Merge tag 'defconfig-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[firefly-linux-kernel-4.4.55.git] / kernel / exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index 1ea4369890a31b6776aeb85bada4bf097594cce2..feff10bbb30777f93c33369a186650a6eb1a2e6a 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -435,7 +435,8 @@ static void exit_mm(struct task_struct *tsk)
        task_unlock(tsk);
        mm_update_next_owner(mm);
        mmput(mm);
-       clear_thread_flag(TIF_MEMDIE);
+       if (test_thread_flag(TIF_MEMDIE))
+               unmark_oom_victim();
 }
 
 static struct task_struct *find_alive_thread(struct task_struct *p)
@@ -1287,9 +1288,15 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
 static int wait_consider_task(struct wait_opts *wo, int ptrace,
                                struct task_struct *p)
 {
+       /*
+        * We can race with wait_task_zombie() from another thread.
+        * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
+        * can't confuse the checks below.
+        */
+       int exit_state = ACCESS_ONCE(p->exit_state);
        int ret;
 
-       if (unlikely(p->exit_state == EXIT_DEAD))
+       if (unlikely(exit_state == EXIT_DEAD))
                return 0;
 
        ret = eligible_child(wo, p);
@@ -1310,7 +1317,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
                return 0;
        }
 
-       if (unlikely(p->exit_state == EXIT_TRACE)) {
+       if (unlikely(exit_state == EXIT_TRACE)) {
                /*
                 * ptrace == 0 means we are the natural parent. In this case
                 * we should clear notask_error, debugger will notify us.
@@ -1337,7 +1344,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
        }
 
        /* slay zombie? */
-       if (p->exit_state == EXIT_ZOMBIE) {
+       if (exit_state == EXIT_ZOMBIE) {
                /* we don't reap group leaders with subthreads */
                if (!delay_group_leader(p)) {
                        /*