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authorLinus Torvalds <torvalds@linux-foundation.org>2011-02-18 22:32:28 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2011-02-18 22:32:28 +0300
commit3c18d4de86e4a7f93815c081e50e0543fa27200f (patch)
treeadea22bccd076266bf94cbda3ed6d9a98eea1206
parent2a324ce7b79a3a90cc2d4ade5d5f960a99000caa (diff)
downloadlinux-3c18d4de86e4a7f93815c081e50e0543fa27200f.tar.xz
Expand CONFIG_DEBUG_LIST to several other list operations
When list debugging is enabled, we aim to readably show list corruption errors, and the basic list_add/list_del operations end up having extra debugging code in them to do some basic validation of the list entries. However, "list_del_init()" and "list_move[_tail]()" ended up avoiding the debug code due to how they were written. This fixes that. So the _next_ time we have list_move() problems with stale list entries, we'll hopefully have an easier time finding them.. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/list.h12
-rw-r--r--lib/list_debug.c39
2 files changed, 35 insertions, 16 deletions
diff --git a/include/linux/list.h b/include/linux/list.h
index 9a5f8a71810c..3a54266a1e85 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -96,6 +96,11 @@ static inline void __list_del(struct list_head * prev, struct list_head * next)
* in an undefined state.
*/
#ifndef CONFIG_DEBUG_LIST
+static inline void __list_del_entry(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+}
+
static inline void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
@@ -103,6 +108,7 @@ static inline void list_del(struct list_head *entry)
entry->prev = LIST_POISON2;
}
#else
+extern void __list_del_entry(struct list_head *entry);
extern void list_del(struct list_head *entry);
#endif
@@ -135,7 +141,7 @@ static inline void list_replace_init(struct list_head *old,
*/
static inline void list_del_init(struct list_head *entry)
{
- __list_del(entry->prev, entry->next);
+ __list_del_entry(entry);
INIT_LIST_HEAD(entry);
}
@@ -146,7 +152,7 @@ static inline void list_del_init(struct list_head *entry)
*/
static inline void list_move(struct list_head *list, struct list_head *head)
{
- __list_del(list->prev, list->next);
+ __list_del_entry(list);
list_add(list, head);
}
@@ -158,7 +164,7 @@ static inline void list_move(struct list_head *list, struct list_head *head)
static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
- __list_del(list->prev, list->next);
+ __list_del_entry(list);
list_add_tail(list, head);
}
diff --git a/lib/list_debug.c b/lib/list_debug.c
index 344c710d16ca..b8029a5583ff 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -35,6 +35,31 @@ void __list_add(struct list_head *new,
}
EXPORT_SYMBOL(__list_add);
+void __list_del_entry(struct list_head *entry)
+{
+ struct list_head *prev, *next;
+
+ prev = entry->prev;
+ next = entry->next;
+
+ if (WARN(next == LIST_POISON1,
+ "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
+ entry, LIST_POISON1) ||
+ WARN(prev == LIST_POISON2,
+ "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
+ entry, LIST_POISON2) ||
+ WARN(prev->next != entry,
+ "list_del corruption. prev->next should be %p, "
+ "but was %p\n", entry, prev->next) ||
+ WARN(next->prev != entry,
+ "list_del corruption. next->prev should be %p, "
+ "but was %p\n", entry, next->prev))
+ return;
+
+ __list_del(prev, next);
+}
+EXPORT_SYMBOL(__list_del_entry);
+
/**
* list_del - deletes entry from list.
* @entry: the element to delete from the list.
@@ -43,19 +68,7 @@ EXPORT_SYMBOL(__list_add);
*/
void list_del(struct list_head *entry)
{
- WARN(entry->next == LIST_POISON1,
- "list_del corruption, next is LIST_POISON1 (%p)\n",
- LIST_POISON1);
- WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2,
- "list_del corruption, prev is LIST_POISON2 (%p)\n",
- LIST_POISON2);
- WARN(entry->prev->next != entry,
- "list_del corruption. prev->next should be %p, "
- "but was %p\n", entry, entry->prev->next);
- WARN(entry->next->prev != entry,
- "list_del corruption. next->prev should be %p, "
- "but was %p\n", entry, entry->next->prev);
- __list_del(entry->prev, entry->next);
+ __list_del_entry(entry);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}