Merge branch 'master' into next

1 files changed, 49 insertions, 14 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index f93efec..d2dd9cf 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -55,10 +55,22 @@ static int sig_handler_ignored(void __user *handler, int sig)
 		(handler == SIG_DFL && sig_kernel_ignore(sig));
 }
 
-static int sig_ignored(struct task_struct *t, int sig)
+static int sig_task_ignored(struct task_struct *t, int sig,
+		int from_ancestor_ns)
 {
 	void __user *handler;
 
+	handler = sig_handler(t, sig);
+
+	if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
+			handler == SIG_DFL && !from_ancestor_ns)
+		return 1;
+
+	return sig_handler_ignored(handler, sig);
+}
+
+static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
+{
 	/*
 	 * Blocked signals are never ignored, since the
 	 * signal handler may change by the time it is
@@ -67,14 +79,13 @@ static int sig_ignored(struct task_struct *t, int sig)
 	if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
 		return 0;
 
-	handler = sig_handler(t, sig);
-	if (!sig_handler_ignored(handler, sig))
+	if (!sig_task_ignored(t, sig, from_ancestor_ns))
 		return 0;
 
 	/*
 	 * Tracers may want to know about even ignored signals.
 	 */
-	return !tracehook_consider_ignored_signal(t, sig, handler);
+	return !tracehook_consider_ignored_signal(t, sig);
 }
 
 /*
@@ -323,7 +334,7 @@ int unhandled_signal(struct task_struct *tsk, int sig)
 		return 1;
 	if (handler != SIG_IGN && handler != SIG_DFL)
 		return 0;
-	return !tracehook_consider_fatal_signal(tsk, sig, handler);
+	return !tracehook_consider_fatal_signal(tsk, sig);
 }
 
 
@@ -629,7 +640,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
  * Returns true if the signal should be actually delivered, otherwise
  * it should be dropped.
  */
-static int prepare_signal(int sig, struct task_struct *p)
+static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
 {
 	struct signal_struct *signal = p->signal;
 	struct task_struct *t;
@@ -713,7 +724,7 @@ static int prepare_signal(int sig, struct task_struct *p)
 		}
 	}
 
-	return !sig_ignored(p, sig);
+	return !sig_ignored(p, sig, from_ancestor_ns);
 }
 
 /*
@@ -782,7 +793,7 @@ static void complete_signal(int sig, struct task_struct *p, int group)
 	    !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
 	    !sigismember(&t->real_blocked, sig) &&
 	    (sig == SIGKILL ||
-	     !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) {
+	     !tracehook_consider_fatal_signal(t, sig))) {
 		/*
 		 * This signal will be fatal to the whole group.
 		 */
@@ -818,8 +829,8 @@ static inline int legacy_queue(struct sigpending *signals, int sig)
 	return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
 }
 
-static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
-			int group)
+static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
+			int group, int from_ancestor_ns)
 {
 	struct sigpending *pending;
 	struct sigqueue *q;
@@ -827,7 +838,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	trace_sched_signal_send(sig, t);
 
 	assert_spin_locked(&t->sighand->siglock);
-	if (!prepare_signal(sig, t))
+
+	if (!prepare_signal(sig, t, from_ancestor_ns))
 		return 0;
 
 	pending = group ? &t->signal->shared_pending : &t->pending;
@@ -876,6 +888,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			break;
 		default:
 			copy_siginfo(&q->info, info);
+			if (from_ancestor_ns)
+				q->info.si_pid = 0;
 			break;
 		}
 	} else if (!is_si_special(info)) {
@@ -894,6 +908,20 @@ out_set:
 	return 0;
 }
 
+static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
+			int group)
+{
+	int from_ancestor_ns = 0;
+
+#ifdef CONFIG_PID_NS
+	if (!is_si_special(info) && SI_FROMUSER(info) &&
+			task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0)
+		from_ancestor_ns = 1;
+#endif
+
+	return __send_signal(sig, info, t, group, from_ancestor_ns);
+}
+
 int print_fatal_signals;
 
 static void print_fatal_signal(struct pt_regs *regs, int signr)
@@ -1138,7 +1166,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid,
 	if (sig && p->sighand) {
 		unsigned long flags;
 		spin_lock_irqsave(&p->sighand->siglock, flags);
-		ret = __group_send_sig_info(sig, info, p);
+		ret = __send_signal(sig, info, p, 1, 0);
 		spin_unlock_irqrestore(&p->sighand->siglock, flags);
 	}
 out_unlock:
@@ -1325,7 +1353,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
 		goto ret;
 
 	ret = 1; /* the signal is ignored */
-	if (!prepare_signal(sig, t))
+	if (!prepare_signal(sig, t, 0))
 		goto out;
 
 	ret = 0;
@@ -1849,9 +1877,16 @@ relock:
 
 		/*
 		 * Global init gets no signals it doesn't want.
+		 * Container-init gets no signals it doesn't want from same
+		 * container.
+		 *
+		 * Note that if global/container-init sees a sig_kernel_only()
+		 * signal here, the signal must have been generated internally
+		 * or must have come from an ancestor namespace. In either
+		 * case, the signal cannot be dropped.
 		 */
 		if (unlikely(signal->flags & SIGNAL_UNKILLABLE) &&
-		    !signal_group_exit(signal))
+				!sig_kernel_only(signr))
 			continue;
 
 		if (sig_kernel_stop(signr)) {