CVS commit: src/sys/arch/amd64

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

Module Name:    src
Committed By:   maxv
Date:           Thu Jan 11 09:00:04 UTC 2018

Modified Files:
        src/sys/arch/amd64/amd64: locore.S machdep.c
        src/sys/arch/amd64/include: frameasm.h types.h

Log Message:
Declare new SVS_* variants: SVS_ENTER_NOSTACK and SVS_LEAVE_NOSTACK. Use
SVS_ENTER_NOSTACK in the syscall entry point, and put it before the code
that touches curlwp. (curlwp is located in the direct map.)

Then, disable __HAVE_CPU_UAREA_ROUTINES (to be removed later). This moves
the kernel stack into pmap_kernel(), and not the direct map. That's a
change I've always wanted to make: because of the direct map we can't add
a redzone on the stack, and basically, a stack overflow can go very far
in memory without being detected (as far as erasing all of the system's
memory).

Finally, unmap the direct map from userland.


To generate a diff of this commit:
cvs rdiff -u -r1.145 -r1.146 src/sys/arch/amd64/amd64/locore.S
cvs rdiff -u -r1.285 -r1.286 src/sys/arch/amd64/amd64/machdep.c
cvs rdiff -u -r1.27 -r1.28 src/sys/arch/amd64/include/frameasm.h
cvs rdiff -u -r1.53 -r1.54 src/sys/arch/amd64/include/types.h

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