From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754736AbaHKTSN (ORCPT ); Mon, 11 Aug 2014 15:18:13 -0400 Received: from a.ns.miles-group.at ([95.130.255.143]:65275 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752527AbaHKTSM (ORCPT ); Mon, 11 Aug 2014 15:18:12 -0400 Message-ID: <53E916F0.80308@nod.at> Date: Mon, 11 Aug 2014 21:18:08 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Vivek Goyal CC: "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , user-mode-linux-devel , sahne@0x90.at Subject: Re: "resource: provide new functions to walk through resources" breaks UML References: <53E7A42E.4090702@nod.at> <20140811122229.GA26869@redhat.com> <53E8B654.2000807@nod.at> <20140811184401.GE1863@redhat.com> In-Reply-To: <20140811184401.GE1863@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 11.08.2014 20:44, schrieb Vivek Goyal: > On Mon, Aug 11, 2014 at 02:25:56PM +0200, Richard Weinberger wrote: >> Hi Vivek, >> >> Am 11.08.2014 14:22, schrieb Vivek Goyal: >>> On Sun, Aug 10, 2014 at 06:56:14PM +0200, Richard Weinberger wrote: >>>> Hi Vivek, >>>> >>>> Daniel Walter reported that UML is currently broken. >>>> The offending commit is: >>>> >>> >>> Hi Richard, >>> >>> Thanks for pointing it out. I will look into it. >>> >>> Would you have link to the report Daniel sent. I am interested in >>> looking at backtrace. >> >> he reported it on IRC to me. >> >> Here is a backtrace: >> RIP: 0033:[<0000000060039b9f>] >> RSP: 0000000081459da0 EFLAGS: 00010202 >> RAX: 0000000000000000 RBX: 00000000219b3fff RCX: 000000006010d1d9 >> RDX: 0000000000000001 RSI: 00000000602dfb94 RDI: 0000000081459df8 >> RBP: 0000000081459de0 R08: 00000000601b59f4 R09: ffffffff0000ff00 >> R10: ffffffff0000ff00 R11: 0000000081459e88 R12: 0000000081459df8 >> R13: 00000000219b3fff R14: 00000000602dfb94 R15: 0000000000000000 >> Kernel panic - not syncing: Segfault with no mm >> CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-10454-g58d08e3 #13 >> Stack: >> 00000000 000080d0 81459df0 219b3fff >> 81459e70 6010d1d9 ffffffff 6033e010 >> 81459e50 6003a269 81459e30 00000000 >> Call Trace: >> [<6010d1d9>] ? kclist_add_private+0x0/0xe7 >> [<6003a269>] walk_system_ram_range+0x61/0xb7 >> [<6000e859>] ? proc_kcore_init+0x0/0xf1 >> [<6010d574>] kcore_update_ram+0x4c/0x168 >> [<6010d72e>] ? kclist_add+0x0/0x2e >> [<6000e943>] proc_kcore_init+0xea/0xf1 >> [<6000e859>] ? proc_kcore_init+0x0/0xf1 >> [<6000e859>] ? proc_kcore_init+0x0/0xf1 >> [<600189f0>] do_one_initcall+0x13c/0x204 >> [<6004ca46>] ? parse_args+0x1df/0x2e0 >> [<6004c82d>] ? parameq+0x0/0x3a >> [<601b5990>] ? strcpy+0x0/0x18 >> [<60001e1a>] kernel_init_freeable+0x240/0x31e >> [<6026f1c0>] kernel_init+0x12/0x148 >> [<60019fad>] new_thread_handler+0x81/0xa3 >> >> RIP is at kernel/resource.c:66. > > Hi Richard, > > Can you please give the attached patch a try and see if it fixes the UML > issue. > > I noticed that previous code had a for() loop which will not execute > if p was null. I have resorted back to same code now. Looks good! Reported-by: Daniel Walter Tested-by: Richard Weinberger Thanks, //richard