Re: [PATCH v13 59/70] mm/mremap: use vma_find_intersection() instead of vma linked list

From: Davidlohr Bueso
Date: Tue Sep 06 2022 - 14:23:27 EST


On Mon, 22 Aug 2022, Liam Howlett wrote:

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

-ENOCHANGELOG


Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>

---
mm/mremap.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/mremap.c b/mm/mremap.c
index e0fba9004246..8644ff278f02 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -716,7 +716,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
if (excess) {
vma->vm_flags |= VM_ACCOUNT;
if (split)
- vma->vm_next->vm_flags |= VM_ACCOUNT;
+ find_vma(mm, vma->vm_end)->vm_flags |= VM_ACCOUNT;
}

return new_addr;
@@ -866,9 +866,10 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
static int vma_expandable(struct vm_area_struct *vma, unsigned long delta)
{
unsigned long end = vma->vm_end + delta;
+
if (end < vma->vm_end) /* overflow */
return 0;
- if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */
+ if (find_vma_intersection(vma->vm_mm, vma->vm_end, end))
return 0;
if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start,
0, MAP_FIXED) & ~PAGE_MASK)

--
2.35.1