This reverts commit a8409956, that
got into master by mistake.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

Currently we support restoring opened /dev/tty reference
if only control terminal belongs to the same process,
ie no inheritance is allowed.

Thus we should refuse to dump in such scenario
otherwise restore will fail.
Reported-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Currently it is only used to get a file descriptor to the mount
namespace root, but if we have only one mntns, we can open "/".

Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Processes can be restored in another mntns, so mnt_id will be
useless in this case. If mntns isn't dumped, we have to dump a path
to a mount point.

Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

There were kernel bug with 32-bit mmap() returning 64-bit pointer.
The fix is in Torvalds master, will be released in v4.12 kernel.
Checkpointing after v4.9 kernel works good, but restoring will
result in application which will mmap() 64-bit addresses resulting
in segfault/memory corruptions/etc.
As our policy is fail on dump if we can't restore on the same target,
error checkpointing for v4.9.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

The idea is simple. Everyone has to wait its children,
a restore is interrupted if we found abandoned zombie.
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

We currently can batch pagemap entries into page-read list, but will
need to queue them into per-pstree_entry one.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

The pages.img will need to get opened one more time w/o the pagemap.img.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

1. Commit 8b99809a ("compel: make plugins .a archives") changed the
   suffix of compel plugins, so this test no longer compiles.

2. "compel plugins" can print auxiliary plugins now, let's use it.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

As we have more than 1 working plugin right now, let's implement
the TODO item for "compel plugins" command.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Ubuntu 14.04 (Travis) doesn't have it.
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Looks-good-to: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Looks-good-to: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Apparently, setup.py from distutils interprets --root= option without
an argument as "--root=." and we end up with what is described
in https://github.com/xemul/criu/issues/309.

Fix is to prepend DESTDIR value (if any) to --prefix argument.

v2: fix uninstall as well
v3: same code, resent via gmail
Reported-by: Juraj Oršulić <juraj.orsulic@fer.hr>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

soccr.h:
After previous patch <linux/types.h> is not needed anymore,
<netinet/tcp.h> is needed as we test for it in feature tests,
i.e., struct tcp_repair_window is declared there.
Also drop forward-declaration of (struct libsoccr_sk) - it's
declared again below.

soccr.c:
Sort headers by name so errors like twice-including errno.h
will not happen again. Also remove assert.h.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

As uint32_t already has occupied the header, use it for all 32-bit
unsigns. That will allow to drop additional include <linux/types.h>.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

When running 'cirt x dir rss' one will see the way pagemap chunks
are scatered across the VMs of processes. Sample output from the
env00 zdtm test is

22
	400000 / 1              00400000 / 5        /root/criu/test/zdtm/static/env00

	604000 / 2              00604000 / 1        /root/criu/test/zdtm/static/env00
	                        00605000 / 1        /root/criu/test/zdtm/static/env00

	853000 / 1              00853000 / 33

	7faba2d4b000 / 6        7faba2d4b000 / 4        /usr/lib64/libc-2.22.so
	                        7faba2d4f000 / 2        /usr/lib64/libc-2.22.so

	7faba2d51000 / 2        7faba2d51000 / 4

	7faba2d54000 / 1        ~

	7faba2f64000 / 3        7faba2f64000 / 3

	7faba2f74000 / 1        7faba2f74000 / 1

	7faba2f75000 / 2        7faba2f75000 / 1        /usr/lib64/ld-2.22.so
	                        7faba2f76000 / 1        /usr/lib64/ld-2.22.so

	7faba2f77000 / 1        7faba2f77000 / 1

	7fffb4de3000 / 3        7fffb4de2000 / 70

	7fffb4e24000 / 2        ~

	7fffb4e27000 / 1        ~

	7fffb4f6a000 / 2        7fffb4f6a000 / 2
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

The same as for Checkpointing - we need to call 32-bit syscall
for compatible tasks here to correctly restore compat_robust_list,
not robust_list.

Note: I check here restorer's *task* arg for compatible mode, not
restorer *thread* arg. As changing application's mode during runtime
is very rare thing itself, application that runs different bitness
threads is most likely not present at all.
If we ever meet such application, this could be improved.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

The kernel keeps two different pointers for 32-bit and 64-bit futex
lists: robust_list and compat_robust_list in task_struct.
So, dump compat_robust_list for ia32 tasks.

Note: this means that one can set *both* compat_robust_list and
robust_list pointers by using as we're here 32-bit and 64-bit syscalls.
That's one of mixed-bitness application questions.
For simplification (and omitting more syscalls), we dump here only
one of the pointers.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Check for presence of robust futex list is in the reality
(futex_rla_len != 0).

That does code on dumping, in get_task_futex_robust_list():
> ret = syscall(SYS_get_robust_list, pid, &head, &len);
> if (ret < 0 && errno == ENOSYS) {
[..]
> 	len = 0;
[..]
> }
[..]
> info->futex_rla_len	= (u32)len;

And in images: futex_rla_len == 0 means that futex is not present.

