From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from MW6PR02CU001.outbound.protection.outlook.com (mail-westus2azon11012005.outbound.protection.outlook.com [52.101.48.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 436E4309F1D for ; Tue, 16 Dec 2025 09:50:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.48.5 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765878658; cv=fail; b=g5tbNVbkPc0f7RIg7tBXbuvirGp1I1IRJSnrrepsvIjEhhGN5+RMJLffo0P2GOWJ5DNZa7huJwduHMHggZgDa0SLK1NRwk7ouoN/svNZ3kzKfnxFdIBqmlTY35uqJcYC6uSle9gJu43OFcJBgMeBYlr6TeckQBJWtrYF9GHZ+hk= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765878658; c=relaxed/simple; bh=3ulmCuu1E8VNLkqnshb0VGiIpRr2Sg8B4AIF+8lASrU=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=EQOBXxmlIJWi51oMwbpSJua6tY11DBBfacNNvsD2BitwYN0qcsBynZ9VNMTi7Ue7xkMCKixqLxI5+kIjfRRd8dWzv6kZ79IfzikCNyLeYHyIcyZ1GO+6A/IZi8pb36VS2xrIijcrYJ04xn/nbtq4UlSr5/sw5j36mouOG/sKROE= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=FFKyiX2z; arc=fail smtp.client-ip=52.101.48.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="FFKyiX2z" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=W//z537DdSCq3DFsEubOzhJT7jT0TSvcybBbhAdSzvsTqAdWbLQ9sbJ6xCp25FjrocFLlbO8hkUNMxJGN8IxjT+XJpeID86WfMHrYm2vCUQ0Bbw7skJtaBx0okG8E1iA7RYVB8iBy1AaaLvxspfdoT9yPzD/QrpKbRzmn1WNRedl1YimBY/3vjO0Ge3xMkFJIDo0C5ahs6IUP4GLC8xNQvhQaPlk9SaFc3srlfbgTCHNzDdfp+ebEMqJaW5xzHzwinXnxELE/ZowfgIgpaiAsyZ+3FdIv+nBr8LE7jwk5cPyIkROGEezFivei3Dy/Q1CS/BYwnPtXNV11x6I5meheg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=NO1IaH3PAty+HUaHa3THuh/HVRt0JvTWbMFw1tDf6jM=; b=oCxr+6xRHcMazIvQoXWwfu2Be7oopcJYHfazh0bFkzwgOgIqYvQefpcPSaqymv+NYIy4KP4pWe8jmq/XEqwSgDa92uE9zVt+KXRJ516WzrDydKOTdFLbkjVMQ8Os8JyDvn+a7ndFzcsiOTVS8Gg0Z/lFAvE1nNBMug5hMFQ1sRQEM00NjYhRSgakYXXH+BaxxJ4eStbBOCtZPHM+LICUVQcvLztDVRQ+ATPS+Pk26OmBjBeJHjHzBSORu3XrVbC+68P/goD7i2Tk1GbRkAcCipHA30iFZPNHzvBCQMbCfoWPg7fpRHONGiBQmKNr0/2aB/b6em78nD9LxjKC/SApgA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=NO1IaH3PAty+HUaHa3THuh/HVRt0JvTWbMFw1tDf6jM=; b=FFKyiX2zvpsbP++ezRvsXFDiDev0rmodJN9mugL5usLVQmH1PBJgDCiM2YY71vZ/JJ+J29p+UovTznQsPenD/Xq3v5vVSZ2hMiFucFUJgCTrl9Zyidn5+G2bWmWDmvsQFE8i0Va8lB3E+EpB4yan7md1+MLcsq1DltlpJ8W6lfEZmcWrWGT/slu9erGAVIS78NXYFKbH4iw9gkAeMYoxJ41GaKHFsJUR4jBcUZc3i6nLcE0AXv+nNHw9lJQ/xA1zEDEaUXHjzti7CUYV4VGTQMIFPkiTTtZH1UBiET2EG37PjYzfJl1hWzAZ4JPyF06xUy2v+7G6DJJpfxcp/EK5tw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by