[USER] Fork syscall

init/init.c

@@ -6,16 +6,16 @@ int main(int argc, char **argv)
   (void) argc;
   (void) argv;
 
-  char *a = malloc(0x100);
-  printf("Pointer: %p\n", a);
-  char *b = malloc(0x100);
-  printf("Pointer: %p\n", b);
-  char *c = malloc(0x10);
-  printf("Pointer: %p\n", c);
-  c[0] = 5;
-  free(a);
-  free(b);
-  free(c);
+  int num = 5;
+
+  if(fork())
+  {
+    num = 10;
+    printf("I am the parent! - %d\n", num);
+  } else {
+    num = 3;
+    printf("I am the child! - %d\n", num);
+  }
 
   for(;;);
   return 0;

kernel/include/syscall.h

@@ -42,3 +42,4 @@ typedef long (*syscall_handler_t)(long num, long, long, long, long, long, long);
 
 SYSCALL_DECL(write);
 SYSCALL_DECL(brk);
+SYSCALL_DECL(fork);

kernel/syscall/sys_proc.c

@@ -0,0 +1,27 @@
+#include <syscall.h>
+#include <process.h>
+#include <thread.h>
+#include <scheduler.h>
+#include <string.h>
+
+SYSCALL_DEF(fork)
+{
+  SYSCALL_INIT();
+
+  // Copy process and memory space
+  process_t *p = get_current_process();
+  process_t *new = process_spawn(p);
+
+  // Copy thread
+  thread_t *th = new_thread(0, 1);
+  memcpy(&th->r, &get_current_thread()->r, sizeof(registers_t));
+
+  // Make new thread return 0
+  th->r.rax = 0;
+  process_attach(new, th);
+  scheduler_insert(th);
+
+  // Return new pid
+  return new->pid;
+
+}

kernel/syscall/syscall.c

@@ -58,6 +58,7 @@ void syscall_init()
     SYSCALL_REGISTER(debug, SYS_DEBUG);
     SYSCALL_REGISTER(write, SYS_WRITE);
     SYSCALL_REGISTER(brk, SYS_BRK);
+    SYSCALL_REGISTER(fork, SYS_FORK);
   }
 
 }

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;
+}