diff --git a/arch/alpha/lib/dbg_stackcheck.S b/arch/alpha/lib/dbg_stackcheck.S
new file mode 100644
index 0000000..cc5ce3a
--- /dev/null
+++ b/arch/alpha/lib/dbg_stackcheck.S
@@ -0,0 +1,27 @@
+/*
+ * arch/alpha/lib/stackcheck.S
+ * Contributed by Richard Henderson (rth@tamu.edu)
+ *
+ * Verify that we have not overflowed the stack.  Oops if we have.
+ */
+
+#include <asm/asm_offsets.h>
+
+	.text
+	.set noat
+
+	.align 3
+	.globl _mcount
+	.ent _mcount
+_mcount:
+	.frame $30, 0, $28, 0
+	.prologue 0
+
+	lda	$0, TASK_SIZE($8)
+	cmpult	$30, $0, $0
+	bne	$0, 1f
+	ret	($28)
+1:	stq	$31, -8($31)	# oops me, damn it.
+	br	1b
+
+	.end _mcount