linux-stable/lib/list_debug.c
Manfred Spraul df89a86463 [PATCH] list_del debug check
A list_del() debugging check.  Has been in -mm for years.  Dave moved
list_del() out-of-line in the debug case, so this is now suitable for
mainline.

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:05 -07:00

80 lines
2.0 KiB
C

/*
* Copyright 2006, Red Hat, Inc., Dave Jones
* Released under the General Public License (GPL).
*
* This file contains the linked list implementations for
* DEBUG_LIST.
*/
#include <linux/module.h>
#include <linux/list.h>
/*
* Insert a new entry between two known consecutive entries.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
if (unlikely(next->prev != prev)) {
printk(KERN_ERR "list_add corruption. next->prev should be %p, but was %p\n",
prev, next->prev);
BUG();
}
if (unlikely(prev->next != next)) {
printk(KERN_ERR "list_add corruption. prev->next should be %p, but was %p\n",
next, prev->next);
BUG();
}
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
EXPORT_SYMBOL(__list_add);
/**
* list_add - add a new entry
* @new: new entry to be added
* @head: list head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
EXPORT_SYMBOL(list_add);
/**
* list_del - deletes entry from list.
* @entry: the element to delete from the list.
* Note: list_empty on entry does not return true after this, the entry is
* in an undefined state.
*/
void list_del(struct list_head *entry)
{
BUG_ON(entry->prev->next != entry);
BUG_ON(entry->next->prev != entry);
if (unlikely(entry->prev->next != entry)) {
printk(KERN_ERR "list_del corruption. prev->next should be %p, "
"but was %p\n", entry, entry->prev->next);
BUG();
}
if (unlikely(entry->next->prev != entry)) {
printk(KERN_ERR "list_del corruption. next->prev should be %p, "
"but was %p\n", entry, entry->next->prev);
BUG();
}
__list_del(entry->prev, entry->next);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);