So, we don't need additional restorer's parameter `has_futex'
which is always true, remove it.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Cleanup: use nr, provided by compel.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Modules pre-load is also slow, but guarding this code with
the presence of criu.kdat cache file seems reasonable.

Or course, one may unload the needed modules by hands, but
such smart user may as well remove the /run/criu.kdat file :)
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Doing kerndat checks on every criu start is way too slow. We
need some way to speed this checks up on a particular box.

As suggested by Andre, Dima and Mike let's try to keep the
collected kdat bits into some tmpfs file. Keeping it on
tmpfs would invaludate this cache on every machine reboot.

There have been many suggestions how to generate this file,
my proposal is to create it once the kdat object is filled
by criu, w/o any explicit command. Optionally we can add
'criu kdat --save|--drop' actions to manage this file.

v2:
* don't ignore return code of write() (some glibcs complain)
* unlink tmp file in case rename failed

v3:
* add one more magic into kerndat_s which is the 'date +%s'
* ignore any errors opening or saving cache. Only size/magic
  mismatch matters (and result in dropping the cache)
* cache file path is Makefile-configurable (RUNDIR)
* don't save cache if kerndat auto-detection failed

v4:
* Use ?= for RUNDIR definition.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

v2: When uffd is present, the reported features may still be 0,
    so we need one more bool for uffd syscall itself.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Introduce 3-state mode and check them always.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Some get_status() methods may allocate data, because
not all of the fields in /proc/[pid]/status file
have the fixed size. For example, NSpid, which
size may vary.

Introduce new method free_status() in counterweight
for such type get_status() methods. it will be called
in case of we go to try_again and need to free allocated
data.

Also, introduce data parameter for a use in the future.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

The goal of this function is to compare everything except caps,
but caps size is took to compare. It's wrong, there must be
used offsetof(struct proc_status_creds, cap_inh) instead.

Also, sigpnd may be different too.

v3: Move excluding sigpnd from comparation in this patch (was in another patch).
    Reorder fields in seize_task_status().
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Having a "header library" is nice if it's small and clean, but
 - we compile its code a few times;
 - there is no distinction between internal and external functions.

Let's separate functions out of header and into a .c file.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

The function is not included into the library, so having its prototype
there was a shortcut. Move it to a separate include file.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

This is an auxiliary source file. The corresponding object file was
cleaned, but .d was not. Add it to SRC/OBJ/DEP so the appropriate files
will be cleaned automatically.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

MAKEFLAGS += -r only works for sub-make, and it is not applicable to
the current instance. Since previous commit make is not re-running
itself (after re-reading deps files), so MAKEFLAGS no longer works.
Use one more way to disable built-in rules that stand in our way.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

As it was pointed out by our esteemed maintainer (let his light shine),
after my recent changes to test/zdtm Makefiles all dependencies are
regenerated even if we only need to build a single test (for example,
cd test/zdtm/static && make env00).

This was caused by "-include $(DEP)" statement. Make sees that these files
are need to be included, but are missing, and since it knows how to generate
them it goes on to do so.

The solution is to use $(wildcard) function which returns the list of
_existing_ files, and so include will only receive the files that exist.
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

inotify_system_nodel.c is supposed to be a symlink to inotify_system.c,
but somehow the file was committed. This, together with the statement
in Makefile to recreate the file, lead to replacing the file with a
symlink during make.

Remove the file, add the symlink, and remove the Makefile rule.

PS yes, I have checked the files are identical.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

When we don't restore any namespaces criu forces tasks to wake
it up two times simply to no-op and wake up tasks back. This
can be optimized by simply omitting the not needed wakeups.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Here's why:

This stage is needed to make sure all tasks have appeared
and did some actions (that are called before restore_finish_stage()).
With this description there's no need in involving criu process
in it, this stage is purely inter-tasks sync point.

Taking into account we do already make root task wait for others
to complete forking (it calls restore_wait_ther_tasks()) we may
rework this stage not to involve criu process in it.

Here's how:

So the criu task starts the forking stage, then goes waiting for
"inprogress tasks". The latter wait is purely about nr_in_progress
counter, thus there's no strict requirement that the stage remains
the same by the time criu is woken up.

Siad that, the root task waits for other tasks to finish forking,
does fini_restore_mntns() (already in the code), then switches
the stage to the next (the RESTORE one). Other tasks do normal
staging barrier. Criu task is not woken up as nr_in_progress
always remains >= 1.

The result is -2 context switches -- from root task to criu and
back -- which gives us good boost when restoring single task app.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Describe what the tasks do during restore and what the
expectations at the sync points are.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Looks like this separate stage is not needed. The scripts
involved in ns restore are synchronized with existing stages
like this:

criu:                    root task:
ROOT_TASK stage
                         <appear>
"setup-ns" script
PREPARE_NAMESPACES
                         prepare_namespace()
"post-setup-ns" script
FORKING
                         restore_task_mnt_ns()
                         <everything else>

which seems to be OK.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

This is wat root task does -- calls prepare_namespace().
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>