rcore-tutorial/os/src/syscall/process.rs
2025-08-03 13:48:14 +08:00

77 lines
2.2 KiB
Rust

//! Process management syscalls
use crate::config::PAGE_SIZE;
use crate::mm::{MapPermission, VPNRange, VirtAddr};
use crate::task::{change_program_brk, create_new_map_area, exit_current_and_run_next, get_current_task_page_table_entry, suspend_current_and_run_next, unmap_virtual_page};
use crate::timer::get_time_ms;
/// task exits and submit an exit code
pub fn sys_exit(exit_code: i32) -> ! {
println!("[kernel] Application exited with code {}", exit_code);
exit_current_and_run_next();
panic!("Unreachable in sys_exit!");
}
/// current task gives up resources for other tasks
pub fn sys_yield() -> isize {
suspend_current_and_run_next();
0
}
/// get current time
pub fn sys_get_time() -> isize {
get_time_ms() as isize
}
/// change data segment size
pub fn sys_sbrk(size: i32) -> isize {
if let Some(old_brk) = change_program_brk(size) {
old_brk as isize
} else {
-1
}
}
/// map files or devices into memory
pub fn sys_mmap(start: usize, len: usize, prot: usize) -> isize {
if start % PAGE_SIZE != 0 || prot & !0x7 != 0 || prot & 0x7 == 0 {
return -1;
}
let vpn_start = VirtAddr::from(start).floor();
let vpn_end = VirtAddr::from(start + len).ceil();
let vpn_range = VPNRange::new(vpn_start, vpn_end);
for vpn in vpn_range {
if let Some(pte) = get_current_task_page_table_entry(vpn) {
if pte.is_valid() {
return -1;
}
}
}
create_new_map_area(
vpn_start.into(),
vpn_end.into(),
MapPermission::from_bits_truncate((prot << 1) as u8) | MapPermission::U
);
0
}
/// unmap files or devices into memory
pub fn sys_munmap(start: usize, len: usize) -> isize {
if start % PAGE_SIZE != 0 {
return -1;
}
let vpn_start = VirtAddr::from(start).floor();
let vpn_end = VirtAddr::from(start + len).ceil();
let vpn_range = VPNRange::new(vpn_start, vpn_end);
for vpn in vpn_range {
if let Some(pte) = get_current_task_page_table_entry(vpn) {
if !pte.is_valid() {
return -1;
}
unmap_virtual_page(vpn)
} else {
return -1;
}
}
0
}