From owner-freebsd-bugs@FreeBSD.ORG Mon Sep 21 01:20:02 2009 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2E71F106568D for ; Mon, 21 Sep 2009 01:20:02 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 0BC978FC0C for ; Mon, 21 Sep 2009 01:20:02 +0000 (UTC) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.3/8.14.3) with ESMTP id n8L1K1Ev000123 for ; Mon, 21 Sep 2009 01:20:01 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.3/8.14.3/Submit) id n8L1K16w000122; Mon, 21 Sep 2009 01:20:01 GMT (envelope-from gnats) Resent-Date: Mon, 21 Sep 2009 01:20:01 GMT Resent-Message-Id: <200909210120.n8L1K16w000122@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, Jacob Myers Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E46CE106566B for ; Mon, 21 Sep 2009 01:12:25 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [IPv6:2001:4f8:fff6::21]) by mx1.freebsd.org (Postfix) with ESMTP id D373B8FC0C for ; Mon, 21 Sep 2009 01:12:25 +0000 (UTC) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.3/8.14.3) with ESMTP id n8L1CPnh051036 for ; Mon, 21 Sep 2009 01:12:25 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.3/8.14.3/Submit) id n8L1CPbT051035; Mon, 21 Sep 2009 01:12:25 GMT (envelope-from nobody) Message-Id: <200909210112.n8L1CPbT051035@www.freebsd.org> Date: Mon, 21 Sep 2009 01:12:25 GMT From: Jacob Myers To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/138999: Lighttpd/php-cgi with freebsd-sendfile enabled causing kernel to not reenter userland 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: Mon, 21 Sep 2009 01:20:02 -0000 >Number: 138999 >Category: kern >Synopsis: Lighttpd/php-cgi with freebsd-sendfile enabled causing kernel to not reenter userland >Confidential: no >Severity: critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon Sep 21 01:20:01 UTC 2009 >Closed-Date: >Last-Modified: >Originator: Jacob Myers >Release: 7.2-RELEASE-p3 >Organization: Wilcox Technologies >Environment: FreeBSD IND-Serv003.Wilcox-Tech.com 7.2-RELEASE-p3 FreeBSD 7.2-RELEASE-p3 #1: Wed Aug 26 23:16:03 EDT 2009 root@IND-Serv003.Wilcox-Tech.com:/usr/obj/usr/src/sys/IND-SERV003 i386 >Description: There is some sort of odd issue involving FreeBSD and lighttpd with respect to lighttpd's use of sendfile(2) causing the kernel to not return to userland (or so we suspect). The kernel responds to ping (and even rate limits ping floods), but all SSH and other connections stop, and all login attempts at the console hang. I have investigated this problem with a friend of mine, and have been unable to draw any conclusions. Testing this problem with debugging symbols compiled in has caused the bug to manifest itself in a new way, in that sendfile(2) continuously returns EAGAIN without end. >How-To-Repeat: 0) Make sure the kernel has no debugging enabled (e.g., witness, etc.) 1) Run lighttpd with php-cgi 2) Set server.network-backend = freebsd-sendfile in lighttpd.conf 3) Attempt to upload a file > 2 MB in length or so using a simple PHP script 4) The machine should then be locked from new logins, but will respond to ping >Fix: None known. >Release-Note: >Audit-Trail: >Unformatted: