Re: [PATCH 2/2] mm/page_alloc.c: add config option to sanitize freed pages

[Anisse Astier <anisse@astier.eu>]

On Mon, Apr 27, 2015 at 11:25 AM, PaX Team <pageexec@freemail.hu> wrote:
>
> the PaX SANITIZE feature does exactly this in mm/page_alloc.c:prep_new_page:
>
> #ifndef CONFIG_PAX_MEMORY_SANITIZE
>         if (gfp_flags & __GFP_ZERO)
>                 prep_zero_page(page, order, gfp_flags);
> #endif
>

Thanks, I'll do that in the next iteration.

>> you'd need to clear memory on boot for example.
>
> it happens automagically because on boot during the transition from the
> boot allocator to the buddy one each page gets freed which will then go
> through the page clearing path.

Interesting, I'll see how it works.

>
> however there's a known problem/conflict with HIBERNATION (see
> http://marc.info/?l=linux-pm&m=132871433416256&w=2) which i think would
> have to be resolved before upstream acceptance.

I don't use hibernation, but I'll see if I can create a swap partition
to test that.

Regards,

Anisse

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