🆕 fork

This commit is contained in:
fslongjin 2022-05-04 23:20:39 +08:00
parent 2ed8bdcfd2
commit 1801ddffbd
6 changed files with 430 additions and 27 deletions

View File

@ -281,7 +281,7 @@ static bool ahci_read(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_t
port->ci = 1 << slot; // Issue command
current_pcb->flags |= PROC_NEED_SCHED;
current_pcb->flags |= PF_NEED_SCHED;
sched_cfs();
int retval = AHCI_SUCCESS;
// Wait for completion
@ -361,7 +361,7 @@ static bool ahci_write(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_
// printk("[slot]{%d}", slot);
port->ci = 1; // Issue command
current_pcb->flags |= PROC_NEED_SCHED;
current_pcb->flags |= PF_NEED_SCHED;
//sched_cfs();
int retval = AHCI_SUCCESS;
@ -465,7 +465,7 @@ static struct ahci_request_packet_t *ahci_make_request(long cmd, uint64_t base_a
void ahci_end_request()
{
ahci_req_queue.in_service->wait_queue.pcb->state = PROC_RUNNING;
ahci_req_queue.in_service->wait_queue.pcb->flags |= PROC_NEED_SCHED;
ahci_req_queue.in_service->wait_queue.pcb->flags |= PF_NEED_SCHED;
kfree((uint64_t *)ahci_req_queue.in_service);
ahci_req_queue.in_service = NULL;

View File

@ -509,7 +509,7 @@ void do_IRQ(struct pt_regs *rsp, ul number)
kBUG("current_pcb->preempt_count<0! pid=%d", current_pcb->pid); // should not be here
// 检测当前进程是否可被调度
if (current_pcb->flags & PROC_NEED_SCHED)
if (current_pcb->flags & PF_NEED_SCHED)
{
// kdebug("to sched");
sched_cfs();

