44cb03f19b
The result is as follows: $ tools/testing/selftests/bpf/test_progs --name=task_under_cgroup #237 task_under_cgroup:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Without the previous patch, there will be RCU warnings in dmesg when CONFIG_PROVE_RCU is enabled. While with the previous patch, there will be no warnings. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20231007135945.4306-2-laoar.shao@gmail.com
77 lines
1.6 KiB
C
77 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2023 Bytedance */
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym;
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long bpf_task_under_cgroup(struct task_struct *task, struct cgroup *ancestor) __ksym;
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void bpf_cgroup_release(struct cgroup *p) __ksym;
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struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym;
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void bpf_task_release(struct task_struct *p) __ksym;
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const volatile int local_pid;
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const volatile __u64 cgid;
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int remote_pid;
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SEC("tp_btf/task_newtask")
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int BPF_PROG(tp_btf_run, struct task_struct *task, u64 clone_flags)
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{
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struct cgroup *cgrp = NULL;
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struct task_struct *acquired;
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if (local_pid != (bpf_get_current_pid_tgid() >> 32))
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return 0;
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acquired = bpf_task_acquire(task);
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if (!acquired)
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return 0;
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if (local_pid == acquired->tgid)
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goto out;
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cgrp = bpf_cgroup_from_id(cgid);
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if (!cgrp)
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goto out;
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if (bpf_task_under_cgroup(acquired, cgrp))
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remote_pid = acquired->tgid;
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out:
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if (cgrp)
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bpf_cgroup_release(cgrp);
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bpf_task_release(acquired);
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return 0;
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}
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SEC("lsm.s/bpf")
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int BPF_PROG(lsm_run, int cmd, union bpf_attr *attr, unsigned int size)
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{
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struct cgroup *cgrp = NULL;
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struct task_struct *task;
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int ret = 0;
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task = bpf_get_current_task_btf();
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if (local_pid != task->pid)
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return 0;
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if (cmd != BPF_LINK_CREATE)
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return 0;
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/* 1 is the root cgroup */
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cgrp = bpf_cgroup_from_id(1);
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if (!cgrp)
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goto out;
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if (!bpf_task_under_cgroup(task, cgrp))
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ret = -1;
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bpf_cgroup_release(cgrp);
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out:
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return ret;
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}
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char _license[] SEC("license") = "GPL";
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