From owner-freebsd-arch Sat Jun 29 23:28:52 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AA7C937B400 for ; Sat, 29 Jun 2002 23:28:49 -0700 (PDT) Received: from sharmas.dhs.org (cpe-66-1-147-119.ca.sprintbbd.net [66.1.147.119]) by mx1.FreeBSD.org (Postfix) with ESMTP id 53ACA43E13 for ; Sat, 29 Jun 2002 23:28:49 -0700 (PDT) (envelope-from adsharma@sharmas.dhs.org) Received: by sharmas.dhs.org (Postfix, from userid 500) id 794345E931; Sat, 29 Jun 2002 23:31:57 -0700 (PDT) Date: Sat, 29 Jun 2002 23:31:57 -0700 From: Arun Sharma To: Terry Lambert Cc: arch@FreeBSD.ORG Subject: Re: Time to make the stack non-executable? Message-ID: <20020630063157.GA16963@sharma-home.net> References: <3D1E28ED.B67A5271@FreeBSD.org> <3D1E3126.C96FFAA5@mindspring.com> <20020629185554.I71376@locore.ca> <20020629232603.GA1361@gnuppy.monkey.org> <3D1E55E5.998DCEBA@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3D1E55E5.998DCEBA@mindspring.com> User-Agent: Mutt/1.3.27i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sat, Jun 29, 2002 at 05:50:45PM -0700, Terry Lambert wrote: > One way to potentially work around this is to allow the stack > pages to be marked executable by explicit linking with an > alternate crt0.o, or, more usefully, by way of an attribute on > the file (e.g. a "chflags"). Linux IA64 took the chflags approach. David Mosberger called it chatr (there is HP-UX utility of the same name). Basically a elf header flag is used to tell the kernel that the stack needs to be executable. XFree86 had to be chatr'ed this way. -Arun To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message