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From:   Alexander Potapenko <glider@google.com>
Date:   Thu, 2 Mar 2023 16:17:11 +0100
Message-ID: <CAG_fn=Ubagz667ZEM2wyabshZhY-wyJRFUzqxZkBj3AES+KnXg@mail.gmail.com>
Subject: Re: [PATCH 1/4] x86: kmsan: Don't rename memintrinsics in
 uninstrumented files
To:     Marco Elver <elver@google.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org,
        dave.hansen@linux.intel.com, hpa@zytor.com,
        akpm@linux-foundation.org, dvyukov@google.com, nathan@kernel.org,
        ndesaulniers@google.com, kasan-dev@googlegroups.com,
        Kees Cook <keescook@chromium.org>
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On Thu, Mar 2, 2023 at 4:13=E2=80=AFPM Marco Elver <elver@google.com> wrote=
:
>
> On Thu, 2 Mar 2023 at 15:28, Alexander Potapenko <glider@google.com> wrot=
e:
> >
> > On Thu, Mar 2, 2023 at 12:14=E2=80=AFPM Marco Elver <elver@google.com> =
wrote:
> > >
> > > On Wed, 1 Mar 2023 at 15:39, Alexander Potapenko <glider@google.com> =
wrote:
> > > >
> > > > KMSAN should be overriding calls to memset/memcpy/memmove and their
> > >
> > > You mean that the compiler will override calls?
> > > All supported compilers that have fsanitize=3Dkernel-memory replace
> > > memintrinsics with __msan_mem*() calls, right?
> >
> > Right. Changed to:
> >
> > KMSAN already replaces calls to to memset/memcpy/memmove and their
> > __builtin_ versions with __msan_memset/__msan_memcpy/__msan_memmove in
> > instrumented files, so there is no need to override them.
>
> But it's not KMSAN - KMSAN is the combined end result of runtime and
> compiler - in this case we need to be specific and point out it's the
> compiler that's doing it. There is no code in the Linux kernel that
> does this replacement.

Agreed. I'll replace with "clang -fsanitize=3Dkernel-memory"