From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Mon, 6 Sep 2021 03:31:46 +0000 (-0400)
Subject: mmap: Move locking of detached tree.
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=99864cc08a9cb9345fdb97f7b464ee1dbd589511;p=users%2Fjedix%2Flinux-maple.git

mmap: Move locking of detached tree.

Fixes lock checking

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

diff --git a/mm/mmap.c b/mm/mmap.c
index a732f116f0ec..a3c8d8b33ff2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2404,7 +2404,6 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
 	 * Detach a range of VMAs from the mm. Using next as a temp variable as
 	 * it is always overwritten.
 	 */
-	mas_lock(&mas_detach);
 	mas_for_each(mas, next, end - 1) {
 		/* Does it split the end? */
 		if (next->vm_end > end) {
@@ -2421,13 +2420,14 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
 		BUG_ON(next->vm_start < start);
 		BUG_ON(next->vm_start > end);
 #endif
+		mas_lock(&mas_detach);
 		vma_mas_store(next, &mas_detach);
+		mas_unlock(&mas_detach);
 		if (next->vm_flags & VM_LOCKED) {
 			mm->locked_vm -= vma_pages(next);
 			munlock_vma_pages_all(next);
 		}
 	}
-	mas_unlock(&mas_detach);
 
 	mas_set(mas, end);
 	next = mas_find(mas, ULONG_MAX);