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From:   Todd Kjos <tkjos@google.com>
Date:   Mon, 29 Oct 2018 17:29:34 -0700
Message-ID: <CAHRSSExHFhwQ_J3X+adyCUkwg6usBRQN6Wz_YshjTOfx4C33eg@mail.gmail.com>
Subject: Re: [PATCH] binder: ipc namespace support for android binder
To:     chouryzhou@tencent.com
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= <arve@android.com>,
        Todd Kjos <tkjos@android.com>, akpm@linux-foundation.org,
        dave@stgolabs.net, LKML <linux-kernel@vger.kernel.org>,
        "open list:ANDROID DRIVERS" <devel@driverdev.osuosl.org>
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+christian@brauner.io

On Sun, Oct 28, 2018 at 7:29 PM chouryzhou(=E5=91=A8=E5=A8=81) <chouryzhou@=
tencent.com> wrote:
...
>
> > It's not obvious from this patch where this dependency comes
> > from...why is SYSVIPC required? I'd like to not have to require IPC_NS
> > either for devices.
>
> Yes, the patch is not highly dependent on SYSVIPC, but it will be conveni=
ent
> if require it. I will update it to drop dependency of it in V2 patch. Thi=
s patch
> doesn't need IPC_NS set at present.

Actually it is dependent on IPC_NS since it makes changes to
ipc/namespace.c which is
compiled only if CONFIG_IPC_NS.

There are a couple more implementations similar to this one.
https://lwn.net/Articles/577957/ and some submissions to AOSP derived
from that one
that introduce a generic registration function for namespace support [1], a=
nd
changes to binder to implement namespaces [2].

If this is really needed, then we should have a solution that works
for devices without
requiring IPC_NS or SYSVIPC. Also, we should not add binder-specific code t=
o
ipc/namespace.c or include/linux/ipc_namespace.h.

-Todd

[1] https://android-review.googlesource.com/c/kernel/common/+/471961
[2] https://android-review.googlesource.com/c/kernel/common/+/471825