[PATCH v4 0/9] bpf: fprobe: rethook: Use ftrace_regs instead of pt_regs

[Masami Hiramatsu (Google)]

Hi,

Here is the 4th version of the series to use ftrace_regs instead of pt_regs
in fprobe.
The previous version is here;

https://lore.kernel.org/all/169181859570.505132.10136520092011157898.stgit@devnote2/

This version fixes the issues pointed in the previous series; fix document
description, keep CONFIG_FPROBE dependency for multi-kprobe, add
static_assert check for ftrace_regs size, reorder the ftrace_partial_regs()
patch for perf fprobe event support, introduce per-cpu pt_regs stack for
perf fprobe event and add Florent's Ack (Thanks!). Also this adds a new
documentation patch to clarify that the $argN and $retval is best effort.

 - 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.
 - Introduce ftrace_partial_regs(). (This changes ARM64 which needs a custom
   implementation)
 - 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.
 - Update bpf multi-kprobe handler use ftrace_partial_regs().
 - Update document for new fprobe callbacks.
 - Add notes for the $argN and $retval.

This series can be applied against the probes/core branch on linux-trace tree.

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) (9):
      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
      ftrace: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
      tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
      bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
      Documentations: probes: Update fprobe document to use ftrace_regs
      Documentation: tracing: Add a note about argument and retval access


 Documentation/trace/fprobe.rst      |   18 +++--
 Documentation/trace/fprobetrace.rst |    8 ++
 Documentation/trace/kprobetrace.rst |    8 ++
 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              |   89 ++++++++++++++++++------
 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         |  131 ++++++++++++++++++++++++++---------
 kernel/trace/trace_probe_tmpl.h     |    2 -
 lib/test_fprobe.c                   |   10 +--
 samples/fprobe/fprobe_example.c     |    4 +
 22 files changed, 267 insertions(+), 109 deletions(-)

--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>