Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210725104618.365790-1-geert@linux-m68k.org> <db2de193-a10-598-a21e-3a305b91d191@linux-m68k.org>
In-Reply-To: <db2de193-a10-598-a21e-3a305b91d191@linux-m68k.org>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 26 Jul 2021 09:34:45 +0200
Message-ID: <CAMuHMdWrg7zUC+iMjXS=RS=Fa7ZVS-0iycjQ2UP6W0pHzdGxKQ@mail.gmail.com>
Subject: Re: [PATCH] m68k: Fix asm register constraints for atomic ops
To:     Finn Thain <fthain@linux-m68k.org>
Cc:     Greg Ungerer <gerg@uclinux.org>, Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Brendan Jackman <jackmanb@google.com>,
        kernel test robot <lkp@intel.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Finn,

On Mon, Jul 26, 2021 at 1:45 AM Finn Thain <fthain@linux-m68k.org> wrote:
> On Sun, 25 Jul 2021, Geert Uytterhoeven wrote:
> > Fixes: d839bae4269aea46 ("locking,arch,m68k: Fold atomic_ops")
> > ...
> > Technically, the issue was present before, but I doubt adding pre-v3.18
> > Fixes tags would make any difference for stable...
>
> There is a better way to constrain backporting, that is Cc:
> stable@vger.kernel.org # 3.12+

I don't want to constrain backporting.

> The reason I mention it is that Fixes tags could be seen as a way to
> identify commits that introduce bugs, e.g. for the purposes of training

OK, had a look through the full log....
There are no other commits introducing the bug (renaming and
merging files without changing functions doesn't count), except for the
initial import into git. So I'll add that one, too.

> AIs, or attributing blame, or measuring quality etc. I think it would be
> unfair to point the finger at Peter's commit.

The first Fixes commit definitely introduced a new buggy user.
The second Fixes commit is debatable, as it copied the bug for a new
function from two functions that were removed in the process.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds