From patchwork Fri Oct 23 12:21:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 68280 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1kVvze-00Dq70-7j; Fri, 23 Oct 2020 12:16:27 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S463707AbgJWMXS (ORCPT + 1 other); Fri, 23 Oct 2020 08:23:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S463694AbgJWMXR (ORCPT ); Fri, 23 Oct 2020 08:23:17 -0400 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A36F2C0613D4 for ; Fri, 23 Oct 2020 05:23:16 -0700 (PDT) Received: by mail-wr1-x442.google.com with SMTP id e17so1557604wru.12 for ; Fri, 23 Oct 2020 05:23:16 -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=MXuVxECtJ78bOiKGDfTFAHp+CJhdgNky1rItm2A5X7tJL5vSSg4lbAVohhini2H0yd xh374IeyDf7uaUzvTG9zdianxpiWqa1UVuaj2eiOwSQsJ2XHInhGqMSD1spurc8v+95N ChQ4jEq74dxOuKfApkooMZETrU8kZ+CcHZQ1Q= 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=hTEUvQGUl8wWY+sNtayfCAUSkse8q9s7axNB+yIkiMf8tjT2d/k9iRQ0i2akUg5U66 tv8WP0XEdCvgPloJrotfnzQxXXGWcDUzQDTN/+zGSyjijkYgiRmG1lQ+vLubHH7slBXV Zd6PmaihpL0K5DCq9BdNmT9zyDb8+WN3rsCGv1m1KqPP1MQ4aj7QE+ErZXVNeK2plArL SJmlMTgZIzFY5LjlPTmFtwTF4n7I3F1T3f8kTELz7hK/jNVTFlrOWOk/j5WfQPj4NVQ+ mfujZHCBpeZ5t85AC7l6DdqAxRWdaNr+bglwMf4paj5KOK+PvEElyXxyPI3BasI2U5qB iyKw== X-Gm-Message-State: AOAM530TnjiDi0hIISt5Y4GPFPtDGLSB4dp9dOeW3DgeBOu2yxMM2DxG d6YZUJiQVyTm2TuUNod0n3JgPQ== X-Google-Smtp-Source: ABdhPJwV5FzPPp/4Ge7bj9kllxBQ6Gec4MZEynrcnFexeILKj2jkWpYJEMkJr7ScFwkgM+ZpKL2Tqg== X-Received: by 2002:a5d:6551:: with SMTP id z17mr2353056wrv.266.1603455795408; Fri, 23 Oct 2020 05:23:15 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id y4sm3056484wrp.74.2020.10.23.05.23.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2020 05:23:14 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Greg Kroah-Hartman , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Bjorn Helgaas , linux-pci@vger.kernel.org Subject: [PATCH 44/65] PCI: Revoke mappings like devmem Date: Fri, 23 Oct 2020 14:21:55 +0200 Message-Id: <20201023122216.2373294-44-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201023122216.2373294-1-daniel.vetter@ffwll.ch> References: <20201021163242.1458885-1-daniel.vetter@ffwll.ch> <20201023122216.2373294-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.5 (--) X-LSpam-Report: No, score=-2.5 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no 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; }