and PID allocation MP-safe. A new process state is added: SDEAD. This
state indicates that a process is dead, but not yet a zombie (has not
yet been processed by the process reaper).
SDEAD processes exist on both the zombproc list (via p_list) and deadproc
(via p_hash; the proc has been removed from the pidhash earlier in the exit
path). When the reaper deals with a process, it changes the state to
SZOMB, so that wait4 can process it.
Add a P_ZOMBIE() macro, which treats a proc in SZOMB or SDEAD as a zombie,
and update various parts of the kernel to reflect the new state.
* Did not check for P_SUGID on ATTACH.
* Did not check for tracing of init on ATTACH.
* Did not turn off single-step mode on RUN or DETACH.
* Might have screwed up reparenting in some cases.
* Allowed anyone to detach the process.
Make NFS serving work (BUT DON'T USE "attach" TO /proc/*/ctl FOR NOW!!!)
Make `curproc' a symbolic link
Add `.' and `..' entries to the directories.
Return better guesses on the size of the files.