From nobody@FreeBSD.org  Thu Apr  6 11:40:37 2006
Return-Path: <nobody@FreeBSD.org>
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id A5D4F16A41F
	for <freebsd-gnats-submit@FreeBSD.org>; Thu,  6 Apr 2006 11:40:37 +0000 (UTC)
	(envelope-from nobody@FreeBSD.org)
Received: from www.freebsd.org (www.freebsd.org [216.136.204.117])
	by mx1.FreeBSD.org (Postfix) with ESMTP id C0F4C43D5E
	for <freebsd-gnats-submit@FreeBSD.org>; Thu,  6 Apr 2006 11:40:36 +0000 (GMT)
	(envelope-from nobody@FreeBSD.org)
Received: from www.freebsd.org (localhost [127.0.0.1])
	by www.freebsd.org (8.13.1/8.13.1) with ESMTP id k36Bean6019545
	for <freebsd-gnats-submit@FreeBSD.org>; Thu, 6 Apr 2006 11:40:36 GMT
	(envelope-from nobody@www.freebsd.org)
Received: (from nobody@localhost)
	by www.freebsd.org (8.13.1/8.13.1/Submit) id k36Beagg019544;
	Thu, 6 Apr 2006 11:40:36 GMT
	(envelope-from nobody)
Message-Id: <200604061140.k36Beagg019544@www.freebsd.org>
Date: Thu, 6 Apr 2006 11:40:36 GMT
From: Jonas Blow <jonas.bulow@servicefactory.se>
To: freebsd-gnats-submit@FreeBSD.org
Subject: libkvm does not support /dev/fwmem0.0 in FreeBSD 6 and later.
X-Send-Pr-Version: www-2.3

>Number:         95405
>Category:       kern
>Synopsis:       [libkvm] libkvm does not support /dev/fwmem0.0 in FreeBSD 6 and later.
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Apr 06 11:50:16 GMT 2006
>Closed-Date:    
>Last-Modified:  Thu Apr 06 15:13:09 GMT 2006
>Originator:     Jonas Blow
>Release:        FreeBSD 6.0-p6
>Organization:
ServiceFactory
>Environment:
uname -a
FreeBSD h177.servicefactory.se 6.0-RELEASE-p6 FreeBSD 6.0-RELEASE-p6 #3: Thu Apr  6 08:14:28 CEST 2006     root@h177.servicefactory.se:/usr/obj/usr/src/sys/DEBUGHOST  i386

>Description:
Programs using libkvm fails with:
<progname>: cannot mmap corefile

Since rev 1.16 of kvm_i386.c libkvm no longer supports /dev/fwmem0.0. The reason seems to be the change to use mmap for i386. 

The failing call in libkvm is:

kvm_i386.c:105             vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0); 

A comment at line 1113 in vm_mmap.c says:

  /*
   * cdevs does not provide private mappings of any kind.
   */


>How-To-Repeat:
dmesg -M /dev/fwmem0.0 -N kernel
dmesg: cannot mmap corefile

# kgdb kernel.debug /dev/fwmem0.0
kgdb: cannot mmap corefile


>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
