rust: add preempt_[disable|enable]_notrace

Make it possible to disable preemption in a region of Rust code. For
now, this is implemented using helpers.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Author: Darksonn

rust/helpers.c

@@ -165,6 +165,18 @@ rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags)
 }
 EXPORT_SYMBOL_GPL(rust_helper_krealloc);
 
+void rust_helper_preempt_enable_notrace(void)
+{
+	preempt_enable_notrace();
+}
+EXPORT_SYMBOL_GPL(rust_helper_preempt_enable_notrace);
+
+void rust_helper_preempt_disable_notrace(void)
+{
+	preempt_disable_notrace();
+}
+EXPORT_SYMBOL_GPL(rust_helper_preempt_disable_notrace);
+
 /*
  * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
  * use it in contexts where Rust expects a `usize` like slice (array) indices.