Return-path: Received: from ms.lwn.net ([45.79.88.28]:47590 "EHLO ms.lwn.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752883AbdFAQLP (ORCPT ); Thu, 1 Jun 2017 12:11:15 -0400 Date: Thu, 1 Jun 2017 10:11:13 -0600 From: Jonathan Corbet To: Jia-Ju Bai Cc: Larry Finger , kvalo@codeaurora.org, linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] b43legacy: Fix a sleep-in-atomic bug in b43legacy_attr_interfmode_store Message-ID: <20170601101113.6dd30d6d@lwn.net> (sfid-20170601_181224_343666_117B2F03) In-Reply-To: <592F6843.9000204@163.com> References: <1496226547-5921-1-git-send-email-baijiaju1990@163.com> <85905124-7167-aeb0-8aff-4ceec09e9542@lwfinger.net> <592F6843.9000204@163.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: 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! jon