From 74e9de1b71c0fd30899c48e0bdddcbb66482f17c Mon Sep 17 00:00:00 2001
From: dbrotz <43593771+dbrotz@users.noreply.github.com>
Date: Tue, 11 Jun 2019 10:45:51 -0700
Subject: [PATCH] Check for RPN stack overflow in linker

---
 src/link/patch.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/link/patch.c b/src/link/patch.c
index 18cd43b0..44dfaa93 100644
--- a/src/link/patch.c
+++ b/src/link/patch.c
@@ -18,13 +18,18 @@
 #include "link/mylink.h"
 #include "link/symbol.h"
 
+#define RPN_STACK_SIZE 256
+
 static struct sSection *pCurrentSection;
-static int32_t rpnstack[256];
+static int32_t rpnstack[RPN_STACK_SIZE];
 static int32_t rpnp;
 int32_t nPC;
 
 static void rpnpush(int32_t i)
 {
+	if (rpnp >= RPN_STACK_SIZE)
+		errx(1, "RPN stack overflow");
+
 	rpnstack[rpnp] = i;
 	rpnp++;
 }