Re: [RFC PATCH v5 0/2] sysctl: add CTLTBL_ENTRY_XXX() macros for ctl_table initialization

[Wen Yang <wen.yang@linux.dev>]

Hi Kees, H jioel,

Gentle ping on this series. Please let me know if there are any
concerns or if further changes are needed.

The series is available at:
https://lore.kernel.org/all/x5stdwwsfp2h22zyexn5ycbxnkyc4ioxscninxsa6q7lf6djqr@jkuppwwqubkp/

Thanks for your time,
Wen


On 3/26/26 02:39, wen.yang@linux.dev wrote:
> From: Wen Yang <wen.yang@linux.dev>
> 
> Historically, changes to how struct ctl_table entries are initialized
> (e.g. removing the child field, const-qualifying ctl_table) required
> touching hundreds of files across all subsystems.  Such series require
> the attention of many maintainers, sometimes need to be pulled into
> mainline in a special way, and create lots of unnecessary churn.  With
> CTLTBL_ENTRY_XXX(), future structural changes to struct ctl_table need
> only update the macro definitions.
> 
> Conversion of existing call sites will proceed incrementally from
> kernel/sysctl.c outward, rather than as a treewide sweep.
> 
> This series:
>   1. Introduces the CTLTBL_ENTRY_XXX() macros in include/linux/sysctl.h,
>      using _Generic() for automatic proc_handler selection, auto
>      address-of, auto maxlen via sizeof(), and compile-time validation.
>      Supported types: int, unsigned int, long, unsigned long, bool, u8.
>   2. Converts kernel/sysctl-test.c as a demonstration, adding a
>      parameterized KUnit test covering all macro variants (V, VM, VMR,
>      VN, VNM, VNMH) across int, u8, bool, and char[] types.
> 
> Based on discussion and suggestions from:
> [1] https://sysctl-dev-rtd.readthedocs.io/en/latest/notes/ctltable_entry_macro.html
> [2] https://lore.kernel.org/all/psot4oeauxi3yyj2w4ajm3tfgtcsvao4rhv5sgd5s6ymmjgojk@p3vrj3qluban/
> 
> ---
> Changes in v5:
>    - Extend __CTL_AUTO_HANDLER to support bool and u8
>    - Replace individual test functions with a single parameterized KUnit
>      test (KUNIT_CASE_PARAM) covering all variants and types
>    - Use struct ctl_table as the expected-value container in the param
>      struct, eliminating custom expected_* fields
> 
> Changes in v4:
>    - Fix Wpointer-type-mismatch warnings detected by lkp:
>      https://lore.kernel.org/oe-kbuild-all/202603050724.SZxrEyyu-lkp@intel.com/
> 
> Changes in v3:
>    - Replace the unique macro with "capital letter approach"
>    - Reduce the name further
>    https://lore.kernel.org/all/rn4rsazh7kxf5byq65vw2phyqgzvwm3scczu3l5h2r4aqit2r6@znlpb24z2zuo/
> 
> Changes in v2:
>    - Add lvalue check, handler type check, etc.
>    https://lore.kernel.org/all/xptwb3uwbzposd4xf7khj52ifv4tchcjdgllhv7aabi6d7wgef@2msurl564v53/
> 
> 
> Wen Yang (2):
>    sysctl: introduce CTLTBL_ENTRY_XXX() helper macros
>    sysctl: convert kernel/sysctl-test.c to use CTLTBL_ENTRY_XXX()
> 
>   include/linux/sysctl.h | 307 +++++++++++++++++++++++++++++++++++++++++
>   kernel/sysctl-test.c   | 237 ++++++++++++++++++-------------
>   kernel/sysctl.c        |   2 +
>   3 files changed, 447 insertions(+), 99 deletions(-)
>