From 318e735fdfc3e3d7d866b96b98e376a9ffef9517 Mon Sep 17 00:00:00 2001
From: ckolivas <kernel@kolivas.org>
Date: Wed, 9 Jul 2014 12:35:40 +0300
Subject: [PATCH] Put sanity upper limit on exponent function used in
 decay_time

---
 src/libckpool.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/libckpool.c b/src/libckpool.c
index 01dca0ac..72df31d8 100644
--- a/src/libckpool.c
+++ b/src/libckpool.c
@@ -1328,11 +1328,15 @@ double tvdiff(tv_t *end, tv_t *start)
 /* Create an exponentially decaying average over interval */
 void decay_time(double *f, double fadd, double fsecs, double interval)
 {
-	double ftotal, fprop;
+	double ftotal, fprop, dexp;
 
 	if (fsecs <= 0)
 		return;
-	fprop = 1.0 - 1 / (exp(fsecs / interval));
+	dexp = fsecs / interval;
+	/* Put Sanity bound on how large the denominator can get */
+	if (unlikely(dexp > 36))
+		dexp = 36;
+	fprop = 1.0 - 1 / exp(dexp);
 	ftotal = 1.0 + fprop;
 	*f += (fadd / fsecs * fprop);
 	*f /= ftotal;