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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42775C433EF for ; Fri, 1 Oct 2021 11:49:08 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F1FBC6109E for ; Fri, 1 Oct 2021 11:49:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F1FBC6109E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ECF326ECD4; Fri, 1 Oct 2021 11:49:00 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id 273CF6ECD4 for ; Fri, 1 Oct 2021 11:49:00 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: alyssa) with ESMTPSA id 02CF11F4552D Date: Fri, 1 Oct 2021 07:48:53 -0400 From: Alyssa Rosenzweig To: Boris Brezillon Cc: Rob Herring , Tomeu Vizoso , Alyssa Rosenzweig , Steven Price , Robin Murphy , dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/panfrost: Add PANFROST_BO_NO{READ,WRITE} flags Message-ID: References: <20210930184723.1482426-1-boris.brezillon@collabora.com> <20210930214030.19f63eac@collabora.com> <20211001084740.051e9d80@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211001084740.051e9d80@collabora.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > > > > > + /* Executable implies readable */ > > > > > + if ((args->flags & PANFROST_BO_NOREAD) && > > > > > + !(args->flags & PANFROST_BO_NOEXEC)) > > > > > + return -EINVAL; > > > > > > > > Generally, executable also implies not-writeable. Should we check that? > > > > > > We were allowing it until now, so doing that would break the backward > > > compat, unfortunately. > > > > Not a problem if you only enforce this starting with the appropriate > > UABI version, but... > > I still don't see how that solves the > situation, since old-userspace doesn't know about the new UABI, and > there's no version field on the CREATE_BO ioctl() to let the kernel > know about the UABI used by this userspace program. I mean, we could > add one, or add a new PANFROST_BO_EXTENDED_FLAGS flag to enforce this > 'noexec implies nowrite' behavior, but is it really simpler than > explicitly passing the NOWRITE flag when NOEXEC is passed? For some reason I thought the ABI version was negotiated (it is in kbase). Don't worry about it. That commit is Reviewed-by: Alyssa Rosenzweig