From ff076af15fa93292b8843e76bd6bab7ac5421095 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Tue, 7 Dec 2004 02:31:22 +0000
Subject: [PATCH] Initial file system tests.

---
 TODO                                |   5 +
 grading/filesys/.cvsignore          |  20 +
 grading/filesys/Make.progs          |  20 +
 grading/filesys/Makefile            |   9 +
 grading/filesys/create.inc          |  17 +
 grading/filesys/fslib.c             | 171 +++++++
 grading/filesys/fslib.h             |  22 +
 grading/filesys/full.inc            |  20 +
 grading/filesys/grow-create.c       |   3 +
 grading/filesys/grow-create.exp     |   5 +
 grading/filesys/grow-dir-lg.c       |   4 +
 grading/filesys/grow-dir-lg.exp     |  53 ++
 grading/filesys/grow-dir.inc        |  41 ++
 grading/filesys/grow-file-size.c    |  32 ++
 grading/filesys/grow-file-size.exp  |   9 +
 grading/filesys/grow-root-lg.c      |   3 +
 grading/filesys/grow-root-lg.exp    |  52 ++
 grading/filesys/grow-root-sm.c      |   3 +
 grading/filesys/grow-root-sm.exp    |  22 +
 grading/filesys/grow-seq-lg.c       |   3 +
 grading/filesys/grow-seq-lg.exp     |   8 +
 grading/filesys/grow-seq-sm.c       |   3 +
 grading/filesys/grow-seq-sm.exp     |   8 +
 grading/filesys/grow-seq.inc        |  20 +
 grading/filesys/grow-sparse.c       |  26 +
 grading/filesys/grow-sparse.exp     |   9 +
 grading/filesys/grow-tell.c         |  31 ++
 grading/filesys/grow-tell.exp       |   8 +
 grading/filesys/grow-two-files.c    |  60 +++
 grading/filesys/grow-two-files.exp  |  11 +
 grading/filesys/lib/.cvsignore      |   1 +
 grading/filesys/lib/user/.cvsignore |   1 +
 grading/filesys/panic.diff          |  20 +
 grading/filesys/random.inc          |  70 +++
 grading/filesys/run-tests           | 736 ++++++++++++++++++++++++++++
 grading/filesys/seq-block.inc       |  21 +
 grading/filesys/seq-random.inc      |  22 +
 grading/filesys/sm-create.c         |   3 +
 grading/filesys/sm-create.exp       |   5 +
 grading/filesys/sm-full.c           |   3 +
 grading/filesys/sm-full.exp         |   8 +
 grading/filesys/sm-random.c         |   4 +
 grading/filesys/sm-random.exp       |   6 +
 grading/filesys/sm-seq-block.c      |   4 +
 grading/filesys/sm-seq-block.exp    |   8 +
 grading/filesys/sm-seq-random.c     |   3 +
 grading/filesys/sm-seq-random.exp   |   8 +
 grading/filesys/tests.txt           |   2 +-
 grading/vm/Make.progs               |  16 +-
 grading/vm/arc4.c                   |  53 --
 grading/vm/arc4.h                   |  18 -
 grading/vm/child-linear.c           |   2 +-
 grading/vm/cksum.c                  |  86 ----
 grading/vm/cksum.h                  |   8 -
 grading/vm/mmap-close.c             |   2 +-
 grading/vm/mmap-shuffle.c           |   4 +-
 grading/vm/page-linear.c            |   2 +-
 grading/vm/page-merge-par.c         |   2 +-
 grading/vm/page-merge-seq.c         |   2 +-
 grading/vm/page-shuffle.c           |   4 +-
 grading/vm/pt-big-stk-obj.c         |   4 +-
 grading/vm/pt-grow-stack.c          |   4 +-
 62 files changed, 1643 insertions(+), 187 deletions(-)
 create mode 100644 grading/filesys/.cvsignore
 create mode 100644 grading/filesys/Make.progs
 create mode 100644 grading/filesys/Makefile
 create mode 100644 grading/filesys/create.inc
 create mode 100644 grading/filesys/fslib.c
 create mode 100644 grading/filesys/fslib.h
 create mode 100644 grading/filesys/full.inc
 create mode 100644 grading/filesys/grow-create.c
 create mode 100644 grading/filesys/grow-create.exp
 create mode 100644 grading/filesys/grow-dir-lg.c
 create mode 100644 grading/filesys/grow-dir-lg.exp
 create mode 100644 grading/filesys/grow-dir.inc
 create mode 100644 grading/filesys/grow-file-size.c
 create mode 100644 grading/filesys/grow-file-size.exp
 create mode 100644 grading/filesys/grow-root-lg.c
 create mode 100644 grading/filesys/grow-root-lg.exp
 create mode 100644 grading/filesys/grow-root-sm.c
 create mode 100644 grading/filesys/grow-root-sm.exp
 create mode 100644 grading/filesys/grow-seq-lg.c
 create mode 100644 grading/filesys/grow-seq-lg.exp
 create mode 100644 grading/filesys/grow-seq-sm.c
 create mode 100644 grading/filesys/grow-seq-sm.exp
 create mode 100644 grading/filesys/grow-seq.inc
 create mode 100644 grading/filesys/grow-sparse.c
 create mode 100644 grading/filesys/grow-sparse.exp
 create mode 100644 grading/filesys/grow-tell.c
 create mode 100644 grading/filesys/grow-tell.exp
 create mode 100644 grading/filesys/grow-two-files.c
 create mode 100644 grading/filesys/grow-two-files.exp
 create mode 100644 grading/filesys/lib/.cvsignore
 create mode 100644 grading/filesys/lib/user/.cvsignore
 create mode 100644 grading/filesys/panic.diff
 create mode 100644 grading/filesys/random.inc
 create mode 100755 grading/filesys/run-tests
 create mode 100644 grading/filesys/seq-block.inc
 create mode 100644 grading/filesys/seq-random.inc
 create mode 100644 grading/filesys/sm-create.c
 create mode 100644 grading/filesys/sm-create.exp
 create mode 100644 grading/filesys/sm-full.c
 create mode 100644 grading/filesys/sm-full.exp
 create mode 100644 grading/filesys/sm-random.c
 create mode 100644 grading/filesys/sm-random.exp
 create mode 100644 grading/filesys/sm-seq-block.c
 create mode 100644 grading/filesys/sm-seq-block.exp
 create mode 100644 grading/filesys/sm-seq-random.c
 create mode 100644 grading/filesys/sm-seq-random.exp
 delete mode 100644 grading/vm/arc4.c
 delete mode 100644 grading/vm/arc4.h
 delete mode 100644 grading/vm/cksum.c
 delete mode 100644 grading/vm/cksum.h

diff --git a/TODO b/TODO
index 9dc05ca..30f3246 100644
--- a/TODO
+++ b/TODO
@@ -23,3 +23,8 @@
   them?
 
