103 lines · c
1// SPDX-License-Identifier: GPL-2.02/* 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 11char _license[] SEC("license") = "GPL";12 13struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym;14struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym;15void bpf_cgroup_release(struct cgroup *p) __ksym;16 17pid_t target_pid;18int css_task_cnt;19u64 cg_id;20 21SEC("lsm/file_mprotect")22int 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 50static inline u64 cgroup_id(struct cgroup *cgrp)51{52 return cgrp->kn->id;53}54 55SEC("?iter/cgroup")56int 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 85SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")86int 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