Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 23 Feb 2003 16:38:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 23 Feb 2003 16:38:13 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:22537 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Sun, 23 Feb 2003 16:38:12 -0500 Date: Sun, 23 Feb 2003 13:45:16 -0800 (PST) From: Linus Torvalds To: John Bradford cc: linux-kernel@vger.kernel.org Subject: Re: Minutes from Feb 21 LSE Call In-Reply-To: <200302232115.h1NLF9wo000201@81-2-122-30.bradfords.org.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1048 Lines: 25 On Sun, 23 Feb 2003, John Bradford wrote: > > I could be wrong, but I always thought that Sparc, and a lot of other > architectures could mark arbitrary areas of memory, (such as the > stack), as non-executable, whereas x86 only lets you have one > non-executable segment. The x86 has that stupid "executablility is tied to a segment" thing, which means that you cannot make things executable on a page-per-page level. It's a mistake, but it's one that _could_ be fixed in the architecture if it really mattered, the same way the WP bit got fixed in the i486. I'm definitely not saying that the x86 is perfect. It clearly isn't. But a lot of people complain about the wrong things, and a lot of people who tried to "fix" things just made them worse by throwing out the good parts too. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/