lxc/start.c: add initial protection from upstream

Signed-off-by: DreamConnected <1487442471@qq.com>

Author: DreamConnected

.github/workflows/code-test.yml

@@ -45,6 +45,7 @@ jobs:
             -Dopenssl=false \
             -Ddbus=false \
             -Dandroid-log=true \
+            -Dlandlock-monitor=true \
             --cross-file aarch64-android-api30.txt
 
         meson compile -C build

.github/workflows/main.yml

@@ -74,6 +74,7 @@ jobs:
             -Dopenssl=true \
             -Ddbus=false \
             -Dandroid-log=true \
+            -Dlandlock-monitor=true \
             --cross-file aarch64-android-api30.txt
 
         meson compile -C build

.gitignore

@@ -6,4 +6,3 @@
 
 # Release tarballs.
 lxc-*.tar.gz*
-/.github/workflows

src/lxc/start.c

@@ -729,10 +729,13 @@ int lxc_handler_mainloop(struct lxc_async_descr *descr, struct lxc_handler *hand
 	pthread_t thread;
 
 	/* Skip protection if a seccomp proxy is setup. */
+#if HAVE_DECL_SECCOMP_NOTIFY_FD
 	if (!handler || !handler->conf || handler->conf->seccomp.notifier.proxy_fd > 0) {
 		/* Landlock not supported when seccomp notify is in use. */
 		SYSERROR("Skipping Landlock due to seccomp notify");
-
+#else
+	if (!handler || !handler->conf) {
+#endif
 		/* We don't need to use thread then */
 		return lxc_mainloop(descr, -1);
 	}