[feature request] chroot escape

[sleirsgoevy]

There seems to be no way to set fd_rdir and fd_jdir via /dev/mira ioctls, which is required in utility apps for accessing PS4 filesystem.

[OsirizX]

I suggest setting it to rootvnode if the request to set prison is root. It works well in my tests.

// CtrlDriver.cpp
// CtrlDriver::SetThreadCredentials
auto l_ThreadCredential = l_Thread->td_ucred;
auto l_ThreadFd = l_Thread->td_proc->p_fd;
...
if (p_Input.Prison == MiraThreadCredentials::_MiraThreadCredentialsPrison::Root) {
    l_ThreadCredential->cr_prison = *(struct prison**)kdlsym(prison0);
    l_ThreadFd->fd_rdir = l_ThreadFd->fd_jdir = *(struct vnode**)kdlsym(rootvnode);
}