From owner-freebsd-hackers Mon Feb 6 20:10:37 1995 Return-Path: hackers-owner Received: (from root@localhost) by freefall.cdrom.com (8.6.9/8.6.6) id UAA04789 for hackers-outgoing; Mon, 6 Feb 1995 20:10:37 -0800 Received: from cs.weber.edu (cs.weber.edu [137.190.16.16]) by freefall.cdrom.com (8.6.9/8.6.6) with SMTP id UAA04783 for ; Mon, 6 Feb 1995 20:10:35 -0800 Received: by cs.weber.edu (4.1/SMI-4.1.1) id AA10165; Mon, 6 Feb 95 21:04:24 MST From: terry@cs.weber.edu (Terry Lambert) Message-Id: <9502070404.AA10165@cs.weber.edu> Subject: Re: MIT SHM X11 extensions? (fwd) To: davidg@Root.COM Date: Mon, 6 Feb 95 21:04:23 MST Cc: jmb@kryten.atinc.com, hackers@FreeBSD.org In-Reply-To: <199502070316.TAA00688@corbin.Root.COM> from "David Greenman" at Feb 6, 95 07:16:56 pm X-Mailer: ELM [version 2.4dev PL52] Sender: hackers-owner@FreeBSD.org Precedence: bulk > > >> Further, Terry's assertion that the > >> binary's vnode has the VTEXT flag turned on (and thus prevents you from > >> overwriting it [ETXTBUSY]) is also WRONG. It does NOT do this, and as such it > >> is perfectly okay to clobber your binary. > > > >Oh ick. > > > >Uh, why is ETXTBUSY still around? > > To protect executing, pageable, binaries from being clobbered...which is > exactly how it is used. The kernel is not a pageable binary, is not "executed" > in the traditional sense. See the first set of quoted material above -- how are you not tagging the vnode, yet you know to return ETXTBUSY? The only locking I can see is advisory. And it *looks* like the VTEXT *is* being used. How does this jive with it being OK to clobber your binary? Or did you think I was talking about the VTEXT flag being set on the kernel vnode? I *know* that doesn't happen: the kernel isn't opened through the VFS, it's opened by the boot code. Is there something here I am missing? Puzzled, Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.