1 files changed, 7 insertions, 0 deletions

diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index bee98f466d66..dec5678fc17f 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -106,6 +106,10 @@ static void deliver_alarm(void)
         unsigned long long this_tick = os_nsecs();
         int one_tick = UM_NSEC_PER_SEC / UM_HZ;
 
+        /* Protection against the host's time going backwards */
+        if ((last_tick != 0) && (this_tick < last_tick))
+                this_tick = last_tick;
+
         if (last_tick == 0)
                 last_tick = this_tick - one_tick;
 
@@ -148,6 +152,9 @@ static int after_sleep_interval(struct timespec *ts)
                 start_usecs = usec;
 
         start_usecs -= skew / UM_NSEC_PER_USEC;
+        if (start_usecs < 0)
+                start_usecs = 0;
+
         tv = ((struct timeval) { .tv_sec  = start_usecs / UM_USEC_PER_SEC,
                                  .tv_usec = start_usecs % UM_USEC_PER_SEC });
         interval = ((struct itimerval) { { 0, usec }, tv });