[RFC PATCH v3 0/6] uprobes: return probe implementation

[Anton Arapov <anton@redhat.com>]

Hello,

  RFC v3 uretprobes implementation. I'd be grateful for review.

  These patches extending uprobes by enabling tools, such as perf(trace_event),
set a breakpoint on probed function's return address. 

v3 changes:
  - removed uretprobe_bypass logic, it will be better to send it as
    independent patch
  - unified xol_get_trampoline_slot() and xol_get_insn_slot()
  - protected uprobe with refcounter in prepare_uretprobe()
  - uprobe_register() routine fails now, if neither consumer is set
  - enclosed implementation into 1/6, 6/6 patches -ENOSYS bits

v2 changes:
  - introduced rp_handler(), get rid of return_consumers
  - get rid of uretprobe_[un]register()
  - introduced arch_uretprobe_get_sp()
  - removed uprobe_task->doomed, kill task immediately
  - fix arch_uretprobe_hijack_return_addr()'s returns
  - address the v1 minor issues

integrated patchset:
  http://github.com/arapov/linux-aa/commits/uretprobes_v3

previous implementations:
  RFCv2: https://lkml.org/lkml/2013/1/9/157
  RFCv1: https://lkml.org/lkml/2012/12/21/133

thanks,
Anton

Anton Arapov (6):
  uretprobes: preparation patch
  uretprobes/x86: hijack return address
  uretprobes: generalize xol_get_insn_slot()
  uretprobes: return probe entry, prepare uretprobe
  uretprobes: invoke return probe handlers
  uretprobes: implemented, thus remove -ENOSYS

 arch/x86/include/asm/uprobes.h |   6 +++
 arch/x86/kernel/uprobes.c      |  29 +++++++++++
 include/linux/uprobes.h        |   6 +++
 kernel/events/uprobes.c        | 112 ++++++++++++++++++++++++++++++++++++++---
 4 files changed, 146 insertions(+), 7 deletions(-)

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1.8.1.2