To make the threads collect code be structured similar to
children collect. This will also help in further patching.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Right now we push all the auxiliary arguments to parasite_infect_seized
while 2 of them are only required to calculate the size of args area.
Let's better keep track of required args size and get rid of excessive
arguments to parasite_infect_seized().
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For that we need to save per-namespace mappings of user and group IDs.
And all id-s for tasks and files are saved from the target user
namespace.
v2: move code into collect_namespaces()
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's a bad idea to a group of processes and only then check
rights for this operation. We need to check permissions a soon as
posible to reduce impacts in case of wrong permissions.
In addtion criu doesn't to parse /proc/pid/state and gets all required
infromation from /proc/pid/status.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We get sig and pgid from a parasite, because we need to get
them from a target pid namespace.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have two reason for that:
* parsing of /proc/pid/status is slow
* parasite returns ids from a target userns
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
CID 73381 (#1 of 1): Out-of-bounds write (OVERRUN)
15. overrun-local: Overrunning array loc_buf of 4096 bytes at byte offset 4096 using index len (which evaluates to 4096).
CID 73355 (#1 of 1): Out-of-bounds write (OVERRUN)
6. overrun-local: Overrunning array loc_buf of 4096 bytes at byte offset 4096 using index ret (which evaluates to 4096)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The parasite daemon set up SIGCHLD handler, but for dumping threads we
use parasite-trap. While doing this the sigchild handler notices the
CHLD arriving on the thread trap, emits an error
(00.020292) Error (parasite-syscall.c:387): si_code=4 si_pid=3485 si_status=5
but wait() reports -1 (task is not dead, just trapped) and handler just exits.
Let's stop a parasite daemon before dumping threads.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We should not have a chance to exit with a wrong code on error paths.
Now dump_one_task() returs zero, if allocation of dfds failed:
ret = collect_mappings(pid, &vmas);
if (ret) {
pr_err("Collect mappings (pid: %d) failed with %d\n", pid, ret);
goto err;
}
if (!shared_fdtable(item)) {
dfds = xmalloc(sizeof(*dfds));
if (!dfds)
goto err;
...
err:
return -1;
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On Wed, Oct 01, 2014 at 04:57:40PM +0400, Pavel Emelyanov wrote:
> On 10/01/2014 01:07 AM, Cyrill Gorcunov wrote:
> > On Tue, Sep 30, 2014 at 09:18:53PM +0400, Cyrill Gorcunov wrote:
> >> If a user requested criu to dump cpuinfo image then we
> >> write one on dump and verify on restore. At the moment
> >> we require all cpu feature bits to match the destination
> >> cpu in a sake of simplicity, but in future we need deps
> >> engine which would filer out bits and test if cpu we're
> >> restoring on is more capable than one we were dumping at
> >> allowing to proceed restore procedure.
> >>
> >> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> >
> > Updated to new img format
Something like attached?
>From 59272a9514311e6736cddee08d5f88aa95d49189 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@openvz.org>
Date: Thu, 25 Sep 2014 16:04:10 +0400
Subject: [PATCH] cpuinfo: x86 -- Add dump and validation of cpuinfo image
If a user requested criu to dump cpuinfo image then we
write one on dump and verify on restore. At the moment
we require all cpu feature bits to match the destination
cpu in a sake of simplicity, but in future we need deps
engine which would filer out bits and test if cpu we're
restoring on is more capable than one we were dumping at
allowing to proceed restore procedure.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On pre-dump we collect only two namespaces -- the mnt one
for criu and mnt one again for root task.
This is not correct. We need all mount namespaces to make
the irmap generation work properly and we need all net
namespaces to have parasite sockets created.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have a use-after-free in predump code:
1st the free_pstree() is called in pre_dump_tasks(), then we
go to irmap_predump_run() which may call the lookup_irmap()
which, in turn, dereferences the root_item to get the root
mount ns fd.
But the problem is bigger than that. After we've released the
tasks (done before freeing pstree on predump) we can no longer
access them by PIDs, so keeping the root-item after irmap
scan is not a fix.
Fix is to get the root fd before releasing the tasks and using
one in irmap scanner.
Caught recently on iterative inotify_irmap test.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
We want to have buffered images to speed up dump and,
slightly, restore. Right now we use plan file descriptors
to write and read images to/from. Making them buffered
cannot be gracefully done on plain fds, so introduce
a new class.
