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Ts'o" Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org References: <20201112093324.8052-1-wenlin.kang@windriver.com> From: Wenlin Kang Message-ID: <6083a93c-4b21-f366-be04-dd098133f7b9@windriver.com> Date: Thu, 17 Dec 2020 15:00:29 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [60.247.85.82] X-ClientProxiedBy: HK2PR02CA0215.apcprd02.prod.outlook.com (2603:1096:201:20::27) To BN7PR11MB2658.namprd11.prod.outlook.com (2603:10b6:406:ae::16) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [128.224.162.167] (60.247.85.82) by HK2PR02CA0215.apcprd02.prod.outlook.com (2603:1096:201:20::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3654.12 via Frontend Transport; Thu, 17 Dec 2020 06:49:36 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 1cb5a690-2b3e-4043-769d-08d8a257ec97 X-MS-TrafficTypeDiagnostic: BN8PR11MB3780: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:203; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BN7PR11MB2658.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(376002)(39850400004)(366004)(346002)(396003)(136003)(2616005)(956004)(6486002)(16576012)(44832011)(66556008)(26005)(8676002)(66946007)(186003)(16526019)(52116002)(83380400001)(66476007)(86362001)(4326008)(2906002)(316002)(36756003)(31686004)(5660300002)(6916009)(8936002)(6706004)(478600001)(31696002)(6666004)(78286007)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?SWlJVS91endPTXg3R1g4UHlGcGhiamJLWXlNVi9TY1o0VTJXRVI3YnAxM21h?= =?utf-8?B?dTd3QndqNEFleVhyMVo2RDZDZ1VBeDNibndZTjA4VytTUVg2SyszbjFKTysz?= =?utf-8?B?ejROTkFjUVJyQUxvTWxFSzJNNW5aVjcwcG5iMzBLTHFwYkUyeHJqQXI3TkhV?= =?utf-8?B?dHd0VTNJb3lOeGZZVWd5UStDeDhUUVp5czlIbUdvSnN0ZjBOS1JKaGdOWS9O?= =?utf-8?B?T2dQUUVKSWNKeXpuSk5jK2NEejRjSWprUWpmWEZOeXVZZVpabVdZSFcyVlNN?= =?utf-8?B?Q1kzdFpQcWp4ckFRNUMwVDQzbFd1WDZBcHVWMWsvbU4yOFpXYkhhckhsQXBO?= =?utf-8?B?QXF6Q2FIc241R0tBbFp2SlpIMVVEdFIwa2txSk5pd0RQMHhPYXNXRC9MdlZ0?= =?utf-8?B?alJwK2UzN2c1ZmRScnBDMVkwc0RTd2kzVVRJWllVQzhoeGJsdE9VaXNFM2oz?= =?utf-8?B?QzZTcHlZdHl1eWo4alNKaHQ0WlhaZjQ3YTNkVWhaUmMzS2xvZEtvK20rS1M2?= =?utf-8?B?U0ZobVg3enlJOW9mOHZtaGFMeVB4V1VJczcyTFAyRVpOUk5qcDdoVXJCUkZQ?= =?utf-8?B?SlY5ZTZKS29VNThBRVp3UHRRaGE4cE41dWFUcU9PQTRzbnM1anRpcVpVUmhV?= =?utf-8?B?VTFlWUNzSDRLTGZqUjRFcXQzai9KeWFCUlNHcnRWWDl2TGsycWRQRUdOdWpD?= =?utf-8?B?cVBpYzVoRWtUUnVxMTBtK3J6NGorOHJwaGtVaFRlSzltWExIR1loWUhBRU1l?= =?utf-8?B?ZHF4dUl1S1ZsSHdaQldPcUxjaS91NlB4VkF1TG9HbzF4cFpwZWpsQVdCcVhS?= =?utf-8?B?VCtzVm1KRmVkdGpuc3R6NmF1QktEdFR5azVoRzVObXYxNHlRakxabS9Lc3ZX?= =?utf-8?B?bnRYWjRDZW1nc0dWbHJzdHZENEdrNkp3QkxlNDUzUjY3WmpZNVVKTUhwYm00?= =?utf-8?B?UUE3OTRLK0JrazZGU2lLRGFXV2RGd2FTaXpSL2prTUUvSzd1MHR2cVhJTlFp?= =?utf-8?B?Vm9TdEZmK3lYVi9uMDBNZWEya0poVWcxZnpobTl3VEpIcWZGY3JrUmlUTjFI?= =?utf-8?B?RmJzaXZpR0oxOG53cENFWXdFOGt2bjV5eUxHQVVxdURIVDFqUm9LY1V6Z0Vi?= =?utf-8?B?NWk0c3Y1MTR5aHF3QXcxWE0zN3kySGtLL2k3QWpVN0RSZ25kRWpzRmZqMUtT?= =?utf-8?B?NUJFVUp6ZHR5M3htQndUUlk1LytQQUVaaFNyd3R6aFZoMFhKWXJHd3Ayemgx?= =?utf-8?B?aG9CRWIzZy9lRTJYeC9XR3hmT1FFVHc1SU54ai9JbFFDVnRySGw5NlN3ZEtC?= =?utf-8?Q?D5hbAyxcl29RQ=3D?= X-OriginatorOrg: windriver.com X-MS-Exchange-CrossTenant-AuthSource: BN7PR11MB2658.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Dec 2020 06:49:38.6499 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ddb2873-a1ad-4a18-ae4e-4644631433be X-MS-Exchange-CrossTenant-Network-Message-Id: 1cb5a690-2b3e-4043-769d-08d8a257ec97 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: p5SxkbVmwWRgDAklQ+54P5ybsczsKc9CJ9f2/TqQL/6UP99rqRwrohOipEkh9IWpOJQrw6DI4YJ9v8YJHT/uliNBF813Yw81pvxM3qmSEiU= X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR11MB3780 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/12/16 下午12:20, Theodore Y. Ts'o wrote: > [Please note this e-mail is from an EXTERNAL e-mail address] > > On Thu, Nov 12, 2020 at 05:33:24PM +0800, Kang Wenlin wrote: >> From: Wenlin Kang >> >> The strncpy() function may create a unterminated string, >> use strscpy_pad() instead. >> >> This fixes the following warning: >> >> fs/ext4/super.c: In function '__save_error_info': >> fs/ext4/super.c:349:2: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation] >> strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func)); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> fs/ext4/super.c:353:3: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation] >> strncpy(es->s_first_error_func, func, >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> sizeof(es->s_first_error_func)); >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > What compiler are you using? s_last_error_func is defined to not > necessarily be NUL terminated. So strscpy_pad() is not a proper > replacement for strncpy() in this use case. My compiler is gcc 8.2.0,  this is found in v4.18, and I see mainline codes is using the same code too,  so sent this patch. But according to your instructions, I just re-check the code, with "__nonstring" attribute, it seems it has fixed. Thank for your explain. > > From Documentation/process/deprecated: > > If a caller is using non-NUL-terminated strings, strncpy() can > still be used, but destinations should be marked with the `__nonstring > `_ > attribute to avoid future compiler warnings. > > s_{first,last}_error_func is properly annotated with __nonstring in > fs/ext4/ext4.h. > > - Ted -- Thanks, Wenlin Kang