use alloc::{string::String, sync::Arc, vec::Vec}; use system_error::SystemError; use crate::{ arch::{ interrupt::TrapFrame, process::table::{USER_CS, USER_DS}, CurrentIrqArch, }, exception::InterruptArch, mm::ucontext::AddressSpace, process::{ exec::{load_binary_file, ExecParam, ExecParamFlags}, ProcessControlBlock, ProcessManager, }, syscall::{user_access::UserBufferWriter, Syscall}, }; impl Syscall { pub fn do_execve( path: String, argv: Vec, envp: Vec, regs: &mut TrapFrame, ) -> Result<(), SystemError> { // 关中断,防止在设置地址空间的时候,发生中断,然后进调度器,出现错误。 let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; let pcb = ProcessManager::current_pcb(); // crate::kdebug!( // "pid: {:?} do_execve: path: {:?}, argv: {:?}, envp: {:?}\n", // pcb.pid(), // path, // argv, // envp // ); let mut basic_info = pcb.basic_mut(); // 暂存原本的用户地址空间的引用(因为如果在切换页表之前释放了它,可能会造成内存use after free) let old_address_space = basic_info.user_vm(); // 在pcb中原来的用户地址空间 unsafe { basic_info.set_user_vm(None); } // 创建新的地址空间并设置为当前地址空间 let address_space = AddressSpace::new(true).expect("Failed to create new address space"); unsafe { basic_info.set_user_vm(Some(address_space.clone())); } // to avoid deadlock drop(basic_info); assert!( AddressSpace::is_current(&address_space), "Failed to set address space" ); // kdebug!("Switch to new address space"); // 切换到新的用户地址空间 unsafe { address_space.read().user_mapper.utable.make_current() }; drop(old_address_space); drop(irq_guard); // kdebug!("to load binary file"); let mut param = ExecParam::new(path.as_str(), address_space.clone(), ExecParamFlags::EXEC)?; // 加载可执行文件 let load_result = load_binary_file(&mut param) .unwrap_or_else(|e| panic!("Failed to load binary file: {:?}, path: {:?}", e, path)); // kdebug!("load binary file done"); // kdebug!("argv: {:?}, envp: {:?}", argv, envp); param.init_info_mut().args = argv; param.init_info_mut().envs = envp; // 把proc_init_info写到用户栈上 let (user_sp, argv_ptr) = unsafe { param .init_info() .push_at( address_space .write() .user_stack_mut() .expect("No user stack found"), ) .expect("Failed to push proc_init_info to user stack") }; // kdebug!("write proc_init_info to user stack done"); // (兼容旧版libc)把argv的指针写到寄存器内 // TODO: 改写旧版libc,不再需要这个兼容 regs.rdi = param.init_info().args.len() as u64; regs.rsi = argv_ptr.data() as u64; // 设置系统调用返回时的寄存器状态 // TODO: 中断管理重构后,这里的寄存器状态设置要删掉!!!改为对trap frame的设置。要增加架构抽象。 regs.rsp = user_sp.data() as u64; regs.rbp = user_sp.data() as u64; regs.rip = load_result.entry_point().data() as u64; regs.cs = USER_CS.bits() as u64; regs.ds = USER_DS.bits() as u64; regs.ss = USER_DS.bits() as u64; regs.es = 0; regs.rflags = 0x200; regs.rax = 1; drop(param); // kdebug!("regs: {:?}\n", regs); // crate::kdebug!( // "tmp_rs_execve: done, load_result.entry_point()={:?}", // load_result.entry_point() // ); return Ok(()); } /// ## 用于控制和查询与体系结构相关的进程特定选项 pub fn arch_prctl(option: usize, arg2: usize) -> Result { let pcb = ProcessManager::current_pcb(); if let Err(SystemError::EINVAL) = Self::do_arch_prctl_64(&pcb, option, arg2, true) { Self::do_arch_prctl_common(option, arg2)?; } Ok(0) } /// ## 64位下控制fs/gs base寄存器的方法 pub fn do_arch_prctl_64( pcb: &Arc, option: usize, arg2: usize, from_user: bool, ) -> Result { let mut arch_info = pcb.arch_info_irqsave(); match option { ARCH_GET_FS => { unsafe { arch_info.save_fsbase() }; let mut writer = UserBufferWriter::new( arg2 as *mut usize, core::mem::size_of::(), from_user, )?; writer.copy_one_to_user(&arch_info.fsbase, 0)?; } ARCH_GET_GS => { unsafe { arch_info.save_gsbase() }; let mut writer = UserBufferWriter::new( arg2 as *mut usize, core::mem::size_of::(), from_user, )?; writer.copy_one_to_user(&arch_info.gsbase, 0)?; } ARCH_SET_FS => { arch_info.fsbase = arg2; // 如果是当前进程则直接写入寄存器 if pcb.pid() == ProcessManager::current_pcb().pid() { unsafe { arch_info.restore_fsbase() } } } ARCH_SET_GS => { arch_info.gsbase = arg2; if pcb.pid() == ProcessManager::current_pcb().pid() { unsafe { arch_info.restore_gsbase() } } } _ => { return Err(SystemError::EINVAL); } } Ok(0) } #[allow(dead_code)] pub fn do_arch_prctl_common(_option: usize, _arg2: usize) -> Result { todo!("do_arch_prctl_common not unimplemented"); } } pub const ARCH_SET_GS: usize = 0x1001; pub const ARCH_SET_FS: usize = 0x1002; pub const ARCH_GET_FS: usize = 0x1003; pub const ARCH_GET_GS: usize = 0x1004;