:wrench: 对物理页的管理功能进行了一些调整

kernel/main.c

@@ -14,7 +14,6 @@
 #include "syscall/syscall.h"
 
 unsigned int *FR_address = (unsigned int *)0xb8000; //帧缓存区的地址
-                                                    // char fxsave_region[512] __attribute__((aligned(16)));
 
 struct memory_desc memory_management_struct = {{0}, 0};
 // struct Global_Memory_Descriptor memory_management_struct = {{0}, 0};
@@ -39,26 +38,52 @@ void show_welcome()
 }
 
 // 测试内存管理单元
-/*
+
 void test_mm()
 {
     kinfo("Testing memory management unit...");
-    //printk("bmp[0]:%#018x\tbmp[1]%#018lx\n", *memory_management_struct.bmp, *(memory_management_struct.bmp + 1));
-    kinfo("Try to allocate 64 memory pages.");
-    struct Page *page = alloc_pages(ZONE_NORMAL, 64, PAGE_PGT_MAPPED | PAGE_ACTIVE | PAGE_KERNEL);
+    struct Page *page = NULL;
+    page = alloc_pages(ZONE_NORMAL, 63, 0);
+    page = alloc_pages(ZONE_NORMAL, 63, 0);
+
+    printk_color(ORANGE, BLACK, "4.memory_management_struct.bmp:%#018lx\tmemory_management_struct.bmp+1:%#018lx\tmemory_management_struct.bmp+2:%#018lx\tzone_struct->count_pages_using:%d\tzone_struct->count_pages_free:%d\n", *memory_management_struct.bmp, *(memory_management_struct.bmp + 1), *(memory_management_struct.bmp + 2), memory_management_struct.zones_struct->count_pages_using, memory_management_struct.zones_struct->count_pages_free);
+
+    for (int i = 80; i <= 85; ++i)
+    {
+        printk_color(INDIGO, BLACK, "page%03d attr:%#018lx address:%#018lx\t", i, (memory_management_struct.pages_struct + i)->attr, (memory_management_struct.pages_struct + i)->addr_phys);
+        i++;
+        printk_color(INDIGO, BLACK, "page%03d attr:%#018lx address:%#018lx\n", i, (memory_management_struct.pages_struct + i)->attr, (memory_management_struct.pages_struct + i)->addr_phys);
+    }
 
-    for (int i = 0; i <= 65; ++i)
+    for (int i = 140; i <= 145; i++)
     {
-        printk("page%d\tattr:%#018lx\tphys_addr:%#018lx\t", i, page->attr, page->addr_phys);
-        ++page;
-        if (((i + 1) % 2) == 0)
-            printk("\n");
+        printk_color(INDIGO, BLACK, "page%03d attr:%#018lx address:%#018lx\t", i, (memory_management_struct.pages_struct + i)->attr, (memory_management_struct.pages_struct + i)->addr_phys);
+        i++;
+        printk_color(INDIGO, BLACK, "page%03d attr:%#018lx address:%#018lx\n", i, (memory_management_struct.pages_struct + i)->attr, (memory_management_struct.pages_struct + i)->addr_phys);
     }
 
+    free_pages(page, 1);
+
+    printk_color(ORANGE, BLACK, "5.memory_management_struct.bmp:%#018lx\tmemory_management_struct.bmp+1:%#018lx\tmemory_management_struct.bmp+2:%#018lx\tzone_struct->count_pages_using:%d\tzone_struct->count_pages_free:%d\n", *memory_management_struct.bmp, *(memory_management_struct.bmp + 1), *(memory_management_struct.bmp + 2), memory_management_struct.zones_struct->count_pages_using, memory_management_struct.zones_struct->count_pages_free);
+
+    for (int i = 75; i <= 85; i++)
+    {
+        printk_color(INDIGO, BLACK, "page%03d attr:%#018lx address:%#018lx\t", i, (memory_management_struct.pages_struct + i)->attr, (memory_management_struct.pages_struct + i)->addr_phys);
+        i++;
+        printk_color(INDIGO, BLACK, "page%03d attr:%#018lx address:%#018lx\n", i, (memory_management_struct.pages_struct + i)->attr, (memory_management_struct.pages_struct + i)->addr_phys);
+    }
 
