From: Johannes Berg <johannes@sipsolutions.net>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: linux-wireless@vger.kernel.org
Subject: Re: [PATCH 2/3] mac80211: use csa counter offsets instead of csa_active
Date: Thu, 22 May 2014 15:45:56 +0200 [thread overview]
Message-ID: <1400766356.4174.14.camel@jlt4.sipsolutions.net> (raw)
In-Reply-To: <1400765294-14732-3-git-send-email-michal.kazior@tieto.com> (sfid-20140522_153530_337542_BA3BCA73)
On Thu, 2014-05-22 at 15:28 +0200, Michal Kazior wrote:
> vif->csa_active is protected by mutexes only. This
> means it is unreliable to depend on it on codeflow
> in non-sleepable beacon and CSA code. There was no
> guarantee to have vif->csa_active update be
> visible before beacons are updated on SMP systems.
>
> Using csa counter offsets which are embedded in
> beacon struct (and thus are protected with single
> RCU assignment) is much safer.
This seems reasonable, but many uses of csa_active remain, no? hwsim for
example seems to access it without locking as well.
johannes
next prev parent reply other threads:[~2014-05-22 13:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-22 13:28 [PATCH 0/3] mac80211: fix csa counters Michal Kazior
2014-05-22 13:28 ` [PATCH 1/3] mac80211: move csa counters from sdata to beacon/presp Michal Kazior
2014-05-22 13:43 ` Johannes Berg
2014-05-22 13:53 ` Michal Kazior
2014-05-22 14:37 ` Johannes Berg
2014-05-22 14:38 ` Johannes Berg
2014-05-22 13:28 ` [PATCH 2/3] mac80211: use csa counter offsets instead of csa_active Michal Kazior
2014-05-22 13:45 ` Johannes Berg [this message]
2014-05-22 13:59 ` Michal Kazior
2014-05-22 14:38 ` Johannes Berg
2014-05-22 13:28 ` [PATCH 3/3] mac80211: make csa_currnet_counter atomic Michal Kazior
2014-05-22 13:50 ` Johannes Berg
2014-05-22 14:03 ` Michal Kazior
2014-05-22 14:36 ` Johannes Berg
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