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Date:   Mon, 6 Jul 2020 22:31:47 -0400
From:   Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
To:     Navid Emamdoost <navid.emamdoost@gmail.com>
Cc:     Rob Herring <robh@kernel.org>,
        Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        Steven Price <steven.price@arm.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        emamd001@umn.edu, wu000273@umn.edu, kjlu@umn.edu,
        mccamant@cs.umn.edu
Subject: Re: [PATCH] drm/panfrost: perfcnt: fix ref count leak in
 panfrost_perfcnt_enable_locked
Message-ID: <20200707023147.GB16527@kevin>
References: <20200614063619.44944-1-navid.emamdoost@gmail.com>
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Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>

On Sun, Jun 14, 2020 at 01:36:19AM -0500, Navid Emamdoost wrote:
> in panfrost_perfcnt_enable_locked, pm_runtime_get_sync is called which
> increments the counter even in case of failure, leading to incorrect
> ref count. In case of failure, decrement the ref count before returning.
> 
> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
> index 6913578d5aa7..92c64b20eb29 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
> @@ -83,11 +83,13 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
>  
>  	ret = pm_runtime_get_sync(pfdev->dev);
>  	if (ret < 0)
> -		return ret;
> +		goto err_put_pm;
>  
>  	bo = drm_gem_shmem_create(pfdev->ddev, perfcnt->bosize);
> -	if (IS_ERR(bo))
> -		return PTR_ERR(bo);
> +	if (IS_ERR(bo)) {
> +		ret = PTR_ERR(bo);
> +		goto err_put_pm;
> +	}
>  
>  	/* Map the perfcnt buf in the address space attached to file_priv. */
>  	ret = panfrost_gem_open(&bo->base, file_priv);
> @@ -168,6 +170,8 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
>  	panfrost_gem_close(&bo->base, file_priv);
>  err_put_bo:
>  	drm_gem_object_put_unlocked(&bo->base);
> +err_put_pm:
> +	pm_runtime_put(pfdev->dev);
>  	return ret;
>  }
>  
> -- 
> 2.17.1
>