Hi Willy,
On Sat, Aug 4, 2018 at 12:36 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> On Wed, Aug 01, 2018 at 08:13:26PM +0900, Yoshinori Sato wrote:
> > I have not tested enough to impose mm on my part, so it may be
> > by chance this too.
> > Restore the constructor and modify it so that __ GFP_ZERO is not specified.
> > Because then I think that it is safer because it is exactly the same as
> > before the fix.
>
> I wish you had cc'd me on patch v2. I think the answer is actually this
> (which restoers the pre-2009 behaviour):
>
> diff --git a/arch/sh/mm/pgtable.c b/arch/sh/mm/pgtable.c
> index 5c8f9247c3c2..7c63aa359c7d 100644
> --- a/arch/sh/mm/pgtable.c
> +++ b/arch/sh/mm/pgtable.c
> @@ -2,7 +2,7 @@
> #include <linux/mm.h>
> #include <linux/slab.h>
>
> -#define PGALLOC_GFP GFP_KERNEL | __GFP_ZERO
> +#define PGALLOC_GFP GFP_KERNEL
>
> static struct kmem_cache *pgd_cachep;
> #if PAGETABLE_LEVELS > 2
> @@ -13,6 +13,7 @@ void pgd_ctor(void *x)
> {
> pgd_t *pgd = x;
>
> + memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
> memcpy(pgd + USER_PTRS_PER_PGD,
> swapper_pg_dir + USER_PTRS_PER_PGD,
> (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
>
> but I haven't even compiled it.
Works equally well on qemu emulating rts7751r2d.
You do want to readd the __GFP_ZERO flag to the second user of PGALLOC_GFP,
don't you?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
