Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933250AbcDYTBr (ORCPT ); Mon, 25 Apr 2016 15:01:47 -0400 Received: from mga02.intel.com ([134.134.136.20]:33555 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932686AbcDYTBq (ORCPT ); Mon, 25 Apr 2016 15:01:46 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,533,1455004800"; d="scan'208";a="91667298" From: Tom Zanussi To: rostedt@goodmis.org Cc: dan.carpenter@oracle.com, linux-kernel@vger.kernel.org, Tom Zanussi Subject: [PATCH 2/2] tracing: Handle tracing_map_alloc_elts() error path correctly Date: Mon, 25 Apr 2016 14:01:28 -0500 Message-Id: X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1512 Lines: 44 If tracing_map_elt_alloc() fails, it will return ERR_PTR() instead of NULL, so change the check to IS_ERROR(). We also need to set the failed entry in the map->elts array to NULL instead of ERR_PTR() so tracing_map_free_elts() doesn't try freeing an ERR_PTR(). tracing_map_free_elts() should also zero out what it frees so a reentrant call won't find previously freed elements. Signed-off-by: Tom Zanussi --- kernel/trace/tracing_map.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index e0f1729..979f6d6 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c @@ -366,10 +366,13 @@ static void tracing_map_free_elts(struct tracing_map *map) if (!map->elts) return; - for (i = 0; i < map->max_elts; i++) + for (i = 0; i < map->max_elts; i++) { tracing_map_elt_free(*(TRACING_MAP_ELT(map->elts, i))); + *(TRACING_MAP_ELT(map->elts, i)) = NULL; + } tracing_map_array_free(map->elts); + map->elts = NULL; } static int tracing_map_alloc_elts(struct tracing_map *map) @@ -383,7 +386,8 @@ static int tracing_map_alloc_elts(struct tracing_map *map) for (i = 0; i < map->max_elts; i++) { *(TRACING_MAP_ELT(map->elts, i)) = tracing_map_elt_alloc(map); - if (!(*(TRACING_MAP_ELT(map->elts, i)))) { + if (IS_ERR(*(TRACING_MAP_ELT(map->elts, i)))) { + *(TRACING_MAP_ELT(map->elts, i)) = NULL; tracing_map_free_elts(map); return -ENOMEM; -- 1.9.3