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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Thu, 14 Oct 2021 11:29:34 -0700
Message-ID: <CAKwvOd=znqwGT_FmUPbWPodjrnFHf+FtHMaYCTfvUeukBCM3xw@mail.gmail.com>
Subject: Re: [PATCH V3 06/49] compiler_types.h: Add __noinstr_section() for noinstr
To:     Lai Jiangshan <jiangshanlai@gmail.com>,
        Miguel Ojeda <ojeda@kernel.org>
Cc:     linux-kernel@vger.kernel.org, x86@kernel.org,
        Lai Jiangshan <laijs@linux.alibaba.com>,
        Borislav Petkov <bp@alien8.de>,
        Kees Cook <keescook@chromium.org>,
        Nathan Chancellor <nathan@kernel.org>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Sami Tolvanen <samitolvanen@google.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Marco Elver <elver@google.com>, Arnd Bergmann <arnd@arndb.de>,
        Ard Biesheuvel <ardb@kernel.org>
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On Wed, Oct 13, 2021 at 8:34 PM Lai Jiangshan <jiangshanlai@gmail.com> wrote:
>
> From: Lai Jiangshan <laijs@linux.alibaba.com>
>
> And it will be extended for C entry code.
>
> Cc: Borislav Petkov <bp@alien8.de>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
> ---
>  include/linux/compiler_types.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
> index b6ff83a714ca..3c77631c68bd 100644
> --- a/include/linux/compiler_types.h
> +++ b/include/linux/compiler_types.h
> @@ -208,10 +208,12 @@ struct ftrace_likely_data {
>  #endif
>
>  /* Section for code which can't be instrumented at all */
> -#define noinstr                                                                \
> -       noinline notrace __attribute((__section__(".noinstr.text")))    \
> +#define __noinstr_section(section)                             \
> +       noinline notrace __attribute((__section__(section)))    \

Can we use __section(section) here (from
include/linux/compiler_attributes.h)? I kind of can't stand seeing
attributes open coded.

>         __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage
>
> +#define noinstr __noinstr_section(".noinstr.text")
> +
>  #endif /* __KERNEL__ */
>
>  #endif /* __ASSEMBLY__ */
> --
> 2.19.1.6.gb485710b
>


-- 
Thanks,
~Nick Desaulniers