From 494eaf4651975127d34d5ae6555c72dedba092c9 Mon Sep 17 00:00:00 2001 From: zhidao su Date: Mon, 2 Mar 2026 17:14:40 +0800 Subject: [PATCH] sched_ext: Replace naked scx_root dereferences in kobject callbacks scx_attr_ops_show() and scx_uevent() access scx_root->ops.name directly. This is problematic for two reasons: 1. The file-level comment explicitly identifies naked scx_root dereferences as a temporary measure that needs to be replaced with proper per-instance access. 2. scx_attr_events_show(), the neighboring sysfs show function in the same group, already uses the correct pattern: struct scx_sched *sch = container_of(kobj, struct scx_sched, kobj); Having inconsistent access patterns in the same sysfs/uevent group is error-prone. The kobject embedded in struct scx_sched is initialized as: kobject_init_and_add(&sch->kobj, &scx_ktype, NULL, "root"); so container_of(kobj, struct scx_sched, kobj) correctly retrieves the owning scx_sched instance in both callbacks. Replace the naked scx_root dereferences with container_of()-based access, consistent with scx_attr_events_show() and in preparation for proper multi-instance scx_sched support. Signed-off-by: zhidao su Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 4c2cf0d7d495..a566d2cc8a43 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -3712,7 +3712,9 @@ static void scx_kobj_release(struct kobject *kobj) static ssize_t scx_attr_ops_show(struct kobject *kobj, struct kobj_attribute *ka, char *buf) { - return sysfs_emit(buf, "%s\n", scx_root->ops.name); + struct scx_sched *sch = container_of(kobj, struct scx_sched, kobj); + + return sysfs_emit(buf, "%s\n", sch->ops.name); } SCX_ATTR(ops); @@ -3756,7 +3758,9 @@ static const struct kobj_type scx_ktype = { static int scx_uevent(const struct kobject *kobj, struct kobj_uevent_env *env) { - return add_uevent_var(env, "SCXOPS=%s", scx_root->ops.name); + const struct scx_sched *sch = container_of(kobj, struct scx_sched, kobj); + + return add_uevent_var(env, "SCXOPS=%s", sch->ops.name); } static const struct kset_uevent_ops scx_uevent_ops = {