kernel.git/tools/testing/selftests/bpf/progs/iters_css.c, branch masterHosts the 0x221E linux distro kernel.
https://git.0xinfinity.dev/distro/kernel.git/atom?h=master2026-01-27T17:06:03Zselftests/bpf: cover BPF_CGROUP_ITER_CHILDREN control option2026-01-27T17:06:03ZMatt Bobrowski2026-01-27T08:51:11Zurn:sha1:1456ebb291ddee67c9144c8f7f38a6dddcd32ed7
Extend some of the existing CSS iterator selftests such that they
cover the newly introduced BPF_CGROUP_ITER_CHILDREN iterator control
option.
Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/r/20260127085112.3608687-2-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: Add tests for open-coded task and css iter2023-10-20T00:02:47ZChuyi Zhou2023-10-18T06:17:46Zurn:sha1:130e0f7af9fc7388b90fb016ca13ff3840c48d4a
This patch adds 4 subtests to demonstrate these patterns and validating
correctness.
subtest1:
1) We use task_iter to iterate all process in the system and search for the
current process with a given pid.
2) We create some threads in current process context, and use
BPF_TASK_ITER_PROC_THREADS to iterate all threads of current process. As
expected, we would find all the threads of current process.
3) We create some threads and use BPF_TASK_ITER_ALL_THREADS to iterate all
threads in the system. As expected, we would find all the threads which was
created.
subtest2:
We create a cgroup and add the current task to the cgroup. In the
BPF program, we would use bpf_for_each(css_task, task, css) to iterate all
tasks under the cgroup. As expected, we would find the current process.
subtest3:
1) We create a cgroup tree. In the BPF program, we use
bpf_for_each(css, pos, root, XXX) to iterate all descendant under the root
with pre and post order. As expected, we would find all descendant and the
last iterating cgroup in post-order is root cgroup, the first iterating
cgroup in pre-order is root cgroup.
2) We wse BPF_CGROUP_ITER_ANCESTORS_UP to traverse the cgroup tree starting
from leaf and root separately, and record the height. The diff of the
hights would be the total tree-high - 1.
subtest4:
Add some failure testcase when using css_task, task and css iters, e.g,
unlock when using task-iters to iterate tasks.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Link: https://lore.kernel.org/r/20231018061746.111364-9-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>