[PATCH 7/8] mm/mmap: Extract validate_mm() from vma_complete()

From: Liam R. Howlett
Date: Tue Jun 11 2024 - 14:03:58 EST


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 ea3edfa8b22c..5334077964b9 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -605,7 +605,6 @@ static inline void vma_complete(struct vma_prepare *vp,
}
if (vp->insert && vp->file)
uprobe_mmap(vp->insert);
- validate_mm(mm);
}

/*
@@ -693,6 +692,7 @@ 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:
@@ -734,6 +734,7 @@ 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;
}

@@ -1062,6 +1063,7 @@ static struct vm_area_struct
}

vma_complete(&vp, vmi, mm);
+ validate_mm(mm);
khugepaged_enter_vma(res, vm_flags);
return res;

@@ -2440,6 +2442,7 @@ 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)
@@ -3308,6 +3311,7 @@ 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