Commit 36076923 authored by Yafang Shao's avatar Yafang Shao Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add selftests for cgroup1 hierarchy 



Add selftests for cgroup1 hierarchy.
The result as follows,

  $ tools/testing/selftests/bpf/test_progs --name=cgroup1_hierarchy
  #36/1    cgroup1_hierarchy/test_cgroup1_hierarchy:OK
  #36/2    cgroup1_hierarchy/test_root_cgid:OK
  #36/3    cgroup1_hierarchy/test_invalid_level:OK
  #36/4    cgroup1_hierarchy/test_invalid_cgid:OK
  #36/5    cgroup1_hierarchy/test_invalid_hid:OK
  #36/6    cgroup1_hierarchy/test_invalid_cgrp_name:OK
  #36/7    cgroup1_hierarchy/test_invalid_cgrp_name2:OK
  #36/8    cgroup1_hierarchy/test_sleepable_prog:OK
  #36      cgroup1_hierarchy:OK
  Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED

Besides, I also did some stress test similar to the patch #2 in this
series, as follows (with CONFIG_PROVE_RCU_LIST enabled):

- Continuously mounting and unmounting named cgroups in some tasks,
  for example:

  cgrp_name=$1
  while true
  do
      mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name
      umount /$cgrp_name
  done

- Continuously run this selftest concurrently,
  while true; do ./test_progs --name=cgroup1_hierarchy; done

They can ran successfully without any RCU warnings in dmesg.

Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-7-laoar.shao@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent bf47300b

tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c

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+158 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */



#include <sys/types.h>

#include <unistd.h>

#include <test_progs.h>

#include "cgroup_helpers.h"

#include "test_cgroup1_hierarchy.skel.h"



static void bpf_cgroup1(struct test_cgroup1_hierarchy *skel)

{

	struct bpf_link *lsm_link, *fentry_link;

	int err;



	/* Attach LSM prog first */

	lsm_link = bpf_program__attach_lsm(skel->progs.lsm_run);

	if (!ASSERT_OK_PTR(lsm_link, "lsm_attach"))

		return;



	/* LSM prog will be triggered when attaching fentry */

	fentry_link = bpf_program__attach_trace(skel->progs.fentry_run);

	ASSERT_NULL(fentry_link, "fentry_attach_fail");



	err = bpf_link__destroy(lsm_link);

	ASSERT_OK(err, "destroy_lsm");

}



static void bpf_cgroup1_sleepable(struct test_cgroup1_hierarchy *skel)

{

	struct bpf_link *lsm_link, *fentry_link;

	int err;



	/* Attach LSM prog first */

	lsm_link = bpf_program__attach_lsm(skel->progs.lsm_s_run);

	if (!ASSERT_OK_PTR(lsm_link, "lsm_attach"))

		return;



	/* LSM prog will be triggered when attaching fentry */

	fentry_link = bpf_program__attach_trace(skel->progs.fentry_run);

	ASSERT_NULL(fentry_link, "fentry_attach_fail");



	err = bpf_link__destroy(lsm_link);

	ASSERT_OK(err, "destroy_lsm");

}



static void bpf_cgroup1_invalid_id(struct test_cgroup1_hierarchy *skel)

{

	struct bpf_link *lsm_link, *fentry_link;

	int err;



	/* Attach LSM prog first */

	lsm_link = bpf_program__attach_lsm(skel->progs.lsm_run);

	if (!ASSERT_OK_PTR(lsm_link, "lsm_attach"))

		return;



	/* LSM prog will be triggered when attaching fentry */

	fentry_link = bpf_program__attach_trace(skel->progs.fentry_run);

	if (!ASSERT_OK_PTR(fentry_link, "fentry_attach_success"))

		goto cleanup;



	err = bpf_link__destroy(fentry_link);

	ASSERT_OK(err, "destroy_lsm");



cleanup:

	err = bpf_link__destroy(lsm_link);

	ASSERT_OK(err, "destroy_fentry");

}



void test_cgroup1_hierarchy(void)

{

	struct test_cgroup1_hierarchy *skel;

	__u64 current_cgid;

	int hid, err;



	skel = test_cgroup1_hierarchy__open();

	if (!ASSERT_OK_PTR(skel, "open"))

		return;



	skel->bss->target_pid = getpid();



	err = bpf_program__set_attach_target(skel->progs.fentry_run, 0, "bpf_fentry_test1");

	if (!ASSERT_OK(err, "fentry_set_target"))

		goto destroy;



	err = test_cgroup1_hierarchy__load(skel);

	if (!ASSERT_OK(err, "load"))

		goto destroy;



