netdev - Re: nt: usb: USB_RTL8153_ECM should not default to y

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CAMuHMdUeoVZSkP24Uu7ni3pUf_9uQHsq2Xm3D6dHnzuQLXeOFA@mail.gmail.com>
Date:   Sat, 18 Sep 2021 12:53:31 +0200
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Jakub Kicinski <kuba@...nel.org>
Cc:     Maciej Żenczykowski <zenczykowski@...il.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linux NetDev <netdev@...r.kernel.org>,
        Hayes Wang <hayeswang@...ltek.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Maciej Zenczykowski <maze@...gle.com>
Subject: Re: nt: usb: USB_RTL8153_ECM should not default to y

Hi Jakub,

On Fri, Sep 17, 2021 at 8:49 PM Jakub Kicinski <kuba@...nel.org> wrote:
> On Fri, 17 Sep 2021 19:59:15 +0200 Maciej Żenczykowski wrote:
> > I've been browsing some usb ethernet dongle related stuff in the
> > kernel (trying to figure out which options to enable in Android 13
> > 5.~15 kernels), and I've come across the following patch (see topic,
> > full patch quoted below).
> >
> > Doesn't it entirely defeat the purpose of the patch it claims to fix
> > (and the patch that fixed)?
> > Certainly the reasoning provided (in general device drivers should not
> > be enabled by default) doesn't jive with me.
> > The device driver is CDC_ETHER and AFAICT this is just a compatibility
> > option for it.
> >
> > Shouldn't it be reverted (ie. the 'default y' line be re-added) ?
> >
> > AFAICT the logic should be:
> >   if we have CDC ETHER (aka. ECM), but we don't have R8152 then we
> > need to have R8153_ECM.
> >
> > Alternatively, maybe there shouldn't be a config option for this at all?
> >
> > Instead r8153_ecm should simply be part of cdc_ether.ko iff r8152=n
> >
> > I'm not knowledgeable enough about Kconfig syntax to know how to
> > phrase the logic...
> > Maybe there shouldn't be a Kconfig option at all, and just some Makefile if'ery.
> >
> > Something like:
> >
> > obj-$(CONFIG_USB_RTL8152) += r8152.o
> > obj-$(CONFIG_USB_NET_CDCETHER) += cdc_ether.o obj-
> > ifndef CONFIG_USB_RTL8152
> > obj-$(CONFIG_USB_NET_CDCETHER) += r8153_ecm.o
> > endif
> >
> > Though it certainly would be nice to use 8153 devices with the
> > CDCETHER driver even with the r8152 driver enabled...
>
> Yeah.. more context here:
>
> https://lore.kernel.org/all/7fd014f2-c9a5-e7ec-f1c6-b3e4bb0f6eb6@samsung.com/
>
> default !USB_RTL8152 would be my favorite but that probably doesn't
> compute in kconfig land. Or perhaps bring back the 'y' but more clearly
> mark it as a sub-option of CDCETHER? It's hard to blame people for
> expecting drivers to default to n, we should make it clearer that this
> is more of a "make driver X support variation Y", 'cause now it sounds
> like a completely standalone driver from the Kconfig wording. At least
> to a lay person like myself.

If it can be a module (tristate), it must be a separate (sub)driver, right?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-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