Re: [PATCH] drm/xe: Fix memory leak on xe_alloc_pf_queue failure

[Matthew Auld <matthew.auld@intel.com>]

On 22/08/2024 09:13, Nirmoy Das wrote:
> Free up previously allocated pf_queue[i].data on error.
> 
> Fixes: 3338e4f90c14 ("drm/xe: Use topology to determine page fault queue size")
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Stuart Summers <stuart.summers@intel.com>
> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_gt_pagefault.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> index 0be4687bfc20..c19944eed5bd 100644
> --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> @@ -437,9 +437,13 @@ int xe_gt_pagefault_init(struct xe_gt *gt)
>   
>   	for (i = 0; i < NUM_PF_QUEUE; ++i) {
>   		ret = xe_alloc_pf_queue(gt, &gt->usm.pf_queue[i]);
> -		if (ret)
> +		if (ret) {
> +			while (i-- > 0)
> +				kfree(gt->usm.pf_queue[i].data);
>   			return ret;
> +		}
>   	}

I think this will then also leak below, if one of the queue create 
fails? Maybe just convert this over to devm_calloc or similar that way 
we don't need to do the manual unwind.

> +
>   	for (i = 0; i < NUM_ACC_QUEUE; ++i) {
>   		gt->usm.acc_queue[i].gt = gt;
>   		spin_lock_init(&gt->usm.acc_queue[i].lock);