restorer: Lost tgt vmas lenght in restorer memory blob hinting

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restore: Sanitize restorer code + args layout

There was a strange thing -- task args size is aligned, but when
threads args ptr is get this alignment was lost. Fix this and make
all the bufs page-aligned.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restorer: Mmap restorer blob separately from the rest

This will avoid exec bit on restorer args and will make
it possible for shared restorer eventually.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restorer: Don't memcpy restorer blob in each task on restore

Instead -- mmap it once in root task and then mremap it later.
No mremap of original restorer can be done, since in that case
the restorer vma would be tied to crtools binary which in turn
will make set-exe-file prctl to fail with EBUSY.

Note -- after mremap the original vmas list becomes non relevant,
but it's OK. Only new holes appear inside which is OK for munmap.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restorer: unify log functions

Add ability to use the same macros in restorer code.
In the future we will add ability to show arguments like printf.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Make termios and winsize being optional params

The dangling slave peers might have no data associate
with them if master peer is closed and link is hanging
up. Thus make this parameters optional to not blow the
image with data which never will be used.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Squash tty_get_sid, tty_get_pgrp into tty_get_sid_pgrp

This patch squashes tty_get_sid, tty_get_pgrp into
one tty_get_sid_pgrp helper (which allows to detect
if dumping terminal is hanging up, the real use of
this ability will be addressed in next patch).

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Dump a hanging up terminal

If we've met a hanging up terminal we can escape
lot of work but dump a minimum information needed
for restore.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Rework tty entry verification

tty entries might have no parameters assigned if they
are hanging on closed master, we should take into
account when we do verify them.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Restore orphan slavery peers

In case if there is no master peer associated
with a slave peer we have two cases

 - the master peer was closed before slave
 - we just have no master peer at all, but
   only slave one

This patch addresses only first case -- we open
fake master and hook slaves on it, then close it
immediately.

The second case will be addressed later.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
zdtm: Enable pty tests

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Cleanup tty mutex preparation

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Sanitize slavery and ctl tty setups

We need to do two non-trivial things with ttys -- interconnect
slaves to masters (or to each other) and setup ctl-tty restoring
task.

Now this is done in subsequently depending on each other steps:

1. collect ttys
2. interconnect slaves and mark ctl-tty tasks
3. collect fake fds for tty-ctl tasks
4. setup orphaned slaves

We can relax this logic in two ways:

1. don't split marking ctl-tty tasks and then creating fds for them
   do it in one step at the end
2. don't interconnect slaves with masters and orphaned slaves in
   two steps -- do it in one place after fds are collected

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Handle tty collecting error

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tty: Remove no longer relevant TODO comment

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
zdtm: Make pty tests being non-ns

Until I figure out how to make them work in ns.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>