From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from vwp2514.webpack.hosteurope.de ([87.230.42.24]:50787 "EHLO vwp2514.webpack.hosteurope.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932096Ab1GVUiA (ORCPT ); Fri, 22 Jul 2011 16:38:00 -0400 Subject: Re: [PATCH] cfg80211: hold reg_mutex when updating regulatory From: Sven Neumann To: "John W. Linville" Cc: libertas-dev@lists.infradead.org, daniel@zonque.org, linux-wireless@vger.kernel.org, mcgrof@gmail.com Date: Fri, 22 Jul 2011 22:37:55 +0200 In-Reply-To: <20110715173240.GD2566@tuxdriver.com> References: <1310456639-16468-1-git-send-email-s.neumann@raumfeld.com> <1310457159-16698-2-git-send-email-s.neumann@raumfeld.com> <20110715173240.GD2566@tuxdriver.com> Content-Type: text/plain; charset="UTF-8" Message-ID: <1311367076.27468.4.camel@bender> (sfid-20110722_223804_694232_D303033B) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, On Fri, 2011-07-15 at 13:32 -0400, John W. Linville wrote: > Luis, any comment on this? > > On Tue, Jul 12, 2011 at 09:52:39AM +0200, Sven Neumann wrote: > > The function wiphy_update_regulatory() uses the static variable > > last_request and thus needs to be called with reg_mutex held. > > This is the case for all users in reg.c, but the function was > > exported for use by wiphy_register(), from where it is called > > without the lock being held. > > > > Fix this by making wiphy_update_regulatory() private and introducing > > regulatory_update() as a wrapper that acquires and holds the lock. > > > > Signed-off-by: Sven Neumann I'd appreciate if someone would review this patch. But probably this is not really an issue except that it's somewhat ugly to export a function that should be called with a lock held and that lock is actually private. But in this particular case it is not a problem, as far as I can see, since the only user of wiphy_update_regulatory() outside net/wireless/reg.c is initialization code. So there is not likely going to be a race condition here. Sven