	/* Setup cgroup1 hierarchy */

	err = setup_classid_environment();

	if (!ASSERT_OK(err, "setup_classid_environment"))

		goto destroy;



	err = join_classid();

	if (!ASSERT_OK(err, "join_cgroup1"))

		goto cleanup;



	current_cgid = get_classid_cgroup_id();

	if (!ASSERT_GE(current_cgid, 0, "cgroup1 id"))

		goto cleanup;



	hid = get_cgroup1_hierarchy_id("net_cls");

	if (!ASSERT_GE(hid, 0, "cgroup1 id"))

		goto cleanup;

	skel->bss->target_hid = hid;



	if (test__start_subtest("test_cgroup1_hierarchy")) {

		skel->bss->target_ancestor_cgid = current_cgid;

		bpf_cgroup1(skel);

	}



	if (test__start_subtest("test_root_cgid")) {

		skel->bss->target_ancestor_cgid = 1;

		skel->bss->target_ancestor_level = 0;

		bpf_cgroup1(skel);

	}



	if (test__start_subtest("test_invalid_level")) {

		skel->bss->target_ancestor_cgid = 1;

		skel->bss->target_ancestor_level = 1;

		bpf_cgroup1_invalid_id(skel);

	}



	if (test__start_subtest("test_invalid_cgid")) {

		skel->bss->target_ancestor_cgid = 0;

		bpf_cgroup1_invalid_id(skel);

	}



	if (test__start_subtest("test_invalid_hid")) {

		skel->bss->target_ancestor_cgid = 1;

		skel->bss->target_ancestor_level = 0;

		skel->bss->target_hid = -1;

		bpf_cgroup1_invalid_id(skel);

	}



	if (test__start_subtest("test_invalid_cgrp_name")) {

		skel->bss->target_hid = get_cgroup1_hierarchy_id("net_cl");

		skel->bss->target_ancestor_cgid = current_cgid;

		bpf_cgroup1_invalid_id(skel);

	}



	if (test__start_subtest("test_invalid_cgrp_name2")) {

		skel->bss->target_hid = get_cgroup1_hierarchy_id("net_cls,");

		skel->bss->target_ancestor_cgid = current_cgid;

		bpf_cgroup1_invalid_id(skel);

	}



	if (test__start_subtest("test_sleepable_prog")) {

		skel->bss->target_hid = hid;

		skel->bss->target_ancestor_cgid = current_cgid;

		bpf_cgroup1_sleepable(skel);

	}



cleanup:

	cleanup_classid_environment();

destroy:

	test_cgroup1_hierarchy__destroy(skel);

}

tools/testing/selftests/bpf/progs/test_cgroup1_hierarchy.c

0 → 100644
+71 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */



#include "vmlinux.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <bpf/bpf_core_read.h>



__u32 target_ancestor_level;

__u64 target_ancestor_cgid;

int target_pid, target_hid;



struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym;

struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym;

void bpf_cgroup_release(struct cgroup *cgrp) __ksym;



static int bpf_link_create_verify(int cmd)

{

	struct cgroup *cgrp, *ancestor;

	struct task_struct *task;

	int ret = 0;



	if (cmd != BPF_LINK_CREATE)

		return 0;



	task = bpf_get_current_task_btf();



	/* Then it can run in parallel with others */

	if (task->pid != target_pid)

		return 0;



	cgrp = bpf_task_get_cgroup1(task, target_hid);

	if (!cgrp)

		return 0;



	/* Refuse it if its cgid or its ancestor's cgid is the target cgid */

	if (cgrp->kn->id == target_ancestor_cgid)

		ret = -1;



	ancestor = bpf_cgroup_ancestor(cgrp, target_ancestor_level);

	if (!ancestor)

		goto out;



	if (ancestor->kn->id == target_ancestor_cgid)

		ret = -1;

	bpf_cgroup_release(ancestor);



out:

	bpf_cgroup_release(cgrp);

	return ret;

}



SEC("lsm/bpf")

int BPF_PROG(lsm_run, int cmd, union bpf_attr *attr, unsigned int size)

{

	return bpf_link_create_verify(cmd);

}



SEC("lsm.s/bpf")

int BPF_PROG(lsm_s_run, int cmd, union bpf_attr *attr, unsigned int size)

{

	return bpf_link_create_verify(cmd);

}



SEC("fentry")

int BPF_PROG(fentry_run)

{

	return 0;

}



char _license[] SEC("license") = "GPL";