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References: <20221219055431.22596-1-ashimida.1990@gmail.com>
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From:   Peter Collingbourne <pcc@google.com>
Date:   Wed, 8 Feb 2023 21:32:03 -0800
Message-ID: <CAMn1gO6hwaSDCqigwoH981ffVbU8OvgJhrGh997kGseCSbpAJA@mail.gmail.com>
Subject: Re: [RFC/RFT 0/3] Add compiler support for Control Flow Integrity
To:     Dan Li <ashimida.1990@gmail.com>
Cc:     gcc-patches@gcc.gnu.org,
        Richard Sandiford <richard.sandiford@arm.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Sami Tolvanen <samitolvanen@google.com>,
        Kees Cook <keescook@chromium.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Tom Rix <trix@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Marco Elver <elver@google.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Song Liu <song@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Uros Bizjak <ubizjak@gmail.com>,
        Kumar Kartikeya Dwivedi <memxor@gmail.com>,
        Juergen Gross <jgross@suse.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Borislav Petkov <bp@suse.de>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Aaron Tomlin <atomlin@redhat.com>,
        Kalesh Singh <kaleshsingh@google.com>,
        Yuntao Wang <ytcoode@gmail.com>,
        Changbin Du <changbin.du@intel.com>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev,
        linux-hardening@vger.kernel.org
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On Sun, Dec 18, 2022 at 10:06 PM Dan Li <ashimida.1990@gmail.com> wrote:
>
> This series of patches is mainly used to support the control flow
> integrity protection of the linux kernel [1], which is similar to
> -fsanitize=kcfi in clang 16.0 [2,3].
>
> I hope that this feature will also support user-mode CFI in the
> future (at least for developers who can recompile the runtime),
> so I use -fsanitize=cfi as a compilation option here.

Please don't. The various CFI-related build flags are confusing enough
without also having this inconsistency between Clang and GCC.

Peter