From owner-freebsd-bugs@FreeBSD.ORG Tue Oct 24 07:10:23 2006 Return-Path: X-Original-To: freebsd-bugs@hub.freebsd.org Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CDAAD16A4DA for ; Tue, 24 Oct 2006 07:10:23 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 29DC143D6B for ; Tue, 24 Oct 2006 07:10:19 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.4/8.13.4) with ESMTP id k9O7AJhq045014 for ; Tue, 24 Oct 2006 07:10:19 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.4/8.13.4/Submit) id k9O7AIYZ045013; Tue, 24 Oct 2006 07:10:18 GMT (envelope-from gnats) Resent-Date: Tue, 24 Oct 2006 07:10:18 GMT Resent-Message-Id: <200610240710.k9O7AIYZ045013@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, user from china Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BDFD916A403 for ; Tue, 24 Oct 2006 07:00:55 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [216.136.204.117]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8CE9443D45 for ; Tue, 24 Oct 2006 07:00:55 +0000 (GMT) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.13.1/8.13.1) with ESMTP id k9O70tx7006040 for ; Tue, 24 Oct 2006 07:00:55 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.13.1/8.13.1/Submit) id k9O70tKD006039; Tue, 24 Oct 2006 07:00:55 GMT (envelope-from nobody) Message-Id: <200610240700.k9O70tKD006039@www.freebsd.org> Date: Tue, 24 Oct 2006 07:00:55 GMT From: user from china To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.0 Cc: Subject: kern/104738: [patch]Reentrant problem with inet_ntoa in the kernel X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Oct 2006 07:10:24 -0000 >Number: 104738 >Category: kern >Synopsis: [patch]Reentrant problem with inet_ntoa in the kernel >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Tue Oct 24 07:10:18 GMT 2006 >Closed-Date: >Last-Modified: >Originator: user from china >Release: 7-CURRENT & 6.1-RELEASE >Organization: none >Environment: >Description: The function inet_ntoa in the /sys/libkern/inet_ntoa.c uses a static array static char buf[4 * sizeof "123"]; to store the result. And it returns the address of the array to the caller. I think this inet_ntoa is not reentrant, though there are several functions calling it. If two functions call it simultaneously, the result will be corruptted. Though I haven't really encountered this situation, it may occur someday, especially when using multi-processor. >How-To-Repeat: >Fix: There is another reentrant version of inet_ntoa called inet_ntoa_r in the same file. It has been there for several years, but just used by ipfw2 for about four times in 7-CURRENT. In my patch, I replaced all the calls to inet_ntoa with calls to inet_ntoa_r. By the way, some of the original calls is written in this style: strcpy(buf, inet_ntoa(ip)) The changed code looks like inet_ntoa_r(ip, buf) This change avoids a call to strcpy, and can save a little time. Here is the patch. http://people.freebsd.org/~delphij/misc/patch-itoa-by-nodummy-at-yeah-net >Release-Note: >Audit-Trail: >Unformatted: