Commit Graph

297 Commits

Author SHA1 Message Date
Shigeru Yoshida
a5a923038d fbdev: fbcon: Properly revert changes when vc_resize() failed
fbcon_do_set_font() calls vc_resize() when font size is changed.
However, if if vc_resize() failed, current implementation doesn't
revert changes for font size, and this causes inconsistent state.

syzbot reported unable to handle page fault due to this issue [1].
syzbot's repro uses fault injection which cause failure for memory
allocation, so vc_resize() failed.

This patch fixes this issue by properly revert changes for font
related date when vc_resize() failed.

Link: https://syzkaller.appspot.com/bug?id=3443d3a1fa6d964dd7310a0cb1696d165a3e07c4 [1]
Reported-by: syzbot+a168dbeaaa7778273c1b@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
CC: stable@vger.kernel.org # 5.15+
2022-08-26 19:56:18 +02:00
Wolfram Sang
8d0268585b fbdev: Move fbdev drivers from strlcpy to strscpy
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Helge Deller <deller@gmx.de>
2022-08-24 22:06:15 +02:00
Shigeru Yoshida
58559dfc1e fbdev: fbcon: Destroy mutex on freeing struct fb_info
It's needed to destroy bl_curve_mutex on freeing struct fb_info since
the mutex is embedded in the structure and initialized when it's
allocated.

Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
2022-08-24 21:47:08 +02:00
Linus Torvalds
607ca0f742 Merge tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial driver updates from Greg KH:
 "Here is the big set of tty and serial driver changes for 6.0-rc1.

  It was delayed from last week as I wanted to make sure the last commit
  here got some good testing in linux-next and elsewhere as it seemed to
  show up only late in testing for some reason.

  Nothing major here, just lots of cleanups from Jiri and Ilpo to make
  the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo).

  Also included in here is the obligatory n_gsm updates from Daniel
  Starke and lots of tiny driver updates and minor fixes and tweaks for
  other smaller serial drivers.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits)
  tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements
  tty: amiserial: Fix comment typo
  tty: serial: document uart_get_console()
  tty: serial: serial_core, reformat kernel-doc for functions
  Documentation: serial: link uart_ops properly
  Documentation: serial: move GPIO kernel-doc to the functions
  Documentation: serial: dedup kernel-doc for uart functions
  Documentation: serial: move uart_ops documentation to the struct
  dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126
  serial: mvebu-uart: uart2 error bits clearing
  tty: serial: fsl_lpuart: correct the count of break characters
  serial: stm32: make info structs static to avoid sparse warnings
  serial: fsl_lpuart: zero out parity bit in CS7 mode
  tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.
  serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()
  tty: vt: initialize unicode screen buffer
  serial: remove VR41XX serial driver
  serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags
  serial: 8250_dwlib: remove redundant sanity check for RS485 flags
  dt_bindings: rs485: Correct delay values
  ...
2022-08-08 11:31:40 -07:00
Dave Airlie
e23a5e14aa Backmerge tag 'v5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Backmerge in rc6 so I can merge msm next easier.

Linux 5.19-rc6

Signed-off-by: Dave Airlie <airlied@redhat.com>
2022-07-13 10:54:56 +10:00
Helge Deller
53a6e66b1b fbcon: Use fbcon_info_from_console() in fbcon_modechange_possible()
Use the fbcon_info_from_console() wrapper which was added to kernel
v5.19 with commit 409d6c95f9 ("fbcon: Introduce wrapper for console->fb_info lookup").

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
2022-07-07 10:52:35 +02:00
Helge Deller
6c11df58fd fbmem: Check virtual screen sizes in fb_set_var()
Verify that the fbdev or drm driver correctly adjusted the virtual
screen sizes. On failure report the failing driver and reject the screen
size change.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v5.4+
2022-07-07 10:52:21 +02:00
Helge Deller
e64242caef fbcon: Prevent that screen size is smaller than font size
We need to prevent that users configure a screen size which is smaller than the
currently selected font size. Otherwise rendering chars on the screen will
access memory outside the graphics memory region.

This patch adds a new function fbcon_modechange_possible() which
implements this check and which later may be extended with other checks
if necessary.  The new function is called from the FBIOPUT_VSCREENINFO
ioctl handler in fbmem.c, which will return -EINVAL if userspace asked
for a too small screen size.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v5.4+
2022-07-07 10:50:46 +02:00
Helge Deller
65a01e601d fbcon: Disallow setting font bigger than screen size
Prevent that users set a font size which is bigger than the physical screen.
It's unlikely this may happen (because screens are usually much larger than the
fonts and each font char is limited to 32x32 pixels), but it may happen on
smaller screens/LCD displays.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v4.14+
2022-07-07 10:50:45 +02:00
Guiling Deng
955f04766d fbdev: fbmem: Fix logo center image dx issue
Image.dx gets wrong value because of missing '()'.

If xres == logo->width and n == 1, image.dx = -16.

Signed-off-by: Guiling Deng <greens9@163.com>
Fixes: 3d8b1933eb ("fbdev: fbmem: add config option to center the bootup logo")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Helge Deller <deller@gmx.de>
2022-07-06 17:04:47 +02:00
Javier Martinez Canillas
ee7a69aa38 fbdev: Disable sysfb device registration when removing conflicting FBs
The platform devices registered by sysfb match with firmware-based DRM or
fbdev drivers, that are used to have early graphics using a framebuffer
provided by the system firmware.

DRM or fbdev drivers later are probed and remove conflicting framebuffers,
leading to these platform devices for generic drivers to be unregistered.

But the current solution has a race, since the sysfb_init() function could
be called after a DRM or fbdev driver is probed and request to unregister
the devices for drivers with conflicting framebuffes.

To prevent this, disable any future sysfb platform device registration by
calling sysfb_disable(), if a driver requests to remove the conflicting
framebuffers.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220607182338.344270-4-javierm@redhat.com
2022-06-29 09:51:50 +02:00
Jiri Slaby
8da443b1a4 tty/vt: consolemap: rename struct vc_data::vc_uni_pagedir*
As a follow-up to the commit 4173f018aa (tty/vt: consolemap: rename
and document struct uni_pagedir), rename also the members of struct
vc_data. I.e. pagedir -> pagedict. And while touching all the places,
remove also the unnecessary vc_ prefix.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220614090537.15557-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27 14:17:12 +02:00
Thomas Zimmermann
2b1333b808 Merge drm/drm-next into drm-misc-next
Backmerging to get new regmap APIs of v5.19-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
2022-06-20 18:21:25 +02:00
Helge Deller
cad564ca55 fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters
The user may use the fbcon=vc:<n1>-<n2> option to tell fbcon to take
over the given range (n1...n2) of consoles. The value for n1 and n2
needs to be a positive number and up to (MAX_NR_CONSOLES - 1).
The given values were not fully checked against those boundaries yet.

To fix the issue, convert first_fb_vc and last_fb_vc to unsigned
integers and check them against the upper boundary, and make sure that
first_fb_vc is smaller than last_fb_vc.

Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYRMojilrtZIgM@p100
2022-06-20 12:12:27 +02:00
Helge Deller
3866cba87d fbcon: Fix accelerated fbdev scrolling while logo is still shown
There is no need to directly skip over to the SCROLL_REDRAW case while
the logo is still shown.

When using DRM, this change has no effect because the code will reach
the SCROLL_REDRAW case immediately anyway.

But if you run an accelerated fbdev driver and have
FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION enabled, console scrolling is
slowed down by factors so that it feels as if you use a 9600 baud
terminal.

So, drop those unnecessary checks and speed up fbdev console
acceleration during bootup.

