turn kdbus support into a runtime option

./configure --enable/disable-kdbus can be used to set the default
behavior regarding kdbus.

If no kdbus kernel support is available, dbus-dameon will be used.

With --enable-kdbus, the kernel command line option "kdbus=0" can
be used to disable kdbus.

With --disable-kdbus, the kernel command line option "kdbus=1" is
required to enable kdbus support.

6 files changed, 1 insertions, 15 deletions

diff --git a/src/core/execute.c b/src/core/execute.c
index a6ff5ac56e..94cc101738 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -1514,7 +1514,6 @@ static int exec_child(
                 }
         }
 
-#ifdef ENABLE_KDBUS
         if (params->bus_endpoint_fd >= 0 && context->bus_endpoint) {
                 uid_t ep_uid = (uid == UID_INVALID) ? 0 : uid;
 
@@ -1524,7 +1523,6 @@ static int exec_child(
                         return r;
                 }
         }
-#endif
 
         /* If delegation is enabled we'll pass ownership of the cgroup
          * (but only in systemd's own controller hierarchy!) to the
diff --git a/src/core/kmod-setup.c b/src/core/kmod-setup.c
index f5584b6b14..e7a6bdc8c4 100644
--- a/src/core/kmod-setup.c
+++ b/src/core/kmod-setup.c
@@ -66,10 +66,8 @@ int kmod_setup(void) {
                 /* this should never be a module */
                 { "unix",      "/proc/net/unix",            true,   true,    NULL      },
 
-#ifdef ENABLE_KDBUS
                 /* IPC is needed before we bring up any other services */
                 { "kdbus",     "/sys/fs/kdbus",             false,  false,   is_kdbus_wanted },
-#endif
 
 #ifdef HAVE_LIBIPTC
                 /* netfilter is needed by networkd, nspawn among others, and cannot be autoloaded */
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 66c9145aa6..aae81c80cb 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -229,9 +229,7 @@ Service.BusName,                 config_parse_bus_name,              0,
 Service.FileDescriptorStoreMax,  config_parse_unsigned,              0,                             offsetof(Service, n_fd_store_max)
 Service.NotifyAccess,            config_parse_notify_access,         0,                             offsetof(Service, notify_access)
 Service.Sockets,                 config_parse_service_sockets,       0,                             0
-m4_ifdef(`ENABLE_KDBUS',
-`Service.BusPolicy,              config_parse_bus_endpoint_policy,   0,                             offsetof(Service, exec_context)',
-`Service.BusPolicy,              config_parse_warn_compat,           DISABLED_EXPERIMENTAL,         0')
+Service.BusPolicy,               config_parse_bus_endpoint_policy,   0,                             offsetof(Service, exec_context)
 EXEC_CONTEXT_CONFIG_ITEMS(Service)m4_dnl
 CGROUP_CONTEXT_CONFIG_ITEMS(Service)m4_dnl
 KILL_CONTEXT_CONFIG_ITEMS(Service)m4_dnl
diff --git a/src/core/manager.c b/src/core/manager.c
index eb80dd1b46..a1f37bbbb3 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -731,7 +731,6 @@ static int manager_setup_notify(Manager *m) {
 }
 
 static int manager_setup_kdbus(Manager *m) {
-#ifdef ENABLE_KDBUS
         _cleanup_free_ char *p = NULL;
 
         assert(m);
@@ -749,7 +748,6 @@ static int manager_setup_kdbus(Manager *m) {
                 return log_debug_errno(m->kdbus_fd, "Failed to set up kdbus: %m");
 
         log_debug("Successfully set up kdbus on %s", p);
-#endif
 
         return 0;
 }
diff --git a/src/core/mount-setup.c b/src/core/mount-setup.c
index c35248eeae..42a6b952b9 100644
--- a/src/core/mount-setup.c
+++ b/src/core/mount-setup.c
@@ -104,10 +104,8 @@ static const MountPoint mount_table[] = {
         { "efivarfs",    "/sys/firmware/efi/efivars", "efivarfs",   NULL,                      MS_NOSUID|MS_NOEXEC|MS_NODEV,
           is_efi_boot,   MNT_NONE                   },
 #endif
-#ifdef ENABLE_KDBUS
         { "kdbusfs",    "/sys/fs/kdbus",             "kdbusfs",    NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
           NULL,       MNT_IN_CONTAINER },
-#endif
 };
 
 /* These are API file systems that might be mounted by other software,
diff --git a/src/core/service.c b/src/core/service.c
index 71252e29e2..fa1e80b710 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -568,14 +568,12 @@ static int service_add_extras(Service *s) {
                 s->notify_access = NOTIFY_MAIN;
 
         if (s->bus_name) {
-#ifdef ENABLE_KDBUS
                 const char *n;
 
                 n = strjoina(s->bus_name, ".busname");
                 r = unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, n, NULL, true);
                 if (r < 0)
                         return r;
-#endif
 
                 r = unit_watch_bus_name(UNIT(s), s->bus_name);
                 if (r < 0)
@@ -1180,7 +1178,6 @@ static int service_spawn(
         } else
                 path = UNIT(s)->cgroup_path;
 
-#ifdef ENABLE_KDBUS
         if (s->exec_context.bus_endpoint) {
                 r = bus_kernel_create_endpoint(UNIT(s)->manager->running_as == MANAGER_SYSTEM ? "system" : "user",
                                                UNIT(s)->id, &bus_endpoint_path);
@@ -1192,7 +1189,6 @@ static int service_spawn(
                  * as the service is running. */
                 exec_params.bus_endpoint_fd = s->bus_endpoint_fd = r;
         }
-#endif
 
         exec_params.argv = argv;
         exec_params.fds = fds;