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Date:   Tue, 21 Dec 2021 02:08:54 +0000
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From:   yajun.deng@linux.dev
Message-ID: <56d8e86231eec9f46abf9117596ffe07@linux.dev>
Subject: Re: [PATCH] init: fix the wrong __setup_param() definition
To:     "Marco Elver" <elver@google.com>
Cc:     keescook@chromium.org, samitolvanen@google.com, ojeda@kernel.org,
        masahiroy@kernel.org, linux-kernel@vger.kernel.org
In-Reply-To: <CANpmjNPsCVkq7SsVL-xpktGe3RsJnRGTJxEPZ60VUt1w_5QgPQ@mail.gmail.com>
References: <CANpmjNPsCVkq7SsVL-xpktGe3RsJnRGTJxEPZ60VUt1w_5QgPQ@mail.gmail.com>
 <20211220035448.12054-1-yajun.deng@linux.dev>
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December 20, 2021 7:20 PM, "Marco Elver" <elver@google.com> wrote:=0A=0A>=
 On Mon, 20 Dec 2021 at 04:55, Yajun Deng <yajun.deng@linux.dev> wrote:=
=0A> =0A>> The parameters in __setup_param() should be four rather than t=
hree when=0A>> MODULE isn't definited.=0A> =0A> This is actually "when MO=
DULE is defined". __setup_param() becomes a=0A> nop when compiling as a m=
odule.=0A> =0A> But that begs the question: why hasn't this been caught b=
efore?=0A> Probably because nobody should be using __setup_param() if som=
ething=0A> can also be compiled as a module, in which case module_param()=
 and=0A> friends should be used. But perhaps there are valid usecases whe=
re i=0A> t's meant to become a nop if MODULE.=0A> =0A> I don't object thi=
s fix, since the !MODULE __setup_param() seems like=0A> it was meant to b=
e defined.=0A> =0A> Just curious: did you actually encounter a problem wi=
th some new code=0A> using __setup_param()?=0A=0ANO, it is just code insp=
ection. But for the current code, it's really a bug.=0Avim drivers/clk/im=
x/clk.c  +161=0A=0A#ifndef MODULE=0A=0A...=0A__setup_param("earlycon", im=
x_keep_uart_earlycon,=0A              imx_keep_uart_clocks_param, 0); =0A=
__setup_param("earlyprintk", imx_keep_uart_earlyprintk,=0A              i=
mx_keep_uart_clocks_param, 0); =0A=0A=0A> =0A>> Fixes: 1da177e4c3f4 ("Lin=
ux-2.6.12-rc2")=0A>> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>=0A>=
> ---=0A>> include/linux/init.h | 2 +-=0A>> 1 file changed, 1 insertion(+=
), 1 deletion(-)=0A>> =0A>> diff --git a/include/linux/init.h b/include/l=
inux/init.h=0A>> index d82b4b2e1d25..62a77850f10e 100644=0A>> --- a/inclu=
de/linux/init.h=0A>> +++ b/include/linux/init.h=0A>> @@ -355,7 +355,7 @@ =
void __init parse_early_options(char *cmdline);=0A>> =0A>> #else /* MODUL=
E */=0A>> =0A>> -#define __setup_param(str, unique_id, fn) /* nothing */=
=0A>> +#define __setup_param(str, unique_id, fn, early)/* nothing */=0A>>=
 #define __setup(str, func) /* nothing */=0A>> #endif=0A>> =0A>> --=0A>> =
2.32.0