[RFC PATCH -tip 0/9] kprobes: Cleanup jprobe implementation

[Masami Hiramatsu <mhiramat@kernel.org>]

Hello,

Since we decided to remove jprobe from kernel last year,
its APIs are disabled and we worked on moving in-kernel
jprobe users to kprobes or trace-events. And now no jprobe
users are here anymore.

I think it is good time to get rid of jprobe implementation
from the kernel. However, I need other arch developers help
to complete it, since jprobe is implemented multi arch wide.
I can remove those code, but can not test all of those.

Here is the series of patches to show how to do that.
I tried to remove it from x86 tree. Basically we need to
do 3 things;

 - Remove jprobe functions (register/unregister,
   setjump/longjump) from generic/arch-dependent code.
   [1/9][2/9][3/9]
 - Remove break_handler related code.
   [4/9][5/9][6/9]
 - Do not disable preemption on exception handler
   [7/9][8/9][9/9]

The [3/9] and [6/9] are destractive changes except for x86
(means causes build errors) since those arch still have some
references of those functions. So we need to write patches
similar to [2/9] and [5/9] for each arch before applying those.
In this series I sorted it as this order just for review,
[3/9] and [6/9] should be applied after all archs have
been fixed.

Also, [7/9] is a kind of destractive, which changes required
behavior for the pre_handlers which changes regs->ip.
So we also need a patch similar to [7/9] for each arch too.
Fortunately, current in-tree such user is very limited, both
works only on x86. So it is not hurry, but we need to change
arch dependent code.

Thank you,

---

Masami Hiramatsu (9):
      kprobes: Remove jprobe API implementation
      x86: kprobes: Remove jprobe implementation
      kprobes: Remove jprobe data structure and interfaces
      kprobes: Ignore break_handler
      x86: kprobes: Ignore break_handler
      kprobes: Remove break_handler from struct kprobe
      x86: kprobes: Do not disable preempt on int3 path
      error-injection: Fix to not enabling preemption in pre_handler
      tracing: kprobes: Fix to not enabling preemption


 Documentation/kprobes.txt        |   13 ++--
 arch/x86/include/asm/kprobes.h   |    3 -
 arch/x86/kernel/kprobes/common.h |   10 ---
 arch/x86/kernel/kprobes/core.c   |  114 ++------------------------------------
 arch/x86/kernel/kprobes/ftrace.c |   21 +------
 arch/x86/kernel/kprobes/opt.c    |    1 
 include/linux/kprobes.h          |   54 ------------------
 kernel/fail_function.c           |    1 
 kernel/kprobes.c                 |  115 ++------------------------------------
 kernel/trace/trace_kprobe.c      |    3 -
 10 files changed, 20 insertions(+), 315 deletions(-)

--
Masami Hiramatsu