sched: programmable: Add convenient helper functions to convert sched entity

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5KUFB
CVE: NA

--------------------------------

Add three helper functions:
1) bpf_sched_entity_is_task is to check whether the sched entity
is a task struct.
2) bpf_sched_entity_to_task is to change the sched entity to a
task struct.
3) bpf_sched_entity_to_tg is to change the sched entity to a task
group.
Signed-off-by: NChen Hui <judy.chenhui@huawei.com>
Signed-off-by: NRen Zhijie <renzhijie2@huawei.com>

include/uapi/linux/bpf.h

@@ -3792,6 +3792,24 @@ union bpf_attr {
  *		different workloads.
  *	Return
  *		Task tag, if used, 0 as default tag, or a negative error in case of failure.
+ *
+ * long bpf_sched_entity_is_task(struct sched_entity *se)
+ *	Description
+ *		Checks whether the sched entity is a task.
+ *	Return
+ *		1 if true, 0 otherwise.
+ *
+ * struct task_struct *bpf_sched_entity_to_task(struct sched_entity *se)
+ *	Description
+ *		Return task struct of *se* if se is a task.
+ *	Return
+ *		Task struct if se is a task, NULL otherwise.
+ *
+ * struct task_group *bpf_sched_entity_to_tg(struct sched_entity *se)
+ *	Description
+ *		Return task group of *se* if se is a task group.
+ *	Return
+ *		Task struct if se is a task group, NULL otherwise.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3957,6 +3975,9 @@ union bpf_attr {
 	FN(sched_entity_belongs_to_cgrp),	\
 	FN(sched_tg_tag_of),	\
 	FN(sched_task_tag_of),	\
+	FN(sched_entity_is_task),	\
+	FN(sched_entity_to_task),	\
+	FN(sched_entity_to_tg),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

kernel/sched/bpf_sched.c

@@ -152,6 +152,61 @@ const struct bpf_func_proto bpf_sched_task_tag_of_proto = {
 	.arg1_btf_id	= &btf_sched_task_ids[0],
 };
 
+BPF_CALL_1(bpf_sched_entity_is_task, struct sched_entity *, se)
+{
+	return entity_is_task(se) ? 1 : 0;
+}
+
+static const struct bpf_func_proto bpf_sched_entity_is_task_proto = {
+	.func		= bpf_sched_entity_is_task,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_sched_entity_ids[0],
+};
+
+BPF_CALL_1(bpf_sched_entity_to_task, struct sched_entity *, se)
+{
+	if (entity_is_task(se)) {
+		struct task_struct *tsk = task_of(se);
+
+		return (unsigned long)tsk;
+	}
+
+	return (unsigned long)NULL;
+}
+
+static const struct bpf_func_proto bpf_sched_entity_to_task_proto = {
+	.func		= bpf_sched_entity_to_task,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_BTF_ID_OR_NULL,
+	.ret_btf_id	= &btf_sched_task_ids[0],
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_sched_entity_ids[0],
+};
+
+BPF_CALL_1(bpf_sched_entity_to_tg, struct sched_entity *, se)
+{
+#if CONFIG_FAIR_GROUP_SCHED
+	if (!entity_is_task(se)) {
+		struct task_group *tg = group_cfs_rq(se)->tg;
+
+		return (unsigned long)tg;
+	}
+#endif
+
+	return (unsigned long)NULL;
+}
+
+static const struct bpf_func_proto bpf_sched_entity_to_tg_proto = {
+	.func		= bpf_sched_entity_to_tg,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_BTF_ID_OR_NULL,
+	.ret_btf_id	= &btf_sched_tg_ids[0],
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_sched_entity_ids[0],
+};
+
 static const struct bpf_func_proto *
 bpf_sched_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -164,6 +219,12 @@ bpf_sched_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_sched_entity_to_cgrpid_proto;
 	case BPF_FUNC_sched_entity_belongs_to_cgrp:
 		return &bpf_sched_entity_belongs_to_cgrp_proto;
+	case BPF_FUNC_sched_entity_is_task:
+		return &bpf_sched_entity_is_task_proto;
+	case BPF_FUNC_sched_entity_to_task:
+		return &bpf_sched_entity_to_task_proto;
+	case BPF_FUNC_sched_entity_to_tg:
+		return &bpf_sched_entity_to_tg_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}

tools/include/uapi/linux/bpf.h

@@ -3792,6 +3792,24 @@ union bpf_attr {
  *		different workloads.
  *	Return
  *		Task tag, if used, 0 as default tag, or a negative error in case of failure.
+ *
+ * long bpf_sched_entity_is_task(struct sched_entity *se)
+ *	Description
+ *		Checks whether the sched entity is a task.
+ *	Return
+ *		1 if true, 0 otherwise.
+ *
+ * struct task_struct *bpf_sched_entity_to_task(struct sched_entity *se)
+ *	Description
+ *		Return task struct of *se* if se is a task.
+ *	Return
+ *		Task struct if se is a task, NULL otherwise.
+ *
+ * struct task_group *bpf_sched_entity_to_tg(struct sched_entity *se)
+ *	Description
+ *		Return task group of *se* if se is a task group.
+ *	Return
+ *		Task struct if se is a task group, NULL otherwise.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3957,6 +3975,9 @@ union bpf_attr {
 	FN(sched_entity_belongs_to_cgrp),	\
 	FN(sched_tg_tag_of),	\
 	FN(sched_task_tag_of),	\
+	FN(sched_entity_is_task),	\
+	FN(sched_entity_to_task),	\
+	FN(sched_entity_to_tg),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper