[PATCH v8 07/21] mm/vma: Extract validate_mm() from vma_complete()

From: Liam R. Howlett
Date: Fri Aug 30 2024 - 00:02:56 EST


From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>

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 | 1 +
mm/vma.c | 5 ++++-
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 548bc45a27bf..dce1cc74ecdb 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1796,6 +1796,7 @@ 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;
}
diff --git a/mm/vma.c b/mm/vma.c
index 6d042cd46cdb..4e08c1654bdd 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -269,6 +269,7 @@ 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)
@@ -548,6 +549,7 @@ 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:
@@ -589,6 +591,7 @@ 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;
}

@@ -668,7 +671,6 @@ void vma_complete(struct vma_prepare *vp,
}
if (vp->insert && vp->file)
uprobe_mmap(vp->insert);
- validate_mm(mm);
}

/*
@@ -1197,6 +1199,7 @@ static struct vm_area_struct
}

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

--
2.43.0