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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?lzF6HQEWbcPlKjS8JMHKixSD08jM64s84Il06uabPPXormCZQZyXSGYQnJP9?= =?us-ascii?Q?V8FhZD9RBJPKVJhv2orVL8jplWAfnoIVY/u/Kk1jDcnkYpXHMu2zI5ALx+WG?= =?us-ascii?Q?wFvS7hS84xxM2aiYU4fu5UBWQt+P42BqvDNnhvU9u+vNHBEbmuGLoW7BNd/p?= =?us-ascii?Q?F1uUkRn1Jvz0CYEfJi99cbKEyFE+SOMy9lb4HfiI9L3F8rzgcp8DZP9QfmfK?= =?us-ascii?Q?As4JZz8Gf/gUAPIGzJ7bFxc2QJaOFfJmSi0aK0tE63A0eNl+mXfV0YY8Klgr?= =?us-ascii?Q?57t0H49YeMheZO/FXPZcxYKh9cjM0YfzB7t7EiW+tH2mCBJONuPfd5PzwtbV?= =?us-ascii?Q?y/qY0Szg1Dy3vSjRVyafy1TMbUE7gnjvxb9rF985aHkkRDusu7lJIlHwUbC1?= =?us-ascii?Q?e0uil5ImITTe0FlWMkRXULUdjgIRZnN1xwJ+2lrC6V2h4RCF4M8BMpCN8idp?= =?us-ascii?Q?UOLvRvuN2xPSfdwNp03LA3iOxfVc9gaVyVn4F1BucXM5HcGdN3stkkgCxhcr?= =?us-ascii?Q?c09yvMDL7V6I1wdenQc43LmOM9CXUgap+dwjBZzq6WPY/a4bOLqcf/Ysqqmm?= =?us-ascii?Q?iBcCYKl4mhSZzRxT7zqXI7k9zTmjkkh8/Z3L72nFO0RZla8Wk7x9wVrjtFTZ?= =?us-ascii?Q?xGimKwwKXvCDrnC44JWQMWNqAlraNmQSsFbRHFL+O5+ZwS27OxaOuzZmQKkw?= =?us-ascii?Q?dwWxhgowUX4C1Knrn0AZFCVkW06kuIK/iMY1Bxkkx/eNQwE0H/81bTMwbdr1?= =?us-ascii?Q?UshQvTMlosYJsdBPt99qt6ukFtQTHFRS5+AuKC367q6mVRVxL2/wsF9TIA9U?= =?us-ascii?Q?XH36736wByOgA31VhRZS+5DG/N+lhsKS8SRSWeAGWwccsyJIcrHchujT2RvT?= =?us-ascii?Q?0d2OW3r7IEAsC8oa+NHxGzpjWp+eVNuKUDAPOFf2aJwwueSvshXbHGRVPLGL?= =?us-ascii?Q?SYvqcP5nx2IOUHJ3AErrMQ39QQ9l6LtuywMkcaf2Wms4/pAfvMVrUscEb98x?= =?us-ascii?Q?k5lClYAC0RrJmsrcLRHd6YzAnvApA410yCc5KUFRpKh90QDZltesKsHsM3su?= =?us-ascii?Q?x3D+8Em1OcJ46tDJPcwgtM9MyDEuyXWBjVnimdiwgBHkVCwNRfUXcHU402fb?= =?us-ascii?Q?ZcF9WkcPtGmopjvirRR0IeD2nh6cu6uGWMuD6sATAIxzffPw8N0Dc5kP2Aap?= =?us-ascii?Q?ejmZF1MXkKl0HPPsjJEf2nVK3PRY+N2Ye+inKZja6KWYVEB6XuaIp1oVBHXQ?= =?us-ascii?Q?amKKXod1ZD7t2iztX5B+r9JBywYPTj8XBIQ9zPaK8MAJ0XVikl1HVW43iFjp?= =?us-ascii?Q?Nkk29pkHsqp0xqXPaxLeihJMYFJGC5vKkmzziXeM1sfeGMWLeGenFIw4D6Wi?= =?us-ascii?Q?CbYWi6SPdf4OrkYP8Oeg0lYgg5581YApjKsfxlS+9nkU/XmryrVmKlY0DYAf?= =?us-ascii?Q?Dm3wuedY6aHKEx5Ssm967AbhN8O/Nw7c17XWx5cxnMriSnm7VChBbZjur73P?= =?us-ascii?Q?P0oIJ/SjOKcwJERJgtjutn1109M3kc+J3dlyiGAbCLrJvOZEATGR/wVYpUBm?= =?us-ascii?Q?BkN05Co+X5HCqWhP+9fYc3EgBoEMCpDjNxxTeFOq?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2214c50c-fa2e-41d5-7d90-08ddcf2cfeb3 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2025 05:50:31.7144 (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: SCrhNDq+uk7addEm5pKO3VksW/zc4wL4yIuucCTkLYnJG1ypZxN3IPENUdkIui/PnyRL8Kwdqx1qugJAtnq/TQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7209 Hi Christian, On Tue, Jul 29, 2025 at 05:03:36PM +0100, Christian Loehle wrote: > scx_bpf_cpu_rq() obviously returns NULL on invalid cpu. > Mark it as such. Makes sense. Maybe add something like the following to the commit message to better justify why we want the verifier to enforce the NULL check: While scx_ops_error() is triggered on invalid CPUs, the BPF scheduler doesn't exit immediately, so there's a window where scx_bpf_cpu_rq() may return NULL and still be dereferenced. With something like that: Acked-by: Andrea Righi Thanks, -Andrea > > Cc: stable@vger.kernel.org > Fixes: 6203ef73fa5c ("sched/ext: Add BPF function to fetch rq") > Signed-off-by: Christian Loehle > --- > kernel/sched/ext.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index 7dd5cbcb7a06..b734f55f3318 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -7599,7 +7599,7 @@ BTF_ID_FLAGS(func, scx_bpf_get_online_cpumask, KF_ACQUIRE) > BTF_ID_FLAGS(func, scx_bpf_put_cpumask, KF_RELEASE) > BTF_ID_FLAGS(func, scx_bpf_task_running, KF_RCU) > BTF_ID_FLAGS(func, scx_bpf_task_cpu, KF_RCU) > -BTF_ID_FLAGS(func, scx_bpf_cpu_rq) > +BTF_ID_FLAGS(func, scx_bpf_cpu_rq, KF_RET_NULL) > #ifdef CONFIG_CGROUP_SCHED > BTF_ID_FLAGS(func, scx_bpf_task_cgroup, KF_RCU | KF_ACQUIRE) > #endif > -- > 2.34.1