RE: [RESEND 1/1] drm/buddy: release free_trees array on buddy mm teardown

["Michał Grzelak" <michal.grzelak@intel.com>]

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On Fri, 19 Dec 2025, Lin, Shuicheng wrote:
> On Fri, Dec 19, 2025 11:33 AM Michał Grzelak wrote:
>> During initialization of DRM buddy memory manager at drm_buddy_init,
>> mm->free_trees array is allocated for both clear and dirty RB trees.
>> During cleanup happening at drm_buddy_fini it is never freed, leading to
>> following memory leaks observed on xe module load & unload cycles:
>>
>>     kmemleak_alloc+0x4a/0x90
>>     __kmalloc_cache_noprof+0x488/0x800
>>     drm_buddy_init+0xc2/0x330 [drm_buddy]
>>     __xe_ttm_vram_mgr_init+0xc3/0x190 [xe]
>>     xe_ttm_stolen_mgr_init+0xf5/0x9d0 [xe]
>>     xe_device_probe+0x326/0x9e0 [xe]
>>     xe_pci_probe+0x39a/0x610 [xe]
>>     local_pci_probe+0x47/0xb0
>>     pci_device_probe+0xf3/0x260
>>     really_probe+0xf1/0x3c0
>>     __driver_probe_device+0x8c/0x180
>>     driver_probe_device+0x24/0xd0
>>     __driver_attach+0x10f/0x220
>>     bus_for_each_dev+0x7f/0xe0
>>     driver_attach+0x1e/0x30
>>     bus_add_driver+0x151/0x290
>>
>> Deallocate array for free trees when cleaning up buddy memory manager in
>> the same way as if going through out_free_tree label.
>>
>> Fixes: d4cd665c98c1 ("drm/buddy: Separate clear and dirty free block trees")
>> Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
>> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
>> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
>
> I also meet this issue. And the fix LGTM. It has the same logic as the failure path of drm_buddy_init().
> Reviewed-by: Shuicheng Lin <shuicheng.lin@intel.com>

Thank you Shuicheng for the review and confirmation. Will update the
commit message along your R-B in next round of resend.

BTW, do you have any recommendation regarding the tree via which this
change should be merged? Asking since I don't have the commit bit to any
of drm-* trees.

BR,
Michał