Re: [PATCH v3 07/16] mm/mmap: Extract validate_mm() from vma_complete()

From: Lorenzo Stoakes
Date: Fri Jul 05 2024 - 15:35:49 EST


On Thu, Jul 04, 2024 at 02:27:09PM GMT, Liam R. Howlett wrote:
> vma_complete() will need to be called during an unsafe time to call
> validate_mm(). Extract the call in all places now so that only one
> location can be modified in the next change.
>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> ---
> mm/mmap.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 2a1a49f98fa3..8d9be791997a 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -646,7 +646,6 @@ static inline void vma_complete(struct vma_prepare *vp,
> }
> if (vp->insert && vp->file)
> uprobe_mmap(vp->insert);
> - validate_mm(mm);
> }
>
> /*
> @@ -734,6 +733,7 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
> vma_iter_store(vmi, vma);
>
> vma_complete(&vp, vmi, vma->vm_mm);
> + validate_mm(vma->vm_mm);
> return 0;
>
> nomem:
> @@ -775,6 +775,7 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
> vma_iter_clear(vmi);
> vma_set_range(vma, start, end, pgoff);
> vma_complete(&vp, vmi, vma->vm_mm);
> + validate_mm(vma->vm_mm);
> return 0;
> }
>
> @@ -1103,6 +1104,7 @@ static struct vm_area_struct
> }
>
> vma_complete(&vp, vmi, mm);
> + validate_mm(mm);
> khugepaged_enter_vma(res, vm_flags);
> return res;
>
> @@ -2481,6 +2483,7 @@ static int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
>
> /* vma_complete stores the new vma */
> vma_complete(&vp, vmi, vma->vm_mm);
> + validate_mm(vma->vm_mm);
>
> /* Success. */
> if (new_below)
> @@ -3353,6 +3356,7 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
> vma_iter_store(vmi, vma);
>
> vma_complete(&vp, vmi, mm);
> + validate_mm(mm);
> khugepaged_enter_vma(vma, flags);
> goto out;
> }
> --
> 2.43.0
>
>

LGTM

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>