Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752956AbdFSS5O (ORCPT + 2 others); Mon, 19 Jun 2017 14:57:14 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52603 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753716AbdFSSiE (ORCPT ); Mon, 19 Jun 2017 14:38:04 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: "David S. Miller" , Willy Tarreau Subject: [PATCH 3.10 150/268] irda: Fix lockdep annotations in hashbin_delete(). Date: Mon, 19 Jun 2017 20:30:49 +0200 Message-Id: <1497897167-14556-151-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu> References: <1497897167-14556-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: "David S. Miller" commit 4c03b862b12f980456f9de92db6d508a4999b788 upstream. A nested lock depth was added to the hasbin_delete() code but it doesn't actually work some well and results in tons of lockdep splats. Fix the code instead to properly drop the lock around the operation and just keep peeking the head of the hashbin queue. Reported-by: Dmitry Vyukov Tested-by: Dmitry Vyukov Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- net/irda/irqueue.c | 34 ++++++++++++++++------------------ 1 file changed, 16 insertions(+), 18 deletions(-) diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c index 7152624..26ccd65 100644 --- a/net/irda/irqueue.c +++ b/net/irda/irqueue.c @@ -385,9 +385,6 @@ EXPORT_SYMBOL(hashbin_new); * for deallocating this structure if it's complex. If not the user can * just supply kfree, which should take care of the job. */ -#ifdef CONFIG_LOCKDEP -static int hashbin_lock_depth = 0; -#endif int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func) { irda_queue_t* queue; @@ -398,22 +395,27 @@ int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func) IRDA_ASSERT(hashbin->magic == HB_MAGIC, return -1;); /* Synchronize */ - if ( hashbin->hb_type & HB_LOCK ) { - spin_lock_irqsave_nested(&hashbin->hb_spinlock, flags, - hashbin_lock_depth++); - } + if (hashbin->hb_type & HB_LOCK) + spin_lock_irqsave(&hashbin->hb_spinlock, flags); /* * Free the entries in the hashbin, TODO: use hashbin_clear when * it has been shown to work */ for (i = 0; i < HASHBIN_SIZE; i ++ ) { - queue = dequeue_first((irda_queue_t**) &hashbin->hb_queue[i]); - while (queue ) { - if (free_func) - (*free_func)(queue); - queue = dequeue_first( - (irda_queue_t**) &hashbin->hb_queue[i]); + while (1) { + queue = dequeue_first((irda_queue_t**) &hashbin->hb_queue[i]); + + if (!queue) + break; + + if (free_func) { + if (hashbin->hb_type & HB_LOCK) + spin_unlock_irqrestore(&hashbin->hb_spinlock, flags); + free_func(queue); + if (hashbin->hb_type & HB_LOCK) + spin_lock_irqsave(&hashbin->hb_spinlock, flags); + } } } @@ -422,12 +424,8 @@ int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func) hashbin->magic = ~HB_MAGIC; /* Release lock */ - if ( hashbin->hb_type & HB_LOCK) { + if (hashbin->hb_type & HB_LOCK) spin_unlock_irqrestore(&hashbin->hb_spinlock, flags); -#ifdef CONFIG_LOCKDEP - hashbin_lock_depth--; -#endif - } /* * Free the hashbin structure -- 2.8.0.rc2.1.gbe9624a