Re: linux-next: manual merge of the drm-xe tree with the drm-misc-fixes tree

[Stephen Rothwell]

Hi all,

On Fri, 4 Oct 2024 12:18:00 +1000 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> Today's linux-next merge of the drm-xe tree got a conflict in:
> 
>   drivers/gpu/drm/xe/xe_guc_submit.c
> 
> between commit:
> 
>   9286a191abe2 ("drm/xe: Drop GuC submit_wq pool")
> 
> from the drm-misc-fixes tree and commit:
> 
>   861108666cc0 ("drm/xe: fix UAF around queue destruction")

This is now also commit

  2d2be279f1ca ("drm/xe: fix UAF around queue destruction")

in Linus' tree.

> from the drm-xe tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> diff --cc drivers/gpu/drm/xe/xe_guc_submit.c
> index 17c25f18e286,8a5c21a87977..000000000000
> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> @@@ -224,11 -224,80 +224,27 @@@ static bool exec_queue_killed_or_banned
>   		 EXEC_QUEUE_STATE_BANNED));
>   }
>   
>  -#ifdef CONFIG_PROVE_LOCKING
>  -static int alloc_submit_wq(struct xe_guc *guc)
>  -{
>  -	int i;
>  -
>  -	for (i = 0; i < NUM_SUBMIT_WQ; ++i) {
>  -		guc->submission_state.submit_wq_pool[i] =
>  -			alloc_ordered_workqueue("submit_wq", 0);
>  -		if (!guc->submission_state.submit_wq_pool[i])
>  -			goto err_free;
>  -	}
>  -
>  -	return 0;
>  -
>  -err_free:
>  -	while (i)
>  -		destroy_workqueue(guc->submission_state.submit_wq_pool[--i]);
>  -
>  -	return -ENOMEM;
>  -}
>  -
>  -static void free_submit_wq(struct xe_guc *guc)
>  -{
>  -	int i;
>  -
>  -	for (i = 0; i < NUM_SUBMIT_WQ; ++i)
>  -		destroy_workqueue(guc->submission_state.submit_wq_pool[i]);
>  -}
>  -
>  -static struct workqueue_struct *get_submit_wq(struct xe_guc *guc)
>  -{
>  -	int idx = guc->submission_state.submit_wq_idx++ % NUM_SUBMIT_WQ;
>  -
>  -	return guc->submission_state.submit_wq_pool[idx];
>  -}
>  -#else
>  -static int alloc_submit_wq(struct xe_guc *guc)
>  -{
>  -	return 0;
>  -}
>  -
>  -static void free_submit_wq(struct xe_guc *guc)
>  -{
>  -
>  -}
>  -
>  -static struct workqueue_struct *get_submit_wq(struct xe_guc *guc)
>  -{
>  -	return NULL;
>  -}
>  -#endif
>  -
> + static void xe_guc_submit_fini(struct xe_guc *guc)
> + {
> + 	struct xe_device *xe = guc_to_xe(guc);
> + 	struct xe_gt *gt = guc_to_gt(guc);
> + 	int ret;
> + 
> + 	ret = wait_event_timeout(guc->submission_state.fini_wq,
> + 				 xa_empty(&guc->submission_state.exec_queue_lookup),
> + 				 HZ * 5);
> + 
> + 	drain_workqueue(xe->destroy_wq);
> + 
> + 	xe_gt_assert(gt, ret);
> + }
> + 
>   static void guc_submit_fini(struct drm_device *drm, void *arg)
>   {
>   	struct xe_guc *guc = arg;
>   
> + 	xe_guc_submit_fini(guc);
>   	xa_destroy(&guc->submission_state.exec_queue_lookup);
>  -	free_submit_wq(guc);
>   }
>   
>   static void guc_submit_wedged_fini(void *arg)

This is now a conflict between the drm-misc-fixes tree and Linus' tree.

-- 
Cheers,
Stephen Rothwell

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