 * Speed up disk routines: filling an 8 MB disk takes a long time.
+
+* Not sure that raw arc4 should really be used so much in the tests.
+  Any reason not to use random_bytes()?
+
+* Grading script patches needed anymore?
diff --git a/grading/filesys/.cvsignore b/grading/filesys/.cvsignore
new file mode 100644
index 0000000..936cf61
--- /dev/null
+++ b/grading/filesys/.cvsignore
@@ -0,0 +1,20 @@
+*.d
+*.dsk
+*.o
+bochsout.txt
+bochsrc.txt
+sm-create
+sm-full
+sm-seq-block
+sm-seq-random
+sm-random
+grow-create
+grow-seq-sm
+grow-seq-lg
+grow-file-size
+grow-tell
+grow-sparse
+grow-root-sm
+grow-root-lg
+grow-dir-lg
+grow-two-files
diff --git a/grading/filesys/Make.progs b/grading/filesys/Make.progs
new file mode 100644
index 0000000..08fed39
--- /dev/null
+++ b/grading/filesys/Make.progs
@@ -0,0 +1,20 @@
+PROGS = sm-create sm-full sm-seq-block sm-seq-random sm-random \
+	grow-create grow-seq-sm grow-seq-lg grow-file-size grow-tell \
+	grow-sparse grow-root-sm grow-root-lg grow-dir-lg grow-two-files
+
+sm_create_SRC = sm-create.c fslib.c ../lib/arc4.c
+sm_full_SRC = sm-full.c fslib.c ../lib/arc4.c
+sm_seq_block_SRC = sm-seq-block.c fslib.c ../lib/arc4.c
+sm_seq_random_SRC = sm-seq-random.c fslib.c ../lib/arc4.c
+sm_random_SRC = sm-random.c fslib.c ../lib/arc4.c
+
+grow_create_SRC = grow-create.c fslib.c ../lib/arc4.c
+grow_seq_sm_SRC = grow-seq-sm.c fslib.c ../lib/arc4.c
+grow_seq_lg_SRC = grow-seq-lg.c fslib.c ../lib/arc4.c
+grow_file_size_SRC = grow-file-size.c fslib.c ../lib/arc4.c
+grow_tell_SRC = grow-tell.c fslib.c ../lib/arc4.c
+grow_sparse_SRC = grow-sparse.c fslib.c ../lib/arc4.c
+grow_root_sm_SRC = grow-root-sm.c fslib.c ../lib/arc4.c
+grow_root_lg_SRC = grow-root-lg.c fslib.c ../lib/arc4.c
+grow_dir_lg_SRC = grow-dir-lg.c fslib.c ../lib/arc4.c
+grow_two_files_SRC = grow-two-files.c fslib.c ../lib/arc4.c
diff --git a/grading/filesys/Makefile b/grading/filesys/Makefile
new file mode 100644
index 0000000..05e4d90
--- /dev/null
+++ b/grading/filesys/Makefile
@@ -0,0 +1,9 @@
+include Make.progs
+
+SRCDIR = ../../src
+
+all: $(PROGS)
+
+include $(SRCDIR)/Makefile.userprog
+
+CFLAGS += -Werror
diff --git a/grading/filesys/create.inc b/grading/filesys/create.inc
new file mode 100644
index 0000000..d378fe3
--- /dev/null
+++ b/grading/filesys/create.inc
@@ -0,0 +1,17 @@
+/* -*- c -*- */
+
+#include <stdio.h>
+#include <syscall.h>
+#include "fslib.h"
+
+static char buf[TEST_SIZE];
+
+int
+main (void) 
+{
+  msg ("begin");
+  check (create ("testfile", TEST_SIZE), "create testfile");
+  check_file ("testfile", buf, TEST_SIZE);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/fslib.c b/grading/filesys/fslib.c
new file mode 100644
index 0000000..36f67f8
--- /dev/null
+++ b/grading/filesys/fslib.c
@@ -0,0 +1,171 @@
+#include "fslib.h"
+#include <random.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <syscall.h>
+#include "../lib/arc4.h"
+
+bool quiet = false;
+
+static void
+vmsg (const char *format, va_list args, bool failure) 
+{
+  if (quiet && !failure)
+    return;
+  
+  printf ("(%s) ", test_name);
+  vprintf (format, args);
+  if (failure)
+    printf (": FAILED");
+  printf ("\n");
+}
+
+void
+msg (const char *format, ...) 
+{
+  va_list args;
+
+  va_start (args, format);
+  vmsg (format, args, false);
+  va_end (args);
+}
+
+void
+fail (const char *format, ...) 
+{
+  va_list args;
+
+  quiet = false;
+  
+  va_start (args, format);
+  vmsg (format, args, true);
+  va_end (args);
+
+  exit (1);
+}
+
+void
+check (bool success, const char *format, ...) 
+{
+  va_list args;
+
+  va_start (args, format);
+  if (success) 
+    {
+      if (!quiet)
+        vmsg (format, args, false); 
+    }
+  else 
+    {
+      vmsg (format, args, true);
+      exit (1);
+    }
+  va_end (args);
+}
+
+void 
+seq_test (const char *filename, void *buf, size_t size,
+          size_t initial_size, int seed,
+          size_t (*block_size_func) (void),
+          void (*check_func) (int fd, long ofs)) 
+{
+  static struct arc4 arc4;
+  size_t ofs;
+  int fd;
+  
+  arc4_init (&arc4, &seed, sizeof seed);
+  arc4_crypt (&arc4, buf, size);
+
+  check (create (filename, initial_size), "create \"%s\"", filename);
+  check ((fd = open (filename)) > 1, "open \"%s\"", filename);
+
+  ofs = 0;
+  msg ("writing \"%s\"", filename);
+  while (ofs < size) 
+    {
+      size_t block_size = block_size_func ();
+      if (block_size > size - ofs)
+        block_size = size - ofs;
+
+      if (write (fd, buf + ofs, block_size) <= 0)
+        fail ("write %zu bytes at offset %zu in \"%s\" failed",
+              block_size, ofs, filename);
+
+      ofs += block_size;
+      if (check_func != NULL)
+        check_func (fd, ofs);
+    }
+  msg ("close \"%s\"", filename);
+  close (fd);
+  check_file (filename, buf, size);
+}
+
+static void
+swap (void *a_, void *b_, size_t size) 
+{
+  uint8_t *a = a_;
+  uint8_t *b = b_;
+  size_t i;
+
+  for (i = 0; i < size; i++) 
+    {
+      uint8_t t = a[i];
+      a[i] = b[i];
+      b[i] = t;
+    }
+}
+
+void
+shuffle (void *buf_, size_t cnt, size_t size) 
+{
+  char *buf = buf_;
+  size_t i;
+
+  for (i = 0; i < cnt; i++)
+    {
+      size_t j = i + random_ulong () % (cnt - i);
+      swap (buf + i * size, buf + j * size, size);
+    }
+}
+
+void
+check_file (const char *filename, const void *buf_, size_t size) 
+{
+  const char *buf = buf_;
+  size_t ofs;
+  char block[512];
+  int fd;
+
+  check ((fd = open (filename)) > 1, "open \"%s\" for verification", filename);
+
+  ofs = 0;
+  while (ofs < size)
+    {
+      size_t block_size = size - ofs;
+      if (block_size > sizeof block)
+        block_size = sizeof block;
+
+      if (read (fd, block, block_size) <= 0)
+        fail ("read %zu bytes at offset %zu in \"%s\" failed",
+              block_size, ofs, filename);
+
+      if (memcmp (buf + ofs, block, block_size))
+        {
+          if (block_size <= 512) 
+            {
+              printf ("Expected data:\n");
+              hex_dump (ofs, buf + ofs, block_size, false);
+              printf ("Actually read data:\n");
+              hex_dump (ofs, block, block_size, false); 
+            }
+          fail ("%zu bytes at offset %zu differed from expected",
+                block_size, ofs);
+        }
+
+      ofs += block_size;
+    }
+
+  msg ("close \"%s\"", filename);
+  close (fd);
+}
diff --git a/grading/filesys/fslib.h b/grading/filesys/fslib.h
new file mode 100644
index 0000000..b157598
--- /dev/null
+++ b/grading/filesys/fslib.h
@@ -0,0 +1,22 @@
+#ifndef FSLIB_H
+#define FSLIB_H
+
+#include <debug.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+extern const char test_name[];
+extern bool quiet;
+
+void msg (const char *, ...) PRINTF_FORMAT (1, 2);
+void fail (const char *, ...) PRINTF_FORMAT (1, 2) NO_RETURN;
+void check (bool, const char *, ...) PRINTF_FORMAT (2, 3);
+
+void shuffle (void *, size_t cnt, size_t size);
+void seq_test (const char *filename,
+               void *buffer, size_t size,
+               size_t initial_size, int seed,
+               size_t (*block_size) (void), void (*check) (int fd, long ofs));
+void check_file (const char *filename, const void *buf, size_t filesize);
+
+#endif /* fslib.h */
diff --git a/grading/filesys/full.inc b/grading/filesys/full.inc
new file mode 100644
index 0000000..32b7c8f
--- /dev/null
+++ b/grading/filesys/full.inc
@@ -0,0 +1,20 @@
+/* -*- c -*- */
+
+#include "fslib.h"
+
+static char buf[TEST_SIZE];
+
+static size_t
+return_test_size (void) 
+{
+  return TEST_SIZE;
+}
+
+int
+main (void) 
+{
+  msg ("begin");
+  seq_test ("quux", buf, sizeof buf, sizeof buf, 2, return_test_size, NULL);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/grow-create.c b/grading/filesys/grow-create.c
new file mode 100644
index 0000000..ba6a40d
--- /dev/null
+++ b/grading/filesys/grow-create.c
@@ -0,0 +1,3 @@
+const char test_name[] = "grow-create";
+#define TEST_SIZE 0
+#include "create.inc"
diff --git a/grading/filesys/grow-create.exp b/grading/filesys/grow-create.exp
new file mode 100644
index 0000000..0bfb05f
--- /dev/null
+++ b/grading/filesys/grow-create.exp
@@ -0,0 +1,5 @@
+(grow-create) begin
+(grow-create) create testfile
+(grow-create) open "testfile" for verification
+(grow-create) close "testfile"
+(grow-create) end
diff --git a/grading/filesys/grow-dir-lg.c b/grading/filesys/grow-dir-lg.c
new file mode 100644
index 0000000..b68ccee
--- /dev/null
+++ b/grading/filesys/grow-dir-lg.c
@@ -0,0 +1,4 @@
+const char test_name[] = "grow-dir-lg";
+#define FILE_CNT 50
+#define DIRECTORY "/x"
+#include "grow-dir.inc"
diff --git a/grading/filesys/grow-dir-lg.exp b/grading/filesys/grow-dir-lg.exp
new file mode 100644
index 0000000..f83f326
--- /dev/null
+++ b/grading/filesys/grow-dir-lg.exp
@@ -0,0 +1,53 @@
+(grow-dir-lg) begin
+(grow-dir-lg) mkdir /x
+(grow-dir-lg) creating and checking "/x/file0"
+(grow-dir-lg) creating and checking "/x/file1"
+(grow-dir-lg) creating and checking "/x/file2"
+(grow-dir-lg) creating and checking "/x/file3"
+(grow-dir-lg) creating and checking "/x/file4"
+(grow-dir-lg) creating and checking "/x/file5"
+(grow-dir-lg) creating and checking "/x/file6"
+(grow-dir-lg) creating and checking "/x/file7"
+(grow-dir-lg) creating and checking "/x/file8"
+(grow-dir-lg) creating and checking "/x/file9"
+(grow-dir-lg) creating and checking "/x/file10"
+(grow-dir-lg) creating and checking "/x/file11"
+(grow-dir-lg) creating and checking "/x/file12"
+(grow-dir-lg) creating and checking "/x/file13"
+(grow-dir-lg) creating and checking "/x/file14"
+(grow-dir-lg) creating and checking "/x/file15"
+(grow-dir-lg) creating and checking "/x/file16"
+(grow-dir-lg) creating and checking "/x/file17"
+(grow-dir-lg) creating and checking "/x/file18"
+(grow-dir-lg) creating and checking "/x/file19"
+(grow-dir-lg) creating and checking "/x/file20"
+(grow-dir-lg) creating and checking "/x/file21"
+(grow-dir-lg) creating and checking "/x/file22"
+(grow-dir-lg) creating and checking "/x/file23"
+(grow-dir-lg) creating and checking "/x/file24"
+(grow-dir-lg) creating and checking "/x/file25"
+(grow-dir-lg) creating and checking "/x/file26"
+(grow-dir-lg) creating and checking "/x/file27"
+(grow-dir-lg) creating and checking "/x/file28"
+(grow-dir-lg) creating and checking "/x/file29"
+(grow-dir-lg) creating and checking "/x/file30"
+(grow-dir-lg) creating and checking "/x/file31"
+(grow-dir-lg) creating and checking "/x/file32"
+(grow-dir-lg) creating and checking "/x/file33"
+(grow-dir-lg) creating and checking "/x/file34"
+(grow-dir-lg) creating and checking "/x/file35"
+(grow-dir-lg) creating and checking "/x/file36"
+(grow-dir-lg) creating and checking "/x/file37"
+(grow-dir-lg) creating and checking "/x/file38"
+(grow-dir-lg) creating and checking "/x/file39"
+(grow-dir-lg) creating and checking "/x/file40"
+(grow-dir-lg) creating and checking "/x/file41"
+(grow-dir-lg) creating and checking "/x/file42"
+(grow-dir-lg) creating and checking "/x/file43"
+(grow-dir-lg) creating and checking "/x/file44"
+(grow-dir-lg) creating and checking "/x/file45"
+(grow-dir-lg) creating and checking "/x/file46"
+(grow-dir-lg) creating and checking "/x/file47"
+(grow-dir-lg) creating and checking "/x/file48"
+(grow-dir-lg) creating and checking "/x/file49"
+(grow-dir-lg) end
diff --git a/grading/filesys/grow-dir.inc b/grading/filesys/grow-dir.inc
new file mode 100644
index 0000000..df3cbdf
--- /dev/null
+++ b/grading/filesys/grow-dir.inc
@@ -0,0 +1,41 @@
+/* -*- c -*- */
+
+#include <syscall.h>
+#include <stdio.h>
+#include "fslib.h"
+
+static char buf[512];
+
+static size_t
+return_block_size (void) 
+{
+  return sizeof buf;
+}
+
+int
+main (void) 
+{
+  size_t i;
+  
+  msg ("begin");
+#ifdef DIRECTORY
+  check (mkdir (DIRECTORY), "mkdir %s", DIRECTORY);
+#define DIR_PREFIX DIRECTORY "/"
+#else
+#define DIR_PREFIX ""
+#endif
+  for (i = 0; i < FILE_CNT; i++) 
+    {
+      char filename[128];
+      snprintf (filename, sizeof filename, "%sfile%zu", DIR_PREFIX, i);
+
+      msg ("creating and checking \"%s\"", filename);
+
+      quiet = true;
+      seq_test (filename, buf, sizeof buf, sizeof buf, 0,
+                return_block_size, NULL); 
+      quiet = false;
+    }
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/grow-file-size.c b/grading/filesys/grow-file-size.c
new file mode 100644
index 0000000..b92ec5b
--- /dev/null
+++ b/grading/filesys/grow-file-size.c
@@ -0,0 +1,32 @@
+/* -*- c -*- */
+
+#include <syscall.h>
+#include "fslib.h"
+
+const char test_name[] = "grow-file-size";
+static char buf[2134];
+
+static size_t
+return_block_size (void) 
+{
+  return 37;
+}
+
+static void
+check_file_size (int fd, long ofs) 
+{
+  long size = filesize (fd);
+  if (size != ofs)
+    fail ("filesize not updated properly: should be %ld, actually %ld",
+          ofs, size);
+}
+
+int
+main (void) 
+{
+  msg ("begin");
+  seq_test ("testfile", buf, sizeof buf, 0, 0,
+            return_block_size, check_file_size);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/grow-file-size.exp b/grading/filesys/grow-file-size.exp
new file mode 100644
index 0000000..fcb5ce4
--- /dev/null
+++ b/grading/filesys/grow-file-size.exp
@@ -0,0 +1,9 @@
+(grow-file-size) begin
+(grow-file-size) create "testfile"
+(grow-file-size) open "testfile"
+(grow-file-size) writing "testfile"
+(grow-file-size) close "testfile"
+(grow-file-size) open "testfile" for verification
+(grow-file-size) close "testfile"
+(grow-file-size) end
+
diff --git a/grading/filesys/grow-root-lg.c b/grading/filesys/grow-root-lg.c
new file mode 100644
index 0000000..537a7e3
--- /dev/null
+++ b/grading/filesys/grow-root-lg.c
