From owner-freebsd-bugs@FreeBSD.ORG Thu Jun 23 16:10:14 2011 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (unknown [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AD8651065676 for ; Thu, 23 Jun 2011 16:10:14 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [69.147.83.40]) by mx1.freebsd.org (Postfix) with ESMTP id 8B5548FC0C for ; Thu, 23 Jun 2011 16:10:14 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p5NGAENq095960 for ; Thu, 23 Jun 2011 16:10:14 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p5NGAE76095959; Thu, 23 Jun 2011 16:10:14 GMT (envelope-from gnats) Resent-Date: Thu, 23 Jun 2011 16:10:14 GMT Resent-Message-Id: <201106231610.p5NGAE76095959@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, Chris Ulrich Received: from mx1.freebsd.org (unknown [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 288311065679 for ; Thu, 23 Jun 2011 16:01:49 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from red.freebsd.org (red.freebsd.org [69.147.83.34]) by mx1.freebsd.org (Postfix) with ESMTP id 18E468FC08 for ; Thu, 23 Jun 2011 16:01:49 +0000 (UTC) Received: from red.freebsd.org (localhost [127.0.0.1]) by red.freebsd.org (8.14.4/8.14.4) with ESMTP id p5NG1m3i067550 for ; Thu, 23 Jun 2011 16:01:48 GMT (envelope-from nobody@red.freebsd.org) Received: (from nobody@localhost) by red.freebsd.org (8.14.4/8.14.4/Submit) id p5NG1mMX067549; Thu, 23 Jun 2011 16:01:48 GMT (envelope-from nobody) Message-Id: <201106231601.p5NG1mMX067549@red.freebsd.org> Date: Thu, 23 Jun 2011 16:01:48 GMT From: Chris Ulrich To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: misc/158206: /bin/sh doesn't properly return IO errors to conditionals in a script 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: Thu, 23 Jun 2011 16:10:14 -0000 >Number: 158206 >Category: misc >Synopsis: /bin/sh doesn't properly return IO errors to conditionals in a script >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Jun 23 16:10:14 UTC 2011 >Closed-Date: >Last-Modified: >Originator: Chris Ulrich >Release: amd64 freebsd 8.2-RELEASE >Organization: CSN Stores >Environment: FreeBSD svn.csnzoo.com 8.2-RELEASE FreeBSD 8.2-RELEASE #0: Thu Feb 17 02:41:51 UTC 2011 root@mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64 >Description: a /bin/sh script writing to a closed file descriptor doesn't pass the IO error it receives from the write to the script itself. >How-To-Repeat: write these two scripts: #!/bin/sh while echo -n . ; do : ; done and #!/bin/sh while printf . ; do : ; done now run each script with std-out closed, ie (assuming your interactive shell is bourne shell or similar): $ sh ./bomb-echo.sh >&- or $ sh ./bomb-printf.sh >&- both should exit instantly because echo *should* get an error from writing to a closed file descriptor. Instead both spin madly until they get a kill signal or you truss them (the last bit of stuff you see when you truss them is: 72238: sigprocmask(SIG_SETMASK,0x0,0x0) = 0 (0x0) 72238: write(1,".",1) ERR#9 'Bad file descriptor' 72238: process exit, rval = 0 which itself is another >Fix: sorry. don't know C. >Release-Note: >Audit-Trail: >Unformatted: