Re: [PATCH 04/12] arm64: Initialise high_memory global variable earlier

Steve Capper
2017-12-12T10:53:09Z

On Mon, Dec 11, 2017 at 12:00:22PM +0000, Catalin Marinas wrote:
> On Mon, Dec 04, 2017 at 02:13:05PM +0000, Steve Capper wrote:
> > The high_memory global variable is used by
> > cma_declare_contiguous(.) before it is defined.
> >
> > We don't notice this as we compute __pa(high_memory - 1), and it looks
> > like we're processing a VA from the direct linear map.
> >
> > This problem becomes apparent when we flip the kernel virtual address
> > space and the linear map is moved to the bottom of the kernel VA space.
> >
> > This patch moves the initialisation of high_memory before it used.
> >
> > Signed-off-by: Steve Capper <steve.capper@arm.com>
>
> It looks like we've had this bug since 3.18 (f7426b983a6a, "mm: cma:
> adjust address limit to avoid hitting low/high memory boundary"). It may
> be worth adding a cc stable on this patch.

Thanks Catalin,
Will add a fixes and cc stable.

Cheers,
--
Steve

>
> --
> Catalin