1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (C) 2023 Chuyi Zhou <zhouchuyi@bytedance.com> */ |
3 | |
4 | #include "vmlinux.h" |
5 | #include <bpf/bpf_helpers.h> |
6 | #include <bpf/bpf_tracing.h> |
7 | #include "bpf_misc.h" |
8 | #include "bpf_experimental.h" |
9 | |
10 | char _license[] SEC("license" ) = "GPL" ; |
11 | |
12 | struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; |
13 | void bpf_cgroup_release(struct cgroup *p) __ksym; |
14 | void bpf_rcu_read_lock(void) __ksym; |
15 | void bpf_rcu_read_unlock(void) __ksym; |
16 | |
17 | SEC("?fentry.s/" SYS_PREFIX "sys_getpgid" ) |
18 | __failure __msg("expected an RCU CS when using bpf_iter_task_next" ) |
19 | int BPF_PROG(iter_tasks_without_lock) |
20 | { |
21 | struct task_struct *pos; |
22 | |
23 | bpf_for_each(task, pos, NULL, BPF_TASK_ITER_ALL_PROCS) { |
24 | |
25 | } |
26 | return 0; |
27 | } |
28 | |
29 | SEC("?fentry.s/" SYS_PREFIX "sys_getpgid" ) |
30 | __failure __msg("expected an RCU CS when using bpf_iter_css_next" ) |
31 | int BPF_PROG(iter_css_without_lock) |
32 | { |
33 | u64 cg_id = bpf_get_current_cgroup_id(); |
34 | struct cgroup *cgrp = bpf_cgroup_from_id(cg_id); |
35 | struct cgroup_subsys_state *root_css, *pos; |
36 | |
37 | if (!cgrp) |
38 | return 0; |
39 | root_css = &cgrp->self; |
40 | |
41 | bpf_for_each(css, pos, root_css, BPF_CGROUP_ITER_DESCENDANTS_POST) { |
42 | |
43 | } |
44 | bpf_cgroup_release(cgrp); |
45 | return 0; |
46 | } |
47 | |
48 | SEC("?fentry.s/" SYS_PREFIX "sys_getpgid" ) |
49 | __failure __msg("expected an RCU CS when using bpf_iter_task_next" ) |
50 | int BPF_PROG(iter_tasks_lock_and_unlock) |
51 | { |
52 | struct task_struct *pos; |
53 | |
54 | bpf_rcu_read_lock(); |
55 | bpf_for_each(task, pos, NULL, BPF_TASK_ITER_ALL_PROCS) { |
56 | bpf_rcu_read_unlock(); |
57 | |
58 | bpf_rcu_read_lock(); |
59 | } |
60 | bpf_rcu_read_unlock(); |
61 | return 0; |
62 | } |
63 | |
64 | SEC("?fentry.s/" SYS_PREFIX "sys_getpgid" ) |
65 | __failure __msg("expected an RCU CS when using bpf_iter_css_next" ) |
66 | int BPF_PROG(iter_css_lock_and_unlock) |
67 | { |
68 | u64 cg_id = bpf_get_current_cgroup_id(); |
69 | struct cgroup *cgrp = bpf_cgroup_from_id(cg_id); |
70 | struct cgroup_subsys_state *root_css, *pos; |
71 | |
72 | if (!cgrp) |
73 | return 0; |
74 | root_css = &cgrp->self; |
75 | |
76 | bpf_rcu_read_lock(); |
77 | bpf_for_each(css, pos, root_css, BPF_CGROUP_ITER_DESCENDANTS_POST) { |
78 | bpf_rcu_read_unlock(); |
79 | |
80 | bpf_rcu_read_lock(); |
81 | } |
82 | bpf_rcu_read_unlock(); |
83 | bpf_cgroup_release(cgrp); |
84 | return 0; |
85 | } |
86 | |
87 | SEC("?fentry/" SYS_PREFIX "sys_getpgid" ) |
88 | __failure __msg("css_task_iter is only allowed in bpf_lsm, bpf_iter and sleepable progs" ) |
89 | int BPF_PROG(iter_css_task_for_each) |
90 | { |
91 | u64 cg_id = bpf_get_current_cgroup_id(); |
92 | struct cgroup *cgrp = bpf_cgroup_from_id(cg_id); |
93 | struct cgroup_subsys_state *css; |
94 | struct task_struct *task; |
95 | |
96 | if (cgrp == NULL) |
97 | return 0; |
98 | css = &cgrp->self; |
99 | |
100 | bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) { |
101 | |
102 | } |
103 | bpf_cgroup_release(cgrp); |
104 | return 0; |
105 | } |
106 | |