[FFmpeg-trac] #6388(avutil:closed): MSan: use-of-uninitialized-value in ff_get_cpu_flags_x86()

[FFmpeg]

#6388: MSan: use-of-uninitialized-value in ff_get_cpu_flags_x86()
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             Reporter:  tsmith      |                    Owner:
                 Type:  defect      |                   Status:  closed
             Priority:  normal      |                Component:  avutil
              Version:  git-master  |               Resolution:  invalid
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Changes (by cehoyos):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 For future tickets: Please always use unpatched FFmpeg source and provide
 the complete, uncut console output, not the excerpt that you consider
 useful. (Your configure line does not allow me to reproduce, I tested with
 `--toolchain=clang-msan`.)

 I cannot reproduce with valgrind.

 The false positive with the clang memory sanitizer can be easily
 reproduced with `make libavutil/tests/cpu && libavutil/tests/cpu`. I guess
 the reason is that initializations through external assembler code are not
 visible to the memory sanitizer. A possible work-around for you is to
 compile with `--disable-yasm`, the internal assembler code is correctly
 analyzed. Given that the yasm-code isn't covered by your tests anyway (or
 is it?), I believe this is the sanest solution.

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Ticket URL: <https://trac.ffmpeg.org/ticket/6388#comment:1>
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