linux/lib/list_debug.c

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/*
* Copyright 2006, Red Hat, Inc., Dave Jones
* Released under the General Public License (GPL).
*
* This file contains the linked list validation for DEBUG_LIST.
*/
#include <linux/export.h>
#include <linux/list.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/rculist.h>
/*
* Check that the data structures for the list manipulations are reasonably
* valid. Failures here indicate memory corruption (and possibly an exploit
* attempt).
*/
bool __list_add_valid(struct list_head *new, struct list_head *prev,
struct list_head *next)
{
if (unlikely(next->prev != prev)) {
WARN(1, "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
prev, next->prev, next);
return false;
}
if (unlikely(prev->next != next)) {
WARN(1, "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
next, prev->next, prev);
return false;
}
if (unlikely(new == prev || new == next)) {
WARN(1, "list_add double add: new=%p, prev=%p, next=%p.\n",
new, prev, next);
return false;
}
return true;
}
EXPORT_SYMBOL(__list_add_valid);
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.
* 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)
{
__list_del_entry(entry);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);