[USER] Fork syscall

libc/syscall_num.h

@@ -2,4 +2,5 @@
 
 #define SYS_WRITE 0x001
 #define SYS_BRK   0x002
+#define SYS_FORK  0x003
 #define SYS_DEBUG 0x3FF

libc/thread.c

@@ -1,4 +1,8 @@
 #include "syscalls.h"
+#include "syscall_num.h"
+#include <pthread.h>
+#include <signal.h>
+long kernel_syscall(int num, ...);
 
 struct pthread *__pt;
 
@@ -19,3 +23,22 @@ SYSCALL_DEF(set_tid_address)
   SYSCALL_INIT();
   return 0;
 }
+
+SYSCALL_DEF(rt_sigprocmask)
+{
+  SYSCALL_INIT(int, how, const sigset_t *, set, sigset_t *, oldset);
+
+  return 0;
+}
+
+SYSCALL_DEF(fork)
+{
+  SYSCALL_INIT();
+  return kernel_syscall(SYS_FORK);
+}
+
+SYSCALL_DEF(gettid)
+{
+  SYSCALL_INIT();
+  return 0;
+}