.I ucp
must have been initialized by a call to
.BR getcontext (3)
-and have a stack allocated for it. The address of the stack must be assigned to \fIucp\->uc_stack.ss_size\fP and the size of the stack to \fIucp\->uc_stack.ss_size\fP. The \fIucp\->uc_link\fP member is used to determine which successor context is run after the context modified by
+and have a stack allocated for it. The address of the stack must be assigned to \fIucp\->uc_stack.ss_sp\fP and the size of the stack to \fIucp\->uc_stack.ss_size\fP. The \fIucp\->uc_link\fP member is used to determine which successor context is run after the context modified by
.BR makecontext ()
returns. If left NULL, the process exits.
.PP
.BR swapcontext ()
returns 0. Otherwise, -1 is returned and
.I errno
-is set to indicate the error. Note that a succesful call to
+is set to indicate the error. Note that a successful call to
.BR swapcontext ()
actually does not return. Only after returning to the context that called
.BR swapcontext ()