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

From: Davidlohr Bueso
Date: Thu Nov 08 2018 - 01:59:57 EST


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