From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f179.google.com (mail-io0-f179.google.com [209.85.223.179]) by kanga.kvack.org (Postfix) with ESMTP id 6C0266B0038 for ; Fri, 23 Oct 2015 05:39:04 -0400 (EDT) Received: by iodv82 with SMTP id v82so118212002iod.0 for ; Fri, 23 Oct 2015 02:39:04 -0700 (PDT) Received: from mail-pa0-x243.google.com (mail-pa0-x243.google.com. [2607:f8b0:400e:c03::243]) by mx.google.com with ESMTPS id l128si14816249ioe.145.2015.10.23.02.39.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Oct 2015 02:39:03 -0700 (PDT) Received: by pagq8 with SMTP id q8so10986516pag.2 for ; Fri, 23 Oct 2015 02:39:03 -0700 (PDT) From: yalin wang Subject: [PATCH] mm: fix kernel crash in khugepaged thread Date: Fri, 23 Oct 2015 17:38:49 +0800 Message-Id: <1445593129-14728-1-git-send-email-yalin.wang2010@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, vbabka@suse.cz, jmarchan@redhat.com, mgorman@techsingularity.net, ebru.akagunduz@gmail.com, willy@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: yalin wang This crash is caused by NULL pointer deference: [ 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 --- mm/huge_memory.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 4b3420a..a5f4d9c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2606,8 +2606,9 @@ out_unmap: collapse_huge_page(mm, address, hpage, vma, node); } out: - trace_mm_khugepaged_scan_pmd(mm, page_to_pfn(page), writable, referenced, - none_or_zero, result, unmapped); + if (page) + trace_mm_khugepaged_scan_pmd(mm, page_to_pfn(page), writable, + referenced, none_or_zero, result, unmapped); return ret; } -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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