From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757593AbYFXIV0 (ORCPT ); Tue, 24 Jun 2008 04:21:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752754AbYFXIVN (ORCPT ); Tue, 24 Jun 2008 04:21:13 -0400 Received: from mgw2.diku.dk ([130.225.96.92]:40175 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752499AbYFXIVL (ORCPT ); Tue, 24 Jun 2008 04:21:11 -0400 Date: Tue, 24 Jun 2008 10:21:07 +0200 (CEST) From: Julia Lawall To: akinobu.mita@gmail.com, rmk@arm.linux.org.uk, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH 1/14] arch/arm: Eliminate NULL test and memset after alloc_bootmem 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 As noted by Akinobu Mita in patch b1fceac2b9e04d278316b2faddf276015fc06e3b, alloc_bootmem and related functions never return NULL and always return a zeroed region of memory. Thus a NULL test or memset after calls to these functions is unnecessary. arch/arm/mm/mmu.c | 1 - 1 file changed, 1 deletion(-) This was fixed using the following semantic patch. (http://www.emn.fr/x-info/coccinelle/) // @@ expression E; statement S; @@ E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...) ... when != E ( - BUG_ON (E == NULL); | - if (E == NULL) S ) @@ expression E,E1; @@ E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...) ... when != E - memset(E,0,E1); // Signed-off-by: Julia Lawall --- Diff -u -p a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -676,7 +676,6 @@ static void __init devicemaps_init(struc * Allocate the vector page early. */ vectors = alloc_bootmem_low_pages(PAGE_SIZE); - BUG_ON(!vectors); for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr));