Re: systemtap runtime and kallsyms_lookup

[Martin Hunt <hunt at redhat dot com>]

On Wed, 2005-09-21 at 14:51 -0700, Hien Nguyen wrote:
> We use the kallsym_lookup function in the function _spt_symbol_sprint 
> just for stack trace purpose. In the thread above Oleg Drokin suggested 
> that implements a dump_stack version that will dump the stack to a 
> supplied buffer, and looks like some people want that.
> 
> I think we should work on that dump_stack_to_buffer routine and submit 
> to the mainline (have it does both verbose and non-verbose), then the 
> systemtap runtime just use that routine instead.

That will certainly simplify stack.c in the runtime.  There are a few
other places where kallsym_lookup is used.  It is nice when you have an
address to print and want it printed symbolically.  It is used in map.c
as an option for printing. I'll put in some appropriate ifdef so it will
just print hex values on unsupported architectures.

Eventually we might be able to have this lookup done in userspace using
the debuginfo.

Martin