From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [BUG] skge: a possible sleep-in-atomic bug in skge_remove Date: Tue, 12 Dec 2017 20:57:01 -0500 (EST) Message-ID: <20171212.205701.569779668163323943.davem@davemloft.net> References: <1e8a8196-f0d1-2a82-3632-b882787c4391@gmail.com> <20171212.083445.2256119006373036925.davem@davemloft.net> <20171212102240.4a09cf9a@xeon-e3> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: baijiaju1990@gmail.com, mlindner@marvell.com, shemminger@osdl.org, shemminger@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: stephen@networkplumber.org Return-path: In-Reply-To: <20171212102240.4a09cf9a@xeon-e3> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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.