Hey,

[...]
> no unfortunately it does not work. First I had to fix a compile error because
> "softe" is not defined for ppc_32 in the linux kernel in ptrace.h. I changed it
> temporary to "mq" in runtime/unwind/ppc_64.h and then I was able to compile my
> probe.
> 
> I gave it a try with a simple main.c which calls a function foo(). My probe was:
> 
> probe process("/usr/local/bin/main").function("foo")
> {
>   print_ubacktrace()
> }
> 

Ok

> But the output is:
> 0x10000448 : foo+0x1c/0x7c [/usr/local/bin/main]
> 
> So the calling function main() was not shown on an ARM architecture a similar
> setup shows:
>  0x83b8 : foo+0x14/0x64 [/usr/local/bin/main]
>  0x8444 : main+0x3c/0x40 [/usr/local/bin/main]
> 
> So there is still something missing for ppc32.

Ah too bad it wasn't a simple plug and play :) Would you mind trying
again but running your script with the added stap option 
'-DDEBUG_UNWIND=99' and supplying the output? (ie, stap -DDEBUG_UNWIND=99
--ldd -ve 'probe... )

Thanks,

Lukas