X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ftime.c;h=d63a4336fad69c85f007788a7932959595f0cb73;hb=f7160c7573615ec82c691e294cf80d920b5d588d;hp=6a08660b4fac30f97ea573b9cd017941401046ff;hpb=2a5f2e3e6cd1ce9fb3f8b186b6bc9aa1f1497a92;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/time.c b/kernel/time.c
index 6a08660b4fa..d63a4336fad 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -669,3 +669,21 @@ EXPORT_SYMBOL(get_jiffies_64);
 #endif
 
 EXPORT_SYMBOL(jiffies);
+
+/*
+ * Add two timespec values and do a safety check for overflow.
+ * It's assumed that both values are valid (>= 0)
+ */
+struct timespec timespec_add_safe(const struct timespec lhs,
+				  const struct timespec rhs)
+{
+	struct timespec res;
+
+	set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec,
+				lhs.tv_nsec + rhs.tv_nsec);
+
+	if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)
+		res.tv_sec = TIME_T_MAX;
+
+	return res;
+}