Replace reference of init pid_ns with init pid_t in dev_ns

This closes Cellrox/devns-patches#4

The dev_ns is coupled to pid_ns at creation time. There is no need for
dev_ns to keep a reference to pid_ns. The reference was used to be able
to tell the pid of the respective init task for use by printk; instead,
store the pid_t itself in dev_ns.

Signed-off-by: Oren Laadan <orenl@cellrox.com>
Reported-by: Jeremy Andrus <jeremya@cs.columbia.edu>
Fix compile errors when CONFIG_DEV_NS is unselected

This closes Cellrox/devns-patches#1

Signed-off-by: Oren Laadan <orenl@cellrox.com>
Reported-by: Jeremy Andrus <jeremya@cs.columbia.edu>
Fix kernel when CONFIG_DEV_NS is unselected

This closes Cellrox/devns-patches#3

When CONFIG_DEV_NS is not selected, then @init_dev_ns is NULL, and
therefore current_dev_ns() is NULL, too.

Remove dependency on @init_dev_ns by using suitable wrappers, such
as is_init_dev_ns(); and verify that current_dev_ns() isn't used
directly either.

(For now, we stay with init_dev_ns being NULL, to avoid the need to
compile dev_namespace.c when CONFIG_DEV_NS is unset).

Signed-off-by: Oren Laadan <orenl@cellrox.com>
Reported-by: Jeremy Andrus <jeremya@cs.columbia.edu>
Fix warning in printk and misc typos

This closes Cellrox/devns-patches#2

Add missing parameter to quiesce a prink warning.
(Also add diffstats to all patches).

Signed-off-by: Oren Laadan <orenl@cellrox.com>
Reported-by: Jeremy Andrus <jeremya@cs.columbia.edu>
fb_devns: don't try swapping zero size buffers

Don't attempts to memory swap zero sized framebuffers. Trying to
do so will cause access violations on memcpy and crash the kernel.

Signed-off-by: Oren Laadan <orenl@cellrox.com>