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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 8CCE7C43461 for ; Mon, 7 Sep 2020 11:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41731207C3 for ; Mon, 7 Sep 2020 11:43:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728991AbgIGLZC (ORCPT ); Mon, 7 Sep 2020 07:25:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:47072 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728807AbgIGLV6 (ORCPT ); Mon, 7 Sep 2020 07:21:58 -0400 Received: from gaia (unknown [46.69.195.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 834A0206D4; Mon, 7 Sep 2020 11:21:21 +0000 (UTC) Date: Mon, 7 Sep 2020 12:21:19 +0100 From: Catalin Marinas To: George Cherian Cc: Yang Yingliang , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "will.deacon@arm.com" , "bhelgaas@google.com" , "guohanjun@huawei.com" , Lorenzo Pieralisi Subject: Re: [PATCH] arm64: PCI: fix memleak when calling pci_iomap/unmap() Message-ID: <20200907112118.GD26513@gaia> References: <20200907104546.GC26513@gaia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + Lorenzo On Mon, Sep 07, 2020 at 10:51:21AM +0000, George Cherian wrote: > Catalin Marinas wrote: > > On Sat, Sep 05, 2020 at 10:48:11AM +0800, Yang Yingliang wrote: > > > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index > > > 1006ed2d7c604..ddfa1c53def48 100644 > > > --- a/arch/arm64/kernel/pci.c > > > +++ b/arch/arm64/kernel/pci.c > > > @@ -217,4 +217,9 @@ void pcibios_remove_bus(struct pci_bus *bus) > > > acpi_pci_remove_bus(bus); > > > } > > > > > > +void pci_iounmap(struct pci_dev *dev, void __iomem *addr) { > > > + iounmap(addr); > > > +} > > > +EXPORT_SYMBOL(pci_iounmap); > > > > So, what's wrong with the generic pci_iounmap() implementation? > > Shouldn't it call iounmap() already? > > Since ARM64 selects CONFIG_GENERIC_PCI_IOMAP and not > CONFIG_GENERIC_IOMAP, the pci_iounmap function is reduced to a NULL > function. Due to this, even the managed release variants or even the explicit > pci_iounmap calls doesn't really remove the mappings leading to leak. Ah, I missed the fact that pci_iounmap() depends on a different config option. > https://lkml.org/lkml/2020/8/20/28 So is this going to be fixed in the generic code? That would be my preference. A problem with the iounmap() in the proposed patch is that the region may have been an I/O port, so we could end up unmapping the I/O space. -- Catalin