> >
> > 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?
> @@ -5832,8 +5888,12 @@ static int __init binder_init(void)
> goto err_init_binder_device_failed;
> }
>
> - return ret;
> + ret = binder_init_ns(&init_ipc_ns);
> + if (ret)
> + goto err_init_namespace_failed;
>
> + return ret;
They are initialized here.
- choury -
On Fri, Nov 9, 2018 at 9:43 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?
>
> > @@ -5832,8 +5888,12 @@ static int __init binder_init(void)
> > goto err_init_binder_device_failed;
> > }
> >
> > - return ret;
> > + ret = binder_init_ns(&init_ipc_ns);
> > + if (ret)
> > + goto err_init_namespace_failed;
> >
> > + return ret;
>
> They are initialized here.
Ok, This init_ipc_ns is a global declared in msgutil.c if SYSVIPC ||
POSIX_MQUEUE. This seems kinda hacky, but now I finally see why the
dependancy... msgutil.c is the only file we can count on if !IPC_NS &&
(SYSVIPC || POSIX_MQUEUE). There must be a cleaner way to do this, I
really don't like this dependency... wouldn't it be cleaner to do:
#ifndef CONFIG_IPC_NS
static struct ipc_namespace binder_ipc_ns;
#define ipcns (&binder_ipc_ns)
#else
#define ipcns (current->nsproxy->ipc_ns)
#endif
(and make the initialization of binder_ipc_ns conditional on IPC_NS)
This gets us the same thing without the incestuous dependency on the
msgutil.c version of init_ipc_ns...and then binder doesn't rely on
SYSVIPC or POSIX_MQUEUE directly.
>
> - choury -
>