Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <fc165d83-bad2-2189-ec7d-2c756275d85c@amd.com>
Date:   Mon, 7 Feb 2022 09:01:48 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH] drm/radeon: Avoid open coded arithmetic in memory
 allocation
Content-Language: en-US
To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Alex Deucher <alexander.deucher@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
References: <1f44de96e6a49e912111fb3b664f087328b4c2cd.1644082664.git.christophe.jaillet@wanadoo.fr>
From:   =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
In-Reply-To: <1f44de96e6a49e912111fb3b664f087328b4c2cd.1644082664.git.christophe.jaillet@wanadoo.fr>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QkZRMXhEZnNLSFphY2R2ak8xRTZuZTJWcGNMSVFnSW81WEVpMjVLZDZGbDV2?=
 =?utf-8?B?RkxyRjZDSitlM0NnYzNETUxjblJheDdqUUQrdEJKdVZ2Z2NpeThSbE94UC9k?=
 =?utf-8?B?aFdCSU1Ya3lNRGxoSml6T3VQOEpHK1I4WThiM2F6NGhsamtYWk9rcEUyalVE?=
 =?utf-8?B?Vy9sbW9JRnYyeEhVbERIdENXV1hhMk9xNEpHd0ZtKzk1TEIvc0Vpbit2Y2ZJ?=
 =?utf-8?B?MllheVJ0cDYrVHdSY05TVjJDTXMzUjM2dnNTQWFESzRXK1RNdWVTeitJRmh5?=
 =?utf-8?B?R015OU9kdENVa1gyS0tBMkdNRVpQVWE2VENJK01USnlwcm9DQXRrWXRVVWgz?=
 =?utf-8?B?N0ZuMndWKzZzcXVzSWdpS1RRZEVyYVBLeS9aN2psczNFMUozemVYQTh0RG9z?=
 =?utf-8?B?eHBmeWVJbUN3TVFTMitDV3d5YVFoY2VCTWk5UmV5R05ibFhyOFVmbk16dUp4?=
 =?utf-8?B?bnpEQ0N6NXpnMGZoSTRpUmkvSDlhL1ludkdqc0lvOVpBY21MWVZaLytySmNq?=
 =?utf-8?B?SUE0aFV2RWJVY2RoS0t5QmtwUjZJWDE0d00yaVQvTzNJWVhqb1BrZS9JbGhL?=
 =?utf-8?B?UXBndWROdnpMVFRTUjA1NzBvSGpaeXF3RU1rSmJyV1Qwd3B4VWxWNzVOTk15?=
 =?utf-8?B?TlFOcno3Um5rM3VBVzk2MjhTdnpGcVovMFAzK0FmR1RKdWpjNUI3QVFYRTNI?=
 =?utf-8?B?RUtudU1UR1JjVldla2NoS0JPQTJNSEE4OEREenIwNTJMTUJ2S1QzNjM1Tnkv?=
 =?utf-8?B?NEY0M1oxV0VERFBaNG1kRXo3dllTOHd1RktFVE9lQTFXSDRMZGh0UVd1eXpN?=
 =?utf-8?B?c2NEV2Zjdy9IamJueEtYZDJROTRMUXY5L3JlaDQ0Zk1XRmt1MVBGckhQTUk5?=
 =?utf-8?B?N2s2UlBNTTJ6REN2SEFoRmxJTE5XdHl0YmNhMHMrck9FaEZnWmNjTWxwdnJH?=
 =?utf-8?B?Y0dnUFdlVkgyMSthM0pVTUNka1VQVjRjL0Fvd2ZNbWRVbS92QjJ6eWRJc05Y?=
 =?utf-8?B?Z3JIWGdqNDV1bmVYalFQZFJNM1gxZmY2V0I3K1FHTGt6Z3R1WURYamdGVmdJ?=
 =?utf-8?B?ck1zQUtMRlVab3BwSjB3TlZKbFFhK25zUGJRa3dQUGE5eWIrbS83a0drQVlT?=
 =?utf-8?B?UlpjL2xHVEkvRGFjQjZ2TDVXdzZPL2FEUjlKRk1MSTlNTG1zRklDSlYxL25i?=
 =?utf-8?B?Q3ZqakYvTE1KY0RvTGNRcTRZcWU2T3pXWVJ2b0YxTzRjQU05eHpxdHJZL3Ry?=
 =?utf-8?B?OWtxZDI0aGR3Y1lIWitlQm84ZzFia0ZNOVpiWWYvY3J0L1ZDNGw5K1FSR01j?=
 =?utf-8?B?RGdiSm1xN3o4cDJRSmltcnlwdkpaUkFkQXVZVXE4NW1YWENRc1BtclpBczVF?=
 =?utf-8?B?NGx2TnNGZm91R0k3Qzg4RDQzcHFMNi91WkNXRVFLTll1cURrZmZzd0g3VHBy?=
 =?utf-8?B?Z29TcFVtMERRRm9LdWF1ZjJSdEowOVE5MmNuZnY0ekJuK200N3o2a0RrLzFP?=
 =?utf-8?B?RFRoWWxNY3NncElsRG5vMmtnZXdUc1E3RTZ3SFZsS1VDeXAvYnMyMGdFMDNi?=
 =?utf-8?B?aDBFdkY4VTFZTHhYK2VlcGtDN0lhc1N1LzhPelg0enprNHJkMUZMQ2xNK09P?=
 =?utf-8?B?TWpQeUIvbEp3cWx2clQ2QXV3MFliSUZpamxpTTJCZXpXM3VVM0d5NVA1TTYv?=
 =?utf-8?B?dERsVEEwMFRxTG1TMmY2bWlFZlNpcWQ2Q3dRS01EVU9xbytWWElkMGZzS29B?=
 =?utf-8?B?VnViMERXK3k2eGV4VmN0T2g5U3ptTE96NmNxK2IwdXhQaWM0Y2g5K1FsU215?=
 =?utf-8?B?Z0JJN2RTajNTMS9ML0FDWnozQnBCc2dXUVZNNGdid0N4eGE5UFk5UHVZdndp?=
 =?utf-8?B?VEVROGFhNjYyWXZQdmkreDdJKy8zaTYvd2dFQVRuRmQ1aFhnOTZGY3hPUWhR?=
 =?utf-8?B?RExEMWlEWnFSeHZWblFXVjBhNEtVdDk1SXU5aXJnNkdYQ1oxcWNVbGtGaHZn?=
 =?utf-8?B?L2xTeVJDTWVsbWdCcDN6ZFk3em90ZzRjOU9KT29KZ2VuM0lNQ1hUOWZWRDJY?=
 =?utf-8?B?M3JSdFhTaUE4ZGRGUDhmOXpLMTBENFVQU3kzbFpwemVnNXZSV0FtRko0aHAz?=
 =?utf-8?B?eS9oeE9nbyt1SnFSejRsTDZyT0ZYd1d3Yjcrc1lHaWJKWEFqNkI2RmlrdTdl?=
 =?utf-8?Q?gfBQB4yYWyHqkQDRIoj9G4k=3D?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 6dfdfa9e-f29e-4008-54e4-08d9ea101c1b
X-MS-Exchange-CrossTenant-AuthSource: BYAPR12MB3589.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Feb 2022 08:01:56.5002
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: geZpJg64laR+YJB+wxmvv7k3T+UeAgvxj0pk9GlLpYXPrc3KAfqF+l6YZQbFZLm9
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN6PR12MB1556
X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,RDNS_NONE,SPF_HELO_NONE,
	T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
	lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Am 05.02.22 um 18:38 schrieb Christophe JAILLET:
> kmalloc_array()/kcalloc() should be used to avoid potential overflow when
> a multiplication is needed to compute the size of the requested memory.
>
> So turn a kzalloc()+explicit size computation into an equivalent kcalloc().
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/radeon/radeon_atombios.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
> index 28c4413f4dc8..7b9cc7a9f42f 100644
> --- a/drivers/gpu/drm/radeon/radeon_atombios.c
> +++ b/drivers/gpu/drm/radeon/radeon_atombios.c
> @@ -897,13 +897,13 @@ bool radeon_get_atom_connector_info_from_supported_devices_table(struct
>   	union atom_supported_devices *supported_devices;
>   	int i, j, max_device;
>   	struct bios_connector *bios_connectors;
> -	size_t bc_size = sizeof(*bios_connectors) * ATOM_MAX_SUPPORTED_DEVICE;
>   	struct radeon_router router;
>   
>   	router.ddc_valid = false;
>   	router.cd_valid = false;
>   
> -	bios_connectors = kzalloc(bc_size, GFP_KERNEL);
> +	bios_connectors = kcalloc(ATOM_MAX_SUPPORTED_DEVICE,
> +				  sizeof(*bios_connectors), GFP_KERNEL);
>   	if (!bios_connectors)
>   		return false;
>