Re: [Libunwind-devel] Libunwind reports the same ip and fp for Fortran code compiled with PGI

[Chris January]

Hello Scott,

The PGI compiled executable is missing the .eh_frame_hdr section. Try
adding -Wl,--eh-frame-hdr to LDFLAGS in Makefile. This fixes the
problem.

Regards,
Chris January - VP Engineering - Allinea Software Ltd.

On Mon, 2015-01-19 at 22:02 +0000, Scott Biersdorff wrote:
> We are looking into an issue with libunwind where it reports the same
> address as both a IP and FP. This happens with a simple PGI compiled
> Fortran example. This same example compiled with gfortran reports
> different addresses:
> 
>  
> 
> ./fortran-standalone.gnu.exe 
> 
>  ip= 0x0000000000400b19  fp= 0x0000000000400aff 
> 
>  ip= 0x0000000000400a45  fp= 0x000000000040098d 
> 
>  ip= 0x0000000000400aa4  fp= 0x0000000000400a82 
> 
>  ip= 0x0000000000400af8  fp= 0x0000000000400ac4 
> 
>  ip= 0x00007f43bad53ec5  fp= 0x00007f43bad53dd0 
> 
>  ip= 0x00000000004008c9  fp= 0x00000000004008a0
> 
>  
> 
> ./fortran-standalone.pgi.exe 
> 
>  ip= 0x00000000004027eb  fp= 0x00000000004027eb 
> 
>  ip= 0x00000000004027b0  fp= 0x00000000004027b0 
> 
>  ip= 0x0000000000402712  fp= 0x0000000000402712 
> 
>  ip= 0x00000000004026c4  fp= 0x00000000004026c4
> 
>  
> 
> (Note that both stacks run into strange addresses unknown in the
> object file; my suspicion is that these are trampoline functions
> somewhere on stack or heap).
> 
>  
> 
> I’ve attached the sources and binaries for this example. Can you help
> us understand what is particular about this binary compiled by PGI
> that causes this? Is there another way to retrieve the function
> pointer?