1 files changed, 7 insertions, 15 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index f072513..7aaa51d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1754,7 +1754,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
 	 * see comment in do_notify_parent() about the following 4 lines
 	 */
 	rcu_read_lock();
-	info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
+	info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent));
 	info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
 	rcu_read_unlock();
 
@@ -1910,7 +1910,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
 		preempt_disable();
 		read_unlock(&tasklist_lock);
 		preempt_enable_no_resched();
-		schedule();
+		freezable_schedule();
 	} else {
 		/*
 		 * By the time we got the lock, our tracer went away.
@@ -1932,13 +1932,6 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
 	}
 
 	/*
-	 * While in TASK_TRACED, we were considered "frozen enough".
-	 * Now that we woke up, it's crucial if we're supposed to be
-	 * frozen that we freeze now before running anything substantial.
-	 */
-	try_to_freeze();
-
-	/*
 	 * We are back.  Now reacquire the siglock before touching
 	 * last_siginfo, so that we are sure to have synchronized with
 	 * any signal-sending on another CPU that wants to examine it.
@@ -2094,7 +2087,7 @@ static bool do_signal_stop(int signr)
 		}
 
 		/* Now we don't run again until woken by SIGCONT or SIGKILL */
-		schedule();
+		freezable_schedule();
 		return true;
 	} else {
 		/*
@@ -2201,15 +2194,14 @@ int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
 	if (unlikely(uprobe_deny_signal()))
 		return 0;
 
-relock:
 	/*
-	 * We'll jump back here after any time we were stopped in TASK_STOPPED.
-	 * While in TASK_STOPPED, we were considered "frozen enough".
-	 * Now that we woke up, it's crucial if we're supposed to be
-	 * frozen that we freeze now before running anything substantial.
+	 * Do this once, we can't return to user-mode if freezing() == T.
+	 * do_signal_stop() and ptrace_stop() do freezable_schedule() and
+	 * thus do not need another check after return.
 	 */
 	try_to_freeze();
 
+relock:
 	spin_lock_irq(&sighand->siglock);
 	/*
 	 * Every stopped thread goes here after wakeup. Check to see if