SoftHSM has been configured to store sensitive data in non-page RAM
(i.e. memory that is not swapped out to disk). This is the default and
most secure configuration.
Slackware, however, is not configured to support this model
in non-privileged accounts (i.e. user accounts).

You can check the setting on your system by running the following
command in a shell:

    ulimit -l

If this does not return "unlimited" and you plan to run SoftHSM from
non-privileged accounts then you should edit the configuration file
/etc/security/limits.conf (Slackware 15 with PAM).

You will need to add the following lines to this file:

#<domain>       <type>          <item>          <value>
*               -               memlock         unlimited

Alternatively, you can elect to disable this feature of SoftHSM by
re-running configure with the option "--disable-non-paged-memory".
Please be advised that this may seriously degrade the security of
SoftHSM.