@@ -0,0 +1,3 @@
+const char test_name[] = "grow-root-lg";
+#define FILE_CNT 50
+#include "grow-dir.inc"
diff --git a/grading/filesys/grow-root-lg.exp b/grading/filesys/grow-root-lg.exp
new file mode 100644
index 0000000..9736808
--- /dev/null
+++ b/grading/filesys/grow-root-lg.exp
@@ -0,0 +1,52 @@
+(grow-root-lg) begin
+(grow-root-lg) creating and checking "file0"
+(grow-root-lg) creating and checking "file1"
+(grow-root-lg) creating and checking "file2"
+(grow-root-lg) creating and checking "file3"
+(grow-root-lg) creating and checking "file4"
+(grow-root-lg) creating and checking "file5"
+(grow-root-lg) creating and checking "file6"
+(grow-root-lg) creating and checking "file7"
+(grow-root-lg) creating and checking "file8"
+(grow-root-lg) creating and checking "file9"
+(grow-root-lg) creating and checking "file10"
+(grow-root-lg) creating and checking "file11"
+(grow-root-lg) creating and checking "file12"
+(grow-root-lg) creating and checking "file13"
+(grow-root-lg) creating and checking "file14"
+(grow-root-lg) creating and checking "file15"
+(grow-root-lg) creating and checking "file16"
+(grow-root-lg) creating and checking "file17"
+(grow-root-lg) creating and checking "file18"
+(grow-root-lg) creating and checking "file19"
+(grow-root-lg) creating and checking "file20"
+(grow-root-lg) creating and checking "file21"
+(grow-root-lg) creating and checking "file22"
+(grow-root-lg) creating and checking "file23"
+(grow-root-lg) creating and checking "file24"
+(grow-root-lg) creating and checking "file25"
+(grow-root-lg) creating and checking "file26"
+(grow-root-lg) creating and checking "file27"
+(grow-root-lg) creating and checking "file28"
+(grow-root-lg) creating and checking "file29"
+(grow-root-lg) creating and checking "file30"
+(grow-root-lg) creating and checking "file31"
+(grow-root-lg) creating and checking "file32"
+(grow-root-lg) creating and checking "file33"
+(grow-root-lg) creating and checking "file34"
+(grow-root-lg) creating and checking "file35"
+(grow-root-lg) creating and checking "file36"
+(grow-root-lg) creating and checking "file37"
+(grow-root-lg) creating and checking "file38"
+(grow-root-lg) creating and checking "file39"
+(grow-root-lg) creating and checking "file40"
+(grow-root-lg) creating and checking "file41"
+(grow-root-lg) creating and checking "file42"
+(grow-root-lg) creating and checking "file43"
+(grow-root-lg) creating and checking "file44"
+(grow-root-lg) creating and checking "file45"
+(grow-root-lg) creating and checking "file46"
+(grow-root-lg) creating and checking "file47"
+(grow-root-lg) creating and checking "file48"
+(grow-root-lg) creating and checking "file49"
+(grow-root-lg) end
diff --git a/grading/filesys/grow-root-sm.c b/grading/filesys/grow-root-sm.c
new file mode 100644
index 0000000..30685eb
--- /dev/null
+++ b/grading/filesys/grow-root-sm.c
@@ -0,0 +1,3 @@
+const char test_name[] = "grow-root-sm";
+#define FILE_CNT 20
+#include "grow-dir.inc"
diff --git a/grading/filesys/grow-root-sm.exp b/grading/filesys/grow-root-sm.exp
new file mode 100644
index 0000000..c9f4bd5
--- /dev/null
+++ b/grading/filesys/grow-root-sm.exp
@@ -0,0 +1,22 @@
+(grow-root-sm) begin
+(grow-root-sm) creating and checking "file0"
+(grow-root-sm) creating and checking "file1"
+(grow-root-sm) creating and checking "file2"
+(grow-root-sm) creating and checking "file3"
+(grow-root-sm) creating and checking "file4"
+(grow-root-sm) creating and checking "file5"
+(grow-root-sm) creating and checking "file6"
+(grow-root-sm) creating and checking "file7"
+(grow-root-sm) creating and checking "file8"
+(grow-root-sm) creating and checking "file9"
+(grow-root-sm) creating and checking "file10"
+(grow-root-sm) creating and checking "file11"
+(grow-root-sm) creating and checking "file12"
+(grow-root-sm) creating and checking "file13"
+(grow-root-sm) creating and checking "file14"
+(grow-root-sm) creating and checking "file15"
+(grow-root-sm) creating and checking "file16"
+(grow-root-sm) creating and checking "file17"
+(grow-root-sm) creating and checking "file18"
+(grow-root-sm) creating and checking "file19"
+(grow-root-sm) end
diff --git a/grading/filesys/grow-seq-lg.c b/grading/filesys/grow-seq-lg.c
new file mode 100644
index 0000000..9cd7c74
--- /dev/null
+++ b/grading/filesys/grow-seq-lg.c
@@ -0,0 +1,3 @@
+const char test_name[] = "grow-seq-lg";
+#define TEST_SIZE 72943
+#include "grow-seq.inc"
diff --git a/grading/filesys/grow-seq-lg.exp b/grading/filesys/grow-seq-lg.exp
new file mode 100644
index 0000000..36953cb
--- /dev/null
+++ b/grading/filesys/grow-seq-lg.exp
@@ -0,0 +1,8 @@
+(grow-seq-lg) begin
+(grow-seq-lg) create "testme"
+(grow-seq-lg) open "testme"
+(grow-seq-lg) writing "testme"
+(grow-seq-lg) close "testme"
+(grow-seq-lg) open "testme" for verification
+(grow-seq-lg) close "testme"
+(grow-seq-lg) end
diff --git a/grading/filesys/grow-seq-sm.c b/grading/filesys/grow-seq-sm.c
new file mode 100644
index 0000000..a99fa0c
--- /dev/null
+++ b/grading/filesys/grow-seq-sm.c
@@ -0,0 +1,3 @@
+const char test_name[] = "grow-seq-sm";
+#define TEST_SIZE 5678
+#include "grow-seq.inc"
diff --git a/grading/filesys/grow-seq-sm.exp b/grading/filesys/grow-seq-sm.exp
new file mode 100644
index 0000000..8fb12e5
--- /dev/null
+++ b/grading/filesys/grow-seq-sm.exp
@@ -0,0 +1,8 @@
+(grow-seq-sm) begin
+(grow-seq-sm) create "testme"
+(grow-seq-sm) open "testme"
+(grow-seq-sm) writing "testme"
+(grow-seq-sm) close "testme"
+(grow-seq-sm) open "testme" for verification
+(grow-seq-sm) close "testme"
+(grow-seq-sm) end
diff --git a/grading/filesys/grow-seq.inc b/grading/filesys/grow-seq.inc
new file mode 100644
index 0000000..2c0e3ba
--- /dev/null
+++ b/grading/filesys/grow-seq.inc
@@ -0,0 +1,20 @@
+/* -*- c -*- */
+
+#include "fslib.h"
+
+static char buf[TEST_SIZE];
+
+static size_t
+return_block_size (void) 
+{
+  return 1234;
+}
+
+int
+main (void) 
+{
+  msg ("begin");
+  seq_test ("testme", buf, sizeof buf, 0, 3, return_block_size, NULL);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/grow-sparse.c b/grading/filesys/grow-sparse.c
new file mode 100644
index 0000000..6180828
--- /dev/null
+++ b/grading/filesys/grow-sparse.c
@@ -0,0 +1,26 @@
+/* -*- c -*- */
+
+#include <syscall.h>
+#include "fslib.h"
+
+const char test_name[] = "grow-sparse";
+static char buf[76543];
+
+int
+main (void) 
+{
+  char zero = 0;
+  int fd;
+  
+  msg ("begin");
+  check (create ("testfile", 0), "create \"testfile\"");
+  check ((fd = open ("testfile")) > 1, "open \"testfile\"");
+  msg ("seek \"testfile\"");
+  seek (fd, sizeof buf - 1);
+  check (write (fd, &zero, 1) > 0, "write \"testfile\"");
+  msg ("close \"testfile\"");
+  close (fd);
+  check_file ("testfile", buf, sizeof buf);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/grow-sparse.exp b/grading/filesys/grow-sparse.exp
new file mode 100644
index 0000000..c7cd00c
--- /dev/null
+++ b/grading/filesys/grow-sparse.exp
@@ -0,0 +1,9 @@
+(grow-sparse) begin
+(grow-sparse) create "testfile"
+(grow-sparse) open "testfile"
+(grow-sparse) seek "testfile"
+(grow-sparse) write "testfile"
+(grow-sparse) close "testfile"
+(grow-sparse) open "testfile" for verification
+(grow-sparse) close "testfile"
+(grow-sparse) end
diff --git a/grading/filesys/grow-tell.c b/grading/filesys/grow-tell.c
new file mode 100644
index 0000000..4f9d517
--- /dev/null
+++ b/grading/filesys/grow-tell.c
@@ -0,0 +1,31 @@
+/* -*- c -*- */
+
+#include <syscall.h>
+#include "fslib.h"
+
+const char test_name[] = "grow-tell";
+static char buf[2134];
+
+static size_t
+return_block_size (void) 
+{
+  return 37;
+}
+
+static void
+check_tell (int fd, long ofs) 
+{
+  long pos = tell (fd);
+  if (pos != ofs)
+    fail ("file position not updated properly: should be %ld, actually %ld",
+          ofs, pos);
+}
+
+int
+main (void) 
+{
+  msg ("begin");
+  seq_test ("foobar", buf, sizeof buf, 0, 1, return_block_size, check_tell);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/grow-tell.exp b/grading/filesys/grow-tell.exp
new file mode 100644
index 0000000..e7788f9
--- /dev/null
+++ b/grading/filesys/grow-tell.exp
@@ -0,0 +1,8 @@
+(grow-tell) begin
+(grow-tell) create "foobar"
+(grow-tell) open "foobar"
+(grow-tell) writing "foobar"
+(grow-tell) close "foobar"
+(grow-tell) open "foobar" for verification
+(grow-tell) close "foobar"
+(grow-tell) end
diff --git a/grading/filesys/grow-two-files.c b/grading/filesys/grow-two-files.c
new file mode 100644
index 0000000..8809c60
--- /dev/null
+++ b/grading/filesys/grow-two-files.c
@@ -0,0 +1,60 @@
+#include <random.h>
+#include <syscall.h>
+#include "fslib.h"
+
+const char test_name[] = "grow-two-files";
+
+#define FILE_SIZE 8143
+static char buf_a[FILE_SIZE];
+static char buf_b[FILE_SIZE];
+
+static void
+write_some_bytes (const char *filename, int fd, const char *buf, size_t *ofs) 
+{
+  if (*ofs < FILE_SIZE) 
+    {
+      size_t block_size = random_ulong () % (FILE_SIZE / 8) + 1;
+      if (block_size > FILE_SIZE - *ofs)
+        block_size = FILE_SIZE - *ofs;
+  
+      if (write (fd, buf + *ofs, block_size) <= 0)
+        fail ("write %zu bytes at offset %zu in \"%s\"",
+              block_size, *ofs, filename);
+      *ofs += block_size;
+    }
+}
+
+int
+main (void) 
+{
+  int fd_a, fd_b;
+  size_t ofs_a, ofs_b;
+
+  random_init (0);
+  random_bytes (buf_a, sizeof buf_a);
+  random_bytes (buf_b, sizeof buf_b);
+
+  check (create ("a", 0), "create \"a\"");
+  check (create ("b", 0), "create \"b\"");
+
+  check ((fd_a = open ("a")) > 1, "open \"a\"");
+  check ((fd_b = open ("b")) > 1, "open \"b\"");
+
+  msg ("write \"a\" and \"b\" alternately");
+  while (ofs_a < FILE_SIZE || ofs_b < FILE_SIZE) 
+    {
+      write_some_bytes ("a", fd_a, buf_a, &ofs_a);
+      write_some_bytes ("b", fd_b, buf_b, &ofs_b);
+    }
+
+  msg ("close \"a\"");
+  close (fd_a);
+
+  msg ("close \"b\"");
+  close (fd_b);
+
+  check_file ("a", buf_a, FILE_SIZE);
+  check_file ("b", buf_b, FILE_SIZE);
+
+  return 0;
+}
diff --git a/grading/filesys/grow-two-files.exp b/grading/filesys/grow-two-files.exp
new file mode 100644
index 0000000..affa63a
--- /dev/null
+++ b/grading/filesys/grow-two-files.exp
@@ -0,0 +1,11 @@
+(grow-two-files) create "a"
+(grow-two-files) create "b"
+(grow-two-files) open "a"
+(grow-two-files) open "b"
+(grow-two-files) write "a" and "b" alternately
+(grow-two-files) close "a"
+(grow-two-files) close "b"
+(grow-two-files) open "a" for verification
+(grow-two-files) close "a"
+(grow-two-files) open "b" for verification
+(grow-two-files) close "b"
diff --git a/grading/filesys/lib/.cvsignore b/grading/filesys/lib/.cvsignore
new file mode 100644
index 0000000..a438335
--- /dev/null
+++ b/grading/filesys/lib/.cvsignore
@@ -0,0 +1 @@
+*.d
diff --git a/grading/filesys/lib/user/.cvsignore b/grading/filesys/lib/user/.cvsignore
new file mode 100644
index 0000000..a438335
--- /dev/null
+++ b/grading/filesys/lib/user/.cvsignore
@@ -0,0 +1 @@
+*.d
diff --git a/grading/filesys/panic.diff b/grading/filesys/panic.diff
new file mode 100644
index 0000000..6134d47
--- /dev/null
+++ b/grading/filesys/panic.diff
@@ -0,0 +1,20 @@
+diff -up /home/blp/cs140/pintos/src/lib/debug.c.\~1.8.\~ /home/blp/cs140/pintos/src/lib/debug.c
+--- /home/blp/cs140/pintos/src/lib/debug.c.~1.8.~	2004-09-12 13:14:11.000000000 -0700
++++ /home/blp/cs140/pintos/src/lib/debug.c	2004-10-17 00:02:32.000000000 -0700
+@@ -5,6 +5,7 @@
+ #include <stdio.h>
+ #include <string.h>
+ #ifdef KERNEL
++#include "threads/init.h"
+ #include "threads/interrupt.h"
+ #include "devices/serial.h"
+ #else
+@@ -83,7 +84,7 @@ debug_panic (const char *file, int line,
+ 
+ #ifdef KERNEL
+   serial_flush ();
+-  for (;;);
++  power_off ();
+ #else
+   exit (1);
+ #endif
diff --git a/grading/filesys/random.inc b/grading/filesys/random.inc
new file mode 100644
index 0000000..e821a59
--- /dev/null
+++ b/grading/filesys/random.inc
@@ -0,0 +1,70 @@
+/* -*- c -*- */
+
+#include <random.h>
+#include <stdio.h>
+#include <string.h>
+#include <syscall.h>
+#include "fslib.h"
+
+#if TEST_SIZE % BLOCK_SIZE != 0
+#error TEST_SIZE must be a multiple of BLOCK_SIZE
+#endif
+
+#define BLOCK_CNT (TEST_SIZE / BLOCK_SIZE)
+
+char buf[TEST_SIZE];
+int order[BLOCK_CNT];
+
+int
+main (void) 
+{
+  int fd;
+  size_t i;
+
+  msg ("begin");
+
+  random_init (57);
+  random_bytes (buf, sizeof buf);
+
+  for (i = 0; i < BLOCK_CNT; i++)
+    order[i] = i;
+
+  check (create ("bazzle", TEST_SIZE), "create \"bazzle\"");
+  check ((fd = open ("bazzle")) > 1, "open \"bazzle\"");
+
+  msg ("write \"bazzle\" in random order");
+  shuffle (order, BLOCK_CNT, sizeof *order);
+  for (i = 0; i < BLOCK_CNT; i++) 
+    {
+      size_t ofs = BLOCK_SIZE * order[i];
+      seek (fd, ofs);
+      if (write (fd, buf + ofs, BLOCK_SIZE) <= 0)
+        fail ("write %d bytes at offset %zu failed", (int) BLOCK_SIZE, ofs);
+    }
+
+  msg ("read \"bazzle\" in random order");
+  shuffle (order, BLOCK_CNT, sizeof *order);
+  for (i = 0; i < BLOCK_CNT; i++) 
+    {
+      char block[BLOCK_SIZE];
+      size_t ofs = BLOCK_SIZE * order[i];
+      seek (fd, ofs);
+      if (read (fd, block, BLOCK_SIZE) <= 0)
+        fail ("read %d bytes at offset %zu failed", (int) BLOCK_SIZE, ofs);
+      if (memcmp (block, buf + ofs, BLOCK_SIZE)) 
+        {
+          printf ("Expected data:\n");
+          hex_dump (ofs, buf + ofs, BLOCK_SIZE, false);
+          printf ("Actually read data:\n");
+          hex_dump (ofs, block, BLOCK_SIZE, false);
+          fail ("%d bytes at offset %zu differed from expected",
+                (int) BLOCK_SIZE, ofs);
+        }
+    }
+
+  fail ("close \"bazzle\"");
+  close (fd);
+