Cc: stable@vger.kernel.org # v5.10+
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYxk7wsBPx3po+@p100
2022-06-20 12:12:23 +02:00
Daniel Vetter
0f95ee9a0c Merge tag 'drm-misc-next-2022-06-08' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for 5.20:

UAPI Changes:

 * connector: export bpc limits in debugfs

 * dma-buf: Print buffer name in debugfs

Cross-subsystem Changes:

 * dma-buf: Improve dma-fence handling; Cleanups

 * fbdev: Device-unregistering fixes

Core Changes:

 * client: Only use driver-validated modes to avoid blank screen

 * dp-aux: Make probing more reliable; Small fixes

 * edit: CEA data-block iterators; Introduce struct drm_edid; Many cleanups

 * gem: Don't use framebuffer format's non-exising color planes

 * probe-helper: Use 640x480 as DisplayPort fallback; Refactoring

 * scheduler: Don't kill jobs in interrupt context

Driver Changes:

 * amdgpu: Use atomic fence helpers in DM; Fix VRAM address calculation;
   Export CRTC bpc settings via debugfs

 * bridge: Add TI-DLPC3433;  anx7625: Fixes;  fy07024di26a30d: Optional
   GPIO reset;  icn6211: Cleanups;  ldb: Add reg and reg-name properties
   to bindings, Kconfig fixes;  lt9611: Fix display sensing;  lt9611uxc:
   Fixes;  nwl-dsi: Fixes;  ps8640: Cleanups;  st7735r: Fixes;  tc358767:
   DSI/DPI refactoring and DSI-to-eDP support, Fixes; ti-sn65dsi83:
   Fixes;

 * gma500: Cleanup connector I2C handling

 * hyperv: Unify VRAM allocation of Gen1 and Gen2

 * i915: export CRTC bpc settings via debugfs

 * meson: Support YUV422 output; Refcount fixes

 * mgag200: Support damage clipping; Support gamma handling; Protect
   concurrent HW access; Fixes to connector; Store model-specific limits
   in device-info structure; Cleanups

 * nouveau: Fixes and Cleanups

 * panel: Kconfig fixes

 * panfrost: Valhall support

 * r128: Fix bit-shift overflow

 * rockchip: Locking fixes in error path; Minor cleanups

 * ssd130x: Fix built-in linkage

 * ttm: Cleanups

 * udl; Always advertize VGA connector

 * fbdev/vesa: Support COMPILE_TEST

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YqBtumw05JZDEZE2@linux-uq9g
2022-06-15 19:12:17 +02:00
Javier Martinez Canillas
873eb3b118 fbdev: Disable sysfb device registration when removing conflicting FBs
The platform devices registered by sysfb match with firmware-based DRM or
fbdev drivers, that are used to have early graphics using a framebuffer
provided by the system firmware.

DRM or fbdev drivers later are probed and remove conflicting framebuffers,
leading to these platform devices for generic drivers to be unregistered.

But the current solution has a race, since the sysfb_init() function could
be called after a DRM or fbdev driver is probed and request to unregister
the devices for drivers with conflicting framebuffes.

To prevent this, disable any future sysfb platform device registration by
calling sysfb_disable(), if a driver requests to remove the conflicting
framebuffers.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220607182338.344270-4-javierm@redhat.com
2022-06-09 16:20:12 +02:00
Geert Uytterhoeven
514c62048b fbcon: Remove obsolete reference to initmem_freed
initmem_freed was removed in v2.1.124, and the underlying issue was
fixed for good in commit 92b004d1aa ("video/logo: prevent use of
logos after they have been freed").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/b8b9147a48e233fe32e072f2085c7b413cd92a00.1654702835.git.geert+renesas@glider.be
2022-06-08 18:29:45 +02:00
Linus Torvalds
2518f226c6 Merge tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie:
 "Intel have enabled DG2 on certain SKUs for laptops, AMD has started
  some new GPU support, msm has user allocated VA controls

