Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230628-pokal-puzzeln-5199c679b051@brauner>
In-Reply-To: <20230628-pokal-puzzeln-5199c679b051@brauner>
From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu, 29 Jun 2023 16:52:43 -0700
Message-ID: <CAHk-=wiBXJOzkez2Rd=cQ5ckttJq6OdYtArFmCtVQHyeuQBGrw@mail.gmail.com>
Subject: Re: [GIT PULL] pid: use flex array
To:     Christian Brauner <brauner@kernel.org>,
        Kees Cook <keescook@chromium.org>
Cc:     linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, 28 Jun 2023 at 03:37, Christian Brauner <brauner@kernel.org> wrote:
>
> This contains Kees' work to make struct upid in struct pid a proper
> flexible array and thus gets rid of a bunch of syzbot UBSAN warnings.

Hmm. Of this, about half were replacing "array + index" with "&array[index]".

Honestly, it makes no difference, but the reverse is also true: the
"array + index" is *very* traditional, and if people have problems
with that simple syntax I really don't know what to say. It's kind of
core C. It's *literally* how arrays work, and what the '[]' operator
means.

And of the remaining half, half again is using a truly disgusting

    struct_size((struct pid *)0, numbers, X)

thing. That is *GARBAGE*. It's garbage for too many reasons for me to
actually pull this sh*t, but let me just name them:

 - 0 isn't a pointer. Stop doing that.

 - dammit, we have 'struct_size_t' that does the above disgusting cast
without getting that simple thing wrong.

In other words, this pull request contained half pointless and
unrelated churn, and 25% actual garbage.

In other words, I'm not pulling this to just get the remaining 25%.

              Linus