This will also help if (when?) we will want to do more
complex changes with images, e.g. store them all in one
file or send them directly to the network.
For now the cr_img just contains one int _fd variable.
This patch chages the prototype of open_image() to
return struct cr_img *, pb_(read|write)* to accept one
and fixes the compilation of the rest of the code :)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Since we're going to switch from int-fd-s to class-image
soon the fdset name will not fit into the new terminology.
This patch is
sed -e 's/fdset/imgset/g' -i *
sed -e 's/imgset_fd/img_from_set/g' -i *
git mv include/fdset.h include/imgset.h
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
The open_pid_proc engine knows itself how to cache
per-pid descriptors. No need in closing it by hands.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have a, well, issue with how we calculate the vma's mnt_id.
Right now get one via criu side file descriptor that it got by
opening the /proc/pid/map_files/ link. The problem is that these
descriptors are 'merged' or 'borrowed' by adjacent vmas from
previous ones. Thus, getting the mnt_id value for each of them
makes no sense -- these files are the same.
So move this mnt_id getting earlier into vma parsing code. This
brings a potential problem -- if we have two adjacent vmas
mapping the same inode (dev:ino pair) but living in different
mount namespaces -- this check would produce wrong result.
"Wrong" from the perspective that on restore correct file would
be opened from wrong namespace.
I propose to live with it, since this is not worse than the
--evasive-devices option, it's _very_ unlikely, but saves a lot
of openeings.
Note, that in case app switched mount namespace and then mapped
some new library (with dlopen) things would work correctly -- new
vmas will likely be not adjacent and for different dev:ino.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have some fields, that are dump-only and some that
are restore only (quite a lot of them actually).
Reshuffle them on the vma_area to explicitly show which
one is which. And rename some of them for easier grep.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
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>
Here we define new api to be used in plugins.
- Plugin should provide a descriptor with help of
CR_PLUGIN_REGISTER macro, or in case if plugin require
no init/exit functions -- with CR_PLUGIN_REGISTER_DUMMY.
- Plugin should define a plugin hook with help of
CR_PLUGIN_REGISTER_HOOK macro.
- Now init/exit functions of plugins takes @stage
argument which tells plugin which stage of criu
it's been called on dump/restore. For exit it
also takes @ret which allows plugin to know if
something went wrong and it needs to cleanup
own resources.
The idea behind is to not limit plugins authors with names
of functions they might need to use for particular hook.
Such new API deprecates olds plugins structure but to keep
backward compatibility we will provide a tiny layer of
additional code to support old plugins for at least a couple
of release cycles.
For example a trivial plugin might look like
| #include <sys/types.h>
| #include <sys/stat.h>
| #include <fcntl.h>
| #include <libgen.h>
| #include <errno.h>
|
| #include <sys/socket.h>
| #include <linux/un.h>
|
| #include <stdio.h>
| #include <stdlib.h>
| #include <string.h>
| #include <unistd.h>
|
| #include "criu-plugin.h"
| #include "criu-log.h"
|
| static int dump_ext_file(int fd, int id)
| {
| pr_info("dump_ext_file: fd %d id %d\n", fd, id);
| return 0;
| }
|
| CR_PLUGIN_REGISTER_DUMMY("trivial")
| CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__DUMP_EXT_FILE, dump_ext_file)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
After patches, that dump locks w/o dfds array, we can even
not allocate one when we don't need it.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have a problem with file locks (bug #2512) -- the /proc/locks
file shows the ID of lock creator, not the owner. Thus, if the
creator died, but holder is still alive, criu fails to dump the
lock held by latter task.
The proposal is to find who _might_ hold the lock by checking
for dev:inode pairs on lock vs file descriptors being dumped.
If the creator of the lock is still alive, then he will take
the priority.
One thing to note about flocks -- these belong to file entries,
not to tasks. Thus, when we meet one, we should check whether
the flock is really held by task's FD by trying to set yet
another one. In case of success -- lock really belongs to fd
we dump, in case it doesn't trylock should fail.
At the very end -- walk the list of locks and dump them all at
once, which is possible by merge of per-task file-locks images
into one global one.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The AUFS support code handles the "bad" information that we get from
the kernel in /proc/<pid>/map_files and /proc/<pid>/mountinfo files.