-   printk("bmp[0]:%#018x\tbmp[1]%#018lx\n", *(memory_management_struct.bmp), *(memory_management_struct.bmp + 1));
+    page = alloc_pages(ZONE_UNMAPPED_IN_PGT, 63, 0);
+
+    printk_color(ORANGE, BLACK, "6.memory_management_struct.bmp:%#018lx\tmemory_management_struct.bmp+1:%#018lx\tzone_struct->count_pages_using:%d\tzone_struct->count_pages_free:%d\n", *(memory_management_struct.bmp + (page->addr_phys >> PAGE_2M_SHIFT >> 6)), *(memory_management_struct.bmp + 1 + (page->addr_phys >> PAGE_2M_SHIFT >> 6)), (memory_management_struct.zones_struct + ZONE_UNMAPPED_INDEX)->count_pages_using, (memory_management_struct.zones_struct + ZONE_UNMAPPED_INDEX)->count_pages_free);
+
+    free_pages(page, 1);
+
+    printk_color(ORANGE, BLACK, "7.memory_management_struct.bmp:%#018lx\tmemory_management_struct.bmp+1:%#018lx\tzone_struct->count_pages_using:%d\tzone_struct->count_pages_free:%d\n", *(memory_management_struct.bmp + (page->addr_phys >> PAGE_2M_SHIFT >> 6)), *(memory_management_struct.bmp + 1 + (page->addr_phys >> PAGE_2M_SHIFT >> 6)), (memory_management_struct.zones_struct + ZONE_UNMAPPED_INDEX)->count_pages_using, (memory_management_struct.zones_struct + ZONE_UNMAPPED_INDEX)->count_pages_free);
+    
+    test_slab();
+    kinfo("Memory management module test completed!");
 }
-*/
 
 void test_slab()
 {
@@ -84,25 +109,23 @@ void test_slab()
     }
 
     // 测试自动扩容
-    kmalloc(kmalloc_cache_group[15].size, 0);
-    kmalloc(kmalloc_cache_group[15].size, 0);
-    kmalloc(kmalloc_cache_group[15].size, 0);
-    kmalloc(kmalloc_cache_group[15].size, 0);
-    kmalloc(kmalloc_cache_group[15].size, 0);
-    kmalloc(kmalloc_cache_group[15].size, 0);
-    kmalloc(kmalloc_cache_group[15].size, 0);
-
+    void *ptrs[7];
+    for (int i = 0; i < 7; ++i)
+        ptrs[i] = kmalloc(kmalloc_cache_group[15].size, 0);
 
     struct slab_obj *slab_obj_ptr = kmalloc_cache_group[15].cache_pool_entry;
-    int count=0;
+    int count = 0;
     do
     {
         kdebug("bmp(%d): addr=%#018lx\t value=%#018lx", count, slab_obj_ptr->bmp, *slab_obj_ptr->bmp);
-        
+
         slab_obj_ptr = container_of(list_next(&slab_obj_ptr->list), struct slab_obj, list);
         ++count;
     } while (slab_obj_ptr != kmalloc_cache_group[15].cache_pool_entry);
 
+    for (int i = 0; i < 7; ++i)
+        kfree(ptrs[i]);
+
     kinfo("SLAB test completed!");
 }
 // 初始化系统各模块
@@ -133,9 +156,10 @@ void system_initialize()
 
     cpu_init();
 
-    test_slab();
-    // 再初始化进程模块。顺序不能调转
-    // process_init();
+    // test_slab();
+    test_mm();
+    //  再初始化进程模块。顺序不能调转
+    //  process_init();
 }
 