  dma-buf:
   - add dma_resv_replace_fences
   - add dma_resv_get_singleton
   - make dma_excl_fence private

  core:
   - EDID parser refactorings
   - switch drivers to drm_mode_copy/duplicate
   - DRM managed mutex initialization

  display-helper:
   - put HDMI, SCDC, HDCP, DSC and DP into new module

  gem:
   - rework fence handling

  ttm:
   - rework bulk move handling
   - add common debugfs for resource managers
   - convert to kvcalloc

  format helpers:
   - support monochrome formats
   - RGB888, RGB565 to XRGB8888 conversions

  fbdev:
   - cfb/sys_imageblit fixes
   - pagelist corruption fix
   - create offb platform device
   - deferred io improvements

  sysfb:
   - Kconfig rework
   - support for VESA mode selection

  bridge:
   - conversions to devm_drm_of_get_bridge
   - conversions to panel_bridge
   - analogix_dp - autosuspend support
   - it66121 - audio support
   - tc358767 - DSI to DPI support
   - icn6211 - PLL/I2C fixes, DT property
   - adv7611 - enable DRM_BRIDGE_OP_HPD
   - anx7625 - fill ELD if no monitor
   - dw_hdmi - add audio support
   - lontium LT9211 support, i.MXMP LDB
   - it6505: Kconfig fix, DPCD set power fix
   - adv7511 - CEC support for ADV7535

  panel:
   - ltk035c5444t, B133UAN01, NV3052C panel support
   - DataImage FG040346DSSWBG04 support
   - st7735r - DT bindings fix
   - ssd130x - fixes

  i915:
   - DG2 laptop PCI-IDs ("motherboard down")
   - Initial RPL-P PCI IDs
   - compute engine ABI
   - DG2 Tile4 support
   - DG2 CCS clear color compression support
   - DG2 render/media compression formats support
   - ATS-M platform info
   - RPL-S PCI IDs added
   - Bump ADL-P DMC version to v2.16
   - Support static DRRS
   - Support multiple eDP/LVDS native mode refresh rates
   - DP HDR support for HSW+
   - Lots of display refactoring + fixes
   - GuC hwconfig support and query
   - sysfs support for multi-tile
   - fdinfo per-client gpu utilisation
   - add geometry subslices query
   - fix prime mmap with LMEM
   - fix vm open count and remove vma refcounts
   - contiguous allocation fixes
   - steered register write support
   - small PCI BAR enablement
   - GuC error capture support
   - sunset igpu legacy mmap support for newer devices
   - GuC version 70.1.1 support

  amdgpu:
   - Initial SoC21 support
   - SMU 13.x enablement
   - SMU 13.0.4 support
   - ttm_eu cleanups
   - USB-C, GPUVM updates
   - TMZ fixes for RV
   - RAS support for VCN
   - PM sysfs code cleanup
   - DC FP rework
   - extend CG/PG flags to 64-bit
   - SI dpm lockdep fix
   - runtime PM fixes

  amdkfd:
   - RAS/SVM fixes
   - TLB flush fixes
   - CRIU GWS support
   - ignore bogus MEC signals more efficiently

  msm:
   - Fourcc modifier for tiled but not compressed layouts
   - Support for userspace allocated IOVA (GPU virtual address)
   - DPU: DSC (Display Stream Compression) support
   - DP: eDP support
   - DP: conversion to use drm_bridge and drm_bridge_connector
   - Merge DPU1 and MDP5 MDSS driver
   - DPU: writeback support

  nouveau:
   - make some structures static
   - make some variables static
   - switch to drm_gem_plane_helper_prepare_fb

  radeon:
   - misc fixes/cleanups

  mxsfb:
   - rework crtc mode setting
   - LCDIF CRC support

  etnaviv:
   - fencing improvements
   - fix address space collisions
   - cleanup MMU reference handling