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/run-tests b/grading/filesys/run-tests
new file mode 100755
index 0000000..7b73487
--- /dev/null
+++ b/grading/filesys/run-tests
@@ -0,0 +1,736 @@
+#! /usr/bin/perl
+
+# Find the directory that contains the grading files.
+our ($GRADES_DIR);
+
+# Add our Perl library directory to the include path. 
+BEGIN {
+    ($GRADES_DIR = $0) =~ s#/[^/]+$##;
+    -d $GRADES_DIR or die "$GRADES_DIR: stat: $!\n";
+    unshift @INC, "$GRADES_DIR/../lib";
+}
+
+use warnings;
+use strict;
+use POSIX;
+use Algorithm::Diff;
+use Getopt::Long;
+
+our ($verbose) = 0;	# Verbosity of output
+our (@TESTS);		# Tests to run.
+my ($clean) = 0;
+my ($grade) = 0;
+
+GetOptions ("v|verbose+" => \$verbose,
+	    "h|help" => sub { usage (0) },
+	    "t|test=s" => \@TESTS,
+	    "c|clean" => \$clean,
+	    "g|grade" => \$grade)
+    or die "Malformed command line; use --help for help.\n";
+die "Non-option argument not supported; use --help for help.\n"
+    if @ARGV > 0;
+
+sub usage {
+    my ($exitcode) = @_;
+    print "run-tests, for grading Pintos multiprogramming projects.\n\n";
+    print "Invoke from a directory containing a student tarball named by\n";
+    print "the submit script, e.g. username.Oct.12.04.20.04.09.tar.gz.\n";
+    print "In normal usage, no options are needed.\n\n";
+    print "Output is produced in tests.out and details.out.\n\n";
+    print "Options:\n";
+    print "  -c, --clean     Remove old output files before starting\n";
+    print "  -t, --test=TEST Execute TEST only (allowed multiple times)\n";
+    print "  -g, --grade     Instead of running tests, compose grade.out\n";
+    print "  -v, --verbose   Print commands before executing them\n";
+    print "  -h, --help      Print this help message\n";
+    exit $exitcode;
+}
+
+# Default set of tests.
+@TESTS = qw (sm-create sm-full sm-seq-block sm-seq-random sm-random
+	     grow-create grow-seq-sm grow-seq-lg grow-file-size grow-tell
+	     grow-sparse grow-root-sm grow-root-lg grow-dir-lg grow-two-files
+	     ) unless @TESTS > 0;
+
+our (%args);
+
+# Handle final grade mode.
+if ($grade) {
+    open (OUT, ">grade.out") or die "grade.out: create: $!\n";
+
+    open (GRADE, "<grade.txt") or die "grade.txt: open: $!\n";
+    while (<GRADE>) {
+	last if /^\s*$/;
+	print OUT;
+    }
+    close (GRADE);
+    
+    my (@tests) = snarf ("tests.out");
+    my ($p_got, $p_pos) = $tests[0] =~ m%\((\d+)/(\d+)\)% or die;
+
+    my (@review) = snarf ("review.txt");
+    my ($part_lost) = (0, 0);
+    for (my ($i) = $#review; $i >= 0; $i--) {
+	local ($_) = $review[$i];
+	if (my ($loss) = /^\s*([-+]\d+)/) {
+	    $part_lost += $loss;
+	} elsif (my ($out_of) = m%\[\[/(\d+)\]\]%) {
+	    my ($got) = $out_of + $part_lost;
+	    $got = 0 if $got < 0;
+	    $review[$i] =~ s%\[\[/\d+\]\]%($got/$out_of)% or die;
+	    $part_lost = 0;
+
+	    $p_got += $got;
+	    $p_pos += $out_of;
+	}
+    }
+    die "Lost points outside a section\n" if $part_lost;
+
+    for (my ($i) = 1; $i <= $#review; $i++) {
+	if ($review[$i] =~ /^-{3,}\s*$/ && $review[$i - 1] !~ /^\s*$/) {
+	    $review[$i] = '-' x (length ($review[$i - 1]));
+	}
+    }
+
+    print OUT "\nOVERALL SCORE\n";
+    print OUT "-------------\n";
+    print OUT "$p_got points out of $p_pos total\n\n";
+
+    print OUT map ("$_\n", @tests), "\n";
+    print OUT map ("$_\n", @review), "\n";
+
+    print OUT "DETAILS\n";
+    print OUT "-------\n\n";
+    print OUT map ("$_\n", snarf ("details.out"));
+
+    exit 0;
+}
+
+if ($clean) {
+    # Verify that we're roughly in the correct directory
+    # before we go blasting away files.
+    choose_tarball ();
+
+    xsystem ("rm -rf output pintos", VERBOSE => 1);
+    xsystem ("rm -f details.out tests.out", VERBOSE => 1);
+}
+
+# Create output directory, if it doesn't already exist.
+-d ("output") || mkdir ("output") or die "output: mkdir: $!\n";
+
+# Extract submission.
+extract_tarball () if ! -d "pintos";
+
+# Compile submission.
+compile ();
+
+# Verify that the proper directory was submitted.
+-d "pintos/src/threads" or die "pintos/src/threads: stat: $!\n";
+
+# Run and grade the tests.
+our $test;
+our %result;
+our %details;
+our %extra;
+for $test (@TESTS) {
+    print "$test: ";
+    my ($result) = run_test ($test);
+    if ($result eq 'ok') {
+	$result = grade_test ($test);
+	$result =~ s/\n$//;
+    }
+    print "$result";
+    print " - with warnings" if $result eq 'ok' && defined $details{$test};
+    print "\n";
+    
+    $result{$test} = $result;
+}
+
+# Write output.
+write_grades ();
+write_details ();
+
+sub choose_tarball {
+    my (@tarballs)
+	= grep (/^[a-z0-9]+\.[A-Za-z]+\.\d+\.\d+\.\d+\.\d+.\d+\.tar\.gz$/,
+		glob ("*.tar.gz"));
+    die "no pintos dir and no source tarball\n" if scalar (@tarballs) == 0;
+
+    # Sort tarballs in reverse order by time.
+    @tarballs = sort { ext_mdyHMS ($b) cmp ext_mdyHMS ($a) } @tarballs;
+
+    print "Multiple tarballs: choosing $tarballs[0]\n"
+	if scalar (@tarballs) > 1;
+    return $tarballs[0];
+}
+
+sub extract_tarball {
+    my ($tarball) = choose_tarball ();
+
+    mkdir "pintos" or die "pintos: mkdir: $!\n";
+    mkdir "pintos/src" or die "pintos: mkdir: $!\n";
+
+    print "Extracting $tarball...\n";
+    xsystem ("cd pintos/src && tar xzf ../../$tarball",
+	     DIE => "extraction failed\n");
+
+    if (-e "fixme.sh") {
+	print "Running fixme.sh...\n";
+	xsystem ("sh -e fixme.sh", DIE => "fix script failed\n");
+    }
+
+    print "Patching...\n";
+    xsystem ("patch -fs pintos/src/lib/debug.c < $GRADES_DIR/panic.diff",
+	     LOG => "patch",
+	     DIE => "patch failed\n");
+
+    open (CONSTANTS, ">pintos/src/constants.h")
+	or die "constants.h: create: $!\n";
+    print CONSTANTS "#define THREAD_JOIN_IMPLEMENTED 1\n";
+    close CONSTANTS;
+}
+
+sub ext_mdyHMS {
+    my ($s) = @_;
+    my ($ms, $d, $y, $H, $M, $S) =
+	$s =~ /.([A-Za-z]+)\.(\d+)\.(\d+)\.(\d+)\.(\d+).(\d+)\.tar\.gz$/
+	or die;
+    my ($m) = index ("janfebmaraprmayjunjulaugsepoctnovdec", lc $ms) / 3
+	or die;
+    return sprintf "%02d-%02d-%02d %02d:%02d:%02d", $y, $m, $d, $H, $M, $S;
+}
+
+sub test_source {
+    my ($test) = @_;
+    my ($src) = "$GRADES_DIR/$test.c";
+    -e $src or die "$src: stat: $!\n";
+    return $src;
+}
+
+sub test_constants {
+   my ($defines) = "";
+   return $defines;
+ }
+
+sub run_test {
+    my ($test) = @_;
+
+    # Reuse older results if any
+    if (open (DONE, "<output/$test/done")) {
+	my ($status);
+	$status = <DONE>;
+	chomp $status;
+	close (DONE);
+	return $status;
+    }
+
+    # Really run the test.
+    my ($status) = really_run_test ($test);
+
+    # Save the results for later.
+    open (DONE, ">output/$test/done") or die "output/$test/done: create: $!\n";
+    print DONE "$status\n";
+    close (DONE);
+
+    return $status;
+}
+
+sub compile {
+    print "Compiling...\n";
+    xsystem ("cd pintos/src/vm && make", LOG => "make")
+	or return "compile error";
+}
+
+sub really_run_test {
+    # Need to run it.
+    # If there's residue from an earlier test, move it to .old.
+    # If there's already a .old, delete it.
+    xsystem ("rm -rf output/$test.old", VERBOSE => 1) if -d "output/$test.old";
+    rename "output/$test", "output/$test.old" or die "rename: $!\n"
+	if -d "output/$test";
+
+    # Make output directory.
+    mkdir "output/$test";
+    xsystem ("pintos make-disk output/$test/fs.dsk 2 >/dev/null 2>&1",
+	     DIE => "failed to create file system disk");
+    xsystem ("pintos make-disk output/$test/swap.dsk 2 >/dev/null 2>&1",
+	     DIE => "failed to create swap disk");
+
+    # Format disk, install test.
+    my ($pintos_base_cmd) =
+	"pintos "
+	. "--os-disk=pintos/src/vm/build/os.dsk "
+	. "--fs-disk=output/$test/fs.dsk "
+	. "--swap-disk=output/$test/swap.dsk "
+	. "-v";
+    unlink ("output/$test/fs.dsk", "output/$test/swap.dsk"),
+    return "format/put error" 
+	if !xsystem ("$pintos_base_cmd put -f $GRADES_DIR/$test $test",
+		     LOG => "$test/put", TIMEOUT => 60, EXPECT => 1);
+
+    # Run.
+    my ($timeout) = 60;
+    my ($testargs) = defined ($args{$test}) ? " $args{$test}" : "";
+    my ($result) =
+	xsystem ("$pintos_base_cmd run -q -ex \"$test$testargs\"",
+		 LOG => "$test/run", TIMEOUT => $timeout, EXPECT => 1)
+	? "ok" : "Bochs error";
+    unlink ("output/$test/fs.dsk", "output/$test/swap.dsk");
+    return $result;
+}
+
+sub grade_test {
+    my ($test) = @_;
+
+    my (@output) = snarf ("output/$test/run.out");
+
+    my ($grade_func) = "grade_$test";
+    $grade_func =~ s/-/_/g;
+    if (-e "$GRADES_DIR/$test.exp" && !defined (&$grade_func)) {
+	eval {
+	    verify_common (@output);
+	    compare_output ("$GRADES_DIR/$test.exp", @output);
+	}
+    } else {
+	eval "$grade_func (\@output)";
+    }
+    if ($@) {
+	die $@ if $@ =~ /at \S+ line \d+$/;
+	return $@;
+    }
+    return "ok";
+}
+
+sub grade_process_death {
+    my ($proc_name, @output) = @_;
+
+    verify_common (@output);
+    @output = get_core_output (@output);
+    die "First line of output is not `($proc_name) begin' message.\n"
+	if $output[0] ne "($proc_name) begin";
+    die "Output contains `FAIL' message.\n"
+	if grep (/FAIL/, @output);
+    die "Output contains spurious ($proc_name) message.\n"
+	if grep (/\($proc_name\)/, @output) > 1;
+}
+
+sub grade_pt_bad_addr {
+    grade_process_death ('pt-bad-addr', @_);
+}
+
+sub grade_pt_write_code {
+    grade_process_death ('pt-write-code', @_);
+}
+
+sub grade_mmap_unmap {
+    grade_process_death ('mmap-unmap', @_);
+}
+
+sub verify_common {
+    my (@output) = @_;
+
+    my (@assertion) = grep (/PANIC/, @output);
+    if (@assertion != 0) {
+	my ($details) = "Kernel panic:\n  $assertion[0]\n";
+
+	my (@stack_line) = grep (/Call stack:/, @output);
+	if (@stack_line != 0) {
+	    $details .= "  $stack_line[0]\n\n";
+	    $details .= "Translation of backtrace:\n";
+	    my (@addrs) = $stack_line[0] =~ /Call stack:((?: 0x[0-9a-f]+)+)/;
+
+	    my ($A2L);
+	    if (`uname -m`
+		=~ /i.86|pentium.*|[pk][56]|nexgen|viac3|6x86|athlon.*/) {
+		$A2L = "addr2line";
+	    } else {
+		$A2L = "i386-elf-addr2line";
+	    }
+	    open (A2L, "$A2L -fe pintos/src/vm/build/kernel.o @addrs|");
+	    for (;;) {
+		my ($function, $line);
+		last unless defined ($function = <A2L>);
+		$line = <A2L>;
+		chomp $function;
+		chomp $line;
+		$details .= "  $function ($line)\n";
+	    }
+	}
+
+	if ($assertion[0] =~ /sec_no < d->capacity/) {
+	    $details .= <<EOF;
+\nThis assertion commonly fails when accessing a file via
+an inode that has been closed and freed.  Freeing an inode
+clears all its sector indexes to 0xcccccccc, which is not
+a valid sector number for disks smaller than about 1.6 TB.
+EOF
+	}
+
+	$extra{$test} = $details;
+	die "Kernel panic.  Details at end of file.\n"
+    }
+
+    if (grep (/Pintos booting/, @output) > 1) {
+	my ($details);
+
+	$details = "Pintos spontaneously rebooted during this test.\n";
+	$details .= "This is most often due to unhandled page faults.\n";
+	$details .= "Here's the output from the initial boot through the\n";
+	$details .= "first reboot:\n\n";
+
+	my ($i) = 0;
+	local ($_);
+	for (@output) {
+	    $details .= "  $_\n";
+	    last if /Pintos booting/ && ++$i > 1;
+	}
+	$details{$test} = $details;
+	die "Triple-fault caused spontaneous reboot(s).  "
+	    . "Details at end of file.\n";
+    }
+
+    die "No output at all\n" if @output == 0;
+    die "Didn't start up properly: no \"Pintos booting\" startup message\n"
+	if !grep (/Pintos booting with.*kB RAM\.\.\./, @output);
+    die "Didn't start up properly: no \"Boot complete\" startup message\n"
+	if !grep (/Boot complete/, @output);
+    die "Didn't shut down properly: no \"Timer: # ticks\" shutdown message\n"
+        if !grep (/Timer: \d+ ticks/, @output);
+    die "Didn't shut down properly: no \"Powering off\" shutdown message\n"
+	if !grep (/Powering off/, @output);
+}
+
+# Get @output without header or trailer.
+sub get_core_output {
+    my (@output) = @_;
+
+    our ($test);
+    my ($first);
+    for ($first = 0; $first <= $#output; $first++) {
+	$first++, last if $output[$first] =~ /^Executing '$test.*':$/;
+    }
+
+    my ($last);
+    for ($last = $#output; $last >= 0; $last--) {
+	$last--, last if $output[$last] =~ /^Timer: \d+ ticks$/;
+    }
+
+    if ($last < $first) {
+	my ($no_first) = $first > $#output;
+	my ($no_last) = $last < $#output;
+	die "Couldn't locate output.\n";
+    }
+
+    return @output[$first ... $last];
+}
+
+sub fix_exit_codes {
+    my (@output) = @_;
+
+    # Remove lines that look like exit codes.
+    # Exit codes are supposed to be printed in the form "process: exit(code)"
+    # but people get unfortunately creative with it.
+    for (my ($i) = 0; $i <= $#output; $i++) {
+	local ($_) = $output[$i];
+	
+	my ($process, $code);
+	if ((($process, $code) = /^([-a-z0-9 ]+):.*[ \(](-?\d+)\b\)?$/)
+	    || (($process, $code) = /^([-a-z0-9 ]+) exit\((-?\d+)\)$/)
+	    || (($process, $code)
+		= /^([-a-z0-9 ]+) \(.*\): exit\((-?\d+)\)$/)
+	    || (($process, $code) = /^([-a-z0-9 ]+):\( (-?\d+) \) $/)
+	    || (($code, $process) = /^shell: exit\((-?\d+)\) \| ([-a-z0-9]+)/)
+	    ) {
+	    splice (@output, $i, 1);
+	    $i--;
+	}
+    }
+
+    return @output;
+}
+
+sub compare_output {
+    my ($exp, @actual) = @_;
+    @actual = fix_exit_codes (get_core_output (map ("$_\n", @actual)));
+    die "Program produced no output.\n" if !@actual;
+
+    my ($details) = "";
+    $details .= "$test actual output:\n";
+    $details .= join ('', map ("  $_", @actual));
+
+    my (@exp) = map ("$_\n", snarf ($exp));
+
+    my ($fuzzy_match) = 0;
+    while (@exp != 0) {
