+#ifdef LISP_FEATURE_SB_THREAD
+ struct user_regs_struct regs;
+ if(ptrace(PTRACE_GETREGS,th->pid,0,®s)){
+ /* probably doesn't exist any more. */
+ fprintf(stderr,"child pid %d, %s\n",th->pid,strerror(errno));
+ perror("PTRACE_GETREGS");
+ }
+ preserve_pointer(regs.ebx);
+ preserve_pointer(regs.ecx);
+ preserve_pointer(regs.edx);
+ preserve_pointer(regs.esi);
+ preserve_pointer(regs.edi);
+ preserve_pointer(regs.ebp);
+ preserve_pointer(regs.eax);
+#endif
+ for (ptr = th->control_stack_end;
+#ifdef LISP_FEATURE_SB_THREAD
+ ptr > regs.esp;
+#else