  gma500:
   - GEM/GTT improvements
   - connector handling fixes

  komeda:
   - switch to plane reset helper

  mediatek:
   - MIPI DSI improvements

  omapdrm:
   - GEM improvements

  qxl:
   - aarch64 support

  vc4:
   - add a CL submission tracepoint
   - HDMI YUV support
   - HDMI/clock improvements
   - drop is_hdmi caching

  virtio:
   - remove restriction of non-zero blob types

  vmwgfx:
   - support for cursormob and cursorbypass 4
   - fence improvements

  tidss:
   - reset DISPC on startup

  solomon:
   - SPI support
   - DT improvements

  sun4i:
   - allwinner D1 support
   - drop is_hdmi caching

  imx:
   - use swap() instead of open-coding
   - use devm_platform_ioremap_resource
   - remove redunant initializations

  ast:
   - Displayport support

  rockchip:
   - Refactor IOMMU initialisation
   - make some structures static
   - replace drm_detect_hdmi_monitor with drm_display_info.is_hdmi
   - support swapped YUV formats,
   - clock improvements
   - rk3568 support
   - VOP2 support

  mediatek:
   - MT8186 support

  tegra:
   - debugabillity improvements"

* tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drm: (1740 commits)
  drm/i915/dsi: fix VBT send packet port selection for ICL+
  drm/i915/uc: Fix undefined behavior due to shift overflowing the constant
  drm/i915/reg: fix undefined behavior due to shift overflowing the constant
  drm/i915/gt: Fix use of static in macro mismatch
  drm/i915/audio: fix audio code enable/disable pipe logging
  drm/i915: Fix CFI violation with show_dynamic_id()
  drm/i915: Fix 'mixing different enum types' warnings in intel_display_power.c
  drm/i915/gt: Fix build error without CONFIG_PM
  drm/msm/dpu: handle pm_runtime_get_sync() errors in bind path
  drm/msm/dpu: add DRM_MODE_ROTATE_180 back to supported rotations
  drm/msm: don't free the IRQ if it was not requested
  drm/msm/dpu: limit writeback modes according to max_linewidth
  drm/amd: Don't reset dGPUs if the system is going to s2idle
  drm/amdgpu: Unmap legacy queue when MES is enabled
  drm: msm: fix possible memory leak in mdp5_crtc_cursor_set()
  drm/msm: Fix fb plane offset calculation
  drm/msm/a6xx: Fix refcount leak in a6xx_gpu_init
  drm/msm/dsi: don't powerup at modeset time for parade-ps8640
  drm/rockchip: Change register space names in vop2
  dt-bindings: display: rockchip: make reg-names mandatory for VOP2
  ...
2022-05-25 16:18:27 -07:00
Dave Airlie
00df0514ab Merge tag 'amd-drm-next-5.19-2022-05-18' of https://gitlab.freedesktop.org/agd5f/linux into drm-next
amd-drm-next-5.19-2022-05-18:

amdgpu:
- Misc code cleanups
- Additional SMU 13.x enablement
- Smartshift fixes
- GFX11 fixes
- Support for SMU 13.0.4
- SMU mutex fix
- Suspend/resume fix

amdkfd:
- static checker fix
- Doorbell/MMIO resource handling fix

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220518205621.5741-1-alexander.deucher@amd.com
2022-05-19 14:09:54 +10:00
Javier Martinez Canillas
3367aa7d74 fbdev: Restart conflicting fb removal loop when unregistering devices
Drivers that want to remove registered conflicting framebuffers prior to
register their own framebuffer, call to remove_conflicting_framebuffers().

This function takes the registration_lock mutex, to prevent a race when
drivers register framebuffer devices. But if a conflicting framebuffer
device is found, the underlaying platform device is unregistered and this
will lead to the platform driver .remove callback to be called. Which in
turn will call to unregister_framebuffer() that takes the same lock.

To prevent this, a struct fb_info.forced_out field was used as indication
to unregister_framebuffer() whether the mutex has to be grabbed or not.

