user/sven/linux.git/include/drm, branch v5.15.197

drm/gem: Fix race in drm_gem_handle_create_tail()

2025-07-17T16:30:49Z

commit bd46cece51a36ef088f22ef0416ac13b0a46d5b0 upstream. Object creation is a careful dance where we must guarantee that the object is fully constructed before it is visible to other threads, and GEM buffer objects are no difference. Final publishing happens by calling drm_gem_handle_create(). After that the only allowed thing to do is call drm_gem_object_put() because a concurrent call to the GEM_CLOSE ioctl with a correctly guessed id (which is trivial since we have a linear allocator) can already tear down the object again. Luckily most drivers get this right, the very few exceptions I've pinged the relevant maintainers for. Unfortunately we also need drm_gem_handle_create() when creating additional handles for an already existing object (e.g. GETFB ioctl or the various bo import ioctl), and hence we cannot have a drm_gem_handle_create_and_put() as the only exported function to stop these issues from happening. Now unfortunately the implementation of drm_gem_handle_create() isn't living up to standards: It does correctly finishe object initialization at the global level, and hence is safe against a concurrent tear down. But it also sets up the file-private aspects of the handle, and that part goes wrong: We fully register the object in the drm_file.object_idr before calling drm_vma_node_allow() or obj->funcs->open, which opens up races against concurrent removal of that handle in drm_gem_handle_delete(). Fix this with the usual two-stage approach of first reserving the handle id, and then only registering the object after we've completed the file-private setup. Jacek reported this with a testcase of concurrently calling GEM_CLOSE on a freshly-created object (which also destroys the object), but it should be possible to hit this with just additional handles created through import or GETFB without completed destroying the underlying object with the concurrent GEM_CLOSE ioctl calls. Note that the close-side of this race was fixed in f6cd7daecff5 ("drm: Release driver references to handle before making it available again"), which means a cool 9 years have passed until someone noticed that we need to make this symmetry or there's still gaps left :-/ Without the 2-stage close approach we'd still have a race, therefore that's an integral part of this bugfix. More importantly, this means we can have NULL pointers behind allocated id in our drm_file.object_idr. We need to check for that now: - drm_gem_handle_delete() checks for ERR_OR_NULL already - drm_gem.c:object_lookup() also chekcs for NULL - drm_gem_release() should never be called if there's another thread still existing that could call into an IOCTL that creates a new handle, so cannot race. For paranoia I added a NULL check to drm_gem_object_release_handle() though. - most drivers (etnaviv, i915, msm) are find because they use idr_find(), which maps both ENOENT and NULL to NULL. - drivers using idr_for_each_entry() should also be fine, because idr_get_next does filter out NULL entries and continues the iteration. - The same holds for drm_show_memory_stats(). v2: Use drm_WARN_ON (Thomas) Reported-by: Jacek Lawrynowicz Tested-by: Jacek Lawrynowicz Reviewed-by: Thomas Zimmermann Cc: stable@vger.kernel.org Cc: Jacek Lawrynowicz Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Simona Vetter Signed-off-by: Simona Vetter Signed-off-by: Simona Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20250707151814.603897-1-simona.vetter@ffwll.ch Signed-off-by: Greg Kroah-Hartman

drm/sched: Increment job count before swapping tail spsc queue

2025-07-17T16:30:49Z

commit 8af39ec5cf2be522c8eb43a3d8005ed59e4daaee upstream. A small race exists between spsc_queue_push and the run-job worker, in which spsc_queue_push may return not-first while the run-job worker has already idled due to the job count being zero. If this race occurs, job scheduling stops, leading to hangs while waiting on the job’s DMA fences. Seal this race by incrementing the job count before appending to the SPSC queue. This race was observed on a drm-tip 6.16-rc1 build with the Xe driver in an SVM test case. Fixes: 1b1f42d8fde4 ("drm: move amd_gpu_scheduler into common location") Fixes: 27105db6c63a ("drm/amdgpu: Add SPSC queue to scheduler.") Cc: stable@vger.kernel.org Signed-off-by: Matthew Brost Reviewed-by: Jonathan Cavitt Link: https://lore.kernel.org/r/20250613212013.719312-1-matthew.brost@intel.com Signed-off-by: Greg Kroah-Hartman

