From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161683AbdAEPKV (ORCPT ); Thu, 5 Jan 2017 10:10:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47452 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161671AbdAEPKJ (ORCPT ); Thu, 5 Jan 2017 10:10:09 -0500 Date: Thu, 5 Jan 2017 08:52:49 -0600 From: Josh Poimboeuf To: Dave Jones Cc: Linux Kernel Subject: Re: stack unwinder warning. Message-ID: <20170105145249.v2q3r3i46vzkg4au@treble> References: <20161227190030.dlyn24um2mcpbuzu@codemonkey.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20161227190030.dlyn24um2mcpbuzu@codemonkey.org.uk> User-Agent: Mutt/1.6.0.1 (2016-04-01) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 05 Jan 2017 14:52:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 27, 2016 at 02:00:30PM -0500, Dave Jones wrote: > I'm not sure what to make of this. Josh ? (4.10-rc1) > > WARNING: kernel stack frame pointer at ffffc900003e7858 in trinity-c6:29122 has bad value ffffffff82103a80 > unwind stack type:0 next_sp: (null) mask:2 graph_idx:0 > ffffc900003e7808: ffffffff811a02e5 (ring_buffer_lock_reserve+0x1d5/0x580) > ffffc900003e7810: ffffffff8119adc3 (rb_commit+0x93/0x350) > ffffc900003e7818: ffffffff811b31d4 (function_trace_call+0x104/0x1f0) > ffffc900003e7820: ffff8804f10ec000 (0xffff8804f10ec000) > ffffc900003e7828: 0000000000000000 ... > ffffc900003e7830: ffffffff8119b3ae (ring_buffer_unlock_commit+0x8e/0x120) > ffffc900003e7838: 0000000000000001 (0x1) > ffffc900003e7840: ffffea0002854e00 (0xffffea0002854e00) > ffffc900003e7848: 000000000000000a (0xa) > ffffc900003e7850: ffffea0002854ec0 (0xffffea0002854ec0) > ffffc900003e7858: ffffea000287c480 (0xffffea000287c480) The value reported by the warning contradicts the value reported by the dump. So this seems to have been caused by dumping the stack of a task which is running on another CPU. There are still some places in the code where that's possible. So I'm going to need to remove these unwinder warnings for now. -- Josh