From: Dave Reisner <dreisner@archlinux.org>
Date: Mon, 29 Oct 2012 19:49:34 +0000 (-0400)
Subject: util: avoid divide by zero FPE
X-Git-Tag: v196~182
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=49371bb50e0fe6e9e90309a20006bcfd9e2fa8f4;ds=sidebyside

util: avoid divide by zero FPE

In early userspace, if kernel initialization happens extremely quickly,
a call to systemd-timestamp can potentially result in division by zero.
Ensure that the check in timespec_load, which only makes sense if tv_sec
is greater than zero, is guarded by this condition.
---

diff --git a/src/shared/util.c b/src/shared/util.c
index e2f8b1fb7..9a45e6058 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -148,7 +148,8 @@ usec_t timespec_load(const struct timespec *ts) {
             ts->tv_nsec == (long) -1)
                 return (usec_t) -1;
 
-        if (USEC_PER_SEC > ((UINT64_MAX - (ts->tv_nsec / NSEC_PER_USEC)) / (usec_t) ts->tv_sec))
+        if (ts->tv_sec > 0 &&
+            USEC_PER_SEC > ((UINT64_MAX - (ts->tv_nsec / NSEC_PER_USEC)) / (usec_t) ts->tv_sec))
                 return (usec_t) -1;
 
         return