The fasttrap provider enables tracing at specific, preprogrammed user process locations. Unlike most other DTrace providers, the fasttrap provider is not designed for tracing system activity. Rather, this provider is meant as a way for DTrace consumers to inject information into the DTrace framework by activating the fasttrap probe.
The fasttrap provider makes available a single probe, fasttrap:::fasttrap, that fires whenever a user-level process makes a certain DTrace call into the kernel. The DTrace call to activate the probe is not available.
The fasttrap provider uses stability mechanism of DTrace to describe its stabilities, as shown in the following table. For more information about the stability mechanism, see DTrace Stability Mechanisms.