View File

@ -9,10 +9,21 @@
#include <sched/sched.h>
#include <filesystem/fat32/fat32.h>
#include <common/stdio.h>
#include <process/spinlock.h>
spinlock_t process_global_pid_write_lock; // 增加pid的写锁
long process_global_pid = 0; // 系统中最大的pid
extern void system_call(void);
extern void kernel_thread_func(void);
/**
* @brief
*
* @param pcb pcb
*/
static inline void process_wakeup(struct process_control_block *pcb);
ul _stack_start; // initial proc的栈基地址虚拟地址
struct mm_struct initial_mm = {0};
struct thread_struct initial_thread =
@ -386,7 +397,7 @@ int kernel_thread(unsigned long (*fn)(unsigned long), unsigned long arg, unsigne
// kdebug("kernel_thread_func=%#018lx", kernel_thread_func);
// kdebug("&kernel_thread_func=%#018lx", &kernel_thread_func);
// kdebug("1111\tregs.rip = %#018lx", regs.rip);
return do_fork(&regs, flags, 0, 0);
return do_fork(&regs, flags | CLONE_VM, 0, 0);
}
/**
@ -406,26 +417,47 @@ void process_init()
initial_mm.rodata_addr_start = (ul)&_rodata;
initial_mm.rodata_addr_end = (ul)&_erodata;
initial_mm.bss_start = (uint64_t)&_bss;
initial_mm.bss_end = (uint64_t)&_ebss;
initial_mm.brk_start = 0;
initial_mm.brk_end = memory_management_struct.kernel_end;
initial_mm.stack_start = _stack_start;
// 初始化进程和tss
// set_tss64((uint *)phys_2_virt(TSS64_Table), initial_thread.rbp, initial_tss[0].rsp1, initial_tss[0].rsp2, initial_tss[0].ist1, initial_tss[0].ist2, initial_tss[0].ist3, initial_tss[0].ist4, initial_tss[0].ist5, initial_tss[0].ist6, initial_tss[0].ist7);
initial_tss[proc_current_cpu_id].rsp0 = initial_thread.rbp;
// ========= 在IDLE进程的顶层页表中添加对内核地址空间的映射 =====================
// 由于IDLE进程的顶层页表的高地址部分会被后续进程所复制为了使所有进程能够共享相同的内核空间
// 因此需要先在IDLE进程的顶层页表内映射二级页表
uint64_t *idle_pml4t_vaddr = (uint64_t *)phys_2_virt((uint64_t)get_CR3() & (~0xfffUL));
for (int i = 256; i < 512; ++i)
{
uint64_t *tmp = idle_pml4t_vaddr + i;
if(*tmp==0)
{
void* pdpt = kmalloc(PAGE_4K_SIZE,0);
memset(pdpt, 0, PAGE_4K_SIZE);
set_pml4t(tmp, mk_pml4t(virt_2_phys(pdpt), PAGE_KERNEL_PGT));
}
}
/*
kdebug("initial_thread.rbp=%#018lx", initial_thread.rbp);
kdebug("initial_tss[0].rsp1=%#018lx", initial_tss[0].rsp1);
kdebug("initial_tss[0].ist1=%#018lx", initial_tss[0].ist1);
*/
// 初始化pid的写锁
spin_init(&process_global_pid_write_lock);
// 初始化进程的循环链表
list_init(&initial_proc_union.pcb.list);
kernel_thread(initial_kernel_thread, 10, CLONE_FS | CLONE_FILES | CLONE_SIGNAL); // 初始化内核进程
kernel_thread(initial_kernel_thread, 10, CLONE_FS | CLONE_SIGNAL); // 初始化内核进程
initial_proc_union.pcb.state = PROC_RUNNING;
initial_proc_union.pcb.preempt_count = 0;
initial_proc_union.pcb.cpu_id = 0;
// 获取新的进程的pcb
// struct process_control_block *p = container_of(list_next(&current_pcb->list), struct process_control_block, list);
@ -446,17 +478,23 @@ void process_init()
unsigned long do_fork(struct pt_regs *regs, unsigned long clone_flags, unsigned long stack_start, unsigned long stack_size)
{
int retval = 0;
struct process_control_block *tsk = NULL;
// kdebug("222\tregs.rip = %#018lx", regs->rip);
// 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_KERNEL);
tsk = (struct process_control_block *)phys_2_virt(pp->addr_phys);
// 为新的进程分配栈空间并将pcb放置在底部
tsk = (struct process_control_block *)kmalloc(STACK_SIZE, 0);
kdebug("struct process_control_block ADDRESS=%#018lx", (uint64_t)tsk);
if (tsk == NULL)
{
retval = -ENOMEM;
return retval;
}
memset(tsk, 0, sizeof(struct process_control_block));
// 将当前进程的pcb复制到新的pcb内
*tsk = *current_pcb;
memcpy(tsk, current_pcb, sizeof(struct process_control_block));
// kdebug("current_pcb->flags=%#010lx", current_pcb->flags);
@ -466,12 +504,62 @@ unsigned long do_fork(struct pt_regs *regs, unsigned long clone_flags, unsigned
