About Intel RDT/CAT feature:
Intel platforms with new Xeon CPU support Intel Resource Director Technology
(RDT). Cache Allocation Technology (CAT) is a sub-feature of RDT, which
currently supports L3 cache resource allocation.
This feature provides a way for the software to restrict cache allocation to a
defined 'subset' of L3 cache which may be overlapping with other 'subsets'.
The different subsets are identified by class of service (CLOS) and each CLOS
has a capacity bitmask (CBM).
For more information about Intel RDT/CAT can be found in the section 17.17
of Intel Software Developer Manual.
About Intel RDT/CAT kernel interface:
In Linux 4.10 kernel or newer, the interface is defined and exposed via
"resource control" filesystem, which is a "cgroup-like" interface.
Comparing with cgroups, it has similar process management lifecycle and
interfaces in a container. But unlike cgroups' hierarchy, it has single level
filesystem layout.
Intel RDT "resource control" filesystem hierarchy:
mount -t resctrl resctrl /sys/fs/resctrl
tree /sys/fs/resctrl
/sys/fs/resctrl/
|-- info
| |-- L3
| |-- cbm_mask
| |-- min_cbm_bits
| |-- num_closids
|-- cpus
|-- schemata
|-- tasks
|-- <container_id>
|-- cpus
|-- schemata
|-- tasks
For runc, we can make use of `tasks` and `schemata` configuration for L3 cache
resource constraints.
The file `tasks` has a list of tasks that belongs to this group (e.g.,
<container_id>" group). Tasks can be added to a group by writing the task ID
to the "tasks" file (which will automatically remove them from the previous
group to which they belonged). New tasks created by fork(2) and clone(2) are
added to the same group as their parent. If a pid is not in any sub group, it
Is in root group.
The file `schemata` has allocation bitmasks/values for L3 cache on each socket,
which contains L3 cache id and capacity bitmask (CBM).
Format: "L3:<cache_id0>=<cbm0>;<cache_id1>=<cbm1>;..."
For example, on a two-socket machine, L3's schema line could be `L3:0=ff;1=c0`
which means L3 cache id 0's CBM is 0xff, and L3 cache id 1's CBM is 0xc0.
The valid L3 cache CBM is a *contiguous bits set* and number of bits that can
be set is less than the max bit. The max bits in the CBM is varied among
supported Intel Xeon platforms. In Intel RDT "resource control" filesystem
layout, the CBM in a group should be a subset of the CBM in root. Kernel will
check if it is valid when writing. e.g., 0xfffff in root indicates the max bits
of CBM is 20 bits, which mapping to entire L3 cache capacity. Some valid CBM
values to set in a group: 0xf, 0xf0, 0x3ff, 0x1f00 and etc.
For more information about Intel RDT/CAT kernel interface:
https://www.kernel.org/doc/Documentation/x86/intel_rdt_ui.txt
An example for runc:
Consider a two-socket machine with two L3 caches where the default CBM is
0xfffff and the max CBM length is 20 bits. With this configuration, tasks
inside the container only have access to the "upper" 80% of L3 cache id 0 and
the "lower" 50% L3 cache id 1:
"linux": {
"intelRdt": {
"l3CacheSchema": "L3:0=ffff0;1=3ff"
}
}
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Fixes: #1557
I'm not quite sure about the root cause, looks like
systemd still want them to be uint64.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
While we have significant protections in place against CVE-2016-9962, we
still were holding onto a file descriptor that referenced the host
filesystem. This meant that in certain scenarios it was still possible
for a semi-privileged container to gain access to the host filesystem
(if they had CAP_SYS_PTRACE).
Instead, open the FIFO itself using a O_PATH. This allows us to
reference the FIFO directly without providing the ability for
directory-level access. When opening the FIFO inside the init process,
open it through procfs to re-open the actual FIFO (this is currently the
only supported way to open such a file descriptor).
Signed-off-by: Aleksa Sarai <asarai@suse.de>
The documentation here:
https://docs.docker.com/engine/security/userns-remap/#user-namespace-known-limitations
says that readonly containers can't be used with user namespaces do to some
kernel restriction. In fact, there is a special case in the kernel to be
able to do stuff like this, so let's use it.
This takes us from:
ubuntu@docker:~$ docker run -it --read-only ubuntu
docker: Error response from daemon: oci runtime error: container_linux.go:262: starting container process caused "process_linux.go:339: container init caused \"rootfs_linux.go:125: remounting \\\"/dev\\\" as readonly caused \\\"operation not permitted\\\"\"".
to:
ubuntu@docker:~$ docker-runc --version
runc version 1.0.0-rc4+dev
commit: ae2948042b08ad3d6d13cd09f40a50ffff4fc688-dirty
spec: 1.0.0
ubuntu@docker:~$ docker run -it --read-only ubuntu
root@181e2acb909a:/# touch foo
touch: cannot touch 'foo': Read-only file system
Signed-off-by: Tycho Andersen <tycho@docker.com>
congfig.Sysctl setting is duplicated.
when contianer is rootless and Linux is nil, runc will panic.
Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
state.json should be a reflection of the container's
realtime state, including resource configurations,
so we should update state.json after updating container
resources.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Fixes: #1228
It can be reproduced by applying this patch:
```diff
@@ -45,6 +46,7 @@ func registerMemoryEvent(cgDir string, evName string, arg string) (<-chan struct
go func() {
defer func() {
close(ch)
+ <-time.After(1 * time.Second)
eventfd.Close()
evFile.Close()
}()
```
We can close channel after fds were closed.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Before this change, some file type would be treated as char devices
(e.g. symlinks).
Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
This allows the libcontainer to automatically clean up runc:[1:CHILD]
processes created as part of nsenter.
Signed-off-by: Alex Fang <littlelightlittlefire@gmail.com>
With this runC also uses RPC to ask CRIU for its version. CRIU supports
a VERSION RPC since CRIU 3.0 and using the RPC interface does not
require parsing the console output of CRIU (which could change anytime).
For older CRIU versions which do not yet have the VERSION RPC runC falls
back to its old CRIU output parsing mode.
Once CRIU 3.0 is the minimum version required for runC the old code can
be removed.
v2:
* adapt to changes in the previous patches based on the review
Signed-off-by: Adrian Reber <areber@redhat.com>
Update criurpc.proto for the upcoming VERSION RPC.
This includes lazy_pages for the upcoming lazy migration support.
Signed-off-by: Adrian Reber <areber@redhat.com>
To use the CRIU VERSION RPC the criuSwrk function is adapted to work
with CriuOpts set to 'nil' as CriuOpts is not required for the VERSION
RPC.
Also do not print c.criuVersion if it is '0' as the first RPC call will
always be the VERSION call and only after that the version will be
known.
Signed-off-by: Adrian Reber <areber@redhat.com>
If the version of criu has already been determined there is no need to
ask criu for the version again. Use the value from c.criuVersion.
v2:
* reduce unnecessary code movement in the patch series
* factor out the criu version parsing into a separate function
Signed-off-by: Adrian Reber <areber@redhat.com>
The checkCriuVersion function used a string to specify the minimum
version required. This is more comfortable for an external interface
but for an internal function this added unnecessary complexity. This
changes to version string like '1.5.2' to an integer like 10502. This is
already the format used internally in the function.
Signed-off-by: Adrian Reber <areber@redhat.com>
go's switch statement doesn't need an explicit break. Remove it where
that is the case and add a comment to indicate the purpose where the
removal would lead to an empty case.
Found with honnef.co/go/tools/cmd/staticcheck
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Handle err return value of fmt.Scanf, os.Pipe and unix.ParseUnixRights.
Found with honnef.co/go/tools/cmd/staticcheck
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Refactor DeviceFromPath in order to get rid of package syscall and
directly use the functions from x/sys/unix. This also allows to get rid
of the conversion from the OS-independent file mode values (from the os
package) to Linux specific values and instead let's us use the raw
file mode value directly.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Updated logrus to use v1 which includes a breaking name change Sirupsen -> sirupsen.
This includes a manual edit of the docker term package to also correct the name there too.
Signed-off-by: Steven Hartland <steven.hartland@multiplay.co.uk>
Use ParseSocketControlMessage and ParseUnixRights from
golang.org/x/sys/unix instead of their syscall equivalent.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
fix#1476
If containerA shares namespace, say ipc namespace, with containerB, then
its ipc namespace path would be the same as containerB and be stored in
`state.json`. Exec into containerA will just read the namespace paths
stored in this file and join these namespaces. So, if containerB has
already been stopped, `docker exec containerA` will fail.
To address this issue, we should always save own namespace paths no
matter if we share namespaces with other containers.
Signed-off-by: Yuanhong Peng <pengyuanhong@huawei.com>
It appears as though these semantics were not fully thought out when
implementing them for rootless containers. It is not necessary (and
could be potentially dangerous) to set the owner of /run/ctr/$id to be
the root inside the container (if user namespaces are being used).
Instead, just use the e{g,u}id of runc to determine the owner.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Use IoctlGetInt and IoctlGetTermios/IoctlSetTermios instead of manually
reimplementing them.
Because of unlockpt, the ioctl wrapper is still needed as it needs to
pass a pointer to a value, which is not supported by any ioctl function
in x/sys/unix yet.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Use unix.Prctl() instead of manually reimplementing it using
unix.RawSyscall. Also use unix.SECCOMP_MODE_FILTER instead of locally
defining it.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Xiaochen Shen