On Linux, use the lsstack or pstack commands instead of the Solaris pstack utility. For example, run the lsstack command as follows:
| # lsstack /tmp/core-file | 
You can also use the GNU project debugger, gdb, to see what is happening at the time of the crash. Run this debugger as follows:
| # gdb ./ldapfwd /tmp/core-file | 
For more information about the useful commands available with the gdb tool, see the gdb man page.