From e11b2ef0c606ab516a4344aeea1dbba22cb1fe5d Mon Sep 17 00:00:00 2001
From: manuel <manuel@mausz.at>
Date: Thu, 21 Jun 2012 16:47:23 +0200
Subject: initial implementation of memory mapped files

---
 userprog/syscall.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 58 insertions(+), 4 deletions(-)

(limited to 'userprog/syscall.c')

diff --git a/userprog/syscall.c b/userprog/syscall.c
index 7f8c397..14cbaab 100644
--- a/userprog/syscall.c
+++ b/userprog/syscall.c
@@ -14,7 +14,8 @@
 #include "userprog/pagedir.h"
 #include "userprog/process.h"
 #include "userprog/syscall.h"
-#include "lib/user/syscall.h"
+#include "vm/mmap.h"
+#include "vm/page.h"
 
 #define STACK_SLOT_SIZE sizeof(int)
 
@@ -226,8 +227,8 @@ syscall_handler (struct intr_frame *f)
     goto fail;
   }
   syscall_sp = sp;
-	result = fp (sp, &segfault);
-	if (segfault)
+  result = fp (sp, &segfault);
+  if (segfault)
     goto fail;
   f->eax = result;
   return;
@@ -574,11 +575,64 @@ syscall_close (void *sp, bool *segfault)
 static int
 syscall_mmap (void *sp, bool *segfault)
 {
-  return 0;
+  int fd;
+  void *addr, *offset;
+  struct file *file, *file2;
+  off_t len;
+
+  /* get arguments */
+  if (! copy_from_user (&fd, STACK_ADDR (sp,1)) ||
+      ! copy_from_user (&addr, STACK_ADDR (sp, 2))) {
+    *segfault = true;
+    return -1;
+  }
+
+  /* address must be valid and page-aligned */
+  if (addr == NULL || pg_ofs (addr))
+    return -1;
+
+  /* file descriptors 0 and 1 are reserved */
+  if (fd == 0 || fd == 1)
+    return -1;
+
+  /* get file */
+  file = process_get_file (fd);
+  if (file == NULL)
+    return -1;
+
+  /* file length must be positiv */
+  len = file_length (file);
+  if (len <= 0)
+    return -1;
+
+  /* check if the pages don't overlap any existing pages */
+  offset = addr;
+  while(offset < addr + len)
+  {
+    if (page_table_fetch (&thread_current ()->page_table, offset))
+      return -1;
+    offset += PGSIZE;
+  }
+
+  process_lock_filesys ();
+  file2 = file_reopen (file);
+  process_unlock_filesys ();
+
+  return (file2 == NULL) ? -1 :
+    mmap_table_insert (&process_current()->mmap_table, addr, file2, len);
 }
 
 static int
 syscall_munmap (void *sp, bool *segfault)
 {
+  mapid_t mapping;
+
+  /* get arguments */
+  if (! copy_from_user (&mapping, STACK_ADDR (sp,1))) {
+    *segfault = true;
+    return 0;
+  }
+
+  mmap_table_remove (&process_current()->mmap_table, mapping);
   return 0;
 }
-- 
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