uti: Add/Modify test programs

Change-Id: I27a39d6b11af5243f93d07c31c2ef80f6727dd53

test/uti/preloadlib.c

@@ -0,0 +1,40 @@
+#include <libsyscall_intercept_hook_point.h>
+#include <syscall.h>
+#include <errno.h>
+#define __USE_GNU
+#include <dlfcn.h>
+
+static int
+hook(long syscall_number,
+	 long arg0, long arg1,
+	 long arg2, long arg3,
+	 long arg4, long arg5,
+	 long *result)
+{
+	if (syscall_number == SYS_getdents) {
+		/*
+		 * Prevent the application from
+		 * using the getdents syscall. From
+		 * the point of view of the calling
+		 * process, it is as if the kernel
+		 * would return the ENOTSUP error
+		 * code from the syscall.
+		 */
+		*result = -ENOTSUP;
+		return 0;
+	} else {
+		/*
+		 * Ignore any other syscalls
+		 * i.e.: pass them on to the kernel
+		 * as would normally happen.
+		 */
+		return 1;
+	}
+}
+
+static __attribute__((constructor)) void
+init(void)
+{
+	// Set up the callback function
+	intercept_hook_point = hook;
+}