[drm-misc-next,v3,0/4] Fixes for vc4 hotplug rework

Message

Danilo Krummrich Aug. 24, 2022, 4:13 p.m. UTC

Hi,

I've found a few potential issues left after the hotplug rework.

In vc4_hdmi.c we're missing two mutex_unlock() calls when the device is
unplugged.

vc4_crtc and vc4_plane seem to miss some drm_dev_enter()/drm_dev_exit() calls
to protect against resource access after the device/driver is unbound, but the
DRM potentially isn't freed yet and userspace can still call into the driver.

Changes in v2:
  - Use drm_device pointer from struct drm_plane (Maxime)
  - Protect entire functions to increase readability (Maxime)
  - Add another patch to fix an uncovered MMIO access in vc4_hvs.c

Changes in v3:
  - vc4_plane: Actually protect entire functions to increase readability (Maxime)

Danilo Krummrich (4):
  drm/vc4: hdmi: unlock mutex when device is unplugged
  drm/vc4: plane: protect device resources after removal
  drm/vc4: crtc: protect device resources after removal
  drm/vc4: hvs: protect drm_print_regset32()

 drivers/gpu/drm/vc4/vc4_crtc.c  | 41 ++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/vc4/vc4_hdmi.c  |  7 ++++--
 drivers/gpu/drm/vc4/vc4_hvs.c   |  4 ++--
 drivers/gpu/drm/vc4/vc4_plane.c | 20 ++++++++++++++++
 4 files changed, 67 insertions(+), 5 deletions(-)


base-commit: 4d07b0bc403403438d9cf88450506240c5faf92f

Comments

Maxime Ripard Aug. 25, 2022, 7:47 a.m. UTC | #1

On Wed, 24 Aug 2022 18:13:23 +0200, Danilo Krummrich wrote:
> I've found a few potential issues left after the hotplug rework.
> 
> In vc4_hdmi.c we're missing two mutex_unlock() calls when the device is
> unplugged.
> 
> vc4_crtc and vc4_plane seem to miss some drm_dev_enter()/drm_dev_exit() calls
> to protect against resource access after the device/driver is unbound, but the
> DRM potentially isn't freed yet and userspace can still call into the driver.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime