Add itimer-related syscall tests

regression/apps/itimer/timer_create.c

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/syscall.h>
+#include <linux/types.h>
+#include <string.h>
+
+#define CLOCKID CLOCK_REALTIME
+#define SIG SIGRTMIN
+
+static void handler(int sig, siginfo_t *si, void *unused)
+{
+	printf("Caught signal %d\n", sig);
+}
+
+int main(int argc, char *argv[])
+{
+	struct sigaction sa;
+	struct sigevent sev;
+	timer_t timerid;
+	struct itimerspec its;
+	memset(&sa, 0, sizeof(sa));
+
+	// Set signal handler
+	sa.sa_flags = SA_SIGINFO;
+	sa.sa_sigaction = handler;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(SIG, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(1);
+	}
+
+	// Create the timer.
+	sev.sigev_notify = SIGEV_THREAD_ID;
+	sev.sigev_signo = SIG;
+	sev.sigev_value.sival_ptr = &timerid;
+	sev._sigev_un._tid = syscall(SYS_gettid);
+	if (timer_create(CLOCKID, &sev, &timerid) == -1) {
+		perror("timer_create");
+		exit(1);
+	}
+
+	// Enable the timer.
+	its.it_value.tv_sec = 5;
+	its.it_value.tv_nsec = 0;
+	its.it_interval.tv_sec = 0;
+	its.it_interval.tv_nsec = 0;
+	if (timer_settime(timerid, 0, &its, NULL) == -1) {
+		perror("timer_settime");
+		exit(1);
+	}
+
+	pause();
+
+	return 0;
+}