[CRIU] [PATCH v2 00/57] Nested pid namespaces support

[Kirill Tkhai]

Hi,

this is the second version of nested pid namespaces support.
Completelly implemented dump and restore of tasks and threads,
and pidns01 test is added.

The most problem and strange thing I bumped to is that a task may
write "/proc/sys/kernel/ns_last_pid" only of its active pid namespace,
independently of in which pid ns the file is open and which caps
task has. To solve this problem, pid_ns helpers populating appropriate
ns_last_pid were implemented. See the corresponding patches for the
details.

Patches [1-5/57] is duplicate of <<[PATCH 0/5] Restore of "/proc/self/ns/net" fixes>>
I sent them today, because it fixes the errors which are seen only after
patch [6/57], and I don't want to receive crappy travis errors.

Also, there is a error with nested net_ns (see <<[net_ns] Problem of
restoring tun in nested net namespace>>), so I temporary switched tun
test off in 6/57 till it's fixed.

The patch set doesnt't do anything to restore pgid/sid if nested pid_ns
is dumped (Pavel Tikhomirov is completelly reworking on pgid/sid
at the moment, so we do not do the same work both),
so for such cases I switch restore of pgid/sid off in [57/57]. If you
want, we may put it into criu option till it's implemented.

v2: Fixed a couple problems with pre-dump. Rebase on fresh criu-dev.

https://travis-ci.org/tkhai/criu/builds/215979013

---

Kirill Tkhai (57):
      user_ns: Close pid proc in create_user_ns_hierarhy_fn()
      ns: Pack functionality of storing ns fd to store_self_ns()
      user_ns: Keep root_user_ns ns fd in fdstore
      ns: Fix wrong opened net ns file
      zdtm: Add proc-self01 test
      net: Do not change net_ns of root_item in create_net_ns()
      cr-restore: Open transport socket earlier
      zdtm: Add pidns00 test
      kerndat: Check that "/proc/[pid]/status" file has NS{pid,..} lines
      pid: Add pid::level field and level argument for __alloc_pstree_item()
      pid: Add equel_pid() helper
      pid: Add last_level_pid() helper
      pid: Make pgid and sid be allocated dynamically
      pid: Use last_level_pid() in restore_pgid()
      pid: Alloc threads dynamically
      pid: Pass thread pid to caller
      pstree: Change arguments of read_pstree_ids()
      pstree: Read ids earlier in read_pstree_image()
      pid: Add top_pid_ns
      pid: Add ns::pid::rb_root
      ids: Copy unexisted ids from root_item
      pstree: Move parent assignment in read_pstree_image() up
      pstree: Assign ids for dead tasks in read_pstree_image()
      pstree: Dump pid and user ns ids for dead tasks
      pstree: Add pid_ns check in read_pstree_image
      pstree: Split lookup_create_pid()
      pstree: Add pid_ns id argument to lookup_create_pid()
      ns: Add MAX_NS_NESTING
      pstree: Make lookup_create_pid() able to create tasks with pid->level > 1
      pid: Implement populate_ns_pids() helper
      proc_parse: Implement collect_pid_status()
      pid_ns: Implement pid_ns_root_off()
      pid: Use collect_pid_status() to populate item's pids
      images: Add NSpids pstree descriptions
      pstree: Dump and restore NSpid, NSsid etc
      pstree: Make get_free_pid() work for different pid_ns and export it
      pstree: Extract __pstree_item_by_virt() to act on any pid_ns
      ns: Reserve pid_ns helpers
      restore: Implement set_next_pid() helper
      pid: Always lock last pid file on clone()
      pid: Add fdstore id for pid_ns descriptor
      fdstore: Init fdstore earlier
      pid: Save created pid_ns fd to fdstore
      ns: Always start usernsd
      pid: Add pid ns futex helper_created
      ns: Install transport fd socket in usernsd
      cr-restore: Add argument to criu_signals_setup()
      ns: Add usernsd signal handler
      pid: Create pid_ns helpers
      pid: Wait till pid_ns created before we create a child of this ns
      pid: Set pid_ns before we create a child
      pid: Teach set_next_pid() working with nested pid_ns
      restorer: Close transport socket later
      restorer: Set NStids in all pid_ns for thread before we create it.
      pid: Check for equality of getpid() of child to last_level_pid
      pstree: Use CLONE_NEWPID only to create child reaper of pid_ns
      ns: Nested pid_ns support


 criu/cr-dump.c                  |  123 +++++++--
 criu/cr-restore.c               |  242 +++++++++++++----
 criu/files-reg.c                |   10 -
 criu/files.c                    |   20 +
 criu/include/kerndat.h          |    1 
 criu/include/namespaces.h       |   21 +
 criu/include/parasite-syscall.h |    2 
 criu/include/pid.h              |   23 ++
 criu/include/proc_parse.h       |   13 +
 criu/include/pstree.h           |   30 +-
 criu/include/restore.h          |    3 
 criu/include/restorer.h         |    6 
 criu/include/rst_info.h         |    1 
 criu/kerndat.c                  |   28 ++
 criu/namespaces.c               |  443 +++++++++++++++++++++++++++++--
 criu/net.c                      |  121 ++++----
 criu/ns-common.c                |   51 ++++
 criu/parasite-syscall.c         |    6 
 criu/pie/restorer.c             |   50 +++
 criu/proc_parse.c               |  123 ++++++++-
 criu/pstree.c                   |  559 +++++++++++++++++++++++++++------------
 criu/seize.c                    |   32 ++
 criu/tty.c                      |    6 
 images/pstree.proto             |   17 +
 test/zdtm/static/Makefile       |    3 
 test/zdtm/static/pidns00.c      |  206 ++++++++++++++
 test/zdtm/static/pidns00.desc   |    1 
 test/zdtm/static/proc-self.c    |    4 
 test/zdtm/static/proc-self01.c  |    1 
 test/zdtm/static/tun.desc       |    2 
 30 files changed, 1732 insertions(+), 416 deletions(-)
 create mode 100644 criu/ns-common.c
 create mode 100644 test/zdtm/static/pidns00.c
 create mode 100644 test/zdtm/static/pidns00.desc
 create mode 120000 test/zdtm/static/proc-self01.c

--
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>