[PATCH v3 0/8] bpf: fprobe: rethook: Use ftrace_regs instead of pt_regs

["Masami Hiramatsu (Google)" <mhiramat@kernel.org>]

Hi,

Here is the 3rd version of RFC series to use ftrace_regs instead of pt_regs.
The previous version is here;

https://lore.kernel.org/all/169139090386.324433.6412259486776991296.stgit@devnote2/

This also includes the generic part and minimum modifications of arch
dependent code. (e.g. not including rethook for arm64.) This series is based
on the discussion at

https://lore.kernel.org/all/20230801112036.0d4ee60d@gandalf.local.home/

This version added some documentation updates, fix typos, fix some build errors
on arm64 and s390, rename config name to HAVE_PT_REGS_TO_FTRACE_REGS_CAST, Use
FTRACE_OPS_FL_SAVE_ARGS in fprobe, add ftrace_regs_get_kernel_stack_nth()
and add check HAVE_REGS_AND_STACK_ACCESS_API=y for ftrace_regs APIs.

 - Document fix for the current fprobe callback prototype
 - Simply replace pt_regs in fprobe_entry_handler with ftrace_regs.
 - Expose ftrace_regs even if CONFIG_FUNCTION_TRACER=n.
 - Replace pt_regs in rethook and fprobe_exit_handler with ftrace_regs. This
   introduce a new HAVE_PT_REGS_TO_FTRACE_REGS_CAST which means ftrace_regs is
   just a wrapper of pt_regs (except for arm64, other architectures do this)
 - Update fprobe-events to use ftrace_regs natively.
 - Introduce ftrace_partial_regs(). (This changes ARM64 which needs a custom
   implementation)
 - Update bpf multi-kprobe handler use ftrace_partial_regs().
 - Update document to new fprobe callbacks.

This series can also be found below branch.

https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=topic/fprobe-ftrace-regs

Thank you,

---

Masami Hiramatsu (Google) (8):
      Documentation: probes: Add a new ret_ip callback parameter
      fprobe: Use fprobe_regs in fprobe entry handler
      tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER
      fprobe: rethook: Use ftrace_regs in fprobe exit handler and rethook
      tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
      ftrace: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
      bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
      Documentations: probes: Update fprobe document to use ftrace_regs


 Documentation/trace/fprobe.rst  |   18 +++++---
 arch/Kconfig                    |    1 
 arch/arm64/include/asm/ftrace.h |   11 +++++
 arch/loongarch/Kconfig          |    1 
 arch/s390/Kconfig               |    1 
 arch/s390/include/asm/ftrace.h  |    4 ++
 arch/x86/Kconfig                |    1 
 arch/x86/kernel/rethook.c       |   13 +++---
 include/linux/fprobe.h          |    4 +-
 include/linux/ftrace.h          |   83 +++++++++++++++++++++++++++++----------
 include/linux/rethook.h         |   11 +++--
 kernel/kprobes.c                |   10 ++++-
 kernel/trace/Kconfig            |    9 ++++
 kernel/trace/bpf_trace.c        |   14 ++++---
 kernel/trace/fprobe.c           |   10 ++---
 kernel/trace/rethook.c          |   16 ++++----
 kernel/trace/trace_fprobe.c     |   69 +++++++++++++++++++-------------
 kernel/trace/trace_probe_tmpl.h |    2 -
 lib/test_fprobe.c               |   10 ++---
 samples/fprobe/fprobe_example.c |    4 +-
 20 files changed, 191 insertions(+), 101 deletions(-)

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>