On 7/21/2026 5:56 PM, Maarten Lankhorst wrote:
Hey,

On 7/21/26 14:10, Thomas Hellström wrote:
Hi, Maarten,

On Tue, 2026-07-21 at 13:46 +0200, Maarten Lankhorst wrote:
Hey,

Can I merge this through drm-misc-next together with the rest of the
series?

Kind regards
~Maarten
For the xe patches, Ack from me.

I do have a v8 that fixes a sashiko comment on the last patch, though,
but I was holding that awaiting a review on the other patches.
Yeah seems about right. Patches themselves look good to me now, so would be 
nice if amd can ack here or in v8.
I have already sent my Reviewed-by for this patch.
Reviewed-by: Arunpravin Paneer Selvam <[email protected]>

Thanks,
Arun.

Series themselves look good, so feel free to add my r-b to entire series: (and 
Thadeu's t-b)

Reviewed-By: Maarten Lankhorst <[email protected]>

Thanks,
Thomas



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;

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