re: rump_server, "panic: uvm_km_alloc failed" on module load

> gdb has an add-symbol-file command.  And
> $OBJDIR/sys/modules/hello/hello/kmod.debug should have symbols.  Note that
> that file probably is not installed to /stand.
>
> add-symbol-file needs the address where the .text section was loaded.  I
> don't know how to get that. 

have a look at src/sys/gdbscripts/mod*.  eg, "modload" has eventually
has this in the inner loop:

   eval "add-symbol-file %s/%s/%s.kmod -s .text 0x%lx -s .data ... "


.mrg.