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pti file, doesnt work yet

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Jack Halford 2018-04-05 19:04:44 +02:00
parent b7855ae56c
commit 1b7ddd12d9
1 changed files with 68 additions and 0 deletions
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68
kernel-rs/src/arch/x86/pti.rs Normal file
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use core::ptr;
use super::paging::ActivePageTable;
// use super::paging::entry::EntryFlags;
#[thread_local]
pub static mut PTI_CPU_STACK: [u8; 256] = [0; 256];
#[thread_local]
pub static mut PTI_CONTEXT_STACK: usize = 0;
#[inline(always)]
unsafe fn switch_stack(old: usize, new: usize) {
let old_esp: usize;
asm!("" : "={esp}"(old_esp) : : : "intel", "volatile");
let offset_esp = old - old_esp;
let new_esp = new - offset_esp;
ptr::copy_nonoverlapping(
old_esp as *const u8,
new_esp as *mut u8,
offset_esp
);
asm!("" : : "{esp}"(new_esp) : : "intel", "volatile");
}
#[inline(always)]
pub unsafe fn map() {
// {
// let mut active_table = unsafe { ActivePageTable::new() };
//
// // Map kernel heap
// let address = active_table.p4()[::KERNEL_HEAP_PML4].address();
// let frame = Frame::containing_address(address);
// let mut flags = active_table.p4()[::KERNEL_HEAP_PML4].flags();
// flags.remove(EntryFlags::PRESENT);
// active_table.p4_mut()[::KERNEL_HEAP_PML4].set(frame, flags);
//
// // Reload page tables
// active_table.flush_all();
// }
// Switch to per-context stack
switch_stack(PTI_CPU_STACK.as_ptr() as usize + PTI_CPU_STACK.len(), PTI_CONTEXT_STACK);
}
#[inline(always)]
pub unsafe fn unmap() {
// Switch to per-CPU stack
switch_stack(PTI_CONTEXT_STACK, PTI_CPU_STACK.as_ptr() as usize + PTI_CPU_STACK.len());
// {
// let mut active_table = unsafe { ActivePageTable::new() };
//
// // Unmap kernel heap
// let address = active_table.p4()[::KERNEL_HEAP_PML4].address();
// let frame = Frame::containing_address(address);
// let mut flags = active_table.p4()[::KERNEL_HEAP_PML4].flags();
// flags.insert(EntryFlags::PRESENT);
// active_table.p4_mut()[::KERNEL_HEAP_PML4].set(frame, flags);
//
// // Reload page tables
// active_table.flush_all();
// }
}