1 use core::arch::asm; 2 3 use crate::{ 4 arch::{asm::csr::CSR_SSTATUS, interrupt::TrapFrame}, 5 process::{ 6 fork::CloneFlags, 7 kthread::{kernel_thread_bootstrap_stage2, KernelThreadCreateInfo, KernelThreadMechanism}, 8 Pid, ProcessManager, 9 }, 10 }; 11 use alloc::sync::Arc; 12 use asm_macros::restore_from_x6_to_x31; 13 use kdepends::memoffset::offset_of; 14 use riscv::register::sstatus::SPP; 15 use system_error::SystemError; 16 17 impl KernelThreadMechanism { 18 /// 伪造trapframe，创建内核线程 19 /// 20 /// ## 返回值 21 /// 22 /// 返回创建的内核线程的pid 23 #[inline(never)] 24 pub fn __inner_create( 25 info: &Arc<KernelThreadCreateInfo>, 26 clone_flags: CloneFlags, 27 ) -> Result<Pid, SystemError> { 28 // WARNING: If create failed, we must drop the info manually or it will cause memory leak. (refcount will not decrease when create failed) 29 let create_info: *const KernelThreadCreateInfo = 30 KernelThreadCreateInfo::generate_unsafe_arc_ptr(info.clone()); 31 32 let mut frame = TrapFrame::new(); 33 frame.a2 = create_info as usize; 34 35 // 使能中断 36 frame.status.update_sie(true); 37 frame.status.update_spp(SPP::Supervisor); 38 frame.status.update_sum(true); 39 40 frame.ra = kernel_thread_bootstrap_stage1 as usize; 41 42 // fork失败的话，子线程不会执行。否则将导致内存安全问题。 43 let pid = ProcessManager::fork(&frame, clone_flags).map_err(|e| { 44 unsafe { KernelThreadCreateInfo::parse_unsafe_arc_ptr(create_info) }; 45 e 46 })?; 47 48 ProcessManager::find(pid) 49 .unwrap() 50 .set_name(info.name().clone()); 51 52 return Ok(pid); 53 } 54 } 55 56 /// 内核线程引导函数的第一阶段 57 /// 58 /// 当内核线程开始执行时，会先执行这个函数，这个函数会将伪造的trapframe中的数据弹出，然后跳转到第二阶段 59 /// 60 /// 跳转之后，指向Box<KernelThreadClosure>的指针将传入到stage2的函数 61 // #[naked] 62 // pub(super) unsafe extern "C" fn kernel_thread_bootstrap_stage1() { 63 // todo!() 64 // } 65 #[naked] 66 pub(super) unsafe extern "C" fn kernel_thread_bootstrap_stage1() { 67 // 这个函数要是naked的，只是因为现在还没有实现，而naked func不能打`unimplemented!()` 68 // 所以先写成了普通函数 69 asm!(concat!( 70 " 71 ld x3, {off_gp}(sp) 72 ld x5, {off_t0}(sp) 73 74 ", 75 restore_from_x6_to_x31!(), 76 77 " 78 ld a0, {off_status}(sp) 79 csrw {csr_status}, a0 80 mv a0, a2 81 j {stage2_func} 82 " 83 ), 84 csr_status = const CSR_SSTATUS, 85 off_status = const offset_of!(TrapFrame, status), 86 off_gp = const offset_of!(TrapFrame, gp), 87 off_t0 = const offset_of!(TrapFrame, t0), 88 off_t1 = const offset_of!(TrapFrame, t1), 89 off_t2 = const offset_of!(TrapFrame, t2), 90 off_s0 = const offset_of!(TrapFrame, s0), 91 off_s1 = const offset_of!(TrapFrame, s1), 92 off_a0 = const offset_of!(TrapFrame, a0), 93 off_a1 = const offset_of!(TrapFrame, a1), 94 off_a2 = const offset_of!(TrapFrame, a2), 95 off_a3 = const offset_of!(TrapFrame, a3), 96 off_a4 = const offset_of!(TrapFrame, a4), 97 off_a5 = const offset_of!(TrapFrame, a5), 98 off_a6 = const offset_of!(TrapFrame, a6), 99 off_a7 = const offset_of!(TrapFrame, a7), 100 off_s2 = const offset_of!(TrapFrame, s2), 101 off_s3 = const offset_of!(TrapFrame, s3), 102 off_s4 = const offset_of!(TrapFrame, s4), 103 off_s5 = const offset_of!(TrapFrame, s5), 104 off_s6 = const offset_of!(TrapFrame, s6), 105 off_s7 = const offset_of!(TrapFrame, s7), 106 off_s8 = const offset_of!(TrapFrame, s8), 107 off_s9 = const offset_of!(TrapFrame, s9), 108 off_s10 = const offset_of!(TrapFrame, s10), 109 off_s11 = const offset_of!(TrapFrame, s11), 110 off_t3 = const offset_of!(TrapFrame, t3), 111 off_t4 = const offset_of!(TrapFrame, t4), 112 off_t5 = const offset_of!(TrapFrame, t5), 113 off_t6 = const offset_of!(TrapFrame, t6), 114 stage2_func = sym jump_to_stage2, 115 options(noreturn), 116 ); 117 } 118 119 fn jump_to_stage2(ptr: *const KernelThreadCreateInfo) { 120 unsafe { kernel_thread_bootstrap_stage2(ptr) }; 121 } 122