root/lib/list_debug.c

DEFINITIONS

1. __list_add
2. list_del

/*
 * 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)
{
        WARN(next->prev != prev,
                "list_add corruption. next->prev should be "
                "prev (%p), but was %p. (next=%p).\n",
                prev, next->prev, next);
        WARN(prev->next != next,
                "list_add corruption. prev->next should be "
                "next (%p), but was %p. (prev=%p).\n",
                next, prev->next, prev);
        next->prev = new;
        new->next = next;
        new->prev = prev;
        prev->next = new;
}
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)
{
        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);
        entry->next = LIST_POISON1;
        entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);