Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751689AbdFEIZq (ORCPT ); Mon, 5 Jun 2017 04:25:46 -0400 Received: from b.ns.miles-group.at ([95.130.255.144]:44723 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751478AbdFEIZp (ORCPT ); Mon, 5 Jun 2017 04:25:45 -0400 Subject: Re: [PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode To: Jia-Ju Bai , dedekind1@gmail.com References: <1496633916-32362-1-git-send-email-baijiaju1990@163.com> Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org From: Richard Weinberger Message-ID: <0687ba2f-f7d5-4632-eebb-50bbadd8a4b0@nod.at> Date: Mon, 5 Jun 2017 10:25:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <1496633916-32362-1-git-send-email-baijiaju1990@163.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 532 Lines: 19 Jia-Ju Bai, Am 05.06.2017 um 05:38 schrieb Jia-Ju Bai: > The driver may sleep under a spin lock, and the function call path is: > ubifs_change_lp (acquire the lock by spin_lock) > change_category > ubifs_remove_from_cat > remove_from_lpt_heap > dbg_check_heap > ubifs_lpt_lookup > ubifs_read_nnode > kzalloc(GFP_NOFS) --> may sleep > > To fix it, "GFP_NOFS" is replaced with "GFP_ATOMIC". So, this happens only when dbg_check_heap() is activated, right? Thanks, //richard