i386_set_ioperm on FreeBSD 5.3

[M. Warner Losh]

In message: <20041227075616.GA9502 at cs.huji.ac.il>
            Tom Alsberg <alsbergt at cs.huji.ac.il> writes:
: Hi there.
: 
: I'm trying to use some code I wrote quite a while ago using Doug
: White's FreeBSD IPMI code (kcs.c, send-kcs-command.c, etc.).
: 
: It still works as it did back then on FreeBSD 4.10.  On FreeBSD 5.3 it
: does not.
: 
: Problem seems to be, that i386_set_ioperm isn't doing what it should.
: The program gets SIGBUS when doing outb, while it shouldn't.
: 
: I looked in /usr/src/sys/i386/i386/sys_machdep.c, not many changes
: from 4.10 - all except one are additions that would return an error in
: case of failure.  One seems to be quite modest (struct change):
: 
: -       if (p->p_addr->u_pcb.pcb_ext == 0)
: -               if ((error = i386_extend_pcb(p)) != 0)
: +       if (td->td_pcb->pcb_ext == 0)
: +               if ((error = i386_extend_pcb(td)) != 0)
: 
: Yet, clearly something fails on FreeBSD 5.3.  I can confirm that this
: is indeed the problem with a few-line program that will
: i386_set_ioperm and then try to do outb.  Any idea if i386_set_ioperm
: broke somehow in 5.3?  Haven't checked much, but it seems that the
: data it is changing is not being used after all.
: 
:   Thanks, any help appreciated,

We had problems with multiple people opening /dev/io and threads in
4.x.  It was a timing related thing.  Maybe you're seeing a different
timing thing in your program?

Warner