From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754654Ab3KZHT0 (ORCPT ); Tue, 26 Nov 2013 02:19:26 -0500 Received: from mail-pd0-f169.google.com ([209.85.192.169]:47252 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754047Ab3KZHTY (ORCPT ); Tue, 26 Nov 2013 02:19:24 -0500 Date: Mon, 25 Nov 2013 23:19:53 -0800 From: Kent Overstreet To: Dave Jones , Linux Kernel , Sasha Levin , Benjamin LaHaise Subject: Re: GPF in aio_migratepage Message-ID: <20131126071953.GE9244@kmo-pixel> References: <20131126032645.GA32301@redhat.com> <20131126060132.GA6400@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131126060132.GA6400@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 26, 2013 at 01:01:32AM -0500, Dave Jones wrote: > On Mon, Nov 25, 2013 at 10:26:45PM -0500, Dave Jones wrote: > > Hi Kent, > > > > I hit the GPF below on a tree based on 8e45099e029bb6b369b27d8d4920db8caff5ecce > > which has your commit e34ecee2ae791df674dfb466ce40692ca6218e43 > > ("aio: Fix a trinity splat"). Is this another path your patch missed, or > > a completely different bug to what you were chasing ? > > And here's another from a different path, this time on 32bit. I'm pretty sure this is a different bug... it appears to be related to aio ring buffer migration, which I don't think I've touched. Any information on what it was doing at the time? I see exit_aio() in the second backtrace, maybe some sort of race between migratepage and ioctx teardown? But it is using the address space mapping, so I dunno. I don't see what's protecting ctx->ring_pages - I imagine it's got to have something to do with the page migration machinery but I have no idea how that works. Ben? > Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC > Modules linked in: tun fuse hidp rfcomm bnep scsi_transport_iscsi l2tp_ppp l2tp_netlink l2tp_core nfc caif_socket caif af_802154 phonet af_rxrpc bluetooth rfkill can_raw can_bcm can llc2 pppoe pppox ppp_generic slhc irda crc_ccitt rds af_key rose x25 atm netrom appletalk ipx p8023 p8022 psnap llc ax25 nouveau video backlight mxm_wmi wmi i2c_algo_bit ttm drm_kms_helper drm i2c_core kvm_intel kvm tg3 ptp pps_core libphy serio_raw pcspkr lpc_ich microcode mfd_core rtc_cmos parport_pc parport shpchp xfs libcrc32c raid0 floppy > CPU: 0 PID: 4517 Comm: trinity-child0 Not tainted 3.13.0-rc1+ #6 > Hardware name: Dell Inc. Precision WorkStation 490 /0DT031, BIOS A08 04/25/2008 > task: ed899630 ti: dea22000 task.ti: dea22000 > EIP: 0060:[] EFLAGS: 00010293 CPU: 0 > EIP is at aio_migratepage+0xad/0x126 > EAX: 00000144 EBX: f6844ed8 ECX: deaf4a84 EDX: 6b6b6b6b > ESI: f68dc508 EDI: deaf4800 EBP: dea23bcc ESP: dea23ba8 > DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 > CR0: 8005003b CR2: 6b6b707b CR3: 2c985000 CR4: 000007f0 > Stack: > 00000000 00000001 deaf4a84 00000286 d709b280 00000000 f68dc508 c11c7955 > f6844ed8 dea23c0c c116aa9f 00000001 00000001 c11c7955 c1179a33 00000000 > 00000000 c114166d f6844ed8 f6844ed8 c1140fc9 dea23c0c 00000000 f6844ed8 > Call Trace: > [] ? free_ioctx+0x62/0x62 > [] move_to_new_page+0x63/0x1bb > [] ? free_ioctx+0x62/0x62 > [] ? mem_cgroup_prepare_migration+0xc1/0x243 > [] ? isolate_migratepages_range+0x3fb/0x675 > [] ? isolate_freepages_block+0x316/0x316 > [] migrate_pages+0x614/0x72b > [] ? isolate_freepages_block+0x316/0x316 > [] compact_zone+0x294/0x475 > [] try_to_compact_pages+0x129/0x196 > [] __alloc_pages_direct_compact+0x91/0x197 > [] __alloc_pages_nodemask+0x863/0xa55 > [] get_huge_zero_page+0x52/0xf9 > [] do_huge_pmd_anonymous_page+0x24e/0x39f > [] ? __mem_cgroup_count_vm_event+0xa6/0x191 > [] ? __mem_cgroup_count_vm_event+0xbf/0x191 > [] handle_mm_fault+0x235/0xd9a > [] ? __do_page_fault+0xf8/0x5a1 > [] __do_page_fault+0x160/0x5a1 > [] ? __do_page_fault+0xf8/0x5a1 > [] ? __do_page_fault+0x5a1/0x5a1 > [] do_page_fault+0xd/0xf > [] error_code+0x6c/0x74 > [] ? memcg_update_all_caches+0x23/0x6b > [] ? __copy_from_user_ll+0x30/0xdb > [] _copy_from_user+0x3f/0x55 > [] SyS_setrlimit+0x27/0x50 > [] ? SyS_gettimeofday+0x33/0x6d > [] ? trace_hardirqs_on_thunk+0xc/0x10 > [] sysenter_do_call+0x12/0x32 > Code: 6e 8d 8f 84 02 00 00 89 c8 89 4d e4 e8 df bf 3f 00 89 45 e8 89 da 89 f0 e8 99 2b fa ff 8b 43 08 3b 47 54 8b 4d e4 73 06 8b 57 50 <89> 34 82 8b 55 e8 89 c8 e8 aa c1 3f 00 8b 45 ec e8 28 c1 3f 00 >