The processes signal mask and stack status are restored from the context.
Execution resumes at the speci- fied pc.
This system call is not available in 4.2 BSD hence it should not be used if backward compatibility is needed. If successful, the system call does not return. Otherwise, a value of -1 is returned and errno is set to indicate the error. Scp points to memory that is not a valid part of the pro- cess address space. The process status longword is invalid or would improperly raise the privilege level of the process.