Messages in this thread | | | Date | Mon, 12 Oct 2009 21:32:29 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH V5] x86: NX protection for kernel data |
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On Mon, 12 Oct 2009 21:03:17 -0400 Siarhei Liakh <sliakh.lkml@gmail.com> 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 script is adjusted so .text always starts and ends on a > page boundary 2. Linker script is adjusted so .rodata and .data > always start and end on a page boundary > 3. void mark_nxdata_nx(void) added to arch/x86/mm/init.c with actual > functionality: NX is set for all pages from _etext through _end. > 4. mark_nxdata_nx() called from free_initmem() (after init has been > released) 5. free_init_pages() sets released memory NX in > arch/x86/mm/init.c > > The patch have been developed for Linux 2.6.31-rc7 x86 by Siarhei > Liakh <sliakh.lkml@gmail.com> and Xuxian Jiang <jiang@cs.ncsu.edu>. >
I like doing this, but... maybe it is useful to have a diff of the pagetable dump (PT_DUMP config option) to show the effect, in the changelog. That'd be like the proof on the pudding...
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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