[PATCH] livepatch hooks, revisted

[Joe Lawrence]

Hi all,

This patch revists the effort that Chris Argus made last year to port
kpatch-style "load hooks" to livepatch:

  https://lkml.org/lkml/2016/8/26/434

Since that discussion, the consistency model has been merged.

This patch locates the hooks in a slightly different place, providing
callbacks to a livepatch module whenever a klp_object is being patched
or unpatched.

A pointer to the current klp_object undergoing (un)patching is also
passed to the hook callback -- with that in hand, the hook
implementation can make decisions based on the current module state
(live, coming, going).

A new Documentation/ file is provided as well as a contrived sample
module and livepatch demo to demonstrate the callbacks.  The example is
about as simple as possible, but could be further embellished to
resemble a real-world livepatch fix if desired.

Thanks,

Joe Lawrence (1):
  livepatch: add (un)patch hooks

 Documentation/livepatch/hooks.txt        |  98 +++++++++++++++++++++++++
 include/linux/livepatch.h                |  32 ++++++++
 kernel/livepatch/core.c                  |   5 --
 kernel/livepatch/patch.c                 |  35 +++++++++
 samples/livepatch/Makefile               |   2 +
 samples/livepatch/livepatch-hooks-demo.c | 122 +++++++++++++++++++++++++++++++
 samples/livepatch/livepatch-hooks-mod.c  |  38 ++++++++++
 7 files changed, 327 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/livepatch/hooks.txt
 create mode 100644 samples/livepatch/livepatch-hooks-demo.c
 create mode 100644 samples/livepatch/livepatch-hooks-mod.c

-- 
1.8.3.1