[PATCH 4/6] exec: Run sync_mm_rss before taking exec_update_mutex

[Eric W. Biederman]

Like exec_mm_release sync_mm_rss is about flushing out the state of
the old_mm, which does not need to happen under exec_update_mutex.

Make this explicit by moving sync_mm_rss outside of exec_update_mutex.

Signed-off-by: "Eric W. Biederman" <ebied...@xmission.com>
---
 fs/exec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/exec.c b/fs/exec.c
index 11a5c073aa35..15682a1dfee9 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1051,13 +1051,14 @@ static int exec_mmap(struct mm_struct *mm)
        tsk = current;
        old_mm = current->mm;
        exec_mm_release(tsk, old_mm);
+       if (old_mm)
+               sync_mm_rss(old_mm);
 
        ret = mutex_lock_killable(&tsk->signal->exec_update_mutex);
        if (ret)
                return ret;
 
        if (old_mm) {
-               sync_mm_rss(old_mm);
                /*
                 * Make sure that if there is a core dump in progress
                 * for the old mm, we get out and die instead of going
-- 
2.20.1