Method to get LTTNG-UST version during runtime?

Hi,

there are some substantial changes in 2.14.0 that afffect how/if
tracing is possible.
For ex. c246521ddcba1d1d28cfa0482aa500b9122e7264 allows doing more work upfront
by calling lttng_ust_init_thread().
With 2.13.x the same code will instead do various syscalls or
allocations during the first tracepoints, violating realtime
constraints and possible abort the process.

I miss an easy method to inspect the Lttng UST Version for checks or
workarounds.

There is the lttng_ust_loaded variable that could be abused to carry
an packed version instead of 1. (Of course that could always cause
fallout)

Regards, Norbert