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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 1D1F2D58B00 for ; Mon, 23 Mar 2026 15:52:01 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4ffd2l5hBbz2ySB; Tue, 24 Mar 2026 02:51:59 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2600:3c04:e001:324:0:1991:8:25" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774281119; cv=none; b=WBt2Qel7GuNO9BVzXZs+sC+sBl/QImEFOG7QHDlOokLvJhQSY7opEz4l+t7nsEtMG89HxDgWb7zdUxkY7GEKvvI3hyFrRJZ1mN1EWpH02iFzoN07B5XjYHXrm1esVIDD1BltarInjKhcy7gY79/RbAizS8ugptw7M1kKGJsPjO+A824/M63LqaTCT89Lhae4NFDRqhBsf1/bcYQqRKiKDhd3FL5AEHo7XOC//3bxHgvXl9S8ukx4dZGZs4OHQ956R294AnKGVc/rH6/PLre0n9bHYUHd2iCNV70CH6YR7KgaaLJPtDGERQvzSbloyJR1SY+IvKVvO0VocslybNeiGg== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774281119; c=relaxed/relaxed; bh=2+P1LJbOhGaADXr0borEizC7CpTJv3YbpsxtYt/vS4k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=c9ArjwTXUZ2J9sBRPxgvwmt28W2+qKKY6j8CRGQlwaXhpuR46/hjd4JO1HMdB4kcFk3sZ+5cCUWSUJGnuBj7rg2wYUSr+yDRYG1jhomc9+uIeyObiKU7InTS8ZatSGDwZ++/fZ10WNks80XnIsa1B8i7+iOcnQSD+4DGp/aW7gdEhKksNptllJfCf2AzOjx3oGXhC4OaQPVwUII+qE12CeVOj91RtfGPu/t9CiveOS2CajPHiuWTrUo1LXRA93R4qamNcgrDSYqk/uontXBD4bObD9TFjNjnYS8EyWVpbCc+Xbm6ixZdPke36z7RsX8Oyk1Fc/3/ZtfVRKAsH28PNg== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=o1THjGW8; dkim-atps=neutral; spf=pass (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=vbabka@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=o1THjGW8; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=vbabka@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [IPv6:2600:3c04:e001:324:0:1991:8:25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4ffd2k650Vz2xN5 for ; Tue, 24 Mar 2026 02:51:58 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id EE492600C4; Mon, 23 Mar 2026 15:51:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCA5BC4CEF7; Mon, 23 Mar 2026 15:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774281115; bh=vZdm4GONA/O1jK4+M6185Q0giqh3AS1i2sFB5Pfd/2Y=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=o1THjGW87BBZn2ZRvUB/ZbG6Bpk46OGuXu9+rNxgEX1JPplRd0PmhhIVaepJQX2x+ tNfnZZ2oJ/LEW/V1kb+Kd4rSlee9+4uD+RKeGWfnc/xNRMj7aASQw2bbJQ+4aFpnT4 D5oU71wAa1icX022onJ8SXq1egN+wMrKLzs0GkJXDMxvnSocAjVWuUsitbcyyxaQfV JJXP9c4lBWKh9RLPX/Xy30cKFsVybbnBnhAp26jeybHA0vntxV0OkXb/w0rzQv6/lE VQ33MGCeDpT2FONGoMZBv7aFNGtJEznzEExGGKYXFQSBLYixZR0A4kZUSTFL4AAduW zfBJEYhpa4mqQ== Message-ID: <47f796ed-ac66-4a75-98c9-64afc8929f35@kernel.org> Date: Mon, 23 Mar 2026 16:51:41 +0100 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 25/25] mm: simplify VMA flag tests of excluded flags To: "Lorenzo Stoakes (Oracle)" , Andrew Morton Cc: David Hildenbrand , "Liam R . Howlett" , Jann Horn , Pedro Falcato , Mike Rapoport , Suren Baghdasaryan , Kees Cook , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Brian Cain , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , Dinh Nguyen , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Richard Weinberger , Anton Ivanov , Johannes Berg , Alexander Viro , Christian Brauner , Jan Kara , Xu Xin , Chengming Zhou , Michal Hocko , Paul Moore , Stephen Smalley , Ondrej Mosnacek , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-um@lists.infradead.org, linux-fsdevel@vger.kernel.org, selinux@vger.kernel.org References: From: "Vlastimil Babka (SUSE)" Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/26 8:38 PM, Lorenzo Stoakes (Oracle) wrote: > We have implemented flag mask comparisons of the form: > > if ((vm_flags & (VM_FOO|VM_BAR|VM_BAZ) == VM_FOO) { ... } > > Like-for-like in the code using a bitwise-and mask via vma_flags_and() and > using vma_flags_same() to ensure the final result equals only the required > flag value. > > This is fine but confusing, make things clearer by instead explicitly > excluding undesired flags and including the desired one via tests of the > form: > > if (vma_flags_test(&flags, VMA_FOO_BIT) && > !vma_flags_test_any(&flags, VMA_BAR_BIT, VMA_BAZ_BIT)) { ... } > > Which makes it easier to understand what is going on. > > No functional change intended. > > Suggested-by: Vlastimil Babka (SUSE) > Signed-off-by: Lorenzo Stoakes (Oracle) Acked-by: Vlastimil Babka (SUSE)