On Jan 6,  3:30pm, pavel@netbsd.org (Pavel Cahyna) wrote:
-- Subject: PR/34186 CVS commit: src/sys/arch/i386/i386

|  Log Message:
|  PR port-i386/34186 by Wolfgang Stukenbrock:
|  mapping of msgbuf during startup may map invalid physical adresses
|  
|  "If the last available physical memory segment on a system is less 16k,
|  than the startup code that will map the kernel message buffer, will fail
|  and map physical pages behind the last segment.  This may either only lead
|  to a message buffer without physical memory behind it, or to an
|  overlapping message buffer with something else."
|  
|  Fix by allowing multiple physical memory segments to be used for msgbuf.
|  Also remove some leftover msgbuf manipulation from pmap.c.
|  
|  Fix supplied by Wolfgang Stukenbrock in the PR, with some modifications
|  from me, mainly to use the already existing constant VM_PHYSSEG_MAX as the
|  static limit of number of msgbuf segments.
|  
|  
|  To generate a diff of this commit:
|  cvs rdiff -r1.588 -r1.589 src/sys/arch/i386/i386/machdep.c
|  cvs rdiff -r1.194 -r1.195 src/sys/arch/i386/i386/pmap.c
|  
|  Please note that diffs are not public domain; they are subject to the
|  copyright notices on the relevant files.

Don't we have the same problem on amd64?

christos