From: Johan Hovold <johan@kernel.org>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Johan Hovold <johan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
"Mychaela N . Falconia" <falcon@freecalypso.org>,
"open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
USB <linux-usb@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/5] serial: core: add sysfs attribute to suppress ready signalling on open
Date: Tue, 1 Dec 2020 14:22:06 +0100 [thread overview]
Message-ID: <X8ZDfvuRbxqsKZMh@localhost> (raw)
In-Reply-To: <CAHp75VdMcYj0H-HZcmyWFU5ROLwSy=8Pan7JABZxGimqXE35WQ@mail.gmail.com>
On Tue, Dec 01, 2020 at 01:19:30PM +0200, Andy Shevchenko wrote:
> On Tue, Dec 1, 2020 at 1:04 PM Johan Hovold <johan@kernel.org> wrote:
> > 0x01 is 1 and is generally treated as boolean true as you know.
>
> Depends how you interpret this. kstrtobool() uses one character (and
> in some cases two) of the input. Everything else is garbage.
> Should we interpret garbage?
No, ideally we should reject the input.
> > So why should a sysfs-interface accept it as valid input and treat it as
> > false? That's just bad design.
>
> I can agree with this.
Looks like part of the problem are commits like 4cc7ecb7f2a6 ("param:
convert some "on"/"off" users to strtobool") which destroyed perfectly
well-defined interfaces.
> > You miss the point; kstrobool accepts "12" today and treats it as true.
> > You cannot extend such an interface to later accept a larger range than
> > 0 and 1 as you didn't return an error for "12" from the start (as someone
> > might now rely on "12" being treated as "1").
>
> Somehow cifs uses kstrtobool() in conjunction with the wider ranges. Nobody
> complained so far. But maybe they had it from day 1.
Wow, that's pretty nasty.
> So, we have two issues here: kstrtobool() doesn't report an error of
> input when it has garbage, the user may rely on garbage to be
> discarded.
Right, parsing is too allowing and there are too many ways to say
true/false.
The power-management attributes use 0 and 1 for boolean like I do here,
and I'd prefer to stick to that until we have deprecated the current
kstrtobool.
Johan
next prev parent reply other threads:[~2020-12-01 13:22 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-30 15:37 [PATCH 0/5] tty: add flag to suppress ready signalling on open Johan Hovold
2020-11-30 15:37 ` [PATCH 1/5] tty: add port " Johan Hovold
2020-11-30 23:36 ` Mychaela Falconia
2020-12-01 5:49 ` Jiri Slaby
2020-12-01 7:09 ` Mychaela Falconia
2020-12-01 7:16 ` Jiri Slaby
2020-12-01 8:46 ` Johan Hovold
2020-11-30 15:37 ` [PATCH 2/5] serial: core: add sysfs attribute " Johan Hovold
2020-11-30 18:27 ` Andy Shevchenko
2020-12-01 8:21 ` Johan Hovold
2020-12-01 10:55 ` Andy Shevchenko
2020-12-01 11:05 ` Johan Hovold
2020-12-01 11:19 ` Andy Shevchenko
2020-12-01 13:22 ` Johan Hovold [this message]
2020-12-01 13:49 ` Andy Shevchenko
2020-12-01 17:43 ` Johan Hovold
2020-12-01 16:44 ` Greg Kroah-Hartman
2020-12-01 17:24 ` Johan Hovold
2020-11-30 15:37 ` [PATCH 3/5] USB: serial: " Johan Hovold
2020-11-30 18:29 ` Andy Shevchenko
2020-11-30 15:37 ` [PATCH 4/5] USB: serial: ftdi_sio: pass port to quirk port_probe functions Johan Hovold
2020-11-30 15:37 ` [PATCH 5/5] USB: serial: ftdi_sio: add support for FreeCalypso DUART28C adapter Johan Hovold
2020-12-01 6:54 ` Jiri Slaby
2020-12-01 8:55 ` Johan Hovold
2020-11-30 21:22 ` [PATCH 0/5] tty: add flag to suppress ready signalling on open Mychaela Falconia
2020-12-01 7:14 ` Jiri Slaby
2020-12-01 7:18 ` Mychaela Falconia
2020-12-02 11:48 ` Johan Hovold
2020-12-04 6:58 ` Jiri Slaby
2020-12-08 9:30 ` Johan Hovold
2020-12-01 8:40 ` Johan Hovold
2020-12-01 10:48 ` Andy Shevchenko
2020-12-01 10:58 ` Johan Hovold
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