Re: [PATCH 5/6] lib: compile generic bitrev.c conditionally on GENERIC_BITREVERSE

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The commit breaks loadable module support for `lib/bitrev.c` by forcibly compiling it statically into the core kernel (`vmlinux`) even when configured as a module (`CONFIG_BITREVERSE=m`).
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commit 7ea6ceee0bfd2cae761187221063672a5947f4c4
Author: Yury Norov <ynorov@nvidia.com>

lib: compile generic bitrev.c conditionally on GENERIC_BITREVERSE

This commit simplifies the build logic for the generic bit-reversal library.
It changes the Makefile to compile lib/bitrev.c based on
CONFIG_GENERIC_BITREVERSE instead of CONFIG_BITREVERSE, and removes the
corresponding preprocessor conditionals from the source file.

> diff --git a/lib/Makefile b/lib/Makefile
> index f33a24bf1c19a..23e07d19d01c9 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -145,7 +145,7 @@ obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
>  obj-$(CONFIG_LIST_HARDENED) += list_debug.o
>  obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
>  
> -obj-$(CONFIG_BITREVERSE) += bitrev.o
> +obj-$(CONFIG_GENERIC_BITREVERSE) += bitrev.o

Will this break loadable module support for lib/bitrev.c?

CONFIG_BITREVERSE is a tristate, allowing the library to be built as a
module. However, CONFIG_GENERIC_BITREVERSE is a boolean. When
CONFIG_BITREVERSE is set to modular, CONFIG_GENERIC_BITREVERSE evaluates
to y.

By switching the Makefile rule to use CONFIG_GENERIC_BITREVERSE, bitrev.o
will be built into the core kernel unconditionally when the generic
implementation is used, even if a modular build was requested.

Could this regression lead to unintended kernel bloat by ignoring the
configuration intent?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260430211351.658193-1-ynorov@nvidia.com?part=5