src/test/test-helper.c

/***
  This file is part of systemd.

  Copyright 2017 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include "test-helper.h"
#include "random-util.h"
#include "alloc-util.h"
#include "cgroup-util.h"

void enter_cgroup_subroot(void) {
        _cleanup_free_ char *cgroup_root = NULL, *cgroup_subroot = NULL;
        CGroupMask supported;

        assert_se(cg_pid_get_path(NULL, 0, &cgroup_root) >= 0);
        assert_se(asprintf(&cgroup_subroot, "%s/%" PRIx64, cgroup_root, random_u64()) >= 0);
        assert_se(cg_mask_supported(&supported) >= 0);

        /* If this fails, then we don't mind as the later cgroup operations will fail too, and it's fine if we handle
         * any errors at that point. */

        if (cg_create_everywhere(supported, _CGROUP_MASK_ALL, cgroup_subroot) < 0)
                return;

        if (cg_attach_everywhere(supported, cgroup_subroot, 0, NULL, NULL) < 0)
                return;
}