Re: [PATCH v3 02/11] arm64: Make use of is_compat_task instead of hardcoding this test

[Alex Ghiti]

On 4/18/19 12:32 AM, Kees Cook wrote:
> On Wed, Apr 17, 2019 at 12:25 AM Alexandre Ghiti <alex@xxxxxxxx> wrote:
> > Each architecture has its own way to determine if a task is a compat task,
> > by using is_compat_task in arch_mmap_rnd, it allows more genericity and
> > then it prepares its moving to mm/.
> >
> > Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>


Thanks !


> -Kees
>
> > ---
> >   arch/arm64/mm/mmap.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
> > index 842c8a5fcd53..ed4f9915f2b8 100644
> > --- a/arch/arm64/mm/mmap.c
> > +++ b/arch/arm64/mm/mmap.c
> > @@ -54,7 +54,7 @@ unsigned long arch_mmap_rnd(void)
> >          unsigned long rnd;
> >
> >   #ifdef CONFIG_COMPAT
> > -       if (test_thread_flag(TIF_32BIT))
> > +       if (is_compat_task())
> >                  rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1);
> >          else
> >   #endif
> > --
> > 2.20.1