* Suren Baghdasaryan <surenb@xxxxxxxxxx> [230801 18:07]:
> Vma write lock assertion always includes mmap write lock assertion and
> additional vma lock checks when per-VMA locks are enabled. Replace
> weaker mmap_assert_write_locked() assertions with stronger
> vma_assert_write_locked() ones when we are operating on a vma which
> is expected to be locked.
>
> Suggested-by: Jann Horn <jannh@xxxxxxxxxx>
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> ---
> mm/hugetlb.c | 2 +-
> mm/khugepaged.c | 5 +++--
> mm/memory.c | 2 +-
> 3 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 64a3239b6407..1d871a1167d8 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -5028,7 +5028,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> src_vma->vm_start,
> src_vma->vm_end);
> mmu_notifier_invalidate_range_start(&range);
> - mmap_assert_write_locked(src);
> + vma_assert_write_locked(src_vma);
> raw_write_seqcount_begin(&src->write_protect_seq);
> } else {
> /*
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 78c8d5d8b628..1e43a56fba31 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1495,7 +1495,7 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
> };
>
> VM_BUG_ON(!PageTransHuge(hpage));
> - mmap_assert_write_locked(vma->vm_mm);
> + vma_assert_write_locked(vma);
>
> if (do_set_pmd(&vmf, hpage))
> return SCAN_FAIL;
> @@ -1525,7 +1525,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v
> pmd_t pmd;
> struct mmu_notifier_range range;
>
> - mmap_assert_write_locked(mm);
> + vma_assert_write_locked(vma);
> if (vma->vm_file)
> lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem);
> /*
> @@ -1570,6 +1570,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
> int count = 0, result = SCAN_FAIL;
> int i;
>
> + /* Ensure vma can't change, it will be locked below after checks */
> mmap_assert_write_locked(mm);
>
> /* Fast check before locking page if already PMD-mapped */
> diff --git a/mm/memory.c b/mm/memory.c
> index 603b2f419948..652d99b9858a 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1312,7 +1312,7 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma)
> * Use the raw variant of the seqcount_t write API to avoid
> * lockdep complaining about preemptibility.
> */
> - mmap_assert_write_locked(src_mm);
> + vma_assert_write_locked(src_vma);
> raw_write_seqcount_begin(&src_mm->write_protect_seq);
> }
>
> --
> 2.41.0.585.gd2178a4bd4-goog
>
