From: Nicolai Stange <nstange@suse.de>
To: Taehee Yoo <ap420073@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>,
David Laight <David.Laight@aculab.com>,
"davem\@davemloft.net" <davem@davemloft.net>,
"kuba\@kernel.org" <kuba@kernel.org>,
"netdev\@vger.kernel.org" <netdev@vger.kernel.org>,
Nicolai Stange <nstange@suse.de>,
"linux-wireless\@vger.kernel.org"
<linux-wireless@vger.kernel.org>,
"wil6210\@qti.qualcomm.com" <wil6210@qti.qualcomm.com>,
"brcm80211-dev-list\@cypress.com"
<brcm80211-dev-list@cypress.com>,
"b43-dev\@lists.infradead.org" <b43-dev@lists.infradead.org>,
"linux-bluetooth\@vger.kernel.org"
<linux-bluetooth@vger.kernel.org>
Subject: Re: [PATCH net 000/117] net: avoid to remove module when its debugfs is being used
Date: Fri, 09 Oct 2020 07:38:59 +0200 [thread overview]
Message-ID: <87r1q8gdqk.fsf@suse.de> (raw)
In-Reply-To: <CAMArcTUkC2MzN9MiTu_Qwouj6rFf0g0ac2uZWfSKWHTW9cR8xA@mail.gmail.com> (Taehee Yoo's message of "Fri, 9 Oct 2020 01:37:26 +0900")
Taehee Yoo <ap420073@gmail.com> writes:
> On Fri, 9 Oct 2020 at 01:14, Johannes Berg <johannes@sipsolutions.net> wrote:
> On Thu, 2020-10-08 at 15:59 +0000, David Laight wrote:
>
>> From: Taehee Yoo
>> > Sent: 08 October 2020 16:49
>> >
>> > When debugfs file is opened, its module should not be removed until
>> > it's closed.
>> > Because debugfs internally uses the module's data.
>> > So, it could access freed memory.
Yes, the file_operations' ->release() to be more specific -- that's not
covered by debugfs' proxy fops.
>> > In order to avoid panic, it just sets .owner to THIS_MODULE.
>> > So that all modules will be held when its debugfs file is opened.
>>
>> Can't you fix it in common code?
>
>> Yeah I was just wondering that too - weren't the proxy_fops even already
>> intended to fix this?
>
> I didn't try to fix this issue in the common code(debugfs).
> Because I thought It's a typical pattern of panic and THIS_MODULE
> can fix it clearly.
> So I couldn't think there is a root reason in the common code.
That's correct, ->owner should get set properly, c.f. my other mail in
this thread.
Thanks,
Nicolai
--
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg), GF: Felix Imendörffer
next prev parent reply other threads:[~2020-10-09 5:39 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 [this message]
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
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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