19468ed514
The cgroup1_hierarchy test uses setup_classid_environment to setup
cgroupv1 environment. The problem is that the environment is set in
/sys/fs/cgroup and therefore, if not run under an own mount namespace,
effectively deletes all system cgroups:
$ ls /sys/fs/cgroup | wc -l
27
$ sudo ./test_progs -t cgroup1_hierarchy
#41/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK
#41/2 cgroup1_hierarchy/test_root_cgid:OK
#41/3 cgroup1_hierarchy/test_invalid_level:OK
#41/4 cgroup1_hierarchy/test_invalid_cgid:OK
#41/5 cgroup1_hierarchy/test_invalid_hid:OK
#41/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK
#41/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK
#41/8 cgroup1_hierarchy/test_sleepable_prog:OK
#41 cgroup1_hierarchy:OK
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED
$ ls /sys/fs/cgroup | wc -l
1
To avoid this, run setup_cgroup_environment first which will create an
own mount namespace. This only affects the cgroupv1_hierarchy test as
all other cgroup1 test progs already run setup_cgroup_environment prior
to running setup_classid_environment.
Also add a comment to the header of setup_classid_environment to warn
against this invalid usage in future.
Fixes: 360769233c ("selftests/bpf: Add selftests for cgroup1 hierarchy")
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240429112311.402497-1-vmalik@redhat.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.