The PA-RISC port (2.4.xx) returns 0xdeadbeef.
The x86-64 port (2.6.0-test5) returns a 0.
i386, alpha, ppc, and IA-64 all work fine.
I think ARM works, but I didn't have a
System.map file on the system I was using.
I didn't check zSeries, ppc64, MIPS, or SPARC.
The following command is supposed to report
an instruction pointer ("nip" or "pc" or "rip"
or whatever), a stack pointer ("r2" or "sp" or
whatever), the kernel address where a process
is waiting, and the kernel function name where
a process is waiting:
ps -eo eip,esp,nwchan,wchan