// list_add(&initial_proc_union.pcb.list, &tsk->list);
tsk->priority = 2;
tsk->preempt_count = 0;
++(tsk->pid);
// 增加全局的pid并赋值给新进程的pid
spin_lock(&process_global_pid_write_lock);
tsk->pid = process_global_pid++;
// 加入到进程链表中
tsk->next_pcb = initial_proc_union.pcb.next_pcb;
initial_proc_union.pcb.next_pcb = tsk;
tsk->parent_pcb = current_pcb;
spin_unlock(&process_global_pid_write_lock);
tsk->cpu_id = proc_current_cpu_id;
tsk->state = PROC_UNINTERRUPTIBLE;
list_init(&tsk->list);
list_add(&initial_proc_union.pcb.list, &tsk->list);
// list_add(&initial_proc_union.pcb.list, &tsk->list);
retval = -ENOMEM;
// 拷贝标志位
if (process_copy_flags(clone_flags, tsk))
goto copy_flags_failed;
// 拷贝内存空间分布结构体
if (process_copy_mm(clone_flags, tsk))
goto copy_mm_failed;
// 拷贝文件
if (process_copy_files(clone_flags, tsk))
goto copy_files_failed;
// 拷贝线程结构体
if (process_copy_thread(clone_flags, tsk, stack_start, stack_size, regs))
goto copy_thread_failed;
// 拷贝成功
retval = tsk->pid;
// 唤醒进程
process_wakeup(tsk);
return retval;
copy_thread_failed:;
// 回收线程
process_exit_thread(tsk);
copy_files_failed:;
// 回收文件
process_exit_files(tsk);
copy_mm_failed:;
// 回收内存空间分布结构体
process_exit_mm(tsk);
copy_flags_failed:;
kfree(tsk);
return retval;
/*
// 将线程结构体放置在pcb的后面
struct thread_struct *thd = (struct thread_struct *)(tsk + 1);
memset(thd, 0, sizeof(struct thread_struct));
@ -498,6 +586,277 @@ unsigned long do_fork(struct pt_regs *regs, unsigned long clone_flags, unsigned
tsk->state = PROC_RUNNING;
sched_cfs_enqueue(tsk);
*/
return 0;
}
/**
* @brief pid获取进程的pcb
*
* @param pid
* @return struct process_control_block*
*/
struct process_control_block *process_get_pcb(long pid)
{
struct process_control_block *pcb = initial_proc_union.pcb.next_pcb;
// 使用蛮力法搜索指定pid的pcb
// todo: 使用哈希表来管理pcb
for (; pcb != &initial_proc_union.pcb; pcb = pcb->next_pcb)
{
if (pcb->pid == pid)
return pcb;
}
return NULL;
}
/**
* @brief
*
* @param pcb pcb
*/
static inline void process_wakeup(struct process_control_block *pcb)
{
pcb->state = PROC_RUNNING;
sched_cfs_enqueue(pcb);
}
/**
* @brief
*
* @param clone_flags
* @param pcb pcb
* @return uint64_t
*/
uint64_t process_copy_flags(uint64_t clone_flags, struct process_control_block *pcb)
{
if (clone_flags & CLONE_VM)
pcb->flags |= PF_VFORK;
return 0;
}
/**
* @brief
*
* @param clone_flags
* @param pcb pcb
* @return uint64_t
*/
uint64_t process_copy_files(uint64_t clone_flags, struct process_control_block *pcb)
{
int retval = 0;
// 如果CLONE_FS被置位那么子进程与父进程共享文件描述符
// 文件描述符已经在复制pcb时被拷贝
if (clone_flags & CLONE_FS)
return retval;
// 为新进程拷贝新的文件描述符
for (int i = 0; i < PROC_MAX_FD_NUM; ++i)
{
if (current_pcb->fds[i] == NULL)
continue;
pcb->fds[i] = (struct vfs_file_t *)kmalloc(sizeof(struct vfs_file_t), 0);
memcpy(pcb->fds[i], current_pcb->fds[i], sizeof(struct vfs_file_t));
}
return retval;
}
/**
* @brief
*
* @param pcb pcb
* @return uint64_t
*/
uint64_t process_exit_files(struct process_control_block *pcb)
{
// 与父进程共享文件描述符
if (pcb->flags & PF_VFORK)
return 0;
for (int i = 0; i < PROC_MAX_FD_NUM; ++i)
{
if (pcb->fds[i] == NULL)
continue;
kfree(pcb->fds[i]);
}
memset(pcb->fds, 0, sizeof(struct vfs_file_t *) * PROC_MAX_FD_NUM);
}
/**
* @brief
*
* @param clone_flags
* @param pcb pcb
* @return uint64_t
*/
uint64_t process_copy_mm(uint64_t clone_flags, struct process_control_block *pcb)
{
int retval = 0;
// 与父进程共享内存空间
if (clone_flags & CLONE_VM)
{
pcb->mm = current_pcb->mm;
return retval;
}
// 分配新的内存空间分布结构体
struct mm_struct *new_mms = (struct mm_struct *)kmalloc(sizeof(struct mm_struct), 0);
memset(new_mms, 0, sizeof(struct mm_struct));
