Hey, Can I merge this through drm-misc-next together with the rest of the series?
Kind regards ~Maarten On 7/7/26 20:05, Arunpravin Paneer Selvam wrote: > > > On 7/3/2026 6:38 PM, Christian König wrote: >> Arun please take a look at this. > Sure Christian. This fix looks correct to me. > Reviewed-by: Arunpravin Paneer Selvam <[email protected]> > > Thanks, > Arun. >> >> Thanks, >> Christian. >> >> On 7/3/26 15:05, Thomas Hellström wrote: >>> drmm_cgroup_register_region() is called before INIT_LIST_HEAD() and >>> gpu_buddy_init() in amdgpu_vram_mgr_init(). If it fails, the function >>> returns early and bypasses those initializations. >>> >>> Since adev->mman.initialized is set to true before amdgpu_vram_mgr_init() >>> is called, a failure triggers amdgpu_ttm_fini(), which calls >>> amdgpu_vram_mgr_fini(), which then: >>> >>> - Calls list_for_each_entry_safe() on reservations_pending and >>> reserved_pages, whose list_head::next pointers are zero-initialized >>> (NULL). The loop does not recognize them as empty and dereferences NULL. >>> >>> - Calls gpu_buddy_fini(), which iterates free_trees[] unconditionally >>> via for_each_free_tree(). Since mm->free_trees is NULL >>> (never allocated), this dereferences NULL. >>> >>> Both result in a kernel panic on the module load error path. >>> >>> Fix by moving drmm_cgroup_register_region() to after the list and buddy >>> allocator are fully initialized, so the teardown path is safe to run. >>> >>> Reported-by: Sashiko-bot <[email protected]> >>> Closes: >>> https://sashiko.dev/#/patchset/[email protected]?part=4 >>> Fixes: 2b624a2c1865 ("drm/ttm: Handle cgroup based eviction in TTM") >>> Cc: Friedrich Vock <[email protected]> >>> Cc: Maarten Lankhorst <[email protected]> >>> Cc: Tejun Heo <[email protected]> >>> Cc: Maxime Ripard <[email protected]> >>> Cc: Christian König <[email protected]> >>> Cc: Alex Deucher <[email protected]> >>> Cc: [email protected] >>> Cc: [email protected] >>> Cc: <[email protected]> # v6.14+ >>> Assisted-by: GitHub_Copilot:claude-sonnet-4.6 >>> Signed-off-by: Thomas Hellström <[email protected]> >>> --- >>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 7 ++++--- >>> 1 file changed, 4 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> index 2a241a5b12c4..ac3f71d77140 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> @@ -918,9 +918,6 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev) >>> struct ttm_resource_manager *man = &mgr->manager; >>> int err; >>> - man->cg = drmm_cgroup_register_region(adev_to_drm(adev), "vram", >>> adev->gmc.real_vram_size); >>> - if (IS_ERR(man->cg)) >>> - return PTR_ERR(man->cg); >>> ttm_resource_manager_init(man, &adev->mman.bdev, >>> adev->gmc.real_vram_size); >>> @@ -935,6 +932,10 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev) >>> if (err) >>> return err; >>> + man->cg = drmm_cgroup_register_region(adev_to_drm(adev), "vram", >>> adev->gmc.real_vram_size); >>> + if (IS_ERR(man->cg)) >>> + return PTR_ERR(man->cg); >>> + >>> ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager); >>> ttm_resource_manager_set_used(man, true); >>> return 0; >
