From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f180.google.com (mail-pd0-f180.google.com [209.85.192.180]) by kanga.kvack.org (Postfix) with ESMTP id 2F69A6B0037 for ; Thu, 27 Feb 2014 10:03:41 -0500 (EST) Received: by mail-pd0-f180.google.com with SMTP id y10so2542926pdj.39 for ; Thu, 27 Feb 2014 07:03:40 -0800 (PST) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTP id fd10si4905270pad.109.2014.02.27.07.03.39 for ; Thu, 27 Feb 2014 07:03:40 -0800 (PST) From: "Kirill A. Shutemov" In-Reply-To: <530F3F0A.5040304@oracle.com> References: <530F3F0A.5040304@oracle.com> Subject: RE: mm: kernel BUG at mm/huge_memory.c:2785! Content-Transfer-Encoding: 7bit Message-Id: <20140227150313.3BA27E0098@blue.fi.intel.com> Date: Thu, 27 Feb 2014 17:03:13 +0200 (EET) Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin , Andrea Arcangeli Cc: "linux-mm@kvack.org" , Andrew Morton , LKML , "Kirill A. Shutemov" Sasha Levin wrote: > Hi all, > > While fuzzing with trinity inside a KVM tools guest running latest -next kernel I've stumbled on the > following spew: > > [ 1428.146261] kernel BUG at mm/huge_memory.c:2785! Hm, interesting. It seems we either failed to split huge page on vma split or it materialized from under us. I don't see how it can happen: - it seems we do the right thing with vma_adjust_trans_huge() in __split_vma(); - we hold ->mmap_sem all the way from vm_munmap(). At least I don't see a place where we could drop it; Andrea, any ideas? > [ 1428.147100] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > [ 1428.148512] Dumping ftrace buffer: > [ 1428.149497] (ftrace buffer empty) > [ 1428.150248] Modules linked in: > [ 1428.151164] CPU: 106 PID: 29430 Comm: trinity-c106 Tainted: G W > 3.14.0-rc4-next-20140226-sasha-00013-g082bdac-dirty #4 > [ 1428.153515] task: ffff8808906c8000 ti: ffff880890aa6000 task.ti: ffff880890aa6000 > [ 1428.154274] RIP: 0010:[] [] > __split_huge_page_pmd+0x3f/0x2e0 > [ 1428.154274] RSP: 0018:ffff880890aa7c98 EFLAGS: 00010287 > [ 1428.154274] RAX: ffff880890f34000 RBX: ffff880b3c6791a0 RCX: 00003ffffffff000 > [ 1428.154274] RDX: ffff880b3c6791a0 RSI: 00007f29869b4000 RDI: ffff8803dcbd6400 > [ 1428.154274] RBP: ffff880890aa7ce8 R08: 00007f29869b5000 R09: 0000000000000000 > [ 1428.154274] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880b3c6791a0 > [ 1428.154274] R13: 00007f2986800000 R14: ffff8803dcbd6400 R15: 00007f29869b4fff > [ 1428.154274] FS: 00007f298bb67700(0000) GS:ffff8803de800000(0000) knlGS:0000000000000000 > [ 1428.154274] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 1428.154274] CR2: 00007f298b978608 CR3: 00000008907c3000 CR4: 00000000000006e0 > [ 1428.154274] DR0: 8200000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 1428.154274] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > [ 1428.154274] Stack: > [ 1428.154274] 00000000001d8400 0000000000000001 ffff880890aa7cc8 ffff880890f34000 > [ 1428.154274] ffffffff876bcfe0 ffff880b3c6791a0 00007f29869b4000 00007f29869b5000 > [ 1428.154274] ffff880890aa7e18 00007f29869b4fff ffff880890aa7d78 ffffffff8127ff06 > [ 1428.154274] Call Trace: > [ 1428.154274] [] unmap_page_range+0x2a6/0x410 > [ 1428.154274] [] unmap_single_vma+0xf1/0x110 > [ 1428.154274] [] unmap_vmas+0x61/0xa0 > [ 1428.154274] [] unmap_region+0xbc/0x120 > [ 1428.154274] [] do_munmap+0x27a/0x350 > [ 1428.154274] [] ? vm_munmap+0x41/0x80 > [ 1428.154274] [] vm_munmap+0x4f/0x80 > [ 1428.154274] [] SyS_munmap+0x27/0x40 > [ 1428.154274] [] tracesys+0xdd/0xe2 > [ 1428.154274] Code: e5 00 00 e0 ff 53 49 89 d4 48 83 ec 28 48 8b 47 40 48 89 45 c8 4c 3b 2f 72 11 > 49 8d 95 00 00 20 00 48 89 55 c0 48 39 57 08 73 11 <0f> 0b 0f 1f 80 00 00 00 00 eb fe 66 0f 1f 44 00 > 00 4c 89 e3 49 > [ 1428.154274] RIP [] __split_huge_page_pmd+0x3f/0x2e0 > [ 1428.154274] RSP > > > Thanks, > Sasha -- Kirill A. Shutemov -- 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