linux-stable.git/drivers/video/fbdev/simplefb.c, branch linux-5.17.y

fbdev: simplefb: Cleanup fb_info in .fb_destroy rather than .remove

2022-05-18T08:28:12+00:00

[ Upstream commit 666b90b3ce9e4aac1e1deba266c3a230fb3913b0 ]

The driver is calling framebuffer_release() in its .remove callback, but
this will cause the struct fb_info to be freed too early. Since it could
be that a reference is still hold to it if user-space opened the fbdev.

This would lead to a use-after-free error if the framebuffer device was
unregistered but later a user-space process tries to close the fbdev fd.

To prevent this, move the framebuffer_release() call to fb_ops.fb_destroy
instead of doing it in the driver's .remove callback.

Strictly speaking, the code flow in the driver is still wrong because all
the hardware cleanupd (i.e: iounmap) should be done in .remove while the
software cleanup (i.e: releasing the framebuffer) should be done in the
.fb_destroy handler. But this at least makes to match the behavior before
commit 27599aacbaef ("fbdev: Hot-unplug firmware fb devices on forced removal").

Fixes: 27599aacbaef ("fbdev: Hot-unplug firmware fb devices on forced removal")
Suggested-by: Daniel Vetter 
Signed-off-by: Javier Martinez Canillas 
Reviewed-by: Thomas Zimmermann 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20220505220456.366090-1-javierm@redhat.com
Signed-off-by: Sasha Levin

Merge drm/drm-next into drm-misc-next

2021-12-16T13:48:27+00:00

Backmerging for v5.16-rc5. Resolves a conflict between drm-misc-next
and drm-misc-fixes in the vc4 driver.

Signed-off-by: Thomas Zimmermann

of: Move simple-framebuffer device handling from simplefb to of

2021-12-16T09:55:26+00:00

This code is required for both simplefb and simpledrm, so let's move it
into the OF core instead of having it as an ad-hoc initcall in the
drivers.

Signed-off-by: Hector Martin 
Reviewed-by: Rob Herring 
Acked-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20211212062407.138309-2-marcan@marcan.st

fbdev: Prevent probing generic drivers if a FB is already registered

2021-11-17T09:15:05+00:00

The efifb and simplefb drivers just render to a pre-allocated frame buffer
and rely on the display hardware being initialized before the kernel boots.

But if another driver already probed correctly and registered a fbdev, the
generic drivers shouldn't be probed since an actual driver for the display
hardware is already present.

This is more likely to occur after commit d391c5827107 ("drivers/firmware:
move x86 Generic System Framebuffers support") since the "efi-framebuffer"
and "simple-framebuffer" platform devices are registered at a later time.

Link: https://lore.kernel.org/r/20211110200253.rfudkt3edbd3nsyj@lahvuun/
Fixes: d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support")
Reported-by: Ilya Trukhanov 
Cc:  # 5.15.x
Signed-off-by: Javier Martinez Canillas 
Reviewed-by: Daniel Vetter 
Tested-by: Ilya Trukhanov 
Link: https://patchwork.freedesktop.org/patch/msgid/20211111115757.1351045-1-javierm@redhat.com

video: fbdev: simplefb: Fix info message during probe

2021-01-20T11:06:32+00:00

The info message was showing the mapped address for the framebuffer. To avoid
security problems, all virtual addresses are converted to __ptrval__, so
the message has pointless information:

simple-framebuffer 3ea9b000.framebuffer: framebuffer at 0x3ea9b000, 0x12c000 bytes, mapped to 0x(____ptrval____)

Drop the extraneous bits to clean up the message:

simple-framebuffer 3ea9b000.framebuffer: framebuffer at 0x3ea9b000, 0x12c000 bytes

Signed-off-by: Peter Robinson 
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede 
Link: https://patchwork.freedesktop.org/patch/msgid/20201228183934.1117012-1-pbrobinson@gmail.com

video: constify fb ops across all drivers

2019-12-05T08:57:53+00:00

Now that the fbops member of struct fb_info is const, we can start
making the ops const as well.

This does not cover all drivers; some actually modify the fbops struct,
for example to adjust for different configurations, and others do more
involved things that I'd rather not touch in practically obsolete
drivers. Mostly this is the low hanging fruit where we can add "const"
and be done with it.

v3:
- un-constify atyfb, mb862xx, nvidia and uvesabf (0day)

v2:
- fix typo (Christophe de Dinechin)
- use "static const" instead of "const static" in mx3fb.c
- also constify smscufx.c

Cc: linux-fbdev@vger.kernel.org
Reviewed-by: Daniel Vetter 
Signed-off-by: Jani Nikula 
Link: https://patchwork.freedesktop.org/patch/msgid/ce67f14435f3af498f2e8bf35ce4be11f7504132.1575390740.git.jani.nikula@intel.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288

2019-06-05T15:36:37+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Alexios Zavras 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman

video: fbdev: simplefb: Stop including

2018-07-03T15:43:09+00:00

Simplefb is not a clock provider, but it uses of_clk_get_parent_count(),
so it can just include  instead.

Signed-off-by: Geert Uytterhoeven 
Acked-by: Hans de Goede 
Acked-by: Stephen Boyd 
Signed-off-by: Bartlomiej Zolnierkiewicz

video: fbdev: simplefb: Separate clk / regulator get and enable steps

2017-01-11T16:09:50+00:00

Currently when a simplefb needs both clocks and regulators and one
of the regulators returns -EPROBE_DEFER when we try to get it, we end
up disabling the clocks. This causes the screen to go blank; and in some
cases my cause hardware state to be lost resulting in the framebuffer not
working at all.

This commit splits the get and enable steps and only enables
clocks and regulators after successfully getting all of them,
fixing the disabling of the clocks which were left enabled by
the firmware setting up the simplefb.

Signed-off-by: Hans de Goede 
Signed-off-by: Bartlomiej Zolnierkiewicz

simplefb: Disable and release clocks and regulators in destroy callback

2016-09-27T08:21:36+00:00

simplefb gets unregister when a proper framebuffer driver comes in and
kicks it out. However the claimed clocks and regulators stay enabled
as they are only released in the platform device remove function, which
in theory would never get called.

Move the clock/regulator cleanup into the framebuffer destroy callback,
which gets called as part of the framebuffer unregister process.

Note this introduces asymmetry in how the resources are claimed and
released.

Signed-off-by: Chen-Yu Tsai 
Reviewed-by: Hans de Goede 
Signed-off-by: Tomi Valkeinen