From patchwork Mon Oct 26 10:58:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 286928 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 DA279C8300E for ; Mon, 26 Oct 2020 10:58:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A09DC2231B for ; Mon, 26 Oct 2020 10:58:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="RdtN9nvq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1772869AbgJZK6v (ORCPT ); Mon, 26 Oct 2020 06:58:51 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:37954 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1772856AbgJZK6u (ORCPT ); Mon, 26 Oct 2020 06:58:50 -0400 Received: by mail-wr1-f67.google.com with SMTP id n18so11879128wrs.5 for ; Mon, 26 Oct 2020 03:58:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rl2aV6v4BUOFD3sWM4dGPxjWFUFBHT1H6eKln2146qM=; b=RdtN9nvqXygrqpRjlwyadHI2Akx5GphSp7V8MoSkao2AUFwNDdcs0pb2/4JjL395li 67V6FN5HHlmjn9vWJcOKZYD+h4GMXwH3UsicvAL/IRAbuzUTcqbK0mc+9nQX8VqJ0N1G QvYjui1JxD/SV+BAqoPjDtW6UkWb8unscHOVc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rl2aV6v4BUOFD3sWM4dGPxjWFUFBHT1H6eKln2146qM=; b=SlGA68xJPDESE7h2+HD6kXnx2tzoEBAvU5+q/n3/6qOkknAcVGlranVMNWSCL8//4n PZ3PxKqabtMrHzNXq22+G87N752in1SGUrTXQUrzIzPZ9rPadEkzARlQCfjnxvKy3SUM JfyV94WeCfQ7j0T+5TOeK5Vj2vKjBPE7Ht20x81/vJ03EG4QEhTlW2FrUhZP6m8n5OfM yeCpH6T0jmkXuivPBPa+bbJ7vOJuJMuHmQPnqgw/6o2jpUFI/QQIxSqAmsqRf7sEy17t NrjJeHQGGHMGfQ3JZrKHyPYioeiCk7NAGvywRBaUSkM+eYfHxJ8cckwEcM+Sw3ETkhNQ kH7g== X-Gm-Message-State: AOAM533X+U3hRfRdO5j5Sj3l8IvJjIOqiVycbxoTbfO+JTYJpt0IfOIU UhBgSJawM3+nuyHnb+gI8Auv+A== X-Google-Smtp-Source: ABdhPJyJEgobhpYPgpR3deeCaVtbSbKMyoksav28TvwMmYamt9hp5XzgBWl2um1YOhVBMyiCN8BNmg== X-Received: by 2002:a5d:498a:: with SMTP id r10mr17440576wrq.106.1603709927066; Mon, 26 Oct 2020 03:58:47 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id w83sm21165156wmg.48.2020.10.26.03.58.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 03:58:46 -0700 (PDT) From: Daniel Vetter To: DRI Development , LKML Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-s390@vger.kernel.org, Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Greg Kroah-Hartman , Bjorn Helgaas , linux-pci@vger.kernel.org Subject: [PATCH v4 15/15] PCI: Revoke mappings like devmem Date: Mon, 26 Oct 2020 11:58:18 +0100 Message-Id: <20201026105818.2585306-16-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> References: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org Since 3234ac664a87 ("/dev/mem: Revoke mappings when a driver claims the region") /dev/kmem zaps ptes when the kernel requests exclusive acccess to an iomem region. And with CONFIG_IO_STRICT_DEVMEM, this is the default for all driver uses. Except there's two more ways to access PCI BARs: sysfs and proc mmap support. Let's plug that hole. For revoke_devmem() to work we need to link our vma into the same address_space, with consistent vma->vm_pgoff. ->pgoff is already adjusted, because that's how (io_)remap_pfn_range works, but for the mapping we need to adjust vma->vm_file->f_mapping. The cleanest way is to adjust this at at ->open time: - for sysfs this is easy, now that binary attributes support this. We just set bin_attr->mapping when mmap is supported - for procfs it's a bit more tricky, since procfs pci access has only one file per device, and access to a specific resources first needs to be set up with some ioctl calls. But mmap is only supported for the same resources as sysfs exposes with mmap support, and otherwise rejected, so we can set the mapping unconditionally at open time without harm. A special consideration is for arch_can_pci_mmap_io() - we need to make sure that the ->f_mapping doesn't alias between ioport and iomem space. There's only 2 ways in-tree to support mmap of ioports: generic pci mmap (ARCH_GENERIC_PCI_MMAP_RESOURCE), and sparc as the single architecture hand-rolling. Both approach support ioport mmap through a special pfn range and not through magic pte attributes. Aliasing is therefore not a problem. The only difference in access checks left is that sysfs PCI mmap does not check for CAP_RAWIO. I'm not really sure whether that should be added or not. Signed-off-by: Daniel Vetter Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: Greg Kroah-Hartman Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Bjorn Helgaas Cc: linux-pci@vger.kernel.org Signed-off-by: Daniel Vetter --- v2: - Totally new approach: Adjust filp->f_mapping at open time. Note that this now works on all architectures, not just those support ARCH_GENERIC_PCI_MMAP_RESOURCE --- drivers/pci/pci-sysfs.c | 4 ++++ drivers/pci/proc.c | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 6d78df981d41..cee38fcb4a86 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -928,6 +928,7 @@ void pci_create_legacy_files(struct pci_bus *b) b->legacy_io->read = pci_read_legacy_io; b->legacy_io->write = pci_write_legacy_io; b->legacy_io->mmap = pci_mmap_legacy_io; + b->legacy_io->mapping = iomem_get_mapping(); pci_adjust_legacy_attr(b, pci_mmap_io); error = device_create_bin_file(&b->dev, b->legacy_io); if (error) @@ -940,6 +941,7 @@ void pci_create_legacy_files(struct pci_bus *b) b->legacy_mem->size = 1024*1024; b->legacy_mem->attr.mode = 0600; b->legacy_mem->mmap = pci_mmap_legacy_mem; + b->legacy_io->mapping = iomem_get_mapping(); pci_adjust_legacy_attr(b, pci_mmap_mem); error = device_create_bin_file(&b->dev, b->legacy_mem); if (error) @@ -1155,6 +1157,8 @@ static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine) res_attr->mmap = pci_mmap_resource_uc; } } + if (res_attr->mmap) + res_attr->mapping = iomem_get_mapping(); res_attr->attr.name = res_attr_name; res_attr->attr.mode = 0600; res_attr->size = pci_resource_len(pdev, num); diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index 3a2f90beb4cb..9bab07302bbf 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -298,6 +298,7 @@ static int proc_bus_pci_open(struct inode *inode, struct file *file) fpriv->write_combine = 0; file->private_data = fpriv; + file->f_mapping = iomem_get_mapping(); return 0; }