[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <87r1q8gdqk.fsf@suse.de>
Date: Fri, 09 Oct 2020 07:38:59 +0200
From: Nicolai Stange <nstange@...e.de>
To: Taehee Yoo <ap420073@...il.com>
Cc: Johannes Berg <johannes@...solutions.net>,
David Laight <David.Laight@...lab.com>,
"davem\@davemloft.net" <davem@...emloft.net>,
"kuba\@kernel.org" <kuba@...nel.org>,
"netdev\@vger.kernel.org" <netdev@...r.kernel.org>,
Nicolai Stange <nstange@...e.de>,
"linux-wireless\@vger.kernel.org" <linux-wireless@...r.kernel.org>,
"wil6210\@qti.qualcomm.com" <wil6210@....qualcomm.com>,
"brcm80211-dev-list\@cypress.com" <brcm80211-dev-list@...ress.com>,
"b43-dev\@lists.infradead.org" <b43-dev@...ts.infradead.org>,
"linux-bluetooth\@vger.kernel.org" <linux-bluetooth@...r.kernel.org>
Subject: Re: [PATCH net 000/117] net: avoid to remove module when its debugfs is being used
Taehee Yoo <ap420073@...il.com> writes:
> On Fri, 9 Oct 2020 at 01:14, Johannes Berg <johannes@...solutions.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
Powered by blists - more mailing lists