Re: SystemTap questions: user/kernel communication & pass compiilation options to module build

[fche at redhat dot com (Frank Ch. Eigler)]

Hi -

Dave Nomura <dcnltc@us.ibm.com> writes:

> I was thinking more along the lines of linking in an archive (*.a or
> *.so) of C routines that could be shared between a SystemTap
> implementation and a non-SystemTap implementation. [...]

You must not have meant .so, since kernel modules don't engage in
shared library linking.  I can't think of a good reason not to permit
additional .a/.o's to be included in a systemtap module.  SOme issues:

- the .a/.o files need to be built to be perfectly compatible with
  the target kernel.  It is rare to do this via means other than
  actually shipping sources and compiling them on the fly, which is
  tantamount to the embedded-C method I already described.
- buildrun.cxx would have to be taught to include references to  
  these libraries/objects in the module makefile
- licenses need to be compatible if the combined result is to be
  distributed
- some headers will need to be shared too in order for the systemtap
  code to be able to refer to the stuff in the .a/.o

- FChE