LXR linux/lib/list

   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 validation for DEBUG_LIST.
   6 */
   7
   8#include <linux/export.h>
   9#include <linux/list.h>
  10#include <linux/bug.h>
  11#include <linux/kernel.h>
  12#include <linux/rculist.h>
  13
  14/*
  15 * Check that the data structures for the list manipulations are reasonably
  16 * valid. Failures here indicate memory corruption (and possibly an exploit
  17 * attempt).
  18 */
  19
  20bool __list_add_valid(struct list_head *new, struct list_head *prev,
  21                      struct list_head *next)
  22{
  23        if (CHECK_DATA_CORRUPTION(next->prev != prev,
  24                        "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
  25                        prev, next->prev, next) ||
  26            CHECK_DATA_CORRUPTION(prev->next != next,
  27                        "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
  28                        next, prev->next, prev) ||
  29            CHECK_DATA_CORRUPTION(new == prev || new == next,
  30                        "list_add double add: new=%px, prev=%px, next=%px.\n",
  31                        new, prev, next))
  32                return false;
  33
  34        return true;
  35}
  36EXPORT_SYMBOL(__list_add_valid);
  37
  38bool __list_del_entry_valid(struct list_head *entry)
  39{
  40        struct list_head *prev, *next;
  41
  42        prev = entry->prev;
  43        next = entry->next;
  44
  45        if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
  46                        "list_del corruption, %px->next is LIST_POISON1 (%px)\n",
  47                        entry, LIST_POISON1) ||
  48            CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
  49                        "list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
  50                        entry, LIST_POISON2) ||
  51            CHECK_DATA_CORRUPTION(prev->next != entry,
  52                        "list_del corruption. prev->next should be %px, but was %px\n",
  53                        entry, prev->next) ||
  54            CHECK_DATA_CORRUPTION(next->prev != entry,
  55                        "list_del corruption. next->prev should be %px, but was %px\n",
  56                        entry, next->prev))
  57                return false;
  58
  59        return true;
  60
  61}
  62EXPORT_SYMBOL(__list_del_entry_valid);
  63