Re: [PATCH] mac80211: fix sw scan locking

[Ben Greear <greearb@candelatech.com>]

On 10/07/2010 03:55 AM, Johannes Berg wrote:
> From: Johannes Berg<johannes.berg@intel.com>
>
> The recent scan overhaul broke locking
> because now we can jump to code that
> attempts to unlock, while we don't have
> the mutex held. Fix this by holding the
> mutex around all the relevant code.
>
> Reported-by: Ben Greear<greearb@candelatech.com>
> Signed-off-by: Johannes Berg<johannes.berg@intel.com>

That does indeed fix the problem for me.

Thanks,
Ben

> ---
>   net/mac80211/scan.c |    3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> --- wireless-testing.orig/net/mac80211/scan.c	2010-10-07 10:50:51.000000000 +0200
> +++ wireless-testing/net/mac80211/scan.c	2010-10-07 10:51:10.000000000 +0200
> @@ -682,8 +682,6 @@ void ieee80211_scan_work(struct work_str
>   		goto out_complete;
>   	}
>
> -	mutex_unlock(&local->mtx);
> -
>   	/*
>   	 * as long as no delay is required advance immediately
>   	 * without scheduling a new work
> @@ -714,6 +712,7 @@ void ieee80211_scan_work(struct work_str
>   	} while (next_delay == 0);
>
>   	ieee80211_queue_delayed_work(&local->hw,&local->scan_work, next_delay);
> +	mutex_unlock(&local->mtx);
>   	return;
>
>   out_complete:
>


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com