DM4PR12MB6616.namprd12.prod.outlook.com (2603:10b6:8:8e::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9434.6; Tue, 16 Dec 2025 09:50:53 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::1b59:c8a2:4c00:8a2c]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::1b59:c8a2:4c00:8a2c%3]) with mapi id 15.20.9412.011; Tue, 16 Dec 2025 09:50:51 +0000 Date: Tue, 16 Dec 2025 10:50:47 +0100 From: Andrea Righi To: Liang Jie Cc: Tejun Heo , David Vernet , Changwoo Min , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , "open list:SCHEDULER - SCHED_EXT" , "open list:SCHEDULER" , liangjie@lixiang.com, kernel test robot , Dan Carpenter Subject: Re: [PATCH] sched_ext: fix uninitialized ret on alloc_percpu() failure Message-ID: References: <20251216093955.2928453-1-buaajxlj@163.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251216093955.2928453-1-buaajxlj@163.com> X-ClientProxiedBy: MI2P293CA0010.ITAP293.PROD.OUTLOOK.COM (2603:10a6:290:45::20) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|DM4PR12MB6616:EE_ X-MS-Office365-Filtering-Correlation-Id: 35b27d77-d59d-4652-fac5-08de3c88992e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?7vskdNXL1KqSF2kjhfrFdN3TKX0v/aLiXmITc+ojn6GhOBUBaGULpD64AuGC?= =?us-ascii?Q?na+T6M321loT5RPTBpxh5uR8PjojHpcDDcmliGw9OCQzpIRC70hpGOWKLy4E?= =?us-ascii?Q?pXTU1cd5WpS1pMZGnKi5J5GyarN8+ApbTSSflHMRWflBSjHpr+WRe5qRPYLX?= =?us-ascii?Q?fjn3m+60mv3qIbthnE0+w58RkFuzDewEyOZjtX7yIvwj65mCWEF62e6ema16?= =?us-ascii?Q?ZKgzvC6vWl6mN0jQk2YPHnHjswUIxq1ZFCo78D3zRIxu+oR+q1nK6xp8ScPU?= =?us-ascii?Q?YtJZl2T18RDw1zSRuUnWXAgoBBZNv431ceqpAWj4BPmAEhwzun8LLM5v3cR0?= =?us-ascii?Q?s/UaPnHsh0mOgo5R+Iyu7lMvn07wgZ2ALxCk3cINR4L0Pa5bfErjUfgwNl/C?= =?us-ascii?Q?GULE5VzaFHsDw5SnGSoMjG25RUL4VUqZiXloBrq8Db7DKuKQzzgogNVjoUpp?= =?us-ascii?Q?gBSXoEHLwfIcsozZpT/BOKjsj+bxkMYIJGsvhjREGksbOa6xoFA7EOgtbSIF?= =?us-ascii?Q?RUkkfbkS6zC9PKjvItFUKWy07wcMlo0pKMRIKvbZNQBgvMg20hisSAQW6Gnw?= =?us-ascii?Q?8UdD0rqj4yQPsfD92V6f7HW3cdTew0xMvbS+5tCgMlIIF8uwQNJOT0mow6W4?= =?us-ascii?Q?mZt7Bj5cBaukeLpYkZYvLNCuCqB0XYUk6FpLIAafHolhMdFH1fgbls8Y6/7M?= =?us-ascii?Q?9+mgh6w+JB0rkGMbtYWnIB7+uY93rXz858C13VH96BLpx2bLpbucz9vDeuLF?= =?us-ascii?Q?H0IIfk9fzppGwosKDu39aaOuCLy1ul5zY4JUMYK17DMM9etk9jwIkp1DIBc1?