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)]
__inner_create( info: &Arc<KernelThreadCreateInfo>, clone_flags: CloneFlags, ) -> Result<Pid, SystemError>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]
kernel_thread_bootstrap_stage1()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 core::arch::naked_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 );
116 }
117
jump_to_stage2(ptr: *const KernelThreadCreateInfo)118 fn jump_to_stage2(ptr: *const KernelThreadCreateInfo) {
119 unsafe { kernel_thread_bootstrap_stage2(ptr) };
120 }
121