From patchwork Tue Jun 13 11:06:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 13278500 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D26DBC88CBC for ; Tue, 13 Jun 2023 11:21:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234872AbjFMLVT (ORCPT ); Tue, 13 Jun 2023 07:21:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239944AbjFMLJ6 (ORCPT ); Tue, 13 Jun 2023 07:09:58 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7516D92; Tue, 13 Jun 2023 04:09:57 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2208021F68; Tue, 13 Jun 2023 11:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1686654596; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=oUnRIcTHa6H21oE7GPa4lsZpMo92bpwHeZ6bJJavWlw=; b=mSFRUqUQbobGhmnqkYx1dFDc+8egV6lSkFz8oTUcuAgIW/a0sHg8EbQrLNlcz2tos7TbuM 9P+DoYiKfYEfEZIQB1Rj68ZNJG7AUJ6HxzrI989CLUnGna5m0xJiB7Pu5DxwALPesk7NJc h5s0uM94kiFYMXiGJt91iL3BE2PgZso= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1686654596; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=oUnRIcTHa6H21oE7GPa4lsZpMo92bpwHeZ6bJJavWlw=; b=aHIwfug4LNQ6Xoi6MIZKcbspYR4gs2kbPTjLgVJNLJt8bpAk4E+k+WOwc8HjKmfvZpB2ZM 951tW79c3qBmZ+Cw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C0B6F13483; Tue, 13 Jun 2023 11:09:55 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id CcMKLoNOiGR8CQAAMHmgww (envelope-from ); Tue, 13 Jun 2023 11:09:55 +0000 From: Thomas Zimmermann To: daniel@ffwll.ch, javierm@redhat.com, sam@ravnborg.org, deller@gmx.de, geert+renesas@glider.be, lee@kernel.org, daniel.thompson@linaro.org, jingoohan1@gmail.com, dan.carpenter@linaro.org, michael.j.ruhl@intel.com Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-sh@vger.kernel.org, linux-omap@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Thomas Zimmermann Subject: [PATCH v3 00/38] fbdev: Make userspace interfaces optional Date: Tue, 13 Jun 2023 13:06:35 +0200 Message-ID: <20230613110953.24176-1-tzimmermann@suse.de> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Add the new config option FB_DEVICE. If enabled, fbdev provides traditional userspace interfaces in devfs, sysfs and procfs, such as /dev/fb0 or /proc/fb. Modern Linux distrobutions have adopted DRM drivers for graphics output and use fbdev only for the kernel's framebuffer console. Userspace has also moved on, with no new fbdev code being written and existing support being removed. OTOH, fbdev provides userspace a way of accessing kernel or I/O memory, which might compromise the system's security. See the recent commit c8687694bb1f ("drm/fbdev-generic: prohibit potential out-of-bounds access") for an example. Disabling fbdev userspace interfaces is therefore a useful feature to limit unnecessary exposure of fbdev code to processes of low privilegues. Patches 1 to 31 fix various bugs and issues in fbdev-related code. In most cases the code uses the fbdev device where it should use the Linux hardware device or something else. Most of these patches fix existing problems and should therefore be considered in any case. Patches 32 to 37 refactor the fbdev core code. The patches move support for backlights, sysfs, procfs and devfs into separate files and hide it behind simple interfaces. These changes will allow to easily build the userspace support conditionally. Patch 38 introduces the config option FB_DEVICE and adapts the fbdev core to support it. The field struct fb_info.dev is now optional, hence the name of the config option. Tested on simpledrm and i915, including the device handover. Future directions: With the support for disabling fbdev userspace interfaces in place, it will be possible to make most fbdev drivers' file-I/O code in struct fb_ops optional as well. v3: * add missing file fb_chrdev.c * fix typo in Kconfig help (Daniel) v2: * fix fsl-diu-fb and sh7760fb * split backlight patches * set 'default y' for FB_CONFIG * minor fixes and corrections Thomas Zimmermann (38): backlight/bd6107: Compare against struct fb_info.device backlight/bd6107: Rename struct bd6107_platform_data.fbdev to 'dev' backlight/gpio_backlight: Compare against struct fb_info.device backlight/gpio_backlight: Rename field 'fbdev' to 'dev' backlight/lv5207lp: Compare against struct fb_info.device backlight/lv5207lp: Rename struct lv5207lp_platform_data.fbdev