Re: [PATCH 2/2] hugetlbfs: convert macros to static inline, fix sparse warning

From: Joe Perches
Date: Tue Nov 12 2019 - 16:13:29 EST


On Tue, 2019-11-12 at 11:45 -0800, Mike Kravetz wrote:
> huge_pte_offset() produced a sparse warning due to an improper
> return type when the kernel was built with !CONFIG_HUGETLB_PAGE.
> Fix the bad type and also convert all the macros in this block
> to static inline wrappers. Two existing wrappers in this block
> had lines in excess of 80 columns so clean those up as well.
>
> No functional change.
>
> Reported-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
> Suggested-by: Jason Gunthorpe <jgg@xxxxxxxx>
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> ---
> include/linux/hugetlb.h | 137 +++++++++++++++++++++++++++++++++-------
> 1 file changed, 115 insertions(+), 22 deletions(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 53fc34f930d0..ef412fe0be3d 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -164,38 +164,130 @@ static inline void adjust_range_if_pmd_sharing_possible(
> {
> }
>
> -#define follow_hugetlb_page(m,v,p,vs,a,b,i,w,n) ({ BUG(); 0; })
> -#define follow_huge_addr(mm, addr, write) ERR_PTR(-EINVAL)
> -#define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; })
> +static inline long follow_hugetlb_page(struct mm_struct *mm,
> + struct vm_area_struct *vma, struct page **pages,
> + struct vm_area_struct **vmas, unsigned long *position,
> + unsigned long *nr_pages, long i, unsigned int flags,
> + int *nonblocking)
> +{
> + BUG();

While this is not different from the original, perhaps this is
also an opportunity to change the BUG()s to WARN()s.

> +static inline int copy_hugetlb_page_range(struct mm_struct *dst,
> + struct mm_struct *src, struct vm_area_struct *vma)
> +{
> + BUG();
> + return 0;
> +}
[]
> +static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
> + unsigned long addr, unsigned long end,
> + unsigned long floor, unsigned long ceiling)
> +{
> + BUG();
> +}
> +
> +static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
> + pte_t *dst_pte,
> + struct vm_area_struct *dst_vma,
> + unsigned long dst_addr,
> + unsigned long src_addr,
> + struct page **pagep)
> +{
> + BUG();
> + return 0;
> +}