[PATCH v1 00/10] tools: Introduce a kernel configuration checker

[Ahmed S. Darwish]

Hi,

A month ago in Prague I proposed a kernel configuration checker:

    PREEMPT_RT configuration: Best practices with kconfig-checker
    https://youtu.be/hqnOmdpGBdQ

This series adds kconfig-checker: a Python tool that checks the kernel
.config against a set of YAML rules and reports all issues by severity.

The series also adds:

     - a PREEMPT_RT configuration ruleset
     - a make checkconfig target
     - support for ruleset overlays

Example:

    $ make defconfig
    $ ./tools/kconfig-checker/check.py check -c .config -r preempt_rt

      Configuration Issues with severity = FATAL
      ==========================================

      * CONFIG_PREEMPT_RT is not in .config

        Rationale:
        https://docs.kernel.org/core-api/real-time/kernel-configuration.html#config-preempt-rt

      Configuration Issues with severity = HIGH
      =========================================

      * CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is unset

        Rationale:
        https://docs.kernel.org/core-api/real-time/kernel-configuration.html#config-cpu-freq-default-gov-performance

      * Below options are set:

        CONFIG_SLUB_DEBUG

        Rationale:
        https://docs.kernel.org/core-api/real-time/kernel-configuration.html#kernel-debug-options

      Configuration Issues with severity = MEDIUM
      ===========================================

      * Below options are set:

        CONFIG_CPU_FREQ_GOV_USERSPACE
        CONFIG_CPU_FREQ_GOV_ONDEMAND

        Rationale:
        https://docs.kernel.org/core-api/real-time/kernel-configuration.html#non-performance-cpu-frequency-governors

      ### ...
      ### More output
      ### ...

The same check can be run through make:

    $ make RULES=preempt_rt checkconfig

If no ruleset is specified, the target prints the available rulesets:

    $ make checkconfig
      Usage: make RULES=<profile> [OVERLAY=<overlay>] checkconfig
      Available RULES: preempt_rt

The overlay mechanism allows distributions, CI systems, and Board Support
Packages to apply additional policy or override existing mainline rules.

For example:

    $ ./tools/kconfig-checker/check.py check	\
          -c path/to/.config			\
          -r preempt_rt				\
          -o path/to/overlay.yml

or:

    $ make RULES=preempt_rt OVERLAY=path/to/overlay.yml checkconfig

Patch 09/10 documents the overlay format and gives an example use case.

My goal is to get this into the kernel and have Debian's PREEMPT_RT kernel
packaging to use it.  I'd also like systemd to use it: its README lists 60
kernel CONFIG_* symbols with different requirements severity.

Thank you!
Ahmed

8<-----

Ahmed S. Darwish (10):
  kconfig-checker: Add schema for rule files
  kconfig-checker: Introduce PREEMPT_RT configuration rules
  kconfig-checker: Add the configuration checker code
  kconfig: Introduce checkconfig target
  Documentation: Describe kconfig-checker usage and design
  kconfig-checker: Split schema to support component reuse
  kconfig-checker: Introduce overlays schema
  kconfig-checker: Add support for rule overlays
  Documentation: Describe kconfig-checker overlays
  kconfig: Introduce OVERLAY= for make checkconfig

 Documentation/admin-guide/README.rst          |  29 +
 .../real-time/kernel-configuration.rst        |   3 +
 Documentation/tools/index.rst                 |   1 +
 Documentation/tools/kconfig_checker.rst       | 101 +++
 scripts/kconfig/Makefile                      |  25 +
 tools/kconfig-checker/check.py                | 686 ++++++++++++++++++
 tools/kconfig-checker/rules/preempt_rt.yml    | 169 +++++
 tools/kconfig-checker/schemas/base.yml        | 114 +++
 tools/kconfig-checker/schemas/overlay.yml     |  28 +
 tools/kconfig-checker/schemas/rules.yml       |  20 +
 10 files changed, 1176 insertions(+)
 
 create mode 100644 Documentation/tools/kconfig_checker.rst
 create mode 100755 tools/kconfig-checker/check.py
 create mode 100644 tools/kconfig-checker/rules/preempt_rt.yml
 create mode 100644 tools/kconfig-checker/schemas/base.yml
 create mode 100644 tools/kconfig-checker/schemas/overlay.yml
 create mode 100644 tools/kconfig-checker/schemas/rules.yml

base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
-- 
2.56.0