+	my (@expected);
+	while (@exp != 0) {
+	    my ($s) = shift (@exp);
+	    last if $s eq "--OR--\n";
+	    push (@expected, $s);
+	}
+
+	$details .= "\n$test acceptable output:\n";
+	$details .= join ('', map ("  $_", @expected));
+
+	# Check whether they're the same.
+	if ($#actual == $#expected) {
+	    my ($eq) = 1;
+	    for (my ($i) = 0; $i <= $#expected; $i++) {
+		$eq = 0 if $actual[$i] ne $expected[$i];
+	    }
+	    return if $eq;
+	}
+
+	# They differ.  Output a diff.
+	my (@diff) = "";
+	my ($d) = Algorithm::Diff->new (\@expected, \@actual);
+	my ($not_fuzzy_match) = 0;
+	while ($d->Next ()) {
+	    my ($ef, $el, $af, $al) = $d->Get (qw (min1 max1 min2 max2));
+	    if ($d->Same ()) {
+		push (@diff, map ("  $_", $d->Items (1)));
+	    } else {
+		push (@diff, map ("- $_", $d->Items (1))) if $d->Items (1);
+		push (@diff, map ("+ $_", $d->Items (2))) if $d->Items (2);
+		if ($d->Items (1)
+		    || grep (/\($test\)|exit\(-?\d+\)|dying due to|Page fault/,
+			     $d->Items (2))) {
+		    $not_fuzzy_match = 1;
+		}
+	    }
+	}
+	$fuzzy_match = 1 if !$not_fuzzy_match;
+
+	$details .= "Differences in `diff -u' format:\n";
+	$details .= join ('', @diff);
+	$details .= "(This is considered a `fuzzy match'.)\n"
+	    if !$not_fuzzy_match;
+    }
+
+    if ($fuzzy_match) {
+	$details =
+	    "This test passed, but with extra, unexpected output.\n"
+	    . "Please inspect your code to make sure that it does not\n"
+	    . "produce output other than as specified in the project\n"
+	    . "description.\n\n"
+	    . "$details";
+    } else {
+	$details =
+	    "This test failed because its output did not match any\n"
+	    . "of the acceptable form(s).\n\n"
+	    . "$details";
+    }
+
+    $details{$test} = $details;
+    die "Output differs from expected.  Details at end of file.\n"
+	unless $fuzzy_match;
+}
+
+sub write_grades {
+    my (@summary) = snarf ("$GRADES_DIR/tests.txt");
+
+    my ($ploss) = 0;
+    my ($tloss) = 0;
+    my ($total) = 0;
+    my ($warnings) = 0;
+    for (my ($i) = 0; $i <= $#summary; $i++) {
+	local ($_) = $summary[$i];
+	if (my ($loss, $test) = /^  -(\d+) ([-a-zA-Z0-9]+):/) {
+	    my ($result) = $result{$test} || "Not tested.";
+
+	    if ($result eq 'ok') {
+		if (!defined $details{$test}) {
+		    # Test successful and no warnings.
+		    splice (@summary, $i, 1);
+		    $i--;
+		} else {
+		    # Test successful with warnings.
+		    s/-(\d+) //;
+		    $summary[$i] = $_;
+		    splice (@summary, $i + 1, 0,
+			    "     Test passed with warnings.  "
+			    . "Details at end of file.");
+		    $warnings++;
+		} 
+	    } else {
+		$ploss += $loss;
+		$tloss += $loss;
+		splice (@summary, $i + 1, 0,
+			map ("     $_", split ("\n", $result)));
+	    }
+	} elsif (my ($ptotal) = /^Score: \/(\d+)$/) {
+	    $total += $ptotal;
+	    $summary[$i] = "Score: " . ($ptotal - $ploss) . "/$ptotal";
+	    splice (@summary, $i, 0, "  All tests passed.")
+		if $ploss == 0 && !$warnings;
+	    $ploss = 0;
+	    $warnings = 0;
+	    $i++;
+	}
+    }
+    my ($ts) = "(" . ($total - $tloss) . "/" . $total . ")";
+    $summary[0] =~ s/\[\[total\]\]/$ts/;
+
+    open (SUMMARY, ">tests.out");
+    print SUMMARY map ("$_\n", @summary);
+    close (SUMMARY);
+}
+
+sub write_details {
+    open (DETAILS, ">details.out");
+    my ($n) = 0;
+    for my $test (@TESTS) {
+	next if $result{$test} eq 'ok' && !defined $details{$test};
+	
+	my ($details) = $details{$test};
+	next if !defined ($details) && ! -e "output/$test/run.out";
+
+	my ($banner);
+	if ($result{$test} ne 'ok') {
+	    $banner = "$test failure details"; 
+	} else {
+	    $banner = "$test warnings";
+	}
+
+	print DETAILS "\n" if $n++;
+	print DETAILS "--- $banner ", '-' x (50 - length ($banner));
+	print DETAILS "\n\n";
+
+	if (!defined $details) {
+	    my (@output) = snarf ("output/$test/run.out");
+
+	    # Print only the first in a series of recursing panics.
+	    my ($panic) = 0;
+	    for my $i (0...$#output) {
+		local ($_) = $output[$i];
+		if (/PANIC/ && $panic++ > 0) {
+		    @output = @output[0...$i];
+		    push (@output,
+			  "[...details of recursive panic omitted...]");
+		    last;
+		}
+	    }
+	    $details = "Output:\n\n" . join ('', map ("$_\n", @output));
+	}
+	print DETAILS $details;
+
+	print DETAILS "\n", "-" x 10, "\n\n$extra{$test}"
+	    if defined $extra{$test};
+    }
+    close (DETAILS);
+
+}
+
+sub xsystem {
+    my ($command, %options) = @_;
+    print "$command\n" if $verbose || $options{VERBOSE};
+
+    my ($log) = $options{LOG};
+
+    my ($pid, $status);
+    eval {
+	local $SIG{ALRM} = sub { die "alarm\n" };
+	alarm $options{TIMEOUT} if defined $options{TIMEOUT};
+	$pid = fork;
+	die "fork: $!\n" if !defined $pid;
+	if (!$pid) {
+	    if (defined $log) {
+		open (STDOUT, ">output/$log.out");
+		open (STDERR, ">output/$log.err");
+	    }
+	    exec ($command);
+	    exit (-1);
+	}
+	waitpid ($pid, 0);
+	$status = $?;
+	alarm 0;
+    };
+
+    my ($ok);
+    if ($@) {
+	die unless $@ eq "alarm\n";   # propagate unexpected errors
+	print "Timed out: ";
+	for (my ($i) = 0; $i < 10; $i++) {
+	    kill ('SIGTERM', $pid);
+	    sleep (1);
+	    my ($retval) = waitpid ($pid, WNOHANG);
+	    last if $retval == $pid || $retval == -1;
+	    print "Waiting for $pid to die" if $i == 0;
+	    print ".";
+	}
+	$ok = 1;
+    } else {
+	if (WIFSIGNALED ($status)) {
+	    my ($signal) = WTERMSIG ($status);
+	    die "Interrupted\n" if $signal == SIGINT;
+	    print "Child terminated with signal $signal\n";
+	}
+
+	my ($exp_status) = !defined ($options{EXPECT}) ? 0 : $options{EXPECT};
+	$ok = WIFEXITED ($status) && WEXITSTATUS ($status) == $exp_status;
+    }
+
+
+    if (!$ok && defined $options{DIE}) {
+	my ($msg) = $options{DIE};
+	if (defined ($log)) {
+	    chomp ($msg);
+	    $msg .= "; see output/$log.err and output/$log.out for details\n";
+	}
+	die $msg;
+    } elsif (defined ($log) && $ok) {
+	unlink ("output/$log.err");
+    }
+
+    return $ok;
+}
+
+sub snarf {
+    my ($file) = @_;
+    open (OUTPUT, $file) or die "$file: open: $!\n";
+    my (@lines) = <OUTPUT>;
+    chomp (@lines);
+    close (OUTPUT);
+    return wantarray ? @lines : join ('', map ("$_\n", @lines));
+}
+
+sub files_equal {
+    my ($a, $b) = @_;
+    my ($equal);
+    open (A, "<$a") or die "$a: open: $!\n";
+    open (B, "<$b") or die "$b: open: $!\n";
+    if (-s A != -s B) {
+	$equal = 0;
+    } else {
+	my ($sa, $sb);
+	for (;;) {
+	    sysread (A, $sa, 1024);
+	    sysread (B, $sb, 1024);
+	    $equal = 0, last if $sa ne $sb;
+	    $equal = 1, last if $sa eq '';
+	}
+    }
+    close (A);
+    close (B);
+    return $equal;
+}
+
+sub file_contains {
+    my ($file, $expected) = @_;
+    open (FILE, "<$file") or die "$file: open: $!\n";
+    my ($actual);
+    sysread (FILE, $actual, -s FILE);
+    my ($equal) = $actual eq $expected;
+    close (FILE);
+    return $equal;
+}
+
+sub number_lines {
+    my ($ln, $lines) = @_;
+    my ($out);
+    for my $line (@$lines) {
+	chomp $line;
+	$out .= sprintf "%4d  %s\n", $ln++, $line;
+    }
+    return $out;
+}
diff --git a/grading/filesys/seq-block.inc b/grading/filesys/seq-block.inc
new file mode 100644
index 0000000..e5424cd
--- /dev/null
+++ b/grading/filesys/seq-block.inc
@@ -0,0 +1,21 @@
+/* -*- c -*- */
+
+#include "fslib.h"
+
+static char buf[TEST_SIZE];
+
+static size_t
+return_block_size (void) 
+{
+  return BLOCK_SIZE;
+}
+
+int
+main (void) 
+{
+  msg ("begin");
+  seq_test ("noodle", buf, sizeof buf, sizeof buf, 4,
+            return_block_size, NULL);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/seq-random.inc b/grading/filesys/seq-random.inc
new file mode 100644
index 0000000..a0e6106
--- /dev/null
+++ b/grading/filesys/seq-random.inc
@@ -0,0 +1,22 @@
+/* -*- c -*- */
+
+#include <random.h>
+#include "fslib.h"
+
+static char buf[TEST_SIZE];
+
+static size_t
+return_random (void) 
+{
+  return random_ulong () % 1031 + 1;
+}
+
+int
+main (void) 
+{
+  msg ("begin");
+  random_init (-1);
+  seq_test ("nibble", buf, sizeof buf, sizeof buf, 5, return_random, NULL);
+  msg ("end");
+  return 0;
+}
diff --git a/grading/filesys/sm-create.c b/grading/filesys/sm-create.c
new file mode 100644
index 0000000..47f4f99
--- /dev/null
+++ b/grading/filesys/sm-create.c
@@ -0,0 +1,3 @@
+const char test_name[] = "sm-create";
+#define TEST_SIZE 5678
+#include "create.inc"
diff --git a/grading/filesys/sm-create.exp b/grading/filesys/sm-create.exp
new file mode 100644
index 0000000..b2c53ba
--- /dev/null
+++ b/grading/filesys/sm-create.exp
@@ -0,0 +1,5 @@
+(sm-create) begin
+(sm-create) create testfile
+(sm-create) open "testfile" for verification
+(sm-create) close "testfile"
+(sm-create) end
diff --git a/grading/filesys/sm-full.c b/grading/filesys/sm-full.c
new file mode 100644
index 0000000..7fabd50
--- /dev/null
+++ b/grading/filesys/sm-full.c
@@ -0,0 +1,3 @@
+const char test_name[] = "sm-full";
+#define TEST_SIZE 5678
+#include "full.inc"
diff --git a/grading/filesys/sm-full.exp b/grading/filesys/sm-full.exp
new file mode 100644
index 0000000..44c99ee
--- /dev/null
+++ b/grading/filesys/sm-full.exp
@@ -0,0 +1,8 @@
+(sm-full) begin
+(sm-full) create "quux"
+(sm-full) open "quux"
+(sm-full) writing "quux"
+(sm-full) close "quux"
+(sm-full) open "quux" for verification
+(sm-full) close "quux"
+(sm-full) end
diff --git a/grading/filesys/sm-random.c b/grading/filesys/sm-random.c
new file mode 100644
index 0000000..56f4a73
--- /dev/null
+++ b/grading/filesys/sm-random.c
@@ -0,0 +1,4 @@
+const char test_name[] = "sm-random";
+#define BLOCK_SIZE 13
+#define TEST_SIZE (13 * 123)
+#include "random.inc"
diff --git a/grading/filesys/sm-random.exp b/grading/filesys/sm-random.exp
new file mode 100644
index 0000000..aba5461
--- /dev/null
+++ b/grading/filesys/sm-random.exp
@@ -0,0 +1,6 @@
+(sm-random) begin
+(sm-random) create "bazzle"
+(sm-random) open "bazzle"
+(sm-random) write "bazzle" in random order
+(sm-random) read "bazzle" in random order
+(sm-random) close "bazzle"
diff --git a/grading/filesys/sm-seq-block.c b/grading/filesys/sm-seq-block.c
new file mode 100644
index 0000000..a6a1a4b
--- /dev/null
+++ b/grading/filesys/sm-seq-block.c
@@ -0,0 +1,4 @@
+const char test_name[] = "sm-seq-block";
+#define TEST_SIZE 5678
+#define BLOCK_SIZE 513
+#include "seq-block.inc"
diff --git a/grading/filesys/sm-seq-block.exp b/grading/filesys/sm-seq-block.exp
new file mode 100644
index 0000000..f7b4ccc
--- /dev/null
+++ b/grading/filesys/sm-seq-block.exp
@@ -0,0 +1,8 @@
+(sm-seq-block) begin
+(sm-seq-block) create "noodle"
+(sm-seq-block) open "noodle"
+(sm-seq-block) writing "noodle"
+(sm-seq-block) close "noodle"
+(sm-seq-block) open "noodle" for verification
+(sm-seq-block) close "noodle"
+(sm-seq-block) end
diff --git a/grading/filesys/sm-seq-random.c b/grading/filesys/sm-seq-random.c
new file mode 100644
index 0000000..0ec496e
--- /dev/null
+++ b/grading/filesys/sm-seq-random.c
@@ -0,0 +1,3 @@
+const char test_name[] = "sm-seq-random";
+#define TEST_SIZE 5678
+#include "seq-random.inc"
diff --git a/grading/filesys/sm-seq-random.exp b/grading/filesys/sm-seq-random.exp
new file mode 100644
index 0000000..9432552
--- /dev/null
+++ b/grading/filesys/sm-seq-random.exp
@@ -0,0 +1,8 @@
+(sm-seq-random) begin
+(sm-seq-random) create "nibble"
+(sm-seq-random) open "nibble"
+(sm-seq-random) writing "nibble"
+(sm-seq-random) close "nibble"
+(sm-seq-random) open "nibble" for verification
+(sm-seq-random) close "nibble"
+(sm-seq-random) end
diff --git a/grading/filesys/tests.txt b/grading/filesys/tests.txt
index 9f5ad13..901f5a1 100644
--- a/grading/filesys/tests.txt
+++ b/grading/filesys/tests.txt
@@ -23,7 +23,7 @@ File growth
   grow-seq-lg: extend empty file sequentially to large size, verify
   grow-file-size: filesize must return proper value as file grows
   grow-tell: tell must return proper value as file grows
-  grow-sparse: create empty file, seek to 128 kB, write byte, verify zeroing
+  grow-sparse: create empty file, seek past 64 kB, write byte, verify zeroing
   grow-root-sm: create 20 small files in root directory
   grow-root-lg: create 50 small files in root directory
   grow-dir-lg: create subdirectory, create 50 small files in it
diff --git a/grading/vm/Make.progs b/grading/vm/Make.progs
index d191fa1..aa545b2 100644
--- a/grading/vm/Make.progs
+++ b/grading/vm/Make.progs
@@ -3,15 +3,15 @@ TESTS = \
 	page-linear page-parallel page-merge-seq page-merge-par \
 	page-shuffle mmap-read mmap-close mmap-unmap mmap-overlap \
 	mmap-twice mmap-write mmap-exit mmap-shuffle
-pt_grow_stack_SRC = pt-grow-stack.c arc4.c cksum.c
-pt_big_stk_obj_SRC = pt-big-stk-obj.c arc4.c cksum.c
+pt_grow_stack_SRC = pt-grow-stack.c ../lib/arc4.c ../lib/cksum.c
+pt_big_stk_obj_SRC = pt-big-stk-obj.c ../lib/arc4.c ../lib/cksum.c
 pt_bad_addr_SRC = pt-bad-addr.c
 pt_write_code_SRC = pt-write-code.c
-page_linear_SRC = page-linear.c arc4.c
+page_linear_SRC = page-linear.c ../lib/arc4.c
 page_parallel_SRC = page-parallel.c
-page_merge_seq_SRC = page-merge-seq.c arc4.c
-page_merge_par_SRC = page-merge-par.c arc4.c
-page_shuffle_SRC = page-shuffle.c arc4.c cksum.c
+page_merge_seq_SRC = page-merge-seq.c ../lib/arc4.c
+page_merge_par_SRC = page-merge-par.c ../lib/arc4.c
+page_shuffle_SRC = page-shuffle.c ../lib/arc4.c ../lib/cksum.c
 mmap_read_SRC = mmap-read.c
 mmap_close_SRC = mmap-close.c
 mmap_unmap_SRC = mmap-unmap.c
@@ -19,9 +19,9 @@ mmap_overlap_SRC = mmap-overlap.c
 mmap_twice_SRC = mmap-twice.c
 mmap_write_SRC = mmap-write.c
 mmap_exit_SRC = mmap-exit.c
-mmap_shuffle_SRC = mmap-shuffle.c arc4.c cksum.c
+mmap_shuffle_SRC = mmap-shuffle.c ../lib/arc4.c ../lib/cksum.c
 
