From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org
Cc: Ben Greear <greearb@candelatech.com>, Eliad Peller <eliad@wizery.com>
Subject: Re: [PATCH 2/5] mac80211: use del_timer_sync for final sta cleanup timer deletion
Date: Fri, 14 Dec 2012 00:26:41 +0100 [thread overview]
Message-ID: <1355441201.9463.42.camel@jlt4.sipsolutions.net> (raw)
In-Reply-To: <1355439573-13206-3-git-send-email-johannes@sipsolutions.net> (sfid-20121213_235927_069921_DDF2F57A)
On Thu, 2012-12-13 at 23:59 +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
>
> This is a very old bug, but there's nothing that prevents the
> timer from running while the module is being removed when we
> only do del_timer() instead of del_timer_sync().
>
> The timer should normally not be running at this point, but
> it's not clearly impossible (or we could just remove this.)
Ok it's very unlikely -- the timer would have to rearm itself and the
fire the exact same moment we try to del_timer() it, so it's still
running when we return, and then we'd have to unload the module quickly
enough to invalidate that code that's running there ... it's a bit of a
stretch, but not completely impossible.
johannes
next prev parent reply other threads:[~2012-12-13 23:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-13 22:59 [PATCH 0/5] mac80211: fix station cleanup/destruction Johannes Berg
2012-12-13 22:59 ` [PATCH 1/5] mac80211: fix station destruction in AP/mesh modes Johannes Berg
2012-12-13 22:59 ` [PATCH 2/5] mac80211: use del_timer_sync for final sta cleanup timer deletion Johannes Berg
2012-12-13 23:26 ` Johannes Berg [this message]
2012-12-13 22:59 ` [PATCH 3/5] mac80211: remove final sta_info_flush() Johannes Berg
2012-12-13 22:59 ` [PATCH 4/5] mac80211: warn if unexpectedly removing stations Johannes Berg
2012-12-13 22:59 ` [PATCH 5/5] mac80211: optimise roaming time again Johannes Berg
2012-12-13 23:32 ` Eliad Peller
2012-12-13 23:41 ` Johannes Berg
2012-12-13 23:57 ` Eliad Peller
2012-12-14 8:33 ` Johannes Berg
2012-12-14 13:57 ` [PATCH] mac80211: optimise AP stop RCU handling Johannes Berg
2012-12-20 11:16 ` Johannes Berg
2012-12-14 18:08 ` [PATCH 0/5] mac80211: fix station cleanup/destruction Ben Greear
2012-12-20 11:12 ` Johannes Berg
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