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Message-ID: <2c13c39acb55df5dbb0d40c806bb1d7dc4bde2ae.camel@perches.com>
Subject: Re: [PATCH v2 05/17] add support for Clang's Shadow Call Stack (SCS)
From:   Joe Perches <joe@perches.com>
To:     samitolvanen@google.com, 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>
Cc:     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@googlegroups.com,
        kernel-hardening@lists.openwall.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Date:   Sat, 26 Oct 2019 08:57:41 -0700
In-Reply-To: <20191024225132.13410-6-samitolvanen@google.com>
References: <20191018161033.261971-1-samitolvanen@google.com>
         <20191024225132.13410-1-samitolvanen@google.com>
         <20191024225132.13410-6-samitolvanen@google.com>
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On Thu, 2019-10-24 at 15:51 -0700, samitolvanen@google.com wrote:
> This change adds generic support for Clang's Shadow Call Stack,
> which uses a shadow stack to protect return addresses from being
> overwritten by an attacker. Details are available here:
[]
> diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
[]
> @@ -42,3 +42,9 @@
>   * compilers, like ICC.
>   */
>  #define barrier() __asm__ __volatile__("" : : : "memory")
> +
> +#if __has_feature(shadow_call_stack)
> +# define __noscs	__attribute__((no_sanitize("shadow-call-stack")))

__no_sanitize__