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Code Issues Releases Wiki Activity

Combine vma (#42)

Browse Source 
* 合并vma

* 调整vma映射，修复bug

* 删除注释

Co-authored-by: fslongjin <longjin@RinGoTek.cn>
Co-authored-by: houmkh <100781004+houmkh@users.noreply.github.com>
This commit is contained in:
houmkh 2022-09-22 00:31:17 +08:00 committed by GitHub
parent cbbf79b2cf
commit be9ac3d58b
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GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 113 additions and 42 deletions
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9
kernel/mm/internal.h
View File

@ -2,6 +2,10 @@
#include "mm.h"
// 当vma被成功合并后的返回值
#define __VMA_MERGED 1
/**
* @brief 将vma结构体插入mm_struct的链表之中
*
@ -69,4 +73,7 @@ int __anon_vma_del(struct vm_area_struct *vma);
* @param paddr 物理地址
* @return struct Page* 创建成功的page
*/
struct Page* __create_mmio_page_struct(uint64_t paddr);
struct Page* __create_mmio_page_struct(uint64_t paddr);
// 判断给定的两个值是否跨越了2M边界
#define CROSS_2M_BOUND(val1, val2) ((val1 & PAGE_2M_MASK) != (val2 & PAGE_2M_MASK))

3
kernel/mm/mm.c
View File

@ -615,7 +615,8 @@ uint64_t mm_do_brk(uint64_t old_brk_end_addr, int64_t offset)
{
struct vm_area_struct *vma = NULL;
mm_create_vma(current_pcb->mm, i, PAGE_2M_SIZE, VM_USER | VM_ACCESS_FLAGS, NULL, &vma);
mm_map_vma(vma, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys);
mm_map(current_pcb->mm, i, PAGE_2M_SIZE, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys);
// mm_map_vma(vma, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys, 0, PAGE_2M_SIZE);
}
current_pcb->mm->brk_end = end_addr;
}

4
kernel/mm/mm.h
View File

@ -462,9 +462,11 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
*
* @param vma 要进行映射的VMA结构体
* @param paddr 起始物理地址
* @param offset 要映射的起始位置在vma中的偏移量
* @param length 要映射的长度
* @return int 错误码
*/
int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr);
int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr, uint64_t offset, uint64_t length);
/**
* @brief 在页表中映射物理地址到指定的虚拟地址（需要页表中已存在对应的vma）

