Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265482AbTIDSms (ORCPT ); Thu, 4 Sep 2003 14:42:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265358AbTIDSms (ORCPT ); Thu, 4 Sep 2003 14:42:48 -0400 Received: from fw.osdl.org ([65.172.181.6]:230 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S265492AbTIDSmR (ORCPT ); Thu, 4 Sep 2003 14:42:17 -0400 Date: Thu, 4 Sep 2003 11:42:02 -0700 (PDT) From: Linus Torvalds To: Jamie Lokier cc: Hugh Dickins , Rusty Russell , Andrew Morton , Ingo Molnar , Subject: Re: [PATCH] Alternate futex non-page-pinning and COW fix In-Reply-To: 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: 943 Lines: 23 On Thu, 4 Sep 2003, Linus Torvalds wrote: > > Oh. I see. Yes - it's accessing "vm_flags" with "MAP_SEM". That's really > wrong, since it's not even the same _domain_. How about something like this that at least gets it closer? It fixes the fact that incorrect usage of PROT_SEM would allow users to set the VM_SHARED bit behind the back of the OS, which sounds like a total disaster and which can potentially confuse other parts of the VM. It's not a very _pretty_ fix, but there really is no excuse for PROT_xxx to not match VM_xxx for the three standard protection flags, so in that sense it is the technically "sane" approach. We might want to just simplify the mmap() code 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/