Description of problem:
Cannot start /sbin/init within the container with lxc driver.
You can start /sbin/init in docker with the native driver:
docker run -it -privileged -e "container=docker" ubuntu:init /sbin/init

However, it does not work for the lxc driver:
docker run -it -privileged -e "container=docker" ubuntu:init /sbin/init
No response from the output, and the container is not started.

docker version:
Client:
Version: 1.8.0-dev
API version: 1.20
Go version: go1.4.2
Git commit: 15cb7df-dirty
Built: Wed Jul 22 07:43:16 UTC 2015
OS/Arch: linux/amd64

Server:
Version: 1.8.0-dev
API version: 1.20
Go version: go1.4.2
Git commit: 15cb7df-dirty
Built: Wed Jul 22 07:43:16 UTC 2015
OS/Arch: linux/amd64

docker info:
Containers: 18
Images: 88
Storage Driver: aufs
Root Dir: /var/lib/docker/aufs
Backing Filesystem: extfs
Dirs: 228
Dirperm1 Supported: true
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 3.19.0-15-generic
Operating System: Ubuntu 15.04
CPUs: 1
Total Memory: 976.6 MiB
Name: ubuntu
ID: 6CKH:DHL3:FSVK:NBWN:ZVYE:DIK3:QOQJ:3JHF:3DON:4F42:2LAZ:3KDM
WARNING: No swap limit support

uname -a:
Linux ubuntu 3.19.0-15-generic #15-Ubuntu SMP Thu Apr 16 23:32:37 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

How reproducible
100%

Steps to Reproduce:
1.You can start /sbin/init in docker with native driver:
docker -d
docker run -it --privileged -e "container=docker" ubuntu:init /sbin/init

2.You can't start /sbin/init in docker with lxc driver,there is nothing put out with lxc driver:
docker -d -e lxc
docker run -it --privileged -e "container=docker" ubuntu:init /sbin/init