 //操作系统内核从这里开始执行

kernel/mm/mm.c

@@ -141,33 +141,30 @@ void mm_init()
 
     memory_management_struct.pages_struct->zone = memory_management_struct.zones_struct;
     memory_management_struct.pages_struct->addr_phys = 0UL;
-    memory_management_struct.pages_struct->attr = 0;
-    memory_management_struct.pages_struct->ref_counts = 0;
+    set_page_attr(memory_management_struct.pages_struct, PAGE_PGT_MAPPED | PAGE_KERNEL_INIT | PAGE_KERNEL);
+    memory_management_struct.pages_struct->ref_counts = 1;
     memory_management_struct.pages_struct->age = 0;
+    // 将第0页的标志位给置上
+    //*(memory_management_struct.bmp) |= 1UL;
 
     // 计算zone结构体的总长度（按照64位对齐）
     memory_management_struct.zones_struct_len = (memory_management_struct.count_zones * sizeof(struct Zone) + sizeof(ul) - 1) & (~(sizeof(ul) - 1));
 
-    /*
-    printk_color(ORANGE, BLACK, "bmp:%#18lx, bmp_len:%#18lx, bits_size:%#18lx\n", memory_management_struct.bmp, memory_management_struct.bmp_len, memory_management_struct.bits_size);
-
-    printk_color(ORANGE, BLACK, "pages_struct:%#18lx, count_pages:%#18lx, pages_struct_len:%#18lx\n", memory_management_struct.pages_struct, memory_management_struct.count_pages, memory_management_struct.pages_struct_len);
-
-    printk_color(ORANGE, BLACK, "zones_struct:%#18lx, count_zones:%#18lx, zones_struct_len:%#18lx\n", memory_management_struct.zones_struct, memory_management_struct.count_zones, memory_management_struct.zones_struct_len);
-    */
-    ZONE_DMA_INDEX = 0;    // need rewrite in the future
-    ZONE_NORMAL_INDEX = 0; // need rewrite in the future
+    ZONE_DMA_INDEX = 0;
+    ZONE_NORMAL_INDEX = 0;
+    ZONE_UNMAPPED_INDEX = 0;
 
-    for (int i = 0; i < memory_management_struct.count_zones; ++i) // need rewrite in the future
+    for (int i = 0; i < memory_management_struct.count_zones; ++i)
     {
         struct Zone *z = memory_management_struct.zones_struct + i;
         // printk_color(ORANGE, BLACK, "zone_addr_start:%#18lx, zone_addr_end:%#18lx, zone_length:%#18lx, pages_group:%#18lx, count_pages:%#18lx\n",
         //             z->zone_addr_start, z->zone_addr_end, z->zone_length, z->pages_group, z->count_pages);
 
         // 1GB以上的内存空间不做映射
-        if (z->zone_addr_start == 0x100000000)
-            ZONE_UNMAPED_INDEX = i;
+        if (z->zone_addr_start >= 0x100000000 && (!ZONE_UNMAPPED_INDEX))
+            ZONE_UNMAPPED_INDEX = i;
     }
+    kdebug("ZONE_DMA_INDEX=%d\tZONE_NORMAL_INDEX=%d\tZONE_UNMAPPED_INDEX=%d", ZONE_DMA_INDEX, ZONE_NORMAL_INDEX, ZONE_UNMAPPED_INDEX);
     // 设置内存页管理结构的地址，预留了一段空间，防止内存越界。
     memory_management_struct.end_of_struct = (ul)((ul)memory_management_struct.zones_struct + memory_management_struct.zones_struct_len + sizeof(long) * 32) & (~(sizeof(long) - 1));
 
