From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E9E0C433E6 for ; Thu, 16 Jul 2020 21:06:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDD9D207DD for ; Thu, 16 Jul 2020 21:06:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="We2uPn5N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726710AbgGPVGF (ORCPT ); Thu, 16 Jul 2020 17:06:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725926AbgGPVGF (ORCPT ); Thu, 16 Jul 2020 17:06:05 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DC85C061755; Thu, 16 Jul 2020 14:06:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=97Vb3ATwIinLeyNU+ffoxlcz4EFi0R63Q1SkJc6H6p4=; b=We2uPn5NrJcfOM7pBBgSN3ww9e lCAo0oiIysNi0p6TlBi8cRG351VfGXXjX3rAOl7pOiKOSVWt+DOKn+ILQxK3iM1PJ6SD27rEejTz0 Nd4LgC6aRVtX7HnRHnpcRI8jiCSSRCk0nOM/9s8RLEA+qF6l33rbGJyfYsJEHkF9wXL1d1ADUxbTT /a4BroaC26YXa89MdHmUgQ/xXWk+m0K1gjIXv1wTwfXSkzGwf1r6lekyLqBKUMG1TGrNe2HnCq3t8 E3Bht6snrABBB2+1XSZweylW1kZLZdojpMa/Evhn9m9eLrtj7EbuPHx5gU/dHhMwDUpe2FHpEKjFA Wnlyrahg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jwB4r-0007Wt-55; Thu, 16 Jul 2020 21:06:01 +0000 Date: Thu, 16 Jul 2020 22:06:01 +0100 From: Matthew Wilcox To: Gabriel Krisman Bertazi Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, kernel@collabora.com, luto@kernel.org, gofmanp@gmail.com, keescook@chromium.org, linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: Re: [PATCH v4 1/2] kernel: Implement selective syscall userspace redirection Message-ID: <20200716210601.GN12769@casper.infradead.org> References: <20200716193141.4068476-1-krisman@collabora.com> <20200716193141.4068476-2-krisman@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200716193141.4068476-2-krisman@collabora.com> Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Thu, Jul 16, 2020 at 03:31:40PM -0400, Gabriel Krisman Bertazi wrote: > selector is an optional pointer to a char-sized userspace memory region > that has a key switch for the mechanism. This key switch is set to > either PR_SYS_DISPATCH_ON, PR_SYS_DISPATCH_OFF to enable and disable the > redirection without calling the kernel. > > The feature is meant to be set per-thread and it is disabled on > fork/clone/execv. Disabled on exec. Disabled in the child on clone/fork (and vfork, I think). That means we don't need to worry about it interacting badly with a setuid program, right?