ustack() and jstack() Functions

The ustack() and jstack() actions store an array of 64-bit values regardless of whether the process is a 32-bit or 64-bit process. The first element of this array is the PID of the process. The remaining elements of the array are the PCs in the process that represent the user stack.

dtrd_action == DTRACEACT_USTACK
dtrd_action == DTRACEACT_JSTACK

The length of this array is stored in the lower 32-bits of the dtrd_arg member of the dtrace_recdesc_t structure.

Data Format for the ustack() and jstack() Actions