[PATCH v4 07/21] mm/mmap: Extract validate_mm() from vma_complete()

[Liam R. Howlett]

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>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
---
 mm/mmap.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 62ff7aa10004..1c9016fb6b5c 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)
@@ -3354,6 +3357,7 @@ 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