[PATCH] device_cgroup: Cleanup cgroup eBPF device filter code

[Tejun Heo]

On Fri, Apr 03, 2020 at 07:55:28PM +0200, Odin Ugedal wrote:
> Original cgroup v2 eBPF code for filtering device access made it
> possible to compile with CONFIG_CGROUP_DEVICE=n and still use the eBPF
> filtering. Change 
> commit 4b7d4d453fc4 ("device_cgroup: Export devcgroup_check_permission")
> reverted this, making it required to set it to y.
> 
> Since the device filtering (and all the docs) for cgroup v2 is no longer
> a "device controller" like it was in v1, someone might compile their
> kernel with CONFIG_CGROUP_DEVICE=n. Then (for linux 5.5+) the eBPF
> filter will not be invoked, and all processes will be allowed access
> to all devices, no matter what the eBPF filter says.

Applied to cgroup/for-5.7-fixes.

Thanks.

-- 
tejun