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

From: Kirill A. Shutemov
Date: Mon Aug 14 2017 - 12:25:08 EST


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).

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

--
Kirill A. Shutemov