Re: [PATCH 2/3] kcov: wire up compiler instrumentation for CONFIG_KCOV_EXT_RECORDS

[Jann Horn]

On Fri, Mar 13, 2026 at 8:54 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> On Wed, 11 Mar 2026 at 22:06, Jann Horn <jannh@xxxxxxxxxx> wrote:
> > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > index 93f356d2b3d9..dddc330ad3ca 100644
> > --- a/lib/Kconfig.debug
> > +++ b/lib/Kconfig.debug
> > @@ -2215,6 +2215,20 @@ config KCOV
> >
> >           For more details, see Documentation/dev-tools/kcov.rst.
> >
> > +config KCOV_EXT_RECORDS
> > +       bool "Support extended KCOV records with function entry/exit records"
> > +       depends on KCOV
> > +       depends on 64BIT
> > +       # TODO: check CLANG_VERSION instead once this has landed in an LLVM
> > +       # release
>
> I think the compiler option check is actually better, since it will
> allow us to test earlier and supports compiler backports.

Makes sense, I'll remove the TODO. (I was thinking about it from the
perspective that every compiler flag test increases the kernel build
time a tiny bit, because it causes an extra compiler invocation at the
start of the build.)

> But it may be good to add a reference to the compiler patch in the
> commit description.

Ack, will add that.

> Otherwise:
>
> Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>

Thanks!