[PATCH v8 00/14] Add support for remote unwind

[He Kuang]

v7 url:
  http://thread.gmane.org/gmane.linux.kernel/2231229/focus=2232166

Currently, perf script uses host unwind methods(local unwind) to parse
perf.data callchain info regardless of the target architecture. So we
get wrong result and no promotion when do remote unwind on other
platforms/machines.

This patchset checks whether a dso is 32-bit or 64-bit according to
elf class info for each thread to let perf use the correct remote
unwind methods instead.

Only x86 and aarch64 is added in this patchset to show the work flow,
other platforms can be added easily.

We can see the right result for unwind info on different machines, for
example: perf.data recorded on i686 qemu with '-g' option and parsed
on x86_64 machine.

before this patchset:

  hello  1219 [001] 72190.667975: probe:sys_close: (c1169d60)
                  c1169d61 sys_close ([kernel.kallsyms])
                  c189c0d7 sysenter_past_esp ([kernel.kallsyms])
                  b777aba9 [unknown] ([vdso32])

after:
(Add vdso into buildid-cache first by 'perf buildid-cache -a' and
libraries are provided in symfs dir)

  hello  1219 [001] 72190.667975: probe:sys_close: (c1169d60)
                  c1169d61 sys_close ([kernel.kallsyms])
                  c189c0d7 sysenter_past_esp ([kernel.kallsyms])
                  b777aba9 __kernel_vsyscall ([vdso32])
                  b76971cc close (/lib/libc-2.22.so)
                   804842e fib (/tmp/hello)
                   804849d main (/tmp/hello)
                  b75d746e __libc_start_main (/lib/libc-2.22.so)
                   8048341 _start (/tmp/hello)

For using remote libunwind libraries, reference this:
  http://thread.gmane.org/gmane.linux.kernel/2224430

and now we can use LIBUNWIND_DIR to specific custom dirctories
containing libunwind libs.

v8:

 - Put unwind__register_ops call into unwind__prepare_access from
   patch 4 to patch 3.
 - Fail thread__insert_map on error.
 - Remove unused macro HAVE_LIBUNWIND_LOCAL_SUPPORT.
 - Return once find that thread->addr_space is valid and check this
   value first.
 - Add comments in file 'util/libunwind/arm64.c',
   'util/libunwind/x86_32.c', and explain the reason for debug-frame
   flag in non-arm arch.

Thanks.

He Kuang (14):
  perf tools: Use LIBUNWIND_DIR for remote libunwind feature check
  perf tools: Decouple thread->address_space on libunwind
  perf tools: Introducing struct unwind_libunwind_ops for local unwind
  perf tools: Move unwind__prepare_access from thread_new into
    thread__insert_map
  perf tools: Don't mix LIBUNWIND_LIBS into LIBUNWIND_LDFLAGS
  perf tools: Separate local/remote libunwind config
  perf tools: Rename unwind-libunwind.c to unwind-libunwind-local.c
  perf tools: Extract common API out of unwind-libunwind-local.c
  perf tools: Export normalize_arch() function
  perf tools: Check the target platform before assigning unwind methods
  perf tools: Change fixed name of libunwind__arch_reg_id to macro
  perf tools: Introduce flag to separate local/remote unwind compilation
  perf callchain: Support x86 target platform
  perf callchain: Support aarch64 cross-platform

 tools/perf/arch/arm/util/Build                |   2 +-
 tools/perf/arch/arm64/util/Build              |   2 +-
 tools/perf/arch/arm64/util/unwind-libunwind.c |   4 +-
 tools/perf/arch/common.c                      |   2 +-
 tools/perf/arch/common.h                      |   1 +
 tools/perf/arch/x86/util/Build                |   2 +-
 tools/perf/arch/x86/util/unwind-libunwind.c   |   6 +-
 tools/perf/config/Makefile                    |  52 +-
 tools/perf/util/Build                         |   3 +
 tools/perf/util/libunwind/arm64.c             |  35 ++
 tools/perf/util/libunwind/x86_32.c            |  37 ++
 tools/perf/util/machine.c                     |  14 +-
 tools/perf/util/thread.c                      |  13 +-
 tools/perf/util/thread.h                      |   9 +-
 tools/perf/util/unwind-libunwind-local.c      | 697 ++++++++++++++++++++++++++
 tools/perf/util/unwind-libunwind.c            | 691 ++-----------------------
 tools/perf/util/unwind.h                      |  27 +-
 17 files changed, 924 insertions(+), 673 deletions(-)
 create mode 100644 tools/perf/util/libunwind/arm64.c
 create mode 100644 tools/perf/util/libunwind/x86_32.c
 create mode 100644 tools/perf/util/unwind-libunwind-local.c

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1.8.5.2