How can i force specific ORA- errors to be written to the alert.log?

the background is, I needed modify a user profile and restrict the limits CPU_PER_CALL and LOGICAL_READS_PER_CALL.

Whenever such a users query hits one of these limits, he get the messages: "ORA-02393: exceeded call limit on CPU usage" or "ORA-02395: exceeded call limit on IO usage"

Both error messages don't appear in the alert.log

For fine-tuning the restrictions, I need to know, how often a user hits these limits.

How can I count the occurrence of these errors without the overhead of tracing all user sessions?

regards

Dieter