Stub out a few system calls

pk/syscall.c

@@ -451,6 +451,10 @@ long do_syscall(long a0, long a1, long a2, long a3, long a4, long a5, unsigned l
     [SYS_readlinkat] = sys_stub_nosys,
     [SYS_rt_sigprocmask] = sys_stub_success,
     [SYS_ioctl] = sys_stub_nosys,
+    [SYS_clock_gettime] = sys_stub_nosys,
+    [SYS_getrusage] = sys_stub_nosys,
+    [SYS_getrlimit] = sys_stub_nosys,
+    [SYS_setrlimit] = sys_stub_nosys,
   };
 
   const static void* old_syscall_table[] = {

pk/syscall.h

@@ -43,6 +43,10 @@
 #define SYS_readlinkat 78
 #define SYS_rt_sigprocmask 135
 #define SYS_ioctl 29
+#define SYS_getrlimit 163
+#define SYS_setrlimit 164
+#define SYS_getrusage 165
+#define SYS_clock_gettime 113
 
 #define OLD_SYSCALL_THRESHOLD 1024
 #define SYS_open 1024