[SRU][jammy][PULL] Kernel livepatch support for s390x

[John Cabaj]

BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x)

[Impact]
* Enables Livepatch support for Jammy s390x generic kernel

[Fix]
b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration")
f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x")
145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target")
ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'")
9c018ab00f18 ("s390/nospec: align and size extern thunks")
110252959a61 ("s390/nospec: add an option to use thunk-extern")
9183918aabab ("s390/nospec: generate single register thunks if possible")
f08372d421dd ("s390: remove unused expoline to BC instructions")
d1de041f86ad ("s390/entry: remove unused expoline thunk")
376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2")
16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()")
3a133e568eea ("sched: Simplify wake_up_*idle*()")
360b90e726cd ("sched,livepatch: Use task_call_func()")
3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()")
2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()")

[Test Case]
* Boot test
* Tested a Livepatch (patch to /proc/meminfo module)

[Other Info]
* Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429)
* UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols
* kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328)

[Where things could go wrong]
* Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions
* s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior

-----

The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9:

  UBUNTU: Start new release (2023-03-02 21:29:10 -0600)

are available in the git repository at:

  git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch

for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e:

  UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600)

----------------------------------------------------------------
Dimitri John Ledkov (1):
      UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x

John Cabaj (1):
      UBUNTU: [Config] s390x: Removing UBSAN from configuration

Josh Poimboeuf (1):
      bug: Use normal relative pointers in 'struct bug_entry'

Peter Zijlstra (6):
      sched: Improve try_invoke_on_locked_down_task()
      sched,rcu: Rework try_invoke_on_locked_down_task()
      sched,livepatch: Use task_call_func()
      sched: Simplify wake_up_*idle*()
      sched,livepatch: Use wake_up_if_idle()
      sched: Improve wake_up_all_idle_cpus() take #2

Vasily Gorbik (6):
      s390/entry: remove unused expoline thunk
      s390: remove unused expoline to BC instructions
      s390/nospec: generate single register thunks if possible
      s390/nospec: add an option to use thunk-extern
      s390/nospec: align and size extern thunks
      s390/nospec: build expoline.o for modules_prepare target

 arch/arm64/include/asm/asm-bug.h          |  4 ++--
 arch/powerpc/include/asm/bug.h            | 14 ++++++++------
 arch/riscv/include/asm/bug.h              |  4 ++--
 arch/s390/Kconfig                         | 15 +++++++++++++++
 arch/s390/Makefile                        | 20 +++++++++++++++-----
 arch/s390/include/asm/bug.h               |  5 +++--
 arch/s390/include/asm/nospec-insn.h       | 91 +++++++++++++++++++++++++++++++++++--------------------------------------------------------
 arch/s390/kernel/entry.S                  |  1 -
 arch/s390/kernel/nospec-branch.c          | 25 +++++--------------------
 arch/s390/lib/Makefile                    |  2 ++
 arch/s390/lib/expoline/Makefile           |  3 +++
 arch/s390/lib/expoline/expoline.S         | 12 ++++++++++++
 arch/s390/tools/gcc-thunk-extern.sh       | 24 ++++++++++++++++++++++++
 arch/x86/include/asm/bug.h                |  2 +-
 debian.master/config/annotations          |  5 +++--
 debian.master/config/config.common.ubuntu |  2 +-
 debian/rules.d/2-binary-arch.mk           |  4 ++++
 include/linux/sched/idle.h                |  4 ++++
 include/linux/wait.h                      |  3 ++-
 kernel/livepatch/transition.c             | 95 ++++++++++++++++++++++++++++++++++++++++++++++++-----------------------------------------------
 kernel/rcu/tasks.h                        | 12 ++++++------
 kernel/rcu/tree_stall.h                   |  8 ++++----
 kernel/sched/core.c                       | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------
 kernel/smp.c                              | 12 +++++-------
 lib/bug.c                                 | 15 +++++++--------
 scripts/mod/modpost.c                     |  5 +++++
 26 files changed, 263 insertions(+), 207 deletions(-)
 create mode 100644 arch/s390/lib/expoline/Makefile
 create mode 100644 arch/s390/lib/expoline/expoline.S
 create mode 100755 arch/s390/tools/gcc-thunk-extern.sh