From 3d6d5aa8562ffafd2ac8d14b2a657235bbc63ce2 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Thu, 2 Sep 2021 14:56:49 -0700
Subject: [PATCH] remap_file_pages: Use vma_lookup() instead of find_vma()

References: bsc#1190208 (MM functional and performance backports)
Patch-mainline: v5.15-rc1
Git-commit: 9b593cb20283e68e5e65b09ca10038935297f05b

Using vma_lookup() verifies the start address is contained in the found vma.
This results in easier to read code.

Link: https://lkml.kernel.org/r/20210817135234.1550204-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 mm/mmap.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 79f4f8ae43ec..52fed230dc21 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2994,14 +2994,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
-	vma = find_vma(mm, start);
+	vma = vma_lookup(mm, start);
 
 	if (!vma || !(vma->vm_flags & VM_SHARED))
 		goto out;
 
-	if (start < vma->vm_start)
-		goto out;
-
 	if (start + size > vma->vm_end) {
 		struct vm_area_struct *next;