From owner-freebsd-current Tue Sep 1 19:22:20 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA16390 for freebsd-current-outgoing; Tue, 1 Sep 1998 19:22:20 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from austin.polstra.com (austin.polstra.com [206.213.73.10]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA16345 for ; Tue, 1 Sep 1998 19:22:14 -0700 (PDT) (envelope-from jdp@austin.polstra.com) Received: from austin.polstra.com (jdp@localhost) by austin.polstra.com (8.8.8/8.8.8) with ESMTP id TAA17213; Tue, 1 Sep 1998 19:21:07 -0700 (PDT) (envelope-from jdp) Message-Id: <199809020221.TAA17213@austin.polstra.com> To: Bruce Evans cc: reilly@zeta.org.au, current@FreeBSD.ORG Subject: Re: ELF binaries size In-reply-to: Your message of "Wed, 02 Sep 1998 12:14:40 +1000." <199809020214.MAA20550@godzilla.zeta.org.au> Date: Tue, 01 Sep 1998 19:21:07 -0700 From: John Polstra Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I think it implies that elf wastes a full page of memory (the space > between the ':'s above) most of the time (unless the ':'s are on a > page boundary), while aout only wastes an average of half a page > (the space between the text ':' and the end of the page). But a.out has a repeat of the same situation at the juncture of data and bss, and ELF does not. > >> Is this a security problem? > > > >I don't think so. Do you? > > Maybe if text is supposed to be unreadable. The system would have > to clear the part of the first data page before the ':' to prevent > leakage. FreeBSD doesn't seem to do this. It's moot on the i386, if I remember correctly. Doesn't execute permission imply read permission on the i386? Also, how does it enhance security to prevent a program from reading its own text segment? If a program doesn't want to read its text segment then it should simply ... not read it. :-) John To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message