Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751479AbdLMFSz (ORCPT ); Wed, 13 Dec 2017 00:18:55 -0500 Received: from mail-pg0-f53.google.com ([74.125.83.53]:36604 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751122AbdLMFSv (ORCPT ); Wed, 13 Dec 2017 00:18:51 -0500 X-Google-Smtp-Source: ACJfBotfPU5iVt7QbUNKbPIhmM3SL1LcipMlszZlLy30bT5HWqWhktMxqXBD7R1f90MDjQ1LASoh6g== Date: Tue, 12 Dec 2017 21:18:49 -0800 From: Stephen Hemminger To: David Miller Cc: baijiaju1990@gmail.com, mlindner@marvell.com, shemminger@osdl.org, shemminger@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [BUG] skge: a possible sleep-in-atomic bug in skge_remove Message-ID: <20171212211849.3e8b43b9@xeon-e3> In-Reply-To: <20171212.205701.569779668163323943.davem@davemloft.net> References: <1e8a8196-f0d1-2a82-3632-b882787c4391@gmail.com> <20171212.083445.2256119006373036925.davem@davemloft.net> <20171212102240.4a09cf9a@xeon-e3> <20171212.205701.569779668163323943.davem@davemloft.net> MIME-Version: 1.0 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: 1451 Lines: 43 On Tue, 12 Dec 2017 20:57:01 -0500 (EST) David Miller wrote: > From: Stephen Hemminger > Date: Tue, 12 Dec 2017 10:22:40 -0800 > > > On Tue, 12 Dec 2017 08:34:45 -0500 (EST) > > David Miller wrote: > > > >> From: Jia-Ju Bai > >> Date: Tue, 12 Dec 2017 16:38:12 +0800 > >> > >> > According to drivers/net/ethernet/marvell/skge.c, the driver may sleep > >> > under a spinlock. > >> > The function call path is: > >> > skge_remove (acquire the spinlock) > >> > free_irq --> may sleep > >> > > >> > I do not find a good way to fix it, so I only report. > >> > This possible bug is found by my static analysis tool (DSAC) and > >> > checked by my code review. > >> > >> This was added by: > >> > >> commit a9e9fd7182332d0cf5f3e601df3e71dd431b70d7 > >> Author: Stephen Hemminger > >> Date: Tue Sep 27 13:41:37 2011 -0400 > >> > >> skge: handle irq better on single port card > >> > >> I think the free_irq() can be moved below the unlock. > >> > >> Stephen, please take a look. > > > > The IRQ was being free twice. > > How did you see it, I really doubt any multi-port SKGE cards > > still exist. > > He sees it by reading the code, please take a look at this > and move the free_irq() out of the spin locked section since > it can sleep. Thanks, I was hoping for some automated static analysis tool.