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Date: Mon, 18 Sep 2017 17:53:47 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Arve =?iso-8859-1?B?SGr4bm5lduVn?= <arve@android.com>,
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        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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Subject: Re: [PATCH] android: binder: fix type mismatch warning
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On Mon, Sep 18, 2017 at 05:35:03PM +0200, Arnd Bergmann wrote:
> On Mon, Sep 18, 2017 at 4:02 PM, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >> However, there is another problem with the Kconfig option: turning
> >> it on or off creates two incompatible ABI versions, a kernel that
> >> has this enabled cannot run user space that was built without it
> >> or vice versa. A better solution might be to leave the option hidden
> >> until the binder code is fixed to deal with both ABI versions.
> >
> > I don't know if that is ever going to be fixed, as it's not an issue
> > that you will ever see "in the wild" from what I can tell...
> 
> Probably not on a native Android device or even a Chromebook that
> ships a binder user space together with a kernel, but what about
> people using "anbox" or similar projects that allow you to run
> Android apps in a container?

Ugh, that's crazy, binder should not be run that way due to a variety of
issues...  Well, as of 4.14 those issues will be gone, so no one is
doing this yet :)

> It seems like a legitimate use case of the binder modules, but
> now there is a kernel Kconfig option that has to match a user
> space binary.

So, should we revert that?

I don't really know what to suggest here, sorry...

greg k-h