Since syscall is outdated and broken for some architectures,
use x/sys/unix instead.
There are still some dependencies on the syscall package that will
remain in syscall for the forseeable future:
Errno
Signal
SysProcAttr
Additionally:
- os still uses syscall, so it needs to be kept for anything
returning *os.ProcessState, such as process.Wait.
Signed-off-by: Christy Perez <christy@linux.vnet.ibm.com>
A freezer cgroup allows to dump processes faster.
If a user wants to checkpoint a container and its storage,
he has to pause a container, but in this case we need to pass
a path to its freezer cgroup to "criu dump".
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
When C/R was implemented, it was enough to call manager.Set to apply
limits and to move a task. Now .Set() and .Apply() have to be called
separately.
Fixes: 8a740d5391 ("libcontainer: cgroups: don't Set in Apply")
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Instead of relying on version numbers it is possible to check if CRIU
actually supports certain features. This introduces an initial
implementation to check if CRIU and the underlying kernel actually
support dirty memory tracking for memory pre-dumping.
Upstream CRIU also supports the lazy-page migration feature check and
additional feature checks can be included in CRIU to reduce the version
number parsing. There are also certain CRIU features which depend on one
side on the CRIU version but also require certain kernel versions to
actually work. CRIU knows if it can do certain things on the kernel it
is running on and using the feature check RPC interface makes it easier
for runc to decide if the criu+kernel combination will support that
feature.
Feature checking was introduced with CRIU 1.8. Running with older CRIU
versions will ignore the feature check functionality and behave just
like it used to.
v2:
- Do not use reflection to compare requested and responded
features. Checking which feature is available is now hardcoded
and needs to be adapted for every new feature check. The code
is now much more readable and simpler.
v3:
- Move the variable criuFeat out of the linuxContainer struct,
as it is not container specific. Now it is a global variable.
Signed-off-by: Adrian Reber <areber@redhat.com>
Previously Host{U,G}ID only gave you the root mapping, which isn't very
useful if you are trying to do other things with the IDMaps.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
The rootless cgroup manager acts as a noop for all set and apply
operations. It is just used for rootless setups. Currently this is far
too simple (we need to add opportunistic cgroup management), but is good
enough as a first-pass at a noop cgroup manager.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This enables the support for the rootless container mode. There are many
restrictions on what rootless containers can do, so many different runC
commands have been disabled:
* runc checkpoint
* runc events
* runc pause
* runc ps
* runc restore
* runc resume
* runc update
The following commands work:
* runc create
* runc delete
* runc exec
* runc kill
* runc list
* runc run
* runc spec
* runc state
In addition, any specification options that imply joining cgroups have
also been disabled. This is due to support for unprivileged subtree
management not being available from Linux upstream.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Effectively, !dumpable makes implementing rootless containers quite
hard, due to a bunch of different operations on /proc/self no longer
being possible without reordering everything.
!dumpable only really makes sense when you are switching between
different security contexts, which is only the case when we are joining
namespaces. Unfortunately this means that !dumpable will still have
issues in this instance, and it should only be necessary to set
!dumpable if we are not joining USER namespaces (new kernels have
protections that make !dumpable no longer necessary). But that's a topic
for another time.
This also includes code to unset and then re-set dumpable when doing the
USER namespace mappings. This should also be safe because in principle
processes in a container can't see us until after we fork into the PID
namespace (which happens after the user mapping).
In rootless containers, it is not possible to set a non-dumpable
process's /proc/self/oom_score_adj (it's owned by root and thus not
writeable). Thus, it needs to be set inside nsexec before we set
ourselves as non-dumpable.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
If we try to pause a container on the system without freezer cgroups,
we can found that runc tries to open ./freezer.state. It is obviously wrong.
$ ./runc pause test
no such directory for freezer.state
$ echo FROZEN > freezer.state
$ ./runc pause test
container not running or created: paused
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
In container process's Init function, we use
fd + execFifoFilename to open exec fifo, so this
field in init config is never used.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
It should not be binded to container creation, for
example, runc restore needs to create a
libcontainer.Container, but it won't need exec fifo.
So create exec fifo when container is started or run,
where we really need it.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
CRIU gets pre-dump to complete iterative migration.
pre-dump saves process memory info only. And it need parent-path
to specify the former memory files.
