Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756011AbaBGMo1 (ORCPT ); Fri, 7 Feb 2014 07:44:27 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41945 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932392AbaBGLu2 (ORCPT ); Fri, 7 Feb 2014 06:50:28 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Larry Finger , "John W. Linville" , Luis Henriques Subject: [PATCH 3.11 116/233] b43: Fix lockdep splat Date: Fri, 7 Feb 2014 11:45:35 +0000 Message-Id: <1391773652-25214-117-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> References: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.4 -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: Luis Henriques --- drivers/net/wireless/b43/main.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c index 0e933bb..bccc6ca 100644 --- 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(struct b43_wldev *dev) 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. */ @@ -4781,9 +4783,6 @@ static int b43_wireless_core_init(struct b43_wldev *dev) b43_set_status(dev, B43_STAT_INITIALIZED); - /* Register HW RNG driver */ - b43_rng_init(dev->wl); - out: return err; @@ -5450,6 +5449,9 @@ static void b43_bcma_remove(struct bcma_device *core) b43_one_core_detach(wldev->dev); + /* Unregister HW RNG driver */ + b43_rng_exit(wl); + b43_leds_unregister(wl); ieee80211_free_hw(wl->hw); @@ -5527,6 +5529,9 @@ static void b43_ssb_remove(struct ssb_device *sdev) 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. -- 1.8.3.2 -- 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/