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From:   Sami Tolvanen <samitolvanen@google.com>
Date:   Mon, 28 Oct 2019 08:19:49 -0700
Message-ID: <CABCJKucUR=reCaOh_n8XGSZixmsckNtFXoaq_NOdB+iw-5UxMA@mail.gmail.com>
Subject: Re: [PATCH v2 05/17] add support for Clang's Shadow Call Stack (SCS)
To:     Joe Perches <joe@perches.com>
Cc:     Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Dave Martin <Dave.Martin@arm.com>,
        Kees Cook <keescook@chromium.org>,
        Laura Abbott <labbott@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Jann Horn <jannh@google.com>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Kernel Hardening <kernel-hardening@lists.openwall.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        LKML <linux-kernel@vger.kernel.org>
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Hi Joe,

On Sat, Oct 26, 2019 at 8:57 AM Joe Perches <joe@perches.com> wrote:
> > +#if __has_feature(shadow_call_stack)
> > +# define __noscs     __attribute__((no_sanitize("shadow-call-stack")))
>
> __no_sanitize__

Sorry, I missed your earlier message about this. I'm following Clang's
documentation for the attribute:

https://clang.llvm.org/docs/ShadowCallStack.html#attribute-no-sanitize-shadow-call-stack

Although __no_sanitize__ seems to work too. Is there a particular
reason to prefer that form over the one in the documentation?

Sami