Merge branch 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:
 "The cgroup2 freezer pulled in this cycle broke strace. This pull
  request includes a workaround for the problem.

  It's not a complete fix in that it may cause spurious frozen state
  flip-flops which is fairly minor. Will push a full fix once it's
  ready"

* 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  signal: unconditionally leave the frozen state in ptrace_stop()

kernel/signal.c

@@ -2113,6 +2113,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t
 		preempt_enable_no_resched();
 		cgroup_enter_frozen();
 		freezable_schedule();
+		cgroup_leave_frozen(true);
 	} else {
 		/*
 		 * By the time we got the lock, our tracer went away.