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From: "H. Peter Anvin" <hpa@zytor.com>
To: Kees Cook <keescook@chromium.org>, Fengguang Wu <fengguang.wu@intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [x86, kaslr] BUG: kernel boot hang
Date: Tue, 14 Jan 2014 10:47:35 -0800	[thread overview]
Message-ID: <52D58647.4010208@zytor.com> (raw)
In-Reply-To: <CAGXu5jKqx6JYBhHf08ru9B62RdD1A_WX7on64Cw-v1wYKT2jnQ@mail.gmail.com>

On 01/14/2014 10:26 AM, Kees Cook wrote:
>>
>> [    0.000000] Base memory trampoline at [ffff880000099000] 99000 size 24576
>> [    0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
>> [    0.000000]  [mem 0x00000000-0x000fffff] page 4k
>> [    0.000000] BRK [0x07886000, 0x07886fff] PGTABLE
>> [    0.000000] BRK [0x07887000, 0x07887fff] PGTABLE
>> [    0.000000] BRK [0x07888000, 0x07888fff] PGTABLE
>> PANIC: early exception 0e rip 10:ffffffff86204c6e error 0 cr2 ffffffff81972b28
>> [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.12.0-rc4-00008-g6e6a493 #614
>> PANIC: early exception 0e rip 10:ffffffff86204f22 error 0 cr2 ffffffff81972b28
> 
> I will try to reproduce this, but it's not clear to me what is causing
> the failure. The generated config doesn't look insane to me, so I'm
> not sure what's happening here. Is QEMU doing something unexpected
> with the ordering of where things go for its boot loader?
> 

It used to, but I fixed it up a long time ago and now it is really bog
standard.

More likely it just happens to trigger a corner condition, which is
actually a good thing... much easier to debug in a simulator.

	-hpa



  reply	other threads:[~2014-01-14 18:47 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-14 13:31 [x86, kaslr] BUG: kernel boot hang Fengguang Wu
2014-01-14 16:02 ` H. Peter Anvin
2014-01-14 18:32   ` Kees Cook
2014-01-14 19:19     ` H. Peter Anvin
2014-01-14 18:26 ` Kees Cook
2014-01-14 18:47   ` H. Peter Anvin [this message]
2014-01-15 12:10   ` Fengguang Wu
2014-01-14 22:33 ` Kees Cook
2014-01-14 23:23   ` H. Peter Anvin
2014-01-14 23:31     ` Kees Cook
2014-01-14 23:45       ` H. Peter Anvin
2014-01-15 12:37   ` Fengguang Wu

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