Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 20 Feb 2001 23:20:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 20 Feb 2001 23:20:05 -0500 Received: from wire.cadcamlab.org ([156.26.20.181]:64518 "EHLO wire.cadcamlab.org") by vger.kernel.org with ESMTP id ; Tue, 20 Feb 2001 23:19:50 -0500 Date: Tue, 20 Feb 2001 22:19:43 -0600 To: BERECZ Szabolcs Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] new setprocuid syscall Message-ID: <20010220221943.A28652@cadcamlab.org> In-Reply-To:

Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.12i In-Reply-To: ; from szabi@inf.elte.hu on Tue, Feb 20, 2001 at 06:04:09PM +0100 From: Peter Samuelson Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org [BERECZ Szabolcs] > The conclusion: it's cannot be implemented without slowdown. Or: it cannot be implemented 100% safely and correctly without slowdown. If you know the use you wish to put this to, and are willing to risk a permission check somewhere being confused momentarily by a non-atomic update of a 32-bit number (or the non-atomic update between several 32-bit numbers, which I think is less serious because then you are not granting more than the union of the two UIDs) go ahead and patch your kernel. > So ignore my patch. For official kernels, I agree. They need to be as safe and deterministic as possible, especially security-wise, and a semaphore on every permission check would be ridiculous. Peter - 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/