kern/45247: Pmap_kenter_pa abuse

[hannken%eis.cs.tu-bs.de@localhost]

>Number:         45247
>Category:       kern
>Synopsis:       Pmap_kenter_pa abuse
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Aug 13 15:20:00 +0000 2011
>Originator:     J. Hannken-Illjes
>Release:        5.99.55
>Organization:
>Environment:
>Description:
sys/arch/x86/x86/pmap.c::pmap_pdp_ctor() abuses pmap_kenter_pa() to
change the protection.  On a Xen Dom0 at least this leads to this console 
message:

pmap_kenter_pa: mapping already present

in a code path flagged as /* This should not happen. */
>How-To-Repeat:

>Fix: