mirror of
https://github.com/DragonOS-Community/DragonOS.git
synced 2025-06-09 11:16:47 +00:00
375 lines
9.4 KiB
C
375 lines
9.4 KiB
C
#include "syscall.h"
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#include "../process/process.h"
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#include <exception/gate.h>
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#include <exception/irq.h>
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#include <driver/disk/ahci/ahci.h>
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#include <mm/slab.h>
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#include <common/errno.h>
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#include <common/fcntl.h>
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#include <filesystem/fat32/fat32.h>
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// 导出系统调用入口函数，定义在entry.S中
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extern void system_call(void);
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extern void syscall_int(void);
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/**
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* @brief 导出系统调用处理函数的符号
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*
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*/
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#define SYSCALL_COMMON(syscall_num, symbol) extern unsigned long symbol(struct pt_regs *regs);
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SYSCALL_COMMON(0, system_call_not_exists); // 导出system_call_not_exists函数
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#undef SYSCALL_COMMON // 取消前述宏定义
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/**
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* @brief 重新定义为：把系统调用函数加入系统调用表
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* @param syscall_num 系统调用号
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* @param symbol 系统调用处理函数
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*/
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#define SYSCALL_COMMON(syscall_num, symbol) [syscall_num] = symbol,
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/**
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* @brief sysenter的系统调用函数，从entry.S中跳转到这里
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*
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* @param regs 3特权级下的寄存器值,rax存储系统调用号
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* @return ul 对应的系统调用函数的地址
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*/
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ul system_call_function(struct pt_regs *regs)
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{
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return system_call_table[regs->rax](regs);
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}
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/**
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* @brief 初始化系统调用模块
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*
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*/
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void syscall_init()
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{
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kinfo("Initializing syscall...");
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set_system_trap_gate(0x80, 0, syscall_int); // 系统调用门
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}
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/**
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* @brief 通过中断进入系统调用
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*
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* @param syscall_id
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* @param arg0
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* @param arg1
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* @param arg2
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* @param arg3
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* @param arg4
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* @param arg5
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* @param arg6
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* @param arg7
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* @return long
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*/
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long enter_syscall_int(ul syscall_id, ul arg0, ul arg1, ul arg2, ul arg3, ul arg4, ul arg5, ul arg6, ul arg7)
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{
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long err_code;
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__asm__ __volatile__(
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"movq %2, %%r8 \n\t"
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"movq %3, %%r9 \n\t"
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"movq %4, %%r10 \n\t"
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"movq %5, %%r11 \n\t"
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"movq %6, %%r12 \n\t"
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"movq %7, %%r13 \n\t"
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"movq %8, %%r14 \n\t"
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"movq %9, %%r15 \n\t"
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"int $0x80 \n\t"
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: "=a"(err_code)
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: "a"(syscall_id), "m"(arg0), "m"(arg1), "m"(arg2), "m"(arg3), "m"(arg4), "m"(arg5), "m"(arg6), "m"(arg7)
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: "memory", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "rcx", "rdx");
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return err_code;
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}
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/**
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* @brief 打印字符串的系统调用
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*
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* 当arg1和arg2均为0时，打印黑底白字，否则按照指定的前景色和背景色来打印
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*
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* @param regs 寄存器
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* @param arg0 要打印的字符串
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* @param arg1 前景色
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* @param arg2 背景色
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* @return ul 返回值
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*/
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ul sys_put_string(struct pt_regs *regs)
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{
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if (regs->r9 == 0 && regs->r10 == 0)
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printk((char *)regs->r8);
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else
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printk_color(regs->r9, regs->r10, (char *)regs->r8);
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// printk_color(BLACK, WHITE, (char *)regs->r8);
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return 0;
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}
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uint64_t sys_open(struct pt_regs *regs)
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{
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char *filename = (char *)(regs->r8);
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int flags = (int)(regs->r9);
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long path_len = strnlen_user(filename, PAGE_4K_SIZE);
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if (path_len <= 0) // 地址空间错误
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{
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return -EFAULT;
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}
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else if (path_len >= PAGE_4K_SIZE) // 名称过长
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{
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return -ENAMETOOLONG;
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}
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// 为待拷贝文件路径字符串分配内存空间
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char *path = (char *)kmalloc(path_len, 0);
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if (path == NULL)
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return -ENOMEM;
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memset(path, 0, path_len);
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strncpy_from_user(path, filename, path_len);
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// 寻找文件
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struct vfs_dir_entry_t *dentry = vfs_path_walk(path, 0);
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kfree(path);
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if (dentry != NULL)
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printk_color(ORANGE, BLACK, "Found %s\nDIR_FstClus:%#018lx\tDIR_FileSize:%#018lx\n", path, ((struct fat32_inode_info_t *)(dentry->dir_inode->private_inode_info))->first_clus, dentry->dir_inode->file_size);
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else
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printk_color(ORANGE, BLACK, "Can`t find file\n");
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if (dentry == NULL)
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return -ENOENT;
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// 暂时认为目标是目录是一种错误
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if (dentry->dir_inode->attribute == VFS_ATTR_DIR)
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return -EISDIR;
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// 创建文件描述符
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struct vfs_file_t *file_ptr = (struct vfs_file_t *)kmalloc(sizeof(struct vfs_file_t), 0);
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memset(file_ptr, 0, sizeof(struct vfs_file_t));
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int errcode = -1;
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file_ptr->dEntry = dentry;
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file_ptr->mode = flags;
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file_ptr->file_ops = dentry->dir_inode->file_ops;
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// 如果文件系统实现了打开文件的函数
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if (file_ptr->file_ops && file_ptr->file_ops->open)
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errcode = file_ptr->file_ops->open(dentry->dir_inode, file_ptr);
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if (errcode != VFS_SUCCESS)
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{
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kfree(file_ptr);
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return -EFAULT;
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}
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if (file_ptr->mode & O_TRUNC) // 清空文件
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file_ptr->dEntry->dir_inode->file_size = 0;
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if (file_ptr->mode & O_APPEND)
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file_ptr->position = file_ptr->dEntry->dir_inode->file_size;
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else
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file_ptr->position = 0;
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struct vfs_file_t **f = current_pcb->fds;
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int fd_num = -1;
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// 在指针数组中寻找空位
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// todo: 当pcb中的指针数组改为动态指针数组之后，需要更改这里（目前还是静态指针数组）
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for (int i = 0; i < PROC_MAX_FD_NUM; ++i)
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{
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if (f[i] == NULL) // 找到指针数组中的空位
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{
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fd_num = i;
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break;
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}
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}
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// 指针数组没有空位了
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if (fd_num == -1)
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{
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kfree(file_ptr);
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return -EMFILE;
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}
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// 保存文件描述符
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f[fd_num] = file_ptr;
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return fd_num;
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}
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/**
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* @brief 关闭文件系统调用
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*
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* @param fd_num 文件描述符号
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*
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* @param regs
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* @return uint64_t
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*/
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uint64_t sys_close(struct pt_regs *regs)
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{
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int fd_num = (int)regs->r8;
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kdebug("sys close: fd=%d", fd_num);
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// 校验文件描述符范围
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if (fd_num < 0 || fd_num > PROC_MAX_FD_NUM)
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return -EBADF;
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// 文件描述符不存在
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if (current_pcb->fds[fd_num] == NULL)
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return -EBADF;
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struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
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uint64_t ret;
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// If there is a valid close function
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if (file_ptr->file_ops && file_ptr->file_ops->close)
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ret = file_ptr->file_ops->close(file_ptr->dEntry->dir_inode, file_ptr);
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kfree(file_ptr);
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current_pcb->fds[fd_num] = NULL;
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return 0;
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}
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/**
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* @brief 从文件中读取数据
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*
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* @param fd_num regs->r8 文件描述符号
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* @param buf regs->r9 输出缓冲区
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* @param count regs->r10 要读取的字节数
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*
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* @return uint64_t
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*/
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uint64_t sys_read(struct pt_regs *regs)
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{
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int fd_num = (int)regs->r8;
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void *buf = (void *)regs->r9;
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int64_t count = (int64_t)regs->r10;
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// kdebug("sys read: fd=%d", fd_num);
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// 校验文件描述符范围
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if (fd_num < 0 || fd_num > PROC_MAX_FD_NUM)
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return -EBADF;
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// 文件描述符不存在
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if (current_pcb->fds[fd_num] == NULL)
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return -EBADF;
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if (count < 0)
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return -EINVAL;
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struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
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uint64_t ret;
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if (file_ptr->file_ops && file_ptr->file_ops->read)
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ret = file_ptr->file_ops->read(file_ptr, (char *)buf, count, &(file_ptr->position));
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return ret;
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}
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/**
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* @brief 向文件写入数据
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*
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* @param fd_num regs->r8 文件描述符号
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* @param buf regs->r9 输入缓冲区
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* @param count regs->r10 要写入的字节数
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*
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* @return uint64_t
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*/
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uint64_t sys_write(struct pt_regs *regs)
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{
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int fd_num = (int)regs->r8;
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void *buf = (void *)regs->r9;
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int64_t count = (int64_t)regs->r10;
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kdebug("sys write: fd=%d", fd_num);
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// 校验文件描述符范围
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if (fd_num < 0 || fd_num > PROC_MAX_FD_NUM)
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return -EBADF;
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// 文件描述符不存在
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if (current_pcb->fds[fd_num] == NULL)
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return -EBADF;
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if (count < 0)
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return -EINVAL;
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struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
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uint64_t ret;
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if (file_ptr->file_ops && file_ptr->file_ops->write)
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ret = file_ptr->file_ops->write(file_ptr, (char *)buf, count, &(file_ptr->position));
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return ret;
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}
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/**
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* @brief 调整文件的访问位置
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*
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* @param fd_num 文件描述符号
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* @param offset 偏移量
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* @param whence 调整模式
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* @return uint64_t
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*/
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uint64_t sys_lseek(struct pt_regs *regs)
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{
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int fd_num = (int)regs->r8;
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long offset = (long)regs->r9;
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int whence = (int)regs->r10;
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kdebug("sys_lseek: fd=%d", fd_num);
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uint64_t retval = 0;
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// 校验文件描述符范围
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if (fd_num < 0 || fd_num > PROC_MAX_FD_NUM)
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return -EBADF;
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// 文件描述符不存在
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if (current_pcb->fds[fd_num] == NULL)
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return -EBADF;
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struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
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if (file_ptr->file_ops && file_ptr->file_ops->lseek)
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retval = file_ptr->file_ops->lseek(file_ptr, offset, whence);
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return retval;
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}
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uint64_t sys_fork(struct pt_regs *regs)
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{
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kdebug("sys_fork");
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return do_fork(regs, 0, regs->rsp, 0);
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}
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uint64_t sys_vfork(struct pt_regs *regs)
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{
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kdebug("sys vfork");
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return do_fork(regs, CLONE_VM | CLONE_FS | CLONE_SIGNAL, regs->rsp, 0);
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}
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ul sys_ahci_end_req(struct pt_regs *regs)
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{
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ahci_end_request();
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return 0;
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}
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// 系统调用的内核入口程序
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void do_syscall_int(struct pt_regs *regs, unsigned long error_code)
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{
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ul ret = system_call_table[regs->rax](regs);
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regs->rax = ret; // 返回码
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}
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system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] =
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{
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[0] = system_call_not_exists,
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[1] = sys_put_string,
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[2] = sys_open,
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[3] = sys_close,
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[4] = sys_read,
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[5] = sys_write,
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[6] = sys_lseek,
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[7 ... 254] = system_call_not_exists,
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[255] = sys_ahci_end_req};
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