Re: [PATCH] x86: NX protection for kernel data

[Arjan van de Ven]

On Sun, 19 Jul 2009 15:43:06 -0400
Siarhei Liakh <sliakh.lkml@xxxxxxxxx> wrote:

> This patch expands functionality of CONFIG_DEBUG_RODATA to set main
> (static) kernel data area as NX.
> The following steps are taken to achieve this:
> 1. Linker scripts are adjusted so .text always starts and end on a
> page boundary 2. Linker scripts are adjusted so .rodata and .data
> always starts and end on a page boundary
> 3. void mark_nxdata_nx(void) added to arch/x86/mm/init_64.c and
> arch/x86/mm/init_32.c with actual functionality: NX is set for all
> pages from _etext through _edata
> 4. mark_nxdata_nx() called from init_post(void) in init/main.c
> 
> The patch have been developed for Linux 2.6.30 x86 by Siarhei Liakh
> <sliakh.lkml@xxxxxxxxx> and Xuxian Jiang <jiang@xxxxxxxxxxx>.

I like the idea, and am happy to see the lack of ifdefs ;)

I wonder if we should have a testcase for this though similar to 
how stackprotector and rodata get tested already....
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