+__DEFINE_LXSYSCALL(pid_t, getpgid)
+{
+ return __current->pgid;
+}
+
+__DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid)
+{
+ struct proc_info* proc = pid ? get_process(pid) : __current;
+
+ if (!proc) {
+ __current->k_status = EINVAL;
+ return -1;
+ }
+
+ pgid = pgid ? pgid : proc->pid;
+
+ struct proc_info* gruppenfuhrer = get_process(pgid);
+
+ if (!gruppenfuhrer || proc->pgid == proc->pid) {
+ __current->k_status = EINVAL;
+ return -1;
+ }
+
+ llist_delete(&proc->grp_member);
+ llist_append(&gruppenfuhrer->grp_member, &proc->grp_member);
+
+ proc->pgid = pgid;
+ return 0;
+}
+
+void
+init_proc_user_space(struct proc_info* pcb)
+{
+ vmm_mount_pd(PD_MOUNT_1, pcb->page_table);
+
+ /*--- 分配用户栈 ---*/
+
+ // 注册用户栈区域
+ region_add(
+ &pcb->mm.regions, USTACK_END, USTACK_TOP, REGION_RW | REGION_RSHARED);
+
+ // 预留地址空间,具体物理页将由Page Fault Handler按需分配。
+ for (uintptr_t i = PG_ALIGN(USTACK_END); i < USTACK_TOP; i += PG_SIZE) {
+ vmm_set_mapping(PD_MOUNT_1, i, 0, PG_ALLOW_USER | PG_WRITE, VMAP_NULL);
+ }
+
+ // todo: other uspace initialization stuff