thanks for comments.

From: cgd@broadcom.com
> * Pick a better name for "SHAM_USPACE."  In fact, I'm not sure why you
>   bother with having a separate variable for it at all.  (I.e., why
>   not expose the actual size to userland, etc.)

i can't imagine better name as i'm bad at english.
please suggest one if you have.

USPACE bytes are actually allocated for kernel stack.
but KSTACK_CHECK_* checks overflow aginst SHAM_USPACE
which is less than USPACE.
(ie. if kernel stack usage exceeds SHAM_SPACE bytes,
 checking code reports overflow. but actually there is
 no overflow because actual kernel stack size is USPACE.)
if KSTACK_SAFE isn't specified, USPACE == SHAM_USPACE.

i don't think KSTACK_SAFE is useful for everyone.
this option was added because i don't want to
reboot machine so frequently. :)
do you think that it's better to remove KSTACK_SAFE
part and SHAM_USPACE?

> * have have extra crud in your conf/files diff.

it's just by mistake. sorry.

> > +	end = (u_int32_t *)((caddr_t)KSTACK_END(p) + KSTACK_SIZE / 2); /* XXX */

> What's the "/ 2" for?!

because the starting part of kernel stack is already
used at that time, we can't fill out whole of stack.
yes, "/ 2" isn't so right. so it's marked as XXX. ;)
I'll change to setup magic before cpu_fork.

---
YAMAMOTO Takashi<yamt@mwd.biglobe.ne.jp>