Subject: Re: [PATCH v2] drm/ttm: check the return value of kzalloc
To: Xiongwei Song <sxwjean@gmail.com>, Hongbo.He@amd.com,
        airlied@linux.ie
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20180102123526.21057-1-sxwjean@gmail.com>
From: =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
Message-ID: <122332a7-727d-1e20-6203-487790232c0d@amd.com>
Date: Tue, 2 Jan 2018 13:36:51 +0100
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Am 02.01.2018 um 13:35 schrieb Xiongwei Song:
> In the function ttm_page_alloc_init, kzalloc call is made for variable
> _manager, we need to check its return value, it may return NULL.
>
> Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
> ---
> v1->v2: delete kfree _manager
> ---
>   drivers/gpu/drm/ttm/ttm_page_alloc.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> index b5ba6441489f..583d73edb7df 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> @@ -1007,6 +1007,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>   	pr_info("Initializing pool allocator\n");
>   
>   	_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
> +	if (!_manager) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}

A simpler "return -ENOMEM" should do here as well.

Regards,
Christian.

>   
>   	ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc", 0);
>   
> @@ -1041,6 +1045,8 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>   	ttm_pool_mm_shrink_init(_manager);
>   
>   	return 0;
> +out:
> +	return ret;
>   }
>   
>   void ttm_page_alloc_fini(void)