diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9dde15b2479d0ad1145dd1e538dc2383e532f3f3..dc63eeed4fd953e7a77a97216a42c70fe83dd5d8 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -309,6 +309,7 @@ enum bpf_return_type {
RET_PTR_TO_ALLOC_MEM_OR_NULL, /* returns a pointer to dynamically allocated memory or NULL */
RET_PTR_TO_BTF_ID_OR_NULL, /* returns a pointer to a btf_id or NULL */
RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL, /* returns a pointer to a valid memory or a btf_id or NULL */
+ RET_PTR_TO_MEM_OR_BTF_ID, /* returns a pointer to a valid memory or a btf_id */
};
/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
@@ -1832,6 +1833,7 @@ extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto;
extern const struct bpf_func_proto bpf_copy_from_user_proto;
extern const struct bpf_func_proto bpf_snprintf_btf_proto;
extern const struct bpf_func_proto bpf_per_cpu_ptr_proto;
+extern const struct bpf_func_proto bpf_this_cpu_ptr_proto;
const struct bpf_func_proto *bpf_tracing_func_proto(
enum bpf_func_id func_id, const struct bpf_prog *prog);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index f3c1b637ab3975b1f42e6488194c78f25626b033..c446394135be374890e9abef5e6860924dd3b773 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3703,6 +3703,18 @@ union bpf_attr {
* Return
* A pointer pointing to the kernel percpu variable on *cpu*, or
* NULL, if *cpu* is invalid.
+ *
+ * void *bpf_this_cpu_ptr(const void *percpu_ptr)
+ * Description
+ * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
+ * pointer to the percpu kernel variable on this cpu. See the
+ * description of 'ksym' in **bpf_per_cpu_ptr**\ ().
+ *
+ * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
+ * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
+ * never return NULL.
+ * Return
+ * A pointer pointing to the kernel percpu variable on this cpu.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3859,6 +3871,7 @@ union bpf_attr {
FN(skb_cgroup_classid), \
FN(redirect_neigh), \
FN(bpf_per_cpu_ptr), \
+ FN(bpf_this_cpu_ptr), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 14fe3f64fd82d619038923285fbbb725c7089a3c..25520f5eeaf687d836079b42ca159aeb977ae0c7 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -639,6 +639,18 @@ const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
.arg2_type = ARG_ANYTHING,
};
+BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
+{
+ return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
+}
+
+const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
+ .func = bpf_this_cpu_ptr,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MEM_OR_BTF_ID,
+ .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
+};
+
const struct bpf_func_proto bpf_get_current_task_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
@@ -707,6 +719,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
return &bpf_jiffies64_proto;
case BPF_FUNC_bpf_per_cpu_ptr:
return &bpf_per_cpu_ptr_proto;
+ case BPF_FUNC_bpf_this_cpu_ptr:
+ return &bpf_this_cpu_ptr_proto;
default:
break;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 216b8ece23ce7bbd2186e924778e90330434ce31..d9dbf271ebabdf31fdc80fecc877fadcc0300787 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5128,7 +5128,8 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL;
regs[BPF_REG_0].id = ++env->id_gen;
regs[BPF_REG_0].mem_size = meta.mem_size;
- } else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL) {
+ } else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL ||
+ fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID) {
const struct btf_type *t;
mark_reg_known_zero(env, regs, BPF_REG_0);
@@ -5146,10 +5147,14 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
tname, PTR_ERR(ret));
return -EINVAL;
}
- regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL;
+ regs[BPF_REG_0].type =
+ fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+ PTR_TO_MEM : PTR_TO_MEM_OR_NULL;
regs[BPF_REG_0].mem_size = tsize;
} else {
- regs[BPF_REG_0].type = PTR_TO_BTF_ID_OR_NULL;
+ regs[BPF_REG_0].type =
+ fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+ PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL;
regs[BPF_REG_0].btf_id = meta.ret_btf_id;
}
} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) {
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 364a322e2898697cedfd9f55d7c30250843d51d8..a136a6a63a7190842a65ab9d04e05af9b6be72be 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1329,6 +1329,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_snprintf_btf_proto;
case BPF_FUNC_bpf_per_cpu_ptr:
return &bpf_per_cpu_ptr_proto;
+ case BPF_FUNC_bpf_this_cpu_ptr:
+ return &bpf_this_cpu_ptr_proto;
default:
return NULL;
}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index f3c1b637ab3975b1f42e6488194c78f25626b033..c446394135be374890e9abef5e6860924dd3b773 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3703,6 +3703,18 @@ union bpf_attr {
* Return
* A pointer pointing to the kernel percpu variable on *cpu*, or
* NULL, if *cpu* is invalid.
+ *
+ * void *bpf_this_cpu_ptr(const void *percpu_ptr)
+ * Description
+ * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
+ * pointer to the percpu kernel variable on this cpu. See the
+ * description of 'ksym' in **bpf_per_cpu_ptr**\ ().
+ *
+ * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
+ * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
+ * never return NULL.
+ * Return
+ * A pointer pointing to the kernel percpu variable on this cpu.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3859,6 +3871,7 @@ union bpf_attr {
FN(skb_cgroup_classid), \
FN(redirect_neigh), \
FN(bpf_per_cpu_ptr), \
+ FN(bpf_this_cpu_ptr), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper