CVS commit: src/sys/arch

["Maxime Villard" <maxv%netbsd.org@localhost>]

Module Name:    src
Committed By:   maxv
Date:           Sun Aug 12 15:31:01 UTC 2018

Modified Files:
        src/sys/arch/amd64/amd64: genassym.cf locore.S machdep.c prekern.c
        src/sys/arch/amd64/include: pmap.h
        src/sys/arch/x86/x86: pmap.c

Log Message:
More ASLR: randomize the location of the PTE area. The PTE slot is not
created in locore anymore, but a little later; by using the already
entered L4 page, rather than the recursive slot itself (which doesn't
exist yet).

In the prekern we still map the slot - the prekern behaves as an external
locore -, because we need it as part of the randomization/relocation
work. The kernel then removes this slot, and regenerates a randomized
one.

Tested on GENERIC and GENERIC_KASLR, Xen doesn't have it and dom0 still
boots fine.


To generate a diff of this commit:
cvs rdiff -u -r1.69 -r1.70 src/sys/arch/amd64/amd64/genassym.cf
cvs rdiff -u -r1.173 -r1.174 src/sys/arch/amd64/amd64/locore.S
cvs rdiff -u -r1.313 -r1.314 src/sys/arch/amd64/amd64/machdep.c
cvs rdiff -u -r1.4 -r1.5 src/sys/arch/amd64/amd64/prekern.c
cvs rdiff -u -r1.52 -r1.53 src/sys/arch/amd64/include/pmap.h
cvs rdiff -u -r1.301 -r1.302 src/sys/arch/x86/x86/pmap.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.