@@ -177,16 +174,31 @@ void mm_init()
     // 初始化内存管理单元结构所占的物理页的结构体
 
     ul mms_max_page = (virt_2_phys(memory_management_struct.end_of_struct) >> PAGE_2M_SHIFT); // 内存管理单元所占据的序号最大的物理页
-    printk("mms_max_page=%ld\n", mms_max_page);
-    for (ul j = 0; j <= mms_max_page; ++j)
+    kdebug("mms_max_page=%ld", mms_max_page);
+
+    struct Page *tmp_page = NULL;
+    ul page_num;
+    // 第0个page已经在上方配置
+    for (ul j = 1; j <= mms_max_page; ++j)
     {
-        page_init(memory_management_struct.pages_struct + j, PAGE_PGT_MAPPED | PAGE_KERNEL | PAGE_KERNEL_INIT | PAGE_ACTIVE);
+        tmp_page = memory_management_struct.pages_struct + j;
+        page_init(tmp_page, PAGE_PGT_MAPPED | PAGE_KERNEL | PAGE_KERNEL_INIT);
+        page_num = tmp_page->addr_phys >> PAGE_2M_SHIFT;
+        *(memory_management_struct.bmp + (page_num >> 6)) |= (1UL << (page_num % 64));
+        ++tmp_page->zone->count_pages_using;
+        --tmp_page->zone->count_pages_free;
     }
 
     global_CR3 = get_CR3();
 
     flush_tlb();
 
+    kdebug("global_CR3\t:%#018lx", global_CR3);
+    kdebug("*global_CR3\t:%#018lx", *phys_2_virt(global_CR3) & (~0xff));
+    kdebug("**global_CR3\t:%#018lx", *phys_2_virt(*phys_2_virt(global_CR3) & (~0xff)) & (~0xff));
+
+    kdebug("1.memory_management_struct.bmp:%#018lx\tzone->count_pages_using:%d\tzone_struct->count_pages_free:%d", *memory_management_struct.bmp, memory_management_struct.zones_struct->count_pages_using, memory_management_struct.zones_struct->count_pages_free);
+
     kinfo("Memory management unit initialize complete!");
 
     // 初始化slab内存池
@@ -198,12 +210,21 @@ void mm_init()
  *
  * @param page 内存页结构体
  * @param flags 标志位
- * 对于新页面： 初始化struct page
- * 对于当前页面属性/flags中含有引用属性或共享属性时，则只增加struct page和struct zone的被引用计数。否则就只是添加页表属性，并置位bmp的相应位。
+ * 本函数只负责初始化内存页，允许对同一页面进行多次初始化
+ * 而维护计数器及置位bmp标志位的功能，应当在分配页面的时候手动完成
  * @return unsigned long
  */
 unsigned long page_init(struct Page *page, ul flags)
 {
+    page->attr |= flags;
+    // 若页面的引用计数为0或是共享页，增加引用计数
+    if ((!page->ref_counts) || (page->attr & PAGE_SHARED))
+    {
+        ++page->ref_counts;
+        ++page->zone->total_pages_link;
+    }
+    return 0;
+    /*
     // 全新的页面
     if (!page->attr)
     {
@@ -231,37 +252,48 @@ unsigned long page_init(struct Page *page, ul flags)
         page->attr |= flags;
     }
     return 0;
+    */
 }
 
