Re: [PATCH 1/2] x86: fix norandmaps

From: Oleg Nesterov
Date: Mon Aug 14 2017 - 12:49:32 EST


On 08/14, Kirill A. Shutemov wrote:
>
> On Mon, Jul 10, 2017 at 01:14:29PM +0200, Oleg Nesterov wrote:
> > Documentation/admin-guide/kernel-parameters.txt says:
> >
> > norandmaps Don't use address space randomization. Equivalent
> > to echo 0 > /proc/sys/kernel/randomize_va_space
> >
> > but it doesn't work because arch_rnd() which is used to randomize
> > mm->mmap_base returns a random value unconditionally.
> >
> > Shift the PF_RANDOMIZE check from arch_mmap_rnd() to arch_rnd().
> >
> > Fixes: 1b028f784e8c ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()")
> > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
>
> It also fixes personality(ADDR_NO_RANDOMIZE).

Yes, good point.

> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

OK, thanks Kirill and Cyrill, I'll resend tomorrow with all acks I got.

Oleg.