Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932307AbbKMMSN (ORCPT ); Fri, 13 Nov 2015 07:18:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:40796 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754225AbbKMMSM (ORCPT ); Fri, 13 Nov 2015 07:18:12 -0500 Subject: Re: [PATCH V6] mm: fix kernel crash in khugepaged thread To: yalin wang , rostedt@goodmis.org, mingo@redhat.com, akpm@linux-foundation.org, riel@redhat.com, ebru.akagunduz@gmail.com, kirill.shutemov@linux.intel.com, jmarchan@redhat.com, mgorman@techsingularity.net, willy@linux.intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <1447416477-24881-1-git-send-email-yalin.wang2010@gmail.com> From: Vlastimil Babka Message-ID: <5645D501.3060202@suse.cz> Date: Fri, 13 Nov 2015 13:18:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1447416477-24881-1-git-send-email-yalin.wang2010@gmail.com> 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 Content-Length: 5640 Lines: 84 On 11/13/2015 01:07 PM, yalin wang wrote: > This crash is caused by NULL pointer deference, in page_to_pfn() marco, > when page == NULL : > > [ 182.639154 ] Unable to handle kernel NULL pointer dereference at virtual address 00000000 > [ 182.639491 ] pgd = ffffffc00077a000 > [ 182.639761 ] [00000000] *pgd=00000000b9422003, *pud=00000000b9422003, *pmd=00000000b9423003, *pte=0060000008000707 > [ 182.640749 ] Internal error: Oops: 94000006 [#1] SMP > [ 182.641197 ] Modules linked in: > [ 182.641580 ] CPU: 1 PID: 26 Comm: khugepaged Tainted: G W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3 > [ 182.642077 ] Hardware name: linux,dummy-virt (DT) > [ 182.642227 ] task: ffffffc07957c080 ti: ffffffc079638000 task.ti: ffffffc079638000 > [ 182.642598 ] PC is at khugepaged+0x378/0x1af8 > [ 182.642826 ] LR is at khugepaged+0x418/0x1af8 > [ 182.643047 ] pc : [] lr : [] pstate: 60000145 > [ 182.643490 ] sp : ffffffc07963bca0 > [ 182.643650 ] x29: ffffffc07963bca0 x28: ffffffc00075c000 > [ 182.644024 ] x27: ffffffc00f275040 x26: ffffffc0006c7000 > [ 182.644334 ] x25: 00e8000048800f51 x24: 0000000006400000 > [ 182.644687 ] x23: 0000000000000002 x22: 0000000000000000 > [ 182.644972 ] x21: 0000000000000000 x20: 0000000000000000 > [ 182.645446 ] x19: 0000000000000000 x18: 0000007ff86d0990 > [ 182.645931 ] x17: 00000000007ef9c8 x16: ffffffc000098390 > [ 182.646236 ] x15: ffffffffffffffff x14: 00000000ffffffff > [ 182.646649 ] x13: 000000000000016a x12: 0000000000000000 > [ 182.647046 ] x11: ffffffc07f025020 x10: 0000000000000000 > [ 182.647395 ] x9 : 0000000000000048 x8 : ffffffc000721e28 > [ 182.647872 ] x7 : 0000000000000000 x6 : ffffffc07f02d000 > [ 182.648261 ] x5 : fffffffffffffe00 x4 : ffffffc00f275040 > [ 182.648611 ] x3 : 0000000000000000 x2 : ffffffc00f2ad000 > [ 182.648908 ] x1 : 0000000000000000 x0 : ffffffc000727000 > [ 182.649147 ] > [ 182.649252 ] Process khugepaged (pid: 26, stack limit = 0xffffffc079638020) > [ 182.649724 ] Stack: (0xffffffc07963bca0 to 0xffffffc07963c000) > [ 182.650141 ] bca0: ffffffc07963be30 ffffffc0000b5044 ffffffc07961fb80 ffffffc00072e630 > [ 182.650587 ] bcc0: ffffffc0005d5090 0000000000000000 ffffffc000197d34 0000000000000000 > [ 182.651009 ] bce0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.651446 ] bd00: ffffffc07963bd90 ffffffc07f1cbf80 000000004f3be003 ffffffc00f2750a4 > [ 182.651956 ] bd20: ffffffc00f3bf000 ffffffc000000001 0000000000000001 ffffffc07f085740 > [ 182.652520 ] bd40: ffffffc00f2ad188 ffffffc000000000 0000000006200000 ffffffc00f275040 > [ 182.652972 ] bd60: ffffffc0006b1a90 ffffffc079638000 ffffffc07963be20 ffffffc00f0144d0 > [ 182.653357 ] bd80: ffffffc000000000 0000000006400000 ffffffc00f0144d0 00000a0800000001 > [ 182.653793 ] bda0: 0000100000000001 ffffffc000000001 ffffffc07f025000 ffffffc00f2750a8 > [ 182.654226 ] bdc0: 00000001000005f8 ffffffc00075a000 0000000006a00000 ffffffc000727000 > [ 182.654522 ] bde0: ffffffc0006e8478 ffffffc000000000 0000000100000000 ffffffc078fb9000 > [ 182.654869 ] be00: ffffffc07963be30 ffffffc000000000 ffffffc07957c080 ffffffc0000cfc4c > [ 182.655225 ] be20: ffffffc07963be20 ffffffc07963be20 0000000000000000 ffffffc000085c50 > [ 182.655588 ] be40: ffffffc0000b4f64 ffffffc07961fb80 0000000000000000 0000000000000000 > [ 182.656138 ] be60: 0000000000000000 ffffffc0000bee2c ffffffc0000b4f64 0000000000000000 > [ 182.656609 ] be80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.657145 ] bea0: ffffffc07963bea0 ffffffc07963bea0 0000000000000000 ffffffc000000000 > [ 182.657475 ] bec0: ffffffc07963bec0 ffffffc07963bec0 0000000000000000 0000000000000000 > [ 182.657922 ] bee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.658558 ] bf00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.658972 ] bf20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.659291 ] bf40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.659722 ] bf60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.660122 ] bf80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.660654 ] bfa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.661064 ] bfc0: 0000000000000000 0000000000000000 0000000000000000 0000000000000005 > [ 182.661466 ] bfe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > [ 182.661848 ] Call trace: > [ 182.662050 ] [] khugepaged+0x378/0x1af8 > [ 182.662294 ] [] kthread+0xdc/0xf4 > [ 182.662605 ] [] ret_from_fork+0xc/0x40 > [ 182.663046 ] Code: 35001700 f0002c60 aa0703e3 f9009fa0 (f94000e0) > [ 182.663901 ] ---[ end trace 637503d8e28ae69e ]--- > [ 182.664160 ] Kernel panic - not syncing: Fatal exception > [ 182.664571 ] CPU2: stopping > [ 182.664794 ] CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3 > [ 182.665248 ] Hardware name: linux,dummy-virt (DT) > > Signed-off-by: yalin wang This is a fix for: http://www.ozlabs.org/~akpm/mmots/broken-out/mm-add-tracepoint-for-scanning-pages.patch Acked-by: Vlastimil Babka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/