new helper: signal_setup_done()

usual "call force_sigsegv or signal_delivered" logics.  Takes
ksignal instead of separate siginfo/k_sigaction.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/signal.h

@@ -286,6 +286,7 @@ struct ksignal {
 };
 
 extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
+extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
 extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);
 extern void exit_signals(struct task_struct *tsk);
 

kernel/signal.c

@@ -2396,6 +2396,15 @@ void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka,
 	tracehook_signal_handler(sig, info, ka, regs, stepping);
 }
 
+void signal_setup_done(int failed, struct ksignal *ksig, int stepping)
+{
+	if (failed)
+		force_sigsegv(ksig->sig, current);
+	else
+		signal_delivered(ksig->sig, &ksig->info, &ksig->ka,
+			signal_pt_regs(), stepping);
+}
+
 /*
  * It could be that complete_signal() picked us to notify about the
  * group-wide signal. Other threads should be notified now to take