Hi, The patchset aims to relax the allowlist for open-coded css_task iter suggested by Alexei[1]. Please see individual patches for more details. And comments are always welcome. Patch summary: * Patch #1: Relax the allowlist and let css_task iter can be used in bpf iters and any sleepable progs. * Patch #2: Add a test in cgroup_iters.c which demonstrates how css_task iters can be combined with cgroup iter. * Patch #3: Add a test to prove css_task iter can be used in normal * sleepable progs. link[1]:https://lore.kernel.org/lkml/CAADnVQKafk_junRyE=-FVAik4hjTRDtThymYGEL8hGTuYoOGpA@xxxxxxxxxxxxxx/ --- Changes in v2: * Fix the incorrect logic in check_css_task_iter_allowlist. Use expected_attach_type to check whether we are using bpf_iters. * Link to v1:https://lore.kernel.org/bpf/20231022154527.229117-1-zhouchuyi@xxxxxxxxxxxxx/T/#m946f9cde86b44a13265d9a44c5738a711eb578fd Changes in v3: * Add a testcase to prove css_task can be used in fentry.s * Link to v2:https://lore.kernel.org/bpf/20231024024240.42790-1-zhouchuyi@xxxxxxxxxxxxx/T/#m14a97041ff56c2df21bc0149449abd275b73f6a3 Changes in v4: * Add Yonghong's ack for patch #1 and patch #2. * Solve Yonghong's comments for patch #2 * Move prog 'iter_css_task_for_each_sleep' from iters_task_failure.c to iters_css_task.c. Use RUN_TESTS to prove we can load this prog. * Link to v3:https://lore.kernel.org/bpf/20231025075914.30979-1-zhouchuyi@xxxxxxxxxxxxx/T/#m3200d8ad29af4ffab97588e297361d0a45d7585d --- Chuyi Zhou (3): bpf: Relax allowlist for css_task iter selftests/bpf: Add tests for css_task iter combining with cgroup iter selftests/bpf: Add test for using css_task iter in sleepable progs kernel/bpf/verifier.c | 16 +++-- .../selftests/bpf/prog_tests/cgroup_iter.c | 33 ++++++++++ .../testing/selftests/bpf/prog_tests/iters.c | 1 + .../selftests/bpf/progs/iters_css_task.c | 63 +++++++++++++++++++ .../selftests/bpf/progs/iters_task_failure.c | 4 +- 5 files changed, 111 insertions(+), 6 deletions(-) -- 2.20.1