= =?us-ascii?Q?Go0eRrk+dK2222EU9C4P6U8pagYxtuq4AOaD2JWD62maUkqEQa6JlQqxdwnX?= =?us-ascii?Q?ZxapbwfYTbsi8GKX2+kRmodjY09M09qFAjxOjANDjA40Km4ACcd/jlTowXS5?= =?us-ascii?Q?e2GoeWmUbLAL55+ZyvM5LvU44Uc7n0nwdpaP4DGwQcUYP5AQSMZh/49mi5J5?= =?us-ascii?Q?YNEOoTZIZvo+bg0mAfI1wjOfEIUpuuwDpAg+R7NNPn9kQxE8PJ9fNQWZ54ms?= =?us-ascii?Q?65kfkhsh1QqegCjCW/0RqWWspz04L2eDNLTQELyNCJbEcHrg/KIsuGJOEZx4?= =?us-ascii?Q?byPwbLMIQRPNbzjHvhxFQW6RQsEkhWvFkeR2CPbz9wyKEPJ7S0S/vLBfByUi?= =?us-ascii?Q?OF5d0NrI0m0hjkbbgkcg/o8g25HYbnZo9nfw5sXw/WfyffsEd4FqN3WnRS5o?= =?us-ascii?Q?3W9+IeIEi6mTf/0+W0NPV813OH2kYk087u+oGvduwa1kj76JTk4GEpexVUw1?= =?us-ascii?Q?ObAqEaKVdxKJsWcR7Nzznyjf38tc2G48MohnYbjsXVQHD37JLmY4Ei08CWRK?= =?us-ascii?Q?v1sCwhvIXXZ3yB3+f0ZsxHdM1549HYEum/LITrkb9scsurwfMdbUGRy9ketU?= =?us-ascii?Q?X/6v4OujFnvXuhNRmYcLVjiTAsFICyk5?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV8PR12MB9620.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?YNj2nYjPSyFuVScV6AbftJ10LAx80m5Io9LCYx/K93cgQd5pUbEMlx4f1cQd?= =?us-ascii?Q?5W9RaP41d2LzrL0tg0+A72rkXHF/EPHC75u45NcuWYqfRL92y2YaUWcZSvIX?= =?us-ascii?Q?KuAyWiS5uz/wSMl84qixc0x1j2FaoiIq2m21leFCmSkpD8FY6905nYXu3gSc?= =?us-ascii?Q?nf6lFvtT9a83q3YBDia3sdVdoLit8uN5fuaBDXmfffqRe8nDQ+EkEttLP1ZV?= =?us-ascii?Q?P0ueQdEv0vwazVIJqb1SITwVyf2HYnG4af25zd3GqMO6J5EP3yCmiRKTHLID?= =?us-ascii?Q?WamQUTFKqNmFRpvAtJVaF5oilsV7X1bruOZyrr+W4uTNH2OOz5Wr0YIfiyRy?= =?us-ascii?Q?F6BrkmRxQc/6tLhJ2t7LTrtCG//TSiMuUABcYFKY1HwzP5gwBnQ5t3E9OuoY?= =?us-ascii?Q?oVBoiCh5cYPYteBbBx2o5A5aZ8mhTF7MFINDmxG1pJfrUmXB1i0Z6Vs7bwqI?= =?us-ascii?Q?ZrWTeXd/bsNwMdzNffCZgA7zTkH0DTEJwTMVTI30UqfCY28kcyj3k1f7mhjw?= =?us-ascii?Q?hF575dLk5Ht+s47xQkqsTXI4tSabfSF58NfVwaVhKZ5iZJwqJU0XULbP4HE0?= =?us-ascii?Q?Ft5/wzyMoR3o5I3Y+AUpwrXva13nM1RGbNmSA9utyl1SbCjdu+CPzBrQImhf?= =?us-ascii?Q?KDm8MOXqZo6xwruuJQ8SZEwrGyq9ea2D8ypdrXqZazVrxdcRS6C3Wenvg/wN?= =?us-ascii?Q?nxMO4/7u+racLyDTHyDXwi1CFmwFiUhr6ugbKfAVC7/HcIlZ54F5FWQ28sYw?= =?us-ascii?Q?E7bHevGfYEhRORjYHRCulOdO9Yyzi9TUfK2FVuOfavHHNWAiX6y3jGo/X7jI?= =?us-ascii?Q?PypaxIU8M8xnHCbFvONvHKh21YPc/uYG/fLdT10fjKO9Dplr4PD558BJX3yZ?= =?us-ascii?Q?+ZEpgB9p1BE8aokneOU6xPIRpKjmncdS8XdVvoEjSsfd9iktpTCedlBNi95k?= =?us-ascii?Q?pyeNTjm7g4r6t7mFl9MJgfk+c/i5QoPe72reShTjqP3PX3ZDajMNxB4qtMNb?= =?us-ascii?Q?fdMbxKtBiFr/9H3kP5V2Nen9Zx3ZAqYz2bwmL2basAj4UhGucX/R9Uc3zH6k?