[SRU][jammy][PATCH v3 0/5] ftrace graph return address recovery support for s390x Livepatch

[John Cabaj]

BugLink: https://bugs.launchpad.net/bugs/2013603 (Kernel livepatch ftrace graph fix)

[Impact]
* Additional patches required to support Livepatch for s390x
* Fixes Livepatch transition issues when using ftrace graph tracing
* Requisite functionality is introduced in "390/unwind: recover kretprobe modified return address in stacktrace" and "s390/unwind: fix fgraph return address recovery"
* Additional patches to kprobes required to introduce is_kretprobe_trampoline() and kretprobe_find_ret_addr()

[Fix]
c574883b9de8 ("kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()")
2726cf7071be ("kprobes: treewide: Make it harder to refer kretprobe_trampoline directly")
d32f6425c25b ("kprobes: Add kretprobe_find_ret_addr() for searching return address")
3f5bf344cb0a ("390/unwind: recover kretprobe modified return address in stacktrace")
faf9293c5088 ("s390/unwind: fix fgraph return address recovery")

[Test Case]
* Compile tested
* Boot tested
* Tested a Livepatch (patch to /proc/meminfo module)
* Tested Livepatch from ftrace graphed function (via https://github.com/SUSE/qa_test_klp/, klp_tc_10.sh)

[Other Info]
* kprobes changes don't relate to Livepatch directly, but to the ftrace graph unwinding, which requires changes to fix return address recovery
* kprobes changes largely required to implement new functionality (functions discussed above) and updating function signatures

[Where things could go wrong]
* Functionality already exists upstream, kernel was boot and Livepatch tested
* Adding functionality, and updating function signatures, issues would likely arise during build process
* Regression potential is low

-v3:
* Fixing application issues due to recent kprobes changes since previous patch submission, likely c3694073333c
* Updating cover letter with more clarity

-v2:
* Created new BugLink

Masami Hiramatsu (3):
  kprobes: treewide: Remove trampoline_address from
    kretprobe_trampoline_handler()
  kprobes: treewide: Make it harder to refer kretprobe_trampoline
    directly
  kprobes: Add kretprobe_find_ret_addr() for searching return address

Sumanth Korikkar (1):
  s390/unwind: fix fgraph return address recovery

Vasily Gorbik (1):
  s390/unwind: recover kretprobe modified return address in stacktrace

 arch/arc/include/asm/kprobes.h                |   2 +-
 arch/arc/kernel/kprobes.c                     |  13 +-
 arch/arm/probes/kprobes/core.c                |   9 +-
 arch/arm64/include/asm/kprobes.h              |   2 +-
 arch/arm64/kernel/probes/kprobes.c            |   5 +-
 arch/arm64/kernel/probes/kprobes_trampoline.S |   4 +-
 arch/csky/include/asm/kprobes.h               |   2 +-
 arch/csky/kernel/probes/kprobes.c             |   4 +-
 arch/csky/kernel/probes/kprobes_trampoline.S  |   4 +-
 arch/ia64/kernel/kprobes.c                    |  11 +-
 arch/mips/kernel/kprobes.c                    |  15 ++-
 arch/parisc/kernel/kprobes.c                  |   6 +-
 arch/powerpc/include/asm/kprobes.h            |   2 +-
 arch/powerpc/kernel/kprobes.c                 |  18 +--
 arch/powerpc/kernel/optprobes.c               |   2 +-
 arch/powerpc/kernel/stacktrace.c              |   2 +-
 arch/riscv/include/asm/kprobes.h              |   2 +-
 arch/riscv/kernel/probes/kprobes.c            |   4 +-
 arch/riscv/kernel/probes/kprobes_trampoline.S |   4 +-
 arch/s390/include/asm/kprobes.h               |   2 +-
 arch/s390/include/asm/unwind.h                |  13 ++
 arch/s390/kernel/kprobes.c                    |  12 +-
 arch/s390/kernel/stacktrace.c                 |   2 +-
 arch/s390/kernel/unwind_bc.c                  |   8 +-
 arch/sh/include/asm/kprobes.h                 |   2 +-
 arch/sh/kernel/kprobes.c                      |  12 +-
 arch/sparc/include/asm/kprobes.h              |   2 +-
 arch/sparc/kernel/kprobes.c                   |  12 +-
 arch/x86/include/asm/kprobes.h                |   1 -
 arch/x86/kernel/kprobes/core.c                |  20 ++--
 include/linux/kprobes.h                       |  40 ++++++-
 kernel/kprobes.c                              | 112 +++++++++++++-----
 kernel/trace/trace_output.c                   |   2 +-
 33 files changed, 221 insertions(+), 130 deletions(-)

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2.34.1