Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

selftests/bpf: Add selftests for cgroup1 hierarchy

Add selftests for cgroup1 hierarchy.
The result as follows,

$ tools/testing/selftests/bpf/test_progs --name=cgroup1_hierarchy
#36/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK
#36/2 cgroup1_hierarchy/test_root_cgid:OK
#36/3 cgroup1_hierarchy/test_invalid_level:OK
#36/4 cgroup1_hierarchy/test_invalid_cgid:OK
#36/5 cgroup1_hierarchy/test_invalid_hid:OK
#36/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK
#36/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK
#36/8 cgroup1_hierarchy/test_sleepable_prog:OK
#36 cgroup1_hierarchy:OK
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED

Besides, I also did some stress test similar to the patch #2 in this
series, as follows (with CONFIG_PROVE_RCU_LIST enabled):

- Continuously mounting and unmounting named cgroups in some tasks,
for example:

cgrp_name=$1
while true
do
mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name
umount /$cgrp_name
done

- Continuously run this selftest concurrently,
while true; do ./test_progs --name=cgroup1_hierarchy; done

They can ran successfully without any RCU warnings in dmesg.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

authored by

Yafang Shao and committed by
Alexei Starovoitov
36076923 bf47300b

+229
+158
tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + /* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */ 3 + 4 + #include <sys/types.h> 5 + #include <unistd.h> 6 + #include <test_progs.h> 7 + #include "cgroup_helpers.h" 8 + #include "test_cgroup1_hierarchy.skel.h" 9 + 10 + static void bpf_cgroup1(struct test_cgroup1_hierarchy *skel) 11 + { 12 + struct bpf_link *lsm_link, *fentry_link; 13 + int err; 14 + 15 + /* Attach LSM prog first */ 16 + lsm_link = bpf_program__attach_lsm(skel->progs.lsm_run); 17 + if (!ASSERT_OK_PTR(lsm_link, "lsm_attach")) 18 + return; 19 + 20 + /* LSM prog will be triggered when attaching fentry */ 21 + fentry_link = bpf_program__attach_trace(skel->progs.fentry_run); 22 + ASSERT_NULL(fentry_link, "fentry_attach_fail"); 23 + 24 + err = bpf_link__destroy(lsm_link); 25 + ASSERT_OK(err, "destroy_lsm"); 26 + } 27 + 28 + static void bpf_cgroup1_sleepable(struct test_cgroup1_hierarchy *skel) 29 + { 30 + struct bpf_link *lsm_link, *fentry_link; 31 + int err; 32 + 33 + /* Attach LSM prog first */ 34 + lsm_link = bpf_program__attach_lsm(skel->progs.lsm_s_run); 35 + if (!ASSERT_OK_PTR(lsm_link, "lsm_attach")) 36 + return; 37 + 38 + /* LSM prog will be triggered when attaching fentry */ 39 + fentry_link = bpf_program__attach_trace(skel->progs.fentry_run); 40 + ASSERT_NULL(fentry_link, "fentry_attach_fail"); 41 + 42 + err = bpf_link__destroy(lsm_link); 43 + ASSERT_OK(err, "destroy_lsm"); 44 + } 45 + 46 + static void bpf_cgroup1_invalid_id(struct test_cgroup1_hierarchy *skel) 47 + { 48 + struct bpf_link *lsm_link, *fentry_link; 49 + int err; 50 + 51 + /* Attach LSM prog first */ 52 + lsm_link = bpf_program__attach_lsm(skel->progs.lsm_run); 53 + if (!ASSERT_OK_PTR(lsm_link, "lsm_attach")) 54 + return; 55 + 56 + /* LSM prog will be triggered when attaching fentry */ 57 + fentry_link = bpf_program__attach_trace(skel->progs.fentry_run); 58 + if (!ASSERT_OK_PTR(fentry_link, "fentry_attach_success")) 59 + goto cleanup; 60 + 61 + err = bpf_link__destroy(fentry_link); 62 + ASSERT_OK(err, "destroy_lsm"); 63 + 64 + cleanup: 65 + err = bpf_link__destroy(lsm_link); 66 + ASSERT_OK(err, "destroy_fentry"); 67 + } 68 + 69 + void test_cgroup1_hierarchy(void) 70 + { 71 + struct test_cgroup1_hierarchy *skel; 72 + __u64 current_cgid; 73 + int hid, err; 74 + 75 + skel = test_cgroup1_hierarchy__open(); 76 + if (!ASSERT_OK_PTR(skel, "open")) 77 + return; 78 + 79 + skel->bss->target_pid = getpid(); 80 + 81 + err = bpf_program__set_attach_target(skel->progs.fentry_run, 0, "bpf_fentry_test1"); 82 + if (!ASSERT_OK(err, "fentry_set_target")) 83 + goto destroy; 84 + 85 + err = test_cgroup1_hierarchy__load(skel); 86 + if (!ASSERT_OK(err, "load")) 87 + goto destroy; 88 + 89 + /* Setup cgroup1 