Bug 27410

Bug #25568's introduced capabilities to specify probes by build-id, but this is not very user friendly.  What users tend to see directly are file names, and occasionally filenames from archives that are not even installed.

The attachment is a demonstration prototype for a stap front-end that can take
a path name and a list of RPM-containing directories.  It computes a buildid-based script template based on finding all buildids for the given path name in any of the RPMs found, and then compiles than via stap -p4.  It uses a temporary instance of debuginfod to build/serve the buildid executables / debuginfo.

% sh stap-multirpm /usr/bin/vi /path/to/RPMs
[starts debuginfod -R /path/to/RPMs ...]
[chance to edit template SCRIPT.stp]
[compiles to stap_hexcode.ko]
[kills debuginfod]
% sudo staprun stap_hexcode.ko &
% /usr/bin/vi   # of any version from any of those RPMs
[watch stap probe hit]


We should consider growing some native systemtap syntax for this.  Suggestions
welcome.  Possibility:

probe rpmsearch("/path/to/RPMs/prefix*").process("/path/name").function(...) { }
probe debsearch(...) { }