Update syscall.c to allow mmap and unmap system calls through helper handler functions for each

src/userprog/syscall.c

@@ -11,11 +11,13 @@
 #include "threads/synch.h"
 #include "userprog/process.h"
 #include "userprog/pagedir.h"
+#include "vm/mmap.h"
 #include <stdio.h>
 #include <syscall-nr.h>
 
 #define MAX_SYSCALL_ARGS 3
 #define EXIT_FAILURE -1
+#define MMAP_FAILURE -1
 
 struct open_file
   {
@@ -45,6 +47,8 @@ static int syscall_write (int fd, const void *buffer, unsigned size);
 static void syscall_seek (int fd, unsigned position);
 static unsigned syscall_tell (int fd);
 static void syscall_close (int fd);
+static mapid_t syscall_mmap (int fd, void *addr);
+static void syscall_munmap (mapid_t mapping);
 
 static struct open_file *fd_get_file (int fd);
 static void validate_user_pointer (const void *start, size_t size, bool write);
@@ -74,6 +78,8 @@ static const struct syscall_arguments syscall_lookup[] =
   [SYS_SEEK] = {(syscall_function) syscall_seek, 2},
   [SYS_TELL] = {(syscall_function) syscall_tell, 1},
   [SYS_CLOSE] = {(syscall_function) syscall_close, 1},
+  [SYS_MMAP] = {(syscall_function) syscall_mmap, 2},
+  [SYS_MUNMAP] = {(syscall_function) syscall_munmap, 1}
 };
 
 /* The number of syscall functions (i.e, number of elements) within the
@@ -394,6 +400,20 @@ syscall_close (int fd)
     }
 }
 
+/* Handles the syscall for memory mapping a file. */
+static mapid_t
+syscall_mmap (int fd, void *addr)
+{
+  return MMAP_FAILURE;
+}
+
+/* Handles the syscall for unmapping a memory mapped file. */
+static void
+syscall_munmap (mapid_t mapping UNUSED)
+{
+
+}
+
 /* Hashing function needed for the open_file table. Returns a hash for an entry,
    based on its FD. */
 unsigned