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

From: Arjan van de Ven
Date: Wed Jan 23 2008 - 11:12:16 EST


On Wed, 23 Jan 2008 16:27:28 +0100
Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:

>
> > What it does is check if the rodata marking was succesful.
>
> The only difference I see is that you check that the TLB flush works,
> but for that it looks awfully incomplete.

you think one level too small.
It tests if mark_rodata_ro() operated correctly.
Yes internally that uses c-p-a, but there's more code there, including a set of boundary conditions etc.
And for the page table to work, cr0 needs to be set up correctly etc etc etc.



> Other than it is identical [modulo the kernel mapping bit on 64bit]--

it's a test of mark_rodata_ro(), not of c-p-a. Not the same thing.


> What I meant using the more extensive test in pageattr-test.c
> to test a few changes in the 64bit kernel mapping too, not moving your
> code. I don't think moving your code makes sense. Sorry for being
> unclear.

then I just don't get your comment at all; sorry.


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