Re: [Patch BUGFIX] kcore: fix its wrong size on x86_64

From: Amerigo Wang
Date: Wed Jun 17 2009 - 22:59:03 EST

On Tue, Jun 16, 2009 at 12:27:36PM -0700, Eric W. Biederman wrote:
>AmÃrico Wang <xiyou.wangcong@xxxxxxxxx> writes:
>>> I think a case can be made either way. ÂIn practice neither answer
>>> gives us a dense offset space on x86_64 so I think I prefer the
>>> current definition which sets or clears the high bits as opposed
>>> to something that mangles the address more.
>> I am trying to dig more... There must be something wrong there.
>How so?

See what you will get for kc_vaddr_to_offset(__va(0))?
It is supposed to be 0.

>>> It uses get_kcore_size and (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
>>> The second definition being bogus as it has nothing to do with which
>>> offsets are accepted.
>> Agreed. Maybe we can just remove the second one and update the doc?
>Yes. It isn't critical but reducing confusion is good.
>Do you want to cook up the patch for that?

Yes, I am cooking a patch set... will send them when ready.
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