Re: [PATCH V2] binder: ipc namespace support for android binder

[Davidlohr Bueso <dave@stgolabs.net>]

On Mon, 29 Oct 2018, chouryzhou(??????) wrote:
>@@ -63,6 +63,12 @@ struct ipc_namespace {
>        unsigned int    mq_msg_default;
>        unsigned int    mq_msgsize_default;
>
>+       /* next fields are for binder */
>+       struct mutex      binder_procs_lock;
>+       struct hlist_head binder_procs;
>+       struct mutex      binder_contexts_lock;
>+       struct hlist_head binder_contexts;

I don't think you want a mutex here protecting the binder_contexts list.
Afaict there is no concurrency going on: you only modify it in when doing
namespace init and exit (for which you have no serialization); do you even
need a lock here? Or at least I would think a more lightweight alternative
(rcu/spinlock/rwlock) would suffice.

Thanks,
Davidlohr