From mboxrd@z Thu Jan 1 00:00:00 1970 From: Larry Finger Subject: Re: [PATCH] b43legacy: Fix a sleep-in-atomic bug in b43legacy_attr_interfmode_store Date: Thu, 1 Jun 2017 12:43:41 -0500 Message-ID: References: <1496226547-5921-1-git-send-email-baijiaju1990@163.com> <85905124-7167-aeb0-8aff-4ceec09e9542@lwfinger.net> <592F6843.9000204@163.com> <20170601101113.6dd30d6d@lwn.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvalo@codeaurora.org, linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jonathan Corbet , Jia-Ju Bai Return-path: In-Reply-To: <20170601101113.6dd30d6d@lwn.net> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 06/01/2017 11:11 AM, Jonathan Corbet wrote: > On Thu, 01 Jun 2017 09:05:07 +0800 > Jia-Ju Bai wrote: > >> I admit my patches are not well tested, and they may not well fix the bugs. >> I am looking forward to opinions and suggestions :) > > May I politely suggest that sending out untested locking changes is a > dangerous thing to do? You really should not be changing the locking in a > piece of kernel code without understanding very well what the lock is > protecting and being able to say why your changes are safe. Without that, > the risk of introducing subtle bugs is very high. > > It looks like you have written a useful tool that could help us to make > the kernel more robust. If you are interested in my suggestion, I would > recommend that you post the sleep-in-atomic scenarios that you are > finding, but refrain from "fixing" them in any case where you cannot offer > a strong explanation of why your fix is correct. > > Thanks for working to find bugs in the kernel! I agree with the suggestion above. Locking changes should only be done in conjunction with testing by someone that actually has the hardware. Larry