X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fuserprog%2Faddrspace.c;h=f535badd1bac08e4fb07fee17ca49e3a05fddd5d;hb=04c55108f55f8a6f4a31a5085151bb729635ff8e;hp=6112484f25162a37cb6c38801297fbd0b9c29644;hpb=f2f8875638593bd5365cfd6a5ba7c9578e52322f;p=pintos-anon

diff --git a/src/userprog/addrspace.c b/src/userprog/addrspace.c
index 6112484..f535bad 100644
--- a/src/userprog/addrspace.c
+++ b/src/userprog/addrspace.c
@@ -4,12 +4,12 @@
 #include <round.h>
 #include <stdio.h>
 #include <string.h>
+#include "userprog/pagedir.h"
 #include "userprog/tss.h"
 #include "filesys/file.h"
 #include "filesys/filesys.h"
 #include "threads/init.h"
 #include "threads/mmu.h"
-#include "threads/paging.h"
 #include "threads/palloc.h"
 #include "threads/thread.h"
 
@@ -96,8 +96,7 @@ bool
 addrspace_load (struct thread *t, const char *filename, void (**start) (void)) 
 {
   struct Elf32_Ehdr ehdr;
-  struct file file;
-  bool file_open = false;
+  struct file *file = NULL;
   off_t file_ofs;
   bool success = false;
   int i;
@@ -108,12 +107,12 @@ addrspace_load (struct thread *t, const char *filename, void (**start) (void))
     LOAD_ERROR (("page directory allocation failed"));
 
   /* Open executable file. */
-  file_open = filesys_open (filename, &file);
-  if (!file_open)
+  file = filesys_open (filename);
+  if (file == NULL)
     LOAD_ERROR (("open failed"));
 
   /* Read and verify executable header. */
-  if (file_read (&file, &ehdr, sizeof ehdr) != sizeof ehdr) 
+  if (file_read (file, &ehdr, sizeof ehdr) != sizeof ehdr) 
     LOAD_ERROR (("error reading executable header"));
   if (memcmp (ehdr.e_ident, "\177ELF\1\1\1", 7) != 0)
     LOAD_ERROR (("file is not ELF"));
@@ -135,8 +134,8 @@ addrspace_load (struct thread *t, const char *filename, void (**start) (void))
     {
       struct Elf32_Phdr phdr;
 
-      file_seek (&file, file_ofs);
-      if (file_read (&file, &phdr, sizeof phdr) != sizeof phdr)
+      file_seek (file, file_ofs);
+      if (file_read (file, &phdr, sizeof phdr) != sizeof phdr)
         LOAD_ERROR (("error reading program header"));
       file_ofs += sizeof phdr;
       switch (phdr.p_type) 
@@ -157,7 +156,7 @@ addrspace_load (struct thread *t, const char *filename, void (**start) (void))
           printf ("unknown ELF segment type %08x\n", phdr.p_type);
           break;
         case PT_LOAD:
-          if (!load_segment (t, &file, &phdr))
+          if (!load_segment (t, file, &phdr))
             goto done;
           break;
         }
@@ -175,8 +174,7 @@ addrspace_load (struct thread *t, const char *filename, void (**start) (void))
  done:
   /* We arrive here whether the load is successful or not.
      We can distinguish based on `success'. */
-  if (file_open)
-    file_close (&file);
+  file_close (file);
   if (!success) 
     addrspace_destroy (t);
   return success;
@@ -223,6 +221,12 @@ load_segment (struct thread *t, struct file *file,
   off_t filesz_left;  /* Bytes left of file data (as opposed to
                          zero-initialized bytes). */
 
+  /* Is this a read-only segment?  Not currently used, so it's
+     commented out.  You'll want to use it when implementing VM
+     to decide whether to page the segment from its executable or
+     from swap. */
+  //bool read_only = (phdr->p_flags & PF_W) == 0;
+
   ASSERT (t != NULL);
   ASSERT (file != NULL);
   ASSERT (phdr != NULL);
@@ -268,7 +272,7 @@ load_segment (struct thread *t, struct file *file,
          file into the page and zero the rest. */
       size_t read_bytes = filesz_left >= PGSIZE ? PGSIZE : filesz_left;
       size_t zero_bytes = PGSIZE - read_bytes;
-      uint8_t *kpage = palloc_get (0);
+      uint8_t *kpage = palloc_get (PAL_USER);
       if (kpage == NULL)
         return false;
 
@@ -300,7 +304,7 @@ setup_stack (struct thread *t)
   uint8_t *kpage;
   bool success = false;
 
-  kpage = palloc_get (PAL_ZERO);
+  kpage = palloc_get (PAL_USER | PAL_ZERO);
   if (kpage != NULL) 
     {
       success = install_page (t, ((uint8_t *) PHYS_BASE) - PGSIZE, kpage);