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Date:   Thu, 24 Feb 2022 16:55:08 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com,
        jpoimboe@redhat.com, andrew.cooper3@citrix.com,
        linux-kernel@vger.kernel.org, ndesaulniers@google.com,
        samitolvanen@google.com, mark.rutland@arm.com,
        alyssa.milburn@intel.com, mbenes@suse.cz, rostedt@goodmis.org,
        mhiramat@kernel.org, alexei.starovoitov@gmail.com
Subject: Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry__ location
Message-ID: <202202241654.1D43F008@keescook>
References: <20220224145138.952963315@infradead.org>
 <20220224151322.714815604@infradead.org>
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On Thu, Feb 24, 2022 at 03:51:50PM +0100, Peter Zijlstra wrote:
> Have ftrace_location() search the symbol for the __fentry__ location
> when it isn't at func+0 and use this for {,un}register_ftrace_direct().
> 
> This avoids a whole bunch of assumptions about __fentry__ being at
> func+0.
> 
> Suggested-by: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Cool. This should help with anything using __fentry__ tricks (i.e.
future CFI...), yes?

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

-- 
Kees Cook