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Mon, 26 Jul 2021 09:17:40 +0000 Date: Mon, 26 Jul 2021 12:17:20 +0300 From: Dan Carpenter To: Hannes Reinecke Cc: Julia Lawall , Arnd Bergmann , Geert Uytterhoeven , NeilBrown , Laurent Pinchart , ksummit@lists.linux.dev Subject: Re: Potential static analysis ideas Message-ID: <20210726091720.GI25548@kadam> References: <20210723191023.GG25548@kadam> <162717033769.3676.6942299974175827854@noble.neil.brown.name> <633614dd-dd88-03f0-c463-d97036c58216@suse.de> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <633614dd-dd88-03f0-c463-d97036c58216@suse.de> User-Agent: Mutt/1.9.4 (2018-02-28) X-ClientProxiedBy: JN2P275CA0030.ZAFP275.PROD.OUTLOOK.COM (2603:1086:0:2::18) To MWHPR1001MB2365.namprd10.prod.outlook.com (2603:10b6:301:2d::28) Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from kadam (102.222.70.252) by JN2P275CA0030.ZAFP275.PROD.OUTLOOK.COM (2603:1086:0:2::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4352.25 via Frontend Transport; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?iDnFlNXof5QWdgmpOPJiId/dJZf5FcubnDOK0iG64Nc1rAfmMC0JOZQEhRhn?= =?us-ascii?Q?ALOCAEHDxamBzBNXNXGqVlZOYW1AeW3dRHFRNP1NeF9yt+r2AM19KMZvjxS4?= =?us-ascii?Q?idbikxDmj/QKcND9YVICgZT2DdlXm89LzpH6XoCz4UGuUNXMXxaK9A6wclp8?= =?us-ascii?Q?3+fRoMJf0OgPIk4jMWEsSW2f4HaNvvG+C8XSeNoIMiRVxGM6AoQQSF9yUIIA?= =?us-ascii?Q?ZFYv/WSByEZHlDGXvUuJy4bKSes8r/allJo5bhI3n7T49DPrq9JEZE+cOhfr?= =?us-ascii?Q?DeAbqbZ3iFFYOgYLK7ExglA+UW3lbwtD5EVnNb3PxHqNq2wEb9vxv5Bcmvwc?= =?us-ascii?Q?c5nQu8Ft7kZhpt0lfKukR+Sf7lGPabmO87DfHiHeeCfEzg8zrqZlBKnjw7aW?= =?us-ascii?Q?lFXCq5ROgLK+SmCF8kfBBwARVt0J99P5dJAZ9hBUY4GbHQPEY1xR8luWP3cK?= =?us-ascii?Q?j1nqXehFLYV4ypFobL/QOnogrDgu2gkdyl/RnDYHpDLDntrYLgfQKxS5XXOU?= =?us-ascii?Q?/GjDTIeC9RCq25Nb8BLM4HmecwmZ9WgmZkgg/XOtLX04vfmBpVfOOhDSYMMm?= =?us-ascii?Q?+kfWdOo8NaxGvhvBLghfnK8H0VzZ8BekTavMntAZp7cbIG3JWpXTc/hXqxn9?= =?us-ascii?Q?h4nalWyJlMvwQ8oOdfUtY8Jw8GqDfTtrISchgYQ2N6b9Fb5M3mk+Rn7G/K96?= =?us-ascii?Q?KJLnEXzElabpUMvhahdTQpsyNRnUzc+lHwnI0Yb4n5hMA2WZunou7C4GI3e8?= =?us-ascii?Q?yvsMAGQdead9qawAYdLfjjBLdKy4+b/Qs9j5aNyJ5YMORtoWGbFmXvwtplBa?= =?us-ascii?Q?5ZOuiNy1aQNXtA5HLL1d8i5YzVQn0m2zvZ2zLexuwF8n1nb/6GqN2+1427RK?= =?us-ascii?Q?ol3k981xC4LN4l4PDLK2NqwuodwCwdGsVMy0lcns6ogWHZ1tIFyp/e1x1HkC?= =?us-ascii?Q?ro33xsrIABaSRpTl6/pSy2rSqkJomXcB8ECo+bn13JP8ogiTqUaVWhoHU4hn?= =?us-ascii?Q?2YLlnYi2Cqv7DdrdqnUhR5HSUSLvFaq3cgPPzMIgmt5+waj830nn7IwghGSc?= =?us-ascii?Q?q2KFlzzTYLPoSrSnXXSbI4ezxehgBlyKc7pbWR9ogUtVeA4/RZeIslMoLxPF?= =?us-ascii?Q?7ALwbOLgzcgrIZipo8SOTtJLCRO/04UZBU3zxRX0ZIFTVX7FehwnFKMNBhxD?= =?us-ascii?Q?q8A9FIGWXDzd4A4yo82dHKDM6BdiyTap6lIo7c+FF9n4tpgbucE2O+vKo35W?= =?us-ascii?Q?SVUFY58JIdwPJJXIngLVDRXu8vfrUjykVv1K41GXQcm4ENLft27cMehoHjfT?= =?us-ascii?Q?jVhRDmaG+krneiohkUB7s/S4?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 53db1a22-a12e-4c69-dc10-08d9501637cb X-MS-Exchange-CrossTenant-AuthSource: MWHPR1001MB2365.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jul 2021 09:17:40.7134 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: NwH0B7ArmLKG54l2DTq1odM1mM+raFtEDn36f6e6QrjVaCLhr85A56VgPkWs0lb1DeWuSpWE1sMqLcGs5DnhVXrchxrHMEVyjJUB339VxJc= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO6PR10MB5570 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10056 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 phishscore=0 suspectscore=0 adultscore=0 malwarescore=0 spamscore=0 mlxlogscore=999 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2107260053 X-Proofpoint-ORIG-GUID: 5aHOJyof_q7tris4JB7tvMGv4KNYbQN8 X-Proofpoint-GUID: 5aHOJyof_q7tris4JB7tvMGv4KNYbQN8 On Mon, Jul 26, 2021 at 11:08:01AM +0200, Hannes Reinecke wrote: > And that I would consider a coding error. > If a function is able to return an error pointer it should _always_ return > an error pointer; here it would be trivial to return -ENXIO instead of NULL > in the first condition. > > Not doing so is just sloppy programming IMO. > > Cheers, But it's not an error. One place where this bit me recently was I was trying to debug some code and I added: if (err) printk("function blah returned err"); But their list iterator returns an error code when it got to the end of the list so I was flooded with errors. It be nicer "if we can't allocate enough memory for the next item return an error pointer. If we come to the end of the loop then return NULL" regards, dan carpenter