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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66DCCC56202 for ; Thu, 29 Oct 2020 09:28:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0403321582 for ; Thu, 29 Oct 2020 09:28:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="MqqqGoYf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726397AbgJ2J2E (ORCPT ); Thu, 29 Oct 2020 05:28:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725808AbgJ2J2D (ORCPT ); Thu, 29 Oct 2020 05:28:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FCD5C0613CF; Thu, 29 Oct 2020 02:28:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=HMNKQsqBsKX9+0k6m5XFcNMbHKyJ5WQO76fwZYbzlHU=; b=MqqqGoYfwKrE3KISkpzbqHy/Ob uwVusthktdIZQSLnndLf88E75ofqEvbWgesgfeJfESvYr36PMyTzf8xDx9ObwIrnCaqC1jXHyrrEL 6JMcnxyv9llSjA36fJwqh/119FIzHvvDdu2PPzJ/ZMlqjGtl3E4yTV495esSFXmAorzfgxzSVhEAn x3+Z9WX0MQlUP/mxT54fA+7vKmCUZkTIkr7rTMgMTNOUgOnrFxHfNf64sjDR+pkCAFSIrpqRRogAo ejWSe3+wxOeEr2U/JYm132fimQVhTTK3d0aumI3wRGQuZE24e5seUrCq9JzOrgmV3Q5iiH/rjO8Gu DV3kSWTQ==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kY4Dw-0000CZ-NJ; Thu, 29 Oct 2020 09:28:00 +0000 Date: Thu, 29 Oct 2020 09:28:00 +0000 From: Christoph Hellwig To: Daniel Vetter Cc: Christoph Hellwig , DRI Development , LKML , KVM list , Linux MM , Linux ARM , linux-samsung-soc , "open list:DMA BUFFER SHARING FRAMEWORK" , linux-s390 Subject: Re: [PATCH v4 00/15] follow_pfn and other iomap races Message-ID: <20201029092800.GA494@infradead.org> References: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> <20201029085749.GB25658@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Thu, Oct 29, 2020 at 10:25:16AM +0100, Daniel Vetter wrote: > On Thu, Oct 29, 2020 at 9:57 AM Christoph Hellwig wrote: > > > > Maybe I'm missing something, but shouldn't follow_pfn be unexported > > at the end of the series? > > kvm is a legit user and modular afaict. But since you can't use this > without an mmu_notifier anyway (or digging around in pagetable > locking), maybe it should be EXPORT_SYMBOL_GPL now at least? I think it should then take the notifier as an argument even if it isn't diretly used as a safety check, and get a new name describing it. EXPORT_SYMBOL_GPL is probably ok for now, but I'm drafting a new EXPORT_SYMBOL_FOR_MODULE() which will export symbols that can only be used by one specific module, with kvm being a prime user due to all the odd exports it requires that aren't really the kernel interface by any normal means.