From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e1.ny.us.ibm.com (e1.ny.us.ibm.com [32.97.182.141]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e1.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id CED29DDED0 for ; Tue, 10 Jul 2007 07:29:30 +1000 (EST) Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e1.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l69LTRfM003349 for ; Mon, 9 Jul 2007 17:29:27 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l69LTRZS492800 for ; Mon, 9 Jul 2007 17:29:27 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l69LTQ3w002130 for ; Mon, 9 Jul 2007 17:29:27 -0400 Date: Mon, 9 Jul 2007 16:29:26 -0500 To: Scott Wood Subject: Re: [PATCH] Allow exec on 32-bit from readable, non-exec pages, with a warning. Message-ID: <20070709212926.GN4457@austin.ibm.com> References: <20070709195743.GA26089@ld0162-tx32.am.freescale.net> <200707092225.25287.arnd@arndb.de> <4692A5B8.9010702@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4692A5B8.9010702@freescale.com> From: linas@austin.ibm.com (Linas Vepstas) Cc: linuxppc-dev@ozlabs.org, paulus@samba.org, Arnd Bergmann List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jul 09, 2007 at 04:16:40PM -0500, Scott Wood wrote: > Arnd Bergmann wrote: > > I may be missing the obvious, but doesn't that defeat the purpose of > > non-executable mappings? > > The hardware in question doesn't support non-executable mappings; > otherwise, it'd never have worked in the first place. Note that this is > only allowed on 32-bit, non-book-E. > > There isn't much value in enforcing non-exec mappings only if it happens > to be the first fault on a given page. Thank you. I was reading this thread last week, and scratching my head, thinking wtf ?? --linas