Re: [PATCH 1/2] rust: kunit: add config to fail kunit tests if a lockdep warning is triggered

[Andreas Hindborg <a.hindborg@kernel.org>]

"Malte Wechter" <maltewechter@gmail.com> writes:

> When running KUnit tests and a lockdep warning is triggered, the test is
> still marked as passed based only on if test assertions are true.
> Thus, add a Kconfig option CONFIG_RUST_LOCKDEP_KUNIT_DEBUG_LOCKS. When
> this option selected, if lockdep triggers during a test, fail the test.
>
> Signed-off-by: Malte Wechter <maltewechter@gmail.com>
> ---
>  lib/kunit/Kconfig    | 13 +++++++++++++
>  rust/macros/kunit.rs | 10 ++++++++++
>  2 files changed, 23 insertions(+)
>
> diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
> index 94ff8e4089bfb..30bac00c42ce1 100644
> --- a/lib/kunit/Kconfig
> +++ b/lib/kunit/Kconfig
> @@ -142,4 +142,17 @@ config KUNIT_UML_PCI
>
>  	  If unsure, say N.
>
> +config RUST_LOCKDEP_KUNIT_DEBUG_LOCKS
> +	bool "Enable extra debug_locks assertion in Rust KUnit tests"
> +	depends on RUST
> +	depends on LOCKDEP
> +	default n
> +	help
> +	  Adds an extra assertion to each Rust kunit test case that asserts
> +	  that the debug_locks flag from `lockdep` is unchanged. This is useful
> +	  when writing unit tests that could potentially trigger a lockdep warning,
> +	  this makes it so the KUnit test does not succeed if the test assertions are
> +	  true, but a lockdep warning is triggered.
> +
> +	  If unsure, say N.
>  endif # KUNIT
> diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
> index ae20ed6768f15..d1cd0349f86f0 100644
> --- a/rust/macros/kunit.rs
> +++ b/rust/macros/kunit.rs
> @@ -144,9 +144,19 @@ macro_rules! assert_eq {
>                  // here to reduce the length of the assert message.
>                  #(#cfg_attrs)*
>                  {
> +                    #[cfg(CONFIG_RUST_LOCKDEP_KUNIT_DEBUG_LOCKS)]
> +                    let __debug_locks_snapshot = ::kernel::bindings::debug_locks;

Why the double underscore start?


Best regards,
Andreas Hindborg