1 use alloc::{ffi::CString, string::String, sync::Arc, vec::Vec}; 2 use system_error::SystemError; 3 4 use crate::{ 5 arch::{ 6 interrupt::TrapFrame, 7 process::table::{USER_CS, USER_DS}, 8 CurrentIrqArch, 9 }, 10 exception::InterruptArch, 11 mm::ucontext::AddressSpace, 12 process::{ 13 exec::{load_binary_file, ExecParam, ExecParamFlags}, 14 ProcessControlBlock, ProcessManager, 15 }, 16 syscall::{user_access::UserBufferWriter, Syscall}, 17 }; 18 19 impl Syscall { 20 pub fn do_execve( 21 path: String, 22 argv: Vec<CString>, 23 envp: Vec<CString>, 24 regs: &mut TrapFrame, 25 ) -> Result<(), SystemError> { 26 // 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。 27 let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; 28 let pcb = ProcessManager::current_pcb(); 29 // log::debug!( 30 // "pid: {:?} do_execve: path: {:?}, argv: {:?}, envp: {:?}\n", 31 // pcb.pid(), 32 // path, 33 // argv, 34 // envp 35 // ); 36 37 let mut basic_info = pcb.basic_mut(); 38 // 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) 39 let old_address_space = basic_info.user_vm(); 40 41 // 在pcb中原来的用户地址空间 42 unsafe { 43 basic_info.set_user_vm(None); 44 } 45 // 创建新的地址空间并设置为当前地址空间 46 let address_space = AddressSpace::new(true).expect("Failed to create new address space"); 47 unsafe { 48 basic_info.set_user_vm(Some(address_space.clone())); 49 } 50 51 // to avoid deadlock 52 drop(basic_info); 53 54 assert!( 55 AddressSpace::is_current(&address_space), 56 "Failed to set address space" 57 ); 58 // debug!("Switch to new address space"); 59 60 // 切换到新的用户地址空间 61 unsafe { address_space.read().user_mapper.utable.make_current() }; 62 63 drop(old_address_space); 64 drop(irq_guard); 65 // debug!("to load binary file"); 66 let mut param = ExecParam::new(path.as_str(), address_space.clone(), ExecParamFlags::EXEC)?; 67 68 // 加载可执行文件 69 let load_result = load_binary_file(&mut param)?; 70 // debug!("load binary file done"); 71 // debug!("argv: {:?}, envp: {:?}", argv, envp); 72 param.init_info_mut().args = argv; 73 param.init_info_mut().envs = envp; 74 75 // 把proc_init_info写到用户栈上 76 let mut ustack_message = unsafe { 77 address_space 78 .write() 79 .user_stack_mut() 80 .expect("No user stack found") 81 .clone_info_only() 82 }; 83 let (user_sp, argv_ptr) = unsafe { 84 param 85 .init_info() 86 .push_at( 87 // address_space 88 // .write() 89 // .user_stack_mut() 90 // .expect("No user stack found"), 91 &mut ustack_message, 92 ) 93 .expect("Failed to push proc_init_info to user stack") 94 }; 95 address_space.write().user_stack = Some(ustack_message); 96 97 // debug!("write proc_init_info to user stack done"); 98 99 // （兼容旧版libc）把argv的指针写到寄存器内 100 // TODO: 改写旧版libc，不再需要这个兼容 101 regs.rdi = param.init_info().args.len() as u64; 102 regs.rsi = argv_ptr.data() as u64; 103 104 // 设置系统调用返回时的寄存器状态 105 // 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。 106 regs.rsp = user_sp.data() as u64; 107 regs.rbp = user_sp.data() as u64; 108 regs.rip = load_result.entry_point().data() as u64; 109 110 regs.cs = USER_CS.bits() as u64; 111 regs.ds = USER_DS.bits() as u64; 112 regs.ss = USER_DS.bits() as u64; 113 regs.es = 0; 114 regs.rflags = 0x200; 115 regs.rax = 1; 116 117 drop(param); 118 119 // debug!("regs: {:?}\n", regs); 120 121 // crate::debug!( 122 // "tmp_rs_execve: done, load_result.entry_point()={:?}", 123 // load_result.entry_point() 124 // ); 125 126 return Ok(()); 127 } 128 129 /// ## 用于控制和查询与体系结构相关的进程特定选项 130 pub fn arch_prctl(option: usize, arg2: usize) -> Result<usize, SystemError> { 131 let pcb = ProcessManager::current_pcb(); 132 if let Err(SystemError::EINVAL) = Self::do_arch_prctl_64(&pcb, option, arg2, true) { 133 Self::do_arch_prctl_common(option, arg2)?; 134 } 135 Ok(0) 136 } 137 138 /// ## 64位下控制fs/gs base寄存器的方法 139 pub fn do_arch_prctl_64( 140 pcb: &Arc<ProcessControlBlock>, 141 option: usize, 142 arg2: usize, 143 from_user: bool, 144 ) -> Result<usize, SystemError> { 145 let mut arch_info = pcb.arch_info_irqsave(); 146 match option { 147 ARCH_GET_FS => { 148 unsafe { arch_info.save_fsbase() }; 149 let mut writer = UserBufferWriter::new( 150 arg2 as *mut usize, 151 core::mem::size_of::<usize>(), 152 from_user, 153 )?; 154 writer.copy_one_to_user(&arch_info.fsbase, 0)?; 155 } 156 ARCH_GET_GS => { 157 unsafe { arch_info.save_gsbase() }; 158 let mut writer = UserBufferWriter::new( 159 arg2 as *mut usize, 160 core::mem::size_of::<usize>(), 161 from_user, 162 )?; 163 writer.copy_one_to_user(&arch_info.gsbase, 0)?; 164 } 165 ARCH_SET_FS => { 166 arch_info.fsbase = arg2; 167 // 如果是当前进程则直接写入寄存器 168 if pcb.pid() == ProcessManager::current_pcb().pid() { 169 unsafe { arch_info.restore_fsbase() } 170 } 171 } 172 ARCH_SET_GS => { 173 arch_info.gsbase = arg2; 174 if pcb.pid() == ProcessManager::current_pcb().pid() { 175 unsafe { arch_info.restore_gsbase() } 176 } 177 } 178 _ => { 179 return Err(SystemError::EINVAL); 180 } 181 } 182 Ok(0) 183 } 184 185 #[allow(dead_code)] 186 pub fn do_arch_prctl_common(_option: usize, _arg2: usize) -> Result<usize, SystemError> { 187 todo!("do_arch_prctl_common not unimplemented"); 188 } 189 } 190 191 pub const ARCH_SET_GS: usize = 0x1001; 192 pub const ARCH_SET_FS: usize = 0x1002; 193 pub const ARCH_GET_FS: usize = 0x1003; 194 pub const ARCH_GET_GS: usize = 0x1004; 195