signals: fold sig_ignored() into handle_stop_signal()

[mirror_ubuntu-zesty-kernel.git] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index 0db1d93c4d68a9f247ee26d39768aa773f0f8481..359c4de7c7721f3cf17c88bb0687b90c32a056a0 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -558,24 +558,25 @@ static int check_kill_permission(int sig, struct siginfo *info,
 static void do_notify_parent_cldstop(struct task_struct *tsk, int why);
 
 /*
- * Handle magic process-wide effects of stop/continue signals.
- * Unlike the signal actions, these happen immediately at signal-generation
+ * Handle magic process-wide effects of stop/continue signals. Unlike
+ * the signal actions, these happen immediately at signal-generation
  * time regardless of blocking, ignoring, or handling.  This does the
  * actual continuing for SIGCONT, but not the actual stopping for stop
- * signals.  The process stop is done as a signal action for SIG_DFL.
+ * signals. The process stop is done as a signal action for SIG_DFL.
+ *
+ * Returns true if the signal should be actually delivered, otherwise
+ * it should be dropped.
  */
-static void handle_stop_signal(int sig, struct task_struct *p)
+static int prepare_signal(int sig, struct task_struct *p)
 {
        struct signal_struct *signal = p->signal;
        struct task_struct *t;
 
-       if (signal->flags & SIGNAL_GROUP_EXIT)
+       if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) {
                /*
-                * The process is in the middle of dying already.
+                * The process is in the middle of dying, nothing to do.
                 */
-               return;
-
-       if (sig_kernel_stop(sig)) {
+       } else if (sig_kernel_stop(sig)) {
                /*
                 * This is a stop signal.  Remove SIGCONT from all queues.
                 */
@@ -644,6 +645,8 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                        signal->flags &= ~SIGNAL_STOP_DEQUEUED;
                }
        }
+
+       return !sig_ignored(p, sig);
 }
 
 /*
@@ -753,7 +756,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
        struct sigqueue *q;
 
        assert_spin_locked(&t->sighand->siglock);
-       handle_stop_signal(sig, t);
+       if (!prepare_signal(sig, t))
+               return 0;
 
        pending = group ? &t->signal->shared_pending : &t->pending;
        /*
@@ -761,7 +765,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
         * exactly one non-rt signal, so that we can get more
         * detailed information about the cause of the signal.
         */
-       if (sig_ignored(t, sig) || legacy_queue(pending, sig))
+       if (legacy_queue(pending, sig))
                return 0;
 
        /*
@@ -1247,10 +1251,8 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
        if (!likely(lock_task_sighand(t, &flags)))
                goto ret;
 
-       handle_stop_signal(sig, t);
-
-       ret = 1;
-       if (sig_ignored(t, sig))
+       ret = 1; /* the signal is ignored */
+       if (!prepare_signal(sig, t))
                goto out;
 
        ret = 0;