[PATCH 11/11] rust: kunit: use `pin_init::zeroed` instead of custom null value

[Gary Guo]

From: Gary Guo <ga...@garyguo.net>

The last null element can be created (constly) using `pin_init::zeroed`,
so prefer to use it instead of adding a custom way of building it.

Signed-off-by: Gary Guo <ga...@garyguo.net>
---
rust/kernel/kunit.rs | 26 +-------------------------
rust/macros/kunit.rs | 4 ++--
2 files changed, 3 insertions(+), 27 deletions(-)

diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 79436509dd73d..034158cdaf06b 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -192,9 +192,6 @@ pub fn is_test_result_ok(t: impl TestResult) -> bool {
}

/// Represents an individual test case.
-///
-/// The [`kunit_unsafe_test_suite!`] macro expects a NULL-terminated list of valid test cases.
-/// Use [`kunit_case_null`] to generate such a delimiter.
#[doc(hidden)]
pub const fn kunit_case(
name: &'static kernel::str::CStr,
@@ -215,27 +212,6 @@ pub const fn kunit_case(
}
}

-/// Represents the NULL test case delimiter.
-///
-/// The [`kunit_unsafe_test_suite!`] macro expects a NULL-terminated list of test cases. This
-/// function returns such a delimiter.
-#[doc(hidden)]
-pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
- kernel::bindings::kunit_case {
- run_case: None,
- name: core::ptr::null_mut(),
- generate_params: None,
- attr: kernel::bindings::kunit_attributes {
- speed: kernel::bindings::kunit_speed_KUNIT_SPEED_NORMAL,
- },
- status: kernel::bindings::kunit_status_KUNIT_SUCCESS,
- module_name: core::ptr::null_mut(),
- log: core::ptr::null_mut(),
- param_init: None,
- param_exit: None,
- }
-}
-
/// Registers a KUnit test suite.
///
/// # Safety
@@ -254,7 +230,7 @@ pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
///
/// static mut KUNIT_TEST_CASES: [kernel::bindings::kunit_case; 2] = [
/// kernel::kunit::kunit_case(kernel::c_str!("name"), test_fn),
-/// kernel::kunit::kunit_case_null(),
+/// pin_init::zeroed(),
/// ];
/// kernel::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES);
/// ```
diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index 516219f5b1356..fd2cfabfaef76 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -74,7 +74,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
// static mut TEST_CASES: [::kernel::bindings::kunit_case; 3] = [
// ::kernel::kunit::kunit_case(::kernel::c_str!("foo"), kunit_rust_wrapper_foo),
// ::kernel::kunit::kunit_case(::kernel::c_str!("bar"), kunit_rust_wrapper_bar),
- // ::kernel::kunit::kunit_case_null(),
+ // ::pin_init::zeroed(),
// ];
//
// ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES);
@@ -159,7 +159,7 @@ macro_rules! assert_eq {
processed_items.push(parse_quote! {
static mut TEST_CASES: [::kernel::bindings::kunit_case; #num_tests_plus_1] = [
#(#test_cases,)*
- ::kernel::kunit::kunit_case_null(),
+ ::pin_init::zeroed(),
];
});
processed_items.push(parse_quote! {
--
2.51.2

[Benno Lossin]

On Thu Dec 11, 2025 at 7:56 PM CET, Gary Guo wrote:
> From: Gary Guo <ga...@garyguo.net>
>
> The last null element can be created (constly) using `pin_init::zeroed`,
> so prefer to use it instead of adding a custom way of building it.
>
> Signed-off-by: Gary Guo <ga...@garyguo.net>

Reviewed-by: Benno Lossin <los...@kernel.org>

Cheers,
Benno

[Tamir Duberstein]

On Thu, Dec 11, 2025 at 2:36 PM Gary Guo <ga...@kernel.org> wrote:
>
> From: Gary Guo <ga...@garyguo.net>
>
> The last null element can be created (constly) using `pin_init::zeroed`,
> so prefer to use it instead of adding a custom way of building it.
>
> Signed-off-by: Gary Guo <ga...@garyguo.net>

Reviewed-by: Tamir Duberstein <tam...@gmail.com>

[Gary Guo]

From: Gary Guo <ga...@garyguo.net>

The last null element can be created (constly) using `pin_init::zeroed`,
so prefer to use it instead of adding a custom way of building it.

Reviewed-by: Tamir Duberstein <tam...@gmail.com>
Reviewed-by: Benno Lossin <los...@kernel.org>
Signed-off-by: Gary Guo <ga...@garyguo.net>

index afbc708cbdc50..cb29f350d5b2b 100644

[Gary Guo]

[David Gow]

On Tue, 13 Jan 2026 at 01:12, Gary Guo <ga...@kernel.org> wrote:
>
> From: Gary Guo <ga...@garyguo.net>
>
> The last null element can be created (constly) using `pin_init::zeroed`,
> so prefer to use it instead of adding a custom way of building it.
>
> Reviewed-by: Tamir Duberstein <tam...@gmail.com>
> Reviewed-by: Benno Lossin <los...@kernel.org>
> Signed-off-by: Gary Guo <ga...@garyguo.net>
> ---

Reviewed-by: David Gow <davi...@google.com>

(Do note, however, that this conflicts with
https://lore.kernel.org/rust-for-linux/20251130211233.36...@gmail.com/)

Cheers,
-- David