From owner-freebsd-fs Fri Apr 10 12:42:57 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA18441 for freebsd-fs-outgoing; Fri, 10 Apr 1998 12:42:57 -0700 (PDT) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from mail.cs.tu-berlin.de (root@mail.cs.tu-berlin.de [130.149.17.13]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id MAA18433 for ; Fri, 10 Apr 1998 12:42:51 -0700 (PDT) (envelope-from wosch@cs.tu-berlin.de) Received: from panke.panke.de (anonymous234.ppp.cs.tu-berlin.de [130.149.17.234]) by mail.cs.tu-berlin.de (8.8.8/8.8.8) with ESMTP id VAA05854; Fri, 10 Apr 1998 21:37:45 +0200 (MET DST) Received: (from wosch@localhost) by panke.panke.de (8.8.5/8.6.12) id VAA01377; Fri, 10 Apr 1998 21:33:27 +0200 (MET DST) Message-ID: <19980410213327.22843@panke.de> Date: Fri, 10 Apr 1998 21:33:27 +0200 From: Wolfram Schneider To: ak@muc.de Cc: freebsd-fs@FreeBSD.ORG Subject: Re: cvs commit: src/sbin/mount mntopts.h mount.8 mount.c src/sys/kern vfs_lookup.c vfs_syscalls.c vfs_vnops.c src/sys/sys mount.h References: <199804081832.LAA04184@freefall.freebsd.org> <19980410164505.27668@panke.de> <19980410171454.39443@fred.muc.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.79 In-Reply-To: <19980410171454.39443@fred.muc.de>; from ak@muc.de on Fri, Apr 10, 1998 at 05:14:54PM +0200 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On 1998-04-10 17:14:54 +0200, ak@muc.de wrote: > > I can add a nonamedpipe option ;-) > Or include that with nodev (or does it do that already?) nodev don't disable named pipes. > > A named pipe race is much harder to implement than a symlink race. > > How do you avoid dead locks? > What deadlocks? the exploit will be "single threaded" but I don't think > there are deadlocks. It is possible, that is what counts. Possible dead lock: A writes 2K into the named pipe B append 8K into the named pipe A read 2K from the named pipe A want write 2K into the named pipe, but B not finished writing. A wait for B and B wait for A .... > Just use O_CREAT|O_EXCL always. -- Wolfram Schneider http://www.freebsd.org/~wosch/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message