linux-kernel - Re: [PATCH] f2fs: Eliminate usage of uninitialized

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Message-ID: <202006151311.138CD1D@keescook>
Date:   Mon, 15 Jun 2020 13:11:38 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Jason Yan <yanaijie@...wei.com>
Cc:     jaegeuk@...nel.org, chao@...nel.org,
        linux-f2fs-devel@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org, kernel-hardening@...ts.openwall.com,
        Chao Yu <yuchao0@...wei.com>
Subject: Re: [PATCH] f2fs: Eliminate usage of uninitialized_var() macro

On Mon, Jun 15, 2020 at 04:51:32PM +0800, Jason Yan wrote:
> This is an effort to eliminate the uninitialized_var() macro[1].
> 
> The use of this macro is the wrong solution because it forces off ANY
> analysis by the compiler for a given variable. It even masks "unused
> variable" warnings.
> 
> Quoted from Linus[2]:
> 
> "It's a horrible thing to use, in that it adds extra cruft to the
> source code, and then shuts up a compiler warning (even the _reliable_
> warnings from gcc)."
> 
> Fix it by remove this variable since it is not needed at all.
> 
> [1] https://github.com/KSPP/linux/issues/81
> [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
> 
> Cc: Kees Cook <keescook@...omium.org>
> Suggested-by: Chao Yu <yuchao0@...wei.com>
> Signed-off-by: Jason Yan <yanaijie@...wei.com>
> ---
>  v2: Directly remove this variable.

Thanks! I've applied this to my uninitialized_var() macro removal
series.

-- 
Kees Cook