| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 12 Apr 2010 09:20:56 +0200
From: Borislav Petkov <bp@...en8.de>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Johannes Weiner <hannes@...xchg.org>,
KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
Rik van Riel <riel@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Minchan Kim <minchan.kim@...il.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Lee Schermerhorn <Lee.Schermerhorn@...com>,
Nick Piggin <npiggin@...e.de>,
Andrea Arcangeli <aarcange@...hat.com>,
Hugh Dickins <hugh.dickins@...cali.co.uk>,
sgunderson@...foot.com
Subject: Re: [PATCH -v2] rmap: make anon_vma_prepare link in all the
anon_vmas of a mergeable VMA
From: Linus Torvalds <torvalds@...ux-foundation.org>
Date: Sun, Apr 11, 2010 at 06:04:39PM -0700
> It checks each anonymous page at unmap time against the vma it gets
> unmapped from. It depends on the previous vma_verify debugging patch, and
> it would be interesting to hear whether this patch causes any new warnngs
> for you..
>
> If the warnings do happen, they are not going to be printing out any
> hugely informative data apart from the fact that the bad case happened at
> all. But If they do trigger, I can try to improve on them - it's just not
> worth trying to make them any more interesting if they never trigger.
Haa, I think you're gonna want to improve them :)
WARN_ONCE(1, "page->mapping does not exist in vma chain");
triggered on the first resume showing a rather messy 4 WARN_ONCEs. Had I
more cores, there maybe would've been more of them :) Maybe need locking
if clean output is of interest (see below).
So, anyway, if I can read this correctly, there is a page->mapping
anon_vma which is _not_ in the anon_vmas chain of the vma
(avc->same_vma).
And the spot we oops on is in page_referenced_anon():
list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
which is actually where we iterate over all vmas associated with this
anon_vma.
So if that previous anon_vma pointed to by the page_mapping has been
falsely unlinked at some point, no wonder we boom on that later.
By the way, I completely understand when you say that your head hurts
from looking at this :).
[ 486.580872] Restarting tasks ... done.
[ 494.167242] [drm] Resetting GPU
[ 495.422354] ------------[ cut here ]------------
[ 495.422407] WARNING: at mm/memory.c:909 unmap_vmas+0x548/0xa29()
[ 495.422442] Hardware name: System Product Name
[ 495.422474] page->mapping does not exist in vma chain
[ 495.422504] Modules linked in:
[ 495.422545] ------------[ cut here ]------------
[ 495.422555] ------------[ cut here ]------------
[ 495.422565] powernow_k8
[ 495.422583] WARNING: at mm/memory.c:909 unmap_vmas+0x548/0xa29()
[ 495.422591] cpufreq_ondemand
[ 495.422597] Hardware name: System Product Name
[ 495.422602] page->mapping does not exist in vma chain cpufreq_powersave
[ 495.422612] Modules linked in: cpufreq_userspace powernow_k8 cpufreq_ondemand cpufreq_powersave cpufreq_userspace freq_table freq_table cpufreq_conservative cpufreq_conservative binfmt_misc binfmt_misc kvm_amd kvm ipv6 vfat fat dm_crypt kvm_amd dm_mod 8250_pnp kvm 8250 serial_core edac_core pcspkr k10temp ohci_hcd
[ 495.422676] ipv6Pid: 2919, comm: udevd Tainted: G W 2.6.34-rc3-00506-g6c62fe4 #1
[ 495.422689] Call Trace:
[ 495.422694] vfat
[ 495.422700] ------------[ cut here ]------------
[ 495.422721] WARNING: at mm/memory.c:909 unmap_vmas+0x548/0xa29()
[ 495.422729] fat [<ffffffff81038fe0>] warn_slowpath_common+0x7c/0x94
[ 495.422746] dm_crypt
[ 495.422751] Hardware name: System Product Name
[ 495.422758] dm_modpage->mapping does not exist in vma chain
[ 495.422767] Modules linked in: 8250_pnp [<ffffffff8103904f>] warn_slowpath_fmt+0x41/0x43
[ 495.422784] powernow_k8 cpufreq_ondemand 8250 cpufreq_powersave [<ffffffff810bcd20>] unmap_vmas+0x548/0xa29
[ 495.422807] serial_core cpufreq_userspace [<ffffffff810bd021>] ? unmap_vmas+0x849/0xa29
[ 495.422828] edac_core freq_table pcspkr cpufreq_conservative [<ffffffff810c17d8>] exit_mmap+0x102/0x1e4
[ 495.422851] binfmt_misc [<ffffffff810c173f>] ? exit_mmap+0x69/0x1e4
[ 495.422863] k10temp [<ffffffff810368bc>] mmput+0x48/0xb9
