Re: [Chicken-users] Strange segfaults when linking with pthreads

[Felix]

From: Peter Bex <address@hidden>
Subject: Re: [Chicken-users] Strange segfaults when linking with pthreads
Date: Thu, 3 Mar 2011 22:56:26 +0100

>> What does "LD_DEBUG=all csi ..." say?
> 
> Nothing. Is that a GNU libc-only option or something?

This should be ELF-specific. I thought it is supported, but looks
like it isn't.

> 
>> What happens when you run it in gdb?
> 
> It also segfaults.  I get this:
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x00007f7ffcd0b884 in pthread_exit () from /usr/lib/libpthread.so.0
> (gdb) bt
> #0  0x00007f7ffcd0b884 in pthread_exit () from /usr/lib/libpthread.so.0
> #1  0x00007f7ffcd0b9db in pthread__cancelled () from /usr/lib/libpthread.so.0
> #2  0x00007f7ffcd0661c in select () from /usr/lib/libpthread.so.0
> #3  0x00007f7ffd943694 in stub285 () from /usr/pkg/lib/libchicken.so

It seems that pthread is hooking into select(2), which is called by
the chicken runtime. I think this might be a bug in the pthreads library,
but perhaps the runtime is doing something with select that it shouldn't
do.

> 
> I get the same error on my server you have access to, if you would like
> to dig in yourself.

Thanks a lot. I will try looking for what call to select(2) causes
this with a debug build. Can you create a ticket for this?  (just so
we don't forget about it - discussions I rather do over e-mail)


cheers,
felix