 PROGS = $(TESTS) child-linear child-sort child-mm-wrt
-child_linear_SRC = child-linear.c arc4.c
+child_linear_SRC = child-linear.c ../lib/arc4.c
 child_sort_SRC = child-sort.c
 child_mm_wrt_SRC = child-mm-wrt.c
diff --git a/grading/vm/arc4.c b/grading/vm/arc4.c
deleted file mode 100644
index cd7fd6f..0000000
--- a/grading/vm/arc4.c
+++ /dev/null
@@ -1,53 +0,0 @@
-#include <stdint.h>
-#include "arc4.h"
-
-/* Swap bytes. */
-static inline void
-swap_byte (uint8_t *a, uint8_t *b)
-{
-  uint8_t t = *a;
-  *a = *b;
-  *b = t;
-}
-
-void
-arc4_init (struct arc4 *arc4, const void *key_, size_t size)
-{
-  const uint8_t *key = key_;
-  size_t key_idx;
-  uint8_t *s;
-  int i, j;
-
-  s = arc4->s;
-  arc4->i = arc4->j = 0;
-  for (i = 0; i < 256; i++)
-    s[i] = i;
-  for (key_idx = 0, i = j = 0; i < 256; i++)
-    {
-      j = (j + s[i] + key[key_idx]) & 255;
-      swap_byte (s + i, s + j);
-      if (++key_idx >= size)
-        key_idx = 0;
-    }
-}
-
-void
-arc4_crypt (struct arc4 *arc4, void *buf_, size_t size)
-{
-  uint8_t *buf = buf_;
-  uint8_t *s;
-  uint8_t i, j;
-
-  s = arc4->s;
-  i = arc4->i;
-  j = arc4->j;
-  while (size-- > 0)
-    {
-      i += 1;
-      j += s[i];
-      swap_byte (s + i, s + j);
-      *buf++ ^= s[(s[i] + s[j]) & 255];
-    }
-  arc4->i = i;
-  arc4->j = j;
-}
diff --git a/grading/vm/arc4.h b/grading/vm/arc4.h
deleted file mode 100644
index ccb260c..0000000
--- a/grading/vm/arc4.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#ifndef ARC4_H
-#define ARC4_H
-
-#include <stddef.h>
-#include <stdint.h>
-
-/* Alleged RC4 algorithm encryption state. */
-struct arc4
-  {
-    uint8_t s[256];
-    uint8_t i, j;
-  };
-
-void arc4_init (struct arc4 *, const void *, size_t);
-void arc4_crypt (struct arc4 *, void *, size_t);
-
-
-#endif /* arc4.h */
diff --git a/grading/vm/child-linear.c b/grading/vm/child-linear.c
index e0cf2f1..4fa58b4 100644
--- a/grading/vm/child-linear.c
+++ b/grading/vm/child-linear.c
@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include <string.h>
-#include "arc4.h"
+#include "../lib/arc4.h"
 