memcpy(new_mms, current_pcb->mm, sizeof(struct mm_struct));
pcb->mm = new_mms;
// 分配顶层页表, 并设置顶层页表的物理地址
new_mms->pgd = (pml4t_t *)virt_2_phys(kmalloc(PAGE_4K_SIZE, 0));
// 拷贝内核空间的页表指针
memcpy(phys_2_virt(new_mms->pgd) + 256, phys_2_virt(initial_proc[proc_current_cpu_id]) + 256, PAGE_4K_SIZE / 2);
pml4t_t *current_pgd = (pml4t_t *)phys_2_virt(current_pcb->mm->pgd);
// 迭代地拷贝用户空间
for (int i = 0; i <= 255; ++i)
{
// 当前页表项为空
if ((current_pgd + i)->pml4t == 0)
continue;
// 分配新的二级页表
pdpt_t *new_pdpt = (pdpt_t *)kmalloc(PAGE_4K_SIZE, 0);
memset(new_pdpt, 0, PAGE_4K_SIZE);
// 在新的一级页表中设置新的二级页表表项
set_pml4t((uint64_t *)(current_pgd + i), mk_pml4t(virt_2_phys(new_pdpt), ((current_pgd + i)->pml4t) & 0xfffUL));
pdpt_t *current_pdpt = (pdpt_t *)phys_2_virt((current_pgd + i)->pml4t & (~0xfffUL));
// 设置二级页表
for (int j = 0; j < 512; ++j)
{
if ((current_pdpt + j)->pdpt == 0)
continue;
// 分配新的三级页表
pdt_t *new_pdt = (pdt_t *)kmalloc(PAGE_4K_SIZE, 0);
memset(new_pdt, 0, PAGE_4K_SIZE);
// 在新的二级页表中设置三级页表的表项
set_pdpt((uint64_t *)new_pdpt, mk_pdpt(virt_2_phys(new_pdt), (current_pdpt + j)->pdpt & 0xfffUL));
pdt_t *current_pdt = (pdt_t *)phys_2_virt((current_pdpt + j)->pdpt & (~0xfffUL));
// 拷贝内存页
for (int k = 0; k < 512; ++k)
{
if ((current_pdt + k)->pdt == 0)
continue;
// 获取一个新页
struct Page *pg = alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED);
set_pdt((uint64_t *)(current_pdt + k), mk_pdt(pg->addr_phys, (current_pdt + k)->pdt & 0x1fffUL));
// 拷贝数据
memcpy(phys_2_virt(pg->addr_phys), phys_2_virt((current_pdt + k)->pdt & (~0x1fffUL)), PAGE_2M_SIZE);
}
}
}
return retval;
}
/**
* @brief
*
* @param pcb
* @return uint64_t
*/
uint64_t process_exit_mm(struct process_control_block *pcb)
{
if (pcb->flags & CLONE_VM)
return 0;
if (pcb->mm == NULL)
{
kdebug("pcb->mm==NULL");
return 0;
}
if (pcb->mm->pgd == NULL)
{
kdebug("pcb->mm->pgd==NULL");
return 0;
}
// 获取顶层页表
pml4t_t *current_pgd = (pml4t_t *)phys_2_virt(pcb->mm->pgd);
// 迭代地释放用户空间
for (int i = 0; i <= 255; ++i)
{
// 当前页表项为空
if ((current_pgd + i)->pml4t == 0)
continue;
// 二级页表entry
pdpt_t *current_pdpt = (pdpt_t *)phys_2_virt((current_pgd + i)->pml4t & (~0xfffUL));
// 遍历二级页表
for (int j = 0; j < 512; ++j)
{
if ((current_pdpt + j)->pdpt == 0)
continue;
// 三级页表的entry
pdt_t *current_pdt = (pdt_t *)phys_2_virt((current_pdpt + j)->pdpt & (~0xfffUL));
// 释放三级页表的内存页
for (int k = 0; k < 512; ++k)
{
if ((current_pdt + k)->pdt == 0)
continue;
// 释放内存页
free_pages(Phy_to_2M_Page((current_pdt + k)->pdt & (~0x1fffUL)), 1);
}
// 释放三级页表
kfree(current_pdt);
}
// 释放二级页表
kfree(current_pdpt);
}
// 释放顶层页表
kfree(current_pgd);
// 释放内存空间分布结构体
kfree(pcb->mm);
return 0;
}
/**
* @brief 线
*
* @param clone_flags
* @param pcb pcb
* @return uint64_t
*/
uint64_t process_copy_thread(uint64_t clone_flags, struct process_control_block *pcb, uint64_t stack_start, uint64_t stack_size, struct pt_regs *current_regs)
{
// 将线程结构体放置在pcb后方
struct thread_struct *thd = (struct thread_struct *)(pcb + 1);
memset(thd, 0, sizeof(struct thread_struct));
pcb->thread = thd;
// 拷贝栈空间
struct pt_regs *child_regs = (struct pt_regs *)((uint64_t)pcb + STACK_SIZE - sizeof(struct pt_regs));
memcpy(child_regs, current_regs, sizeof(struct pt_regs));
child_regs->rax = 0;
child_regs->rsp = stack_start;
thd->rbp = (uint64_t)pcb + STACK_SIZE;
thd->rsp = (uint64_t)child_regs;
thd->fs = current_pcb->thread->fs;
thd->gs = current_pcb->thread->gs;
// 根据是否为内核线程,设置进程的开始执行的地址
if (pcb->flags & PF_KTHREAD)
thd->rip = (uint64_t)kernel_thread_func;
else
thd->rip = (uint64_t)ret_from_system_call;
kdebug("new proc's ret addr = %#018lx\tchild_regs->rsp = %#018lx", child_regs->rbx, child_regs->rsp);
return 0;
}

