From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752115AbaHJBr0 (ORCPT ); Sat, 9 Aug 2014 21:47:26 -0400 Received: from mail.active-venture.com ([67.228.131.205]:64896 "EHLO mail.active-venture.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751874AbaHJBrZ (ORCPT ); Sat, 9 Aug 2014 21:47:25 -0400 X-Originating-IP: 108.223.40.66 Message-ID: <53E6CF2B.6090709@roeck-us.net> Date: Sat, 09 Aug 2014 18:47:23 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" , Kees Cook CC: Linus Torvalds , Oleg Nesterov , Andy Lutomirski Subject: Runtime trouble with commit dbd952127d (seccomp: introduce writer locking) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi folks, I am having some trouble with commit dbd952127d (seccomp: introduce writer locking) when running my qemu tests on the upstream kernel. With powerpc, I get the following crash. ftrace: allocating 20093 entries in 59 pages ------------[ cut here ]------------ kernel BUG at kernel/fork.c:1108! Oops: Exception in kernel mode, sig: 5 [#1] PREEMPT PowerMac Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 3.16.0-yocto-standard+ #1 task: c08a03d0 ti: c08e4000 task.ti: c08e4000 NIP: c002b98c LR: c002b988 CTR: c03837ec REGS: c08e5e30 TRAP: 0700 Not tainted (3.16.0-yocto-standard+) MSR: 00021032 CR: 22282048 XER: 20000000 GPR00: c002b988 c08e5ee0 c08a03d0 00000001 c0a9b878 00000800 c783603c 00000020 GPR08: c783603c 00000003 00000001 c08f61fc 22222044 00000000 07c5ac10 00800300 GPR16: c7870000 00000010 00000000 07de7fa4 00000000 c08f594c c08f0000 c78702d0 GPR24: 00000000 c08f0000 c08f5940 c000422c c08a8ea0 c7870310 00000000 c7808400 NIP [c002b98c] copy_process.part.52+0x794/0x13e4 LR [c002b988] copy_process.part.52+0x790/0x13e4 Call Trace: [c08e5ee0] [c002b988] copy_process.part.52+0x790/0x13e4 (unreliable) [c08e5f60] [c002c768] do_fork+0xb8/0x3bc [c08e5fa0] [c00041c8] rest_init+0x30/0x94 [c08e5fb0] [c083cf98] start_kernel+0x368/0x37c [c08e5ff0] [00003438] 0x3438 Instruction dump: 7d400124 38600001 48027e95 55e903e1 41820b84 80e202c0 90f002c0 81420570 91500570 38600001 48027e75 39400001 <0f0a0000> 81420568 8162056c 91500568 ---[ end trace dc8fa200cb88537f ]--- With mips (both 32 bit and 64 bit), I get NR_IRQS:256 CPU frequency 200.00 MHz Console: colour dummy device 80x25 console [tty0] enabled bootconsole [uart0] disabled [ and then there is silence ] In all cases I bisected the problem to the above mentioned commit. Failures are seen in both linux-next and the tip of Linus' tree. Test results are on http://server.roeck-us.net:8010/builders (look for qwmu results). Build and test scripts are in the mips, mips64, and powerpc subdirectories of https://github.com/groeck/linux-build-test/tree/master/rootfs. Any idea, anyone, what might be going on, or how I could do to help tracking this down ? Thanks, Guenter