For details see comments in sysfs_parse.c.
The main motivation for this work was dumping and restoring Docker
containers which by default use the AUFS graph driver. For dump,
--aufs-root <container_root> should be added to the command line options.
For restore, there is no need for AUFS-specific command line options
but the container's AUFS filesystem should already be set up before
calling criu restore.
[ xemul: With AUFS files sometimes, in particular -- in case of a
mapping of an executable file (likekely the one created at elf load),
in the /proc/pid/map_files/xxx link target we see not the path
by which the file is seen in AUFS, but the path by which AUFS
accesses this file from one of its "branches". In order to fix
the path we get the info about branches from sysfs and when we
meet such a file, we cut the branch part of the path. ]
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We've moved signinfos on core entry, thus the bits with
siginfo-s themselves cannot sit on stack any longer.
Otherwise we would overwritem them with next batch and
will feed stack pointer to the caller, thus causing a
data and garbage on the stack to be written into image
instead of siginfo data.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The se variable is just an array of pointers on these
objects. Need to allocate the objects themselves.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Every thread has it's own private signals stored at thread_core->signals_p
and leader thread has also shared signals stored at tc->signals_s.
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We need it to be able to dump signals into cores
before calling parasite_infect_seized().
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Needed for future user namespace support. Capabilities will have to be
dumped from the parasite, ie from inside the namespace since there is no
obvious way to 'translate' capabilities from the global namespace (unlike
with uids and gids, where the id mappings can be used for translation).
[ additional explanation from Andrew Vagin:
"capabilities" are not translated between namespaces. They can exist
only in one userns, where a process lives. If a process is created in a
new userns, it gets a full set of capabilities in this userns, and
loses all caps in a parent userns.
So if capabilities are not shown in /proc/pid/stat, we have no way to
get it except of using parasite code. ]
Signed-off-by: Sophie Blee-Goldman <ableegoldman@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For that mnt namespaces should be dumped after files.
v2: rework enumeration of namespaces in dump_mnt_namespaces()
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
During the dump phase, /proc/cgroups is parsed to find co-mounted cgroups.
Then, for each task /proc/self/cgroup is parsed for the cgroups that it is a
member of, and that cgroup is traversed to find any child cgroups which may
also need restoring. Any cgroups not currently mounted will be temporarily
mounted and traversed. All of this information is persisted along with the
original cg_sets, which indicate which cgroups a task is a member of.
On restore, an initial phase creates all the cgroups which were saved. Tasks
are then restored into these cgroups via cg_sets as usual.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The implementation is pretty straightforward. When dumping per-thread
misc data with parasite, collect one, then write in thread_core_info.
On restore wait for creds restore and put the value back (some creds
changes drop it to zero).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Robust lists may be disabled, for example if the "futex_cmpxchg_enabled"
variable in the kernel is unset.
Detect that case by checking that both "get_robust_list" and "set_robust_list"
syscalls return ENOSYS and do not make criu dump fail in that case, but simply
assume an empty list, which is consistent with the syscalls not being
available.
Tested: Successfully ran the zdtm test suite on a kernel where the
"get_robust_list" and "set_robust_list" syscalls are disabled.
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
vvar zone is mapped by a kernel and must not ever
been dumped into image, the data present there is
valid on running kernel only.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Each task points to a single ID of cgroup-set it lives in. This
is done so to save some space in the image, as tasks likely
live in the same set of cgroups.
Other than this we keep track of what cgroup set we dump the
subtree from. If it happens, that root task lives in the same
cgroup set as criu does, we don't allow for any other sub-cgroups
and make restore (next patch) much simpler and faster.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Preserve the dumpable flag, which affects whether a core dump will be
generated, but also affects the ownership of the virtual files under
/proc/$pid after restoring a process.
Tested: Restored a process with a criu including this patch and looked
at /proc/$pid to confirm that the virtual files were no longer all owned
by root:root.
zdtm tests pass except for cow01 which seems to be broken.
(see https://bugzilla.openvz.org/show_bug.cgi?id=2967 for details.)
This patch fixes https://bugzilla.openvz.org/show_bug.cgi?id=2968
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Change-Id: I8c386508448a84368a86666f2d7500b252a78bbf
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