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@ -15,7 +15,7 @@
#include "../mm/mm.h"
#include "../syscall/syscall.h"
#include "ptrace.h"
#include <common/errno.h>
#include <filesystem/VFS/VFS.h>
// 进程最大可拥有的文件描述符数量
@ -46,9 +46,9 @@
#define USER_DS (0x30)
// 进程初始化时的数据拷贝标志位
#define CLONE_FS (1 << 0)
#define CLONE_FILES (1 << 1)
#define CLONE_SIGNAL (1 << 2)
#define CLONE_FS (1 << 0) // 在进程间共享打开的文件
#define CLONE_SIGNAL (1 << 1)
#define CLONE_VM (1 << 2) // 在进程间共享虚拟内存空间
/**
* @brief
@ -63,6 +63,8 @@ struct mm_struct
ul data_addr_start, data_addr_end;
// 只读数据段空间
ul rodata_addr_start, rodata_addr_end;
// BSS段的空间
uint64_t bss_start, bss_end;
// 动态内存分配区(堆区域)
ul brk_start, brk_end;
// 应用层栈基地址
@ -89,8 +91,10 @@ struct thread_struct
// ========= pcb->flags =========
// 进程标志位
#define PF_KTHREAD (1UL << 0)
#define PROC_NEED_SCHED (1UL << 1) // 进程需要被调度
#define PF_KTHREAD (1UL << 0) // 内核线程
#define PF_NEED_SCHED (1UL << 1) // 进程需要被调度
#define PF_VFORK (1UL << 2) // 标志进程是否由于vfork而存在资源共享
/**
* @brief
*
@ -110,7 +114,7 @@ struct process_control_block
// 进程切换时保存的状态信息
struct thread_struct *thread;
// 连接各个pcb的双向链表
// 连接各个pcb的双向链表todo删除这个变量
struct List list;
// 地址空间范围
@ -125,6 +129,11 @@ struct process_control_block
// 进程拥有的文件描述符的指针数组
// todo: 改用动态指针数组
struct vfs_file_t *fds[PROC_MAX_FD_NUM];
// 链表中的下一个pcb
struct process_control_block *next_pcb;
// 父进程的pcb
struct process_control_block *parent_pcb;
};
// 将进程的pcb和内核栈融合到一起,8字节对齐
@ -148,7 +157,9 @@ union proc_union
.priority = 2, \
.preempt_count = 0, \
.cpu_id = 0, \
.fds = { 0 } \
.fds = {0}, \
.next_pcb = &proc, \
.parent_pcb = &proc \
}
/**
@ -254,6 +265,27 @@ void process_init();
*/
unsigned long do_fork(struct pt_regs *regs, unsigned long clone_flags, unsigned long stack_start, unsigned long stack_size);
/**
* @brief pid获取进程的pcb
*
* @param pid
* @return struct process_control_block*
*/
struct process_control_block *process_get_pcb(long pid);
/**
* @brief
* @param prev pcb
* @param next pcb
*
*/
#define process_switch_mm(prev, next) \
do \
{ \
asm volatile("movq %0, %%cr3 \n\t" ::"r"(next->mm->pgd) \
: "memory"); \
} while (0)
// 获取当前cpu id
#define proc_current_cpu_id (current_pcb->cpu_id)

