[PATCH v2 0/4] perf: parse the dwarf backtrace info from .debug_frame section

[Jean Pihet]

On ARM the debug info is not present in the .eh_frame sections but
in .debug_frame instead, in dwarf format.

This patch set uses libunwind to load and parse the dwarf debug info from
the .debug_frame section if no .eh_frame_hdr section is found; also it
sets the hooks in the perf_regs and libunwind code for ARMv7.

Dependencies:
 . if present, libunwind >= 1.1 is needed to prevent a segfault when
   parsing the dwarf info,
 . libunwind needs to be configured with --enable-debug-frame
   to prevent a linkage error. Note: --enable-debug-frame is automatically
   selected on ARM).

The generated perf has been tested on ARMv7 (OMAP4, Marvell Armada XP) and
x86_64, using the following commands:
 perf record -g [dwarf] -- <binary>
 perf report --sort symbol --call-graph --stdio


Jean Pihet (2):
  perf tools: Check libunwind for availability of dwarf parsing feature
  perf: parse the .debug_frame section in case .eh_frame is not present

Will Deacon (2):
  ARM: perf: add support for perf registers API
  ARM: perf: wire up perf_regs and unwind support for ARM

 arch/arm/Kconfig                        |  2 +
 arch/arm/include/uapi/asm/Kbuild        |  1 +
 arch/arm/include/uapi/asm/perf_regs.h   | 23 +++++++++++
 arch/arm/kernel/Makefile                |  1 +
 arch/arm/kernel/perf_regs.c             | 30 ++++++++++++++
 tools/perf/arch/arm/Makefile            |  3 ++
 tools/perf/arch/arm/include/perf_regs.h | 54 +++++++++++++++++++++++++
 tools/perf/arch/arm/util/unwind.c       | 48 ++++++++++++++++++++++
 tools/perf/config/Makefile              |  7 +++-
 tools/perf/config/feature-tests.mak     | 11 ++++-
 tools/perf/util/unwind.c                | 71 +++++++++++++++++++++++++--------
 11 files changed, 232 insertions(+), 19 deletions(-)
 create mode 100644 arch/arm/include/uapi/asm/perf_regs.h
 create mode 100644 arch/arm/kernel/perf_regs.c
 create mode 100644 tools/perf/arch/arm/include/perf_regs.h
 create mode 100644 tools/perf/arch/arm/util/unwind.c

-- 
1.7.11.7