[PATCH] ARM: Remove address checking for MMUless devices

[Yanjun Yang]

Hi,
Apologies for not CCing the relevant maintainers in my previous email.

On Tue, Jun 11, 2024 at 6:09 PM Yanjun Yang <yangyj.ee at gmail.com> wrote:
>
> Commit 169f9102f9198b ("ARM: 9350/1: fault:
> Implement copy_from_kernel_nofault_allowed()") added the function to check
> address before use. However, for devices without MMU, addr > TASK_SIZE
> will always fail.  This patch move this function after the #ifdef
> CONFIG_MMU statement.
>
> Also reported at https://bugzilla.kernel.org/show_bug.cgi?id=218953
>
> Signed-off-by: Yanjun Yang <yangyj.ee at gmail.com>
> ---
>  arch/arm/mm/fault.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
> index 67c425341a95..ab01b51de559 100644
> --- a/arch/arm/mm/fault.c
> +++ b/arch/arm/mm/fault.c
> @@ -25,6 +25,8 @@
>
>  #include "fault.h"
>
> +#ifdef CONFIG_MMU
> +
>  bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
>  {
>         unsigned long addr = (unsigned long)unsafe_src;
> @@ -32,8 +34,6 @@ bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
>         return addr >= TASK_SIZE && ULONG_MAX - addr >= size;
>  }
>
> -#ifdef CONFIG_MMU
> -
>  /*
>   * This is useful to dump out the page tables associated with
>   * 'addr' in mm 'mm'.
> --
> 2.45.2
>