Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Sun, 14 Jul 2019 12:51:57 +0300
From:   Alexey Dobriyan <adobriyan@gmail.com>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>, izbyshev@ispras.ru,
        Oleg Nesterov <oleg@redhat.com>,
        Michal Kubecek <mkubecek@suse.cz>, shasta@toxcorp.com,
        linux-kernel@vger.kernel.org, security@kernel.org
Subject: Re: [PATCH] proc: revert /proc/*/cmdline rewrite
Message-ID: <20190714095157.GA2276@avx2>
References: <20190713072855.GB23167@avx2>
 <CAHk-=wj_mrNnM-q_z95GcNB=Ab4LaUC6Bi6Q-+3Q9u9NC=3iDA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <CAHk-=wj_mrNnM-q_z95GcNB=Ab4LaUC6Bi6Q-+3Q9u9NC=3iDA@mail.gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

	[re-add lists]

On Sat, Jul 13, 2019 at 10:50:20AM -0700, Linus Torvalds wrote:
> On Sat, Jul 13, 2019 at 12:29 AM Alexey Dobriyan <adobriyan@gmail.com> wrote:
> >
> > /proc/*/cmdline continues to cause problems:
> 
> If we're reverting this, then we should revert all the way back to the
> original fixed-length one that had the original semantics and was
> simple.

No, because all those Java applications have command lines measured in
dozens of kilobytes.

> What was the problem with the one-line fix instead?

The problem is that I can't even drag this trivia in out of _fear_ that
it is userspace observable:

	https://marc.info/?t=155863429700002&r=1&w=4
	[PATCH] elf: fix "start_code" evaluation

and yet the patch which did a regression and an infoleak continues
to be papered over and for which the only justification was
"simplify and clarify".