Test cases [[/25]]
------------------
  -15 Didn't write own test cases
  -10 Insufficient testing

Design [[/100]]
---------------

Quality of DESIGNDOC
  -10 Arg passing
  -20 Copying data around:
      User-to-kernel copying.
      Kernel-to-user copying.
      String copying.
  -20 System calls:
      Allocation of file descriptors.
      Handling exceptions and related cleanup.
      pid_t rationale (if they changed tid_t -> pid_t mapping).
      Synchronization of system calls and filesystem.

Overall:
  -1 Gratuitous use of malloc() (e.g. for allocating a list or a lock)
  -1 Inappropriate use of ASSERT (e.g. to verify that malloc() succeeded)

Program arguments:
  +1 Support multiple pages of arguments.

User/kernel copying:
  -5 Too many copies of user/kernel copying code
  -10 Doesn't check for page boundaries
  -3 Imperfect checking for page boundaries
  -5 Doesn't check whether pointers are at or above PHYS_BASE
  -2 Imperfect checking whether pointers are at or above PHYS_BASE
  +3 Copies large chunks while properly observing page boundaries
  +3 Scans for string null terminators w/o checking individual bytes
     while properly observing page boundaries
  +3 Uses get_user() and put_user() functions from FAQ for copying

System call design:
  -5 Disables interrupts without reasonable justification
  -2 Doesn't close open files at process exit
  -2 Doesn't acquire file system lock to close files at process exit
  -5 Buffer overflow in read or write system call
  -5 System call error exit leaks memory/fails to release global lock
  -5 Uses a pointer as a file descriptor or pid without justifying

Style [[/25]]
-------------
  -5 Extraneous output caused warnings
  -5 Didn't print process termination messages
  -5 One big function for handling system calls
  -5 No attempt to conform to existing coding style

Comments
--------