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author | Thomas Zimmermann <tzimmermann@suse.de> | 2023-06-13 13:07:13 +0200 |
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committer | Thomas Zimmermann <tzimmermann@suse.de> | 2023-06-27 09:58:51 +0200 |
commit | 701d2054fa317188cd4039c84e72c73254013b23 (patch) | |
tree | 8f866db3aeb00cf6d257f4d4cedab6bff1d5c290 /drivers/video/fbdev/omap2 | |
parent | ff8fbcf605f59c5b7b82805c9f7a7dfe6abac784 (diff) | |
download | linux-stable-701d2054fa317188cd4039c84e72c73254013b23.tar.gz linux-stable-701d2054fa317188cd4039c84e72c73254013b23.tar.bz2 linux-stable-701d2054fa317188cd4039c84e72c73254013b23.zip |
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
Diffstat (limited to 'drivers/video/fbdev/omap2')
-rw-r--r-- | drivers/video/fbdev/omap2/omapfb/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/video/fbdev/omap2/omapfb/Kconfig b/drivers/video/fbdev/omap2/omapfb/Kconfig index 69f9cb03507e..21069fdb7cc2 100644 --- a/drivers/video/fbdev/omap2/omapfb/Kconfig +++ b/drivers/video/fbdev/omap2/omapfb/Kconfig @@ -5,9 +5,9 @@ config OMAP2_VRFB menuconfig FB_OMAP2 tristate "OMAP2+ frame buffer support" depends on FB + depends on FB_DEVICE depends on DRM_OMAP = n depends on GPIOLIB - select FB_OMAP2_DSS select OMAP2_VRFB if ARCH_OMAP2 || ARCH_OMAP3 select FB_CFB_FILLRECT |