 /**
  * @brief 从已初始化的页结构中搜索符合申请条件的、连续num个struct page
  *
  * @param zone_select 选择内存区域, 可选项：dma, mapped in pgt(normal), unmapped in pgt
- * @param num 需要申请的连续内存页的数量 num<=64
+ * @param num 需要申请的连续内存页的数量 num<64
  * @param flags 将页面属性设置成flag
  * @return struct Page*
  */
 struct Page *alloc_pages(unsigned int zone_select, int num, ul flags)
 {
     ul zone_start = 0, zone_end = 0;
+    if (num >= 64 && num <= 0)
+    {
+        kerror("alloc_pages(): num is invalid.");
+        return NULL;
+    }
+
+    ul attr = flags;
     switch (zone_select)
     {
     case ZONE_DMA:
         // DMA区域
         zone_start = 0;
         zone_end = ZONE_DMA_INDEX;
+        attr |= PAGE_PGT_MAPPED;
         break;
     case ZONE_NORMAL:
         zone_start = ZONE_DMA_INDEX;
         zone_end = ZONE_NORMAL_INDEX;
+        attr |= PAGE_PGT_MAPPED;
         break;
     case ZONE_UNMAPPED_IN_PGT:
         zone_start = ZONE_NORMAL_INDEX;
-        zone_end = ZONE_UNMAPED_INDEX;
+        zone_end = ZONE_UNMAPPED_INDEX;
+        attr = 0;
         break;
 
     default:
-        kwarn("In alloc_pages: param: zone_select incorrect.");
+        kerror("In alloc_pages: param: zone_select incorrect.");
         // 返回空
         return NULL;
         break;
@@ -274,30 +306,36 @@ struct Page *alloc_pages(unsigned int zone_select, int num, ul flags)
 
         struct Zone *z = memory_management_struct.zones_struct + i;
 
-        // 区域对应的起止页号以及区域拥有的页面数
+        // 区域对应的起止页号
         ul page_start = (z->zone_addr_start >> PAGE_2M_SHIFT);
         ul page_end = (z->zone_addr_end >> PAGE_2M_SHIFT);
-        ul page_num = (z->zone_length >> PAGE_2M_SHIFT);
 
         ul tmp = 64 - page_start % 64;
-        for (ul j = page_start; j <= page_end; j += ((j % 64) ? tmp : 64))
+        for (ul j = page_start; j < page_end; j += ((j % 64) ? tmp : 64))
         {
             // 按照bmp中的每一个元素进行查找
             // 先将p定位到bmp的起始元素
             ul *p = memory_management_struct.bmp + (j >> 6);
 
             ul shift = j % 64;
-
-            for (ul k = shift; k < 64 - shift; ++k)
+            ul tmp_num = ((1UL << num) - 1);
+            for (ul k = shift; k < 64; ++k)
             {
                 // 寻找连续num个空页
-                if (!(((*p >> k) | (*(p + 1) << (64 - k))) & (num == 64 ? 0xffffffffffffffffUL : ((1UL << num) - 1))))
+                if (!((k ? ((*p >> k) | (*(p + 1) << (64 - k))) : *p) & tmp_num))
+
                 {
-                    ul start_page_num = j + k - shift; // 计算得到要开始获取的内存页的页号（书上的公式有问题，这个是改过之后的版本）
+                    ul start_page_num = j + k - shift; // 计算得到要开始获取的内存页的页号
                     for (ul l = 0; l < num; ++l)
                     {
                         struct Page *x = memory_management_struct.pages_struct + start_page_num + l;
-                        page_init(x, flags);
+
+                        // 分配页面，手动配置属性及计数器
+                        // 置位bmp
+                        *(memory_management_struct.bmp + ((x->addr_phys >> PAGE_2M_SHIFT) >> 6)) |= (1UL << (x->addr_phys >> PAGE_2M_SHIFT) % 64);
+                        ++z->count_pages_using;
+                        --z->count_pages_free;
+                        x->attr = attr;
                     }
                     // 成功分配了页面，返回第一个页面的指针
                     // printk("start page num=%d\n",start_page_num);
@@ -309,44 +347,94 @@ struct Page *alloc_pages(unsigned int zone_select, int num, ul flags)
     return NULL;
 }
 