View File

@ -51,13 +51,13 @@ void sched_cfs_enqueue(struct process_control_block *pcb)
void sched_cfs()
{
cli();
current_pcb->flags &= ~PROC_NEED_SCHED;
current_pcb->flags &= ~PF_NEED_SCHED;
struct process_control_block *proc = sched_cfs_dequeue();
if (current_pcb->virtual_runtime >= proc->virtual_runtime || current_pcb->state != PROC_RUNNING) // 当前进程运行时间大于了下一进程的运行时间,进行切换
{
if (current_pcb->state = PROC_RUNNING) // 本次切换由于时间片到期引发,则再次加入就绪队列,否则交由其它功能模块进行管理
if (current_pcb->state == PROC_RUNNING) // 本次切换由于时间片到期引发,则再次加入就绪队列,否则交由其它功能模块进行管理
sched_cfs_enqueue(current_pcb);
if (sched_cfs_ready_queue[proc_current_cpu_id].cpu_exec_proc_jiffies <= 0)
@ -75,6 +75,7 @@ void sched_cfs()
}
}
// kdebug("before switch, next.rip = %#018lx\tnext->gs=%#018lx", proc->thread->rip, proc->thread->gs);
process_switch_mm(current_pcb, proc);
switch_proc(current_pcb, proc);
}
else // 不进行切换
@ -127,7 +128,7 @@ void sched_update_jiffies()
}
// 时间片耗尽,标记可调度
if (sched_cfs_ready_queue[proc_current_cpu_id].cpu_exec_proc_jiffies <= 0)
current_pcb->flags |= PROC_NEED_SCHED;
current_pcb->flags |= PF_NEED_SCHED;
}
/**

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@ -336,6 +336,17 @@ uint64_t sys_lseek(struct pt_regs *regs)
return retval;
}
uint64_t sys_fork(struct pt_regs *regs)
{
kdebug("sys_fork");
return do_fork(regs, 0, regs->rsp, 0);
}
uint64_t sys_vfork(struct pt_regs *regs)
{
kdebug("sys vfork");
return do_fork(regs, CLONE_VM | CLONE_FS | CLONE_SIGNAL, regs->rsp, 0);
}
ul sys_ahci_end_req(struct pt_regs *regs)
{
ahci_end_request();