From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261877AbUARPs2 (ORCPT ); Sun, 18 Jan 2004 10:48:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261953AbUARPs2 (ORCPT ); Sun, 18 Jan 2004 10:48:28 -0500 Received: from mail.fh-wedel.de ([213.39.232.194]:6617 "EHLO mail.fh-wedel.de") by vger.kernel.org with ESMTP id S261877AbUARPs0 (ORCPT ); Sun, 18 Jan 2004 10:48:26 -0500 Date: Sun, 18 Jan 2004 16:48:02 +0100 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Lennert Buytenhek Cc: linux-kernel@vger.kernel.org, netdev@oss.sgi.com Subject: [PATCH] Re: [2.6.0, pktgen] divide-by-zero Message-ID: <20040118154802.GE10397@wohnheim.fh-wedel.de> References: <20031231111316.GA10218@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20031231111316.GA10218@gnu.org> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 31 December 2003 06:13:16 -0500, Lennert Buytenhek wrote: > > When generating packets with pktgen with count=10, I get a divide-by-zero > oops in inject(). > > Line 273 in net/core/pktgen.c seems unsafe: > __u64 pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000); > > What if total < 1000 ? Since noone else seemed to care, try this patch. Against -test11, yeah, I'm lazy again. Jörn -- Time? What's that? Time is only worth what you do with it. -- Theo de Raadt --- old/net/core/pktgen.c 2003-11-26 21:44:47.000000000 +0100 +++ new/net/core/pktgen.c 2004-01-18 16:27:10.000000000 +0100 @@ -720,7 +720,9 @@ { char *p = info->result; - __u64 pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000); + __u32 safe_total = (__u32)(total) / 1000; + safe_total += 1 - (!!safe_total); /* avoid divide-by-zero */ + __u64 pps = (__u32)(info->sofar * 1000) / safe_total; __u64 bps = pps * 8 * (info->pkt_size + 4); /* take 32bit ethernet CRC into account */ p += sprintf(p, "OK: %llu(c%llu+d%llu) usec, %llu (%dbyte,%dfrags) %llupps %lluMb/sec (%llubps) errors: %llu", (unsigned long long) total,