blob: c24c2f7e296fa15e5431ef7dc4a31f8551e37c15 [file] [log] [blame]
Dave Jones199a9af2006-09-29 01:59:00 -07001/*
2 * Copyright 2006, Red Hat, Inc., Dave Jones
3 * Released under the General Public License (GPL).
4 *
5 * This file contains the linked list implementations for
6 * DEBUG_LIST.
7 */
8
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -05009#include <linux/export.h>
Dave Jones199a9af2006-09-29 01:59:00 -070010#include <linux/list.h>
Paul Gortmaker50af5ea2012-01-20 18:35:53 -050011#include <linux/bug.h>
Paul Gortmakerb116ee42012-01-20 18:46:49 -050012#include <linux/kernel.h>
Dave Jones559f9ba2012-03-14 22:17:39 -040013#include <linux/rculist.h>
Dave Jones199a9af2006-09-29 01:59:00 -070014
15/*
16 * Insert a new entry between two known consecutive entries.
17 *
18 * This is only for internal list manipulation where we know
19 * the prev/next entries already!
20 */
21
22void __list_add(struct list_head *new,
23 struct list_head *prev,
24 struct list_head *next)
25{
Dave Jones924d9ad2008-07-25 01:45:55 -070026 WARN(next->prev != prev,
27 "list_add corruption. next->prev should be "
28 "prev (%p), but was %p. (next=%p).\n",
29 prev, next->prev, next);
30 WARN(prev->next != next,
31 "list_add corruption. prev->next should be "
32 "next (%p), but was %p. (prev=%p).\n",
33 next, prev->next, prev);
Chris Metcalf17a801f2012-05-29 15:07:31 -070034 WARN(new == prev || new == next,
35 "list_add double add: new=%p, prev=%p, next=%p.\n",
36 new, prev, next);
Dave Jones199a9af2006-09-29 01:59:00 -070037 next->prev = new;
38 new->next = next;
39 new->prev = prev;
40 prev->next = new;
41}
42EXPORT_SYMBOL(__list_add);
43
Linus Torvalds3c18d4d2011-02-18 11:32:28 -080044void __list_del_entry(struct list_head *entry)
45{
46 struct list_head *prev, *next;
47
48 prev = entry->prev;
49 next = entry->next;
50
51 if (WARN(next == LIST_POISON1,
52 "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
53 entry, LIST_POISON1) ||
54 WARN(prev == LIST_POISON2,
55 "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
56 entry, LIST_POISON2) ||
57 WARN(prev->next != entry,
58 "list_del corruption. prev->next should be %p, "
59 "but was %p\n", entry, prev->next) ||
60 WARN(next->prev != entry,
61 "list_del corruption. next->prev should be %p, "
62 "but was %p\n", entry, next->prev))
63 return;
64
65 __list_del(prev, next);
66}
67EXPORT_SYMBOL(__list_del_entry);
68
Dave Jones199a9af2006-09-29 01:59:00 -070069/**
Dave Jones199a9af2006-09-29 01:59:00 -070070 * list_del - deletes entry from list.
71 * @entry: the element to delete from the list.
72 * Note: list_empty on entry does not return true after this, the entry is
73 * in an undefined state.
74 */
75void list_del(struct list_head *entry)
76{
Linus Torvalds3c18d4d2011-02-18 11:32:28 -080077 __list_del_entry(entry);
Dave Jones199a9af2006-09-29 01:59:00 -070078 entry->next = LIST_POISON1;
79 entry->prev = LIST_POISON2;
80}
81EXPORT_SYMBOL(list_del);
Dave Jones559f9ba2012-03-14 22:17:39 -040082
83/*
84 * RCU variants.
85 */
86void __list_add_rcu(struct list_head *new,
87 struct list_head *prev, struct list_head *next)
88{
89 WARN(next->prev != prev,
Paul E. McKenney5cf05ad2012-05-17 15:12:45 -070090 "list_add_rcu corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
Dave Jones559f9ba2012-03-14 22:17:39 -040091 prev, next->prev, next);
92 WARN(prev->next != next,
Paul E. McKenney5cf05ad2012-05-17 15:12:45 -070093 "list_add_rcu corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
Dave Jones559f9ba2012-03-14 22:17:39 -040094 next, prev->next, prev);
95 new->next = next;
96 new->prev = prev;
97 rcu_assign_pointer(list_next_rcu(prev), new);
98 next->prev = new;
99}
100EXPORT_SYMBOL(__list_add_rcu);