93
kernel/mm/mmap.c
View File

@ -2,6 +2,7 @@
#include "slab.h"
#include "internal.h"
#include <common/compiler.h>
#include <debug/bug.h>
extern uint64_t mm_total_2M_pages;
@ -319,6 +320,10 @@ void mm_unmap_proc_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_sta
int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flags_t vm_flags, struct vm_operations_t *vm_ops, struct vm_area_struct **res_vma)
{
int retval = 0;
// 输入的地址如果不是4K对齐，则报错
if (unlikely(vaddr & (PAGE_4K_SIZE - 1)))
return -EINVAL;
struct vm_area_struct *vma = vm_area_alloc(mm);
if (unlikely(vma == NULL))
return -ENOMEM;
@ -328,12 +333,16 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
vma->vm_end = vaddr + length;
// 将VMA加入mm的链表
retval = vma_insert(mm, vma);
if (retval == -EEXIST) // 之前已经存在了相同的vma，直接返回
if (retval == -EEXIST || retval == __VMA_MERGED) // 之前已经存在了相同的vma，直接返回
{
*res_vma = vma_find(mm, vma->vm_start);
kfree(vma);
return -EEXIST;
if (retval == -EEXIST)
return -EEXIST;
else
return 0;
}
if (res_vma != NULL)
*res_vma = vma;
return 0;
@ -344,11 +353,16 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
*
* @param vma 要进行映射的VMA结构体
* @param paddr 起始物理地址
* @param offset 要映射的起始位置在vma中的偏移量
* @param length 要映射的长度
* @return int 错误码
*/
int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr, uint64_t offset, uint64_t length)
{
int retval = 0;
int retval = 0;
uint64_t mapped = 0;
BUG_ON((offset & (PAGE_4K_SIZE - 1)) != 0);
length = PAGE_4K_ALIGN(length); // 将length按照4K进行对齐
// 获取物理地址对应的页面
struct Page *pg;
uint64_t page_flags = 0;
@ -374,17 +388,39 @@ int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
// 将anon vma与vma进行绑定
__anon_vma_add(pg->anon_vma, vma);
barrier();
uint64_t length = vma->vm_end - vma->vm_start;
// ==== 将地址映射到页表 ====
uint64_t len_4k = length % PAGE_2M_SIZE;
uint64_t len_2m = length - len_4k;
// 长度超过界限
BUG_ON(vma->vm_start + offset + length > vma->vm_end);
/*
todo: 限制页面的读写权限
*/
// kdebug("len2m=%d", len_2m);
// 先映射2M页
// ==== 将地址映射到页表 ====
uint64_t len_4k, len_2m;
// 将地址使用4k页填补，使得地址按照2M对齐
len_4k = PAGE_2M_ALIGN(vma->vm_start + offset) - (vma->vm_start + offset);
if (len_4k > 0)
len_4k = (len_4k > length) ? length : len_4k;
if (len_4k)
{
if (vma->vm_flags & VM_USER)
page_flags |= PAGE_USER_4K_PAGE;
else
page_flags |= PAGE_KERNEL_4K_PAGE;
// 这里直接设置user标志位为false，因为该函数内部会对其进行自动校正
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + offset, paddr, len_4k, page_flags, false, false, true);
if (unlikely(retval != 0))
goto failed;
mapped += len_4k;
length -= len_4k;
}
len_4k = length % PAGE_2M_SIZE;
len_2m = length / PAGE_2M_SIZE;
// 映射连续的2M页
if (likely(len_2m > 0))
{
if (vma->vm_flags & VM_USER)
@ -392,31 +428,32 @@ int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
else
page_flags |= PAGE_KERNEL_PAGE;
// 这里直接设置user标志位为false，因为该函数内部会对其进行自动校正
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start, paddr, len_2m, page_flags, false, false, false);
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + offset + mapped, paddr + mapped, len_2m, page_flags, false, false, false);
if (unlikely(retval != 0))
goto failed;
mapped += len_2m;
}
// 最后再使用4K页填补
if (likely(len_4k > 0))
{
len_4k = ALIGN(len_4k, PAGE_4K_SIZE);
if (vma->vm_flags & VM_USER)
page_flags |= PAGE_USER_4K_PAGE;
else
page_flags |= PAGE_KERNEL_4K_PAGE;
// 这里直接设置user标志位为false，因为该函数内部会对其进行自动校正
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + len_2m, paddr + len_2m, len_4k, page_flags, false, false, true);
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + offset + mapped, paddr + mapped, len_4k, page_flags, false, false, true);
if (unlikely(retval != 0))
goto failed;
mapped += len_4k;
}
if (vma->vm_flags & VM_IO)
vma->page_offset = 0;
else
{ // 计算当前vma的起始地址在对应的物理页中的偏移量
vma->page_offset = paddr - (paddr & PAGE_2M_MASK);
}
flush_tlb();
return 0;
failed:;
@ -436,6 +473,7 @@ failed:;
int mm_map(struct mm_struct *mm, uint64_t vaddr, uint64_t length, uint64_t paddr)
{
int retval = 0;
uint64_t offset = 0;
for (uint64_t mapped = 0; mapped < length;)
{
@ -446,17 +484,20 @@ int mm_map(struct mm_struct *mm, uint64_t vaddr, uint64_t length, uint64_t paddr
return -EINVAL;
}
if (unlikely(vma->vm_start != (vaddr + mapped)))
{
kerror("Map addr failed: addr_start is not equal to current: %#018lx.", vaddr + mapped);
return -EINVAL;
}
// if (unlikely(vma->vm_start != (vaddr + mapped)))
// {
// kerror("Map addr failed: addr_start is not equal to current: %#018lx.", vaddr + mapped);
// return -EINVAL;
// }
retval = mm_map_vma(vma, paddr + mapped);
offset = vaddr + mapped - vma->vm_start;
uint64_t m_len = vma->vm_end - vma->vm_start - offset;
// kdebug("start=%#018lx, offset=%ld", vma->vm_start, offset);
retval = mm_map_vma(vma, paddr + mapped, offset, m_len);
if (unlikely(retval != 0))
goto failed;
mapped += vma->vm_end - vma->vm_start;
mapped += m_len;
}
return 0;
failed:;

2
kernel/mm/slab.c
View File

@ -708,6 +708,6 @@ unsigned long kfree(void *address)
} while (slab_obj_ptr != kmalloc_cache_group[i].cache_pool_entry);
}
kBUG("kfree(): Can't free memory.");
kBUG("kfree(): Can't free memory. address=%#018lx", address);
return ECANNOT_FREE_MEM;
}

