Re: /proc/kcore has a unreasonable size(281474974617600) in x86_64 2.6.30-rc8.

Tao Ma
2009-06-05T09:01:19Z

Amerigo Wang wrote:
> On Fri, Jun 05, 2009 at 02:56:36PM +0800, Tao Ma wrote:
>>
>> Amerigo Wang wrote:
>>> On Fri, Jun 05, 2009 at 02:07:58PM +0800, Tao Ma wrote:
>>>> Amerigo Wang wrote:
>>>>> On Fri, Jun 05, 2009 at 12:03:52PM +0800, Tao Ma wrote:
>>>>>> Hi list,
>>>>>> In 2.6.30-rc8, /proc/kcore in x86_64's size is unreasonable
>>>>>> large to be 281474974617600.
>>>>>> While in a x86 box, it is 931131392 which looks sane.
>>>>>>
>>>>>> [root@test8 ~]# ll /proc/kcore
>>>>>> -r-------- 1 root root 281474974617600 Jun 5 11:15 /proc/kcore
>>>>>>
>>>>>> [root@ocfs2-test9 ~]$ ll /proc/kcore
>>>>>> -r-------- 1 root root 931131392 Jun 5 11:58 /proc/kcore
>>>>> Hmm, what is your physical RAM size on test8?
>>>>> /proc/kcore looks fine on my x86_64 box.
>>>> Only 4G.
>>> Hmm, my x86_box has 8G mem, the size of kcore looks much
>>> saner than the above huge number, but it is still wrong
>>> according to what the man page describes...
>>>
>>> Please do what Andrew said, it will be helpful.
>>>
>>>>>> I just noticed this when kexec fails in "Can't find kernel text
>>>>>> map area from kcore".
>>>>>>
>>>>>> Is there something wrong?
>>>>> It looks like that error message is from userspace?
>>>> I just started kdump and get the error message.
>>> IIRC, kdump should use /proc/vmcore, instead of /proc/kcore...
>>> nothing related.
>> in el5, when start kdump service it will do something like
>> /sbin/kexec --args-linux -p '--command-line=ro root=LABEL=/ rhgb quiet
>> irqpoll maxcpus=1' --initrd=/boot/initrd-2.6.18-53.el5kdump.img
>> /boot/vmlinuz-2.6.18-53.el5
>>
>> And the error message is from there.
>
>>From /sbin/kexec? I just checked the source code of kexec-tools,
> I haven't found that message...
No, it is there.
See kexec-tools-1.101-reloc-update.patch.
src rpm is kexec-tools-1.101-194.4.el5.src.rpm. So it is a patch from el5.

Regards,
Tao