From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755317AbcESRU3 (ORCPT ); Thu, 19 May 2016 13:20:29 -0400 Received: from mga03.intel.com ([134.134.136.65]:2375 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754983AbcESRU1 (ORCPT ); Thu, 19 May 2016 13:20:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,334,1459839600"; d="scan'208";a="984710540" From: ville.syrjala@linux.intel.com To: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Andrew Morton , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Subject: [PATCH] dma-debug: Avoid spinlock recursion when disabling dma-debug Date: Thu, 19 May 2016 20:20:21 +0300 Message-Id: <1463678421-18683-1-git-send-email-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ville Syrjälä With netconsole (at least) the pr_err("... disabling\n") call can recurse back into the dma-debug code, where it'll try to grab free_entries_lock again. Avoid the problem by doing the printk after dropping the lock. Cc: stable@vger.kernel.org Cc: Andrew Morton Signed-off-by: Ville Syrjälä --- lib/dma-debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 4a1515f4b452..51a76af25c66 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -657,9 +657,9 @@ static struct dma_debug_entry *dma_entry_alloc(void) spin_lock_irqsave(&free_entries_lock, flags); if (list_empty(&free_entries)) { - pr_err("DMA-API: debugging out of memory - disabling\n"); global_disable = true; spin_unlock_irqrestore(&free_entries_lock, flags); + pr_err("DMA-API: debugging out of memory - disabling\n"); return NULL; } -- 2.7.4