forked from Minki/linux
c475ffad58
The default rlimit RLIMIT_MEMLOCK is 64KB. In certain cases, e.g. in a test machine mimicking our production system, this test may fail due to unable to charge the required memory for prog load: $ ./test_dev_cgroup libbpf: load bpf program failed: Operation not permitted libbpf: failed to load program 'cgroup/dev' libbpf: failed to load object './dev_cgroup.o' Failed to load DEV_CGROUP program ... Changing the default rlimit RLIMIT_MEMLOCK to unlimited makes the test pass. This patch also fixed a problem where when bpf_prog_load fails, cleanup_cgroup_environment() should not be called since setup_cgroup_environment() has not been invoked. Otherwise, the following confusing message will appear: ... (/home/yhs/local/linux/tools/testing/selftests/bpf/cgroup_helpers.c:95: errno: No such file or directory) Opening Cgroup Procs: /mnt/cgroup.procs ... Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
/* Copyright (c) 2017 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <assert.h>
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#include <sys/time.h>
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#include <sys/resource.h>
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#include <linux/bpf.h>
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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#include "cgroup_helpers.h"
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#define DEV_CGROUP_PROG "./dev_cgroup.o"
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#define TEST_CGROUP "test-bpf-based-device-cgroup/"
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int main(int argc, char **argv)
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{
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struct rlimit limit = { RLIM_INFINITY, RLIM_INFINITY };
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struct bpf_object *obj;
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int error = EXIT_FAILURE;
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int prog_fd, cgroup_fd;
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__u32 prog_cnt;
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if (setrlimit(RLIMIT_MEMLOCK, &limit) < 0)
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perror("Unable to lift memlock rlimit");
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if (bpf_prog_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE,
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&obj, &prog_fd)) {
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printf("Failed to load DEV_CGROUP program\n");
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goto out;
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}
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if (setup_cgroup_environment()) {
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printf("Failed to load DEV_CGROUP program\n");
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goto err;
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}
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/* Create a cgroup, get fd, and join it */
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cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
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if (!cgroup_fd) {
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printf("Failed to create test cgroup\n");
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goto err;
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}
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if (join_cgroup(TEST_CGROUP)) {
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printf("Failed to join cgroup\n");
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goto err;
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}
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/* Attach bpf program */
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if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_DEVICE, 0)) {
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printf("Failed to attach DEV_CGROUP program");
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goto err;
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}
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if (bpf_prog_query(cgroup_fd, BPF_CGROUP_DEVICE, 0, NULL, NULL,
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&prog_cnt)) {
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printf("Failed to query attached programs");
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goto err;
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}
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/* All operations with /dev/zero and and /dev/urandom are allowed,
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* everything else is forbidden.
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*/
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assert(system("rm -f /tmp/test_dev_cgroup_null") == 0);
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assert(system("mknod /tmp/test_dev_cgroup_null c 1 3"));
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assert(system("rm -f /tmp/test_dev_cgroup_null") == 0);
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/* /dev/zero is whitelisted */
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assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0);
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assert(system("mknod /tmp/test_dev_cgroup_zero c 1 5") == 0);
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assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0);
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assert(system("dd if=/dev/urandom of=/dev/zero count=64") == 0);
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/* src is allowed, target is forbidden */
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assert(system("dd if=/dev/urandom of=/dev/full count=64"));
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/* src is forbidden, target is allowed */
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assert(system("dd if=/dev/random of=/dev/zero count=64"));
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error = 0;
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printf("test_dev_cgroup:PASS\n");
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err:
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cleanup_cgroup_environment();
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out:
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return error;
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}
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