[RFC PATCH 00/14] kprobes: Unify kretprobe trampoline handlers

[Masami Hiramatsu <mhiramat@kernel.org>]

Hi Peter,

Here is the series of patches to unify the kretprobe trampoline handler
implementation across all architectures which are currently kprobes supported.
Also, this finally removes the in_nmi() check from pre_kretprobe_handler()
since we can avoid double-lock deadlock from NMI by kprobe_busy_begin/end().

The unified generic kretprobe trampoline handler is based on x86 code, which
already support frame-pointer checker. I've enabled it on the arm and
arm64 which I can test. For other architecutres, currently the frame-pointer
checker does not work. If someone wants to enable it, please set the correct
frame pointer to ri->fp and pass it to kretprobe_trampoline_handler() as the
3rd parameter, instead of NULL.

Peter's lockless patch is not included yet because there seems more isses
to be solved. It seems that the cleanup_rp_inst() will be the biggest piece
of this pazzle.


Thank you,

---

Masami Hiramatsu (14):
      kprobes: Add generic kretprobe trampoline handler
      x86/kprobes: Use generic kretprobe trampoline handler
      arm: kprobes: Use generic kretprobe trampoline handler
      arm64: kprobes: Use generic kretprobe trampoline handler
      arc: kprobes: Use generic kretprobe trampoline handler
      csky: kprobes: Use generic kretprobe trampoline handler
      ia64: kprobes: Use generic kretprobe trampoline handler
      mips: kprobes: Use generic kretprobe trampoline handler
      parisc: kprobes: Use generic kretprobe trampoline handler
      powerpc: kprobes: Use generic kretprobe trampoline handler
      s390: kprobes: Use generic kretprobe trampoline handler
      sh: kprobes: Use generic kretprobe trampoline handler
      sparc: kprobes: Use generic kretprobe trampoline handler
      kprobes: Remove NMI context check


 arch/arc/kernel/kprobes.c          |   55 +----------------
 arch/arm/probes/kprobes/core.c     |   79 +-----------------------
 arch/arm64/kernel/probes/kprobes.c |   79 +-----------------------
 arch/csky/kernel/probes/kprobes.c  |   78 +-----------------------
 arch/ia64/kernel/kprobes.c         |   79 +-----------------------
 arch/mips/kernel/kprobes.c         |   55 +----------------
 arch/parisc/kernel/kprobes.c       |   78 ++----------------------
 arch/powerpc/kernel/kprobes.c      |   55 ++---------------
 arch/s390/kernel/kprobes.c         |   81 +------------------------
 arch/sh/kernel/kprobes.c           |   59 +-----------------
 arch/sparc/kernel/kprobes.c        |   52 +---------------
 arch/x86/kernel/kprobes/core.c     |  109 +---------------------------------
 include/linux/kprobes.h            |   32 +++++++++-
 kernel/kprobes.c                   |  117 ++++++++++++++++++++++++++++++++----
 14 files changed, 182 insertions(+), 826 deletions(-)

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