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
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