From: David Laight <David.Laight@ACULAB.COM>
To: 'Johannes Berg' <johannes@sipsolutions.net>,
Greg KH <gregkh@linuxfoundation.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"nstange@suse.de" <nstange@suse.de>,
"ap420073@gmail.com" <ap420073@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
"rafael@kernel.org" <rafael@kernel.org>
Subject: RE: [CRAZY-RFF] debugfs: track open files and release on remove
Date: Fri, 9 Oct 2020 09:00:41 +0000 [thread overview]
Message-ID: <e086db3e422b401d9a4df896696f75b8@AcuMS.aculab.com> (raw)
In-Reply-To: <e3a807b1d5f728c178f43b453f3b495bf53abfce.camel@sipsolutions.net>
From: Johannes Berg
> Sent: 09 October 2020 09:45
>
> On Fri, 2020-10-09 at 08:34 +0000, David Laight wrote:
> >
...
> > Does it ever make any sense to set .owner to anything other than
> > THIS_MODULE?
>
> No. But I believe THIS_MODULE is NULL for built-in code, so we can't
> just WARN_ON(!fops->owner).
...
> > I was also wondering if this affects normal opens?
> > They should hold a reference on the module to stop it being unloaded.
> > Does that rely on .owner being set?
>
> Yes.
Sound like the module load code should be verifying it then.
Looking at one of my modules (which does set .owner).
Perhaps cdev_init() could be a #define that picks up THIS_MODULE.
This could then be checked against the one in fops or saved
in the 'struct cdev'.
I presume debugfs (which I've not used) has some similar calls.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-10-09 9:00 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
2020-10-09 8:34 ` David Laight
2020-10-09 8:44 ` Johannes Berg
2020-10-09 9:00 ` David Laight [this message]
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
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