From patchwork Mon Oct 26 10:58:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11856465 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9DBEA14C0 for ; Mon, 26 Oct 2020 10:58:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B55C2242C for ; Mon, 26 Oct 2020 10:58:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="AyLC83NY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1772860AbgJZK6t (ORCPT ); Mon, 26 Oct 2020 06:58:49 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:54883 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1772848AbgJZK6r (ORCPT ); Mon, 26 Oct 2020 06:58:47 -0400 Received: by mail-wm1-f67.google.com with SMTP id w23so10050865wmi.4 for ; Mon, 26 Oct 2020 03:58:46 -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=kkmJ6ZmKgmcd6yJ6bv+WDWEfAJ+atBjrBRrq3Oi6xEA=; b=AyLC83NYGpnIvuLIFq1n+EYb5RD2pj+8NwDHlA6VA5HNxtYkzMI28Z+nvka4pfH0sh 7KSsyqM99nYdq6/YaTlJmbbjYh4uyOjgl1qj0NJ0XKlEnX0r9gulONO+zSqW5ASovylx roszmSmlQTJoMIlY94WrJZfxbZNLo6JFHhNE0= 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=kkmJ6ZmKgmcd6yJ6bv+WDWEfAJ+atBjrBRrq3Oi6xEA=; b=LiwTDnnAkVasYOFqE0VNeUiGMpCH7A8LUF5eJEbO8HQK/6JLJ8Bw+Dqu792po8Siop WBbjmBd8THYcw4/nBX3pepg8yPQQDJp94fM70SRF3UaNayAoUWPXvBBGwwWD/jXPD855 FEiXTxT4hls288CQ2Lrhf/nC46SGg63WUaeEnDMAkPop7aegsi6ETlDCJvUWCfMZ/Jxf aPEpK2Nz6VOlgxMYYygutPz0Al6364mF1fnWxsirHXXGmVfhHNiuXq1Y3jE6Y29pkxH4 WVYmg/bcPvbeGPWHfxbviV2ZPizlZ1d//3KSq5ymEtKmaECneGjTuEGJWyJTfc+xabOs PjSA== X-Gm-Message-State: AOAM531d0tnOL+NVbRVn6+mGGvqHGSUZ5ENlH2Adi9y1ju46yMvCNTxd /NGO4pf6W1Wnu/UtdggZ9011Ng== X-Google-Smtp-Source: ABdhPJytw73HXFA7BGESL3jqxl9OmapvxqxjO7CWItldlXvB0eWL3Kk5ZZkwwQloESg/WFGowlh1eg== X-Received: by 2002:a1c:4306:: with SMTP id q6mr16417557wma.189.1603709925752; Mon, 26 Oct 2020 03:58:45 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id w83sm21165156wmg.48.2020.10.26.03.58.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 03:58:45 -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 , Greg Kroah-Hartman , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Bjorn Helgaas , linux-pci@vger.kernel.org, "Rafael J. Wysocki" , Christian Brauner , "David S. Miller" , Michael Ellerman , Sourabh Jain , Mauro Carvalho Chehab , Nayna Jain Subject: [PATCH v4 14/15] sysfs: Support zapping of binary attr mmaps Date: Mon, 26 Oct 2020 11:58:17 +0100 Message-Id: <20201026105818.2585306-15-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-pci@vger.kernel.org We want to be able to revoke pci mmaps so that the same access rules applies as for /dev/kmem. Revoke support for devmem was added in 3234ac664a87 ("/dev/mem: Revoke mappings when a driver claims the region"). The simplest way to achieve this is by having the same filp->f_mapping for all mappings, so that unmap_mapping_range can find them all, no matter through which file they've been created. Since this must be set at open time we need sysfs support for this. Add an optional mapping parameter bin_attr, which is only consulted when there's also an mmap callback, since without mmap support allowing to adjust the ->f_mapping makes no sense. Reviewed-by: Greg Kroah-Hartman 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: 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 Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Christian Brauner Cc: "David S. Miller" Cc: Michael Ellerman Cc: Sourabh Jain Cc: Daniel Vetter Cc: Mauro Carvalho Chehab Cc: Nayna Jain Signed-off-by: Daniel Vetter --- fs/sysfs/file.c | 11 +++++++++++ include/linux/sysfs.h | 2 ++ 2 files changed, 13 insertions(+) diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index eb6897ab78e7..9d8ccdb000e3 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -169,6 +169,16 @@ static int sysfs_kf_bin_mmap(struct kernfs_open_file *of, return battr->mmap(of->file, kobj, battr, vma); } +static int sysfs_kf_bin_open(struct kernfs_open_file *of) +{ + struct bin_attribute *battr = of->kn->priv; + + if (battr->mapping) + of->file->f_mapping = battr->mapping; + + return 0; +} + void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr) { struct kernfs_node *kn = kobj->sd, *tmp; @@ -240,6 +250,7 @@ static const struct kernfs_ops sysfs_bin_kfops_mmap = { .read = sysfs_kf_bin_read, .write = sysfs_kf_bin_write, .mmap = sysfs_kf_bin_mmap, + .open = sysfs_kf_bin_open, }; int sysfs_add_file_mode_ns(struct kernfs_node *parent, diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 34e84122f635..a17a474d1601 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -164,11 +164,13 @@ __ATTRIBUTE_GROUPS(_name) struct file; struct vm_area_struct; +struct address_space; struct bin_attribute { struct attribute attr; size_t size; void *private; + struct address_space *mapping; ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *, char *, loff_t, size_t); ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *,