From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754924AbbK0QNG (ORCPT ); Fri, 27 Nov 2015 11:13:06 -0500 Received: from cmta12.telus.net ([209.171.16.85]:47724 "EHLO cmta12.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752117AbbK0QNE (ORCPT ); Fri, 27 Nov 2015 11:13:04 -0500 X-Authority-Analysis: v=2.1 cv=PLPygqeC c=1 sm=2 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=aatUQebYAAAA:8 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=IkcTkHD0fZMA:10 a=VwQbUJbxAAAA:8 a=61A1xia_-z2hh-UrLH8A:9 a=QEXdDO2ut3YA:10 X-Telus-Outbound-IP: 173.180.45.4 From: "Doug Smythies" To: "'Borislav Petkov'" Cc: , "Doug Smythies" References: <000301d12867$19ba3030$4d2e9090$@net> <20151126180934.GB18183@pd.tnic> In-Reply-To: <20151126180934.GB18183@pd.tnic> Subject: RE: As of kernel 4.4-rc1 segmentation fault if msr module not loaded. [REGRESSION][BISECTED] Date: Fri, 27 Nov 2015 08:12:59 -0800 Message-ID: <000401d1292e$7c50ce80$74f26b80$@net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AdEodZ2MrJ7IsyTYT4q6aLv4Efk7TwAuF0QQ Content-Language: en-ca Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015.11.26 10:10 Borislav Petkov wrote: > On Thu, Nov 26, 2015 at 08:25:43AM -0800, Doug Smythies wrote: >> >> In some distros, the msr module is not loaded by default. >> (I guess not built in by default, would be more correct.) >> I often forget to load it before using "rdmsr" or "wrmsr". >> It was never an issue before, but as of Kernel 4.4-rc1 >> it causes a segmentation fault crash. Example: >> >> # rdmsr -a 0x19a >> Segmentation fault (core dumped) > You can either cherrypick > http://git.kernel.org/tip/2d5be37d686c4dae8e60d20283d6f44ac2c44f65 Just for completeness: I confirm that the above commit fixes the issue raised herein. Thanks. ... Doug