src/core/bpf-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include "bpf-dlopen.h"
   4 #include "bpf-util.h"
   5 #include "cgroup-util.h"
   6 #include "initrd-util.h"
   7 #include "log.h"
   8
   9 bool cgroup_bpf_supported(void) {
  10         static int supported = -1;
  11         int r;
  12
  13         if (supported >= 0)
  14                 return supported;
  15
  16         r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
  17         if (r < 0) {
  18                 log_warning_errno(r, "Can't determine whether the unified hierarchy is used: %m");
  19                 return (supported = false);
  20         }
  21
  22         if (r == 0) {
  23                 log_info_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
  24                                "Not running with unified cgroup hierarchy, disabling cgroup BPF features.");
  25                 return (supported = false);
  26         }
  27
  28         r = dlopen_bpf();
  29         if (r < 0) {
  30                 log_full_errno(in_initrd() ? LOG_DEBUG : LOG_INFO,
  31                                r, "Failed to open libbpf, cgroup BPF features disabled: %m");
  32                 return (supported = false);
  33         }
  34
  35         return (supported = true);
  36 }