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