From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 45BE9830A8 for ; Thu, 21 Apr 2016 20:38:57 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id 203so93583879pfy.2 for ; Thu, 21 Apr 2016 17:38:57 -0700 (PDT) Received: from mail-pa0-x234.google.com (mail-pa0-x234.google.com. [2607:f8b0:400e:c03::234]) by mx.google.com with ESMTPS id z73si3386861pfa.225.2016.04.21.17.38.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Apr 2016 17:38:56 -0700 (PDT) Received: by mail-pa0-x234.google.com with SMTP id fs9so34092671pac.2 for ; Thu, 21 Apr 2016 17:38:56 -0700 (PDT) From: "Shi, Yang" Subject: [BUG linux-next] kernel NULL pointer dereference on linux-next-20160420 Message-ID: <5719729E.7000101@linaro.org> Date: Thu, 21 Apr 2016 17:38:54 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, sfr@canb.auug.org.au, hughd@google.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, yang.shi@linaro.org Hi folks, I did the below test with huge tmpfs on linux-next-20160420: # mount -t tmpfs huge=1 tmpfs /mnt # cd /mnt Then clone linux kernel Then I got the below bug, such test works well on non-huge tmpfs. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] release_freepages+0x18/0xa0 PGD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: CPU: 6 PID: 110 Comm: kcompactd0 Not tainted 4.6.0-rc4-next-20160420-WR7.0.0.0_standard #4 Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.10.0025.030220091519 03/02/2009 task: ffff880361708040 ti: ffff880361704000 task.ti: ffff880361704000 RIP: 0010:[] [] release_freepages+0x18/0xa0 RSP: 0018:ffff880361707cf8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88036ffde7c0 RCX: 0000000000000009 RDX: 0000000000001bf1 RSI: 000000000000000f RDI: ffff880361707dd0 RBP: ffff880361707d20 R08: 0000000000000007 R09: 0000160000000000 R10: ffff88036ffde7c0 R11: 0000000000000000 R12: 0000000000000000 R13: ffff880361707dd0 R14: ffff880361707dc0 R15: ffff880361707db0 FS: 0000000000000000(0000) GS:ffff880363cc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000002206000 CR4: 00000000000006e0 Stack: ffff88036ffde7c0 0000000000000000 0000000000001a00 ffff880361707dc0 ffff880361707db0 ffff880361707da0 ffffffff8119f13d ffffffff81196239 0000000000000000 ffff880361708040 0000000000000001 0000000000100000 Call Trace: [] compact_zone+0x55d/0x9f0 [] ? fragmentation_index+0x19/0x70 [] kcompactd_do_work+0x10f/0x230 [] kcompactd+0x90/0x1e0 [] ? wait_woken+0xa0/0xa0 [] ? kcompactd_do_work+0x230/0x230 [] kthread+0xdd/0x100 [] ret_from_fork+0x22/0x40 [] ? kthread_create_on_node+0x180/0x180 Code: c1 fa 06 31 f6 e8 a9 9b fd ff eb 98 0f 1f 80 00 00 00 00 66 66 66 66 90 55 48 89 e5 41 57 41 56 41 55 49 89 fd 41 54 53 48 8b 07 <48> 8b 10 48 8d 78 e0 49 39 c5 4c 8d 62 e0 74 70 49 be 00 00 00 RIP [] release_freepages+0x18/0xa0 RSP CR2: 0000000000000000 ---[ end trace 855da7e142f7311f ]--- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org