Re: [RFC PATCH v4 1/7] kernel/api: introduce kernel API specification framework

[Randy Dunlap <rdunlap@infradead.org>]

Hi Sasha,


On 8/25/25 11:14 AM, Sasha Levin wrote:
> Add a comprehensive framework for formally documenting kernel APIs with
> inline specifications. This framework provides:
> 
> - Structured API documentation with parameter specifications, return
>   values, error conditions, and execution context requirements
> - Runtime validation capabilities for debugging (CONFIG_KAPI_RUNTIME_CHECKS)
> - Export of specifications via debugfs for tooling integration
> - Support for both internal kernel APIs and system calls
> 
> The framework stores specifications in a dedicated ELF section and
> provides infrastructure for:
> - Compile-time validation of specifications
> - Runtime querying of API documentation
> - Machine-readable export formats
> - Integration with existing SYSCALL_DEFINE macros
> 
> This commit introduces the core infrastructure without modifying any
> existing APIs. Subsequent patches will add specifications to individual
> subsystems.
> 
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  .gitignore                                    |    1 +
>  Documentation/admin-guide/kernel-api-spec.rst |  507 ++++++

To me, none of this feels like Documentation/admin-guide/ material.
I don't think that many sysadmins will be using it.

Maybe Documentation/dev-tools/ ?
Closer to developer material that admin?


>  MAINTAINERS                                   |    9 +
>  arch/um/kernel/dyn.lds.S                      |    3 +
>  arch/um/kernel/uml.lds.S                      |    3 +
>  arch/x86/kernel/vmlinux.lds.S                 |    3 +
>  include/asm-generic/vmlinux.lds.h             |   20 +
>  include/linux/kernel_api_spec.h               | 1559 +++++++++++++++++
>  include/linux/syscall_api_spec.h              |  125 ++
>  include/linux/syscalls.h                      |   38 +
>  init/Kconfig                                  |    2 +
>  kernel/Makefile                               |    1 +
>  kernel/api/Kconfig                            |   35 +
>  kernel/api/Makefile                           |    7 +
>  kernel/api/kernel_api_spec.c                  | 1155 ++++++++++++
>  15 files changed, 3468 insertions(+)
>  create mode 100644 Documentation/admin-guide/kernel-api-spec.rst
>  create mode 100644 include/linux/kernel_api_spec.h
>  create mode 100644 include/linux/syscall_api_spec.h
>  create mode 100644 kernel/api/Kconfig
>  create mode 100644 kernel/api/Makefile
>  create mode 100644 kernel/api/kernel_api_spec.c
thanks.
-- 
~Randy