From: Sander Eikelenboom <linux@eikelenboom.it>
To: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>,
linux-kernel@vger.kernel.org, <x86@kernel.org>,
David Vrabel <david.vrabel@citrix.com>, <xen-devel@lists.xen.org>,
<mingo.kernel.org@gmail.com>
Subject: Re: [Xen-devel] Linux 4.4 MW: Boot under Xen fails with CONFIG_DEBUG_WX enabled: RIP: ptdump_walk_pgd_level_core
Date: Thu, 5 Nov 2015 15:02:52 +0100 [thread overview]
Message-ID: <1565834186.20151105150252@eikelenboom.it> (raw)
In-Reply-To: <563B5F64.1010806@oracle.com>
Thursday, November 5, 2015, 2:53:40 PM, you wrote:
> On 11/05/2015 04:13 AM, Sander Eikelenboom wrote:
>>
>> It makes "cat /sys/kernel/debug/kernel_page_tables" work and
>> prevents a kernel with CONFIG_DEBUG_WX=y from crashing at boot.
> Great. Our nightly runs also failed spectacularly due to this bug.
>>
>> It now does give a warning about an insecure W+X mapping, so
>> CONFIG_DEBUG_WX=y
>> seems to be working. No idea how to interpret it though (and if it's a
>> legit
>> warning).
>>
>> --
>> Sander
>>
>> [ 19.034706] Freeing unused kernel memory: 1104K (ffffffff822fc000 -
>> ffffffff82410000)
>> [ 19.041339] Write protecting the kernel read-only data: 18432k
>> [ 19.052596] Freeing unused kernel memory: 1144K (ffff880001ae2000 -
>> ffff880001c00000)
>> [ 19.060285] Freeing unused kernel memory: 1560K (ffff88000207a000 -
>> ffff880002200000)
>> [ 19.067079] ------------[ cut here ]------------
>> [ 19.073931] WARNING: CPU: 5 PID: 1 at
>> arch/x86/mm/dump_pagetables.c:225 note_page+0x619/0x7e0()
> Yes, this apparently is a known issue: https://lkml.org/lkml/2015/11/4/476
> -boris
Ah thx for the pointer :)
--
Sander
next prev parent reply other threads:[~2015-11-05 14:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-04 11:55 Sander Eikelenboom
2015-11-04 15:52 ` Stephen Smalley
2015-11-04 18:06 ` Ingo Molnar
2015-11-04 18:16 ` Sander Eikelenboom
2015-11-04 18:28 ` Sander Eikelenboom
2015-11-04 18:47 ` Stephen Smalley
2015-11-04 20:02 ` Sander Eikelenboom
2015-11-04 23:13 ` [Xen-devel] " Boris Ostrovsky
2015-11-05 9:13 ` Sander Eikelenboom
2015-11-05 13:53 ` Boris Ostrovsky
2015-11-05 14:02 ` Sander Eikelenboom [this message]
2015-11-04 20:15 ` Boris Ostrovsky
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