drm/atomic: clarify the rules around drm_atomic_state->allow_modeset

2025-06-04T12:38:04Z

[ Upstream commit c5e3306a424b52e38ad2c28c7f3399fcd03e383d ] msm is automagically upgrading normal commits to full modesets, and that's a big no-no: - for one this results in full on->off->on transitions on all these crtc, at least if you're using the usual helpers. Which seems to be the case, and is breaking uapi - further even if the ctm change itself would not result in flicker, this can hide modesets for other reasons. Which again breaks the uapi v2: I forgot the case of adding unrelated crtc state. Add that case and link to the existing kerneldoc explainers. This has come up in an irc discussion with Manasi and Ville about intel's bigjoiner mode. Also cc everyone involved in the msm irc discussion, more people joined after I sent out v1. v3: Wording polish from Pekka and Thomas Acked-by: Pekka Paalanen Acked-by: Dmitry Baryshkov Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: Pekka Paalanen Cc: Rob Clark Cc: Simon Ser Cc: Manasi Navare Cc: Ville Syrjälä Cc: Abhinav Kumar Cc: Dmitry Baryshkov Signed-off-by: Simona Vetter Signed-off-by: Simona Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20250108172417.160831-1-simona.vetter@ffwll.ch Signed-off-by: Sasha Levin

drm/dp_mst: Fix drm RAD print

2025-04-10T12:31:58Z

[ Upstream commit 6bbce873a9c97cb12f5455c497be279ac58e707f ] [Why] The RAD of sideband message printed today is incorrect. For RAD stored within MST branch - If MST branch LCT is 1, it's RAD array is untouched and remained as 0. - If MST branch LCT is larger than 1, use nibble to store the up facing port number in cascaded sequence as illustrated below: u8 RAD[0] = (LCT_2_UFP << 4) | LCT_3_UFP RAD[1] = (LCT_4_UFP << 4) | LCT_5_UFP ... In drm_dp_mst_rad_to_str(), it wrongly to use BIT_MASK(4) to fetch the port number of one nibble. [How] Adjust the code by: - RAD array items are valuable only for LCT >= 1. - Use 0xF as the mask to replace BIT_MASK(4) V2: - Document how RAD is constructed (Imre) V3: - Adjust the comment for rad[] so kdoc formats it properly (Lyude) Fixes: 2f015ec6eab6 ("drm/dp_mst: Add sideband down request tracing + selftests") Cc: Imre Deak Cc: Ville Syrjälä Cc: Harry Wentland Cc: Lyude Paul Reviewed-by: Lyude Paul Signed-off-by: Wayne Lin Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20250113091100.3314533-2-Wayne.Lin@amd.com Signed-off-by: Sasha Levin

drm/probe-helper: Create a HPD IRQ event helper for a single connector

2025-03-13T11:50:48Z

[ Upstream commit 0464ed1a79b818d5e3eda1ac3c23a057ac0cc7c3 ] The drm_helper_hpd_irq_event() function is iterating over all the connectors when an hotplug event is detected. During that iteration, it will call each connector detect function and figure out if its status changed. Finally, if any connector changed, it will notify the user-space and the clients that something changed on the DRM device. This is supposed to be used for drivers that don't have a hotplug interrupt for individual connectors. However, drivers that can use an interrupt for a single connector are left in the dust and can either reimplement the logic used during the iteration for each connector or use that helper and iterate over all connectors all the time. Since both are suboptimal, let's create a helper that will only perform the status detection on a single connector. Signed-off-by: Maxime Ripard Reviewed-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210914101724.266570-2-maxime@cerno.tech Stable-dep-of: 666e19604641 ("drm/rockchip: cdn-dp: Use drm_connector_helper_hpd_irq_event()") Signed-off-by: Sasha Levin

