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Date:   Wed, 22 Mar 2023 11:33:18 -0700
From:   Josh Poimboeuf <jpoimboe@kernel.org>
To:     Sami Tolvanen <samitolvanen@google.com>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Jason Baron <jbaron@akamai.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ard Biesheuvel <ardb@kernel.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Will McVicker <willmcvicker@google.com>,
        Kees Cook <keescook@chromium.org>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 08/11] arm64/static_call: Fix static call CFI
 violations
Message-ID: <20230322183318.pqu2jjmi33j4an33@treble>
References: <cover.1679456900.git.jpoimboe@kernel.org>
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 <CABCJKuf5hsddHpnON5q9LpAXr-8s=5dL0iTpRD-hFzcBynB+Gw@mail.gmail.com>
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On Wed, Mar 22, 2023 at 11:07:21AM -0700, Sami Tolvanen wrote:
> > +/*
> > + * Make a dummy reference to a function pointer in C to force the compiler to
> > + * emit a __kcfi_typeid_ symbol for asm to use.
> > + */
> > +#define GEN_CFI_SYM(func)                                              \
> > +       static typeof(func) __used __section(".discard.cfi") *__UNIQUE_ID(cfi) = func
> 
> Couldn't we just use __ADDRESSABLE instead of adding a separate macro?
> The type of the variable shouldn't matter here, as long as we take the
> address of func.

Oh I did pretty much reimplement __ADDRESSABLE didn't I ;-)

-- 
Josh