Comment 3 for bug 1537125

> For ubuntu 14.04.03, systemtap 2.3 worked because it has a older kernel and older
> systemtap. Its no more the case now. The systemtap version needs to be upgraded.

I have just tested with the systemtap 2.9 package presently in xenial, and the following test case fails the same way there as with systemtap 2.3 in trusty:

# stap -v -e 'probe vfs.read {printf("read performed\n"); exit()}'
Pass 1: parsed user script and 110 library script(s) using 55872virt/47296res/6912shr/37504data kb, in 260usr/0sys/259real ms.
semantic error: while resolving probe point: identifier 'kernel' at /usr/share/systemtap/tapset/linux/vfs.stp:882:18
        source: probe vfs.read = kernel.function("vfs_read")
                                 ^

semantic error: no match

semantic error: while resolving probe point: identifier 'vfs' at <input>:1:7
        source: probe vfs.read {printf("read performed\n"); exit()}
                      ^

semantic error: no match

Pass 2: analyzed script: 0 probe(s), 0 function(s), 0 embed(s), 0 global(s) using 57024virt/49792res/8064shr/38656data kb, in 0usr/10sys/8real ms.
Pass 2: analysis failed. [man error::pass2]
Tip: /usr/share/doc/systemtap/README.Debian should help you get started.

It does not appear that an update to a newer systemtap version is going to be of any use on 14.04.

You also had the following warning in your test case output:

WARNING: cannot find module kernel debuginfo: No DWARF information found
[man warning::debuginfo]

This warning is present when using systemtap 2.3, it is not present when using systemtap 2.8 and 2.9. So *this* problem is fixed in later versions of systemtap, but we would need a test case that actually works correctly with later versions of systemtap before anyone could even entertain backporting.