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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 0CC55C79F82 for ; Tue, 8 Sep 2026 20:36:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3954E10ED75; Tue, 8 Sep 2026 20:36:30 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="Vw+3Z/GT"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id EBA4510ED75 for ; Tue, 8 Sep 2026 20:36:26 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 3D57A601F7; Tue, 8 Sep 2026 20:36:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E7401F00A3D; Tue, 8 Sep 2026 20:36:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788899785; bh=wAJ7ikObQ7BdyD8JmXGdd6lEUfR3W8m2ceywh5stGKo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Vw+3Z/GTh+Dohhq4+9hT2hyhF257D90BGoxNyy/dMiyI/kx8l6o6yVGHmfV6TsCbu QJrR/OaDvqjzK6rjaBrKBmWKgVL/Q7kn9hHdw9Yli24KxnWoBB/40l/JJQKCI9AM3c jDuNOhAciZQLyDR5AIG4nLKerI+QUAy1b9L1JOqJM7pbEh1f/xZ2yfRPm+OSXyJFtC 3rpdr03OoNwCl+Y0FoCgxz7P5cjya9oXD2mhS23ex3fN17k/sqm1E6HiawWTZoDkkZ RAvKOnbiNyGtmQfyRwUQA0S4cRYW+mG98TCfG40v4QN0a11r/k8Sgu3XfmUZVckyR4 Irs0EZPvowRcg== From: sashiko-bot@kernel.org Subject: Re: [PATCH 20/39] mm/gup: error out early on !VMA_MAYREAD_BIT VMAs To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Christian Borntraeger" , linux-s390@vger.kernel.org, bpf@vger.kernel.org, "Oliver Upton" , dri-devel@lists.freedesktop.org, kvm@vger.kernel.org, selinux@vger.kernel.org, linux-perf-users@vger.kernel.org, "Marc Zyngier" , "Alexander Gordeev" , linux-trace-kernel@vger.kernel.org, "Vasily Gorbik" , "Heiko Carstens" , kvmarm@lists.linux.dev, linux-scsi@vger.kernel.org In-Reply-To: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-20-dacf19cce22b@kernel.org> References: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> <20260908-b4-mmap-prepare-vma-flag-sanify-v1-20-dacf19cce22b@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 08 Sep 2026 20:36:24 +0000 Message-Id: <20260908203625.2E7401F00A3D@smtp.kernel.org> 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: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > When populating a VMA range via the aptly named populate_vma_page_range() > an unreadable VMA will always eventually fail with -EFAULT. >=20 > That a VMA is accessible is always checked, however VMA_MAYREAD_BIT is no= t. >=20 > All user mappings always have VMA_MAYREAD_BIT set, so this check only > impacts kernel mappings. >=20 > It is implemented specifically to disallow population of uprobes XOL > mappings which are exec-only. >=20 > A nasty interaction with these mappings may occur if they are mlocked, so > actively disallow this early. >=20 > This allows a subsequent commit to remove the VM_IO check in > __mm_populate() which otherwise requires non-MMIO mappings to be wrongly > flagged simply as a workaround. >=20 > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260908-b4-mmap-pr= epare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org?part=3D20