kernel/linux.git/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c, branch v6.6.132

drm/amdgpu: Fix NULL pointer dereference in VRAM logic for APU devices

2025-11-24T09:29:57+00:00

[ Upstream commit 883f309add55060233bf11c1ea6947140372920f ] Previously, APU platforms (and other scenarios with uninitialized VRAM managers) triggered a NULL pointer dereference in `ttm_resource_manager_usage()`. The root cause is not that the `struct ttm_resource_manager *man` pointer itself is NULL, but that `man->bdev` (the backing device pointer within the manager) remains uninitialized (NULL) on APUs—since APUs lack dedicated VRAM and do not fully set up VRAM manager structures. When `ttm_resource_manager_usage()` attempts to acquire `man->bdev->lru_lock`, it dereferences the NULL `man->bdev`, leading to a kernel OOPS. 1. **amdgpu_cs.c**: Extend the existing bandwidth control check in `amdgpu_cs_get_threshold_for_moves()` to include a check for `ttm_resource_manager_used()`. If the manager is not used (uninitialized `bdev`), return 0 for migration thresholds immediately—skipping VRAM-specific logic that would trigger the NULL dereference. 2. **amdgpu_kms.c**: Update the `AMDGPU_INFO_VRAM_USAGE` ioctl and memory info reporting to use a conditional: if the manager is used, return the real VRAM usage; otherwise, return 0. This avoids accessing `man->bdev` when it is NULL. 3. **amdgpu_virt.c**: Modify the vf2pf (virtual function to physical function) data write path. Use `ttm_resource_manager_used()` to check validity: if the manager is usable, calculate `fb_usage` from VRAM usage; otherwise, set `fb_usage` to 0 (APUs have no discrete framebuffer to report). This approach is more robust than APU-specific checks because it: - Works for all scenarios where the VRAM manager is uninitialized (not just APUs), - Aligns with TTM's design by using its native helper function, - Preserves correct behavior for discrete GPUs (which have fully initialized `man->bdev` and pass the `ttm_resource_manager_used()` check). v4: use ttm_resource_manager_used(&adev->mman.vram_mgr.manager) instead of checking the adev->gmc.is_app_apu flag (Christian) Reviewed-by: Christian König Suggested-by: Lijo Lazar Signed-off-by: Jesse Zhang Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: reject gang submissions under SRIOV

2025-11-24T09:29:39+00:00

[ Upstream commit d7ddcf921e7d0d8ebe82e89635bc9dc26ba9540d ] Gang submission means that the kernel driver guarantees that multiple submissions are executed on the HW at the same time on different engines. Background is that those submissions then depend on each other and each can't finish stand alone. SRIOV now uses world switch to preempt submissions on the engines to allow sharing the HW resources between multiple VFs. The problem is now that the SRIOV world switch can't know about such inter dependencies and will cause a timeout if it waits for a partially running gang submission. To conclude SRIOV and gang submissions are fundamentally incompatible at the moment. For now just disable them. Signed-off-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: Use memdup_array_user in amdgpu_cs_wait_fences_ioctl

2025-11-24T09:29:38+00:00

[ Upstream commit dea75df7afe14d6217576dbc28cc3ec1d1f712fb ] Replace kmalloc_array() + copy_from_user() with memdup_array_user(). This shrinks the source code and improves separation between the kernel and userspace slabs. Signed-off-by: Tvrtko Ursulin Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: prevent BO_HANDLES error from being overwritten

2024-10-22T13:46:28+00:00

commit c0ec082f10b7a1fd25e8c1e2a686440da913b7a3 upstream. Before this patch, if multiple BO_HANDLES chunks were submitted, the error -EINVAL would be correctly set but could be overwritten by the return value from amdgpu_cs_p1_bo_handles(). This patch ensures that if there are multiple BO_HANDLES, we stop. Fixes: fec5f8e8c6bc ("drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit") Signed-off-by: Mohammed Anees Reviewed-by: Christian König Signed-off-by: Pierre-Eric Pelloux-Prayer Signed-off-by: Alex Deucher (cherry picked from commit 40f2cd98828f454bdc5006ad3d94330a5ea164b7) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit

2024-10-10T09:57:32+00:00

[ Upstream commit fec5f8e8c6bcf83ed7a392801d7b44c5ecfc1e82 ] Before this commit, only submits with both a BO_HANDLES chunk and a 'bo_list_handle' would be rejected (by amdgpu_cs_parser_bos). But if UMD sent multiple BO_HANDLES, what would happen is: * only the last one would be really used * all the others would leak memory as amdgpu_cs_p1_bo_handles would overwrite the previous p->bo_list value This commit rejects submissions with multiple BO_HANDLES chunks to match the implementation of the parser. Signed-off-by: Pierre-Eric Pelloux-Prayer Reviewed-by: Christian König Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: reject gang submit on reserved VMIDs

2024-09-12T09:11:37+00:00

[ Upstream commit 320debca1ba3a81c87247eac84eff976ead09ee0 ] A gang submit won't work if the VMID is reserved and we can't flush out VM changes from multiple engines at the same time. Signed-off-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/amdgpu: command submission parser for JPEG

2024-08-29T15:33:44+00:00

[ Upstream commit 470516c2925493594a690bc4d05b1f4471d9f996 ] Add JPEG IB command parser to ensure registers in the command are within the JPEG IP block. Reviewed-by: Alex Deucher Signed-off-by: David (Ming Qiang) Wu Signed-off-by: Alex Deucher (cherry picked from commit a7f670d5d8e77b092404ca8a35bb0f8f89ed3117) Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

drm/amdgpu: fix visible VRAM handling during faults

2024-05-02T14:32:41+00:00

[ Upstream commit a6ff969fe9cbf369e3cd0ac54261fec1122682ec ] When we removed the hacky start code check we actually didn't took into account that *all* VRAM pages needs to be CPU accessible. Clean up the code and unify the handling into a single helper which checks if the whole resource is CPU accessible. The only place where a partial check would make sense is during eviction, but that is neglitible. Signed-off-by: Christian König Fixes: aed01a68047b ("drm/amdgpu: Remove TTM resource->start visible VRAM condition v2") Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher CC: stable@vger.kernel.org Signed-off-by: Sasha Levin

drm/amdgpu: correct chunk_ptr to a pointer to chunk.

2023-12-13T17:45:01+00:00

[ Upstream commit 50d51374b498457c4dea26779d32ccfed12ddaff ] The variable "chunk_ptr" should be a pointer pointing to a struct drm_amdgpu_cs_chunk instead of to a pointer of that. Signed-off-by: YuanShang Reviewed-by: Christian König Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: lower CS errors to debug severity

2023-11-28T17:20:17+00:00

commit 17daf01ab4e3e5a5929747aa05cc15eb2bad5438 upstream. Otherwise userspace can spam the logs by using incorrect input values. Signed-off-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman