[PATCH v2] arm/memremap: fix arch_memremap_can_ram_remap()

[Linus Walleij]

On Mon, Apr 14, 2025 at 4:32 PM Ross Stutterheim
<ross.stutterheim at garmin.com> wrote:

> commit 260364d112bc ("arm[64]/memremap: don't abuse pfn_valid() to ensure
> presence of linear map") added the definition of
> arch_memremap_can_ram_remap() for arm[64] specific filtering of what pages
> can be used from the linear mapping. memblock_is_map_memory() was called
> with the pfn of the address given to arch_memremap_can_ram_remap();
> however, memblock_is_map_memory() expects to be given an address for arm,
> not a pfn.
>
> This results in calls to memremap() returning a newly mapped area when
> it should return an address in the existing linear mapping.
>
> Fix this by removing the address to pfn translation and pass the
> address directly.
>
> Fixes: 260364d112bc ("arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map")
> Signed-off-by: Ross Stutterheim <ross.stutterheim at garmin.com>

OMG
Reviewed-by: Linus Walleij <linus.walleij at linaro.org>

Also add Cc: stable at vger.kernel.org as pointed out by Catalin.

Yours,
Linus Walleij