rust: task: Add __rust_helper to helpers

This is needed to inline these helpers into Rust code.

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20260105-define-rust-helper-v2-21-51da5f454a67@google.com

Author: Darksonn

rust/helpers/signal.c

@@ -2,7 +2,7 @@
 
 #include <linux/sched/signal.h>
 
-int rust_helper_signal_pending(struct task_struct *t)
+__rust_helper int rust_helper_signal_pending(struct task_struct *t)
 {
 	return signal_pending(t);
 }

rust/helpers/task.c

@@ -3,60 +3,60 @@
 #include <linux/kernel.h>
 #include <linux/sched/task.h>
 
-void rust_helper_might_resched(void)
+__rust_helper void rust_helper_might_resched(void)
 {
 	might_resched();
 }
 
-struct task_struct *rust_helper_get_current(void)
+__rust_helper struct task_struct *rust_helper_get_current(void)
 {
 	return current;
 }
 
-void rust_helper_get_task_struct(struct task_struct *t)
+__rust_helper void rust_helper_get_task_struct(struct task_struct *t)
 {
 	get_task_struct(t);
 }
 
-void rust_helper_put_task_struct(struct task_struct *t)
+__rust_helper void rust_helper_put_task_struct(struct task_struct *t)
 {
 	put_task_struct(t);
 }
 
-kuid_t rust_helper_task_uid(struct task_struct *task)
+__rust_helper kuid_t rust_helper_task_uid(struct task_struct *task)
 {
 	return task_uid(task);
 }
 
-kuid_t rust_helper_task_euid(struct task_struct *task)
+__rust_helper kuid_t rust_helper_task_euid(struct task_struct *task)
 {
 	return task_euid(task);
 }
 
 #ifndef CONFIG_USER_NS
-uid_t rust_helper_from_kuid(struct user_namespace *to, kuid_t uid)
+__rust_helper uid_t rust_helper_from_kuid(struct user_namespace *to, kuid_t uid)
 {
 	return from_kuid(to, uid);
 }
 #endif /* CONFIG_USER_NS */
 
-bool rust_helper_uid_eq(kuid_t left, kuid_t right)
+__rust_helper bool rust_helper_uid_eq(kuid_t left, kuid_t right)
 {
 	return uid_eq(left, right);
 }
 
-kuid_t rust_helper_current_euid(void)
+__rust_helper kuid_t rust_helper_current_euid(void)
 {
 	return current_euid();
 }
 
-struct user_namespace *rust_helper_current_user_ns(void)
+__rust_helper struct user_namespace *rust_helper_current_user_ns(void)
 {
 	return current_user_ns();
 }
 
-pid_t rust_helper_task_tgid_nr_ns(struct task_struct *tsk,
-				  struct pid_namespace *ns)
+__rust_helper pid_t rust_helper_task_tgid_nr_ns(struct task_struct *tsk,
+						struct pid_namespace *ns)
 {
 	return task_tgid_nr_ns(tsk, ns);
 }