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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EEE2C433EF for ; Mon, 13 Jun 2022 09:19:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240699AbiFMJTc (ORCPT ); Mon, 13 Jun 2022 05:19:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbiFMJT0 (ORCPT ); Mon, 13 Jun 2022 05:19:26 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A8E4714D1E for ; Mon, 13 Jun 2022 02:19:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655111964; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=w+/GwuuQGFS111woXNsLKjQljVwtMltJeO1V2zF9Vjo=; b=OXfG0gHHepiYL44lqwJxL1RmwGMvuYK+GXgNrEi0PSfMWis5kAG2SfhNxR+nEGJ0JlFDBg 7XNceyuyUm+MYNDkDXad0thlTFGAkNcUQesp83fw60yKaQjgL5uEBNlr1ZlmKvNKIxzia1 MHPjLqode15kaFi+YIuxOcdsrUJkjN4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-619-t37ddbngOHOr1NtMTjiYhg-1; Mon, 13 Jun 2022 05:19:21 -0400 X-MC-Unique: t37ddbngOHOr1NtMTjiYhg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2B90A101E9BE; Mon, 13 Jun 2022 09:19:21 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.62]) by smtp.corp.redhat.com (Postfix) with ESMTP id 201EC492CA2; Mon, 13 Jun 2022 09:19:19 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: To: Al Viro Cc: dhowells@redhat.com, Sudip Mukherjee , Dominique Martinet , Mike Marshall , Gao Xiang , linux-afs@lists.infradead.org, v9fs-developer@lists.sourceforge.net, devel@lists.orangefs.org, linux-erofs@lists.ozlabs.org, linux-cachefs@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: mainline build failure due to 6c77676645ad ("iov_iter: Fix iter_xarray_get_pages{,_alloc}()") MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1075695.1655111958.1@warthog.procyon.org.uk> Date: Mon, 13 Jun 2022 10:19:18 +0100 Message-ID: <1075696.1655111958@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Al Viro wrote: > The reason we can't overflow on multiplication there, BTW, is that we have > nr <= count, and count has come from weirdly open-coded > DIV_ROUND_UP(size + offset, PAGE_SIZE) > IMO we'd better make it explicit, so how about the following: > > Signed-off-by: Al Viro It seems reasonable. Reviewed-by: David Howells