feat: implement readlink(2) readlinkat(2)

[lunaix-os.git] / lunaix-os / kernel / process.c

diff --git a/lunaix-os/kernel/process.c b/lunaix-os/kernel/process.c
index a41c6a6f170ffd7814169982cdee4ac79cc00bb5..a9baaadd20aafac221136b9133662652190f3c21 100644 (file)
--- a/lunaix-os/kernel/process.c
+++ b/lunaix-os/kernel/process.c
@@ -47,7 +47,7 @@ __dup_pagetable(pid_t pid, uintptr_t mount_point)
             pt->entry[j] = pte;
         }
 
-        ptd->entry[i] = (uintptr_t)pt_pp | PG_PREM_RW;
+        ptd->entry[i] = (uintptr_t)pt_pp | PG_ENTRY_FLAGS(ptde);
     }
 
     ptd->entry[PG_MAX_ENTRIES - 1] = NEW_L1_ENTRY(T_SELF_REF_PERM, ptd_pp);
@@ -114,7 +114,7 @@ __DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid)
     struct proc_info* proc = pid ? get_process(pid) : __current;
 
     if (!proc) {
-        __current->k_status = LXINVL;
+        __current->k_status = EINVAL;
         return -1;
     }
 
@@ -123,7 +123,7 @@ __DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid)
     struct proc_info* gruppenfuhrer = get_process(pgid);
 
     if (!gruppenfuhrer || proc->pgid == proc->pid) {
-        __current->k_status = LXINVL;
+        __current->k_status = EINVAL;
         return -1;
     }
 
@@ -135,27 +135,38 @@ __DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid)
 }
 
 void
-init_proc(struct proc_info* pcb)
+init_proc_user_space(struct proc_info* pcb)
 {
-    memset(pcb, 0, sizeof(*pcb));
+    vmm_mount_pd(PD_MOUNT_1, pcb->page_table);
 
-    pcb->pid = alloc_pid();
-    pcb->created = clock_systime();
-    pcb->state = PROC_CREATED;
-    pcb->pgid = pcb->pid;
+    /*---  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
+
+    vmm_unmount_pd(PD_MOUNT_1);
 }
 
 void
 __mark_region(uintptr_t start_vpn, uintptr_t end_vpn, int attr)
 {
-    for (size_t i = start_vpn; i < end_vpn; i++) {
+    for (size_t i = start_vpn; i <= end_vpn; i++) {
         x86_pte_t* curproc = &PTE_MOUNTED(PD_REFERENCED, i);
         x86_pte_t* newproc = &PTE_MOUNTED(PD_MOUNT_1, i);
         cpu_invplg(newproc);
 
-        if (attr == REGION_RSHARED) {
+        if ((attr & REGION_MODE_MASK) == REGION_RSHARED) {
             // 如果读共享，则将两者的都标注为只读，那么任何写入都将会应用COW策略。
             cpu_invplg(curproc);
+            cpu_invplg(i << 12);
             *curproc = *curproc & ~PG_WRITE;
             *newproc = *newproc & ~PG_WRITE;
         } else {
@@ -168,43 +179,38 @@ __mark_region(uintptr_t start_vpn, uintptr_t end_vpn, int attr)
 pid_t
 dup_proc()
 {
-    struct proc_info pcb;
-    init_proc(&pcb);
-    pcb.mm = __current->mm;
-    pcb.intr_ctx = __current->intr_ctx;
-    pcb.parent = __current;
+    struct proc_info* pcb = alloc_process();
+    pcb->mm.u_heap = __current->mm.u_heap;
+    pcb->intr_ctx = __current->intr_ctx;
+    pcb->parent = __current;
 
-    region_copy(&__current->mm.regions, &pcb.mm.regions);
+    region_copy(&__current->mm.regions, &pcb->mm.regions);
 
-    setup_proc_mem(&pcb, PD_REFERENCED);
+    setup_proc_mem(pcb, PD_REFERENCED);
 
     // 根据 mm_region 进一步配置页表
-    if (!__current->mm.regions) {
-        goto not_copy;
-    }
 
     struct mm_region *pos, *n;
-    llist_for_each(pos, n, &pcb.mm.regions->head, head)
+    llist_for_each(pos, n, &pcb->mm.regions.head, head)
     {
         // 如果写共享，则不作处理。
         if ((pos->attr & REGION_WSHARED)) {
             continue;
         }
 
-        uintptr_t start_vpn = PG_ALIGN(pos->start) >> 12;
-        uintptr_t end_vpn = PG_ALIGN(pos->end) >> 12;
+        uintptr_t start_vpn = pos->start >> 12;
+        uintptr_t end_vpn = pos->end >> 12;
         __mark_region(start_vpn, end_vpn, pos->attr);
     }
 
-not_copy:
     vmm_unmount_pd(PD_MOUNT_1);
 
     // 正如同fork，返回两次。
-    pcb.intr_ctx.registers.eax = 0;
+    pcb->intr_ctx.registers.eax = 0;
 
-    push_process(&pcb);
+    commit_process(pcb);
 
-    return pcb.pid;
+    return pcb->pid;
 }
 
 extern void __kernel_end;
@@ -241,12 +247,6 @@ setup_proc_mem(struct proc_info* proc, uintptr_t usedMnt)
     // 我们不需要分配内核的区域，因为所有的内核代码和数据段只能通过系统调用来访问，任何非法的访问
     // 都会导致eip落在区域外面，从而segmentation fault.
 
-    // 定义用户栈区域，但是不分配实际的物理页。我们会在Page fault
-    // handler里面实现动态分配物理页的逻辑。（虚拟内存的好处！）
-    // FIXME: 这里应该放到spawn_proc里面。
-    // region_add(proc, USTACK_END, USTACK_SIZE, REGION_PRIVATE |
-    // REGION_RW);
-
     // 至于其他的区域我们暂时没有办法知道，因为那需要知道用户程序的信息。我们留到之后在处理。
     proc->page_table = pt_copy;
 }
\ No newline at end of file