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From:   Alexander Potapenko <glider@google.com>
Date:   Wed, 31 May 2023 09:57:57 +0200
Message-ID: <CAG_fn=VOsPw=EqN=P3zPfDyD=ZKYtzUVZ=y42HcqrY2hznx6Ug@mail.gmail.com>
Subject: Re: [PATCH v2] string: use __builtin_memcpy() in strlcpy/strlcat
To:     Kees Cook <keescook@chromium.org>
Cc:     andy@kernel.org, Andrew Morton <akpm@linux-foundation.org>,
        nathan@kernel.org, dvyukov@google.com, elver@google.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        kasan-dev@googlegroups.com, ndesaulniers@google.com
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On Wed, May 31, 2023 at 1:10=E2=80=AFAM Kees Cook <keescook@chromium.org> w=
rote:
>
> On Tue, 30 May 2023 10:39:11 +0200, Alexander Potapenko wrote:
> > lib/string.c is built with -ffreestanding, which prevents the compiler
> > from replacing certain functions with calls to their library versions.
> >
> > On the other hand, this also prevents Clang and GCC from instrumenting
> > calls to memcpy() when building with KASAN, KCSAN or KMSAN:
> >  - KASAN normally replaces memcpy() with __asan_memcpy() with the
> >    additional cc-param,asan-kernel-mem-intrinsic-prefix=3D1;
> >  - KCSAN and KMSAN replace memcpy() with __tsan_memcpy() and
> >    __msan_memcpy() by default.
> >
> > [...]
>
> Applied to for-next/hardening, thanks!
>
> [1/1] string: use __builtin_memcpy() in strlcpy/strlcat
>       https://git.kernel.org/kees/c/cfe93c8c9a7a

Note that Andrew also picked it to mm-unstable