linux-kernel - Re: gpio desc flags being lost

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Fri, 5 Jul 2019 23:53:25 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Chris Packham <Chris.Packham@...iedtelesis.co.nz>
Cc:     Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: gpio desc flags being lost

On Wed, Jul 3, 2019 at 11:30 PM Chris Packham
<Chris.Packham@...iedtelesis.co.nz> wrote:

> The problem is caused by commit 3edfb7bd76bd1cba ("gpiolib: Show correct
> direction from the beginning"). I'll see if I can whip up a patch to fix it.

Oh. I think:

               if (chip->get_direction && gpiochip_line_is_valid(chip, i))
                        desc->flags = !chip->get_direction(chip, i) ?
                                        (1 << FLAG_IS_OUT) : 0;
                else
                        desc->flags = !chip->direction_input ?
                                        (1 << FLAG_IS_OUT) : 0;


Needs to have desc->flags |=  ... &= ~

if (!chip->get_direction(chip, i))
    desc->flags |= (1 << FLAG_IS_OUT);
else
    desc->flags &= ~(1 << FLAG_IS_OUT);

And the same for direction_input()

Yours,
Linus Walleij