From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752737AbaEWOhQ (ORCPT ); Fri, 23 May 2014 10:37:16 -0400 Received: from mail1.windriver.com ([147.11.146.13]:46666 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbaEWOhO (ORCPT ); Fri, 23 May 2014 10:37:14 -0400 Message-ID: <537F5CEE.5000409@windriver.com> Date: Fri, 23 May 2014 10:36:30 -0400 From: Paul Gortmaker User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Stanislav Meduna , "linux-rt-users@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Linux ARM Kernel Subject: Re: BUG: sleeping function called from invalid context (do_force_sig_info) References: <537E83C0.9040406@meduna.org> In-Reply-To: <537E83C0.9040406@meduna.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [128.224.56.57] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14-05-22 07:09 PM, Stanislav Meduna wrote: > Hi, > > this is on a i.MX28 running a 3.12.19-rt30 > > [27284.008123] BUG: sleeping function called from invalid context at /home/nxtdev/Kernels/linux-stable-rt/kernel/rtmutex.c:673 > [27284.008143] in_atomic(): 0, irqs_disabled(): 128, pid: 1335, name: nxt Would be worthwhile to enable irq on/off debugging so you get the output from print_irqtrace_events() here to see who last futzed with interrupts. Probably a broken driver leaving interrupts off? > [27284.008170] CPU: 0 PID: 1335 Comm: nxt Not tainted 3.12.19-rt30+ #178 > [27284.008255] [] (unwind_backtrace+0x0/0xf4) from [] (show_stack+0x10/0x14) > [27284.008306] [] (show_stack+0x10/0x14) from [] (rt_spin_lock+0x18/0x2c) > [27284.008348] [] (rt_spin_lock+0x18/0x2c) from [] (do_force_sig_info+0x20/0xd8) > [27284.008387] [] (do_force_sig_info+0x20/0xd8) from [] (__do_user_fault+0x88/0xc8) Dies because of non-raw siglock in do_force_sig_info: spin_lock_irqsave(&t->sighand->siglock, flags); and we aren't going to convert that one to raw either. > [27284.008419] [] (__do_user_fault+0x88/0xc8) from [] (do_bad_area+0x64/0x70) > [27284.008452] [] (do_bad_area+0x64/0x70) from [] (do_translation_fault+0x6c/0xa8) > [27284.008483] [] (do_translation_fault+0x6c/0xa8) from [] (do_DataAbort+0x34/0x98) > [27284.008520] [] (do_DataAbort+0x34/0x98) from [] (__dabt_usr+0x3c/0x40) > [27284.008531] Exception stack(0xc1173fb0 to 0xc1173ff8) > [27284.008554] 3fa0: b6634b48 d6634b44 d6634a94 07ffffff > [27284.008583] 3fc0: b6634c1c b6ef1160 b6ef1000 00000152 b6635460 b6ee6b34 00000000 b6634b4c > [27284.008605] 3fe0: 00000152 b6634a80 001f813c 00203888 60000010 ffffffff > > There are some changes to the stock 3.12.19-rt30 (added drivers) where > I can not exclude that there is some bug lurking, and a bug in userspace > is even more probable; I am just forwarding it because of the sleeping > from invalid context thing. > > After a reboot I am unfortunately not able to easily reproduce it. There > was no core dump (they are enabled) and the application did not exit > (there is no SEGV handler). It is calling user_fault and not kernel_fault, so if you create a broken program that intentionally tries to stomp on memory it doesn't own, can you then reproduce it? You might not, if the culprit leaving IRQs off only does so sporadically -- in which case you'd want to keep re-launching the broken program in a tight loop while exercising the various drivers. Paul. -- > > Thanks >