From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 16 Mar 2021 16:35:18 +0000 (-0400)
Subject: mm/mmap: Fix remap_file_pages() locking to work with new do_mmap()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4ca513d30e09c470d37351caf51474fe175f4e8d;p=users%2Fjedix%2Flinux-maple.git

mm/mmap: Fix remap_file_pages() locking to work with new do_mmap()

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index b425510cd64a..601632be18d9 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2979,7 +2979,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
-	mas_lock(&mas);
+	rcu_read_lock();
 	mas_set(&mas, start);
 	vma = mas_walk(&mas);
 
@@ -3028,7 +3028,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 			prot, flags, pgoff, &populate, NULL);
 	fput(file);
 out:
-	mas_unlock(&mas);
+	rcu_read_unlock();
 	mmap_write_unlock(mm);
 	if (populate)
 		mm_populate(ret, populate);