ba0b5e26 ("libcontainer: remove all mount logic from nsexec") introduced
a request function that handles two tasks:
- the exchanges with the request and response channels
- the closing of the request channel.
From 1.21, the closing of the request channel may be done with
context.AfterFunc(). Moreover, context.AfterFunc() is guaranteed to run
once.
Link: https://pkg.go.dev/context#AfterFunc
Suggested-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Ariel Otilibili <otilibil@eurecom.fr>
Set the process personality early to ensure it takes effect before
seccomp is initialized. If seccomp filters are applied first and they
block personality-related system calls (e.g., `personality(2)`),
subsequent attempts to set the personality will fail.
Signed-off-by: lifubang <lifubang@acmcoder.com>
The linux.intelRdt.enableMonitoring field enables the creation of
a per-container monitoring group. The monitoring group is removed when
the container is destroyed.
Signed-off-by: Markus Lehtonen <markus.lehtonen@intel.com>
The main benefit here is when we are using a systemd cgroup driver,
we actually ask systemd to add a PID, rather than doing it ourselves.
This way, we can add rootless exec PID to a cgroup.
This requires newer opencontainers/cgroups and coreos/go-systemd.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Remove cgroupPaths field from struct setnsProcess, because:
- we can get base cgroup paths from p.manager.GetPaths();
- we can get sub-cgroup paths from p.process.SubCgroupPaths.
But mostly because we are going to need separate cgroup paths when
adopting cgroups.AddPid.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Implement support for the linux.intelRdt.schemata field of the spec.
This allows management of the "schemata" file in the resctrl group in a
generic way.
Signed-off-by: Markus Lehtonen <markus.lehtonen@intel.com>
These sysctls are all per-userns (termed `ucounts` in the kernel code) are
settable with CAP_SYS_RESOURCE in the user namespace.
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
libcontainer/user was marked as deprecated in d9ea71bf96 ("deprecate
libcontainer/user") and users have had plenty of time to migrate to
github.com/moby/sys/user.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
In certain deployments, it's possible for runc to be spawned by a
process with a restrictive cpumask (such as from a systemd unit with
CPUAffinity=... configured) which will be inherited by runc and thus the
container process by default.
The cpuset cgroup used to reconfigure the cpumask automatically for
joining processes, but kcommit da019032819a ("sched: Enforce user
requested affinity") changed this behaviour in Linux 6.2.
The solution is to try to emulate the expected behaviour by resetting
our cpumask to correspond with the configured cpuset (in the case of
"runc exec", if the user did not configure an alternative one). Normally
we would have to parse /proc/stat and /sys/fs/cgroup, but luckily
sched_setaffinity(2) will transparently convert an all-set cpumask (even
if it has more entries than the number of CPUs on the system) to the
correct value for our usecase.
For some reason, in our CI it seems that rootless --systemd-cgroup
results in the cpuset (presumably temporarily?) being configured such
that sched_setaffinity(2) will allow the full set of CPUs. For this
particular case, all we care about is that it is different to the
original set, so include some special-casing (but we should probably
investigate this further...).
Reported-by: ningmingxiao <ning.mingxiao@zte.com.cn>
Reported-by: Martin Sivak <msivak@redhat.com>
Reported-by: Peter Hunt <pehunt@redhat.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Also, use GetPath() in Apply to get the resctrl group path, similar to
other methods of intelRdtManager.
Signed-off-by: Markus Lehtonen <markus.lehtonen@intel.com>
If intelRdt is specified in the spec, check that the resctrl fs is
actually mounted. Fixes e.g. the case where "intelRdt.closID" is
specified but runc silently ignores this if resctrl is not mounted.
Signed-off-by: Markus Lehtonen <markus.lehtonen@intel.com>
This was added in 2ee9cbbd12 ("It's /proc/stat, not /proc/stats") with
no actual justification, and doesn't really make much sense on further
inspection:
* /proc/net is a symlink to "self/net", which means that /proc/net/dev
is a per-process file, and so overmounting it would only affect pid1.
Any other program that cares about /proc/net/dev would see their own
process's configuration, and unprivileged processes wouldn't be able
to see /proc/1/... data anyway.
In addition, the fact that this is a symlink means that runc will
deny the overmount because /proc/1/net/dev is not in the proc
overmount allowlist. This means that this has not worked for many
years, and probably never worked in the first place.
* /proc/self/net is already namespaced with network namespaces, so the
primary argument for allowing /proc overmounts (lxcfs-like masking of
procfs files to emulate namespacing for files that are not properly
namespaced for containers -- such as /proc/cpuinfo) is moot.
It goes without saying that lxcfs has never overmounted
/proc/self/net/... files, so the general "because lxcfs"
justification doesn't hold water either.
* The kernel has slowly been moving towards blocking overmounts in
/proc/self/. Linux 6.12 blocked overmounts for fd, fdinfo, and
map_files; future Linux versions will probably end up blocking
everything under /proc/self/.
Fixes: 2ee9cbbd12 ("It's /proc/stat, not /proc/stats")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Since opencontainers/cgroups v0.0.2 (commit b206a015), all stuct
Resources fields are annotated with "omitempty" attribute.
As a result, the loaded configuration may have Resources == nil.
It is totally OK (rootless containers may have no resources configured)
except since commit 6c5441e5, cgroup v1 fs manager requires Resources to
be set in the call to NewManager (this is a cgroup v1 deficiency,
or maybe our implementation deficiency, or both).
To work around this, let's add code to ensure Resources is never nil
after loading from state.json.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The per-file deprecation in cgroup_deprecated.go is not working,
let's replace it.
Link to Hooks.Run in Hook.Run deprecation notice.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Implement support for passing Linux Network Devices to the container
network namespace.
The network device is passed during the creation of the container,
before the process is started.
It implements the logic defined in the OCI runtime specification.
Signed-off-by: Antonio Ojea <aojea@google.com>
Instead of generating a list of tmpfs mount and have a special function
to check whether the path is in the list, let's go over the list of
mounts directly. This simplifies the code and improves readability.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Since its code is now trivial, and it is only called from a single
place, it does not make sense to have it as a separate function.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It makes sense to ignore cgroup mounts much early in the code,
saving some time on unnecessary operations.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Replace the big "if !" block with the if block and continue,
simplifying the code flow.
2. Move comments closer to the code, improving readability.
This commit is best reviewed with --ignore-all-space or similar.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
While debugging an issue involving failing mounts, I discovered that
just returning the plain mount error message when we are in the fallback
code for handling locked mounts leads to unnecessary confusion.
It also doesn't help that podman currently forcefully sets "rw" on
mounts, which means that rootless containers are likely to hit the
locked mounts issue fairly often.
So we should improve our error messages to explain why the mount is
failing in the locked flags case.
Fixes: 7c71a22705 ("rootfs: remove --no-mount-fallback and finally fix MS_REMOUNT")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Ariel Otilibili