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[Bug 1248289] Re: Missing libunwind support in perf


looks like this issue is rather tricky. adding libunwind to build
dependecies actually gives nothing, there is still no dwarf support.
Digging deeper I found that following test, which detects libunwind
support for perf is not passed:

"gcc -o test-libunwind test-libunwind.c -lunwind -lunwind-x86 -lelf" fails with 
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libunwind-x86.so: undefined reference to `lzma_stream_buffer_decode'
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libunwind-x86.so: undefined reference to `lzma_index_uncompressed_size'
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libunwind-x86.so: undefined reference to `lzma_index_end'
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libunwind-x86.so: undefined reference to `lzma_index_buffer_decode'
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libunwind-x86.so: undefined reference to `lzma_stream_footer_decode'
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libunwind-x86.so: undefined reference to `lzma_index_size'
collect2: error: ld returned 1 exit status

adding -llzma to the test above doesn't solve the problem. During
further investigation I found that there are problem with libunwind8-dev
- its libraries lacks dependant libs. I filed bug on libunwind and
proposed solution for x86 platform. Link to the bug is

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  Missing libunwind support in perf

Status in “linux” package in Ubuntu:
  In Progress

Bug description:

  I'm trying to use perf's libunwind support in 13.04 with kernel
  3.11.0-12-generic on amd64.  Typically you can do this by using the
  "-g dwarf" flag, but it appears the perf command included in linux-
  tools-3.11.0-12-generic was not compiled with libunwind.  This may be
  as simple as the build machine didn't have libunwind installed.
  Having dwarf support in perf with default Ubuntu kernels would be very
  useful as it provides a way to get profiling information when
  -fomitframepointer is used.

  Relevant upstream code:


  Let me know if I can provide any other information.

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