Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272689AbTHPKEW (ORCPT ); Sat, 16 Aug 2003 06:04:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272691AbTHPKEW (ORCPT ); Sat, 16 Aug 2003 06:04:22 -0400 Received: from mail.lmcg.wisc.edu ([144.92.101.145]:1735 "EHLO mail.lmcg.wisc.edu") by vger.kernel.org with ESMTP id S272689AbTHPKEU (ORCPT ); Sat, 16 Aug 2003 06:04:20 -0400 Date: Sat, 16 Aug 2003 05:04:15 -0500 From: Daniel Forrest To: Peter Kjellerstedt Cc: "'Daniel Forrest'" , "'Timothy Miller'" , "'Willy Tarreau'" , linux-kernel mailing list Subject: Re: generic strncpy - off-by-one error Message-ID: <20030816050415.A6986@rda07.lmcg.wisc.edu> Reply-To: Daniel Forrest References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from peter.kjellerstedt@axis.com on Sat, Aug 16, 2003 at 11:19:30AM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1150 Lines: 58 On Sat, Aug 16, 2003 at 11:19:30AM +0200, Peter Kjellerstedt wrote: > > Actually, it should be: > > while (count && ((long)tmp & (sizeof(long) - 1))) > Oops, you're right, I forgot that the count could be small. But, now that I think of it, maybe this would be best... char *strncpy(char *dest, const char *src, size_t count) { char *tmp = dest; while (count && *src) { *tmp++ = *src++; count--; } - if (count) { + if (count >= sizeof(long)) { size_t count2; - while (count && ((long)tmp & (sizeof(long) - 1))) { + while ((long)tmp & (sizeof(long) - 1)) { *tmp++ = '\0'; count--; } count2 = count / sizeof(long); while (count2) { *((long *)tmp)++ = '\0'; count2--; } count &= (sizeof(long) - 1); - while (count) { - *tmp++ = '\0'; - count--; - } + } + + while (count) { + *tmp++ = '\0'; + count--; } return dest; } -- Dan - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/