Re: [PATCH] s390/mm: Fix type mismatch in get_align_mask().

[Sven Schnelle <svens@linux.ibm.com>]

Gerald Schaefer <gerald.schaefer@linux.ibm.com> writes:

> Commit 86f48f922ba79 ("s390/mmap: disable mmap alignment when
> randomize_va_space = 0") introduced get_align_mask() with return type of
> 'int', while the target field 'info.align_mask' in struct
> vm_unmapped_area_info is 'unsigned long'.
>
> With currently used masks, this should not cause truncation issues, but
> fix it and return 'unsigned long' to avoid future problems.
>
> Fixes: 86f48f922ba79 ("s390/mmap: disable mmap alignment when randomize_va_space = 0")
> Cc: stable@vger.kernel.org # v6.9+
> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> ---
>  arch/s390/mm/mmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
> index 2a222a7e14f4..ef7bfc87758c 100644
> --- a/arch/s390/mm/mmap.c
> +++ b/arch/s390/mm/mmap.c
> @@ -64,7 +64,7 @@ static inline unsigned long mmap_base(unsigned long rnd,
>  	return PAGE_ALIGN(STACK_TOP - gap - rnd);
>  }
>  
> -static int get_align_mask(struct file *filp, unsigned long flags)
> +static unsigned long get_align_mask(struct file *filp, unsigned long flags)
>  {
>  	if (filp && is_file_hugepages(filp))
>  		return huge_page_mask_align(filp);
>
> base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>