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From:   Marco Elver <elver@google.com>
Date:   Tue, 22 Oct 2019 15:02:37 +0200
Message-ID: <CANpmjNPcToD2Joe_BE4xgLDOGCscHrtJdqivDPfFjE6nCpq5PQ@mail.gmail.com>
Subject: Re: [PATCH v2 8/8] x86, kcsan: Enable KCSAN for x86
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     LKMM Maintainers -- Akira Yokosawa <akiyks@gmail.com>,
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On Tue, 22 Oct 2019 at 14:59, Mark Rutland <mark.rutland@arm.com> wrote:
>
> On Thu, Oct 17, 2019 at 04:13:05PM +0200, Marco Elver wrote:
> > This patch enables KCSAN for x86, with updates to build rules to not use
> > KCSAN for several incompatible compilation units.
> >
> > Signed-off-by: Marco Elver <elver@google.com>
> > ---
> > v2:
> > * Document build exceptions where no previous above comment explained
> >   why we cannot instrument.
> > ---
> >  arch/x86/Kconfig                      | 1 +
> >  arch/x86/boot/Makefile                | 2 ++
> >  arch/x86/boot/compressed/Makefile     | 2 ++
> >  arch/x86/entry/vdso/Makefile          | 3 +++
> >  arch/x86/include/asm/bitops.h         | 6 +++++-
> >  arch/x86/kernel/Makefile              | 7 +++++++
> >  arch/x86/kernel/cpu/Makefile          | 3 +++
> >  arch/x86/lib/Makefile                 | 4 ++++
> >  arch/x86/mm/Makefile                  | 3 +++
> >  arch/x86/purgatory/Makefile           | 2 ++
> >  arch/x86/realmode/Makefile            | 3 +++
> >  arch/x86/realmode/rm/Makefile         | 3 +++
> >  drivers/firmware/efi/libstub/Makefile | 2 ++
> >  13 files changed, 40 insertions(+), 1 deletion(-)
>
> > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> > index 0460c7581220..693d0a94b118 100644
> > --- a/drivers/firmware/efi/libstub/Makefile
> > +++ b/drivers/firmware/efi/libstub/Makefile
> > @@ -31,7 +31,9 @@ KBUILD_CFLAGS                       := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
> >                                  -D__DISABLE_EXPORTS
> >
> >  GCOV_PROFILE                 := n
> > +# Sanitizer runtimes are unavailable and cannot be linked here.
> >  KASAN_SANITIZE                       := n
> > +KCSAN_SANITIZE                       := n
> >  UBSAN_SANITIZE                       := n
> >  OBJECT_FILES_NON_STANDARD    := y
>
> Not a big deal, but it might make sense to move the EFI stub exception
> to patch 3 since it isn't x86 specific (and will also apply for arm64).

Thanks for spotting, moved for v3.

-- Marco

> Otherwise this looks good to me.
>
> Thanks,
> Mark.