[ 495.422876] kvm_amd [<ffffffff8103ad90>] exit_mm+0x110/0x11d
[ 495.422889] ohci_hcd kvm
[ 495.422903] [<ffffffff8103c9e6>] do_exit+0x1c5/0x6e5
[ 495.422909] ipv6Pid: 2916, comm: udevd Tainted: G W 2.6.34-rc3-00506-g6c62fe4 #1
[ 495.422927] [<ffffffff81065387>] ? trace_hardirqs_off_caller+0x1f/0xa9
[ 495.422934] Call Trace:
[ 495.422940] vfat [<ffffffff8141016d>] ? retint_swapgs+0xe/0x13
[ 495.422956] fat [<ffffffff81038fe0>] warn_slowpath_common+0x7c/0x94
[ 495.422972] dm_crypt dm_mod 8250_pnp [<ffffffff8103cf8a>] do_group_exit+0x84/0xb0
[ 495.422989] 8250 serial_core [<ffffffff8103cfcd>] sys_exit_group+0x17/0x1b
[ 495.423013] [<ffffffff8100221b>] system_call_fastpath+0x16/0x1b
[ 495.423019] edac_core
[ 495.423025] ---[ end trace d9664ac54d1edb0e ]---
[ 495.423031] pcspkr k10temp ohci_hcd
[ 495.423043] Pid: 2914, comm: udevd Tainted: G W 2.6.34-rc3-00506-g6c62fe4 #1
[ 495.423055] [<ffffffff8103904f>] warn_slowpath_fmt+0x41/0x43
[ 495.423063] Call Trace:
[ 495.423073] [<ffffffff810bcd20>] unmap_vmas+0x548/0xa29
[ 495.423087] [<ffffffff81038fe0>] warn_slowpath_common+0x7c/0x94
[ 495.423100] [<ffffffff810bd021>] ? unmap_vmas+0x849/0xa29
[ 495.423111] [<ffffffff8103904f>] warn_slowpath_fmt+0x41/0x43
[ 495.423123] [<ffffffff810bcd20>] unmap_vmas+0x548/0xa29
[ 495.423134] [<ffffffff810bd021>] ? unmap_vmas+0x849/0xa29
[ 495.423147] [<ffffffff810c17d8>] exit_mmap+0x102/0x1e4
[ 495.423159] [<ffffffff810c17d8>] exit_mmap+0x102/0x1e4
[ 495.423172] [<ffffffff810c173f>] ? exit_mmap+0x69/0x1e4
[ 495.423184] [<ffffffff810c173f>] ? exit_mmap+0x69/0x1e4
[ 495.423194] [<ffffffff810368bc>] mmput+0x48/0xb9
[ 495.423204] [<ffffffff810368bc>] mmput+0x48/0xb9
[ 495.423214] [<ffffffff8103ad90>] exit_mm+0x110/0x11d
[ 495.423225] [<ffffffff8103ad90>] exit_mm+0x110/0x11d
[ 495.423236] [<ffffffff8103c9e6>] do_exit+0x1c5/0x6e5
[ 495.423246] [<ffffffff8103c9e6>] do_exit+0x1c5/0x6e5
[ 495.423266] [<ffffffff81065387>] ? trace_hardirqs_off_caller+0x1f/0xa9
[ 495.423277] [<ffffffff81065387>] ? trace_hardirqs_off_caller+0x1f/0xa9
[ 495.423292] [<ffffffff8141016d>] ? retint_swapgs+0xe/0x13
[ 495.423303] [<ffffffff8141016d>] ? retint_swapgs+0xe/0x13
[ 495.423315] [<ffffffff8103cf8a>] do_group_exit+0x84/0xb0
[ 495.423325] [<ffffffff8103cfcd>] sys_exit_group+0x17/0x1b
[ 495.423334] [<ffffffff8103cf8a>] do_group_exit+0x84/0xb0
[ 495.423346] [<ffffffff8100221b>] system_call_fastpath+0x16/0x1b
[ 495.423357] [<ffffffff8103cfcd>] sys_exit_group+0x17/0x1b
[ 495.423365] ---[ end trace d9664ac54d1edb0f ]---
[ 495.423386] [<ffffffff8100221b>] system_call_fastpath+0x16/0x1b
[ 495.423402] ---[ end trace d9664ac54d1edb10 ]---
[ 495.424191] WARNING: at mm/memory.c:909 unmap_vmas+0x548/0xa29()
[ 495.424215] Hardware name: System Product Name
[ 495.424238] page->mapping does not exist in vma chain
[ 495.424259] Modules linked in: powernow_k8 cpufreq_ondemand cpufreq_powersave cpufreq_userspace freq_table cpufreq_conservative binfmt_misc kvm_amd kvm ipv6 vfat fat dm_crypt dm_mod 8250_pnp 8250 serial_core edac_core pcspkr k10temp ohci_hcd
[ 495.424693] Pid: 1923, comm: udevd Tainted: G W 2.6.34-rc3-00506-g6c62fe4 #1
[ 495.424723] Call Trace:
[ 495.424758] [<ffffffff81038fe0>] warn_slowpath_common+0x7c/0x94
[ 495.424788] [<ffffffff8103904f>] warn_slowpath_fmt+0x41/0x43
[ 495.424816] [<ffffffff810bcd20>] unmap_vmas+0x548/0xa29
[ 495.424843] [<ffffffff810bd021>] ? unmap_vmas+0x849/0xa29
[ 495.424875] [<ffffffff810c17d8>] exit_mmap+0x102/0x1e4
[ 495.424901] [<ffffffff810c173f>] ? exit_mmap+0x69/0x1e4
[ 495.424926] [<ffffffff810368bc>] mmput+0x48/0xb9
[ 495.424954] [<ffffffff8103ad90>] exit_mm+0x110/0x11d
[ 495.424981] [<ffffffff8103c9e6>] do_exit+0x1c5/0x6e5
[ 495.425008] [<ffffffff81065387>] ? trace_hardirqs_off_caller+0x1f/0xa9
[ 495.425038] [<ffffffff8141016d>] ? retint_swapgs+0xe/0x13
[ 495.425065] [<ffffffff8103cf8a>] do_group_exit+0x84/0xb0
[ 495.425091] [<ffffffff8103cfcd>] sys_exit_group+0x17/0x1b
[ 495.425119] [<ffffffff8100221b>] system_call_fastpath+0x16/0x1b
[ 495.425156] ---[ end trace d9664ac54d1edb11 ]---
--
Regards/Gruss,
Boris.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists