fixup! [LibOS] Allow forceful termination of IPC leader when SIGTERM …

…was received

Signed-off-by: Stefan Berger <[email protected]>

libos/include/libos_ipc.h

@@ -64,7 +64,7 @@ int init_ipc_worker(void);
 /*!
  * \brief Terminate the IPC worker thread.
  *
- * \param force  Whether to force the termination even if the IPC thread is the leader
+ * \param force  Whether to force the termination of the IPC thread
  */
 void terminate_ipc_worker(bool force);
 

libos/src/ipc/libos_ipc_worker.c

@@ -397,10 +397,12 @@ static int create_ipc_worker(void) {
     }
 
     /* IPC leader gets a notifier used in terminate_ipc_leader */
-    if (is_ipc_leader() &&
-        (ret = PalEventCreate(&g_leader_notifier, /*init_signaled=*/false, /*auto_clear=*/false)) < 0) {
-        log_error("IPC leader: PalEventCreate() failed");
-        return pal_to_unix_errno(ret);;
+    if (is_ipc_leader()) {
+        ret = PalEventCreate(&g_leader_notifier, /*init_signaled=*/false, /*auto_clear=*/false);
+        if (ret < 0) {
+            log_error("IPC leader: PalEventCreate() failed");
+            return pal_to_unix_errno(ret);
+        }
     }
 
     g_worker_thread = get_new_internal_thread();
@@ -425,9 +427,10 @@ int init_ipc_worker(void) {
     return create_ipc_worker();
 }
 
-/* Terminate the IPC worker. If 'force' is set, the IPC leader will not wait
- * until it has 0 connections but terminate immediatel, otherwise it will
- * wait until all child processes have died and there are 0 connections.
+/* Terminate the IPC worker. If 'force' is set, the IPC leader will not wait until it has 0
+ * connections but terminate immediately, otherwise it will wait until all child processes have
+ * died and there are 0 connections. 'force' will for example be set when the user sends a SIGTERM
+ * signal to the Gramine process.
  */
 void terminate_ipc_worker(bool force) {
     if (is_ipc_leader() && !force) {

libos/src/sys/libos_exit.c

@@ -18,12 +18,6 @@
 #include "pal.h"
 
 static noreturn void libos_clean_and_exit(int exit_code, int term_signal) {
-    /*
-     * TODO: if we are the IPC leader, we need to either:
-     * 1) kill all other Gramine processes
-     * 2) wait for them to exit here, before we terminate the IPC helper
-     */
-
     shutdown_sync_client();
 
     struct libos_thread* async_thread = terminate_async_worker();
@@ -53,6 +47,10 @@ static noreturn void libos_clean_and_exit(int exit_code, int term_signal) {
      */
     release_id(get_cur_thread()->tid);
 
+    /* Terminate the IPC worker and wait until all child processes have also terminated. However,
+     * if we received a SIGTERM then the IPC worker will be forcefully terminated without waiting
+     * for child processes. Once we exit, all child proceses will the also exit.
+     */
     terminate_ipc_worker(term_signal == SIGTERM);
 
     log_debug("process %u exited with status %d", g_process_ipc_ids.self_vmid, exit_code);
@@ -147,7 +145,8 @@ noreturn void thread_exit(int error_code, int term_signal) {
 
     /* At this point other threads might be still in the middle of an exit routine, but we don't
      * care since the below will call `exit_group` eventually. */
-    libos_clean_and_exit(term_signal ? 128 + (term_signal & ~__WCOREDUMP_BIT) : error_code, term_signal);
+    libos_clean_and_exit(term_signal ? 128 + (term_signal & ~__WCOREDUMP_BIT) : error_code,
+                         term_signal);
 }
 
 static int mark_thread_to_die(struct libos_thread* thread, void* arg) {