On Tue, Apr 28, 2020 at 11:28 AM Joerg Roedel <j...@8bytes.org> wrote: > > From: Joerg Roedel <jroe...@suse.de> > > The code inserted by the stack protector does not work in the early > boot environment because it uses the GS segment, at least with memory > encryption enabled. Make sure the early code is compiled without this > feature enabled. > > Signed-off-by: Joerg Roedel <jroe...@suse.de> > --- > arch/x86/kernel/Makefile | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > index ba89cabe5fcf..1192de38fa56 100644 > --- a/arch/x86/kernel/Makefile > +++ b/arch/x86/kernel/Makefile > @@ -35,6 +35,10 @@ ifdef CONFIG_FRAME_POINTER > OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o := y > endif > > +# make sure head64.c is built without stack protector > +nostackp := $(call cc-option, -fno-stack-protector) > +CFLAGS_head64.o := $(nostackp) > + > # If instrumentation of this dir is enabled, boot hangs during first second. > # Probably could be more selective here, but note that files related to irqs, > # boot, dumpstack/stacktrace, etc are either non-interesting or can lead to
The proper fix would be to initialize MSR_GS_BASE earlier. -- Brian Gerst
