Re: 1.7.5-1: fork throw segfault with g++ 4.3.4

[Dave Korn <dave dot korn dot cygwin at googlemail dot com>]

On 27/04/2010 08:02, Tim Wilson-Brown wrote:
> Hi,
> 
> I have identified a reproducible segfault when throwing exceptions in the
> thrift IPC library under cygwin 1.7.5-1.

  Thanks for the simple testcase :)

  I have debugged what is happening, and it appears that the typeinfo for the
stringexcept class is getting corrupted in the child process, apparently
because a pseudo-reloc is being applied twice.  I will debug this further
shortly and figure out a fix; it also appears that the problem will be masked
in the upcoming gcc-4.5.0 release (as a side-effect of the fact that the new
libstdc++ dll will export typeinfos directly, rather than leaving them as
static objects in the libstdc++ import library as is the practice in the 4.3.4
release; this avoids needing a pseudo-reloc, apparently, but the bug would
presumably still turn up in other circumstances.)

    cheers,
      DaveK




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