[RFC PATCH 0/6] livepatch: Introduce replace set support

[Yafang Shao <laoar.shao@gmail.com>]

We previously proposed a BPF+livepatch method to enable rapid
experimentation with new kernel features without interrupting production
workloads:

  https://lore.kernel.org/live-patching/20260402092607.96430-1-laoar.shao@gmail.com/

In the resulting discussion, Song and Petr suggested adding a "replace set"
to support scenarios where specific livepatches can be selectively replaced
or skipped.

- Patch #1:
  Adds replace set support for livepatch functions.

- Patch #2~#5:
  Derived from Petr's original patchset:

    https://lore.kernel.org/all/20250115082431.5550-3-pmladek@suse.com/

  All the selftests are not included in this RFC.
  Note: Due to a significant refactor in Patch #5, I have omitted Petr's
  Signed-off-by for that specific patch. Please let me know if this is not
  the preferred approach.

- Patch #6:
  Adds replace set support for the shadow variable API.

Petr Mladek (3):
  livepatch: Add callbacks for introducing and removing states
  livepatch: Allow to handle lifetime of shadow variables using the
    livepatch state
  livepatch: Remove "data" from struct klp_state

Yafang Shao (3):
  livepatch: Support scoped atomic replace using replace set
  livepatch: Remove obsolete per-object callbacks
  livepatch: Support replace_set in shadow variable API

 .../livepatch/cumulative-patches.rst          |  17 +-
 Documentation/livepatch/livepatch.rst         |  23 ++-
 include/linux/livepatch.h                     |  30 ++--
 include/linux/livepatch_external.h            |  62 ++++---
 kernel/livepatch/core.c                       |  51 ++----
 kernel/livepatch/core.h                       |  33 ----
 kernel/livepatch/shadow.c                     |  70 +++++---
 kernel/livepatch/state.c                      | 165 +++++++++++++++++-
 kernel/livepatch/state.h                      |   8 +
 kernel/livepatch/transition.c                 |  29 +--
 scripts/livepatch/init.c                      |   9 +-
 scripts/livepatch/klp-build                   |  14 +-
 tools/include/linux/livepatch_external.h      |  62 ++++---
 tools/objtool/klp-diff.c                      |  16 +-
 14 files changed, 373 insertions(+), 216 deletions(-)

-- 
2.47.3