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Lee" , Daniel Borkmann , Alexei Starovoitov , Andrii Nakryiko , Yonghong Song Cc: bpf@vger.kernel.org, netdev@vger.kernel.org References: <20221217153821.2285-1-danieltimlee@gmail.com> <20221217153821.2285-4-danieltimlee@gmail.com> From: Yonghong Song In-Reply-To: <20221217153821.2285-4-danieltimlee@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR03CA0223.namprd03.prod.outlook.com (2603:10b6:a03:39f::18) To SN6PR1501MB2064.namprd15.prod.outlook.com (2603:10b6:805:d::27) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN6PR1501MB2064:EE_|SA1PR15MB4823:EE_ X-MS-Office365-Filtering-Correlation-Id: 57bd00df-a083-406d-c243-08dae0570e2b X-FB-Source: Internal X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 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:SN6PR1501MB2064.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(4636009)(376002)(396003)(346002)(136003)(39860400002)(366004)(451199015)(41300700001)(4326008)(8676002)(36756003)(38100700002)(5660300002)(8936002)(2906002)(83380400001)(31686004)(53546011)(6506007)(478600001)(6486002)(316002)(110136005)(66476007)(66556008)(66946007)(2616005)(86362001)(31696002)(186003)(6512007)(45980500001)(43740500002);DIR:OUT;SFP:1102; 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Lee wrote: > Currently, compiling samples/bpf with LLVM warns about the uninitialized > use of variable with test_current_task_under_cgroup. > > ./samples/bpf/test_current_task_under_cgroup_user.c:57:6: > warning: variable 'cg2' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > if (setup_cgroup_environment()) > ^~~~~~~~~~~~~~~~~~~~~~~~~~ > ./samples/bpf/test_current_task_under_cgroup_user.c:106:8: > note: uninitialized use occurs here > close(cg2); > ^~~ > ./samples/bpf/test_current_task_under_cgroup_user.c:57:2: > note: remove the 'if' if its condition is always false > if (setup_cgroup_environment()) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ./samples/bpf/test_current_task_under_cgroup_user.c:19:9: > note: initialize the variable 'cg2' to silence this warning > int cg2, idx = 0, rc = 1; > ^ > = 0 > 1 warning generated. > > This commit resolve this compiler warning by pre-initialize the variable > with error for safeguard. > > Signed-off-by: Daniel T. Lee Acked-by: Yonghong Song