hierarchy */ 90 + err = setup_classid_environment(); 91 + if (!ASSERT_OK(err, "setup_classid_environment")) 92 + goto destroy; 93 + 94 + err = join_classid(); 95 + if (!ASSERT_OK(err, "join_cgroup1")) 96 + goto cleanup; 97 + 98 + current_cgid = get_classid_cgroup_id(); 99 + if (!ASSERT_GE(current_cgid, 0, "cgroup1 id")) 100 + goto cleanup; 101 + 102 + hid = get_cgroup1_hierarchy_id("net_cls"); 103 + if (!ASSERT_GE(hid, 0, "cgroup1 id")) 104 + goto cleanup; 105 + skel->bss->target_hid = hid; 106 + 107 + if (test__start_subtest("test_cgroup1_hierarchy")) { 108 + skel->bss->target_ancestor_cgid = current_cgid; 109 + bpf_cgroup1(skel); 110 + } 111 + 112 + if (test__start_subtest("test_root_cgid")) { 113 + skel->bss->target_ancestor_cgid = 1; 114 + skel->bss->target_ancestor_level = 0; 115 + bpf_cgroup1(skel); 116 + } 117 + 118 + if (test__start_subtest("test_invalid_level")) { 119 + skel->bss->target_ancestor_cgid = 1; 120 + skel->bss->target_ancestor_level = 1; 121 + bpf_cgroup1_invalid_id(skel); 122 + } 123 + 124 + if (test__start_subtest("test_invalid_cgid")) { 125 + skel->bss->target_ancestor_cgid = 0; 126 + bpf_cgroup1_invalid_id(skel); 127 + } 128 + 129 + if (test__start_subtest("test_invalid_hid")) { 130 + skel->bss->target_ancestor_cgid = 1; 131 + skel->bss->target_ancestor_level = 0; 132 + skel->bss->target_hid = -1; 133 + bpf_cgroup1_invalid_id(skel); 134 + } 135 + 136 + if (test__start_subtest("test_invalid_cgrp_name")) { 137 + skel->bss->target_hid = get_cgroup1_hierarchy_id("net_cl"); 138 + skel->bss->target_ancestor_cgid = current_cgid; 139 + bpf_cgroup1_invalid_id(skel); 140 + } 141 + 142 + if (test__start_subtest("test_invalid_cgrp_name2")) { 143 + skel->bss->target_hid = get_cgroup1_hierarchy_id("net_cls,"); 144 + skel->bss->target_ancestor_cgid = current_cgid; 145 + bpf_cgroup1_invalid_id(skel); 146 + } 147 + 148 + if (test__start_subtest("test_sleepable_prog")) { 149 + skel->bss->target_hid = hid; 150 + skel->bss->target_ancestor_cgid = current_cgid; 151 + bpf_cgroup1_sleepable(skel); 152 + } 153 + 154 + cleanup: 155 + cleanup_classid_environment(); 156 + destroy: 157 + test_cgroup1_hierarchy__destroy(skel); 158 + }
+71
tools/testing/selftests/bpf/progs/test_cgroup1_hierarchy.c
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + /* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */ 3 + 4 + #include "vmlinux.h" 5 + #include <bpf/bpf_helpers.h> 6 + #include <bpf/bpf_tracing.h> 7 + #include <bpf/bpf_core_read.h> 8 + 9 + __u32 target_ancestor_level; 10 + __u64 target_ancestor_cgid; 11 + int target_pid, target_hid; 12 + 13 + struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym; 14 + struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym; 15 + void bpf_cgroup_release(struct cgroup *cgrp) __ksym; 16 + 17 + static int bpf_link_create_verify(int cmd) 18 + { 19 + struct cgroup *cgrp, *ancestor; 20 + struct task_struct *task; 21 + int ret = 0; 22 + 23 + if (cmd != BPF_LINK_CREATE) 24 + return 0; 25 + 26 + task = bpf_get_current_task_btf(); 27 + 28 + /* Then it can run in parallel with others */ 29 + if (task->pid != target_pid) 30 + return 0; 31 + 32 + cgrp = bpf_task_get_cgroup1(task, target_hid); 33 + if (!cgrp) 34 + return 0; 35 + 36 + /* Refuse it if its cgid or its ancestor's cgid is the target cgid */ 37 + if (cgrp->kn->id == target_ancestor_cgid) 38 + ret = -1; 39 + 40 + ancestor = bpf_cgroup_ancestor(cgrp, target_ancestor_level); 41 + if (!ancestor) 42 + goto out; 43 + 44 + if (ancestor->kn->id == target_ancestor_cgid) 45 + ret = -1; 46 + bpf_cgroup_release(ancestor); 47 + 48 + out: 49 + bpf_cgroup_release(cgrp); 50 + return ret; 51 + } 52 + 53 + SEC("lsm/bpf") 54 + int BPF_PROG(lsm_run, int cmd, union bpf_attr *attr, unsigned int size) 55 + { 56 + return bpf_link_create_verify(cmd); 57 + } 58 + 59 + SEC("lsm.s/bpf") 60 + int BPF_PROG(lsm_s_run, int cmd, union bpf_attr *attr, unsigned int size) 61 + { 62 + return bpf_link_create_verify(cmd); 63 + } 64 + 65 + SEC("fentry") 66 + int BPF_PROG(fentry_run) 67 + { 68 + return 0; 69 + } 70 + 71 + char _license[] SEC("license") = "GPL";