parasite: remove useless check from parasite_stop_on_syscall() (v2)

We have the same check a few lines above.

v2: fix the subject
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
util: mkdirp -- Print exactly what is failed

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
ptrace: Skip GETREGS on exits from syscalls when possible

The PTRACE_SYSCALL traps task twice -- first on enter into
and then on exit from syscall. If we trace a single task (and
we do it on dump two times per task) we may skip half of all
getregs calls -- on exit we don't need them.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
timerfd: Setup @ticks only if nonzero

If @ticks is zero the kernel returns error
because on creation the @ticks is already zero,
so simply setup @ticks if real value present.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
security: change CR_FD_PERM from rw-rw-r-- to rw-r--r--

This makes only root to be able to modify images by default.
When using criu with suid bit set, group of the images is set
to user group, which is not safe, considering current CR_FD_PERM.

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
fixed kernel version detection

My debian testing produces the following output for uname:
$ uname -r
3.14-2-amd64

and so:
$ set -- `uname -r | sed 's/\./ /g'`
$ echo $1
3
$ echo $2
14-2-amd64

this causes zdtm.sh to fail for me on line 293:
[ $1 -eq 3 -a $2 -ge 11 ] && return 0

because "14-2-amd64 -ge 11" is false.

Signed-off-by: Matthias Neuer <matthias.neuer@uni-ulm.de>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
cg: Fix separator search in parse_task_cgroup

If there is no separator in first place we should
avoid implicit + 1 which make @name = 1 in worst case.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restore: return -1 if fail

In cr_dump_tasks() we expect restore_root_task to return < 0 if
error ocures.

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
remap: add remap_type field and use it

Maintain backwards compatibility for old images, but don't set the REMAP_GHOST
bit going forward, only use the remap_type field.

v2: * preserve remap_id in GHOST_REMAP case
    * protobuf field is remap_type enum not u32

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
proc: Use fopen_proc in fdinfo parsing

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
proc: Use fopen_proc instead of fopen("/proc...")

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
rst: Don't allocate page for child stack (v2)

When clone-ing kids we can set their stack on current, as
it will anyway be COW-ed later. One thing to note -- we do
need to reserve some space on the stack for glibc's arguments
and retcode allocation. 128 bytes should be enough for 16
pointers while clone has 5 arguments.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
helpers: Create helpers with shared files and fs

They don't change these objects, so can share them
with parent (will be created slightly faster :) ).

The plan is to make them CLONE_VM, but it's not that
easy.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
plugin: Explicit assign plugin hooks

So it won't depend on the order in declaration.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
proc: Don't use FILE* for reading personality

It turned out, that fdopen (used in fopen_proc) always maps
a 4k buffer for reads and this buffer gets unmap-ed later
on fclose.

Taking into account the amount of proc files we read (~20
per task plus one file per opened file descriptor) this
mmap+munmap result in quite a lot of useless CPU time.

E.g. for a container of 20 tasks we have 1000 calls taking
~8% of total dump time.

So lets first stop doing this for simple cases -- one line
proc files.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
proc: Don't use FILE * to reach children

The same reasoning as for personality file -- switch to
plan open + read + close.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
mount: skip the criu's mount namespace if tasks live in another mntns

Currently here is a bug, because when we see criu's mount namespace,
we go to the "out" mark and don't validate mounts.

Reported-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restore: TASK_HELPERs live until RESTORE stage ends

In order to use TASK_HELPERS to open files from dead processes, they should
persist until criu is done restoring the filesystem, which happens in the
RESTORE stage. To do this, we need to pass each helper's PIDs to the restorer
blob, so that it can wait() on them when the restore stage is done.

This commit is in preparation for the remap_dead_pid commits.

v2: wait() on helpers after restore stage is over
v3: add CR_STATE_RESTORE_FS stage
v4: CR_STATE_RESTORE_FS waits for nr_tasks + nr_helpers, not nr_threads
v5: ditch CR_STATE_RESTORE_FS in favor of passing helpers to restorer blob

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
remap: add a dead pid /proc remap

If a file like /proc/20/mountinfo is open, but 20 is a zombie (or doesn't exist
any more), we can't read this file at all, so a link remap won't work. Instead,
we add a new remap, called the dead process remap, which forks a TASK_HELPER as
that dead pid so that the restore task can open the new /proc/20/mountinfo
instead.

This commit also adds a new stage CR_STATE_RESTORE_SHARED. Since new
TASK_HELPERS are added when loading the shared resource images, we need to wait
to start forking tasks until after these resources are loaded.

v2: fix a mutex bug

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
test: add a test for remap_dead_pid

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>