i386/120541: coretemp causes kernel panic on pentium III

[Rui Paulo]

The following reply was made to PR i386/120541; it has been noted by GNATS.

From: Rui Paulo <rpaulo at fnop.net>
To: Bruce Becker <hostmaster at gts.infra-service.ca>
Cc: freebsd-gnats-submit at FreeBSD.org
Subject: Re: i386/120541: coretemp causes kernel panic on pentium III
Date: Mon, 11 Feb 2008 20:25:55 +0000

 On Feb 11, 2008, at 5:12 PM, Bruce Becker wrote:
 
 >
 >> Number:         120541
 >> Category:       i386
 >> Synopsis:       coretemp causes kernel panic on pentium III
 >> Confidential:   no
 >> Severity:       critical
 >> Priority:       medium
 >> Responsible:    freebsd-i386
 >> State:          open
 >> Quarter:
 >> Keywords:
 >> Date-Required:
 >> Class:          sw-bug
 >> Submitter-Id:   current-users
 >> Arrival-Date:   Mon Feb 11 17:20:00 UTC 2008
 >> Closed-Date:
 >> Last-Modified:
 >> Originator:     Bruce Becker
 >> Release:        7.0-PRERELEASE
 >> Organization:
 > InfraService
 >> Environment:
 > FreeBSD twain 7.0-PRERELEASE FreeBSD 7.0-PRERELEASE #6: Sun Feb 10  
 > 20:43:49 EST 2008     root at twain:/usr/obj/usr/src/sys/TWAIN  i386
 >
 >> Description:
 >
 > When "device coretemp" is included into the /sys/i386/conf config  
 > file, the kernel panics with a general protection fault when "/etc/ 
 > rc.d/initrandom" executes "sysctl -a"
 >
 >> How-To-Repeat:
 >
 > On a pentium III system:
 >
 > kldload coretemp.ko; sysctl -a
 >
 >> Fix:
 >
 >
 >> Release-Note:
 >> Audit-Trail:
 >> Unformatted:
 > _______________________________________________
 > freebsd-i386 at freebsd.org mailing list
 > http://lists.freebsd.org/mailman/listinfo/freebsd-i386
 > To unsubscribe, send any mail to "freebsd-i386- 
 > unsubscribe at freebsd.org"
 
 
 
 This is a known issue and we can't do much about it unless try to  
 reject module initialization if the CPU model is lower than a Pentium  
 4. It's Intel's fault that querying Thermal sensors on a PIII returns  
 true.
 
 Can you test this patch?
 
 Index: coretemp.c
 ===================================================================
 RCS file: /home/ncvs/src/sys/dev/coretemp/coretemp.c,v
 retrieving revision 1.5
 diff -u -p -r1.5 coretemp.c
 --- coretemp.c	10 Jan 2008 16:09:22 -0000	1.5
 +++ coretemp.c	11 Feb 2008 07:23:45 -0000
 @@ -143,6 +143,9 @@ coretemp_attach(device_t dev)
   	cpu_model += ((cpu_id >> 16) & 0xf) << 4;
   	cpu_mask = cpu_id & 15;
 
 +	if (cpu_model < 0xe)
 +		return (ENXIO);
 +	
   #if 0 /*
          * XXXrpaulo: I have this CPU model and when it returns from C3
          * coretemp continues to function properly.
 
 
 Regards.
 --
 Rui Paulo