[PATCH v2 0/4] x86: Intel Processor Trace Logger

[Takao Indoh]

Hi all,

These patch series provide logging feature for Intel Processor Trace
(Intel PT).

Intel PT is a new feature of Intel CPU "Broadwell", it captures
information about program execution flow. Here is a article about Intel
PT.
https://software.intel.com/en-us/blogs/2013/09/18/processor-tracing

Once Intel PT is enabled, the events which change program flow, like
branch instructions, exceptions, interruptions, traps and so on are
logged in the memory. This is very useful for debugging because we can
know the detailed behavior of software.

This patch creates log buffer for Intel PT and enable logging at boot
time. When kernel panic occurs, we can get this log buffer from
crashdump file by kdump, and reconstruct the flow that led to the panic.

changelog:
v2:
- Reimplement using perf_event_create_kernel_counter

v1:
https://lkml.org/lkml/2015/7/29/6

Takao Indoh (4):
  perf/trace: Add function to find event type by name
  perf: Add function to enable perf events in kernel with ring buffer
  perf/x86/intel/pt: Add Intel PT logger
  x86: Stop Intel PT and save its registers when panic occurs

 arch/x86/Kconfig                          |   16 +++
 arch/x86/include/asm/intel_pt_log.h       |   13 ++
 arch/x86/kernel/cpu/Makefile              |    2 +
 arch/x86/kernel/cpu/intel_pt_log.c        |  178 +++++++++++++++++++++++++++++
 arch/x86/kernel/cpu/perf_event_intel_pt.c |    6 +
 arch/x86/kernel/crash.c                   |    9 ++
 include/linux/perf_event.h                |   10 ++
 include/linux/trace_events.h              |    2 +
 kernel/events/core.c                      |   70 +++++++++++-
 kernel/trace/trace_event_perf.c           |   22 ++++
 10 files changed, 323 insertions(+), 5 deletions(-)
 create mode 100644 arch/x86/include/asm/intel_pt_log.h
 create mode 100644 arch/x86/kernel/cpu/intel_pt_log.c


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