From 44cb03f19b38c11cfc5bf76ea6d6885da210ded2 Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 7 Oct 2023 13:59:45 +0000 Subject: [PATCH] selftests/bpf: Add selftest for bpf_task_under_cgroup() in sleepable prog The result is as follows: $ tools/testing/selftests/bpf/test_progs --name=task_under_cgroup #237 task_under_cgroup:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Without the previous patch, there will be RCU warnings in dmesg when CONFIG_PROVE_RCU is enabled. While with the previous patch, there will be no warnings. Signed-off-by: Yafang Shao Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20231007135945.4306-2-laoar.shao@gmail.com --- .../bpf/prog_tests/task_under_cgroup.c | 11 ++++++-- .../bpf/progs/test_task_under_cgroup.c | 28 ++++++++++++++++++- 2 files changed, 36 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c index 4224727fb36448..626d76fe43a210 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c +++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c @@ -30,8 +30,15 @@ void test_task_under_cgroup(void) if (!ASSERT_OK(ret, "test_task_under_cgroup__load")) goto cleanup; - ret = test_task_under_cgroup__attach(skel); - if (!ASSERT_OK(ret, "test_task_under_cgroup__attach")) + /* First, attach the LSM program, and then it will be triggered when the + * TP_BTF program is attached. + */ + skel->links.lsm_run = bpf_program__attach_lsm(skel->progs.lsm_run); + if (!ASSERT_OK_PTR(skel->links.lsm_run, "attach_lsm")) + goto cleanup; + + skel->links.tp_btf_run = bpf_program__attach_trace(skel->progs.tp_btf_run); + if (!ASSERT_OK_PTR(skel->links.tp_btf_run, "attach_tp_btf")) goto cleanup; pid = fork(); diff --git a/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c b/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c index 56cdc0a553f086..7e750309ce274c 100644 --- a/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c +++ b/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c @@ -18,7 +18,7 @@ const volatile __u64 cgid; int remote_pid; SEC("tp_btf/task_newtask") -int BPF_PROG(handle__task_newtask, struct task_struct *task, u64 clone_flags) +int BPF_PROG(tp_btf_run, struct task_struct *task, u64 clone_flags) { struct cgroup *cgrp = NULL; struct task_struct *acquired; @@ -48,4 +48,30 @@ int BPF_PROG(handle__task_newtask, struct task_struct *task, u64 clone_flags) return 0; } +SEC("lsm.s/bpf") +int BPF_PROG(lsm_run, int cmd, union bpf_attr *attr, unsigned int size) +{ + struct cgroup *cgrp = NULL; + struct task_struct *task; + int ret = 0; + + task = bpf_get_current_task_btf(); + if (local_pid != task->pid) + return 0; + + if (cmd != BPF_LINK_CREATE) + return 0; + + /* 1 is the root cgroup */ + cgrp = bpf_cgroup_from_id(1); + if (!cgrp) + goto out; + if (!bpf_task_under_cgroup(task, cgrp)) + ret = -1; + bpf_cgroup_release(cgrp); + +out: + return ret; +} + char _license[] SEC("license") = "GPL";