Arla 0.42-RC2

[Jeffrey Hutzelman]

On Tuesday, April 04, 2006 04:32:33 PM +0200 Tomas Olsson 
<tol at stacken.kth.se> wrote:

> Jeffrey Hutzelman <jhutz at cmu.edu> writes:
>> Yup; you're going to have that problem with 2.6.16, because they went
>> off and moved things into different sections.  Worse, if the kernel is
>> compiled with CONFIG_DEBUG_RODATA, then on some platforms the system
>> call table will actually be stored in read-only pages, and attempts to
>> update it will result in a panic.
>>
> How... oh well, as usual I guess. This is new for 2.6.16, right?

Yeah; both putting the syscall table in .rodata (or, in some cases, .text) 
and making those sections read-only seem to be new.  I don't think it's a 
deliberate attempt to cause problems for us, but it does have that effect.



>> We probably should do something about getting updated syscall table
>> probing code back into Arla.
>>
> Or just throw the syscall code away. Do people really need it?

Good question.  I think I've seen more people complain about the warning 
message than about tools not working because the AFS syscall didn't work. 
The real problem, of course, is....

> Is it
> possible to use the keyrings for reasonable pag storage nowadays?

Unclear.  Derrick supposedly had written code to do this for OpenAFS, but 
(if I rembmber right) was blocking on the kernel folks exporting some 
keyring-management operations so we could do setpag.  But I don't think 
I've ever actually seen that code, so I can't vouch for its correctness or 
even for its not having been accidentally deleted. :-)

I think we get to keep the syscall code a bit longer...

-- Jeff