to 'dev' fbdev/atyfb: Reorder backlight and framebuffer init/cleanup fbdev/atyfb: Use hardware device as backlight parent fbdev/aty128fb: Reorder backlight and framebuffer init/cleanup fbdev/aty128fb: Use hardware device as backlight parent fbdev/broadsheetfb: Call device_remove_file() with hardware device fbdev/ep93xx-fb: Alloc DMA memory from hardware device fbdev/ep93xx-fb: Output messages with fb_info() and fb_err() fbdev/ep93xx-fb: Do not assign to struct fb_info.dev fbdev/fsl-diu-fb: Output messages with fb_*() helpers fbdev/mb862xxfb: Output messages with fb_dbg() fbdev/metronomefb: Use hardware device for dev_err() fbdev/nvidiafb: Reorder backlight and framebuffer init/cleanup fbdev/nvidiafb: Use hardware device as backlight parent fbdev/pxa168fb: Do not assign to struct fb_info.dev fbdev/radeonfb: Reorder backlight and framebuffer cleanup fbdev/radeonfb: Use hardware device as backlight parent fbdev/rivafb: Reorder backlight and framebuffer init/cleanup fbdev/rivafb: Use hardware device as backlight parent fbdev/sh7760fb: Use fb_dbg() in sh7760fb_get_color_info() fbdev/sh7760fb: Output messages with fb_dbg() fbdev/sh7760fb: Alloc DMA memory from hardware device fbdev/sh7760fb: Use hardware device with dev_() output during probe fbdev/sm501fb: Output message with fb_err() fbdev/smscufx: Detect registered fb_info from refcount fbdev/tdfxfb: Set i2c adapter parent to hardware device fbdev/core: Pass Linux device to pm_vt_switch_*() functions fbdev/core: Move framebuffer and backlight helpers into separate files fbdev/core: Add fb_device_{create,destroy}() fbdev/core: Move procfs code to separate file fbdev/core: Move file-I/O code into separate file fbdev/core: Rework fb init code fbdev: Make support for userspace interfaces configurable Documentation/gpu/todo.rst | 13 + arch/sh/boards/mach-ecovec24/setup.c | 2 +- arch/sh/boards/mach-kfr2r09/setup.c | 2 +- drivers/staging/fbtft/Kconfig | 1 + drivers/video/backlight/bd6107.c | 2 +- drivers/video/backlight/gpio_backlight.c | 6 +- drivers/video/backlight/lv5207lp.c | 2 +- drivers/video/fbdev/Kconfig | 13 + drivers/video/fbdev/aty/aty128fb.c | 12 +- drivers/video/fbdev/aty/atyfb_base.c | 18 +- drivers/video/fbdev/aty/radeon_backlight.c | 2 +- drivers/video/fbdev/aty/radeon_base.c | 3 +- drivers/video/fbdev/broadsheetfb.c | 2 +- drivers/video/fbdev/core/Makefile | 7 +- drivers/video/fbdev/core/fb_backlight.c | 33 ++ drivers/video/fbdev/core/fb_chrdev.c | 485 +++++++++++++++ drivers/video/fbdev/core/fb_info.c | 78 +++ drivers/video/fbdev/core/fb_internal.h | 67 +++ drivers/video/fbdev/core/fb_procfs.c | 62 ++ drivers/video/fbdev/core/fbcon.c | 1 + drivers/video/fbdev/core/fbmem.c | 592 +------------------ drivers/video/fbdev/core/fbsysfs.c | 134 +---- drivers/video/fbdev/ep93xx-fb.c | 21 +- drivers/video/fbdev/fsl-diu-fb.c | 26 +- drivers/video/fbdev/mb862xx/mb862xxfbdrv.c | 9 +- drivers/video/fbdev/metronomefb.c | 2 +- drivers/video/fbdev/nvidia/nv_backlight.c | 2 +- drivers/video/fbdev/nvidia/nvidia.c | 8 +- drivers/video/fbdev/omap2/omapfb/Kconfig | 2 +- drivers/video/fbdev/pxa168fb.c | 2 +- drivers/video/fbdev/riva/fbdev.c | 10 +- drivers/video/fbdev/sh7760fb.c | 50 +- drivers/video/fbdev/sm501fb.c | 2 +- drivers/video/fbdev/smscufx.c | 4 +- drivers/video/fbdev/tdfxfb.c | 4 +- include/linux/fb.h | 6 +- include/linux/platform_data/bd6107.h | 2 +- include/linux/platform_data/gpio_backlight.h | 2 +- include/linux/platform_data/lv5207lp.h | 2 +- 39 files changed, 922 insertions(+), 769 deletions(-) create mode 100644 drivers/video/fbdev/core/fb_backlight.c create mode 100644 drivers/video/fbdev/core/fb_chrdev.c create mode 100644 drivers/video/fbdev/core/fb_info.c create mode 100644 drivers/video/fbdev/core/fb_internal.h create mode 100644 drivers/video/fbdev/core/fb_procfs.c base-commit: 63a468ec7c7652afa80e3fa6ad203f9e64d04e83 prerequisite-patch-id: 0aa359f6144c4015c140c8a6750be19099c676fb prerequisite-patch-id: c67e5d886a47b7d0266d81100837557fda34cb24 prerequisite-patch-id: cbc453ee02fae02af22fbfdce56ab732c7a88c36 prerequisite-patch-id: 7c401614cf55c033f742bced317575b9f5b77bb1 prerequisite-patch-id: d3145eae4b35a1290199af6ff6cd5abfebc82033 prerequisite-patch-id: 242b6bc45675f1f1a62572542d75c89d4864f15a Acked-by: Lee Jones