sched: programmable: add bpf_sched_tg_tag_of helper function

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

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

This helper function read the task group tag for a task.
The bpf prog obtains the tags to detect different workloads.
Signed-off-by: NRen Zhijie <renzhijie2@huawei.com>
Signed-off-by: NChen Hui <judy.chenhui@huawei.com>

include/uapi/linux/bpf.h

@@ -3777,6 +3777,14 @@ union bpf_attr {
  *		to be enabled.
  *	Return
  *		1 if the sched entity belongs to a cgroup, 0 otherwise.
+ *
+ * long bpf_sched_tg_tag_of(struct task_group *tg)
+ *	Description
+ *		Return task group tag of *tg* if CONFIG_CGROUP_SCHED enabled.
+ *		The bpf prog obtains the tags to detect different workloads.
+ *	Return
+ *		Task group tag, if CONFIG_CGROUP_SCHED enabled, 0 as default tag, or
+ *		a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3940,6 +3948,7 @@ union bpf_attr {
 	FN(sched_entity_to_tgidpid),	\
 	FN(sched_entity_to_cgrpid),		\
 	FN(sched_entity_belongs_to_cgrp),	\
+	FN(sched_tg_tag_of),	\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

kernel/bpf/helpers.c

@@ -658,6 +658,7 @@ const struct bpf_func_proto bpf_probe_read_user_proto __weak;
 const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
 const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
 const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
+const struct bpf_func_proto bpf_sched_tg_tag_of_proto __weak;
 
 const struct bpf_func_proto *
 bpf_base_func_proto(enum bpf_func_id func_id)
@@ -697,6 +698,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return &bpf_ringbuf_discard_proto;
 	case BPF_FUNC_ringbuf_query:
 		return &bpf_ringbuf_query_proto;
+	case BPF_FUNC_sched_tg_tag_of:
+		return &bpf_sched_tg_tag_of_proto;
 	default:
 		break;
 	}

kernel/bpf/verifier.c

@@ -5020,10 +5020,10 @@ static bool check_btf_id_ok(const struct bpf_func_proto *fn)
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) {
-		if (fn->arg_type[i] == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i])
+		if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i])
 			return false;
 
-		if (fn->arg_type[i] != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i])
+		if (base_type(fn->arg_type[i]) != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i])
 			return false;
 	}
 

kernel/sched/bpf_sched.c

@@ -112,6 +112,29 @@ static const struct bpf_func_proto bpf_sched_entity_belongs_to_cgrp_proto = {
 	.arg2_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_1(bpf_sched_tg_tag_of, struct task_group *, tg)
+{
+	int ret = 0;
+
+#ifdef CONFIG_CGROUP_SCHED
+	if (tg == NULL)
+		return -EINVAL;
+	ret = tg->tag;
+#endif
+
+	return ret;
+}
+
+BTF_ID_LIST_SINGLE(btf_sched_tg_ids, struct, task_group)
+
+const struct bpf_func_proto bpf_sched_tg_tag_of_proto = {
+	.func		= bpf_sched_tg_tag_of,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= PTR_MAYBE_NULL | ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_sched_tg_ids[0],
+};
+
 static const struct bpf_func_proto *
 bpf_sched_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {

scripts/bpf_helpers_doc.py

@@ -436,6 +436,7 @@ class PrinterHelpers(Printer):
             'struct path',
             'struct btf_ptr',
             'struct sched_entity',
+            'struct task_group',
     ]
     known_types = {
             '...',
@@ -480,6 +481,7 @@ class PrinterHelpers(Printer):
             'struct path',
             'struct btf_ptr',
             'struct sched_entity',
+            'struct task_group',
     }
     mapped_types = {
             'u8': '__u8',

tools/include/uapi/linux/bpf.h

@@ -3777,6 +3777,14 @@ union bpf_attr {
  *		to be enabled.
  *	Return
  *		1 if the sched entity belongs to a cgroup, 0 otherwise.
+ *
+ * long bpf_sched_tg_tag_of(struct task_group *tg)
+ *	Description
+ *		Return task group tag of *tg* if CONFIG_CGROUP_SCHED enabled.
+ *		The bpf prog obtains the tags to detect different workloads.
+ *	Return
+ *		Task group tag, if CONFIG_CGROUP_SCHED enabled, 0 as default tag, or
+ *		a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3940,6 +3948,7 @@ union bpf_attr {
 	FN(sched_entity_to_tgidpid),	\
 	FN(sched_entity_to_cgrpid),		\
 	FN(sched_entity_belongs_to_cgrp),	\
+	FN(sched_tg_tag_of),	\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper