Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <202210251659.tRMs78RH-lkp@intel.com>
In-Reply-To: <202210251659.tRMs78RH-lkp@intel.com>
From:   Sami Tolvanen <samitolvanen@google.com>
Date:   Wed, 26 Oct 2022 08:36:29 -0700
Message-ID: <CABCJKudMzRcgZCVv4gF3QwKGxq3F2aVQj87WkMdh1ZFvy10DoQ@mail.gmail.com>
Subject: Re: ld.lld: error: undefined symbol: __kcfi_typeid_ftrace_stub_graph
To:     kernel test robot <lkp@intel.com>
Cc:     Peter Zijlstra <peterz@infradead.org>, llvm@lists.linux.dev,
        kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Kees Cook <keescook@chromium.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Oct 25, 2022 at 1:22 AM kernel test robot <lkp@intel.com> wrote:
> >> ld.lld: error: undefined symbol: __kcfi_typeid_ftrace_stub_graph
>    >>> referenced by entry-ftrace.S:299 (arch/arm64/kernel/entry-ftrace.S:299)
>    >>>               arch/arm64/kernel/entry-ftrace.o:(.text+0x48) in archive vmlinux.a

We don't seem to have any C translation units that would take the
address of ftrace_stub_graph with this config, which means the
compiler won't generate the __kcfi_typeid_ftrace_stub_graph symbol.
Adding __ADDRESSABLE(ftrace_stub_graph) to a suitable place would fix
this issue, perhaps somewhere in arch/arm64/kernel/ftrace.c?

Sami