Re: [PATCH v8 07/17] iio: test: add kunit tests for channel prefix naming generation

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The tristate Kconfig option IIO_CHANNEL_PREFIX_KUNIT_TEST allows a configuration where the test is built-in but KUnit is a module, causing linker failures.
--

--- Patch [7]: [PATCH v8 07/17] iio: test: add kunit tests for channel prefix naming generation ---
commit 103d8c2a68a52f0447bd7dca00d5cedd2334e131
Author: Rodrigo Alencar <rodrigo.alencar@analog.com>

iio: test: add kunit tests for channel prefix naming generation

This commit adds a KUnit test suite for the internal helper function
__iio_chan_prefix_emit(), which builds IIO sysfs attribute name prefixes.
Because the function is static, the test file is included directly into
industrialio-core.c.

> diff --git a/drivers/iio/test/Kconfig b/drivers/iio/test/Kconfig
> index 4fc17dd0dcd77..7d2c29cc583b9 100644
> --- a/drivers/iio/test/Kconfig
> +++ b/drivers/iio/test/Kconfig
[ ... ]
> @@ -4,6 +4,20 @@
>  #
>  
>  # Keep in alphabetical order
> +config IIO_CHANNEL_PREFIX_KUNIT_TEST
> +	tristate "Test IIO channel prefix" if !KUNIT_ALL_TESTS
> +	depends on KUNIT && IIO
> +	default KUNIT_ALL_TESTS
[ ... ]
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index b365922d84810..3909255212f5e 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
[ ... ]
> @@ -2230,6 +2230,10 @@ EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
>  subsys_initcall(iio_init);
>  module_exit(iio_exit);
>  
> +#if IS_ENABLED(CONFIG_IIO_CHANNEL_PREFIX_KUNIT_TEST)
> +#include "test/iio-test-channel-prefix.c"
> +#endif

[Severity: High]
Does this setup cause linker errors if CONFIG_IIO is built-in (y) and
CONFIG_KUNIT is built as a module (m)?

Looking at the Kconfig, IIO_CHANNEL_PREFIX_KUNIT_TEST is a tristate that
depends on KUNIT && IIO. If CONFIG_IIO=y and CONFIG_KUNIT=m, the test config
evaluates to 'm'.

Because IS_ENABLED() is true for both 'y' and 'm', this preprocessor check
will include the test code directly into industrialio-core.o, which is built-in.

Since the test code references KUnit symbols that are isolated in a loadable
module, could this result in undefined reference errors during the final
vmlinux link stage?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714-ad9910-iio-driver-v8-0-36939c3c07d2@analog.com?part=7