From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: Re: [BUG] skge: a possible sleep-in-atomic bug in skge_remove Date: Wed, 13 Dec 2017 15:42:56 +0800 Message-ID: References: <1e8a8196-f0d1-2a82-3632-b882787c4391@gmail.com> <20171212.083445.2256119006373036925.davem@davemloft.net> <20171212102240.4a09cf9a@xeon-e3> <20171212.205701.569779668163323943.davem@davemloft.net> <20171212211849.3e8b43b9@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , mlindner@marvell.com, shemminger@osdl.org, shemminger@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Stephen Hemminger Return-path: In-Reply-To: <20171212211849.3e8b43b9@xeon-e3> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 2017/12/13 13:18, Stephen Hemminger wrote: > 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. This bug was found by an automated static analysis tool named DSAC, which is written by myself. Then I manually checked driver source code, and finally sent the bug report. Thanks, Jia-Ju Bai