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Increase kernel stack size to 2mb, move from cooperative to timer

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preemption based scheduling, add correct save_lock on aarch64, add
simple IPC (read, write, manage), and simple and unsecure SHM, add
per-process kernel stacks, add copy_cstr_to_user, always use run_next
for aarch64, remove primitives from the kernel
This commit is contained in:
csd4ni3l
2026-05-26 09:53:59 +02:00
parent 7070b53355
commit 6ebc6ada09
37 changed files with 1065 additions and 475 deletions
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kernel/src/arch/x86_64/syscall.rs
+50 -38
View File
@@ -3,7 +3,7 @@ use core::arch::asm;
use x86_64::instructions::tlb::flush_all;
use crate::{
arch::x86_64::gdt::{GDT, TSS},
arch::x86_64::gdt::{GDT, TSS_MUTEX},
task::context::UserContext,
};
@@ -21,7 +21,7 @@ pub struct PerCpuData {
pub kernel_rsp: u64,
}
static mut PER_CPU: PerCpuData = PerCpuData {
pub static mut PER_CPU: PerCpuData = PerCpuData {
user_rsp: 0,
kernel_rsp: 0,
};
@@ -65,8 +65,9 @@ pub fn init_syscalls() {
asm!("mov gs, ax", in("ax") 0u16);
let kernel_stack_top = TSS.privilege_stack_table[0].as_u64();
PER_CPU.kernel_rsp = kernel_stack_top;
if let Some(tss) = TSS_MUTEX.lock().as_ref() {
PER_CPU.kernel_rsp = tss.privilege_stack_table[0].as_u64();
}
#[allow(function_casts_as_integer)]
wrmsr(IA32_LSTAR, syscall_entry as u64); // set syscall entry function
@@ -94,7 +95,7 @@ unsafe extern "C" fn syscall_entry() {
mov gs:[0], rsp
mov rsp, gs:[8]
sub rsp, 128
sub rsp, 144
mov qword ptr [rsp + 0], r15
mov qword ptr [rsp + 8], r14
@@ -115,6 +116,11 @@ unsafe extern "C" fn syscall_entry() {
mov rax, qword ptr gs:[0]
mov qword ptr [rsp + 120], rax
mov rax, qword ptr [rsp + 96]
mov qword ptr [rsp + 128], rax
mov rax, qword ptr [rsp + 32]
mov qword ptr [rsp + 136], rax
mov rbx, rsp // rbx = frame base
// ctx_save(frame)
@@ -123,7 +129,6 @@ unsafe extern "C" fn syscall_entry() {
call ctx_save
mov rsp, rbx
// syscall_dispatch(num,arg0..arg5)
mov rdi, qword ptr [rbx + 112]
mov rsi, qword ptr [rbx + 72]
mov rdx, qword ptr [rbx + 64]
@@ -131,28 +136,23 @@ unsafe extern "C" fn syscall_entry() {
mov r8, qword ptr [rbx + 40]
mov r9, qword ptr [rbx + 56]
lea rsp, [rbx - 24] // rsp%16==8 before call
lea rsp, [rbx - 24]
mov rax, qword ptr [rbx + 48]
mov qword ptr [rsp + 0], rax
call syscall_dispatch
mov rsp, rbx
// save return value into frame (so normal restore uses it)
mov qword ptr [rbx + 112], rax
// ctx_save(frame) again so saved_ctx.rax reflects return value
mov rdi, rbx
lea rsp, [rbx - 8]
call ctx_save
mov rsp, rbx
// maybe switch tasks (this should not return if it switches)
lea rsp, [rbx - 8]
call check_and_reschedule
mov rsp, rbx
test rax, rax
jnz .done
mov rax, qword ptr [rsp + 128]
mov qword ptr [rsp + 96], rax
mov rax, qword ptr [rsp + 136]
mov qword ptr [rsp + 32], rax
// restore registers from frame
mov rax, qword ptr [rsp + 112]
@@ -165,12 +165,11 @@ unsafe extern "C" fn syscall_entry() {
mov r8, qword ptr [rsp + 56]
mov r9, qword ptr [rsp + 48]
mov r10, qword ptr [rsp + 40]
mov r11, qword ptr [rsp + 32] // rflags — sysretq loads RFLAGS from r11
mov r11, qword ptr [rsp + 32]
mov r12, qword ptr [rsp + 24]
mov r13, qword ptr [rsp + 16]
mov r14, qword ptr [rsp + 8]
mov r15, qword ptr [rsp + 0]
// don't restore rsp from frame — use the user rsp we saved in gs:[0]
mov rsp, qword ptr gs:[0]
swapgs
sysretq
@@ -182,27 +181,40 @@ unsafe extern "C" fn syscall_entry() {
#[unsafe(naked)]
#[unsafe(no_mangle)]
pub unsafe fn run_next(ctx: *const UserContext, user_rsp: u64) {
pub unsafe fn run_next(ctx: *const UserContext, user_rsp: u64, user_cs: u64, user_ss: u64) {
core::arch::naked_asm!(
"mov gs:[0], rsi", // store new user rsp
"mov rsp, rdi",
"mov r15, qword ptr [rsp + 0]",
"mov r14, qword ptr [rsp + 8]",
"mov r13, qword ptr [rsp + 16]",
"mov r12, qword ptr [rsp + 24]",
"mov r11, qword ptr [rsp + 32]", // rflags
"mov r10, qword ptr [rsp + 40]",
"mov r9, qword ptr [rsp + 48]",
"mov r8, qword ptr [rsp + 56]",
"mov rsi, qword ptr [rsp + 64]",
"mov rdi, qword ptr [rsp + 72]",
"mov rbp, qword ptr [rsp + 80]",
"mov rdx, qword ptr [rsp + 88]",
"mov rcx, qword ptr [rsp + 96]", // rip
"mov rbx, qword ptr [rsp + 104]",
"mov rax, qword ptr [rsp + 112]",
"mov rsp, qword ptr [rsp + 120]", // user rsp
// rdi = ctx, rsi = user_rsp, rdx = user_cs, rcx = user_ss
"mov gs:[0], rsi",
"mov rax, rcx",
"and eax, 0xFFFC",
"mov ds, ax",
"mov es, ax",
// save ctx ptr on stack, then build iret frame
"push rdi",
"push rcx",
"push rsi",
"push qword ptr [rdi + 136]",
"push rdx",
"push qword ptr [rdi + 128]",
// load all gp regs via rdi
"mov r15, qword ptr [rdi + 0]",
"mov r14, qword ptr [rdi + 8]",
"mov r13, qword ptr [rdi + 16]",
"mov r12, qword ptr [rdi + 24]",
"mov r11, qword ptr [rdi + 32]",
"mov r10, qword ptr [rdi + 40]",
"mov r9, qword ptr [rdi + 48]",
"mov r8, qword ptr [rdi + 56]",
"mov rsi, qword ptr [rdi + 64]",
"mov rbp, qword ptr [rdi + 80]",
"mov rdx, qword ptr [rdi + 88]",
"mov rcx, qword ptr [rdi + 96]",
// ctx_ptr is at [rsp + 40]
"mov rax, qword ptr [rsp + 40]",
"mov rbx, qword ptr [rax + 104]",
"mov rdi, qword ptr [rax + 72]",
"mov rax, qword ptr [rax + 112]",
"swapgs",
"sysretq",
"iretq",
);
}