This patch add pre-dump and parent-path arguments to runc checkpoint
Signed-off-by: Deng Guangxing <dengguangxing@huawei.com>
Signed-off-by: Adrian Reber <areber@redhat.com>
If we pass a file descriptor to the host filesystem while joining a
container, there is a race condition where a process inside the
container can ptrace(2) the joining process and stop it from closing its
file descriptor to the stateDirFd. Then the process can access the
*host* filesystem from that file descriptor. This was fixed in part by
5d93fed3d2 ("Set init processes as non-dumpable"), but that fix is
more of a hail-mary than an actual fix for the underlying issue.
To fix this, don't open or pass the stateDirFd to the init process
unless we're creating a new container. A proper fix for this would be to
remove the need for even passing around directory file descriptors
(which are quite dangerous in the context of mount namespaces).
There is still an issue with containers that have CAP_SYS_PTRACE and are
using the setns(2)-style of joining a container namespace. Currently I'm
not really sure how to fix it without rampant layer violation.
Fixes: CVE-2016-9962
Fixes: 5d93fed3d2 ("Set init processes as non-dumpable")
Signed-off-by: Aleksa Sarai <asarai@suse.de>
`HookState` struct should follow definition of `State` in runtime-spec:
* modify json name of `version` to `ociVersion`.
* Remove redundant `Rootfs` field as rootfs can be retrived from
`bundlePath/config.json`.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
This implements {createTTY, detach} and all of the combinations and
negations of the two that were previously implemented. There are some
valid questions about out-of-OCI-scope topics like !createTTY and how
things should be handled (why do we dup the current stdio to the
process, and how is that not a security issue). However, these will be
dealt with in a separate patchset.
In order to allow for late console setup, split setupRootfs into the
"preparation" section where all of the mounts are created and the
"finalize" section where we pivot_root and set things as ro. In between
the two we can set up all of the console mountpoints and symlinks we
need.
We use two-stage synchronisation to ensures that when the syscalls are
reordered in a suboptimal way, an out-of-place read() on the parentPipe
will not gobble the ancilliary information.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This allows a user to send a signal to all the processes in the
container within a single atomic action to avoid new processes being
forked off before the signal can be sent.
This is basically taking functionality that we already use being
`delete` and exposing it ok the `kill` command by adding a flag.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
In user namespaces devices are bind-mounted from the host, so
we need to add them as external mounts for CRIU.
Reported-by: Ross Boucher <boucher@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Depending on your SELinux setup, the order in which you join namespaces
can be important. In general, user namespaces should *always* be joined
and unshared first because then the other namespaces are correctly
pinned and you have the right priviliges within them. This also is very
useful for rootless containers, as well as older kernels that had
essentially broken unshare(2) and clone(2) implementations.
This also includes huge refactorings in how we spawn processes for
complicated reasons that I don't want to get into because it will make
me spiral into a cloud of rage. The reasoning is in the giant comment in
clone_parent. Have fun.
In addition, because we now create multiple children with CLONE_PARENT,
we cannot wait for them to SIGCHLD us in the case of a death. Thus, we
have to resort to having a child kindly send us their exit code before
they die. Hopefully this all works okay, but at this point there's not
much more than we can do.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This avoids us from running into cases where libcontainer thinks that a
particular namespace file is a different type, and makes it a fatal
error rather than causing broken functionality.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
if a container state is running or created, the container.Pause()
method can set the state to pausing, and then paused.
this patch update the comment, so it can be consistent with the code.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
1. According to docs of Cmd.Path and Cmd.Args from package "os/exec":
Path is the path of the command to run. Args holds command line
arguments, including the command as Args[0]. We have mixed usage
of args. In InitPath(), InitArgs only take arguments, in InitArgs(),
InitArgs including the command as Args[0]. This is confusing.
2. InitArgs() already have the ability to configure a LinuxFactory
with the provided absolute path to the init binary and arguements as
InitPath() does.
3. exec.Command() will take care of serching executable path.
4. The default "/proc/self/exe" instead of os.Args[0] is passed to
InitArgs in order to allow relative path for the runC binary.
Signed-off-by: Yang Hongyang <imhy.yang@gmail.com>
This removes the use of a signal handler and SIGCONT to signal the init
process to exec the users process.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Christy Perez
Mrunal Patel
Harshal Patil
Andrei Vagin
Qiang Huang
Adrian Reber
Aleksa Sarai
Michael Crosby
Mrunal Patel
Deng Guangxing
Zhang Wei
Xianlu Bird
Wang Long
rajasec
Phil Estes
Yang Hongyang
Petar Petrov