From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751585Ab0HUJaW (ORCPT ); Sat, 21 Aug 2010 05:30:22 -0400 Received: from mgw2.diku.dk ([130.225.96.92]:36385 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003Ab0HUJaT (ORCPT ); Sat, 21 Aug 2010 05:30:19 -0400 Date: Sat, 21 Aug 2010 11:30:17 +0200 (CEST) From: Julia Lawall To: David Howells , Koichi Yasutake , linux-am33-list@redhat.com, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] arch/mn10300/mm: eliminate NULL dereference Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Julia Lawall dev_name always dereferences its argument, so it should not be called if the argument is NULL. The function indeed later tests the argument for being NULL. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression dev,E; @@ *dev_name(dev) ... when != dev = E ( *dev == NULL | *dev != NULL ) // Signed-off-by: Julia Lawall --- arch/mn10300/mm/dma-alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c index 4e34880..159acb0 100644 --- a/arch/mn10300/mm/dma-alloc.c +++ b/arch/mn10300/mm/dma-alloc.c @@ -25,7 +25,8 @@ void *dma_alloc_coherent(struct device *dev, size_t size, unsigned long addr; void *ret; - printk("dma_alloc_coherent(%s,%zu,,%x)\n", dev_name(dev), size, gfp); + pr_debug("dma_alloc_coherent(%s,%zu,%x)\n", + dev ? dev_name(dev) : "?", size, gfp); if (0xbe000000 - pci_sram_allocated >= size) { size = (size + 255) & ~255;