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Date:   Thu, 3 Feb 2022 00:00:32 +0300
From:   Alexey Dobriyan <adobriyan@gmail.com>
To:     Shuah Khan <skhan@linuxfoundation.org>
Cc:     Kees Cook <keescook@chromium.org>,
        Eric Biederman <ebiederm@xmission.com>,
        Shuah Khan <shuah@kernel.org>, linux-kselftest@vger.kernel.org,
        Ariadne Conill <ariadne@dereferenced.org>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        Christian Brauner <brauner@kernel.org>,
        Rich Felker <dalias@libc.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH] selftests/exec: Avoid future NULL argv execve warning
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References: <20220201000807.2453486-1-keescook@chromium.org>
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 <7af32164-dbdf-26f1-1aaa-b720365f9743@linuxfoundation.org>
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On Wed, Feb 02, 2022 at 10:38:57AM -0700, Shuah Khan wrote:
> On 2/2/22 8:13 AM, Alexey Dobriyan wrote:
> > On Mon, Jan 31, 2022 at 04:08:07PM -0800, Kees Cook wrote:
> > > Build actual argv for launching recursion test to avoid future warning
> > > about using an empty argv in execve().
> > 
> > > --- a/tools/testing/selftests/exec/recursion-depth.c
> > > +++ b/tools/testing/selftests/exec/recursion-depth.c
> > > @@ -24,8 +24,14 @@
> > >   #include <sys/mount.h>
> > >   #include <unistd.h>
> > > +#define FILENAME "/tmp/1"
> > > +#define HASHBANG "#!" FILENAME "\n"
> > > +
> > >   int main(void)
> > >   {
> > > +	char * const argv[] = { FILENAME, NULL };
> > > +	int rv;
> > 
> > Can we move out of -Wdeclaration-after-statement mentality in tests at least?
> 
> selftest like the rest of the kernel follows the same coding guidelines.
> It will follow the moving "-Wdeclaration-after-statement mentality" when
> the rest of the kernel does.
> 
> Looks like this topic was discussed in the following:
> https://patchwork.kernel.org/project/linux-kbuild/patch/c6fda26e8d134264b04fadc3386d6c32@gmail.com/

The only real argument is "gcc miscompiles /proc" to which adding -Wdeclaration-after-statement
looks like a too big hammer.

Why can't we have nice things?