static void xol_free_insn_slot(struct task_struct *tsk)
{
	struct xol_area *area;
	unsigned long vma_end;
	unsigned long slot_addr;

	if (!tsk->mm || !tsk->mm->uprobes_state.xol_area || !tsk->utask)
		return;

	slot_addr = tsk->utask->xol_vaddr;
	if (unlikely(!slot_addr))
		return;

	area = tsk->mm->uprobes_state.xol_area;
	vma_end = area->vaddr + PAGE_SIZE;
	if (area->vaddr <= slot_addr && slot_addr < vma_end) {
		unsigned long offset;
		int slot_nr;

		offset = slot_addr - area->vaddr;
		slot_nr = offset / UPROBE_XOL_SLOT_BYTES;
		if (slot_nr >= UINSNS_PER_PAGE)
			return;

		clear_bit(slot_nr, area->bitmap);
		atomic_dec(&area->slot_count);
		smp_mb__after_atomic(); /* pairs with prepare_to_wait() */
		if (waitqueue_active(&area->wq))
			wake_up(&area->wq);

		tsk->utask->xol_vaddr = 0;
	}
}
Unknown