> >>   - It is unclear why it is necessary at all.
> >>     http://mail-index.netbsd.org/tech-kern/2005/11/04/0005.html
> > 
> > 
> > why unclear, while you know where it's used?
> 
> Because I don't know why the whole set of credentials needs to be 
> compared. Until now, no one has answered this question.

read the code. :-)
it checks if given credential is the same as existing one.

> >>   - It is the only reason for sorting group lists
> >>     when they enter the kernel via setgroups(),
> >>     which itself is considered unwanted.
> >>     http://mail-index.netbsd.org/tech-kern/2005/11/03/0021.html
> > 
> > 
> > i don't think the result of setgroups is fed into crcmp.
> > the change didn't fix anything and should be backed out, IMO.
> 
> See the ChangeLog for src/sys/kern/kern_prot.c.

what do you mean?

> >>   - It has a big FIXME comment.
> >>     src/sys/kern/kern_prot.c
> > 
> > i don't see why it needs to be fixed.
> > credentials with the different order of groups are different.
> 
> Please explain why the order of groups is important. I don't see it.

what david said isn't enough?
http://mail-index.netbsd.org/tech-kern/2005/11/03/0021.html

YAMAMOTO Takashi