[Fix] Do not use lightuserdata for traceback

LuaJIT limits lightuserdata usage to 47 bits. On Arm64, this leads to
break of the C <-> Lua interoperability using this type.

This rework has changed traceback function behaviour from lightuserdata
opaque pointer (GString * in particular) to luaL_Buffer.

Issue: #2906

2 files changed, 9 insertions, 15 deletions

diff --git a/src/libstat/backends/redis_backend.c b/src/libstat/backends/redis_backend.c
index d54767c12..5976968a7 100644
--- a/src/libstat/backends/redis_backend.c
+++ b/src/libstat/backends/redis_backend.c
@@ -148,7 +148,6 @@ rspamd_redis_expand_object (const gchar *pattern,
 	struct rspamd_statfile_config *stcf;
 	lua_State *L = NULL;
 	struct rspamd_task **ptask;
-	GString *tb;
 	const gchar *rcpt = NULL;
 	gint err_idx;
 
@@ -172,16 +171,15 @@ rspamd_redis_expand_object (const gchar *pattern,
 			rspamd_lua_setclass (L, "rspamd{task}", -1);
 
 			if (lua_pcall (L, 1, 1, err_idx) != 0) {
-				tb = lua_touserdata (L, -1);
-				msg_err_task ("call to user extraction script failed: %v", tb);
-				g_string_free (tb, TRUE);
+				msg_err_task ("call to user extraction script failed: %s",
+						lua_tostring (L, -1));
 			}
 			else {
 				rcpt = rspamd_mempool_strdup (task->task_pool, lua_tostring (L, -1));
 			}
 
 			/* Result + error function */
-			lua_pop (L, 2);
+			lua_settop (L, err_idx - 1);
 		}
 
 		if (rcpt) {
diff --git a/src/libstat/backends/sqlite3_backend.c b/src/libstat/backends/sqlite3_backend.c
index cf7291ee0..61bc5bbd3 100644
--- a/src/libstat/backends/sqlite3_backend.c
+++ b/src/libstat/backends/sqlite3_backend.c
@@ -314,7 +314,6 @@ rspamd_sqlite3_get_user (struct rspamd_stat_sqlite3_db *db,
 	const gchar *user = NULL;
 	struct rspamd_task **ptask;
 	lua_State *L = db->L;
-	GString *tb;
 
 	if (db->cbref_user == -1) {
 		user = rspamd_task_get_principal_recipient (task);
@@ -330,16 +329,15 @@ rspamd_sqlite3_get_user (struct rspamd_stat_sqlite3_db *db,
 		rspamd_lua_setclass (L, "rspamd{task}", -1);
 
 		if (lua_pcall (L, 1, 1, err_idx) != 0) {
-			tb = lua_touserdata (L, -1);
-			msg_err_task ("call to user extraction script failed: %v", tb);
-			g_string_free (tb, TRUE);
+			msg_err_task ("call to user extraction script failed: %s",
+					lua_tostring (L, -1));
 		}
 		else {
 			user = rspamd_mempool_strdup (task->task_pool, lua_tostring (L, -1));
 		}
 
 		/* Result + error function */
-		lua_pop (L, 2);
+		lua_settop (L, err_idx - 1);
 	}
 
 
@@ -377,7 +375,6 @@ rspamd_sqlite3_get_language (struct rspamd_stat_sqlite3_db *db,
 	struct rspamd_mime_text_part *tp;
 	struct rspamd_task **ptask;
 	lua_State *L = db->L;
-	GString *tb;
 
 	if (db->cbref_language == -1) {
 		for (i = 0; i < task->text_parts->len; i++) {
@@ -401,9 +398,8 @@ rspamd_sqlite3_get_language (struct rspamd_stat_sqlite3_db *db,
 		rspamd_lua_setclass (L, "rspamd{task}", -1);
 
 		if (lua_pcall (L, 1, 1, err_idx) != 0) {
-			tb = lua_touserdata (L, -1);
-			msg_err_task ("call to language extraction script failed: %v", tb);
-			g_string_free (tb, TRUE);
+			msg_err_task ("call to language extraction script failed: %s",
+					lua_tostring (L, -1));
 		}
 		else {
 			language = rspamd_mempool_strdup (task->task_pool,
@@ -411,7 +407,7 @@ rspamd_sqlite3_get_language (struct rspamd_stat_sqlite3_db *db,
 		}
 
 		/* Result + error function */
-		lua_pop (L, 2);
+		lua_settop (L, err_idx - 1);
 	}