Re: CVS commit: src/sys/arch

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Tue, Nov 14, 2017 at 03:06:00PM +0100, Maxime Villard wrote:
> Le 11/11/2017 à 10:10, Manuel Bouyer a écrit :
> > Module Name:	src
> > Committed By:	bouyer
> > Date:		Sat Nov 11 09:10:19 UTC 2017
> > 
> > Modified Files:
> > 	src/sys/arch/x86/x86: cpu.c fpu.c identcpu.c
> > 	src/sys/arch/xen/x86: cpu.c
> > 
> > Log Message:
> > Revert http://mail-index.netbsd.org/source-changes/2017/11/08/msg089525.html,
> > it breaks Xen:
> > http://www-soc.lip6.fr/~bouyer/NetBSD-tests/xen/HEAD/amd64/201711082340Z_anita.txt
> > 
> > 
> > To generate a diff of this commit:
> > cvs rdiff -u -r1.139 -r1.140 src/sys/arch/x86/x86/cpu.c
> > cvs rdiff -u -r1.25 -r1.26 src/sys/arch/x86/x86/fpu.c
> > cvs rdiff -u -r1.65 -r1.66 src/sys/arch/x86/x86/identcpu.c
> > cvs rdiff -u -r1.114 -r1.115 src/sys/arch/xen/x86/cpu.c
> > 
> > Please note that diffs are not public domain; they are subject to the
> > copyright notices on the relevant files.
> 
> You have %rdi = 0xffffa0000c194c18, so the stack is not aligned to 64 bytes,
> and that's why fxsave faults. Looks like you are triggering another bug earlier
> in the boot procedure - on my dom0-amd64 fxsave worked correctly.

The stack on AMD64 is not 64byte aligned, but depending on when exactly
you check, 16byte aligned with or without an offset of 8byte.

Joerg