec0953d2d1abaa05e37e89b29c7cc63.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=David.Laight@aculab.com \
--cc=ap420073@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nstange@suse.de \
--cc=rafael@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).