drm/printer: Allow NULL data in devcoredump printer

2024-10-17T13:11:32Z

[ Upstream commit 53369581dc0c68a5700ed51e1660f44c4b2bb524 ] We want to determine the size of the devcoredump before writing it out. To that end, we will run the devcoredump printer with NULL data to get the size, alloc data based on the generated offset, then run the devcorecump again with a valid data pointer to print. This necessitates not writing data to the data pointer on the initial pass, when it is NULL. v5: - Better commit message (Jonathan) - Add kerenl doc with examples (Jani) Cc: Maarten Lankhorst Acked-by: Maarten Lankhorst Signed-off-by: Matthew Brost Reviewed-by: Jonathan Cavitt Link: https://patchwork.freedesktop.org/patch/msgid/20240801154118.2547543-3-matthew.brost@intel.com Signed-off-by: Sasha Levin

drm/mipi-dsi: use correct return type for the DSC functions

2024-06-16T11:39:30Z

[ Upstream commit de1c705c50326acaceaf1f02bc5bf6f267c572bd ] The functions mipi_dsi_compression_mode() and mipi_dsi_picture_parameter_set() return 0-or-error rather than a buffer size. Follow example of other similar MIPI DSI functions and use int return type instead of size_t. Fixes: f4dea1aaa9a1 ("drm/dsi: add helpers for DSI compression mode and PPS packets") Reviewed-by: Marijn Suijten Reviewed-by: Jessica Zhang Signed-off-by: Dmitry Baryshkov Link: https://patchwork.freedesktop.org/patch/msgid/20240408-lg-sw43408-panel-v5-2-4e092da22991@linaro.org Signed-off-by: Sasha Levin

drm-print: add drm_dbg_driver to improve namespace symmetry

2024-05-02T14:24:47Z

[ Upstream commit 95a77b6331c2d2313aa843fa77ec91cd092ab0e4 ] drm_print defines all of these: drm_dbg_{core,kms,prime,atomic,vbl,lease,_dp,_drmres} but not drm_dbg_driver itself, since it was the original drm_dbg. To improve namespace symmetry, change the drm_dbg defn to drm_dbg_driver, and redef grandfathered name to symmetric one. This will help with nouveau, which uses its own stack of macros to construct calls to dev_info, dev_dbg, etc, for which adaptation means drm_dbg_##driver constructs. Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220912052852.1123868-7-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman Stable-dep-of: a60ccade88f9 ("drm/vmwgfx: Fix crtc's atomic check conditional") Signed-off-by: Sasha Levin

drm/ttm: add ttm_resource_fini v2

2024-03-26T22:21:25Z

[ Upstream commit de3688e469b08be958914674e8b01cb0cea42388 ] Make sure we call the common cleanup function in all implementations of the resource manager. v2: fix missing case in i915, rudimentary kerneldoc, should be filled in more when we add more functionality Signed-off-by: Christian König Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20220124122514.1832-2-christian.koenig@amd.com Stable-dep-of: 89709105a609 ("drm/vmwgfx: fix a memleak in vmw_gmrid_man_get_node") Signed-off-by: Sasha Levin

drm: Don't treat 0 as -1 in drm_fixp2int_ceil

2024-03-26T22:21:25Z

[ Upstream commit cf8837d7204481026335461629b84ac7f4538fa5 ] Unit testing this in VKMS shows that passing 0 into this function returns -1, which is highly counter- intuitive. Fix it by checking whether the input is >= 0 instead of > 0. Fixes: 64566b5e767f ("drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil") Signed-off-by: Harry Wentland Reviewed-by: Simon Ser Reviewed-by: Melissa Wen Signed-off-by: Melissa Wen Link: https://patchwork.freedesktop.org/patch/msgid/20231108163647.106853-2-harry.wentland@amd.com Signed-off-by: Sasha Levin