On Thu, 10 Oct 2019 11:31:17 +0800 Gaowei Pu <pugaowei@xxxxxxxxx> wrote:
> get_unmapped_area already cover the offset_in_page() check and returned
> with error ptr. So replace offset_in_page() with IS_ERR_VALUE().
>
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2997,7 +2997,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
> flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
>
> error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
> - if (offset_in_page(error))
> + if (IS_ERR_VALUE(error))
> return error;
>
> error = mlock_future_check(mm, mm->def_flags, len);
./include/linux/err.h:22:49: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
#define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO)
^
./include/linux/compiler.h:78:42: note: in definition of macro unlikely
# define unlikely(x) __builtin_expect(!!(x), 0)
^
mm/mmap.c:3006:6: note: in expansion of macro IS_ERR_VALUE
if (IS_ERR_VALUE(error))
