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Date:   Fri, 15 May 2020 19:47:03 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Xiaoming Ni <nixiaoming@huawei.com>
Cc:     mcgrof@kernel.org, yzaikin@google.com, adobriyan@gmail.com,
        mingo@kernel.org, peterz@infradead.org, akpm@linux-foundation.org,
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        bigeasy@linutronix.de, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, wangle6@huawei.com
Subject: Re: [PATCH 2/4] proc/sysctl: add shared variables -1
Message-ID: <202005151946.C6335E92@keescook>
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On Sat, May 16, 2020 at 10:32:19AM +0800, Xiaoming Ni wrote:
> On 2020/5/16 0:05, Kees Cook wrote:
> > On Fri, May 15, 2020 at 05:06:28PM +0800, Xiaoming Ni wrote:
> > > On 2020/5/15 16:06, Kees Cook wrote:
> > > > On Fri, May 15, 2020 at 12:33:42PM +0800, Xiaoming Ni wrote:
> > > > > Add the shared variable SYSCTL_NEG_ONE to replace the variable neg_one
> > > > > used in both sysctl_writes_strict and hung_task_warnings.
> > > > > 
> > > > > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
> > > > > ---
> > > > >    fs/proc/proc_sysctl.c     | 2 +-
> > > > >    include/linux/sysctl.h    | 1 +
> > > > >    kernel/hung_task_sysctl.c | 3 +--
> > > > >    kernel/sysctl.c           | 3 +--
> > > > 
> > > > How about doing this refactoring in advance of the extraction patch?
> > > Before  advance of the extraction patch, neg_one is only used in one file,
> > > does it seem to have no value for refactoring?
> > 
> > I guess it doesn't matter much, but I think it's easier to review in the
> > sense that neg_one is first extracted and then later everything else is
> > moved.
> > 
> Later, when more features sysctl interface is moved to the code file, there
> will be more variables that need to be extracted.
> So should I only extract the neg_one variable here, or should I extract all
> the variables used by multiple features?

Hmm -- if you're going to do a consolidation pass, then nevermind, I
don't think order will matter then.

Thank you for the cleanup! Sorry we're giving you back-and-forth advice!

-Kees

-- 
Kees Cook