From: Johannes Berg <johannes@sipsolutions.net>
To: Arik Nemtsov <arik@wizery.com>
Cc: Eliad Peller <eliad@wizery.com>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH 4/4] cfg80211: prevent race condition on scan request cleanup
Date: Thu, 05 Dec 2013 16:53:47 +0100 [thread overview]
Message-ID: <1386258827.4182.12.camel@jlt4.sipsolutions.net> (raw)
In-Reply-To: <CA+XVXffcA+TKAaH6MuybncUAe7jgaWEFdo5nL7+FnTR-7pc1+g@mail.gmail.com> (sfid-20131205_165233_922106_BD55352E)
On Thu, 2013-12-05 at 17:52 +0200, Arik Nemtsov wrote:
> >> > But the whole thing was intended to catch buggy drivers :)
> >> >
> >> yeah, you have a point here :)
> >> anyway, i guess it's either leaking scan_req and hoping the driver
> >> really forgot about it, or keeping it and hoping the driver will
> >> finally indicate completion.
> >>
> >> since i don't think this is a real-world scenario, i'm ok with
> >> dropping this patch.
> >
> > Well, it can be made to crash, so ...
> >
> > Can we maybe avoid the crash in a different way? Disallow a new scan
> > somehow?
>
> Maybe we should drop the whole netdev-notified doing ___cfg80211_scan_done?
> I mean if a workaround for buggy drivers is causing bugs for
> legitimate drivers..
>
> Something simple for buggy drivers would be doing this in the notifier
> - BUG_ON(!rdev->scan_req->notified)
BUG_ON is probably a bit heavy-handed, but yeah, I suppose we can drop
this. We used to have more bugs with drivers and even mac80211, but that
should be a thing of the past.
johannes
next prev parent reply other threads:[~2013-12-05 15:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-05 9:21 [PATCH 1/4] cfg80211: stop sched scan only when needed Eliad Peller
2013-12-05 9:21 ` [PATCH 2/4] mac80211: determine completed scan type by defined ops Eliad Peller
2013-12-05 9:21 ` [PATCH 3/4] mac80211: start_next_roc only if scan was actually running Eliad Peller
2013-12-05 9:21 ` [PATCH 4/4] cfg80211: prevent race condition on scan request cleanup Eliad Peller
2013-12-05 14:31 ` Johannes Berg
2013-12-05 14:36 ` Eliad Peller
2013-12-05 14:43 ` Johannes Berg
2013-12-05 15:39 ` Eliad Peller
2013-12-05 15:45 ` Johannes Berg
2013-12-05 15:52 ` Arik Nemtsov
2013-12-05 15:53 ` Johannes Berg [this message]
2013-12-05 16:14 ` Johannes Berg
2013-12-05 16:32 ` Eliad Peller
2013-12-05 16:18 ` [PATCH 1/4] cfg80211: stop sched scan only when needed Johannes Berg
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