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Date:   Mon, 13 Jun 2022 09:10:43 -0700
From:   Josh Poimboeuf <jpoimboe@kernel.org>
To:     Sami Tolvanen <samitolvanen@google.com>
Cc:     linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>, x86@kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Joao Moreira <joao@overdrivepizza.com>,
        Sedat Dilek <sedat.dilek@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        linux-hardening@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev
Subject: Re: [RFC PATCH v3 15/20] objtool: Disable CFI warnings
Message-ID: <20220613161043.4wiqservfyxeme4f@treble>
References: <20220610233513.1798771-1-samitolvanen@google.com>
 <20220610233513.1798771-16-samitolvanen@google.com>
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On Fri, Jun 10, 2022 at 04:35:08PM -0700, Sami Tolvanen wrote:
> The __cfi_ preambles contain int3 padding and a mov instruction that
> embeds the KCFI type identifier in the following format:
> 
>   ; type preamble
>   __cfi_function:
>     int3
>     int3
>     mov <id>, %eax
>     int3
>     int3
>   function:
>     ...
> 
> While the preamble symbols are STT_FUNC and contain valid
> instructions, they are never executed and always fall through. Skip
> the warning for them.
> 
> .kcfi_traps sections point to CFI traps in text sections. Also skip
> the warning about them referencing !ENDBR instructions.
> 
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>

-- 
Josh