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: 11856511 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 84A49921 for ; Mon, 26 Oct 2020 10:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6122121BE5 for ; Mon, 26 Oct 2020 10:59:17 +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 S1772877AbgJZK64 (ORCPT ); Mon, 26 Oct 2020 06:58:56 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:54076 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1772854AbgJZK6t (ORCPT ); Mon, 26 Oct 2020 06:58:49 -0400 Received: by mail-wm1-f65.google.com with SMTP id d78so11148343wmd.3 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=R75ztz6TRSCeluvUntfqk0msd8LGyITgc6vI8rKUA4tFvEUCupUXJtoTbaTfnOZMoB J3CbZy81v20yE///CKgCqtqCFpgIb9FlhAcUZSsbTleWn6KGgdxYOAPdM2hiTDqBg2Eu Y5MkGWjC8D9RwhJLh0lwPfHiCBve1CSqEmmIx7Wr1IchSGhd4ohcnXVyJN4BM5gOZD7Z iUjt4jspmupDkhzso/0eZlTwrr6KaeKxKLM3C5DvaflBT/PacQtvkDii6mGzR82bqIvD VQFAFL+ctRVLP/d/wOKo2kYk/hsW+d7adXGlVfSl5+JHgQsMBa+DExFzeKGcs+S+hJdj Fp/g== X-Gm-Message-State: AOAM532ghBLCW0uFz4XNOOB2XivZ/gd3a9mFCmjWUgCkGegKLCMrpPeR MMlBNPHNVWdXk/x5cKswcpCOpw== 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-media@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 *,