112 lines
3.7 KiB
Rust
112 lines
3.7 KiB
Rust
///! Process syscalls
|
|
|
|
use core::str;
|
|
|
|
use arch;
|
|
use arch::interrupt::halt;
|
|
use arch::paging::{ActivePageTable, Page, VirtualAddress, entry};
|
|
use context;
|
|
use elf;
|
|
use syscall::{self, Error, Result};
|
|
|
|
pub fn brk(address: usize) -> Result<usize> {
|
|
//TODO: Make this more efficient
|
|
let mut active_table = unsafe { ActivePageTable::new() };
|
|
let mut current = arch::USER_HEAP_OFFSET;
|
|
{
|
|
let min_page = Page::containing_address(VirtualAddress::new(arch::USER_HEAP_OFFSET));
|
|
let max_page = Page::containing_address(VirtualAddress::new(arch::USER_HEAP_OFFSET + arch::USER_HEAP_SIZE - 1));
|
|
for page in Page::range_inclusive(min_page, max_page) {
|
|
if active_table.translate_page(page).is_none() {
|
|
break;
|
|
}
|
|
current = page.start_address().get() + 4096;
|
|
}
|
|
}
|
|
if address == 0 {
|
|
//println!("Brk query {:X}", current);
|
|
Ok(current)
|
|
} else if address > current {
|
|
let start_page = Page::containing_address(VirtualAddress::new(current));
|
|
let end_page = Page::containing_address(VirtualAddress::new(address - 1));
|
|
for page in Page::range_inclusive(start_page, end_page) {
|
|
//println!("Map {:X}", page.start_address().get());
|
|
if active_table.translate_page(page).is_none() {
|
|
//println!("Not found - mapping");
|
|
active_table.map(page, entry::PRESENT | entry::WRITABLE | entry::NO_EXECUTE | entry::USER_ACCESSIBLE);
|
|
active_table.flush(page);
|
|
} else {
|
|
//println!("Found - skipping");
|
|
}
|
|
}
|
|
//let new = end_page.start_address().get() + 4096;
|
|
//println!("Brk increase {:X}: from {:X} to {:X}", address, current, new);
|
|
Ok(address)
|
|
} else {
|
|
let start_page = Page::containing_address(VirtualAddress::new(address));
|
|
let end_page = Page::containing_address(VirtualAddress::new(current - 1));
|
|
for page in Page::range_inclusive(start_page, end_page) {
|
|
//println!("Unmap {:X}", page.start_address().get());
|
|
if active_table.translate_page(page).is_some() {
|
|
//println!("Found - unmapping");
|
|
active_table.unmap(page);
|
|
active_table.flush(page);
|
|
} else {
|
|
//println!("Not found - skipping");
|
|
}
|
|
}
|
|
//let new = start_page.start_address().get();
|
|
//println!("Brk decrease {:X}: from {:X} to {:X}", address, current, new);
|
|
Ok(address)
|
|
}
|
|
}
|
|
|
|
pub fn exit(status: usize) -> ! {
|
|
println!("Exit {}", status);
|
|
loop {
|
|
unsafe { halt() };
|
|
}
|
|
}
|
|
|
|
pub fn exec(path: &[u8], _args: &[[usize; 2]]) -> Result<usize> {
|
|
//TODO: Use args
|
|
//TODO: Unmap previous mappings
|
|
//TODO: Drop init_data
|
|
|
|
let init_file = syscall::open(path, 0)?;
|
|
let mut init_data = vec![];
|
|
loop {
|
|
let mut buf = [0; 4096];
|
|
let count = syscall::read(init_file, &mut buf)?;
|
|
if count > 0 {
|
|
init_data.extend_from_slice(&buf[..count]);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
let _ = syscall::close(init_file);
|
|
|
|
match elf::Elf::from(&init_data) {
|
|
Ok(elf) => {
|
|
elf.run();
|
|
Ok(0)
|
|
},
|
|
Err(err) => {
|
|
println!("failed to execute {}: {}", unsafe { str::from_utf8_unchecked(path) }, err);
|
|
Err(Error::NoExec)
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn getpid() -> Result<usize> {
|
|
let contexts = context::contexts();
|
|
let context_lock = contexts.current().ok_or(Error::NoProcess)?;
|
|
let context = context_lock.read();
|
|
Ok(context.id)
|
|
}
|
|
|
|
pub fn sched_yield() -> Result<usize> {
|
|
unsafe { context::switch(); }
|
|
Ok(0)
|
|
}
|