In a case where the host /proc mount has already been overmounted, the
MS_MOVE handling would get ENOENT when trying to hide (for instance)
"/proc/bus" because it had already hidden away "/proc". This revealed
two issues in the previous implementation of this hardening feaure:
1. No checks were done to make sure the mount was a "full" mount (it is
a mount of the root of the filesystem), but the kernel doesn't permit
a non-full mount to be converted to a full mount (for reference, see
mnt_already_visible). This just removes extra busy-work during setup.
2. ENOENT was treated as a critical error, even though it actually
indicates the mount doesn't exist and thus isn't a problem. A more
theoretically pure solution would be to store the set of mountpoints
to be hidden and only ignore the error if an ancestor directory of
the current mountpoint was already hidden, but that would just add
complexity with little justification.
In addition, better document the reasoning behind this logic so that
folks aren't confused when looking at it.
Fixes: 28a697cce3 ("rootfs: umount all procfs and sysfs with --no-pivot")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
If the values of CMT and MBM counters are zero, they will be omitted as
empty items when getting Intel RDT stats.
Remove 'omitempty' property from CMT and MBM counters to display zero
values.
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
I played with shfmt options (-bn, -ci, -sr) a bit trying to minimize
the patch generated (and also because I don't have a strong preference
on these matters), and it appears to be that the patch size is about the
same nevertheless, so I chose no options.
This commit is brought to you by
shfmt -ln bash -w man/*.sh script/*.sh tests/*.sh tests/integration/*.bash
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Various bats tests use various types of indentation (about half
is tabs, the rest is 2 spaces, 4 spaces, etc.).
Let's bring it to one style (tabs) using recently added
shfmt support for bats files (see [1]).
This commit is brought to you by
shfmt -ln bats -w tests/integration/*.bats
[1] https://github.com/mvdan/sh/issues/600
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
If the cgroup's init process doesn't complete successfully, Wait returns a
non-nil error. We should still kill all the process in the cgroup if process
namespace is shared. Otherwise, it may result in process leak.
Fixes#2632
Signed-off-by: Chaitanya Bandi <kbandi@cs.stonybrook.edu>
Commit 27d3dd3df3 ("don't fail when subsystem not mounted") added
ignoring "not found" error to enableKmem, and as a result the function
now tries to call Mkdir with an empty path, which results in a weird
error message. For example, this is a failure from a
libcontainer/integration test:
> === RUN TestRunWithKernelMemorySystemd
> exec_test.go:704: runContainer failed with kernel memory limit: container_linux.go:370: starting container process caused: process_linux.go:327: applying cgroup configuration for process caused: mkdir : no such file or directory
I am not entirely sure if it is a good idea to silently ignore set
limits, but at least let's fix the error handling.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit a1d5398afa ("Respect container's cgroup path") added a
cgroupPath argument to FindCgroupMountpoint to make runc/libcontainer
work in a custom multitenant environment with multiple cgroup mount
points.
It also added passing c.Path as an argument to FindCgroupMountpoint
for systemd (v1) controller. This is wrong, because
1. systemd controller do not use c.Path at all (and c.Path is never set
by specconv) -- instead, it uses Name and Parent.
2. c.Path, if set, is not absolute -- it is relative to /sys/fs/cgroup
-- but it is used as an absolute path here.
Since c.Path is never set, the change did not result in any breakage, so
this code sit quietly for some time and the issue might not have been
discovered -- until we started running libcontainer/integration tests
in a CentOS 7 VM, which resulted in a following weird error:
> FAIL: TestPidsSystemd: utils_test.go:55: exec_test.go:630: unexpected error: container_linux.go:353: starting container process caused: process_linux.go:326: applying cgroup configuration for process caused: mountpoint for devices not found
The error was "fixed" in commit f57bb2fe3d by changing the tests'
cgroups Path to be "/sys/fs/cgroup/". This actually resulted in
creation of cgroup directories like /sys/fs/cgroup/memory/sys/fs/cgroup,
/sys/fs/cgroup/devices/sys/fs/cgroup and so on.
The proper fix to the test case is implemented in the previous commit,
which sets c.Name and c.Parent.
This commit just removes the invalid use of c.Path, and tells the whole
story.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It seems that a few tests add a cgroup mount in case userns is not set.
Let's do it inside newTemplateConfig() for all tests.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
...so we can add more fields later.
This commit is mostly courtesy of
sed -i 's/newTemplateConfig(rootfs)/newTemplateConfig(\&tParam{rootfs: rootfs})/g'
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Move the functionality of opening a cgroup file into a separate
function, OpenFile, which, similar to ReadFile and WriteFile,
use separate dir and file arguments.
Change ReadFile and WriteFile to rely on OpenFile, and use lower-level
read and write instead of ones from ioutil.
It changes the semantics of WriteFile a bit -- it no longer uses
O_CREAT flag. This is good for real cgroup as there is no need to try
creating the files in there, but can potentially break WriteFile users
-- previously, EPERM error was returned for non-existing files, and
now it's ENOENT.
This also breaks the fs/fs2 unit tests since they write to pseudo-cgroup
files inside a test directory (not to a real cgroup fs), and now
fscommon.WriteFile do not create or truncate files, so we have to add a
variable that is set by the unit tests.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
While at it,
- change some functions to not be methods of CpusetCgroup as
they don't use any members;
- simplify isEmpty.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
fscommon.WriteFile is added specifically to work with cgroup files,
and the error it returns does not need to be wrapped.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This removes package dependency on cgroup, as following commits
make cgroup use fscommon, which would result in dependency cycle.
The code to find out memory cgroup root is not really needed,
as 99% of test envrionments will have it at /sys/fs/cgroup/memory.
If not, that means we're either on cgroupv2 or on some very custom
system, so just skip the test.
The code that checks if we're on cgroupv2 is replaced by the check
of the particular v1 control file.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Akihiro Suda