Re: [PATCH v2 08/28] x86, build: use objtool mcount

Kees Cook
2020-09-03T21:58:47Z

On Thu, Sep 03, 2020 at 01:30:33PM -0700, Sami Tolvanen wrote:
> Select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION is selected to use
> objtool to generate __mcount_loc sections for dynamic ftrace with
> Clang and gcc <5.
>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Am I right to understand that this fixes mcount for Clang generally
(i.e. it's not _strictly_ related to LTO, though LTO depends on this
change)? And does this mean mcount was working for gcc < 5?

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

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Kees Cook