[PATCH] drm/amdgpu: fix userq resource double freed

[Liang, Prike]

[AMD Official Use Only - AMD Internal Distribution Only]

> From: Koenig, Christian <Christian.Koenig at amd.com>
> Sent: Wednesday, May 14, 2025 3:02 PM
> To: Liang, Prike <Prike.Liang at amd.com>; amd-gfx at lists.freedesktop.org
> Cc: Deucher, Alexander <Alexander.Deucher at amd.com>
> Subject: Re: [PATCH] drm/amdgpu: fix userq resource double freed
>
> On 5/12/25 09:30, Prike Liang wrote:
> > As the userq resource was already freed at the drm_release early
> > phase, it should avoid freeing userq resource again at the later kms
> > postclose callback.
>
> Clear NAK. You are just hiding a bug.
>
> The userq resources should always be only cleaned up here and that function
> can't be called twice.
The original issue is that the userq resource is freed first at amdgpu_drm_release(), and then second freed at amdgpu_driver_postclose_km().
At this point, it's more reasonable to remove the userq resource cleanup at drm file release phase and just keep freeing the userq resource at postclose moment?

>
> Regards,
> Christian.
>
> >
> > Signed-off-by: Prike Liang <Prike.Liang at amd.com>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > index 8d4a2aed7231..cf0f35a7daee 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
> > @@ -1502,10 +1502,11 @@ void amdgpu_driver_postclose_kms(struct
> drm_device *dev,
> >             amdgpu_bo_unreserve(pd);
> >     }
> >
> > -   fpriv->evf_mgr.fd_closing = true;
> > -   amdgpu_userq_mgr_fini(&fpriv->userq_mgr);
> > -   amdgpu_eviction_fence_destroy(&fpriv->evf_mgr);
> > -
> > +   if (!fpriv->evf_mgr.fd_closing) {
> > +           fpriv->evf_mgr.fd_closing = true;
> > +           amdgpu_userq_mgr_fini(&fpriv->userq_mgr);
> > +           amdgpu_eviction_fence_destroy(&fpriv->evf_mgr);
> > +   }
> >     amdgpu_ctx_mgr_fini(&fpriv->ctx_mgr);
> >     amdgpu_vm_fini(adev, &fpriv->vm);
> >