linux-imx/Documentation/gpu
Thomas Zimmermann 701d2054fa fbdev: Make support for userspace interfaces configurable
Add Kconfig option CONFIG_FB_DEVICE and make the virtual fbdev
device optional. If the new option has not been selected, fbdev
does not create files in devfs, sysfs or procfs.

Most modern Linux systems run a DRM-based graphics stack that uses
the kernel's framebuffer console, but has otherwise deprecated fbdev
support. Yet fbdev userspace interfaces are still present.

The option makes it possible to use the fbdev subsystem as console
implementation without support for userspace. This closes potential
entry points to manipulate kernel or I/O memory via framebuffers. It
also prevents the execution of driver code via ioctl or sysfs, both
of which might allow malicious software to exploit bugs in the fbdev
code.

A small number of fbdev drivers require struct fbinfo.dev to be
initialized, usually for the support of sysfs interface. Make these
drivers depend on FB_DEVICE. They can later be fixed if necessary.

v3:
	* effect -> affect in Kconfig help (Daniel)
v2:
	* set FB_DEVICE default to y (Geert)
	* comment on {get,put}_device() (Sam)
	* Kconfig fixes (Sam)
	* add TODO item about FB_DEVICE dependencies (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-39-tzimmermann@suse.de
2023-06-27 09:58:51 +02:00
..
amdgpu drm/amd: Update driver-misc.html for Rembrandt-R 2023-06-09 10:40:22 -04:00
bridge
dp-mst
rfc drm/doc/rfc: Introduce the merge plan for the Xe driver. 2023-04-26 23:59:00 -04:00
afbc.rst
backlight.rst
driver-uapi.rst drm/i915: Fix missing docbook chapters for i915 uapi. 2021-07-16 10:52:59 +02:00
drivers.rst Documentation/gpu: Reorganize DC documentation 2021-12-13 16:33:16 -05:00
drm-client.rst
drm-internals.rst drm/doc: Add KUnit documentation 2022-06-27 13:46:03 +02:00
drm-kms-helpers.rst drm/bridge: Document the expected behaviour of DSI host controllers 2022-12-08 09:56:57 +01:00
drm-kms.rst drm/doc: Fix title underline length 2022-12-01 11:12:44 +01:00
drm-mm.rst drm/gem: rename GEM CMA helpers to GEM DMA helpers 2022-08-03 18:31:49 +02:00
drm-uapi.rst drm/doc: make drm-uapi igt-tests more readable 2022-11-23 20:34:46 +01:00
drm-usage-stats.rst drm/doc: Relax fdinfo string constraints 2023-05-24 18:03:33 +02:00
i915.rst drm/i915/mtl: Handle wopcm per-GT and limit calculations. 2022-11-14 10:11:47 -08:00
index.rst Docs/subsystem-apis: Remove '[The ]Linux' prefixes from titles of listed documents 2023-01-24 15:27:08 -07:00
introduction.rst drm/doc: Add sections about tiny drivers and external refs to intro page 2022-04-22 13:56:31 +02:00
kms-properties.csv
komeda-kms.rst
mcde.rst
meson.rst
msm-crash-dump.rst
pl111.rst
tegra.rst
todo.rst fbdev: Make support for userspace interfaces configurable 2023-06-27 09:58:51 +02:00
tve200.rst
v3d.rst
vc4.rst drm/vc4: Improve the KUnit documentation 2022-12-15 08:54:08 +01:00
vga-switcheroo.rst
vgaarbiter.rst PCI/VGA: Move vgaarb to drivers/pci 2022-03-09 18:30:46 -06:00
vkms.rst drm/vkms: drop "Rotation" TODO 2023-05-08 09:57:24 -03:00
xen-front.rst