1 use crate::{ 2 arch::{ 3 ipc::signal::X86_64SignalArch, 4 syscall::nr::{SYS_ARCH_PRCTL, SYS_RT_SIGRETURN}, 5 CurrentIrqArch, 6 }, 7 exception::InterruptArch, 8 ipc::signal_types::SignalArch, 9 libs::align::SafeForZero, 10 mm::VirtAddr, 11 process::ProcessManager, 12 syscall::{Syscall, SYS_SCHED}, 13 }; 14 use system_error::SystemError; 15 16 use super::{ 17 interrupt::{entry::set_system_trap_gate, TrapFrame}, 18 mm::barrier::mfence, 19 }; 20 21 pub mod nr; 22 23 /// ### 存储PCB系统调用栈以及在syscall过程中暂存用户态rsp的结构体 24 /// 25 /// 在syscall指令中将会从该结构体中读取系统调用栈和暂存rsp, 26 /// 使用`gsbase`寄存器实现，后续如果需要使用gsbase寄存器，需要相应设置正确的偏移量 27 #[repr(C)] 28 #[derive(Debug, Clone)] 29 pub(super) struct X86_64GSData { 30 pub(super) kaddr: VirtAddr, 31 pub(super) uaddr: VirtAddr, 32 } 33 34 impl X86_64GSData { 35 /// ### 设置系统调用栈，将会在下一个调度后写入KernelGsbase 36 pub fn set_kstack(&mut self, kstack: VirtAddr) { 37 self.kaddr = kstack; 38 } 39 } 40 41 unsafe impl SafeForZero for X86_64GSData {} 42 43 extern "C" { 44 fn syscall_int(); 45 fn syscall_64(); 46 } 47 48 macro_rules! syscall_return { 49 ($val:expr, $regs:expr, $show:expr) => {{ 50 let ret = $val; 51 $regs.rax = ret as u64; 52 53 if $show { 54 let pid = ProcessManager::current_pcb().pid(); 55 crate::kdebug!("syscall return:pid={:?},ret= {:?}\n", pid, ret as isize); 56 } 57 58 unsafe { 59 CurrentIrqArch::interrupt_disable(); 60 } 61 return; 62 }}; 63 } 64 65 #[no_mangle] 66 pub extern "sysv64" fn syscall_handler(frame: &mut TrapFrame) { 67 let syscall_num = frame.rax as usize; 68 // 防止sys_sched由于超时无法退出导致的死锁 69 if syscall_num == SYS_SCHED { 70 unsafe { 71 CurrentIrqArch::interrupt_disable(); 72 } 73 } else { 74 unsafe { 75 CurrentIrqArch::interrupt_enable(); 76 } 77 } 78 79 let args = [ 80 frame.rdi as usize, 81 frame.rsi as usize, 82 frame.rdx as usize, 83 frame.r10 as usize, 84 frame.r8 as usize, 85 frame.r9 as usize, 86 ]; 87 mfence(); 88 let pid = ProcessManager::current_pcb().pid(); 89 let show = false; 90 // let show = if syscall_num != SYS_SCHED && pid.data() >= 7 { 91 // true 92 // } else { 93 // false 94 // }; 95 96 if show { 97 crate::kdebug!("syscall: pid: {:?}, num={:?}\n", pid, syscall_num); 98 } 99 100 // Arch specific syscall 101 match syscall_num { 102 SYS_RT_SIGRETURN => { 103 syscall_return!( 104 X86_64SignalArch::sys_rt_sigreturn(frame) as usize, 105 frame, 106 show 107 ); 108 } 109 SYS_ARCH_PRCTL => { 110 syscall_return!( 111 Syscall::arch_prctl(args[0], args[1]) 112 .unwrap_or_else(|e| e.to_posix_errno() as usize), 113 frame, 114 show 115 ); 116 } 117 _ => {} 118 } 119 syscall_return!( 120 Syscall::handle(syscall_num, &args, frame).unwrap_or_else(|e| e.to_posix_errno() as usize) 121 as u64, 122 frame, 123 show 124 ); 125 } 126 127 /// 系统调用初始化 128 pub fn arch_syscall_init() -> Result<(), SystemError> { 129 // kinfo!("arch_syscall_init\n"); 130 unsafe { set_system_trap_gate(0x80, 0, VirtAddr::new(syscall_int as usize)) }; // 系统调用门 131 unsafe { init_syscall_64() }; 132 return Ok(()); 133 } 134 135 /// syscall指令初始化函数 136 pub(super) unsafe fn init_syscall_64() { 137 let mut efer = x86::msr::rdmsr(x86::msr::IA32_EFER); 138 efer |= 0x1; 139 x86::msr::wrmsr(x86::msr::IA32_EFER, efer); 140 141 let syscall_base = (1_u16) << 3; 142 let sysret_base = ((4_u16) << 3) | 3; 143 let high = (u32::from(sysret_base) << 16) | u32::from(syscall_base); 144 // 初始化STAR寄存器 145 x86::msr::wrmsr(x86::msr::IA32_STAR, u64::from(high) << 32); 146 147 // 初始化LSTAR,该寄存器存储syscall指令入口 148 x86::msr::wrmsr(x86::msr::IA32_LSTAR, syscall_64 as usize as u64); 149 x86::msr::wrmsr(x86::msr::IA32_FMASK, 0xfffffffe); 150 } 151