From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758673AbcCCWxa (ORCPT ); Thu, 3 Mar 2016 17:53:30 -0500 Received: from mail.kernel.org ([198.145.29.136]:42884 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751420AbcCCWx2 (ORCPT ); Thu, 3 Mar 2016 17:53:28 -0500 Date: Thu, 3 Mar 2016 16:53:23 -0600 From: Rob Herring To: Sergey Senozhatsky Cc: Frank Rowand , Grant Likely , Petr Mladek , Andrew Morton , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: Re: [PATCH] of/unittest: fix infinite loop in of_unittest_destroy_tracked_overlays() Message-ID: <20160303225323.GB17541@rob-hp-laptop> References: <1456917889-4416-1-git-send-email-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456917889-4416-1-git-send-email-sergey.senozhatsky@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 02, 2016 at 08:24:49PM +0900, Sergey Senozhatsky wrote: > of_overlay_destroy() can return `-ENODEV' error code once it > failed to find the requested overlay in `ov_idr'. However, > of_unittest_destroy_tracked_overlays() does not handle this > error code correctly and continues to call of_overlay_destroy() > on the 'missing' overlay over and over again. This results in > a printk flood > > [..] > [ 33.497583] of_overlay_destroy: Could not find overlay #6 > [ 33.497583] of_overlay_destroy: Could not find overlay #6 > [ 33.497584] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6 > [ 33.497584] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6 > [ 33.497586] of_overlay_destroy: Could not find overlay #6 > [ 33.497586] of_overlay_destroy: Could not find overlay #6 > [ 33.497587] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6 > [ 33.497587] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6 > [..] > > which is not really good due to printk design, and can lead to soft > lockups, hard lockups, etc. (depending on the context console_unlock() > is being called from). The problem has bee observed in real life > and reported by Ying Huang. > > This patch does not address the root cause of missing overlay in > `ov_idr', it fixes the endless loop only. > > Signed-off-by: Sergey Senozhatsky > Reported-by: kernel test robot > Link: lkml.kernel.org/r/87fuwk1c0o.fsf@yhuang-dev.intel.com > --- > drivers/of/unittest.c | 5 +++++ > 1 file changed, 5 insertions(+) Applied, thanks. Rob