BUG: Bad page map in process indicator-appli pte:7c79010208000000 pmd:00050067

[Alan Jenkins]

No idea what triggered this. EDIT: I failed at reporting this bug clearly. Please read the comments first, then you can read the rest of this description if you like.

--

20 seconds prior to the BUG, you'll see a SaK in the kernel logs (Secure Attention Key, aka "please kill everything on this vt, and let init/kdm give me a new login screen". This is legitimate. I invoked it due to software issues which were not obviously kernel related. I am able to reproduce the software issues, but they don't trigger the BUG, and I haven't been able to reproduce the BUG at so far.

Software issue: blowing away all your dotfiles and dotdirectories seems to leave you with a panel-less, dock-less desktop. So that's what I was using SaK to get out of. (I think ctrl+alt+del would have worked, but it wouldn't have given me a "log out" option, only a "shutdown" option). Behavior I was expecting: GNOME should recreate dotfiles with default settings. But that wasn't actually a new bug; it had just defaulted to Unity, which doesn't quite work on my installation. So I'm not complaining about that at all.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.42
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: alan 1228 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfdff8000 irq 42'
   Mixer name : 'Realtek ALC883'
   Components : 'HDA:10ec0883,105bb603,00100002'
   Controls : 37
   Simple ctrls : 21
Date: Wed Jun 29 14:34:43 2011
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.
MachineType: OEM OEM
ProcEnviron:
 PATH=(custom, user)
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=/dev/mapper/username--desktop.Linux-karmic ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-8-generic N/A
 linux-backports-modules-2.6.38-8-generic N/A
 linux-firmware 1.52
RfKill:

SourcePackage: linux
UpgradeStatus: Upgraded to natty on 2011-06-19 (9 days ago)
dmi.bios.date: 07/26/2007
dmi.bios.vendor: Phoenix Technologies, LTD
dmi.bios.version: 6.00 PG
dmi.board.name: 946 7MA Series
dmi.board.vendor: Foxconn
dmi.chassis.type: 3
dmi.chassis.vendor: OEM
dmi.chassis.version: OEM
dmi.modalias: dmi:bvnPhoenixTechnologies,LTD:bvr6.00PG:bd07/26/2007:svnOEM:pnOEM:pvrOEM:rvnFoxconn:rn9467MASeries:rvr:cvnOEM:ct3:cvrOEM:
dmi.product.name: OEM
dmi.product.version: OEM
dmi.sys.vendor: OEM

[Alan Jenkins (aj504)]

In case it's not clear, the BUG message is in the first attachment: "Boot log including full BUG call trace (85.2 KiB, text/plain)". There's actually several, but here's the first one for your convenience -

[17274.612715] SAK: killed process 17780 (Xorg): task_session(p)==tty->session
[17291.004267] swap_free: Bad swap file entry 3e3c8081040000
[17291.004306] BUG: Bad page map in process indicator-appli pte:7c79010208000000 pmd:00050067
[17291.004347] addr:00007fee25dd5000 vm_flags:08000070 anon_vma: (null) mapping:ffff880078057858 index:1d6
[17291.004418] vma->vm_ops->fault: filemap_fault+0x0/0x4a0
[17291.004447] vma->vm_file->f_op->mmap: ext4_file_mmap+0x0/0x60
[17291.004477] Pid: 14270, comm: indicator-appli Not tainted 2.6.38-8-generic #42-Ubuntu
[17291.004479] Call Trace:
[17291.004485] [<ffffffff8112d04d>] ? print_bad_pte+0x1dd/0x270
[17291.004488] [<ffffffff8112f439>] ? zap_pte_range+0x349/0x450
[17291.004492] [<ffffffff8112f70d>] ? unmap_page_range+0x1cd/0x2a0
[17291.004497] [<ffffffff811784e8>] ? do_sys_poll+0x1d8/0x240
[17291.004500] [<ffffffff8112fe54>] ? unmap_vmas+0x174/0x2f0
[17291.004504] [<ffffffff8113746a>] ? exit_mmap+0xba/0x180
[17291.004508] [<ffffffff81063532>] ? mmput+0x52/0x120
[17291.004512] [<ffffffff8106a2aa>] ? exit_mm+0x12a/0x160
[17291.004517] [<ffffffff810dc97b>] ? taskstats_exit+0x16b/0x190
[17291.004523] [<ffffffff815c2e15>] ? _raw_spin_lock_irq+0x15/0x20
[17291.004526] [<ffffffff8106a436>] ? do_exit+0x156/0x410
[17291.004529] [<ffffffff8106a8a8>] ? do_group_exit+0x58/0xd0
[17291.004533] [<ffffffff8107aba7>] ? get_signal_to_deliver+0x247/0x410
[17291.004538] [<ffffffff8100b936>] ? do_signal+0x56/0x180
[17291.004541] [<ffffffff81166421>] ? get_empty_filp+0xd1/0x170
[17291.004546] [<ffffffff81180ea7>] ? alloc_fd+0xf7/0x150
[17291.004549] [<ffffffff815c2cbe>] ? _raw_spin_lock+0xe/0x20
[17291.004553] [<ffffffff81174f49>] ? set_close_on_exec+0x79/0xc0
[17291.004556] [<ffffffff8117552a>] ? do_fcntl+0x2ea/0x3e0
[17291.004559] [<ffffffff8100bae5>] ? do_notify_resume+0x65/0x80
[17291.004562] [<ffffffff8100c2d0>] ? int_signal+0x12/0x17
[17291.004565] Disabling lock debugging due to kernel taint

[Alan Jenkins (aj504)]

_Sounds_ like a page is marked as being paged out to the swap file, when it's actually a mmapped file (so it should be backed by the specific file, not the swap file).

You know what's really odd? I don't have a swap file!

$ cat /proc/swaps
Filename Type Size Used Priority
$

[Alan Jenkins (aj504)]

I couldn't find much on Google, although maybe it's related to #766152 .

I'd look it up on kerneloops.org, but... let's just say I've just tagged my bookmark of that site as "state:dead" :-).

[penalvch (penalvch)]

Alan Jenkins, thank you for reporting this bug and helping make Ubuntu better. This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/ .

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux <replace-with-bug-number>

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

[Alan Jenkins (aj504)]

You mean, has this happened again? Not really.

I've had a general protection fault in ksmd, kernel 3.0.0-15-generic. (KSM, the shareable-memory scanner for KVM. I was running a a VM at the time, I think). So, maybe similar, in that it relates to apparent corruption in page tables.

Other than that, it hasn't crashed again, and I don't know what might have triggered it.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]