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Message-ID: <20230606142031.361364275@linutronix.de>
From:   Thomas Gleixner <tglx@linutronix.de>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     Frederic Weisbecker <frederic@kernel.org>,
        Anna-Maria Behnsen <anna-maria@linutronix.de>,
        John Stultz <jstultz@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Eric Biederman <ebiederm@xmission.com>,
        Oleg Nesterov <oleg@redhat.com>
Subject: [patch 06/45] selftests/timers/posix-timers: Validate timer_gettime()
References: <20230606132949.068951363@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Date:   Tue,  6 Jun 2023 16:37:28 +0200 (CEST)
Precedence: bulk

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>
---
 tools/testing/selftests/timers/posix_timers.c |   60 +++++++++++++++++++++++++-
 1 file changed, 59 insertions(+), 1 deletion(-)

--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -523,10 +523,65 @@ static void check_sigev_none(int which,
 		ksft_test_result_fail("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;
+	timer_settime(timerid, 0, &its, NULL);
+
+	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()");
+
+	if (wraps > 1)
+		ksft_test_result_pass("check_gettime %s\n", name);
+	else
+		ksft_test_result_fail("check_gettime %s\n", name);
+}
+
 int main(int argc, char **argv)
 {
 	ksft_print_header();
-	ksft_set_plan(12);
+	ksft_set_plan(15);
 
 	check_itimer(ITIMER_VIRTUAL, "ITIMER_VIRTUAL");
 	check_itimer(ITIMER_PROF, "ITIMER_PROF");
@@ -550,6 +605,9 @@ 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();
 }