Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935863AbaBDW0W (ORCPT ); Tue, 4 Feb 2014 17:26:22 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56594 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933881AbaBDVIS (ORCPT ); Tue, 4 Feb 2014 16:08:18 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, yury , Larry Finger , "John W. Linville" Subject: [PATCH 3.12 044/133] b43: Fix lockdep splat Date: Tue, 4 Feb 2014 13:07:25 -0800 Message-Id: <20140204210738.279996310@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.1.163.gd7aced9 In-Reply-To: <20140204210737.008598235@linuxfoundation.org> References: <20140204210737.008598235@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Larry Finger commit 09164043f63c947a49797750a09ca1cd7c31108e upstream. In https://bugzilla.kernel.org/show_bug.cgi?id=67561, a locking dependency is reported when b43 is used with hostapd, and rfkill is used to kill the radio output. The lockdep splat (in part) is as follows: ====================================================== [ INFO: possible circular locking dependency detected ] 3.12.0 #1 Not tainted ------------------------------------------------------- rfkill/10040 is trying to acquire lock: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20 but task is already holding lock: (rfkill_global_mutex){+.+.+.}, at: [] rfkill_fop_write+0x6a/0x170 [rfkill] --snip-- Chain exists of: rtnl_mutex --> misc_mtx --> rfkill_global_mutex The fix is to move the initialization of the hardware random number generator outside the code range covered by the rtnl_mutex. Reported-by: yury Tested-by: yury Signed-off-by: Larry Finger Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/b43/main.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) --- a/drivers/net/wireless/b43/main.c +++ b/drivers/net/wireless/b43/main.c @@ -2424,6 +2424,7 @@ error: static int b43_one_core_attach(struct b43_bus_dev *dev, struct b43_wl *wl); static void b43_one_core_detach(struct b43_bus_dev *dev); +static int b43_rng_init(struct b43_wl *wl); static void b43_request_firmware(struct work_struct *work) { @@ -2475,6 +2476,10 @@ start_ieee80211: goto err_one_core_detach; wl->hw_registred = true; b43_leds_register(wl->current_dev); + + /* Register HW RNG driver */ + b43_rng_init(wl); + goto out; err_one_core_detach: @@ -4636,9 +4641,6 @@ static void b43_wireless_core_exit(struc if (!dev || b43_status(dev) != B43_STAT_INITIALIZED) return; - /* Unregister HW RNG driver */ - b43_rng_exit(dev->wl); - b43_set_status(dev, B43_STAT_UNINIT); /* Stop the microcode PSM. */ @@ -4795,9 +4797,6 @@ static int b43_wireless_core_init(struct b43_set_status(dev, B43_STAT_INITIALIZED); - /* Register HW RNG driver */ - b43_rng_init(dev->wl); - out: return err; @@ -5464,6 +5463,9 @@ static void b43_bcma_remove(struct bcma_ b43_one_core_detach(wldev->dev); + /* Unregister HW RNG driver */ + b43_rng_exit(wl); + b43_leds_unregister(wl); ieee80211_free_hw(wl->hw); @@ -5541,6 +5543,9 @@ static void b43_ssb_remove(struct ssb_de b43_one_core_detach(dev); + /* Unregister HW RNG driver */ + b43_rng_exit(wl); + if (list_empty(&wl->devlist)) { b43_leds_unregister(wl); /* Last core on the chip unregistered. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/