This patch switches away from {Nonnull,}LockRefPtr to the non-locking
smart pointers throughout the kernel.
I've looked at the handful of places where these were being persisted
and I don't see any race situations.
Note that the process file descriptor table (Process::m_fds) was already
guarded via MutexProtected.
From now on, we don't allow jailed processes to open all device nodes in
/dev, but only allow jailed processes to open /dev/full, /dev/zero,
/dev/null, and various TTY and PTY devices (and not including virtual
consoles) so we basically restrict applications to what they can do when
they are in jail.
The motivation for this type of restriction is to ensure that even if a
remote code execution occurred, the damage that can be done is very
small.
We also don't restrict reading and writing on device nodes that were
already opened, because that limit seems not useful, especially in the
case where we do want to provide an OpenFileDescription to such device
but nothing further than that.
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:
- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable
This patch renames the Kernel classes so that they can coexist with
the original AK classes:
- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable
The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
This will replace the /dev/tty symlink created by SystemServer, so
instead of a symlink, a character device will be created. When doing
read(2), write(2) and ioctl(2) on this device, it will "redirect" these
operations to the attached TTY of the current process.
