From: Seunghun Lee <shiin.lee@samsung.com>
Date: Thu, 2 May 2024 06:16:36 +0000 (+0900)
Subject: server: Unlock objects_mutex before locking connection_mutex to avoid deadlock
X-Git-Tag: accepted/tizen/unified/x/20240507.050949
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Ftags%2Faccepted%2Ftizen%2Funified%2Fx%2F20240507.050949;p=platform%2Fupstream%2Fwayland.git

server: Unlock objects_mutex before locking connection_mutex to avoid deadlock

In wl_client_connection_data, threads may try to acquire two locks in
different orders, potentially causing deadlock.

Change-Id: I4acde7c0a93b4774632d3283a6fa1c946d498de8
---

diff --git a/src/wayland-server.c b/src/wayland-server.c
index 2106451..eca5f1e 100644
--- a/src/wayland-server.c
+++ b/src/wayland-server.c
@@ -2222,15 +2222,15 @@ wl_resource_create(struct wl_client *client,
 	pthread_mutex_lock(&client->objects_mutex);
 //TIZEN_ONLY : END
 	if (wl_map_insert_at(&client->objects, 0, id, resource) < 0) {
+//TIZEN_ONLY(20231208) : Add lock/unlock when adding resource id to wl_map
+		pthread_mutex_unlock(&client->objects_mutex);
+//TIZEN_ONLY : END
 		if (errno == EINVAL) {
 			wl_resource_post_error(client->display_resource,
 					       WL_DISPLAY_ERROR_INVALID_OBJECT,
 					       "invalid new id %d", id);
 		}
 		free(resource);
-//TIZEN_ONLY(20231208) : Add lock/unlock when adding resource id to wl_map
-		pthread_mutex_unlock(&client->objects_mutex);
-//TIZEN_ONLY : END
 		return NULL;
 	}
 //TIZEN_ONLY(20231208) : Add lock/unlock when adding resource id to wl_map
@@ -2716,15 +2716,15 @@ wl_client_add_resource(struct wl_client *client,
 		}
 	} else if (wl_map_insert_at(&client->objects, WL_MAP_ENTRY_LEGACY,
 				  resource->object.id, resource) < 0) {
+//TIZEN_ONLY(20231208) : Add lock/unlock when adding resource id to wl_map
+		pthread_mutex_unlock(&client->objects_mutex);
+//TIZEN_ONLY : END
 		if (errno == EINVAL) {
 			wl_resource_post_error(client->display_resource,
 					       WL_DISPLAY_ERROR_INVALID_OBJECT,
 					       "invalid new id %d",
 					       resource->object.id);
 		}
-//TIZEN_ONLY(20231208) : Add lock/unlock when adding resource id to wl_map
-		pthread_mutex_unlock(&client->objects_mutex);
-//TIZEN_ONLY : END
 		return 0;
 	}
 //TIZEN_ONLY(20231208) : Add lock/unlock when adding resource id to wl_map