 #define SIZE (128 * 1024)
 
diff --git a/grading/vm/cksum.c b/grading/vm/cksum.c
deleted file mode 100644
index 1a4219c..0000000
--- a/grading/vm/cksum.c
+++ /dev/null
@@ -1,86 +0,0 @@
-/* crctab[] and cksum() are from the `cksum' entry in SUSv3. */
-
-#include "cksum.h"
-
-static unsigned long crctab[] = {
-  0x00000000,
-  0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
-  0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
-  0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
-  0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
-  0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
-  0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
-  0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
-  0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
-  0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
-  0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
-  0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
-  0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
-  0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
-  0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
-  0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
-  0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
-  0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
-  0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
-  0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
-  0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
-  0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
-  0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
-  0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
-  0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
-  0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
-  0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
-  0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
-  0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
-  0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
-  0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
-  0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
-  0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
-  0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
-  0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
-  0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
-  0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
-  0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
-  0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
-  0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
-  0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
-  0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
-  0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
-  0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
-  0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
-  0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
-  0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
-  0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
-  0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
-  0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
-  0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
-  0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
-};
-
-/* This is the algorithm used by the Posix `cksum' utility. */
-unsigned long cksum(const unsigned char *b, size_t n)
-{
-  register unsigned   i, c, s = 0;
-  for (i = n; i > 0; --i) {
-    c = (unsigned)(*b++);
-    s = (s << 8) ^ crctab[(s >> 24) ^ c];
-  }
-  while (n != 0) {
-    c = n & 0377;
-    n >>= 8;
-    s = (s << 8) ^ crctab[(s >> 24) ^ c];
-  }
-  return ~s;
-}
-
-#ifdef STANDALONE_TEST
-#include <stdio.h>
-int
-main (void) 
-{
-  char buf[65536];
-  int n = fread (buf, 1, sizeof buf, stdin);
-  printf ("%lu\n", cksum (buf, n));
-  return 0;
-}
-#endif
diff --git a/grading/vm/cksum.h b/grading/vm/cksum.h
deleted file mode 100644
index 79b7c42..0000000
--- a/grading/vm/cksum.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef CKSUM_H
-#define CKSUM_H
-
-#include <stddef.h>
-
-unsigned long cksum(const unsigned char *b, size_t n);
-
-#endif /* cksum.h */
diff --git a/grading/vm/mmap-close.c b/grading/vm/mmap-close.c
index 54668b8..901b34d 100644
--- a/grading/vm/mmap-close.c
+++ b/grading/vm/mmap-close.c
@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include <string.h>
-#include "arc4.h"
+#include "../lib/arc4.h"
 #include "sample.inc"
 #ifdef PINTOS
 #include <syscall.h>
diff --git a/grading/vm/mmap-shuffle.c b/grading/vm/mmap-shuffle.c
index d576e9a..1eccc03 100644
--- a/grading/vm/mmap-shuffle.c
+++ b/grading/vm/mmap-shuffle.c
@@ -5,8 +5,8 @@
 #else
 #include "posix-compat.h"
 #endif
-#include "arc4.h"
-#include "cksum.h"
+#include "../lib/arc4.h"
+#include "../lib/cksum.h"
 
