Exemplo n.º 1
0
int init_new_context(struct task_struct *task, struct mm_struct *mm)
{
 	struct mm_context *from_mm = NULL;
	struct mm_context *to_mm = &mm->context;
	unsigned long stack = 0;
	int ret = -ENOMEM;

	if (skas_needs_stub) {
		stack = get_zeroed_page(GFP_KERNEL);
		if (stack == 0)
			goto out;
	}

	to_mm->id.stack = stack;
	if (current->mm != NULL && current->mm != &init_mm)
		from_mm = &current->mm->context;

	if (proc_mm) {
		ret = new_mm(stack);
		if (ret < 0) {
			printk(KERN_ERR "init_new_context_skas - "
			       "new_mm failed, errno = %d\n", ret);
			goto out_free;
		}
		to_mm->id.u.mm_fd = ret;
	}
	else {
		if (from_mm)
			to_mm->id.u.pid = copy_context_skas0(stack,
							     from_mm->id.u.pid);
		else to_mm->id.u.pid = start_userspace(stack);

		if (to_mm->id.u.pid < 0) {
			ret = to_mm->id.u.pid;
			goto out_free;
		}
	}

	ret = init_new_ldt(to_mm, from_mm);
	if (ret < 0) {
		printk(KERN_ERR "init_new_context_skas - init_ldt"
		       " failed, errno = %d\n", ret);
		goto out_free;
	}

	return 0;

 out_free:
	if (to_mm->id.stack != 0)
		free_page(to_mm->id.stack);
 out:
	return ret;
}
Exemplo n.º 2
0
int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
{
 	struct mmu_context_skas *from_mm = NULL;
	struct mmu_context_skas *to_mm = &mm->context.skas;
	unsigned long stack = 0;
	int ret = -ENOMEM;

	if(skas_needs_stub){
		stack = get_zeroed_page(GFP_KERNEL);
		if(stack == 0)
			goto out;

		/* This zeros the entry that pgd_alloc didn't, needed since
		 * we are about to reinitialize it, and want mm.nr_ptes to
		 * be accurate.
		 */
		mm->pgd[USER_PTRS_PER_PGD] = __pgd(0);

		ret = init_stub_pte(mm, CONFIG_STUB_CODE,
				    (unsigned long) &__syscall_stub_start);
		if(ret)
			goto out_free;

		ret = init_stub_pte(mm, CONFIG_STUB_DATA, stack);
		if(ret)
			goto out_free;

		mm->nr_ptes--;
	}

	to_mm->id.stack = stack;
	if(current->mm != NULL && current->mm != &init_mm)
		from_mm = &current->mm->context.skas;

	if(proc_mm){
		ret = new_mm(stack);
		if(ret < 0){
			printk("init_new_context_skas - new_mm failed, "
			       "errno = %d\n", ret);
			goto out_free;
		}
		to_mm->id.u.mm_fd = ret;
	}
	else {
		if(from_mm)
			to_mm->id.u.pid = copy_context_skas0(stack,
							     from_mm->id.u.pid);
		else to_mm->id.u.pid = start_userspace(stack);
	}

	ret = init_new_ldt(to_mm, from_mm);
	if(ret < 0){
		printk("init_new_context_skas - init_ldt"
		       " failed, errno = %d\n", ret);
		goto out_free;
	}

	return 0;

 out_free:
	if(to_mm->id.stack != 0)
		free_page(to_mm->id.stack);
 out:
	return ret;
}