Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
MIME-Version: 1.0
References: <20221219061758.23321-1-ashimida.1990@gmail.com>
 <20230325085416.95191-1-ashimida.1990@gmail.com> <20230327093016.GB4253@hirez.programming.kicks-ass.net>
 <CABCJKueH6ohH27xCPz9a_ndRR26Na_mo=MGF3eqjwV2=gJy+wQ@mail.gmail.com>
In-Reply-To: <CABCJKueH6ohH27xCPz9a_ndRR26Na_mo=MGF3eqjwV2=gJy+wQ@mail.gmail.com>
From:   Dan Li <ashimida.1990@gmail.com>
Date:   Wed, 13 Dec 2023 16:48:50 +0800
Message-ID: <CAE+Z0PFZaa2bwtfY5P7ZDYH4JjMxKpJgqz0m+KJ_ks4dctzAKA@mail.gmail.com>
Subject: Re: [RFC/RFT,V2] CFI: Add support for gcc CFI in aarch64
To:     Sami Tolvanen <samitolvanen@google.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Aaron Tomlin <atomlin@redhat.com>,
        Alexander Potapenko <glider@google.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Boqun Feng <boqun.feng@gmail.com>,
        Borislav Petkov <bp@alien8.de>, Borislav Petkov <bp@suse.de>,
        Brian Gerst <brgerst@gmail.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Changbin Du <changbin.du@intel.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        gcc-patches@gcc.gnu.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Juergen Gross <jgross@suse.com>,
        Kalesh Singh <kaleshsingh@google.com>,
        Kees Cook <keescook@chromium.org>,
        Kumar Kartikeya Dwivedi <memxor@gmail.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Marco Elver <elver@google.com>,
        Mark Brown <broonie@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Michael Roth <michael.roth@amd.com>,
        Michal Marek <michal.lkml@markovi.net>,
        Miguel Ojeda <ojeda@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Richard Sandiford <richard.sandiford@arm.com>,
        Song Liu <song@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tom Rix <trix@redhat.com>, Uros Bizjak <ubizjak@gmail.com>,
        Will Deacon <will@kernel.org>, x86@kernel.org,
        Yuntao Wang <ytcoode@gmail.com>, Yu Zhao <yuzhao@google.com>,
        Zhen Lei <thunder.leizhen@huawei.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, linux-arch@vger.kernel.org,
        linux-modules@vger.kernel.org, linux-perf-users@vger.kernel.org,
        wanglikun@lixiang.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

+ Likun

On Tue, 28 Mar 2023 at 06:18, Sami Tolvanen <samitolvanen@google.com> wrote=
:
>
> On Mon, Mar 27, 2023 at 2:30=E2=80=AFAM Peter Zijlstra <peterz@infradead.=
org> wrote:
> >
> > On Sat, Mar 25, 2023 at 01:54:16AM -0700, Dan Li wrote:
> >
> > > In the compiler part[4], most of the content is the same as Sami's
> > > implementation[3], except for some minor differences, mainly includin=
g:
> > >
> > > 1. The function typeid is calculated differently and it is difficult
> > > to be consistent.
> >
> > This means there is an effective ABI break between the compilers, which
> > is sad :-( Is there really nothing to be done about this?
>
> I agree, this would be unfortunate, and would also be a compatibility
> issue with rustc where there's ongoing work to support
> clang-compatible CFI type hashes:
>
> https://github.com/rust-lang/rust/pull/105452
>
> Sami