use alloc::{ffi::CString, string::String, vec::Vec}; use riscv::register::sstatus::{FS, SPP}; use system_error::SystemError; use crate::{ arch::{interrupt::TrapFrame, CurrentIrqArch}, exception::InterruptArch, mm::ucontext::AddressSpace, process::{ exec::{load_binary_file, ExecParam, ExecParamFlags}, ProcessManager, }, syscall::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::debug!( // "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" ); // debug!("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); // debug!("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)?; // debug!("load binary file done"); // debug!("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 mut ustack_message = unsafe { address_space .write() .user_stack_mut() .expect("No user stack found") .clone_info_only() }; let (user_sp, argv_ptr) = unsafe { param .init_info() .push_at( // address_space // .write() // .user_stack_mut() // .expect("No user stack found"), &mut ustack_message, ) .expect("Failed to push proc_init_info to user stack") }; address_space.write().user_stack = Some(ustack_message); // debug!("write proc_init_info to user stack done"); regs.a0 = param.init_info().args.len(); regs.a1 = argv_ptr.data(); // 设置系统调用返回时的寄存器状态 regs.sp = user_sp.data(); regs.epc = load_result.entry_point().data(); regs.status.update_spp(SPP::User); regs.status.update_fs(FS::Clean); regs.status.update_sum(true); drop(param); return Ok(()); } /// ## 用于控制和查询与体系结构相关的进程特定选项 #[allow(dead_code)] pub fn arch_prctl(_option: usize, _arg2: usize) -> Result { unimplemented!("Syscall::arch_prctl") } }