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References: <20210930180531.1190642-1-samitolvanen@google.com>
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From: Sami Tolvanen <samitolvanen@google.com>
Date: Wed, 6 Oct 2021 10:45:41 -0700
Message-ID: <CABCJKudTuheEd5jyhXmfJHup7iYzOz3_OcO92hFnpRK1MapJSg@mail.gmail.com>
Subject: Re: [PATCH v4 06/15] ftrace: Use an opaque type for functions not
 callable from C
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>, X86 ML <x86@kernel.org>, 
	Kees Cook <keescook@chromium.org>, Peter Zijlstra <peterz@infradead.org>, 
	Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, 
	Sedat Dilek <sedat.dilek@gmail.com>, linux-hardening@vger.kernel.org, 
	LKML <linux-kernel@vger.kernel.org>, llvm@lists.linux.dev
Content-Type: text/plain; charset="UTF-8"

On Wed, Oct 6, 2021 at 9:58 AM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Wed, 6 Oct 2021 09:31:04 -0700
> Sami Tolvanen <samitolvanen@google.com> wrote:
>
> > > > On Thu, Sep 30, 2021 at 11:05:22AM -0700, Sami Tolvanen wrote:
> > > > > With CONFIG_CFI_CLANG, the compiler changes function references to point
> > > > > to the CFI jump table. As ftrace_call, ftrace_regs_call, and mcount_call
> > > > > are not called from C, use DECLARE_ASM_FUNC_SYMBOL to declare them.
> > >
> > > "not called from C" is a bit confusing.
> >
> > Any thoughts on how to make this less confusing?
>
>  "Not called by C code, but injected by the compiler."
>
> ?

Sure, sounds good to me. I'll update this in v5.

Sami