kernel/linux.git/drivers/gpu/drm/drm_atomic.c, branch v6.6.132

drm/atomic: Fix potential use-after-free in nonblocking commits

2023-07-21T16:53:30+00:00

This requires a bit of background. Properly done a modeset driver's unload/remove sequence should be drm_dev_unplug(); drm_atomic_helper_shutdown(); drm_dev_put(); The trouble is that the drm_dev_unplugged() checks are by design racy, they do not synchronize against all outstanding ioctl. This is because those ioctl could block forever (both for modeset and for driver specific ioctls), leading to deadlocks in hotunplug. Instead the code sections that touch the hardware need to be annotated with drm_dev_enter/exit, to avoid accessing hardware resources after the unload/remove has finished. To avoid use-after-free issues all the involved userspace visible objects are supposed to hold a reference on the underlying drm_device, like drm_file does. The issue now is that we missed one, the atomic modeset ioctl can be run in a nonblocking fashion, and in that case it cannot rely on the implied drm_device reference provided by the ioctl calling context. This can result in a use-after-free if an nonblocking atomic commit is carefully raced against a driver unload. Fix this by unconditionally grabbing a drm_device reference for any drm_atomic_state structures. Strictly speaking this isn't required for blocking commits and TEST_ONLY calls, but it's the simpler approach. Thanks to shanzhulig for the initial idea of grabbing an unconditional reference, I just added comments, a condensed commit message and fixed a minor potential issue in where exactly we drop the final reference. Reported-by: shanzhulig Suggested-by: shanzhulig Reviewed-by: Maxime Ripard Cc: Maarten Lankhorst Cc: Thomas Zimmermann Cc: David Airlie Cc: stable@kernel.org Signed-off-by: Daniel Vetter Signed-off-by: Daniel Vetter Signed-off-by: Linus Torvalds

drm/connector: Print connector colorspace in state debugfs

2023-06-09T16:46:41+00:00

v3: Fix kerneldocs (kernel test robot) v4: Avoid returning NULL from drm_get_colorspace_name Signed-off-by: Harry Wentland Reviewed-by: Sebastian Wick Reviewed-by: Joshua Ashton Reviewed-by: Simon Ser Cc: Pekka Paalanen Cc: Sebastian Wick Cc: Vitaly.Prosyak@amd.com Cc: Uma Shankar Cc: Ville Syrjälä Cc: Joshua Ashton Cc: Jani Nikula Cc: Simon Ser Cc: Melissa Wen Cc: dri-devel@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org Signed-off-by: Alex Deucher

Merge remote-tracking branch 'drm/drm-next' into msm-next

2023-03-20T17:31:25+00:00

Merge drm-next into msm-next to pick up external clk and PM dependencies for improved a6xx GPU reset sequence. Signed-off-by: Rob Clark

drm: add helper functions to retrieve old and new crtc

2023-03-13T01:43:49+00:00

Add new helper functions, drm_atomic_get_old_crtc_for_encoder and drm_atomic_get_new_crtc_for_encoder to retrieve the corresponding crtc for the encoder. Signed-off-by: Sankeerth Billakanti Signed-off-by: Vinod Polimera Reviewed-by: Douglas Anderson Reviewed-by: Daniel Vetter Patchwork: https://patchwork.freedesktop.org/patch/524718/ Link: https://lore.kernel.org/r/1677774797-31063-2-git-send-email-quic_vpolimer@quicinc.com Signed-off-by: Dmitry Baryshkov

drm/connector: print max_requested_bpc in state debugfs

2023-03-07T20:55:18+00:00

This is useful to understand the bpc defaults and support of a driver. Signed-off-by: Harry Wentland Cc: Pekka Paalanen Cc: Sebastian Wick Cc: Vitaly.Prosyak@amd.com Cc: Uma Shankar Cc: Ville Syrjälä Cc: Joshua Ashton Cc: Jani Nikula Cc: dri-devel@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org Reviewed-By: Joshua Ashton Link: https://patchwork.freedesktop.org/patch/msgid/20230113162428.33874-3-harry.wentland@amd.com Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org

drm: use new debugfs device-centered functions on DRM core files

2022-12-22T17:58:21+00:00

Replace the use of drm_debugfs_create_files() with the new drm_debugfs_add_files() function in all DRM core files, centering the debugfs files management on the drm_device instead of drm_minor. Signed-off-by: Maíra Canal Reviewed-by: Maxime Ripard Reviewed-by: Melissa Wen Acked-by: Daniel Vetter Signed-off-by: Maíra Canal Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-3-mcanal@igalia.com

drm/atomic: Constify the old/new state accessors

2022-11-28T10:46:50+00:00

The drm_atomic_get_(old|new)_*_state don't modify the passed drm_atomic_state, so we can make it const. Reviewed-by: Javier Martinez Canillas Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20221123-rpi-kunit-tests-v1-9-051a0bb60a16@cerno.tech

drm: Drop drm_blend.h from drm_crtc.h

2022-06-20T20:53:55+00:00

drm_crtc.h has no need for drm_blend.h, so don't include it. Avoids useless rebuilds of the entire universe when touching drm_blend.h. Quite a few placs do currently depend on drm_blend.h without actually including it directly. All of those need to be fixed up. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220613200317.11305-4-ville.syrjala@linux.intel.com Acked-by: Sam Ravnborg Acked-by: Jani Nikula

drm: Drop drm_framebuffer.h from drm_crtc.h

2022-06-20T20:53:55+00:00

drm_crtc.h has no need for drm_frambuffer.h, so don't include it. Avoids useless rebuilds of the entire universe when touching drm_framebuffer.h. Quite a few placs do currently depend on drm_framebuffer.h without actually including it directly. All of those need to be fixed up. v2: Fix up msm some more v2: Deal with ingenic and shmobile as well Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220614095449.29311-1-ville.syrjala@linux.intel.com Acked-by: Sam Ravnborg Acked-by: Jani Nikula

drm/atomic: Add atomic_print_state to private objects

2022-03-31T08:19:45+00:00

A number of drivers (amdgpu, komeda, vc4, etc.) leverage the drm_private_state structure, but we don't have any infrastructure to provide debugging like we do for the other components state. Let's add an atomic_print_state hook to be consistent. Reviewed-by: Daniel Vetter Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220328124304.2309418-3-maxime@cerno.tech