From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f45.google.com (mail-pa0-f45.google.com [209.85.220.45]) by kanga.kvack.org (Postfix) with ESMTP id CC99F6B0037 for ; Mon, 16 Dec 2013 20:14:47 -0500 (EST) Received: by mail-pa0-f45.google.com with SMTP id fb1so3707103pad.18 for ; Mon, 16 Dec 2013 17:14:47 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id qz9si10294208pab.307.2013.12.16.17.14.45 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 16 Dec 2013 17:14:45 -0800 (PST) Message-ID: <52AFA331.9070108@oracle.com> Date: Mon, 16 Dec 2013 20:04:49 -0500 From: Sasha Levin MIME-Version: 1.0 Subject: mm: kernel BUG at mm/mlock.c:82! Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: "linux-mm@kvack.org" , Michel Lespinasse Hi all, While fuzzing with trinity inside a KVM tools guest running latest -next kernel, I've stumbled on the following spew. Codewise, it's pretty straightforward. In try_to_unmap_cluster(): page = vm_normal_page(vma, address, *pte); BUG_ON(!page || PageAnon(page)); if (locked_vma) { mlock_vma_page(page); /* no-op if already mlocked */ if (page == check_page) ret = SWAP_MLOCK; continue; /* don't unmap */ } And the BUG triggers once we see that 'page' isn't locked. I couldn't find anything that recently changed in those codepaths, so I'm a bit lost. [ 253.869145] kernel BUG at mm/mlock.c:82! [ 253.869549] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 253.870098] Dumping ftrace buffer: [ 253.870098] (ftrace buffer empty) [ 253.870098] Modules linked in: [ 253.870098] CPU: 10 PID: 9162 Comm: trinity-child75 Tainted: G W 3.13.0-rc 4-next-20131216-sasha-00011-g5f105ec-dirty #4137 [ 253.873310] task: ffff8800c98cb000 ti: ffff8804d34e8000 task.ti: ffff8804d34e8000 [ 253.873310] RIP: 0010:[] [] mlock_vma_page+0x18 /0xc0 [ 253.873310] RSP: 0000:ffff8804d34e99e8 EFLAGS: 00010246 [ 253.873310] RAX: 006fffff8038002c RBX: ffffea00474944c0 RCX: ffff880807636000 [ 253.873310] RDX: ffffea0000000000 RSI: 00007f17a9bca000 RDI: ffffea00474944c0 [ 253.873310] RBP: ffff8804d34e99f8 R08: ffff880807020000 R09: 0000000000000000 [ 253.873310] R10: 0000000000000001 R11: 0000000000002000 R12: 00007f17a9bca000 [ 253.873310] R13: ffffea00474944c0 R14: 00007f17a9be0000 R15: ffff880807020000 [ 253.873310] FS: 00007f17aa31a700(0000) GS:ffff8801c9c00000(0000) knlGS:000000000000 0000 [ 253.873310] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 253.873310] CR2: 00007f17a94fa000 CR3: 00000004d3b02000 CR4: 00000000000006e0 [ 253.873310] DR0: 00007f17a74ca000 DR1: 0000000000000000 DR2: 0000000000000000 [ 253.873310] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 253.873310] Stack: [ 253.873310] 0000000b3de28067 ffff880b3de28e50 ffff8804d34e9aa8 ffffffff8128bc31 [ 253.873310] 0000000000000301 ffffea0011850220 ffff8809a4039000 ffffea0011850238 [ 253.873310] ffff8804d34e9aa8 ffff880807636060 0000000000000001 ffff880807636348 [ 253.873310] Call Trace: [ 253.873310] [] try_to_unmap_cluster+0x1c1/0x340 [ 253.873310] [] try_to_unmap_file+0x20a/0x2e0 [ 253.873310] [] try_to_unmap+0x73/0x90 [ 253.873310] [] __unmap_and_move+0x18d/0x250 [ 253.873310] [] unmap_and_move+0xb9/0x180 [ 253.873310] [] migrate_pages+0xeb/0x2f0 [ 253.873310] [] ? queue_pages_pte_range+0x1a0/0x1a0 [ 253.873310] [] migrate_to_node+0x9c/0xc0 [ 253.873310] [] do_migrate_pages+0x1b8/0x240 [ 253.873310] [] SYSC_migrate_pages+0x316/0x380 [ 253.873310] [] ? SYSC_migrate_pages+0xac/0x380 [ 253.873310] [] ? vtime_account_user+0x96/0xb0 [ 253.873310] [] SyS_migrate_pages+0xe/0x10 [ 253.873310] [] tracesys+0xdd/0xe2 [ 253.873310] Code: 0f 1f 00 65 48 ff 04 25 10 25 1d 00 48 83 c4 08 5b c9 c3 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 48 8b 07 48 89 fb a8 01 75 10 <0f> 0b 66 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 f0 0f ba 2f 15 [ 253.873310] RIP [] mlock_vma_page+0x18/0xc0 [ 253.873310] RSP [ 253.904194] ---[ end trace be59c4a7f8edab3f ]--- -- 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