= =?us-ascii?Q?YF7YE3KxbWXwW5JSQz20bxfqYv1YPtEz2hm8KX37v21REwZHIV9ZHL4Z5Nbx?= =?us-ascii?Q?TEw/keJzBOwK8DSCQWg4gMVFgbLSGU4fR5dVFdJP6Pspq1aCCLZFMEKvxGVR?= =?us-ascii?Q?3t+t1rtkpsgjS2ilIfqfm4iESuhtjnPHZEqpF+W7pja0TorIE9VGWiigdg2c?= =?us-ascii?Q?b21QT0OrRAWK+XCNb0y4D9fOG8oU4LL4tpOCKQyjgggKcdEE3q7wOvOhc/OC?= =?us-ascii?Q?aTvKd1ZxfJK8CNXACT4oTdUcLq6/nDL8SER6EemgtqAcXf5j9HZ7XyFBAXxl?= =?us-ascii?Q?axRRca21pdTjGBmmYPJ2Goxx+K2iTK19TkuByCtRjvj1HxgqseZGOPeuVYPn?= =?us-ascii?Q?Ap1iniy50/w3ANHn/CC/0p9JRag598HRaOQCGFRvD+2R4hXJ50njOMcesa4I?= =?us-ascii?Q?3LXyAZO3rC/D1/w0C/jTENHsOhfF2oFPtt8oAm88VD2JHIx+dUHQqrv0jEQs?= =?us-ascii?Q?YxWdFqyWEervV6pJ+AZbkuIyDRHUxOBentIIIY/M?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 35b27d77-d59d-4652-fac5-08de3c88992e X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Dec 2025 09:50:51.8566 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: C5MoFuW4ci9dhVsWvHtCMpXVksGcLVfgdlO1kFrpwqhpoCKpDCxo6s+OIDeqKOihFyiSrLXG/KuD2XmaqTKXkA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB6616 On Tue, Dec 16, 2025 at 05:39:55PM +0800, Liang Jie wrote: > From: Liang Jie > > Smatch reported: > > kernel/sched/ext.c:5332 scx_alloc_and_add_sched() warn: passing zero to 'ERR_PTR' > > In scx_alloc_and_add_sched(), the alloc_percpu() failure path jumps to > err_free_gdsqs without initializing @ret. That can lead to returning > ERR_PTR(0), which violates the ERR_PTR() convention and confuses > callers. > > Set @ret to -ENOMEM before jumping to the error path when > alloc_percpu() fails. > > Reported-by: kernel test robot > Closes: https://lore.kernel.org/r/202512141601.yAXDAeA9-lkp@intel.com/ > Reported-by: Dan Carpenter > Fixes: c201ea1578d3 ("sched_ext: Move event_stats_cpu into scx_sched") > Signed-off-by: Liang Jie Makes sense to me, good catch. Reviewed-by: Andrea Righi Thanks, -Andrea > --- > kernel/sched/ext.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index 05f5a49e9649..8ea243b04dc9 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -4761,8 +4761,10 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops) > } > > sch->pcpu = alloc_percpu(struct scx_sched_pcpu); > - if (!sch->pcpu) > + if (!sch->pcpu) { > + ret = -ENOMEM; > goto err_free_gdsqs; > + } > > sch->helper = kthread_run_worker(0, "sched_ext_helper"); > if (IS_ERR(sch->helper)) { > -- > 2.25.1 >