+/**
+ * @brief 清除页面的引用计数， 计数为0时清空除页表已映射以外的所有属性
+ *
+ * @param p 物理页结构体
+ * @return unsigned long
+ */
 unsigned long page_clean(struct Page *p)
 {
-    if (!p->attr)
-        p->attr = 0;
-    else if ((p->attr & PAGE_REFERENCED) || (p->attr & PAGE_K_SHARE_TO_U))
+    --p->ref_counts;
+    --p->zone->total_pages_link;
+
+    // 若引用计数为空，则清空除PAGE_PGT_MAPPED以外的所有属性
+    if (!p->ref_counts)
     {
-        // 被引用的页或内核共享给用户态的页
-        --p->ref_counts;
-        --p->zone->total_pages_link;
+        p->attr &= PAGE_PGT_MAPPED;
+    }
+    return 0;
+}
 
-        // 当引用为0时
-        if (!p->ref_counts)
-        {
-            p->attr = 0;
-            --p->zone->count_pages_using;
-            ++p->zone->count_pages_free;
-        }
+/**
+ * @brief Get the page's attr
+ *
+ * @param page 内存页结构体
+ * @return ul 属性
+ */
+ul get_page_attr(struct Page *page)
+{
+    if (page == NULL)
+    {
+        kBUG("get_page_attr(): page == NULL");
+        return EPAGE_NULL;
     }
     else
+        return page->attr;
+}
+
+/**
+ * @brief Set the page's attr
+ *
+ * @param page 内存页结构体
+ * @param flags  属性
+ * @return ul 错误码
+ */
+ul set_page_attr(struct Page *page, ul flags)
+{
+    if (page == NULL)
     {
-        // 将bmp复位
-        *(memory_management_struct.bmp + ((p->addr_phys >> PAGE_2M_SHIFT) >> 6)) &= ~(1UL << ((p->addr_phys >> PAGE_2M_SHIFT) % 64));
-
-        p->attr = 0;
-        p->ref_counts = 0;
-        --p->zone->count_pages_using;
-        ++p->zone->count_pages_free;
-        --p->zone->total_pages_link;
+        kBUG("get_page_attr(): page == NULL");
+        return EPAGE_NULL;
+    }
+    else
+    {
+        page->attr = flags;
+        return 0;
     }
 }
-
 /**
  * @brief 释放连续number个内存页
  *
  * @param page 第一个要被释放的页面的结构体
  * @param number 要释放的内存页数量 number<64
  */
+
 void free_pages(struct Page *page, int number)
 {
-    // @todo: 释放连续number个内存页
+    if (page == NULL)
+    {
+        kerror("free_pages() page is invalid.");
+        return;
+    }
+
+    if (number >= 64 || number <= 0)
+    {
+        kerror("free_pages(): number %d is invalid.", number);
+        return;
+    }
+
+    ul page_num;
+    for (int i = 0; i < number; ++i, ++page)
+    {
+        page_num = page->addr_phys >> PAGE_2M_SHIFT;
+        // 复位bmp
+        *(memory_management_struct.bmp + (page_num >> 6)) &= ~(1UL << (page_num % 64));
+        // 更新计数器
+        --page->zone->count_pages_using;
+        ++page->zone->count_pages_free;
+        page->attr = 0;
+    }
+
+    return;
 }

kernel/mm/mm.h

@@ -43,26 +43,26 @@
 #define ZONE_UNMAPPED_IN_PGT (1 << 2)
 
 // ===== 页面属性 =====
-// 页面在页表中已被映射
+// 页面在页表中已被映射 mapped=1 unmapped=0
 #define PAGE_PGT_MAPPED (1 << 0)
-// 内核初始化程序的页
+
+// 内核初始化程序的页 init-code=1 normal-code/data=0
 #define PAGE_KERNEL_INIT (1 << 1)
-// 引用的页
-#define PAGE_REFERENCED (1 << 2)
-// 脏页
-#define PAGE_DIRTY (1 << 3)
-// 使用中的页
-#define PAGE_ACTIVE (1 << 4)
-// 过时的页
-#define PAGE_UP_TO_DATE (1 << 5)
-// 设备对应的页
-#define PAGE_DEVICE (1 << 6)
-// 内核层页
-#define PAGE_KERNEL (1 << 7)
-// 内核共享给用户态程序的页面
-#define PAGE_K_SHARE_TO_U (1 << 8)
-// slab内存分配器的页
-#define PAGE_SLAB (1 << 9)
+
+// 1=设备寄存器映射的内存 0=物理内存
+#define PAGE_DEVICE (1 << 2)
+
+// 内核层页 kernel=1 memory=0
+#define PAGE_KERNEL (1 << 3)
+
+// 共享的页 shared=1 single-use=0
+#define PAGE_SHARED (1<<4)
+
+
+
+// ===== 错误码定义 ====
+// 物理页结构体为空
+#define EPAGE_NULL 1
 
