1443 static int xol_add_vma(struct mm_struct *mm, struct xol_area *area)  in xol_add_vma()  argument
1456 	if (!area->vaddr) {  in xol_add_vma()
1458 		area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE,  in xol_add_vma()
1460 		if (area->vaddr & ~PAGE_MASK) {  in xol_add_vma()
1461 			ret = area->vaddr;  in xol_add_vma()
1466 	vma = _install_special_mapping(mm, area->vaddr, PAGE_SIZE,  in xol_add_vma()
1468 				&area->xol_mapping);  in xol_add_vma()
1476 	smp_store_release(&mm->uprobes_state.xol_area, area); /* ^^^ */  in xol_add_vma()
1487 	struct xol_area *area;  in __create_xol_area()  local
1489 	area = kmalloc(sizeof(*area), GFP_KERNEL);  in __create_xol_area()
1490 	if (unlikely(!area))  in __create_xol_area()
1493 	area->bitmap = kcalloc(BITS_TO_LONGS(UINSNS_PER_PAGE), sizeof(long),  in __create_xol_area()
1495 	if (!area->bitmap)  in __create_xol_area()
1498 	area->xol_mapping.name = "[uprobes]";  in __create_xol_area()
1499 	area->xol_mapping.fault = NULL;  in __create_xol_area()
1500 	area->xol_mapping.pages = area->pages;  in __create_xol_area()
1501 	area->pages[0] = alloc_page(GFP_HIGHUSER);  in __create_xol_area()
1502 	if (!area->pages[0])  in __create_xol_area()
1504 	area->pages[1] = NULL;  in __create_xol_area()
1506 	area->vaddr = vaddr;  in __create_xol_area()
1507 	init_waitqueue_head(&area->wq);  in __create_xol_area()
1509 	set_bit(0, area->bitmap);  in __create_xol_area()
1510 	atomic_set(&area->slot_count, 1);  in __create_xol_area()
1511 	arch_uprobe_copy_ixol(area->pages[0], 0, &insn, UPROBE_SWBP_INSN_SIZE);  in __create_xol_area()
1513 	if (!xol_add_vma(mm, area))  in __create_xol_area()
1514 		return area;  in __create_xol_area()
1516 	__free_page(area->pages[0]);  in __create_xol_area()
1518 	kfree(area->bitmap);  in __create_xol_area()
1520 	kfree(area);  in __create_xol_area()
1534 	struct xol_area *area;  in get_xol_area()  local
1540 	area = READ_ONCE(mm->uprobes_state.xol_area); /* ^^^ */  in get_xol_area()
1541 	return area;  in get_xol_area()
1549 	struct xol_area *area = mm->uprobes_state.xol_area;  in uprobe_clear_state()  local
1555 	if (!area)  in uprobe_clear_state()
1558 	put_page(area->pages[0]);  in uprobe_clear_state()
1559 	kfree(area->bitmap);  in uprobe_clear_state()
1560 	kfree(area);  in uprobe_clear_state()
1585 static unsigned long xol_take_insn_slot(struct xol_area *area)  in xol_take_insn_slot()  argument
1591 		slot_nr = find_first_zero_bit(area->bitmap, UINSNS_PER_PAGE);  in xol_take_insn_slot()
1593 			if (!test_and_set_bit(slot_nr, area->bitmap))  in xol_take_insn_slot()
1599 		wait_event(area->wq, (atomic_read(&area->slot_count) < UINSNS_PER_PAGE));  in xol_take_insn_slot()
1602 	slot_addr = area->vaddr + (slot_nr * UPROBE_XOL_SLOT_BYTES);  in xol_take_insn_slot()
1603 	atomic_inc(&area->slot_count);  in xol_take_insn_slot()
1614 	struct xol_area *area;  in xol_get_insn_slot()  local
1617 	area = get_xol_area();  in xol_get_insn_slot()
1618 	if (!area)  in xol_get_insn_slot()
1621 	xol_vaddr = xol_take_insn_slot(area);  in xol_get_insn_slot()
1625 	arch_uprobe_copy_ixol(area->pages[0], xol_vaddr,  in xol_get_insn_slot()
1638 	struct xol_area *area;  in xol_free_insn_slot()  local
1649 	area = tsk->mm->uprobes_state.xol_area;  in xol_free_insn_slot()
1650 	vma_end = area->vaddr + PAGE_SIZE;  in xol_free_insn_slot()
1651 	if (area->vaddr <= slot_addr && slot_addr < vma_end) {  in xol_free_insn_slot()
1655 		offset = slot_addr - area->vaddr;  in xol_free_insn_slot()
1660 		clear_bit(slot_nr, area->bitmap);  in xol_free_insn_slot()
1661 		atomic_dec(&area->slot_count);  in xol_free_insn_slot()
1663 		if (waitqueue_active(&area->wq))  in xol_free_insn_slot()
1664 			wake_up(&area->wq);  in xol_free_insn_slot()
1804 	struct xol_area *area;  in uprobe_copy_process()  local
1818 	area = mm->uprobes_state.xol_area;  in uprobe_copy_process()
1819 	if (!area)  in uprobe_copy_process()
1825 	t->utask->dup_xol_addr = area->vaddr;  in uprobe_copy_process()
1838 	struct xol_area *area;  in get_trampoline_vaddr()  local
1842 	area = READ_ONCE(current->mm->uprobes_state.xol_area); /* ^^^ */  in get_trampoline_vaddr()
1843 	if (area)  in get_trampoline_vaddr()
1844 		trampoline_vaddr = area->vaddr;  in get_trampoline_vaddr()