From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: Re: [PATCH] acpi: scan: Fix a possible data race in acpi_scan_hotplug_enabled Date: Wed, 9 May 2018 11:17:38 +0800 Message-ID: <1b7f1bff-b38b-fe10-3e1c-2b465b36f193@gmail.com> References: <20180508030811.12256-1-baijiaju1990@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: "Rafael J. Wysocki" , Len Brown , ACPI Devel Maling List , Linux Kernel Mailing List List-Id: linux-acpi@vger.kernel.org On 2018/5/9 4:17, Rafael J. Wysocki wrote: > On Tue, May 8, 2018 at 5:08 AM, Jia-Ju Bai wrote: >> The write operation to "hotplug->enabled" is protected by >> the lock on line 1760, but the read operation to >> this data on line 1755 is not protected by the lock. >> Thus, there may exist a data race for "hotplug->enabled". > Either it does exist, or it doesn't. > > If it exists, it needs to be fixed. If it doesn't exist, nothing > needs to be done. > > Which is the case? I only read the code and find this possible data race. It is not found in real driver execution. I am not sure of it, so I use "may" and "possible" here. Best wishes, Jia-Ju Bai