Re: Core dump on 32-bit Cygwin if program calls dlopen

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

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On Jul 24 15:08, Kai Tietz wrote:
> 2014-07-22 15:20 GMT+02:00 Corinna Vinschen wrote:
> > On Jul 22 13:59, Jon TURNEY wrote:
> >> On 22/07/2014 09:27, Corinna Vinschen wrote:
> >> >On Jul 17 20:24, Corinna Vinschen wrote:
> >> >>On Jul 17 16:31, Jon TURNEY wrote:
> >> >>>On 17/07/2014 08:37, Corinna Vinschen wrote:
> >> >>>>It's the libgcc DLL which gives us grief, so a new libgcc package is
> >> >>>>sufficent, afaics.  We should check if this DLL fixes the problem and
> >> >>>>then make it "curr" soon, I think.
> >> >>>
> >> >>>I briefly tested this other patch with my test case from the mail above, and
> >> >>>it doesn't seem to help.
> >> >>>[...]
> >> >>I asked DJ to take another look, but I guess ultimately we need the
> >> >>attention of one of the GCC Windows maintainers.  Kai Tietz seems to be
> >> >>unavailable right now, unfortunately.
> >> >
> >> >Looks like I totally misunderstood DJ's patch.  The patch does *not*
> >> >change libgcc, it changes cygmin-crtbegin.c, thus the crtbegin.o file
> >> >which is statically linked into the executable.
> >> >
> >> >That means, to fix the issue, you don't have to replace libgcc, you
> >> >have to recompile the executable against the new crtbegin.o.
> >> >
> >> >DJ still claims his patch is the correct one.  The simple testcase
> >> >dlopen'ing cyggs-9.dll works fine with the new crtbegin.o, according to
> >> >him.
> >>
> >> Sorry, I hadn't tested it correctly.
> >
> > No worries, this was my fault.  Talking about building a new libgcc
> > rather than building a new crtbegin.o was bound to lead everyone
> > off track :|
> >
> >> Building my test with an updated crtbegin.o as well, my test case is fixed.
> >
> > Nice!
> >
> >> I agree this patch seems better than my suggested one, as it makes crtbegin
> >> do the right thing in the face of unbalanced libgcc load/unload, rather than
> >> attempting to balance the libgcc load/unload as mine does.
> >
> > Ok.  I CC'ed DJ so he knows all is good, and then we probably need a
> > windows GCC maintainer to approve the patch I guess.  Kai?  Ping?
> >
> 
> Hi  Corinna
> 
> As I we spoke yesterday on irc, I took already a look to DJ's patch
> and it is sensible.  If DJ sends patch upstream to gcc's ML, and put
> me CC, I will review it asap.

Thanks a lot!

JonY, any chance we could get a gcc package with the new crtbegin.o
soon?


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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