signal: Push pid type down into __send_signal

This information is already available in the callers and by pushing it
down it makes the code a little clearer, and allows implementing
better handling of signales set to a group of processes in fork.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

kernel/signal.c

@@ -998,7 +998,7 @@ static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_str
 #endif
 
 static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
-			int group, int from_ancestor_ns)
+			enum pid_type type, int from_ancestor_ns)
 {
 	struct sigpending *pending;
 	struct sigqueue *q;
@@ -1012,7 +1012,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			from_ancestor_ns || (info == SEND_SIG_FORCED)))
 		goto ret;
 
-	pending = group ? &t->signal->shared_pending : &t->pending;
+	pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending;
 	/*
 	 * Short-circuit ignored signals and support queuing
 	 * exactly one non-rt signal, so that we can get more
@@ -1096,9 +1096,9 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 out_set:
 	signalfd_notify(t, sig);
 	sigaddset(&pending->signal, sig);
-	complete_signal(sig, t, group);
+	complete_signal(sig, t, type != PIDTYPE_PID);
 ret:
-	trace_signal_generate(sig, info, t, group, result);
+	trace_signal_generate(sig, info, t, type != PIDTYPE_PID, result);
 	return ret;
 }
 
@@ -1112,7 +1112,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			   !task_pid_nr_ns(current, task_active_pid_ns(t));
 #endif
 
-	return __send_signal(sig, info, t, type != PIDTYPE_PID, from_ancestor_ns);
+	return __send_signal(sig, info, t, type, from_ancestor_ns);
 }
 
 static void print_fatal_signal(int signr)
@@ -1377,7 +1377,7 @@ int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid,
 
 	if (sig) {
 		if (lock_task_sighand(p, &flags)) {
-			ret = __send_signal(sig, info, p, 1, 0);
+			ret = __send_signal(sig, info, p, PIDTYPE_TGID, 0);
 			unlock_task_sighand(p, &flags);
 		} else
 			ret = -ESRCH;