On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> wrote:
> In function __mcopy_atomic_hugetlb, we use two variables to deal with
> huge page size: vma_hpagesize and huge_page_size.
>
> Since they are the same, it is not necessary to use two different
> mechanism. This patch makes it consistent by all using vma_hpagesize.
>
> --- a/mm/userfaultfd.c
> +++ b/mm/userfaultfd.c
> @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
> pte_t dst_pteval;
>
> BUG_ON(dst_addr >= dst_start + len);
> - VM_BUG_ON(dst_addr & ~huge_page_mask(h));
> + VM_BUG_ON(dst_addr & (vma_hpagesize - 1));
>
> /*
> * Serialize via hugetlb_fault_mutex
> @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
> mutex_lock(&hugetlb_fault_mutex_table[hash]);
>
> err = -ENOMEM;
> - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h));
> + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize);
> if (!dst_pte) {
> mutex_unlock(&hugetlb_fault_mutex_table[hash]);
> goto out_unlock;
> @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
>
> err = copy_huge_page_from_user(page,
> (const void __user *)src_addr,
> - pages_per_huge_page(h), true);
> + vma_hpagesize / PAGE_SIZE,
> + true);
> if (unlikely(err)) {
> err = -EFAULT;
> goto out;
Looks right.
We could go ahead and remove local variable `h', given that
hugetlb_fault_mutex_hash() doesn't actually use its first arg..