 /**
  * @brief 刷新TLB的宏定义
@@ -169,7 +169,7 @@ extern char _end;
 
 int ZONE_DMA_INDEX = 0;
 int ZONE_NORMAL_INDEX = 0;  // low 1GB RAM ,was mapped in pagetable
-int ZONE_UNMAPED_INDEX = 0; // above 1GB RAM,unmapped in pagetable
+int ZONE_UNMAPPED_INDEX = 0; // above 1GB RAM,unmapped in pagetable
 
 ul *global_CR3 = NULL;
 
@@ -181,8 +181,8 @@ void mm_init();
  *
  * @param page 内存页结构体
  * @param flags 标志位
- * 对于新页面： 初始化struct page
- * 对于当前页面属性/flags中含有引用属性或共享属性时，则只增加struct page和struct zone的被引用计数。否则就只是添加页表属性，并置位bmp的相应位。
+ * 本函数只负责初始化内存页，允许对同一页面进行多次初始化
+ * 而维护计数器及置位bmp标志位的功能，应当在分配页面的时候手动完成
  * @return unsigned long
  */
 unsigned long page_init(struct Page *page, ul flags);
@@ -205,17 +205,17 @@ unsigned long *get_CR3()
  * @brief 从已初始化的页结构中搜索符合申请条件的、连续num个struct page
  *
  * @param zone_select 选择内存区域, 可选项：dma, mapped in pgt(normal), unmapped in pgt
- * @param num 需要申请的内存页的数量 num<=64
+ * @param num 需要申请的内存页的数量 num<64
  * @param flags 将页面属性设置成flag
  * @return struct Page*
  */
 struct Page *alloc_pages(unsigned int zone_select, int num, ul flags);
 
 /**
- * @brief 释放内存页
- *
- * @param page 内存页结构体
- * @return unsigned long
+ * @brief 清除页面的引用计数， 计数为0时清空除页表已映射以外的所有属性
+ * 
+ * @param p 物理页结构体
+ * @return unsigned long 
  */
 unsigned long page_clean(struct Page *page);
 
@@ -227,6 +227,23 @@ unsigned long page_clean(struct Page *page);
  */
 void free_pages(struct Page *page, int number);
 
+/**
+ * @brief Get the page's attr
+ * 
+ * @param page 内存页结构体
+ * @return ul 属性
+ */
+ul get_page_attr(struct Page* page);
+
+/**
+ * @brief Set the page's attr
+ * 
+ * @param page 内存页结构体
+ * @param flags  属性
+ * @return ul 错误码
+ */
+ul set_page_attr(struct Page* page, ul flags);
+
 /**
  * @brief 内存页表结构体
  *

kernel/process/process.c

@@ -233,7 +233,7 @@ unsigned long do_fork(struct pt_regs *regs, unsigned long clone_flags, unsigned
     struct process_control_block *tsk = NULL;
 
     // 获取一个物理页并在这个物理页内初始化pcb
-    struct Page *pp = alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED | PAGE_ACTIVE | PAGE_KERNEL);
+    struct Page *pp = alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED | PAGE_KERNEL);
 
     tsk = (struct process_control_block *)phys_2_virt(pp->addr_phys);