CVS commit: src

[Michał Górny <mgorny%netbsd.org@localhost>]

Module Name:    src
Committed By:   mgorny
Date:           Sat Oct 24 07:14:30 UTC 2020

Modified Files:
        src/sys/arch/x86/include: cpufunc.h fpu.h
        src/sys/arch/x86/x86: fpu.c
        src/sys/dev/nvmm/x86: nvmm_x86_svm.c nvmm_x86_vmx.c
        src/tests/lib/libc/sys: t_ptrace_x86_wait.h

Log Message:
Issue 64-bit versions of *XSAVE* for 64-bit amd64 programs

When calling FXSAVE, XSAVE, FXRSTOR, ... for 64-bit programs on amd64
use the 64-suffixed variant in order to include the complete FIP/FDP
registers in the x87 area.

The difference between the two variants is that the FXSAVE64 (new)
variant represents FIP/FDP as 64-bit fields (union fp_addr.fa_64),
while the legacy FXSAVE variant uses split fields: 32-bit offset,
16-bit segment and 16-bit reserved field (union fp_addr.fa_32).
The latter implies that the actual addresses are truncated to 32 bits
which is insufficient in modern programs.

The change is applied only to 64-bit programs on amd64.  Plain i386
and compat32 continue using plain FXSAVE.  Similarly, NVMM is not
changed as I am not familiar with that code.

This is a potentially breaking change.  However, I don't think it likely
to actually break anything because the data provided by the old variant
were not meaningful (because of the truncated pointer).


To generate a diff of this commit:
cvs rdiff -u -r1.41 -r1.42 src/sys/arch/x86/include/cpufunc.h
cvs rdiff -u -r1.22 -r1.23 src/sys/arch/x86/include/fpu.h
cvs rdiff -u -r1.75 -r1.76 src/sys/arch/x86/x86/fpu.c
cvs rdiff -u -r1.81 -r1.82 src/sys/dev/nvmm/x86/nvmm_x86_svm.c
cvs rdiff -u -r1.80 -r1.81 src/sys/dev/nvmm/x86/nvmm_x86_vmx.c
cvs rdiff -u -r1.29 -r1.30 src/tests/lib/libc/sys/t_ptrace_x86_wait.h

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