1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (C) 2023 Chuyi Zhou <zhouchuyi@bytedance.com> */ |
3 | |
4 | #include "vmlinux.h" |
5 | #include <errno.h> |
6 | #include <bpf/bpf_helpers.h> |
7 | #include <bpf/bpf_tracing.h> |
8 | #include "bpf_misc.h" |
9 | #include "bpf_experimental.h" |
10 | |
11 | char _license[] SEC("license" ) = "GPL" ; |
12 | |
13 | struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym; |
14 | struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; |
15 | void bpf_cgroup_release(struct cgroup *p) __ksym; |
16 | |
17 | pid_t target_pid; |
18 | int css_task_cnt; |
19 | u64 cg_id; |
20 | |
21 | SEC("lsm/file_mprotect" ) |
22 | int BPF_PROG(iter_css_task_for_each, struct vm_area_struct *vma, |
23 | unsigned long reqprot, unsigned long prot, int ret) |
24 | { |
25 | struct task_struct *cur_task = bpf_get_current_task_btf(); |
26 | struct cgroup_subsys_state *css; |
27 | struct task_struct *task; |
28 | struct cgroup *cgrp; |
29 | |
30 | if (cur_task->pid != target_pid) |
31 | return ret; |
32 | |
33 | cgrp = bpf_cgroup_from_id(cg_id); |
34 | |
35 | if (!cgrp) |
36 | return -EPERM; |
37 | |
38 | css = &cgrp->self; |
39 | css_task_cnt = 0; |
40 | |
41 | bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) |
42 | if (task->pid == target_pid) |
43 | css_task_cnt++; |
44 | |
45 | bpf_cgroup_release(cgrp); |
46 | |
47 | return -EPERM; |
48 | } |
49 | |
50 | static inline u64 cgroup_id(struct cgroup *cgrp) |
51 | { |
52 | return cgrp->kn->id; |
53 | } |
54 | |
55 | SEC("?iter/cgroup" ) |
56 | int cgroup_id_printer(struct bpf_iter__cgroup *ctx) |
57 | { |
58 | struct seq_file *seq = ctx->meta->seq; |
59 | struct cgroup *cgrp = ctx->cgroup; |
60 | struct cgroup_subsys_state *css; |
61 | struct task_struct *task; |
62 | |
63 | /* epilogue */ |
64 | if (cgrp == NULL) { |
65 | BPF_SEQ_PRINTF(seq, "epilogue\n" ); |
66 | return 0; |
67 | } |
68 | |
69 | /* prologue */ |
70 | if (ctx->meta->seq_num == 0) |
71 | BPF_SEQ_PRINTF(seq, "prologue\n" ); |
72 | |
73 | BPF_SEQ_PRINTF(seq, "%8llu\n" , cgroup_id(cgrp)); |
74 | |
75 | css = &cgrp->self; |
76 | css_task_cnt = 0; |
77 | bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) { |
78 | if (task->pid == target_pid) |
79 | css_task_cnt++; |
80 | } |
81 | |
82 | return 0; |
83 | } |
84 | |
85 | SEC("?fentry.s/" SYS_PREFIX "sys_getpgid" ) |
86 | int BPF_PROG(iter_css_task_for_each_sleep) |
87 | { |
88 | u64 cgrp_id = bpf_get_current_cgroup_id(); |
89 | struct cgroup *cgrp = bpf_cgroup_from_id(cgrp_id); |
90 | struct cgroup_subsys_state *css; |
91 | struct task_struct *task; |
92 | |
93 | if (cgrp == NULL) |
94 | return 0; |
95 | css = &cgrp->self; |
96 | |
97 | bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) { |
98 | |
99 | } |
100 | bpf_cgroup_release(cgrp); |
101 | return 0; |
102 | } |
103 | |