[PATCH 10/64] kernel/exit: teach exit_mm() about range locking

[Davidlohr Bueso]

From: Davidlohr Bueso <dave@xxxxxxxxxxxx>

... and use mm locking wrappers -- no change is semantics.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
 kernel/exit.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index 42ca71a44c9a..a9540f157eb2 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -495,6 +495,7 @@ static void exit_mm(void)
 {
 	struct mm_struct *mm = current->mm;
 	struct core_state *core_state;
+	DEFINE_RANGE_LOCK_FULL(mmrange);
 
 	mm_release(current, mm);
 	if (!mm)
@@ -507,12 +508,12 @@ static void exit_mm(void)
 	 * will increment ->nr_threads for each thread in the
 	 * group with ->mm != NULL.
 	 */
-	down_read(&mm->mmap_sem);
+        mm_read_lock(mm, &mmrange);
 	core_state = mm->core_state;
 	if (core_state) {
 		struct core_thread self;
 
-		up_read(&mm->mmap_sem);
+	        mm_read_unlock(mm, &mmrange);
 
 		self.task = current;
 		self.next = xchg(&core_state->dumper.next, &self);
@@ -530,14 +531,14 @@ static void exit_mm(void)
 			freezable_schedule();
 		}
 		__set_current_state(TASK_RUNNING);
-		down_read(&mm->mmap_sem);
+		mm_read_lock(mm, &mmrange);
 	}
 	mmgrab(mm);
 	BUG_ON(mm != current->active_mm);
 	/* more a memory barrier than a real lock */
 	task_lock(current);
 	current->mm = NULL;
-	up_read(&mm->mmap_sem);
+	mm_read_unlock(mm, &mmrange);
 	enter_lazy_tlb(mm, current);
 	task_unlock(current);
 	mm_update_next_owner(mm);
-- 
2.13.6