Re: [patch] x86: test case for the RODATA config option

From: Arjan van de Ven
Date: Wed Jan 23 2008 - 09:49:35 EST


On 23 Jan 2008 10:09:58 +0100
Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:

> Arjan van de Ven <arjan@xxxxxxxxxxxxx> writes:
>
> > This patch adds a test module for the DEBUG_RODATA config
> > option to make sure change_page_attr() did indeed make
> > "const" data read only.
>
> The only that this does that is not done pretty much equivalently
> by pageattr-test.c (it just checks G instead of W) is testing the
> kernel text mapping on 64bit. On 32bit it is fully redundant I
> believe.

What it does is check if the rodata marking was succesful. That's more than just checking
change_page_attr() itself, and basically a reasonably self self-check of mark_rodata_const().


> Testing the kernel mapping might be a good idea, but I would
> suggest adding it to pageattr-test.c

where we move the actual test function... I don't really care. Once pageattr-test.c
is merged I have absolutely no problem moving it there if it's the right place...
(one can argue that it should be in or near the mark_rodata_const() function instead
since it tests that one).
Just like the NX test I wrote yesterday (and will post later today) probably wants to live
somewhere close to the NX code.

> Yes I'm sure these basic facts will not stop it from being
> applied anyways; just wanted to point it out for the benefit
> of the list readers.

Please spare me the bitter, undeserved sarcasm; I don't remember doing anything
to you to deserve that.
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