From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943188AbcJSOsD (ORCPT ); Wed, 19 Oct 2016 10:48:03 -0400 Received: from mga11.intel.com ([192.55.52.93]:6844 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932654AbcJSOsB (ORCPT ); Wed, 19 Oct 2016 10:48:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,514,1473145200"; d="scan'208";a="1056087678" Date: Wed, 19 Oct 2016 18:50:37 +0530 From: Vinod Koul To: Sinan Kaya Cc: dmaengine@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] dmaengine: qcom_hidma: remove useless debugfs file removal Message-ID: <20161019132037.GM2467@localhost> References: <1475792489-1415-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1475792489-1415-1-git-send-email-okaya@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 06, 2016 at 06:21:29PM -0400, Sinan Kaya wrote: > Since 'commit acc29fb8f792 ("debugfs: ->d_parent is never NULL or > negative")', HIDMA object removal is no longer working. This is due to > redundant debugfs remove call in hidma_debug_uninit. > > debugfs_remove_recursive(dmadev->debugfs); > debugfs_remove_recursive(dmadev->stats); > > The first remove is for the directory. Second remove is for the file under > the directory. The directory remove makes file remove invalid. > > Unable to handle kernel NULL pointer dereference at virtual address > > [] down_write+0x18/0x68 > [] debugfs_remove_recursive+0x50/0x1c0 > [] hidma_debug_uninit+0x20/0x30 > [] hidma_remove+0x48/0x98 > [] platform_drv_remove+0x24/0x68 > [] __device_release_driver+0x80/0x118 > [] device_release_driver+0x24/0x38 > [] unbind_store+0xe8/0x110 > [] drv_attr_store+0x20/0x30 > [] sysfs_kf_write+0x48/0x58 > [] kernfs_fop_write+0xb0/0x1d8 > [] __vfs_write+0x1c/0x110 > [] vfs_write+0xa0/0x1b8 > [] SyS_write+0x44/0xa0 > [] el0_svc_naked+0x24/0x28 > > Removing the second line. Applied, thanks -- ~Vinod