From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Subject: mm/mremap: use vma_find_intersection() instead of vma linked list

Link: https://lkml.kernel.org/r/20220426150616.3937571-61-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

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

--- a/mm/mremap.c~mm-mremap-use-vma_find_intersection-instead-of-vma-linked-list
+++ a/mm/mremap.c
@@ -716,7 +716,7 @@ static unsigned long move_vma(struct vm_
 	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 @@ out:
 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)
_