2.6.25-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jeff Dike commit 06e1e4ffbd1932e288839b3140cda6b8141eb684 upstream Protection against the host's time going backwards (eg, ntp activity on the host) by keeping track of the time at the last tick and if it's greater than the current time, keep time stopped until the host catches up. Cc: Nix Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/um/os-Linux/time.c | 7 +++++++ 1 file changed, 7 insertions(+) --- 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 t 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 }); -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/