Upgrading using pg_dumpall

Postgres-9.3.4 was built directly from the web site download source. It's
installed in /usr/lib/postgresql/9.3.4/. Postgresql-9.4.5 was built from the
SlackBuilds.org script and installed in /usr/lib/postgresql/9.4/. The bin/
subdirectory of the 9.4 version has all the excutable files, but that of the
9.3.4 version seens to contain only a few postgis files.

When I run psql with a database name I see this:
$ psql crm
psql (9.4.5, server 9.3.4)
Type "help" for help.

crm=#

so it appears to me that 9.4.5 is running while using the 9.3.4 data
directory.

I want to move all data from 9.3.4 to 9.4.5. Data are in
/var/lib/pgsql/9.3.4/data/ (405 M) and I want to move them to
the empty (only 4.0 K) /var/lib/pgsql/9.4/data/.

Reading the pg_upgrade man page tells me I need the old bin/ and data/
directories as well as the new ones. I've no idea where the 9.3.4 bin
directory now is; /usr/bin/postgres is a soft link to
/usr/lib/postgresql/9.4/bin/postgres. This suggests that I need to use
pg_dumpall, then read in the file using psql with the 9.4.5 version. I've
dumped all databases to a .sql file and am unsure how to proceed.

Clue stick needed,

Rich