Re: [RFC PATCH v2 15/21] objtool: Don't warn about __cfi_ preambles falling through

Kees Cook
2022-05-14T21:56:51Z

On Fri, May 13, 2022 at 01:21:53PM -0700, Sami Tolvanen wrote:
> The __cfi_ preambles contain valid instructions, which embed KCFI
> type information in the following format:
>
> __cfi_function:
> int3
> int3
> mov <id>, %eax
> int3
> int3
> function:
> ...
>
> While the preambles are STT_FUNC and contain valid instructions,
> they are not executed and always fall through. Skip the warning for
> them.
>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

--
Kees Cook