But this could be unsafe, since the fbdev core is making assumptions about
what drivers may or may not do in their .remove callbacks. Allowing to run
these callbacks with the registration_lock held can cause deadlocks, since
the fbdev core has no control over what drivers do in their removal path.

A better solution is to drop the lock before platform_device_unregister(),
so unregister_framebuffer() can take it when called from the fbdev driver.
The lock is acquired again after the device has been unregistered and at
this point the removal loop can be restarted.

Since the conflicting framebuffer device has already been removed, the
loop would just finish when no more conflicting framebuffers are found.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220511113039.1252432-1-javierm@redhat.com
2022-05-13 13:48:28 +02:00
Daniel Vetter
89bfd4017e fbdev: Prevent possible use-after-free in fb_release()
Most fbdev drivers have issues with the fb_info lifetime, because call to
framebuffer_release() from their driver's .remove callback, rather than
doing from fbops.fb_destroy callback.

Doing that will destroy the fb_info too early, while references to it may
still exist, leading to a use-after-free error.

To prevent this, check the fb_info reference counter when attempting to
kfree the data structure in framebuffer_release(). That will leak it but
at least will prevent the mentioned error.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220505220413.365977-1-javierm@redhat.com
2022-05-06 09:21:20 +02:00
Javier Martinez Canillas
135332f34b Revert "fbdev: Make fb_release() return -ENODEV if fbdev was unregistered"
This reverts commit aafa025c76. That commit
attempted to fix a NULL pointer dereference, caused by the struct fb_info
associated with a framebuffer device to not longer be valid when the file
descriptor was closed.

The issue was exposed by commit 27599aacba ("fbdev: Hot-unplug firmware
fb devices on forced removal"), which added a new path that goes through
the struct device removal instead of directly unregistering the fb.

Most fbdev drivers have issues with the fb_info lifetime, because call to
framebuffer_release() from their driver's .remove callback, rather than
doing from fbops.fb_destroy callback. This meant that due to this switch,
the fb_info was now destroyed too early, while references still existed,
while before it was simply leaked.

The patch we're reverting here reinstated that leak, hence "fixed" the
regression. But the proper solution is to fix the drivers to not release
the fb_info too soon.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220504115917.758787-1-javierm@redhat.com
2022-05-06 09:19:02 +02:00
Alex Deucher
26817fb7b0 Revert "fbdev: fbmem: add a helper to determine if an aperture is used by a fw fb"
This reverts commit 9a45ac2320.

This was added a helper for amdgpu to workaround a runtime pm regression
caused by a runtime pm fix in efifb.  We now have a better workaround
in amdgpu in
commit f95af4a923 ("drm/amdgpu: don't runtime suspend if there are displays attached (v3)")
so this workaround is no longer necessary.  Since amdgpu was the only
user of this interface, we can remove it.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2022-05-05 16:50:08 -04:00
Javier Martinez Canillas
aafa025c76 fbdev: Make fb_release() return -ENODEV if fbdev was unregistered
A reference to the framebuffer device struct fb_info is stored in the file
private data, but this reference could no longer be valid and must not be
accessed directly. Instead, the file_fb_info() accessor function must be
used since it does sanity checking to make sure that the fb_info is valid.

This can happen for example if the registered framebuffer device is for a
driver that just uses a framebuffer provided by the system firmware. In
that case, the fbdev core would unregister the framebuffer device when a
real video driver is probed and ask to remove conflicting framebuffers.

The bug has been present for a long time but commit 27599aacba ("fbdev:
Hot-unplug firmware fb devices on forced removal") unmasked it since the
fbdev core started unregistering the framebuffers' devices associated.

Fixes: 27599aacba ("fbdev: Hot-unplug firmware fb devices on forced removal")
Reported-by: Maxime Ripard <maxime@cerno.tech>
Reported-by: Junxiao Chang <junxiao.chang@intel.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220502135014.377945-1-javierm@redhat.com
2022-05-03 17:24:51 +02:00