On Wed, Jul 13, 2022 at 09:54:01AM +0200, Jiri Slaby wrote: > On 13. 07. 22, 9:45, Jiri Slaby wrote: > > On 12. 07. 22, 20:39, Greg Kroah-Hartman wrote: > > > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > > > > > commit 9bb2ec608a209018080ca262f771e6a9ff203b6f upstream. > > > > > > Update retpoline validation with the new CONFIG_RETPOLINE requirement of > > > not having bare naked RET instructions. > > > > Hi, > > > > this breaks compilation on i386: > > > arch/x86/kernel/../../x86/xen/xen-head.S:35: Error: no such > > instruction: `annotate_unret_safe' > > > > Config: > > https://raw.githubusercontent.com/openSUSE/kernel-source/stable/config/i386/pae > > > > > > And yeah, upstream¹⁾ is affected too. > > > > ¹⁾I am at commit b047602d579b4fb028128a525f056bbdc890e7f0. > > A naive fix is: > --- a/arch/x86/kernel/head_32.S > +++ b/arch/x86/kernel/head_32.S > @@ -23,6 +23,7 @@ > #include <asm/cpufeatures.h> > #include <asm/percpu.h> > #include <asm/nops.h> > +#include <asm/nospec-branch.h> > #include <asm/bootparam.h> > #include <asm/export.h> > #include <asm/pgtable_32.h> > > The question (I don't know answer to) is whether x86_32 should actually do > ANNOTATE_UNRET_SAFE. I doubt it should be doing that, but I'll let others answer more definitively. Your commit seems sane, for some reason I thought Boris tested i386 builds, but maybe in the end something snuck in that broke it. thanks, greg k-h