28
kernel/mm/vma.c
View File

@ -122,21 +122,35 @@ int vma_insert(struct mm_struct *mm, struct vm_area_struct *vma)
{
struct vm_area_struct *prev;
prev = vma_find(mm, vma->vm_start);
if (prev && prev->vm_start <= vma->vm_start && prev->vm_end >= vma->vm_end)
{
// 已经存在了相同的vma
return -EEXIST;
}
else if (prev && (prev->vm_start == vma->vm_start || prev->vm_end == vma->vm_end)) // 暂时不支持扩展vma
// todo: bugfix: 这里的第二种情况貌似从来不会满足
else if (prev && ((vma->vm_start >= prev->vm_start && vma->vm_start <= prev->vm_end) || (prev->vm_start <= vma->vm_end && prev->vm_start >= vma->vm_start)))
{
kwarn("Not support: expand vma");
return -ENOTSUP;
//部分重叠
if ((!CROSS_2M_BOUND(vma->vm_start, prev->vm_start)) && (!CROSS_2M_BOUND(vma->vm_end, prev->vm_end))&& vma->vm_end)
{
//合并vma 并改变链表vma的范围
kdebug("before combining vma:vm_start = %#018lx, vm_end = %#018lx\n", vma->vm_start, vma->vm_end);
prev->vm_start = (vma->vm_start < prev->vm_start )? vma->vm_start : prev->vm_start;
prev->vm_end = (vma->vm_end > prev->vm_end) ? vma->vm_end : prev->vm_end;
// 计算page_offset
prev->page_offset = prev->vm_start - (prev->vm_start & PAGE_2M_MASK);
kdebug("combined vma:vm_start = %#018lx, vm_end = %#018lx\nprev:vm_start = %018lx, vm_end = %018lx\n", vma->vm_start, vma->vm_end, prev->vm_start, prev->vm_end);
kinfo("vma has same part\n");
return __VMA_MERGED;
}
}
prev = vma_find(mm, vma->vm_end);
if (prev)
prev = prev->vm_prev;
// prev = vma_find(mm, vma->vm_start);
if (prev == NULL) // 要将当前vma插入到链表的尾部
{
struct vm_area_struct *ptr = mm->vmas;
@ -151,6 +165,8 @@ int vma_insert(struct mm_struct *mm, struct vm_area_struct *vma)
}
}
}
else
prev = prev->vm_prev;
__vma_link_list(mm, vma, prev);
return 0;
}

16
kernel/process/process.c
View File

@ -259,7 +259,7 @@ static int process_load_elf_file(struct pt_regs *regs, char *path)
pos = phdr->p_offset;
uint64_t virt_base = 0;
uint64_t beginning_offset = 0; // 由于页表映射导致的virtbase与实际的p_vaddr之间的偏移量
uint64_t beginning_offset = 0; // 由于页表映射导致的virtbase与实际的p_vaddr之间的偏移量
if (remain_mem_size >= PAGE_2M_SIZE) // 接下来存在映射2M页的情况，因此将vaddr按2M向下对齐
virt_base = phdr->p_vaddr & PAGE_2M_MASK;
@ -278,11 +278,13 @@ static int process_load_elf_file(struct pt_regs *regs, char *path)
uint64_t pa = alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys;
struct vm_area_struct *vma = NULL;
int ret = mm_create_vma(current_pcb->mm, virt_base, PAGE_2M_SIZE, VM_USER | VM_ACCESS_FLAGS, NULL, &vma);
// 防止内存泄露
if (ret == -EEXIST)
free_pages(Phy_to_2M_Page(pa), 1);
else
mm_map_vma(vma, pa);
mm_map(current_pcb->mm, virt_base, PAGE_2M_SIZE, pa);
// mm_map_vma(vma, pa, 0, PAGE_2M_SIZE);
io_mfence();
memset((void *)virt_base, 0, PAGE_2M_SIZE);
map_size = PAGE_2M_SIZE;
@ -298,10 +300,12 @@ static int process_load_elf_file(struct pt_regs *regs, char *path)
struct vm_area_struct *vma = NULL;
int val = mm_create_vma(current_pcb->mm, virt_base + off, PAGE_4K_SIZE, VM_USER | VM_ACCESS_FLAGS, NULL, &vma);
// kdebug("virt_base=%#018lx", virt_base + off);
if (val == -EEXIST)
kfree(phys_2_virt(paddr));
else
mm_map_vma(vma, paddr);
mm_map(current_pcb->mm, virt_base + off, PAGE_4K_SIZE, paddr);
// mm_map_vma(vma, paddr, 0, PAGE_4K_SIZE);
io_mfence();
memset((void *)(virt_base + off), 0, PAGE_4K_SIZE);
}
@ -335,7 +339,7 @@ static int process_load_elf_file(struct pt_regs *regs, char *path)
if (val == -EEXIST)
free_pages(Phy_to_2M_Page(pa), 1);
else
mm_map_vma(vma, pa);
mm_map_vma(vma, pa, 0, PAGE_2M_SIZE);
}
// 清空栈空间
@ -957,7 +961,7 @@ uint64_t process_copy_mm(uint64_t clone_flags, struct process_control_block *pcb
if (unlikely(ret == -EEXIST))
free_pages(Phy_to_2M_Page(pa), 1);
else
mm_map_vma(new_vma, pa);
mm_map_vma(new_vma, pa, 0, PAGE_2M_SIZE);
memcpy((void *)phys_2_virt(pa), (void *)(vma->vm_start + i * PAGE_2M_SIZE), (vma_size >= PAGE_2M_SIZE) ? PAGE_2M_SIZE : vma_size);
vma_size -= PAGE_2M_SIZE;
@ -974,7 +978,7 @@ uint64_t process_copy_mm(uint64_t clone_flags, struct process_control_block *pcb
if (unlikely(ret == -EEXIST))
kfree((void *)va);
else
mm_map_vma(new_vma, virt_2_phys(va));
mm_map_vma(new_vma, virt_2_phys(va), 0, map_size);
memcpy((void *)va, (void *)vma->vm_start, vma_size);
}