WATCHDOG: define and use _MAX_TICKS as 3 Instead of using the number 3 directly, let's introduce and use WATCHDOG_MAX_TICKS. Reviewed-by: Petr Čech <pcech@redhat.com>

watchdog: cope with time shift When a time is changed into the past during sssd runtime (e.g. on boot during time correction), it is possible that we never hit watchdog tevent timer since it is based on system time. This patch adds a past-time shift detection mechanism. If a time shift is detected we restart watchdog. Resolves: https://fedorahosted.org/sssd/ticket/3154 Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com> Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>

UTIL: Fix warning Wmissing-braces Older versions of gcc does not like initialisation of struct sigevent because the first member of structure is union (sigval_t) src/util/util_watchdog.c: In function 'setup_watchdog': src/util/util_watchdog.c:77:12: warning: missing braces around initializer [-Wmissing-braces] struct sigevent sev = { 0 }; ^ src/util/util_watchdog.c:77:12: warning: (near initialization for 'sev.sigev_value') [-Wmissing-braces] src/util/util_watchdog.c:77:12: warning: initialization makes integer from pointer without a cast src/util/util_watchdog.c:77:12: warning: (near initialization for 'sev.sigev_value.sival_int') Reviewed-by: Sumit Bose <sbose@redhat.com>

Util: Add watchdog helper The watchdog uses a kernel timer to issue a signal to the process. It checks if the ticker is not being reset by the main event loop, which would indicate that the process got stuck. At the same time it sets a tevent timer to clear the watchdog ticker, so that the watchdog handler is kept happy. If the watchdog detects that the timer event failed to reset the watchdog for three times in a row then the process is killed. Normally the monitor will detect the child terminated and will rescheduled it. Related: https://fedorahosted.org/sssd/ticket/2921 Reviewed-by: Jakub Hrozek <jhrozek@redhat.com> Reviewed-by: Pavel Březina <pbrezina@redhat.com>