From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Mon, 8 Jul 2024 20:14:36 +0000 (-0400)
Subject: Fix: remove use of offset_of for ust_app_session lists
X-Git-Url: http://git.lttng.org./?a=commitdiff_plain;h=a1e1dc8b80d88321052a87cb5b2b19a351a457e1;p=lttng-tools.git

Fix: remove use of offset_of for ust_app_session lists

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I17429be1ce0a48257b75532582552720aaec1e0d
---

diff --git a/src/bin/lttng-sessiond/ust-app.cpp b/src/bin/lttng-sessiond/ust-app.cpp
index 61d3774bf..c28f568ae 100644
--- a/src/bin/lttng-sessiond/ust-app.cpp
+++ b/src/bin/lttng-sessiond/ust-app.cpp
@@ -1016,7 +1016,6 @@ static void delete_ust_app_session(int sock, struct ust_app_session *ua_sess, st
 static void delete_ust_app(struct ust_app *app)
 {
 	int ret, sock;
-	struct ust_app_session *ua_sess, *tmp_ua_sess;
 	struct lttng_ht_iter iter;
 	struct ust_app_event_notifier_rule *event_notifier_rule;
 	bool event_notifier_write_fd_is_open;
@@ -1031,10 +1030,13 @@ static void delete_ust_app(struct ust_app *app)
 	app->sock = -1;
 
 	/* Wipe sessions */
-	cds_list_for_each_entry_safe (ua_sess, tmp_ua_sess, &app->teardown_head, teardown_node) {
-		/* Free every object in the session and the session. */
+	{
 		const lttng::urcu::read_lock_guard read_lock;
-		delete_ust_app_session(sock, ua_sess, app);
+
+		for (const auto ua_sess : app->sessions_to_teardown) {
+			/* Free every object in the session and the session. */
+			delete_ust_app_session(sock, ua_sess, app);
+		}
 	}
 
 	/* Remove the event notifier rules associated with this app. */
@@ -1114,7 +1116,7 @@ static void delete_ust_app(struct ust_app *app)
 	lttng_fd_put(LTTNG_FD_APPS, 1);
 
 	DBG2("UST app pid %d deleted", app->pid);
-	free(app);
+	delete app;
 }
 
 /*
@@ -4049,9 +4051,13 @@ struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
 		goto error;
 	}
 
-	lta = zmalloc<ust_app>();
-	if (lta == nullptr) {
-		PERROR("malloc");
+	try {
+		lta = new ust_app;
+	} catch (const std::bad_alloc&) {
+		ERR_FMT("Failed to allocate ust application instance: name=`{}`, pid={}, uid={}",
+			msg->name,
+			msg->pid,
+			msg->uid);
 		goto error_free_pipe;
 	}
 
@@ -4100,7 +4106,6 @@ struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock)
 	pthread_mutex_init(&lta->sock_lock, nullptr);
 	lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long) lta->sock);
 
-	CDS_INIT_LIST_HEAD(&lta->teardown_head);
 	return lta;
 
 error_free_pipe:
@@ -4389,7 +4394,7 @@ static void ust_app_unregister(ust_app& app)
 			}
 		}
 
-		cds_list_add(&ua_sess->teardown_node, &app.teardown_head);
+		app.sessions_to_teardown.emplace_back(ua_sess);
 	}
 
 	/*
@@ -4420,7 +4425,6 @@ static void ust_app_unregister(ust_app& app)
  */
 void ust_app_unregister_by_socket(int sock_fd)
 {
-	struct ust_app *app;
 	struct lttng_ht_node_ulong *node;
 	struct lttng_ht_iter ust_app_sock_iter;
 	int ret;
@@ -4432,10 +4436,10 @@ void ust_app_unregister_by_socket(int sock_fd)
 	node = lttng_ht_iter_get_node<lttng_ht_node_ulong>(&ust_app_sock_iter);
 	assert(node);
 
-	app = caa_container_of(node, struct ust_app, sock_n);
+	const auto app = lttng::utils::container_of(node, &ust_app::sock_n);
 
-	DBG_FMT("Application unregistering after socket activity: pid={}, socket_fd={}",
-		app->pid,
+	DBG_FMT("Application unregistering after socket activity: app={}, socket_fd={}",
+		*app,
 		sock_fd);
 
 	/* Remove application from socket hash table */
diff --git a/src/bin/lttng-sessiond/ust-app.hpp b/src/bin/lttng-sessiond/ust-app.hpp
index 02c4d7d0e..b007583d0 100644
--- a/src/bin/lttng-sessiond/ust-app.hpp
+++ b/src/bin/lttng-sessiond/ust-app.hpp
@@ -20,6 +20,7 @@
 #include <common/uuid.hpp>
 
 #include <stdint.h>
+#include <list>
 
 #define UST_APP_EVENT_LIST_SIZE 32
 
@@ -320,7 +321,6 @@ public:
 	struct lttng_credentials real_credentials = {};
 	/* Effective UID and GID. Same as the tracing session. */
 	struct lttng_credentials effective_credentials = {};
-	struct cds_list_head teardown_node = {};
 	/*
 	 * Once at least *one* session is created onto the application, the
 	 * corresponding consumer is set so we can use it on unregistration.
@@ -398,7 +398,7 @@ struct ust_app {
 	 * ht_del of ust_app_session associated to this app. This list is NOT used
 	 * when a session is destroyed.
 	 */
-	struct cds_list_head teardown_head;
+	std::list<ust_app_session *> sessions_to_teardown;
 	/*
 	 * Hash table containing ust_app_channel indexed by channel objd.
 	 */