From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: * X-Spam-Status: No, score=1.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, PDS_HP_HELO_NORDNS,RDNS_NONE,SPF_HELO_NONE,SPF_NONE,SPOOFED_FREEMAIL_NO_RDNS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail-lf1-f65.google.com ([209.85.167.65]:39884 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730096AbgCKQfX (ORCPT ); Wed, 11 Mar 2020 12:35:23 -0400 MIME-Version: 1.0 References: <20200301100755.4532-1-hdanton@sina.com> <20200309120327.3656-1-hdanton@sina.com> In-Reply-To: <20200309120327.3656-1-hdanton@sina.com> From: Fabio Estevam Date: Wed, 11 Mar 2020 13:35:09 -0300 Message-ID: Subject: Re: rcu_sched stalls on 4.14 To: Hillf Danton Cc: paulmck@kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, rcu@vger.kernel.org, linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: Hi Hillf and Paul, On Mon, Mar 9, 2020 at 9:03 AM Hillf Danton wrote: > Hi Fabio, two minutes to take a look at the softirq part in the syzbot report > BUG: soft lockup in sys_exit_group. > > https://lore.kernel.org/lkml/s5h8sk9svdd.wl-tiwai@suse.de/T/#m0402638ecd30cf5a3c8bb44f03952ccad7a041d8 A different user reported the same bug and it turns out it was an USB CDC ACM related issue: https://www.spinics.net/lists/linux-usb/msg192162.html Thanks for your help! Fabio Estevam