[MIPS] N32: Fix N32 rt_sigtimedwait and rt_sigsuspend breakage.

Originally found through an oops in the Gentoo N32 userland build; patch
based on original patch by Daniel Jacobwitz.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
index 5a37760..3e168c0 100644
--- a/arch/mips/kernel/signal_n32.c
+++ b/arch/mips/kernel/signal_n32.c
@@ -81,6 +81,39 @@
 #endif
 };
 
+extern void sigset_from_compat (sigset_t *set, compat_sigset_t *compat);
+
+save_static_function(sysn32_rt_sigsuspend);
+__attribute_used__ noinline static int
+_sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
+{
+	compat_sigset_t __user *unewset, uset;
+	size_t sigsetsize;
+	sigset_t newset;
+
+	/* XXX Don't preclude handling different sized sigset_t's.  */
+	sigsetsize = regs.regs[5];
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	unewset = (compat_sigset_t __user *) regs.regs[4];
+	if (copy_from_user(&uset, unewset, sizeof(uset)))
+		return -EFAULT;
+	sigset_from_compat (&newset, &uset);
+	sigdelsetmask(&newset, ~_BLOCKABLE);
+
+	spin_lock_irq(&current->sighand->siglock);
+	current->saved_sigmask = current->blocked;
+	current->blocked = newset;
+        recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
+}
+
 save_static_function(sysn32_rt_sigreturn);
 __attribute_used__ noinline static void
 _sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)