selftests/timers/posix-timers: Validate timer_gettime()

timer_gettime() must return the correct expiry time for interval timers
even when the timer is not armed, which is the case when a signal is
pending but blocked.

Works correctly for regular posix timers, but not for posix CPU timers.

Add a selftest to validate the fixes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index 097a132615f6039132c7aecfd06072f8c2ee4455..4c993dbbdbf287780d091cf1c93622a9f217ca7b 100644 (file)
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -487,10 +487,63 @@ static void check_sigev_none(int which, const char *name)
                         "check_sigev_none %s\n", name);
 }
 
+static void check_gettime(int which, const char *name)
+{
+       struct itimerspec its, prev;
+       struct timespec start, now;
+       struct sigevent sev;
+       timer_t timerid;
+       int wraps = 0;
+       sigset_t set;
+
+       /* Block the signal */
+       sigemptyset(&set);
+       sigaddset(&set, SIGUSR1);
+       if (sigprocmask(SIG_BLOCK, &set, NULL))
+               fatal_error(name, "sigprocmask(SIG_BLOCK)");
+
+       memset(&sev, 0, sizeof(sev));
+       sev.sigev_notify = SIGEV_SIGNAL;
+       sev.sigev_signo = SIGUSR1;
+
+       if (timer_create(which, &sev, &timerid))
+               fatal_error(name, "timer_create()");
+
+       /* Start the timer to expire in 100ms and 100ms intervals */
+       its.it_value.tv_sec = 0;
+       its.it_value.tv_nsec = 100000000;
+       its.it_interval.tv_sec = 0;
+       its.it_interval.tv_nsec = 100000000;
+       if (timer_settime(timerid, 0, &its, NULL))
+               fatal_error(name, "timer_settime()");
+
+       if (timer_gettime(timerid, &prev))
+               fatal_error(name, "timer_gettime()");
+
+       if (clock_gettime(which, &start))
+               fatal_error(name, "clock_gettime()");
+
+       do {
+               if (clock_gettime(which, &now))
+                       fatal_error(name, "clock_gettime()");
+               if (timer_gettime(timerid, &its))
+                       fatal_error(name, "timer_gettime()");
+               if (its.it_value.tv_nsec > prev.it_value.tv_nsec)
+                       wraps++;
+               prev = its;
+
+       } while (calcdiff_ns(now, start) < NSECS_PER_SEC);
+
+       if (timer_delete(timerid))
+               fatal_error(name, "timer_delete()");
+
+       ksft_test_result(wraps > 1, "check_gettime %s\n", name);
+}
+
 int main(int argc, char **argv)
 {
        ksft_print_header();
-       ksft_set_plan(12);
+       ksft_set_plan(15);
 
        ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n");
        ksft_print_msg("based timers if other threads run on the CPU...\n");
@@ -518,6 +571,9 @@ int main(int argc, char **argv)
        check_delete();
        check_sigev_none(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
        check_sigev_none(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+       check_gettime(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
+       check_gettime(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+       check_gettime(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
 
        ksft_finished();
 }