help for install kexec-tools

[申王睿]

i modified both kexec-tools and module in kernel to ingnore some validity checking. but when the code in kernel is going to copy the new kernel to old kernel, a pagefault exception is receive like this:
~ # kexec -e
Starting new kernel
Unhandled kernel unaligned access[#1]:
Cpu 1
$ 0   : 0000000000000000 0000000000000001 a80000002331fbb0 ffffffffffffffff
$ 4   : ffffffff8113981c ffffffff8113cf18 ffffffff8113cf14 ffffffff01100000
$ 8   : 000000000000ffff a80000002331fb90 000000000000000a ffffffff813d85d8
$12   : 0000000010008ce1 000000001000001e ffffffff81169a90 00000001200049d0
$16   : a80000002331fb90 fffffffffc440000 ffffffff83fe0000 ffffff0000000000
$20   : ffffffff81140000 a8000000231c5800 a800000021b17000 0000000000000008
$24   : 0000000000000079 0000000000000000                                  
$28   : a80000002331c000 a80000002331fb60 000000ffffe0ca40 ffffffff81132544
Hi    : 0000000009600000
Lo    : 0000000005a0d200
epc   : ffffffff81139840 do_ade+0x2e0/0x470
    Not tainted
ra    : ffffffff81132544 ret_from_exception+0x0/0x10
Status: 10008ce3    KX SX UX KERNEL EXL IE 
Cause : 00800014
BadVA : ffffffff01100000
PrId  : 000d0401 (Cavium Octeon)
Modules linked in:
Process kexec (pid: 827, threadinfo=a80000002331c000, task=a80000000bec4040, tls=000000555557eb20)
Stack : ffffffff83fdc1b7 0000000000000000 0000000000000000 ffffffff83fe0000
        000000000000001e ffffffff81132544 0000000000000000 0000000000000001
        ffffffff01100000 ffffffff81430000 ffffffffffffffff 0000000000000001
        ffffffffffffffff 00000000000017d5 000000000000ffff ffffffff83fcc190
        000000000000000a ffffffff813d85d8 0000000000000020 ffffffff8127fd4c
        ffffffff81169a90 00000001200049d0 0000000000000000 0000000000000000
        ffffffff83fe0000 000000000000001e ffffffff81140000 a8000000231c5800
        a800000021b17000 0000000000000008 0000000000000079 0000000000000000
        ffffffff81140000 a8000000231c5800 a80000002331c000 a80000002331fcf0
        000000ffffe0ca40 ffffffff8113cf04 0000000010008ce3 0000000009600000
        ...
Call Trace:
[<ffffffff81139840>] do_ade+0x2e0/0x470
[<ffffffff81132544>] ret_from_exception+0x0/0x10
[<ffffffff8113cf14>] machine_kexec+0xd4/0x1d0
[<ffffffff81182c64>] kernel_kexec+0x84/0x90
[<ffffffff81169c6c>] sys_reboot+0x1dc/0x210
[<ffffffff8113bdfc>] handle_sys+0xfc/0x118


Code: 000210f8  0202102d  dc430000 <b0e30000> b4e30007  24030000  1460ffd8  00000000  8e020124 
Segmentation fault

i do some test, that i copy something to user space .text segment before also receive a segementation fault. This means the readonly .text cannot be written. How to avoid this in the context of KEXEC?

PS: my kernel version is 2.6.27


------------------ 原始邮件 ------------------
>From: Simon Horman <horms at verge.net.au>
>Reply-To: 
>To: 申王睿<06120216 at bjtu.edu.cn>
>Subject: Re: help for install kexec-tools
>Date: Fri, 13 Nov 2009 13:44:01 +1100
>
>On Thu, Nov 12, 2009 at 04:18:11PM +0800, 申王睿 wrote:
>> Currently, i'm trying to install kexec-tools on a box which have a octeon mips cpu with a gcc compiler tuned by cavium. unfortunately, some compiler error happens.
>> Is it possible to run your tools on such a environment? if possible, i will spend more time to fix the error.
>
>Hi,
>
>I expect that it is possible to get things working.
>Perhaps posting the errors to the kexec mailing list
>would help?
>
>