[PATCH v4 0/4] Have xe_vm and xe_exec_queue take references to xef

[Lucas De Marchi]

On Fri, Jul 19, 2024 at 07:16:19AM GMT, Matthew Brost wrote:
>On Thu, Jul 18, 2024 at 02:05:44PM -0700, Umesh Nerlige Ramappa wrote:
>> Just posting the revision that will be pushed for reference. This rev
>> only has documentation changes compared to v2, so will not run CI on
>> this.
>> -----

great. indeed no need to wait for CI.

>> xe_file_close triggers an asynchronous queue cleanup and then frees up
>> the xef object. Since queue cleanup flushes all pending jobs and the KMD
>> stores client usage stats into the xef object after jobs are flushed, we
>> see a use-after-free for the xef object. Resolve this by taking a
>> reference to xef from xe_exec_queue.
>>
>> Issue: https://gitlab.freedesktop.org/drm/xe/kernel/issues/1908
>
>It looks like not having ref to vm->xref is causing other issues too [1]
>[2].
>
>Let's get this in ASAP.

IN it is. There was only a minor conflict with drm-misc-next, but that
was trivial to solve.

Thanks for this fix,

Lucas De Marchi

>
>Matt
>
>[1] https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2273
>[2] https://patchwork.freedesktop.org/patch/605099/?series=136240&rev=1
>
>>
>> The series adds xef refcounting and ensures all consumers of xef take a
>> ref to it.
>>
>> v2:
>> - Include review comments from v1
>> - Squash patch 3 and 5 from v1 to add Fixes/Closes tags
>>
>> v3:
>> - kernel-doc fixes (Lucas, Matt)
>>
>> v4: Rebase to drm-tip
>>
>> Note: Patches 1 - 3 can be merged independently
>>
>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>>
>> Umesh Nerlige Ramappa (4):
>>   drm/xe: Move part of xe_file cleanup to a helper
>>   drm/xe: Add ref counting for xe_file
>>   drm/xe: Take a ref to xe file when user creates a VM
>>   drm/xe: Fix use after free when client stats are captured
>>
>>  drivers/gpu/drm/xe/xe_device.c           | 58 +++++++++++++++++++-----
>>  drivers/gpu/drm/xe/xe_device.h           |  3 ++
>>  drivers/gpu/drm/xe/xe_device_types.h     |  3 ++
>>  drivers/gpu/drm/xe/xe_drm_client.c       |  5 +-
>>  drivers/gpu/drm/xe/xe_exec_queue.c       | 10 +++-
>>  drivers/gpu/drm/xe/xe_exec_queue_types.h |  7 ++-
>>  drivers/gpu/drm/xe/xe_vm.c               |  6 ++-
>>  7 files changed, 71 insertions(+), 21 deletions(-)
>>
>> --
>> 2.38.1
>>