X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.c;h=8b1665a06568de2bc90a4a90e61b40e35af4800c;hp=c93f93dc9add8333c07470688ae95f14a8f1ec80;hb=fb54cdbf2a8ff53e9dc11403a8aca643bbdde9c0;hpb=d7b3776ffb1bef894e7bc4cbfe45c5c2d58b8600

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index c93f93dc9..8b1665a06 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -25,6 +25,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <urcu/compiler.h>
+#include <lttng/ust-error.h>
 
 #include <common/common.h>
 #include <common/sessiond-comm/sessiond-comm.h>
@@ -976,9 +977,10 @@ static struct ust_app_session *create_ust_app_session(
 		ret = ustctl_create_session(app->sock);
 		if (ret < 0) {
 			ERR("Creating session for app pid %d", app->pid);
+			delete_ust_app_session(-1, ua_sess);
 			/* This means that the tracer is gone... */
 			ua_sess = (void*) -1UL;
-			goto error;
+			goto end;
 		}
 
 		ua_sess->handle = ret;
@@ -993,11 +995,6 @@ static struct ust_app_session *create_ust_app_session(
 end:
 	health_code_update(&health_thread_cmd);
 	return ua_sess;
-
-error:
-	delete_ust_app_session(-1, ua_sess);
-	health_code_update(&health_thread_cmd);
-	return NULL;
 }
 
 /*
@@ -1510,8 +1507,16 @@ void ust_app_unregister(int sock)
 	/* Assign second node for deletion */
 	iter.iter.node = &lta->pid_n.node;
 
+	/*
+	 * Ignore return value since the node might have been removed before by an
+	 * add replace during app registration because the PID can be reassigned by
+	 * the OS.
+	 */
 	ret = lttng_ht_del(ust_app_ht, &iter);
-	assert(!ret);
+	if (ret) {
+		DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
+				lta->pid);
+	}
 
 	/* Free memory */
 	call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
@@ -1576,7 +1581,7 @@ int ust_app_list_events(struct lttng_event **events)
 		}
 
 		while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
-						&uiter)) != -ENOENT) {
+					&uiter)) != -LTTNG_UST_ERR_NOENT) {
 			health_code_update(&health_thread_cmd);
 			if (count >= nbmem) {
 				/* In case the realloc fails, we free the memory */
@@ -1654,7 +1659,7 @@ int ust_app_list_event_fields(struct lttng_event_field **fields)
 		}
 
 		while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
-						&uiter)) != -ENOENT) {
+					&uiter)) != -LTTNG_UST_ERR_NOENT) {
 			health_code_update(&health_thread_cmd);
 			if (count >= nbmem) {
 				/* In case the realloc fails, we free the memory */
@@ -1702,21 +1707,22 @@ error:
 void ust_app_clean_list(void)
 {
 	int ret;
+	struct ust_app *app;
 	struct lttng_ht_iter iter;
-	struct lttng_ht_node_ulong *node;
 
 	DBG2("UST app cleaning registered apps hash table");
 
 	rcu_read_lock();
 
-	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, node, node) {
+	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
 		ret = lttng_ht_del(ust_app_ht, &iter);
 		assert(!ret);
-		call_rcu(&node->head, delete_ust_app_rcu);
+		call_rcu(&app->pid_n.head, delete_ust_app_rcu);
 	}
 
 	/* Cleanup socket hash table */
-	cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, node, node) {
+	cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
+			sock_n.node) {
 		ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
 		assert(!ret);
 	}
@@ -1978,6 +1984,7 @@ int ust_app_disable_all_event_glb(struct ltt_ust_session *usess,
 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
 		struct ltt_ust_channel *uchan)
 {
+	int ret = 0;
 	struct lttng_ht_iter iter;
 	struct ust_app *app;
 	struct ust_app_session *ua_sess;
@@ -2009,9 +2016,11 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
 		ua_sess = create_ust_app_session(usess, app);
 		if (ua_sess == NULL) {
 			/* The malloc() failed. */
+			ret = -1;
 			goto error;
 		} else if (ua_sess == (void *) -1UL) {
 			/* The application's socket is not valid. Contiuing */
+			ret = -1;
 			continue;
 		}
 
@@ -2019,16 +2028,15 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
 		ua_chan = create_ust_app_channel(ua_sess, uchan, app);
 		if (ua_chan == NULL) {
 			/* Major problem here and it's maybe the tracer or malloc() */
+			ret = -1;
 			goto error;
 		}
 	}
 
 	rcu_read_unlock();
 
-	return 0;
-
 error:
-	return -1;
+	return ret;
 }
 
 /*
@@ -2558,7 +2566,8 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
 	}
 
 	ua_sess = create_ust_app_session(usess, app);
-	if (ua_sess == NULL) {
+	if (ua_sess == NULL || ua_sess == (void *) -1UL) {
+		/* Tracer is gone for this session and has been freed */
 		goto error;
 	}