On 03/15/23 14:31, Kirill A. Shutemov wrote:
> MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
> can deliver is MAX_ORDER-1.
>
> Fix MAX_ORDER usage in tsb_grow().
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Cc: sparclinux@xxxxxxxxxxxxxxx
> Cc: David Miller <davem@xxxxxxxxxxxxx>
> ---
> arch/sparc/mm/tsb.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
> index 912205787161..dba8dffe2113 100644
> --- a/arch/sparc/mm/tsb.c
> +++ b/arch/sparc/mm/tsb.c
> @@ -402,8 +402,8 @@ void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
> unsigned long new_rss_limit;
> gfp_t gfp_flags;
>
> - if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
> - max_tsb_size = (PAGE_SIZE << MAX_ORDER);
> + if (max_tsb_size > (PAGE_SIZE << (MAX_ORDER - 1)))
> + max_tsb_size = (PAGE_SIZE << (MAX_ORDER - 1));
>
> new_cache_index = 0;
> for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {
>
Fortunately, I think this only comes into play if MAX_ORDER <= 7.
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
--
Mike Kravetz
