sh64: ppoll/pselect6() and restartable syscalls.

This patch was hanging around for some time while we were waiting
for the compiler situation to improve.. now that all is well again,
finally merge it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh64/kernel/signal.c b/arch/sh64/kernel/signal.c
index b76bdfa..c8525ad 100644
--- a/arch/sh64/kernel/signal.c
+++ b/arch/sh64/kernel/signal.c
@@ -698,7 +698,9 @@
 	if (try_to_freeze())
 		goto no_signal;
 
-	if (!oldset)
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else if (!oldset)
 		oldset = &current->blocked;
 
 	signr = get_signal_to_deliver(&info, &ka, regs, 0);
@@ -706,6 +708,15 @@
 	if (signr > 0) {
 		/* Whee!  Actually deliver the signal.  */
 		handle_signal(signr, &info, &ka, oldset, regs);
+
+		/*
+		 * If a signal was successfully delivered, the saved sigmask
+		 * is in its frame, and we can clear the TIF_RESTORE_SIGMASK
+		 * flag.
+		 */
+		if (test_thread_flag(TIF_RESTORE_SIGMASK))
+			clear_thread_flag(TIF_RESTORE_SIGMASK);
+
 		return 1;
 	}
 
@@ -713,13 +724,27 @@
 	/* Did we come from a system call? */
 	if (regs->syscall_nr >= 0) {
 		/* Restart the system call - no handlers present */
-		if (regs->regs[REG_RET] == -ERESTARTNOHAND ||
-		    regs->regs[REG_RET] == -ERESTARTSYS ||
-		    regs->regs[REG_RET] == -ERESTARTNOINTR) {
+		switch (regs->regs[REG_RET]) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
 			/* Decode Syscall # */
 			regs->regs[REG_RET] = regs->syscall_nr;
 			regs->pc -= 4;
+			break;
+
+		case -ERESTART_RESTARTBLOCK:
+			regs->regs[REG_RET] = __NR_restart_syscall;
+			regs->pc -= 4;
+			break;
 		}
 	}
+
+	/* No signal to deliver -- put the saved sigmask back */
+	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
+		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+	}
+
 	return 0;
 }