Re: [PATCH v2] lib: Use PFN_PHYS() in devmem_is_allowed()

From: Kefeng Wang
Date: Wed Aug 04 2021 - 01:03:15 EST

On 2021/8/4 8:20, Palmer Dabbelt wrote:
On Fri, 30 Jul 2021 00:04:05 PDT (-0700), wrote:

On 2021/7/30 14:49, Liang Wang wrote:
The physical address may exceed 32 bits on ARM(when ARM_LPAE enabled),
use PFN_PHYS() in devmem_is_allowed(), or the physical address may
overflow and be truncated.

This bug was initially introduced from v2.6.37, and the function was moved
to lib when v5.10.

Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem")
Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()")
Cc: stable@xxxxxxxxxxxxxxx # v2.6.37
Signed-off-by: Liang Wang <wangliang101@xxxxxxxxxx>
Reviewed-by: Kefeng Wang <>
v2: update subject and changelog
  lib/devmem_is_allowed.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
Acked-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>

I only see the reply so I'm assuming this is going in through some other tree, but LMK if you want it via the RISC-V tree as IIRC we're using it too.

Hi Palmer,  there is a v3 with changelog updated,