> > > I still don't understand the dependencies on SYSVIPC or POSIX_MQUEUE.
> > > It seems like this mechanism would work even if both are disabled --
> > > as long as IPC_NS is enabled. Seems cleaner to change init/Kconfig and
> > > allow IPC_NS if CONFIG_ANDROID_BINDER_IPC and change this line to
> > > "#ifndef CONFIG_IPC_NS"
> >
> > Let me explain it in detail. If SYSIPC and IPC_NS are both defined,
> > current->nsproxy->ipc_ns will save the ipc namespace variables. We just use
> > it. If SYSIPC (or POSIX_MQUEUE) is defined while IPC_NS is not set,
> > current->nsproxy->ipc_ns will always refer to init_ipc_ns in ipc/msgutil.c,
> > which is also fine to us. But if neither SYSIPC nor POSIX_MQUEUE is set
> > (IPC_NS can't be set in this situation), there is no current->nsproxy->ipc_ns.
> > We make a fack init_ipc_ns here and use it.
>
> Yes, I can read the code. I'm wondering specifically about SYSVIPC and
> POSIX_MQUEUE. Even with your code changes, binder has no dependency on
> these configs. Why are you creating one? The actual dependency with
> your changes is on "current->nsproxy->ipc_ns" being initialized for
> binder -- which is dependent on CONFIG_IPC_NS being enabled, isn't it?
>
> If SYSVIPC or POSIX_MQUEUE are enabled, but IPC_NS is disabled, does this work?
If IPC_NS is disabled, "current-nsporxy->ipc_ns" will also exists, it will be a static
reference of "init_ipc_ns" (in ipc/msgutil.c, not defined in binder.c by me) with
no namespace-ization. You will get the same one in all processes, everything is
the same as without this patch.
- choury -
On Fri, Nov 9, 2018 at 8:43 PM chouryzhou(周威) <[email protected]> wrote:
>
> If IPC_NS is disabled, "current-nsporxy->ipc_ns" will also exists, it will be a static
> reference of "init_ipc_ns" (in ipc/msgutil.c, not defined in binder.c by me) with
> no namespace-ization. You will get the same one in all processes, everything is
> the same as without this patch.
except, as far as I can tell, binder_init_ns() would never have been
called on it so the mutex and list heads are not initialized so its
completely broken. Am I missing something? How do those fields get
initialized in this case?
>
> - choury -
>