2007-10-12 Martin Hunt <hunt@redhat.com>

	Changes to separate the symbols from the command channel.

	* cap.c (init_cap): Add CAP_DAC_OVERRIDE.
	* staprun.h: Change init_ctl_channel prototype.
	* ctl.c (init_ctl_channel): Modify to open either
	a command or symbol channel. Use ".cmd" and ".symbols"
	as the new names.
	* mainloop.c (init_stapio): Call init_ctl_channel(0);
	* staprun.c (cleanup): Call stop_symbol_thread().
	(main): Call start_symbol_thread().
	* staprun_funcs.c (handle_symbols): Make a thread.
	(start_symbol_thread): New.
	(stop_symbol_thread): New.

1 files changed, 36 insertions, 10 deletions

diff --git a/runtime/staprun/staprun_funcs.c b/runtime/staprun/staprun_funcs.c
index eec4ae63..86a72985 100644
--- a/runtime/staprun/staprun_funcs.c
+++ b/runtime/staprun/staprun_funcs.c
@@ -385,8 +385,10 @@ int check_permissions(void)
 	return check_path();
 }
 
-/* wait for symbol requests and reply */
-void handle_symbols(void)
+pthread_t symbol_thread_id = (pthread_t)0;
+
+/* Symbol handling thread */
+void *handle_symbols(void __attribute__((unused)) *arg)
 {
 	ssize_t nb;
 	void *data;
@@ -395,12 +397,6 @@ void handle_symbols(void)
 
 	dbug(2, "waiting for symbol requests\n");
 
-	/* create control channel */
-	if (init_ctl_channel() < 0) {
-		err("Failed to initialize control channel.\n");
-		exit(1);
-	}
-
 	while (1) { /* handle messages from control channel */
 		nb = read(control_channel, recvbuf, sizeof(recvbuf));
 		if (nb <= 0) {
@@ -417,7 +413,7 @@ void handle_symbols(void)
 		{
 			dbug(2, "STP_MODULES request received\n");
 			do_module(data);
-			goto done;
+			break;
 		}		
 		case STP_SYMBOLS:
 		{
@@ -439,6 +435,36 @@ void handle_symbols(void)
 			err("WARNING: ignored message of type %d\n", (type));
 		}
 	}
-done:
+
+	return NULL;
+}
+
+void start_symbol_thread(void)
+{
+	int status;
+
+	/* create symbol control channel */
+	status = do_cap(CAP_DAC_OVERRIDE, init_ctl_channel, 1);
+	drop_cap(CAP_DAC_OVERRIDE);
+	if (status < 0) {
+		err("Failed to initialize control channel.\n");
+		exit(1);
+	}
+	status = pthread_create(&symbol_thread_id, NULL, handle_symbols, NULL);
+	if (status) {
+		perr("Failed to create symbol thread.\n");
+		exit(1);
+	}
+}
+
+void stop_symbol_thread(void)
+{
+
+	if (symbol_thread_id) {
+		dbug(2, "Stopping symbol thread.\n");
+		pthread_cancel(symbol_thread_id);
+		pthread_join(symbol_thread_id, NULL);
+	}
 	close_ctl_channel();
 }
+