mm: no lock abstraction until mainline d8ed45c5dcd

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/queue/mm-madvise-fix-vma-user-after-free.patch b/queue/mm-madvise-fix-vma-user-after-free.patch
index 33213ac..da23be3 100644
--- a/queue/mm-madvise-fix-vma-user-after-free.patch
+++ b/queue/mm-madvise-fix-vma-user-after-free.patch
@@ -1,4 +1,4 @@
-From 7867fd7cc44e63c6673cd0f8fea155456d34d0de Mon Sep 17 00:00:00 2001
+From 4b82272a64326ce4803fcdce6965f0a6c693d841 Mon Sep 17 00:00:00 2001
 From: Yang Shi <shy828301@gmail.com>
 Date: Fri, 4 Sep 2020 16:35:55 -0700
 Subject: [PATCH] mm: madvise: fix vma user-after-free
@@ -69,20 +69,20 @@
 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
 diff --git a/mm/madvise.c b/mm/madvise.c
-index dd1d43cf026d..d4aa5f776543 100644
+index ae56d0ef337d..9c43c8515cef 100644
 --- a/mm/madvise.c
 +++ b/mm/madvise.c
-@@ -289,9 +289,9 @@ static long madvise_willneed(struct vm_area_struct *vma,
+@@ -308,9 +308,9 @@ static long madvise_willneed(struct vm_area_struct *vma,
  	 */
- 	*prev = NULL;	/* tell sys_madvise we drop mmap_lock */
+ 	*prev = NULL;	/* tell sys_madvise we drop mmap_sem */
  	get_file(file);
--	mmap_read_unlock(current->mm);
+-	up_read(&current->mm->mmap_sem);
  	offset = (loff_t)(start - vma->vm_start)
  			+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
-+	mmap_read_unlock(current->mm);
++	up_read(&current->mm->mmap_sem);
  	vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED);
  	fput(file);
- 	mmap_read_lock(current->mm);
+ 	down_read(&current->mm->mmap_sem);
 -- 
 2.27.0