diff mbox series

[v6,13/15] arm64: disable SCS for hypervisor code

Message ID 20191206221351.38241-14-samitolvanen@google.com (mailing list archive)
State New, archived
Headers show
Series [v6,01/15] arm64: mm: avoid x18 in idmap_kpti_install_ng_mappings | expand

Commit Message

Sami Tolvanen Dec. 6, 2019, 10:13 p.m. UTC 
Filter out CC_FLAGS_SCS for code that runs at a different exception
level.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/kvm/hyp/Makefile | 3 +++
 1 file changed, 3 insertions(+)

Comments

Will Deacon Jan. 16, 2020, 5:47 p.m. UTC | #1 
On Fri, Dec 06, 2019 at 02:13:49PM -0800, Sami Tolvanen wrote:
> Filter out CC_FLAGS_SCS for code that runs at a different exception
> level.
> 
> Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: Mark Rutland <mark.rutland@arm.com>
> ---
>  arch/arm64/kvm/hyp/Makefile | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
> index ea710f674cb6..17ea3da325e9 100644
> --- a/arch/arm64/kvm/hyp/Makefile
> +++ b/arch/arm64/kvm/hyp/Makefile
> @@ -28,3 +28,6 @@ GCOV_PROFILE	:= n
>  KASAN_SANITIZE	:= n
>  UBSAN_SANITIZE	:= n
>  KCOV_INSTRUMENT	:= n
> +
> +# remove the SCS flags from all objects in this directory
> +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))

Same comment as for the vDSO; can we remove the -ffixed-x18 as well?

Will
Sami Tolvanen Jan. 16, 2020, 8:16 p.m. UTC | #2 
On Thu, Jan 16, 2020 at 9:47 AM Will Deacon <will@kernel.org> wrote:
>
> On Fri, Dec 06, 2019 at 02:13:49PM -0800, Sami Tolvanen wrote:
> > Filter out CC_FLAGS_SCS for code that runs at a different exception
> > level.
> >
> > Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > Reviewed-by: Mark Rutland <mark.rutland@arm.com>
> > ---
> >  arch/arm64/kvm/hyp/Makefile | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
> > index ea710f674cb6..17ea3da325e9 100644
> > --- a/arch/arm64/kvm/hyp/Makefile
> > +++ b/arch/arm64/kvm/hyp/Makefile
> > @@ -28,3 +28,6 @@ GCOV_PROFILE        := n
> >  KASAN_SANITIZE       := n
> >  UBSAN_SANITIZE       := n
> >  KCOV_INSTRUMENT      := n
> > +
> > +# remove the SCS flags from all objects in this directory
> > +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
>
> Same comment as for the vDSO; can we remove the -ffixed-x18 as well?

Sure, I don't see why not. I'll change this in the next version.

Sami
diff mbox series

Patch

diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index ea710f674cb6..17ea3da325e9 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -28,3 +28,6 @@  GCOV_PROFILE	:= n
 KASAN_SANITIZE	:= n
 UBSAN_SANITIZE	:= n
 KCOV_INSTRUMENT	:= n
+
+# remove the SCS flags from all objects in this directory
+KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))