From b4b2c67514c354a0d8235c27af250320981f54d8 Mon Sep 17 00:00:00 2001
From: fslongjin <longjin@RinGoTek.cn>
Date: Thu, 11 Aug 2022 19:07:58 +0800
Subject: [PATCH] =?UTF-8?q?vma=E7=9A=84=E4=B8=80=E4=BA=9B=E6=96=B9?=
 =?UTF-8?q?=E6=B3=95?=
MIME-Version: 1.0
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---
 kernel/mm/mm-types.h     |  2 +-
 kernel/mm/mm.h           | 52 ++++++++++++++++++++++++++++++++++++++++
 kernel/process/process.h |  1 -
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/kernel/mm/mm-types.h b/kernel/mm/mm-types.h
index 0d4f2c742..e9fa9b7fa 100644
--- a/kernel/mm/mm-types.h
+++ b/kernel/mm/mm-types.h
@@ -39,7 +39,7 @@ struct vm_area_struct
     uint64_t vm_start;       // 区域的起始地址
     uint64_t vm_end;         // 区域的结束地址
     struct mm_struct *vm_mm; // 虚拟内存区域对应的mm结构体
-    uint64_t vm_flags;       // 虚拟内存区域的标志位
+    uint64_t vm_flags;       // 虚拟内存区域的标志位, 具体可选值请见mm.h
 
     struct vm_operations_t *vm_ops; // 操作方法
     uint64_t ref_count;             // 引用计数
diff --git a/kernel/mm/mm.h b/kernel/mm/mm.h
index 754c41a70..399f89f72 100644
--- a/kernel/mm/mm.h
+++ b/kernel/mm/mm.h
@@ -2,6 +2,8 @@
 
 #include <common/glib.h>
 #include <mm/mm-types.h>
+#include <process/process.h>
+
 
 // 每个页表的项数
 // 64位下，每个页表4k，每条页表项8B，故一个页表有512条
@@ -368,7 +370,57 @@ ul set_page_attr(struct Page *page, ul flags);
 #define mk_pt(addr, attr) ((unsigned long)(addr) | (unsigned long)(attr))
 #define set_pt(ptptr, ptval) (*(ptptr) = (ptval))
 
+/*
+ *  vm_area_struct中的vm_flags的可选值
+ * 对应的结构体请见mm-types.h
+ */
+#define VM_NONE 0
+#define VM_READ (1 << 0)
+#define VM_WRITE (1 << 1)
+#define VM_EXEC (1 << 2)
+#define VM_SHARED (1 << 3)
+#define VM_IO (1 << 4) // MMIO的内存区域
+#define VM_SOFTDIRTY (1 << 5)
+
+/* VMA basic access permission flags */
+#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
+
 /**
+ * @brief 初始化虚拟内存区域结构体
+ *
+ * @param vma
+ * @param mm
+ */
+static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm)
+{
+    memset(vma, 0, sizeof(struct vm_area_struct));
+    vma->vm_mm = mm;
+    vma->vm_ops = NULL;
+    list_init(&vma->list);
+}
+
+/**
+ * @brief 判断给定的vma是否为当前进程所属的vma
+ *
+ * @param vma 给定的vma结构体
+ * @return true
+ * @return false
+ */
+static inline bool vma_is_foreign(struct vm_area_struct *vma)
+{
+    if (current_pcb->mm == NULL)
+        return true;
+    if (current_pcb->mm != vma->vm_mm)
+        return true;
+    return false;
+}
+
+static inline bool vma_is_accessible(struct vm_area_struct *vma)
+{
+    return vma->vm_flags & VM_ACCESS_FLAGS;
+}
+
+/** 
  * @brief 重新初始化页表的函数
  * 将所有物理页映射到线性地址空间
  */
diff --git a/kernel/process/process.h b/kernel/process/process.h
index fe70e143b..9e9b3cf04 100644
--- a/kernel/process/process.h
+++ b/kernel/process/process.h
@@ -11,7 +11,6 @@
 #pragma once
 #include <common/cpu.h>
 #include <common/glib.h>
-#include <mm/mm.h>
 #include <syscall/syscall.h>
 #include "ptrace.h"
 #include <common/errno.h>