Commit 0b04c9e3 authored by Jeremy Soller's avatar Jeremy Soller Committed by GitHub

Merge pull request #783 from redox-os/fix_virtualbox_issues

Fix Virtualbox failures
parents 041dc7ea 4586dbc6
#[macro_use]
#[macro_export]
pub mod int_like;
......@@ -3,6 +3,7 @@
//! The Redox OS Kernel is a hybrid kernel that supports X86_64 systems and
//! provides Unix-like syscalls for primarily Rust applications
#![deny(warnings)]
#![feature(alloc)]
#![feature(arc_counts)]
#![feature(asm)]
......@@ -46,7 +47,6 @@ use core::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
use scheme::FileHandle;
#[macro_use]
#[macro_export]
/// Shared data structures
pub mod common;
......
......@@ -450,6 +450,41 @@ pub fn clone(flags: usize, stack_base: usize) -> Result<ContextId> {
Ok(pid)
}
fn empty(context: &mut context::Context, reaping: bool) {
if reaping {
// Memory should already be unmapped
assert!(context.image.is_empty());
assert!(context.heap.is_none());
assert!(context.stack.is_none());
assert!(context.tls.is_none());
} else {
// Unmap previous image, heap, grants, stack, and tls
context.image.clear();
drop(context.heap.take());
drop(context.stack.take());
drop(context.tls.take());
}
// FIXME: Looks like a race condition.
// Is it possible for Arc::strong_count to return 1 to two contexts that exit at the
// same time, or return 2 to both, thus either double freeing or leaking the grants?
if Arc::strong_count(&context.grants) == 1 {
let mut grants = context.grants.lock();
for grant in grants.drain(..) {
if reaping {
println!("{}: {}: Grant should not exist: {:?}", context.id.into(), unsafe { ::core::str::from_utf8_unchecked(&context.name.lock()) }, grant);
let mut new_table = unsafe { InactivePageTable::from_address(context.arch.get_page_table()) };
let mut temporary_page = TemporaryPage::new(Page::containing_address(VirtualAddress::new(arch::USER_TMP_GRANT_OFFSET)));
grant.unmap_inactive(&mut new_table, &mut temporary_page);
} else {
grant.unmap();
}
}
}
}
pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
let entry;
let mut sp = arch::USER_STACK_OFFSET + arch::USER_STACK_SIZE - 256;
......@@ -508,24 +543,7 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
// Set name
context.name = Arc::new(Mutex::new(canonical));
// Unmap previous image, heap, grants, stack, and tls
context.image.clear();
drop(context.heap.take());
drop(context.stack.take());
drop(context.tls.take());
let mut unmap_grants = Vec::new();
// FIXME: Looks like a race condition.
// Is it possible for Arc::strong_count to return 1 to two contexts that exit at the
// same time, or return 2 to both, thus either double freeing or leaking the grants?
if Arc::strong_count(&context.grants) == 1 {
mem::swap(context.grants.lock().deref_mut(), &mut unmap_grants);
}
context.grants = Arc::new(Mutex::new(Vec::new()));
for grant in unmap_grants {
grant.unmap();
}
empty(&mut context, false);
if stat.st_mode & syscall::flag::MODE_SETUID == syscall::flag::MODE_SETUID {
context.euid = stat.st_uid;
......@@ -807,23 +825,7 @@ pub fn exit(status: usize) -> ! {
let (vfork, children) = {
let mut context = context_lock.write();
context.image.clear();
drop(context.heap.take());
drop(context.stack.take());
drop(context.tls.take());
let mut unmap_grants = Vec::new();
// FIXME: Looks like a race condition.
// Is it possible for Arc::strong_count to return 1 to two contexts that exit at the
// same time, or return 2 to both, thus either double freeing or leaking the grants?
if Arc::strong_count(&context.grants) == 1 {
mem::swap(context.grants.lock().deref_mut(), &mut unmap_grants);
}
context.grants = Arc::new(Mutex::new(Vec::new()));
for grant in unmap_grants {
grant.unmap();
}
empty(&mut context, false);
let vfork = context.vfork;
context.vfork = false;
......@@ -911,7 +913,14 @@ fn reap(pid: ContextId) -> Result<ContextId> {
}
let mut contexts = context::contexts_mut();
contexts.remove(pid).ok_or(Error::new(ESRCH)).and(Ok(pid))
let context_lock = contexts.remove(pid).ok_or(Error::new(ESRCH))?;
{
let mut context = context_lock.write();
empty(&mut context, true);
}
drop(context_lock);
Ok(pid)
}
pub fn waitpid(pid: ContextId, status_ptr: usize, flags: usize) -> Result<ContextId> {
......
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