Commit | Line | Data |
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199a9afc DJ |
1 | /* |
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 | ||
8bc3bcc9 | 9 | #include <linux/export.h> |
199a9afc | 10 | #include <linux/list.h> |
50af5ead | 11 | #include <linux/bug.h> |
b116ee4d | 12 | #include <linux/kernel.h> |
559f9bad | 13 | #include <linux/rculist.h> |
199a9afc | 14 | |
5c2c2587 DW |
15 | static struct list_head force_poison; |
16 | void list_force_poison(struct list_head *entry) | |
17 | { | |
18 | entry->next = &force_poison; | |
19 | entry->prev = &force_poison; | |
20 | } | |
21 | ||
199a9afc DJ |
22 | /* |
23 | * Insert a new entry between two known consecutive entries. | |
24 | * | |
25 | * This is only for internal list manipulation where we know | |
26 | * the prev/next entries already! | |
27 | */ | |
28 | ||
29 | void __list_add(struct list_head *new, | |
30 | struct list_head *prev, | |
31 | struct list_head *next) | |
32 | { | |
5c2c2587 DW |
33 | WARN(new->next == &force_poison || new->prev == &force_poison, |
34 | "list_add attempted on force-poisoned entry\n"); | |
924d9add DJ |
35 | WARN(next->prev != prev, |
36 | "list_add corruption. next->prev should be " | |
37 | "prev (%p), but was %p. (next=%p).\n", | |
38 | prev, next->prev, next); | |
39 | WARN(prev->next != next, | |
40 | "list_add corruption. prev->next should be " | |
41 | "next (%p), but was %p. (prev=%p).\n", | |
42 | next, prev->next, prev); | |
17a801f4 CM |
43 | WARN(new == prev || new == next, |
44 | "list_add double add: new=%p, prev=%p, next=%p.\n", | |
45 | new, prev, next); | |
199a9afc DJ |
46 | next->prev = new; |
47 | new->next = next; | |
48 | new->prev = prev; | |
1c97be67 | 49 | WRITE_ONCE(prev->next, new); |
199a9afc DJ |
50 | } |
51 | EXPORT_SYMBOL(__list_add); | |
52 | ||
3c18d4de LT |
53 | void __list_del_entry(struct list_head *entry) |
54 | { | |
55 | struct list_head *prev, *next; | |
56 | ||
57 | prev = entry->prev; | |
58 | next = entry->next; | |
59 | ||
60 | if (WARN(next == LIST_POISON1, | |
61 | "list_del corruption, %p->next is LIST_POISON1 (%p)\n", | |
62 | entry, LIST_POISON1) || | |
63 | WARN(prev == LIST_POISON2, | |
64 | "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", | |
65 | entry, LIST_POISON2) || | |
66 | WARN(prev->next != entry, | |
67 | "list_del corruption. prev->next should be %p, " | |
68 | "but was %p\n", entry, prev->next) || | |
69 | WARN(next->prev != entry, | |
70 | "list_del corruption. next->prev should be %p, " | |
71 | "but was %p\n", entry, next->prev)) | |
72 | return; | |
73 | ||
74 | __list_del(prev, next); | |
75 | } | |
76 | EXPORT_SYMBOL(__list_del_entry); | |
77 | ||
199a9afc DJ |
78 | /** |
79 | * list_del - deletes entry from list. | |
80 | * @entry: the element to delete from the list. | |
81 | * Note: list_empty on entry does not return true after this, the entry is | |
82 | * in an undefined state. | |
83 | */ | |
84 | void list_del(struct list_head *entry) | |
85 | { | |
3c18d4de | 86 | __list_del_entry(entry); |
199a9afc DJ |
87 | entry->next = LIST_POISON1; |
88 | entry->prev = LIST_POISON2; | |
89 | } | |
90 | EXPORT_SYMBOL(list_del); | |
559f9bad DJ |
91 | |
92 | /* | |
93 | * RCU variants. | |
94 | */ | |
95 | void __list_add_rcu(struct list_head *new, | |
96 | struct list_head *prev, struct list_head *next) | |
97 | { | |
98 | WARN(next->prev != prev, | |
5cf05ad7 | 99 | "list_add_rcu corruption. next->prev should be prev (%p), but was %p. (next=%p).\n", |
559f9bad DJ |
100 | prev, next->prev, next); |
101 | WARN(prev->next != next, | |
5cf05ad7 | 102 | "list_add_rcu corruption. prev->next should be next (%p), but was %p. (prev=%p).\n", |
559f9bad DJ |
103 | next, prev->next, prev); |
104 | new->next = next; | |
105 | new->prev = prev; | |
106 | rcu_assign_pointer(list_next_rcu(prev), new); | |
107 | next->prev = new; | |
108 | } | |
109 | EXPORT_SYMBOL(__list_add_rcu); |