int copy_thread_tt(int nr, unsigned long clone_flags, unsigned long sp,
unsigned long stack_top, struct task_struct * p,
struct pt_regs *regs)
{
int (*tramp)(void *);
int new_pid, err;
unsigned long stack;
if(current->thread.forking)
tramp = fork_tramp;
else {
tramp = new_thread_proc;
p->thread.request.u.thread = current->thread.request.u.thread;
}
err = os_pipe(p->thread.mode.tt.switch_pipe, 1, 1);
if(err < 0){
printk("copy_thread : pipe failed, err = %d\n", -err);
return(err);
}
stack = alloc_stack(0, 0);
if(stack == 0){
printk(KERN_ERR "copy_thread : failed to allocate "
"temporary stack\n");
return(-ENOMEM);
}
clone_flags &= CLONE_VM;
p->thread.temp_stack = stack;
new_pid = start_fork_tramp(task_stack_page(p), stack, clone_flags, tramp);
if(new_pid < 0){
printk(KERN_ERR "copy_thread : clone failed - errno = %d\n",
-new_pid);
return(new_pid);
}
if(current->thread.forking){
sc_to_sc(UPT_SC(&p->thread.regs.regs), UPT_SC(®s->regs));
SC_SET_SYSCALL_RETURN(UPT_SC(&p->thread.regs.regs), 0);
if(sp != 0)
SC_SP(UPT_SC(&p->thread.regs.regs)) = sp;
}
p->thread.mode.tt.extern_pid = new_pid;
current->thread.request.op = OP_FORK;
current->thread.request.u.fork.pid = new_pid;
os_usr1_process(os_getpid());
/* Enable the signal and then disable it to ensure that it is handled
* here, and nowhere else.
*/
change_sig(SIGUSR1, 1);
change_sig(SIGUSR1, 0);
err = 0;
return(err);
}
int fork_tramp(void *stack)
{
local_irq_disable();
arch_init_thread();
init_new_thread_stack(stack, finish_fork_handler);
os_usr1_process(os_getpid());
change_sig(SIGUSR1, 1);
return(0);
}
int set_user_mode(void *t)
{
struct task_struct *task;
task = t ? t : current;
if(task->thread.mode.tt.tracing)
return(1);
task->thread.request.op = OP_TRACE_ON;
os_usr1_process(os_getpid());
return(0);
}
void initial_thread_cb_tt(void (*proc)(void *), void *arg)
{
if(os_getpid() == tracing_pid){
(*proc)(arg);
}
else {
current->thread.request.op = OP_CB;
current->thread.request.u.cb.proc = proc;
current->thread.request.u.cb.arg = arg;
os_usr1_process(os_getpid());
change_sig(SIGUSR1, 1);
change_sig(SIGUSR1, 0);
}
}
static int new_thread_proc(void *stack)
{
/* local_irq_disable is needed to block out signals until this thread is
* properly scheduled. Otherwise, the tracing thread will get mighty
* upset about any signals that arrive before that.
* This has the complication that it sets the saved signal mask in
* the sigcontext to block signals. This gets restored when this
* thread (or a descendant, since they get a copy of this sigcontext)
* returns to userspace.
* So, this is compensated for elsewhere.
* XXX There is still a small window until local_irq_disable() actually
* finishes where signals are possible - shouldn't be a problem in
* practice since SIGIO hasn't been forwarded here yet, and the
* local_irq_disable should finish before a SIGVTALRM has time to be
* delivered.
*/
local_irq_disable();
init_new_thread_stack(stack, new_thread_handler);
os_usr1_process(os_getpid());
change_sig(SIGUSR1, 1);
return(0);
}
void flush_thread_tt(void)
{
unsigned long stack;
int new_pid;
stack = alloc_stack(0, 0);
if(stack == 0){
printk(KERN_ERR
"flush_thread : failed to allocate temporary stack\n");
do_exit(SIGKILL);
}
new_pid = start_fork_tramp(task_stack_page(current), stack, 0, exec_tramp);
if(new_pid < 0){
printk(KERN_ERR
"flush_thread : new thread failed, errno = %d\n",
-new_pid);
do_exit(SIGKILL);
}
if(current_thread->cpu == 0)
forward_interrupts(new_pid);
current->thread.request.op = OP_EXEC;
current->thread.request.u.exec.pid = new_pid;
unprotect_stack((unsigned long) current_thread);
os_usr1_process(os_getpid());
change_sig(SIGUSR1, 1);
change_sig(SIGUSR1, 0);
enable_timer();
free_page(stack);
protect_memory(uml_reserved, high_physmem - uml_reserved, 1, 1, 0, 1);
stack_protections((unsigned long) current_thread);
force_flush_all();
unblock_signals();
}
void halt_tt(void)
{
current->thread.request.op = OP_HALT;
os_usr1_process(os_getpid());
change_sig(SIGUSR1, 1);
}
void reboot_tt(void)
{
current->thread.request.op = OP_REBOOT;
os_usr1_process(os_getpid());
change_sig(SIGUSR1, 1);
}
void new_thread_proc(void *stack, void (*handler)(int sig))
{
init_new_thread_stack(stack, handler);
os_usr1_process(os_getpid());
}