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

From: Josh Poimboeuf <[email-masked]>
Date: Mon, 20 Apr 2020 10:53:30 -0500

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 \