i386/75686: Random device source not compatible with many 486's

[David LeCount]

>Number:         75686
>Category:       i386
>Synopsis:       Random device source not compatible with many 486's
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Dec 31 05:30:23 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     David LeCount
>Release:        5.3 cvsupped
>Organization:
>Environment:
FreeBSD gateway.princekenshi.com 5.0-RELEASE FreeBSD 5.0-RELEASE #0: Thu Jan 16 22:16:53 GMT 2003     root at hollin.btc.adaptec.com:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
I have attempted upgrading my 486 from 5.0-RELEASE to 5.3. I am building on my Pentium 3, though that doesn't seem to have anything to do with the issue. I've used different combinations of CPUTYPE=i486, CPUTYPE?=i486, NO_CPU_CFLAGS=true, and NO_CPU_COPTFLAGS all with the same result. The kernel panics at cpuid in the random_ident_hardware function in /usr/src/sys/dev/random/probe.c. The issue is that my processor doesn't support the cpuid opcode, just as many 486's don't. I found nothing in UPDATING regarding the issue. I also inquired about it on the mailing lists 3 times, so I believe it's not my error.
>How-To-Repeat:
Compile a 5.3 kernel on a 486 processor that doesn't support the cpuid opcode and try to boot to it.
>Fix:
Edit the code so it doesn't use the cpuid opcode on processors that do not support it. The 5.0 kernel works so it must use an algorithm that's compatible with these 486's.
>Release-Note:
>Audit-Trail:
>Unformatted: