test: Add prints out in static test

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

test/testee-static-syssleep.c

@@ -16,6 +16,7 @@
 # define always_inline		__always_inline
 #endif
 
+#define __NR_write	1
 #define __NR_nanosleep 35
 
 static always_inline long syscall2(int nr, unsigned long arg0, unsigned long arg1)
@@ -28,11 +29,33 @@ static always_inline long syscall2(int nr, unsigned long arg0, unsigned long arg
 	return ret;
 }
 
+static always_inline long syscall3(int nr, unsigned long arg0, unsigned long arg1,
+				   unsigned long arg2)
+{
+	long ret;
+	asm volatile(
+		"movl %1, %%eax		\t\n"
+		"movq %2, %%rdi		\t\n"
+		"movq %3, %%rsi		\t\n"
+		"movq %4, %%rdx		\t\n"
+		"syscall		\t\n"
+		"movq %%rax, %0		\t\n"
+		: "=r"(ret)
+		: "g" ((int)nr), "g" (arg0), "g" (arg1), "g" (arg2)
+		: "rax", "rdi", "rsi", "rdx", "memory");
+	return ret;
+}
+
 static always_inline long sys_nanosleep(struct timespec *req, struct timespec *rem)
 {
 	return syscall2(__NR_nanosleep, (unsigned long)req, (unsigned long)rem);
 }
 
+static always_inline long sys_write(unsigned long fd, const void *buf, unsigned long count)
+{
+	return syscall3(__NR_write, fd, (unsigned long)buf, count);
+}
+
 static void always_inline local_sleep(long seconds)
 {
 	struct timespec req, rem;
@@ -45,11 +68,13 @@ static void always_inline local_sleep(long seconds)
 	sys_nanosleep(&req, &rem);
 }
 
-
 int main(int argc, char *argv[])
 {
-	for (;;)
+	const char msg[] = "I'm alive\n";
+	for (;;) {
+		sys_write(1, msg, sizeof(msg));
 		local_sleep(5);
+	}
 
 	return 0;
 }