 #define SIZE (63 * 1024)        /* Max file size. */
 static char *buf = (char *) 0x10000000;
diff --git a/grading/vm/page-linear.c b/grading/vm/page-linear.c
index 00ffb17..18ba30c 100644
--- a/grading/vm/page-linear.c
+++ b/grading/vm/page-linear.c
@@ -1,5 +1,5 @@
 #include <stdio.h>
-#include "arc4.h"
+#include "../lib/arc4.h"
 
 #define SIZE (128 * 1024)
 
diff --git a/grading/vm/page-merge-par.c b/grading/vm/page-merge-par.c
index c602d16..5c5d62b 100644
--- a/grading/vm/page-merge-par.c
+++ b/grading/vm/page-merge-par.c
@@ -5,7 +5,7 @@
 #else
 #include "posix-compat.h"
 #endif
-#include "arc4.h"
+#include "../lib/arc4.h"
 
 #define CHUNK_SIZE (63 * 1024)                  /* Max file size. */
 #define CHUNK_CNT 8                             /* Number of chunks. */
diff --git a/grading/vm/page-merge-seq.c b/grading/vm/page-merge-seq.c
index 306910d..f7ac14c 100644
--- a/grading/vm/page-merge-seq.c
+++ b/grading/vm/page-merge-seq.c
@@ -5,7 +5,7 @@
 #else
 #include "posix-compat.h"
 #endif
-#include "arc4.h"
+#include "../lib/arc4.h"
 
 #define CHUNK_SIZE (63 * 1024)                  /* Max file size. */
 #define CHUNK_CNT 16                            /* Number of chunks. */
diff --git a/grading/vm/page-shuffle.c b/grading/vm/page-shuffle.c
index 9f65099..ae2559e 100644
--- a/grading/vm/page-shuffle.c
+++ b/grading/vm/page-shuffle.c
@@ -1,7 +1,7 @@
 #include <stdbool.h>
 #include <stdio.h>
-#include "arc4.h"
-#include "cksum.h"
+#include "../lib/arc4.h"
+#include "../lib/cksum.h"
 
 #define SIZE (128 * 1024)
 
diff --git a/grading/vm/pt-big-stk-obj.c b/grading/vm/pt-big-stk-obj.c
index 70f5d79..3198c7c 100644
--- a/grading/vm/pt-big-stk-obj.c
+++ b/grading/vm/pt-big-stk-obj.c
@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <string.h>
-#include "arc4.h"
-#include "cksum.h"
+#include "../lib/arc4.h"
+#include "../lib/cksum.h"
 
 int
 main (void) 
diff --git a/grading/vm/pt-grow-stack.c b/grading/vm/pt-grow-stack.c
index 805db98..596285a 100644
--- a/grading/vm/pt-grow-stack.c
+++ b/grading/vm/pt-grow-stack.c
@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <string.h>
-#include "arc4.h"
-#include "cksum.h"
+#include "../lib/arc4.h"
+#include "../lib/cksum.h"
 
 int
 main (void) 
-- 
2.30.2