Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[~andy/linux] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 68d87103b493a3bc104771b02cf3d46197699be7..105f273b6f86a74984d2b62b7d3ba19f95369a78 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2905,9 +2905,14 @@ static void cgroup_enable_task_cg_lists(void)
                 * We should check if the process is exiting, otherwise
                 * it will race with cgroup_exit() in that the list
                 * entry won't be deleted though the process has exited.
+                * Do it while holding siglock so that we don't end up
+                * racing against cgroup_exit().
                 */
+               spin_lock_irq(&p->sighand->siglock);
                if (!(p->flags & PF_EXITING) && list_empty(&p->cg_list))
                        list_add(&p->cg_list, &task_css_set(p)->tasks);
+               spin_unlock_irq(&p->sighand->siglock);
+
                task_unlock(p);
        } while_each_thread(g, p);
        read_unlock(&tasklist_lock);