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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAAE3C433EF for ; Wed, 15 Jun 2022 13:11:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D7A8C6B0073; Wed, 15 Jun 2022 09:11:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D2A736B0074; Wed, 15 Jun 2022 09:11:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BF1AF6B0075; Wed, 15 Jun 2022 09:11:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id B049C6B0073 for ; Wed, 15 Jun 2022 09:11:33 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 7B7BE20411 for ; Wed, 15 Jun 2022 13:11:33 +0000 (UTC) X-FDA: 79580506866.22.E89B164 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf03.hostedemail.com (Postfix) with ESMTP id 796F22009D for ; Wed, 15 Jun 2022 13:11:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=23fuZknXWJF9QBCvVKnf+w/lvfeYy7BfvncZnj8bjoA=; b=idpbFzDRpIvCjGQ7N4rn9peFBW Ld93jiEdubqoNDuN5iiaykZ+VlrKcP/DX6LTJcKRZ9GiTWV2of4NK0c+Hd/XPc3cxXMwIEz29n0l2 WZ/rWDPqQmQTbeYvmCuJaCWnErVPD/jdlouZT8Lbh1NpgJ/RPAlV2G2HJGLGp6oyu6EUyKH2VyKkD WJwuTmn/yOanLFwt4+uxTHq+EAeDteZRzimqSxvBh4uzxk+DgkvRByCrOGmMbM3yy001wraamHFkq akYVnVYsDIFV9RbOjtDciLnqLA8BozD6Tq7KXyomZkVmbjoCSmqqLnmMWZsGlyRDhaDCdjtZ6N0+6 OihDilpg==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1o1SnX-00Edgx-9m; Wed, 15 Jun 2022 13:11:03 +0000 Date: Wed, 15 Jun 2022 06:11:03 -0700 From: Christoph Hellwig To: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Dan Williams , Paolo Bonzini , Jane Chu , "Aneesh Kumar K . V" , Sean Christopherson , Tianyu Lan , Mike Rapoport , Rick Edgecombe , linux-mm@kvack.org, Borislav Petkov , x86@kernel.org Subject: Re: [RFC 1/2] x86/mm/cpa: always fail when user address is passed Message-ID: References: <20220614063933.13030-1-42.hyeyoo@gmail.com> <20220614063933.13030-2-42.hyeyoo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220614063933.13030-2-42.hyeyoo@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655298693; a=rsa-sha256; cv=none; b=b7mwvkNOGCv+RMxzWnlU0Nk7CebTDw4YN8haAenWsC7U4QlLEA/NfADGtIrI1/kl9NBSuX 1tvErQdJd6nPsUKCUdH9i9hlBBwU7FSF0/XF+8NyeOUwU27ATDEbfJagMJ7vmVwk8ToRA0 N8oh8R14E0UxYf5i08jSAJtEa4hV5xg= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=idpbFzDR; spf=none (imf03.hostedemail.com: domain of BATV+cd04db8a85bff7cd13dc+6870+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+cd04db8a85bff7cd13dc+6870+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655298693; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=23fuZknXWJF9QBCvVKnf+w/lvfeYy7BfvncZnj8bjoA=; b=18shxfwxeQ0NwGcpqIn1FyH+VjY0h7t+n7MPMroEMQw7Xn8vxkOBizK4Vwbo+Gb1g246NH SNnTmEL47ftlvLa36Lrg9iSIeiXRnxw/zP/YLL5xF+TXAUQ2cImpTkDBrzdATSSdNXZB6Z Sq4w8Yy3kECm/69/OMz5HIbjkj51YG0= X-Stat-Signature: a53ahe6oznfdc65bt5oqghojphyui3n7 X-Rspamd-Queue-Id: 796F22009D Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=idpbFzDR; spf=none (imf03.hostedemail.com: domain of BATV+cd04db8a85bff7cd13dc+6870+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+cd04db8a85bff7cd13dc+6870+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1655298692-697595 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jun 14, 2022 at 03:39:32PM +0900, Hyeonggon Yoo wrote: > + > + if (WARN((IS_ENABLED(CONFIG_EFI) ? cpa->pgd != efi_mm.pgd : true) > + && address <= TASK_SIZE_MAX, > + KERN_WARNING "CPA: Got a user address")) > + return -EINVAL; This looks rather unreadable. Why not something like: static bool cpa_addr_valid(struct cpa_data *cpa, unsigned long address) { if (address > TASK_SIZE_MAX) return true; if (IS_ENABLED(CONFIG_EFI) && cpa->pgd == efi_mm.pgd) return true; return false; } .... if (WARN_ON_ONCE(!cpa_addr_valid(cpa, address))) return -EINVAL;