Re: linux-next: Tree for Apr 20 (objtool warning)

From: Josh Poimboeuf
Date: Mon Apr 20 2020 - 11:53:41 EST


On Mon, Apr 20, 2020 at 08:29:04AM -0700, Randy Dunlap wrote:
> On 4/19/20 9:26 PM, Stephen Rothwell wrote:
> > Hi all,
> >
> > Changes since 20200417:
> >
>
> on x86_64:
>
> arch/x86/kvm/svm/vmenter.o: warning: objtool: __svm_vcpu_run()+0xe4: BP used as a scratch register
>
> Full randconfig file is included.

Yeah, frame pointers are toast in that function. We'll need something
like:

diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index a789759b7261..221e2bd7e76d 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -3,6 +3,10 @@
ccflags-y += -Iarch/x86/kvm
ccflags-$(CONFIG_KVM_WERROR) += -Werror

+ifeq ($(CONFIG_UNWINDER_FRAME_POINTER),y)
+OBJECT_FILES_NON_STANDARD_vmenter.o := y
+endif
+
KVM := ../../../virt/kvm

kvm-y += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \