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Thu, 20 Nov 2025 18:00:50 +0000 From: Date: Thu, 20 Nov 2025 10:00:48 -0800 To: Dave Hansen , Xu Yilun CC: , , , , , , , , , , , , Message-ID: <691f575028ae4_1a375100a0@dwillia2-mobl4.notmuch> In-Reply-To: <13e894a8-474f-465a-a13a-5d892efbfadb@intel.com> References: <20251117022311.2443900-1-yilun.xu@linux.intel.com> <20251117022311.2443900-9-yilun.xu@linux.intel.com> <62bec236-4716-4326-8342-1863ad8a3f24@intel.com> <13e894a8-474f-465a-a13a-5d892efbfadb@intel.com> Subject: Re: [PATCH v1 08/26] x86/virt/tdx: Add tdx_enable_ext() to enable of TDX Module Extensions Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR03CA0286.namprd03.prod.outlook.com (2603:10b6:a03:39e::21) To PH8PR11MB8107.namprd11.prod.outlook.com (2603:10b6:510:256::6) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR11MB8107:EE_|DS0PR11MB8737:EE_ X-MS-Office365-Filtering-Correlation-Id: bba8daab-6b1a-4470-6c0d-08de285ebd3b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024; 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I thought that all of these were logically > equivalent: > > void *foo __free(foofree) = alloc_foo(); > > void *foo __free(foofree) = NULL: > foo = alloc_foo(); > > void *foo __free(foofree) = NULL; > populate_foo(&foo); > > Is there something special about doing the variable assignment at the > variable declaration spot? On this topic I argue in cleanup.h that the: void *foo __free(foofree) = alloc_foo(); ...form, should be preferred. The NULL initialization form potentially destroys the first-in-last-out ordering of cleanup callbacks. Linus mentions here [1] though that it is not a hard and fast rule. That was part of the rationale for documenting the preference in cleanup.h, but not in coding-style, nor in checkpatch.pl [2]. [1]: http://lore.kernel.org/CAHk-=whPZoi03ZwphxiW6cuWPtC3nyKYS8_BThgztCdgPWP1WA@mail.gmail.com [2]: http://lore.kernel.org/769268a5035b5a711a375591c25d48d077b46faa.camel@perches.com