Ensure kdbus isn't used (#3501)

Delete the dbus1 generator and some critical wiring. This prevents
kdbus from being loaded or detected. As such, it will never be used,
even if the user still has a useful kdbus module loaded on their system.

Sort of fixes #3480. Not really, but it's better than the current state.

5 files changed, 4 insertions, 48 deletions

diff --git a/src/core/busname.c b/src/core/busname.c
index f03a95c24e..730be2ee14 100644
--- a/src/core/busname.c
+++ b/src/core/busname.c
@@ -998,12 +998,7 @@ static int busname_get_timeout(Unit *u, usec_t *timeout) {
 }
 
 static bool busname_supported(void) {
-        static int supported = -1;
-
-        if (supported < 0)
-                supported = is_kdbus_available();
-
-        return supported;
+        return false;
 }
 
 static int busname_control_pid(Unit *u) {
diff --git a/src/core/kmod-setup.c b/src/core/kmod-setup.c
index 3503db52ed..fd1021f706 100644
--- a/src/core/kmod-setup.c
+++ b/src/core/kmod-setup.c
@@ -64,9 +64,6 @@ int kmod_setup(void) {
                 /* this should never be a module */
                 { "unix",      "/proc/net/unix",            true,   true,    NULL      },
 
-                /* IPC is needed before we bring up any other services */
-                { "kdbus",     "/sys/fs/kdbus",             false,  false,   is_kdbus_wanted },
-
 #ifdef HAVE_LIBIPTC
                 /* netfilter is needed by networkd, nspawn among others, and cannot be autoloaded */
                 { "ip_tables", "/proc/net/ip_tables_names", false,  false,   NULL      },
diff --git a/src/core/manager.c b/src/core/manager.c
index 5c0fee935d..012aa6cd53 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -814,28 +814,6 @@ static int manager_setup_cgroups_agent(Manager *m) {
         return 0;
 }
 
-static int manager_setup_kdbus(Manager *m) {
-        _cleanup_free_ char *p = NULL;
-
-        assert(m);
-
-        if (m->test_run || m->kdbus_fd >= 0)
-                return 0;
-        if (!is_kdbus_available())
-                return -ESOCKTNOSUPPORT;
-
-        m->kdbus_fd = bus_kernel_create_bus(
-                        MANAGER_IS_SYSTEM(m) ? "system" : "user",
-                        MANAGER_IS_SYSTEM(m), &p);
-
-        if (m->kdbus_fd < 0)
-                return log_debug_errno(m->kdbus_fd, "Failed to set up kdbus: %m");
-
-        log_debug("Successfully set up kdbus on %s", p);
-
-        return 0;
-}
-
 static int manager_connect_bus(Manager *m, bool reexecuting) {
         bool try_bus_connect;
 
@@ -1244,7 +1222,6 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 
         /* We might have deserialized the kdbus control fd, but if we
          * didn't, then let's create the bus now. */
-        manager_setup_kdbus(m);
         manager_connect_bus(m, !!serialization);
         bus_track_coldplug(m, &m->subscribed, &m->deserialized_subscribed);
 
diff --git a/src/core/mount-setup.c b/src/core/mount-setup.c
index 40fc548b42..f9c9b4a91f 100644
--- a/src/core/mount-setup.c
+++ b/src/core/mount-setup.c
@@ -108,8 +108,6 @@ static const MountPoint mount_table[] = {
         { "efivarfs",    "/sys/firmware/efi/efivars", "efivarfs",   NULL,                      MS_NOSUID|MS_NOEXEC|MS_NODEV,
           is_efi_boot,   MNT_NONE                   },
 #endif
-        { "kdbusfs",    "/sys/fs/kdbus",             "kdbusfs",    NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
-          is_kdbus_wanted,       MNT_IN_CONTAINER },
 };
 
 /* 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 14da6a58a9..78c33b1530 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -574,20 +574,9 @@ static int service_setup_bus_name(Service *s) {
         if (!s->bus_name)
                 return 0;
 
-        if (is_kdbus_available()) {
-                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 log_unit_error_errno(UNIT(s), r, "Failed to add dependency to .busname unit: %m");
-
-        } else {
-                /* If kdbus is not available, we know the dbus socket is required, hence pull it in, and require it */
-                r = unit_add_dependency_by_name(UNIT(s), UNIT_REQUIRES, SPECIAL_DBUS_SOCKET, NULL, true);
-                if (r < 0)
-                        return log_unit_error_errno(UNIT(s), r, "Failed to add dependency on " SPECIAL_DBUS_SOCKET ": %m");
-        }
+        r = unit_add_dependency_by_name(UNIT(s), UNIT_REQUIRES, SPECIAL_DBUS_SOCKET, NULL, true);
+        if (r < 0)
+                return log_unit_error_errno(UNIT(s), r, "Failed to add dependency on " SPECIAL_DBUS_SOCKET ": %m");
 
         /* Regardless if kdbus is used or not, we always want to be ordered against dbus.socket if both are in the transaction. */
         r = unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_DBUS_SOCKET, NULL, true);