[PATCH v1 0/3] list: add primitives for private list manipulations

[Pasha Tatashin]

Recently linux introduced the ability to mark structure members as
__private and access them via ACCESS_PRIVATE(). This mechanism ensures
that internal implementation details are only accessible by the owning
subsystem, enforcing better encapsulation.

However, struct list_head is frequently used as an internal linkage
mechanism within these private sections. The standard macros in
<linux/list.h> (such as list_entry and list_for_each_entry) do not
support ACCESS_PRIVATE() natively. Consequently, subsystems using
private lists are forced to implement ad-hoc workarounds, verbose
casting, or local iterator macros to avoid compiler warnings and access
violations.

This series introduces <linux/list_private.h>, which provides a set of
primitives identical in function to those in <linux/list.h>, but
designed specifically for cases where the embedded struct list_head is a
private member.

The series is structured as follows:
Core Implementation: Adds the list_private.h header with support for
entry retrieval and iteration (forward, reverse, safe, etc.).

Testing: Adds a KUnit test suite to verify that the macros compile
correctly and handle pointer offsets/qualifiers as expected.

Adoption: Updates the liveupdate subsystem to use the new generic API,
replacing its local luo_list_for_each_private implementation.

Pasha Tatashin (3):
  list: add primitives for private list manipulations
  list: add kunit test for private list primitives
  liveupdate: luo_file: Use private list

 Documentation/core-api/list.rst  |   9 ++
 include/linux/list_private.h     | 256 +++++++++++++++++++++++++++++++
 kernel/liveupdate/luo_file.c     |   7 +-
 kernel/liveupdate/luo_internal.h |   7 -
 lib/Kconfig.debug                |  14 ++
 lib/tests/Makefile               |   1 +
 lib/tests/list-private-test.c    |  76 +++++++++
 7 files changed, 360 insertions(+), 10 deletions(-)
 create mode 100644 include/linux/list_private.h
 create mode 100644 lib/tests/list-private-test.c


base-commit: 663d0d1af3faefe673cabf4b6b077149a87ad71f
-- 
2.52.0.487.g5c8c507ade-goog